JPH0450987Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a clamp device for fixing a press mold etc. that is attached to the bed of a press machine.

[Conventional technology]

In a press machine, when fixing a lower die of a press mold or a lower frame of a die set on the bed of the press machine, a clamping device is known which has a mechanism in which the lower die of the press mold or the lower frame of the die set is fixed by a clamp claw operated by a hydraulic cylinder.

This known clamp device uses a hydraulic cylinder to drive a clamp pawl that swings about a horizontal axis, and the clamp pawl cannot be moved back and forth. Therefore, the tip of the clamp claw always protrudes from the front end of the main body of the clamp device.

Therefore, with the clamp claws loosened, the lower ridge of the mold or die set is inserted between the substrate and the lower part of the clamp claws, and then the hydraulic cylinder is activated to press the tip of the clamp claws against the ridge. is necessary, and when removing it, the operation is the opposite.

However, when attaching a mold or die set by automatic operation such as a robot, it is extremely difficult, although not impossible, to insert the protrusion of the mold into the narrow gap between the substrate and the clamp claw. High precision control is required.

As a clamping device that solves these problems, the clamping claw is moved forward and backward by the drive of a hydraulic cylinder, as in the devices described in Utility Model Application No. 57-160838 and Utility Model Publication No. 59-200. There is.

In the case of a hydraulic clamping device in which the clamp claws move back and forth as shown above, the clamp claws are initially retracted and are pushed out to the fixed position during clamping, so when placing a mold etc. on the board, the clamp claws are retracted. It has the advantage of not getting in the way.

However, in both of the above-mentioned clamping devices, since the hydraulic cylinder is installed in series behind the main body of the clamping device, the total length of the device increases in the clamping direction. A disadvantage is that the hydraulic cylinder protrudes from the edge of the board.

In addition, in the former clamping device mentioned above, after the clamping claw hits the mold and stops, the clamping action is performed while rubbing the side of the mold, so a large resistance is generated at the contact area between the clamping claw and the mold, causing the problem of prying. This has the disadvantage of causing scratches on the mold surface.

On the other hand, in the latter type of clamping device, the clamp claw is moved to a fixed position by a rack and pinion driven by a hydraulic cylinder, so parts such as a pinion rack mechanism and a support must be installed inside the device, resulting in a complicated structure. There is. Further, since the clamp claw is supported by a rotationally supported column and a pin, there is also a drawback that it is difficult to obtain sufficient strength against a large clamping force.

Therefore, the object of this invention is to provide a hydraulic clamping device that can reduce the installation space, has a simple structure, can move the clamping claw to a fixed position, and has the strength to withstand a large clamping force.

[Means for solving problems]

In order to solve the above problems, this idea
A guide hole is provided in the main body that is fixed on the substrate, into which the clamp claw fits so that it can move linearly in the front and back direction and swing up and down, and a swing fulcrum for the clamp claw is provided between the upper surface of the guide hole and the clamp claw. Additionally, a first spring that pulls back the clamp claw and a second spring that pushes up the front part of the clamp claw are provided between the clamp claw and the main body, and a spring that is perpendicular to the moving direction of the clamp claw is provided on the side of the main body. A hydraulic cylinder is provided with a piston rod whose tip moves forward and backward in the direction of the guide hole, and a groove into which the tip of the piston rod enters is provided on the lower surface rearward from the swing fulcrum of the clamp claw, and a clamp facing this groove. A first slope is formed on the side surface of the pawl facing the piston rod, and the first slope is in contact with the piston rod to generate a force that moves the clamp pawl forward, and the tip of the piston rod is provided with a second slope that slopes upward from the tip to the rear end. form,
A spherical recess is provided in the lower surface of the groove of the clamp claw, and a swinging member having a spherical surface that fits the spherical recess and an inclined surface that fits the second slope is connected to the spherical recess and the second slope. The structure is such that when the tip of the piston rod passes through the first slope and moves forward, the second slope comes into contact with the swinging member.

[Effect]

In the above configuration, when the piston rod is retracted from the guide hole, the clamp claw is in the first position.
It is in a state where it is pulled back by the action of a spring.

In this state, when the piston rod is moved forward into the guide hole by driving the hydraulic cylinder, the tip of the piston rod pushes the first slope and moves the clamp claw forward.

When the tip of the piston rod passes through the first slope and moves forward, the clamp pawl is pressed against the piston rod and positioned by the bias of the first spring, and the second slope of the rod moves the clamp pawl through the swinging member. Push up. Therefore, the clamp claw rotates around the pivot point, and the front part descends to press the mold onto the substrate.

In the above case, as the clamp pawl rotates, the inclination between the bottom surface of the groove of the clamp pawl and the second slope of the piston rod changes. Since the state of contact between the inclined surface of the swinging member and the second inclined surface is maintained constant, the pushing up force of the piston rod is stably transmitted to the clamp claw.

[Embodiment] In the figure, reference numeral 1 denotes a substrate such as the bed of a press machine, and a main body 2 is fixed onto this substrate 1 by means such as bolting. This main body 2 is provided with a guide hole 3 that longitudinally traverses the main body in the front-rear direction.

The guide hole 3 is a square hole as shown in FIG. 4, and a clamp claw 5 having a square cross section is movably fitted into the hole 3. Reference numeral 6 denotes a fulcrum member, which is in the shape of a broken sphere, the flat part of which comes into slidable contact with the upper surface of the guide hole 3, and the spherical part of which is a spherical recess provided on the upper surface of the front side of the clamp claw 5. It's coming to 7.

Also, the clamp claw 5 slightly in front of the spherical recess 7
A pair of left and right recessed holes 8 having a predetermined depth are formed in the lower surface of the holder, and a ball 10 pushed down by a spring 9 is fitted into both recessed holes 8 as shown in FIG. This ball 10 is pressed against the bottom surface of the guide hole 3, and its reaction force pushes up the front part of the clamp claw 5.

Reference numeral 12 denotes a receiving plate fixed to the lower front portion of the main body 2, and its upper edge projects toward the lower portion of the front opening of the guide hole 3. Further, as shown in FIG. 3, a tubular slider 16 pushed forward by a spring 15 is fitted in a recessed hole 14 formed rearward from the front end of the lower part of the clamp claw 5. 16
By crimping the front end of the front receiving plate 12,
The reaction force pushes the clamp claw 5 backward.

18 is a hydraulic cylinder, as shown in FIG.
It is fixed to the side of the main body 2 near the rear. This hydraulic cylinder 18 has a piston 19 that moves back and forth in a direction perpendicular to the direction of movement of the clamp claw 5,
A piston rod 20 integrated in the front part is
It fits into the main body 2 from the front part of the cylinder while maintaining oil tightness.

In addition, as shown in FIG.
2 and 23 are communicated with the hydraulic unit via a switching valve.

On the other hand, a groove 13 through which the piston rod 20 is inserted laterally is formed on the lower surface of the clamp claw 5 on the rear side of the fulcrum member 6, and one side of the tip of the piston rod 20 is formed on the side surface of the groove 13 facing the piston rod 20. A first slope 25 is formed to abut. This first slope 25 is inclined in the front-rear direction as shown in FIG.
When pressed, the clamp claw 5 is guided forward.

A spherical recess 26 is provided on the lower surface of the groove 13, and a semispherical swinging member 27 is fitted into the spherical recess 26 so as to be swingable. Here, 28 is a retaining screw screwed into the swinging member 27, and this screw 28 is loosely fitted into a vertical hole provided at the bottom of the recess 26.
While allowing the swinging member 27 to move slightly, the swinging member 27 is prevented from coming off the recess 26.

In addition, the top surface of the tip of the piston rod 20 is
As shown in FIG. 4, there is a second slope 30 that slopes forward and downward, and the lower surface of the swinging member 27 is formed as an inclined surface that conforms to the second slope 30.

Note that the rear end opening of the guide hole 3 of the main body 2 is closed by screwing a cover plate 31.

In the above embodiment, FIG.
This shows the retraction status of the piston 19.
moves backward, and the tip of the piston rod 20 touches the receiving member 2.
7, the front part of the clamp claw 5 is raised by the action of the spring 9, and its tip almost coincides with the front end of the main body 2. Therefore, the protruding edge 32 of a press mold or the like can be placed on the substrate 1 without being hindered by the clamp claws 5.

Next, when the switching valve of the hydraulic cylinder 18 is operated to move the piston 19 forward, the rod 20 integrated with the piston 19 moves forward, and one side of its tip pushes the first slope 25 of the clamp claw 5, causing the clamp claw 5 to move forward. It is moved forward against the spring 15, and its front part is projected onto the projecting edge 32.

When the tip of the rod 20 passes through the first slope 25, the clamp claw 5 stops moving forward, and the elasticity of the spring 15 pushes the rear end of the lower surface against the rod 20, thereby positioning it at the clamp position.

Further, at the same time as the positioning, the second slope 30 at the tip of the rod 20 pushes up the swinging member 27, so the clamp claw 5 rotates about the fulcrum member 6 while compressing the spring 9, and the front end of the clamp claw 5 rotates while compressing the spring 9. As shown in the figure, it is crimped onto the protrusion 32 and pressed onto the substrate 1.

When the clamp pawl 5 rotates in this manner, the slope of the lower surface of the groove 13 of the clamp pawl 5 changes moment by moment with respect to the second slope 30 of the piston rod 20 that moves linearly in the lateral direction. 27 swings in the spherical recess 26, the swinging member 2
7 and the second slope 30 are maintained in contact with each other. For this reason, no prying or the like occurs between the piston rod 20 and the swinging member 27, and the upward force from the piston rod is stably transmitted to the clamp claw 5.

On the other hand, when the hydraulic circuit is switched from the clamped state shown in FIG. 3 to move the piston 19 backward, the piston rod 20 also moves back.
Since it is sliding in contact with the rear end, the clamp claw 5
does not retreat.

However, since the second slope 30 at the tip of the piston rod 20 slides on the lower surface of the swinging member 27 and retreats, the front portion of the clamp pawl 5 rises due to the action of the spring 9 and separates from the flange 32.

In this way, the tip end side of the piston rod 20 engages with the first slope 25, and when it retreats further, the rod 20 retreats along the first slope 25, so the clamp pawl 5 is moved backward by the spring 15, and the rod 20 is moved backward by the spring 15.
When the clamp is completely retracted, the clamp claw is also completely retracted, resulting in the state shown in FIG.

In the above embodiment, the fulcrum member 6 in the form of a broken sphere is used as the fulcrum of the clamp claw 5, but any other means can be used instead, such as using a horizontal shaft and a long hole.

〔effect〕

As mentioned above, in this invention, the driving direction of the hydraulic cylinder is perpendicular to the moving direction of the clamp claw, so the overall length is shorter than that of a cylinder installed at the rear of the main body, and it is suitable for presses, etc. When installed near the end of the table, there is an effect that the cylinder does not protrude from the end of the table.

In addition, the clamp claw is provided with a groove through which the piston rod passes and a first slope that the rod contacts, and the piston rod is provided with a second slope that pushes up the clamp claw, so that by moving the piston rod forward, the clamp claw moves forward. The positioning and rotation movements can be performed continuously, and the movement of the clamp claw to the tightening position and the tightening operation can be performed reliably with an extremely simple structure.

Furthermore, by providing a swinging member between the second slope of the piston rod and the lower surface of the groove of the clamp claw,
The swinging member can absorb changes in the inclination between the second slope and the bottom surface of the groove due to rotation of the clamp claw,
The pushing up force of the piston rod can be stably transmitted to the clamp claw. Therefore, there is an advantage that a large clamping force can be transmitted reliably and a structure with high strength can be realized.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the clamping device of this invention, Fig. 2 is a partially cutaway front view of the same as above, Fig. 3 is a longitudinal sectional side view taken along line A-A in Fig. 1, and Fig. 4 is FIG. 3 is a longitudinal cross-sectional rear view taken along the line B--B, and FIG. 5 is a longitudinal cross-sectional side view when the clamp claw is retracted. 1... Board, 2... Main body, 3... Guide hole, 5
... Clamp claw, 9 ... Spring, 13 ... Groove, 15
... Spring, 18 ... Hydraulic cylinder, 19 ... Piston, 20 ... Piston rod, 25 ... First slope, 27 ... Swinging member, 30 ... Second slope.

Claims (1)

[Scope of utility model registration request] A guide hole is provided in the main body that is fixed on the substrate, into which the clamp claw fits so that it can move linearly in the front and back direction and swing up and down, and a swing fulcrum for the clamp claw is provided between the upper surface of the guide hole and the clamp claw. Additionally, a first spring that pulls back the clamp claw and a second spring that pushes up the front part of the clamp claw are provided between the clamp claw and the main body, and a spring that is perpendicular to the moving direction of the clamp claw is provided on the side of the main body. A hydraulic cylinder is provided with a piston rod whose tip moves forward and backward in the direction of the guide hole, and a groove into which the tip of the piston rod enters is provided on the lower surface rearward from the swing fulcrum of the clamp claw, and a clamp facing this groove. A first slope is formed on the side surface of the pawl facing the piston rod, and the first slope is in contact with the piston rod to generate a force that moves the clamp pawl forward, and the tip of the piston rod is provided with a second slope that slopes upward from the tip to the rear end. form,
A spherical recess is provided in the lower surface of the groove of the clamp claw, and a swinging member having a spherical surface that fits the spherical recess and an inclined surface that fits the second slope is connected to the spherical recess and the second slope. 1. A hydraulic clamping device, characterized in that the swinging member is interposed between the piston rod and the second slope and the swinging member comes into contact with the second slope when the tip of the piston rod passes through the first slope and moves forward.