JPH0226584Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention provides a clamp configured to switch the clamp claw between a forward position for clamping and a backward position for evacuation, when the clamp claw is in the forward position or the backward position. In some cases, for devices equipped with a function to detect this, to prevent erroneous control from occurring when controlling other devices based on the detection signal,
This technology allows the overall length of the clamp to be shortened and allows for easy adjustment of the detection position.

[Conventional technology]

The present invention has a prerequisite structure as shown in FIGS. 1 and 2 or 3 and 4, in which a clamp body 1 is provided with a clamp claw 4, and at least the action point 4c of the clamp claw 4 is used for clamping. A limit switch 7 for detecting the forward movement of the clamp claw 4 and a limit switch 8 for detecting the backward movement of the clamp claw 4 are fixed to the rear part of the clamp body 1, and both limit switches 7, 8 are provided so as to be movable back and forth between the forward position C and the backward position B for evacuation. This relates to a device configured to be interlocked with the clamp claw 4 via a switch operation interlocking device 9.

Conventionally, in this prerequisite structure, there is a structure configured as shown in FIG. 3 and FIG. −187422).

That is, the switch operation interlocking device 9 includes one detection rod 88, and at the rear of this detection rod 88, from the front to the rear, there are a backward detection switch operation part 89, a switch release groove 90, and a forward movement detection switch. The operation section 91 is formed in order. The switch opening groove 90 is formed to be short. The limit switch 8 for backward detection is placed on the front side, and the limit switch 7 for forward movement detection is placed on the rear side.

5 and 6 were proposed by the present inventor prior to the present invention, and each shows an improved example of the above-mentioned conventional example.

Improved example 1 in FIG. 5 has the structure of the conventional example,
The switch opening groove 90 is formed long.

Further, in the improvement example 2 shown in FIG. 6, in the improvement example 1 described above, after each switch operation part 89, 91 is adjusted forward or backward by screw fitting, the lock nut 9 is adjusted.
It is designed to lock at 2.93.

[Problem that the invention attempts to solve]

First, the above conventional example has the following problem.

(a) The solid line diagram in FIG. 4 shows a state in which the clamp claw 4 is in the retracted position B, and the retracting detection limit switch 8 is turned on. Further, the dash-dot line diagram shows a state in which the clamp claw 4 is in the forward position C, and the forward movement detection limit switch 7 is turned on.

During the transition period when the clamp claw 4 switches between the retreat position B and the forward position C, both limit switches 7 and 8 are turned on at the same time because the switch release groove 90 is short. Then, the forward position detection signal and the backward position detection signal are transmitted simultaneously. For this reason, when controlling other equipment such as a press machine based on both of the above-mentioned signals, both of the signals or both of the equipment controlled by these signals may interfere with each other, causing erroneous control.

Next, the above-mentioned improved example 1 shown in FIG. 5 will be explained. Since the switch release groove 90 is long, both limit switches 7 and 8 are turned off simultaneously during the transition period of switching movement, so both the signals or both limit switches 7 and 8 are turned off at the same time. It is excellent in that it eliminates interference between devices and eliminates erroneous control. However, the following problem arises.

(b) Due to the lengthening of the switch release groove 90,
The forward movement detection switch operating portion 91 is shifted rearward and protrudes significantly rearward.

Therefore, the overall length of the clamp becomes longer. Moreover, since the length occupied by the clamp on the fixed base P becomes longer, the maximum dimension of the fixed object D such as a mold or a workpiece that can be fixed on the fixed base P becomes smaller.

On the other hand, the above-mentioned improved example 2 shown in FIG. 6 is excellent in that the positions at which the limit switches 7 and 8 are operated can be adjusted arbitrarily, but there are the following problems.

(c) The backward detection switch operation part 89 and its lock nut 92 are located deep inside the vehicle, making it difficult for the fingers to reach them when adjusting them by inserting the fingers from behind, making the adjustment difficult and time-consuming. Yes, there is a large error in the accuracy of adjustment.

The present invention solves the above problems (a) to (c), eliminates erroneous control caused by simultaneous transmission of both signals, shortens the overall length of the clamp, and easily adjusts the operating position of the limit switch with high precision. The purpose is to be able to adjust the

[Means for solving problems]

In order to achieve the above object, the present invention has been developed, for example, as shown in FIG. 1 and FIG. The forward movement detection rod 47 is supported by the clamp body 1 so as to be movable back and forth within the range of a predetermined dimension E, and is pressed toward the backward side by a backward movement spring 52. 53, the forward operating section 54 of the clamp claw 4 is placed so as to be able to engage and drive from the rear side with a distance F for free running, and the switch operating section 58 at the rear end of the forward detecting rod 47 is connected to the forward operating limit switch 7. The retraction detection rod 48 is opposed to the contactor 7a from behind so that it can be approached and separated from the rear, and the retraction detection rod 48 is supported by the clamp body 1 so as to be movable back and forth within a predetermined dimension e, and is pressed forward by the forward movement spring 61 to detect retraction. The retraction operation section 63 of the clamp claw 4 is opposed to the retraction input section 62 at the tip of the retraction detection rod 48 so that it can be engaged and driven from the front with a distance f for idle running, and the switch at the rear end of the retraction detection rod 48 is operated. Section 64
It is characterized in that it is opposed to the contact 8a of the limit switch 8 for backward detection so as to be able to approach and separate from the front.

[Effect]

The invention works as follows.

In FIGS. 1 and 2, the solid line diagram shows a state in which the clamp claw 4 is in the forward position C, and only the forward movement detection limit switch 7 is turned on. The dash-dotted line diagram shows a state in which the clamp claw 4 is in the retracted position B, and only the retracting detection limit switch 8 is turned on.

The clamp claw 4 is operated backward from the forward position C shown in the solid line to the backward position B shown in the dashed-dotted line.

Then, at the initial stage X of the retreat, the forward operation section 5
4, the forward movement detection rod 47 is moved backward by the movement spring 52, and the forward movement detection switch operating section 58 opens the contactor 7a to turn off the forward movement detection limit switch 7.

Furthermore, in the middle stage of backward movement Y, the forward operation section 54 moves away from the forward motion input section 53, leaving behind the forward motion detection rod 47 and the forward motion detection switch operation section 58, so that the forward motion detection limit switch 7 is turned off. It remains as it is. At this time, since the backward operation section 63 has not yet come into contact with the reverse input section 62, the backward detection rod 48 and the backward detection switch operation section 64 are moved forward by the forward spring 61, and the backward detection limit switch is activated. 8 remains off.

Then, at the end of the backward movement Z, the backward operation section 63 starts pushing the backward input section 62 and moves the backward detection rod 48 backward against the forward movement spring 61. contact 8
Push in a to turn on the backward detection limit switch 8.

As described above, at the initial stage X of the retraction of the clamp claw 4, only the forward position detection signal is transmitted, at the middle stage Y, both the forward position detection signal and the rearward position detection signal are stopped, and at the final stage Z, the rearward position detection signal is transmitted. will be sent only.

Conversely, when the clamp claw 4 is moved forward from the retreat position B to the advance position C, the process is reverse to that described above. That is, at the beginning of forward movement, only the backward position detection signal is transmitted, at the middle stage both signals are stopped, and at the end stage, only the forward position detection signal is transmitted.

Therefore, when the clamp claw 4 is switched between the forward position C and the backward position B in either the backward or forward direction, the forward detection limit switch 7 and the backward detection limit switch 8 can be turned on at the same time. It disappears.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view taken along the - line in FIG. 2, and FIG. 2 is a vertical side view of the hydraulic clamp.

In the figure, P is a fixed stand for a mold such as an injection molding machine.
A mold D placed on this fixed base P is pressed and fixed by a hydraulic clamp.

1 is a clamp body of a hydraulic clamp, 2 is a bottom plate thereof, and a transmission chamber 3 is formed in the clamp body 1 in the shape of a front opening. Front side of transmission chamber 3 (left side in the diagram)
A clamp pawl 4 is inserted into the transmission chamber 3 so as to be movable back and forth and swingable up and down, and a hydraulic cylinder 5 for driving the clamp pawl 4 is provided at the rear of the transmission chamber 3. A limit switch storage box 6 is provided on the rear side (right side in the figure) of the clamp body 1, and a limit switch 7 for detecting the forward movement of the clamp claw 4 and a limit switch 8 for detecting the backward movement of the clamp claw 4 are provided within the storage box 6. Both limit switches 7 and 8 are interlocked with the clamp claw 4 via a switch operation interlocking device 9.

First, the clamp claw 4 will be explained.

The clamp pawl 4 is inserted into the transmission chamber 3 so as to be movable in the front-rear direction, and a stopper 11 is provided at the intermediate portion of the clamp body 1 in the front-rear direction to restrict forward movement beyond a predetermined amount. This stopper 11 receives a locking shaft 12 that is inserted laterally into the rear part of the clamp claw 4.

Further, a fulcrum part 4a is provided on the rear lower surface of the clamp claw 4, and the clamp claw 4 is centered around this fulcrum part 4a.
is vertically swingable on the bottom plate 2. On the other hand, a force point part 4b is formed on the front upper surface of the clamp claw 4, and an action point part 4c is formed at the swing end of the front lower surface. A scraper 13, which is pressed toward the bottom plate 2 by a return spring 14, is inserted into the lower swing end of the clamp claw 4 so as to be vertically slidable.

A wedge-shaped space 16 is formed between the force point portion 4b of the clamp pawl 4 and the upper surface of the transmission chamber 3, and the wedge-shaped space 16 tapers toward the front. inserted from. This tightening wedge 17
is operatively connected to the hydraulic cylinder 5 described above.
Note that a scraper 18 made of a spring is in contact with the upper surface side of the clamp claw 4.

Next, the hydraulic cylinder 5 will be explained.

A cylinder chamber 5a extending in the front-rear direction is formed at the upper rear side of the clamp body 1, and this cylinder chamber 5a
The piston 21 is slidably inserted in an oil-tight manner. A clamp drive oil chamber 22 is formed on the rear side of the piston 21, and an unclamp drive oil chamber 23 is formed on the front side of the piston 21. Oil supply and drainage ports 27 and 28 are opened in these driving oil chambers 22 and 23, respectively.

An oil chamber cover 24 is screwed to the right open end of the clamp driving oil chamber 22 via an O-ring 25 in an oil-tight manner. On the other hand, a cylindrical piston rod 26 projects forward from the left side of the piston 21 and is slidably inserted into the clamp body 1 in an oil-tight manner.

The tightening wedge 17 is integrally formed on the upper front part of the piston rod 26. Further, a clamp state retaining spring 29 is installed in the clamp driving oil chamber 22 so as to extend between the bottom wall of the cylindrical hole 26a of the piston rod 26 and the oil chamber cover 24. The clamping wedge 17 is always pressed forward by the clamping state retaining spring 29.

Further, an engaging portion 31 is provided across the piston rod 26 and the clamp pawl 4 to retract the clamp pawl 4 after the tightening wedge 17 is retracted by a predetermined distance, and a pawl extrusion portion 31 is provided to press the clamp pawl 4 forward. A spring 32 is provided.

That is, an engagement hole 34 extending in the front-back direction is formed in the upper part of the clamp claw 4, and a stepped portion 35 is provided by reducing the diameter of the rear part of the engagement hole 34. Engagement hole 34
A bolt-shaped engagement rod 36 is inserted therein. The legs of this engaging rod 36 are screwed and fixed to the front part of the piston rod 26, and the head 3 of the engaging rod 36
6a connects to the stepped portion 3 of the engagement hole 34 via the engagement piece 37.
It is said that it is possible to make contact with 5. The above-mentioned engaging portion 3 is
1 is configured.

The clamp claw 4 and the engagement rod 36 are connected in the engagement hole 34.
A claw extrusion spring 32 made of a compression coil spring is mounted over the entire length. That is, the disc-shaped spring base end support part 38 is inserted between the base end 32a of the claw push spring 32 and the head 36a of the engagement rod 36, while the tip end 32b of the claw push spring 32 is engaged. It is received by a spring tip support part 39 screwed to the front part of the hole 34.

As a result, when the piston rod 26 moves forward, the engagement rod 36 moves the spring base end support part 38 forward together, and this spring base end support part 38 presses the pawl extrusion spring 32, and this pressing force causes the spring base end support part 38 to press forward. Clamp 4 is advanced. When the piston rod 26 is further advanced, the clamp pawl 4 is received by the stopper 11 via the locking shaft 12, while the engaging rod 3
6 compresses the claw pushing spring 32 via the spring base end support 38, the tightening wedge 17 is allowed to move forward, the clamp claw 4 is pushed down (as shown by the two-dot chain line), and the advancing clamp State A is obtained. When moving the piston rod 26 backward from the above state, the clamping wedge 17 is moved back while pressing the clamp claw 4 forward by the elastic force of the claw pushing spring 32, and the force point 4b of the clamp claw 4 is released. , the clamp claw 4 is returned upward and swung by the elastic force of the return spring 14 (as shown by the solid line). As a result, an advanced unclamping state C is obtained in which the action point 4c of the clamp claw 4 moves to the forward clamping position. When the piston rod 26 further retreats, the head 36a of the engagement rod 36 comes into contact with the stepped portion 35 via the engagement piece 37, causing the clamp claw 4 to retreat, and the action point 4
c is retracted into the front surface of the transmission chamber 3 (as shown by the dashed line), and as a result, the action point 4c of the clamp pawl 4
An unclamped retracted state B is obtained in which the unclamped member is moved to the retracted position for evacuation.

Also, to explain the clamp state retaining spring 29, this is installed in the clamp drive oil chamber 22 via a telescopic rod 41, and when the clamp claw 4 is set to the advanced clamp state A, the clamp state retaining spring 29 is used for tightening. The wedge 17 is pressed forward and the clamp drive oil chamber 22
This is to maintain the wedge engagement and keep the clamp claw 4 in the clamped state even if the oil pressure inside the clamp decreases due to oil leakage or the like.

The above-mentioned telescopic rod 41 has a cylindrical spring seat 42.
It is composed of a sliding shaft 43 slidably inserted into the spring seat 42, and a spring seat 44 screwed to the front part of the sliding shaft 43. Both ends 29a and 29b of the clamp state retaining spring 29 are mounted between the spring seats 42 and 44 in a compressed state. The front spring seat 44 is received by a spring receiving surface 21a formed on the bottom wall of the piston rod 26, and the rear spring seat 42 is received by a spring receiving surface 24a formed on the bottom wall of the oil chamber cover 24. It is being
When the piston 21 is most advanced toward the clamp side, the total length of the telescopic rod 41 at maximum extension is set to be slightly longer than the maximum distance between the spring bearing surfaces 21a and 24a. ing.

The interlocking device 9 for operating the limit switches 7, 8 for detecting the forward and backward movement of the clamp 4 will be explained mainly with reference to FIG. It is equipped with both detection rods 47 and 48.
are placed side by side at approximately the same height.

The forward movement detection rod 47 is supported in a support hole 49 of a support plate 46 fixed to the rear part of the clamp body 1 so as to be movable back and forth within a predetermined dimension E, and is urged backward by a backward spring 52. Ru. On the other hand, a forward operation section 54, which is L-shaped when viewed from the bottom, is screwed to the rear part of the clamp claw 4 with set bolts 55, 55. The leg portion of the locking bolt 55 is inserted into the circumferential groove 12a of the locking shaft 12, and movement of the locking shaft 12 in the axial direction is restricted.

In the position where the clamp claw 4 is retracted to the unclamp retracted state B (indicated by the dashed line in the figure),
Forward movement input section 53 at the tip of the forward movement detection rod 47
On the rear surface, the front wall of the forward operation section 54 is located at the free running distance F.
They are opposed to each other so that they can be engaged with each other. Further, a switch operation part 58 is screwed to the rear end of the forward movement detection rod 47 so as to be adjustable in forward and backward directions, and this switch operation part 58 faces the contact 7a of the forward movement detection limit switch 7 so as to be able to approach and separate from the rear. Note that the switch operation section 58 is locked with a lock bolt 59.

Then, when the hydraulic cylinder 5 advances the clamp claw 4 from the unclamp retracted state B (shown by the dashed line) to the advanced unclamp state C (shown by the solid line), the forward operation section 54 moves forward via the forward input section 53. The detection rod 47 is moved forward, and the switch operating section 58 pushes in the contact 7a of the forward detection limit switch 7 to operate it.

Further, the backward detection rod 48 is supported in a support hole 50 at the rear of the clamp body 1 so as to be movable back and forth within a predetermined dimension e, and is supported by a forward movement spring 6.
At 1, the forward side is suppressed. On the other hand, a retraction operation portion 63 is formed on the rear surface of the clamp claw 4.

Then, at the position where the clamp claw 4 is advanced to the advanced unclamped state C (shown by the solid line in the figure), the backward operation section 63 opens the idle distance f to the backward input section 62 at the tip of the backward detection rod 48. and is opposed to the engagement driving force from the front side. Further, a switch operation part 64 is screwed to the rear end of the backward detection rod 48 so as to be adjustable forward and backward, and this switch operation part 64 faces the contact 8a of the backward detection limit switch 8 so as to be able to move toward and away from the front side. . In addition, the switch operation section 6
4 is locked with a lock bolt 65.

Then, when the hydraulic cylinder 5 moves the clamp claw 4 backward from the advanced unclamping state C (shown by the solid line) to the unclamping retracted state B (shown by the one-dot chain line), the backward operation section 63 moves back via the backward input section 62. The detection rod 48 is moved backward, and the switch operating section 64 pushes in the contact 8a of the backward detection limit switch 8 to operate it.

[Effect of thinking]

The present invention has the following effects because it is configured and operates as described above.

(b) When moving the clamp claw backward from the forward position to the backward position, only the forward position detection signal is transmitted at the beginning of the backward movement, both the forward position detection signal and the backward position detection signal are stopped during the middle period, and the signal is stopped at the final stage. Only the reverse position detection signal is transmitted. Conversely, when moving the clamp claw forward from the backward position to the forward position, only the backward position detection signal is sent at the beginning of the forward movement, both signals are stopped at the middle stage, and at the end of the movement, only the backward position detection signal is sent. Only the forward position detection signal is transmitted.

As described above, even when the clamp claw is switched between the forward position and the backward position in either the backward or forward direction, both limit switches are not turned on at the same time. This eliminates erroneous control due to simultaneous transmission of both signals.

(b) When the clamp claw is operated backward, the forward detection rod and the forward detection switch operation part are left behind after the forward movement detection limit switch is turned off, and then the backward movement detection switch operation part stops operating. The above-mentioned left-behind condition is maintained until. Therefore, the switch operating section for detecting forward movement does not protrude significantly rearward, and the overall length of the clamp can be shortened.

(c) When adjusting the operating position of the limit switch from the rear, the operating section of the switch for detecting backward motion is also located right in front of you, making it easier to reach the switch operating section with your fingers. Therefore, the adjustment operation becomes easy and the accuracy of the adjustment is also increased.

[Brief explanation of the drawing]

Figures 1 and 2 show one embodiment of the present invention, Figure 1 is a sectional view taken along the - line in Figure 2, Figure 2 is a longitudinal side view, and Figures 3 and 4 are conventional 3 is a vertical side view, FIG. 4 is a cross-sectional view taken along the line - in FIG. 3, and FIGS. 5 and 6 are views corresponding to FIG. . 1... Clamp body, 4... Clamp claw, 4c
... Point of action, 7... Limit switch for forward detection, 7a... Contact, 8... Limit switch for backward detection, 8a... Contact, 9... Interlocking device for switch operation, 47... Rod for forward detection ,48...
...Backward detection rod, 52...Backward spring, 53
...Forward input section, 54...Forward operation section, 58...
...Switch operation unit, 61...Forward spring, 62...
...Reverse input section, 63...Reverse operation section, 64...
Switch operation part, B... Unclamp retracted state (retracted position for evacuation), C... Advance unclamped state (advanced position for clamping), E, e... Predetermined dimensions,
F, f...distance for free running.

Claims (1)

[Scope of utility model registration request] The clamp body 1 is provided with a clamp pawl 4, and at least the action point 4c of the clamp pawl 4 is provided so as to be movable back and forth between the forward position C for clamping and the backward position B for evacuation.
The forward movement detection limit switch 7 and the backward movement detection limit switch 8 are fixed, and both limit switches 7 and 8 are interlocked with the clamp claw 4 via a switch operation interlocking device 9. In the clamp, the switch operation interlocking device 9 includes a forward detection rod 47 and a backward detection rod 48, and the forward detection rod 47 is supported by the clamp body 1 so as to be movable back and forth within a predetermined dimension E. The backward spring 52 presses the forward movement detection rod 4 toward the backward direction.
The forward operation section 54 of the clamp claw 4 is opposed to the forward input section 53 at the tip of the forward motion detection rod 47 so as to be able to be engaged and driven from the rear side with a distance F for free running, and the switch operation section at the rear end of the forward motion detection rod 47 58 is made to face the contact 7a of the forward detection limit switch 7 so as to be able to approach and separate from the rear, and the backward detection rod 48 is connected to the clamp body 1.
is supported so as to be movable back and forth within a predetermined dimension e, and is pressed forward by a forward spring 61, and the backward operation section 63 of the clamp claw 4 is inserted into the backward input section 62 at the tip of the backward detection rod 48. The switch operating portion 64 at the rear end of the backward detection rod 48 is opposed to the contact 8a of the backward detection limit switch 8 from the front so that it can be engaged and driven from the front with a travel distance f. A clamp with a clamp claw forward/backward detection function.