JP2000042850A - Clamping and unclamping equipment for movable body of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable both operations, clamping and unclamping a pallet relative to a table without providing a hydraulic unit. SOLUTION: This clamping and unclamping equipment 13 is provided with: a hydraulic cylinder 14 for driving a clamping member 12 for clamping a pallet 4 relative to a table by supplying hydraulic oil 17 to an upper cylinder chamber 34 or a lower hydraulic chamber 32; a clamping pneumatic-hydraulic booster 35 for increasing and converting pressure of compressed air to and into given pressure of hydraulic oil so that the hydraulic oil may be supplied to the upper cylinder chamber 34; an unclamping pneumatic-hydraulic booster 33 for increasing and converting the pressure of the compressed air to and into the given pressure of the hydraulic oil so that the hydraulic oil may by supplied to the lower cylinder chamber 32; a pneumatic circuit 31 capable of switching the supply direction of the compressed air supplied to the booster 35 or 33; and a control device for switching the supply direction of the compressed air in the pneumatic circuit, supplying the hydraulic oil to the cylinder chamber 34 or 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp and unclamping device for clamping and unclamping a movable body with respect to a fixed body of a machine tool by driving a hydraulic cylinder device or the like.

[0002]

2. Description of the Related Art Machining center (hereinafter referred to as MC)
Automatic pallet changers (hereinafter APC)
Described). The APC automatically exchanges a pallet as a movable body on which a workpiece is placed with respect to a table as a fixed body. The pallet is clamped and unclamped against the table by a clamp member using a clamp and unclamping device. The pallet clamping and unclamping device includes a hydraulic cylinder device (hereinafter referred to as a cylinder), and uses a hydraulic oil (pressure oil) set to a predetermined pressure supplied from a hydraulic unit to perform both clamping and unclamping. The operation is performed.

[0003]

As described above, the apparatus for clamping and unclamping a pallet usually includes a hydraulic unit. In recent years, society has been calling for energy saving and environmental measures, but the hydraulic unit uses a drive motor that operates constantly to circulate hydraulic oil, which consumes a large amount of power and goes against energy saving. become.

[0004] In addition, the working oil is constantly circulated as the temperature rises and gradually deteriorates, so that it is periodically replaced. Therefore, it is difficult to treat the waste oil generated at this time. If oil leaks to the outside during the oil change operation or operation, the recovery is difficult, and if it cannot be recovered, the surrounding environment may be adversely affected. In addition, there is a risk that an operator or the like may slip and be injured by oil leaking to the floor of the factory, and thus improvement in workability has been demanded. Further, when the hydraulic unit is mounted on the main body of the machine tool via the mounting member, if the mounting location and the mounting method are not good, the hydraulic unit itself may act as a vibration source and a heat source and adversely affect machining accuracy. . Therefore, there is a need for a technique capable of performing pallet clamping and unclamping operations without using a hydraulic unit.

[0005] By the way, boosters (pressure intensifiers) for increasing the pressure of air pressure to hydraulic pressure are known. For example,
Japanese Patent Application Laid-Open No. 121484 discloses a technique relating to a spindle head of a machine tool. In the technique of this publication, the hydraulic pressure is supplied to an unclamping cylinder for performing an unclamping operation at the time of manual operation by an air booster type first hydraulic pressure supply device. However, the unclamping cylinder is returned by a return spring. This conventional technique is a simple technique of supplying or not supplying hydraulic pressure to one cylinder chamber of a cylinder. It cannot be used for devices that perform operation and unclamping operation.

If it is possible to realize a so-called hydraulic unit-less operation that does not use a hydraulic unit as a drive source for all hydraulic drive mechanisms of a machine tool, energy saving, improvement in environmental and workability of the entire machine tool, improvement of the machine tool body, Thus, it is possible to prevent adverse effects on machining accuracy due to the transmission of vibration and heat of the hydraulic unit.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a fluid which performs both operations of clamping and unclamping a movable body such as a pallet to a fixed body such as a table without providing a hydraulic unit. An object of the present invention is to provide a clamp and unclamping device for a movable body of a machine tool capable of supplying a working fluid of a predetermined pressure to a first chamber on a clamp side and a second chamber on an unclamping side of a pressure actuator device. I do.

[0008]

In order to achieve the above object, a clamp and unclamping device according to the present invention comprises a movable member which is clamped and unclamped by driving a hydraulic actuator with respect to a stationary member of a machine tool. A clamp / unclamping device for supplying a working fluid at a predetermined pressure to the first chamber on the clamp side or the second chamber on the unclamping side provided on the fixed body side,
The fluid pressure actuator device for driving a clamp member for clamping the movable body with respect to the fixed body, and a cylinder chamber having a different pressure receiving area for supplying the working fluid at a predetermined pressure to the first chamber. A clamping air pressure-fluid pressure booster for increasing and converting the pressure of the compressed air to a predetermined pressure of the working fluid, and a different pressure receiving area for supplying the working fluid at a predetermined pressure to the second chamber. An unclamping pneumatic-fluid pressure booster having a cylinder chamber for increasing the pressure of the compressed air to a predetermined pressure of the working fluid; and the pneumatic-fluid pressure booster for clamping or the pneumatic-fluid for unclamping. A pneumatic circuit capable of switching a supply direction of the compressed air to be supplied to the pressure booster; and a pneumatic circuit for switching a supply direction of the compressed air of the pneumatic circuit. Or and a controller for controlling to supply the predetermined pressure of the working fluid in the second chamber.

In the clamping and unclamping apparatus, the pneumatic-fluid pressure booster for clamping and the pneumatic-fluid pressure booster for unclamping are supplied with a small-diameter cylinder chamber in which the working fluid is pressurized and the compressed air. A large-diameter cylinder chamber, and a piston that is fitted into the small-diameter cylinder chamber and the large-diameter cylinder chamber and that can move forward and backward by supplying the compressed air to the large-diameter cylinder chamber. A small-diameter cylinder chamber for clamping of the hydraulic pressure booster and the pneumatic pressure for unclamping; a small-diameter cylinder chamber for clamping or the small-diameter cylinder for unclamping which is connected to the small-diameter cylinder chamber for unclamping of the hydraulic pressure booster. When the working fluid in the cylinder chamber is about to become insufficient or excessive, An air-working fluid converter capable of supplying or recovering the working fluid and a clamp small-diameter cylinder chamber, and a first pressure fluid path from the clamp small-diameter cylinder chamber to the first chamber is closed circuit. Or a mechanical valve for clamping that switches between communicating the small-diameter cylinder chamber for clamping and the air-working fluid converter, and a small-diameter cylinder chamber for unclamping. An unclamping mechanical valve for switching between a closed circuit in the second pressure fluid passage up to the second chamber and a communication between the small diameter cylinder chamber for unclamping and the air-working fluid converter. Is preferred.

The fluid pressure actuator device is a fluid pressure cylinder device provided with the first chamber and the second chamber vertically, and the clamp member is fixed to a piston rod of the fluid pressure cylinder device. The control device is provided so as to be movable in the vertical direction, and when the movable body is changed from the unclamped state to the clamped state, the control fluid of the predetermined pressure is supplied to the second chamber provided on the lower side. It is preferable that the supply be stopped and the movable body be controlled to supply the working fluid of the predetermined pressure to the first chamber after descending by its own weight.

[0011] Further, there is provided a cleaning air jetting means connected to a discharge circuit of the pneumatic circuit and jetting the compressed air to clean the contact portion between the movable body and the fixed body, and
Preferably, when the movable body is clamped to the fixed body, the compressed air exhausted from the unclamping pneumatic-fluid pressure booster is jetted to the close contact portion for cleaning.

Preferably, the pneumatic circuit has a check valve provided on the compressed air source side of the pneumatic circuit and capable of maintaining the air pressure in the pneumatic circuit.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. (First Embodiment) FIG. 1 is a partial sectional view of a machine tool, and FIG.
1 is a circuit diagram of a pallet clamping and unclamping device according to a first embodiment of the present invention. 1 and 2, the machine tool is a vertical MC (machining center) 1
APC (automatic pallet changer) is provided in MC1.

In the MC 1 with APC, a plurality of (for example, two) pallets 4 are prepared for one table 5. The APC carries in and out the pallet 4 on which the workpiece 3 is placed with respect to the table 5 and sequentially exchanges it. The MC 1 is provided with a spindle head 8, and the spindle head 8 is provided with a spindle 7 so as to be rotatable. The table 5 is provided below the spindle head 8. The tool 9 mounted on the mounting portion of the main shaft 7 moves relative to the table 5 in the X, Y, and Z-axis directions, and cuts the workpiece 3 on the pallet 4 clamped on the table 5.

In the MC 1, when the machining of the workpiece 3 on the pallet 4 clamped on the table 5 is completed, the APC is driven, and the pallet 4 on which the machined workpiece 3 is placed and the pallet 4 on which the machining is to be performed. A pallet on which an unprocessed workpiece to be mounted is loaded and unloaded from the table 5 is exchanged. A jig for attaching a workpiece is fixed to the pallet 4, and the workpiece 3 is often mounted on the pallet 4 by the jig. The movable body is constituted by the pallet 4, the jig for attaching the workpiece, the workpiece 3, and the like, and the weight of the entire movable body is considerably heavy.

A clamp / unclamp device 1 is provided in MC1.
3 are provided. Clamping and unclamping device 13
Are for detachably clamping and unclamping a pallet 4 as a movable body to and from a table 5 as a fixed body by a clamp member 12. The table 5 is provided with one or more (two in this embodiment) hydraulic cylinder devices 14 constituting the clamp / unclamp device 13. Hydraulic cylinder device 14
Is a type of fluid pressure actuator device, and includes an upper cylinder chamber (first chamber on the clamp side) 34 and a lower cylinder chamber (second chamber on the unclamping side) 32 vertically. The clamp member 12 is fixed to a piston rod of a piston 15 of the hydraulic cylinder device 14 by a fastening member such as a bolt 16 and is provided so as to be movable in a vertical direction.

The hydraulic cylinder device 14 supplies the working fluid (working fluid) 17 of a predetermined pressure to the upper cylinder chamber 34 or the lower cylinder chamber 32, thereby the clamp member 12
Drive. That is, the hydraulic cylinder device 14 switches the supply direction of the hydraulic oil (pressure oil) 17 of a predetermined pressure supplied to the hydraulic cylinder device 14 so that the clamp member 12 can move up and down in the vertical direction. Thus, the pallet 4 is clamped and unclamped with respect to the table 5. 2 to 5, the hatched portion indicates the hydraulic oil 17. When moved upward, the clamp member 12 guides the pallet 4 so as to be movable in the horizontal direction. It is preferable that cam followers (not shown) are provided on the clamp member 12 at predetermined intervals, and the roller outer peripheral portion of the cam follower rolls to guide the pallet 4 movably. When moved downward, the clamp member 12 positions the pallet 4 at a predetermined position on the table 5 and clamps the pallet 4 by pressing the clamped portion of the pallet 4 against a clamping surface of the table 5.

By the way, in the factory where MC1 is installed,
Usually, a compressed air source 25 such as a compressor is used to supply compressed air 26 used for cleaning a workpiece, cleaning a pallet clamp surface, operating equipment, and the like to equipment in a factory.
Is installed. The compressed air 26 supplied from the compressed air source 25 flows through the compressed air supply channel 27 and is supplied to each facility. Therefore, in the present invention, the hydraulic cylinder device 14 is driven by utilizing the compressed air 26 and converting the air pressure into a hydraulic pressure (fluid pressure).

The clamp / unclamp device 13 is provided in a hydraulic cylinder device (fluid pressure cylinder device) 14 and a hydraulic circuit 29 of the hydraulic cylinder device 14 to increase and convert the air pressure of the compressed air 26 to the hydraulic pressure of the hydraulic oil 17. A pneumatic-fluid pressure booster (in this case, a pneumatic-hydraulic intensifier; hereinafter, referred to as a booster) 28 and a hydraulic circuit 29 are provided in the hydraulic circuit 29 between the hydraulic cylinder device 14 and the booster 28. When the oil 17 is likely to be insufficient, the hydraulic oil is supplied. When the hydraulic oil is likely to be excessive in the hydraulic circuit 29, an air-hydraulic fluid converter for recovering the hydraulic oil from the hydraulic circuit 29 (this embodiment) The embodiment is an air-hydraulic oil converter, and includes a converter (hereinafter referred to as a converter) 30. Furthermore, a clamping / unclamping device 1
Reference numeral 3 denotes a pneumatic circuit 31 for supplying the compressed air 26 to the booster 28 and switching a supply direction of the compressed air 26, and a supply direction of the compressed air 26 of the pneumatic circuit 31 for switching the upper cylinder chamber 34 or the lower cylinder chamber. 3
A control device for controlling the supply of the hydraulic oil 17 at a predetermined pressure to the control unit 2. Then, by switching the supply direction of the compressed air 26 in the pneumatic circuit 31, the booster 28 converts the air pressure into hydraulic pressure, and the hydraulic cylinder device 14 drives the clamp member 12 to move the pallet 4 to the table 5. Both clamping and unclamping operations can be performed.

The booster 28 includes an unclamping booster (unclamping air pressure-fluid pressure booster) 33 connected to the lower cylinder chamber 32 of the hydraulic cylinder device 14.
A clamp booster (pneumatic-fluid pressure booster for clamp) 35 connected to the upper cylinder chamber 34 is provided. A pneumatic circuit 31 is connected to the booster 28. The unclamping booster 33 is provided in the lower cylinder chamber 3.
In order to supply the hydraulic oil 17 with a predetermined pressure to the cylinder 2, a cylinder chamber having a different pressure receiving area is provided, and the pressure of the compressed air 27 is increased and converted to a predetermined pressure of the hydraulic oil 17. The unclamping booster 33 includes a second cylinder chamber 37a and a first cylinder chamber 37b in which the large diameter portion 36a of the piston 23 slides.
And a third cylinder chamber (small-diameter cylinder chamber for unclamping) 39a in which the small-diameter portion 38a of the piston 23 slides and the hydraulic oil 17 is pressurized.

The second cylinder chamber 37a and the first cylinder chamber 37b constitute a large-diameter cylinder chamber to which the compressed air 27 is supplied. The piston 23 fitted in the third cylinder chamber 39a and the large-diameter cylinder chamber moves forward and backward by supplying the compressed air 27 to the large-diameter cylinder chamber. Ports P _2a and P _1a for compressed air 26 are provided in the second cylinder chamber 37a and the first cylinder chamber 37b, respectively. As well as supply of compressed air to the first cylinder chamber 37b from the port P _1a, the second cylinder chamber 37a
When the compressed air is exhausted from the port _P2a , the compressed air 26
The air pressure of the piston 23 causes the third cylinder chamber 39a to move.
Advance to the side.

Since the port _P3a for hydraulic oil is closed by the advance of the piston 23, the hydraulic circuit of the lower cylinder chamber 32, the flow path 41, and the third cylinder chamber 39a becomes a closed circuit, and the hydraulic circuit of the lower cylinder chamber 32, Pascal is based on the principle of Pascal. 3 cylinder chamber 39a
, The hydraulic oil 17 reaches a predetermined pressure. Second from port P _2a
As well as supply in the cylinder chamber 37a, when the exhaust compressed air in the first cylinder chamber 37b from the port P _1a, the piston 23 is retracted by the air pressure of the compressed air 26, the converter 30 and the third cylinder chamber 39a Communicates with the third
The hydraulic oil in the cylinder chamber 39a returns to the atmospheric pressure. Also,
When the piston 23 retreats even after the converter 30 and the third cylinder chamber 39a communicate with each other, the operating oil
Is supplied to the third cylinder chamber 39a side.

The port P _3a of the third cylinder chamber 39a is
It is arranged near the front side of the second cylinder chamber 37 a and communicates with the lower part of the converter 30 via the flow path 40. In the third cylinder chamber 39a, an unclamping mechanical valve 36 constituted by a port _P3a and a small diameter portion 38a of the piston 23 is provided. The mechanical valve 36 for unclamping is a small-diameter portion 3 of the piston 23.
8a moves back and forth in the third cylinder chamber 39a and
Opening or closing _3a opens or closes.
A port _P4a is provided on the front side of the third cylinder chamber 39a. The port P _4a communicates with the lower cylinder chamber 32 of the hydraulic cylinder device 14 via the flow path 41. The mechanical valve 36 for unclamping is used to close the flow path (second pressure fluid path) 41 from the third cylinder chamber 39a to the lower cylinder chamber 32 or to set the third cylinder chamber 3
It is possible to switch whether the communication between the converter 9a and the converter 30 is established.

The clamp booster 35 has cylinder chambers having different pressure receiving areas to supply the hydraulic oil 17 at a predetermined pressure to the upper cylinder chamber 34, and increases the pressure of the compressed air 27 to a predetermined pressure of the hydraulic oil 17. Pressure conversion. The clamp booster 35 includes a second cylinder chamber 59a and a first cylinder chamber 59b in which the large-diameter portion 36b of the piston 24 slides.
And a third cylinder chamber (small-diameter cylinder chamber for clamping) 39b in which the small-diameter portion 38b of the piston 24 slides.

The first cylinder chamber 59b and the second cylinder chamber 59a constitute a large-diameter cylinder chamber to which the compressed air 27 is supplied. The piston 24 fitted into the third cylinder chamber 39b and the large-diameter cylinder chamber moves forward and backward by supplying compressed air 27 to the large-diameter cylinder chamber. Ports P _2b and P _1b for compressed air 26 are provided in the second cylinder chamber 59a and the first cylinder chamber 59b, respectively. The compressed air is supplied from the port P _1b to the first cylinder chamber 59b, and the second cylinder chamber 59a is
When the compressed air is exhausted from the port P _2b , the compressed air 26
The piston 24 moves forward by the air pressure.

Since the port P _3b for hydraulic oil is closed by the advance of the piston 24, the hydraulic circuit of the upper cylinder chamber 34, the flow path 42 and the third cylinder chamber 39b becomes a closed circuit, and the hydraulic circuit of the upper cylinder chamber 34, Pascal's principle is used. 3 cylinder chamber 39b
, The hydraulic oil 17 reaches a predetermined pressure. Second from port P _2b
As well as supply in the cylinder chamber 59a, when the exhaust compressed air in the first cylinder chamber 59b through the port P _1b, the piston 24 is retracted by the air pressure of the compressed air 26, the converter 30 and the third cylinder chamber 39b Communicates with the third
The hydraulic oil in the cylinder chamber 39b returns to the atmospheric pressure. Also,
When the piston 24 retreats even after the converter 30 and the third cylinder chamber 39b communicate with each other, the operating oil
Is supplied to the third cylinder chamber 39b side.

The port P _3b of the third cylinder chamber 39b is
It is arranged near the front side of the second cylinder chamber 59a and communicates with the lower part of the converter 30 via the flow path 40. The third cylinder chamber 39 b, the mechanical valve 37 is provided for clamping constituted by a small diameter portion 38b of the port P _3b and the piston 24. The mechanical valve for clamping 37 is opened or closed by the small diameter portion 38b of the piston 24 moving forward and backward in the third cylinder chamber 39b to open and close the port _P3b . A port P _4b is provided on the front side of the third cylinder chamber 39b. The port P _4b communicates with the upper cylinder chamber 34 of the hydraulic cylinder device 14 via the flow path 42. The mechanical valve for clamping 37 has a flow path (first pressure fluid path) from the third cylinder chamber 39b to the upper cylinder chamber.
It is possible to switch between the closed circuit 42 and the communication between the third cylinder chamber 39b and the converter 30.

The boosters 33 and 35 are provided on the bed,
Since the hydraulic cylinder device 14 is provided on the movable table 5, a part of the flow paths 41 and 42 is connected by a hose 43 made of a pressure-resistant flexible resin or rubber. If the table 5 does not move, it may be fixedly connected by a steel pipe for piping. Hydraulic cylinder device 1
4, boosters 33 and 35, converter 30, flow path 40,
The hydraulic circuit 29 is constituted by 41, 42 and the like.

The converter 30 includes the booster 3 for clamping.
5 and the third cylinder chamber 39a of the unclamping booster 33 are connected to the third cylinder chamber 39b.
When the hydraulic oil 17 of b or 39a is likely to be short or excessive, the hydraulic oil 17 can be supplied or collected. The hydraulic oil 17 is always stored in the converter 30, and the upper space 44 serving as an air layer communicates with the atmosphere. The converter 30 is disposed above the boosters 33 and 35, and supplies or collects hydraulic oil into the third cylinder chambers 39a and 39b when the converter 30 is in communication with the third cylinder chambers 39a and 39b. Can be. The converter 30 has a function of setting the pressure in the third cylinder chambers 39a and 39b to the atmospheric pressure when the converter 30 is in communication with the third cylinder chambers 39a and 39b. It is also possible to vent the air in the interior 29. further,
Converter 30 transfers hydraulic oil 17 to third cylinder chamber 39.
The air is not mixed with the hydraulic oil when supplying and recovering the a and 39b.

The pneumatic circuit 31 is connected to the compressed air supply channel 27. Switching control of the supply direction of the compressed air 26 supplied to the boosters 33 and 35 is performed by an electromagnetic switching valve (hereinafter, referred to as an electromagnetic switching valve).
(Described as a switching valve) 45. The switching valve 45 is provided in a supply-side flow path 47 that has a check valve 46 and is connected to the compressed air supply flow path 27. The switching valve 45 includes solenoids 58a and 58b, and an exhaust port is provided with a muffler 54 for discharging used compressed air into the atmosphere.

Switching valve 45 and unclamping booster 3
A quick exhaust valve 48 for the third port P _2a, one-way throttle valve for port P _1b of the clamp booster 35 (speed control valve)
49 are connected by a flow path 50. The switching valve 45, the one-way throttle valve 51 for the port P ₁ a of the unclamping booster 33, and the quick exhaust valve 52 for the port P 2 _b of the clamping booster 35 are connected by a flow path 53. Switching valve 45, check valve 46, quick exhaust valve 48,5
2. The pneumatic circuit 31 is composed of the one-way throttle valves 51, 49, the flow paths 47, 50, 53, and the like. Check valve 46
Is provided on the compressed air source 25 side of the pneumatic circuit 31 so that the air pressure in the pneumatic circuit 31 can be maintained even when the supply of the compressed air 26 from the compressed air source 25 is stopped.

The compressed air supply channel 27 is connected to a cleaning air channel 55. The cleaning air flow path 55 is a flow path for supplying the compressed air 26 to a close contact portion where the pallet 4 and the table 5 are in close contact with each other at the time of clamping, and performing cleaning. The cleaning air flow path 55 is provided with an electromagnetic switching valve 56 having a solenoid 58c and a nozzle 57 for ejecting compressed air to a close contact portion. The cleaning is performed by supplying to the cleaning section.

Next, the operation of the clamp / unclamp device 13 will be described. In the MC 1, the pallet 4 on which the workpiece 3 is placed is mounted on the clamp / unclamp device 1.
In a state where it is clamped to the table 5 by 3 (the state shown in FIG. 2), the spindle 7 is rotationally driven by a spindle motor,
The workpiece 9 is cut by the tool 9 by relatively moving the tool 9 and the workpiece 3 in the X, Y, and Z axes.
When the machining of the workpiece 3 in the MC 1 is completed and a program for pallet exchange (for example, M60) is executed,
The pallet changing operation starts under the control of the control device. The control device positions the table 5 and the like at a predetermined pallet replacement position.

Next, the clamp / unclamp device 13
Is unclamped to put the pallet 4 in an unclamped state. To this end, the solenoid 5 of the switching valve 45
8b is excited, the flow path 47 on the supply side of the compressed air 26 is connected to one flow path 53, and the other flow path 50 is connected to the muffler 54. Then, the compressed air 26 supplied from the compressed air supply flow path 27 is unclamped through the check valve 46, the switching valve 45, and the one-way throttle valve 51 of one flow path 53 of the flow path 47 on the supply side. From the port P _{1a of the} booster 33
Is supplied to the cylinder chamber 37b. The compressed air in the second cylinder chamber 37a is supplied to the quick exhaust valve 48,
More exhausted.

In the unclamping booster 33, when the piston 23 moves forward due to the air pressure of the compressed air 26 in the first cylinder chamber 37b, part of the hydraulic oil in the third cylinder chamber 39a is transferred from the port _P3a . Converter 3
Collected on the 0 side. Further, when the piston 23 moves forward, the small-diameter portion 38a of the piston 23 causes the port P _{3a to} move.
Is closed, that is, the mechanical valve for unclamping 36 is closed. Further, the air in the second cylinder chamber 37a is exhausted from the port _{P2a by} the quick exhaust valve 48 and the muffler 54 of the other flow path 50. In addition, piston 2
3 moves forward, the lower cylinder chamber 32, the flow path 41,
The hydraulic oil confined in the closed circuit constituted by the third cylinder chamber 39a is increased in pressure by the pressure of the compressed air 26, and the hydraulic oil in the third cylinder chamber 39a, the flow path 41 and the lower cylinder chamber 32 is increased. The pressure at 17 rises.

On the other hand, in the clamp booster 35,
The compressed air 2 supplied from the switching valve 45 to one flow path 53
6 is supplied to the second cylinder chamber 59a through the port P _2b from quick exhaust valve 52. First cylinder chamber 59b
The compressed air inside communicates with the atmosphere from the port P _1b through the one-way throttle valve 49, the switching valve 45, and the muffler 54 of the other flow path 50.

As a result, the piston 24 of the clamp booster 35 moves backward by the air pressure of the compressed air 26 supplied to the second cylinder chamber 59a, and the air in the first cylinder chamber 59b is exhausted from the silencer 54. As a result, the pressure of the hydraulic oil 17 in the upper cylinder chamber 34 also decreases. Eventually, when the port P _3b is opened, the flow path 42 on the upper cylinder chamber 34 side communicates with the flow path 40 on the converter 30 side, so that the pressure of the hydraulic oil 17 in the upper cylinder chamber 34 It becomes atmospheric pressure by communication. Further, since the piston 24 moves backward, the hydraulic oil 17
0 flows into the third cylinder chamber 39b. as a result,
Since the piston 15 and the clamp member 12 of the hydraulic cylinder device 14 rise, the pallet 4 is in an unclamped state.

Next, the APC is driven, and the processed workpiece 3
After the pallet 4 on which the unprocessed workpiece is mounted is moved to the outside of the MC 1 after the pallet 4 on which the
It is moved to a predetermined position on the table 5 by the PC. Thereafter, the pallet 4 is clamped on the table 5 by operating the clamp / unclamp device 13. for that purpose,
When the solenoid 58a of the switching valve 45 is excited, the solenoid 58
When the switching control for demagnetizing b is performed to the state shown in FIG. 2, the flow path 47 to which the compressed air 26 is supplied becomes the other flow path 5
Communicate with 0. The compressed air 26 flowing from the switching valve 45 through the other flow path 50 is supplied from the quick exhaust valve 48 on the unclamping booster 33 side to the second cylinder chamber 37a, and from the one-way throttle valve 49 on the clamping booster 35 side. It is supplied to the first cylinder chamber 59b.

One channel 53 is provided with a silencer 54 of the switching valve 45.
The compressed air in the first cylinder chamber 37b of the unclamping booster 33 is exhausted. The second cylinder chamber 59a of the clamp booster 35
The compressed air inside is exhausted from the quick exhaust valve 52 and the silencer 54, and the second cylinder chamber 59a becomes atmospheric pressure. When the compressed air 26 is supplied, the piston 23 of the unclamping booster 33 retreats by air pressure, so that the mechanical valve 36 for unclamping is opened and the flow paths 41 and 40 are opened.
, The lower cylinder chamber 32 communicates with the converter 30, and the pressure of the hydraulic oil 17 in the lower cylinder chamber 32 becomes the atmospheric pressure. On the other hand, since the piston 24 of the clamp booster 35 moves forward, the port P _3b is closed by the small diameter portion 38b of the piston 24, and the mechanical valve for clamp 37 is closed, and the upper cylinder chamber 34, the flow path 42, The third cylinder chamber 39b has a closed circuit, and the air pressure is increased and converted to the hydraulic pressure of the hydraulic oil 17.

As a result, the hydraulic pressure in the upper cylinder chamber 34 of the hydraulic cylinder device 14 becomes high, and the lower cylinder chamber 32 is at atmospheric pressure. Thus, the clamp member 12 is pushed down together with the piston 15 by a predetermined force, and the pallet 4 is clamped. It is clamped to the table 5 by the member 12. During this clamping operation, the cleaning air passage 5
5, the switching control for exciting the solenoid 58c of the electromagnetic switching valve 56 is performed to open the electromagnetic switching valve 56, and the compressed air 26 is supplied from the nozzle 57 to the close contact portion between the pallet 4 and the table 5 to perform cleaning. ing.

As described above, by driving the APC and operating the clamp / unclamp device 13, the pallet replacement procedure is completed. When this pallet changing operation is completed, the MC 1 shifts to the processing operation after closing the opening / closing cover separating the processing area and the non-processing area. When exchanging a workpiece on the setup table, the operator must
After removing the processed workpiece from the pallet 4 carried out from 1 onto the setup table, a setup operation for mounting a new unprocessed workpiece is performed.

In the clamp / unclamp apparatus 13, in both the clamped state and the unclamped state, when the supply of the compressed air is stopped, the air flow path communicating with the booster 28 to which the compressed air 26 is supplied is stopped. When the power is shut off, the inside of the cylinder chamber on the high pressure side of the booster 28 is maintained at a predetermined pressure by the check valve 46 or the like, which is safe. In other words, during the cutting process in the clamped state, the compressed air source side will fail and compressed air will not be supplied, the pressure of the compressed air will decrease due to the use of other equipment, the power supply will be cut off, etc. Also, the clamp / unclamp device 13 can be maintained in that state, which is safe.

(Second Embodiment) FIGS. 3 and 4 are circuit diagrams of a pallet clamping and unclamping device 60 according to a second embodiment of the present invention. FIG. FIG. 4 shows a clamped state.
In the following embodiments, the same or corresponding parts as those of the other embodiments are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described.

In the second embodiment, the pallet 4 is moved downward by utilizing its own weight such as a movable body having a considerably large weight.
After the downward movement, the booster 28 is operated only when the clamp is finally performed to perform the clamp operation. 1, 3 and 4, the pallet 4 is arranged horizontally, so that the clamp member 12 can be moved up and down with respect to the table 5. For this reason, the hydraulic cylinder device 14 is arranged with its central axis oriented in the vertical direction.

In the clamping and unclamping device 60 of this embodiment, when the control device clamps the pallet 4 in the unclamped state, the control device first stops the supply of the hydraulic oil 17 to the lower cylinder chamber 32 of the hydraulic cylinder device 14. Then, the pallet 4 is lowered by its own weight such as a movable body including the pallet 4. After the pallet 4 is lowered, the hydraulic oil 1 is transferred to the upper cylinder chamber 34 by the clamp booster 35a.
The pallet 4 is clamped by controlling the supply of the pallet 4.

In the clamp / unclamp device 60, the pneumatic circuit 31a has two switching valves 45a and 45b. The one switching valve 45a is for switching and controlling the supply direction of the compressed air 26 supplied to the unclamping booster 33. The other switching valve 45b is for switching and controlling the supply direction of the compressed air 26 supplied to the clamping booster 35a. One switching valve 45a includes solenoids 58a and 58b, and a silencer 54 is provided at an exhaust port. The other switching valve 45b includes solenoids 58d and 58e, and a muffler 54 is provided at the exhaust port.
Is provided. Non-return valves 46a and 46b are provided in flow paths 47a and 47b for supplying the compressed air 26 to the switching valves 45a and 45b, respectively.

The flow path 6 connecting the first cylinder chamber 37b of the unclamping booster 33 and one of the switching valves 45a.
2 is provided with a one-way throttle valve 51. The flow path 63 connecting the second cylinder chamber 37a of the unclamping booster 33 and one of the switching valves 45a is connected to the converter 30a.
Is connected to the air layer 64 on the upper side of the. Converter 30
a is for making the oil pressure equal to the compressed air or the air pressure of the atmosphere, and has almost the same function as the converter 30. First clamp booster 35a
A one-way throttle valve 49 is provided in a flow path 65 connecting the cylinder chamber 59b of the first and second switching valves 45b. The second cylinder chamber 59a and the other switching valve 45b are connected to a flow path 66.
Connected by

In the clamp / unclamp apparatus 60, when the unclamping state shown in FIG. 3 is set, both switching valves 45a and 45b are simultaneously switched and controlled. Therefore, the solenoids 58 of both switching valves 45a, 45b
b, 58e are excited, and the solenoids 58a, 58d are demagnetized. In the unclamping booster 33, the compressed air 26
Is supplied from the channel 62 to the first cylinder chamber 37b. The compressed air in the second cylinder chamber 37a is exhausted through the channel 63 and the muffler 54 of one of the switching valves 45a. As a result, the piston 23 of the unclamping booster 33 moves forward, so that the air pressure of the compressed air is increased and converted to the oil pressure of the hydraulic oil 17, and the oil pressure of the lower cylinder chamber 32 becomes high.

On the other hand, in the clamping booster 35a, the compressed air 26 is supplied to the second cylinder chamber 59a via the flow path 66, and the compressed air in the first cylinder chamber 59b is switched between the flow path 65 and the other. Air is exhausted through the silencer 54 of the valve 45b. Then, the piston 24 of the clamp booster 35a retreats and the port _P3b opens to open the clamp mechanical valve 37, so that the flow path 42 connected to the upper cylinder chamber 34 and the flow of atmospheric pressure Road 63
The upper cylinder chamber 34 is brought to the atmospheric pressure by communication with the oil layer 67 of the converter 30a communicating with the upper cylinder chamber 34a. This allows
Piston 15 and clamp member 1 of hydraulic cylinder device 14
2 rises due to the oil pressure in the lower cylinder chamber 32, so that the pallet 4 is in an unclamped state.

When the pallet 4 is clamped on the table 5 by the clamp / unclamp device 60 after the pallet exchange by APC, first, as shown in FIG.
Switching control is performed to excite the solenoid 58a of one of the switching valves 45a for the unclamping booster 33 and demagnetize the solenoid 58b. With one of the switching valves 45a, the compressed air 2
6 is supplied to the second cylinder chamber 37a of the unclamping booster 33 from the flow path 63, and the compressed air in the first cylinder chamber 37b is supplied through the flow path 62 and the muffler 54 on one switching valve 45a side. Release into the atmosphere. Then, the piston 23 of the unclamping booster 33 retreats, and the flow path 41 connected to the lower cylinder chamber 32 communicates with the flow path 40 on the converter 30a side, so that the lower cylinder chamber 32 has the same pressure as the air pressure of the compressed air. become. At this time, since the pressure increasing operation is not performed in the clamp booster 35a, the upper cylinder chamber 34 is also at the same pressure as the air pressure via the converter 30a.

Since the pressures in the upper and lower cylinder chambers 34 and 32 are the same, the pallet 4 descends to the lower position by the weight of the movable body including the pallet 4, the clamp member 12, the piston 15 and the like. After the pallet 4 moves downward, FIG.
As shown in the figure, the solenoid 58d of the other switching valve 45b
Is switched to excite the solenoid and demagnetize the solenoid 58e. Then, the compressed air 26 is supplied from the flow path 65 to the first cylinder chamber 59b of the clamp booster 35a,
The compressed air in the second cylinder chamber 59a is discharged into the atmosphere through the flow passage 66 and the muffler 54 of the other switching valve 45b. The piston 24 of the clamp booster 35a moves forward, closes the port _P3b , closes the mechanical valve 37 for clamping, and increases and converts the air pressure to the hydraulic pressure of the hydraulic oil 17. As a result, the piston 15 of the hydraulic cylinder device 14 is pressed downward by the hydraulic pressure, and the pallet 4 is clamped to the table 5 by the clamp member 12.

In this embodiment, at the time of the clamping operation, the movable body including the pallet 4, the clamp member 12, the piston 1
Since the pallet 4 is moved downward by its own weight such as 5, the clamp booster 35a can be made smaller than the clamp booster 35 of the first embodiment. Therefore, the consumption of the compressed air can be significantly reduced as compared with the first embodiment. Pallet 4
Is firmly clamped by the hydraulic pressure of the hydraulic oil 17 after descending.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
FIG. 6 is a circuit diagram of a pallet clamping / unclamping device 70 according to the embodiment. As shown in FIGS. 1 and 5, in the clamp / unclamp apparatus 70, the cleaning air flow path 55 is connected to the pneumatic circuit 31 (or
31a) and connect the pallet 4 to the table 5
At the time of clamping, the used compressed air exhausted from the booster 28 is ejected from the cleaning air flow path 55 through the pneumatic circuit 31 to the close contact portion between the pallet 4 and the table 5 for cleaning. I have. The flow path 71 provided in the pneumatic circuit 31 connects the switching valve 45 of the pneumatic circuit 31 and the electromagnetic switching valve 56 of the cleaning air flow path 55. The flow path 71 and the cleaning air flow path 55 constitute cleaning air blowing means for blowing compressed air to the close contact portion for cleaning.

According to this embodiment, the compressed air released into the atmosphere during the operation of the clamp / unclamp can be effectively used for the air blow at the contact portion between the pallet 4 and the table 5. As a result, the overall air consumption of the MC 1 can be reduced, so that the power consumption of the compressor and the like can be reduced and energy can be saved.

In the first to third embodiments, the case where the fixed body is the table 5 and the movable body is the pallet 4 has been described. However, the present invention relates to an apparatus for clamping / unclamping another movable body to the fixed body. Can also be applied. For example, it is installed in a machine tool such as a machining center and clamps and unclamps an index table (movable body) that has completed indexing operation to a saddle (fixed body), etc., and a tool post indexing machine tool such as a lathe. The present invention can also be applied to a turret clamping / unclamping device for fixing a turret (movable body) provided and having completed an indexing operation to a tool rest body (fixed body). That is, the present invention can be applied to a clamp / unclamp device for a movable body of a machine tool that performs a clamp / unclamp operation by driving a fluid pressure actuator device.

In each of the embodiments, the movable body is clamped by the clamp member that moves in the vertical direction. However, in other embodiments except the second embodiment, the clamp member that moves in the direction inclined by a predetermined angle is used. The movable member may be clamped by, for example, the clamp member may be moved in the horizontal direction and clamped. Also, the case where the fluid pressure actuator device is a fluid pressure cylinder device such as the hydraulic cylinder device 14 has been described, but a rotary actuator (a swinging device) having a first chamber on the clamp side and a second chamber on the unclamped side is described. Actuator). The working fluid for operating the fluid pressure actuator device has been described using a working oil, but is not limited to this. That is,
The working fluid may be an incompressible fluid or a less compressible fluid such as water.

According to the present invention, the hydraulic unit of the clamp / unclamp device for the movable body is not required, so that the power consumption is reduced, energy can be saved, and the entire machine tool can be made compact. That is, the compressed air is
Energy is not consumed except when the fluid pressure actuator device moves forward and backward for the unclamping operation. Since the hydraulic oil is not constantly circulating, there is almost no increase in the oil temperature and there is no deterioration. Therefore, periodic oil change is not required, and hydraulic oil does not leak outside during a change operation or the like. Also, no waste oil is generated. As a result, a machine tool having excellent environmental performance and workability can be provided.

Further, since vibration and heat are not transmitted from the hydraulic unit to the machine tool, the machining accuracy is not reduced. Boosters, converters, hydraulic circuits, pneumatic circuits, etc. can be easily mounted on the back of a machine tool column, etc., making transport and maintenance work easier. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0059]

Since the present invention is constructed as described above, it is possible to perform both operations of clamping and unclamping a movable body such as a pallet without providing a hydraulic unit.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a machine tool.

FIG. 2 is a circuit diagram of a pallet clamping and unclamping device according to the first embodiment of the present invention.

FIG. 3 is a circuit diagram of a pallet clamping and unclamping device according to a second embodiment of the present invention, showing an unclamped state.

FIG. 4 is a circuit diagram of the clamp / unclamp apparatus shown in FIG. 3, showing a clamped state.

FIG. 5 is a circuit diagram of a pallet clamping and unclamping device according to a third embodiment of the present invention.

[Description of Signs] 1 Machining center (machine tool) 4 Pallet (movable body) 5 Table (fixed body) 12 Clamp member 13, 60, 70 Clamp / unclamp device 14 Hydraulic cylinder device (fluid pressure actuator device) 17 Hydraulic oil ( Working fluid) 23, 24 Piston 25 Compressed air source 26 Compressed air 30, 30a Air-working oil converter (air-working fluid converter) 31, 31a Pneumatic circuit 32 Lower cylinder chamber (second chamber on unclamping side) 33 Booster for clamp (pneumatic-fluid pressure booster for unclamping) 34 Upper cylinder chamber (first chamber on clamp side) 35, 35a Booster for clamp (pneumatic-fluid pressure booster for clamp) 36 Mechanical valve for unclamping 37 For clamping Mechanical valve 37a, 59a No. Cylinder chamber (cylinder chamber) 37b, 59b First cylinder chamber (cylinder chamber) 39a Third cylinder chamber (small-diameter cylinder chamber for unclamping, cylinder chamber) 39b Third cylinder chamber (small-diameter cylinder chamber for clamping, cylinder Chamber) 41 flow path (second pressure fluid path) 42 flow path (first pressure fluid path) 46, 46a, 46b check valve

Claims (5)

[Claims] 1. A clamping and unclamping device for clamping and unclamping a movable body with respect to a stationary body of a machine tool by driving a fluid pressure actuator device, wherein the clamping and unclamping apparatus is provided on the stationary body side, and is provided on the clamp side. A fluid pressure actuator device for driving a clamp member for clamping the movable body with respect to the fixed body by supplying a working fluid having a predetermined pressure to the first chamber or the second chamber on the unclamping side; In order to supply the working fluid at a predetermined pressure to the first chamber, a cylinder air chamber having a different pressure receiving area is provided, and a clamp air pressure-fluid pressure for increasing the pressure of the compressed air to a predetermined pressure of the working fluid. A booster; and a cylinder chamber having a different pressure receiving area for supplying the working fluid at a predetermined pressure to the second chamber. An unclamping air pressure-fluid pressure booster for increasing the pressure to a constant pressure; and an air pressure capable of switching a supply direction of the compressed air supplied to the clamping air pressure-fluid pressure booster or the unclamping air pressure-fluid pressure booster. A circuit and a supply direction of the compressed air of the pneumatic circuit,
A controller for controlling the supply of the working fluid at the predetermined pressure to the first chamber or the second chamber. 2. The pneumatic-fluid booster for clamping and the pneumatic-fluid booster for unclamping,
The small-diameter cylinder chamber to which the working fluid is pressurized, the large-diameter cylinder chamber to which the compressed air is supplied, and the compressed air that fits into the small-diameter cylinder chamber and the large-diameter cylinder chamber and flows into the large-diameter cylinder chamber And a piston which can move forward and backward by the supply of the air pressure and the small diameter cylinder chamber for clamping of the air pressure-fluid pressure booster for clamping and the small diameter cylinder chamber for unclamping of the air pressure-fluid pressure booster for clamping.
When the working fluid in the small-diameter cylinder chamber for clamping or the small-diameter cylinder chamber for unclamping is likely to be insufficient or excessive due to the reciprocating movement of the piston,
An air-working fluid converter capable of supplying or recovering the working fluid, and provided in the small-diameter cylinder chamber for clamping, and a first pressure fluid passage from the small-diameter cylinder chamber for clamping to the first chamber in a closed circuit. Or a mechanical valve for clamping that switches between communicating the small-diameter cylinder chamber for clamping and the air-working fluid converter, and a mechanical valve provided in the small-diameter cylinder chamber for unclamping. An unclamping mechanical valve for switching between a closed circuit in the second pressure fluid passage up to the second chamber and a communication between the small diameter cylinder chamber for unclamping and the air-working fluid converter. The apparatus for clamping and unclamping a movable body of a machine tool according to claim 1, wherein: 3. The fluid pressure actuator device is a fluid pressure cylinder device provided with the first chamber and the second chamber vertically, and the clamp member is fixed to a piston rod of the fluid pressure cylinder device. The control device is configured to operate the predetermined pressure on the lower second chamber when the movable body is changed from the unclamped state to the clamped state. The method according to claim 1, wherein the supply of the fluid is stopped, and the movable body is controlled to supply the working fluid of the predetermined pressure to the first chamber after descending by its own weight. 4. Clamping and unclamping device for movable bodies of machine tools. 4. Connected to a discharge circuit of the pneumatic circuit,
Cleaning air jetting means for jetting and cleaning the compressed air to a close contact portion between the movable body and the fixed body, wherein when clamping the movable body to the fixed body, the unclamping air pressure-fluid The clamp / unclamp of a movable body of a machine tool according to any one of claims 1 to 3, wherein the compressed air exhausted from a pressure booster is jetted to the close contact portion to be cleaned. apparatus. 5. The pneumatic circuit according to claim 1, further comprising a check valve provided on a compressed air source side of the pneumatic circuit and capable of maintaining the air pressure in the pneumatic circuit. A clamping and unclamping device for a movable body of a machine tool according to any one of the above items.