JP7656175B2 - Bending device and bending method - Google Patents

Description

The present invention relates to a bending device and a bending method.

As is well known, hollow, curved metal structural components used in automobiles, various machines, etc., are required to be lightweight and strong. Conventionally, this type of hollow curved part has been manufactured by, for example, cold bending, welding of pressed products, punching of thick plates, or forging. However, there are limitations to how light and strong hollow curved parts can be manufactured using these manufacturing methods, and it has not been easy to achieve these goals.

In recent years, the production of this type of hollow curved part using the so-called tube hydroforming method has been actively considered, as disclosed in, for example, Non-Patent Document 1. However, as described on page 28 of Non-Patent Document 1, the tube hydroforming method faces challenges such as the development of materials to be used and the expansion of the freedom of shapes that can be formed, and further development is necessary in the future.

In order to meet such a demand, the present applicants have disclosed a bending apparatus as described in Patent Document 1. Fig. 7 is a perspective view that shows a schematic diagram of this bending apparatus 10A.
As shown in Figure 7, in this bending apparatus 10A, in a push-through bending method for metal material, a metal material Pm (workpiece) rotatably held by a support means 11A is pushed out successively or continuously from the upstream side while being bent downstream of the support means 11A. The metal material Pm is clamped by a movable roller die 12A provided downstream of the support means 11A, and while controlling the position and/or moving speed of the movable roller die 12A, the metal material Pm is heated to a temperature range in which local plastic deformation is possible and which can be hardened using heating means 13A and cooling means 14A arranged on the entry side of the movable roller die 12A and on the outer periphery of the metal material Pm, and a bending moment is applied to the heated portion, followed by rapid cooling.

Furthermore, the applicants have also disclosed a manufacturing apparatus for bent products described in Patent Document 2. Fig. 8 is a plan view that shows a schematic diagram of this manufacturing apparatus 10B for bent products.
As shown in Figure 8, in this manufacturing apparatus, the steel pipe Pm is supported at a first position A while being fed in its longitudinal direction, the steel pipe Pm is partially heated at a second position B, the heated portion of the steel pipe Pm is cooled at a third position C, and in a region D downstream of the third position C, the position of the holding means 11B that holds the steel pipe Pm is changed to a three-dimensional direction including the feed direction of the steel pipe Pm within a workspace including the space upstream of the third position C in the feed direction of the steel pipe Pm, and a bending moment is applied to the heated portion of the steel pipe Pm to produce a bent product.

The devices described in Patent Documents 1 and 2 make it possible to manufacture bent parts that have bent sections that bend in three dimensions, either intermittently or continuously along the longitudinal direction.

International Publication No. 2006/093006 International Publication No. 2010/050460

Automotive Technology Vol. 57, No. 6, 2003 pages 23-28

On the other hand, in recent years, there has been a demand to increase the structural strength of long skeletal components used in large vehicles such as buses. However, such skeletal components are long, for example, reaching 3000 mm in length. Therefore, simply increasing the thickness of the skeletal components would significantly increase the vehicle weight, and the number of passengers would have to be reduced accordingly. Therefore, in order to obtain lightweight, high-strength skeletal components, it was considered to apply the techniques disclosed in the above-mentioned Patent Documents 1 and 2.

However, in the first place, neither of Patent Documents 1 nor 2 assumes bending of long parts as described above, and there are many problems to be solved in putting them into practical use.
Specifically, when using the bending apparatus disclosed in Patent Document 1, the tip of the metal material Pm is not held while bending, so that the tip of the metal material Pm, which protrudes long, is bent downwards significantly due to its own weight as the metal material Pm is fed, and the processing accuracy cannot be maintained. Moreover, the large bending moment caused by this bending is concentrated on the support means 11A and the movable roller die 12A, which may cause misalignment of their axes or even damage. To avoid this problem, even if the tip of the metal material Pm is held and supported by some means, for example, a robot installed in a fixed position, the length of the robot arm must be made extremely long to match the long metal material Pm in order to handle the entire process. However, it is not realistic to equip a robot with such a long robot arm, and even if it were possible, it would lead to an increase in the cost of facility construction.

In addition, in the case of Patent Document 2, there is almost no freedom in processing the steel pipe Pm along the Z-axis direction in Figure 8, i.e., the freedom in the holding height of the tip of the steel pipe Pm. In the case of long parts as described above, even if slight bends are added sequentially, the accumulation of these slight bends may cause the tip to move significantly in the Z-axis direction, but this device cannot continue to hold the tip to such a height. In addition, in the case of the bending device of Patent Document 2, when the bent parts are to be lowered after manufacture, the worker must manually remove the bent parts from the device and stack them in the disposal area, but because they are long, manual lowering is a heavy workload. Even if a robot dedicated to lowering is installed to eliminate this inconvenience, it will lead to increased facility construction costs.

The present invention was made in consideration of the above circumstances, and aims to provide a bending device and bending method that can manufacture long bent parts with high precision and at low cost.

In order to solve the above problems and achieve the above object, the present invention employs the following aspects.
(1) A bending apparatus according to one aspect of the present invention comprises:
A feed section that feeds a metal workpiece that is long in one direction along a feed direction;
a support section that supports the workpiece at a downstream position of the feed section;
a heating section that partially heats the workpiece at a downstream position of the support section;
a cooling section that cools the workpiece at a position downstream of the heating section;
a bending force applying section that holds the workpiece at a position downstream of the cooling section and applies a bending force to the workpiece;
Equipped with
The bending force applying portion is
An arm portion that moves a gripping position of the workpiece in three dimensional directions while gripping the workpiece;
an arm base to which a pivot shaft at a base end of the arm is connected and which slides so that the pivot shaft moves along a first linear movement trajectory;
a first slide mechanism that slides the arm base so that the pivot shaft moves along the first linear movement path;
has.
Here, a supplementary explanation will be given regarding the first linear movement locus of the pivot shaft.
For example, in the case where two parallel straight rails are used as the device configuration for moving the arm base, the first linear movement trajectory of the pivot shaft is the trajectory of the range in which the pivot shaft slides on a virtual straight line that is parallel to the two straight rails and passes through the center of the pivot shaft when viewed in a plane.
In addition, when one or three or more straight rails are used as the device configuration for moving the arm base, the first linear movement trajectory of the pivot shaft is the trajectory of the range in which the pivot shaft slides on a virtual straight line that is parallel to the rails and through which the center of the pivot shaft passes in a plan view.
The sliding range of the pivot shaft is the range of movement of the pivot shaft on the virtual straight line required to form the part. Since the pivot shaft is connected to the arm base and slides integrally therewith, the sliding range of the pivot shaft is the same as the sliding range of the arm base.
In this specification, the term "straight line" is used to mean a "line segment" having a finite length unless otherwise specified. For example, the term "first moving straight line trajectory" should be called the "first moving line segment trajectory" since it has a finite length according to the length of the product to be processed, but since this is not a common term, it will be called the "first moving straight line trajectory" in accordance with the usual practice.

(2) In the above aspect (1),
an extension line of an axis along the feed direction of the workpiece at the position of the support portion;
the first linear movement trajectory;
may overlap in a plan view.

(3) In the above aspect (1),
The first linear movement trajectory may be shifted in a plan view with respect to an extension line of an axis along the feed direction of the workpiece at the position of the support portion.

(4) In any one of the above (1) to (3),
The first linear movement trajectory and an extension line of an axis along the feed direction of the workpiece at the position of the support portion may be parallel to each other in a plan view.
The term "parallel" here allows for some degree of misalignment due to the positioning accuracy and operation accuracy of each component of the bending device, and is not limited to being strictly parallel. However, "parallel" here does not include being intentionally angled.

(5) In any one of the above (1) to (4),
The bending force applying portion is
The arm base may further include a second sliding mechanism that slides so that the pivot axis moves along a second linear movement trajectory that intersects, in a planar view, an extension line of an axis line of the support part along the feed direction.
The term "intersect" as used here includes both cases in which the "direction of intersection in a planar view" intersects with the "extension of the axis" at a right angle (a) and at an angle other than a right angle.
For example, if two parallel straight rails are used as the "second linear movement trajectory," the "second linear movement trajectory" is the trajectory of the range in which the pivot axis slides on a virtual straight line that is parallel to the two straight rails and through which the center of the pivot axis passes, as viewed in a plane.
Alternatively, when one or three or more straight rails are used, the "second straight movement trajectory" is the trajectory of the range in which the pivot shaft slides on a virtual straight line that is parallel to the rails and through which the center of the pivot shaft passes in a plan view.
Therefore, the above-mentioned "second linear movement trajectory that slides along a direction intersecting the extension line of the axis in a plan view" means that the "second linear movement trajectory" exists in a direction intersecting the extension line of the axis in a plan view (this direction is infinite). Therefore, the "second linear movement trajectory" only needs to have an "orientation (direction)" along a direction intersecting the extension line of the axis along the feed direction of the support part in a plan view. For example, even if the "second linear movement trajectory" has a finite length defined by a limit switch or the like for preventing the carriage from departing from the rail end on the rail and this "second linear movement trajectory" does not overlap with the "extension line" in a plan view, it has a "direction intersecting the extension line of the axis in a plan view", so it is included in this paragraph (5).

(6) In any one of the above (1) to (5),
The arm base may further include a rotating portion that rotates the orientation of the first linear movement locus about a vertical axis.

(7) A bending method according to one aspect of the present invention includes:
A feeding step of feeding a metal workpiece that is long in one direction along a feeding direction;
supporting the workpiece at a first position;
a heating step of partially heating the workpiece at a second location downstream from the first location;
a cooling step of cooling the workpiece at a third position downstream of the second position;
a bending force imparting step of gripping the workpiece with an arm unit at a fourth position downstream of the third position and moving a gripping position of the arm unit in a three-dimensional direction including at least the feed direction;
having
The bending force applying step includes an arm moving step of sliding an arm base to which a pivot shaft is connected so that the pivot shaft at the base end of the arm slides along a first linear movement trajectory.
Here, a supplementary explanation will be given regarding the first linear movement locus of the pivot shaft.
For example, in the case where two parallel straight rails are used as the device configuration for moving the arm base, the first linear movement trajectory of the pivot shaft is the trajectory of the range in which the pivot shaft slides on a virtual straight line that is parallel to the two straight rails in a plan view and through which the center of the pivot shaft passes.
In addition, when one or three or more straight rails are used as the device configuration for moving the arm base, the first straight-line movement trajectory of the pivot shaft is a trajectory of the range in which the pivot shaft slides on a virtual straight line that is parallel to the rails in a plan view and through which the center of the pivot shaft passes.
The sliding range of the pivot shaft is the range of movement of the pivot shaft on the virtual straight line required to form the part. Since the pivot shaft is connected to the arm base and slides integrally therewith, the sliding range of the pivot shaft is the same as the sliding range of the arm base.

(8) In the above aspect (7),
an extension line of an axis along the feed direction of the workpiece at the first position;
the first linear movement trajectory;
may overlap in a plan view.

(9) In the above aspect (7),
With respect to an extension line of an axis along the feed direction of the workpiece at the first position,
The first linear movement trajectory may be shifted in a plan view.
The term "shift" used here refers to moving the first linear movement trajectory in a direction perpendicular to the feed direction in plan view relative to the axis along the feed direction to change the position so that they do not overlap with each other. In other words, "shifting" refers to the fact that "an extension line of the axis of the workpiece in the feed direction at the first position" and "the first linear movement trajectory" do not overlap in plan view.

(10) In any one of the above (7) to (9),
The first linear movement trajectory and an extension line of an axis along the feed direction of the workpiece at the first position may be parallel to each other in a plan view.
The term "parallel" as used herein allows for some degree of deviation due to the positioning accuracy and operation accuracy of each component device of the bending apparatus, and is not limited to being strictly parallel.

(11) In any one of the above (7) to (10),
The method may further include a first position adjustment step of moving the position of the pivot axis along a second linear movement trajectory that intersects, in a planar view, an extension line of an axis line along the feed direction of the workpiece at the first position.
The term "intersect" as used here includes both cases in which the "direction of intersection in a planar view" intersects with the "extension of the axis" at a right angle (a) and at an angle other than a right angle (b).

(12) In any one of the above (7) to (11),
The method may further include a second position adjustment step of rotating an orientation of the first linear movement locus in a plan view about a vertical axis.

In the bending apparatus according to the above aspects (1) to (6), the bending force imparting unit has an arm unit that moves the gripping position of the workpiece in three dimensions while gripping the workpiece, an arm base unit to which a pivot shaft at the base end of the arm unit is connected and which slides so that the pivot shaft moves along a first linear movement locus, and a first slide mechanism that slides the arm base unit so that the pivot shaft moves along the first linear movement locus.
According to this configuration, the gripping position of the workpiece by the arm moves as the bending process progresses, but the longest movement distance in the feed direction among the movement directions can be covered by the movement of the pivot shaft. As a result, the workpiece can be bent to the end while the arm continues to grip the gripping position. Therefore, deviation from the normal shape due to bending of the workpiece during bending can be corrected, and highly accurate bent parts can be manufactured. Moreover, since the movement distance of the pivot shaft along the first linear movement trajectory can absorb the movement distance of the gripping position in the feed direction, it is not necessary to install an expensive robot with a long arm, and the facility construction cost can be reduced. This also makes it possible to reduce the manufacturing cost of bent parts.

In the bending method according to the above aspects (7) to (12), the bending force imparting step includes an arm portion moving step of sliding the arm base portion to which the pivot shaft is connected so that the pivot shaft at the base end of the arm portion slides along a first linear movement trajectory.
According to this bending method, it is possible to obtain the same effect as the bending apparatus according to the above aspects (1) to (6). That is, according to this bending method, the gripping position of the workpiece by the arm moves as the bending process progresses, but the longest movement distance in the feed direction among the movement directions can be covered by the arm movement process. As a result, the workpiece can be bent to the end while the gripping position is always held by the arm. Therefore, deviation from the normal shape due to bending of the workpiece during bending can be corrected, and a highly accurate bent part can be manufactured. Moreover, since the movement distance of the arm movement process can absorb the movement distance of the gripping position along the feed direction, it is not necessary to equip an expensive bending force applying unit with a long arm, and the facility construction cost can be reduced. This also makes it possible to reduce the manufacturing cost of bent parts.

1 is a plan view showing a bending apparatus according to a first embodiment of the present invention; FIG. 11 is a plan view showing a bending apparatus according to a second embodiment of the present invention; FIG. 11 is a plan view showing a bending apparatus according to a third embodiment of the present invention. FIG. 11 is a plan view showing a schematic view of a main part of a bending device according to a fourth embodiment of the present invention. FIG. 11 is a plan view for explaining CASEs 1 to 6, which are variations in the combination of the relative positional relationship between the extension line EX and the first linear movement trajectory TR and the presence or absence of cooperative control. 5A to 5C are plan views for explaining the length of the arm, where (a) to (c) show states in which the arm is bent, and (d) shows a state in which the arm is linearly extended. FIG. 1 is a perspective view showing an example of a conventional bending apparatus. FIG. 11 is a perspective view showing another example of a conventional bending device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, a hollow workpiece Pm made of steel (metal) and having a circular or rectangular cross-sectional shape is used as a material, and a bending process is performed on this workpiece Pm to manufacture bent parts such as strength parts, reinforcing parts, or structural parts used in automobiles and various machines. The workpiece Pm can be a circular tube having a circular cross-sectional shape, a square tube having a rectangular cross-sectional shape, or a steel tube having an elliptical or various irregular cross-sectional shapes. Furthermore, metal tubes other than steel tubes may be used as the workpiece Pm.
In addition, components common to each embodiment may be given the same reference numerals and their repeated explanation may be omitted.

[First embodiment]
[Bending device]
FIG. 1 is a plan view showing a bending apparatus according to the present embodiment. In FIG. 1, the +X direction toward the left of the paper is the feed direction of the workpiece Pm. In FIG. 1, the +Y direction toward the bottom of the paper is the direction perpendicular to the X-axis direction in the horizontal plane and toward the left when looking at the traveling direction of the workpiece Pm. And the +Z direction facing the front side perpendicular to the paper is the height direction perpendicular to both the X-axis direction and the Y-axis direction. Here, the +X direction means the + direction of the X-axis. The opposite direction of the +X direction is the -X direction. Also, it means the + direction of the Y-axis. The opposite direction of the +Y direction is the -Y direction. Similarly, it means the + direction of the Z-axis. The opposite direction of the +Z direction is the -Z direction. The direction including both the +X direction and the -X direction is the X-axis direction. Also, the direction including both the +Y direction and the -Y direction is the Y-axis direction. Similarly, the direction including both the +Z direction and the -Z direction is the Z-axis direction. The above description of the directions is common to the following description and the subsequent descriptions of each embodiment. Note that the Z-axis may be referred to as the vertical axis.

As shown in FIG. 1 , the bending apparatus includes a feed section 10 , a support section 20 , a heating section 30 , a cooling section 40 , a bending force applying section 50 , and a control section 60 .
(1) Feed section 10
The feed section 10 includes a feed jig 11 and a push-out section 12, and feeds the workpiece Pm intermittently or continuously in the +X direction. The feed jig 11 may be configured to hold and feed the workpiece Pm using a chuck mechanism, or may be configured to simply push the workpiece Pm by contact. The drive means of the feed section 10 may be, for example, a type using an electric servo cylinder, but is not limited to a specific type, and any known type such as a type using a ball screw, a type using a timing belt or a chain, etc. may be used.

(2) Support portion 20
The support section 20 is disposed at a first position A downstream of the feed section 10 along the feed direction of the workpiece Pm. In this embodiment, a block is used as the support section 20. The block has a through hole 21 through which the workpiece Pm can be inserted with a gap. Although not shown, the block may be divided into a plurality of parts, and hydraulic cylinders or air cylinders may be connected to clamp and support the workpiece Pm. In addition, the support section 20 is not limited to a specific type, and any known type of support device of this type may be used. For example, as another configuration, one or more pairs of hole-shaped rolls arranged opposite each other may be arranged side by side.
The support unit 20 is fixedly disposed on a mounting base (not shown). However, the present invention is not limited to this embodiment, and the support unit 20 may be supported by an end effector (not shown) of an industrial robot.
After passing through the first position A where the support portion 20 is installed, the workpiece Pm is further fed in the +X direction.

(3) Heating unit 30
The heating section 30 is disposed at a second position B downstream of a first position A along the feed direction of the workpiece Pm. The heating section 30 heats the entire circumference of a cross section of a portion of the workpiece Pm in the longitudinal direction, which is fed from the support section 20. An induction heating device is used as the heating section 30. This induction heating device may be any device having a coil capable of, for example, high-frequency induction heating the workpiece Pm, and any known device may be used. As an installation means for the heating section 30, for example, an end effector of a well-known industrial robot may be exemplified, but any known device may be used.
The heating coil of the heating unit 30 is disposed at a predetermined distance from the outer surface of the workpiece Pm so as to surround the entire circumference of a cross section of the workpiece Pm in a part of the longitudinal direction. The workpiece Pm is then partially rapidly heated by the heating unit 30.

(4) Cooling section 40
The cooling section 40 is disposed at a third position C downstream of the second position B along the feed direction of the workpiece Pm. The cooling section 40 rapidly cools the portion of the workpiece Pm that was heated at the second position B. By cooling the workpiece Pm in the cooling section 40, the portion between the first portion heated by the heating section 30 and the second portion cooled by the cooling section 40 is in a state of high temperature and significantly reduced deformation resistance. The cooling section 40 includes a primary cooling device 41 disposed adjacent to and immediately downstream of the heating coil. If necessary, another cooling device (secondary cooling device, not shown) may be disposed next to the primary cooling device 41 downstream, or only the primary cooling device 41 may be provided as shown in FIG. 1.

(5) Bending force applying portion 50
The bending force applying unit 50 is disposed at a fourth position D downstream of the third position C along the feed direction of the workpiece Pm. The bending force applying unit 50 moves the gripping position of the workpiece Pm in two-dimensional or three-dimensional directions. In this way, the bending force applying unit 50 bends the workpiece Pm.
The bending force applying section 50 includes a stand 51 , a first slide mechanism 52 , and an industrial robot 53 .
The stand 51 is fixedly disposed at a fourth position D. The stand 51 is long in the X-axis direction, and a first linear movement trajectory TR passing through the center of the stand 51 in the width direction (Y-axis direction) is disposed at a position that is parallel to an extension line EX of the axis CL of the workpiece Pm at the first position A in a plan view and shifted by a dimension sh in the +Y direction from the extension line EX. Note that "parallel" here allows for some deviation due to the positioning accuracy and operation accuracy of each component device of the bending apparatus, and is not limited to being strictly parallel.

The first slide mechanism 52 includes a pair of rails 52a, one ball screw 52b, a motor 52c, and a carriage 52d.
The pair of rails 52a are laid parallel to each other along the X-axis direction on the upper surface of the stand 51. The height of these rails 52a is the same at each position in the X-axis direction. In the plan view shown in FIG. 1, these rails 52a are arranged side by side at positions parallel to the extension line EX and shifted in the +Y direction. In the plan view shown in FIG. 1, the first linear movement trajectory TR of the pivot axis SA is defined as a range in which the center of the pivot axis SA slides on a virtual straight line CL1 that is parallel to the pair of rails 52a and passes through the center of the pivot axis SA at the base end of the arm section 53e described later. The base end of the arm section 53e is the base end of the arm 53b.
In this embodiment, the first linear movement trajectory TR on the virtual line CL1 is located at the center of the gap between the two outermost rails 52a at each position in the longitudinal direction of the pair of rails 52a in a plan view. The virtual line CL1 and the first linear movement trajectory TR on the virtual line CL1 do not have to be located at the center of the gap between the two outermost rails 52a.

Here, a supplementary explanation will be given regarding the first linear movement locus TR of the pivot axis SA.
For example, in the case where two parallel rails 52a are used as in this embodiment as an apparatus configuration for moving the main body (arm base) 53a described later, the first linear movement trajectory TR of the rotation axis SA is a trajectory that is parallel to these two rails 52a in a planar view and is the range in which the center of the rotation axis SA slides on a virtual straight line CL1 through which the center of the rotation axis SA passes.
Alternatively, in the case where one or three or more straight rails (not shown) are adopted as the device configuration for moving the main body 53a, the first linear movement trajectory TR of the rotation axis SA is defined as a trajectory that is parallel to the one or three or more straight rails when viewed in a plane and is the range in which the center of the rotation axis SA slides on a virtual straight line CL1 through which the center of the rotation axis SA passes.

The range in which the pivot axis SA slides is the range of movement of the pivot axis SA on the virtual straight line CL1 required to form a product from the workpiece Pm. The pivot axis SA is connected to the main body 53a and slides as an integral unit, so the range in which the pivot axis SA slides is the same as the sliding range of the main body 53a. Therefore, the pivot axis SA and the main body 53a share the first linear movement trajectory TR. In the case of FIG. 1, the first linear movement trajectory TR of the pivot axis SA is the trajectory of the pivot axis SA that moves along the line segment connecting one end TRa and the other end TRb, and is shorter than the length of the ball screw 52b and the length of the pair of rails 52a. In addition, the first linear movement trajectory TR overlaps the axis of the ball screw 52b in a plan view.

In FIG. 1, the first linear movement trajectory TR on the virtual straight line CL1, which is the range of movement of the pivot axis SA, coincides with the center position of the rail interval between the pair of rails 52a in a plan view. In this case, it is preferable because the center of gravity balance of the industrial robot 53 is easily stabilized. The center of gravity of the industrial robot 53 needs to take into account the weight including the arm base (main body 53a) and the arm part 53e, but since the arm part 53e is lighter than the main body 53a, the center of gravity can be considered to be the center of the pivot axis SA. The first linear movement trajectory TR does not need to coincide with the center position of the interval between the two outermost rails or the first linear movement trajectory TR. In the case of an industrial robot with a relatively long arm part 53e, the first linear movement trajectory TR may be offset from the center position of the interval between the two outermost rails in consideration of the center of gravity balance. In addition, in FIG. 2 described later, the axis of the ball screw 52b is also located in the center of the gap between the two outermost rails at each position in the longitudinal direction of the pair of rails 52a in a plan view, and coincides with the first linear movement trajectory TR on the virtual line CL1. This configuration is preferable because it prevents excessive force from being applied to the ball screw 52b. The axis of the ball screw 52b does not have to coincide with the center of the gap between the two outermost rails or the first linear movement trajectory on the virtual line CL1.

In this specification, the term "straight line" is used to mean a "line segment" having a finite length, unless otherwise specified. For example, the above-mentioned "first moving straight line trajectory TR" should be called the "first moving line segment trajectory TR" because it has a finite length according to the length of the product to be processed, but since this is not a common term, it will be called the "first moving straight line trajectory TR" in accordance with the usual practice.
In principle, the first linear movement path TR is located on the extension line EX of the feed axis CL in Fig. 1, but a degree of deviation in the Y-axis direction that is unavoidable in terms of construction is permitted. Even in this case, however, it is preferable to deviate the first linear movement path TR in a direction away from the extension line EX of the feed axis CL.

The ball screw 52b is laid along the X-axis direction on the upper surface of the stand 51. The height of the ball screw 52b is the same at each position in the X-axis direction. In the plan view shown in FIG. 1, the ball screw 52b is arranged in parallel to the extension line EX and shifted by a dimension sh in the +Y direction from the extension line EX. The ball screw 52b is arranged between the pair of rails 52a and in parallel to these rails 52a. The ball screw 52b is rotatably supported at two points, one end close to the third position C and the other end far from the third position C.
The motor 52c is fixed to the upper surface of the stand 51. The motor 52c is also coaxially connected to the other end of the ball screw 52b, and rotates the ball screw 52b forward or backward. The motor 52c is a servo motor, and the amount and speed of rotation thereof can be controlled by receiving an instruction from the control unit 60.

The dolly 52d has a plurality of ball bearings (not shown) on its underside. These ball bearings can move linearly along the +X and -X directions while being guided by the rails 52a. Therefore, the dolly 52d can move along the +X and -X directions. A female screw (not shown) having an axis along the X-axis direction is formed at the center of the width of the dolly 52d. The ball screw 52b is inserted and screwed into this female screw. Therefore, when the motor 52c is rotated forward, the dolly 52d moves in the +X direction, and when the motor 52c is rotated backward, the dolly 52d moves in the -X direction. During this movement, the dolly 52d can move back and forth linearly while being guided by the pair of rails 52a. In addition, the movement distance of the dolly 52d can be controlled arbitrarily by controlling the amount of rotation of the motor 52c. Therefore, the slide drive unit is provided with a combination of the motor 52c and the ball screw 52b.

The first slide mechanism 52 having the above configuration is fixed in a fixed position in a plan view. More specifically, the stand 51 is installed and fixed to the floor surface (ground surface). When installed and fixed in this manner, there is an advantage that it is easier to control the application of bending force to the workpiece Pm by the industrial robot 53. In addition, there is also an advantage that the rigidity of the support structure for the industrial robot 53 is improved, and the machining accuracy is improved accordingly.

In a conventional industrial robot 70 (see FIG. 1) with a fixed position, the movement of the hand 73c along the X-axis direction is performed by the movement of the arm 73b. In this embodiment, the movement of the hand 53c along the X-axis direction can be performed only by the movement of the carriage 52d along the X-axis direction (i.e., the movement of the main body 53a along the X-axis direction). Alternatively, the movement of the hand 53c along the X-axis direction can be performed by a combination of the movement of the carriage 52d along the X-axis direction and the movement of the arm part 53e.

In this embodiment, the combination of the ball screw 52b and the motor 52c is provided as a slide drive unit that slides the main body (arm base) 53a so that the pivot axis SA moves along the first linear movement trajectory TR, but the slide drive unit of the present invention is not limited to this configuration. Any mechanism that can move the position of the main body 53a may be used, and other drive mechanisms such as a pinion rack mechanism may be used as the slide drive unit.
Similarly, in the present embodiment, the carriage 52d is configured to include the ball bearings, but the present invention is not limited to this configuration. The carriage 52d may be provided with a plurality of wheels instead of the ball bearings, and the carriage 52d may be made to travel linearly along the +X direction and the -X direction while being guided by the rails 52a.

The industrial robot 53 includes a main body (arm base) 53a and an arm unit 53e. The arm unit 53e includes an arm 53b and a hand 53c. The arm 53b and the hand 53c of the arm unit 53e are driven and controlled in response to instructions from a control unit 60, which will be described later.
The main body 53a is fixed integrally to the top of the carriage 52d.
The arm 53b has a single joint or multiple joints, and can move the hand 53c in a three-dimensional direction at the fourth position D by bending at the joints. A general-purpose product having a general length can be used as the arm 53b of this embodiment. A rotation axis SA is provided at the base end of the arm 53b. The rotation axis SA is connected to the main body 53a, so that the arm 53b is supported by the main body 53a. The main body 53a is also provided with a rotation drive unit (not shown) that rotates the rotation axis SA around its central axis. The rotation drive unit (not shown) that rotates the rotation axis SA may be built into the rotation axis SA itself, or may be provided in the main body 53a to which the rotation axis SA is connected. A drive source (not shown) that drives the movement of each arm with the joint as a fulcrum is built into the joint between each arm of the arm unit 53e. Similarly, a drive source (not shown) for driving the relative movement of the hand 53c with respect to the arm 53b is also built into the connection point between the arm 53b and the hand 53c.
The hand 53c pinches and holds the workpiece Pm by a gripping portion g located near the tip of the workpiece Pm. The position of the gripping portion g is a position on the central axis of the portion of the workpiece Pm that is located near the tip of the workpiece Pm and is held by the hand 53c. The hand 53c is not limited to a configuration in which the workpiece Pm is gripped from the outside, and other holding mechanisms may be used. For example, the hand 53c may have a plurality of claws (not shown) that are inserted into the open end of the workpiece Pm and then opened to hold the workpiece Pm from the inside.

(6) Control unit 60
The control unit 60 comprehensively controls the operation of each unit, including the feed unit 10, the support unit 20, the heating unit 30, the cooling unit 40, and the bending force applying unit 50. The operation of each unit is controlled in response to instructions from the control unit 60, thereby performing a bending method, which will be described later. For example, the control unit 60 sends drive control signals to the industrial robot 53 and the first slide mechanism 52, thereby controlling the movements of the arm unit 53e (the arm 53b and the hand 53c) and the cart 52d carrying the main body 53a.

As described above, the bending apparatus of this embodiment includes a feed section 10 that feeds a metal workpiece Pm that is long in one direction along its feed direction (+X direction); a support section 20 that supports the workpiece Pm at a position downstream of the feed section 10; a heating section 30 that partially heats the workpiece Pm at a position downstream of the support section 20; a cooling section 40 that cools the workpiece Pm at a position downstream of the heating section 30; and a bending force applying section 50 that grips the workpiece Pm at a position downstream of the cooling section 40 and applies a bending force to it.
The bending force applying unit 50 has an arm unit 53e that moves the gripping position (position of the gripping unit g) in three dimensions while gripping the workpiece Pm; a main body 53a (arm base) to which a pivot axis SA at the base end of the arm unit 53e is connected and which slides so that the pivot axis SA moves along a first linear movement locus TR; and a first slide mechanism 52 that slides the main body 53a so that the pivot axis SA moves along the first linear movement locus TR.

In this embodiment, in the plan view shown in FIG. 1, the extension line EX of the axis along the feed direction of the workpiece Pm at the position of the support part 20 (first position A) and the first linear movement trajectory TR of the pivot axis SA are parallel to each other. By arranging them in parallel in this way, the movement loss in the Y-axis direction is reduced compared to the case of arranging them diagonally, so that the movement stroke of the hand 53c by the arm 53b along the X-axis direction can be maximized. However, if there is no need to make parts of multiple shapes, such as making parts separately for left and right, they may be made diagonal rather than parallel in plan view according to the product shape. On the other hand, if it is necessary to make parts separately for left and right, it is also effective to rotate on the XY plane (rotate around the Z axis) as described in the fourth embodiment described later. In this case, the rotation around the Z axis may be electric by a combination of a motor and gears not shown, or may be manual by a combination of a handle and gears not shown.

[Bending method]
A bending method using the bending apparatus having the above configuration will be described below.
1, first, the workpiece Pm is supported by the support unit 20 disposed at the first position A and the hand 53c disposed at the fourth position D while being relatively fed in its longitudinal direction by the feed unit 10. At this point, the workpiece Pm has a straight shape without any bent parts.

After supporting the workpiece Pm in this manner, the workpiece Pm being fed is rapidly heated partially by the heating section 30 at the second position B. When steel is used as the raw material, the heating temperature of the workpiece Pm at this time is desirably set to the Ac3 point or higher of the steel that constitutes the workpiece Pm. By setting the heating temperature to the Ac3 point or higher, the workpiece Pm can be quenched by appropriately setting the cooling rate during the cooling process that follows heating. Moreover, the deformation resistance of the workpiece Pm can be reduced to a level at which partial bending can be applied.

Next, at the third position C, a cooling medium is sprayed from the nozzle of the cooling section 40 toward the workpiece Pm. This cools the heated portion of the workpiece Pm. Although it depends on the type of steel of the workpiece Pm, by setting the cooling rate during this cooling to 100° C./sec or more, the bent portion Pb can be quenched to increase its strength.
This cooling forms in the workpiece Pm a first portion heated by the heating section 30 and a second portion cooled by the cooling section 40. The area between the first and second portions of the workpiece Pm is in a high temperature state, and the deformation resistance is significantly reduced.

At the fourth position D, the carriage 52d is caused to travel on the pair of rails 52a in the +X direction at the same feed speed as that of the workpiece Pm in synchronization with the feed of the workpiece Pm. The feed speed and feed amount of the carriage 52d at this time can be adjusted by the control unit 60 controlling the rotation speed and rotation amount of the motor 52c.
When the workpiece Pm is fed straight without bending, the hand 53c gripping the gripping portion g also moves along the extension line EX in a plan view. At this time, the hand 53c moves in the +X direction at the same feed speed and feed amount as the carriage 52d. Since the main body 53a and the swivel axis SA are fixed to the carriage 52d, the movement of the carriage 52d is the same as the movement of the main body 53a and the swivel axis SA. Also, here, a case is described where the "cooperative control" described below is not performed, but as described below with reference to FIG. 5 and the like, cooperative control may be performed as necessary.
The workpiece Pm does not bend in the Z-axis direction because its gripping portion g is gripped by the hand 53c. In addition, if the workpiece Pm is long and prone to bending due to its own weight, the position of the hand 53c in the Z-axis direction can be controlled to correct deviations from the normal shape due to bending. Deviations from the normal shape in the Y-axis and Z-axis directions that may occur due to residual stress and warping during tube manufacturing of the hollow material Pm and other factors can also be corrected in the same way. Here, the normal shape means a shape including the tolerance allowed for the designed shape of a bent part.

On the other hand, when a bending force is applied to the workpiece Pm, the arm 53b is rotated and bent to change the position of the gripping portion g of the hand 53c in three dimensional directions in synchronization with the feeding of the workpiece Pm. As a result, the portion of the workpiece Pm where the deformation resistance is significantly reduced is bent to form a bent portion R, as shown in FIG.
When the position of the gripping portion g is moved in the +Y direction, a bent portion R is formed that is bent in the +Y direction with respect to the workpiece Pm. When the position of the gripping portion g is moved in the -Y direction, a bent portion R is formed that is bent in the -Y direction with respect to the workpiece Pm. When the position of the gripping portion g is moved in the +Z direction, a bent portion R is formed that is bent in the +Z direction with respect to the workpiece Pm. When the position of the gripping portion g is moved in the -Z direction, a bent portion R is formed that is bent in the -Z direction with respect to the workpiece Pm.

In both cases where bending is applied to the workpiece Pm and where bending is not applied to the workpiece Pm, if the workpiece Pm undergoes transformation expansion due to partial heating and cooling, the expansion margin can be absorbed by making the combined speed of the feed speed of the carriage 52d and the speed applied to the gripping portion g of the workpiece Pm by the hand 53c faster than the feed speed of the workpiece Pm. In addition, if the feed speed of the carriage 52d is made slower than the feed speed of the workpiece Pm, compression can be applied to the heated portion of the workpiece Pm. Conversely, if the feed speed of the carriage 52d is made faster than the feed speed of the workpiece Pm, tension can be applied to the heated portion of the workpiece Pm.
As described above, according to the bending method using the bending apparatus of this embodiment, it is possible to manufacture a bent part by continuously or intermittently forming various bent parts R in the workpiece Pm. In addition, as described above, it is also possible to correct deviation in the Z direction from the normal shape due to the weight of the workpiece Pm.

As described above, the bending method of this embodiment includes a feeding step of feeding the metal workpiece Pm long in one direction along its feeding direction (+X direction), a supporting step of supporting the workpiece Pm at a first position A, a heating step of partially heating the workpiece Pm at a second position B downstream of the first position A, a cooling step of cooling the workpiece Pm at a third position C downstream of the second position B, and a bending force applying step of gripping the workpiece Pm with the arm portion 53e at a fourth position D downstream of the third position C and moving the gripping position of the arm portion 53e in a three-dimensional direction including at least the feed direction. The bending force applying step includes an arm portion moving step of sliding the main body 53a (arm base) to which the pivot axis SA is connected so that the pivot axis SA at the base end of the arm portion 53e slides along the first linear movement trajectory TR.
Furthermore, in this arm movement process, an extension line EX of the axis CL along the feed direction of the workpiece Pm at the first position A and a first linear movement trajectory TR of the pivot axis SA of the arm 53b are parallel in a planar view and are shifted by a dimension sh in the +Y direction from the extension line EX.

In contrast to the configuration and method of this embodiment described above, conventionally, bending was performed by an industrial robot 70 fixed in a fixed position on the floor surface, as shown by the two-dot chain line in Figure 1. The industrial robot 70 is installed at a position away from the side of the workpiece Pm in a plan view, and its main body 73a is fixed in a fixed position. A multi-joint arm 73b extends from the main body 73a toward the gripping portion g, and a hand 73c is connected to the tip of the arm 73b. The gripping portion g of the workpiece Pm is gripped by the hand 73c.

In the case of this conventional structure, the arm 73b continues to support the gripping part g while rotating and extending or bending in synchronization with the feed of the workpiece Pm in the +X direction, so in order to bend a workpiece Pm that is longer than conventional (more than 2000 mm and less than 3500 mm, for example 3000 mm), an arm 73b with an extremely long overall length as shown in Figure 1 is required. An industrial robot 70 equipped with such a long arm 73b is expensive, which leads to increased facility construction costs.

Of the X-axis, Y-axis, and Z-axis directions, the movement of the gripper g in the X-axis direction is overwhelmingly larger. Therefore, in the bending device of this embodiment, the movement in the X-axis direction is achieved by the sliding motion of the carriage 52d. Therefore, there is no need to lengthen the overall length of the arm 53b, and a general-purpose industrial robot 53 can be used. This reduces the cost of building facilities, making it possible to manufacture bent parts at low cost.
Furthermore, since the bending force applying unit 50 has a large amount of movement along the X-axis direction for its arm 53b and hand 53c, it is also possible for this industrial robot 53 to lower the manufactured bent part to a lowering location (not shown).

In addition, in this embodiment, the bending force applying unit 50 is arranged so that the first linear movement trajectory TR is "parallel" and "shifted" to the extension line EX in the plan view shown in FIG. 1. By making the first linear movement trajectory TR "parallel," the length of the first linear movement trajectory TR can be maximized, and a general-purpose industrial robot 53 with a short arm 53b can be used. This reduces the cost of building equipment. In addition, by making the first linear movement trajectory TR "parallel," the relative position between the extension line EX and the first linear movement trajectory TR can be kept constant, making it easier to control when applying bending force.

Furthermore, by combining "shift" with the above-mentioned "parallel", it is possible to adopt a cheaper and more versatile industrial robot 53. This makes it possible to further reduce the cost of building facilities. In addition, it is possible to simplify the movement of the arm 53b.

As variations in the relative positional relationship between the extension line EX and the linear movement trajectory TR and the presence or absence of cooperative control, for example, CASEs 1 to 6 shown in Fig. 5 are possible. Note that, although CASEs 1 to 6 are examples of bending the workpiece Pm into a single circular arc shape, they do not exclude cases where the workpiece Pm is bent into a shape other than a single circular arc.
The presence or absence of cooperative control refers to whether or not the hand 53c is caused to move in the direction of the linear movement trajectory TR. More precisely, it refers to whether or not the hand 53c is caused to move relative to the main body 53a (arm base) in the direction of the linear movement trajectory TR by the movement of the arm 53b.

Here, each symbol in FIG. 5 will be explained. Symbol d indicates the linear distance from the position of the gripping part g to the pivot axis SA in a plan view when the arm 53b is folded to the shortest. Symbol d' indicates the linear distance from the position of the gripping part g to the pivot axis SA in a plan view required to make a curved part having a front end a and a rear end b. At this time, the arm 53b is in a state in which the opening angle at the joint between the two arm parts (joint e in FIG. 6) is widened to 180°. The linear distances d and d' from the position of the gripping part g to the pivot axis SA mean the length from the center of the pivot axis SA at the base end of the arm 53b to the position of the gripping part g by the hand 53c. The "position of the gripping part g by the hand 53c" referred to here is the position (point) in the hand 53c that overlaps with the position (point) of the gripping part g of the workpiece Pm gripped by the hand 53c.

A supplementary explanation will be given below regarding the relationship between the linear distances d and d' shown in FIG. 5 and the movement of the arm portion 53e.
In the industrial robot 53 shown in FIG. 1, the orientation of the hand 53c can be rotated around the Z axis with respect to the attachment position of the arm 53b. That is, the orientation of the hand 53c can be changed separately from the bending and rotating motions of the arm 53b. Therefore, the linear distances d and d' from the pivot axis SA to the position of the gripper g are determined by the bending state of the arm 53b and the orientation of the hand 53c. For example, in a state in which the arm 53b is linearly extended along the XY plane (horizontal plane), the linear distance d from the pivot axis SA to the position of the gripper g is shorter when the orientation of the hand 53c is tilted with respect to the extension direction than when the orientation of the hand 53c is oriented in the same extension direction as the arm 53b. In addition, when the hand 53c is attached to the tip of the arm 53b facing vertically downward in a plan view, the linear distance d from the pivot axis SA to the position of the gripper g can be made approximately equal to the entire length of the arm 53b. The same explanation applies to the linear distance d'.
As described above, the linear distances d, d' shown in FIG. 5 are appropriately realized by a combination of the bending state of the arm 53b and the orientation of the hand 53c.

Among CASEs 1 to 6, CASEs 1, 3, and 5 show cases where cooperative control is not performed, i.e., where the arm unit 53e is not caused to move in the direction of the linear movement trajectory TR. Also, CASEs 2, 4, and 6 show cases where cooperative control is performed, i.e., where the arm unit 53e is caused to move in the direction of the linear movement trajectory TR.
Of these CASE 1 to 6, this embodiment corresponds to CASE 1 and 2. Here, the movement of the pivot axis SA and the relative movement of the hand 53c by the arm 53b with respect to the pivot axis SA are combined into one movement. As a result, the hand 53c is moved in a three-dimensional direction at the fourth position D, and in the case of this embodiment, part of the movement of the pivot axis SA in the X-axis direction is also shared by the hand 53c of the arm part 53e and the arm 53b. That is, as the relative movement of the hand 53c by the arm 53b with respect to the pivot axis SA, in addition to the direction perpendicular to the moving linear trajectory TR (here, the X-axis direction) (here, the Y-axis direction and Z-axis direction), the hand 53c is also moved in the X-axis direction. Moving the hand 53c in a three-dimensional direction at the fourth position D in this way is called cooperative control. On the other hand, when the arm 53b moves the hand 53c relative to the rotation axis SA in a direction perpendicular to the X-axis direction (here, the Y and Z axes directions) without sharing the movement in the X-axis direction, this is called no cooperative control.
In the following explanation of Cases 1 to 6, the bending process will be described as being performed on a horizontal plane in a direction (Y-axis direction) perpendicular to the direction of the linear movement trajectory TR (X-axis direction).
Cooperative control is preferable because it allows the length of the linear movement path TR to be shortened without increasing the length of the arm 53b.

In CASE 1 where no cooperative control is performed, it is preferable to set the shift amount sh to the sum of the amount of bending of the bent part in the Y-axis direction in plan view and the linear distance d when the arm 53b is folded to its shortest in plan view. In other words, it is preferable to set the shift amount sh equal to the linear distance d' at the start of processing. Then, at the end of processing, it is preferable to fold the arm 53b to its shortest in plan view to approach the linear distance d. This allows for a compact equipment configuration. In this case, the cart 52d takes over the X-axis movement that was previously performed by the industrial robot 70 in the conventional device configuration, instead of the industrial robot 70.

On the other hand, as shown in CASE 2, it is also possible to perform cooperative control in which the arm 53b also shares the movement in the X-axis direction. This cooperative control makes it possible to shorten the length of the first linear movement trajectory TR without increasing the length of the arm 53b of the industrial robot 53 compared to when cooperative control is not performed. As shown in CASE 2, it is preferable to set the shift amount sh to the same length as the bending amount in the Y-axis direction of the curved part in a plan view. In other words, it is preferable to set the shift amount sh to be equal to the linear distance d' at the start of processing. On the other hand, it is preferable to fold the arm 53b to the shortest in a plan view during bending processing to approach the linear distance d. Then, at the end of processing, it is preferable to extend the arm 53b to the longest in a plan view to obtain the linear distance d' and to position the hand 53c on the extension line of the first linear movement trajectory TR.
When CASE 1 and CASE 2 are compared, the linear distance d' when the arm 53b is extended can also be made shorter in CASE 2 than in CASE 1.

When cooperative control is performed, the control of the movements of the cart 52d carrying the main body 53a, the arm 53b, and the hand 53c becomes complicated, but depending on the length and degree of bending of the curved parts to be manufactured, it may be possible to reduce the total equipment construction costs.
In CASE 1 and CASE 2, examples are shown in which the length of the arm portion 53e of the industrial robot 53 is short. However, if there is sufficient length in the arm portion 53e of the industrial robot 53, the length of the first linear movement trajectory TR can be further shortened by cooperative control.

[Second embodiment]
A second embodiment of the present invention will now be described with reference to FIG.
In this embodiment, only the arrangement of the bending force application part is changed from the configuration described in the first embodiment. Therefore, in the following description, the configuration other than the bending force application part 150 is the same as the configuration of the first embodiment, and a duplicated description will be omitted.

[Bending device]
The bending force applying unit 150 is disposed at a fourth position D downstream of the third position C along the feed direction of the workpiece Pm. The bending force applying unit 150 moves the gripping position of the workpiece Pm in two-dimensional or three-dimensional directions. In this way, the bending force applying unit 150 applies a bending force to the workpiece Pm.
The bending force applying section 150 includes a stand 151 , a first sliding mechanism 152 , and an industrial robot 153 .
The stand 151 is fixedly disposed at a fourth position D. The stand 151 is long in the X-axis direction, and is disposed so that a first linear movement trajectory TR, which will be described later, coincides with an extension line EX of an axis CL of the workpiece Pm at the first position A in a plan view.

The first slide mechanism 152 includes a pair of rails 152a, one ball screw 152b, a motor 152c, and a carriage 152d.
The pair of rails 152a are laid parallel to each other along the X-axis direction on the upper surface of the stand 151. The height of these rails 152a is the same at each position in the X-axis direction. In the plan view shown in FIG. 2, these rails 152a are arranged parallel to the extension line EX and sandwich the extension line EX. The distance between one rail 152a and the extension line EX is equal to the distance between the other rail 152a and the extension line EX. Here, the first linear movement trajectory TR is defined as a trajectory of the range in which the center of the pivot axis SA slides on a virtual straight line that is parallel to the pair of rails 152a in the plan view and through which the center of the pivot axis SA at the base end of the arm 153b of the arm section 153e described later passes.

Here, a supplementary explanation will be given regarding the first linear movement locus TR of the pivot axis SA.
For example, in the case where two parallel rails 152a are used as in this embodiment as an apparatus configuration for moving the main body (arm base) 153a described later, the first linear movement trajectory TR of the rotation axis SA is a trajectory of the range in which the center of the rotation axis SA slides on a virtual straight line that is parallel to these two rails 152a in a planar view and through which the center of the rotation axis SA passes.
Alternatively, in the case where one or three or more straight rails (not shown) are adopted as the device configuration for moving the main body 153a, the first linear movement trajectory TR of the rotation axis SA is defined as the trajectory of the range in which the center of the rotation axis SA slides on a virtual straight line through which the center of the rotation axis SA passes, as viewed in a plane.

The sliding range of the pivot axis SA is the range of movement of the pivot axis SA on the virtual straight line required to form a product from the workpiece Pm. The pivot axis SA is connected to the main body 153a and slides integrally therewith, so the sliding range of the pivot axis SA is the same as the sliding range of the main body 153a. Therefore, the pivot axis SA and the main body 153a share the first linear movement trajectory TR. In the case of FIG. 2, the first linear movement trajectory TR is the trajectory of the pivot axis SA that moves along a straight line connecting one end TRa and the other end TRb, and is shorter than the length of the ball screw 152b and the length of the pair of rails 152a.

2, the first linear movement trajectory TR on the virtual line, which is the range of movement of the pivot axis SA, coincides with the center position between the two outermost rails at each position in the longitudinal direction of the pair of rails 152a in a plan view. In this case, it is preferable because the center of gravity balance of the industrial robot 153 is easily stabilized. The center of gravity of the industrial robot 153 needs to take into account the weight including the main body 153a and the arm part 153e, but since the arm part 153e is lighter than the main body 153a, it is safe to assume that the position of the center of gravity coincides with the center position of the pivot axis SA. The first linear movement trajectory TR does not need to coincide with the center position between the two outermost rails or the first linear movement trajectory TR. When an industrial robot 153 with a relatively long arm part 153e is adopted, the center of gravity balance of the industrial robot 153 as a whole is taken into consideration. In other words, the first linear movement trajectory TR may be offset from the center position between the two outermost rails.

In addition, in FIG. 2, the axis of the ball screw 152b is also located in the center between the two outermost rails 152a at each position in the longitudinal direction of the pair of rails 152a in a plan view, and coincides with the first linear movement trajectory TR on the virtual straight line CL1. This configuration is preferable because it prevents excessive force from being applied to the ball screw 152b. However, the axis of the ball screw 152b does not have to coincide with the center between the two outermost rails 152a or with the first linear movement trajectory TR on the virtual straight line CL1.

The first linear movement trajectory TR coincides with the extension line EX in the plan view shown in FIG. 2. Note that the "coincidence" mentioned here allows for some deviation due to the positioning accuracy and operation accuracy of each component of the bending device in the plan view, and is not limited to being strictly coincident.

The ball screw 152b is laid along the X-axis direction on the upper surface of the stand 151. The height of the ball screw 152b is the same at each position in the X-axis direction. The ball screw 152b coincides with the extension line EX in the plan view shown in FIG. 2. Thus, the ball screw 152b is disposed between the pair of rails 152a and parallel to these rails 152a. The ball screw 152b is rotatably supported at two points, one end close to the third position C and the other end far from the third position C.
The motor 152c is fixed to the upper surface of the stand 151. The motor 152c is also coaxially connected to the other end of the ball screw 152b, and rotates the ball screw 152b forward or backward. The motor 152c is a servo motor, and the amount and speed of rotation thereof can be controlled by receiving instructions from the control unit 60.

The dolly 152d has a plurality of ball bearings (not shown) on its underside. These ball bearings can move linearly along the +X and -X directions while being guided by the rails 152a. Therefore, the dolly 152d can move along the +X and -X directions. A female screw (not shown) having an axis along the X-axis direction is formed at the center of the width of the dolly 152d. The ball screw 152b is inserted and screwed into this female screw. Therefore, when the motor 152c is rotated forward, the dolly 152d moves toward the +X direction, and when the motor 152c is rotated backward, the dolly 152d moves toward the -X direction. During this movement, the dolly 152d can move back and forth linearly while being guided by the pair of rails 152a. In addition, by controlling the amount of rotation of the motor 152c, the movement distance of the dolly 152d can also be controlled arbitrarily. Therefore, the slide drive unit is equipped with a combination of motor 152c and ball screw 152b.

In this embodiment, the combination of the ball screw 152b and the motor 152c is provided as a slide drive unit that slides the main body (arm base) 153a along the first linear movement trajectory TR so that the pivot axis SA moves along the first linear movement trajectory TR, but the slide drive unit of the present invention is not limited to this configuration. Any mechanism that can move the position of the main body 153a may be used, and other drive mechanisms such as a pinion rack mechanism may be used as the slide drive unit.
Similarly, in this embodiment, the carriage 152d is configured to include the ball bearings, but the present invention is not limited to this configuration. Instead of the ball bearings, the carriage 152d may be provided with a plurality of wheels, and the carriage 152d may be made to travel linearly along the +X direction and the -X direction while being guided by the rails 152a.

The industrial robot 153 includes a main body 153a and an arm unit 153e. The arm unit 153e includes an arm 153b and a hand 153c. The drive control of the arm 153b and the hand 153c of the arm unit 153e is performed according to instructions from the control unit 60.
The main body 153a is fixed integrally to the top of the carriage 152d.
The arm 153b has a single joint or multiple joints, and by bending at this joint, it is possible to move the hand 153c in a three-dimensional direction at the fourth position D. For the arm 153b of this embodiment, a general-purpose product having a general length can be used.
The hand 153c pinches and holds the workpiece Pm by a gripping portion g located near the tip of the workpiece Pm. The hand 153c is not limited to a configuration in which the workpiece Pm is held from the outside, and other holding mechanisms may be used. For example, the hand 153c may have a plurality of claws (not shown) that are inserted into the open end of the workpiece Pm and then opened to hold the workpiece Pm from the inside.

As described above, the bending apparatus of this embodiment includes a feed section 10 that feeds a metal workpiece Pm that is long in one direction along the feed direction (+X direction); a support section 20 that supports the workpiece Pm at a position downstream of the feed section 10; a heating section 30 that partially heats the workpiece Pm at a position downstream of the support section 20; a cooling section 40 that cools the workpiece Pm at a position downstream of the heating section 30; and a bending force application section 150 that grips the workpiece Pm at a position downstream of the cooling section 40 and applies a bending force to it. The bending force applying unit 150 has an arm unit 153e that moves the gripping position (position of the gripping unit g) in three dimensions while gripping the workpiece Pm; a main body 153a (arm base) to which a pivot axis SA at the base end of the arm unit 153e is connected and which slides so that the pivot axis SA moves along a first linear movement trajectory TR; and a first slide mechanism 152 that slides the main body 153a so that the pivot axis SA moves along the first linear movement trajectory TR.
In this embodiment, in the plan view shown in Figure 2, an extension line EX extending from an axis along the feed direction of the workpiece Pm at the position of the support portion 20 (first position A) overlaps with and is parallel to the first linear movement trajectory TR of the main body 153a (arm base).

[Bending method]
A bending method using the bending apparatus having the above configuration will be described below.
2, first, the workpiece Pm is supported by the support unit 20 disposed at the first position A and the hand 153c disposed at the fourth position D while being relatively fed in its longitudinal direction by the feed unit 10. At this point, the workpiece Pm has a straight shape without any bent parts.

After supporting the workpiece Pm in this manner, the workpiece Pm being fed is rapidly heated partially by the heating section 30 at the second position B. When steel is used as the raw material, the heating temperature of the workpiece Pm at this time is desirably set to the Ac3 point or higher of the steel that constitutes the workpiece Pm. By setting the heating temperature to the Ac3 point or higher, the workpiece Pm can be quenched by appropriately setting the cooling rate during the cooling process that follows heating. Moreover, the deformation resistance of the workpiece Pm can be reduced to a level at which partial bending can be applied.

Next, at the third position C, a cooling medium is sprayed from the nozzle of the cooling section 40 toward the workpiece Pm. This cools the heated portion of the workpiece Pm. Although it depends on the type of steel of the workpiece Pm, by setting the cooling rate during this cooling to 100° C./sec or more, the bent portion Pb can be quenched to increase its strength.
This cooling forms in the workpiece Pm a first portion heated by the heating section 30 and a second portion cooled by the cooling section 40. The area between the first and second portions of the workpiece Pm is in a high temperature state, and the deformation resistance is significantly reduced.

At the fourth position D, the carriage 152d is caused to travel on the pair of rails 152a at the same feed speed in the +X direction in synchronization with the feed of the workpiece Pm. The feed speed and feed amount of the carriage 152d at this time can be adjusted by controlling the rotation speed and rotation amount of the motor 152c.
When the workpiece Pm is fed straight without bending, the hand 153c holding the gripping portion g also moves along the extension line EX in a plan view. At this time, the hand 153c moves in the +X direction at the same feed speed and feed amount as the carriage 152d. Since the gripping portion g of the workpiece Pm is held by the hand 153c, the workpiece Pm does not bend in the Z-axis direction. In addition, when the workpiece Pm is long and prone to bending due to its own weight, the position of the hand 153c in the Z-axis direction can be controlled to correct the deviation from the normal shape due to the bending. In addition, the deviation from the normal shape in the Y-axis and Z-axis directions that may occur due to residual stress or warping during tube making of the hollow material Pm and other factors can also be corrected in the same way.

On the other hand, when bending the workpiece Pm, the arm 153b is rotated and bent to change the position of the gripping part g in three-dimensional directions in synchronization with the feeding of the workpiece Pm. As a result, as shown in FIG. 2, the part of the workpiece Pm where the deformation resistance is greatly reduced is bent to form a bent part R.
When the position of the gripping portion g is moved in the +Y direction, a bent portion R is formed that is bent in the +Y direction with respect to the workpiece Pm. When the position of the gripping portion g is moved in the -Y direction, a bent portion R is formed that is bent in the -Y direction with respect to the workpiece Pm. When the position of the gripping portion g is moved in the +Z direction, a bent portion R is formed that is bent in the +Z direction with respect to the workpiece Pm. When the position of the gripping portion g is moved in the -Z direction, a bent portion R is formed that is bent in the -Z direction with respect to the workpiece Pm.

In both cases where bending is applied to the workpiece Pm and where bending is not applied to the workpiece Pm, when the workpiece Pm undergoes transformation and expansion due to partial heating and cooling, the expansion margin can be absorbed by making the combined speed of the feed speed of the carriage 152d and the speed applied to the gripping portion g of the workpiece Pm by the hand 153c faster than the feed speed of the workpiece Pm. In addition, when the feed speed of the carriage 152d is made slower than the feed speed of the workpiece Pm, compression can be applied to the heated portion of the workpiece Pm. Conversely, when the feed speed of the carriage 152d is made faster than the feed speed of the workpiece Pm, tension can be applied to the heated portion of the workpiece Pm.
As described above, according to the bending method using the bending apparatus of this embodiment, it is possible to manufacture a bent part by continuously or intermittently forming a variety of bent portions R in the workpiece Pm.

As described above, the bending method of this embodiment includes a feeding step of feeding the metal workpiece Pm long in one direction along its feeding direction (+X direction); a supporting step of supporting the workpiece Pm at a first position A; a heating step of partially heating the workpiece Pm at a second position B downstream of the first position A; a cooling step of cooling the workpiece Pm at a third position C downstream of the second position B; and a bending force applying step of gripping the workpiece Pm with the arm portion 153e at a fourth position D downstream of the third position C and moving the gripping position (position of the gripping portion g) of the arm portion 153e in a three-dimensional direction including at least the feed direction. The bending force applying step includes an arm portion moving step of sliding the main body 153a (arm base) to which the pivot axis SA is connected so that the pivot axis SA at the base end of the arm portion 153e slides along the first linear movement trajectory TR.
Furthermore, in this arm movement process, an extension line EX extending from the axis CL along the feed direction of the workpiece Pm at the first position A and a first linear movement trajectory TR of the main body 153a, which is the base of the arm portion 153e, overlap and are parallel in a planar view.

In contrast to the configuration and method of this embodiment, conventionally, bending was performed by the industrial robot 70 fixed at a fixed position on the floor surface, as indicated by the two-dot chain line in FIG.
As explained in the first embodiment, in the case of this conventional structure, the arm 73b continues to support the gripping portion g while rotating and bending in synchronization with the feeding of the workpiece Pm in the +X direction, so in order to bend a workpiece Pm that is longer than conventional (more than 2000 mm and less than 3500 mm, for example, 3000 mm), an arm 73b with an extremely long overall length as shown in Fig. 2 is required. An industrial robot 70 equipped with such a long arm 73b is expensive, which leads to an increase in facility construction costs.

Of the X-axis, Y-axis, and Z-axis directions, the movement of the gripper g in the X-axis direction is overwhelmingly larger. Therefore, in the bending device of this embodiment, the movement in the X-axis direction is achieved by the sliding motion of the carriage 152d. Therefore, it is not necessary to lengthen the overall length of the arm 153b of the arm portion 153e, and a general-purpose industrial robot 153 can be used. This reduces the cost of building facilities, making it possible to manufacture bent parts at low cost.
Furthermore, since the bending force applying unit 150 has a large amount of movement along the X-axis direction of the arm 153b and hand 153c of the arm unit 153e, it is also possible for this industrial robot 153 to lower a bent part after manufacture to a lowering location not shown.

Moreover, in this embodiment, the bending force applying section 150 is arranged so that the first linear movement trajectory TR overlaps the extension line EX in a plan view. More specifically, the center position of the pivot axis SA at the base end of the arm section 153e is located so as to overlap the extension line EX in a plan view. The bending of the workpiece Pm is mainly performed by moving the workpiece Pm in the +Y direction, -Y direction, +Z direction, and -Z direction with the central axis CL as a reference. Therefore, according to the configuration of this embodiment in which the position of the main body 153a is as close as possible to a position that is previously close to the reference, the required length of the arm 153b can be minimized. Therefore, in addition to the first slide mechanism 152 along the X-axis direction of the carriage 152d, the length of the arm 153b can be minimized by arranging the carriage 152d so that it overlaps the extension line EX in a plan view. This further reduces the facility construction cost and makes it possible to manufacture cheaper bent parts at a low cost.

In terms of FIG. 5 shown above, this embodiment corresponds to cases 3 and 4.
As shown in CASE 3, when cooperative control is not performed, the cart 152d can take over the movement in the X-axis direction that was previously performed by the industrial robot 70 in the conventional device configuration.
At the start of processing, the length of the robot arm, i.e., the length of the arm portion 153e, is set to the length when the arm 153b is folded to the shortest length when viewed in a plan view. At this time, the distance from the rotation axis SA to the position of the gripper g is the linear distance d. Then, as processing starts, the arm 153b moves the hand 153c relative to the main body 153a in a direction perpendicular to the first linear movement trajectory TR (+Y direction). Then, at the end of processing, the movement of the arm portion 53e is controlled so that the distance from the rotation axis SA to the position of the gripper g is the linear distance d'.

On the other hand, as shown in CASE 4, when cooperative control is performed, the movement in the X-axis direction can be shared not only by the carriage 152d but also by the arm portion 153e as the relative movement of the hand 153c with respect to the carriage 152d.
At the start of processing, the length of the arm 153e is set to the length when the arm 153b is folded to the shortest length when viewed from above. At this time, the distance from the pivot axis SA to the position of the gripper g is the linear distance d. Then, at the end of processing, the distance from the pivot axis SA to the position of the gripper g in the direction perpendicular to the first linear movement trajectory TR is controlled to be the linear distance d'. That is, the hand 153c is made to share the relative movement in the -X direction with the main body 153a. As a result, the linear distance d' can be made shorter in CASE 4 than in CASE 3. In this case, although the cooperative control becomes more complex, the length of the first linear movement trajectory TR can be shortened, so that the total facility construction cost can be reduced.
CASE 4 and CASE 5 show examples in which the length of the arm portion 153e of the industrial robot 153 is short. However, if there is sufficient length in the arm portion 153e of the industrial robot 153, the length of the first linear movement trajectory TR can be further shortened by using cooperative control.

[Third embodiment]
A third embodiment of the present invention will now be described with reference to FIG.
In this embodiment, only the configuration and arrangement of the bending force applying portion are changed from the configuration described in the first embodiment. Therefore, in the following description, the configuration other than the bending force applying portion 250 is the same as the configuration of the first embodiment, and redundant description will be omitted.

[Bending device]
The bending force applying section 250 of the bending device of this embodiment is disposed at a fourth position D downstream of the third position C along the feed direction of the workpiece Pm. The bending force applying section 250 moves the gripping position of the workpiece Pm in two-dimensional or three-dimensional directions. In this way, the bending force applying section 250 applies a bending force to the workpiece Pm.
The bending force applying section 250 includes a base 254 d , a first slide mechanism 252 , a second slide mechanism 254 , and an industrial robot 253 .
The stand 251 is disposed so as to be freely movable in the +Y and -Y directions at the fourth position D. The stand 251 is long in the X-axis direction, and an axis passing through the center position in the width direction (Y-axis direction) of the stand 251 can be adjusted in a plan view to either coincide with, be shifted in the +Y direction, or be shifted in the -Y direction with respect to an extension line EX of the axis CL of the workpiece Pm at the first position A.

The first slide mechanism 252 includes a pair of rails 252a, one ball screw 252b, a motor 252c, and a carriage 252d.
The pair of rails 252a are laid parallel to each other along the X-axis direction on the upper surface of the stand 251. The height of these rails 252a is the same at each position in the X-axis direction. These rails 252a are parallel to the extension line EX in the plan view shown in FIG. 3. The pair of rails 252a can be adjusted to either coincide with the extension line EX, shift in the +Y direction, or shift in the -Y direction with respect to the extension line EX in the plan view. The first linear movement trajectory TR of the rotation axis SA is defined as the range in which the center of the rotation axis SA slides on a virtual straight line that is parallel to the pair of rails 252a in the plan view and through which the center of the rotation axis SA at the base end of the arm section 253e described later passes.

Here, a supplementary explanation will be given regarding the first linear movement locus TR of the pivot axis SA.
For example, in the case where two parallel rails 252a are used as in this embodiment as an apparatus configuration for moving the main body (arm base) 253a described later, the first linear movement trajectory TR of the rotation axis SA is a trajectory of the range in which the center of the rotation axis SA slides on a virtual straight line that is parallel to the two rails 252a in a planar view and through which the center of the rotation axis SA passes.
Alternatively, in the case where one or three or more straight rails (not shown) are adopted as the device configuration for moving the main body 253a, the first linear movement trajectory TR of the rotation axis SA is defined as a trajectory within the range in which the center of the rotation axis SA slides on a virtual straight line that is parallel to the one or three or more straight rails when viewed in a plane and through which the center of the rotation axis SA passes.

The range in which the pivot axis SA slides is the range of movement of the pivot axis SA on the virtual straight line or the central axis line required to form a product from the workpiece Pm. The pivot axis SA is connected to the main body 253a and slides as an integral unit, so the range in which the pivot axis SA slides is the same as the sliding range of the main body 253a. Therefore, the pivot axis SA and the main body 253a share the first linear movement trajectory TR. In the case of FIG. 3, the first linear movement trajectory TR of the pivot axis SA is the trajectory of the pivot axis SA that moves along a straight line (line segment) connecting one end TRa and the other end TRb that overlap the central axis line of the ball screw 252b in a plan view, and is shorter than the length of the ball screw 252b and the length of the pair of rails 252a.

In FIG. 3, the first linear movement trajectory TR on the virtual straight line, which is the moving range of the pivot axis SA, coincides with the center position between the two outermost rails at each position in the longitudinal direction of the pair of rails 252a in a plan view. In this case, it is preferable because the center of gravity balance of the industrial robot is easily stabilized. The center of gravity of the industrial robot needs to take into account the weight including the main body (arm base) 253a and the arm part 253e, but since the arm part 253e is lighter than the main body 253a, the center of gravity can be considered to be the center of the pivot axis SA. The first linear movement trajectory TR does not need to coincide with the center position between the two outermost rails or the first linear movement trajectory TR. In the case of an industrial robot with a relatively long arm part 253e, the first linear movement trajectory TR may be offset from the center position between the two outermost rails in consideration of the center of gravity balance. 2, the axis of the ball screw 252b is also located at the center of the gap between the two outermost rails at each position in the longitudinal direction of the pair of rails 252a in a plan view, and coincides with the first linear movement locus TR on the virtual straight line CL1. This configuration is preferable because it is possible to prevent excessive force from being applied to the ball screw 252b. The axis of the ball screw 252b does not have to coincide with the center of the gap between the two outermost rails or the first linear movement locus TR on the virtual straight line CL1.
The first linear movement trajectory TR coincides with the extension line EX in the state shown in FIG. 3, but can be shifted in the +Y direction or the -Y direction as necessary.

The ball screw 252b is laid along the X-axis direction on the upper surface of the stand 251. The height of the ball screw 252b is the same at each position in the X-axis direction. The ball screw 252b is arranged parallel to the extension line EX in the plan view shown in FIG. 3. Therefore, the ball screw 252b is arranged in a position between the pair of rails 252a and parallel to these rails 252a. The ball screw 252b is rotatably supported at two points, one end close to the third position C and the other end far from the third position C.
The motor 252c is fixed to the upper surface of the stand 251. The motor 252c is also coaxially connected to the other end of the ball screw 252b, and rotates the ball screw 252b forward or backward. The motor 252c is a servo motor, and the amount of rotation thereof can be controlled.

The dolly 252d has a plurality of ball bearings (not shown) on its underside. These ball bearings can move linearly along the +X and -X directions while being guided by the rails 252a. Therefore, the dolly 252d can move along the +X and -X directions. A female screw (not shown) having an axis along the X-axis direction is formed at the center of the width of the dolly 252d. The ball screw 252b is inserted and screwed into this female screw. Therefore, when the motor 252c is rotated forward, the dolly 252d moves in the +X direction, and when the motor 252c is rotated backward, the dolly 252d moves in the -X direction. During this movement, the dolly 252d can move back and forth linearly while being guided by the pair of rails 252a. In addition, the movement distance of the dolly 252d can be controlled arbitrarily by controlling the amount of rotation of the motor 252c.

The second slide mechanism 254 includes a base 251, a pair of rails 254a, one ball screw 254b, and a motor 254c.
The pair of rails 254a are laid parallel to each other along the Y-axis direction on the upper surface of the base 254d. The height of the rails 254a is the same at each position in the Y-axis direction. The rails 254a are disposed perpendicular to the extension line EX in the plan view shown in FIG.

For example, in the case of this embodiment in which two parallel rails 254a are used as an apparatus configuration for moving the stand 251 together with the main body (arm base) 253a, the second linear movement trajectory TR1 is a trajectory that is parallel to these two rails 254a in a planar view, and is a trajectory of the range in which the central position of the linear movement trajectory TR slides on a virtual straight line through which the central position (midpoint) of the linear movement trajectory TR passes.
Alternatively, in the case where one or three or more straight rails (not shown) are adopted as the device configuration for moving the stand 251 together with the main body 253a, the second linear movement trajectory TR1 is defined as a trajectory within the range in which the center position of the linear movement trajectory TR slides on a virtual straight line that is parallel to the one or three or more straight rails when viewed in a plane and through which the center position of the linear movement trajectory TR passes.
Here, the second linear movement trajectory TR1 coincides with the trajectory of the range in which the first linear movement trajectory TR slides by the second sliding mechanism 254 when the center of the rotation axis SA is positioned at the central position (midpoint) of the first linear movement trajectory TR.

The pivot axis SA is connected to the main body 253a and slides integrally therewith, so the range in which the pivot axis SA slides is the same as the sliding range of the main body 253a. Therefore, when the center of the pivot axis SA is positioned at the center position (midpoint) of the first linear movement trajectory TR, the pivot axis SA and the main body 253a share the second linear movement trajectory TR1. As shown in FIG. 3, the second linear movement trajectory TR1 is a straight line segment connecting one end TR1a and the other end TR1b, and is shorter than the length of the ball screw 254b and the length of the pair of rails 254a.

The ball screw 254b is laid along the Y-axis direction on the upper surface of the base 254d. The height of the ball screw 254b is the same at each position in the Y-axis direction. The ball screw 254b is disposed so as to be perpendicular to the extension line EX in the plan view shown in FIG. 3. The ball screw 254b is disposed between the pair of rails 254a and parallel to these rails 254a. The ball screw 254b is rotatably supported on the base 254d at two points on both ends.
The motor 254c is fixed to the upper surface of the base 254d. The motor 254c is coaxially connected to the other end of the ball screw 254b and rotates the ball screw 254b forward or backward. The motor 254c is a servo motor, and the amount and speed of rotation of the motor 254c can be controlled.

The platform 251 has a plurality of ball bearings (not shown) on its underside. These ball bearings can move linearly along the +Y and -Y directions while being guided by the rails 254a. Therefore, the platform 251 can move along the +Y and -Y directions. The platform 251 has a female screw (not shown) with an axis along the Y-axis direction. The ball screw 254b is inserted and screwed into this female screw. Therefore, when the motor 254c is rotated forward, the platform 251 moves in the +Y direction, and when the motor 254c is rotated backward, the platform 251 moves in the -Y direction. During this movement, the platform 251d can reciprocate linearly while being guided by the pair of rails 254a. In addition, the movement distance of the platform 251 can be controlled arbitrarily by controlling the amount of rotation of the motor 254c in response to an instruction from the control unit 60.

In the above-described second slide mechanism 254, the slide drive unit including the ball screw 254b and the motor 254c is provided, but the present invention is not limited to this. In this case, the base 251 may be moved manually along the Y-axis direction after the base 251 is released from the fixed position.
Furthermore, instead of the second slide mechanism 254 configured as described above, a crane (not shown) may be used to move the platform 251 carrying the industrial robot 253 along the Y-axis direction. In this case, after the movement in the Y-axis direction, the platform 251 may be fixed to the floor surface with a bolt, pin, or wedge-shaped key (not shown).
The combination of the first slide mechanism 252 and the second slide mechanism 254 described above constitutes an XY table.

In this embodiment, the first slide mechanism 252 that slides the main body (arm base) 253a so that the pivot axis SA moves along the first linear movement trajectory TR is exemplified by a configuration including a combination of a ball screw 252b and a motor 252c. Also, the second slide mechanism 254 that moves the first linear movement trajectory TR along the second linear movement trajectory TR1 is exemplified by a configuration including a combination of a ball screw 254b and a motor 254c. However, the present invention is not limited to these configurations. In other words, any mechanism that can move the position of the main body 253a in a two-dimensional direction may be used, and other drive mechanisms such as a pinion rack mechanism may be used.
In the present embodiment, the carriage 252d is configured to include the ball bearings, but the present invention is not limited to this configuration. Instead of the ball bearings, the carriage 252d may be provided with a plurality of wheels, and the carriage 252d may be made to travel linearly along the X-axis direction while being guided by the rails 252a.
Similarly, in this embodiment, the base 251 is configured to include the ball bearings, but the present invention is not limited to this configuration. Instead of the ball bearings, the base 251 may be provided with a plurality of wheels, and the base 251 may be made to move linearly along the +Y direction and the -Y direction while being guided by the rails 254a.

The industrial robot 253 comprises a main body 253a and an arm unit 253e. The arm unit 253e comprises an arm 253b and a hand 253c. The drive control of the arm 253b and the hand 253c is performed by instructions from the control unit 60, which will be described later.

The main body 253a is fixed integrally to the top of the carriage 252d.
The arm 253b has a single joint or multiple joints, and can move the hand 253c in three-dimensional directions at the fourth position D by bending at the joints. A general-purpose product having a general length can be used as the arm 253b in this embodiment. A rotation axis SA is provided at the base end of the arm 253b. The rotation axis SA is connected to the main body 253a, so that the arm 253b is pivotally supported by the main body 253a.
The hand 253c pinches and holds the workpiece Pm by a gripping portion g located near the tip of the workpiece Pm. The hand 253c is not limited to a configuration in which the workpiece Pm is held from the outside, and other holding mechanisms may be used. For example, the hand 253c may have a plurality of claws (not shown) that are inserted into the open end of the workpiece Pm and then opened to hold the workpiece Pm from the inside.

As described above, the bending apparatus of this embodiment comprises a feed section 10 that feeds a metal workpiece Pm that is long in one direction along its feed direction (+X direction); a support section 20 that supports the workpiece Pm at a position downstream of the feed section 10; a heating section 30 that partially heats the workpiece Pm at a position downstream of the support section 20; a cooling section 40 that cools the workpiece Pm at a position downstream of the heating section 30; and a bending force applying section 250 that grips the workpiece Pm at a position downstream of the cooling section 40 and applies a bending force to it. The bending force applying unit 250 has an arm unit 253e that moves the gripping position (the position of the gripping unit g) in three dimensions while gripping the workpiece Pm; a main body 253a (arm base) to which the pivot axis SA at the base end of the arm unit 253e is connected and which slides so that the pivot axis SA moves along the first linear movement trajectory TR; and a first slide mechanism 252 that slides the main body 253a so that the pivot axis SA moves along the first linear movement trajectory TR.

In this embodiment, in the plan view shown in FIG. 3, the first linear movement trajectory TR of the pivot axis SA can move in the +Y direction or the -Y direction relative to an extension line EX of the axis line CL along the feed direction of the workpiece Pm at the position of the support part 20. That is, in this embodiment, the main body 253a (arm base) further has a second linear movement trajectory TR1 along the Y-axis direction that intersects the extension line EX at a right angle in the plan view. Note that the second linear movement trajectory TR1 may intersect the extension line EX at an angle other than a right angle.

In other words, the second linear movement trajectory TR1 along the pair of rails 254a intersects the first linear movement trajectory TR along the pair of rails 252a at a right angle in a plan view. With this configuration, the length of the second linear movement trajectory TR1 along the pair of rails 254a can be utilized to the maximum extent for the movement of the industrial robot 253 along the Y-axis direction.
It should be noted that the movement of the second slide mechanism 254 (the movement of the main body 253a in the Y direction) may be stopped while the bending force is being applied by the arm portion 253e. In this case, it is easy to control the application of the bending force.

The second linear movement trajectory TR1 will be described.
In the case where, for example, two parallel rails 254a are used as in the present embodiment, the second moving straight-line trajectory TR1 is parallel to these two rails 254a in a planar view and has a trajectory within the range in which the central position of the moving straight-line trajectory TR slides on a virtual straight line through which the central position (midpoint) of the first moving straight-line trajectory TR passes.
On the other hand, when one or three or more straight rails are used (not shown), the second linear movement trajectory TR1 is a trajectory of the range in which the pivot axis SA slides on a virtual straight line that is parallel to these one or three or more straight rails when viewed in a plane and passes through the center position of the linear movement trajectory TR.

Therefore, the above-mentioned "second linear movement trajectory TR1 along the Y-axis direction intersecting at right angles with the extension line EX in a plan view" means that the second linear movement trajectory TR1 exists in a direction intersecting with the extension line EX of the axis in a plan view (this direction is infinite). Therefore, the second linear movement trajectory TR1 only needs to have a "direction" along the direction intersecting with the extension line EX of the axis along the feed direction of the support part 20 in a plan view. For example, even if the second linear movement trajectory TR1 has a finite length determined by a limit switch (not shown) or the like for preventing the platform 251 from departing from the end of the rail 254a on the rail 254a and this second linear movement trajectory TR1 does not overlap with the extension line EX in a plan view, it has a "direction intersecting with the extension line of the axis in a plan view", so it is included in the above-mentioned "second linear movement trajectory TR1 along the Y-axis direction intersecting at right angles with the extension line EX in a plan view".

[Bending method]
A bending method using the bending apparatus having the above configuration will be described below. In this embodiment, the method of bending the workpiece Pm at the fourth position D is characteristic, and the other steps are the same as those described in the first embodiment. Therefore, only the differences from the bending method in the first embodiment will be described below.

3, the carriage 252d is caused to travel on the pair of rails 252a at the same feed speed in the +X direction in synchronization with the feed of the workpiece Pm. The feed speed and feed amount of the carriage 252d at this time can be adjusted by controlling the rotation speed and rotation amount of the motor 252c.
When the workpiece Pm is fed straight without bending, the hand 253c gripping the gripping portion g also moves along the extension line EX in a plan view. At this time, the hand 253c moves in the +X direction at the same feed speed and feed amount as the carriage 252d. Since the tip of the workpiece Pm is gripped by the hand 253c, it does not bend in the Z-axis direction. Furthermore, when the workpiece Pm is long and prone to bending due to its own weight, the deviation from the normal shape due to bending can be corrected by controlling the position of the hand 253c in the Z-axis direction.

On the other hand, when bending the workpiece Pm, the arm 253b is basically rotated and bent to change the position of the gripping part g in three-dimensional directions in synchronization with the feeding of the workpiece Pm. As a result, as shown in FIG. 3, the part of the workpiece Pm where the deformation resistance is significantly reduced is bent to form a bent part R. At this time, for example, when bending the workpiece Pm in the -Y direction, which is the opposite direction to that in FIG. 3, if the position of the main body 253a is fixed, it becomes necessary to bend the arm 253b extremely so that it becomes shorter in a plan view. However, since there is a limit to the bending range of the arm 253b, this limits the possible bending range.
In contrast, since this embodiment also includes the second slide mechanism 254, the position of the main body 253a can be moved in the -Y direction instead of bending the arm 253b excessively. Therefore, the bending range can be made wider.

As described above, the bending method of this embodiment includes a feeding step of feeding the metal workpiece Pm, which is long in one direction, along its feeding direction (+X direction); a supporting step of supporting the workpiece Pm at a first position A; a heating step of partially heating the workpiece Pm at a second position B downstream of the first position A; a cooling step of cooling the workpiece Pm at a third position C downstream of the second position B; and a bending force applying step of gripping the workpiece Pm with the arm portion 253e at a fourth position D downstream of the third position C and moving the gripping position (position of the gripping portion g) of the arm portion 253e in a three-dimensional direction including at least the feed direction. The bending force applying step includes an arm portion moving step of sliding the main body 253a (arm base) to which the pivot axis SA is connected so that the pivot axis SA at the base end of the arm 253b slides along the first linear movement trajectory TR.

Furthermore, in this arm movement process, the first linear movement trajectory TR of the main body 253a, which is the base of the arm 253b, can be shifted in the +Y direction and the -Y direction in a planar view relative to the extension line EX of the axis CL along the feed direction of the workpiece Pm at the first position A.
Furthermore, the bending method of this embodiment further includes a first position adjustment step of moving the main body 253a so that the rotation axis SA moves (slides) along a second linear movement trajectory TR1 (a second linear movement trajectory TR1 along the +Y direction and the -Y direction) that intersects, in a planar view, an extension line EX of the axis CL along the feed direction of the workpiece Pm at the first position A (first position).

According to the bending method using the bending apparatus of this embodiment, in addition to obtaining the same effects as those of the first embodiment, the bending range can be further expanded. Also, as in the above-mentioned embodiments, the conventional industrial robot 70 equipped with the long arm 73b is not required.
In this embodiment, the stand 251 is electrically moved by the driving force of the motor 254c, but the present invention is not limited to this configuration, and the stand 251 may be manually slid in the +Y direction and the -Y direction. Alternatively, the motor 254c may receive an instruction from the control unit 60 and automatically control the motor 254c.

In addition, the pair of rails 254a, the ball screw 254b, and the base 254d may be eliminated from the portion indicated by the symbol CT in FIG. 3. In this case, the constraints on the space required for installing the device can be alleviated.

Conversely, the pair of rails 254a, the ball screw 254b, and the base 254d may be placed in a position shifted in the -Y direction from the extension line EX in a plan view while being contained within the size indicated by the symbol CT in Fig. 3. In this case, the first linear movement trajectory TR can be shifted in the -Y direction in a plan view with respect to the extension line EX and placed parallel to it.
Alternatively, the equipment arrangement indicated by the symbol CT may be arranged at a position shifted in the +Y direction from the extension line EX in a plan view. In this case, the first movement linear trajectory TR can be shifted in the +Y direction in a plan view with respect to the extension line EX and arranged parallel to it.
In either case, a small bending force applying section 250 can be used, which reduces the cost of constructing the equipment.

Furthermore, in this case, the same effects as those in the first embodiment can be obtained.
That is, in this embodiment, in the plan view shown in FIG. 3, the bending force application portion 250 can be disposed so that the first linear movement trajectory TR is "parallel" to and "shifted" from the extension line EX.
By making the first linear movement trajectory TR "parallel", the length of the first linear movement trajectory TR can be maximized, and therefore a general-purpose industrial robot 253 having a short arm 253b can be adopted. This allows the cost of facility construction to be reduced. In addition, by making the first linear movement trajectory TR "parallel", the relative position between the extension line EX and the first linear movement trajectory TR can be kept constant, making it easier to control when applying bending force.

Furthermore, by combining the "shift" with the "parallel" motion, a cheaper and more versatile industrial robot 253 can be used. This makes it possible to further reduce the cost of building facilities. In addition, the movement of the arm 253b can be simplified.
Note that, before applying the bending force by the industrial robot 253, the movement in the Y-axis direction by the second slide mechanism 254 may be stopped and the position of the main body 253a may be fixed in a fixed position by a locking mechanism or the like. In this case, there is an advantage that vibrations in the Y-axis direction during bending by the industrial robot 253 can be suppressed, thereby improving the bending accuracy.

In the bending device of this embodiment, as shown in FIG. 3, a platform 251 having a track along the X-axis direction is placed on a base 254d having a track along the Y-axis direction and fixed at a fixed position. The platform 251 can move along the Y-axis direction on the base 254d. When the bending force is applied by the industrial robot 253, the position of the main body 253a in the Y-axis direction can be fixed by the locking mechanism or the like. Therefore, the movement of the industrial robot 253 when applying the bending force can be limited to only the X-axis direction, and vibration in the Y-axis direction can also be suppressed, so that the equipment has the advantage of high accuracy and rigidity. Therefore, it has the excellent advantage of being compact and low-cost, yet capable of being controlled with high accuracy. In addition, since the basic configuration is that the industrial robot 253 moves in the X-axis direction when applying the bending force, it is particularly suitable for processing members that are long in the X-axis direction and have a relatively small amount of bending in the Y-axis direction.

For example, an alternative device configuration could be one in which a platform with a track along the Y-axis direction is placed on a base with a track along the X-axis direction and fixed in a fixed position, which is the opposite of the above device configuration. However, from the perspective of achieving the objective of the present invention, which is to "manufacture long bent parts with high precision and at low cost," the device configuration of this embodiment is a more suitable option. Therefore, this embodiment employs a device configuration in which "a platform 251 with a track along the X-axis direction is placed on a base 254d with a track along the Y-axis direction and fixed in a fixed position."

[Fourth embodiment]
A fourth embodiment of the present invention will now be described with reference to FIG.
In this embodiment, only the configuration of the bending force applying unit is changed from the configuration described in the first embodiment. Therefore, in the following description, the configuration other than the bending force applying unit 350 is the same as the configuration of the first embodiment, and a duplicated description will be omitted. Note that, in Fig. 4, arms and the like are not shown to make the description easier to understand. The industrial robot used is the industrial robot 53 described in the first embodiment.

[Bending device]
The bending force applying unit 350 of the bending device of this embodiment is disposed at a fourth position D downstream of the third position C along the feed direction of the workpiece Pm. The bending force applying unit 350 includes a stand 351 and a rotating unit (not shown) instead of the stand 51 fixed at a fixed position. The rotating unit causes the stand 351 to rotate horizontally in the +Y and -Y directions around an axis (vertical axis) SW along the vertical direction (Z-axis direction) as shown in FIG. 4. The rotating unit may be an electric mechanism driven by a motor (not shown), or may be a manual mechanism. The position of the axis SW in a plan view is not limited to the position shown in FIG. 4, and may be set at other positions. For example, as shown in FIG. 4, an axis SW1 along the vertical direction (Z-axis direction) may be provided near the center of the length and width of the stand 351, and the stand 351 may be rotated around the axis SW1. In this case, the axis SW1 can be brought closer to the center of gravity of the base 351 in a plan view, which has the advantage that the base 351 can be rotated with less force.

Note that the arm 53e may be caused to move about the axis SW of the main body 53a before the application of the bending force by the arm 53e starts, and may stop moving during the application of the bending force. In this case, it is easy to control the application of the bending force.
Rotation of the base 351 around the axis SW or SW1 can be realized, for example, by providing a rotation mechanism on a base (not shown) placed on the installation surface and connecting the base 351 to the base so that it can rotate freely. Here, a base having a track for moving the base 351 in the Y-axis direction may be used as the base. Furthermore, the rotation mechanism of this embodiment may be combined with the third embodiment.

[Bending method]
In the bending method using the bending apparatus having the above configuration, the method of bending the workpiece Pm at the fourth position D is characteristic, and the other steps are as described in the first embodiment above.
That is, when bending the workpiece Pm, the arm 53b is basically rotated and bent to change the gripping position (the position of the gripping portion g) in three-dimensional directions in synchronization with the feeding of the workpiece Pm. As a result, the portion of the workpiece Pm where the deformation resistance is significantly reduced is bent to form the bent portion R. At this time, for example, when bending the workpiece Pm in the +Y direction, if the position of the main body 53a is fixed, it is necessary to bend the arm 53b extremely so that it becomes shorter in a plan view. However, since there is a limit to the bending range of the arm 53b, the possible bending range is restricted.
In contrast, since the present embodiment is also provided with the rotation mechanism, the position of the body 53a can be rotated in the +Y direction instead of bending the arm 53b excessively. Therefore, the bending range can be made wider.

In terms of FIG. 5 shown above, this embodiment corresponds to cases 5 and 6.
Here, the cooperative control refers to combining the movement of the carriage 52d and the relative movement of the hand 53c by the arm 53b with respect to the rotation axis SA into one movement to move the hand 53c in three-dimensional directions at the fourth position D. Specifically, in the case of this embodiment, the cooperative control refers to allocating a part of the movement of the carriage 52d in the X-axis direction to the hand 53c of the arm section 53e and the arm 53b, and moving the hand 53c in the X'-axis direction as a relative movement of the hand 53c by the arm 53b with respect to the rotation axis SA in a direction perpendicular to the direction of the linear movement trajectory TR (here, referred to as the X'-axis direction) (here, the Y'-axis direction, which is a direction perpendicular to the X'-axis direction on a horizontal plane, and the Z-axis direction, which is a vertical direction) and to the direction perpendicular to the direction of the linear movement trajectory TR (here, referred to as the X'-axis direction), to move the hand 53c in the X'-axis direction. On the other hand, the relative movement of the hand 53c by the arm 53b with respect to the rotation axis SA is referred to as not being coordinated, in that the arm 53b moves in directions perpendicular to the X'-axis direction (Y'-axis direction and Z-axis direction) without sharing the movement in the X'-axis direction.

5, when the coordinated control shown in CASE 5 is not performed, when forming a bent portion R that bends in the +Y direction in the workpiece Pm, the first linear movement trajectory TR of the pivot axis SA is arranged so as to be parallel to a straight line connecting the leading end a of the bend and the trailing end b of the bent part in a plan view. In other words, the first linear movement trajectory TR needs to be arranged so that the pivot axis SA passes through a position on the path of the hand 53c required for forming the bent portion R and at the position closest to the first linear movement trajectory TR (the position of the leading end a of the bend and the position of the trailing end b of the bend) that is at least the linear distance d away in a direction perpendicular to the line.
Here, the linear distance d is the distance from the pivot axis SA to the position of the gripping portion g in a plan view. For example, if the trajectory of the hand 53c for forming the bent portion R is a part of a circular or elliptical arc in a plan view, the distance between the tip end a and the rear end b of the bend and the arm base may be set to d.

6(a) to 6(c), the arm 53b is formed by connecting two arm parts 53b1 and 53b2 via a joint e. Due to the structure of the joint e, the linear distance d from the position of the gripping part g of the hand 53c to the rotation axis SA cannot be set to zero, and a certain distance must be secured.
Therefore, it is preferable to determine the base end position of the arm 53b (the position of the rotation axis SA) based on the minimum straight-line distance d for the industrial robot 53 to be adopted and the trajectory of the hand 53c for forming the bent portion R, and to configure the rotation mechanism so that the cart 52d carrying the main body 53a passes through that base end position.

As shown in Fig. 6(a) to (d), when the length of the arm part 53b1 constituting the arm 53b is A1 (mm) and the length of the arm part 53b2 is A2 (mm), the following formula 1 needs to be satisfied in order to allow the angle of the hand 53c to have a degree of freedom. Here, the linear distance d' is the longest distance from the pivot axis SA to the position of the grip part g when the arm 53b is extended straight so that the hand 53c is farthest from the main body 53a, which is necessary to form the bent part R. More specifically, as shown in Fig. 6(d), it shows the distance from the pivot axis SA to the position of the grip part g when the arm 53b is extended to the maximum and the angle of the hand 53c is in the direction in which the arm is extended. That is, Fig. 6(d) shows a state in which the two arm parts 53b1 and 53b2 are opened 180 degrees at the joint e, and the linear distance d' in this case is d' = A1 + A2 + A3. Therefore, when setting the position of the trolley 52d (setting the position of the first linear movement trajectory TR), the position is set to satisfy the following formula 1 so that the hand 53c can reach the gripping portion g of the workpiece Pm.
Note that A3 indicates the length from the joint between the arm 53b and the hand 53c to the position of the gripping portion g of the hand 53c. In the following formula 1, the hand 53c is oriented in the same extension direction as the arm parts 53b1 and 53b2, but as described above, by changing the orientation of the hand 53c, the length A3 can be made zero in a plan view.

A1+A2+A3≧d'...(Formula 1)

When performing the coordinated control shown in CASE 6 of Fig. 5, for example, the arm 53b and hand 53c are extended almost straight at both ends of the bent portion R (see Fig. 6(d)) to ensure the linear distance d', and the arm 53b is shortened in the middle (see Figs. 6(a) to (c)) to form the bent portion R, and the movements of the arm 53b and hand 53c and the movement of the base (main body 53a) can be coordinated to control this. This makes it possible to shorten the travel length of the main body 53a, and also reduces the construction costs of the entire facility.
In CASE 5 and CASE 6, examples are shown in which the length of the arm 53b of the industrial robot 53 is short. However, if there is sufficient length in the arm 53b of the industrial robot 53, the length of the first linear movement trajectory TR can be further shortened by using cooperative control.

When the bending force is applied by the industrial robot 53, the rotation of the stand 351 may be stopped and the position of the main body 53a may be fixed in a fixed position by a locking mechanism (not shown) or the like. In this case, there is an advantage that rotational vibrations around the Z axis during bending by the industrial robot 53 can be suppressed, thereby improving the bending accuracy.

As described above, in the bending processing device of this embodiment, the main body 53a (arm base) further has the rotation mechanism that rotates the first linear movement trajectory TR of the pivot axis SA relative to the extension line EX of the axis CL along the feed direction of the workpiece Pm at the position of the support part 20 in a plan view.
The bending method of this embodiment further includes a second position adjusting step of rotating the orientation of the first linear movement trajectory TR in a plan view about the vertical axis (Z-axis).
According to the bending method using the bending apparatus of this embodiment, the same effects as those of the first embodiment can be obtained, and in addition, the bending range can be further expanded.
In addition, the rotation of the first linear movement trajectory TR in the second position adjustment process may be performed manually, or may be performed electrically using a motor (not shown), or may be configured so that the motor receives instructions from the control unit 60 and is automatically controlled.

In addition, in each of the above embodiments, the case where the arms 53b, 153b, and 253b of the industrial robot are bent in a plan view is illustrated, but the present invention is not limited to this example. That is, the arms 53b, 153b, and 253b may be bent in a side view (i.e., on a vertical plane), or the arms 53b, 153b, and 253b may be bent in both a plan view and a side view. In addition, in FIGS. 1 to 3 and 6, a horizontal articulated robot in which the joints of each industrial robot 53, 153, and 253 are three axes including the rotation axis SA is illustrated, but this is not limited thereto, and a vertical articulated industrial robot having six axes or a number of joints other than these may also be used.

The first to fourth embodiments of the present invention have been described above, but the present invention is not limited to these configurations and may be modified as appropriate without departing from the spirit of the present invention. For example, the third embodiment may be combined with the fourth embodiment.

The bent part manufactured by the manufacturing method according to the present invention can be used, for example, in the applications (i) to (vii) exemplified below.
(i) Structural members of automobile bodies, such as front side members, cross members, side members, suspension members, roof members, A-pillar reinforcements, B-pillar reinforcements, bumper reinforcements, etc.; (ii) Strength members and reinforcing members of automobiles, such as seat frames and seat cross members; (iii) Exhaust system parts, such as exhaust pipes of automobiles; (iv) Frames and cranks of bicycles and motorcycles; (v) Reinforcing members and bogie parts (bogie frames, various beams, etc.) of vehicles such as trains.
(vi) Frame parts and reinforcing members for ship hulls, etc. (vii) Strength members, reinforcing members or structural members for home appliances

The dimensions of the bent part manufactured by the manufacturing method according to the present invention can be exemplified by a member having a bending force application part with a bending radius of 2000 mm and a bending angle of 8.6 degrees in the Y-axis direction, a straight part of 200 mm in front of it and 2500 mm in rear, and a total length of 3000 mm. If a bent part with this dimension is to be processed by a conventional stationary industrial robot, it is necessary to place an industrial robot with a minimum arm length (length when the arm is stretched straight) of 1500 mm at a position 1500 mm downstream from the processing start position. On the other hand, when a slide drive unit is provided as in the present invention, a total length of 60 mm for the arm of the industrial robot is sufficient. Even when considering the delivery of the product after processing, an arm length of 1500 mm is not necessary, and the initial investment can be significantly reduced.

10: Feed section 20: Support section 30: Heating section 40: Cooling section 50, 150, 250, 350: Bending force applying section 52, 152, 252: First slide mechanism 53a, 153a, 253a: Main body (arm base)
53e, 153e, 253e Arm portion 254 Second slide mechanism A First position B Second position C Third position CL Axis line D Fourth position EX Extension line Pm Workpiece SA Swivel axis TR First linear movement path TR1 Second linear movement path

Claims (12)

A feed section that feeds a metal workpiece that is long in one direction along a feed direction;
a support section that supports the workpiece at a downstream position of the feed section;
a heating section that partially heats the workpiece at a downstream position of the support section;
a cooling section that cools the workpiece at a position downstream of the heating section;
a bending force applying section that holds the workpiece at a position downstream of the cooling section and applies a bending force to the workpiece;
Equipped with
The bending force applying portion is
An arm portion that moves a gripping position of the workpiece in three dimensional directions while gripping the workpiece;
an arm base to which a pivot shaft at a base end of the arm is connected and which slides so that the pivot shaft moves along a first linear movement trajectory;
a first slide mechanism that slides the arm base so that the pivot shaft moves along the first linear movement path;
A bending apparatus comprising: an extension line of an axis along the feed direction of the workpiece at the position of the support portion;
the first linear movement trajectory;
The bending apparatus according to claim 1, characterized in that The bending device according to claim 1, characterized in that the first linear movement trajectory is shifted in a planar view with respect to an extension line of an axis along the feed direction of the workpiece at the position of the support portion. The bending device according to any one of claims 1 to 3, characterized in that the first linear movement trajectory and an extension line of an axis along the feed direction of the workpiece at the position of the support part are parallel to each other in a planar view. The bending force applying portion is
The bending device according to any one of claims 1 to 4, further comprising a second slide mechanism for sliding the arm base so that the pivot axis moves along a second linear movement trajectory that intersects, in a planar view, an extension line of an axis line of the support part along the feed direction. 6. The bending device according to claim 1, wherein the arm base further comprises a rotation portion for rotating the first linear movement locus about a vertical axis. A feeding step of feeding a metal workpiece that is long in one direction along the feeding direction;
supporting the workpiece at a first position;
a heating step of partially heating the workpiece at a second location downstream from the first location;
a cooling step of cooling the workpiece at a third position downstream of the second position;
a bending force imparting step of gripping the workpiece with an arm unit at a fourth position downstream of the third position and moving a gripping position of the arm unit in a three-dimensional direction including at least the feed direction;
having
A bending method characterized in that the bending force applying process includes an arm portion moving process of sliding an arm base portion to which the pivot shaft is connected so that the pivot shaft at the base end of the arm portion slides along a first linear movement trajectory. an extension line of an axis along the feed direction of the workpiece at the first position;
the first linear movement trajectory;
The bending method according to claim 7, characterized in that the parts overlap each other in a plan view. With respect to an extension line of an axis along the feed direction of the workpiece at the first position,
The bending method according to claim 7, wherein the first linear movement locus is shifted in a plan view. The bending method according to any one of claims 7 to 9, characterized in that the first linear movement trajectory and an extension line of an axis along the feed direction of the workpiece at the first position are parallel to each other in a planar view. The bending method according to any one of claims 7 to 10, further comprising a first position adjustment step of moving the position of the pivot axis along a second linear movement trajectory that intersects, in a planar view, an extension line of an axis line along the feed direction of the workpiece at the first position. The bending method according to any one of claims 7 to 11, further comprising a second position adjustment step of rotating an orientation of the first linear movement locus in a plan view about a vertical axis.

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