JPH0620939Y2 - Pilot operated check valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention obtains a free flow of fluid from a fluid supply / discharge channel to a load channel connected to a fluid actuator and from the load channel to the supply / discharge channel. The present invention relates to a pilot operated check valve that presses a poppet valve element with a pilot piston to separate it from a valve seat to obtain a controlled flow of fluid.

[Conventional technology]

Conventionally, a pilot operated check valve of this type has a load passage 2 connected to a fluid actuator 37 as shown in FIG.
4 and the fluid supply / exhaust flow passage 22 are opened at a distance in the axial direction, and a valve hole 25 having a large diameter valve seat 26 formed between the opening of the load flow passage 24 and the opening of the supply / exhaust flow passage 22 Provided on the valve body 21,
A large-diameter poppet valve body 27 is provided which is slidably inserted in the valve hole 25 from the large-diameter valve seat 26 to the opening side of the load passage 24 so as to be attached to and detached from the large-diameter valve seat 26. 27, a first inner hole 28 opening to the head side and a second inner hole 29 having a diameter larger than that of the first inner hole 28 and connected to the first inner hole 28 and opening to the back side.
And a small-diameter valve seat 30 is formed at a step portion connecting the first inner hole 28 and the second inner hole 29, and the second inner hole 29 communicates with the load passage 24 through the opening hole 34. In addition, the small diameter poppet valve body 31 which is attached to and detached from the small diameter valve seat 30 is slidably fitted in the axial direction. Then, when the switching valve 36 is switched from the illustrated state to the left position, the large-diameter poppet valve body 27 receives the acting force based on the fluid pressure from the supply / discharge channel 22 on the large-diameter poppet valve body 27 head. With the small-diameter poppet valve body 31 in the leftward direction in the figure, the acting force based on the fluid pressure from the load passage 24 acting on the back portion and the spring 33 force applied in the seating direction via the small-diameter poppet valve body 31 are resisted. Small diameter poppet valve body 3
1 Slide until the small diameter poppet valve body 31 comes into contact with the flow rate adjusting member 35 provided on the back side, and separate from the large diameter valve seat 26,
A free flow from the supply / discharge channel 22 to the load channel 24 is obtained,
The fluid actuator 37 connects the load passage 2 to the rod chamber 37B.
Fluid from the head chamber 37A is supplied to the switching valve 3
It is discharged via 6 and rises. Further, when the switching valve 36 is switched from the illustrated state to the right position, the load passage 24 in which the small diameter poppet valve body 31 acts on the back portion by the pilot piston 32 that slides in the axial direction by receiving the acting force based on the pilot fluid pressure. Is pressed against the acting force based on the fluid pressure from the spring and the force of the spring 33, and the flow rate adjusting member 3 is moved leftward in the drawing.
5 slides away from the small-diameter valve seat 30 and the large-diameter poppet valve body 27 is seated on the large-diameter valve seat 26 by the acting force based on the fluid pressure from the load flow passage 24 acting on the back. In the illustrated state, the axial opening amount of the small diameter poppet valve body 31 is adjusted according to the axial advance / retreat position of the flow rate adjusting member 35, and a control flow from the load flow path 24 to the supply / discharge flow path 22 is obtained. In the fluid actuator 37, the fluid in the rod chamber 37B is discharged to the load passage 24 and descends. Then, the axial opening amount of the small diameter poppet valve body 31 is changed and adjusted by changing the axial advancing / retreating position of the flow path adjusting member 35. As a result, the large diameter poppet valve body 27 obtains the free flow function and the small diameter poppet valve body 31 obtains the control flow function.

[Problems to be solved by the invention]

However, in the valve having such a configuration, the control flow from the load flow path 24 to the supply / discharge flow path 22 is controlled by the small diameter poppet valve body 31 fitted in the large diameter poppet valve body 27.
Even if the axial opening amount of the small diameter poppet valve body 31 which is separated from the small diameter valve seat 30 by the flow rate adjusting member 35 is fully opened, the fluid from the load flow passage 24 flows through the small diameter valve seat 26 having a small diameter. Therefore, there is a problem that the large flow rate cannot be controlled and the flow rate adjustment range is narrow.

The present invention solves such a problem, and provides a pilot operated check valve capable of satisfactorily controlling a control flow from a load flow path to a supply / discharge flow path from a small flow rate to a large flow rate.

[Means for solving problems]

Therefore, according to the present invention, the load flow path connected to the fluid actuator and the fluid supply / discharge flow path are opened with a gap in the axial direction between the load flow path opening and the supply / discharge flow path opening. A valve hole with a valve seat is provided in the valve body, and the poppet valve element axially slidably inserted into the valve hole on the load flow path opening side from the valve seat is urged to the valve seat by the spring force of the spring. The opening of the valve hole is closed with a lid member to form a working chamber with the valve hole, the poppet valve body back portion and the lid member, and the working chamber is provided in communication with the load flow path,
A load that acts on the poppet valve body on the back of the poppet valve by axially sliding under the action force based on the pilot fluid pressure Presses against the action force based on the fluid pressure from the flow passage to separate from the valve seat and load To obtain a controlled flow from the flow passage to the supply / exhaust flow passage, slide the pilot piston in the axial direction from the valve seat to the valve hole on the supply / exhaust flow passage opening side so that the projection part is abuttable on the poppet valve head. The rod-shaped flow rate adjusting member is provided so as to be movably fitted and inserted so as to face the pilot piston, and is rotatably screwed into the lid member. The tip end extends in the working chamber so as to adjust the axial opening amount formed by the poppet valve body and the valve seat that are pressed and separated from the valve seat, and the tip end is inserted through the poppet valve body in the axial direction. Insert it into the hole and Comprising arranged freely contact.

[Action]

In the structure of the present invention, the poppet valve body is separated from the valve seat regardless of the axial advancing / retreating position of the flow rate adjusting member by receiving the acting force based on the fluid pressure from the supply / exhaust passage on the poppet valve body head. The axial opening is fully opened to obtain a large flow rate of free flow from the supply / discharge channel to the load channel. In addition, the pilot piston axially slides in response to the acting force based on the pilot fluid pressure, and the protruding portion presses the poppet valve body against the acting force based on the fluid pressure from the load flow passage that acts on the back of the poppet valve body. The protrusion of the pilot piston comes into contact with the flow rate adjustment member that is inserted into the insertion hole of the poppet valve body, so that the poppet valve element that is separated from the valve seat has an axial opening amount that is the axial advance / retreat position of the flow rate adjustment member. The control flow from the load flow path to the supply / discharge flow path is obtained according to the above. Then, by changing the axial advance / retreat position of the flow rate adjusting member, the control flow is changed by changing and adjusting the axial opening amount of the poppet valve element between the fully open state and the fully closed state similar to the free flow.
Therefore, it is possible to obtain a small flow rate by changing and adjusting the axial direction opening amount of the poppet valve body, which can obtain a large flow rate flow by fully opening the axial direction opening amount, so that a small flow rate can be obtained from the load flow rate. It is possible to satisfactorily control the control flow to the flow passage from a small flow rate to a large flow rate.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a main body, which is a small diameter hole 1A and a large diameter hole 1B.
And the valve holes 1C are provided so as to penetrate through the inside in the axial direction and open at both ends, and both end openings of the valve hole 1C are closed by the lid members 2 and 3 to form the valve body V. The valve hole 1C connects the load passage 6 connected to the rod chamber 7A of the vertically arranged fluid actuator to the large diameter hole 1B and the switching valve 5 to connect the switching valve 5
The supply and discharge passages 4 for the fluid that are switched and communicated with the pressure source P and the low pressure side T by the operation of are provided in the small diameter holes 1A respectively, and the load passages 6 are opened at intervals in the axial direction. A valve seat 8 is formed in a continuous step portion of the small diameter hole 1A and the large diameter hole 1B between the openings of the supply / discharge channel 4. Reference numeral 9 is a poppet valve body axially slidably inserted into the large diameter hole 1B on the opening side of the load passage 6 from the valve seat 8 of the valve hole 1C, and acting force based on the fluid pressure from the load passage 6 Is pressed against the valve seat 8 in the direction of sitting on the valve seat 8 to prevent the flow from the load flow path 6 to the supply / discharge flow path 4 and to exert an action force based on the fluid pressure from the supply / discharge flow path 4 By being received by the portion and pressed in the direction away from the valve seat 8 and separated from the valve seat 8, a free flow from the supply / discharge passage 4 to the load passage 6 is obtained. 10 is a poppet valve body 9 on the back of the poppet valve body 9, a large diameter hole 1B of a valve hole 1C, and a lid member 3
In the action chamber defined by and, the fluid from the load flow passage 6 is passed through the small diameter 9A provided in the poppet valve body 9 so that the action force based on the fluid pressure from the load flow passage 6 acts on the back of the poppet valve body 9. I am trying to introduce. Reference numeral 11 denotes a spring that is housed in the working chamber 10 and urges the poppet valve body 9 in a seating direction on the valve seat 8. Reference numeral 13 is a pilot piston axially slidably inserted into a small diameter hole 1A on the side of the supply / exhaust passage 4 opening from the valve seat 8 of the valve hole 1C. The fluid pressure from the load flow path 6 that introduces the poppet valve body 9 into the working chamber 10 by contacting the head portion of the poppet valve body 9 with the protruding portion 13A that slides in the direction and is formed to project toward the poppet valve body 9 Based on force and spring 1
It is pressed against one force to separate from the valve seat 8 to obtain a control flow from the load passage 6 to the supply / discharge passage 4. 14
Is pilot piston 13 Pilot piston 1 on the back
3 and the small diameter hole 1A of the valve hole 1C and the lid member 2 define a pilot chamber, which is connected to the head chamber 7B of the fluid actuator and is switched and communicated with the pressure source P and the low pressure side T by operating the switching valve 5. A pilot flow path 15A branched from the supply / discharge flow path 15 communicates so that a part of the fluid pressure in the supply / discharge flow path 15 acts as a pilot fluid pressure on the back of the pilot piston 13. Reference numeral 12 denotes a rod-shaped flow rate adjusting member which is closely fitted by a seal 16 in a fitting insertion hole 9B axially provided in the poppet valve body 9 so as to face the protruding portion 13A of the pilot piston 13 and which penetrates the working chamber 10. Is provided on the cover member 3 and is rotatably engaged with the cover member 3 to project outward, and has a knob 12A at the projecting end. Then, the flow rate adjusting member 12 is provided so as to be movable back and forth in the axial direction by rotating the knob 12A, the other is inserted into the fitting insertion hole 9B of the poppet valve body 9, and the head is pressed by the projecting portion 13A of the pilot piston 13. It is provided so as to come into contact with the projecting portion 13A of the pilot piston 13 so as to adjust the axial opening amount of the poppet valve body 9 during the control flow in which the poppet valve body 9 separates from the valve seat 8.

Next, the operation of this configuration will be described.

In the first illustrated state, the switching valve 5 is in the neutral position, the supply and discharge flow paths 4 and 15 are switched and communicated with the low pressure side T, and the poppet valve body 9 is the fluid pressure from the load flow path 6 introduced into the working chamber 10. Is applied to the valve seat 8 to prevent the fluid from flowing from the load passage 6 to the supply / discharge passage 4, and the fluid actuator 7 is stopped and held at the position shown in the figure. When the state switching valve 5 is switched to the left position in the drawing and the supply / exhaust flow 4 is switched to the pressure source P and the supply / exhaust flow path position 5 is switched to the low pressure side T, the pressure source P flows to the supply / exhaust flow path 4. The generated fluid pressure acts on the head of the poppet valve body 9 and, as shown in FIG.
Is the action chamber 10 by the action force based on the fluid pressure acting on the head irrespective of the axial advance / retreat position of the flow rate adjusting member 12.
From the supply / exhaust passage 4 in which the axial force of the poppet valve body 9 is fully opened, and the poppet valve body 9 is separated from the valve seat 8 against the acting force based on the fluid pressure from the load passage 6 and the force of the spring 11. A large flow rate of free flow to the load passage 6 is obtained, the fluid is supplied from the pressure source P through the supply / discharge passage 4, the valve seat 8 and the load passage 6 to the rod chamber 7A of the fluid actuator 7, The fluid actuator 7 circulates the fluid in the head chamber 7B through the supply / discharge channel group 15 and discharges it to the low-pressure side T to rise. At this time, the pilot piston 13 receives the acting force based on the fluid pressure in the supply / discharge passage 4, and is held in the first illustrated state. Then, when the switching valve 5 is set to the neutral position, the supply / discharge flow paths 4 and 15 are switched and communicated to the low pressure side T, and the poppet valve body 9 is operated by the acting force based on the fluid pressure in the working chamber 10 and the force of the spring 11 to cause the valve seat 8 to move. And the fluid actuator 7 is stopped and held. From this state, when the switching valve 5 is switched to the right position in the drawing to switch the supply / discharge channel 4 to the low pressure side T and the supply / discharge channel 15 to the pressure source P, the pressure source P is connected to the supply / discharge channel 15. A part of the fluid that flows and is supplied to the head chamber 7B of the fluid actuator 7 flows through the pilot channel 15A as a pilot fluid and is introduced into the pilot chamber 14 at the back of the pilot piston 13, and the pilot piston 13 becomes the pilot fluid pressure. The action force based on this is received by the back portion and axially slid to the left in the drawing, the protrusion 13A comes into contact with the head portion of the poppet valve body 9, and the poppet valve body 9 is introduced into the working chamber 10 as shown in FIG. The valve seat 8 is pressed against the acting force based on the fluid pressure from the load passage 6 and the spring 11 force.
From the pilot piston 13 to the flow rate adjusting member 12 fitted into the fitting hole 9B of the poppet valve body 9.
The contact of 3A adjusts the axial opening amount of the poppet valve body 9 to obtain a control flow from the load flow passage 6 to the supply / discharge flow passage 4, and the fluid actuator 7 causes the fluid in the rod chamber 7A to flow through the load flow. The fluid flows through the passage 6, the valve seat 8, and the supply / discharge passage 4, is discharged from the switching valve 5 to the low pressure side T, and the fluid actuator 7 descends. This control flow can change and adjust the axial opening amount of the poppet valve body 9 between fully open and fully closed by rotating the knob 12A to change the axially advancing / retreating position of the flow rate adjusting member 12. Then, when the switching valve 5 is set to the neutral position, the supply / discharge channels 4 and 15 are switched and communicated with the low pressure side T, and the poppet valve body 9 is operated by the acting force based on the fluid pressure in the working chamber 10 and the force of the spring 11 to cause the valve seat to move. 8 and the fluid actuator 7 is stopped and held. At this time, the pilot piston 13 slides back together with the poppet valve body 9 to the first illustrated state.

With such an operation, when the control flow from the load flow path 6 to the supply / discharge flow path 4 is performed, the knob 12A is rotated to change the axial advance / retreat position of the flow rate adjusting member 12, whereby the axial direction of the poppet valve body 9 is changed. Since the control flow can be changed by changing and adjusting the opening amount between full opening and full closing similar to free flow, the opening amount in the axial direction of the poppet valve body 9 can be obtained by fully opening the opening amount in the axial direction. Since a small flow rate can be obtained by changing and adjusting the flow rate adjusting member 12, the control flow from the load flow path 6 to the supply / discharge flow path 4 can be favorably controlled from a small flow rate to a large flow rate. Further, since a single poppet valve body 9 can obtain a free flow from the supply / discharge channel 4 to the load channel 6 and a control flow from the load channel 6 to the supply / discharge channel 4, the free flow and the control can be achieved. The number of parts can be reduced and the structure can be simplified as compared with a conventional valve that requires two poppet valve bodies to obtain a flow.

[Effect of device]

As described above, according to the present invention, the load flow passage connected to the fluid actuator and the fluid supply / discharge flow passage are opened with a gap in the axial direction, and the load flow passage opening and the supply / discharge flow passage opening are formed. A valve hole with a valve seat formed between them is provided in the valve body, and the poppet valve element axially slidably inserted into the valve hole on the load passage opening side from the valve seat is moved to the valve seat by the spring force of the spring. The valve body is urged, and the opening of the valve hole is closed by the lid member to form a working chamber by the valve hole, the poppet valve body back portion and the lid member. Load acting on the poppet valve body that acts on the back of the poppet valve due to the acting force based on the pressure. From the valve seat to the valve hole on the supply / exhaust passage opening side to obtain the control flow that flows from the passage to the intake / exhaust passage A pilot piston having an abutting portion that can come into contact with is provided so as to be slidable in the axial direction, and a rod-shaped flow rate adjusting member is rotatably screwed to the lid member by being arranged so as to face the pilot piston. The flow rate adjusting member extends into the working chamber so as to adjust the axial opening amount formed by the poppet valve body and the valve seat, the head of which is pushed away by the protruding portion of the pilot piston and which is separated from the valve seat. The control flow from the load flow path to the supply / exhaust flow path can be reduced from a small flow rate by inserting the tip end into the axially penetrating fitting insertion hole of the poppet valve and abutting on the protruding part of the pilot piston. It can control well up to a large flow rate and can be applied to a wide range of applications.

Further, the flow rate adjusting member extends into the working chamber so as to adjust the axial opening amount formed by the poppet valve body and the valve seat, which are pushed away from the valve seat by pressing the head portion by the protruding portion of the pilot piston. By inserting the tip into the axially penetrating insertion hole of the poppet valve and making it possible to abut the projecting part of the pilot piston, the fluid pressure from the load flow passage acts to press in the seating direction. The operating area of the poppet valve body can be reduced by the amount of the cross-sectional area of the flow rate adjusting member, and the pilot piston can be downsized, and thus the valve as a whole can be downsized.

Further, since a single poppet valve body can obtain a free flow from the supply / exhaust passage to the load passage and a control flow from the load passage to the supply / exhaust passage, a free flow and a control flow can be obtained. In comparison with a conventional valve that requires two poppet valve bodies, the number of parts can be reduced and the structure can be simplified.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a fluid circuit diagram showing a longitudinal section of a pilot operated check valve, FIG. 2 and FIG. 3 are respectively shown. FIG. 4 is an operation state diagram of the pilot operated check valve, and FIG. 4 is a diagram showing a conventional example. 1 ... Valve body, 4 ... Supply / exhaust flow path, 6 ... Load flow path, 7 ...
... Fluid actuator, 8 ... Valve seat, 9 ... Poppet valve body, 9B ... Fitting hole, 12 ... Flow rate adjusting member, 13 ...
Pilot piston, 13A ... projection.

Claims (1)

[Scope of utility model registration request] 1. A valve seat which opens a load flow passage connected to a fluid actuator and a fluid supply / discharge flow passage with an axial gap between the load flow passage opening and the supply / discharge flow passage opening. A valve hole with a valve is formed in the valve body, and the poppet valve body that is axially slidably inserted into the valve hole on the load passage opening side from the valve seat is urged to the valve seat by the spring force of the spring. Provided, the opening of the valve hole is closed by the lid member to form the working chamber by the valve hole, the poppet valve body back and the lid member, and the working chamber is provided in communication with the load flow passage, and acts based on the pilot fluid pressure. The poppet valve body slides in the axial direction under a force and acts on the back part of the poppet valve body against the acting force based on the fluid pressure from the load flow passage, and pushes it away from the valve seat to supply / exhaust flow from the load flow passage. A protruding part can be freely abutted on the poppet valve body head to the valve hole on the side of the supply / exhaust flow path opening from the valve seat to obtain a control flow that flows to the passage. The provided pilot piston is slidably fitted in the axial direction, and a rod-shaped flow rate adjusting member is provided so as to face the pilot piston so as to be rotatably screwed to the lid member. The head portion of the poppet valve body is extended by extending into the action chamber so as to adjust the axial opening amount formed by the poppet valve body and the valve seat whose head is pressed by the protrusion of the piston and is separated from the valve seat. A pilot operated check valve that is inserted through an insertion hole that extends axially so as to come into contact with the protruding portion of the pilot piston.