JP3206383B2 - Forming machine for forming a flat work into a cylindrical shape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming apparatus for forming a flat work into a cylindrical shape, and more particularly, to forming a metal net for protecting a catalyst used on the outer periphery of an exhaust gas purifying catalyst for an automobile. The present invention relates to a molding apparatus.

[0002]

2. Description of the Related Art Metal nets are used to protect impact-sensitive automobile exhaust gas purifying catalysts from impact. The metal net is formed in a cylindrical shape, and covers the outer periphery of the exhaust gas purifying catalyst with the metal net. The step of manufacturing the metal net includes a corrugating step of pulling out one end of the metal mesh member from a reel around which the band-shaped metal mesh member is wound and forming a helical rack-like waveform on the metal mesh member. After a predetermined number of waveforms are formed on the metal mesh member, a cutting step of cutting the metal mesh member, bending the metal mesh member, and overlapping the cut end with the end opposite to this end. It mainly consists of a welding step of welding the overlapped portion while making the metal mesh member cylindrical. In the above-described metal net manufacturing process, the corrugating process and the cutting process are automatically processed using a general device. However, the work of bending the metal mesh member cut in the cutting step and mounting it on the welding device is performed by an operator.

[0003]

As described above, in the manufacturing process of the metal net, the work after the cutting process of the metal mesh member is performed by an operator. For this reason, in the work after the cutting step of the metal net, there is a problem in that many manual operations are performed by an operator, and the time required to manufacture the metal net is lengthened. At the time of the welding process, the metal mesh member must be mounted and welded while paying attention to the tip of the welding rod, and there is a problem that the working efficiency is low. Therefore, it is desired to further improve the workability of the production work of the metal net.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems and to provide a metal net forming and processing apparatus for automatically performing operations after a metal net cutting step, and for automatically manufacturing a metal net. And

[0005]

According to the first aspect of the present invention, the elasticity
Forming a flat work with a cylinder into a cylindrical shape
An apparatus for applying a workpiece of a predetermined length to the workpiece.
A waveform deforming means for performing an oblique wavy deformation process, and the waveform
The both ends of the work deformed by the deformation means are
Gripping means for gripping along the waveforms of
While holding at least one of the gripping means
Is moved by a predetermined distance so as to approach one of the gripping means.
Moving means and the two gripping hands while gripping the work
Rotate the base of each gripping means to bring the steps closer together
Invert each as the center,
A reversing means for aligning the shapes and polymerizing each other;
And joining means for joining both ends of the joint .

According to a second aspect of the present invention, there is provided a flat plate according to the first aspect.
In a molding machine that molds a workpiece into a cylinder,
The flat work with elasticity is used to purify exhaust gas for automobiles.
For protecting the catalyst used by wrapping it around the catalyst
It is a genus net.

[0007] A third aspect of the present invention, the molding apparatus for molding a plate-shaped workpiece according to claim 1 or 2, wherein the tubular, gripping means, gripping the opposite ends of the workpiece at a predetermined distance away from the center of rotation It is characterized by doing.

[0008] The invention of claim 4 is the invention of claim 1, 2, or 3.
In a forming apparatus for forming a flat work into a cylindrical shape according to the description, lifting means for raising or lowering one of the two holding means holding the work by a predetermined distance in the overlapping direction of both ends of the work. The lifting means is configured to raise and lower one gripping means in directions opposite to each other before and after the operation of the reversing means.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an apparatus for automatically forming and processing a metal net for protecting an exhaust gas purifying catalyst for automobiles from impact. In FIG. 1, reference numeral 1 denotes a flat metal mesh member having elasticity. This forming apparatus includes a material supply unit 2 for supplying a metal mesh member 1, a corrugation on the metal mesh member 1, and a metal mesh member 1.
And a cutting device 4 for cutting the metal mesh member 1 fed by a predetermined length.
And a forming device 5 for forming the flat metal mesh member 1 into a cylindrical shape and carrying out a completed metal net, and a spot welding device for welding and joining both ends of the cylindrical metal mesh member 1 to each other. 6, an unloading device 7 for unloading the metal net formed by each of the above-described devices to the transport chute, a control device 8 for controlling the operation of each unit, and an operation panel 9 for operating the forming apparatus. ing.

First, a material supply unit 2 and a tooth shape plastic working device 3
And the cutting device 4 will be described. These components are similar to those of the related art, and will be described briefly. Material supply unit 2,
As shown in FIG. 1, the tooth shape plastic working device 3 and the cutting device 4 are linearly arranged in this order. The material supply unit 2 includes a reel 2a around which a band-shaped metal mesh member 1 is wound. Tooth shape plastic working device 3
Has a helical gear 3a, 3b and a sensor 3c for counting the number of gear teeth when the helical gear 3a, 3b rotates, as shown in FIG. Helical gears 3a, 3
b is disposed at an angle of about 30 degrees with respect to the rotation axis of the gear. The cutting device 4 is disposed at an angle of approximately 30 degrees with respect to the transport direction of the metal mesh member 1 in order to cut the metal mesh member 1 substantially in parallel with the waveform formed on the metal mesh member 1. As shown in FIG. 5, the upper blade 4a and the lower blade 4b have a pair of blades, and the upper blade 4a can be moved up and down by an air cylinder (not shown).
The metal mesh member 1 is cut by lowering a. The operations of the tooth-shaped plastic working device 2 and the cutting device 3 are controlled by the control device 8.

Next, the molding apparatus 5 will be described. As shown in FIG. 2, the forming apparatus 5 mainly includes a conveyor 10 driven by a chain for transporting the metal mesh member 1, and a first gripper 15 and a second gripper 20 for gripping the metal mesh member 1. Be composed. In FIG. 2, reference numeral 1a
Indicates a metal mesh member cut to a predetermined length by the cutting device 4.

In the vicinity of one end of the conveyor 10, a drive motor 11 for driving the conveyor 10 so as to convey the metal mesh member 1a in the direction of arrow A is provided. At the downstream end of the conveyor 10, a stopper 12 for locking the metal mesh member 1a at a predetermined position is provided. A lift means 1 for raising the metal mesh member 1a by a predetermined distance from the conveying surface of the conveyor 10 is provided substantially at the center of the conveyor 10.
3 are provided.

[0013] The first holding portion 15 is provided with the metal mesh member 1.
The first hand 16 is disposed on the downstream side in the transport direction A and adjacent to the conveyor 10 and serves as a gripper for gripping the end of the metal mesh member 1a from above and below.
A first moving means 17 for moving the first hand 16 toward the center of the metal mesh member 1a; and a second moving means 17 for turning the first hand 16 around the base of the first hand 16 as a center of rotation. And one reversing means 18.

The first moving means 17 is provided with a guide 17a disposed in the same direction as the conveying direction A of the metal mesh member 1a.
And a ball screw (not shown) provided in parallel with the guide 17a, supported by the ball screw,
It comprises a table 17b movable along a guide 17a and a servomotor 17c for rotating a ball screw. This table 17b
A first reversing means 18 having a rotation center axis in a direction orthogonal to the conveyor 10 side with respect to the moving direction is provided. As the first reversing means 18, a known rotary air cylinder that can rotate 180 degrees is used.

The first reversing means 18 includes the first hand 1
As shown in FIG. 3, the first hand 16 uses a well-known parallel chuck driven by air, and bar-shaped claws 16a and 16b are fixed to the tip of the parallel chuck. . The claws 16a and 16b are substantially three-way with respect to the direction orthogonal to the transport direction A of the metal mesh member 1a so as to follow the angle of the waveform formed on the metal mesh member 1a.
It is inclined at 0 degrees.

The second holding portion 20 is provided with the metal mesh member 1.
a second hand 21 which is disposed upstream of the conveying direction a and is located on the left side with respect to the conveying direction A, and as a gripping means for gripping an end of the metal mesh member 1a; A second moving means 22 for moving the second hand 21 toward the center of the metal mesh member 1a, and a second hand for turning the second hand 21 around the base of the second hand 21 as a center of rotation.
Reversing means 23, third moving means 24 for moving the second gripper 20 in the near and far directions with respect to the conveyor 10,
And raising / lowering means 25 for raising / lowering the reversing means 22 in a direction perpendicular to the conveying surface of the metal mesh member 1a.

The second moving means 22 includes the first moving means 1
Like FIG. 7, the guide 22a includes a guide 22a disposed in the same direction as the transport direction A of the metal mesh member 1a, a table 22b movable along the guide 22a, and a servomotor 22c moving the table 22b. ing.

As shown in FIG. 4, above the table 22b, there is provided a second rotation axis having a rotation center axis in a direction perpendicular to the direction of movement of the table 22b toward the conveyor 10 (a direction perpendicular to the paper surface). Are provided. Between the table 22b and the second reversing means 23, an elevating means 25 for raising or lowering the second reversing means 23 in a direction perpendicular to the upper surface of the table 22b is provided. It is connected to the reversing means 23. A well-known rotary air cylinder that can rotate 180 degrees is used for the second reversing means 23, and a well-known air cylinder is used for the elevating means 25. Second reversing means 2
3, a second hand 21 is fixed. The second hand 21 uses a well-known parallel chuck similarly to the first hand 16, and a metal mesh member 1 a is attached to the tip of the parallel chuck. Has a claw that is inclined by approximately 30 degrees with respect to a direction perpendicular to the transport direction A.

The third moving means 24 includes a second moving means 2
2, a pair of guides 24a provided in parallel to the direction of the waveform formed on the metal mesh member 1a, a table 24b movable along these guides 24a, and a table 24b. And an air cylinder 24c for driving the motor. At one end of the table 24b, a plate cam 24d for driving the unloading device 7 is integrally provided in a direction parallel to the guide 24a.

An unloading chute 14 for unloading the metal net formed by forming the metal mesh member 1a from the forming device 5 is provided between the conveyor 10 and the second holding portion 20.
It is arranged substantially parallel to 0. A negative electrode plate 34 of the spot welding device 6 is formed on the metal mesh member 1a above the conveyor 10 and at a substantially intermediate position between the first grip 15 and the second grip 20. It is arranged so as to be parallel to the direction of the waveform to be formed.

Note that the first hand 16 and the second hand 21 each have an initial state in which the claws 16a, 16b, 21b and 21a are open, and the first inversion means 18 and the second inversion means 23. As shown in FIG. 2, the positions where the first hand 16 and the second hand 21 face outward are set as the origin positions, and the third moving means 24 approaches the conveyor 10 as shown in FIG. 2. The position where the second reversing means 23 is lowered is defined as the origin position, and the first moving means 17 and the second moving means 22 define the claw 16a, 16b, Positions where 21b and 21a are located outside both end surfaces of the metal mesh member 1a are defined as origin positions.

The unloading device 7 is, as shown in FIGS.
An arm portion 30 disposed above the plate cam 24d for carrying out the metal net to the carry-out chute 14, a driving portion 31 for operating the arm portion 30, and a support column 32 for swingably supporting the arm portion 30; Consists of One end of the arm 30 is provided with a claw 30a for sweeping the metal net, and the other end of the arm 30 is loosely fitted with one end of the drive unit 31. The arm 30 is formed in a substantially crank shape, and a bearing 30 b is provided at a bent portion on the other end side of the arm 30. The bearing 30 b is provided on a shaft 3 provided at the tip of a stay fixed to the support 32.
2a rotatably supported.

The driving section 31 is supported by a guide 31a so as to be vertically movable and has wheels 31b rotating on a plate cam 24d, and is moved up and down by the operation of the plate cam 24d. When the drive unit 31 moves up and down, the other end of the arm 30 swings about the shaft 32a.

Next, the spot welding apparatus 6 will be described with reference to FIGS. The spot welding apparatus 6 includes a welding head 35 disposed above the overlapping portion where both ends of the metal mesh member 1a overlap each other, and a negative electrode corresponding to the welding head 35 disposed below the welding head 35. It is composed of a plate 34 (see FIG. 2) and a spot welding apparatus main body 37. Welding head 35 and negative electrode plate 34
Are connected to the spot welding apparatus main body 37 by flexible wires.

A substantially L-shaped support column 5a extends upward at the base of the molding device 5 adjacent to the first grip portion 15. A welding head 35 is supported at the distal end of the support column 5 a via an air cylinder 36 that moves up and down the welding head 35 and a guide 37. The welding head 35 is
Four welding rods 35a of the positive electrode and these welding rods 35a
And an attachment plate 39 to which the air cylinder 38 is attached. Mounting plate 39
Is provided with a pair of mounting grooves 39a parallel to each other, and one end of an air cylinder 38 is fixed to the mounting grooves 39a by bolts 40. Each air cylinder 38
Are fixed to welding ends 35a, respectively. Each welding rod 35a is attached to the mounting groove 38a by loosening the bolt 40 and moving it along the mounting groove 39a.
Can be fixed at an arbitrary position within the range. The air cylinder 36 is a cylinder for bringing the welding head 35 close to the overlapping portion, and the air cylinder 38 contacts the metal mesh member 1a.

Next, the control device 8 will be described. The control device 8 is connected to sensors provided in each section, servo motors, solenoid valves for driving each air cylinder, and the like. The control device 8 is composed of a well-known sequencer, and controls the driving of a servomotor, an electromagnetic valve, and the like according to a signal from the operation panel 9 and each sensor or a stored program. The operation panel 9 is provided with a start switch, a stop switch, and the like for operating the forming apparatus.

Next, the operation of the forming apparatus will be described. Material supply unit 2, tooth shape plastic working device 3, and cutting device 4
The operation of each unit is the same as that of the conventional one, and will be described briefly. When the start switch on the operation panel 9 is pressed, the control device 8 drives the double helical gears 3a and 3b to rotate. In FIG. 8, the double helical gears 3a, 3b
With this rotation, the metal mesh member 1 is pulled out from the reel 2a, and the metal mesh member 1 is corrugated in a helical tooth rack shape at approximately 30 degrees with respect to a direction orthogonal to the drawing direction.

When the number of teeth of the helical gear 3a detected by the sensor 3c is equal to the predetermined number of teeth stored in advance, the control device 8 lowers the upper blade 4a of the cutting device 4 to lower the metal. The mesh member 1 is cut at a predetermined length. Since both ends of the metal mesh member 1a are overlapped in the forming device 5, the front end and the rear end of the metal mesh member 1 need to have the same shape as shown in FIGS. 9 (a) and 9 (b). Since there are two types of end shapes, mountain shape and valley shape,
If one end of the metal mesh member 1a is mountain-shaped, the other end also needs to be mountain-shaped. Conversely, if one end has a valley shape, the other end must also have a valley shape. Therefore, the length L of the metal mesh member 1, that is,
The number of teeth stored in the control device 8 in advance is set such that the front end and the rear end of the metal mesh member 1 always have the same shape.

Next, the forming operation of forming the metal mesh member into a cylindrical shape by the forming device 5 will be described in detail. In FIG. 2, when the metal mesh member 1a whose front end and rear end have the same waveform is conveyed from the cutting device 4 to the conveyor 10, the front end of the metal mesh member 1a
, The metal mesh member 1a is locked at a predetermined position. When it is detected that the metal mesh member 1a is locked at the predetermined position, this detection signal is input to the control device 8, and the control device 8 drives the lift means 13 to move the metal mesh member 1a to the conveyor 10. The metal mesh member 1a is raised from the transfer surface by a distance necessary for forming the metal mesh member 1a into a cylindrical shape. When the rise of the metal mesh member 1a is detected, the servo motors 17c and 22c are driven, respectively, so that the first hand 16 and the second hand 21
The tables 17b and 22b are respectively moved until they reach the positions where they grip both ends of "a". Table 17
After the stop of b, 22b, the parallel chuck is driven, and the pawl 16
Both ends of the metal mesh member 1a are gripped by the members a, 16b, 21b, and 21a (see FIG. 3). Positions at which both ends of the metal mesh member 1a are gripped are determined in advance, and as shown in FIGS. 9A and 9B, a predetermined length l from the end to the center of the metal mesh member 1a. , That is, the second position of the waveform from the end of the metal mesh member 1a.

When it is detected that the metal mesh member 1a has been gripped, the elevating means 25 is operated, and the second hand 21 and the second hand 21 and the second hand 21 are held in a state where the metal mesh member 1a is gripped.
Is reversed by a predetermined distance. Second hand 2
When the rise of the first and second reversing means 23 is detected, the first
As shown in FIG. 10, the inversion means 18 and the second inversion means 23 of the first hand 18 and the second hand 21
Metal mesh member 1a with the base of each hand as the center of rotation
Invert toward the center of each. In conjunction with this operation, the first moving means 17 and the second moving means 22
The first hand 18 and the second hand 21 are respectively moved toward the center of the metal mesh member 1a. By these reversing operation and moving operation, the metal mesh member 1
The both ends of a are moved to the upper part of the negative electrode plate 34, and the metal mesh member 1a is formed in a cylindrical shape. FIG.
After these reversing and moving operations are completed,
The second hand 21 and the second reversing means 23 are moved down by the elevating means 25, and both ends of the metal mesh member 1a are overlapped with each other. The reversing speed of the second reversing means 23 is determined by the first reversing means 18 and the second reversing means 23.
Is set to be slower than the reversing speed of the first reversing means 18 so that the second hand 21 is on the upper side at the end of the reversing.

Referring to FIG. 13, the operation of forming the metal mesh member 1a into a cylindrical shape will be described. The locus of the point of the metal mesh member 1a gripped by the claws 16a, 16b is
The locus from point a to point b is the locus of the point of the metal mesh member 1a gripped by the claws 21b, 21a.
It is a locus from point to point d. These trajectories are X = r
(T-sint), Y = r (1-cost) is a cycloid curve given by two equations. Note that r is a distance from the rotation center of each of the reversing means 16 and 21 to the metal mesh member 1a.
Is the distance to the point at which X is held, X and Y are the coordinates,
Indicates a coefficient. In addition, by moving both end portions of the metal mesh member 1a along the cycloid curve, the center portion is curved downward,
The metal mesh member 1a is formed in a cylindrical shape. Claws 16a,
Since 16b, 21b and 21a are inclined by approximately 30 degrees from the rotation center of each of the reversing means 16 and 21, when this angle changes, the value of r in the above equation also changes. Accordingly, the maximum and minimum values of the length and width of the metal mesh member 1a are determined by the value of r.

As shown in FIG. 11, the metal mesh member 1
When the both ends of “a” are overlapped with each other, the welding head 35 is lowered by the air cylinder 36, and the tip of the welding rod 35 a approaches the overlapping portion of the metal mesh member 1 a. When the lowering of the welding head 35 is completed, each air cylinder 38
One of the air cylinders 38 descends and the welding rod 3
The tip of 5a is brought into contact with the overlapping portion. Air cylinder 38
Has a margin in its stroke even when the tip of the welding rod 35a abuts on the overlapping portion, and further presses the overlapping portion with the tip of the welding rod 35a. When the end of the lowering of the welding rod 35a is detected, a high voltage is applied to the welding rod 35a from the spot welding apparatus main body 37 via a flexible wire, and is discharged between the welding rod 35a and the negative electrode plate 34 to polymerize. The parts are welded. After the welding is completed, the welding rod 35a is raised, and the overlapping portion is welded by the next welding rod 35a. This operation is repeated several times, and both ends of the metal mesh member 1a are welded to each other to form a cylindrical metal net 1b.

5 and 12, the metal net 1b
Is formed, the first hand 16 releases the grip of the metal net 1b and opens the metal net 1b. When the opening of the metal net 1b is detected, the third moving means 24 is driven to move the table 24b away from the conveyor 10. Immediately before the metal net 1b is positioned on the carry-out chute 14, the second hand 21 releases the grip of the metal net 1b and opens the metal net 1b.

On the other hand, the plate cam 24d is also moved by the movement of the table 24b, and the operation of the unloading device 7 is started. The movement of the plate cam 24d raises the wheel 31a in contact with the plate cam 24d. Due to this rise, the drive unit 31 moves up in the direction of arrow B ₁ (see FIG. 5), the other end of the arm 30 swings about the shaft 32a, and the claw 30a also moves about the shaft 32a as an arrow. B ₂ (FIG. 5
(See Reference). In synchronization with the opening of the metal net 1b, the claw 30a sweeps one corner of the metal net 1b and the table 24b continues to move away from the conveyor 10, so that the metal net 1b is dropped onto the transport chute 14 and It is carried out. Also,
By providing a device for transferring the metal net 1b from the second hand 21 to another process, a further continuous process can be configured.

By the operation described above, the metal net 1b is automatically formed from the metal mesh member 1. By continuing these operations, a large amount of metal net 1b can be manufactured.

[0036]

[0037]

As described above , according to the present invention,
A shaping apparatus, a waveform deforming means, a gripping means, a moving means,
Since it has a reversing means and a joining device, when a flat plate-like work having a predetermined length having elasticity is supplied to the forming apparatus, a waveform is formed on the work by the waveform deforming means, and a gripping means,
The work is curved and formed into a tubular shape by the moving means and the reversing means, and both ends of the work are overlapped with each other,
The overlapping portion is joined by the joining means, and the tubular member is automatically formed. Therefore, a flat work is corrugated.
After being deformed, it can be automatically formed into a cylindrical shape,
Manual work by the operator can be reduced, and work efficiency can be improved. Since the joining means automatically joins both ends of the work, it is not necessary to pay attention to the tip of the welding rod, and the work becomes easier and the work efficiency is improved. Further, the production time of the metal net is shortened, and the number of produced metal nets is increased.

[Brief description of the drawings]

FIG. 1 is an overall schematic plan view of a molding apparatus according to the present invention.

FIG. 2 is an enlarged plan view of a molding device.

FIG. 3 is an enlarged perspective view of a gripping means.

FIG. 4 is a side view of the second moving means.

FIG. 5 is a front view of the carrying-out device.

FIG. 6 is a front view of a welding head of the spot welding apparatus.

FIG. 7 is a plan view of a welding head.

FIG. 8 is a schematic configuration diagram of a tooth shape plastic working device and a cutting device.

FIGS. 9A and 9B are explanatory diagrams illustrating the shape and the gripping position of the cut end of the metal mesh member, where FIG. 9A shows a case where the shape of the cut end is a valley, and FIG. Shows a case where the shape of is a mountain shape.

FIG. 10 is an operation diagram of a molding apparatus for explaining an operation of forming a metal mesh member into a cylindrical shape.

FIG. 11 is an enlarged view of a superposed portion at both ends of a metal mesh member.

FIG. 12 is an operation diagram of a forming device and a carrying-out device for explaining carrying-out of a metal net.

FIG. 13 is a schematic diagram showing a change of the metal mesh member when the metal mesh member is formed in a cylindrical shape, and a locus of a gripping position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Metal mesh member 1b Metal net 2 Material supply part 3 Tooth plasticity processing device 4 Cutting device 5 Forming device 6 Spot welding device 7 Unloading device 8 Control device 9 Operation panel 10 Conveyor 13 Lifting means 15 First gripping part 16 First 1 hand 16a, 16b, 21a, 21b Claw 17 First moving means 18 First reversing means 20 Second gripper 21 Second hand 22 Second moving means 23 Second reversing means 24 Third Moving means 25 Elevating means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B21D 5/01 B21C 37/08 F01N 3/28 311

Claims (4)

(57) [Claims] 1. A forming apparatus for forming a flat work having elasticity into a cylindrical shape, comprising: a waveform deforming means for performing an oblique wavy deformation process on a work of a predetermined length; Gripping means for gripping both ends of the work deformed by the waveform deforming means along the waveform of the work, and at least one gripping means approaching the other gripping means in a state where the work is gripped. A moving means for moving the work by a predetermined distance, and, while holding the work, the bases of the gripping means are turned around each other so that the two gripping means come closer to each other, and the waveforms at both ends of the work are aligned with each other. A forming apparatus for forming a flat work into a cylindrical shape, comprising: a reversing means for superimposing, and a joining means for joining both ends of the superposed work. . 2. The flat plate-like work according to claim 1, wherein said flat plate-like work having elasticity is a metal net for protecting the catalyst which is used by being wound around the outer periphery of an exhaust gas purifying catalyst for automobiles. A forming device for forming a work into a cylindrical shape. 3. A forming process for forming a flat workpiece into a cylindrical shape according to claim 1 or 2, wherein said gripping means grips both ends of said workpiece at positions separated by a predetermined distance from said rotation center. Processing equipment. 4. A lifting means for raising or lowering one of the gripping means gripping the work by a predetermined distance in the overlapping direction of both ends of the work, the lifting means comprising: 4. The forming apparatus according to claim 1, wherein said one gripping means is moved up and down in opposite directions before and after the operation of said means.