JP2002089509A - Compressed air supply and exhaust device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To powerfully drive a double acting air cylinder. SOLUTION: A first passage 51 is connected to a first supply and exhaust opening 23 for clamping a double acting air cylinder 12 and a second passage 52 is connected to a second supply and exhaust opening 52 for unclamping. A booster pump 53 is provided in the midway on the first passage to boost compressed air in a primary passage 51a of the first passage to supply the same to a secondary passage 51b. A selector valve 54 allows to select a first position D connecting a pressurized air source 55 to the primary passage 51a and connecting the second passage 52 to the atmosphere and a second position E connecting a pressurized air source 55 to the second passage 52 and connecting the primary passage 51a to the atmosphere. An open and close valve 56 is provided in an air release passage 84 branching off from the secondary passage 51b and a pilot passage 86 for opening operation of the open and close valve 56 is connected to the second passage 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for supplying and discharging compressed air to and from a double-acting pneumatic cylinder.

[0002]

2. Description of the Related Art In general, a supply / discharge device of this type is configured such that two supply / discharge ports of a double-acting pneumatic cylinder are selectively connected to a pneumatic source and outside air by a switching valve.

[0003]

The above prior art has a problem that the output of the pneumatic cylinder is small when the pressure of the pneumatic source is low. An object of the present invention is to enable a pneumatic cylinder to be driven strongly.

[0004]

Means for Solving the Problems In order to achieve the above object, the invention of claim 1 is constituted as follows, for example, as shown in FIG. A device for supplying and discharging compressed air to a first supply / discharge port 23 and a second supply / discharge port 24 of the double-acting pneumatic cylinder 12, wherein the first passage communicates with the first supply / discharge port 23. The second passage 52 communicated with the second supply / drain port 51 and the second supply / discharge port 24, and the compressed air in the primary passage 51a provided at an intermediate portion of the first passage 51 are supplied to the secondary passage 51b by increasing the pressure. A first position D that connects the booster pump 53 and the air pressure source 55 to the primary path 51a and the second passage 52 to the outside air and the air pressure source 55 to the second passage 52. Switching valve 54 having a second position E
And a pressure release path 84 branched from the secondary path 51b.
And the on-off valve 56 provided in the pressure release passage 84.

The first aspect of the present invention operates as follows, for example, as shown in FIG. The above pneumatic cylinder 1
When the second piston 20 advances to the left, the on-off valve 56 is maintained at the closed position M and the switching valve 5
4 is switched to the first position D. Then, the piston 20
The compressed air in the second chamber 22 on the left side of the
, The second passage 52 and the switching valve 54 at the first position D, and are discharged to the outside air. At the same time, the compressed air of the air pressure source 55 is supplied to the booster pump 53 via the switching valve 54 at the first position D and the primary path 51a of the first passage 51, and the supplied compressed air is The pressure is increased by the booster pump 53, and the increased pressure air is supplied to the first chamber 21 on the right side of the piston 20 through the secondary path 51b and the first supply / discharge port 23. Therefore, the high pressure air in the first chamber 21 causes the piston 2
0 moves to the left strongly.

On the other hand, when returning the piston 20 to the right, the switching valve 54 is switched to the second position E and the open / close valve 56 is switched to the open position N. Then, the compressed air of the air pressure source 55 is
The switching valve 54 at the position E, the second passage 52, and the second
The air is supplied to the second chamber 22 through the supply / discharge port 24. At the same time, the high-pressure air in the first chamber 21
The air is discharged to the outside air through the supply / discharge port 23, the secondary path 51b, and the open / close valve 56 at the opening position N. Therefore, the piston 20 is quickly returned to the right by the compressed air in the second chamber 22.

According to the first aspect of the present invention, as described above, compressed air having a higher pressure than the compressed air of the pneumatic source can be supplied to the first supply / discharge port. The pressure cylinder can be driven strongly. In addition, when the pneumatic cylinder is returned, the high-pressure compressed air can be quickly discharged from the first supply port to the outside air by opening the on-off valve, so that the pneumatic cylinder is quickly returned.

According to a second aspect of the present invention, in the first aspect of the present invention, the on-off valve 56 is provided with a spring 85
It is preferable that the pilot passage 86 be closed by the urging force and be opened by the pressure of the pilot passage 86, and the pilot passage 86 be connected to the second passage 52. The invention of claim 2 has the following operation and effect. When returning the pneumatic cylinder, the switching valve is set to the first position.
When switching from the position to the second position, the compressed air of the pneumatic source is supplied to the pilot path through the second passage, and the pressure of the pilot path switches the open / close valve to the open position. . Since the switching valve and the on-off valve are linked in this way, it is possible to reliably prevent the on-off valve from being accidentally opened. Moreover, in order to prevent the erroneous operation, it is only necessary to connect the pilot path to the second path, so that the circuit for preventing the pilot path is simplified, and the supply / discharge device can be made compact.

[0009] The invention of claim 3 provides the above-mentioned claim 1 or 2
The following configuration is added to the invention of (1). For example, FIG.
As shown in FIG. 2 (or FIG. 2), one end of a piston 20 inserted into the cylinder portion 13 of the pneumatic cylinder 12 is provided with a first chamber 21 for clamping which communicates with the first supply / discharge port 23.
And a second chamber 22 for unclamping communicating with the second supply / discharge port 24 at the other end of the piston 20.
, And the piston 20 was connected to the clamp 10 via the booster mechanism 30. According to the third aspect of the present invention, the piston can be strongly driven by supplying high-pressure compressed air to the first chamber for clamping by the booster pump, and subsequently, the driving force of the piston is doubled. The force can be converted by the force mechanism and transmitted to the clamp.
Therefore, a large clamping force can be obtained even when the pressure of the compressed air of the pneumatic source is relatively low.

According to a fourth aspect of the present invention, when the booster mechanism 30 is provided in the pneumatic cylinder 12 in the third aspect of the present invention, the internal space of the pneumatic cylinder is reduced. It can be used as an installation space for a boost mechanism. Therefore, the booster type pneumatic clamp device can be made compact.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
6 will be described with reference to FIG. In this embodiment, a case where the supply / discharge device of the present invention is applied to a system for clamping a die of a press machine is illustrated. As shown in the system diagram of FIG. 1, the system includes a plurality of pneumatic clamping devices 3 for fixing a mold 2 placed on an upper surface of a bolster 1 of a press machine, and compressed air is supplied to these clamping devices 3. And a supply / discharge device 4 for supplying and discharging the air. Here, only one clamp device 3 is shown.

First, the structure of the clamp device 3 will be described with reference to FIGS. 2 and 3 and FIGS. 4A and 4B. FIG.
FIG. 3 is a longitudinal sectional view of the clamp device 3 in an unclamped state. FIG. 3 is a longitudinal sectional view of the same clamp device 3 in a clamped state. FIG. 4A is 4A-4A in FIG.
It is sectional drawing of the left side view equivalent to a broken line arrow view. FIG. 4B
FIG. 4 is a right side view corresponding to the arrow 4B-4B in FIG.

The clamp device 3 has a support block 6, and a T leg 7 provided at a lower portion of the support block 6 is engaged with a T groove 8 of the bolster 1. An upper groove 9 is formed in the upper part of the support block 6, and a clamp arm 10 is inserted into the upper groove 9. The fulcrum 10a of the clamp arm 10 is swingably supported by the pivot pins 11 on the side walls 9a and 9b of the upper groove 9. Further, the T leg 7 is projected leftward on FIG.
Faces the output portion 10b of the clamp arm 10 in the up-down direction.

The cylinder portion 13 of the double-acting pneumatic cylinder 12 is fixed to the right surface of the upper half of the support block 6. More specifically, the cylinder portion 13 includes a cylinder barrel 14, a right end wall 15 as a first end wall, and a second end wall.
And an end plate 16 which is an end wall. The end plate 16 is inserted into the left end of the cylinder barrel 14 in a hermetically sealed manner and is prevented from falling off by a retaining ring 17. Then, as shown in FIG. 4B, four brackets 14a from the left end of the cylinder barrel 14 are formed.
The bracket 14a is provided with four bolts 1
8 detachably attached to the support block 6.

An annular piston 20 is inserted into the cylinder barrel 14 in a hermetically movable manner in the axial direction. A first chamber 21 for clamping is formed between the piston 20 and the right end wall 15, and a second chamber 22 for unclamping is formed between the piston 30 and the end plate 16. A first supply / discharge port 23 communicating with the first chamber 21 and a second supply / discharge port 24 communicating with the second chamber 22 are provided at a lateral portion of the cylinder barrel 14. A compression spring 25 for holding the clamp is mounted in the first chamber 21.

An output rod 26 is disposed concentrically with the piston 20 inside the piston 20 in the radial direction.
The output rod 26 is inserted into the through hole 16a of the end plate 16 in a sealed manner so as to be movable in the axial direction via a sealer 27 and a scraper 28. A predetermined radial gap G is provided between the outer peripheral surface of the output rod 26 and the through hole 16a on the left and right sides of the sealing member 27 and the scraper 28. The output gap 26 can be slightly swung up and down by the radial gap G.

A booster mechanism 30 is provided between the right half of the output rod 26 and the piston 20. The boosting mechanism 30 will be described with reference to FIGS. 5A to 5C and 6 with reference to FIGS. 5A to 5C are explanatory diagrams of the operation of the booster mechanism 30. FIG. 5A shows a release state, FIG. 5B shows a lock start state, and FIG. 5C shows a lock end state. . FIG. 6 is a schematic cross-sectional view of the booster mechanism 30 as viewed from the left side, in which the right half shows the released state and the left half shows the locked end state.

A first pressure receiving member 31 and a second pressure receiving member 32 face each other in the annular space between the piston 20 and the output rod 26 in the second chamber 22 in the axial direction.
An annular engagement space 33 is formed between the first and second pressure receiving members 31 and 32 so as to narrow inward in the radial direction. A plurality of engagement balls (engagement members) 34 are inserted into the engagement space 33 at predetermined intervals in the circumferential direction. The first cam surface 31a of the first pressure receiving member 31 and the second pressure receiving member 32
Although not shown, the second cam surface 32a of
It is preferable to form radially extending shallow U-shaped grooves at predetermined intervals in the circumferential direction, and to insert the engaging balls 34 into the respective U-shaped grooves. A pressing ring 36 is fitted on the inner periphery of the piston 20, and a pressing surface 37 of the pressing ring 36 is in contact with the plurality of engaging balls 34. As shown in FIGS. 5A to 5C, the pressing surface 37 includes an arc surface 38, a tapered surface 39, and a straight surface 40 formed in order from the left.

The first pressure receiving member 31 is formed in a nut shape and has a right end (first end) 26a of the output rod 26.
Screwed. The second pressure receiving member 32 is formed integrally with the end plate 16. Further, a lower groove 43 is formed in a lower portion of the clamp arm 10, and the lower end 43 (second end) 26 of the output rod 26 is formed in the lower groove 43.
b is inserted. The left end 26b is swingably connected to the input portions 10c provided on both side walls of the lower groove 43 by a connection pin 44.

The clamp device 3 operates as follows. In the unclamped state in FIG. 2, the compressed air is discharged from the first chamber 21 and the compressed air is supplied to the second chamber 22. Therefore, the piston 20 moves to the right (first end direction) against the urging force of the compression spring 25 by the pressure of the second chamber 22, and at the same time, the piston 20 The output rod 26 is turned leftward by pressure.
(The second end direction), and the clamp arm 10 is switched to the unclamping position Y. Therefore, a clamping clearance H is formed between the output portion 10b of the clamp arm 10 and the mold 2 described above. In order to surely return the clamp arm 10 to the unclamping position Y, the clamp arm 10
It is preferable to mount a return spring (not shown) between the input unit 10c and the end plate 16. In the unclamped state, as shown in the right half view of FIGS. 5A and 6, the booster mechanism 30 is switched to the released state, and the engaging ball 34 has a radius of the engaging space 33. Moving outward in direction.

When switching from the unclamped state of FIG. 2 to the clamped state of FIG. 3, the compressed air is supplied to the first chamber 21 and the compressed air is discharged from the second chamber 22. Thus, the piston 20 moves leftward by the pressure of the first chamber 21 and the urging force of the compression spring 25. That is, in the first embodiment, the driving means 47 is constituted by the compressed air supplied to the first chamber 21 and the compression spring 25.

By starting the leftward movement of the piston 20, first, as shown in FIG.
The arc surface 38 rapidly presses the engagement ball 34 inward in the radial direction of the engagement space 33 to rapidly move the output rod 26 to the right. Swings rapidly in the counterclockwise direction, and the output portion 10b comes into contact with the mold 2. Subsequently, as shown in FIG. 5C, the tapered surface 39 of the pressing ring 36 strongly presses the engaging ball 34 inward in the radial direction to strongly push the output rod 26 to the right. Move to As a result, as shown in FIG. 3, the clamp arm 10 is switched to the clamp position X, and the output portion 10b of the clamp arm 10 strongly presses the mold 2 against the upper surface of the bolster 1.

The T-slot 8 of the bolster 1
There is a fitting gap between this and the T leg 7. For this reason, in the case of a general T-leg that does not have the above-described protrusion 7a, the support block 6 is formed by a reaction force acting on the clamp arm 10 from the mold 2 during the clamp.
Tilt in the clockwise direction in FIG. 3, and it is required that the clamp arm 10 be additionally swingably driven. However, according to the present invention, since the protruding portion 7a is provided on the T-leg 7, the mold 2 can be sandwiched straight between the protruding portion 7a and the output portion 10b.
Therefore, unnecessary swing of the clamp arm 10 can be omitted, and the stroke of the pneumatic cylinder 12 can be reduced. As a result, the clamping device 3 is made compact and the consumption of compressed air is reduced.

In the clamped state shown in FIG. 3, even if the pressure in the first chamber 21 drops or disappears for some reason, the compression spring 25
A large sliding resistance can be applied to the components of the booster mechanism 30 by the urging force. Therefore, the booster mechanism 30
Is held in the locked state, and the clamp arm 10 can be securely held at the clamp position X.

When the clamped state shown in FIG. 3 is released, the compressed air in the first chamber 21 is discharged and the compressed air is supplied to the second chamber 22. Then, as shown in FIG. 2, the pressure of the compressed air causes the piston 20 to return to the right against the urging force of the compression spring 25. The output rod 26 returns to the left by the pressure of the compressed air. As a result, as shown in FIG. 2, the clamp arm 10 swings clockwise, and the output portion 10b of the clamp arm 10 is separated from the mold 2.

Next, the supply / discharge device 4 will be described with reference to FIG. 1 while referring to FIG. 2 and FIG. As shown in FIG. 1, the supply / discharge device 4 includes a first passage 51 and a second passage 52 connected to the first supply / discharge port 23 and the second supply / discharge port 24, respectively. Air / pneumatic booster pump 5 provided in the middle of passage 51
3, the primary passage 51a of the first passage 51 and the second passage 5
2 is provided with a switching valve 54 for connecting one of them to the pneumatic pressure source 55 and connecting the other to outside air, and an on-off valve 56 branched from the secondary passage 51b of the first passage 51 described above.

The switching valve 54 is a four-port, two-position solenoid valve, and can be switched between a first position D for clamping and a second position E for unclamping. . At the first position D, the compressed air from the air pressure source 55 is supplied to the primary passage 51a, and the compressed air from the second passage 52 is discharged to the outside air. At the second position E, the compressed air from the air pressure source 55 is supplied to the second passage 52 and the compressed air from the primary passage 51a is discharged to the outside air.

The booster pump 53 includes a casing 5
8, the pressure-increasing piston 60 inserted in the small-diameter hole 59 of the casing 58 in a hermetically sealed state, the drive piston 62 inserted in the large-diameter hole 61 of the casing 58 in the hermetically sealed state, and the pistons 60 and 62 described above. The piston rod 63 is provided. The booster pump 53 operates to supply compressed air having a pressure higher than the pressure of the air pressure source 55 to the first supply / discharge port 23.

More specifically, in the state shown in FIG. 1, the compressed air from the pneumatic source 55 is
a and the left and right inlet check valves 65 and 66 to the left
And the compressed air in the primary passage 51a is supplied to the left driving chamber 73 through the pressure regulating valve 70 and the switching valve 71 for reversing the right driving position R.
The right driving chamber 74 is communicated with the outside air via the switching valve 71 for inversion. Therefore, the drive piston 62 and the pressure-intensifying piston 60 move rightward to increase the pressure of the compressed air in the right pressure-increasing chamber 68, and the pressure-increased compressed air is transmitted to the right outlet check valve 78 and the right Is supplied to the first chamber 21 through the secondary passage 51b and the first supply / discharge port 23 in order. The pressure of the increased compressed air can be changed by adjusting the set pressure of the pressure regulating valve 70.

When the pressure increasing piston 60 moves to the vicinity of the right stroke end and presses the switching rod 80 rightward,
The reversing switching valve 71 is switched to the left driving position L. Then, the compressed air of the pressure regulating valve 70 is supplied to the right driving chamber 74 and the left driving chamber 73
Is communicated to the outside air. For this reason, the driving piston 6
2 and the pressure-increasing piston 60 moves to the left to increase the pressure of the compressed air in the left pressure-increasing chamber 67, and the pressure-increased compressed air is supplied to the left outlet check valve 77, the secondary path 51b, and the First
The air is supplied to the first chamber 21 through the supply / discharge port 23 in order. When the driving piston 62 moves to the vicinity of the left stroke end and presses the switching rod 80 to the left, the reversing switching valve 71 is moved to the left driving position L.
Is switched to the right driving position R, and the driving piston 62 and the pressure-intensifying piston 60 move rightward.

As described above, high-pressure compressed air is supplied to the first chamber 21 through the secondary passage 51b of the first passage 51 by reciprocation of the pressure-intensifying piston 60, and the high-pressure compressed air is As a result, the piston 20 is strongly driven leftward. Subsequently, as described above, the piston 20 further strongly clamps the output rod 26 and the clamp arm 10 via the booster mechanism 30. Therefore, even when the pressure of the compressed air from the pneumatic source 55 is relatively low, the clamp device 3 having a strong clamping force can be provided. In addition, the above-mentioned secondary path 51
When the pressure b rises to the set pressure, the pressure switch 82 detects the pressure, and it can be confirmed from the detection signal that the clamp device 3 is in the clamped state.

The pressure release path 84 branches from the secondary path 51b, and the open / close valve 56 is provided in the pressure release path 84. The on-off valve 56 is a pilot type 2
A switching valve of a port 2 position type, which is switched to the closed position M by the urging force of the spring 85 and is switched to the open position N by the pressure of the pilot passage 86 connected to the second passage 52. I have.

When switching the clamp device 3 from the clamped state to the unclamped state, the switching valve 54 may be switched from the first position D to the second position E. Then, the compressed air from the air pressure source 55 is supplied to the second chamber 22 through the second passage 52 and the second supply / discharge port 24. At the same time, the open / close valve 56 is switched to the open position N by the pressure of the pilot passage 86, so that the compressed air in the first chamber 21 is discharged to the outside air through the open / close valve 56. Thereby, the clamp arm 10 is unclamped as described above.

The above embodiment can be modified as follows. The switching valve 54 has a second position E for unclamping.
It is only necessary to supply compressed air to the second passage 52 when switching to the second position E, and it is not essential to discharge the compressed air from the primary passage 51a at the second position E. The open / close valve 56 may be another type of valve such as a solenoid valve instead of the illustrated pneumatic valve. The booster pump 53 is not limited to the illustrated type, and may be, for example, a single-acting spring return type instead of a double-acting type.

The clamp device 3 to which compressed air is supplied and discharged is
The type is not limited to the illustrated example, but may be a type in which the output rod 26 is pushed instead of the type in which the output rod 26 is pulled. The above clamping device 3
May be provided with another type of booster mechanism in place of the illustrated type of booster mechanism 30. More specifically, instead of providing the exemplified booster mechanism 30 between the piston 20 and the output rod 26, for example, an eccentric shaft is provided between the output rod 26 and the clamp arm 10. That is, a booster mechanism of the type is provided.

The above-described clamp device 3 may be a device for fixing another type of fixed object such as a work piece, instead of the illustrated mold 2. The supply / discharge device 4 of the present invention can be applied to a clamp device of a type that does not include the above-described boosting mechanism. The supply / discharge device 4 is a double-acting pneumatic cylinder 1
It is only necessary to supply and discharge compressed air to the apparatus 2, and it is needless to say that the use of the clamp device is not limited.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a system diagram of a mold fixing system using a supply / discharge device of the present invention.

FIG. 2 is a longitudinal sectional view of an unclamped state of a clamp device provided in the system.

FIG. 3 is a longitudinal sectional view of the clamp device in a clamped state.

FIG. 4A is a left side sectional view corresponding to a 4A-4A broken line arrow in FIG. 2 described above. FIG. 4B is a right side view corresponding to the arrow 4B-4B in FIG.

5A to 5C are explanatory diagrams of the operation of the booster mechanism of the clamp device. 5A shows a release state, FIG. 5B shows a lock start state, and FIG. 5C shows a lock end state.

FIG. 6 is a schematic cross-sectional view of the above-described boosting mechanism as viewed from the left side, in which the right half shows the release state and the left half shows the lock end state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Clamping tool (clamp arm), 12 ... Pneumatic cylinder, 13 ... Cylinder part, 20 ... Piston, 21 ... First chamber for clamping, 22 ... Second chamber for unclamping, 23
... First supply and discharge port, 24... Second supply and discharge port, 30.
DESCRIPTION OF SYMBOLS 1 ... 1st passage, 51a ... Primary path, 51b ... Secondary path, 52
... Second passage, 53 ... Booster pump, 54 ... Switching valve, 5
5: pneumatic pressure source, 56: open / close valve, 84: pressure release path, 85: spring, 86: pilot path, D: first position of the switching valve 54
(First position for clamping), E: second position of the switching valve 54
(Second position for unclamping).

Claims (4)

[Claims] A first supply / discharge port of a double-acting pneumatic cylinder (12).
(23) and a second supply / discharge port (24) for supplying and discharging compressed air, comprising: a first passageway (51) connected to the first supply / discharge port (23); 2 The second passage (5) communicated with the supply / discharge port (24).
2) a booster pump (53) provided in the middle of the first passage (51) to increase the pressure of the compressed air in the primary passage (51a) and supply the compressed air to the secondary passage (51b); (55) to the primary path (51a) and the second path (5
2) to the outside air at the first position (D) and the pneumatic source (5).
A switching valve (54) having a second position (E) communicating the second passage (5) with the second passage (52), and a pressure release passage (84) branched from the secondary passage (51b). And a switching valve (56) provided in the pressure release path (84). 2. The compressed air supply / discharge device according to claim 1, wherein the on-off valve (56) is closed by the urging force of a spring (85) and opened by the pressure of the pilot path (86). And the pilot path (86) is connected to the second path
(52) A compressed air supply / discharge device connected to (52). 3. The compressed air supply / discharge device according to claim 1, wherein one end of a piston (20) inserted into a cylinder portion (13) of the pneumatic cylinder (12) is provided with the second end. 1 supply and discharge port (2
A first chamber (21) for clamping communicating with 3) is provided, and the second supply / drain port is provided at the other end of the piston (20).
A second chamber (22) for unclamping communicating with the clamping device (24), wherein the piston (20) is connected to the clamping device (10) via a booster mechanism (30). Supply and discharge device. 4. The compressed air supply / discharge device according to claim 3, wherein the booster mechanism (30) is provided in the pneumatic cylinder (12). Discharge device.