JP7132874B2 - pressure control valve - Google Patents

Description

The present invention relates to pressure control valves.

The pressure control valve is a valve that adjusts the valve opening pressure to control the pressure on the upstream side. Used for valves.

A variable damping valve using a pressure control valve, for example, has an annular valve seat provided in the middle of a flow path leading from a cylinder of a shock absorber to a reservoir, and a main valve that opens and closes the flow path by separating and seating on the annular valve seat. a body, a pilot passage branched from the flow passage, an orifice provided in the middle of the pilot passage, a pressure control valve provided downstream of the orifice in the pilot passage, and a valve seat side of the main valve body. A back pressure chamber is provided on the rear side and into which the pressure between the orifice and the pressure control valve is introduced.

In the variable damping valve configured in this manner, the main valve body is pressed against the valve seat side by the pressure in the back pressure chamber, and the main valve body is flexed from the upstream side of the flow path in front of the main valve body. Pressure acts to force it off the seat. Therefore, the variable damping valve opens when the force of the pressure on the upstream side of the flow path, which separates the main valve body from the valve seat, exceeds the force of the pressure in the back pressure chamber, which presses the main valve body against the valve seat.

In addition, the pressure control valve includes a valve seat member having a valve seat, a valve body that is seated on and off the valve seat, and a valve body that is interposed between the valve body and the valve seat member to separate the valve body from the valve seat. It is composed of a coil spring that biases in a direction and a solenoid that provides a thrust in a direction to bring the valve element closer to the valve seat. The pressure control valve configured in this way adjusts the valve opening pressure when the valve body is separated from the valve seat by adjusting the thrust force of the solenoid, thereby controlling the pressure in the back pressure chamber.

Since the pressure in the back pressure chamber can be adjusted by the pressure control valve in this way, the variable damping valve can adjust the resistance given to the flow of hydraulic oil passing through the flow path, and can generate a desired damping force in the shock absorber. (See Patent Document 1, for example).

JP 2014-173714 A

A conventional pressure control valve is provided with a coil spring between a valve body and a valve seat member to bias the valve body away from the valve seat in order to adjust the valve opening pressure by adjusting the thrust force of the solenoid. Structurally, hydraulic fluid that has passed between the valve body and the valve seat flows downstream through the wire rods of the coil spring.

On the other hand, since the shock absorber is housed in a narrow mounting space between the vehicle body and the wheels, the pressure control valve is often small, and when the hydraulic oil passes through the narrow wires of the coil spring, , pressure loss occurs. Further, when the amount of hydraulic oil passing between the wire rods of the coil spring increases, a large fluid force is generated, which may cause the coil spring to vibrate.

In this way, if pressure loss occurs or the coil spring vibrates when hydraulic oil passes between the wires of the coil spring that urges the valve body of the pressure control valve, the pressure on the upstream side fluctuates and buffers. The damping force of the device is disturbed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pressure control valve capable of stable pressure control.

In order to solve the above-described problems, the pressure control valve of the present invention comprises a valve seat, a valve body that sits on and off the valve seat, a spring that urges the valve body in a direction to move the valve body away from the valve seat, and a valve body that includes the valve seat. and a passage that communicates the space on the side of the valve seat partitioned by the spring with the downstream without intervening between one end and the other end of the spring.

When the pressure control valve is configured in this way, the hydraulic fluid that passes through the pressure control valve and moves downstream from the space on the valve seat side passes through this narrow gap from one end to the other end of the spring. Passages that bypass the gap can also be passed, reducing the flow of hydraulic fluid through the narrow gap between one end of the spring and the other. In addition, the passage may be provided in the valve seat member, or may be provided in the valve body.

Further, in forming the passage, the valve seat member is composed of a valve seat side member having a valve seat and a tubular member that is fitted to the valve seat side member and accommodates the spring therein. The passage may be formed by a recess provided in the assembly of the members. According to the pressure control valve configured in this way, manufacturing costs can be reduced.

According to the pressure control valve of the present invention, stable pressure control becomes possible.

1 is a cross-sectional view of a variable damping valve to which a pressure control valve according to one embodiment is applied; FIG. 1 is a cross-sectional view of a damper equipped with a variable damping valve to which a pressure control valve is applied according to one embodiment; FIG. 1 is an enlarged cross-sectional view of a pressure control valve in one embodiment; FIG. FIG. 4 is an enlarged cross-sectional view of a pressure control valve in a first modified example of one embodiment; FIG. 7 is an enlarged cross-sectional view of a pressure control valve in a second modified example of one embodiment;

The present invention will be described below based on an illustrated embodiment. As shown in FIG. 1, the pressure control valve PV in one embodiment includes a valve seat 1a, a valve body 2 that is seated on and off the valve seat 1a, and a biasing force that moves the valve body 2 away from the valve seat 1a. It is composed of a spring 3, a solenoid Sol as an actuator capable of applying thrust in a direction to bring the valve body 2 closer to the valve seat 1a, and a passage P. In this embodiment, the valve body 2 is used for the variable damping valve DV. and constitutes a part of the variable damping valve DV.

The variable damping valve DV is applied to the shock absorber D, and the shock absorber D generates damping force mainly by giving resistance to the fluid passing through the variable damping valve DV during expansion and contraction.

The damper D to which the variable damping valve DV is applied includes, for example, a cylinder 100, a piston 101 slidably inserted into the cylinder 100, and a piston 101 movably inserted into the cylinder 100, as shown in FIG. A rod 102 connected to a piston 101, a rod side chamber 103 and a piston side chamber 104 partitioned by the piston 101 inserted into the cylinder 100, and an intermediate portion that covers the outer periphery of the cylinder 100 and forms a discharge passage 105 between the cylinder 100 and the cylinder 100. It comprises a cylinder 106 and an outer cylinder 108 that covers the outer circumference of the intermediate cylinder 106 and forms a reservoir 107 between itself and the intermediate cylinder 106 . is filled with hydraulic oil as a fluid, and the reservoir 107 is filled with gas in addition to the hydraulic oil. It should be noted that any fluid other than hydraulic oil can be used as long as it is capable of exerting a damping force.

In the case of this shock absorber D, there is only a suction passage 109 that allows only the flow of hydraulic fluid from the reservoir 107 to the piston side chamber 104, and only the flow of hydraulic fluid from the piston side chamber 104 to the rod side chamber 103 provided in the piston 101. The discharge passage 105 communicates the rod side chamber 103 and the reservoir 107, and the variable damping valve DV is provided in the middle of the discharge passage 105.

Therefore, when the shock absorber D performs a compression operation, the piston 101 moves downward in FIG. Move to At the time of this compression operation, the rod 102 enters the cylinder 100, and the working oil corresponding to the rod entering volume becomes excessive in the cylinder 100, and the excess working oil is pushed out from the cylinder 100 and flows through the discharge passage 105 to the reservoir 107. is discharged to The damper D raises the pressure in the cylinder 100 and exerts compression side damping force by applying resistance to the flow of the hydraulic oil passing through the discharge passage 105 and moving to the reservoir 107 with the variable damping valve DV.

On the contrary, when the shock absorber D is extended, the piston 101 moves upward in FIG. do. During this extension operation, the piston 101 moves upward to expand the volume of the piston-side chamber 104 , and hydraulic oil corresponding to this expansion is supplied from the reservoir 107 through the suction passage 109 . The shock absorber D raises the pressure in the rod side chamber 103 by applying resistance to the flow of hydraulic oil moving to the reservoir 107 through the discharge passage 105 with the variable damping valve DV, thereby exerting a rebound damping force. do.

As can be understood from the above description, when the shock absorber D exhibits an expansion and contraction operation, the hydraulic oil is always discharged from the cylinder 100 through the discharge passage 105 to the reservoir 107, and the hydraulic oil flows into the piston-side chamber 104 and the rod-side chamber 103. , and the reservoir 107 in order in a one-way circulation, and damping forces on both expansion and compression sides are generated by a single variable damping valve DV. If the cross-sectional area of the rod 102 is set to 1/2 of the cross-sectional area of the piston 101, the amount of hydraulic fluid discharged from the cylinder 100 can be set equally on both sides of the expansion and compression if the amplitude is the same. With this setting, the damping force on the expansion side and the compression side can be made equal if the resistance given to the flow by the variable damping valve DV is the same.

Next, in this embodiment, the variable damping valve DV is mounted on the outer periphery of the valve disk 10 fitted in the sleeve 106a provided in the opening of the intermediate cylinder 106 and the assembly shaft 10c provided on the valve disk 10. a hollow valve housing 12 connected to an assembly shaft 10c of the valve disc 10; a pilot passage PP; and a main valve body communicating with the pilot passage PP. 11, a pressure control valve PV provided in the middle of the pilot passage PP for controlling the pressure in the back pressure chamber BP, and a fail valve FV.

As shown in FIG. 1, the valve disc 10 includes a large-diameter base portion 10d fitted into the sleeve 106a, an assembly shaft 10c projecting from the base portion 10d to the right in FIG. A hollow portion 10e formed so as to axially penetrate through 10c and forming a part of the pilot passage PP, an orifice 10f provided in the middle of the hollow portion 10e, and a plurality of base portions 10d penetrating from the left end to the right end in FIG. and an annular main valve seat 10b provided at the right end of the base portion 10d in FIG. 1 and formed on the outer peripheral side of the outlet of the port 10a.

The port 10a penetrates the base portion 10d as described above, and the opening of the port 10a on the left end side of the base portion 10d in FIG. The opening of the base portion 10d of the port 10a on the right end side in FIG. That is, in the case of this shock absorber D, hydraulic oil is discharged from the rod side chamber 103 through the discharge passage 105 and the port 10a to the reservoir 107 during expansion and contraction, and the rod side chamber 103 is upstream of the port 10a. 1 of the hollow portion 10e also communicates with the rod-side chamber 103 via the discharge passage 105, like the port 10a.

A small diameter portion 10g formed by reducing the diameter of the base portion 10d of the valve disk 10 on the left side in FIG. It is Since the seal ring 13 thus seals between the sleeve 106a and the valve disc 10, communication between the discharge passage 105 and the reservoir 107 through the outer periphery of the base portion 10d is blocked.

Next, on the right end of the base portion 10d of the valve disk 10 in FIG. 1, a main valve body 11 is stacked which is seated on and off the main valve seat 10b to open and close the port 10a. The main valve body 11 is an annular laminated leaf valve, the inner periphery of which is assembled to the assembly shaft 10c and sandwiched between the valve disc 10 and the valve housing 12 screwed to the assembly shaft 10c. there is Therefore, the main valve body 11 is seated on the main valve seat 10b with the bending of the outer peripheral side allowed, and when the outer peripheral side bends, it leaves the main valve seat 10b to open the port 10a.

Although the main valve body 11 is configured as a laminated leaf valve in which a plurality of annular plates are laminated, the number of annular plates is arbitrary. A main valve seat 10b on which the main valve body 11 is seated is provided with an orifice O formed of a notch.

1, a spacer 15, an annular plate spring 16 and a spacer 17 are laminated in order on the right side of the main valve body 11 in FIG. 1, and are assembled to the assembly shaft 10c. A valve housing 12 is screwed to the right end in FIG. 1, which is the tip of the assembly shaft 10c. Then, the main valve body 11, the spacer 15, the leaf spring 16 and the spacer 17 assembled to the assembly shaft 10c are sandwiched between the base portion 10d of the valve disc 10 and the valve housing 12 and fixed.

The valve housing 12, as shown in FIG. 1, is cylindrical, and has a small-diameter cylindrical portion 12a on the left in FIG. 1 and a large-diameter cylindrical portion 12b on the right in FIG. , an annular groove 12c provided on the outer periphery of the large-diameter cylindrical portion 12b, and a pressure introduction hole 12d that opens from the left end of the large-diameter cylindrical portion 12b and communicates with the inner periphery of the large-diameter cylindrical portion 12b. Further, the valve housing 12 is connected to the valve disc 10 by inserting and screwing the assembly shaft 10c of the valve disc 10 into the screw hole portion 12e provided inside the small-diameter cylindrical portion 12a. The large-diameter cylindrical portion 12b is provided with an annular protrusion 12f on the inner peripheral side of the right end in FIG. It has an annular fail valve seat 12h protruding to the middle right, and a fail passage 12i that opens from the inner periphery of the large-diameter cylindrical portion 12b and communicates with the annular groove 12g.

The inside of the valve housing 12 communicates with the hollow portion 10e of the valve disc 10 and communicates with the rod side chamber 103 upstream of the port 10a via an orifice 10f. The inside of the valve housing 12 functions as part of the pilot passage PP together with the hollow portion 10e.

A synthetic resin ring 18 is mounted in an annular groove 12c provided on the outer periphery of the large-diameter cylindrical portion 12b of the valve housing 12, and a cylindrical spool 19 is slidably mounted on the outer periphery of the ring 18. is installed. The spool 19 has a tubular shape, and has a flange 19a provided at the lower end and protruding inward, and an annular projection 19b below the flange 19a. That is, the spool 19 can move in the lateral direction in FIG. 1, which is the axial direction with respect to the valve housing 12 .

1, the outer periphery of a leaf spring 16 is in contact with the right end of the flange 19a in FIG. The annular projection 19b is in contact with the side of the main valve body 11 opposite to the main valve seat.

The spool 19 cooperates with the leaf spring 16 and the valve housing 12 to form a back pressure chamber BP on its inner peripheral side. It communicates with the inside of the valve housing 12 . Therefore, the hydraulic fluid discharged from the rod side chamber 103 is guided to the back pressure chamber BP via the orifice 10f, and the pressure upstream of the port 10a is reduced by the orifice 10f and introduced into the back pressure chamber BP. be done. As described above, in addition to the biasing force of the leaf spring 16 that biases the spool 19, the main valve body 11 is subjected to a biasing force that presses the main valve body 11 toward the main valve seat 10b due to the internal pressure of the back pressure chamber BP. is doing.

That is, when the shock absorber D expands and contracts, the main valve body 11 receives the pressure in the rod side chamber 103 from the front side through the port 10a, and receives the pressure inside the back pressure chamber BP and the leaf spring from the back side. 16 is biased. A hole may be provided in the plate spring 16 so that the pressure in the back pressure chamber BP directly acts on the main valve body 11 .

1 overcomes the internal pressure of the back pressure chamber BP and the urging force of the leaf spring 16, the pressure in the rod side chamber 103 causes the main The valve body 11 is bent and separated from the main valve seat 10b to form a gap between the main valve body 11 and the main valve seat 10b, thereby opening the port 10a.

Next, a pressure control valve PV is assembled inside the valve housing 12 and to the right of the screw hole portion 12e in FIG. The pressure control valve PV is provided in the middle of the pilot passage PP, closes the pilot passage PP when not energized, and performs pressure control when energized.

As shown in FIGS. 1 and 3, the pressure control valve PV includes a valve seat member 1 having a valve seat 1a and a valve housing cylinder 1b, a valve body 2 which is seated on and off the valve seat 1a, and a valve body 2. It is composed of a spring 3 that biases the valve body 2 in a direction to separate it from the valve seat 1a, a solenoid Sol as an actuator that applies thrust to the valve body 2 and drives it in the axial direction, and a passage P.

The valve seat member 1 is fitted into the large-diameter cylindrical portion 12b of the valve housing 12 and is positioned radially by being superimposed on the right end of the large-diameter cylindrical portion 12b in FIG. Attached. The valve seat member 1 includes a bottomed cylindrical valve accommodating cylinder 1b having a flange 1c on the outer periphery of the right end in FIG. A seat 1a, an outer cylindrical portion 1d provided on the outer periphery of the flange 1c toward the right in FIG. and a channel P formed by a groove provided over the portion 1d.

A fail valve body 21, which is an annular leaf valve, is attached to the outer periphery of the valve housing cylinder 1b of the valve seat member 1. As shown in FIG. When the valve housing cylinder 1b is inserted into the valve housing 12 and the valve seat member 1 is assembled to the valve housing 12, the inner periphery of the fail valve valve element 21 is aligned with the flange 1c of the valve seat member 1 and the right end of the valve housing 12 in FIG. is clamped and fixed. Therefore, the fail valve body 21 is seated on the fail valve valve seat 12h provided on the valve housing 12 on the outer peripheral side while being initially flexed, and closes the annular groove 12g. The fail valve body 21 bends when the pressure acting in the annular groove 12g through the fail passage 12i reaches the valve opening pressure, thereby opening the fail passage 12i to communicate with the reservoir 107. As shown in FIG. Thus, the fail valve FV is formed by the fail valve body 21 and the fail valve seat 12h.

The outer diameter of the valve housing cylinder 1b is smaller than the inner diameter of the valve housing 12. When the valve housing cylinder 1b is inserted into the valve housing 12 and the valve seat member 1 is assembled to the valve housing 12, the transparent The hole 1e communicates with the rod-side chamber 103 through the hollow portion 10e.

Further, a valve body 2 is slidably inserted into the valve housing cylinder 1b of the valve seat member 1. As shown in FIG. Specifically, the valve body 2 has a small diameter portion 2a provided on the left side in FIG. A large-diameter portion 2b provided in the valve, an annular recess 2c provided between the small-diameter portion 2a and the large-diameter portion 2b, a flange-like spring receiving portion 2d provided on the outer periphery of the end opposite to the valve seat member, and the valve It is composed of a communicating passage 2e penetrating from the front end to the rear end of the body 2 and an orifice 2f provided in the middle of the communicating passage 2e.

As described above, the valve body 2 has a larger outer diameter on the side opposite to the valve seat member than the recessed portion 2c. It has an annular seat portion 2g facing the . Therefore, when the valve body 2 moves in the axial direction with respect to the valve seat member 1 and moves away from the valve seat member 1, the seat portion 2g is seated and separated from the valve seat 1a. When the seat portion 2g is seated on the valve seat 1a, the pressure control valve PV is closed, and when the seat portion 2g is separated from the valve seat 1a, the pressure control valve PV is opened. The pressure control valve PV communicates the rod side chamber 103 with the reservoir 107 via the hollow portion 10e when opened, and cuts off communication between the rod side chamber 103 and the reservoir 107 via the hollow portion 10e when closed.

The valve body 2 can move in the axial direction with respect to the valve seat member 1, and is maintained in a state in which the concave portion 2c faces the through hole 1e until the valve body 2 is separated from the seated state on the valve seat member 1 to the maximum. Therefore, when the pressure control valve PV is opened, hydraulic fluid flowing from the hollow portion 10e of the valve disc 10 to the reservoir 107 can pass between the valve housing cylinder 1b and the recessed portion 2c of the valve seat member 1. FIG. On the other hand, when the valve seat member 1 is separated from the valve seat member 1 to the maximum in the axial direction, the spring receiving portion 2d of the valve body 2 comes into contact with the cap 20, which will be described later, and closes the pilot passage PP. It becomes impossible to pass through the PV.

Thus, in this embodiment, the pressure control valve PV is closed when the seat portion 2g is seated on the valve seat 1a, and closed even when the valve body 2 is separated from the valve seat member 1 as much as possible. do. Even when the pressure control valve PV is closed, the fail passage 12i is always communicated with the rod-side chamber 103 through the hollow portion 10e, so the pressure in the rod-side chamber 103 is equal to the opening pressure of the fail valve FV. When it reaches, the fail valve body 21 bends to open the fail valve FV, and the pressure in the back pressure chamber BP is adjusted by the fail valve FV to the valve opening pressure of the fail valve FV.

When the valve body 2 is inserted into the valve housing cylinder 1b of the valve seat member 1, the valve body 2 forms a space K inside the valve housing cylinder 1b on the distal end side of the through hole 1e. This space K communicates with the outside of the valve body 2 via a communicating passage 2e and an orifice 2f provided in the valve body 2. As shown in FIG. As a result, when the valve body 2 moves in the axial direction, i.e., the left-right direction in FIG. , the vibrational movement of the valve body 2 can be suppressed.

Further, a spring 3 is interposed between the spring receiving portion 2d of the valve body 2 and the flange 1c of the valve seat member 1 to urge the valve body 2 in the axial direction away from the valve seat member 1. It is In this embodiment, the spring 3 is a conical coil spring. It is fitted to the outer periphery of the large-diameter portion 2b of the valve body 2 and is positioned with respect to the valve seat member 1 and the valve body 2 in the radial direction.

The spring 3 is annular and is interposed between the valve seat member 1 and the valve body 2, and the space between the valve seat member 1 and the valve body 2 is formed on the valve seat side facing the valve seat 1a. It is partitioned into a space A1 and a space A2 on the side opposite to the valve seat 1a not facing the valve seat 1a. In terms of the flow of hydraulic fluid, a spring 3 separates a space A1 on the upstream side facing the valve seat 1a from a space A2 on the downstream side of the space A1. , from the rod-side chamber 103 to the reservoir 107, it passes through the space A1 and the space A2 in this order.

On the other hand, the passage P provided in the valve seat member 1 extends from the flange 1c to the end of the outer cylindrical portion 1d, and opens from the inner peripheral side of the large diameter side end 3a of the spring 3. It leads to the outer peripheral side of the end portion 3a. Therefore, the passage P is formed into a space A1 on the upstream side of the valve seat and a space A2 on the downstream side opposite to the valve seat without passing between the end 3a which is one end of the spring 3 and the end 3b which is the other end of the spring 3. are communicating. Therefore, the hydraulic oil that passes through the pressure control valve PV and moves from the space A1 on the side of the valve seat to the space A2 on the side opposite to the valve seat passes through not only the narrow gap between the wires of the spring 3 but also the space between the wires of the spring 3. It can also pass through the passage P that bypasses the gap between . By providing the passage P in this way, the flow rate of hydraulic oil passing through the gaps between the wires of the spring 3 can be reduced, so the pressure loss and fluid force when passing through the gaps between the wires of the spring 3 can be reduced. . If the passage area of the passage P is made larger than the total passage area of the helical gap between the wires of the spring 3, the passage P with less resistance is preferentially passed through, so that the pressure loss and the fluid force are more effective. can be reduced significantly. In this embodiment, the spring 3 is a conical coil spring, but it may be a cylindrical coil spring or a disc spring with grooves such as a diaphragm spring. Any number of passages P may be provided as long as a sufficiently large flow passage area is secured.

A cap 20 is fitted to the right end of the valve housing 12 in FIG. The cap 20 has an annular shape, and includes a socket 20a fitted to the outer periphery of the large-diameter tubular portion 12b of the valve housing 12, a fitting portion 20b fitted to the end of the outer tubular portion 1d of the valve seat member 1, It comprises a through hole 20c penetrating the socket 20a, an annular valve seat 20d protruding to the inner circumference at the right end in FIG. 3, and a notch groove 20e provided at the right end in FIG. .

When the socket 20a of the cap 20 is fitted to the valve housing 12 and the fitting portion 20b is fitted to the outer cylindrical portion 1d of the valve seat member 1, the valve seat member 1 is placed against the cap 20 and the valve housing 12. It is positioned in the radial direction, sandwiched between the cap 20 and the valve housing 12 and fixed to both together with the fail valve body 21 .

A spring receiving portion 2d of the valve body 2 is seated on and away from the annular valve seat 20d of the cap 20, and when the valve body 2 is separated from the valve seat member 1 to the maximum extent in the axial direction, the spring receiving portion is closed. 2d is seated on the annular valve seat 20d, otherwise the spring seat 2d is spaced from the annular valve seat 20d.

When the cap 20 is attached to the valve housing 12, the space in which the pressure control valve PV is accommodated is partitioned. While the communication between the space and the reservoir 107 is cut off through the gap, the space and the reservoir 107 are communicated with each other by the notch groove 20e when the valve element 2 is separated from the annular valve seat 20d.

In summary, the variable damping valve DV communicates the rod-side chamber 103 and the reservoir 107 through the port 10a, and the main valve body 11 opens and closes the port 10a. In addition to the route passing through the port 10a, the hollow portion 10e of the valve disc 10, the inside of the valve housing 12, the through hole 1e provided in the valve seat member 1, the inside of the valve seat member 1, the recessed portion 2c provided in the valve body 2. , the space A1, the passage P, the space A2, and the notched groove 20e, the rod-side chamber 103 and the reservoir 107 are communicated with each other to form a pilot passage PP. This pilot passage PP communicates with the back pressure chamber BP through a pressure introduction hole 12d provided in the valve housing 12, and the pressure upstream of the port 10a is reduced by an orifice 10f provided in the middle of the pilot passage PP. introduced into the chamber BP. Further, the pilot passage PP is opened and closed by the pressure control valve PV, and the pressure in the back pressure chamber BP can be controlled by adjusting the opening pressure of the pressure control valve PV. The pressure control valve PV includes a solenoid Sol as an actuator that applies thrust to the valve body 2 for adjusting the valve opening pressure. When the solenoid Sol does not apply thrust to the valve body 2, the valve body 2 is separated from the valve seat member 1 by the spring 3 to the maximum extent, and the pressure control valve PV is closed. Since the upstream of PV communicates with the fail passage 12 i , when the pressure in the pilot passage PP rises and reaches the opening pressure of the fail valve FV, the fail valve FV opens to communicate the rod side chamber 103 with the reservoir 107 . The actuator is not limited to the solenoid Sol, but may be, for example, a linear motor, an air cylinder, or the like, which can adjust the opening pressure of the pressure control valve PV by applying a thrust force to the valve body 2 against the biasing force of the spring 3. I wish I had.

The solenoid Sol is housed in a cylindrical case 35 with a bottom screwed onto the outer periphery of a sleeve 108a attached to an opening provided in an outer cylinder 108. an annular solenoid bobbin 39 fixed to the bottom of the solenoid bobbin 35; A cylindrical second stationary core 41 and a non-magnetic non-magnetic material that is similarly fitted to the inner circumference of the solenoid bobbin 39 and is interposed to form a gap between the first stationary core 40 and the second stationary core 41 . It comprises a body filler ring 42 , a cylindrical movable core 43 arranged on the inner peripheral side of the first fixed core 40 , and a shaft 44 fixed to the inner periphery of the movable core 43 .

The case 35 includes a cylindrical portion 35a and a bottom portion 35b that is fixed by crimping the open end of the cylindrical portion 35a. A bobbin holder 36 is fixed to the inner circumference of the. The bobbin holder 36 holds a solenoid bobbin 39 , and the solenoid bobbin 39 is attached to the case 35 via the bobbin holder 36 .

When the case 35 is screwed to the sleeve 108a, the flange 41a provided on the outer periphery of the second fixed core 41 is sandwiched between the case 35 and the sleeve 108a, and the second fixed core 41 clamps the filler ring 42 and the first A stationary core 40 is fixed within the case 35 .

The movable iron core 43 has a tubular shape, and a shaft 44 extending from both ends of the movable iron core 43 to the left and right in FIG. The shaft 44 includes an annular bush 45 provided at the bottom of the first fixed core 40 and an annular bush 47 held on the inner periphery of an annular guide 46 fitted to the inner periphery of the second fixed core 41. , and these bushes 45 and 47 guide the axial movement of the shaft 44 .

Further, when the second fixed core 41 is fixed to the case 35 as described above, the guide 46 fitted to the inner circumference of the second fixed core 41 contacts the cap 20, and the cap 20, the valve seat member 1, the fail valve A valve body 21 , a valve housing 12 and a valve disc 10 are fixed to the damper D.

The left end of the shaft 44 in FIG. 1 is in contact with the perforated disc 32 fitted to the right end of the valve body 2 in FIG. , the spring 3 not only biases the valve body 2, but also serves to bias the shaft 44 as a part of the solenoid Sol.

The second fixed iron core 41 has a cylindrical sleeve 41b fitted to the inner circumference of the sleeve 108a, whereby each member constituting the solenoid Sol is radially positioned with respect to the sleeve 108a. there is A notch (not shown) is provided on the outer periphery of the cap 20, and the gap between the valve body 2 and the solenoid Sol communicates with the reservoir 107 through this notch and the notch groove 20e. There is no danger of interfering with the movement of 2.

The guide 46 is provided with a hole 46a penetrating in the axial direction, so that no pressure difference occurs between the left side and the right side of the guide 46 in FIG. A hole 43a penetrating through the movable core 43 is provided so that smooth movement of the movable core 43 is not hindered due to a pressure difference between the left side and the right side of the movable core 43 in FIG.

As described above, in this solenoid Sol, the magnetic path is formed to pass through the first fixed core 40, the movable core 43 and the second fixed core 41, and when the winding 38 is excited, The movable iron core 43 arranged near the first fixed iron core 40 is attracted to the second fixed iron core 41 side, and a thrust toward the left side in FIG. 1 acts on the movable iron core 43 .

As shown in FIG. 1, the shaft 44 that moves integrally with the movable iron core 43 is in contact with the valve body 2 so that the thrust of the solenoid Sol is transmitted to the valve body 2 .

1 to the valve body 2 via the movable iron core 43 which is attracted when the solenoid Sol is excited to seat the valve body 2 on the valve seat 1a. Accordingly, the valve opening pressure of the pressure control valve PV is adjusted. Specifically, by adjusting the energization amount of the winding 38 of the solenoid Sol, the thrust applied to the valve body 2 can be adjusted, and the opening pressure of the pressure control valve PV can be controlled.

In addition, since the solenoid Sol does not apply thrust to the valve body 2 when not energized, the valve body 2 is pushed by the spring 3 to separate from the valve seat 1a and move away from the valve seat member 1 as much as possible to control the pressure. Close the valve PV.

The pressure control valve PV is constructed as described above and incorporated in the variable damping valve DV, and changes the damping force generated by the shock absorber D by adjusting the thrust of the solenoid Sol as an actuator.

Specifically, when the shock absorber D expands and contracts and hydraulic oil is discharged from the rod-side chamber 103 through the variable damping valve DV to the reservoir 107, when the pressure control valve PV operates normally, the port 10a and the pilot passage PP , the pressure between the orifice 10f in the pilot passage PP and the pressure control valve PV increases in the back pressure chamber BP. be guided.

The internal pressure of the back pressure chamber BP is controlled to be equal to the valve opening pressure of the pressure control valve PV, and the valve opening pressure is adjusted by a solenoid Sol. Therefore, the pressure control valve PV can adjust the pressure acting on the back surface of the main valve body 11, and in turn can control the valve opening pressure at which the main valve body 11 opens the port 10a.

The pressure control valve PV of the present invention includes a valve seat 1a, a valve body 2 that is seated on and away from the valve seat 1a, a spring 3 that biases the valve body 2 in a direction to separate it from the valve seat 1a, and a valve body 2. A space A1 on the side of the valve seat partitioned by a solenoid (actuator) Sol capable of applying a thrust in a direction to approach the valve seat 1a, and a space (downstream ) and a passage P communicating with A2.

When the pressure control valve PV is configured in this way, the hydraulic oil that passes through the pressure control valve PV and moves from the valve seat side space A1 to the space (downstream) A2 passes through the narrow gap between the wires of the spring 3. Besides, it can also pass through the passage P bypassing the gap between the wires of the spring 3.

According to the pressure control valve PV of the present invention, the passage P is provided to reduce the flow rate of hydraulic oil passing through a narrow gap between one end and the other end of the spring 3. It can reduce pressure loss and fluid force when passing through the gap.

Therefore, according to the pressure control valve PV of the present invention, pressure loss and fluid force when passing through the gap between one end and the other end of the spring 3 can be reduced. It is possible to solve the problem that the pressure becomes difficult and that the spring 3 vibrates to cause pressure fluctuations, and stable pressure control becomes possible.

Further, if the flow area of the passage P is made larger than the total flow area of the gap from one end of the spring 3 to the other end, the hydraulic oil preferentially passes through the passage P with less resistance. Since the pressure loss and fluid force due to the hydraulic fluid passing through the gap from one end to the other end of the valve can be minimized, more effective and stable pressure control is possible.

Further, in forming the passage P, a valve seat side member 1A having a valve seat 1a and a spring 3 which is fitted to the valve seat side member 1A, like the pressure control valve PV1 of the first modified example shown in FIG. The valve seat member 1 may be configured with a cap 20A as a cylindrical member that accommodates the valve seat side member 1A and the passage P may be formed by recesses 50 and 51 provided in both the combined portion of the valve seat side member 1A and the cap 20A. Specifically, the valve-seat-side member 1A includes a valve housing cylinder 1b having a bottomed cylindrical shape and having a flange 1c on the outer periphery at the right end in FIG. A spring 3 is seated from the outer periphery of the combined portion 1A1 in which the annular valve seat 1a protruding from the outer periphery of the flange 1c is fitted with a cap 20A formed of a stepped portion provided on the outer periphery of the flange 1c. and a recessed portion 50 that opens to the inner peripheral side of the portion. In addition, the cap 20A as a cylindrical member has a cylindrical fitting portion 20b that accommodates the spring 3 inside and is fitted to a combination portion 1A1 provided on the flange 1c of the valve seat side member 1A as a combination portion. It has the same configuration as the cap 20 described above, except that it has a recessed portion 51 axially provided from the left end in FIG. 4 on the inner periphery of the fitting portion 20b.

When the fitting portion 20b of the cap 20A is combined with the combination portion 1A1 of the valve seat side member 1A, the recess 50 and the recess 51 are communicated to form a passage P. The passage P is formed in a combined portion (fitting portion 20b) of a valve seat side member 1A having a valve seat 1a and a cap 20A as a tubular member that fits into the valve seat side member 1A and accommodates the spring 3. Therefore, the space A1 on the side of the valve seat partitioned by the spring 3 can be communicated with the space (downstream) A2 without intervening from one end of the spring 3 to the other end. In this way, when the passage P is formed by the concave portions 50 and 51 provided in the valve seat member 1 between the combination portion 1A1 of the valve seat side member 1A and the fitting portion 20b as a combination portion of the cap 20A as a cylindrical member, the valve If the seat side member 1A and the cap 20A as the cylindrical member are manufactured by sintering, the passage P can also be formed. In addition, since the valve seat side member 1A and the cap 20A as a cylindrical member are combined by the combining portion, both are positioned in the radial direction, and the outer periphery of the spring 3 is supported by the inner periphery of the fitting portion 20b of the cap 20A. Positioning of the spring 3 can also be performed by restraining it.

Furthermore, although the passage P is provided in the valve seat member 1 in the above description, the passage P may be provided in the valve body 2 like the pressure control valve PV2 in the second modification shown in FIG. . In this case, as shown in FIG. 5, an opening is opened from the left side in FIG. When the passage P is provided so as to lead to the side, the upstream space A1 can be communicated with the downstream space A2 by detouring the gap between the wires from one end to the other end of the spring 3. Therefore, even with the pressure control valve PV2 configured in this way, the pressure loss and fluid force when passing through the gap between one end and the other end of the spring 3 can be reduced, so stable pressure control is possible. becomes.

In addition, in the variable damping valve DV to which the pressure control valve PV is applied, a thrust corresponding to the current supplied to the solenoid Sol is applied to the pressure control valve PV to control the internal pressure of the back pressure chamber BP, thereby controlling the main valve The valve opening pressure in body 11 is adjusted. Therefore, the internal pressure of the back pressure chamber BP can be adjusted as intended without depending on the flow rate flowing through the pilot passage PP, and even when the piston speed of the shock absorber D is in the low speed range, the damping force against the current supplied to the solenoid Sol Changes are close to linear, improving controllability. Further, since the internal pressure of the back pressure chamber BP, which biases the main valve body 11 by applying a thrust corresponding to the current supplied to the solenoid Sol, to the valve body 2, the variation in the damping force can be reduced.

In the event of a failure, the current supply to the solenoid Sol is cut off, the pressure control valve PV is pressed by the spring 3 and closed, and when the pressure in the rod-side chamber 103 reaches the opening pressure of the fail valve FV, the fail valve FV is opened. The valve is opened to connect the pilot passage PP to the reservoir 107 . Therefore, the fail valve FV acts as resistance to the flow of hydraulic oil, and the damper D can function as a passive damper. By setting the valve opening pressure of the fail valve FV, it is possible to arbitrarily set in advance the damping characteristic at the time of failure with respect to the piston speed of the shock absorber D.

In this embodiment, the pressure control valve PV is applied to the variable damping valve DV. is not lost.

Although preferred embodiments of the invention have been described in detail above, modifications, variations, and changes are possible without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1... Valve seat member 1A... Valve seat side member 1a... Valve seat 1A1... Combination part 2... Valve body 3... Spring 20A... Cap ( Cylindrical member), 20b... Fitting portion (combination portion), 50, 51... Concave portion, A1... Space, P... Passage, PV, PV1, PV2... Pressure control valve, Sol.・・Solenoid (Actuator)

Claims (4)

a valve seat;
a valve body that sits on and off the valve seat;
a spring that biases the valve body in a direction away from the valve seat;
an actuator capable of applying thrust in a direction to bring the valve body closer to the valve seat;
A pressure control valve, comprising: a passage that connects a space on the side of the valve seat partitioned by the spring to a downstream side without interposing between one end and the other end of the spring. A valve seat member having the valve seat,
2. The pressure control valve according to claim 1, wherein the passage is provided in the valve seat member. The valve seat member has a valve seat side member having the valve seat, and a cylindrical member that fits into the valve seat side member and accommodates the spring therein,
3. The pressure control valve according to claim 2, wherein the passage is formed by a concave portion provided in a combined portion of the valve seat side member and the cylindrical member. 2. The pressure control valve according to claim 1, wherein the passage is provided in the valve body.

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