JPH0640964Y2 - Operate check device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an operating check device used for controlling a cylinder.

(Prior Art) In the conventional apparatus shown in FIGS. 3 to 5, a pair of actuator ports 2 and 3 are formed in the valve body 1, and one actuator port 2 is connected to the rod side chamber 4 of the cylinder S. The other actuator port 3 is connected to the piston side chamber 5.

A spool hole 6 is formed in the valve body 1, and a spool 7 is slidably mounted in the spool hole 6. When the spool 7 is at the neutral position in the drawing, the actuator ports 2 and 3 are prevented from communicating with either the pump passage 8 or the tank passage 9.

The spool 7 thus configured has the first and second annular grooves 10, 11
Is formed.

Then, when the spool 7 is switched to the right in the drawing,
The pump passage 8 and one actuator port 2 communicate with each other through the first annular groove 10 and the second annular groove.
The other actuator port 3 communicates with the tank passage 9 via 11. Further, when the spool 7 is switched to the left in the drawing, the actuator port 2 side becomes the first annular groove 10
And the actuator port 3 communicates with the pump passage 8 through the second annular groove 11.

Further, a sleeve is provided on the actuator port 2 side.
Although the sleeve 12 is fitted therein, the sleeve 12 is provided with a recess 21 at the outer end thereof which runs in the axial direction, and the recess 21
A communication hole 22 is formed in the. A port member 13 is screwed onto the outside of the sleeve 12. Also, port member
A plurality of oil passage holes 26 communicating with the recess 21 are formed in the port 13, and a second fixed throttle 27 is formed at the center of the port member 13.
Is formed.

The sleeve 12 thus constructed has the first check poppet.
A slit 23 is formed on the outer circumference of the first check poppet 14, and the slit 23 and the communication hole 22 of the sleeve 12 together form a variable orifice.

Further, the first check poppet 14 is formed with a first fixed diaphragm 25, and a space 24 is formed between the outer circumference of the first check poppet 14 and the sleeve 12. The first check poppet 14 normally closes the seat portion 15 formed on the sleeve 12 by the action of the spring y.

Further, a piston chamber 16 is formed in the sleeve 12 on the side opposite to the first check poppet 14, and a piston 17 is housed in this piston chamber 16 and the pressure on the other actuator port 3 side is applied to this piston 17. While acting as pilot pressure, the push rod 18 is in contact with the side surface opposite to the pilot pressure acting surface. Further, the push rod 18 penetrates a sliding hole 19 formed in the sleeve 12 and projects toward the first check poppet 14 side.

Then, when the spool 7 is switched to the right in the drawing, the pump passage 8 communicates with one actuator port 2 side. Therefore, the pressure of the supply fluid from the pump passage 8 causes the first check poppet 14 to resist the spring y. And move to open the seat portion 15. When the first check poppet 14 moves in this way, the pressure fluid supplied to the actuator port 2 side as described above is transferred to the back surface of the first check poppet 14 via the seat portion 15 → the space 24 → the first fixed throttle 25. It enters and becomes a free flow through the second fixed throttle 27 and is supplied to the rod side chamber 4 of the cylinder S. When the flow rate supplied from the pump passage 8 increases, the first check poppet 14
Moves further, and the slit 23 opens in the communication hole 22, so that in addition to the above-mentioned flow path, the seat portion 15 → the space 24 → the communication hole 22
→ It is supplied to the cylinder S via the oil passage hole 26 in the same manner as above.

Further, at this time, the other actuator port 3 communicates with the tank passage 9, so that the return fluid of the piston side chamber 5 returns from the actuator port 3 to the tank passage 9 and increases the load W of the cylinder S.

When the spool 7 is switched to the left, which is the opposite of the above, the pressure fluid in the pump passage 8 causes the pressure fluid in the pump passage 8 to move.
Is supplied to the piston side chamber 5 via the, and the supply pressure at this time also acts on the piston 17.

Therefore, the piston 17 moves to the left in the drawing and pushes the first check poppet 14 against the spring y through the push rod 18 to open it. When the first check poppet 14 is opened, the fluid in the rod-side chamber 4 flows into the oil passage hole of the port member 13.
26 → recess 21 → communication hole 22 → through an external flow path leading to space 24, second fixed throttle 27 of port member 13 → first fixed throttle 25,
Flowing from the seat portion 15 to the tank passage 9 via the actuator port 2 → the first annular groove 10 → through the internal passage that reaches the space 24 and merges with the external passage, the cylinder S lowers the load W. . However, when the pressure on the actuator port 3 side is low, the opening of the first check poppet 14 is small, and the slit 23 of the variable orifice is closed, the return fluid from the cylinder S is the second fixed throttle.
The actuator port 2 is returned to the tank passage 9 via 27 and the first fixed throttle 25, and the cylinder S slowly lowers the load W.

Reference numeral 20 in the drawing is a damper orifice.

(Problems to be Solved by the Present Invention) In the conventional device as described above, the pilot flow acts on the piston 17 to form the control flow in which the return flow path from the cylinder S is formed in the first check poppet 14. At, the pressure of the control flow directly acts on the first check poppet as back pressure. Therefore, there is a problem that the hunting phenomenon is likely to occur and the inching property of the device is deteriorated.

Further, the actuator port 2 communicates with the pump passage 8 and the first check poppet 14 opens, and the first check poppet 14 is opened as a free flow.
When the fluid passes through the check poppet, the pressure loss in the second fixed throttle 27 becomes large, and the back pressure of the first check poppet 14 becomes high, so that the first check poppet 14 increases.
However, there is a problem that it is difficult to move against the spring y.

The purpose of this invention is to prevent the occurrence of hunting, and
It is an object of the present invention to provide an operating check device with less pressure loss.

(Means for solving the problem) The first check poppet is internally provided inside the sleeve, the back side chamber of the first check poppet is defined by the poppet case at the outer end of the sleeve, and the port member is screwed to the outside of the poppet case. Let

In such a structure, the poppet case is internally provided with the second check poppet and the spring, and the second check poppet allows only free flow to the cylinder.

(Operation of the Present Invention) In the present invention, when the first check poppet is free to open due to the fluid pressure supplied to the cylinder, the second check poppet of the poppet case is pushed open to flow into the cylinder.

When the pilot pressure acts on the piston and the fluid in the cylinder is in a control flow returning to the tank passage, the first check poppet is opened by the piston, but the second check poppet of the poppet case remains closed. Prevents pressure rise in the back chamber of the first check poppet.

(Effect of the present invention) This invention is characterized in that the pilot pressure acts on the piston to
When the check poppet is in the control flow with the valve opened, the second
Since the check poppet is closed, the first and second check poppet fixed throttles do not generate an internal / external differential pressure.
The hunting phenomenon of the check poppet can be prevented.

Therefore, the inching operability of the load W is improved even in the minute flow rate range.

Since the second check poppet is provided in addition to the first check poppet, the flow path in the free flow can be formed sufficiently large. Therefore, the internal resistance of the flow path system is reduced.

(Embodiment of the present invention) The sleeve 12 of the embodiment shown in FIGS.
A check poppet 14 is provided as an interior, a poppet case 30 is fitted to the outer end of the check poppet 14, and a port member 31 is screwed to the outside of the poppet case 30. The poppet case 30 has a second check poppet 30a made of a ball.
And a spring 30b are provided inside and communication holes 29 and 32 are formed.

A piston chamber 16 is formed in the sleeve 12 inside the insertion hole on the opposite side of the first check poppet 14, and a piston 17 is housed inside the piston chamber 16. This piston 17 has the other actuator port 3
Side pressure acts as pilot pressure, and push rod 18 is provided on the side opposite to the pilot pressure acting surface.
Abut. This push rod 18 has a sleeve 12
The first check poppet 14 through the sliding hole 19 formed in
It projects to the side.

The push rod 18 and the piston 17 form the pressing body of the present invention.

Then, when the spool 7 is switched to the right in the drawing and the pressure fluid is supplied to the actuator port 2 side, the pressure action causes the first check poppet 14 to move against the spring y and the seat portion 15 open. When the first check poppet 14 moves in this way, the variable orifice of the pressure fluid supplied to the actuator port 2 side does not open when the supply flow rate is small, so the seat portion 15 → space 24 → first fixed throttle 25 is passed through. It flows into the back surface of the first check poppet 14 and reaches the communication hole 29, and the second hole is provided against the spring 30b.
The check poppet 30a is pushed open and supplied from the communication hole 32 to the rod side chamber 4 of the cylinder S. Further, when the supply flow rate is large, the movement amount of the first check poppet 14 is also large, so that a variable orifice is formed, and the slit 23 opens to the communication hole 22. It is supplied as a free flow to the cylinder S via the communication hole 22 and the space 28 in the same manner as above.

When the spool 7 is returned to the neutral position shown in the figure, the first check poppet 14 is closed and holds the load W of the cylinder S. At this time, the second check poppet 30a of the poppet case 30 is closed by the action of the spring 30b. Therefore, the pressure on the cylinder S side is prevented from acting on the back surface of the first check poppet 14.

Next, when the spool 7 is switched to the left side in the drawing opposite to the above and the pressure fluid is supplied to the actuator port 3 side, the pressure acts on the piston 17, so that the piston 17 moves and First with push rod 18
Press check poppet 14. When the first check poppet 14 is pushed in this way, the seat portion 15 opens, but
Variable orifice slit when check poppet 14 opens
23 opens in the communication hole 22, and is returned to the actuator port 2 via the space 28 → the communication hole 22 → the slit 23 of the variable orifice → the seat portion 15.

Then, at this time, since the second check poppet 30a of the poppet case 30 is closed, the first check poppet 1
No flow path into 4 is formed. Therefore, the pressure on the cylinder S side does not act as a back pressure on the first check poppet 14, and the seat portion 15 of the first check poppet 14 can maintain a desired opening degree.

In addition, reference numeral 33 in the drawing denotes a rear side chamber, which is the first check poppet.
The back side chamber 33 is formed between the 14 and the poppet case 30, and the back side chamber 33 is formed by the second check poppet 30a.
It is divided into 1.

Also, inside the first check poppet 14, the rear side chamber 33 and the second
The check poppet constitutes a free-flow passage communicating with the port member 31.

Furthermore, the outside of the sleeve 30, the outside of the poppet case, and the slit 23 that is the variable stop of the first check poppet.
Thus, the control flow passage communicating with the port member 31 is configured.

[Brief description of drawings]

FIGS. 1 and 2 show an embodiment of the present invention.
FIG. 2 is a sectional view, FIG. 2 is an enlarged sectional view of an essential part, FIGS. 3 to 5 are sectional views of a conventional device, FIG. 3 is a sectional view, FIG. It is a side view of 1 check poppet. 1 ... Valve body, 2, 3 ... Actuator port, S ...
Cylinder, 7 ... Spool, 8 ... Pump passage, 9 ... Tank passage, 12 ... Sleeve, 13 ... Port member, 14 ... First check poppet, 17 ... Piston forming the pressing body of the present invention,
18 ... Push rod which constitutes the pressing body of the present invention, 30a ...
Second check poppet, 31 ... Port member.

Claims (1)

[Scope of utility model registration request] 1. A pair of actuator ports are formed in a valve body, the actuator ports are connected to a cylinder, and one of the actuator ports is connected to a pump passage depending on a switching direction of a spool provided in the valve body. In addition, the other actuator port is connected to the tank passage, and a sleeve is provided inside the valve body, and a port member is fitted on the outside of the sleeve, and the flow from one actuator port to the cylinder is applied to this sleeve. In an operating check device in which a first check poppet that is a free flow is provided, and the first check poppet is opened by a pressing body that moves by the pressure action on the other actuator port side, and the return to the tank is a control flow, Attach the poppet case to the outside of the sleeve and attach the poppet The second check poppet is provided in the case, the back side chamber of the first check poppet is partitioned by the second check poppet, and the second check poppet is configured to allow only free flow through the back side chamber, In addition, a control flow channel that connects the sleeve to the outside of the poppet case and the seat portion of the first check poppet is provided, and the opening degree is variable according to the movement amount of the first check poppet in the control flow channel process. An operating check device, wherein an orifice is provided, and a free-flow passage that communicates with a port member is formed in the first check poppet, the back side chamber, and the second check poppet.