JP4968862B2 - Fluid pressure on-off valve - Google Patents

Description

  The present invention provides, for example, a fluid pressure that is provided between a pipe flow path that connects a hydraulic pressure source (primary fluid pressure side) and a hydraulic cylinder (secondary fluid pressure side), and that allows the hydraulic cylinder to be operated and stopped by opening and closing. The present invention relates to an on-off valve.

  2. Description of the Related Art Conventionally, two types of on-off valves are known for use in a hydraulic drive system that reaches a pressure of 30 MPa, such as a hydraulic forging press and a hydraulic extrusion press. One type is a “push-up type poppet type” (see Non-Patent Document 1) shown in FIG. 4, and the other type is a “lever” in a “hydraulic valve for work equipment” proposed in Patent Document 1. "Spool type".

First, the “push-up type poppet type” shown in FIG. 4 will be described. This figure is cited from Non-Patent Document 1.
The water pressure valve includes a poppet portion (A), a push-up rod portion (B), a swing link portion (C), and a balance rod portion (D).

Details of the poppet part (A) are shown in FIG. 5 and described below.
The parent valve 26 is configured to operate up and down with a valve sleeve 25 incorporated in the valve block 21 as a guide. The valve sleeve 25 is fixed to the valve block 21 by a parent valve presser 28, and outside air, the primary pressure port 22 and the secondary pressure port 24 are separated by an external seal 32 and an internal seal 33. An upper chamber 23 is formed on the upper part of the parent valve 26, and the pressure of the primary pressure port 22 is guided to the upper chamber 23 through a chamber conduction hole 25 a provided in the valve sleeve 25. With this pressure, the parent valve 26 is always pressed downward, abuts against the valve seat 26b of the valve sleeve 25, and the parent valve seat surface is fully closed. Thereby, the flow of water from the primary side to the secondary side is blocked.

The primary side pressure port 22 connected to the high pressure accumulator of the factory is always in a high pressure state of, for example, 30 MPa, and the pressure chamber 23 is also at the same pressure. The secondary pressure port 24 is mainly connected to the cylinder load side, and takes a value between the tank pressure in the circuit and the primary pressure depending on the load pressure. Therefore, water always tries to flow from the primary side to the secondary side when the valve is open.
Next, by raising the push-up rod 34, a portion protruding in the shape of a navel at the tip of the child valve 29 installed inside the parent valve 26 (hereinafter referred to as a navel portion 29 c) is pushed into the parent valve 26. As a result, the seat surface 29b of the child valve 29 is opened, and the compressed volume of the water in the upper chamber 23 instantaneously passes through the inner space of the child valve 29, the child valve conduction hole 29a, and the parent valve conduction hole 26a. It flows out to the port 24 side, and the pressure in the upper chamber 23 drops to the same pressure as the secondary side pressure port 24. The balance between the upper and lower pressures allows the parent valve 26 to rise without resistance while riding on the tip of the push-up rod 34. As a result, the seat surface 26b of the parent valve 26 opens. That is, a “push-up type hydraulic pressure on-off valve” is configured by raising and lowering the push-up rod 34 and opening and closing the parent valve 26.

As shown in FIG. 4, the push-up rod portion (B) is composed of a push-up rod 34, a rod guide 35, a V packing 36, and a packing presser 37, and seals the guide and water pressure when the rod is driven.
The swing link portion (C) includes a stroke adjusting screw 38, a swing rod 39, and a swing plate 40, and adjusts the push-up position of the parent valve 26.
The balance rod portion (D) has the same structure and dimensions as the push-up rod portion (B), and cancels the push-down of the push-up rod 34 generated by the pressure of the secondary side pressure port 24.

Next, a “spool type” on-off valve shown in Patent Document 1 and used as a hydraulic valve for a work machine such as a forklift will be described.
This valve is provided in a flow path between the cylinder and a check valve lower chamber communicating with the inlet port or the outlet port by a spool drive. Opened with pressurized water from the inlet port during operation of the work implement, and when the work implement is held at the set position, the flow path is set by the pressure difference between the lower pressure in the lower part of the check valve and the pressurized water in the cylinder. Cut off. For this reason, the check valve closes the flow path with a face sheet due to the differential pressure, and even if pressurized water is used as the working fluid, leakage from the gap can be almost prevented by the valve, especially when the working machine is held at a fixed position. There is almost no leakage even when using, and the setting position and setting posture can be accurately maintained.

JP 2002-106736 A

By Ernst Mu¨ller, Ventilantrieb mit entrastor Hess. "Hydrauliche Schmiedepressen und Kraftwasseragengen", published by Springer-Verlag, 1952, abb. 100, 124 pages

However, among the conventional valves, the former “push-up type poppet type” has drawbacks in the following three points.
(1) The first point is a situation where the lower end of the navel portion 29c is plastically deformed by the push-up operation of the push-up rod 34, and is further worn away, so that the protruding height is remarkably reduced and there is no navel portion 29c. It is easy.
If the height of the navel portion 29c is greatly reduced, the lift amount of the child valve 29 is greatly reduced, the pressure of the upper chamber 23 becomes difficult to escape, and the lift of the parent valve 26 proportional to the push-up amount of the push-up rod 34 is obtained. There was a drawback that the opening and closing operation became impossible.
In addition, in rare cases, the navel portion 29c of the child valve 29 breaks, and the child valve 29 cannot be opened. As a result, the parent valve 26 cannot be opened and does not function as a water pressure valve. It was.

  The phenomenon that the lower end of the navel portion 29c is plastically deformed and further worn and broken is due to the following causes. First, due to the structure of the child valve 29 that is pushed up from below, the diameter of the bellows portion that is pushed up is limited to a size that is smaller than the minimum diameter of the child valve seat surface 29c by the gap necessary for pressure relief. This is because the contact area cannot be increased because it must be done. For this reason, every time the push-up rod 34 is pushed up, the contact surface pressure of the navel portion lower end 29c is a very high value, which is a phenomenon of plastic deformation and wear. Further, in order to reduce the plastic deformation and wear, there has been an attempt to increase the hardness of only the navel portion 29c by surface quenching or partial quenching, but in many cases, the phenomenon that the navel portion 29c is broken occurs. . The second reason is that the hardness is increased, but it is influenced by a decrease in toughness, and the cause is that it cannot withstand the impact during repeated push-up.

(2) As the second point, under the condition that the parent valve 26 is opened by the push-up rod 34, the pressures of the primary pressure port 22 and the secondary pressure port 24 are both the same value of 30 MPa or emergency When the value is close to, the parent valve 26 does not follow the downward movement of the push-up rod 34. That is, even if the push-up rod 34 starts to descend instantaneously, the parent valve remains without starting to descend, and there is a phenomenon that it descends after one breath. This is a structural problem that the push-up rod 34 is not connected to the parent valve 26. When the push-up rod 34 is lowered, the child valve 26 is closed, and the pressurized water from the chamber conduction hole 25a enters the upper chamber 23 to close the parent valve 26. However, if there is no difference in the pressure above and below the parent valve 26, This is because pressurized water cannot enter the upper chamber 23 from the chamber conduction hole 25a and the parent valve 26 cannot descend downward. On the other hand, since the push-up rod 34 is controlled by a hydraulic servo having an extremely high response speed, the parent valve 26 has a drawback that it always causes a response delay with respect to the push-up rod 34.

The chamber conduction hole 25a guides the pressure of the primary side pressure port 22 to the upper chamber 23 of the parent valve 26, and presses the parent valve seat surface 26b against the valve sleeve 25 by the primary side pressure, thereby maintaining the closed state of the parent valve 26. Has function. Considering the transient state during the opening / closing operation of the parent valve 26, it is very difficult to appropriately determine the size of the conduction hole 25a. When the valve opening operation is performed, the child valve 29 is pushed up by the push-up rod 34 so that the pressure in the upper chamber 23 is instantaneously released, and the force for pressing the parent valve 26 against the valve sleeve 25 disappears. Although the parent valve 26 is instantaneously opened by the rod 34, if the conduction hole 25a is too large, even if the child valve 29 is pushed up by the push-up rod 34, the pressure in the upper chamber 23 is not released. Not completely done and pressure remains. Accordingly, the force for pressing the parent valve 26 against the valve sleeve 25 remains, and the parent valve 26 cannot be opened by the push-up rod 34. Or a phenomenon that takes time to open the valve occurs.
At the time of the valve closing operation, conversely, if the conduction hole 25a is too small, the amount of water flowing into the upper chamber 23 is insufficient, the valve closing speed of the parent valve 26 becomes slow, and a phenomenon that takes time to close occurs.
As described above, due to the structural problem that the push-up rod 34 is not coupled to the parent valve 26, it is very difficult to determine the conduction hole 25a to an appropriate size.

(3) As a third point, when the parent valve 26 is used as a proportional valve, the passage area suddenly increases with respect to the amount of change in the lift amount of the rod 34 and is linearly proportional to the shape of the lower end of the valve. Since the opening area cannot be obtained, it is difficult to linearly control the amount of water passing through the valve with respect to the amount of change in the lift amount of the rod 34.

  Also, among the conventional valves, the latter needs to be used in combination with a check valve and a control device for the check valve in order to keep the position of the device such as a cylinder constant, and the entire valve becomes large and complicated. The drawback was that it would be difficult to maintain.

  The present invention is based on the above circumstances, and is generated with a significant decrease in the plastic deformation, wear, and protruding height of the navel part by eliminating the navel part of the child valve existing in the conventional valve. It is possible to eliminate the disadvantages of proportional control failure and valve opening failure.

  That is, among the fluid pressure on / off valves of the present invention, the invention according to claim 1 is a fluid pressure on / off valve that is provided in a pipe flow path between a primary fluid pressure side and a secondary fluid pressure side to set an opening degree. The main valve body is movable in the axial direction in a valve sleeve having a primary fluid pressure side port and a secondary fluid pressure side port that communicate with the primary fluid pressure side and the secondary fluid pressure side, respectively. The main valve element is configured to contact the valve seat provided in the valve sleeve by moving forward in the valve sleeve to close the valve flow path, and to open the valve flow path by retreating. A pressure receiving surface to which the fluid pressure of the primary fluid is applied is provided on the rear surface side, and a pressure release passage that further connects the fluid pressure side that applies pressure to the pressure receiving surface and the secondary fluid pressure side is provided. The main valve body has a shaft relative to the main valve body. A sub-valve element that is movable in the direction of the main valve element and the amount of reverse movement relative to the main valve element is disposed, and the sub-valve element contacts the valve seat provided in the main valve element by moving forward with respect to the main valve element. The actuator is configured to contact and close the pressure relief flow path and to retreat to open the pressure relief flow path, and to actuate the actuator that causes the sub valve body to move the sub valve body along the axial direction. The sub-valve body is urged from the front side toward the rear side by the sub-valve body cap that supports the flange-like front end engagement portion of the operating portion on the rear side. The actuating part urging means is provided, and the actuating part is connected to the sub-valve element by the sub-valve cap and the actuating part urging means.

  According to a second aspect of the present invention, the fluid pressure on-off valve according to the first aspect is configured such that the fluid on the secondary fluid pressure side is applied to the pressure receiving surface outside the main valve body when the main valve body is closed. In order to instantaneously replenish the fluid pressure side, a check valve conducting path is provided that connects the fluid pressure side that applies pressure to the pressure receiving surface and the secondary fluid pressure side, and the check valve conducting path is connected to the secondary fluid pressure side from the secondary fluid pressure side. A check valve that enables introduction of fluid only on the fluid pressure side that applies pressure to the pressure receiving surface is provided.

  According to a third aspect of the invention, the main valve body includes a main valve body cap that supports the sub valve body on the rear side, and the sub valve body. And a main valve body urging means for urging the rear side from the front side toward the rear side.

  A fluid pressure on-off valve according to a fourth aspect of the present invention is the fluid pressure on-off valve according to any one of the first to third aspects, wherein the valve sleeve is provided with a primary fluid pressure side port on a side wall thereof, and the sleeve hole at the tip is secondary. It is assigned to the fluid pressure side port.

  According to a fifth aspect of the present invention, the main valve body operates as a switching valve by a separating operation with respect to the valve sleeve valve seat. It is characterized by being.

  According to a sixth aspect of the present invention, the main valve element operates as a proportional valve in accordance with a separating operation with respect to the valve sleeve valve seat. It is characterized by being.

  A fluid pressure on-off valve according to a seventh aspect of the invention is the invention according to any one of the first to sixth aspects, wherein the main valve body is adjusted to an amount of contact / disengagement with respect to an annular valve sleeve valve seat. It has the nose which can obtain the opening area proportional to primary.

That is, according to the present invention, when the valve is closed, the pressure on the primary fluid is received by the main valve body by closing the pressure relief passage of the main valve body by placing the sub-valve body in the forward position by the actuator operating portion. The main valve body is placed in the forward position in addition to the surface. As a result, the main valve body comes into contact with the valve seat of the valve sleeve and the valve flow path is closed.
In addition, when the valve is opened, if the sub valve body is moved backward by the actuator operating portion, the pressure release passage of the main valve body is opened, and the fluid on the primary fluid pressure side, which is applying pressure to the pressure receiving surface, passes through the pressure release passage. The pressure flowing out to the secondary fluid pressure side and applied to the pressure receiving surface is reduced, and the stress that makes the main valve body abut against the valve seat of the valve sleeve is reduced or lost. When the actuator operating part is further retracted, the retraction of the sub-valve element with respect to the main valve element is restricted, the main valve element retreats together with the sub-valve element, and the contact of the main valve element with the seat of the valve sleeve is released, and the valve flow The road is opened.

Further, the main valve body is supported by a main valve body cap provided on the main valve body and supported from the rear side, and a sub-valve body urging means for urging the front valve from the front side to the rear side. When the body and the subvalve body move together, the positional relationship between them can be made constant.
Further, the actuator operating portion is supported by the sub-valve body cap that is supported on the rear side and the operating portion urging means that urges the actuator from the front side toward the rear, so that the actuator operating portion and the sub-valve body are supported. The positional relationship can be made constant. By combining with the above configuration, the positional relationship between the actuator operating portion and the main valve body can be made constant.

By applying the separation / contact operation of the main valve body to the valve seat to the opening / closing operation of the flow path, switching of the opening / closing can be performed smoothly. Further, if the separating operation of the main valve body with respect to the valve seat is performed as a proportional valve for adjusting the opening / closing amount, the opening / closing amount can be adjusted appropriately.
With respect to the configuration of the present invention, in addition to the means for solving the above problem, the proportional valve has a structure in which a nose having a height substantially the same as the valve diameter is attached to the tip of the main valve body to reduce the flow rate change relative to the unit lift amount of the main valve body Can be. The nose shape may be a shape in which the opening area increases approximately linearly with respect to the lift change amount. As a result, when used as a proportional valve, the passage area gradually increases with respect to the amount of change in the lift amount of the actuator operating portion, and a linearly proportional opening area is obtained. Proportional control can be performed almost linearly with respect to the amount of change.

  Further, a check valve conducting path is provided for connecting the fluid pressure side for applying pressure to the pressure receiving surface and the secondary fluid pressure side, and the check valve conducting path is provided on the fluid pressure side for applying pressure to the pressure receiving surface from the secondary fluid pressure side. If a check valve that allows the introduction of fluid due to the pressure difference is provided, the supply of fluid to the pressure receiving surface side that is required as the main valve body moves forward during the valve closing operation is checked from the secondary fluid pressure side. This is easily done through the valve and check valve conduit. As a result, the valve is instantaneously closed, and the position of the main valve body can be controlled in synchronism mechanically without delay in response by the position control by the actuator.

As described above, according to the present invention, a fluid pressure on-off valve that is provided in a pipe flow path between a primary fluid pressure side and a secondary fluid pressure side and sets an opening degree, the primary fluid pressure side and the secondary fluid pressure side A main valve body is disposed in a valve sleeve having a primary fluid pressure side port and a secondary fluid pressure side port that communicate with each other via a valve flow path, and is movable in the axial direction. The body is configured to contact the valve seat provided in the valve sleeve by advancing in the valve sleeve to close the valve flow path, and to open the valve flow path by moving backward, and the rear surface side A pressure receiving surface to which a fluid pressure of the primary fluid is applied to the pressure receiving surface, and further includes a pressure release passage for communicating the fluid pressure side for applying pressure to the pressure receiving surface and the secondary fluid pressure side. In addition, the main valve body is movable in the axial direction with respect to the main valve body. A sub-valve element with a regulated retraction amount is disposed, and the sub-valve element moves forward relative to the main valve element to contact a valve seat provided on the main valve element to close the pressure release passage. In addition, the pressure relief flow path is configured to open by retreating, and the actuator operating unit that moves the sub valve body along the axial direction is connected to the sub valve body. As a structure, a new method (“pull-up type” (an example of vertical arrangement)) is adopted from the conventional “push-up type”.
Furthermore, the actuator operating portion is supported by the sub-valve body cap that is supported on the rear side and the operating portion urging means that urges the actuator from the front side toward the rear, thereby The positional relationship can be made constant.

  And according to the said structure, damage to a subvalve body can be reduced, the lifetime of the whole valve is extended, and there exists an effect by which the time and expense which a maintenance requires are saved. Conventionally, the push-up rod and the parent valve have a separate structure, but the movement of the operating part is directly controlled by connecting the tip of the operating part into the sub-valve so that it can be integrated. In addition, the movement of the sub-valve and the main valve body has been replaced, enabling proportional control with high responsiveness as a fluid pressure valve such as water pressure. Conventionally, the upper chamber only had a conduction hole with the primary side pressure port, but since it was possible to newly provide a conduction path with the secondary side pressure port via the check valve, The upper chamber can be instantly replenished with a fluid such as water, which is effective for highly responsive switching control. Further, if the main valve body is provided with a nose, it is possible to adjust the amount of passing water that is linearly proportional to the lift amount, and the position control and pressure control of the actuator become easy.

It is sectional drawing which shows the apparatus containing the on-off valve in one Embodiment of this invention. It is an expanded sectional view showing an on-off valve of an embodiment similarly. It is sectional drawing which shows a part of on-off valve in other embodiment of this invention. It is sectional drawing which shows the apparatus containing the conventional on-off valve. It is sectional drawing which similarly shows an on-off valve.

Hereinafter, an embodiment of a fluid pressure on-off valve of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the fluid pressure on-off valve is composed of a poppet portion + a pulling rod portion (A) and a control cylinder portion (B). In this embodiment, the same structure as that of the conventional example shown in FIGS.

First, the configuration and function of the poppet portion + the pulling rod portion (A) will be described.
The bubble block 21 is provided with a primary pressure port 22 and a secondary pressure port 24, and a valve sleeve 25 is interposed therebetween. The valve sleeve 25 is fixed to the valve block 21 and separates the outside air from the primary side pressure port 22 and the secondary side pressure port 24 by an external seal 32 and an internal seal 33. The valve sleeve 25 communicates with the primary pressure port 22 through a side wall port 22a formed on the side wall, and communicates with the secondary pressure port 24 through a tip opening port 24a. A space in the valve sleeve 25 between the opening ports 24a is assigned to the valve flow path.

  In the valve sleeve 25, a cylindrical main valve body 1 that can move up and down using this as a guide is disposed. The main valve body 1 has a nose 3 whose diameter decreases toward the front end through the annular step portion 2 on the front end side, and the rear end is connected to the main valve body space 1a in the nose 3. A pressure release channel 4 whose tip opens to the secondary pressure port 24 side is formed along the axial direction. Further, when the main valve body 1 advances, the annular sleeve 2 contacts the valve sleeve 25 with the inner wall on the front end side beyond the side wall port 22a, and the valve flow path between the side wall port 22a and the front end opening port 24a. An annular valve seat 26b is provided for closing. The nose 3 is substantially the same height as the diameter of the valve surrounded by the valve seat 26b, has a shape in which the opening area increases almost linearly with respect to the axial movement amount, and functions as a proportional valve.

  A cylindrical sub-valve body 10 that is movable up and down with respect to the main valve body 1 is disposed in the internal space 1 a of the main valve body 1. The sub-valve body 10 has a small cylindrical abutting portion 11 at the tip, and the tip of the abutting portion 11 is one end of the pressure release channel 4 when the sub-valve body 10 moves forward. The pressure release passage 4 is closed by contacting the valve seat 4a. A compression coil spring 5 is disposed as a main valve body urging member between the sub-valve body 10 and the inner wall of the inner space 1a of the main valve body 1 to urge the sub-valve body 10 backward. Yes. On the other hand, a main valve body cap 6 is fitted and fixed at the rear end of the main valve body 1 and integrated with the main valve body 1, and the reverse position of the sub-valve body 10 is regulated by the main valve body cap 6. ing. Thereby, the sub-valve body 10 is sandwiched and supported by the compression coil spring 5 and the main valve body cap 6.

  Further, the sub-valve element 10 is formed with a sub-valve element conducting path 12 that communicates between the internal space 10 a of the sub-valve element 10 and the main valve element internal space 1 a around the abutting portion 11. Furthermore, the tip of the operating rod 50 penetrating the main valve body cap 6 from above is located in the internal space 10a of the sub-valve body 10. The actuating rod 50 corresponds to the actuator actuating part of the present invention. A flange member 52 having a diameter slightly smaller than the inner diameter of the internal space 10a of the sub-valve element 10 is fixed to the distal end portion of the operating rod 50, and between the flange member 52 and the inner wall of the distal end of the internal space 10a. A compression coil spring 15 is disposed as a sub-valve urging member, and urges the flange member 52 rearward. On the other hand, a sub-valve cap 16 is fitted and fixed at the rear end of the sub-valve body 10 so as to be integrated with the sub-valve body 10 to restrict the reverse position of the flange member 52. Thus, the flange member 52 is sandwiched and supported by the compression coil spring 15 and the sub-valve cap 16, and the sub-valve body 10 and the operating rod 50 are connected.

  The operating rod 50 is formed with a rod conduction path 50a having one end communicating with the upper chamber 23 located behind the main valve body 1. The rod conduction path 50a extends forward in the rod 50. Open to the internal space 10a of the auxiliary valve body 10. The upper chamber 23 communicates with the primary pressure port 22 through a chamber conduction hole 25 a provided in the valve sleeve 25. That is, the primary pressure is applied to the main valve body 1 through the chamber conduction hole 25a, and the rear end surface of the main valve body 1 is assigned to the pressure receiving surface 6a of the present invention together with the rear end surface of the main valve body cap 6. Yes.

Next, the configuration and function of the control cylinder part (B) will be described.
A hydraulic cylinder 55 equipped with a switching valve or servo valve 54 is attached to a valve cover 56 via a coupling bolt 53 above the valve block 21. The hydraulic cylinder 55 corresponds to the actuator of the present invention, and is arranged with the cylinder rod 55a facing downward.
The operating rod 50 is connected to the tip of the cylinder rod 55a through a coupling nut 67.

  The operating rod 50 can slide up and down along a rod guide 57 incorporated in the valve cover 56, and the internal pressure 30 MPa of the upper chamber 23 is sealed by the V packing 58 and the packing presser 59. A check valve 62 is incorporated in the valve cover 56 so that the upper chamber 23 and the secondary pressure port 24 side can communicate with each other through the check valve 62 through a check valve conducting path 63. The check valve 62 prevents fluid movement from the upper chamber 23 to the secondary pressure port 24 side, and allows fluid to move from the secondary pressure port 24 side to the upper chamber 23 by the differential pressure. Further, above the hydraulic cylinder 55, a detection rod 55b that is interlocked with the cylinder rod 55a is extended so that the position sensor 65 can detect the operation amount of the cylinder rod 55a, that is, the operation rod 50.

  In the above configuration, the pressure of the primary side pressure port 22 is guided to the upper chamber 23 through the chamber conduction hole 25a provided in the valve sleeve 25 without the secondary valve body 10 being pulled up by the operating rod 50, and the main valve body 1 Always push downward. As a result, the annular step portion 2 of the main valve body 1 contacts the valve seat 26b of the valve sleeve 25, the valve flow path is fully closed, and the flow of water from the primary side to the secondary side is blocked.

  In the valve opening operation state, the hydraulic cylinder 55 is operated, and the operating rod 50 is raised through the cylinder rod 55a. Then, the flange portion 52 at the tip of the operating rod 50 pulls up the auxiliary valve body cap 16 attached to the upper end of the auxiliary valve body 10 together with the auxiliary valve body 10. As a result, the sub-valve body 10 rises, the abutting portion 11 moves away from the valve seat 4a at one end of the pressure relief channel 4, opens the pressure relief channel 4, and the compression volume in the upper chamber 23 is guided by the rod. Passing through the passage 50a, passing through the secondary valve body passage 12 and the pressure release passage 4, the secondary pressure port 24 instantaneously flows out, and the pressure in the upper chamber 23 drops to the same pressure as the secondary pressure port 24. To do. The force that pushes down the main valve body 1 with the fluid disappears due to the balance between the upper and lower pressures, and the main valve body 1 rises without resistance while the main valve body cap 6 rides on the upper surface of the sub-valve body 10. Then, the annular step portion 2 of the main valve body is separated from the valve seat 26b of the valve sleeve 25, the sealing surface is opened, and the valve flow path is opened.

  The primary pressure port 22 connected to the factory high pressure accumulator is always at a pressure of 30 MPa, and the upper chamber 23 is also at the same pressure. The secondary pressure port 24 is mainly connected to the cylinder load side, and takes a value between the tank pressure in the circuit and the primary pressure depending on the load pressure. Therefore, water always tries to flow from the primary side to the secondary side when the valve is open.

  Furthermore, in the proportional valve, the lower end of the main valve body 1 has a nose 3 having a shape that is almost the same height as the valve diameter and whose opening area increases almost linearly with respect to the amount of change in lift. In this case, the passage area gradually increases with respect to the amount of change in the lift amount of the actuating rod 50, and an opening area proportional to the first order is obtained. Proportional control is possible. At this time, since the position of the operating rod 50 is always detected by a position sensor 65 attached to the hydraulic cylinder 55, the valve opening amount can be easily controlled.

  On the other hand, in the valve closing operation state, the main valve body 1 and the sub-valve body 10 are lowered by operating the hydraulic cylinder 55 and lowering the operating rod 50 via the cylinder rod 55a. Then, the annular step portion 2 of the main valve body 1 is seated on the valve seat 26 b of the valve sleeve 25. At that time, the compression coil spring 15 contracts to reduce the impact at the time of sitting. When the descent is further advanced, the sub-valve element 10 further descends with respect to the main valve element 1 that is seated and stopped, and finally the abutting portion 11 comes into contact with the valve seat 4a. Also at this time, the compression coil spring 5 contracts to reduce the impact at the time of contact. By this contact, the pressure release flow path 4 is closed, and the pressure in the upper chamber 23 is applied to the pressure receiving surface 6a of the main valve body 1 to push down the main valve body 1 by the fluid, thereby reliably and firmly contacting the valve seat. Shall.

  When the pressure relief channel 4 is closed, water is instantaneously replenished from the secondary pressure port 24 to the upper chamber 23 via the check valve conducting channel 63 and the check valve 62. That is, during the valve closing operation, the supply of pressure water to the upper chamber 23 required as the parent valve 26 is lowered pushes and opens the check valve 62 from the secondary side pressure port 24 and easily passes through the check valve conduction path 63. Thus, the valve closing is instantaneously performed, and the position of the main valve body 1 can be controlled mechanically synchronously without delay in response by the position control of the hydraulic cylinder 55.

According to the present invention, the conventional installation of the child valve navel portion as shown in FIG. 5 is abolished, and the opening that occurs with a significant decrease in the plastic deformation, wear, and protrusion height of the navel portion in the valve opening operation state. It was possible to eliminate the disadvantages of valve inability and proportional control inability.
Furthermore, by adopting this structure, the contact area where the actuating rod pulls up the sub-valve element is not restricted by the pressure relief flow path, and can be about twice as large as the conventional push-up type. This makes it possible to prevent the conventional problems of plastic deformation, wear, and breakage from occurring due to the increased contact area.

  In the valve closing operation state, the operating rod 50 is assembled in the sub valve body 10 with the upper and lower sides sandwiched between the sub valve body cap 16 and the compression spring 15, and the sub valve body 10 itself. However, the position of the main valve body 1 always coincides with the position of the actuating rod 50 because the upper and lower sides are sandwiched between the main valve body cap 6 and the compression spring 5 and incorporated in the main valve body 1. Even when the secondary side pressure becomes equal to the primary side pressure of 30 MPa, the position of the main valve body is opened and closed in a mechanically synchronized manner without delay in response by the position control of the hydraulic cylinder 55 by the switching valve or the servo valve 54. It is possible to control the position arbitrarily.

In the above embodiment, the case where the on-off valve is used as a proportional valve has been described.
As described above, the present invention can be used as a switching valve in addition to being used as a proportional valve.
FIG. 3 shows a modified configuration of the main valve body. The tip of the main valve body 100 is not provided with a nose for operating as a proportional valve, and is a conical portion that can contact the valve seat of the valve sleeve 25. Constitutes a sealing surface. According to this on-off valve, the opening / closing switching operation of the valve can be smoothly performed as the main valve body moves up and down.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to description of the said embodiment, In the range of this invention, it can change suitably.

DESCRIPTION OF SYMBOLS 1 Main valve body 2 Annular step part 3 Nose 4 Pressure release flow path 4a Valve seat 5 Compression coil spring 6 Main valve body cap 6a Pressure receiving surface 10 Sub valve body 11 Butting part 12 Sub valve body conduction path 15 Compression coil spring 16 Sub valve body Cap 22 Primary pressure port 23 Upper chamber 24 Secondary pressure port 25 Valve sleeve 25a Chamber conducting hole 26 Parent valve 26b Valve seat 50 Actuating rod 50a Rod conducting path 52 Flange 55 Hydraulic cylinder

Claims (7)

  A fluid pressure on-off valve that is provided in a pipe flow path between a primary fluid pressure side and a secondary fluid pressure side and sets an opening degree. The fluid pressure on-off valve communicates with the primary fluid pressure side and the secondary fluid pressure side. A main valve body is disposed in a valve sleeve having a primary fluid pressure side port and a secondary fluid pressure side port communicating with each other via an axial direction, and the main valve body moves forward in the valve sleeve. It is configured to close the valve flow path in contact with a valve seat provided on the valve sleeve and open the valve flow path by retreating, and the pressure receiving pressure to which the fluid pressure of the primary fluid is applied to the rear surface side And a pressure relief passage that communicates the fluid pressure side that applies pressure to the pressure receiving surface and the secondary fluid pressure side. The main valve body has an axial direction with respect to the main valve body. A sub-valve element that is movable and whose retraction amount with respect to the main valve element is regulated The sub-valve body moves forward with respect to the main valve body to contact the valve seat provided on the main valve body to close the pressure relief flow path, and moves backward to relieve the pressure relief flow path. An actuating part of an actuator for moving the sub-valve body along the axial direction is connected to the sub-valve element, and the sub-valve element has a flange-like tip of the actuating part. A sub-valve body cap that supports the engaging portion on the rear side; and an operating portion urging means that urges the tip engaging portion from the front side toward the rear side. A fluid pressure on-off valve, wherein the actuating part is connected to the sub-valve element by an urging means.   A fluid pressure side for applying pressure to the pressure receiving surface and a fluid pressure side for supplying the fluid on the secondary fluid pressure side to the fluid pressure side for applying pressure to the pressure receiving surface instantaneously outside the main valve body when the main valve body is closed. A check valve having a check valve conducting path that conducts to the secondary fluid pressure side, and a check valve that allows introduction of fluid only to the fluid pressure side that applies pressure to the pressure receiving surface from the secondary fluid pressure side to the check valve conducting path The fluid pressure on-off valve according to claim 1, wherein   The main valve body includes a main valve body cap that supports the sub valve body on the rear side, and a sub valve body urging means that urges the sub valve body from the front side toward the rear side. The fluid pressure on-off valve according to claim 1 or 2, characterized in that:   The fluid pressure opening and closing according to any one of claims 1 to 3, wherein the valve sleeve is provided with a primary fluid pressure side port on a side wall thereof, and a sleeve hole at a tip is assigned to the secondary fluid pressure side port. valve.   The fluid pressure on-off valve according to any one of claims 1 to 4, wherein the main valve body operates as a switching valve by a separating operation with respect to the valve sleeve valve seat.   The fluid pressure on-off valve according to any one of claims 1 to 5, wherein the main valve element operates as a proportional valve in accordance with a separating operation with respect to the valve sleeve valve seat.   The said main valve body has a nose which can obtain the opening area which is linearly proportional to the amount of contact / separation with respect to the annular valve sleeve valve seat by the contact / separation operation. A fluid pressure on-off valve according to claim 1.

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