JPH0575538B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a clamp device for fixing a workpiece to, for example, a base.

(Prior Art) Conventionally, the technology disclosed in Japanese Unexamined Utility Model Publication No. 59-74038 has been known as an example of a work clamping device for fixing a workpiece having a flange portion at the end, such as an automobile transmission case, to a base during processing. ing.

This type of work clamping device pivots the fulcrum part of the clamp member, which forms a fulcrum part, a force point part, and an actuation point part, and uses a cylinder that acts on the force point part to move the clamp member out of the clamp position of the workpiece. When the clamping member is rotated to the clamping position and the clamping member is rotated to the workpiece clamping position, the actuating point portion presses the workpiece toward the base, and the workpiece is clamped between the clamping member and the base.

However, in the conventional clamping device described above, when the thickness of the workpiece differs depending on the type of workpiece, that is, the thickness of the flange portion clamped between the clamping member and the base, the clamping member rotates from the non-clamping position to the clamping position. A difference occurs between the amount of rotation and the amount of stroke of the cylinder.

In this way, if there is a difference between the amount of rotation of the clamp member and the amount of stroke of the cylinder, it is not possible to properly detect these clamp states with a single detector, which causes the problem of requiring multiple detectors. There is.

(Object of the invention) This invention was made to solve the above-mentioned conventional problems, and even if the thickness of the workpiece is slightly different,
An object of the present invention is to provide a workpiece clamping device that can detect a clamping state using a single detector.

(Structure of the Invention) In order to achieve the above object, the work clamp device according to the present invention has a clamp lever that rotates between a clamp position and a non-clamp position of the work, and has a clamp lever that is spaced apart in the axial direction of the clamp lever. A bifurcated clamp member having a work holding part and a posture holding part is pivotally supported.

A contact member is provided opposite to the posture holding portion, and a concave arcuate surface having a radius equal to the distance from the pivot portion to the holding end of the posture holding portion is formed on the posture holding portion side of the contact member. It is structured as follows.

Therefore, when the clamp lever rotates from the non-clamping position of the workpiece to the clamping position, the tip surface of the workpiece holding part of the clamp member presses the workpiece, and the tip surface of the posture holding part presses the concave part of the contact member. Clamping is achieved by contacting the arcuate surface.

On the other hand, if the thickness of the workpiece becomes slightly thicker,
Immediately before the clamp lever reaches the above-mentioned clamp position, the tip of the presser part of the clamp member comes into contact with the workpiece, and when the clamp member reaches the clamp position, the clamp member rotates about the pivot point. do.

Then, the tip of the posture holding portion is displaced and abuts against the concave arcuate surface of the abutment member, thereby performing clamping. In other words, even if the thickness of the workpieces differs, this difference in thickness can be absorbed by the rotation of the clamp member.

Therefore, the clamp position of the clamp lever does not change.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a workpiece clamping device according to the present invention, and in the figure, reference numeral 1 denotes a workpiece that has been set in advance on a base 2. FIG.

In this embodiment, the workpiece 1 is a truss transmission case of an automobile, and the peripheral flange portion 1a is clamped by three clamping devices 3.

Each clamp device 3 is composed of a clamp lever 4, a clamp member 5, and a contact member 6, as shown in FIGS. 2 and 3, and the clamp lever 4 has a pin 7.
The contact member 6 is rotatably supported by arm portions 8, 8 provided on one side of the front surface of the contact member 6, and the contact member 6 is attached to the front surface of the base plate 2 by bolts 9.

The clamp member 5 is pivotally supported 10 at one end of the clamp lever 4 by a pin. And the work holding part 5A is spaced apart in the axial direction of the clamp lever 4.
It is formed into a bifurcated shape having a posture holding portion 5B.

That is, the work holding part 5 is placed on the front side of the pivot part 10.
At the rear side of A, a posture holding section 5B protrudes toward the base 2, and a contact member 6 is located opposite the posture holding section 5B.

A concave arcuate surface 11 whose radius is the distance from the pivot portion 10 to the distal end surface of the posture holding section 5B is formed on the front surface of the abutment member 6, that is, on the side of the posture holding section 5B.

Reference numeral 12 designates a clamp cylinder as a driving source, and its clamp cylinder 13 passes through the base 2 and is supported by a bush 14 so as to be slidable in the axial direction, and the other end of the clamp lever 4 is rotatably connected to the tip. ing.

A detection rod 15 is attached parallel to the clamp rod 13 via an arm 16, and a pair of dogs 17A and 17B are attached at an appropriate distance.An actuator of an unclamped state detector 18A is attached to one dog 17A. Correspondingly, the actuator of the clamp state detector 18B corresponds to the other dog 17B. In the figure, reference numeral 19 is fixed to the front surface of the base plate 2 with reference gold.

The operation of the above configuration will be explained.

As shown in FIG. 1, the workpiece 1 is set on the base 2, the clamp rod 13 of the clamp cylinder 12 in FIG. The clamp member 5 is rotatably held in the clamp position and is in the standby position indicated by the imaginary line x3.

In this case, one of the dogs 17A attached to the detection rod 15 is connected to the unclamped state detector 18.
The unclamped state of the workpiece 1 is detected by contacting the actuator A.

When the thickness of the flange portion 1a of the workpiece 1 is the thickness shown by the solid line, the clamp cylinder 12 is activated,
When the clamp rod 13 moves to the front end of the stroke shown by the solid line, the clamp lever 4 rotates about the pin 7 to the clamp position shown by the solid line. As a result, the end surface of the workpiece holding part 5A in the clamp member 5 comes into contact with the front surface of the flange part 1a of the workpiece 1 as shown by the solid line, and the end surface of the posture holding part 5B comes into contact with the concave arc surface 11 of the contact member 6. Being pushed.

In this way, the posture holding part 5B of the Kunlap member 5
By pressing the tip of the clamp member 5B against the concave arcuate surface 11 of the contact member 6, the posture of the clamp member 5B is maintained in the state shown by the solid line, and the tip of the workpiece holding portion 5A is pressed against the workpiece 1 due to the pressing reaction force applied to the posture holding portion 5B. The workpiece 1 is clamped by the reference metal 19, that is, the base plate 2, pressing the flange portion 1a of the workpiece 1.

In this case, the other dog 17B comes into contact with the actuator of the clamp state detector 18B and the workpiece 1
Detects the clamp state of.

On the other hand, the thickness of the flange portion 1a of the workpiece 1 is indicated by the solid line as shown by the dashed line y1.
If the workpiece 1 is thicker than a, just before the clamp lever 4 reaches the clamping position shown by the solid line from the non-clamping position shown by the imaginary line The clamp member 5 contacts the front surface of the flange portion 1a, and rotates counterclockwise about the pivot portion 10.

Almost at the same time, the clamp lever 4 reaches the clamp position shown by the solid line, and the tip of the posture holding part 5B of the clamp member 5 hits the concave arc surface 11 of the contact member 6.
, the clamp member 5 is pressed against the dashed line y2
The posture is maintained in the state shown in FIG.
is pressed against the reference metal 19 to clamp the workpiece 1.

That is, even if there is a slight difference in the thickness of the flange portion 1a of the workpiece 1, this can be absorbed by the rotation of the clamp member 5, so that the clamping position of the clamp lever 4 does not vary.

Therefore, the clamping state of the workpiece 1 is detected by the same clamping state detector 18B that is used when the workpiece 1 having the thin flange portion 1a described above is clamped.

(Effects of the Invention) As explained above, according to the present invention, the clamp state can be detected by a single clamp state detector even if the thickness of the workpiece is slightly different.
Unlike conventional methods, multiple detectors are not required.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of a work clamping device according to the present invention, FIG. 2 is an enlarged sectional view taken along the - line in FIG. 1, and FIG. 3 is a view taken in the direction of the - arrow in FIG. 2. . 1... Workpiece, 4... Clamp lever, 5...
Clamp member, 5A... Work holding part, 5B...
Posture holding part, 6...Abutting member, 11...Concave arcuate surface.

Claims (1)

[Claims] 1. A clamp lever that rotates between a clamping position and a non-clamping position of a workpiece is provided, and one end of this clamp lever has a bifurcated shape having a workpiece holding part and a posture holding part separated from each other in the longitudinal direction of the clamp lever. A clamp member is pivotally supported, and a contact member is provided opposite to the posture holding portion, and a distance from the pivot portion to the distal end surface of the posture holding portion is defined as a radius on the posture holding portion side of the contact member. A work clamping device characterized by having a concave arc surface formed therein.