JP2000107966A - Work holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work holding device which can improve the reliability of transmitting of control signals, and is not necessary to reform a distributer, as well as can make the distributer in a small size. SOLUTION: In this work holding device 1, a signal wiring 26a and a power wiring 28a are collected to a single common wiring 30, and passed the center of a distributer 20, and connected to the slaves 36 and 38 at the upper side of a clamp device 2. As a result, signals are transmitted through wires, from the noncontact switches 6c, 6d, 14c, and 14d of hydraulic cylinders 6 and 14, to a PC 26. Since solenoid valves 42 and 44 are provided at the side of the clamp device 2, the flow passage number of the distributer 20 can be made in the minimum number two, so as to make the size of the turntable 18 in a necessary minimum size. Further, even when it is necessary to increase the hydraulic cylinders of the clamp device 2, only new hydraulic piping is drawn from a solenoid valve group 40, and it is unnecessary to reform the distributer 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device for clamping a work by pressing the work against a reference surface by a clamper operated by an oil-air pressure cylinder when the work is machined by the machine tool. And a turntable that rotates with respect to the workpiece.

[0002]

2. Description of the Related Art When a workpiece is machined by a machine tool, a workpiece holding device for clamping the workpiece and rotating the workpiece about a predetermined axis for machining a plurality of surfaces of the workpiece. May be used. As an example of such a workpiece holding device, there is a workpiece holding device 100 shown in FIG. The workpiece holding device 100 performs rotation indexing of the workpiece W about a vertical axis in order to clamp the workpiece W and process a plurality of surfaces of the workpiece W. The workpiece holding device 100 includes a turntable 118 installed at a predetermined position facing a machining spindle of a machine tool (not shown), and a clamp device 102 fixed on the turntable 118 and rotated integrally with the turntable 118. Have been.

In a clamping device 102, a clamping hydraulic cylinder 106 and a reference surface jig 112 are fixed to a framework (main body) 104 thereof. A clamper 110 is fixed to an upper end of a cylinder rod 108 of the hydraulic cylinder 106 for clamping. When the workpiece W is loaded into the clamp device 102 by an automatic loading / unloading device (not shown) and positioned, the hydraulic cylinder 106 for clamping is operated, and the clamper 110 is raised. As a result, the workpiece W is pressed against the lower surface (reference surface) of the reference surface jig 112, clamped and positioned.

A knock pin cylinder 114 is mounted on the reference surface jig 112, and a knock pin 116 projects downward by hydraulic pressure and fits into a positioning hole provided in a workpiece W as shown in the figure. This confirms that the workpiece W has been correctly positioned. The hydraulic pressure for operating the clamping hydraulic cylinder 106 and the knock pin cylinder 114 is supplied from a pump unit 124 via a distributor 120 and a solenoid valve group 122. Distributor 120 is fixed to turntable 118, and rotates integrally with table base 118a fixed on base 100a of the machine tool. Then, while rotating, the hydraulic pressure from the external hydraulic pipe 122a is applied to the hydraulic pipes 106a, 106b, 114 in the clamp device 102.
a, 114b.

A proximity switch for detecting the state of each cylinder is attached to the hydraulic cylinder for clamping 106 and the knock pin cylinder 114. That is, the cylinder rod 10 is
Proximity switch 106 for detecting that 8 is in the retracted position
and a proximity switch 106d for detecting that the cylinder rod 108 is at the forward position. Also,
A proximity switch 114c that detects that the knock pin 116 is at the retracted position is provided on the knock pin cylinder 114,
A proximity switch 114d for detecting that the knock pin 116 is at the forward position is provided.

[0006] These proximity switches 106c, 106
d, 114c, and 114d, signal wires 138a, 138b, 138c, and 138d for transmitting detection signal currents
It is connected to the relay box 138. Then, they are connected to signal wires 128a and 128b via a known non-contact signal transmission means 136 provided near the workpiece holding device 100. The signal wires 128a and 128b are connected to the control box 1
26 (hereinafter referred to as “PC”)
Abbreviated. ) 128. Thus, the proximity switches 106c, 106d, 114c, 11
The detection signal from 4d is input to PC128.

On the other hand, a control signal for controlling the solenoid valve group 122 is transmitted through signal lines 128c and 128d.
Output from C128. Power for operating the solenoid valve group 122 is supplied from a power supply 130 in the control box 126 via a power wiring 130a. Thus, the two hydraulic cylinders 10 of the workpiece holding device 100
6 and 114 are controlled by an external solenoid valve group 122 via a distributor 120 and four hydraulic pipings 122a to 122a.

[0008]

However, since the non-contact signal transmission means 136 is installed near the workpiece holding device 100, it is exposed to bad environments such as dust, chips, and coolant, and changes in temperature and radio waves. Noise easily occurs. Therefore, the reliability of signal transmission from the proximity switch is reduced. It is also possible to transmit a power current for operating the solenoid valve in a non-contact manner, but since the cost is extremely high, a wired type using the power wiring 130a is used. However, in the case of the wired type, if the solenoid valve group is provided on the clamp device 102, the turning operation of the turntable 118 is hindered. Therefore, the solenoid valve group which does not turn is located outside the clamp device 102, that is, in front of the distributor. It has to be provided on the side. Therefore, the solenoid valve group 1
After branching at 22, the hydraulic cylinders 106 and 114 of the clamp device 102 must be provided with the necessary number of channels in the distributor 120.
20 and, consequently, the entire workpiece holding device 100 becomes large.

Further, when the number of hydraulic cylinders is increased due to the improvement of the clamp device 102 or the like, the distributor 120 and the turntable 118 must be remodeled, resulting in a remarkable increase in running cost. Further, since the solenoid valve group 122 is mounted on the machine tool side outside the work holding device 100, the work holding device 10
Even if the assembly of No. 0 is completed, the operation of the workpiece holding device 100 cannot be confirmed until after the machine tool is completed. At this time, a defect may be discovered for the first time, and the lead time until the start of the operation of the machine tool is significantly increased.

Therefore, in the invention according to claims 1 and 2 of the present application, the reliability of transmission of control signals can be improved, the distributor can be downsized, and even if the specifications of the clamp device are changed. It is an object of the present invention to provide a workpiece holding device that does not require a rework of a turntable section and can shorten a lead time until the operation of a machine tool starts.

It is another object of the present invention to provide a work holding apparatus capable of further reducing the size of a distributor and hence the entire work holding apparatus.

[0012]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, there is provided a turntable which is rotatable at an arbitrary angular position, and is fixed on the turntable. A clamp device that rotates integrally with the turntable and presses and clamps a workpiece against a reference surface by a clamper operated by an oil-pressure cylinder; A distributor that transmits the hydraulic pressure to the hydraulic cylinder of the clamp device regardless of the rotation of the table; and an electromagnetic valve that is provided in the clamp device and that switches a flow path of the pressure oil or compressed air to the hydraulic pressure cylinder. A power line for supplying power from an external power supply for operating the solenoid valve and a power line for controlling the solenoid valve. Signal wiring for transmitting necessary control signals to and from an external control device passes through the inside of the distributor and is connected to the clamping device, and the power wiring and the signal wiring are stacked several times before the distributor. A work holding device with a wound spiral section was created. Here, the hydraulic cylinder may be a cylinder that operates with hydraulic pressure or a cylinder that operates with pneumatic pressure.

In this work holding device, the work is clamped by a clamper of a clamp device which is fixed on a turntable and rotates integrally. An electromagnetic valve that supplies pressure oil or compressed air to an oil pressure cylinder that operates the clamper is provided in the clamp device. Then, power wiring for operating the solenoid valve and signal wiring for controlling the solenoid valve pass through the distributor inside the turntable and are guided into the clamp device. These power wiring and signal wiring are wound several times before entering the distributor to form a spiral portion. Therefore, even if the turntable rotates, no twisting force is applied to the power wiring and the signal wiring, and there is no possibility of disconnection.

As described above, since the signal wiring for transmitting the control signal is connected to the clamp device through the distributor, unlike the case of the non-contact signal transmission means, it is hardly affected by the surroundings, and the signal transmission is performed. Significantly improves the reliability. Also, by connecting the power wiring to the clamp device through the distributor,
A solenoid valve can be provided on the clamping device side. Thus, the distributor may be provided with a minimum necessary flow path before branching by the solenoid valve, and the distributor and thus the workpiece holding device are reduced in size.

Further, even when the number of hydraulic cylinders of the clamping device increases, it is only necessary to add an electromagnetic valve, and there is no need to rebuild the distributor and the turntable, so that the running cost is significantly reduced. Also,
Since the solenoid valve is attached to the clamp device, the operation can be checked when the work holding device is completed, and there is no need to wait for the completion of the machine tool, so the lead time until the start of operation of the machine tool can be reduced. it can.

In this way, the signal wiring and the power wiring are passed through the clamp device via the distributor,
By providing a solenoid valve on the clamp device side, the reliability of control signal transmission can be improved, the distributor can be downsized, and there is no need to make it to the specifications of the clamp device, and the lead time until the start of operation of the machine tool Can be shortened.

According to a second aspect of the present invention, there is provided the workpiece holding apparatus according to the first aspect, wherein the distributor has only two pressure oil or compressed air flow paths. Was created.

In this work holding apparatus, there are only two flow paths of the distributor connected to the hydraulic cylinder of the clamping device, that is, one is a pressurized flow path and the other is a return flow path. As described above, the flow path of the pressure oil or the compressed air is provided only with the minimum number of flow paths, and thereafter, the branch is performed by the solenoid valve provided in the clamp device, thereby minimizing the size of the distributor and the turntable. be able to. In this manner, a work holding apparatus that can further reduce the size of the distributor and thus the entire work holding apparatus is obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. First, regarding the overall configuration of the workpiece holding device of the present embodiment,
This will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating an overall configuration of an embodiment of a workpiece holding device.

As shown in FIG. 1, the work holding apparatus 1 includes a turntable 18 rotatable with respect to a table 18a fixed on a base 1a of a machine tool, and a worktable 1 mounted on the turntable 18. Clamp device 2
It is constituted by. In the clamping device 2,
The clamping hydraulic cylinder 6 and the reference surface jig 12 are fixed to the frame (body) 4. A clamper 10 is fixed to an upper end of a cylinder rod 8 of the hydraulic cylinder 6 for clamping. When the workpiece W is loaded into the clamp device 2 and positioned by an automatic loading / unloading device (not shown),
The hydraulic cylinder for clamping 6 is operated, and the clamper 10 is raised. As a result, the workpiece W is pressed against the lower surface (reference surface) of the reference surface jig 12, and is firmly clamped and positioned.

The reference surface jig 12 has a knock pin cylinder 1
The knock pin 16 projects downward by hydraulic pressure, and fits into a positioning hole provided in the workpiece W as shown in the figure. This confirms that the workpiece W has been correctly positioned. The hydraulic pressure for operating the clamping hydraulic cylinder 6 and the knock pin cylinder 14 is supplied from an external pump unit 22 via the solenoid valve group 40 and the distributor 20.

That is, two hydraulic pipes, a pressure pipe 22a and a return pipe 22b, extend from the external pump unit 22 through the table 18a.
0 are respectively connected to the two flow paths. FIG.
In the figure, the flow path of the distributor 20 for piping other than the hydraulic piping is not shown. The distributor 20 is fixed to the turntable 18, and rotates integrally with a table base 18a fixed on the base 1a of the machine tool. Then, while rotating, the connection between the external hydraulic piping 22a, 22b and the hydraulic piping 46a, 46b connected to the upper surface of the distributor 20 can be maintained. The hydraulic pipe 46a is a pressure pipe connected to the pressure pipe 22a, and the hydraulic pipe 46b is a return pipe 2
It is a return pipe connected to 2b.

These hydraulic lines 46a and 46b are connected to a group of solenoid valves 40 provided on the upper part of the clamp device 2. In the solenoid valve group 40, the hydraulic piping 46a, 46b
Is branched and connected to each solenoid valve. Of these, solenoid valve 4
2 is connected to the knock pin cylinder 14 by hydraulic piping 14a, 14b. Hydraulic pressure is applied to the hydraulic pipe 14a when the knock pin 16 is moved forward (downward),
Oil pressure is applied to the hydraulic pipe 14b when the knock pin 16 is retracted (raised).

The solenoid valve 44 is connected to the hydraulic piping 6a, 6b
Is connected to the hydraulic cylinder 6 for clamping.
The hydraulic pressure is applied to the hydraulic pipe 6a when the clamp W clamps the workpiece W by moving the cylinder rod 8 forward (up). The cylinder rod 8 is moved backward (downward) to the hydraulic pipe 6b so that the workpiece W
Hydraulic pressure is applied when releasing the clamp.

These two hydraulic cylinders 6 and 14 have:
A proximity switch for detecting the forward / backward movement of the cylinder rod 8 or the knock pin 16 is provided. The clamping hydraulic cylinder 6 is provided with a proximity switch 6c for detecting that the cylinder rod 8 is at the retracted position and a proximity switch 6d for detecting that the cylinder rod 8 is at the advanced position. These proximity switches 6c, 6c
signal wirings 38c and 38 for transmitting a detection signal current from
d is a slave 38 installed above the clamp device 2.
It is connected to the.

The knock pin cylinder 14 is provided with a proximity switch 14c for detecting that the knock pin 16 is at the retreat position and a proximity switch 14d for detecting that the knock pin 16 is at the forward position. Signal wirings 38a and 38b for transmitting detection signal currents from the proximity switches 14c and 14d are also connected to the slave 38 provided above the clamp device 2.

The electric wiring in the workpiece holding device 1 of the present embodiment will be described in more detail. The external control box 24 is provided with a PC 26 and a power supply 28. The signal wiring 26a from the PC 26 and the power wiring 28a from the power supply 28 are combined into one common wiring (multi-core cable) 30 by known wiring saving means.

This shared wiring 30 is a bed 1a of a machine tool.
Through the inside, it passes through the center of the distributor 20 from below the turntable 18. Immediately before entering the distributor 20, a spiral portion 30a in which the shared wiring 30 is wound several times is provided. By providing the spiral portion 30a, even if the turntable 18 rotates 360 degrees clockwise or counterclockwise, no twisting force is applied to the common wiring 30, and there is no fear of disconnection or the like. This allows the turntable 1 to rotate
The power wiring and the signal wiring can be passed from the outside to the inside of the clamp device 2 also via the cable 8.

The common wiring 30 is connected to the distributor 20
From the upper part of the terminal box, it branches into two power lines 32a and 32b and one signal line 34 in a terminal box (not shown). The power wiring 32a is connected to the slave 38 described above.
, And the power wiring 32 b is connected to a slave 36 installed on the solenoid valve group 40. Also, the signal wiring 34
Are two signal wirings 34a, 34 above the clamp device 2.
The signal line 34a is connected to the slave 36, and the signal line 34b is connected to the slave 38.

The slaves 36 and 38 constitute a known wiring saving means, and realize wiring saving by converting all external connections into connectors. From these slaves 36 and 38, as many wires as necessary are provided according to the number of solenoid valves, the number of proximity switches, and the like.
The signal transmission by the shared wiring 30 is serial communication, and the signal is transmitted by sequentially sending a set of the address and the signal.

A control signal for controlling the switching of the ports of the solenoid valves 42 and 44 is transmitted to the PC 2 in the control box 24.
6, the signal wiring 26a, the common wiring 30, the signal wiring 3
4 and 34a, and is input from the slave 36 to the solenoid valve group 40. Also, ON / OF of the proximity switches 6c, 6d, 14c, 14d indicating the state of the hydraulic cylinders 6, 14
The F signal is supplied to the signal lines 38a, 38b, 38 as described above.
c, 38d, and enters the slave 38, and the signal wiring 34b,
34, the common wiring 30, and the signal wiring 26a.
Is input to

The operating power of the solenoid valves 42 and 44 is supplied from the power source 28 in the control box 24 to the solenoid valve group 40 from the slave 36 through the power wiring 28a, the common wiring 30, and the power wiring 32b. Also, from the power wiring 32a,
The operating power of the proximity switches 6c, 6d, 14c, 14d is supplied via the slave 38 by power wiring (not shown).

FIG. 1 is a schematic view showing the hydraulic piping 6
a, 6b, 14a, 14b, 46a, 46b, signal wirings 34, 34a, 34b, 38a, 38b, 38c, 38
d, the power wires 32a, 32b are shown as extending out of the framework 4 of the clamping device 2. However, actually, as described below, it is housed in a space for piping and wiring provided in the frame 4.

Next, the structure of the frame 4 of the clamp device 2 will be described with reference to FIG. FIG. 2 is a perspective view showing the structure of the framework of the clamp device in the workpiece holding device of the present embodiment. As shown in FIG. 2, the frame 4 of the clamp device 2 is configured by connecting an upper plate 50 and a lower plate 52 by a pair of left and right reinforcing plates 54 and 56. The reinforcing plates 54 and 56 have through holes 54a through which the workpiece W can pass.
56a are respectively formed. Holes 50a and 52a are also formed in the upper plate 50 and the lower plate 52, respectively. The hole 50a of the upper plate 50 is connected to the hydraulic piping 14a, 14b of the knock pin cylinder 14 and the signal wiring 38a, 3b.
8b. The hole 52 of the lower plate 52
a is a shared wiring 30 penetrating through the distributor 20;
And the hydraulic piping 46a, 46b.

The reinforcing plate 54 has a pair of spacers 58A, 58B at positions separated from the left and right end faces of the reinforcing plate 54.
Has been fixed. These spacers 58A, 58B are shorter in length than the reinforcing plate 54, and gaps are formed above and below the spacers 58A, 58B. These spacers 58A,
Mounting plates 60A and 60B are fixed on 58B, respectively. An annular spacer 62 is fixed around the through hole 54a of the reinforcing plate 54. The thickness of the annular spacer 62 is set to match the thickness of the spacers 58A, 58B and the thickness of the mounting plates 60A, 60B.

Although not shown in the drawing, a similar pair of spacers and a mounting plate are also fixed to the reinforcing plate 56.
A similar annular spacer 64 is fixed around the through hole 56a of the reinforcing plate 56. The spacers 58A, 58B and the like and the annular spacers 62, 64 also serve to reinforce the frame 4 of the clamp device 2. Thereby, the rigidity of the frame 4 is further enhanced. A bracket 6 is provided inside the reinforcing plates 54 and 56.
6A, 66B, 68A, 68B are fixed. The lower brackets 66A and 66B are for attaching a fixing jig for mounting the hydraulic cylinder 6 for clamping. The upper brackets 68A and 68B are for attaching a fixing jig for attaching the knock pin cylinder 14.

Further, notches 50b,
50c is provided. The notch 50b is the reinforcing plate 5
This is for passing piping and wiring from above into a space formed by the cover 4 and the spacers 58A and 58B, the annular spacer 62, and a lid which will be described later and which is mounted over the mounting plates 60A and 60B. Similarly, the notch 50c is used for the reinforcing plate 56.
This is for passing piping and wiring from above in the space formed by the spacer, the annular spacer 64 and the lid.

Next, the entire configuration of the clamp device 2 in a completed state in which necessary equipment, piping, wiring, and the like are mounted on the frame 4 having such a structure will be described with reference to FIG. FIG. 3 is a perspective view showing the overall configuration of the clamp device in the workpiece holding device of the present embodiment. As shown in FIG. 3, a lid 70 having a through hole of the same shape as the through hole 54a of the reinforcing plate 54 is mounted on the mounting plates 60A and 60B of FIG. A similar lid 71 is attached to the reinforcing plate 56 side.

From the mounting plate 60A to the front end surface of the reinforcing plate 54, a corner cover 72A having a substantially U-shaped cross section is mounted. A similar corner cover 72B is attached from the attachment plate 60B to the other end surface of the reinforcing plate 54. A similar corner cover 72C and another corner cover (not shown) are also attached to the reinforcing plate 56.

Further, in the schematic diagram of FIG. 1, only one clamping hydraulic cylinder 6 and one clamper 10 are shown, but in actuality, as shown in FIGS. And there are two clampers. Thereafter, 6
A, 10A for the clamper, 6B for the opposite cylinder not shown in FIG. 3, and 10B for the clamper. The clampers 10A and 10B are respectively pushed up by the cylinder rods 8A and 8B of the two hydraulic cylinders 6A and 6B for clamping, and the workpiece is clamped. Therefore, the hydraulic piping 6a, 6b of the clamping hydraulic cylinders 6A, 6B
And two signal lines 38c and 38d of the proximity switch are also provided.

These clamping hydraulic cylinders 6A, 6A
B is attached to each of the fixing jigs 73A and 73B, and the front surface of the fixing jig 73A is covered with a cover 75. The other side of the fixing jig 73B is also covered with a cover (not shown). Further, as shown in FIG. 3, guide rods 7A and 7B are provided on the left and right sides of the clamping hydraulic cylinder 6A. The upper ends of these guide rods 7A, 7B are fixed to the lower surface of the clamper 10A, and slide with respect to the fixing jig 73 to move up and down integrally with the cylinder rod 8A. By these guide rods 7A and 7B, the clamper 10A moves vertically without tilting.

The pair of hydraulic pipes 46a and 46b connected to the distributor 20 shown in FIG. 1 are formed by the reinforcing plate 56 shown in FIG. 3, a spacer not shown, a mounting plate, an annular spacer 64, and a lid 71. It passes through the space and is taken out from the notch 50c to the upper part. And
The block 7 fixed on the upper plate 50 of the clamp device 2
6, it is connected to the solenoid valve group 40. Solenoid valve group 40
The hydraulic pressure distributed in the step (1) operates the hydraulic cylinders 6A, 6B, and 14 through hydraulic pressure pipes connected to the block 76.

That is, of the hydraulic pipes 6a and 6b connected to the left side surface of the block 76, the hydraulic pipe 6b for retreating (lowering) the hydraulic cylinder 6A for clamping penetrates the upper plate 50 and is connected to the reinforcing plate 56 as shown in FIG. Is connected to the clamping hydraulic cylinder 6A through a space formed by the spacer, the mounting plate, and the corner cover 72C which do not appear in the above. A hydraulic pipe 6a for advancing (raising) the hydraulic cylinder 6B for clamping passes through the upper plate 50 and a reinforcing plate 56 and a spacer not shown in the drawing.
It is connected to the clamping hydraulic cylinder 6B through a space formed by the mounting plate and the corner cover on the other side.

On the other hand, of the hydraulic piping 6a, 6b connected to the right side of the block 76, the clamping hydraulic cylinder 6A
Is connected to the clamping hydraulic cylinder 6A through a space below the similarly formed corner cover 72A. The hydraulic pipe 6b for retreating the hydraulic cylinder 6B for clamping is provided with a corner cover 72B.
And is connected to the hydraulic cylinder for clamping 6B through the space below. Further, the forward (downward) hydraulic pipe 14a and the backward (upward) hydraulic pipe 14b connected to the right side surface of the block 76 pass through the hole 50a of the upper plate 50 and are connected to the knock pin cylinder 14.

Next, the electric wiring will be described. As described above, the common wiring 30 penetrating the distributor 20
Are two power wires 32a and 32b and one signal wire 3
Branch to 4. These three electric wires 32a, 32b,
The upper part 34 is taken out from the notch 50b of the upper plate 50 through a space formed by the reinforcing plate 54, the spacer not shown in FIG. 3, the mounting plate and the lid 70. The power wiring 32 passes through a guide 74 having a substantially U-shaped cross section.
a is connected to the slave 38, and the power wiring 32b is connected to the slave 36. The signal wiring 34 branches into signal wirings 34a and 34b before the slave 36, and the signal wiring 34a is connected to the slave 36 as it is, and the signal wiring 34b is connected to the slave 38.

The slave 36 is mounted on the solenoid valve group 40. The slave 38 is mounted on the lower surface of a mounting plate 80 fixed to a bracket 78 fixed to a block 76. Note that the four guides 74 to 74 fixed on the upper plate 50 are guide members for orderly wiring electric wiring.

As described with reference to FIG. 1, two proximity switches 6c and 6d are mounted at the forward and backward positions of the hydraulic cylinder 6A for clamping, respectively. Two signal wirings 3 from these proximity switches 6c and 6d
8c and 38d are taken out of the notch 50c through a space formed below the corner cover 72C. Then, it passes through the inside of the three guides 74 to 74 and turns to the right side of the upper plate 50, and is connected to the slave 38.

Also, two signal wires 38 from the two proximity switches 6c and 6d of the clamping hydraulic cylinder 6B are provided.
The c and 38d pass through a space formed below the corner cover 72B, are taken out of the notch 50b, and are connected to the slave 38. On the other hand, the two signal wires 38a and 38b from the two proximity switches 14c and 14d of the knock pin cylinder 14 pass through the hole 50a of the upper plate 50,
Connected to slave 38.

Next, a state where the cover of the clamp device 2 is removed will be described with reference to FIG. FIG. 4 shows the corner covers 72A and 72C of the clamp device 2 and the cover 75.
It is a front view which shows the state which removed. As shown in FIG. 4, a fixing jig 73A is attached to the brackets 66A and 66B, and a clamping hydraulic cylinder 6A is fixed to the fixing jig 73A, and a pair of guide rods 7A,
7B is slidably mounted. When the cylinder rod 8A rises, the clamper 10A
Is raised, and the workpiece W is pressed against the lower surface (reference surface) of the reference surface jig 12 and clamped.

Therefore, the hydraulic pipe 6 for raising the cylinder rod 8A (and the cylinder rod 8B, which is not shown in the drawing) is used.
It can be seen that hydraulic pressure is supplied to a. The knock pin 16 of the knock pin cylinder 14 projects downward,
Since it is fitted in the positioning hole provided in the workpiece W,
The workpiece W is correctly positioned.

On the other hand, a manifold 82 is provided at the center of the lower plate 52 of the clamp device 2. Common wiring 30 and hydraulic piping 4 passing through distributor 20
6a and 46b enter this manifold 82. The hydraulic pipes 46a and 46b exit from the left side, and as described above, the reinforcing plate 56 and the spacer 58C, the spacer 58 not shown in the drawing.
D, mounting plate 60C, mounting plate 60D and lid 7 not shown
1 and above the upper plate 50 through the space formed by
Connected to block 76.

The common wiring 30 exits from the right side and enters the terminal box 84, where it is branched into two power wirings and one signal wiring. These three electric wires are connected to the reinforcing plate 5.
4, spacer 58A, spacer 58B not shown in the figure,
It passes through the space formed by the mounting plate 60A, the mounting plate 60B (not shown) and the lid 70, and exits above the upper plate 50, and is connected to the slaves 36 and 38.

Next, the structure around the manifold 82 will be described in more detail with reference to FIG. FIG.
FIG. 5 is a plan view showing a cross section taken along line VV of FIG. 4. As shown in FIG. 5, the manifold 82 is installed right above the distributor 20 not shown in the figure, and
2a protrudes into the clamp device 2. The hydraulic piping 46a, 46b connected to the distributor 20
After exiting the manifold 82 and passing through a hole provided at the lower end of the reinforcing plate 56, the reinforcing plate 56 and the spacers 58C, 58D,
It enters the space formed by the mounting plates 60C and 60D and the lid 71. And it goes out to the upper part of the clamp device 2 through this space.

On the other hand, the common wiring 30 passing through the center of the distributor 20 exits the manifold 82 and enters the terminal box 84, in which two power wirings 32a and 32b
Is branched into one signal wiring 34. These three electric wires pass through a hole provided at the lower end of the reinforcing plate 56, and the reinforcing plate 54, the spacers 58A, 58B, the mounting plates 60A, 60
It enters the space formed by B and the lid 70. And it goes out to the upper part of the clamp device 2 through this space.

On the other hand, as shown in FIG.
And spacer 58A, mounting plate 60A and corner cover 72.
Another space is also formed by A. Similarly, another space is formed by the reinforcing plate 54 and the spacer 58B, the mounting plate 60B, and the corner cover 72B. Further, spaces are also formed by the reinforcing plate 56 and the spacer 58C, the mounting plate 60C and the corner cover 72C, the reinforcing plate 56 and the spacer 58D, and the mounting plate 60D and the corner cover 72D. As described above, each of these hydraulic pipes or signal wiring is also accommodated in these spaces.

The manner in which hydraulic piping and electric wiring are accommodated in these spaces will be described with reference to FIGS. 6 and 7. FIG. 6 shows the lid 70 and the corner covers 72A, 7A.
It is a right view of the clamp device 2 which shows the state which removed 2B. In FIG. 6, through holes 5 provided in the reinforcing plate 54 are provided.
4a through a pair of internal hydraulic cylinders 6 for clamping.
A, 6B and clampers 10A, 10B are shown. The workpiece W is pressed against the reference surface jig 12 and clamped by the pair of clampers 10A and 10B.

These clamping hydraulic cylinders 6A, 6A
Of B, a hydraulic pipe 6a for raising the hydraulic cylinder 6A for clamping comes out of the block 76, penetrates the upper plate 50, and enters a space between the lid 70 and the reinforcing plate 54. Then, it is bent leftward, passes through a gap between the spacer 58A (not shown) and the upper plate 50, and is housed in a space below the corner cover 72A which is removed in the figure. Then, it is bent downward in the depth direction of the paper, reaches the front side through a notch 54c provided in the reinforcing plate 54, and is connected to the clamping hydraulic cylinder 6A as shown in FIG.

On the other hand, the hydraulic pipe 6b for lowering the hydraulic cylinder 6B for clamping also comes out of the block 76, penetrates the upper plate 50, and enters the space between the lid 70 and the reinforcing plate 54. Then, it is bent rightward, passes through a gap between the spacer 58B (not shown) and the upper plate 50, and is housed in a space below the corner cover 72B which is removed in the figure. Then, it is bent downward in the depth direction of the paper, and the reinforcing plate 5
4 to the rear side through the notch 54d provided in
It is connected to the hydraulic cylinder for clamping 6B. Also,
Clamping hydraulic cylinder 6B connected to slave 38
The signal wiring 38c, 38d for the proximity switch of
After passing through the 0 notch 50b, it is connected to the clamping hydraulic cylinder 6B through a similar route.

The three electric wires 32a, 32b, and 34 branched by the terminal box 84 pass through holes 54b formed at the lower end of the reinforcing plate 54, and are connected to the outside of the annular spacer 62 and the space 58A. Between, lid 7 removed in the figure
It is housed in the space below zero. And it is connected to the slaves 36 and 38 through the notch 50a of the upper plate 50. Thus, the hydraulic pipes 6a, 6b and the electric wires 32a, 32b, 34, 38c, 38d are connected to the reinforcing plate 54.
And spacers 58A, 58B, mounting plate 6 not shown in the figure.
0A and 60B, and the lid 70 or the corner cover 72A or the corner cover 72B which is removed in the figure.
And is accommodated in the space formed by

Next, FIG. 7 will be described. FIG. 7 is a left side view of the clamp device 2 showing a state where the lid 71 and the corner covers 72C and 72D are removed. As shown in FIG. 7, the hydraulic piping 46a,
46b passes through a hole 56b formed in the lower end of the reinforcing plate 56, and is accommodated in the space between the outside of the annular spacer 64 and the spacer, below the lid 71 which is removed in the drawing.
And, it is connected to the block 76 through the notch 50b of the upper plate 50.

The hydraulic pipe 6a for raising the hydraulic cylinder 6B for clamping comes out of the block 76, penetrates the upper plate 50, and is located in the space between the lid 71 and the reinforcing plate 56 which are removed in the drawing. Is in. The corner cover 72 is bent leftward, passes through a gap between the spacer 58D (not shown) and the upper plate 50, and is removed in the figure.
D is housed in the space below. A notch 56c provided in the reinforcing plate 56 is bent downward in the depth direction of the drawing.
Through to the rear side, and is connected to the hydraulic cylinder for clamping 6B.

On the other hand, the hydraulic pipe 6b for lowering the hydraulic cylinder 6A for clamping also comes out of the block 76, penetrates the upper plate 50, and enters the space between the lid 70 and the reinforcing plate 54 which are removed in the drawing. Is in. The corner cover 72 is bent rightward, passes through a gap between the spacer 58C (not shown) and the upper plate 50, and is removed in the figure.
It is housed in the space below C. The notch 56d is bent downward in the depth direction of the paper and provided in the reinforcing plate 56.
And reaches the front side, and is connected to a clamping hydraulic cylinder 6A as shown in FIG.

The signal wiring 38 for the proximity switch of the hydraulic cylinder 6A for clamping connected to the slave 38
After passing through the notch 50c of the upper plate 50, c and 38d are also connected to the clamping hydraulic cylinder 6A through a similar route. Thus, the hydraulic piping 6a, 6b, 4
6a, 46b and signal wirings 38c, 38d include a reinforcing plate 56, spacers 58C, 58D, mounting plates 60C, 60D not shown, and a lid 71 or a corner cover 72C or a corner cover 7 which are removed in the drawing.
It is housed in a space formed by 2D.

As shown in FIGS. 6 and 7, an annular spacer 62 fixed around the through hole 54a of the reinforcing plate 54 and an annular spacer 64 fixed around the through hole 56a of the reinforcing plate 56 are provided. Because of this, the electric wiring 32a, 32
b, 34 and the hydraulic piping 46a, 46b have through holes 54a, 5b.
6a is reliably prevented from protruding. As a result, the clamp device 2 in the workpiece holding device 1 of the present embodiment is a clamp device that can more reliably prevent an accident that a pipe or wiring is hooked when the workpiece W is loaded or unloaded.

As described above, in the workpiece holding device 1 of the present embodiment, the signal wiring 26a and the power wiring 28
“a” is combined into one common wiring 30, passes through the center of the distributor 20, and is connected to the slaves 36 and 38 above the clamp device 2. Thereby, the proximity switches 6c, 6d, 14c, 1 of the hydraulic cylinders 6, 14
4d is connected to the external PC 26 by wire, so that it is less affected by surroundings and the reliability of signal transmission is improved.

Also, a solenoid valve 42,
44, the distributor 2
Of the zero flow paths, the minimum number of flow paths connected to the hydraulic piping is two. As a result, the size of the distributor 20 and the turntable 18 can be minimized, and the overall size of the workpiece holding device 1 can be reduced. further,
When it is necessary to increase the number of hydraulic cylinders of the clamp device 2, it is only necessary to draw a new hydraulic pipe from the solenoid valve group 40, and there is no need to rebuild the distributor 20 and the turntable 18. As a result, running costs can be significantly reduced.

Further, the solenoid valves 42 and 44 are
Is provided, when the assembly of the workpiece holding device 1 is completed, the operation can be checked simply by preparing a simple hydraulic power source, power supply and PC for operation check. Therefore, it is not necessary to wait for the completion of the machine tool main body to confirm the operation as in the case of the conventional work holding apparatus, so that the lead time until the operation of the entire machine tool can be reduced.

In the present embodiment, the signal wiring 26a and the power wiring 28a are combined into one common wiring 30 and then passed through the distributor 20.
6a and the power wiring 28a may be separately wound and wound several times before passing through the distributor 20. Further, in the present embodiment, an example in which the hydraulic cylinders 6A and 6B are used as the hydraulic cylinders has been described, but a pneumatic cylinder may be used. In this case, the hydraulic piping of the present embodiment is a pneumatic piping. The structure, shape, dimensions, material,
The connection relation and the like are not limited to the present embodiment.

[0069]

According to the first and second aspects of the present invention, the reliability of the transmission of control signals can be improved, the size of the distributor can be reduced, and there is no need to remodel the distributor in accordance with the specifications of the clamping device. The lead time until the start of the operation of the device can be shortened. Further, in the invention according to the second aspect, the distributor and thus the entire workpiece holding device can be further downsized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire configuration of an embodiment of a workpiece holding device according to the present invention.

FIG. 2 is a perspective view illustrating a structure of a frame of a clamp device in one embodiment of a workpiece holding device.

FIG. 3 is a perspective view showing an entire configuration of a clamp device in one embodiment of a workpiece holding device.

FIG. 4 is a front view showing a state in which a corner cover and a cover of the clamp device in one embodiment of the workpiece holding device are removed.

5 is a view showing a cross section taken along line VV of FIG. 4, and is a plan view showing a structure near a lower plate of the clamp device in one embodiment of the workpiece holding device.

FIG. 6 is a right side view showing a state where a lid and a corner cover of the clamp device are removed in one embodiment of the workpiece holding device.

FIG. 7 is a left side view showing a state in which a lid and a corner cover of the clamp device are removed in one embodiment of the workpiece holding device.

FIG. 8 is a schematic diagram showing an entire configuration of an example of a conventional workpiece holding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work holding apparatus 2 Clamp apparatus 6, 6A, 6B Hydraulic pressure cylinder 10 Clamp 18 Turntable 20 Distributor 26a Signal wiring 28a Power wiring 30a Spiral part 42,44 Solenoid valve W Work

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyoshi Nakamura 1-1-1 Asahi-cho, Kariya-shi, Aichi F-term (reference) in Toyota Industries Co., Ltd. 3C016 BA02 CA03 CB03 CC01 3C048 AA07 BC02 DD12

Claims (2)

[Claims] 1. A turntable which is rotatable and indexable at an arbitrary angular position, and is fixed on the turntable, rotates integrally with the turntable, and presses a workpiece against a reference surface by a clamper operated by an oil pressure cylinder. A clamp device provided inside the turntable, for transmitting hydraulic pressure supplied from the outside to the hydraulic cylinder of the clamp device regardless of rotation of the turntable; and a clamp device. And a solenoid valve for switching a flow path of the pressure oil or compressed air to the hydraulic cylinder, and a power supply line for supplying electric power for operating the solenoid valve, and controlling the solenoid valve. Signal wiring for transmitting necessary control signals is passed through the inside of the distributor and connected to the clamp device. And, in front of the distributor provided with a helical portion wound with the power wiring and the signal wiring many layers or workholding device. 2. The workpiece holding device according to claim 1, wherein the distributor has only two flow paths for the pressure oil or the compressed air.