JPH0615549A - Clamp-unclamp confirmation device - Google Patents

Abstract

PURPOSE:To provide a clamp-unclamp confirmation device that is high in reliability of clamp and unclamp operation confirmation and capable of performing the automation and unmanning promotion of detaching motions of a workpiece. CONSTITUTION:When a workpiece is set on a mount 10 and brought into a state of being clamped, a plunger part 30 is pressed by a movable part 15b of a work fixing jig 15 and thereby moved to some extent, closing at least one side of an inlet 41 and an outlet 42 of both passage holes 40a and 40b. At this time, a passage for each pressure fluid in these passage holes 40a, 40b is shut off, whereby the pressure rises, and two pressure sensors 46a and 46b detect variation in this pressure. When the workpiece is not in a state of being clamped, the pressure does not rise, so whether the workpiece is surely clamped or not is thus confirmed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp / unclamp confirmation device for confirming a clamped or unclamped state of a workpiece fixed to a work fixture on a pallet.

[0002]

2. Description of the Related Art In an NC machine tool machining system called FMS or FMC, a workpiece is fixed to a work mounting jig on a pallet, and the workpiece on the pallet is conveyed by an NC machine tool. It is transported inside and processed. As a method of fixing a work piece to this work mounting jig, a method of fixing using a screw or a method of fixing using a hydraulic / pneumatic actuator is well known.

Further, in order to reduce the preparation time, the clamping and unclamping operations of the work piece of the workpiece mounting jig using a hydraulic / pneumatic actuator, a nut runner, etc. are automated. Furthermore, the workpiece is supplied by a robot,
Some of them are designed to automate and unmanner the attachment / detachment operation of the workpiece, and the technique is disclosed in Japanese Patent Laid-Open No. 61-192448.

In such an automated workpiece mounting jig, since no problem occurs during cutting, the workpiece is reliably clamped, and the workpiece transfer operation with the robot or the like is performed reliably. Therefore, it is necessary to confirm the clamp and unclamp operations.

[0005]

However, it is necessary to attach a detector such as a limit switch or a proximity switch for detecting clamp and unclamp operation to a work attaching jig provided on a pallet conveyed by a conveying device or the like. Had a problem with the wire handling to the detector. for that reason,
Japanese Unexamined Patent Publication (Kokai) No. 61-192448 discloses a technique of detecting a clamp or unclamping operation confirmation of a workpiece mounting jig on a moving body by a limit switch and transmitting a signal to a fixed body side by a non-contact signal transmitting means. Has been done.

However, if the limit switch or the non-contact signal transmission means is provided on the upper surface or the side surface of the pallet, which is not environmentally friendly, in which a large amount of chips and cutting agents are scattered, a malfunction occurs in the limit switch and the non-contact transmission means. Easy to
On the contrary, there is a possibility that reliability may be deteriorated. Also,
The number of non-contact transmission means also increases as the number of locations required to confirm the operation increases.

When an erroneous signal is output, for example,
If a signal is output in the clamped state despite the unclamped state, the work force jumps out of the workpiece mounting jig due to the cutting force during cutting, leading to damage to the work piece and the NC machine tool, and outside the NC machine tool. There was a problem such as a safety problem for workers when jumping to.

On the contrary, when the unclamp signal is output in the clamped state, the robot conveys the workpiece to the clamped workpiece mounting jig, which causes the workpiece, workpiece mounting jig, robot, etc. There was also a problem that the machining system was stopped due to a great deal of damage.

The present invention has been made by paying attention to the problems of the prior art as described above, and the reliability of confirmation of clamping and unclamping operations is high, and the attachment / detachment operation of a workpiece can be automated and unmanned. It is an object of the present invention to provide a clamp / unclamp confirmation device that can be easily performed.

[0010]

The gist of the present invention for achieving the above object is to provide a work mounting jig provided on a pallet or table for clamping a workpiece on the pallet or table. Fixed part, a movable part movably provided on the fixed part between a clamp position and an unclamp position, an airtight chamber provided on the fixed part adjacent to the movable part, and a pressure fluid to the airtight chamber. A first passage provided so as to communicate the airtight chamber with a pressure supply source for supply, a second passage provided for delivering the pressure fluid in the airtight chamber to a non-pressure supply side, Either the first passage or the second passage is slidably provided in the airtight chamber and is pressed by the movable portion when the movable portion is in a clamped state or an unclamped state. A plunger member that moves so as to block one passage opening and that moves so as to connect the first passage and the second passage when the pressing of the movable portion is released, and the plunger member provided in the first passage. And a pressure detecting means for detecting a change in the pressure value of the first passage.

[0011]

In the unclamped state before the work piece is mounted on the mounting base, the plunger portions on the clamp side of the plurality of workpiece mounting jigs have the inlet and outlet of the through hole opened in the airtight chamber.
At this time, the pressure fluid is supplied from the pressure source into the through hole through the airtight chamber, and the outlet side of the airtight chamber is opened to the atmospheric pressure. The plurality of through holes are connected in parallel, and the pressure of the through holes is constantly monitored by the pressure sensor at the position before being connected in parallel.

When the workpiece is mounted on the mounting table and is in a clamped state, the plunger portion is pushed and moved by the movable portion of the workpiece mounting jig to close at least one of the inlet and the outlet of the through hole. At this time, the passage of the pressure fluid in the through hole is blocked, the pressure rises, and the pressure sensor detects this change in pressure. If even one of the plurality of workpiece mounting jigs is not in the clamped state, the pressure does not rise, and it is possible to confirm from the detection result whether or not the workpiece is securely clamped.

The unclamping side can also be detected by the same method.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. In the various embodiments, the same parts are designated by the same reference numerals, and the duplicated description will be omitted.

FIG. 1 is a block diagram of a clamp and a first embodiment of the present invention.
The schematic structure of the unclamp confirmation apparatus is shown.

As shown in FIG. 1, the mounting base 10 is a pallet that can be replaced by an automatic pallet changing device. Mounting base 1
The work mounting jig 15 is provided on the mounting surface 12 above 0, and the airtight chamber 20 is formed inside the fixed portion 15a of the work mounting jig 15.
It has a projecting hole 13.

Inside the airtight chamber 20, a plunger portion 30 is provided.
Is housed. The plunger portion 30 has a protruding portion 31 that can protrude from the fixed portion 15 a of the work attaching jig 15 through the protruding hole 13, and the protruding portion 3 is formed by the spring 32.
1 projects from the surface of the fixed portion 15a and is biased in a direction to detect a clamped state or an unclamped state. The projecting portion 31 of the plunger portion 30 is the work attaching jig 15
It is pushed by the movable portion 15b of the above and moves in the airtight chamber 20.

A through hole 40 is provided inside the fixed portion 15a.
a and 40b are formed. The through holes 40a and 40b are
The airtight chamber 20 has an inlet 41 and an outlet 42. The inlet 41 is formed at a position which is closed by the side surface 33 of the plunger portion 30 when the protrusion 31 is pressed by the movable portion 15b to be in the clamp or unclamp position.

The airtight chamber 20, the plunger portion 30, and the through holes 40a and 40b are set as one set, and these three sets are provided on a plurality of workpiece mounting jigs.

It is possible to supply compressed air as a medium into the through hole 40 through the airtight chamber 20.
A pressure source 45 is connected to the pressure source 45, and the pressure source 45 is connected to the through hole 40a.
Compressed air is supplied inside. The through hole 40b is open to the atmospheric pressure side. A pressure sensor 46 is connected to the through hole 40a, and the pressure sensor 46 is adapted to detect changes in the pressure of air in the plurality of through holes 40a.

The connection joint 47 is connected by a known means such as a cylinder so that compressed air can be supplied when the pallet is positioned at a predetermined position.

Then, in a state where the protruding portion 31 of the plunger portion 30 is urged to the fixed portion 15a by the spring 32, the plunger portion opens the inlet 41 of the through hole 40, and the compressed air is supplied from the pressure source 50. Since it escapes to the outlet 42 through the airtight chamber 20, the pressure monitored by the pressure sensor 46 shows a value close to the atmospheric pressure.

When the protrusion 31 is pushed by the movable portion 15b and retracted, the plunger 30 moves with the movement of the protrusion 31 to close the inlet 41 of the through hole 40a. At this time, the compressed air supplied into the through hole 40a is shut off and its pressure rises to a value close to the pressure of the pressure source, and the pressure sensor 46 detects this pressure change. From this detection result, it is possible to confirm whether or not the clamp and unclamp operations of the workpiece mounting jig 15 are being performed reliably.

Similarly, in other work mounting jigs, the through holes 40a are arranged in parallel on the clamp side or the unclamp side.
If the operation is defective even at one place, the pressure change state is different, so that it can be confirmed by the pressure sensor 60 at one place.

FIG. 2 is a diagram showing the relationship between the work W and the work attachment jigs 15a and 15b having the detection portion of the clamp / unclamp confirmation device. Work W on the mount 10
Are fixed by a plurality of work attachment jigs 15a and 15b.

FIGS. 3 to 6 are views showing a concrete structure of a work mounting jig having a detection portion of the clamp / unclamp confirmation device.

3 and 4 show a second embodiment of the present invention. The clamp / unclamp confirmation device will be described with reference to FIGS. 3 and 4. 3 is a sectional view showing an embodiment of a work mounting jig having a detecting portion of the clamp / unclamp confirmation device, and FIG. 4 is a sectional view taken along line IV-IV of FIG.

The jig body 51 is fixed to the upper portion of the block 52. This jig body 51 has a stepped sliding contact hole 51a.
A through hole 51b is formed in a direction orthogonal to the axial direction of the stepped sliding contact hole 51a. A cover 51d is fixed to the lower part of the large diameter hole of the stepped sliding contact hole 51a of the jig body 51, and a shaft body 53 is slidably inserted in the axial direction in the stepped sliding contact hole 51a.

A piston 54 is inserted into the large-diameter hole portion of the stepped sliding contact hole 51a, and the piston 54 is fixed to the shaft body 53. A cylinder chamber 51c is formed by the large-diameter hole portion of the stepped sliding hole 51a, the piston 54, the cover 51a, etc., and the shaft body 53 is moved upward by the supply of pressure fluid.

At the position facing the cylinder chamber 51c of the large-diameter hole portion of the stepped sliding hole 51a, a disc spring 55 as a biasing member is provided.
The piston 54 and the shaft body 53 are constantly urged downward with respect to the stepped portion of the stepped sliding hole 51a.
That is, the shaft body 53 moving upward against the biasing force of the disc spring 55 due to the supply of the pressure fluid to the cylinder chamber 51a moves downward due to the biasing force of the disc spring 55 when the supply of the pressure fluid is stopped. Move to.

A pinion 53a is formed in the central portion of the shaft body 53, and the clamp member 50 is fixed to the upper portion of the pinion shaft 53 with the rotation direction thereof restricted by a key. That is, the clamp member 50 moves up and down via the shaft body 53 by the pressure supply to the cylinder chamber 51c and the disc spring 55, and the work W is pressed and fixed to the block 52 side.

At both ends of the through hole 51b, the through hole 51
The covers 61, 61 fitted and positioned in b are provided,
The rack 57 is inserted into the inner peripheral portions of the covers at both ends,
The tooth portion of the rack 57 meshes with the pinion 53a of the shaft body 53. Cylinder chambers 61a and 61b are formed between the inner peripheral portions of the covers 61 and 61 at both ends and the rack 57. The cylinder chamber 61a or the cylinder chamber 61b is formed.
When the pressurized fluid is supplied to the rack 57, the rack 57 moves back and forth in the axial direction, and the clamp member 50 rotates via the shaft body 53 meshing with the rack 57.

Further, in the jig body 51, airtight chambers 51d, 51 having an axis line in a direction parallel to the axial direction of the rack 57.
e is formed, and plungers 59a and 59b are slidably inserted in the airtight chambers 51d and 51e in the axial direction. The springs 60a, 6 are provided in the airtight chambers 51d, 51e.
0b is internally provided, and the plungers 59a and 59b are always biased toward each other.

The jig body has through holes 40a and 40c for communicating the pressure fluid supply source 45 with the airtight chambers 51d and 51e.
And through-holes 40b and 40d for communicating the atmospheric pressure side with the airtight chambers 51d and 51e are formed.
59b connects and blocks the through holes 40a and 40b and the through holes 40c and 40d.

A pin 58 is provided on the rack 57 so that the pin 58 presses one of the projecting portions of the plungers 59a and 59b as the rack 57 moves back and forth to connect the through holes. Shut off. That is, it is possible to detect whether the clamp member 50 is rotated to the clamp side or the unclamp side. The pin 62 is a member for positioning the rack 57.

Next, the operation of the clamp / unclamp confirmation device provided on the work mounting jig 15 will be described.

A pressure fluid is supplied from the pressure supply source 45 to the cylinder chambers 51c of the plurality of workpiece mounting jigs 15 to raise the clamp member 50. After rising, the pressurized fluid is supplied to the cylinder chamber 61a side, the rack 57 is moved, and the clamp member 50 is rotated to the unclamp side.

The fact that the clamp members 50 of all the workpiece mounting jigs 15 have moved to the unclamping side indicates that the pressure switch 46 communicating in parallel with the plurality of through holes 40c (FIG. 1).
Detected at. That is, it is detected that there is no obstacle on the work mounting surface.

The work W is supplied by a transfer means such as a robot. After the transfer of the work W is completed, the supply of the pressure fluid to the cylinder chamber 61a side is stopped and the pressure fluid is supplied to the cylinder chamber 61b side. The rack 57 moves in the axial direction, and the clamp member 50 rotates toward the clamp side. When the supply of the pressurized fluid to the cylinder chamber 51c is stopped, the work W is pressed and fixed by the clamp member 50 by the urging force of the spring 55. At this time, the movement of the clamp member 50 toward the clamp side is detected by the pressure switch 46 communicating with the plurality of through holes 40c.

FIG. 5 shows a third embodiment of the present invention. The third embodiment will be described with reference to FIG.

Jig body 51, piston 54, spring 55,
The shaft body 53 and the clamp member 50 are the same as those in the second embodiment shown in FIG. Since the shaft body 53 of this embodiment is restricted from moving in the rotational direction, it can slide only in the axial direction.

The jig main body 51, the clamp member 50 and the like rotate about a support shaft 72 as a fulcrum with respect to the jig base 73 by a driving body (not shown) such as a rotary reactor. This rotation detects the movement to the clamp side and the unclamp side.

A cylinder 71 is fixed to the block 70. An airtight chamber 51f is formed on the inner peripheral portion of the cylindrical body 71. A plunger 59c is inserted in the airtight chamber 51f and is constantly urged by a spring 60c.

The cylinder 71 is provided with a pressure supply source 45 and an airtight chamber 51f.
With the through hole 40e communicating with the atmospheric pressure side and the airtight chamber 51.
A through hole 40f that communicates with f is formed. That is, when the clamp member 50 or the like rotates about the support shaft 72 as a fulcrum toward the unclamp side, the protrusion of the plunger 59c is pressed and moved, and the space between the through hole 40c and the through hole 40f is cut off, whereby the unclamped state is established. Is detected.

The fourth embodiment will be described with reference to FIG.

Jig body 51, shaft body 53, clamp member 5
0, the piston 54, and the spring 55 are the same as those in the second embodiment shown in FIG. 3, and the pressure supply to the cylinder chamber 51c and the spring 55 are performed.
Causes the clamp member 50 to move up and down. In this embodiment, the airtight chamber 51g is provided on the axis of the shaft 53 of the block 52.
Is provided, and the coupling between the through hole 40g for communicating the pressure supply source and the airtight chamber 51g with the through hole 40h for communicating the atmospheric pressure side with the airtight chamber 51g is blocked by the vertical movement of the shaft body 53 to unclamp. The condition is detected.

The present invention is not limited to the above-mentioned embodiment, and utilizes the movement of the movable part that occurs when the clamping and unclamping operations of the workpiece mounting jig are used, and a through hole communicating with the pressure supply source side is provided. , And the through hole communicating with the atmospheric pressure side,
Any configuration may be used as long as it can detect a pressure change caused by coupling or blocking. In this detection, both the clamped state and the unclamped state may be detected, or either one of them may be detected.

[0048]

According to the clamp / unclamp confirmation apparatus of the present invention, the movable portion of the work mounting jig is moved to press the plunger portion in the airtight chamber so that the through holes are joined in the airtight chamber. It is a simple structure that shuts off the gap and detects the pressure change of the pressure fluid caused by it.
It is possible to reliably detect the clamped and unclamped states with high reliability.

Further, since the clamped or unclamped state can be reliably detected, the attachment / detachment operation of the work piece can be easily automated and unmanned in combination with the transfer means such as the robot, and the NC machine tool can be machined. The system can be automated and unmanned.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a clamp / unclamp confirmation device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a relationship between a work attachment jig and a work of the clamp / unclamp confirmation device.

FIG. 3 is a sectional view of a work mounting jig of a clamp / unclamp confirmation device of a second embodiment.

4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a sectional view of a work mounting jig of a clamp / unclamp confirmation device of a third embodiment.

FIG. 6 is a sectional view of a work mounting jig of a clamp / unclamp confirmation device of a fourth embodiment.

[Explanation of symbols]

10 ... Mounting base, 12 ... Mounting surface, 15 ... Work mounting jig, 20 ... Airtight chamber, 30 ... Plunger part, 40 ... Through hole,
41 ... Inlet, 42 ... Outlet, 45 ... Pressure source, 46 ... Pressure sensor, 47 ... Connection joint.

Claims (1)

[Claims] 1. A fixed part of a work mounting jig provided on a pallet or a table for clamping a workpiece on the pallet or a table, and the fixed part is movable between a clamp position and an unclamp position. A movable part provided, an airtight chamber provided in the fixed part adjacent to the movable part, and provided so as to connect the airtight chamber and a pressure supply source so as to supply a pressure fluid to the airtight chamber. A first passage; a second passage provided for delivering the pressure fluid in the airtight chamber to a non-pressure supply side; and a slidable passage in the airtight chamber, in which the movable portion is in a clamped state or an unclamped state. When the pressure is released by the movable portion, the movable portion is moved so as to block the passage opening of either the first passage or the second passage, and the pressing of the movable portion is released. A plunger member that moves so as to connect the first passage and the second passage to each other, and pressure detection means that is provided in the first passage and detects a change in the pressure value of the first passage. Clamp / unclamp confirmation device characterized in that