JP2005315349A - Control valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control valve device, preventing back flow by holding a seat valve element in a seated position even if the pressure of the inlet chamber side is smaller than the pressure on the outlet side. <P>SOLUTION: A variable throttle 27 and a shuttle valve 201 are disposed in a seat valve element 24. The shuttle valve 201 is constructed by a passage 203 positioned on the inlet 22 side and a passage 204 positioned on a variable throttle 27 side, and positioned between a passage 28 connecting an inlet chamber 22 and a variable throttle 27, a passage 202 communicated with an outlet chamber 23, a passage 203 and a passage 204, and adapted to select high pressure side pressure between the pressure of the inlet chamber 22 and the pressure of the outlet chamber 23 and guide the same to the passage 204. When a control valve element 30 is closed, in the case where the pressure in the inlet chamber 22 is high, pressure medium is guided to a control pressure chamber 25 through the passage 203, the shuttle valve 201, the passage 204 and the variable throttle 27, and in the case where the pressure in the outlet chamber 23 is high, the pressure medium is guided to the control pressure chamber 25 through the passage 202, the shuttle valve 201, the passage 204 and the variable throttle 27. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a seat valve type control valve device, and more particularly to a control valve device suitable for a construction machine and a pressure circuit suitable for a hydraulic circuit of the construction machine.

  Conventionally, as a seat valve type control valve device, there is one configured by combining a seat type main valve and a pilot control valve. This control valve device is applied to, for example, a construction machine, and is disposed at a coupling portion of a main circuit between a pressure source and an actuator, or is disposed at a coupling portion of a main circuit between an actuator and a tank. It controls the operating speed and direction of motion of the actuator. As an example of such a control valve device, there is a control valve device described in Japanese Patent Publication No. 4-27401. This control valve device is provided with a control pressure chamber for energizing the main valve in the valve closing direction on the back side of the seat-type main valve, and through a variable throttle whose opening amount changes according to the displacement of the main valve. The valve inlet side is connected to the control pressure chamber, the control pressure chamber is connected to the main valve outlet side via the pilot passage, the pilot valve is arranged in the pilot passage, and the displacement of the main valve is adjusted according to the pilot valve displacement. It is intended to be controlled.

  FIG. 5 is a view showing a conventional seat valve type control valve device. The housing 1 is formed with a circular valve seat 2 and a cylindrical wall 3 extending in the axial direction from the valve seat 2. The valve body 4 slides with respect to the wall 3 as a cylindrical plunger inside the cylindrical wall 3. A throttle is formed in the flow path 5 inside the valve body 4, and a variable throttle whose opening amount increases as the distance of the valve body 4 from the valve seat 2 increases. The flow path 5 includes at least one notch or groove in the axial direction, for example, and is formed on the outer wall surface of the valve body 4. In the closed position of the valve body 4 shown in FIG. 5, the end of the groove 5 far from the valve seat 2 is the step of the cylindrical wall 3 surrounding the valve body 4, that is, the end of the sliding wall 3 farthest from the valve seat 2. It is located slightly outside the edge 6. Thereby, a small connection 9 is formed between the inlet chamber 7 and the control pressure chamber 8 behind the valve body 4 at all times, ie even when the valve body 4 abuts against the valve seat 2, thereby When the pilot control valve 10 is completely closed, the pressure in the control pressure chamber 8 becomes the same as that in the inlet chamber 7. When the pilot control valve 10 is operated and the pilot flow is allowed to pass, the pressure medium flows through the throttle of the flow path 5, whereby the seat valve body 4 urges the seat valve body in the valve closing direction. The pressure in the control pressure chamber 8 behind the body 4, the pressure in the inlet chamber 7, and the pressure in the outlet chamber 11 move away from the valve seat 2 as much as necessary to balance. The pilot control valve 10 acts as an adjustable throttle, and the more pilot flow through the pilot control valve 10, the more the seat valve body 4 moves from the valve seat 2 and the more main flow through the seat valve is. When the pilot control valve 10 is fully opened, the maximum flow rate through the seat valve is obtained.

  FIG. 6 is a view showing another conventional seat valve type control valve device. The same parts as those in FIG. The difference from FIG. 5 is the position of the inlet chamber 7 and the outlet chamber 11 and the shape of the flow path 5, and the operation is the same as in FIG. 5.

  In the above prior art, since the pilot flow rate through the pilot control valve 10 is a small flow rate of the total flow rate, the pilot control valve 10 can be controlled with a small force. Easy to control.

Japanese Patent Publication No. 4-27401

  In the conventional seat valve type control valve device, the control valve device shown in FIG. 5 is arranged at the coupling portion of the main circuit between the pressure source and the actuator, and the pressure source and the inlet chamber 7 of the control valve device are connected. When used in a circuit in which the outlet chamber 11 and the actuator are connected, even if the pilot control valve 10 is closed, the seat valve 4 is turned off when the pressure Ps in the inlet chamber 7 becomes smaller than the pressure Pr in the outlet chamber 11. It could not be held at the position seated on the valve seat 2. Hereinafter, this point will be described in detail.

The effective pressure receiving area of the annular part 4a located in the inlet chamber 7 of the seat valve body 4 is As, the effective pressure receiving area of the seat part 4b located in the outlet chamber 11 is Ar, and the effective of the sliding part 4c located in the control pressure chamber 8 If the pressure receiving area is Ac, the pressure in the inlet chamber 7 is Ps, the pressure in the outlet chamber 11 is Pr, and the pressure in the control pressure chamber 8 is Pc, each pressure receiving area As, Ar, Ac of the seat valve body 4 is ,
Ac = As + Ar (1)
From the balance of pressure applied to the seat valve body 4,
Ac / Pc = As / Ps + Ar / Pr (2)
Holds. For example, when the pilot control valve 10 is operated by setting the pressure source to a high pressure and the pressure medium is supplied to the actuator through the seat valve, the inlet chamber 7 and the control pressure chamber 8 are closed. Is in communication with the flow path 5, the pressure Ps in the inlet chamber 7 and the pressure Pc in the control pressure chamber 8 are equal,
Ac / Pc> As / Ps + Ar / Pr (3)
Thus, the seat valve body 4 is closed and held at the position seated on the valve seat 2, the pressure medium on the load pressure side of the actuator is sealed, and the actuator can be held so as not to operate.

However, for example, when a switching valve or the like communicating with the tank is arranged at the coupling portion of the main circuit that connects the pressure source and the control valve device to reduce the pressure of the pressure source, the pressure Pc in the control pressure chamber 8 decreases.
Ac / Pc <As / Ps + Ar / Pr (4)
Thus, the seat valve body 4 is opened, and the pressure medium flows backward.

  Further, even if the pressure of the pressure source is maintained to be equal to or higher than the load pressure of the actuator and the seat valve body 4 is closed, if the load pressure of the actuator suddenly increases for some reason, the seat valve body 4 is opened. As a result, the pressure medium flows backward through the seat valve, which causes a problem that the actuator cannot be held.

  6 is a circuit in which the control valve device shown in FIG. 6 is arranged at the coupling portion of the main circuit between the pressure source and the actuator, the pressure source and the inlet chamber 7 of the control valve device are connected, and the outlet chamber 11 and the actuator are connected. For example, when a switching valve or the like communicating with the tank is disposed at the coupling portion of the main circuit that connects the pressure source and the control valve device, the same problem as the control valve device of FIG. 5 described above occurs.

  In such a conventional control valve device, a circuit that holds the pressure on the outlet chamber side, for example, a pressure circuit that needs to hold the load pressure of the actuator, such as a hydraulic circuit of a construction machine, or the load pressure of the actuator suddenly increases. Cannot be used for pressure circuits that increase rapidly.

  An object of the present invention is to improve a conventional seat valve type control valve device, and prevent a backflow by holding a seat valve body in a seating position even when the pressure on the inlet chamber side becomes smaller than the pressure on the outlet side. A control valve device and a pressure circuit using the control valve device are provided.

  In order to solve the above-described problem, in the first aspect of the present invention, an inlet chamber and an outlet chamber provided in the housing, and a slidably provided in the housing, the opening amount between the inlet chamber and the outlet chamber is reduced. A seat valve body to be controlled, a control pressure chamber that is provided in a housing on the back side of the seat valve body and urges the seat valve body in a valve closing direction, and a displacement of the seat valve body that is provided in the seat valve body A variable throttle that changes an opening amount to the control pressure chamber according to the first passage, a first passage that communicates the inlet chamber and the variable throttle, a pilot passage that communicates the control pressure chamber and the outlet chamber, In the control valve device provided with the pilot control valve body provided in the pilot passage, the second passage communicating with the outlet chamber and a part of the first passage are configured and positioned on the inlet chamber side. Other than the third passage and the first passage A part of the fourth passage located on the variable throttle side, located between the second passage and the third passage, and is a high pressure of the pressure in the inlet chamber and the pressure in the outlet chamber. And a valve device that selects the pressure on the side and guides it to the fourth passage.

  With this configuration, when the pilot control valve is closed and no pilot flow is allowed to flow, the seat valve body is closed, the seat valve body is held in the seating position, and the pressure in the outlet chamber is higher than the pressure in the inlet chamber. Since the pressure in the outlet chamber is applied to the control pressure chamber via the valve device and the variable throttle, the pressure in the control pressure chamber is almost the same as the pressure in the outlet chamber, and the seat valve body is closed due to the difference in pressure receiving area. It is retained and can prevent backflow.

  In addition, when the pilot control valve is opened and the seat valve body is open, when the pressure in the outlet chamber suddenly increases and becomes greater than the pressure in the inlet chamber, the seat valve body closes and backflow occurs. Can be prevented. At this time, by closing the variable throttle immediately before the valve is closed, the valve closing speed of the seat valve body is suppressed, and the collision of the seat valve body with the valve seat can be mitigated.

  According to a second aspect of the invention, the second passage, the third passage, the fourth passage, and the valve device are formed and arranged inside the seat valve body.

  If comprised in this way, it is not necessary to provide the said 2nd-4th channel | path and a valve apparatus in the said housing, and the magnitude | size of the said housing can be made small.

  According to a third aspect of the present invention, the portion of the seat valve body that faces the inlet chamber is located on the radially outer side of the valve seat, and the portion of the seat valve body that faces the outlet chamber is on the radially inner side of the valve seat. It is characterized by being located in.

  According to a fourth aspect of the present invention, a portion of the seat valve body facing the inlet chamber is located radially inside the valve seat, and a portion of the seat valve body facing the outlet chamber is radially outward of the valve seat. It is characterized by being located in.

  Since the control valve device and the pressure circuit of the present invention are configured as described above, there is an effect that the load pressure on the outlet chamber side, which could not be realized by the conventional technology, can be maintained and the backflow can be prevented. .

  Further, the valve opening speed can be suppressed immediately before the seat valve body is closed, and the impact at the time of closing the valve can be mitigated.

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

  First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 are views showing a hydraulic system (pressure circuit) including a control valve device according to a first embodiment of the present invention. FIG. 1 is a schematic sectional view showing the control valve device. FIG. 2 is a diagram showing the whole hydraulic system (pressure circuit) in a hydraulic circuit diagram.

  In FIG. 1, the present embodiment has a control valve device 100, which has a seat-type main valve, that is, a seat valve body 24 slidably inserted into a housing 21. The opening amount between the inlet chamber 22 and the outlet chamber 23 is controlled. A control pressure chamber 25 that urges the seat valve body 24 in the valve closing direction is formed on the back side of the seat valve body 24. A spring 35 that biases the seat valve body 24 in the valve closing direction is disposed in the control pressure chamber 25, and the spring 35 is held by the seat valve body 24 and the housing 21. The spring 35 applies a preset force in the valve closing direction to the seat valve body 24 at a position where the seat valve body 24 is seated on a valve seat 26 provided in the housing 21, and the movement distance of the seat valve body 24 is increased. Accordingly, the urging force in the valve closing direction increases, and the spring 35 does not adhere until the moving distance of the seat valve body 24 reaches the maximum position. The power gets bigger.

  When configured as described above, the control force for opening and closing the seat valve body 24 is a combined force of the force due to the pressure acting on the seat valve body 24 and the biasing force of the spring 35. Further, for example, when the pressure in the inlet chamber 22 and the pressure in the outlet chamber 23 are equal to the pressure in the control pressure chamber 25, the valve opening force and the valve closing force due to the pressure acting on the seat valve body 24 are balanced. Even in this case, the seat valve body 24 can be closed by the urging force of the spring 35 in the valve closing direction, and the reliability of the valve closing function is improved.

  In the seat valve body 24, the opening amount to the control pressure chamber 25 changes according to the displacement of the seat valve body 24, and a variable throttle 27 having a slight opening amount even at the position where the seat valve body 24 is seated, and an inlet A first passage 28 that connects the chamber 22 and the variable throttle 27 and a second passage 202 that communicates with the outlet chamber 23 are formed. The first passage 28 includes a third passage 203 located on the inlet 22 side and a fourth passage 204 located on the variable throttle 27 side. Further, the seat valve body 24 is located between the second passage 203 and the third passage 204 and selects the pressure on the high pressure side of the pressure in the inlet chamber 22 and the pressure in the outlet chamber 23 to select the fourth pressure. A shuttle valve 201 that leads to the passage 204 is installed. As described above, since the first passage 28 (third and fourth passages 202 and 203), the second passage 202, and the shuttle valve 201 are provided in the seat valve 23, the control pressure chamber 25 is the inlet chamber. 22 and the high pressure side of the outlet chamber 23.

  Since the control pressure chamber 25 communicates with the high pressure side of the inlet chamber 22 and the outlet chamber 23 even at the position where the seat valve body 24 is seated as described above, the pressure in the inlet chamber 22 is higher than the pressure in the outlet chamber 23. When the pressure is high, the pressure in the control pressure chamber 25 is equal to the pressure in the inlet chamber 22, and the pressure receiving area of the pressure in the inlet chamber 22 in the seat valve body 24 and the control pressure chamber 25 in the seat valve body 24. Due to the difference from the pressure receiving area of the internal pressure, the force that biases the seat valve body 24 in the valve closing direction is large, and the seat valve body 24 can be held in the valve closed state.

  When the pressure in the outlet chamber 23 is higher than the pressure in the control pressure chamber 25 regardless of whether the seat valve body 24 is opened or closed, the pressure medium flows from the outlet chamber 23 toward the control pressure chamber 25 and the control pressure chamber The valve closing force that increases the pressure in the valve 25 and biases the seat valve body 4 increases. At this time, the pressure in the control pressure chamber 25 is equal to the pressure in the outlet chamber 23, and the pressure receiving area of the pressure in the outlet chamber 23 in the seat valve body 24 and the control pressure chamber 25 in the seat valve body 24. Due to the difference between the inner pressure and the pressure receiving area, the force that urges the seat valve body 24 in the valve closing direction is large, and the seat valve body 24 can be held in the closed state to prevent backflow.

  The control valve device 100 also has pilot passages 29 and 33. A pilot control valve body 30 is provided in the pilot passages 29 and 33. When the pilot control valve body 30 is opened, the control pressure chamber 25 and the outlet chamber 23 are provided. And communicate.

  The control valve device 100 having the functions described above is suitable for the following pressure circuit. The inlet chamber 22 and the pressure source 101 are connected, the pressure medium is supplied from the pressure source 101 to the inlet chamber 22, and the maximum pressure of the pressure medium supplied from the pressure source 101 is set so that the control valve device 100 does not break at high pressure. A relief valve device 102 to be regulated is provided. The control valve device 103 is controlled in conjunction with the control valve device 100. When the control valve device 100 is closed, the control valve device 103 is opened to communicate the pressure source 101 with the tank, and the pressure source 101 Reduce the pressure in the side circuit. When the actuator 104 is actuated, the control valve device 103 is throttled to increase the pressure in the circuit, and the amount of valve opening of the control valve device 104 is adjusted to control the pressure medium. When the control valve device 100 is fully open, the control valve device 103 is closed and supplies the control valve device 100 with the entire flow rate of the pressure medium from the pressure source 101. The outlet chamber 23 and the holding pressure side port of the actuator 104 are connected, and the pressure medium controlled by the control valve device 100 is supplied from the outlet chamber 23 to the holding pressure side port of the actuator 104.

  When the pilot pressure is supplied to the pilot port 37 of the pilot control valve body 30, the pilot control valve body 30 is operated and the pilot flow rate is controlled, the opening amount to the control pressure chamber 25 changes according to the displacement of the seat valve body 24. The amount of movement of the seat valve body 24 corresponding to the pilot flow rate is determined by the action of the variable throttle 27. For this reason, the opening amount between the inlet chamber 22 and the outlet chamber 23 corresponding to the moving amount of the seat valve body 24 is controlled, and the main flow rate is adjusted.

  Further, when the pilot control valve 30 is open and the seat valve body 24 is open (therefore, pressure oil is supplied to the actuator 104 and the actuator 104 is moving), the load W of the actuator 104 increases suddenly. There is a case. As an example of such a case, there is a case where the control valve device 100 of the present embodiment is used as a control valve for driving a hydraulic cylinder for an arm of a hydraulic excavator and an arm cloud operation is performed to perform excavation work. When performing excavation work with arm cloud operation, the load of the hydraulic cylinder for the arm (load W of the actuator 104) is light before the bucket bites into the ground, and the hydraulic cylinder operates at a speed corresponding to the supply flow rate of pressure oil However, when the bucket bites into the ground, the load of the hydraulic cylinder for the arm (the load W of the actuator 104) increases rapidly due to the excavation resistance of the ground.

  Thus, when the pilot control valve body 30 is opened and the seat valve body 24 is opened, the load W of the actuator increases, and the pressure in the outlet chamber 23 becomes higher than the pressure in the inlet chamber 22. 23, the pressure medium in the outlet chamber 23 tends to flow back into the inlet chamber 22, but the pressure medium in the outlet chamber 23 passes through the second passage 202, the shuttle valve 201, the fourth passage 204, and the variable throttle 27 in the seat valve 24. Is supplied to the control pressure chamber 25, the pressure in the control pressure chamber 25 rises, and the seat valve body 24 closes. Since the pressure in the control pressure chamber 25 is almost the same as the pressure in the outlet chamber 23, the valve closed state can be maintained and the backflow can be prevented by the difference in the pressure receiving area, and the load check function is achieved. The actuator 104 can be prevented from returning.

  When the seat valve body 24 begins to close, the pressure medium is supplied to the control pressure chamber 25 through the second passage 202, the shuttle valve 201, the fourth passage 204, and the variable throttle 27 in the seat valve 24 in a short time. Therefore, high response of the load check function can be obtained. Further, just before the seat valve body 24 is closed, the variable throttle 27 is throttled and the pressure in the control pressure chamber 25 is lowered, and the valve closing speed is also lowered accordingly. As a result, the speed decreases when the seat valve body 24 contacts the valve seat 26, the collision speed when the valve is closed is suppressed, and the impact can be mitigated.

  The pilot control valve body 30 is operated, the main flow rate is adjusted as described above, and the pilot control valve body 30 is closed from the state where the pressure medium is supplied to the actuator 104, and the seat valve body 24 is closed. In the state just before, the pressure in the inlet chamber 22 and the pressure in the control pressure chamber 25 are equal and larger than the pressure in the outlet chamber 23, but the control valve device 103 is opened and the pressure source 101 When the tank is connected and the pressure in the circuit on the pressure source 101 side decreases and the pressure in the inlet chamber 22 decreases, a pressure difference between the inlet chamber 22 and the control pressure chamber 25 is generated, and the sliding provided in the housing 21 The pressure medium leaks from the control pressure chamber 25 toward the inlet chamber 22 through a slight annular gap between the surface 36 and the sliding surface 36 of the seat valve body 24. In the case of a conventional control valve device that does not include the second passage 32, the third passage 33, and the second valve device 34 shown in the embodiment of the present invention, the control pressure chamber 25 is directed toward the inlet chamber 22. When the pressure in the control pressure chamber 25 decreases due to leakage of the pressure medium and the acting force in the valve closing direction of the seat valve body 24 becomes smaller than the acting force in the valve opening direction of the seat valve body 24, the seat valve body 24 The valve is opened, and the pressure medium in the outlet chamber 23 flows backward to the inlet chamber 22 so that the actuator 104 cannot be held. In the embodiment of the present invention, when the pressure in the control pressure chamber 25 decreases and becomes lower than the pressure in the outlet chamber 23, the pressure medium in the outlet chamber 23 becomes the second passage 202 in the seat valve 24, the shuttle valve. 201, the fourth passage 204, and the variable throttle 27 are supplied to the control pressure chamber 25, the pressure of the control pressure chamber 25 increases, and the pressure of the control pressure chamber 25 becomes substantially the same as the pressure of the outlet chamber 23. Therefore, the state in which the acting force in the valve closing direction of the seat valve body 24 is larger than the acting force in the valve opening direction of the seat valve body 24 is maintained due to the difference in pressure receiving area. For this reason, the valve closed state can be maintained, the backflow can be prevented, and the actuator 104 can be prevented from returning.

  A second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a schematic sectional view showing a control valve device according to the second embodiment, and the other parts are shown in a hydraulic circuit diagram. FIG. 4 is a hydraulic system (pressure circuit) including the control valve device. It is a figure which shows the whole with a hydraulic circuit diagram. 3 and 4, the same reference numerals are given to the same parts as those shown in FIG. 1 and FIG. 2, and the other parts are designated by the suffix A added to the reference numerals corresponding to the corresponding parts in FIG. 1. Is attached. The difference between FIGS. 1 and 2 and FIGS. 3 and 4 is that the positions of the inlet chamber 22A and the outlet chamber 23A and the shape of the first passage 28A (therefore, the shapes of the third and fourth passages 203A and 204A), The operation of the second passage 202A in the state in which the pilot control valve body 30 is opened is the same as in FIGS.

  In the first embodiment shown in FIGS. 1 and 2, the portion of the seat valve body 24 facing the inlet chamber 22 is located radially outward of the valve seat 26 and faces the outlet chamber 23 of the seat valve body 24. The portion to be positioned is located radially inside the valve seat 26. On the other hand, in the present embodiment shown in FIGS. 4 and 5, the portion of the seat valve body 24A facing the inlet chamber 22A is located radially inside the valve seat 26, and the outlet chamber 23A of the seat valve body 24A. The portion facing the valve seat 26 is located outside the valve seat 26 in the radial direction.

  In the first embodiment, the pilot control valve element 30 is operated as described above, the main flow rate is adjusted, and the pilot control valve element 30 is closed from the state where the pressure medium is supplied to the actuator 104. The problem that the pressure medium leaks from the control pressure chamber 25 toward the inlet chamber 22 and the pressure in the control pressure chamber 25 decreases as time elapses from the state immediately before the seat valve body 24 is closed is solved. . However, a slight annular gap between the sliding surface 36 provided on the housing 21 in which the pressure medium leaks in the first embodiment and the sliding surface 36 of the seat valve body 24 is not in the second embodiment. In the embodiment, since the outlet chamber 23A and the control pressure chamber 25 are communicated with each other, the pressure difference is small, and the pressure drop in the control pressure chamber 25 due to the leakage of the pressure medium from the control pressure chamber 25 toward the outlet chamber 23A is the outlet. Since it stops at the pressure in the chamber 23A or higher, there is no problem. Conversely, when the pressure in the control pressure chamber 25 is lower than the pressure in the outlet chamber 23A, the pressure medium from the outlet chamber 23A toward the control pressure chamber 25 This works in the direction of suppressing the pressure drop in the control pressure chamber 25 due to the leakage. However, since the pressure in the control pressure chamber 25 decreases due to the leakage of the pressure medium from the annular clearance of the sliding portion of the pilot control valve body 30, the pressure medium in the outlet chamber 23A flows backward through the second passage 202A. Then, the fourth passage 204A and the variable throttle 27 are caused to flow backward through the shuttle valve 201 and supplied to the control pressure chamber 25, so that the closed state of the seat valve body 24A is maintained and the reverse flow is prevented. Return can be prevented.

  In the first and second embodiments, the means for driving the pilot control valve 30 is configured to guide the pilot pressure to the pilot pressure port 37. However, the present invention is not limited to this. You may comprise by the means which thrusts the pilot control valve 30 directly with a lever. Further, since the pilot flow rate through the pilot control valve 30 is a small flow rate that is a part of the total flow rate that passes through the control valve device 100 or 100A, the pilot control valve body 30 can be configured in a small size and controlled with a small force. Therefore, for example, it may be configured by means for pushing the pilot control valve body 30 directly by a solenoid, and it is conceivable to remotely control the valve by an electric signal or the like.

  The first and second embodiments described above are examples in which the present invention is applied to a hydraulic system in which the pressure medium is hydraulic as a pressure circuit. The present invention is not limited to this, and the pressure medium may be hydraulic or pneumatic. It can be applied to any pressure circuit.

  Furthermore, in the first and second embodiments, the pressure source 101 is a general term for a pump, an accumulator, an inertial load pressure source, a cylinder on which a load is applied, and the like, and can be a constant pressure, a variable pressure, or a constant volume. The variable capacity is not limited to any one.

FIG. 1 is a diagram showing a first embodiment of a control valve device and a hydraulic system (pressure circuit) according to the present invention, showing the control valve device in a schematic cross-sectional view, and showing the other parts in a hydraulic circuit diagram. FIG. FIG. 2 is a diagram showing a first embodiment of a control valve device and a hydraulic system (pressure circuit) of the present invention, and is a diagram showing the entire hydraulic system in a hydraulic circuit diagram. FIG. 3 is a diagram showing a control valve device and a hydraulic system (pressure circuit) according to a second embodiment of the present invention, in which the control valve device is shown in a schematic sectional view, and the other parts are shown in a hydraulic circuit diagram. FIG. FIG. 5 is a diagram showing a second embodiment of the control valve device and the hydraulic system (pressure circuit) of the present invention, and is a diagram showing the entire hydraulic system in a hydraulic circuit diagram. FIG. 5 is a view showing a conventional control valve device. FIG. 6 is a view showing a conventional control valve device.

Explanation of symbols

100; 100A Control valve device 101 Pressure source 102 Relief valve device 103 Control valve device 104 Actuator 105 Control valve 106 Tank 1 Housing 2 Valve seat 3 Sliding surface 4 Seat valve body 5 Flow path 6 Edge 7 Inlet chamber 8 Control pressure chamber 9 Small connecting portion 10 Pilot control valve body 11 Outlet chamber 21 Housing 22; 22A Inlet chamber 23; 23A Outlet chamber 24; 24A Seat valve body 25 Control pressure chamber 26 Valve seat 27 Variable throttle 28 First passage 29 Pilot passage 30 Pilot Control valve body 35 Spring 36 Sliding surface 37 Pilot pressure port 201 Shuttle valve (valve device)
202; 202A second passage 203; 203A third passage 204; 204A fourth passage

Claims (4)

An inlet chamber and an outlet chamber provided in the housing, a seat valve body that is slidably provided in the housing and controls an opening amount between the inlet chamber and the outlet chamber, and a housing on the back side of the seat valve body A control pressure chamber for urging the seat valve body in the valve closing direction, and a variable throttle provided in the seat valve body, the opening amount of the control pressure chamber being changed according to the displacement of the seat valve body A first passage that communicates with the inlet chamber and the variable throttle, a pilot passage that communicates with the control pressure chamber and the outlet chamber, and a pilot control valve provided in the pilot passage In the valve device,
A second passage communicating with the exit chamber;
A third passage that forms part of the first passage and is located on the inlet chamber side;
A fourth passage that constitutes another part of the first passage and is located on the variable throttle side;
A valve device located between the second passage and the third passage, for selecting a pressure on the high pressure side of the pressure in the inlet chamber and the pressure in the outlet chamber and leading the pressure to the fourth passage; A control valve device.   2. The control valve device according to claim 1, wherein the second passage, the third passage, the fourth passage, and the valve device are formed and arranged inside the seat valve body. Control valve device.   2. The control valve device according to claim 1, wherein a portion of the seat valve body facing the inlet chamber is located on a radially outer side of the valve seat, and a portion of the seat valve body facing the outlet chamber is a radius of the valve seat. A control valve device, which is located on the inner side in the direction.   2. The control valve device according to claim 1, wherein a portion of the seat valve body facing the inlet chamber is located radially inside the valve seat, and a portion of the seat valve body facing the outlet chamber is a radius of the valve seat. A control valve device, characterized by being positioned on the outside in the direction.

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