JP2012112532A - Cylinder apparatus with booster mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact cylinder apparatus with a booster mechanism.SOLUTION: An output rod (2) is inserted in a housing (1) so as to be moved up and down. A first piston (21) inserted in the upper part of the housing (1) is fixed to the output rod (2) and a second piston (22) inserted in the lower upper part of the housing (1) is externally fit on the output rod (2) so as to be moved up and down. A lock chamber (25) is arranged between the first piston (21) and the second piston (22). A first release chamber (31) is arranged above the first piston (21), and a second release chamber (32) is arranged below the second piston (21). Pressure fluid is supplied to and discharged from the chambers (25, 31, 32). The engaging ball (40) of the booster mechanism (36) reverses a force of the pressure fluid pushing the second piston (22) downward to a force turning upward, and also transmits the force to the output rod (2) after booster conversion.

Description

  The present invention relates to a cylinder device provided with a booster mechanism. More specifically, the present invention relates to a technique suitable for firmly fixing an object to be fixed such as a workpiece or a mold and maintaining the fixed state.

  Conventionally, this type of cylinder device with a booster mechanism is described in Patent Document 1 (Japan, JP 2007-268625 A). The prior art is configured as follows.

A clamp rod as an output rod is inserted into the housing so as to be movable in the vertical direction. A first piston for a rod inserted into the upper portion of the housing is fixed to the clamp rod, and a first lock chamber and a first release chamber are formed on both upper and lower sides of the first piston. A second piston for boosting inserted in the lower part of the housing is fitted on the clamp rod so as to be movable in the vertical direction, and a second lock chamber and a second release chamber are provided on both upper and lower sides of the second piston. Is formed.
When the clamp rod is driven to lock, compressed air is supplied to the first lock chamber and the second lock chamber to drive the first piston and the second piston downward. Then, first, the first piston drives the clamp rod downward during the low load stroke of the lock drive, and the second piston doubles the clamp rod downward via the booster mechanism during the subsequent high load stroke. Power driven.
Conventionally, the booster mechanism includes an engagement groove provided at a lower portion of the clamp rod and a plurality of claw members supported swingably at the lower portion of the housing. During the boost driving, the tapered surface of the second piston driven downward swings the claw member inward in the radial direction, and engages the claw member with the engagement groove.

JP 2007-268625 A

The above prior art has the following problems.
At the time of the boost driving, the downwardly driven second piston boosts the clamp rod downward via the claw member and the engaging groove, so that a large reaction force at the boost driving is the engagement groove. Acting upward on the claw member, and pulling the claw member strongly upward. For this reason, the structure for supporting the claw member on the housing in a swingable manner needs to be strengthened, and the support structure becomes large, and the cylinder device becomes large.
In the above prior art, it is necessary to partition the first release chamber formed on the lower side of the first piston and the second lock chamber formed on the upper side of the second piston. It is necessary to provide a thick partition wall. For this reason, the height of the housing is increased, and the cylinder device is further increased in size.
An object of the present invention is to make a cylinder device with a booster mechanism small.

In order to achieve the above object, each of the following first and second inventions includes a cylinder device with a booster mechanism as shown in FIGS. 1A to 1D, FIG. 2, or FIGS. 3A to 3D, for example. The configuration is as follows.
[About the first invention]
An output rod 2 inserted into the housing 1 so as to be movable in the axial direction, a first piston 21 for the rod connected to the output rod 2 in the housing 1, and the first piston 21 in the housing 1. On the other hand, a booster second piston 22 is provided which is arranged in series and is externally fitted to the output rod 2 so as to be movable in the axial direction. When the output rod 2 is driven for boosting, the second piston 22 boosts the output rod 2 via the boosting mechanism 36, and the first piston 21 also drives the output rod 2. Constitute. Between the first piston 21 and the second piston 22, a lock chamber 25 to which pressure fluid is supplied and discharged is disposed, and the lock chamber 25 is formed between the first piston 21 and the second piston 22. Both are configured to be pushed in the direction in which they are separated. A first release chamber 31 that is arranged to push the first piston 21 toward the second piston 22 and that is supplied and discharged with pressure fluid, and to push the second piston 22 toward the first piston 21. And a second release chamber 32 through which pressure fluid is supplied and discharged. The booster mechanism 36 is formed to be radially inwardly narrowed between the transmission portion 37 provided on the output rod 2 and the receiving portion 38 provided on the housing 1 during the above-described boost drive. A wedge space 39, an engagement ball 40 inserted into the wedge space 39 at a predetermined interval in the circumferential direction, and the second piston 22 to push the engagement ball 40 inward in the radial direction. The pressure fluid supplied to the lock chamber 25 is connected to the second piston 22 in a state where the pressure fluid is discharged from the first release chamber 31 and the second release chamber 32. The force that pushes away from the first piston 21 is reversed to the force toward the first piston 21 via the engagement ball 40, and is converted to a boost and transmitted to the output rod 2.

Said 1st invention has the following effect.
By supplying the pressure fluid to the lock chamber disposed between the first piston and the second piston, the first piston can be pushed toward one end of the housing and the second piston can be pushed toward the other end of the housing. . The force with which the pressure fluid in the lock chamber pushes the second piston toward the other end is reversed and transmitted to the output rod via the engagement ball of the booster mechanism. For this reason, a large reaction force at the time of boost driving acts on the housing from the output rod via the boost mechanism. Therefore, the present invention can employ a structure for receiving a compressive force instead of the structure for receiving the pulling force in the prior art as a structure for receiving a large reaction force at the time of boost drive. As a result, the receiving structure can be simply configured, and the cylinder device can be made small.

  In the present invention, a lock chamber is formed between the first piston and the second piston, and a first release chamber and a second release chamber are formed outside the first piston and outside the second piston. Therefore, unlike the above-described prior art, it is not necessary to provide a thick partition wall in the middle height portion of the housing. In addition, since the pressure fluid is supplied to and discharged from the first release chamber and the second release chamber, it is not necessary to attach a release return spring to each of the release chambers. It became possible to omit. For this reason, the height of the housing can be greatly reduced to make the cylinder device more compact.

[About the second invention]
An output rod 2 inserted into the housing 1 movably toward the first end side and the second end side as one end side and the other end side in the axial direction, and disposed on the first end side in the housing 1 A first piston 21 for the rod connected to the output rod 2 and a booster arranged on the second end side in the housing 1 and externally fitted to the output rod 2 so as to be movable in the axial direction And a lock chamber 25 disposed between the first piston 21 and the second piston 22 for supplying and discharging a pressure fluid, the first piston 21 being the first piston 21. A lock chamber 25 configured to push the second piston 22 to the second end side while pushing to the end side, and the first piston 21 to push the first piston 21 to the second end side. When placed on one end, The first release chamber 31 to which pressure fluid is supplied and discharged, and the second piston 22 are arranged on the second end side so as to push the second piston 22 toward the first end side, and the pressure fluid is supplied. And a second release chamber 32 to be discharged. Further, in a state where the pressure fluid is discharged from the first release chamber 31 and the second release chamber 32, a pressure fluid supplied to the lock chamber 25 pushes the second piston 22 toward the second end side, A booster mechanism 36 configured to convert the force into the force toward the first end and transmit the force to the output rod 2 is provided. The booster mechanism 36 is formed to be radially inwardly narrowed between the transmission portion 37 provided on the output rod 2 and the receiving portion 38 provided on the housing 1 during the above-described boost drive. A wedge space 39, an engagement ball 40 inserted into the wedge space 39 at a predetermined interval in the circumferential direction, and the second piston 22 to push the engagement ball 40 inward in the radial direction. And the second piston 22 boosts the output rod 2 to the first end side via the engagement ball 40 when the output rod 2 is boosted. The first piston 21 is also configured to drive the output rod 2 toward the first end.
Said 2nd invention has an effect substantially the same as the effect of the said 1st invention.

  In the present invention, the first release chamber 31, the first piston 21, the lock chamber 25, the second piston 22, and the second release chamber 32 are sequentially arranged in the axial direction. A communication hole 34 for connecting the first release chamber 31 and the second release chamber 32 is preferably provided in the output rod 2.

  In this case, there is no need to provide a hole or pipe for connecting the two release chambers outside the housing body or the housing, so that the cylinder device can be made even smaller.

  Furthermore, it is preferable that the present invention adds a unique configuration described in each embodiment described later.

1A to 1D are schematic views showing a first embodiment of the present invention. FIG. 1A is a sectional view in an elevational view of a released state of the cylinder device. FIG. 1B is a view similar to FIG. 1A, showing an end state of a low load stroke in the lock driving stroke of the cylinder device. FIG. 1C shows an initial state of boost driving of the cylinder device, and is a view similar to FIG. 1A. FIG. 1D shows a locked state at the end of the boost drive of the cylinder device, and is a view similar to FIG. 1A. It is a figure which shows the cylinder apparatus of 2nd Embodiment of this invention, and is equivalent to the said FIG. 1C. 3A to 3D show a third embodiment of the present invention. FIG. 3A is a view showing a retracted state of a swing-type clamp member provided in the cylinder device, and is a view similar to FIG. 1A. FIG. 3B shows a state where the rotation of the clamp member is completed in the lock driving process of the cylinder device, and corresponds to a state between the state shown in FIG. 1A and the state shown in FIG. 1B. FIG. 3C is a view similar to FIG. 1C, showing a state in which the clamp member is prepared for locking. FIG. 3D is a view similar to FIG. 1D, showing a locked state of the clamp member. It is an enlarged view of the booster mechanism provided in the said 3rd Embodiment, Comprising: The left half figure has shown the release state, and the right half figure has shown the locked state. It is a figure which shows the modification of the said booster mechanism, and is equivalent to the release state of the left half figure of the said FIG.

1A to 1D are schematic views showing a first embodiment of the present invention.
First, the structure of the cylinder device with a booster mechanism will be described with reference to FIG. 1A showing the released state.
An output rod 2 is inserted into the housing 1 so as to be movable in the vertical direction. The upper rod portion 2a of the output rod 2 is supported in a tightly sealed manner by the upper hole 5 provided in the upper end wall (first end wall) 1a of the housing 1 via the sealing member 6, and the lower end wall of the housing 1 The lower rod portion 2b of the output rod 2 is supported by the lower hole 7 provided in the (second end wall) 1b. The lower rod portion 2b is formed with a larger diameter than the upper rod portion 2a.

  A first cylinder hole 11 and a second cylinder hole 12 are formed in the body 1c of the housing 1 in the vertical direction. A first piston 21 for a rod is inserted into the first cylinder hole 11 via a sealing member 14 in a tightly sealed manner, and the first piston 21 is fixed to the output rod 2. Further, the second piston 22 for boosting is inserted into the second cylinder hole 12 via the outer sealing member 16 in a close-packed manner, and the second piston 22 is inserted into the output rod 2 via the inner sealing member 17. It can be moved in the vertical direction and is externally fitted tightly.

A lock chamber 25 is disposed between the first piston 21 and the second piston 22. Locked compressed air can be supplied to and discharged from the lock chamber 25 via a lock supply / discharge passage 26 and a lock port (not shown).
A first release chamber 31 is disposed above the first piston 21 and a second release chamber 32 is disposed below the second piston 22. The first release chamber 31 and the second release chamber 32 are connected by a communication hole 34 formed in the output rod 2. Thereby, compressed air for release can be supplied to and discharged from the first release chamber 31 and the second release chamber 32 through the release supply / discharge passage 27 and the release port (not shown). .

  In the second release chamber 32, a booster mechanism 36 is provided on the output rod 2 and the second piston 22. The booster mechanism 36 inverts the force that the compressed air supplied to the lock chamber 25 pushes the second piston 22 downward into an upward force and converts the force to the output rod 2 by converting the boost. Configured as follows.

  The booster mechanism 36 is configured as shown in FIG. 1C or later-described FIG. 2 (initial state of boost drive). That is, an annular wedge space 39 is formed between the transmission portion 37 provided at the lower end portion of the lower rod portion 2b and the receiving portion 38 provided at the lower end wall 1b so as to narrow inward in the radial direction. . A plurality of engagement balls 40 are inserted into the wedge space 39 at predetermined intervals in the circumferential direction. A booster 41 is provided on the second piston 22 so as to push the engagement ball 40 inward in the radial direction. More specifically, each of the above members is configured as follows.

In the first embodiment, four recesses 43 are formed at substantially equal intervals in the circumferential direction on the outer peripheral surface of the lower end of the lower rod portion 2b. The bottom wall of each recess 43 constitutes the transmission portion 37 described above. The transmission part 37 is inclined so as to approach the axis as it goes downward.
Four lateral grooves 46 are formed in the circumferential direction on the upper portion of the cylindrical portion 45 that protrudes upward from the lower end wall 1 b of the housing 1. The receiving portion 38 is constituted by the bottom wall of each lateral groove 46.
The booster 41 is constituted by an inclined surface provided on the inner peripheral surface of the second piston 22. A pressing portion 48 described later is provided below the booster portion 41 so as to continue to the booster portion 41. Here, the pressing portion 48 is constituted by an inclined surface.

The cylinder device having the above configuration operates as follows.
In the release state of FIG. 1A, the compressed air is discharged from the lock chamber 25 and the compressed air is supplied to the first release chamber 31 and the second release chamber 32. Thereby, the compressed air in the second release chamber 32 pushes the second piston 22 upward, and the compressed air in the first release chamber 31 pushes the first piston 21 downward.
In this case, a stopper portion provided at an intermediate height portion of the body portion 1c of the housing 1 by a differential force between an upward force acting on the second piston 22 and a downward force acting on the first piston 21 and the output rod 2. The outer peripheral portion of the upper surface of the second piston 22 is received by 49, and the lower surface of the first piston 21 is received by the central portion of the upper surface of the second piston 22. A predetermined gap G is formed between the pressing portion 48 of the second piston 22 and the engagement ball 40.

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 25 in the release state of FIG. 1A.
Then, first, the compressed air in the lock chamber 25 pushes the first piston 21 upward and pushes the second piston 22 downward. As a result, as shown in FIG. 1B (the final state of the low load stroke of the lock driving stroke), the pressing portion 48 of the second piston 22 is received by the receiving portion 38 of the lower end wall 1b via the engagement ball 40, The pushing portion 48 pushes the engaging ball 40 inward in the radial direction toward the outer peripheral surface of the output rod 2 to contact the outer peripheral surface, and the frictional force resulting from the contact and the sealing member 6 , 14 and 17, the compressed air in the lock chamber 25 moves up the output rod 2 through the first piston 21 against a low load caused by the frictional force of the friction force of the first, second, and 17th members.

  When the output rod 2 is raised, the wedge space 39 is formed between the transmission portion 37 provided below the output rod 2 and the receiving portion 38 provided on the lower end wall 1b (see FIG. 1C). The portion 48 pushes the engagement ball 40 into the wedge space 39, so that the boost driving can be started.

  Next, as shown in FIG. 1C (initial state of boost driving), the output rod 2 is further raised, and the upper end of the output rod 2 is received by a work (not shown), and the output rod 2 is When a load is applied, the booster 41 of the second piston 22 pushes the engagement ball 40 inward in the radial direction. Thereby, the downward thrust acting on the second piston 22 is boosted upward via the booster 41, the engagement ball 40, the receiving part 38 and the transmission part 37, and the output rod 2 is turned upward. Powerfully driven.

  Subsequently, as shown in FIG. 1D (the locked state at the end of the boost drive), the second piston 22 moves the boost mechanism 36 to the output rod 2 received by the work (not shown) and prevented from rising. Push upwards through. For this reason, the output rod 2 is strongly pushed upward by the resultant force of the push-up force by the booster mechanism 36 and the push-up force by the first piston 21.

Incidentally, in the booster mechanism 36, when the friction coefficient is 0.08 to 0.15, the “pushing force by the booster mechanism 36” with respect to the “downward thrust of the second piston 22” is about 2-3. .5 times.
In the locked state of FIG. 1D, the holding force by the booster mechanism 36 (the force that prevents the external force acting on the output rod 2 from releasing the locked state) is the “second piston 22 downward thrust”. About 5 to 10 times. For this reason, the locked state can be held mechanically powerfully.

Here, the downward thrust of the second piston 22 is inverted upward and transmitted to the output rod 2 via the booster 41, the engagement ball 40, the receiving part 38 and the transmitting part 37. For this reason, a large reaction force at the time of the boost drive acts as a compressive force on the lower end wall 1 b of the housing 1 from the output rod 2 through the engagement ball 40 and the receiving portion 38. Therefore, as shown in FIG. 1D, the structure for receiving a large reaction force at the time of boost driving is a simple structure in which the cylinder portion 45 for receiving the compression force is provided on the lower end wall 1b. As a result, the cylinder device Can be made small.
The inclination angle of the pressing portion 48 with respect to the axis of the output rod 2 is set to a value larger than the inclination angle of the booster portion 41 with respect to the axis. Thereby, the force by which the pushing portion 48 pushes the engagement ball 40 inward in the radial direction is smaller than the force by which the boosting portion 41 pushes the engagement ball 40 inward in the radial direction. For this reason, at the time of the low load stroke, the frictional force due to the contact between the outer peripheral surface of the output rod 2 and the engagement ball 40 becomes small, and the output rod 2 rises smoothly.

  When the cylinder device is switched from the locked state of FIG. 1D to the released state of FIG. 1A, the compressed air in the lock chamber 25 is discharged and the compressed air is supplied to the first release chamber 31 and the second release chamber 32 in FIG. To do.

Then, first, the compressed air in the second release chamber 32 raises the second piston 22 with respect to the output rod 2 whose lowering is prevented by the engagement ball 40. When the second piston 22 is further raised, the engagement ball 40 is switched to the state shown in FIG. 1B through the state shown in FIG. 1C, and the output rod 2 and the first piston 21 are allowed to descend. Next, the second piston 22 raised by the compressed air in the second release chamber 32 is received by the stopper portion 49, and then the first piston 21 descends the output rod 2 as shown in FIG. 1A (release state). The lower surface of the first piston 21 contacts the upper surface of the second piston 22.
At the end of the lowering of the output rod 2, the gap G shown in FIG. 1 is formed between the pressing portion 48 of the second piston 22 and the engagement ball 40, so that it engages with the outer peripheral surface of the output rod 2. The frictional force acting between the balls 40 is almost eliminated, and the output rod 2 is smoothly lowered.

  In the first embodiment described above, the shape of the recess 43 that constitutes the transmitting portion 37 and the lateral groove 46 that constitutes the receiving portion 38 may be an arc-shaped groove, a U-shaped groove, a Gothic arch groove, or the like. It is done. This also applies to other embodiments and modifications described later.

  FIG. 2 shows a second embodiment of the present invention, FIGS. 3A to 3D and FIG. 4 show a third embodiment of the present invention, and FIG. 5 shows a modification of the booster mechanism. In these other embodiments and modifications, the same members (or similar members) as the constituent members of the first embodiment will be described with the same reference numerals in principle.

The second embodiment of FIG. 2 illustrates the case where a link type clamp mechanism for fixing a workpiece (not shown) is provided in the cylinder device. FIG. 2 shows an initial state of the boost drive of the cylinder device, and corresponds to FIG. 1C described above.
The second embodiment shown in FIG. 2 differs from the first embodiment described above in the following points.

  The housing 1 is attached to a fixed base T such as a table. The left end portion of the clamp member 55 is supported by the upper portion of the output rod 2 projecting upward from the upper end wall (first end wall) 1a of the housing 1 via the first pin 51 so as to be rotatable in the vertical direction. Is done. The upper portion of the link member 56 is rotatably supported by the intermediate portion in the lateral direction of the clamp member 55 via the second pin 52. A lower portion of the link member 56 is rotatably supported by a support portion 57 that protrudes upward from the upper end wall 1 a via a third pin 53.

  The pressing portion 48 provided at the lower portion of the second piston 22 is configured as an arc surface in a sectional view, instead of the inclined surface of the first embodiment. The receiving part 38 provided in the upper part of the lower end wall (2nd end wall) 1b of the housing 1 is comprised by the bottom wall of the inclination groove | channel, and is inclined so that it may approach an axial center as it goes below.

When the cylinder device is driven to lock, first, as shown in FIG. 2, the compressed air in the lock chamber 25 raises the output rod 2 via the first piston 21, and the booster mechanism 36 is in the initial state of boost drive. And the clamp member 55 is quickly rotated in the clockwise direction. Subsequently, when the push bolt 58 provided at the right end of the clamp member 55 comes into contact with a work (not shown) from above and a high load acts on the output rod 2, the compressed air in the lock chamber 25 is compressed. Strongly pushes up the output rod 2 via the second piston 22 and the engagement ball 40 of the booster mechanism 36, whereby the clamp member 55 is driven strongly in the clockwise direction.
The release drive of the cylinder device is performed in the reverse procedure to the lock drive as described in the first embodiment.

The second embodiment described above can be modified as follows.
The lower part of the output rod 2 is protruded downward from the lower end wall 1b, and the protruding portion is inserted into the lower end wall 1b in a tight manner. And the to-be-detected part of the operation state of a cylinder apparatus is connected to the lower part of the said protrusion part, and sensors, such as a limit switch, are made to face the to-be-detected part.

The third embodiment shown in FIGS. 3A to 3D and FIG. 4 exemplifies a case where a turning clamp mechanism for fixing a fixed object (not shown) such as a work is provided in the cylinder device.
First, the structure of the cylinder device will be described with reference to FIG. 3A (released state).
A first cylinder hole 11 and a second cylinder hole 12 are formed upward in the body 1c of the housing 2. The rod first piston 21 is inserted into the lower first cylinder hole 11, and the boosting second piston 22 is inserted into the upper second cylinder hole 12. A first release chamber 31 is disposed below the first piston 21, and a second release chamber 32 is disposed above the second piston 22. The booster mechanism 36 is disposed in the second release chamber 32.

That is, in the third embodiment, the first piston 21, the second piston 22, and the booster mechanism 36 are disposed upside down as compared with the first and second embodiments.
More specifically, in each drawing of the above-described embodiments, the first end side that is one end side in the axial direction of the output rod 2 is the upper side, and the second end side that is the other end side in the axial direction is the upper side. In contrast to the lower side, in each drawing of the third embodiment, the first end side which is one end side in the axial direction of the output rod 2 is set as the lower side and the other end in the axial direction. The second end side which is the side is the upper side.

The lower rod portion 2b of the output rod 2 is supported in the lower hole 7 of the lower end wall (first end wall) 1b of the housing 1 so as to be movable in the vertical direction and rotatable about the axis. The upper rod portion 2a of the output rod 2 is supported in a close-packed manner in the upper hole 5 of the upper end wall (second end wall) 1a so as to be movable in the vertical direction and rotatable about the axis. The output rod 2 protrudes above the upper end wall 1a, and a clamp member 55 (see FIGS. 3B to 3D) configured by a cantilever arm is attached to the protruding portion of the output rod 2 with a nut 61.
The rod body 2c of the output rod 2 is formed to have a larger diameter than the upper rod portion 2a.

A guide mechanism 62 is provided on the lower end wall 1b and the lower rod portion 2b. The guide mechanism 62 has a known structure and is configured as follows (see, for example, Japanese Patent Application Laid-Open No. 2004-1163).
In the lower rod portion 2b, a plurality of guide grooves 63 are formed at equal intervals in the circumferential direction (only one guide groove 63 is shown here). Each guide groove 63 is configured by connecting a spiral turning groove 63a and a rectilinear groove 63b upward (see FIG. 3B). The guide balls 64 fitted in the respective guide grooves 63 are inserted into through holes 66 provided in the cylindrical member 65 protruding upward from the lower end wall 1b. A rotating sleeve 67 is fitted on the plurality of guide balls 64.

The booster mechanism 36 is configured as follows mainly as shown in the enlarged view of FIG. In FIG. 4, the left half view shows the released state, and the right half view shows the locked state.
The transmission portion 37 is formed in a step portion 69 provided between the upper rod portion 2a and the rod body 2c. That is, four recesses 43 are formed in the step portion 69 at substantially equal intervals in the circumferential direction (only one recess 43 is shown here), and the bottom wall of each recess 43 is A transmission unit 37 is configured. The transmission part 37 is inclined so as to approach the axis as it goes upward.

Further, a receiving sleeve 71 is secured to the upper end wall (second end wall) 1 a of the housing 1 by a pin 72. The receiving portion 38 is formed below the receiving sleeve 71. The receiving portion 38 is constituted by the bottom wall of the groove. And the said receiving part 38 is provided with the inner inclination wall 74 and the outer inclination wall 75 which approach an axial center as it goes below.
The stopper portion 49 provided on the body portion 1c of the housing 1 is constituted by a retaining ring.

The cylinder device having the above configuration operates as follows.
In the release state of FIG. 3A, the compressed air is discharged from the lock chamber 25 and the compressed air is supplied to the first release chamber 31 and the second release chamber 32. Thereby, the compressed air in the second release chamber 32 pushes the second piston 22 downward, and the compressed air in the first release chamber 31 pushes the first piston 21 upward.
Thereby, the clamp member 55 is switched to the swivel retracted state.

When the cylinder device is locked, 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 25 in the release state of FIG. 3A.
Then, first, the compressed air in the lock chamber 25 pushes the first piston 21 downward, lowers the output rod 2 with a low load, and pushes the second piston 22 upward. As a result, as shown in FIG. 3B, the guide ball 64 is lowered while turning the output rod 2 and the clamp member 55 with a low load through the turning groove 63a. The wedge space 39 starts to be formed between the transmitting portion 37 provided in the stepped portion 69 and the receiving portion 38 provided in the receiving sleeve 71.

  Subsequently, as shown in FIG. 3C (initial state of the boost drive), the guide ball 64 causes the output rod 2 to go straight down with a low load through the straight advance groove 63b of the guide groove 63, and then the clamp When the lower surface of the right portion of the member 55 is received by a work (not shown) and a high load is applied to the output rod 2, the upward thrust of the second piston 22 causes the engaging ball 40 to be engaged via the booster 41. Push inward in the radial direction. As a result, the upward thrust of the second piston 22 is boosted and converted into downward force via the booster 41, the engagement ball 40, the receiving part 38, and the transmitting part 37, and the output rod 2 is powerfully moved downward. Driven by.

  Thereafter, as shown in FIG. 3D (the locked state at the end of the boost drive), the second piston 22 engages the ball of the boost mechanism 36 with the output rod 2 that has been prevented from descending by the workpiece (not shown). Press down forcefully through 40. Therefore, due to the resultant force of the pressing force by the booster mechanism 36 and the pressing force by the first piston 21, the output rod 2 causes the work to be fixed to a work table (not shown) such as a table via the clamp member 55. Press strongly.

  When the cylinder device is switched from the locked state of FIG. 3D to the released state of FIG. 3A, the compressed air in the lock chamber 25 is discharged and the compressed air is supplied to the first release chamber 31 and the second release chamber 32 in FIG. To do. As a result, the cylinder device is switched to the released state in the reverse procedure of the lock driving.

  The inclination angle of the transmission part 37 with respect to the axis of the output rod 2 is preferably in the range of 20 degrees to 60 degrees, and more preferably in the range of 25 degrees to 45 degrees. The inclination angle of the booster 41 with respect to the axis of the output rod 2 is preferably in the range of 8 to 15 degrees. These points are the same in the above-described embodiments.

The third embodiment described above can be modified as follows.
Of course, the guide mechanism 62 is not limited to the illustrated structure. For example, the guide member fitted into the guide groove 63 may use a cylindrical pin instead of the exemplified ball 64. Further, the rotating sleeve 67 may be omitted.
The bottom wall of the groove constituting the receiving portion 38 may be constituted only by a horizontal wall.
Further, the lower part of the output rod 2 is projected downward from the lower end wall 1b, and the projecting part is inserted into the lower end wall 1b in a tight manner, and the operating state of the cylinder device is placed below the projecting part. A detected part may be connected, and a sensor such as a limit switch may face the detected part.

FIG. 5 shows a modified example of the booster mechanism 36, and corresponds to the released state shown in the left half of FIG.
In this case, the pressing portion 48 of the second piston 22 is formed in an arc shape in a sectional view. Moreover, the receiving part 38 is comprised by the inclined surface which approaches an axial center as it goes upwards.

Each of the above embodiments and modifications can be further modified as follows.
The first release chamber 31 and the second release chamber 32 may be configured to be able to supply and discharge the release pressure fluid, and may be provided with a return spring.
The structure for connecting the first release chamber 31 and the second release chamber 32 may be a communication hole provided in the body 1c of the housing 1 instead of the communication hole 34 provided in the output rod 2. Furthermore, a pipe provided outside the housing 1 may be used.
It is preferable to provide three or four transmitting portions 37 and receiving portions 38 in the circumferential direction, but two or five or more may be provided. Further, the transmitting portion 37 or the receiving portion 38 may be formed on the surface of a member in which the recess or groove is omitted instead of being formed in the illustrated recess or groove.

The number of the engagement balls 40 is preferably three or four, but may be two or five or more.
The compressed fluid used in the cylinder device of the present invention may be other compressed gas, pressurized oil, or the like instead of the exemplified compressed air.
In addition, it is needless to say that various modifications can be made within a range that can be assumed by those skilled in the art.

  1: housing, 1a (1b): first end wall, 1b (1a): second end wall, 2: output rod, 21: first piston, 22: second piston, 25: lock chamber, 31: first Release chamber, 32: second release chamber, 34: communication hole, 36: booster mechanism, 37: transmission part, 38: receiving part, 39: wedge space, 40: engagement ball, 41: booster part, 43: Recess, 48: Pushing part, 55: Clamp member, 62: Guide mechanism.

Claims (3)

An output rod (2) inserted into the housing (1) so as to be movable in the axial direction; a first piston (21) for the rod connected to the output rod (2) in the housing (1); A second booster piston (22) arranged in series with respect to the first piston (21) in the housing (1) and externally fitted to the output rod (2) so as to be movable in the axial direction. ), And
When the output rod (2) is driven for boosting, the second piston (22) boosts the output rod (2) via the boosting mechanism (36), and the first piston (21) is driven. Is also configured to drive the output rod (2),
A lock chamber (25) disposed between the first piston (21) and the second piston (22) and supplied and discharged with pressure fluid, the first piston (21) and the second piston (22). A lock chamber (25) configured to push both the piston (22) and the two in the direction away from each other;
A first release chamber (31) which is arranged to push the first piston (21) toward the second piston (22) and to which pressure fluid is supplied and discharged;
A second release chamber (32) arranged to push the second piston (22) toward the first piston (21) and supplied and discharged with a pressure fluid;
The booster mechanism (36) is configured such that, when the booster is driven, a radial direction between a transmission part (37) provided on the output rod (2) and a receiving part (38) provided on the housing (1). A wedge space (39) formed so as to narrow inwardly, an engagement ball (40) inserted into the wedge space (39) at a predetermined interval in the circumferential direction, and the engagement ball ( 40) and a booster (41) provided in the second piston (22) so as to push inward in the radial direction, and pressure is applied from the first release chamber (31) and the second release chamber (32). In a state where the fluid is discharged, the pressure fluid supplied to the lock chamber (25) applies a force pushing the second piston (22) away from the first piston (21). It is configured to reverse the force toward the first piston (21) and to convert the boost to the output rod (2) via ,
A cylinder device with a booster mechanism. An output rod (2) inserted into the housing (1) so as to be movable toward the first end side and the second end side as one end side and the other end side in the axial direction;
A first piston (21) for a rod disposed on the first end side in the housing (1) and connected to the output rod (2);
A second piston (22) for boosting, which is disposed on the second end side in the housing (1) and is externally fitted to the output rod (2) so as to be movable in the axial direction;
A lock chamber (25) disposed between the first piston (21) and the second piston (22) and supplied and discharged with pressure fluid, wherein the first piston (21) is connected to the first piston (21). A lock chamber (25) configured to push toward the end and push the second piston (22) toward the second end;
A first release chamber (31) which is disposed on the first end side of the first piston (21) so as to push the first piston (21) toward the second end side and which is supplied and discharged with pressure fluid. When,
A second release chamber (32) that is arranged on the second end side of the second piston (22) so as to push the second piston (22) toward the first end side and that is supplied and discharged with pressure fluid. When,
With the pressure fluid discharged from the first release chamber (31) and the second release chamber (32), the pressure fluid supplied to the lock chamber (25) causes the second piston (22) to move to the second end. A booster mechanism (36) configured to convert a force pushing toward the side into a force toward the first end and transmit it to the output rod (2);
The booster mechanism (36) is configured such that, when the booster is driven, a radial direction between a transmission part (37) provided on the output rod (2) and a receiving part (38) provided on the housing (1). A wedge space (39) formed so as to narrow inwardly, an engagement ball (40) inserted into the wedge space (39) at a predetermined interval in the circumferential direction, and the engagement ball ( 40) and a booster portion (41) provided on the second piston (22) so as to push inward in the radial direction,
When the output rod (2) is driven with a boost, the second piston (22) boosts the output rod (2) to the first end via the engagement ball (40), and The first piston (21) also drives the output rod (2) to the first end side.
A cylinder device with a booster mechanism. In the cylinder device with a booster mechanism according to claim 1 or 2,
The first release chamber (31), the first piston (21), the lock chamber (25), the second piston (22), and the second release chamber (32) are sequentially arranged in the axial direction,
A communication hole (34) for connecting the first release chamber (31) and the second release chamber (32) is provided in the output rod (2).
A cylinder device with a booster mechanism.

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