JP2002160030A - Clamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamp device which performs positioning and fixing of the workpiece by operating one cylinder. SOLUTION: In a clamp device 20, when the parallel link system (swing arm 23, clamp arm 24, first link 25 and second link 26) changes from a lying position to a standing position by operating a cylinder 35, since a swing arm 23 in the standing position is regulated by a second stopper 32 to rotate in the bottom mold direction, a clamp arm 24 in the standing position is rotated in the clamp direction. In this way, the work guide 27 comes into contact with a work W loaded on the bottom mold 40 and performs positioning on this. The clamp arm 24 clamps down the work W on the bottom mold 40 using a clamp click. Accordingly, positioning and fixing of the work is performed by the one operating a cylinder 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device used for fixing a work hemmed by a hemming device to a lower die.

[0002]

2. Description of the Related Art Conventionally, as a clamp device for fixing a workpiece to be hemmed by a hemming device to a lower mold, there is a "clamping device for a material to be hemmed" disclosed in Japanese Patent Application Laid-Open No. 8-197149, for example. In this clamping device, the operation of a single cylinder allows the transfer and retraction of the clamp arm and the clamping and
With the double action structure that provides the unclamping operation, the clamp arm is moved out of the interference area of the robot hand performing the preliminary bending. This solves the problem of interference between the clamp arm and the robot hand, and makes it possible to perform preliminary bending using parallel rollers.

[0003]

However, according to the conventional clamping device as described above, the work can be fixed to the lower mold, but only has the function of clamping the work to the lower mold. Therefore, the work placed on the lower mold cannot be adjusted to an appropriate position before being fixed by the clamp device. Therefore, the work placed on the lower mold must be aligned by a separately provided positioning device, etc., and in terms of automation of equipment, equipment cost and equipment maintenance, the clamping device and the positioning device must be connected. The problem was that they had to be handled separately.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a clamp device capable of positioning a work and fixing the work by operating one cylinder. It is in.

[0005]

According to a first aspect of the present invention, there is provided a parallel link mechanism including a clamp arm for fixing a workpiece to be hemmed by a hemming device to a lower mold. A clamp device comprising: a swing arm having one end rotatably supported by the lower die; an intermediate portion supported by the other end of the swing arm; and a tip between the lower die and the lower die. A clamp arm having a clamp claw for clamping a work, a first link pivotally supported at one end by a base end of the clamp arm and having the same length as the swing arm;
The other end of the link is pivotally supported at one end, and the other end is pivotally supported at one end of the swing arm.
A second link for holding the link in parallel, and a parallel link mechanism comprising the swing arm, the clamp arm, the first link and the second link, for urging the clamp arm in the unclamping direction. Urging means, a first stopper for restricting rotation of the clamp arm in the unclamping direction by the urging means, provided on the lower mold or the swing arm, wherein the swing arm is moved from a standing position to the lower mold side. A second stopper that restricts rotation of the swing arm; a second stopper rotatably supported by the lower mold; and a tip end rotatably connected to the first link. The clamp arm is displaced to a standing position and a falling position around a pivot point of the lower mold, and the parallel link mechanism is operated at the standing position to move the clamp arm to the urging means. A cylinder for pivoting the clamping direction against the biasing force that is provided on the swing arm,
And a work guide for positioning the work by contacting the work placed on the lower die when the parallel link mechanism is displaced to the upright position.

According to a second aspect of the present invention, in the first aspect, the first link or the swing arm includes a third stopper that restricts rotation of the clamp arm in a clamping direction at a predetermined position. Is a technical feature.

According to the first aspect of the present invention, the parallel link mechanism including the swing arm, the clamp arm, the first link, and the second link is erected around a pivot point with the lower die of the swing arm by the operation of the cylinder. Displaced between the position and the lying position. The parallel link mechanism rotates the clamp arm in the clamp direction by operating the parallel link mechanism at a standing position by the cylinder. Therefore, when the parallel link mechanism is displaced from the lying position to the standing position by the operation of the cylinder, the second stopper restricts the swing arm from rotating from the standing position to the lower die side.
At the upright position, the clamp arm is rotated in the clamp direction. Thus, the work guide can contact the work placed on the lower mold to position the work, and the clamp arm can clamp the work to the lower mold by its clamp claws.

According to the second aspect of the present invention, since the first link or the swing arm includes the third stopper for restricting the rotation of the clamp arm in the clamping direction at a predetermined position, the first link or the swing arm is moved by the cylinder at the standing position of the parallel link mechanism. Even when the parallel link mechanism is operated, the rotation of the clamp arm in the clamping direction is regulated at the predetermined position by the third stopper. Thereby, the pressing force of the work by the clamp claws of the clamp arm can be set according to the predetermined position.
The disadvantage that the surface of the work is scratched by the clamp claws can be avoided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a clamping device according to the present invention will be described.
One embodiment applied to a work fixing jig of the roller type hemming device 10 will be described with reference to FIGS. First, an outline of the configuration and operation of the hemming device 10 will be described with reference to FIG. As shown in FIG. 2, the hemming device 10 includes:
It mainly comprises a robot 12 and a hem roller 15,
A hem roller 15 is attached to the tip of the robot arm 12a. A table 50 to which the lower die 40 is fixed is located within the movable range of the robot arm 12a, and a plurality of (for example, eight) ) Clamping device 20
Is arranged.

The work W (the inner panel Wi and the outer panel Wo) is placed on the lower mold 40 having the above-described configuration, and the periphery of the work W is fixed by the clamp device 20. Then, when the hem roller 15 is rolled along the bent portion of the outer panel Wo corresponding to the outer peripheral edge of the work W by the trajectory control of the robot arm 12a, the bent portion is continuously bent inward. Thereby, hemming of the workpiece W can be performed.

Further, at this time, when the hem roller 15 approaches, the clamp device 20 for fixing the periphery of the work W releases the fixation of the work W and retreats to the lateral outside of the lower mold 40. Thereby, since the interference between the hem roller 15 and the clamp device 20 during the rolling can be avoided, continuous hemming processing by the hem roller 15 is enabled.

Next, the structure of the clamp device 20 will be described with reference to FIGS. 1, 3 and 4. FIG. As shown in FIGS. 1 and 3, the clamp device 20 mainly includes the bracket 2.
2, parallel link mechanism, work guide 27, spring 2
9, the air cylinder 35, and the like, and the parallel link mechanism includes a swing arm 23, a clamp arm 24, a first link 25, and a second link 26.

The bracket 22 has a function of fixing the clamp device 20 to the lower mold 40 via the tap plate 21 attached to the lower mold 40, and is fixed to the lower mold 40 by screwing with bolts. In addition, this bracket 22
The link mechanism support portion 22a and the cylinder support portion 2
2b is formed so as to protrude laterally outside the lower mold 40.

The link mechanism support portion 22a is composed of two L-shaped plates arranged in parallel so that their surfaces face each other at a predetermined interval, and a shaft hole is formed at an end portion. On the other hand, the cylinder support portion 22b is formed of a substantially triangular plate, and has an axial hole at an end portion similarly to the link mechanism support portion 22a. Thus, in the link mechanism supporting portion 22a, the parallel link mechanism is sandwiched and rotatably supported by the shaft portion 30a, and in the cylinder supporting portion 22b, the air cylinder 35 is supported by the shaft portion 30f.
Are rotatably supported (see FIG. 3).

The swing arms 23 are constituted by two substantially rectangular plates arranged in parallel so that their surfaces face each other at a predetermined interval, and shaft holes are formed at both ends.
One end 23a of the swing arm 23 is connected to the shaft portion 30a so as to be sandwiched by the link mechanism support portion 22a of the bracket 22.
And are rotatably supported. For this reason, the swing arm 23 is configured to be swingable with respect to the bracket 22 fixed to the lower mold 40. Also swing arm 23
A bar-shaped post 28b capable of hooking one end of a spring 29 described later is provided upright at one end 23a (see FIG. 3).

The clamp arm 24 is formed of a slender thick plate, and has a clamp claw 24d formed in an inverted L shape at one end 24a. On the other hand, a shaft hole for connecting to the first link 25 is formed at the base end 24b of the clamp arm 24, and a shaft hole for connecting to the other end 23b of the swing arm 23 is formed at the intermediate portion 24c. Have been. Thereby, the intermediate portion 24c of the clamp arm 24 is rotatably supported by the shaft portion 30b so as to be sandwiched by the other end 23b of the swing arm 23.

Similarly to the swing arm 23, the first link 25 is configured in parallel so that two substantially rectangular plates are opposed to each other, and has the same length as the swing arm 23. Shaft holes are formed at both ends of the first link 25. One end 25a is pivotally supported by the shaft portion 30c so as to sandwich the base end 24b of the clamp arm 24, and the other end 25b is connected to one end 26 of the second link 26.
a is rotatably supported by a shaft portion 30d.

The first link 25 has a knuckle receiving portion 25c formed at an intermediate portion thereof, whereby the knuckle 38 attached to the tip of the cylinder rod 37 is formed.
(See FIG. 3). First
A spring 2 to be described later is provided on one end 25a side of the link 25.
A bar-shaped post 28a capable of hooking the other end of 9 is provided upright (see FIG. 3).

The second link 26 is composed of a single plate having a substantially rectangular shape, and has shaft holes formed at both ends thereof. One end 26a of the second link 26 is connected to the first link 2
5 is rotatably supported by a shaft portion 30d so as to be sandwiched by the other end 25b.
Is rotatably supported by a shaft portion 30a so as to be sandwiched by one end 23a of the shaft.

As described above, the swing arm 23, the clamp arm 24, the first link 25 and the second link 2
6 and the shaft portions 30a to 30d that support these components,
A substantially parallelogram limited chain, that is, a parallel link mechanism is configured. The parallel link mechanism is rotatably supported on the lower mold 40 by a bracket 22 and a shaft 30a. As a result, the parallel link mechanism as a whole is
Can swing up and down.

As shown in FIGS. 1 and 4, the work guide 27 is formed of a thick plate having an elliptical shape, and has a notch 27c at one end 27a and a notch 27c at the other end.
A screw hole 27d is formed in b. The notch 27c of the one end 27a is formed so as to conform to the contour shape of the shoulder 40a located on the outer peripheral edge of the lower die 40 so as to be able to abut, and the screw hole 27d of the other end 27b is formed.
The swing arm 23 is formed so as to be screw-fixed to a middle part thereof by a bolt (not shown).

As a result, as shown in FIG. 4A, the outer panel Wo (work W) placed on the lower mold 40 is shifted to the outside of the lower mold 40 without being placed at a predetermined position. When the notch 27c of the work guide 27 comes into contact with the shoulder 40a of the lower mold 40, the bent portion of the outer panel Wo is connected to one end 27 of the work guide 27.
a contacts. As a result, as shown in FIG. 4B, the outer panel Wo is pushed back inward of the lower die 40, so that the work W on the lower die 40 can be positioned at a predetermined position by the work guide 27.

As shown in FIGS. 1 and 3, the spring 29 is a tension coil spring, and both ends of the spring 29 are engaged with the post 28a of the first link 25 and the post 28b of the swing arm 23. As a result, a biasing force for displacing the swing arm 23 and the first link 25 to reduce the facing distance is exerted on the parallel link mechanism.

As shown in FIG. 1, the first stopper 31
It has a role of setting the minimum distance between the swing arm 23 and the first link 25, and
Swing arm 23 so as to be located between
Attached to the side. Accordingly, even if the biasing force of the spring 29 that pulls the swing arm 23 and the first link 25 in the direction of reducing the facing distance between the swing arm 23 and the first link 25 is applied, the first stopper 31 can maintain a constant interval between the two. Therefore, the state of displacement of the parallel link mechanism by the spring 29 can be maintained in a constant form.
It should be noted that the first stopper 31 functions in the same manner as in the present embodiment even when attached to the first link 25 side.

The second stopper 32 is connected to the swing arm 23
The swing arm 23 has a role of restricting the upward rotation at a predetermined position. When the swing arm 23 is rotated upward about the shaft portion 30a, the bracket 22 and the swing arm 23 are positioned between the bracket 22 and the swing arm 23. It is attached to the bracket 22 side so as to be positioned between the brackets. As a result, the rotation of the entire parallel link mechanism around the shaft portion 30a is stopped by the second stopper 32 at a position where the swing arm 23 is positioned substantially parallel to the outer peripheral wall of the lower die 40. The second stopper 32 functions in the same manner as in the present embodiment even when attached to the swing arm 23 side.

The third stopper 33 has a role of restricting the upward displacement of the parallel link mechanism at a predetermined position. The first stopper 33 is provided between the swing arm 23 and the first link 25.
The first link 25 is positioned below the stopper 31.
Attached to the side. As a result, even if a driving force for displacing the swing arm 23 and the first link 25 so as to narrow the facing distance between the swing arm 23 and the lower die 40 in the upward direction acts on the first link 25, the driving force is applied above the third stopper 33. It comes into contact with the located first stopper 31. Therefore, even if a driving force by an air cylinder 35 described later acts on the first link 25, the displacement state of the parallel link mechanism can be maintained in a constant form. Note that the first stopper 31 is connected to the first link 25.
When mounted on the side, the third stopper 33 is configured to be mounted above the first stopper 31 on the swing arm 23 side. Thereby, the same operation as in the case of the present embodiment is performed.

As shown in FIGS. 1 and 3, the air cylinder 35 has a function of expanding and contracting the cylinder rod 37 by pressurizing air supplied to the supply ports 36a and 36b. Part 22b
Is rotatably supported by a shaft portion 30f. A knuckle 38 is fixed to the tip of the cylinder rod 37, and the shaft 30a attached to the knuckle 38 is fixed.
Are carried by the knuckle receiving portion 25c of the first link 25. Thereby, the driving force due to the expansion and contraction of the cylinder rod 37 of the air cylinder 35 is transmitted to the knuckle 38 and the shaft 3.
0e and the first link 2 via the knuckle receiving portion 25c.
5, the shaft portion 3 as a shaft fulcrum
The entire parallel link mechanism can be turned around 0a.

The shaft portion 3 of the above-mentioned parallel link mechanism or the like is used.
Nos. 0a to 30f are supported via bearing members that do not require lubricating oil. Accordingly, wear of the shaft portions 30a to 30f due to high-speed operation and aging can be suppressed, and rattling of the parallel link mechanism itself, the air cylinder 35, and the cylinder rod 37 can be prevented. Therefore, each operation of the clamp device 20 can be performed smoothly. In addition, by using the parallel link mechanism as described above, compared with a mechanism in which a connecting pin moves in a long hole as in a “clamping device for hemmed material” disclosed in Japanese Patent Application Laid-Open No. 8-197149. In addition, problems such as breakage of the connecting pin can be prevented. Thereby, the durability of the clamp device 20 can be improved.

Next, the operation of the clamp device 20 will be described with reference to FIGS. In the clamp device 20 configured as described above, the cylinder rod 37 expands and contracts due to the air supplied to the air cylinder 35, and the expansion causes a series of operations as shown in FIGS. 5 (A) to 5 (C). Perform the operation.

As shown in FIG. 5A, the air cylinder 35
When the cylinder rod 37 is in a contracted state due to the air supplied to the cylinder die 37, the parallel link mechanism is pulled by the cylinder rod 37 about the shaft portion 30a and is rotated below the lower die 40. That is, the parallel link mechanism is in the down position, and the clamp arm 24 and the work guide 27 are located apart from the side of the lower die 40. Therefore, the clamp device 20 is in an unclamped state in which the work W is released without clamping the work W to the lower mold 40.

In this state, when the cylinder rod 37 starts to be expanded by the air supplied to the air cylinder 35, the parallel link mechanism is entirely displaced by the urging force of the spring 29 while maintaining the entire shaft portion 30a. Is rotated up by the cylinder rod 37 around the lower mold 40. Thereby, the clamp arm 24 and the work guide 27 gradually approach the lower mold 40, and the parallel link mechanism is displaced to the standing position. At this time, as shown in FIG. 4A, if the outer panel Wo (work W) placed on the lower mold 40 is shifted to the outside of the lower mold 40, the work guide is attached to the shoulder 40a of the lower mold 40. Before the notch 27c of the 27 abuts, one end 27a of the work guide 27 abuts on the end of the outer panel Wo. Therefore, the outer panel Wo is pushed back toward the inside of the lower mold 40 by the work guide 27, so that the outer panel Wo can be positioned before being fixed by the clamp arm 24, as shown in FIG.

As shown in FIG. 5B, the cylinder rod 3
When the parallel link mechanism is displaced to the upright position by the extension of 7, the swing arm 23 contacts the second stopper 32,
At substantially the same time, the work guide 27 comes into contact with the lower mold 40.
Thereby, the outer panel Wo by the work guide 27 is provided.
And inner panel W mounted on outer panel Wo
The alignment of i is completed. In this state, the parallel link mechanism is still maintaining a constant displacement state by the urging force of the spring 29, and the cylinder rod 37 of the air cylinder 35 is in the state of being extended.

When the extension of the cylinder rod 37 further advances, the rotation of the parallel link mechanism in the upright position toward the lower die 40 is restricted by the second stopper 32, so that the driving force of the air cylinder 35 is reduced. , Spring 29
And acts in a direction to displace the parallel link mechanism upward in the lower mold 40 against the urging force of the lower mold 40. That is, the swing arm 23
The parallel link mechanism is displaced so as to move the first link 25 in the upward direction of the lower die 40 in a state where the position is fixed. As a result, the base end 24b of the clamp arm 24 is pushed upward, so that the clamp claw 24d of the clamp arm 24 is pushed down in the direction of the lower die 40 around the shaft portion 30b of the swing arm 23.

Therefore, as shown in FIG. 5 (C), the air supplied to the air cylinder 35 causes the cylinder rod 3
When the extension of 7 is completed, the clamp claw 24d of the clamp arm 24 is pushed down so as to press the inner panel Wi (work W) placed on the outer panel Wo. Thereby, the outer panel Wo and the inner panel Wi are clamped between the lower mold 40 and the clamp arm 24, and the clamping by the clamp device 20 is completed.

In the unclamping operation, the operation of the clamp arm 24 described above is performed in the opposite direction. That is, when the cylinder rod 37 expands and contracts by the air supplied to the air cylinder 35, the parallel link mechanism operates in the order of FIGS. 5 (C), 5 (B) and 5 (A). The clamp arm 24 fixing the workpiece W releases the work W, and then retreats to the side outside of the lower mold 40. Thereby, interference between the hem roller 15 and the clamp device 20 during the rolling can be avoided.

As described above, according to the clamp device 20, the parallel link mechanism constituted by the swing arm 23, the clamp arm 24, the first link 25, and the second link 26 is operated by the operation of the cylinder 35. About the shaft 30a with the lower mold 40. The parallel link mechanism rotates the clamp arm 24 in the clamp direction by the cylinder 35 operating at the upright position of the parallel link mechanism.
Therefore, when the parallel link mechanism is displaced from the lying position to the upright position by the operation of the cylinder 35, the second stopper 3
2, the rotation of the swing arm 23 from the standing position to the lower die side is restricted, so that the clamp arm 24 is rotated in the clamping direction at the standing position. Thereby, the work guide 27 is attached to the outer panel W placed on the lower mold 40.
o, the outer panel Wo can be positioned, and the clamp arm 24 has its clamp claws 24d.
Accordingly, the inner panel Wi and the outer panel Wo can be clamped to the lower mold 40. Therefore, the work W can be positioned and fixed by the operation of one cylinder 35.

Since the first link 25 has the third stopper 33 for restricting the displacement of the parallel link mechanism in the clamping direction at a predetermined position, the first link 25 uses the air cylinder 35 to operate the parallel link mechanism at the standing position of the parallel link mechanism. Even when it is operated, the rotation of the clamp arm 24 in the clamping direction is restricted at a predetermined position by the third stopper 33. This allows
The pressing force of the inner panel Wi and the outer panel Wo by the clamp claw 24d of the clamp arm 24 can be set according to the predetermined position.
Accordingly, it is possible to avoid a problem that the surface of the inner panel Wi is scratched. Therefore, it is possible to prevent the surface quality of the inner panel Wi from deteriorating due to the clamp.

[0038]

According to the first aspect of the present invention, the swing arm,
The parallel link mechanism constituted by the clamp arm, the first link, and the second link is displaced by the operation of the cylinder between an upright position and a fall position around a pivot point with the lower die of the swing arm. The parallel link mechanism rotates the clamp arm in the clamp direction by operating the parallel link mechanism at a standing position by the cylinder. For this reason, when the parallel link mechanism is displaced from the lying position to the standing position by the operation of the cylinder, the second stopper restricts the swing arm from rotating from the standing position to the lower die side. The arm is rotated in the clamp direction. Thus, the work guide can contact the work placed on the lower mold to position the work, and the clamp arm can clamp the work to the lower mold by its clamp claws. Therefore, there is an effect that the operation of one cylinder can position the work and fix the work.

According to the second aspect of the present invention, since the first link or the swing arm is provided with the third stopper for restricting the rotation of the clamp arm in the clamping direction at a predetermined position, the first link or the swing arm is provided by the cylinder at the standing position of the parallel link mechanism. Even when the parallel link mechanism is operated, the rotation of the clamp arm in the clamping direction is regulated at the predetermined position by the third stopper. Thereby, the pressing force of the work by the clamp claws of the clamp arm can be set according to the predetermined position.
The disadvantage that the surface of the work is scratched by the clamp claws can be avoided. Therefore, in addition to the above-described effects, there is also an effect that the surface quality of the work can be prevented from deteriorating due to the clamp.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of a clamp device according to the present embodiment.

FIG. 2 is a perspective view illustrating a configuration example of a hemming apparatus to which the clamp device according to the embodiment is applied.

FIG. 3 is a view as seen from the direction of the line III shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a configuration and an operation of a work guide of the clamp device according to the present embodiment.

5A and 5B are explanatory views showing the operation of the clamp device according to the present embodiment. FIG.
FIG. 5B shows a state where the work is aligned, and FIG. 5C shows a state where the work is clamped.

[Explanation of symbols]

 Reference Signs List 10 Hemming device 20 Clamp device 22 Bracket (lower die) 23 Swing arm (Parallel link mechanism) 23a One end 23b Other end 24 Clamp arm (Parallel link mechanism) 24a One end 24b Base end 24c Intermediate part 24d Clamp claw 25 First link (Parallel) 25a one end 25b other end 26 second link (parallel link mechanism) 26a one end 26b other end 27 work guide 29 spring (biasing means) 30a shaft (shaft fulcrum) 31 first stopper 32 second stopper 33 third Stopper 35 Air cylinder (cylinder) 40 Lower die W Work Wi Inner panel (Work) Wo Outer panel (Work)

Claims (2)

[Claims] 1. A clamping device having a parallel link mechanism including a clamp arm for fixing a work to be hemmed by a hemming device to a lower mold, wherein the lower mold has a shaft rotatably provided at one end. A swing arm supported, a clamp arm having an intermediate portion pivotally supported by the other end of the swing arm, and a clamp arm having a tip for clamping the work between the lower die and a base end of the clamp arm. A first link having one end pivotally supported and formed to have the same length as the swing arm; the other end of the first link pivotally supported at one end and the other end pivotally supported at one end of the swing arm; A second link that holds a swing arm and the first link in parallel; and a parallel link machine including the swing arm, the clamp arm, the first link, and the second link. A biasing means for biasing the clamp arm in the unclamping direction, a first stopper for restricting rotation of the clamp arm in the unclamping direction by the biasing means, the lower mold or the swing A second stopper provided on the arm for restricting the swing arm from rotating from the upright position toward the lower mold; and a second stopper rotatably supported by the lower mold, and a tip pivoted by the first link. The clamp arm by displacing the parallel link mechanism between an upright position and a falling position centering on a pivot point of the swing arm with the lower mold, and operating the parallel link mechanism at the upright position. A cylinder provided in the swing arm for rotating in the clamping direction against the urging force of the urging means; and Clamping device characterized by and a work guide for positioning the workpiece in contact with the workpiece placed on the lower mold. 2. The clamp device according to claim 1, wherein the first link or the swing arm includes a third stopper that restricts rotation of the clamp arm in a clamping direction at a predetermined position.