JPH0453880Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a work clamping device used for selectively clamping, positioning and fixing a plurality of types of workpieces.

(Prior Art) The above-mentioned work clamp device includes, for example, a plurality of work clamp units that clamp a work by swinging a clamp member relative to a fixed member based on the operation of a cylinder, and are arranged in parallel according to the type of work. Some devices are equipped with a unit selection mechanism that selectively reciprocates the work clamp units between the use position and the standby position. It has the configuration shown in Figures 5a and 5b.

This work clamp unit is provided with a gauge part 1a having a shape corresponding to the shape of the workpiece at the tip of a plate-shaped gauge post 1, and pivots the intermediate part of the clamp arm 2, and also has a gauge part 1a on the side of the gauge post 1. A cylindrical air cylinder 3 is pivotally supported, and a piston rod 3a of the air cylinder 3 is axially connected to one end of the clamp arm 2. With this structure, this work clamp unit is able to control the operation of the air cylinder 3. By swinging the clamp arm 2 based on this, it is possible to clamp, position and fix the workpiece between the other end of the clamp arm 2 and the gauge section 1a.

The unit selection mechanism pivots the gauge post 1 so as to be able to swing, and is also provided with an air cylinder for each gauge post 1. By selectively operating these air cylinders, the required workpiece can be selected. The clamp unit can be swung between a use position and a standby position.

(Problem to be solved by the invention) However, in the conventional workpiece clamping device described above, since the cylindrical cylinder 3 is used in the workpiece clamping unit, it is difficult to obtain sufficient clamping force to clamp the workpiece. As a result, the outer diameter of the cylinder and, ultimately, the thickness dimension of the work clamp unit will increase, and due to restrictions on the size of the part of the work that must be positioned, the number of work clamp units that can be placed in one work clamp device will increase. There was a problem that the number of types of workpieces that could be shared by one workpiece clamping device was small.

Also, for the above reason, the outer diameter of the cylinder is larger than the width of the gauge part, so as shown in FIG.
When spot welding is attempted near a portion that is positioned and fixed by the gauge portion, there is a problem in that the posture of the welding gun 5 is restricted, making welding difficult in some cases.

This invention provides a device that advantageously solves the above-mentioned problems.

(Means for Solving the Problems) The work clamp device of this invention includes a plurality of work clamp units arranged in parallel that clamp the work by swinging the clamp member relative to the fixed member based on the operation of the cylinder. The work clamp unit is also provided with a unit selection means for selectively reciprocating the work clamp units between a use position and a standby position, the cylinder is made into a flat shape, and the operation of the cylinder is transmitted to a toggle mechanism. It is characterized in that the clamp member is swung by a toggle mechanism.

(Function) In such a device, a predetermined work clamp unit is placed in the use position based on the operation of the unit selection means, and the force of the cylinder is increased through the toggle mechanism based on the operation of the cylinder of the work clamp unit. The clamp member swings.

Therefore, according to this device, a workpiece can be held between the clamping member and the fixing member of the workpiece clamp unit corresponding to the type of workpiece.

Moreover, in this device, the cylinder of the work clamp unit is flattened, and the decrease in clamping force caused by this is compensated for by a toggle mechanism, so the thickness direction dimension of the work clamp unit can be reduced without reducing the clamping force. It becomes smaller.

Therefore, according to this device, one workpiece clamping device can be used in common for many types of workpieces, and restrictions on the posture of the welding gun can be eliminated.

(Example) Hereinafter, an example of this invention will be described in detail based on the drawings.

Figures 1a and 1b are a plan view and a front view showing an embodiment in which the work clamping device of this invention is applied to a work clamping device for positioning and fixing body side panels on a main body assembly stage of an automobile body assembly line. 11 in the figure
is the body side panel as a workpiece, 12,1
3 and 14 indicate workpiece clamping devices, respectively.

The work clamp devices 12 to 14 here each have the same configuration, and the work clamp device 12 will be described here as a representative.

The workpiece clamping device 12 is shown in FIGS. 2a and 2b.
As shown in FIG. 2, two supporting plates 16 are provided upright on both opposing ends of the base plate 15, and a connecting plate 17 that integrally connects the supporting plates 16 is provided upright. A support ring 18 is fixed to the upper part of the support plate 16, respectively, and a through hole 16 passing through the support plate 16 and the support ring 18 is formed.
a, 18a, and at least one of the support rings 1.
The swing shaft 19 is fixed to the
In addition, four clamp units 20 and four clamp units 21 are pivotally supported in parallel with each other and alternately at slight intervals through spacers.

3a and 3b are a front view and a side view showing one of the clamp units 20. The clamp unit 20 has a bush 23 that fits with the swing shaft 18 at the base (lower part in the figure) of a gauge post 22 made of a steel plate material, and a contact part 2
On the other hand, a gauge block 24 is fitted to the tip end (the upper end in the drawing) of the gauge post 22 as a fixed member having a gauge portion 24a formed thereon in a shape corresponding to the shape of a predetermined portion of a predetermined type of body side panel 11, and the gauge block 24 is replacedably fixed to the tip end with screws. Two cranks 25 and 26 are further pivotally supported to the tip end of the gauge post 22 via a crimping pin 27 so as to be swingable. The cranks 25 and 26 are connected to each other via two links 28 and the crimping pin 27 to form a toggle mechanism 29. The crank 25 is provided with a gauge portion 24a.
A clamp tip 30 as a clamp member having a clamp portion 30a having a shape corresponding to the shape of
It is fixed with bolts so that it can be replaced, and a flat air cylinder 31 is pivoted via a pin 34 to the side of the gauge post 22. The piston rod 31a of the air cylinder 31 is connected to the other crank 26 via a connecting member 32 and a crimping pin 33. Furthermore, a pin hole 22b is formed in the side of the gauge post 22 opposite the air cylinder 31.

Here, as shown in FIG. 4, the air cylinder 31 has a hole 31c having an oval cross-sectional shape formed inside a cylinder block 31b having a rectangular cross-sectional outer shape. , has an oval cross-sectional shape and an annular groove 31d on the outer peripheral surface.
A piston 31e having a cylinder block 31b and a piston 31e is fitted in a slidable manner, and an O-ring 31f is fitted into the annular groove 31d to make the space between the cylinder block 31b and the piston 31e airtight, and the piston rod 31a is fixed to the piston 31e. , both ends of the cavity 31c are hermetically sealed by an end member 31g bolted to the cylinder block 31b via a sealant to define air chambers A and B, and the piston rod 31a is hermetically and slidably attached to one end member 31g. Ports 31h are formed in both end members 31g to communicate with the air chambers A and B, respectively. In the figure, numeral 35 indicates reed switches fixed to the end member 31g, and these reed switches 35 are actuated by a magnet (not shown) provided on the piston 31e to
1e's approach, and the operating state of the air cylinder 31 is detected and output.

In the work clamp unit 20 configured as described above, when air pressure is selectively applied to the two ports 31h of the air cylinder 31, the piston 31e is moved by the air pressure in the air chamber A or B, and the piston rod is moved. 31a moves forward and backward, and the toggle mechanism 29 moves the clamp tip 30 to the clamp position shown by the solid line in FIG. 30
A and the gauge part 24a are swung between a release position shown by a phantom line in the figure, where the gauge part 24a is separated by a large distance. Then, the toggle mechanism 29 connects the crank 26 and the link 28 in the vicinity of the clamp position of the clamp tip 30.
Due to the positional relationship between the clamp tip 30 and the piston rod 31a, the clamp tip 30 is
is pressed in a direction in which the clamp portion 30a approaches the gauge portion 24a.

Therefore, according to this work clamp unit 20, the gauge portion 24a of the gauge block 24 and the clamp tip 3 are connected based on the operation of the air cylinder 31.
The body side panel 11 can be held and positioned between the body side panel 11 and the clamp portion 30a of 0, and the body side panel 11 can be released.

Moreover, this work clamp unit 20 uses a flat air cylinder 31, and the toggle mechanism 29 compensates for the decrease in clamping force caused by this, thereby clamping the body side panel 11 with sufficient clamping force. As shown in FIG. 3b, it is possible to make the thickness direction dimension of the workpiece clamp unit approximately equal to the thickness of the gauge post 22 without reducing the clamping force.

Note that the other clamp units 20 also have a gauge part 2.
The work clamp unit 20 is the same as the work clamp unit 20 described above except for the shapes of the clamp portion 4a and the clamp portion 30a. In addition, the work clamp unit 21 has the shape of the gauge post 22 such that the pin hole 22c can be provided at a position substantially opposing the pin hole 22b with the bush 23 in between, as shown by the imaginary line in FIG. is constructed similarly to the work clamp unit 20.

The work clamp device 12 further includes:
Unit selection device 39 as unit selection means
will be established. As shown in FIG. 2, this unit selection device 39 fixes approximately L-shaped brackets 36 and 37 on the connection plate 17 at positions corresponding to the work clamp units 20 and 21, respectively, and fixes the bases of these brackets. Flat-shaped air cylinders 38 configured similarly to the air cylinder 31 are each pivotally supported at one end near the plate 15, and piston rods 38a of these air cylinders 38 are mounted.
, by pin 39 to the work clamp unit 2.
The workpiece clamp unit 20 is connected to the pin holes 22b and 22c of 0 and 21, and the workpiece clamp unit 20 shown in FIG. Stopper portions 36a and 37a are formed, respectively, which abut against the contact portion 22a of the post 22 and specify the rocking limit positions of the work clamp units 20 and 21.

Work clamp device 12 configured as described above
14, in this example, as shown in FIG.
It is attached to the wrist part 41a of a Cartesian coordinate type robot 41 which has three degrees of freedom (up and down, left and right, and front and back), and is capable of parallel movement to any position within a certain range based on the operation of the robot 41. Regarding the device 12, furthermore, the work clamping device 1
An inclination angle selection device 42 is provided between the wrist portion 41a and the wrist portion 41a.
Positioning of rear pillar portions 1a with different inclination angles between the body side panel 11 of vehicle type A shown by the solid line in FIG. Make it possible to share it in a fixed manner.

Here, as shown in FIG. 2, the inclination angle selection device 42 is provided with a mounting flange 44 for attachment to the robot 41 at one end (the lower end in the figure) of the fixed sleeve 43, and a The rotating sleeve 45 is rotatably supported via two ball bearings 46, and the fixed sleeve 4
The base plate 15 of the workpiece clamping device 12 is fixed to a flange 47 integrated with the end of the rotating sleeve 45 that protrudes from the other end of the rotary sleeve 45, and the air cylinder 48 for changing the angle is pivotally attached to the base plate 15. On the other hand, an arm 49 is provided protruding from the outer peripheral surface of the fixed sleeve 43, and an air cylinder 48 is attached to the arm 49.
The piston rod 48a is connected to the rotary sleeve 45, and a stopper (not shown) is further provided to specify the rotation limit position of the rotary sleeve 45.

In this tilt angle selection device 42, when the air cylinder 48 is actuated, its piston rod 48a pushes or pulls the arm 49, and the reaction force causes the rotating sleeve 45 to rotate until it comes into contact with the stopper. , the work clamp device 12 is selectively positioned at angles suitable for the two types of body side panels. In addition, instead of the air cylinder 48,
By using a drive mechanism in which a ball screw is driven by a servo motor, it is possible to position the work clamp device at an arbitrary inclination angle.

According to the workpiece clamping devices 12 to 14, the inclination angle selection device 42, and the robot 41, for example, the workpiece clamping device 14 can
Rear fender part 1 of body side panel 11
A specific work clamp unit 20 or 21 having a gauge portion 24a having a shape corresponding to the shape of the positioning portion 1b is selected by the unit selection device 3.
9, by the operation of the air cylinder 38 connected to the work clamp unit 20 or 21, as shown in FIG. While the other work clamp units 20 and 21 are placed in the use position, the other work clamp units 20 and 21 are moved to the gauge section 2 by the operation of the other air cylinder 38 of the unit selection device 39.
4a approaches the base plate 15, and the work clamp devices 12 and 13 are provided with a gauge portion 24a having a shape corresponding to the shape of the positioning portion of the rear pillar portion 11a of the body side panel 11 of the vehicle type A. One workpiece clamping unit 20 or 21 for each particular workpiece clamping device which has, respectively, the unit selection device 39 selects these workpiece clamping units 20 or 21 respectively.
Alternatively, the other clamp units 20 and 21 are placed in the use position by actuation of the air cylinder 38 connected to the unit selection device 39.
As shown in FIG. The inclination angle is set to correspond to the inclination angle of the rear pillar portion 11a of No. 11, and furthermore, by the operation of the robot 41, each work clamp device 1
By arranging 2 to 14 at positions corresponding to the above-mentioned respective positioning parts of the body side panel 11 of the vehicle type A, the body side panel 1 of the vehicle type A
The gauge portion 24a suitable for the positioning of the workpiece clamp device 12 to 14 can be placed at one position for the rear fender portion 11b and at two positions for the rear pillar portion 11a. By operating the air cylinder 31 of the work clamp unit 20 or 21 placed in the
The body side panel 11 of vehicle type A can be positioned and fixed at a predetermined position by sandwiching each of the positioning portions of the body side panel 11 between the body side panel 4a and the body side panel 4a.

Further, for example, for the work clamp devices 12 and 14, the body side panel 1 of the vehicle type B
The unit selection device 3 selects a specific work clamp unit 20 or 21 having a gauge portion 24a having a shape corresponding to the shape of the positioning portion of the rear pillar portion 11a and the rear fender portion 11b.
9 is placed in the use position, the other work clamp units 20 and 21 are placed in the standby position, and the work clamp device 12 is placed in the use position by the piston rod 48 of the air cylinder 48 of the tilt angle selection device 42.
By the operation of reversing the body side panel a, the inclination angle corresponds to the inclination angle of the rear pillar portion 11a of the body side panel 11 of the vehicle type B, and further, by the operation of the robot 41, the work clamp devices 12 and 14 are respectively moved to the body side panel of the vehicle type B. By arranging the gauge portion 24a at a position corresponding to each of the above-mentioned positioning portions of the rear pillar portion 11a, the gauge portion 24a suitable for positioning the body side panel 11 of the vehicle type B
and the rear fender portion 11b can be placed at predetermined positioning positions, and by operating the work clamp unit 20 or 21 placed at the above-mentioned use position of the work clamp devices 12, 14, The body side panels 11 can be sandwiched and positioned and fixed at a predetermined position.

Incidentally, since each of the work clamping devices 12 to 14 in the above example is equipped with a total of eight work clamp units 20 and 21, the work clamping devices 12 to 14 described above are also equipped with six other types of work clamping units 20 and 21. It is also possible to position and fix the vehicle type or body type.

Therefore, the work clamp devices 12 to 1 in this example
According to No. 4, the work clamp units 20, 21
The work clamp unit 20, 2
1 can be made extremely small without reducing the clamping force, and as a result, one workpiece clamping device can be used commonly for positioning and fixing many types of body side panels. It is possible to eliminate restrictions on the posture of the welding gun.

Although the above has been explained based on the illustrated example, this invention is not limited to the above-mentioned example, and can be applied to other vehicle body panels such as floor main panels and rear panels, and also to clamping other types of workpieces. can. The number of clamp units can also be changed as required.

(Effect of the invention) Thus, according to the work clamping device of this invention, the dimension in the thickness direction of the work clamp unit can be reduced without reducing the clamping force, and one work clamping device can be used for many different types. The welding gun can be used in common with other workpieces, and furthermore, restrictions on the posture of the welding gun can be eliminated.

[Brief explanation of the drawing]

Figures 1a and b are plan and front views showing an embodiment of the work clamping device of this invention applied to an automobile body assembly line, and Figures 2a and b are enlarged views of the work clamping device of the above example. Figures 3a and 3b are front and side views of the work clamp unit used in the above example, and Figure 4 is taken along the - line in Figure 3 showing the air cylinder of the work clamp unit. The sectional view and FIGS. 5a and 5b are a plan view and a front view of a conventional device. 11...Body side panel, 12, 13, 1
4... Work clamp device, 19... Swing axis, 2
0, 21... Work clamp unit, 24...
Gauge block, 29... Toggle mechanism, 30...
Clamp tip, 31... Air cylinder, 39...
...Unit selection device.

Claims (1)

[Scope of Claim for Utility Model Registration] A plurality of work clamp units are arranged in parallel to clamp a work by swinging the clamp member relative to a fixed member based on the operation of a cylinder, and the work clamp units are arranged in the operating position. In the work clamp device, the workpiece clamping device is provided with a unit selection means for selectively reciprocating between a standby position and a standby position. A work clamp device characterized by swinging a member.