JP6208480B2 - Cylinder device with booster mechanism - Google Patents

Description

  The present invention relates to a cylinder device provided with a booster mechanism, and more particularly to a technique suitable for detecting an operating state of the cylinder device.

Conventionally, this type of cylinder device with a booster mechanism is described in Patent Document 1 (Japan, JP 2007-268625 A).
In the conventional cylinder device, a first piston for advancing and retracting and a second piston for boosting are provided in a housing, an output rod is connected to the first piston, and the force of the pressure fluid applied to the second piston. Is boosted and transmitted to the output rod.

  JP 2007-268625 A

The above prior art is excellent in that the output rod can be driven strongly, but there is a problem that the operating state of the cylinder device cannot be detected.
An object of the present invention is to enable detection of an operating state of a cylinder device with a booster mechanism with a simple configuration.

In order to achieve the above object, according to the present invention, for example, as shown in FIGS. 1A to 3B (or FIGS. 4 and 5), a cylinder device with a booster mechanism is configured as follows.
A first piston 11 for advancing and retracting and a second piston 12 for a booster are provided in the housing 2. An output rod 13 is connected to the first piston 11. The force of the pressure fluid applied to the second piston 12 is boosted by the booster mechanism 40 and transmitted to the output rod 13. A detection valve 72 is provided in a detection air passage 70 formed in the housing 2. The detection valve 72 is opened and closed by the second piston 12 when the second piston 12 moves to a predetermined position.

  In the present invention, when the second piston for boosting moves to a predetermined position such as an end stroke, the second piston opens (or closes) the detection valve. For this reason, the pressure of the air passage for detection changes, and the operating state of the cylinder device can be detected by detecting the pressure change with a sensor such as a pressure switch. Therefore, the operating state of the cylinder device with a booster mechanism can be detected with a simple configuration.

In order to achieve the above object, another invention is configured as follows, as shown in FIGS. 1A to 3B (or FIG. 4 and FIG. 5), with a cylinder device with a booster mechanism.
A cylinder device configured to lock and drive an output rod 13 inserted into the housing 2 so as to be movable in the vertical direction, and a cylinder hole 3 formed in the housing 2 and a lower portion of the cylinder hole 3. A first piston 11 inserted and connected to the lower portion of the output rod 13 and a second piston 12 inserted into the upper portion of the cylinder hole 3 and externally fitted to the output rod 13 so as to be movable in the vertical direction. A lock chamber 23 that is disposed between the first piston 11 and the second piston 12 to supply and discharge pressure fluid, and is disposed below the first piston 11 to supply and discharge pressure fluid. A first release chamber 31 to be discharged; a second release chamber 32 which is arranged above the second piston 12 and to which pressure fluid is supplied and discharged; and the lock chamber 2. Is disposed in the second release chamber 32 so as to invert the force pushing the second piston 12 upward to a downward force and convert the force to the output rod 13 after being converted. A booster mechanism 40, which is arranged at a predetermined interval in the circumferential direction with a booster portion 48 provided on the second piston 12 and is wedge-driven inward in the radial direction by the booster portion 48. A booster mechanism 40 having a plurality of engaging balls 47, and a detection valve 72 for opening and closing a detection air passage 70 formed in the housing 2, wherein the second piston 12 moves to a predetermined position. And a detection valve 72 that is opened and closed by the second piston 12.

Another invention described above has the following effects.
By supplying the pressure fluid to the lock chamber disposed between the first piston and the second piston, the first piston can be pushed downward and the second piston can be pushed upward. Then, the force by which the pressure fluid in the lock chamber pushes the second piston upward is reversed downward through the booster portion of the booster mechanism and the engagement ball, and is strongly transmitted to the output rod.
Further, when the second piston moves to a predetermined position such as an end stroke, the second piston opens (or closes) the detection valve. For this reason, the pressure of the air passage for detection changes, and the operating state of the cylinder device can be detected by detecting the pressure change with a sensor such as a pressure switch. Therefore, the operating state of the cylinder device with a booster mechanism can be detected with a simple configuration.

In each of the above inventions, for example, as shown in FIGS. 1A to 3B (or FIGS. 4 and 5), the detection valve 72 is moved when the second piston 12 moves to the lock side stroke end as the predetermined position. Preferably, the second piston 12 is configured to be closed when the second piston 12 moves from the stroke end to the release side by a predetermined amount.
In this case, the lock side stroke end of the second piston can be detected with a simple configuration.

In the another invention, for example, as shown in FIGS. 1A to 3B, the cylinder hole 3 has an upper hole 4 and a lower hole 5 having a diameter larger than that of the upper hole 4. It is preferable to insert the first piston 11 and insert the second piston 12 into the upper hole 4.
As described above, the first piston is inserted into the large-diameter pilot hole and the second piston is inserted into the small-diameter upper hole. Therefore, when the cylinder device is switched from the locked state to the release state, the first piston is supplied to the first release chamber. The pressurized fluid can powerfully release drive the output rod via the large-diameter first piston.

In the above-mentioned another invention, for example, as shown in FIGS. 1A to 3B, the detection valve 72 is contacted with a valve member 77 protruding into the second release chamber 32 and the valve member 77. It is preferable to include a valve seat 81 and a closing spring 83 that urges the valve member 77 toward the valve seat 81.
In this case, the detection valve can be configured simply and compactly.

  FIG. 1A shows an embodiment of a clamping system using the cylinder device with a booster mechanism of the present invention, and is a sectional view in an elevational view of the clamping system in a released state. FIG. 1B is an enlarged view of a detection valve provided in the clamping system.   FIG. 2 is a view similar to FIG. 1A, showing the locked state of the clamping system.   FIG. 3A shows an abnormal state of the clamping system and is similar to FIG. 1A. FIG. 3B is a view similar to FIG. 1B above.   FIG. 4 is a view similar to FIG. 1B, showing a modification of the detection valve.   FIG. 5 is a view similar to FIG. 3B described above, showing the open state of the detection valve of the modified example.

1A-3B illustrate one embodiment of the present invention.
In this embodiment, the case where the present invention is applied to a system for clamping a workpiece by using a hole of the workpiece is illustrated.
First, the overall configuration of the clamping system will be described mainly with reference to FIGS. 1A and 1B.

  A housing 2 is attached to a clamp pallet 1 as a fixed base, and a cylinder hole 3 is formed in the housing 2. The cylinder hole 3 has an upper hole 4 and a lower hole 5 having a larger diameter than the upper hole 4.

The first piston 11 is inserted into the lower hole 5 via the lower sealing member 7 in a tightly packed manner. The first piston 11 is connected to the lower portion of the lower rod portion 14 of the output rod 13. The upper rod portion 15 of the output rod 13 is inserted into the cylindrical portion 2 a provided on the upper portion of the housing 2 via the upper sealing member 8 in a tightly packed manner.
Further, the annular second piston 12 is inserted into the upper hole 4 via the outer sealing member 18 in a close-packed manner, and the second piston 12 is inserted into the lower rod portion 14 via the inner sealing member 17. It is externally fitted so that it can move in the vertical direction. The lower rod portion 14 is formed with a larger diameter than the upper rod portion 15.
In this embodiment, both the first piston 11 and the output rod 13 are integrally formed. However, both the members may be formed separately.

A lock chamber 23 into which compressed air (pressure fluid) is supplied and discharged is disposed between the first piston 11 and the second piston 12. The lock chamber 23 communicates with the lock port 25 through the lock supply / discharge path 24.
A holding spring 27 is mounted between the first piston 11 and the second piston 12 in the lock chamber 23. The holding spring 27 is composed of a compression coil spring and urges the second piston 12 upward with respect to the first piston 11.

  In addition, a first release chamber 31 to which compressed air is supplied and discharged is disposed below the first piston 11, and compressed air is supplied and discharged to the upper side of the second piston 12. A release chamber 32 is arranged. The second release chamber 32 communicates with a release port (not shown) through a release supply / discharge path 34. The first release chamber 31 communicates with the second release chamber 32 through a communication passage 37 formed in the first piston 11 and the output rod 13.

  A booster mechanism 40 is disposed in the second release chamber 32. The booster mechanism 40 is configured so that the pressure fluid supplied to the lock chamber 23 inverts the force pushing the second piston 12 upward to a downward force, converts the boost, and transmits the force to the output rod 13. Is done. The booster mechanism 40 is configured as follows.

Four lateral grooves 41 are formed in the lower portion of the cylindrical portion 2a provided on the upper portion of the housing 2 with a predetermined interval in the circumferential direction. A receiving portion 42 is constituted by the bottom wall of each lateral groove 41. Further, four recesses 43 are formed on the outer peripheral surface of the intermediate height portion of the output rod 13 with a predetermined interval in the circumferential direction. A transmission portion 44 is constituted by the bottom wall of each recess 43. The transmission portion 44 is formed so as to approach the axis of the output rod 13 as it goes upward. The upper part of the communication passage 37 is opened at the bottom surface of the recess 43.
A wedge space 46 is formed between each of the receiving portions 42 and the transmitting portions 44 so as to narrow inward in the radial direction. An engagement ball 47 is inserted into the wedge space 46. A booster 48 is provided on the second piston 12 so as to push the engagement ball 47 inward in the radial direction. The booster 48 includes an inclined surface provided on the inner peripheral surface of the second piston 12. An arcuate pressing portion 49 is provided on the upper side of the boosting portion 48 at the upper portion of the second piston 12.

A lower flange 52 of the cap 51 is inserted into the upper portion of the housing 2 so as to be horizontally movable and vertically movable. The cap 51 is biased upward by the advance spring 53.
A plurality of guide holes 55 are penetrated through the peripheral wall of the cap 51 at predetermined intervals in the circumferential direction (only one guide hole 55 is shown here). A push member 56 is inserted into each guide hole 55 so as to be movable in the horizontal direction. The pressing member 56 includes a base portion 57 received on the upper surface of the lower flange 52 and a grip portion 58 for pressing the inner peripheral surface of the hole H of the workpiece W.

A belt-like elastic body 60 is attached to the outer periphery of the base portion 57 of the plurality of pressing members 56, and the elastic body 60 biases each pressing member 56 toward the axis of the cap 51. Note that the inner peripheral lip portion of the scraper 61 is brought into contact with the outer peripheral surface of the belt-shaped elastic body 60.
The plurality of push members 56 can be moved outward in the radial direction by the tapered surface 64 of the pull rod 63. A T leg 63a provided at the lower portion of the pull rod 63 is fitted to the upper portion of the output rod 13 so as to be horizontally movable.

  A detection air passage 70 is formed in the upper portion of the housing 2. A poppet type detection valve 72 is provided in the middle of the air passage 70. A pressurized air supply port 71 communicates with the lower portion of the supply passage 70a of the air passage 70, and a discharge passage 70b of the air passage 70 communicates with outside air. The detection valve 72 is configured as follows mainly as shown in FIG. 1B.

A valve hole 73 having a large diameter hole 74 and a small diameter hole 75 is formed in the upper part of the housing 2 in the vertical direction, and the lower end of the valve hole 73 is opened to the upper part of the second release chamber 32. A valve member 77 is inserted into the valve hole 73 so as to be vertically movable. The valve member 77 includes a main body portion 78 inserted into the large diameter hole 74 and a rod portion 79 inserted into the small diameter hole 75.
A valve seat 81 is formed at the step between the large-diameter hole 74 and the small-diameter hole 75, and the valve surface 82 formed on the lower surface of the main body 78 is biased to the valve seat 81 by a closing spring 83. Is done. The outer periphery of the rod portion 79 is sealed by the sealing member 85, and the lower end of the rod portion 79 protrudes into the second release chamber 32.
A jet passage 87 communicates with the large-diameter hole 74, and an upper portion of the jet passage 87 is opened to a seating surface S provided on the upper surface of the housing 2.

The clamping system configured as described above operates as follows.
1A and 1B, the compressed air in the lock chamber 23 is discharged and the compressed air is supplied to the first release chamber 31 and the second release chamber 32. As a result, the first piston 11 and the output rod 13 are raised, and the second piston 12 is lowered. Further, since the output rod 13 raises the pull rod 63, the elastic body 60 moves the plurality of pushing members 56 inward in the radial direction, and the advance spring 53 raises the cap 51 and the pushing member 56. Energizing position.

In this state, the workpiece W is carried into the upper part of the housing 2, and the hole H of the workpiece W is fitted on the cap 51 and the pressing member 56. Then, the lower surface of the workpiece W is received by the receiving surface R of the pressing member 56. For this reason, a seating gap G is formed between the lower surface of the workpiece W and the seating surface S of the housing 2.
Further, with respect to the detection valve 72, the urging force of the closing spring 83 brings the valve surface 82 into contact with the valve seat 81 against the upward force acting on the rod portion 79 from the compressed air in the second release chamber 32. For this reason, the detection valve 72 is kept closed.
Accordingly, the pressurized air in the supply port 71 is discharged to the outside through the ejection passage 87 and the seating gap G, and the pressure in the supply port 71 becomes lower than a predetermined pressure. By detecting the pressure state with a sensor such as a pressure switch, it can be confirmed that the clamping system is in the released state.

When the cylinder device is driven to lock, the compressed air in the first release chamber 31 and the second release chamber 32 is discharged and the compressed air is supplied to the lock chamber 23 in the release state of FIG. 1A. Then, the pressing portion 49 of the second piston 12 quickly moves the engagement ball 47 inward in the radial direction, and subsequently, as shown in FIG. 2, the booster portion 48 causes the engagement ball 47 to move in the radial direction. Strongly push inward.
Thus, the upward thrust acting on the second piston 12 is boosted downward through the booster 48 and the engagement ball 47, and the output rod 13 is driven strongly downward. For this reason, the output rod 13 is strongly driven downward by the resultant force of the pressing force by the booster mechanism 40 and the pressing force by the first piston 11.

  At the time of the above-described boosting drive, the tapered surface 64 of the pull rod 63 pushes the pressing member 56 held in the raised position by the urging force of the advance spring 53 outward in the radial direction, and the grip portion 58 of each pressing member 56 is moved. The workpiece W is brought into contact with the inner peripheral surface of the hole H of the workpiece W, and then the workpiece W is pulled down with the lining of the hole H. As a result, the workpiece W is strongly pressed against the seating surface S at the upper end of the housing 2.

In the locked state of FIG. 2, the detection valve 72 is held in the closed state as shown in FIG. 2 (and FIG. 1B). Further, the upper end of the ejection path 87 is closed by the lower surface of the workpiece W. For this reason, it can be confirmed that the pressure of the supply port 71 rises above the set value and the cylinder device is in the locked state.
In the locked state, since the holding spring 27 holds the engagement ball 47 driven by the wedge in the wedge engaged state, the locked state of the output rod 13 is reliably maintained. For this reason, even when the pressure in the lock chamber 23 disappears, the locked state can be maintained.

  When the cylinder device is switched from the locked state of FIG. 2 to the released state of FIG. 1A, the compressed air in the lock chamber 23 is discharged and the compressed air is supplied to the first release chamber 31 and the second release chamber 32. Then, first, the second piston 12 is lowered with respect to the output rod 13, and then the large-diameter first piston 11 strongly raises the pull rod 63 via the output rod 13. For this reason, the taper engagement between the tapered surface 64 of the pull rod 63 and the inner peripheral surface of the pressing member 56 can be reliably released.

The clamping system operates as follows as shown in FIGS. 3A and 3B.
For example, when the inner diameter dimension of the hole H of the workpiece W loaded is larger than the allowable range, the pushing member 56 remains held in the raised position by the advance spring 53 when the lock driving is performed as described above. Since the rod moves excessively outward in the radial direction, the pull rod 63, the output rod 13, and the first piston 11 are lowered to the lower limit position, and the second piston 12 is raised to the upper limit position (lock side stroke end). The upper part of the piston 12 raises the valve member 77 of the detection valve 72. As a result, the valve surface 82 is separated from the valve seat 81.
The detection valve 72 is closed when the second piston 12 is lowered by a predetermined amount from the upper limit position.

  In the state of FIG. 3A described above, for example, when an abnormal external force acts downward on the workpiece W and the lower surface of the workpiece W contacts the seating surface S, the ejection path 87 is closed. End up. However, since the detection valve 72 is opened as described above, the pressurized air of the supply port 71 causes the annular gap between the lower portion of the large diameter hole 74 of the valve hole 73 and the small diameter hole 75 and the rod portion 79. And are discharged to the outside through the discharge path 70b in order. For this reason, the pressure of the supply port 71 becomes lower than the predetermined pressure. By detecting the pressure state with a sensor such as a pressure switch, it can be confirmed that the clamping system is in an abnormal state.

The above embodiment can be modified as follows.
The receiving surface R of the pressing member 56 may be omitted. In this case, in the released state of FIG. 1A, the seating gap G is eliminated, and the lower surface of the workpiece W comes into contact with the seating surface S, so that the ejection path 87 is closed. Therefore, it can be confirmed that the clamping system is in an abnormal state when the second piston 12 rises to the upper limit position (lock side stroke end) and the detection valve 72 is opened during the lock driving described above.
Note that the ejection path 87 may be omitted.
The clamp member for clamping the workpiece W may use one annular collet instead of using the plurality of pressing members 56.

  4 and 5 show a modified example of the detection valve 72, and the detection valve 72 is configured in a spool type. FIG. 4 is a view similar to FIG. 1B, showing the closed state of the detection valve 72. FIG. 5 is a view similar to FIG. 3B, showing the open state of the detection valve 72. In this modification, the same reference numerals are given to members having the same functions as the members of the above embodiment.

A partition surface 90 is formed on the inner peripheral surface of the large-diameter hole 74 between the downstream end of the supply passage 70a and the upstream end of the discharge passage 70b. A closing surface 91 is formed on the outer peripheral surface of the main body 78 of the valve member 77.
In the state of FIG. 4, the closed surface 91 descends to the upper end of the partition surface 90, so that the pressurized air in the supply path 70 a is prevented from flowing out to the discharge path 70 b. Further, in the open state of FIG. 5, the closing surface 91 rises higher than the upper end of the partition surface 90. For this reason, the pressurized air in the supply path 70 a flows out to the discharge path 70 b through the annular gap between the partition surface 90 and the valve member 77.

The above embodiments and modifications can be further modified as follows.
The means for biasing the valve member 77 of the detection valve 72 toward the closing side may use the pressure of the second release chamber 32 instead of the illustrated closing spring 83. In this case, it is conceivable that a working chamber is formed on the upper side of the valve member 77 and the working chamber communicates with the second release chamber 32 through a longitudinal through hole formed in the valve member 77.
The detection valve 72 detects a predetermined position such as a lower limit position or an intermediate position of the second piston 12 instead of detecting an upper limit position (lock side stroke end) of the second piston 12. Also good. The arrangement posture of the detection valve 72 may be horizontal or oblique instead of the illustrated vertical orientation.
The first piston 11 and the second piston 12 may be arranged in parallel instead of being arranged in series as illustrated. In this case, it is conceivable that the second piston is fitted on the first piston so as to be movable up and down, and a lock chamber and a release chamber are formed on the lower side and the upper side of the two pistons, respectively.

The cylinder device of the present invention is not limited to the use for clamping a workpiece, but can also be used for clamping a work pallet, a mold, an attachment, or the like. As a member for clamping the clamping object such as the workpiece, a ball or the like can be used instead of the pressing member or the collet described above.
The pressure fluid for locking and releasing may be nitrogen gas or the like instead of compressed air, or may be a liquid such as pressurized oil.
The cylinder device may be disposed upside down from the illustration, or may be disposed obliquely.
It goes without saying that the present invention can be modified in other ways within the scope of those skilled in the art.

  2: housing, 3: cylinder hole, 4: upper hole, 5: lower hole, 11: first piston, 12: second piston, 13: output rod, 23: lock chamber, 31: first release chamber, 32: Second release chamber, 40: booster mechanism, 47: engagement ball, 48: booster, 70: air passage, 72: detection valve, 77: valve member, 81: valve seat, 83: closing spring.

Claims (5)

A first piston (11) for advancing and retreating provided in the housing (2) ;
A second piston (12) for boosting provided on the upper side of the first piston (11) in the housing (2) ;
An output rod (13) connected to the first piston (11);
A lock chamber (23) disposed between the first piston (11) and the second piston (12) to supply and discharge a pressure fluid;
A first release chamber (31) disposed under the first piston (11) to supply and discharge pressure fluid;
A second release chamber (32) disposed above the second piston (12) to which pressure fluid is supplied and discharged;
A booster mechanism (40) for converting the force of the pressure fluid applied to the second piston (12) to a booster and transmitting it to the output rod (13);
A detection valve (72) formed in the housing (2) for opening and closing a detection air passage (70) having one end communicating with a pressurized air supply port (71) and the other end communicating with outside air. A detection valve (72) that is opened and closed by the second piston (12) when the second piston (12) moves to a predetermined position;
Equipped with a,
The detection valve (72) includes a valve member (77) protruding into the second release chamber (32), a valve seat (81) with which the valve member (77) is abutted, and the valve member ( 77) and a closing spring (83) for urging the valve seat (81),
When the second piston (12) rises to the lock-side stroke end as the predetermined position, the second piston (12) raises the valve member (77) from the valve seat (81) to the valve. A cylinder device with a booster mechanism, wherein the member (77) is separated . A cylinder device configured to lock and drive the output rod (13) inserted into the housing (2) so as to be movable in the vertical direction,
A cylinder hole (3) formed in the housing (2);
A first piston (11) inserted into a lower portion of the cylinder hole (3) and connected to a lower portion of the output rod (13);
A second piston (12) inserted into the upper part of the cylinder hole (3) and externally fitted to the output rod (13) so as to be movable in the vertical direction;
A lock chamber (23) disposed between the first piston (11) and the second piston (12) to supply and discharge a pressure fluid;
A first release chamber (31) disposed under the first piston (11) to supply and discharge pressure fluid;
A second release chamber (32) disposed above the second piston (12) to which pressure fluid is supplied and discharged;
The pressure fluid supplied to the lock chamber (23) reverses the force pushing the second piston (12) upward to a downward force and converts the force to transmit to the output rod (13). A booster mechanism (40) disposed in the second release chamber (32), and disposed at a predetermined interval in the circumferential direction from the booster part (48) provided in the second piston (12). And a plurality of engagement balls (47) wedge-driven radially inwardly by the booster (48);
A detection valve (72) formed in the housing (2) for opening and closing a detection air passage (70) having one end communicating with a pressurized air supply port (71) and the other end communicating with outside air. A detection valve (72) that is opened and closed by the second piston (12) when the second piston (12) moves to a predetermined position;
Equipped with a,
The detection valve (72) includes a valve member (77) protruding into the second release chamber (32), a valve seat (81) with which the valve member (77) is abutted, and the valve member ( 77) and a closing spring (83) for urging the valve seat (81),
The valve member (77) is separated from the valve seat (81) when the second piston (12) is raised to the predetermined position by raising the valve member (77) by a predetermined amount. A cylinder device with a booster mechanism. The cylinder device with a booster mechanism according to claim 1 or 2,
The detection valve (72) is opened when the second piston (12) moves to the lock side stroke end as the predetermined position, and the second piston (12) is moved from the stroke end to the release side. Configured to close when moved only by a fixed amount,
A cylinder device with a booster mechanism. The cylinder device with a booster mechanism according to claim 2,
The cylinder hole (3) has an upper hole (4) and a lower hole (5) having a diameter larger than that of the upper hole (4).
The first piston (11) was inserted into the lower hole (5), and the second piston (12) was inserted into the upper hole (4).
A cylinder device with a booster mechanism. A cylinder device configured to lock and drive the output rod (13) inserted into the housing (2) so as to be movable in the vertical direction,
A cylinder hole (3) formed in the housing (2);
A first piston (11) inserted into a lower portion of the cylinder hole (3) and connected to a lower portion of the output rod (13);
A second piston (12) inserted into the upper part of the cylinder hole (3) and externally fitted to the output rod (13) so as to be movable in the vertical direction;
A lock chamber (23) disposed between the first piston (11) and the second piston (12) to supply and discharge a pressure fluid;
A first release chamber (31) disposed under the first piston (11) to supply and discharge pressure fluid;
A second release chamber (32) disposed above the second piston (12) to which pressure fluid is supplied and discharged;
The pressure fluid supplied to the lock chamber (23) reverses the force pushing the second piston (12) upward to a downward force and converts the force to transmit to the output rod (13). A booster mechanism (40) disposed in the second release chamber (32), and disposed at a predetermined interval in the circumferential direction from the booster part (48) provided in the second piston (12). And a plurality of engagement balls (47) wedge-driven radially inwardly by the booster (48);
A detection valve (72) formed in the housing (2) for opening and closing a detection air passage (70) having one end communicating with a pressurized air supply port (71) and the other end communicating with outside air. A detection valve (72) that is opened and closed by the second piston (12) when the second piston (12) moves to a predetermined position;
With
The detection valve (72) includes a valve member (77) that is inserted into a valve hole (73) that opens into the second release chamber (32) and protrudes into the second release chamber (32), and the valve A closed surface (91) formed on the outer peripheral surface of the member (77), a downstream end of the supply passage (70a) of the air passage (70), and an upstream end of the discharge passage (70b) of the air passage (70) The valve member (77) so that the partition surface (90) formed on the inner peripheral surface of the valve hole (73) and the closing surface (91) descend to the upper end of the partition surface (90) A closing spring (83) for biasing
When the second piston (12) rises to the predetermined position where the valve member (77) is raised by a predetermined amount, the closing surface (91) rises above the upper end of the partition surface (90). A cylinder device with a booster mechanism.

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