JP6424555B2 - Hot three-dimensional bending machine - Google Patents

Description

  The present invention relates to a hot three-dimensional bending apparatus.

  Patent Document 1 discloses a hot three-dimensional bending apparatus 1 (hereinafter referred to as "3DQ apparatus") whose outline is shown in FIG. Hereinafter, this 3DQ device 1 will be described.

As shown in FIG. 1, the feeder 4 is positioned while a hollow work material 2 having a closed cross section (in the following explanation, a steel pipe is taken as an example) is positioned by a support roll 3 fixedly arranged at a predetermined position. Thus, the steel pipe 2 is sent in the axial direction (direction indicated by the arrow in FIG. 1). On the downstream side of the feeding direction of the steel pipe 2 from the support roll 3 (hereinafter, also referred to simply as "downstream side", the opposite positional relationship is simply referred to as "upstream side"), an annular high frequency heating the steel pipe 2 from the periphery. An induction heating coil 5 (hereinafter, also simply referred to as a "coil") is disposed. A high frequency power is supplied from a bus bar (feeder) 6 that suspends and supports the coil 5 to the coil 5 to heat the steel pipe 2 to be sent to Ac ₃ or more. Cooling water is injected to the outer periphery of the heated steel pipe 2 from an annular water-cooling device 7 disposed on the downstream side in the feed direction of the coil 5 to harden the steel pipe 2.

  And, in the high temperature portion 2a of the steel pipe 2 formed in the region from the heating by the coil 5 to the cooling by the water cooling device 7, the holding means or the holding means 8 disposed downstream of the water cooling device 7 By applying a bending moment continuously or intermittently by the support roll 3, the steel pipe 2 is subjected to a hot bending process to manufacture a bending member 9.

  In order to improve the dimensional accuracy of the bending member 9, it is desirable that the axial length of the high temperature portion 2a be as short as possible within the range in which bending can be performed. For this reason, the water cooling device 7 is disposed in the immediate vicinity of the coil 5. In many cases, the water cooling device 7 and the coil 5 are connected to be an integral body, which is advantageous in terms of space saving.

  By the way, products manufactured by hot three-dimensional bending by 3DQ device 1 are mainly members for automobiles (for example, suspension arms), and products require strict dimensional accuracy of ± 0.5 mm as an example. Be

  Since it is inevitable that a slight bend (warpage) exists in the steel pipe 2 to be sent out in paragraph 0004 of Patent Document 2, when the steel pipe 2 coming out of the support roll 3 passes through the inside of the coil 5, the steel pipe 2 The gap between the outer circumference of the coil and the inner circumference of the coil 5 becomes uneven in the circumferential direction, and a temperature difference is generated in the steel pipe 1 between the portion where the distance to the inner circumference of the coil 5 is short and the portion where this distance is long It is described that there is a possibility that the processing accuracy of

  As a countermeasure, in Patent Document 2, it is described that the movable gantry on which the coil is fixed is floatingly supported on the stationary gantry through the floating supporting means, and the movable gantry is provided with a plurality of guide members that abut the outer peripheral surface of the steel pipe. It is done. Thus, the coil can be centered along with the movable base according to the bending (warpage) of the steel pipe, and the gap between the outer circumference of the steel pipe and the inner circumference of the coil can be made uniform, so that the steel pipe can be heated uniformly in the circumferential direction There is.

JP, 2008-23573, A JP 2012-55963 A

  As a result of intensive studies by the present inventors, the bending member manufactured by the 3DQ device has a flat cross-sectional shape with small strength in the height direction, and is extremely high, for example, ± 0.5 mm. It has been found that, in the case of parts requiring dimensional accuracy, it is not possible to manufacture a bending member having a desired dimensional accuracy even using the bending apparatus disclosed by Patent Document 2.

  An object of the present invention is to provide a 3DQ device capable of manufacturing a bending member which is a flat shape having a small strength in the height direction and which has a very high dimensional accuracy of, for example, ± 0.5 mm. It is to be.

  The inventors examined the 3DQ device 1 in detail. In this examination, it was assumed that the workpiece 2 by the 3DQ device 1 was a hollow square tube having a flat and closed cross section. As a result of this examination, the following novel findings A and B were obtained to complete the present invention.

  (A) When the 3DQ device 1 is in operation, the heat generated by the coil 5 supplies high frequency power to the coil 5 and expands the bus bar 6 that suspends and supports the coil 5. Due to expansion of the bus bar 6, the coil 5 fixed to the lower part of the bus bar 6 and the water cooling device 7 integrated with the coil 5 are mainly displaced downward from the initial installation position, and the coil 5 and the water cooling device 7 It is eccentric to the square tube 2.

  FIG. 2A is a graph showing the displacement of the coil 5 when the heating of the coil 5 is turned on and off by suspending and supporting the coil 5 by the bus bar 6 having a length of 600 mm in the vertical direction. ) Is an explanatory view extracting and showing the vicinity of the coil 5 and the bus bar 6.

  As shown in FIGS. 2 (a) and 2 (b), when the heating of the coil 5 is turned on, the bus bar 6 thermally expands, whereby the coil 5 is displaced approximately 0.5 mm downward from the position before heating. Therefore, the coil 5 and the water cooling device 7 are eccentric to the square tube 2.

When this eccentricity occurs, the dimensional accuracy of the product (bending member) 9 is significantly reduced.
(B) In order to investigate which of the eccentricity of the coil 5 and the eccentricity of the water cooling device 7 is affected by the reduction in the dimensional accuracy of the bending member 9, the water cooling device 7 and the coil 5 are not integrated As a component, only the water cooling device 7 was eccentric to the square tube 2 without eccentricity of the coil 5.

  FIG. 3 (a) shows the degree of deterioration of the dimensional accuracy in the height direction when both the coil 5 and the water cooling device 7 are eccentric in a square tube 7 having a flat cross section, as well as the water cooling device 7 It is a graph which shows the grade of the dimensional accuracy fall of the height direction at the time of making it eccentric only by (circle) mark, FIG.3 (b) is explanatory drawing which shows the cross-sectional dimension of the square tube 2. FIG.

  As shown in FIGS. 3 (a) and 3 (b), the degree of reduction in the dimensional accuracy of the bending member 9 in the case where only the water cooling device 7 is eccentric is, surprisingly, either the coil 5 or the water cooling device 7 The degree of accuracy reduction of the bending member 9 in the case of eccentricity was also the same.

  From this, it is not the eccentricity of the coil with respect to the square tube 2 that mainly affects the decrease in the dimensional accuracy of the bending member 9 but the eccentricity of the water cooling device 7 with respect to the square tube 2 It turned out to be.

The present invention is as listed below.
(1) A feeding mechanism for feeding a hollow workpiece having a flat and closed cross section in the longitudinal direction;
A support mechanism fixedly disposed at a predetermined position downstream of the feed mechanism in the feed direction of the workpiece and positioning the workpiece;
A high frequency induction heating coil disposed at a predetermined position on the downstream side of the support mechanism and heating the workpiece;
Wherein while the high-frequency induction heating coil supporting lifting, and bus bars for supplying power to the high-frequency induction heating coil,
A water cooling device which is integrated with the high frequency induction heating coil downstream of the high frequency induction heating coil in the feed direction of the work material and injects cooling water onto the outer periphery of the heated work material;
The apparatus further includes a holding mechanism disposed movably in three dimensions downstream of the water cooling device and holding the work movably or a holding mechanism that fixes and holds the work.
The holding mechanism or the holding mechanism and the support mechanism apply a bending moment to the high temperature portion of the workpiece formed in the region from the heating by the high frequency induction heating coil to the cooling by the water cooler. And further,
A control mechanism for controlling the position of the water cooling device so as to offset the displacement of the water cooling device due to the expansion of the bus bar due to the supply of power to the high frequency induction heating coil ;
The control mechanism comprises a robot having a manipulator supporting a high frequency power supply connected to the bus bar;
Wherein the control mechanism obtains a change pattern of the arrangement position of the water-cooling unit in advance, 3DQ apparatus characterized that you control the operation of the manipulator in response to said change pattern obtained.

(2) A feeding mechanism for feeding a hollow workpiece having a flat and closed cross section in the longitudinal direction;
A support mechanism fixedly disposed at a predetermined position downstream of the feed mechanism in the feed direction of the workpiece and positioning the workpiece;
A high frequency induction heating coil disposed at a predetermined position on the downstream side of the support mechanism and heating the workpiece;
A bus bar supporting the high frequency induction heating coil and supplying power to the high frequency induction heating coil;
A water cooling device which is integrated with the high frequency induction heating coil downstream of the high frequency induction heating coil in the feed direction of the work material and injects cooling water onto the outer periphery of the heated work material;
The apparatus further includes a holding mechanism disposed movably in three dimensions downstream of the water cooling device and holding the work movably or a holding mechanism that fixes and holds the work.
The holding mechanism or the holding mechanism and the support mechanism apply a bending moment to the high temperature portion of the workpiece formed in the region from the heating by the high frequency induction heating coil to the cooling by the water cooler. And further,
A control mechanism for controlling the position of the water cooling device so as to offset the displacement of the water cooling device due to the expansion of the bus bar due to the supply of power to the high frequency induction heating coil;
The control mechanism comprises a robot having a manipulator supporting a high frequency power supply connected to the bus bar;
The control mechanism measures a change in the arrangement position of the water cooling device at the time of operation, and feedback controls the operation of the manipulator based on the result of the measurement.
Hot three-dimensional bending apparatus characterized by
( 3 ) The 3DQ apparatus according to (1) or (2) , wherein the bus bar suspends and supports the high frequency induction heating coil .

( 4 ) The bus bar has a substantially L-shaped outer shape including a first portion extending substantially in the vertical direction and a second portion connecting the first portion and extending substantially in the horizontal direction The hot three-dimensional bending apparatus described in any one of (1) to ( 3 ).

  The invention makes it possible to produce hollow bending members, in particular automotive parts (e.g. suspension arms), having a flat, closed cross-section which satisfies very high dimensional accuracy, for example. +-. 0.5 mm.

FIG. 1 is an explanatory view showing an outline of a 3DQ device. FIG. 2 (a) is a graph showing the amount of displacement of the coil when the coil is suspended and supported by a bus bar having a length of 600 mm in the vertical direction and the coil is turned ON and OFF, and FIG. 2 (b) is a coil and bus bar. It is explanatory drawing which extracts and shows vicinity. FIG. 3 (a) shows the degree of deterioration of the dimensional accuracy in the height direction when both the coil and the water cooling device are eccentric in a square tube having a flat cross section, and only the water cooling device is eccentric. It is a graph which shows the extent of the fall of the dimensional accuracy in the height direction at the time of carrying out by (circle) mark, FIG.3 (b) is explanatory drawing which shows the cross-sectional dimension of a square tube. FIG. 4 is an explanatory view extracting and showing a coil, a bus bar, a water cooler and a control mechanism in the 3DQ device according to the present invention. FIG. 5 is an explanatory view showing a bus bar of a modified example.

  The invention will be described with reference to the accompanying drawings. In addition, since the difference of the 3DQ device 10 according to the present invention with respect to the 3DQ device 1 shown in FIG. 1 is the supporting mode of the bus bar 6, the following description will be made with reference to FIG.

  As shown in FIG. 1, the 3DQ apparatus 10 according to the present invention comprises a feed mechanism 4, a support mechanism 3, a high frequency induction heating coil 5, a bus bar 6, a water cooler 7, and a holding mechanism or holding mechanism 8. Have.

  FIG. 4 is an explanatory view extracting and showing the coil 5, the bus bar 6, the water cooling device 7 and the control mechanism 11 in the 3DQ device 10 according to the present invention.

  The 3DQ apparatus 10 performs hot three-dimensional bending on a hollow workpiece 2 having a flat closed cross section to produce a hollow bending member 9 having a flat closed cross section. Examples of the cross-sectional shape of the workpiece 2 include a rectangle, an ellipse, and an oval. In the following description, the case where the workpiece 2 is a hollow square steel tube 2 having a rectangular cross-sectional shape is taken as an example.

[Feed mechanism 4]
The feed mechanism 4 may be any one capable of feeding the square tube 2 in its longitudinal direction, and is not limited to a specific feed mechanism. As the feeding mechanism, a well-known and commonly used feeding mechanism can be used as this type of feeding mechanism, and specifically, one using a ball screw, one using a conveyance roller, and the like are exemplified. Furthermore, an industrial robot may be used as the feeding mechanism 4.

[Supporting mechanism 3]
The support mechanism 3 is fixedly disposed at a predetermined position downstream of the feeding mechanism 4 in the feeding direction of the square tube 2. The support mechanism 3 sends the square tube 2 in its longitudinal direction while positioning. A well-known and commonly-used support mechanism of this type can be used as the support mechanism 3, and specifically, a pair of drive rolls abutting on the outer surface of the square tube 4 is exemplified. In the example shown in FIG. 1, a pair of drive rolls 3 are arranged in two sets in tandem.

[Coil 5]
The high frequency induction heating coil 5 is disposed at a predetermined position downstream of the support mechanism 3. The coil 5 is disposed to surround the square tube 2 at a predetermined distance from the periphery of the square tube 2. The coil 5 generates a high frequency magnetic field and supplies high frequency energy to the square tube 2 to heat the square tube 2 to Ac ₃ points or more. As the coil 5, a well-known and commonly used coil of this type can be used.

[Bus bar 6]
The bus bar 6 suspends and supports the coil 5 so that the coil 5 is disposed at the predetermined position described above. Further, the bus bar 6 is made of a conductor (for example, made of copper) that can withstand high voltage and high current, and is formed in a plate shape in order to securely hold the coil 5 and the water cooling device 7. The bus bar 6 has a predetermined surface area so that the current density does not exceed a specified value.

  The upper portion of the bus bar 6 is fixed to a high frequency power supply device 6-1 disposed at the top of the bus bar 6. For this reason, the bus bar 6 is mainly displaced downward upon thermal expansion.

[Water cooling device 7]
The water cooling device 7 is disposed at a predetermined position downstream of the coil 5 in the feeding direction of the square tube 2. As described above, it is advantageous to increase the bending accuracy by shortening the axial length of the high temperature portion 2 a formed in the rectangular tube 2 within a range in which the bending can be performed. For this reason, the water cooling device 7 is installed close to the coil 5. Accordingly, the water cooling device 7 is provided integrally with the coil 5. The water cooling device 7 rapidly cools and quenches the square tube 2 heated to a point of Ac ₃ or more by the coil 5 by injecting cooling water to the entire circumference of the square tube 2.

[Pinching mechanism or gripping mechanism 8]
The holding mechanism or holding mechanism 8 is disposed movably in three dimensions downstream of the water cooling device 7. The sandwiching mechanism 8 movably sandwiches the square tube 2 is, for example, constituted of a pair of drive rolls that abut on the outer surface of the square tube 2. On the other hand, the holding mechanism 8 holds the square tube 2 by being fixedly attached to the inner surface or the outer surface of the square tube 2, and for example, a chucking mechanism fixedly arranged inside the square tube 2 is exemplified. Be done.

  In the 3DQ device 10, any of the holding mechanism and the holding mechanism 8 can be used, and may be appropriately selected according to the situation. In order to movably arrange the holding mechanism or the holding mechanism 8 in three dimensions, it is convenient to hold the holding mechanism or the holding mechanism 8 by an industrial robot.

  The holding mechanism or holding mechanism 8 and the support mechanism 3 apply a bending moment to the high temperature portion 2 a of the square tube 2 formed in the region from the heating by the coil 5 to the cooling by the water cooler 7. This produces a hollow bending element 9 having a rectangular closed cross section.

[Control mechanism 11]
As described above, when the 3DQ device 10 is in operation, the heat generated by the coil 5 expands the bus bar 6 that suspends and supports the coil 5. Since the water cooling device 7 is integrally formed with the coil 5 by the expansion of the bus bar 6, the coil 5 fixed to the lower portion of the bus bar 6 and the water cooling device 7 integrated with the coil 5 are mainly To the bottom. Therefore, the coil 5 and the water cooling device 7 are eccentric to the square tube 2. Then, due to the eccentricity of the water cooling device 7 with respect to the square tube 2, the dimensional accuracy of the bending member 9 manufactured by the 3DQ device 10 is reduced.

  Therefore, the 3DQ device 10 has a control mechanism 11. The control mechanism 11 controls the position of the water cooling device 7 so as to offset the displacement of the water cooling device 7 so as to offset the displacement of the water cooling device 7 caused by the expansion of the bus bar 6 due to the supply of power to the coil 5. It has a function to prevent eccentricity.

  The control mechanism 11 may be any mechanism as long as it has such a function, and is not limited to a particular mechanism. However, as shown in FIG. 4, it is most simple to configure the control mechanism 11 to suspend and support the high frequency power supply device 6-1 connected to the upper portion of the bus bar 6 by the manipulator 11a of the industrial robot 11. Yes, desirable.

  The industrial robot 11 cancels the displacement of the water cooling device 7 caused by the expansion of the bus bar 6 due to the supply of the power to the coil 5, the high frequency power supply 6-1, the bus bar 6, the coil 5 and the water cooling device 7 It is displaced in the direction opposite to the displacement direction of the water cooling device 7 by the same amount as the displacement amount of the water cooling device 7. In this manner, the industrial robot 11 prevents the eccentricity of the water cooling device 7 with respect to the square tube 2 by controlling the position of the water cooling device 7.

In order to operate the industrial robot 11,
(I) determining the displacement pattern of the water cooling device 7 in advance, and teaching the industrial robot 11 according to the determined change pattern to operate the manipulator 11a of the industrial robot 11;
(II) The change of the arrangement position of the water cooling device 7 at the time of operation is measured by a suitable position measuring device which is commonly used, and the teaching program of the industrial robot 11 is corrected based on the result of this measurement. Operating the 11 manipulators 11 a is illustrated.

FIG. 5 is an explanatory view showing a bus bar 6-1 according to a modification.
As shown in FIG. 5, the bus bar 6-1 has a first portion 12 extending substantially vertically and a second portion 13 connected to the first portion 12 and extending substantially horizontally. It is desirable to have a substantially L-shaped outer shape consisting of. Since the bus bar 6-1 has a substantially L-shaped outer shape, the thermal expansion in the vertical direction can be released upward.

2 Square tube 2a High temperature part 3 Support mechanism 4 Feed mechanism 5 High frequency induction heating coil 6 Bus bar 6-1 High frequency power supply device 7 Water cooling device 8 Water holding device 8 Holding mechanism or holding mechanism 9 Bending member 10 3DQ device 11 of the present invention Industrial robot 11a Manipulator

Claims (4)

A feeding mechanism for feeding a hollow workpiece having a flat closed cross section in the longitudinal direction;
A support mechanism fixedly disposed at a predetermined position downstream of the feed mechanism in the feed direction of the workpiece and positioning the workpiece;
A high frequency induction heating coil disposed at a predetermined position on the downstream side of the support mechanism and heating the workpiece;
Wherein while the high-frequency induction heating coil supporting lifting, and bus bars for supplying power to the high-frequency induction heating coil,
A water cooling device which is integrated with the high frequency induction heating coil downstream of the high frequency induction heating coil in the feed direction of the work material and injects cooling water onto the outer periphery of the heated work material;
The apparatus further includes a holding mechanism disposed movably in three dimensions downstream of the water cooling device and holding the work movably or a holding mechanism that fixes and holds the work.
The holding mechanism or the holding mechanism and the support mechanism apply a bending moment to the high temperature portion of the workpiece formed in the region from the heating by the high frequency induction heating coil to the cooling by the water cooler. And further,
A control mechanism for controlling the position of the water cooling device so as to offset the displacement of the water cooling device due to the expansion of the bus bar due to the supply of power to the high frequency induction heating coil ;
The control mechanism comprises a robot having a manipulator supporting a high frequency power supply connected to the bus bar;
Wherein the control mechanism, the preliminarily determine the variation pattern of the arrangement position of the water-cooling unit, the obtained hot three-dimensional bending device, characterized that you control the operation of the manipulator in response to said change pattern.   A feeding mechanism for feeding a hollow workpiece having a flat closed cross section in the longitudinal direction;
  A support mechanism fixedly disposed at a predetermined position downstream of the feed mechanism in the feed direction of the workpiece and positioning the workpiece;
  A high frequency induction heating coil disposed at a predetermined position on the downstream side of the support mechanism and heating the workpiece;
  A bus bar supporting the high frequency induction heating coil and supplying power to the high frequency induction heating coil;
  A water cooling device which is integrated with the high frequency induction heating coil downstream of the high frequency induction heating coil in the feed direction of the work material and injects cooling water onto the outer periphery of the heated work material;
  The apparatus further includes a holding mechanism disposed movably in three dimensions downstream of the water cooling device and holding the work movably or a holding mechanism that fixes and holds the work.
  The holding mechanism or the holding mechanism and the support mechanism apply a bending moment to the high temperature portion of the workpiece formed in the region from the heating by the high frequency induction heating coil to the cooling by the water cooler. And further,
  A control mechanism for controlling the position of the water cooling device so as to offset the displacement of the water cooling device due to the expansion of the bus bar due to the supply of power to the high frequency induction heating coil;
  The control mechanism comprises a robot having a manipulator supporting a high frequency power supply connected to the bus bar;
  The control mechanism measures a change in the arrangement position of the water cooling device at the time of operation, and feedback controls the operation of the manipulator based on the result of the measurement.
Hot three-dimensional bending apparatus characterized by The bus bar may have been hot three-dimensional bending device according to claim 1 or claim 2, supported by suspending the high-frequency induction heating coil. The bus bar has a substantially L-shaped outer shape including a first portion extending substantially vertically and a second portion connected to the first portion and substantially horizontally extending. The hot three-dimensional bending apparatus described in any one of claims 1 to 3 .

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