KR102531495B1 - fluid pressure cylinder - Google Patents

Abstract

In the fluid pressure cylinder 10 in which the working piston 20 and the booster piston 22 are installed in tandem with a partition wall 26, high-pressure fluid is sealed in two axially adjacent pressure chambers. In the operating process, the high-pressure fluid is allowed to communicate between the pressure chambers in which the high-pressure fluid is sealed. Then, when the working piston 20 moves to the end side, the fluid communication between the two pressure chambers is prevented by the power-increase switching mechanism 33, and the high-pressure fluid in one pressure chamber is exhausted.

Description

fluid pressure cylinder

The present invention relates to a fluid pressure cylinder.

In a working machine such as a clamping device or a locking device, a large driving force is usually not required in the first half of the working process, but a large driving force is sometimes required in the second half of the working process. For this reason, as a fluid pressure cylinder used in such a working machine, a hydraulic pressure cylinder with a boost mechanism in which the thrust of the second half of the forward stroke of the piston rod is increased by a boost mechanism has been proposed.

For example, in the fluid pressure cylinder disclosed in Japanese Unexamined Patent Publication No. 2018-17269, thrust is increased by providing a booster piston as a booster mechanism and locking the booster piston to a piston rod in the middle of a stroke.

[0003] In a fluid pressure cylinder with a boost mechanism, a reduction in consumption of a new working fluid is required so as to reduce energy consumption.

Therefore, an object of the present invention is to provide a fluid pressure cylinder with a boost function capable of reducing the consumption of working fluid without complicating the structure.

One aspect of the present invention is a cylinder body having a sliding hole extending in an axial direction, a partition wall dividing the sliding hole into a head-side actuating cylinder chamber and an end-side boosting cylinder chamber, and disposed in the actuating cylinder chamber to form the actuating cylinder An actuating piston that divides a seal into a first pressure chamber on the head side and a second pressure chamber on the end side, and a working piston disposed in the boosting cylinder chamber to divide the booster cylinder chamber into a third pressure chamber on the head side and a fourth pressure chamber on the end side. a booster piston and a piston rod connected to the actuating piston and booster piston and extending to an end side through the bulkhead, wherein the first pressure chamber, the second pressure chamber, the third pressure chamber, and the fourth pressure chamber are provided. In the middle, while the high-pressure fluid is sealed in two adjacent pressure chambers, while the working piston is located on the head side from a predetermined position, the high-pressure fluid is allowed to communicate between the two pressure chambers, while the working piston When it moves to the end side from this predetermined position, it blocks the communication of the high-pressure fluid between the two pressure chambers, and further exhausts the high-pressure fluid in one of the two pressure chambers. , in the fluid pressure cylinder.

According to the fluid pressure cylinder according to the present invention, high-pressure fluid is sealed in two adjacent pressure chambers among the first to fourth pressure chambers. When the working piston is located on the head side from a predetermined position, communication of high-pressure fluid is allowed between two adjacent pressure chambers. In this case, a pressure difference does not occur between two adjacent pressure chambers, and thrust does not increase. On the other hand, when the working piston moves near the end of the stroke, communication between two adjacent pressure chambers is prevented, and the high-pressure fluid in one pressure chamber is exhausted. Thereby, a thrust corresponding to the pressure difference between the two adjacent pressure chambers is generated, so that the thrust of the piston rod can be increased in the vicinity of the stroke end. Since the high-pressure fluid is exhausted at the end side of the stroke, the amount of fluid used for increasing thrust can be suppressed.

1 is a cross-sectional view of a fluid pressure cylinder according to a first embodiment, and a partially enlarged view in the figure is an enlarged cross-sectional view of a third check valve 56. As shown in FIG.
Fig. 2 is a side view of the end side of the fluid pressure cylinder of Fig. 1;
Fig. 3A is an enlarged cross-sectional view of the vicinity of the bulkhead of the fluid pressure cylinder in Fig. 1, and Fig. 3B is an enlarged cross-sectional view in a state in which the working piston approaches the vicinity of the bulkhead of Fig. 3A.
FIG. 4A is a fluid circuit diagram showing a connection state in an operating process of a fluid pressure cylinder according to an embodiment, and FIG. 4B is a fluid circuit diagram showing a connection state in a return process of the fluid pressure cylinder in FIG. 4A.
FIG. 5 is a cross-sectional view of the fluid pressure cylinder of FIG. 1 in an operating process.
Fig. 6 is a cross-sectional view of the fluid pressure cylinder shown in Fig. 1 in a step of increasing pressure.
Fig. 7 is a cross-sectional view (Fig. 1) of the fluid pressure cylinder in Fig. 1 in a return step.
Fig. 8 is a cross-sectional view (Fig. 2) of the fluid pressure cylinder in Fig. 1 in a return step.
Fig. 9A is a plan view of a fluid pressure cylinder according to a second embodiment, and Fig. 9B is a side view of the fluid pressure cylinder of Fig. 9A.
10 is a cross-sectional view of the fluid pressure cylinder of FIG. 9A at a stroke start position.
FIG. 11A is a fluid circuit diagram of the drive device for the hydraulic cylinder of FIG. 9A, showing a connected state of a selector valve at a first position, and FIG. 11B shows a connected state of a selector valve of the drive device of FIG. 11A at a second position. It is a fluid circuit diagram showing.
Fig. 12 is a cross-sectional view of the fluid pressure cylinder of Fig. 9A in a boosting process.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the dimensional ratios in the drawings are exaggerated for convenience of description and may differ from actual ratios. In addition, in this specification, the direction toward the end of a stroke is referred to as "end direction" or "end side", and the direction at the start of the stroke is referred to as "head direction" or "head side". In addition, in this specification, "air" means a gaseous working fluid, and is not specifically limited to air.

(First Embodiment)

A fluid pressure cylinder 10 according to the present embodiment includes a cylinder body 12 and a driving device 120, as shown in FIGS. 4A and 4B.

As shown in FIG. 1, the fluid pressure cylinder 10 has a cylinder body 12 elongated in the axial direction. As shown in FIG. 2, the cylinder body 12 may be rectangular, and is formed of, for example, a metal material such as aluminum alloy.

As shown in Fig. 1, a circular sliding hole 12a (cylinder chamber) extending in the axial direction is formed inside the cylinder body 12. The cylinder body 12 is formed between the head-side body 14 installed on the head side, the end-side body 16 installed on the end side, and between the head-side body 14 and the end-side body 16. A partition wall 26 is provided. As shown in FIG. 2, the head side body portion 14, the partition wall 26, and the end side body portion 16 are axially fastened by a connecting rod or bolt 16b.

As shown in FIG. 1, a circular actuation cylinder chamber 14a is formed inside the head-side main body 14, and a circular boost cylinder chamber 16a is formed inside the end-side main body 16. has been The working cylinder chamber 14a and the boost cylinder chamber 16a are formed with the same inner diameter, and constitute the sliding hole 12a of the cylinder body 12. The working cylinder chamber 14a and the boost cylinder chamber 16a are separated by a partition wall 26.

An operating piston 20 is disposed in the working cylinder chamber 14a, and a booster piston 22 is disposed in the boosting cylinder chamber 16a. The actuating piston 20 and the boosting piston 22 are connected to a piston rod 18 extending through the bulkhead 26 and the cylinder body 12 toward the end.

The head-side port 28, the head cover 46, and the working piston 20 are installed in the head-side body portion 14. The head cover 46 is attached to the end of the working cylinder chamber 14a on the head side, and the head side of the working cylinder chamber 14a is blocked by the head cover 46 .

A head side port 28 is formed near the head cover 46 . The head side port 28 is formed through the head side main body 14 . The head side port 28 is provided in the vicinity of the head side end of the working cylinder chamber 14a and communicates with the working cylinder chamber 14a (first pressure chamber 38) via an opening 28a.

The working piston 20 is accommodated in the working cylinder chamber 14a so as to be able to slide in the axial direction. An annular packing mounting groove 21a is formed on the outer circumferential surface of the working piston 20, and the packing 21 is mounted in the packing mounting groove 21a. The packing 21 adheres to the inner circumferential surface of the working cylinder chamber 14a while being elastically deformed, thereby airtightly partitioning the working cylinder chamber 14a into a first pressure chamber 38 and a second pressure chamber 40. The first pressure chamber 38 is a vacant chamber formed between the working piston 20 and the head cover 46, and is formed on the head side rather than the working piston 20. Moreover, the 2nd pressure chamber 40 is a void formed between the working piston 20 and the partition wall 26, and is formed in the end side rather than the working piston 20. The first pressure chamber 38 communicates with the head side port 28 via the opening 28a.

The working piston 20 is connected to the piston rod 18 at the head side connecting portion 18a of the piston rod 18, and is configured to be displaced integrally with the piston rod 18.

On the other hand, the booster piston 22, the rod cover 48, the end-side port 30, and the auxiliary oil passage 76 are installed in the end-side body portion 16.

The booster piston 22 is axially slidably disposed in the booster cylinder chamber 16a of the end-side main body 16. An annular packing mounting groove 23a and an annular magnet mounting groove 24a are provided on the outer circumferential surface of the booster piston 22 . A ring-shaped packing 23 made of an elastic material such as rubber is attached to the packing mounting groove 23a. In addition, a circular ring-shaped magnet 24 is mounted in the magnet mounting groove 24a. A wear ring (not shown) is attached to the outer periphery of the magnet 24 .

The booster piston (22) airtightly divides the booster cylinder chamber (16a) into a third pressure chamber (42) and a fourth pressure chamber (44) via a packing (23). The third pressure chamber 42 is a head-side empty chamber of the booster piston 22, and is formed between the booster piston 22 and the partition wall 26. Further, the fourth pressure chamber 44 is an empty chamber on the end side of the booster piston 22, and is formed between the booster piston 22 and the rod cover 48. The fourth pressure chamber 44 communicates with the end port 30 .

Further, a ring-shaped damper mounting groove 25a is formed on the end surface of the head side of the booster piston 22, and the damper 25 is attached to the damper mounting groove 25a. The damper 25 is made of an elastic material such as rubber and is configured to prevent a collision between the booster piston 22 and the bulkhead 26. The booster piston 22 is connected to the piston mounting portion 18b installed in the central portion of the piston rod 18, and is configured to be integrally displaced with the piston rod 18 in the axial direction.

The rod cover 48 is mounted on the end side of the booster cylinder chamber 16a. The rod cover 48 is formed in a disk shape, and an annular packing mounting groove 48d is formed on its outer periphery. A circular ring-shaped packing 48c is mounted in the packing mounting groove 48d. The packing 48c hermetically seals the packing mounting groove 48d.

An insertion hole 48a for inserting the piston rod 18 is formed extending in the axial direction near the center of the rod cover 48 in the radial direction. A rod packing 48b for preventing leakage of air along the piston rod 18 is provided in the insertion hole 48a. Further, a ring-shaped damper mounting groove 47a is formed on the end surface of the rod cover 48 on the head side, and the damper 47 is attached to the damper mounting groove 47a. The damper 47 is made of an elastic member formed in a circular ring shape, and prevents collision between the booster piston 22 and the rod cover 48 by protruding toward the booster cylinder chamber 16a.

Further, a pull-out prevention clip 49 for fixing the rod cover 48 is attached to the end side of the rod cover 48 . The fall-off prevention clip 49 is a plate member engaged with the engagement groove 49a formed along the inner circumferential surface of the end-side body portion 16 . The anti-falling clip 49 is a ring-shaped plate member with a part cut in the circumferential direction, which is engaged with the engaging groove 49a by elastic restoring force and abuts with the end surface of the rod cover 48 on the end side of the rod cover. (48) is prevented from dropping out.

The end-side port 30 is formed in the vicinity of the end-side end of the end-side main body 16 . The end-side port 30 is formed penetrating from the outer periphery of the end-side main body portion 16 toward the booster cylinder chamber 16a, and at the end of the booster cylinder chamber 16a on the end side, the fourth pressure chamber ( 44) are in communication.

The auxiliary passage 76 is a passage formed inside the end-side main body 16 and extends in the axial direction. The auxiliary flow passage 76 has one end communicating with the end-side port 30 and the other end communicating with the adjustment port 32 of the partition wall 26 described later.

The third check valve 56 is installed in the middle of the auxiliary flow passage 76. The third check valve 56 has a cavity 56a having a larger diameter than the auxiliary flow path 76 and a valve body 56b inserted into the cavity 56a. A member formed in the shape of a cylindrical cup with a bottom, and a bottom 56c is disposed on the downstream side in the direction of blocking the flow of air. An annular protrusion 56d is formed on the bottom 56c of the valve body 56b to abut against the end surface of the hollow portion 56a and close the auxiliary passage 76 communicating with the hollow portion 56a.

In addition, a cutout 56e is formed on the side of the valve body 56b to allow air to pass therethrough. Regarding air flowing from the bottom 56c side, the annular protrusion 56d of the valve body 56b is spaced apart from the end face of the cavity 56a and is configured to pass air through the cutout 56e. . Also, for the air in the reverse direction, the portion of the bottom 56c of the valve body 56b receives the pressure of the air, and the annular projection 56d abuts against the end face of the cavity 56a, and the auxiliary flow path 76 ) to block the flow of air.

In addition, a pressing member such as a spring that presses the annular protrusion 56d of the valve body 56b in a direction in contact with the end surface of the cavity 56a so that the third check valve 56 can operate smoothly ( 56f) may be installed in the cavity 56a. In addition, the 1st check valve 52 and the 2nd check valve 54 mentioned later also have the same structure as the 3rd check valve 56.

As shown in FIG. 3A, the partition wall 26 has a plate-shaped main body 60. The main body 60 is formed with a first connecting portion 63 projecting toward the head and inserted into the working cylinder chamber 14a, and a second connecting portion 64 projecting toward the end and inserted into the booster cylinder chamber 16a. . The first connecting portion 63 is formed in a cylindrical shape with an outer diameter substantially equal to the inner diameter of the working cylinder chamber 14a, and a packing 63a is attached to its outer periphery. Further, the second connecting portion 64 is formed in a cylindrical shape with an outer diameter approximately equal to the inner diameter of the booster cylinder chamber 16a, and a packing 64a is attached to its outer periphery. The packing 63a seals the gap between the working cylinder chamber 14a and the first connection part 63, and the packing 64a seals the gap between the boost cylinder chamber 16a and the second connection part 64.

In the vicinity of the center of the partition wall 26 in the radial direction, a through portion 61 for inserting the piston rod 18 is formed extending in the axial direction. A packing 62 for preventing leakage of air along the piston rod 18 is installed in the penetrating portion 61 .

In addition, the partition wall 26 includes a communication passage 34 constituting the power increasing switching mechanism 33, a communication switching valve 35 provided in the communication passage 34, an exhaust passage 36, and an exhaust passage ( 36) has an exhaust selector valve 37 installed.

The communication passage 34 is a passage through which air flows between the second pressure chamber 40 and the third pressure chamber 42, and includes a through hole 65 penetrating the partition wall 26 in the axial direction; It is composed of an internal passage 35e of the communication switching pin 35a inserted into the through hole 65 and a hole portion 66b of the stopper 66.

The through hole 65 is formed to penetrate the partition wall 26 in the axial direction, and has a large diameter portion 65a formed on the head side, a small diameter portion 65b formed in the center in the axial direction, and a stopper insertion formed on the end side. It has a hole 65c. The large diameter portion 65a and the stopper insertion hole 65c are formed with a larger inner diameter than the small diameter portion 65b. Communication switching pins 35a are inserted into the large-diameter portion 65a and the small-diameter portion 65b. A stopper 66 is inserted into the stopper insertion hole 65c. The stopper 66 is connected to the end side of the communication switching pin 35a of the communication switching valve 35 and is integrally displaced with the communication switching pin 35a. Further, when the stopper 66 is stopped within the stopper insertion hole 65c, the movement of the communication switching pin 35a to the head side is restricted.

The communication switching valve 35 is configured with a communication switching pin 35a. The communication switching pin 35a has a closed portion 35c formed on the head side and a rod portion 35d extending in the axial direction toward the end side. The rod portion 35d is formed with approximately the same diameter as the inner diameter of the small-diameter portion 65b of the through hole 65, and is slidably inserted into the small-diameter portion 65b in the axial direction. The closed portion 35c is formed to have a substantially the same diameter as the inner diameter of the large-diameter portion 65a of the through hole 65, and is configured to be inserted into the large-diameter portion 65a. A ring-shaped packing 35b is attached to the outer periphery of the closing portion 35c. The packing 35b is configured to come into close contact with the large-diameter portion 65a and seal the communication passage 34 when the closed portion 35c is pushed into the large-diameter portion 65a.

Further, a pressing member 35f is attached to the end side of the closed portion 35c of the communication switching pin 35a. The biasing member 35f is made of, for example, a spring, and is inserted into the gap between the large-diameter portion 65a and the communication switching pin 35a. The pressing member 35f presses the communication switching pin 35a toward the head side, and separates the closed portion 35c from the through hole 65 to protrude toward the second pressure chamber 40 side. That is, the communication switching valve 35 is configured so as not to obstruct the communication of the communication passage 34 in a state where the communication switching pin 35a is not pushed toward the end side by the actuating piston 20.

On the other hand, the exhaust passage 36 is opened at the end surface of the partition wall 26 on the side of the first connecting portion 63, and includes a detecting pin accommodating hole 67 extending in the axial direction, a detecting pin accommodating hole 67, and an adjusting port. It has a connection passage 71 communicating with (32). Among these, the detection pin accommodating hole 67 has a large diameter portion 67a formed on the head side, a small diameter portion 67b formed on the end side of the large diameter portion 67a, and a stopper insertion hole 67c. A stopper 68 is inserted into the stopper insertion hole 67c. The stopper 68 is connected to the index pin 37a and is integrally displaced with the index pin 37a. The stopper 68 restricts the movement range of the detection pin 37a to the head side by stopping at the end side of the small diameter portion 67b.

The connection passage 71 communicates with the detection pin accommodation hole 67 in the opening 71a formed on the side of the small diameter portion 67b. The small-diameter portion 67b has a diameter enlarged in a predetermined range around the opening 71a, and forms a gap between it and the exhaust selector valve 37.

A first check valve 52 is provided in the connection passage 71 to pass air only in the direction from the opening 71a to the adjustment port 32 . The first check valve 52 is disposed in a direction allowing air to be exhausted from the second pressure chamber 40 .

The exhaust selector valve 37 has a detecting pin 37a. The detecting pin 37a includes a pin body portion 37b extending in a cylindrical shape in the axial direction, and a flange portion 37c extending outward in the radial direction at the head side end of the pin body portion 37b. The flange portion 37c is formed with a diameter slightly smaller than the inner diameter of the large-diameter portion 67a, and is configured to be inserted into the large-diameter portion 67a. A biasing member 37f made of a spring or the like is attached to the large-diameter portion 67a. The pressing member 37f is configured so as to project the flange portion 37c toward the second pressure chamber 40 side by abutting against the flange portion 37c and pressing the index pin 37a toward the head side.

The pin body portion 37b is formed with a diameter slightly smaller than the inner diameter of the small diameter portion 67b, and is configured to be slidable in the axial direction along the small diameter portion 67b. On the outer periphery of the pin body portion 37b, a packing 37d and a packing 37e are disposed at intervals in the axial direction. The packing 37d and the packing 37e come into close contact with the small-diameter portion 67b in a state where the detection pin 37a is not pressed against the working piston 20, and the detection pin accommodating hole 67 and the connection passage 71 ) is arranged at a position to block the communication of That is, the exhaust switching valve 37 blocks communication with the exhaust passage 36 in a state where the working piston 20 is not pressurized.

A replenishment oil passage 78 and a second check valve 54 are provided in the head side main body 14 near the adjustment port 32 . The replenishment oil passage 78 communicates with the adjustment port 32 and the second pressure chamber 40 . A second check valve 54 is installed in the replenishment passage 78 . One end of the second check valve 54 communicates with the adjustment port 32 through the replenishment passage 78 . In addition, the other end of the second check valve 54 communicates with the second pressure chamber 40 through the replenishment passage 78 . The second check valve 54 allows air to pass only in the direction from the control port 32 toward the second pressure chamber 40 and blocks air from passing in the opposite direction. That is, the second check valve 54 is configured to allow the flow of air replenished in the second pressure chamber 40 and block air in the opposite direction.

The fluid pressure cylinder 10 of this embodiment is structured as described above, and is driven by the driving device 120 as shown in FIG. 4A.

The driving device 120 includes a fourth check valve 86, a throttling valve 88, a switching valve 102, a high-pressure air supply source (high-pressure fluid supply source) 104, and an exhaust port 106, there is. This driving device 120 is configured to supply high-pressure air to the first pressure chamber 38 of the working cylinder chamber 14a in the operating process. In addition, as shown in FIG. 4B , in the return step, the driving device 120 supplies a part of the air accumulated in the first pressure chamber 38 toward the fourth pressure chamber 44, and also supplies the second It is configured to supply high-pressure air to the pressure chamber 40 .

The switching valve 102 is, for example, a 5-port, 2-position valve, and has a first port 102a to a fifth port 102e, a first position (see FIG. 4A) and a second position (see FIG. 4B). ) can be switched. As shown in Figs. 4A and 4B, the first port 102a is connected to the head side port 28 by a pipe. The second port 102b is connected to the adjustment port 32 by a pipe. The third port 102c is connected to the exhaust port 106 by a pipe. The fourth port 102d is connected to the high-pressure air supply source 104 through a pipe. The fifth port 102e is connected to the exhaust port 106 through the throttle valve 88 by a pipe and is connected to the end port 30 through the fourth check valve 86.

As shown in Fig. 4A, when the selector valve 102 is in the first position, the first port 102a and the fourth port 102d are connected, and the second port 102b and the third port are connected. 102c is connected.

In addition, as shown in FIG. 4B, when the selector valve 102 is in the second position, the first port 102a and the fifth port 102e are connected, and the second port 102b and the fourth A port 102d is connected. The switching valve 102 is switched between the first position and the second position by the pilot pressure from the high-pressure air supply source 104 or the solenoid valve.

The fourth check valve 86 allows air to flow from the head port 28 to the end port 30 when the selector valve 102 is in the second position, and the end port 30 The flow of air from the to the head side port 28 is blocked.

The throttling valve 88 is installed to limit the amount of air in the first pressure chamber 38 exhausted from the exhaust port 106, and is configured as a variable throttling valve capable of changing the passage area so as to adjust the exhaust flow rate. there is.

In addition, an air tank is provided in the middle of the piping connecting the fourth check valve 86 and the fourth pressure chamber 44, and air is supplied from the head port 28 to the end port 30 in the return step. may be allowed to accumulate. By providing the air tank, it is possible to accumulate a sufficient amount of air to fill the fourth pressure chamber 44 during the return operation, so that the return operation can be stabilized. In this case, the capacity of the air tank may be set to about half of the maximum capacity of the first pressure chamber 38, for example. An air tank is unnecessary if the capacity of the pipe can be sufficiently secured.

The fluid pressure cylinder 10 and the driving device 120 are configured as described above, and their action and operation will be described below.

(start-up process)

In the starting process, high-pressure air is filled into the second pressure chamber 40 and the third pressure chamber 42 prior to starting use of the fluid pressure cylinder 10 . Note that high-pressure air is air at a pressure higher than atmospheric pressure. Here, the fluid pressure cylinder 10 is set to the starting position of the stroke as shown in FIG. Moreover, the selector valve 102 of the driving device 120 is set to the second position (see FIG. 4B). In this way, the high-pressure air supply source 104 is connected to the regulating port 32 . As shown in FIG. 4B , high-pressure air from the high-pressure air supply source 104 is introduced into the second pressure chamber 40 through the second check valve 54 . In addition, the high-pressure air introduced into the second pressure chamber 40 is also introduced into the third pressure chamber 42 through the communication passage 34 . As a result, the second pressure chamber 40 and the third pressure chamber 42 are filled with high-pressure air. The starting process only needs to be performed once before the first stroke of the fluid pressure cylinder 10 .

(Operating process)

As shown in FIG. 4A , the operating process of the fluid pressure cylinder 10 is performed with the selector valve 102 of the driving device 120 in the first position. The high-pressure air from the high-pressure air supply source 104 is supplied to the head-side port 28 through the first port 102a of the switching valve 102. The 4th check valve 86 is connected to the 5th port 102e side, and high pressure air does not flow to the 4th check valve 86 side. The 4th pressure chamber 44 is connected to the exhaust port 106 via the 3rd check valve 56, the adjustment port 32, and the 2nd port 102b.

As shown in FIG. 5 , in the operating process, high-pressure air from the high-pressure air supply source 104 flows into the first pressure chamber 38 as shown by arrow B. The force acting on the working piston by the high-pressure air in the second pressure chamber 40 and the force acting on the booster piston 22 by the high-pressure air charged in the third pressure chamber 42 are equal in magnitude and in opposite directions. Because it is balanced, it does not contribute to thrust. Therefore, thrust corresponding to the pressure difference between the first pressure chamber 38 adjacent to the working piston 20 and the fourth pressure chamber 44 adjacent to the booster piston 22 is generated in the piston rod 18. And, the piston rod 18 strokes toward the end side.

Accompanying the stroke of the working piston 20, the fluid pressure cylinder 10 is supplied with high-pressure air in an amount equal to the volume of the first pressure chamber 38 from the high-pressure air supply source 104 (see FIG. 4A). According to the strokes of the actuating piston 20 and the boosting piston 22, the high-pressure air in the second pressure chamber 40 moves to the third pressure chamber 42 through the communication passage 34. During the operation process, the pressure of the high-pressure air accumulated in the second pressure chamber 40 and the third pressure chamber 42 is kept constant. In addition, air in the fourth pressure chamber 44 is exhausted from the fourth pressure chamber 44 along with the stroke of the booster piston 22 . In this case, the air in the fourth pressure chamber 44 passes through the adjustment port 32 via the third check valve 56 and the auxiliary flow path 76, and as shown in FIG. 4A, the switching valve 102 ) is exhausted from the exhaust port 106 through the second port 102b.

(increase process)

As shown in FIG. 6, along with the stroke of the working piston 20, the communication switching pin 35a (see FIG. 3B) of the communication switching valve 35 is pressed toward the end side, and the exhaust switching valve 37 The detecting pin 37a (see FIG. 3B) of is also pushed toward the end side.

As a result, as shown in FIG. 3B, the closed portion 35c of the communication switching pin 35a is inserted into the large diameter portion 65a of the through hole 65. Then, the packing 35b of the closing portion 35c closes the communication passage 34 by sealing the gap between the large diameter portion 65a and the closing portion 35c. That is, the flow of air between the second pressure chamber 40 and the third pressure chamber 42 via the communication passage 34 is blocked by the communication switching valve 35 .

Further, as the detection pin 37a of the exhaust switching valve 37 is displaced toward the end side, the packing 37d sealing the gap between the detection pin 37a and the detection pin accommodating hole 67 is concave. It moves to the recessed opening 71a. As a result, the exhaust passage 36 is opened, and the adjustment port 32 and the second pressure chamber 40 communicate with each other via the exhaust passage 36 . The high-pressure air accumulated in the second pressure chamber 40 is exhausted from the exhaust port 106 through the first check valve 52 and the adjustment port 32. As a result, the internal pressure of the second pressure chamber 40 decreases, and thrust is generated in the working piston 20 according to the difference in internal pressure between the second pressure chamber 40 and the first pressure chamber 38 .

Also, thrust is generated in the booster piston 22 according to a pressure difference between the pressure of the high-pressure air accumulated in the third pressure chamber 42 and the pressure in the fourth pressure chamber 44 . As a result, the fluid pressure cylinder 10 can increase thrust near the stroke end. The increase in thrust in the fluid pressure cylinder 10 is generated by exhausting the high-pressure air in the second pressure chamber 40 within the range where the communication switching valve 35 and the exhaust switching valve 37 operate.

(return process)

As shown in FIG. 4B, the process of returning the fluid pressure cylinder 10 is performed by setting the selector valve 102 of the driving device 120 to the second position. The high-pressure air from the high-pressure air supply source 104 is supplied to the adjustment port 32 through the second port 102b of the switching valve 102. The first port 102a of the switching valve 102 is connected to the fifth port 102e, and the head side port 28 is connected to the end side port 30 via the fourth check valve 86. In addition, the head side port 28 is connected to the exhaust port 106 through the throttling valve 88. As a result, a part of the air accumulated in the first pressure chamber 38 is supplied to the fourth pressure chamber 44 through the fourth check valve 86 side. Also, part of the remaining air accumulated in the first pressure chamber 38 is exhausted from the exhaust port 106 .

As shown in FIG. 7 , in the return process, high-pressure air from the high-pressure air supply source 104 is supplied to the adjustment port 32 of the fluid pressure cylinder 10 as indicated by arrow B. The high-pressure air supplied to the adjustment port 32 flows into the second pressure chamber 40 via the replenishment passage 78 and the second check valve 54 . The capacity of the high-pressure air supplied to the second pressure chamber 40 is equal to the amount of high-pressure air exhausted from the second pressure chamber 40 in the pressure increasing process. That is, high-pressure air required for the boosting process is supplemented during the return process. At that time, the amount of high-pressure air supplied is small compared to the amount of high-pressure air required for the stroke of the working piston 20, and it is sufficient to add only a small amount of high-pressure air.

In the return process, since the internal pressure of the second pressure chamber 40 becomes the same as that of the third pressure chamber 42, the force exerted by the second pressure chamber 40 on the working piston 20 and the third pressure The forces exerted by the seal 42 on the booster piston 22 are balanced and cancel each other out.

On the other hand, a part of the high-pressure air exhausted from the first pressure chamber 38 is introduced into the fourth pressure chamber 44 as shown by arrow A. As the exhaust of the air in the first pressure chamber 38 progresses, the pressure difference between the fourth pressure chamber 44 and the first pressure chamber 38 increases, and the working piston 20 and the boosting piston 22 and the piston rod 18 starts moving toward the head side. Accordingly, the communication switching valve 35 returns to its original position, and the second pressure chamber 40 and the third pressure chamber 42 communicate with each other through the communication passage 34 . In addition, the exhaust switching valve 37 seals the exhaust passage 36 and prevents communication between the regulating port 32 and the second pressure chamber 40 .

After that, as shown in FIG. 8, while air is introduced into the fourth pressure chamber 44, the exhaust of the first pressure chamber 38 proceeds, and the working piston 20 and the boosting piston 22 rotate By returning to the starting position, the return process is complete.

The fluid pressure cylinder 10 according to the present embodiment achieves the following effects.

In the fluid pressure cylinder (10), the fluid pressure cylinder (10) includes a communication passage (34) communicating with the second pressure chamber (40) and the third pressure chamber (42) as a power increasing conversion mechanism (33), 2. While the exhaust passage 36 communicating with the pressure chamber 40 and the working piston 20 are located on the head side from a predetermined position, the communication passage 34 is opened and the working piston 20 moves beyond a predetermined position. The communication switching valve 35 that closes the communication passage 34 when it moves to the end side and the exhaust passage 36 while the working piston 20 is located on the head side than the predetermined position, together with the working piston 20 ) has an exhaust selector valve 37 that opens the exhaust passage 36 to exhaust the high-pressure fluid in the second pressure chamber 40 when it moves toward the end side from a predetermined position. As a result, the second pressure chamber 40 and the third pressure chamber 42 are separated near the stroke end, and the pressure of the second pressure chamber 40 is maintained while maintaining the high-pressure air in the third pressure chamber 42. High-pressure air can be exhausted. Thereby, in addition to the thrust of the actuating piston 20, the thrust of the booster piston 22 is added, and the thrust can be increased in the latter half of the stroke.

In the fluid pressure cylinder 10, the partition wall 26 has an adjustment port 32, and the exhaust passage 36 may exhaust the high-pressure fluid in the second pressure chamber 40 through the adjustment port 32. there is.

In the fluid pressure cylinder 10, the boost switching mechanism 33 can cause the exhaust switching valve 37 to open the exhaust passage 36 after the communication switching valve 35 closes the communication passage 34. In this way, the outflow of high-pressure air from the third pressure chamber 42 through the second pressure chamber 40 can be prevented, and the amount of high-pressure air used can be suppressed.

In the fluid pressure cylinder 10, the communication switching valve 35 has a communication switching pin 35a with one end protruding toward the second pressure chamber 40 and the other end inserted into the communication passage 34, and the communication switching pin When (35a) is pushed by the working piston 20 and displaced toward the end, the communication passage 34 can be closed. Thereby, the communication switching valve 35 can be operated using the stroke operation of the actuating piston 20, and the device configuration can be simplified.

In the fluid pressure cylinder (10), the exhaust switching valve (37) seals the exhaust passage (36) and has a detecting pin (37a) with one end protruding into the second pressure chamber (40). 37a is pushed by the working piston 20 and displaced to the end side, so that the sealing of the exhaust passage 36 can be released. This makes it possible to exhaust the second pressure chamber 40 through the exhaust passage 36 using the stroke operation of the working piston 20, and the device configuration is simplified.

In the fluid pressure cylinder (10), the first check valve allows air to pass through the exhaust passage (36) only in the direction from the second pressure chamber (40) toward the adjustment port (32), and blocks air in the opposite direction. (52) may be installed. Thereby, malfunction of the exhaust selector valve 37 can be prevented in the return process.

The fluid pressure cylinder (10) further has a supplementary oil passage (78) communicating with the regulating port (32) and the second pressure chamber (40). A second check valve 54 that passes air only in the direction toward (40) and blocks air in the opposite direction may be installed. By providing the second check valve 54, inflow of excessive high-pressure air into the second pressure chamber 40 can be suppressed in the return step.

In the fluid pressure cylinder 10 described above, an auxiliary flow passage 76 communicating with the fourth pressure chamber 44 and the adjustment port 32 may be further provided. In this way, air in the fourth pressure chamber 44 can be exhausted through the adjustment port 32 in the operation process and the pressure increase process.

In the above-mentioned fluid pressure cylinder 10, the auxiliary flow path 76 passes only the air in the direction from the fourth pressure chamber 44 to the adjustment port 32, and the third check block prevents air in the opposite direction. A valve 56 may be installed. This prevents the high-pressure air from flowing into the fourth pressure chamber 44 when the high-pressure air is supplied to the regulating port 32 in the return step, and the consumption of the high-pressure air can be suppressed.

The fluid pressure cylinder (10) further includes a driving device (120) connected to the first pressure chamber (38), the second pressure chamber (40) and the fourth pressure chamber (44) of the fluid pressure cylinder (10). The driving device 120 has a switching valve 102, a high-pressure air supply source 104, an exhaust port 106, and a fourth check valve 86, and is located in the first position of the switching valve 102. In this case, the first pressure chamber 38 communicates with the high-pressure air supply source 104, and the fourth pressure chamber 44 and the adjustment port 32 (power conversion mechanism 33) communicate with the exhaust port 106. In the second position of the switching valve 102, the first pressure chamber 38 communicates with the fourth pressure chamber 44 through the fourth check valve 86, and the first pressure chamber 38 It can be configured to communicate with the exhaust port 106 and communicate with the high-pressure air supply source 104 through the adjustment port 32 of the second pressure chamber 40 . In this way, in the return process, the air accumulated in the first pressure chamber 38 can be supplied to the fourth pressure chamber 44, so that the consumption of high-pressure air can be suppressed.

In the above fluid pressure cylinder 10, a throttling valve 88 may be installed between the first pressure chamber 38 and the exhaust port 106. Thereby, the amount of air supplied to the fourth pressure chamber 44 can be appropriately adjusted.

(Second Embodiment)

The fluid pressure cylinder 10a of this embodiment has a head side main body 14A and an end side main body 16A, as shown in Fig. 9A. In this embodiment, the high-pressure fluid is sealed in the end-side main body 16A. In addition, the size (width and height) of the end-side main body 16A is larger than that of the head-side main body 14A so that the thrust at the stroke end can be further increased.

As shown in Fig. 9B, the head side body portion 14A and the end side body portion 16A are formed in a prismatic cross section. The head side body portion 14A and the end side body portion 16A are axially connected by a connecting rod or bolt.

As shown in FIG. 10, the cylinder body 12a of the fluid pressure cylinder 10a has a head side body portion 14A and an end side body portion 16A, both of which are axial through the partition wall portion 126. direction is connected. The head side port 28A and the end side port 30A are provided in the head side main body 14A. An adjustment port 32A is provided in the vicinity of the end side of the end side body portion 16A.

Also, a stored air exhaust port 162 for discharging high-pressure air sealed in the boost cylinder chamber 116a is formed near the outer periphery of the partition wall portion 126. The saved air exhaust port 162 communicates with the third pressure chamber 42 through the control valve 160 . The stored air exhaust port 162 discharges high-pressure air stored in the booster cylinder chamber 116a during maintenance of the hydraulic cylinder 10a, etc., or introduces high-pressure air into the booster cylinder chamber 116a when starting up. used to do

An insertion hole 126c into which the piston rod 18A is slidably inserted is formed in the central portion of the partition wall portion 126 . A packing 118 for preventing leakage of fluid in the axial direction is provided in the insertion hole 126c. The partition wall portion 126 is provided with a head side connection portion 126a that extends toward the head side and is inserted into the working cylinder chamber 14a. Further, on the end side of the partition wall portion 126, an end side connecting portion 126b inserted into the booster cylinder chamber 116a is provided. A ring-shaped buffer member 124 for avoiding collision with the booster piston 22A is attached to the end-side connection portion 126b.

The end-side body portion 16A has a body portion 116. Inside the body portion 116, a booster cylinder chamber 116a made of a circular hollow portion is formed. The booster cylinder chamber 116a extends in the axial direction. Inside the booster cylinder chamber 116a, a booster piston 22A is disposed so as to be slidable in the axial direction. The booster piston 22A is connected to the piston rod 18A. A magnet 24 and a packing 23 are attached to the outer periphery of the booster piston 22A. The booster piston 22A divides the booster cylinder chamber 116a into a third pressure chamber 42 on the head side and a fourth pressure chamber 44 on the end side.

In addition, the booster piston 22A is provided with a communication switching valve 35A for switching the communication state of the high-pressure fluid between the third pressure chamber 42 and the fourth pressure chamber 44 adjacent in the axial direction. has been The communication switching valve 35A has a through hole 122 passing through the booster piston 22A in the axial direction, and a communication switching pin 35a inserted into the through hole 122.

The through hole 122 has an end-side diameter-expanded portion 122a, a diameter-reduced portion 122b, and a head-side diameter-expanded portion 122c. The communication switching pin 35a of the communication switching valve 35A is the same as the communication switching pin 35a described with reference to FIG. 3A. The rod portion 35d of the communication switching pin 35a is inserted into the reduced diameter portion 122b. Further, on the side of the end-side diameter enlarged portion 122a, a closed portion 35c of the communication switching pin 35a is disposed. The communication switching pin 35a protrudes toward the end side by the pressing force of the pressing member 35f.

And, through the through hole 122 and the internal flow path 35e of the communication conversion pin 35a, the third pressure chamber 42 and the fourth pressure chamber 44 can be communicated with high pressure air. Consists of. That is, in this embodiment, the communication passage is constituted by the through hole 122 and the internal passage 35e. Further, the communication switching pin 35a is pressed by the rod cover 48A when the booster piston 22A moves to the end side, so that the closing portion 35c and the packing 35b of its outer periphery are inserted into the through hole 122. It is inserted, blocks the through hole 122, and prevents communication between the third pressure chamber 42 and the fourth pressure chamber 44.

The rod cover 48A is provided in the vicinity of the end side end of the end side main body 16A, and seals the end side end of the boost cylinder chamber 116a. The rod cover 48A is provided with an exhaust selector valve 37A for switching the exhaust of the high-pressure air in the fourth pressure chamber 44 . The exhaust switching valve 37A has a through hole 139 penetrating the rod cover 48A in the axial direction, and a detection pin 137 inserted into the through hole 139.

The end of the through hole 139 is blocked by a cover member 150, and a detection pin 137 is disposed on the head side of the cover member 150. The detection pin 137 is pressed toward the head by a biasing member 140 such as a spring disposed between the cover member 150 and the detection pin 137. Therefore, the front end of the detection pin 137 on the head side protrudes into the fourth pressure chamber 44 .

An annular packing 141 and a packing 142 are attached to the outer periphery of the proximal end 138 of the detection pin 137, spaced apart from each other in the axial direction. The packing 141 and the packing 142 seal the gap between the through hole 139 and the index pin 137. A flow path 143 is provided between the packing 141 and the packing 142 . The flow path 143 communicates with the through hole 139 on the inside and communicates with the ventilation groove 144 on the outside. The ventilation groove 144 is an annular groove formed over the entire circumferential direction of the outer peripheral portion of the rod cover 48A, and communicates with the adjusting port 32A. A packing 146 is installed on the head side of the ventilation groove 144, and a packing 148 is installed on the end side. By these packings 146 and 148, the ventilation groove 144 is kept airtight. The adjustment port 32A is capable of communicating with the fourth pressure chamber 44 through the ventilation groove 144, the flow path 143, and the through hole 139. That is, in this embodiment, the through hole 139, the flow path 143, and the ventilation groove 144 constitute an exhaust flow path.

When the detection pin 137 is moved to the head side, the through hole 139 is closed by the packings 141 and 142, and the high-pressure fluid in the fourth pressure chamber 44 is not exhausted. On the other hand, when the booster piston 22A moves to the end side, the detection pin 137 is pressed to the end side, and the packings 141 and 142 are configured to move to the end side rather than the flow path 143. When the packings 141 and 142 move toward the end side from the passage 143, the fourth pressure chamber 44 and the adjustment port 32A communicate with each other.

The fluid pressure cylinder 10a of the present embodiment configured as described above is driven by the driving device 120A shown in FIGS. 11A and 11B.

As shown in FIG. 11A, the driving device 120A includes a fourth check valve 86, a throttling valve 88, a switching valve 102, a high-pressure air supply source 104, and an exhaust port 106. and a fifth check valve 108. This driving device 120A is configured to supply high-pressure air to the first pressure chamber 38 of the working cylinder chamber 14a in the operating process. In addition, as shown in FIG. 11B, the driving device 120A supplies a part of the air accumulated in the first pressure chamber 38 toward the second pressure chamber 40 in the return process, and the fourth pressure It is configured to supply high-pressure air to the seal 44.

The switching valve 102 is, for example, a 5-port, 2-position valve, and has a first port 102a to a fifth port 102e, a first position (see Fig. 11a) and a second position (see Fig. 11b). ) can be converted. As shown in Figs. 11A and 11B, the first port 102a is connected to the head side port 28A by a pipe. The second port 102b is connected to the downstream side of the adjustment port 32A and the fifth check valve 108 by a pipe. The third port 102c is connected to the exhaust port 106 by a pipe. The fourth port 102d is connected to the high-pressure air supply source 104 through a pipe. The 5th port 102e is connected to the exhaust port 106 via the throttle valve 88 by a pipe, and the end side port 30A and the 5th check valve 108 via the 4th check valve 86 ) is connected to the upstream side of

As shown in Fig. 11A, when the selector valve 102 is in the first position, the first port 102a and the fourth port 102d are connected, and the second port 102b and the third port are connected. 102c is connected.

Further, as shown in FIG. 11B, when the selector valve 102 is in the second position, the first port 102a and the fifth port 102e are connected, and the second port 102b and the fourth port 102a are connected. A port 102d is connected. The switching valve 102 is switched between the first position and the second position by the pilot pressure from the high-pressure air supply source 104 or the solenoid valve.

When the selector valve 102 is in the second position, the fourth check valve 86 allows air to flow from the head port 28A to the end port 30A, and the end port 30A The flow of air from the port to the head side port 28A is blocked. Further, the fifth check valve 108 blocks the flow of high pressure air from the second port 102b to the end port 30A when the selector valve 102 is in the second position.

The fluid pressure cylinder 10a and its driving device 120A according to the present embodiment are configured as described above, and their actions will be described below along with operations.

(Operating process)

As shown in FIG. 11A, the operating process of the fluid pressure cylinder 10a is performed with the selector valve 102 of the driving device 120A in the first position. The high-pressure air from the high-pressure air supply source 104 is supplied to the head side port 28A through the first port 102a of the switching valve 102. The 4th check valve 86 is connected to the 5th port 102e side, and high-pressure air does not flow to the 4th check valve 86 side. The second pressure chamber 40 is connected to the exhaust port 106 via the end port 30A and the fifth check valve 108. Also, the adjustment port 32A is connected to the exhaust port 106.

As shown in Fig. 10, in the operating process, high-pressure air from the high-pressure air supply source 104 flows into the first pressure chamber 38 from the head-side port 28A. Thereby, thrust toward the end side is generated in the actuating piston 20 . As a result, the piston rod 18A strokes toward the end side. In addition, since the high-pressure air sealed in the third pressure chamber 42 and the fourth pressure chamber 44 communicates with each other through the communication switching valve 35A, no thrust is generated in the booster piston 22A.

Accompanying the stroke of the working piston 20, high-pressure air corresponding to the volume of the first pressure chamber 38 is supplied to the fluid pressure cylinder 10a from the high-pressure air supply source 104 (see FIG. 11A). During the operating process, the pressure of the high-pressure air accumulated in the third pressure chamber 42 and the fourth pressure chamber 44 is kept constant. In addition, the air in the second pressure chamber 40 is exhausted from the second pressure chamber 40 in accordance with the stroke of the working piston 20 . In this case, the air in the second pressure chamber 40 is exhausted from the exhaust port 106 through the end port 30A and the fifth check valve 108, as shown in FIG. 11A.

(increase process)

As shown in Fig. 12, along with the stroke of the booster piston 22A, the communication switching pin 35a of the communication switching valve 35A is pressed toward the head side, and the detection pin 37a of the exhaust switching valve 37A. ) is pressed to the end side.

As a result, the closed portion 35c of the communication switching pin 35a is inserted into the through hole 122 to close the through hole 122. Thereby, the communication of the high-pressure air between the 3rd pressure chamber 42 and the 4th pressure chamber 44 is blocked.

Further, as the detection pin 37a of the exhaust switching valve 37A is displaced toward the end side, the packings 141 and 142 sealing the gap between the detection pin 37a and the through hole 139 are displaced to the flow path 143. ), the adjustment port 32A and the fourth pressure chamber 44 communicate with each other. As a result, the high-pressure air accumulated in the fourth pressure chamber 44 is exhausted from the exhaust port 106 . That is, the internal pressure of the fourth pressure chamber 44 decreases while the high-pressure air is maintained in the stored state in the third pressure chamber 42 . As a result, thrust is generated in the booster piston 22A according to the difference in internal pressure between the fourth pressure chamber 44 and the third pressure chamber 42 . Since this thrust is added to the thrust of the working piston 20, the thrust of the fluid pressure cylinder 10a increases near the stroke end. In this way, the increase in the thrust of the fluid pressure cylinder 10a is generated by exhausting the high-pressure air in the fourth pressure chamber 44 within the operating range of the communication switching valve 35A and the exhaust switching valve 37A. .

(return process)

As shown in FIG. 11B, the process of returning the fluid pressure cylinder 10a is performed by setting the selector valve 102 of the driving device 120A to the second position. High-pressure air from the high-pressure air supply source 104 is supplied to the regulating port 32A through the second port 102b of the switching valve 102. The first port 102a of the switching valve 102 is connected to the fifth port 102e, and the head side port 28A is connected to the end side port 30A via the fourth check valve 86. Also, the head side port 28A is connected to the exhaust port 106 via the throttling valve 88. As a result, part of the air accumulated in the first pressure chamber 38 is supplied to the second pressure chamber 40 through the fourth check valve 86 side. Also, part of the remaining air accumulated in the first pressure chamber 38 is exhausted from the exhaust port 106 .

In the return process, high-pressure air from the high-pressure air supply source 104 is supplied to the adjustment port 32A of the fluid pressure cylinder 10a. The high-pressure air supplied to the adjustment port 32A flows into the fourth pressure chamber 44 . This replenishes the high-pressure air exhausted in the pressure boosting step. At that time, the amount of high-pressure air replenished is small compared to the amount of high-pressure air required for the stroke of the working piston, and only a small amount of high-pressure air is added.

Meanwhile, a part of the high-pressure air exhausted from the first pressure chamber 38 flows into the second pressure chamber 40 . As air is exhausted from the first pressure chamber 38, the pressure difference between the second pressure chamber 40 and the first pressure chamber 38 increases, and the working piston 20 moves toward the head side. Then, the working piston 20 and the boosting piston 22A return to the starting position of the stroke, and the returning process is completed. In this way, since the air required for the return of the working piston 20 is supplied from the first pressure chamber 38, there is no need to supply high-pressure air to the second pressure chamber 40.

The fluid pressure cylinder 10a according to the present embodiment achieves the following effects.

In the fluid pressure cylinder 10a of this embodiment, high-pressure fluid is sealed in the third pressure chamber 42 and the fourth pressure chamber 44, and the boost switching mechanism 33A is a communication switching valve installed on the boost piston 22A. 35A and an exhaust selector valve 37A installed on the rod cover 48A. According to this fluid pressure cylinder 10a, thrust can be increased at the stroke end without providing a complicated locking mechanism. In addition, since a mechanical locking mechanism for connecting the piston and the piston rod is unnecessary, it is difficult to cause nonconformity with respect to impact in the axial direction, and reliability is excellent.

Further, in the fluid pressure cylinder 10a of this embodiment, the diameter of the booster piston 22A can be made larger than the diameter of the actuating piston 20. Therefore, by increasing the diameter of the booster piston 22A, the diameter of the working piston 20 can be reduced while maintaining the thrust at the stroke end, and the consumption of high-pressure air can be further reduced.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and it goes without saying that various changes are possible within a range not departing from the spirit of the present invention. does not exist.

That is, in the above embodiment, an example in which the drive devices 120 and 120A of the fluid pressure cylinders 10 and 10A are disposed outside the fluid pressure cylinders 10 and 10A has been shown, but the present invention is limited to this It is not. Some or all of the members constituting the driving devices 120 and 120A may be incorporated in the cylinder body 12.

In addition, high-pressure fluid is filled in the first pressure chamber 38 and the second pressure chamber 40 of the fluid pressure cylinder 10, and a working stroke is performed with the booster piston 22, so that the actuating piston 20 ) can also be configured to generate additional thrust from

Claims (16)

A cylinder body 12 having a sliding hole 12a extending in the axial direction;
a partition wall (26) dividing the sliding hole into a head-side working cylinder chamber (14a) and an end-side boosting cylinder chamber (16a);
a working piston (20) disposed in the working cylinder chamber to divide the working cylinder chamber into a first pressure chamber (38) on the head side and a second pressure chamber (40) on the end side;
a booster piston (22) disposed in the booster cylinder chamber to partition the booster cylinder chamber into a head-side third pressure chamber (42) and an end-side fourth pressure chamber (44);
A piston rod 18 connected to the working piston and the boosting piston and extending to an end side through the partition wall,
The high-pressure fluid is sealed in two adjacent pressure chambers among the first pressure chamber, the second pressure chamber, the third pressure chamber, and the fourth pressure chamber,
While the working piston is located on the head side from the predetermined position, communication of the high-pressure fluid between the two pressure chambers is allowed, while when the working piston moves to the end side from the predetermined position, the two pressure chambers and a power conversion mechanism (33) for blocking communication of the high-pressure fluid therebetween and exhausting the high-pressure fluid in one of the two pressure chambers,
High-pressure fluid is sealed in the second pressure chamber and the third pressure chamber,
The power conversion mechanism,
A communication passage 34 communicating with the second pressure chamber and the third pressure chamber;
An exhaust passage 36 communicating with the second pressure chamber;
A communication switching valve (35) that opens the communication passage while the working piston is located at the head side from a predetermined position and closes the communication passage when the working piston moves to the end side from a predetermined position;
While the working piston is located on the head side from a predetermined position, the exhaust passage is closed, and when the working piston moves to the end side from a predetermined position, the exhaust passage is opened to exhaust the high-pressure fluid in the second pressure chamber. Exhaust switching valve 37 that performs
A fluid pressure cylinder having delete The method of claim 1,
The fluid pressure cylinder wherein the communication passage, the exhaust passage, the communication switching valve, and the exhaust switching valve are installed on the partition wall. A cylinder body 12 having a sliding hole 12a extending in the axial direction;
a partition wall (26) dividing the sliding hole into a head-side working cylinder chamber (14a) and an end-side boosting cylinder chamber (16a);
a working piston (20) disposed in the working cylinder chamber to divide the working cylinder chamber into a first pressure chamber (38) on the head side and a second pressure chamber (40) on the end side;
a booster piston (22) disposed in the booster cylinder chamber to partition the booster cylinder chamber into a head-side third pressure chamber (42) and an end-side fourth pressure chamber (44);
A piston rod 18 connected to the working piston and the boosting piston and extending to an end side through the partition wall,
The high-pressure fluid is sealed in two adjacent pressure chambers among the first pressure chamber, the second pressure chamber, the third pressure chamber, and the fourth pressure chamber,
While the working piston is located on the head side from the predetermined position, communication of the high-pressure fluid between the two pressure chambers is allowed, while when the working piston moves to the end side from the predetermined position, the two pressure chambers and a power conversion mechanism (33) for blocking communication of the high-pressure fluid therebetween and exhausting the high-pressure fluid in one of the two pressure chambers,
High-pressure fluid is sealed in the third pressure chamber and the fourth pressure chamber,
The power conversion mechanism,
A communication passage (35e) communicating with the third pressure chamber and the fourth pressure chamber;
An exhaust passage communicating with the fourth pressure chamber;
A communication switching valve that opens the communication passage while the working piston is located at the head side from a predetermined position and closes the communication passage when the working piston moves to the end side from a predetermined position;
While the working piston is located at the head side from a predetermined position, the exhaust passage is closed, and when the working piston moves to the end side from a predetermined position, the exhaust passage is opened to exhaust the high-pressure fluid in the fourth pressure chamber. Exhaust switching valve that performs
A fluid pressure cylinder having The method of claim 4,
A fluid pressure cylinder in which the communication passage and the communication switching valve are installed in the booster piston. The method of claim 5,
A rod cover 48 sealing an end of the fourth pressure chamber at an end side,
The rod cover includes the exhaust passage and the exhaust switching valve. According to claim 1 or 4,
The cylinder body has an adjustment port (32) communicating with the exhaust passage, and the exhaust passage exhausts high-pressure fluid through the adjustment port. According to claim 1 or 4,
The fluid pressure cylinder according to claim 1 , wherein, in the boost switching mechanism, after the communication switching valve closes the communication passage, the exhaust switching valve opens the exhaust passage. According to claim 1 or 4,
The communication conversion valve has one end protruding toward one of the two pressure chambers and the other end having a communication conversion pin (35a) inserted into the communication passage, and the communication conversion pin accompanies the displacement of the operating piston A fluid pressure cylinder that closes the communication passage by being pressurized in the axial direction. According to claim 1 or 4,
The exhaust selector valve has a proximal end inserted into the exhaust passage to seal the exhaust passage and a detection pin 37a whose front end protrudes toward the head, and the detection pin is pressed by the actuation piston or the booster piston to end the exhaust passage. A fluid pressure cylinder in which the sealing of the exhaust passage is released by displacement to the side. According to claim 1 or 3,
A fluid pressure cylinder in which a first check valve (52) is installed in the exhaust passage to pass fluid only in the discharge direction and block fluid in the opposite direction. According to claim 1 or 3,
It further has a supplementary passage 78 communicating with the second pressure chamber,
A fluid pressure cylinder in which a second check valve (54) is installed in the replenishment passage to pass the fluid directed to the second pressure chamber. The method of claim 7,
It further has an auxiliary flow path 76 communicating with the fourth pressure chamber and the adjustment port,
A fluid pressure cylinder in which a third check valve (56) is installed in the auxiliary flow passage to pass only the fluid in a direction from the fourth pressure chamber to the adjustment port and block the fluid in the opposite direction. The method of claim 1,
Further comprising a driving device 120 connected to the first pressure chamber, the second pressure chamber and the fourth pressure chamber,
The driving device has a switching valve 102, a high-pressure fluid supply source 104, an exhaust port 106, and a fourth check valve 86,
In the first position of the switching valve, the first pressure chamber communicates with the high-pressure fluid supply source, and the fourth pressure chamber and the power conversion mechanism communicate with the exhaust port;
In the second position of the switching valve, the first pressure chamber communicates with the fourth pressure chamber through the fourth check valve, and the first pressure chamber communicates with the exhaust port, and furthermore, the second pressure chamber communicates with the exhaust port. A pressure chamber communicates with the high-pressure fluid supply source,
fluid pressure cylinder. The method of claim 4,
Further comprising a driving device (120A) connected to the first pressure chamber, the second pressure chamber and the fourth pressure chamber,
The driving device has a switching valve, a high-pressure fluid supply source, an exhaust port, and a fourth check valve,
In the first position of the switching valve, the first pressure chamber communicates with the high-pressure fluid supply source, and the fourth pressure chamber and the second pressure chamber communicate with the exhaust port;
In the second position of the switching valve, the first pressure chamber communicates with the second pressure chamber through the fourth check valve, and the first pressure chamber communicates with the exhaust port, and furthermore, the fourth check valve communicates with the second pressure chamber. A pressure chamber communicates with the high-pressure fluid supply source,
fluid pressure cylinder. According to claim 14 or 15,
A fluid pressure cylinder with a throttling valve (88) installed between the first pressure chamber and the exhaust port.

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