JPH025925B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-speed cylinder device that is applied to emergency activation of a power circuit breaker.

A cylinder device capable of high-speed operation is used as the drive means for emergency activation of power circuit breakers at substations.
In order to operate the circuit breaker in an emergency, a cylinder device having an operating speed of several hundred meters/minute is required.

Conventionally, as a means of achieving high speed performance of a cylinder device, there is a method in which a differential circuit is incorporated into the hydraulic pressure circuit of the cylinder, and a poppet type valve with a high flow gain is used as a switching valve for forward and backward movement of the cylinder. However, although this type of cylinder device can achieve the operating speed necessary for emergency operation of the power circuit breaker, it has the following problems.

In other words, no matter how precisely machined the cylinders and the various valves that control the switching of the pressurized liquid used to operate them, there will be minute differences between the surfaces of their mating parts and on the seat surface due to tolerances and changes over time. Generally, a gap occurs, and if high-pressure liquid acts on such a part, the pressure liquid will leak from the gap. In this case, there is no problem as long as the liquid leaks from a part that does not interfere with the cylinder device, but for example, if pressure liquid is supplied to the head side of the cylinder by switching a valve and the piston is moved to the forward end. When the piston is to be held at the forward end position after the piston is moved to the backward end position, or when the piston is moved to the backward end position by supplying pressure fluid to the rod side of the cylinder and the piston is to be held at the backward position, the switch is used. If liquid leaks from the seat surface of the valve or between the outer peripheral surface of the piston and the inner wall of the cylinder, the piston will no longer be able to hold its forward or backward end, and the piston will move by itself. For example, when a power circuit breaker is opened to perform maintenance on the power transmission system, there is a risk that the circuit breaker will close due to the self-propelled piston, putting the worker in an extremely dangerous situation. In addition, in the opposite case to the above, the circuit breaker will be inadvertently shut off.

Also, if liquid pressure is always applied in the direction of movement of the piston to prevent it from moving on its own, there will be no problem even if the pressure liquid leaks, but when trying to shut off the circuit breaker in an emergency, the operation of the switching valve This causes a delay, which in turn causes a delay in the emergency shutoff operation of the circuit breaker. Therefore, after one operation of the cylinder, it is desirable to automatically return the valve in preparation for the next operation.

This invention solves the above problems by automatically returning the cylinder operating switching valve in preparation for the next operation after the cylinder completes one operation, and preventing a slight liquid leakage after one operation is completed. It also compensates for this and maintains the current forward and backward end positions of the cylinder, making it possible to speed up cylinder operation and improve response performance from the time an operation command is given until the operation is completed. The purpose of this invention is to provide a high-speed cylinder device with high speed.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, 1 is a cylinder tube, 2 is a piston inserted into the cylinder tube 1 so as to be able to reciprocate, and 3 is a piston rod integrally constructed with the piston 2.
The opening on the rod side of the cylinder tube 1 is closed by a cover 4, and the opening on the head side of the cylinder tube 1 is closed by a cover member 5 which also serves to mount the cylinder and various control valves. Also,
Throttling valve bodies 6 and 7 are formed concentrically and integrally on both sides of the piston 2, and the tips of the valve bodies 6 and 7 are tapered, and the circumferential surface of the valve bodies 6 and 7 is tapered. A large number of V grooves extending in the axial direction are formed. At the forward end of the piston 2, at the end facing the rod-side cylinder chamber 8 and the cover 4, a liquid inlet 9, which the valve body 6 engages with, is formed concentrically with the piston rod 3. and the valve body 6 constitute a buffer means for absorbing the shock at the forward end of the piston 2, and a ring with which the valve body 7 engages is provided at the end of the head side cylinder chamber 10 at the backward end of the piston 2. A sheet member 11 having a shape is provided, and this sheet member 11
The valve body 7 and the valve body 7 constitute a buffer means for absorbing the shock of the piston 2 at its retreating end. Further, a poppet-shaped check valve 12 is built into the axial center of the valve body 6, and this check valve 1
2, the piston 2 is at the forward end, and the valve body 6
is inserted into the liquid outflow port 9, when the piston 2 is commanded to retreat and liquid pressure in the communication chamber 13 concentric with the liquid outflow port 9 is applied, it opens and the liquid in the communication chamber 13 is transferred to the inlet passage 12a, Exit passage 12
The air is allowed to flow into the cylinder chamber 8 through b. Similarly, a poppet-shaped check valve 14 is built in the axial center of the valve body 7.
This check valve 14 is a communication formed in the cover member 5 via the seat member 11 when the piston 2 is at the backward end and the valve body 7 is engaged with the seat member 11 when the piston 2 is commanded to move forward. It opens when liquid pressure is applied to the chamber 15, and the liquid in the communication chamber 15 is transferred to the inlet passage 14a and the outlet passage 14b.
It is made to flow into the cylinder chamber 10 through the cylinder chamber 10.

In the head side cover member 5, a pressure chamber 16 and a liquid return chamber 17 communicating with the communication chamber 15 formed therein are formed at the upper and lower portions of the communication chamber 15, respectively, with their axes aligned with each other. A seat portion 18 is formed on the opening side of the chamber 16 to the communication chamber 15, and a poppet 19 is provided coaxially with the pressure chamber 16 so as to be able to freely connect and disconnect between the communication chamber 15 and the pressure chamber 16 by coming into contact with and separating from the seat portion 18. A compression spring 22 is inserted between the poppet 19 and a cap 21 that is slidably inserted into the cylindrical portion 20 of the cylindrical portion 20 and seals the rear end of the cylindrical portion 20, so that the poppet 19 is always pressed against the seat portion 18. to strengthen The seat portion 18, poppet 19, and spring 22 constitute a main valve that causes the piston 2 to reciprocate.

Further, a seat portion 23 is formed on the opening side of the return chamber 17 to the communication chamber 15, and a poppet 24 is attached to and separated from the seat portion 23 to freely connect and disconnect between the communication chamber 15 and the return chamber 17. A compression spring 27 is inserted between the poppet 24 and a cap 26 that is slidably inserted into the cylindrical portion 25 coaxial with the cylindrical portion 25 and seals the rear end of the cylindrical portion 25, thereby constantly pressing the poppet 24 against the seat portion 23. urge to do so. In addition, in the poppet 24,
A pilot piston 28 that slides in the axial direction is provided, and the diameter of the pilot piston 28 is made large so that the pressure receiving area on the working chamber 31 side is larger than the pressure receiving area on the pressure chamber 16 side of the poppet 19. It is formed. The tip of the rod 28a of the pilot piston 28 that extends toward the communication chamber 15 is engaged with the poppet 19 on the main valve side, and a spring 29 is provided within the pilot piston 28 as shown in FIG.
A check poppet 30, which is always biased in the opening direction, is fitted so as to be slidable in the axial direction. Both sides of the pressure receiving end of the pilot piston 28 are connected to the spring receiving surface of the poppet 24 and the cap 2.
When pilot pressure is applied to the working chamber 31, the pilot piston 28 is opened in both pressure chambers.
operates to separate the main valve side poppet 19 from the seat portion 18, and when no pilot pressure is applied to the action chamber 31, the pilot piston 28 is held in a free state and the check poppet 30 is separated from the seat and communicated. Hole 32 in which chamber 15 is formed in pilot piston 28
The check poppet 30 is opened to the working chamber 31 through a hole 33 formed in the check poppet 30. The poppet 24 opens and closes the communication chamber 15 to the return chamber 17 in this way, the pilot piston 28 operates to open the main valve poppet 19,
The spring 27, check poppet 30, and action chamber 31 constitute a sub-valve.

The use of such main valves and sub-valves allows each valve to automatically return to its original position after the piston 2 completes its forward movement in preparation for the next movement (backward movement), and also prevents even the slightest liquid leakage from the valve seat. This is to compensate for this and maintain the current forward end position of the piston 2.

In FIG. 2, reference numeral 34 denotes a block integrally attached to the cover member 5. A passage 35 is formed in this block 34 to communicate between the communication chamber 15 and the return chamber 17, and a passage 35 is formed in the passage 35 to communicate between the communication chamber 15 and the return chamber 17. is provided with an on-off valve 37 that is always urged in the opening direction by a spring 36, and this on-off valve 37 is connected to the communication chamber 1.
5 is designed to close when placed under high pressure. Further, the on-off valve 37 prevents the pressure in the communication chamber 15 from increasing due to liquid leakage from each seat over a long period of time at the piston's backward end, thereby preventing the piston 2 from moving forward in the forward direction.

The pressure chamber 16 is connected to liquid passages 38 and 39 extending in the left-right direction within the cover member 5, as shown in FIG. 1, and the extended ends of the passages 38 and 39 are connected to separate pressure charging ports 40 or 41. and the pressure charging port 40
or 41 is connected to an external liquid pressure source (not shown), and connection ports 42, 43 are provided in the middle of the passages 38, 39 to connect separate accumulators (not shown). Further, the cylinder tube 1 is provided with liquid passages 44 and 45 along its axial direction, and one end of each passage 44 and 45 is connected to the passage 38 or 39.
In addition, the other end is connected to a communication chamber 13 on the rod side. Furthermore, in the return chamber 17,
As shown in FIG. 1, return passages 46 and 47 formed in the cover member 5 are connected, and the open end thereof is connected to an oil tank (not shown).

1 and 4, reference numeral 48 denotes a pilot liquid passage formed in the cover member 5 to connect the liquid passage 38 and the working chamber 31 of the sub-valve. A check valve 49 for directional control to open and close is provided. This direction control check valve 49
As shown in FIG. 4, a cylindrical portion 49a is always in communication with the passage 48, and a piston 49c is slidably inserted into the cylindrical portion 49a and engages with a seat portion 49b on the opening side to the working chamber 31. and a spring 49d that presses the piston 49c against the seat portion 49b, and further includes a pilot valve 50 for opening and closing the direction control check valve 49. The pilot valve 50 is
Cylindrical portion 49 of the directional control check valve 49
It is installed in a passage connecting the cylindrical part 49a and an escape passage 52 formed in a block member 51 that closes the piston a, and as shown in FIG.
has a ball 50b integrally attached to a,
Then, the spring 49d of the direction control check valve 49 constantly presses the ball 50b against the seat portion 53 on the side of the escape passage 52.
9a and the escape passage 52 are closed. Further, the block member 51 is provided with an operating rod 54 for advancing the cylinder so as to coincide with the axis in the moving direction of the pilot piston 50a, and the insertion end of the operating rod 54 is connected to the ball 50b of the pilot piston 50a. The outwardly projecting end of the operating rod 54 is connected to a solenoid (not shown) or the like.

1 and 4, reference numeral 55 denotes a liquid passage formed in the cover member 5 to connect the working chamber 31 and the return passage 47, and this liquid passage 55 has a direction control for opening and closing it. Another check valve 56 is provided for this purpose. As shown in FIG. 4, the direction control check valve 56 includes a cylindrical portion 56a that is always in communication with the action chamber 31, and a seat portion 56b that is slidably inserted into the cylindrical portion 56a and that is open to the liquid passage 55. and a piston 56c that engages with the seat portion 5.
6b, and a pilot valve 57 for opening and closing the directional control check valve 56. The pilot valve 57 is installed in a passage connecting the cylindrical portion 56a and a relief passage 52 formed in the blocking member 51 that closes the cylindrical portion 56a of the direction control check valve 56.
As shown in FIG. 5, it has a pilot piston 57a and a ball 57b integrally attached to the pilot piston 57a, and the ball 57b is released by the spring 56d of the directional control check valve 56 to the seat part on the passage 52 side. 58 to close the cylindrical portion 56a and the relief passage 52. The block member 51 also includes the pilot piston 57a.
An operating rod 59 for retracting the cylinder is provided so as to coincide with the axis in the moving direction of the piston, and the insertion end of this operating rod 59 is connected to the pilot piston 57a.
The operating rod 59 is engaged with a ball 57b, and the outwardly projecting end of the operating rod 59 is connected to a solenoid (not shown). In FIG. 6, reference numeral 60 indicates a passageway that communicates between the relief passageway 52 and the liquid passageway 55.

Next, the operation of the apparatus of the present invention configured as described above will be explained.

In FIG. 2, the pressure liquid from the liquid pressure source and the accumulator acts on the cylinder chamber 8, and the piston 2
That is, this indicates a state in which the high-speed cylinder is in a retracted state. In this state, when the high-speed cylinder is moved forward at high speed, for example, when shutting off a power circuit breaker, the operating rod 54 is first pressed by a solenoid or the like that has received an operation command. Then, the operating rod 54 pushes the pilot valve 5 against the spring 49d.
0 ball 50b and pilot piston 50a
(see Figures 4 and 5) and press down on the ball 5.
0b is separated from the seat portion 53 and the cylindrical portion 49a of the direction control check valve 49 is connected to the relief passage 52.
open to Along with this, the liquid pressure applied to the spring mounting side through the through hole of the piston 49c becomes almost zero, and only the spring pressure of the spring 49d remains, so the piston 49c is moved by the liquid pressure applied to the liquid passage 48. The liquid pressure in the liquid passage 48 , that is, the pressure liquid from the accumulated pressure accumulator and the liquid pressure source is introduced into the action chamber 31 . Therefore, the check poppet 30 constituting the sub-valve has a spring 29
(see FIG. 3) and presses the poppet 30 against the seating surface in the pilot piston 28, closing the passage to the communication chamber 15 through the hole 33 in the poppet 30. Then, the liquid pressure inside the action chamber 31 generated by this is applied to the pilot piston 28.
Acts on the lower end surface of. At this time, the liquid pressure in the pressure chamber 16 acting on the back surface of the poppet 19 through the hole is equal to the liquid pressure in the action chamber 31 of the pilot piston 28, but there is a gap between the poppet 19 and the pilot piston as shown in FIG. Since there is a difference in the pressure receiving area depending on the diameter, the pilot piston 28 moves upward in FIG. 2, pushing up the poppet 19 forming the main valve against the spring 22.
The pressure chamber 16 and the communication chamber 15 are communicated with each other. Therefore, pressure liquid from a liquid pressure source (not shown) passes through the passage 38 or 39 and the pressure chamber 16 to the communication chamber 15.
flow inside. Accordingly, the on-off valve 37 closes the passage 35 against the spring 36, and the pressure liquid that has flowed into the communication chamber 15 acts on the end surface of the valve body 7 that is integrated with the piston 2, and the check valve 1
4 to open the check valve 14. Therefore, the pressure liquid in the communication chamber 15 is transferred to the inlet passage 14a.
and is introduced into the cylinder chamber 10 through the outlet passage 14b. Then, the piston 2 is moved forward to the right in FIG.
6 and into the cylinder chamber 10 through the communication chamber 15, thereby causing the piston 2 to move forward to the right at high speed, and shutting off the power circuit breaker connected to the piston rod 3 at high speed. Also, when the piston 2 reaches near the forward end, the valve body 6 moves from its tip to the liquid outlet 9.
When the valve body 6 is gradually inserted into the interior, the gap between the outer circumferential surface of the valve body 6 and the inner circumferential surface of the liquid inlet/outlet 9 forms a tapered surface - V groove.
The flow rate from the cylinder chamber 8 to the communication chamber 13 gradually decreases, absorbing the shock when the piston 2 stops at the forward end, and causing the piston 2 to move forward without a shock.
is stopped at the forward end.

When the piston 2 reaches the forward end and stops, the pressure in the communication chamber 15 will be maintained at the discharge pressure of the liquid pressure source, but this pressure is the same as the pressure acting on the pressure chamber 16 and the action chamber 31. Therefore, the check poppet 30 of the pilot piston 28 is pushed back by the spring 29 as shown in FIG.
The communication chamber 15 and the action chamber 31 are communicated through holes 32 and 33. The poppet 19 on the main valve side, which had been pushed upward by the pilot piston 28 and operated to open, is pushed down by the spring pressure of the spring 22 and engages with the seat portion 18, thereby blocking the connection between the communication chamber 15 and the pressure chamber 16. At the same time, the pilot piston 28 is pushed down and returned to the state shown in FIG. At this time, the spring 27 is inserted into the poppet 24 on the sub-valve side from the action chamber 31 side.
Due to the spring pressure acting on the poppet 24, the poppet 24 is pressed against the seat 23 and the communication chamber 15 is not opened to the return chamber 17.

When the pressing force on the operating rod 54 is removed, the piston 49c, pilot piston 50a, ball 50b, and operating rod 54 of the direction control check valve 49 are moved to the position shown in FIG. 4 by the fluid pressure from the spring 49d and the passage 48. to return to. on the other hand,
If a small amount of liquid leaks from the seat part 23 of the poppet 24 and the seat part of the on-off valve 37 while the piston 2 is at the forward end, the amount of liquid equivalent to this leakage will flow into the liquid pressure source and the accumulator. Since the fluid flows from the communication chamber 13, which is always in communication, into the communication chamber 15 through the space between the outer circumferences of the piston 2, the forward end state of the piston 2 is maintained as it is. That is, piston 2
is maintained at the forward end position and is not self-propelled.

Next, when the piston, that is, the high-speed cylinder moves forward as described above, when an external force is applied to the backward operating rod 59 by a solenoid or the like and the operating rod 59 is pressed, the operating rod 59 resists the spring 56d and moves the pilot piston of the pilot valve 57. 5
7a and the ball 57b (see FIGS. 4 and 5), the ball 57b is separated from the seat part 58, and the cylindrical part 5 of the direction control check valve 56 is pressed down.
6a is opened to the escape passage 52. Along with this, the liquid pressure applied to the spring mounting side through the through hole of the piston 56c becomes almost zero, and only the spring pressure of the spring 56d remains, so that the piston 56
c is pushed up by the liquid pressure in the working chamber 31, opening the working chamber 31 to a liquid passage 55 communicating with the return passage 47 to the oil tank. Then, since the liquid pressure in the action chamber 31 decreases, the poppet 24 and the pilot piston 28, which constitute the sub-valve,
is applied to the communication chamber 15 by the pressure of the liquid pressure source and the accumulator, causing the spring 27 to
, and the communication chamber 15 is opened to the return chamber 17. At this time, the poppet 19 constituting the main valve is pressed against the seat portion 1 by the spring 22.
8, pressure chamber 16 and communication chamber 1
The cut-off state is maintained for 5 minutes as shown in FIG. Further, by opening the communication chamber 15 to the return chamber 17, the cylinder chamber 10 is connected to the communication chamber 15, the return chamber 17,
open to the tank through return passages 46, 47;
The discharge pressure from the liquid pressure source is applied to the connecting chamber 13 on the rod side through the passage 38 or 39 and the passages 44, 45. At this time, since the piston 2 is at the forward end and the valve body 6 is inserted into the liquid outlet 9, the pressure liquid from the liquid pressure source first opens the check valve 12, and the passage 12a, It flows into the cylinder chamber 8 through 12b. As a result, when the piston 2 moves backward, the valve body 6 escapes from the liquid outlet 9, so that the pressure liquid from the liquid pressure source is introduced into the cylinder chamber 8 from the liquid outlet 9, causing the piston 2 to move backward. Further, when the piston 2 reaches near the retreating end and the valve body 7 begins to be sequentially inserted into the seat member 11 from its tip, there is a gap between the outer circumferential surface of the valve body 7 and the inner circumferential surface of the seat member 11. The flow rate changes between the taper surface and the V groove, and the flow rate from the cylinder chamber 10 to the communication chamber 15 gradually decreases, absorbing the impact when the piston 2 stops at the rearward end, and stops the piston 2 at the rearward end without shock. let When the liquid pressure in the communication chamber 15 drops to a predetermined pressure, the poppet 24 constituting the sub-valve is moved upward by the spring 27 and pressed against the seat portion 23, thereby closing the communication chamber 15 and the return chamber 17.
Further, when the liquid pressure in the communication chamber 15 becomes lower than a predetermined pressure, the on-off valve 37 is opened by the spring 36, and the communication chamber 15 and the return chamber 17 are communicated with each other through the passage 35.

At the stage when the piston 2 has reached the backward end shown in FIG.
6d returns to the position shown in FIG. Further, when the pressing force acting on the operating rod 59 is removed, the pilot piston 57a, ball 57b and operating rod 59 are returned to the state shown in FIG. 4 by the spring 56d. Furthermore, even if the pressure fluid in the cylinder chamber 8 leaks to the communication chamber 15 side through the gap between the outer circumference of the piston 2 and the inner circumferential surface of the cylinder tube when the piston 2 has reached the retreating end, the leakage Since the liquid flows out into the return chamber 17 via the open/close valve 37 and the passage 35 in the open state, the pressure in the communication chamber 15 does not increase due to this leaked liquid, and therefore the piston 2 automatically moves forward in the forward direction. Never run.

Note that the cylinder device with the above configuration has an oil storage amount of 5,
A piston-type accumulator with a gas pressure of 200Kg/cm ² is applied, and the operating pressure oil is 350Kg/cm ^{2 .}
When the cylinder device is operated with a load of Kg combined, the operating speed of the cylinder device is 600m/mm.
(10m/sec), therefore, the time from when the operation command signal is given to the solenoid etc. until the piston of the cylinder device reaches the forward end, that is, the forward movement is completed, is less than 3/100sec, and the emergency This makes it extremely suitable for operation.

As described above, according to the high speed cylinder device of the present invention, the following effects can be obtained.

(a) A communication chamber 15 that communicates with the head-side cylinder chamber 10 of the piston 2, and a fluid pressure source that communicates with this communication chamber 15, is formed in the head-side cover member 5, and is provided with an accumulator. and a pressure chamber 16 which is connected to the rod-side cylinder chamber 8 of the piston 2, and this pressure chamber 1.
6 and the communication chamber 15, a poppet 24 which is always urged in the direction of closing between the communication chamber 15 and the return chamber 17, and a poppet 24 that can be slid into the poppet 24. A pilot piston 28 is fitted into the main valve to open the main valve, and the pilot piston 28 is slidably installed in the pilot piston 28 and normally communicates between the communication chamber 15 and the working chamber 31 and is shut off by the pressure acting on the working chamber 31. Since it is equipped with a sub-valve consisting of a check poppet 30, when the action chamber 31 is communicated with a liquid pressure source by operating the directional control valve 49, the pilot piston 28 of the sub-valve is operated by the liquid pressure applied to the action chamber 31, and the main valve is opened. Operate the opening,
The liquid pressure source and the pressure liquid in the cylinder chamber 8 on the rod side of the cylinder are transferred to the communication chamber 15 via the pressure chamber 16.
This allows the piston to move forward at high speed, increasing the operating speed of the cylinder to several hundred meters per minute during forward movement, and completing the forward movement of the piston. However, when the liquid pressure in the communication chamber 15 becomes equal to the liquid pressure in the action chamber 31, the check poppet 30 opens and the pilot piston 2
8 returns to its original position, and the main valve can be automatically returned to the closed state.

Furthermore, when the piston 2 is at the forward end position, when the action chamber 31 is opened to the tank by operating the directional control valve 56, the poppet 24 of the sub-valve is opened by the fluid pressure in the communication chamber 15, opening the head side of the cylinder to the tank. At the same time, pressure liquid is introduced from a liquid pressure source into the cylinder chamber 8 on the rod side of the cylinder to move the piston backward, and after the backward movement is completed, the poppet 24 of the sub-valve is automatically returned to the closed state by the spring 27. can. Moreover, since the main valve and sub-valve are poppet type, they have good responsiveness to operation commands, and are suitable for emergency shutoff of a power circuit breaker.

In addition, even if the pressure on the head side leaks from the valve seat when the cylinder is at the forward end position, this is automatically replenished by the liquid from the rod side leaking from the outer circumference of the piston. The piston can be held at the current position without self-propelling in the return direction due to leakage from the valve seat.

Furthermore, an on-off valve 37 that opens when the liquid pressure in the communication chamber 15 falls below a predetermined pressure is provided in the passage 35 that communicates between the communication chamber 15 and the return chamber 17, so that after the cylinder retreats, From the outer periphery of piston 2 to the head side (communication chamber 15 side)
Even if liquid leaks, this can prevent the piston 2 from moving forward in the forward direction. In other words, since liquid leakage is compensated for after one cylinder operation is completed, there is no chance of the cylinder operating inadvertently.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of a high-speed cylinder device according to the present invention, FIG. 2 is a sectional view taken along the - line in FIG. 1, FIG. 5 is an enlarged sectional view of the pilot valve and operating rod portion in FIG. 4, and FIG. 6 is a sectional view taken along the line - in FIG. 1. 1...Cylinder tube, 2...Piston, 3
...Piston rod, 4...Rod side cover, 5
...Head side cover member, 6, 7... Valve body, 8...
...Rod side cylinder chamber, 9...Liquid outflow inlet, 1
0... Head side cylinder chamber, 11... Seat member, 12, 14... Check valve, 13, 15
...Communication room, 16...Pressure room, 17...Return room,
18... Seat part, 19... Poppet, 22...
Spring, 23... Seat portion, 24... Poppet, 27... Spring, 28... Pilot piston, 29... Spring, 30... Check poppet, 31... Action chamber, 35... Passage, 37
...Opening/closing valve, 38, 39...Liquid passage, 40, 4
1... Pressure charging port, 42, 43... Accumulator connection port, 44, 45... Liquid passage,
46, 47...Return passage, 48...Liquid passage, 4
9... Check valve for direction control, 50... Pilot valve, 52... Relief passage, 54... Operation rod for forward movement, 55... Liquid passage, 56... Check valve for direction control, 57... Pilot valve, 5
9...Reverse operation rod.

Claims (1)

[Claims] 1 a cylinder tube 1; a piston 2 fitted reciprocally into the cylinder tube 1 and having a piston rod 3 on one side;
A communication chamber 15 communicates with the head-side cylinder chamber 10 of the piston 2, and a fluid pressure source that communicates with the communication chamber 15 and is formed in the head-side cover member 5 and that is provided with an accumulator. and the rod side cylinder chamber 8 of the piston 2.
a poppet-shaped main valve disposed within the head side cover member 5 and normally biased in the closing direction so as to cut off communication between the pressure chamber 16 and the communication chamber 15; Contact room 15 above
a return chamber 17 formed in the head-side cover member 5 in communication with the liquid discharge side;
A poppet 24 is disposed on the head side cover member 5 and is normally biased in the closing direction so as to cut off communication between the return chamber 17 and the communication chamber 15, and a poppet 24 that is slidably fitted into the poppet 24 and connected to the main From a pilot piston 28 that opens the valve and a check poppet 30 that is slidably mounted in the pilot piston 28 and normally communicates between the communication chamber 15 and the working chamber 31 and shuts off the communication by the pressure acting on the working chamber 31. A sub-valve is provided in the passage between the working chamber 31 and the liquid pressure source, and is normally biased in the closing direction, and when opened, the pilot piston 28 of the sub-valve is actuated by the liquid pressure applied to the working chamber 31. a directional control valve 49 for opening the main valve;
It is provided between the action chamber 31 and the return passage 47 to the tank and is normally biased in the closing direction, and when opened, the action chamber 31 is opened to the return passage 47 and the poppet 24 of the sub-valve is opened. It is characterized by being composed of a control valve 56 and an on-off valve 37 which is provided between the communication chamber 15 and the return chamber 17 and is normally biased in the open direction to release leaked liquid from the rod chamber side to the return chamber 17. High-speed cylinder device.