JPH0429952Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a workpiece clamping device for clamping and fixing a workpiece.

<Prior art> Conventionally, when tightening and fixing a workpiece for processing, a workpiece clamping device as shown in FIGS. 4 and 5, for example, has been used.
(See Publication No. 2168).

To explain this, a spacer 3 for adjusting the height of the clamp 2 is in contact with the lower surface 2a of the other end of the clamp 2, which has the work clamp part 1 formed on one end, and this spacer 3 is connected to the work clamp device. It is screw-fitted with a height adjustment pedestal 5 attached to the main body 4 of.

Also, adjust the position of the approximate center of the clamp 2 to the device body 4.
A stud bolt 6 fixed to the hole passes through the hole.

Then, the casting is placed in the work clamp part 1 of the clamp 2.
After setting the workpiece 7 such as a forged product, tighten the spherical nut 8 having a convex spherical surface that fits into the threaded part formed on the tip side of the stud bolt 6. The clamp 2 is pressed downward via the spherical washer 9 having a spherical seat.

As a result, the clamp 2 is pressed downward against the reaction force of the spring 10 interposed between the lower surface of the clamp 2 and the device main body 4, and the workpiece 7 is clamped.

<Problems to be solved by the invention> By the way, in such a conventional workpiece clamping device, when tightening and fixing the workpiece 7, the spherical nut 8 is manually tightened using, for example, a spanner, so a plurality of screws are used. There was a problem in that it was impossible to tighten and fix the workpieces 7 at the same time.

Also, when adjusting the tightening height due to the difference in the shape of the workpiece 7, the threaded fitting part between the spacer 3 and the pedestal 5 is adjusted, and the threaded fitting part between the spherical nut 8 and the stud bolt 6 is adjusted. Adjust and tighten 2
There was a problem in that the overall height had to be adjusted and adjustments were required at two locations, making the work cumbersome.

Furthermore, since the contact surface 3a of the spacer 3 with the lower surface 2a of the clamp 2 is flat, if the portion of the workpiece 7 to be clamped and fixed is inclined with respect to the lower surface 2a of the clamp 2 (for example, , the state indicated by the broken line in FIG. 5), the clamp 2 is tilted in accordance with the tilt of the workpiece 7 due to the spherical fitting action of the spherical nut 8 and the spherical washer 9, so that the clamp 2 and the spacer 3 are There is a problem that a point contact state may occur, and the tightening and fixing of the workpiece 7 becomes unstable.

The present invention was devised in view of these conventional problems, and an object of the present invention is to solve the above problems by improving a work clamping device.

<Means for Solving the Problems> For this reason, the present invention provides a workpiece clamping device in which a workpiece is clamped and fixed by a workpiece clamp portion formed at one end of the clamp, in which a stud is installed upright on the device body. A bolt is inserted into the middle part of the clamp, a spherical nut having a spherical seat is screwed onto the stud bolt, and a washer having a spherical seat that fits into the spherical seat of the spherical nut is connected to the clamp and the spherical nut. A clamp-pressing actuator is provided between the device body and the clamp-pressing actuator, which includes a spring that biases the clamp toward the spherical nut, and has a piston that abuts the lower surface of the other end of the clamp via a spacer. In addition, a spherical fitting portion is formed at the contact portion between the spacer and the piston, and a downward position regulating stopper that abuts on the device body is screwed onto the piston.

<Operation> With this configuration, for example, when tightening and fixing a work, the work clamp portion of the clamp is first moved to above the tightening and fixing position of the work.

Next, when the clamp pressing actuator is activated to operate the piston, the work clamp part of the clamp operates using the part of the clamp where the reaction force of the spring is acting as a fulcrum, thereby tightening and fixing the work. will be held.

At this time, even if the surface of the workpiece to be tightened and fixed is not flat and the clamp is inclined, the inclination will be absorbed by the spherical seat between the spherical nut and the seat and the spherical fitting between the spacer and the piston. be done.

<Example> The example shown in FIGS. 1 to 3 will be described below. The same elements as those in the conventional example will be described with the same reference numerals as in FIGS. 4 and 5.

The main body 11 of the work clamp device is provided with a hydraulic cylinder 13 which is a clamp pressing actuator and has a piston 12 that contacts the lower surface 2a of the other end of the clamp 2 via a spacer 19.

A flange portion 12a that is a sliding portion with the cylinder 14 is formed on the base end side of the piston 12 fitted into the cylinder 14 of the hydraulic cylinder 13, and a step between the end face of the flange portion 12a and the upper part of the cylinder 14 is formed. A return spring 15 is interposed between the attachment part and the attachment part.

A threaded portion 16 is formed on the outer periphery of the distal end of the piston 12, and a spherical seat 17 consisting of a spherical depression is formed on the distal end.

The threaded portion 16 of the piston 12 has the piston 1
A stopper 18 that restricts the lowering position of 2 is fitted with a screw.

Between the clamp 2 and the piston 12, the piston 1
A spacer 19 having a spherical portion 19a that fits into the second spherical seat 17 is interposed.

The bottom wall of the cylinder 14 has openings 20 that are bifurcated in the middle and are formed in the side wall and bottom wall of the device body 11, respectively.
A hydraulic oil flow passage 20 having a and 20b is open.

Further, a stud bolt 6 having a threaded portion at its distal end and fixed to the device main body 11 at its proximal end passes through a substantially central portion of the clamp 2.

A spherical nut 8 having a convex spherical surface is threadedly fitted onto the tip side of the stud bolt 6, and a spherical nut 8 is fitted between the spherical nut 8 and the clamp 2. A spherical washer 9 having a concave spherical seat is interposed.

Further, a spring 10 is interposed between the lower surface of the clamp 2 and the device main body 11 and on the outside of the stud bolt 6 to press the clamp 2 upward.

With this configuration, for example, when tightening and fixing the workpiece 7, the workpiece clamping portion 1 of the clamp 2 is first moved to above the tightening and fixing position of the workpiece 7.

Next, for example, when hydraulic oil is supplied from the opening 20a of the flow passage 20 and the piston 12 is slid upward against the reaction force of the return spring 15, the clamp 2 on which the reaction force of the spring 10 is acting The work clamp part 1 of the clamp 2 is
moves downward, and the workpiece 7 is tightened and fixed.

At this time, even if the surface of the workpiece 7 to be tightened and fixed is not flat and the clamp 2 is inclined, the amount of the inclination (for example, the angle of inclination α in FIG. 3) will be Spherical seat 1 of piston 12
7 and the spherical portion 19a of the spacer 19, it is absorbed by the spherical fit.

In addition, when releasing the clamping fixation of the workpiece 7, first, operate the directional control valve etc. to release the flow path 2.
0 opening 20b to a hydraulic tank or the like, and the piston 12 is lowered by the reaction force of the return spring 15 to a position where the stopper 18 fitted to the piston 12 abuts the upper surface of the device body 11.

Thereby, the clamping fixation of the workpiece 7 can be released.

Therefore, according to the above-mentioned configuration, by providing a plurality of clamps 2 and allowing each to be operated by the hydraulic cylinder 13, it becomes possible to tighten and fix a plurality of works 7 at once.

In addition, when adjusting the tightening height due to a difference in the shape of the workpiece 7, the spherical seat 1 of the piston 12
7 and the spherical portion 19a of the spacer 19 as a sliding fulcrum, for example, by tightening the spherical nut 8, the height position of the work clamp portion 1 of the clamp 2 can be adjusted. Since only one adjustment location is required, the adjustment work can be made extremely easy.

Further, as described above, even if the clamp 2 is tilted due to the tightening and fixing of the workpiece 7, the tilt is compensated by the spherical nut 8, the spherical washer 9, and the spherical washer 1 of the piston 12.
7 and the spherical portion 19a of the spacer 19, the piston 12 and the spacer 1
Since the workpiece 7 is not in a point contact state but in a line contact state, the workpiece 7 can be firmly tightened and fixed. At this time, the spherical nut 8 and the washer 9 form a spherical seat, and the spacer 19 and the piston 12
Since a spherical fitting portion is formed in the clamp to absorb the inclination, it is possible to use the conventional clamp 2 for the clamp 2 to improve tightening defects caused by the inclination of the clamp. Moreover, without forming a spherical part on the clamp 2,
Since spherical parts are formed on the spherical nut 8, washer 9, piston 12, and spacer 19, the clamp 2 can be replaced when parts need to be replaced due to wear or the like.
Because only the necessary parts can be replaced without having to replace the Repairability can be improved.

Furthermore, since the stopper 18 is screwed onto the piston 12 to restrict the downward position of the piston 12, the height of the workpiece clamp section 1 can be adjusted and fixed after the adjustment by the stopper 18. The versatility of the system can be improved.

<Effects of the Invention> As explained above, according to the present invention, by providing a plurality of clamps and allowing each to be operated by an actuator, it becomes possible to tighten and fix a plurality of workpieces at once.

In addition, when adjusting the tightening height due to differences in the shape of the workpiece, the height of the workpiece clamping part of the fastener can be adjusted by using the spherical fitting part of the spacer and the piston as a swinging fulcrum, and using the spherical nut and stud bolt. Since the position can be adjusted and only one adjustment location is required, the adjustment work can be made extremely easy.

Furthermore, even if the clamp is tilted due to tightening and fixing the workpiece, the tilt is absorbed by the spherical fitting part between the spherical nut and washer and the spherical fitting part between the piston and the spacer, so the workpiece can be tightened and fixed. In addition to being robust, it also makes it easier to replace parts, improve repairability, and improve the versatility of the device, which has great practical effects.

[Brief explanation of the drawing]

Figure 1 is a front view showing one embodiment of the present invention;
1, FIG. 3 is a side view of FIG. 1, FIG. 4 is a diagram showing a conventional work clamp device, and FIG. 5 is a side view of FIG. 4. 2... Clamp, 2a... Lower surface of the other end, 6... Stud bolt, 8... Spherical nut, 9... Spherical washer, 10... Spring, 11... Device main body, 1
2...Piston, 13...Hydraulic cylinder, 17
... Spherical seat, 19 ... Spacer, 19a ... Spherical part.

Claims (1)

[Scope of Claim for Utility Model Registration] In a work clamping device in which a workpiece is clamped and fixed by a workpiece clamp portion formed at one end of the clamp, a stud bolt erected on the device body is connected to a middle portion of the clamp. A spherical nut having a spherical seat is screwed onto the stud bolt, and a washer having a spherical seat that fits into the spherical seat of the spherical nut is interposed between the clamp and the spherical nut. A spring for biasing the metal toward the spherical nut is provided, and a clamping actuator having a piston that abuts the lower surface of the other end of the clamping member via a spacer is provided in the apparatus main body, and the spacer and the piston A spherical fitting part is formed at the contact part with the
A work clamping device characterized in that a stopper for regulating a lowering position that comes into contact with a main body of the device is screwed onto the piston.