JP2024044934A - valve - Google Patents

Abstract

The present invention aims to provide a valve capable of suppressing vibration of a valve body without requiring a high degree of machining precision. [Solution] The valve V of the present invention comprises a hollow housing having a valve seat 3b on its inner circumference, a valve element 20 accommodated within the housing 3 so as to be movable in the axial direction and seated on and off the valve seat 3b, a spring retainer 21 provided within the housing 3, a spring 22 interposed between the valve element 20 and the spring retainer 21 for biasing the valve element 20 in a direction to seat on the valve seat 3b, and a dashpot chamber 23 for suppressing the movement of the valve element 20 by increasing and decreasing its volume as the valve element 20 moves in the axial direction. The valve element 20 has a valve portion 24 having a seating portion 24c which seats on and off the valve seat 3b and is restricted from moving radially relative to the housing 3, and a spring retainer portion 25 having a valve element side spring retainer 25a which supports one end of the spring 22 and is allowed to move radially relative to the valve portion 24 while abutting the valve portion 24, and the dashpot chamber 23 is formed between the spring retainer portion 25 and the spring retainer 21. [Selected Figure] Figure 2

Description

This invention relates to a valve.

Some valves are used in dampers, for example, and cause the damper to exert damping force by providing resistance to the flow of hydraulic oil as the damper expands and contracts. Such a valve, for example, pivots a piston rod that fits into both ends of an outer cylinder that forms a tank between cylinders in a dual cylinder damper and is movably inserted into the cylinder. It is used by being incorporated into a rod guide that is connected to a piston rod and inserted into a cylinder to partition the inside of the cylinder into a rod side chamber and a piston side chamber.

Such a valve, for example, includes a rod guide having a valve hole that connects the rod side chamber with the tank as a housing, the housing, an annular valve seat provided on the inner circumference of the valve hole, a valve body that is inserted axially into the valve hole and seats and disengages from the annular valve seat, and a coil spring that biases the valve body toward the annular valve seat (see, for example, Patent Document 1).

In addition, the double-tube damper is equipped with a check valve that only allows the flow of working fluid from the piston side chamber to the rod side chamber, and a suction valve that only allows the flow of working fluid from the reservoir to the piston side chamber. Even if the cylinder contracts, the working fluid is discharged from the cylinder to the tank through the valve hole.In any case, the valve provides resistance to the flow of working fluid from the cylinder to the tank, creating a damping force. It is designed to be effective.

Japanese Patent Application Publication No. 2012-13120

In this conventional valve, the valve body is biased by a coil spring, and the initial load of this coil spring adjusts the valve opening pressure, and the spring constant of the coil spring adjusts the damping characteristics of the double-tube damper. can be adjusted.

However, in such a damping valve that biases the valve body with a coil spring, when the double-tube damper exhibits high-speed operation, axial vibration of the valve body is excited by pressure fluctuations within the cylinder and oscillates. There is a problem in that the damping force generated by the double-tube shock absorber is unstable and vibrates.

Therefore, conventional valves are provided with a cylindrical case in which the valve body moves in and out of a spring holder that supports a coil spring and forms a dashpot chamber together with the valve body. The dashpot chamber is communicated with the outside of the case through a small gap between the outer circumference of the valve body and the inner circumference of the case, and when the valve body enters the case, the hydraulic oil in the dashpot chamber is compressed and overcomes resistance. The object passes through the gap while receiving the object. Therefore, in conventional valves, when the valve body retreats from the annular valve seat and moves into the case, it increases the pressure in the dashpot chamber and generates a force that impedes the movement of the valve body, causing axial vibration of the valve body. It can be suppressed.

However, in conventional valves, the valve body has a structure in which the valve body is provided with a guide shaft that is slidably inserted into a part with a small inner diameter provided in the valve hole, and the movement of the valve body in the axial direction is guided by the housing. It becomes. Therefore, in conventional valves, the valve body must be placed concentrically with both the housing and the case, requiring a high degree of machining accuracy, and large dimensional errors can make assembly difficult. The vibration of the valve body cannot be suppressed unless a pot chamber is provided.

Therefore, the present invention aims to provide a valve that can suppress vibration of the valve body without requiring high machining precision.

The valve of the present invention comprises a hollow housing having a valve seat on its inner circumference, a valve body accommodated within the housing so as to be movable in the axial direction and capable of being seated on and removed from the valve seat, a spring retainer provided within the housing, a spring interposed between the valve body and the spring retainer for biasing the valve body in a direction to seat on the valve seat, and a dashpot chamber that increases or decreases in volume as the valve body moves in the axial direction to suppress movement of the valve body. The valve body has a valve section having a seating portion that seats on and removes from the valve seat and whose radial movement relative to the housing is restricted, and a spring retaining portion having a valve body-side spring retainer that supports one end of the spring and abuts against the valve section while being allowed to move radially, and the dashpot chamber is formed between the spring retaining portion and the spring retainer.

A valve constructed in this manner is made up of two parts: a valve section in which the valve body is seated on and off the valve seat and whose radial movement is restricted by the housing, and a spring receiving section which is allowed to move radially relative to the valve section and supports one end of the spring. Since the spring receiving section can move radially relative to the valve section, even in cases where the valve section and the spring receiving section are aligned separately, the spring receiving section can be aligned to the housing or spring receiving section without being restrained by the valve section.

Further, one of the valve part and the spring receiving part has a convex part that projects in the axial direction from the contact end that comes into contact with the other of the valve part and the spring receiving part. On the other hand, the valve may be configured to include a recess that opens at the abutting end that abuts one of the valve portion and the spring receiving portion and into which the convex portion is inserted so as to be movable in the radial direction. According to the valve configured in this manner, by inserting the convex part into the concave part when assembling the valve body of the valve, it is possible to position the spring receiving part in the radial direction to a certain extent with respect to the valve part, and the valve body is assembled. Easy to assemble.

According to the valve of the present invention, vibration of the valve body can be suppressed without requiring high processing accuracy.

FIG. 2 is a diagram showing a circuit configuration of a damper to which a valve is applied in one embodiment. FIG. 2 is a cross-sectional view of a valve according to one embodiment. FIG. 2 is an exploded perspective view of a valve body of the valve according to the embodiment; It is a sectional view of the valve in the 1st modification of one embodiment.

The present invention will be described below based on the illustrated embodiment. As shown in Figs. 1 and 2, the valve V in one embodiment is applied to the damper D with a piston 3 as a housing, which is inserted axially movably into the cylinder 1 of the damper D and divides the cylinder 1 into an expansion side chamber R1 and a compression side chamber R2. The valve V is configured with a piston 3 as a housing having a valve hole 3a, which is hollow and has an annular valve seat 3b as a valve seat on the inner circumference of the valve hole 3a, a valve body 20 accommodated in the piston 3, a spring bearing 21 provided in the piston 3, a spring 22 interposed between the valve body 20 and the spring bearing 21 and biasing the valve body 20 in a direction to seat on the annular valve seat 3b, and a dashpot chamber 23 that increases or decreases in volume by the axial movement of the valve body 20 to suppress the movement of the valve body 20.

As shown in FIG. 1, the damper D in one embodiment includes a cylinder 1, a piston rod 2 movably inserted into the cylinder 1, a piston 3 movably inserted into the cylinder 1 and connected to the piston rod 2, and dividing the inside of the cylinder 1 into an extension side chamber R1 and a compression side chamber R2, a tank 4, a relief passage formed by a valve hole 3a provided in the piston 3 and communicating the extension side chamber R1 and the compression side chamber R2, a valve V provided in the relief passage, and a valve V provided in the piston 3 and dividing the extension side chamber R1 and the compression side chamber R2. 2, an extension side damping valve 6 provided in the extension side damping passage 5 to allow hydraulic oil to flow only from the extension side chamber R1 to the compression side chamber R2 and to provide resistance to the flow of hydraulic oil, a compression side damping passage 7 and a suction passage 8 providing communication between the compression side chamber R2 and the tank 4, a compression side damping valve 9 provided in the compression side damping passage 7, a check valve 10 provided in the suction passage 8, an extension side relief passage 11 providing communication between the extension side chamber R1 and the tank 4, and an extension side relief valve 12 provided in the extension side relief passage 11.

The extension side chamber R1 and the compression side chamber R2 are filled with hydraulic oil as a liquid, and the tank 4 is filled with gas in addition to hydraulic oil. In addition to hydraulic oil, water or an aqueous solution can also be used as the liquid. The tank 4 does not need to be pressurized by compressing and filling it with gas, but it may be pressurized.

The valve V and each part of the damper D to which the valve V is applied will be described in detail below. The cylinder 1 is cylindrical, with the right end in FIG. 1 closed by a lid 13 and an annular rod guide 14 attached to the left end in FIG. 1. The piston rod 2 is inserted into the cylinder 1 via the inner circumference of the rod guide 14 so as to be movable in the axial direction, and the left end in FIG. 1 protrudes outward from the cylinder 1.

The damper D also includes an outer cylinder 15 that covers the outer periphery of the cylinder 1. The left and right ends of the outer cylinder 15 in FIG. There is.

The tip of the piston rod 2, which is the right end in FIG. 1, is connected to the piston 3 inserted in the cylinder 1, and the base end of the piston rod 2, which is the left end in FIG. 1, protrudes outside the cylinder 1 through the inner circumference of the rod guide 14. In addition, a bracket (not shown) is provided on the other end of the piston rod 2, which is the left end in FIG. 1, and on the lid 13 that closes the right end of the cylinder 1 so that the damper D can be attached to the installation location.

The piston 3 is used as a housing for the valve V, and is attached to the piston rod 2 at its tip. Further, the piston 3 is inserted into the cylinder 1 so as to be movable in the axial direction, and its outer periphery slides against the inner periphery of the cylinder 1 to partition the inside of the cylinder 1 into a growth side chamber R1 and a compression side chamber R2. . The piston 3 is provided with a relief passage formed by a valve hole 3a that communicates the compression side chamber R2 and the rebound side chamber R1, a recovery side damping passage 5 that communicates the expansion side chamber R1 and the compression side chamber R2, and a relief passage. A valve V and a growth-side damping valve 6 installed in the growth-side damping passage 5 are provided.

The growth side damping passage 5 communicates the growth side chamber R1 and the compression side chamber R2, and has a section along the way that allows only the flow of hydraulic oil from the growth side chamber R1 to the compression side chamber R2, and also allows the flow of hydraulic oil to flow from the growth side chamber R1 to the compression side chamber R2. A rebound damping valve 6 is provided to provide resistance. The growth-side damping valve 6 sets the growth-side damping passage 5 as a one-way passageway that only allows the flow of hydraulic oil from the growth-side chamber R1 toward the compression-side chamber R2. In this embodiment, the growth side damping valve 6 opens when the pressure in the growth side chamber R1 on the upstream side is higher than the pressure in the pressure side chamber R2 on the downstream side, and the difference between the two reaches the valve opening pressure. It is a pressure regulating valve that opens the growth side damping passage 5 and connects the growth side chamber R1 to the compression side chamber R2. The expansion side damping valve 6, which is a pressure regulating valve, opens when the valve opening pressure is reached, and as the passing flow rate increases after the valve is opened, the pressure loss increases at a higher rate than in the valve V described above. It has pressure characteristics, and increases the upstream pressure in response to an increase in flow rate to increase the damping force.

The piston 3 as a housing of the valve V is provided with a valve hole 3a that opens from the right end facing the pressure side chamber R2 in FIG. 2 and communicates with the left end facing the expansion side chamber R1. The inner diameter of the valve hole 3a expands in the middle, and the inner diameter on the left end side in FIG. A portion 3a2 is provided. As described above, a stepped portion between the small diameter portion 3a1 and the large diameter portion 3a2 is formed on the inner periphery of the hollow valve hole 3a of the piston 3, and the piston 3 as a housing is formed on the inner periphery of the valve hole 3a. The valve seat 3b is provided with an annular valve seat 3b formed by the stepped portion.

The valve V includes a valve body 20 housed in the valve hole 3a that forms the hollow portion of the piston 3, a spring retainer 21 provided in the large diameter portion 3a2 of the valve hole 3a, a spring 22 made of a coil spring interposed between the valve body 20 and the spring retainer 21 and housed in the valve hole 3a, and a dashpot chamber 23 formed between the valve body 20 and the spring retainer 21.

The valve body 20 is inserted into the valve hole 3a so as to be movable in the left-right direction in FIG. 2, which is the axial direction, and is divided into two parts, a valve portion 24 and a spring receiving portion 25, midway in the axial direction. As shown in FIG. 2 and FIG. 3, the valve portion 24 has a tip portion 24a slidably inserted into the inner circumference of the small diameter portion 3a1 of the valve hole 3a, a disk-shaped flange 24b with an annular seat portion 24c connected to the rear end of the tip portion 24a and facing the annular valve seat 3b, and a recess 24d provided in the center of the rear end of the flange 24b. The tip portion 24a is cylindrical and has a notch 24a1 formed on the side from the tip to the rear end, and is slidably inserted into the small diameter portion 3a1 of the valve hole 3a. The valve part 24 is restricted from moving radially by having the tip 24a slidably inserted into the small diameter part 3a1, and is guided by the inner circumference of the small diameter part 3a1 so that it can move axially within the valve hole 3a without axial wobble.

The flange 24b has a disc shape and is connected to the rear end of the tip 24a, and has an annular end face facing the tip as a seat 24c, which faces the annular valve seat 3b in the axial direction. When brought into contact with the annular valve seat 3b, communication between the small diameter portion 3a1 and the large diameter portion 3a2 of the valve hole 3a can be cut off. Further, a recess 24d having a circular cross section is provided at the center of the rear end of the flange 24b, which is the left end in FIG. The left end of the flange 24b in FIG. 2 is an abutting end that comes into contact with a spring receiver 25, which will be described later, and the recess 24d opens at the abutting end of the flange 24b.

When the seating portion 24c of the flange 24b is seated on the annular valve seat 3b on the inner periphery of the valve hole 3a, the tip portion 24a of the valve portion 24 is completely inserted into the small diameter portion 3a1 and closes the valve hole 3a. , the communication between the pressure side chamber R2 and the expansion side chamber R1 through the relief passage formed by the valve hole 3a is cut off. On the other hand, when the seating portion 24c is spaced apart from the annular valve seat 3b, the notch 24a1 of the tip portion 24a faces into the large diameter portion 3a2, so the small diameter portion 3a1 and the large diameter portion 3a2 communicate with each other via the notch 24a1. , the pressure side chamber R2 and the expansion side chamber R1 are communicated with each other by a relief passage formed by the valve hole 3a.

As shown in FIGS. 2 and 3, the spring receiver 25 includes a disk-shaped valve body side spring receiver 25a that comes into contact with the end surface of the flange 24b of the valve part 24 on the side opposite to the tip, and a valve body side spring receiver 25a in FIG. A cylindrical fitting part 25b protrudes axially from the left end side and fits into the inner periphery of the spring 22, and a cylindrical fitting part 25b protrudes axially from the left end side in FIG. 2 of the fitting part 25b and is inserted into the inner periphery of the spring 22. 2, a cylindrical rod 25d protruding in the axial direction from the left end side of the spring guide 25c in FIG. A convex portion 25e that projects in the axial direction toward the portion 24 is provided.

The valve body side spring support 25a has a disc shape and faces the flange 24b of the valve part 24 in the axial direction, and is directed toward the valve part 24 at the center of the valve part side end which is the abutting end that comes into contact with the valve part 24. A convex portion 25e is provided which protrudes in the axial direction and has an outer diameter smaller than the inner diameter of the concave portion 24d. The axial length of the convex portion 25e is shorter than the axial length of the concave portion 24d, so that the entire convex portion 25e can be inserted into the concave portion 24d. Therefore, when the valve body side spring receiver 25a of the spring receiver part 25 is directly opposed to the flange 24b of the valve part 24 and the convex part 25e is inserted into the recess 24d, the valve body side end surface of the valve body side spring receiver 25a and the flange 24b are inserted. The end face on the spring receiving part side comes into contact with the spring receiving part side. Furthermore, since the outer diameter of the protrusion 25e is smaller than the inner diameter of the recess 24d, the protrusion 25e can be inserted into the recess 24d so as to be movable in the radial direction. The spring receiving part 25 can be displaced in the radial direction relative to the valve part 24 in which the spring receiving part 25 and the valve part 24 remain in contact with each other by the amount of the gap formed between the spring receiving part 25 and the valve part 24 . In this way, the spring receiving part 25 is allowed to move in the radial direction relative to the valve part 24, although the amount of movement is limited by the insertion of the convex part 25e into the concave part 24d.

The spring bearing 21 is cylindrical and has a screw portion 21a with a screw groove on its outer periphery that screws into the screw portion 3a21 provided on the left end side of the large diameter portion 3a2 in the valve hole 3a of the piston 3 in FIG. 2, and a cylindrical case 21b that protrudes in the axial direction from the right end of the screw portion 21a in FIG. 2 toward the valve body 20.

The threaded portion 21a is provided with a notch 21a1 on a part of its outer periphery, and even when fixed within the large diameter portion 3a2 of the valve hole 3a, the inside of the valve hole 3a and the expansion side chamber R1 are communicated via the notch 21a1. The case 21b has an inner diameter larger than the outer diameter of the rod 25d in the spring receiver 25 of the valve body 20, and when the spring receiver 21 is screwed and fixed to the valve hole 3a, the rod 25d is inserted inside. be done. In this way, when the rod 25d is inserted into the case 21b, the dashpot chamber 23 is formed in the space between the bottom of the case 21b and the tip of the rod 25d. It is communicated with the outside of the case 21b through a slight gap between the rod 25d and the outer periphery of the rod 25d. The gap between the inner periphery of the case 21b and the outer periphery of the rod 25d forms a restricted flow path that provides resistance to the flow of hydraulic oil into and out of the dashpot chamber 23. Since the dashpot chamber 23 and the outside of the case 21b are communicated with each other through a restricted flow path that provides resistance to the flow of hydraulic oil passing therethrough, the valve body 20 is axially connected to the piston 3 within the valve hole 3a. When moving to the dashpot chamber 23, hydraulic oil can flow back and forth between the dashpot chamber 23 and the outside of the case 21b, and the pressure in the dashpot chamber 23 fluctuates. Then, when the valve body 20 moves in the axial direction within the valve hole 3a and the rod 25d moves in and out of the case 21b to expand and contract the dashpot chamber 23, the pressure in the dashpot chamber 23 increases or decreases, causing the rod 25d to move in and out of the case 21b. On the other hand, a force is applied to the valve body 20 to suppress movement relative to the case 21b. In this way, the dashpot chamber 23 provides resistance to the movement of the valve body 20 in the axial direction with respect to the piston 3, thereby suppressing rapid displacement and vibration of the valve body 20.

The spring 22 is a coil spring, and is inserted in a compressed state between the left end in FIG. 2 of the valve body side spring receiver 25a of the spring receiver 25 and the right end in FIG. 2 of the threaded portion 21a of the spring receiver 21. The valve body 20 is urged toward the annular valve seat 3b. The spring 22 has one end supported by the valve body side spring receiver 25a of the spring receiver 25, and is fitted into the outer periphery of the fitting portion 25b. Further, a spring guide 25c of the spring receiver 25 is inserted into the inner periphery of one end of the spring 22, and the spring guide 25c prevents eccentricity in the radial direction when the spring 22 is compressed. Interference with the inner periphery of the large diameter portion 3a2 on the side is prevented. Further, the other end of the spring 22 is supported by the screw portion 21a of the spring receiver 21, and is fitted to the outer periphery of the large diameter portion of the outer periphery of the base end of the case 21b. A case 21b of the spring receiver 21 is inserted into the inner periphery of the other end of the spring 22, and the case 21b prevents eccentricity in the radial direction when the spring 22 is compressed. Interference with the inner periphery of the diameter portion 3a2 is prevented. Note that the spring 22 may be a spring other than a coil spring as long as it is interposed between the spring receiver 25 and the spring receiver 21 and does not block the restricted flow path.

The valve body 20 of the valve V receives the pressure of the pressure side chamber R2 with the cross-sectional area of the tip 24a of the valve part 24 as a pressure receiving area, and is pushed toward the left in FIG. The area obtained by subtracting the cross-sectional area of the rod 25d from the cross-sectional area of the small diameter portion 3a1 is the pressure-receiving area, which receives the pressure of the growth-side chamber R1, and is pressed toward the right in FIG. 2 by the pressure of the growth-side chamber R1. Therefore, when the pressure in the compression side chamber R2 becomes higher than the pressure in the expansion side chamber R1 and the difference between the pressure in the compression side chamber R2 and the pressure in the expansion side chamber R1 reaches a predetermined pressure (valve opening pressure), the valve V opens the pressure side chamber R2. The force pushing the valve body 20 to the left in FIG. 2 due to the pressure in the expansion side chamber R1 and the urging force of the spring 22 exceeds the force pushing the valve body 20 to the right in FIG. The valve is opened by being separated from the seat 3b, and the valve hole 3a is opened to allow passage of hydraulic oil. When the valve portion 24 is separated from the annular valve seat 3b, the more the valve portion 24 is separated from the annular valve seat 3b, the more the notch 24a1 in the tip portion 24a faces the inside of the large diameter portion 3a2, increasing the flow path area. Make it bigger. Therefore, the valve V is set so that when the flow rate of hydraulic oil increases, the valve opening degree is increased so that the pressure override does not increase.

On the other hand, when the difference between the pressure in the compression side chamber R2 and the pressure in the expansion side chamber R1 is less than the valve opening pressure, the force pushing the valve body 20 to the left in FIG. 2 by the pressure in the compression side chamber R2 is smaller than the force pushing the valve body 20 to the right in FIG. 2 by the pressure in the expansion side chamber R1 and the biasing force of the spring 22, so the valve body 20 is seated on the annular valve seat 3b, blocking the valve hole 3a and preventing the passage of hydraulic oil. In addition, since the valve V is equipped with a dashpot chamber 23, it is possible to provide resistance to the axial movement of the valve body 20 relative to the piston 3 and suppress sudden displacement and vibration of the valve body 20. The valve opening pressure of the valve V can be set by setting the spring constant and natural length of the spring 22 and the pressure-receiving area that receives the pressure of the compression side chamber R2 and the expansion side chamber R1 of the valve body 20.

In the valve V configured in this manner, the valve portion 24 of the valve body 20 is aligned with the piston 3 and moves in the axial direction. On the other hand, the dashpot chamber 23 is formed between the spring receiver 25 and the spring receiver 21, and has a restricted flow path communicating between the inside and outside of the dashpot chamber 23 between the spring receiver 25 and the spring receiver 21. Due to their formation, the spring receiver 25 must be aligned with the spring receiver 21. The valve V of this embodiment includes a valve portion 24 in which the valve body 20 is seated on and off the annular valve seat 3b and whose movement in the radial direction is restricted by the piston 3 as a housing, and Since it is composed of two parts, the spring receiving part 25 supports one end of the spring 22, and the spring receiving part 25 is allowed to move, and the spring receiving part 25 supports one end of the spring 22. Since it is movable in the radial direction relative to the valve part 24, the spring receiver 25 can be aligned by the spring receiver 21 without being constrained by the valve part 24 which is aligned with the piston 3. Therefore, according to the valve V of this embodiment, there is no longer a restriction that the valve body must be arranged concentrically with respect to both the housing and the case forming the dashpot chamber as in conventional valves. Therefore, a high degree of processing accuracy is not required for the valve body 20, the piston 3 as a housing, and the spring receiver 21, and the valve V can be easily assembled even if the dimensional error is large.

In this embodiment, a recess 24d is provided in the valve portion 24, and a protrusion 25e is provided in the spring receiving portion 25. When assembling the valve body 20 of the valve V, the protrusion 25e, whose outer diameter is smaller than the inner diameter of the recess 24d, is inserted into the recess 24d, thereby making it possible to position the spring receiving portion 25 in the radial direction relative to the valve portion 24 to a certain extent, and facilitating the insertion of the rod 25d of the spring receiving portion 25 into the case 21b of the spring receiving portion 21. By inserting the protrusion 25e into the recess 24d, the maximum radial movement of the spring receiving portion 25 relative to the valve portion 24 is determined by the width of the gap between the recess 24d and the protrusion 25e, but the maximum movement should be set so as not to impede the insertion of the rod 25d into the case 21b that forms the dashpot chamber 23.

The valve body 20 is composed of two parts, the valve portion 24 and the spring receiving portion 25, but since the spring receiving portion 25 is provided with a valve body side spring receiving portion 25a that supports one end of the spring 22 that biases the valve body 20 toward the annular valve seat 3b, the spring receiving portion 25 is constantly pressed toward the valve portion 24, so the valve portion 24 and the spring receiving portion 25 do not separate and become separate. Therefore, the recess 24d of the valve portion 24 and the protrusion 25e of the spring receiving portion 25 may be eliminated, and the end face of the flange 24b of the valve portion 24 on the spring receiving portion side and the end face of the spring receiving portion 25 on the valve portion side may be flat surfaces perpendicular to the axial direction, and the flat surfaces may be abutted against each other. Furthermore, the recess 24d is provided in the valve portion 24 and the protrusion 25e is provided in the spring receiving portion 25, but conversely, a protrusion may be provided in the valve portion 24 and a recess may be provided in the spring receiving portion 25. Furthermore, because the cross-sectional shapes of the recess 24d and the protrusion 25e are both circular, it is easy to set the maximum amount of movement of the spring receiving portion 25 relative to the valve portion 24 described above, and they will not be damaged even if the outer peripheral surface of the protrusion 25e abuts against the inner peripheral surface of the recess 24d. However, as described above, in order to improve ease of assembly, the cross-sectional shapes of the recess 24d and the protrusion 25e may be shapes other than circular, as long as a certain degree of radial movement of the spring receiving portion 25 relative to the valve portion 24 is permitted.

As described above, the restricting flow path that connects the dashpot chamber 23 to the outside of the case 21b is a gap formed between the rod 25d and the case 21b by making the inner diameter of the case 21b into which the rod 25d is inserted larger than the outer diameter of the rod 25d of the spring receiving portion 25. However, when the rod 25d is slidably inserted into the case 21b, a groove that functions as a restricting flow path or a hole that connects the inside and outside of the dashpot chamber 23 may be formed on the outer periphery of the rod 25d or the inner periphery of the case 21b.

Furthermore, the side of the rod 25d may be tapered so that the diameter is smaller at the rear end side, which is the left end in FIG. 2, or the inner diameter of the case 21b may be a cone surface so that the tip side, which is the right end in FIG. 2, becomes larger. In this case, as the rod 25d in the valve body 20 penetrates into the case 21b, the flow area of the restricted flow path gradually decreases. When the valve V is configured in this way, when the valve body 20 moves from the state where it is seated on the annular valve seat 3b to the left in FIG. 2 within the valve hole 3a, there is little resistance from the dashpot chamber 23 at the beginning of the movement of the valve body 20, so the valve body 20 can quickly separate from the annular valve seat 3b, and as the valve body 20 separates from the annular valve seat 3b, the resistance from the dashpot chamber 23 increases, and the movement of the valve body 20 can be slowed down. Therefore, with a valve V configured in this manner, it can open with good responsiveness when the valve opening pressure is reached, and as the degree of opening increases, the movement of the valve body 20 slows down, suppressing sudden changes in the degree of opening of the valve body 20 and suppressing vibration of the valve body 20.

Next, the lid 13 is provided with a compression side damping passage 7 and a suction passage 8 that connect the compression side chamber R2 and the tank 4, a compression side damping valve 9 provided in the compression side damping passage 7, and a check valve 10 provided in the suction passage 8.

The pressure side damping passage 7 communicates the pressure side chamber R2 and the tank 4, and there is a passage along the way that allows only the flow of hydraulic oil from the pressure side chamber R2 toward the tank 4, and provides resistance to the flow of the hydraulic oil. A pressure side damping valve 9 is provided. This pressure side damping valve 9 sets the pressure side damping passage 7 to be a one-way passage that only allows the flow of hydraulic oil from the pressure side chamber R2 toward the tank 4. In addition, in this embodiment, the pressure side damping valve 9 opens when the pressure in the pressure side chamber R2 on the upstream side is higher than the pressure in the tank 4 on the downstream side and the difference between the two reaches the valve opening pressure. It is a pressure regulating valve that opens the damping passage 7 and communicates the pressure side chamber R2 with the tank 4. The pressure-side damping valve 9, which is a pressure regulating valve, opens when the valve opening pressure is reached, and as the passing flow rate increases after the valve is opened, the pressure loss increases at a higher rate than the above-mentioned valve V. As the flow rate increases, the upstream pressure increases to increase the damping force. Further, the opening pressure of the pressure-side damping valve 9 is set to a slightly larger pressure value than the opening pressure of the valve V.

The suction passage 8 connects the compression side chamber R2 to the tank 4, and a check valve 10 is provided in the suction passage 8 to allow only the flow of liquid from the tank 4 to the compression side chamber R2. The suction passage 8 is set as a one-way passage by the check valve 10 to allow only the flow of hydraulic oil from the tank 4 to the compression side chamber R2. The check valve 10 allows the hydraulic oil to pass with almost no resistance. When the damper D extends, hydraulic oil is supplied from the tank 4 to the cylinder 1 via the suction passage 8, and volume compensation is performed when the damper D extends.

The rod guide 14 is provided with a growth side relief passage 11 that communicates the growth side chamber R1 and the tank 4, and a growth side relief valve 12 provided in the growth side relief passage 11. The growth side relief valve 12 opens to open the growth side relief passage 11 when the pressure in the growth side chamber R1 is higher than the pressure in the tank 4 and the difference between the pressure in the growth side chamber R1 and the pressure in the tank 4 exceeds a predetermined pressure. The hydraulic oil is allowed to pass from the expansion side chamber R1 to the tank 4. The growth side relief valve 12 is activated when the pressure in the growth side chamber R1 is higher than the pressure in the tank 4 but the difference between the pressure in the growth side chamber R1 and the pressure in the tank 4 is less than a predetermined pressure, and when the pressure in the growth side chamber R1 is higher than the pressure in the tank 4. If the pressure is lower than 4, the valve is closed to block the expansion side relief passage 11 and prevent passage of hydraulic oil. In this way, the growth side relief valve 12 opens when the difference between the pressure in the growth side chamber R1 and the pressure in the tank 4 (valve opening pressure) becomes a predetermined pressure or more, and the pressure in the growth side chamber R1 is set in advance. Do not exceed the upper limit.

The operation of the damper D configured as above will be explained. First, the operation of the damper D when the damper D is extended will be explained. When the damper D is extended, the piston 3 moves inside the cylinder 1 to the left in FIG. 1 to compress the expansion side chamber R1 and expand the compression side chamber R2. The compressed hydraulic oil in the growth side chamber R1 pushes open the growth side damping valve 6, passes through the growth side damping passage 5, and moves to the compression side chamber R2. When the damper D is extended, the piston rod 2 withdraws from the cylinder 1, so there is a shortage of hydraulic oil in the pressure side chamber R2 for the volume of the piston rod 2 withdrawing from the cylinder 1. is supplied from the tank 4 to the pressure side chamber R2 via the suction passage 8 when the check valve 10 opens.

Therefore, the pressure in the compression side chamber R2 becomes approximately equal to the pressure in the tank 4, while the pressure in the expansion side chamber R1 becomes higher than the pressure in the compression side chamber R2 due to the expansion side damping valve 6. The high pressure of the expansion side chamber R1 acts on the left end surface of the piston 3 in FIG. 1, and the tank pressure acts on the right end surface of the piston 3 in FIG. 1, a damping force that prevents the damper D from moving to the left, that is, a damping force that prevents the damper D from extending. When the damper D expands at a very high speed and the pressure in the growth side chamber R1 reaches a predetermined pressure, which is the opening pressure of the growth side relief valve 12, the growth side relief valve 12 opens and the pressure in the growth side chamber R1 decreases. This suppresses the rise and prevents the damping force generated when the damper D is extended from becoming excessive.

Subsequently, when the damper D performs a contraction operation, the piston 3 moves to the right in FIG. 1 within the cylinder 1 to compress the compression side chamber R2 and expand the expansion side chamber R1. In a state where the difference between the pressure in the compression side chamber R2 to be compressed and the pressure in the expansion side chamber R1 to be expanded does not reach the opening pressure of the valve V, the valve V and the compression side damping valve 9 remain closed, and the compression The pressure in the expanded compression side chamber R2 increases, and the pressure in the expanded expansion side chamber R1 decreases.

When the contraction operation of the damper D progresses and the difference between the pressure in the compression side chamber R2 and the pressure in the expansion side chamber R1 becomes equal to or higher than the opening pressure of the valve V, the valve V opens and a relief is formed in the valve hole 3a. The hydraulic oil in the compression side chamber R2 comes to move into the expansion side chamber R1 via the passage. Note that the compression side damping valve 9 maintains a closed state.

Furthermore, when the contraction operation of the damper D progresses and the difference between the pressure in the compression side chamber R2 and the pressure in the tank 4 exceeds the opening pressure of the compression side damping valve 9, the compression side damping valve 9 opens and a volume of hydraulic oil corresponding to the volume of the piston rod 2 entering the cylinder 1 through the compression side damping passage 7 is discharged from the compression side chamber R2 to the tank 4.

The movement distance of the piston 3 relative to the cylinder 1 from the beginning of the contraction operation of the damper D to the opening of the compression side damping valve 9 is extremely small, but when the damper D is retracted, the movement distance of the piston 3 with respect to the cylinder 1 is extremely small. Subsequently, the pressure side damping valve 9 opens. In this way, the valve V opens when the difference between the pressure in the pressure side chamber R2 and the pressure in the growth side chamber R1 (valve opening pressure) exceeds a predetermined pressure, and the pressure in the pressure side chamber R2 is set at a preset upper limit. Do not exceed.

In this way, when the damper D is contracted, the hydraulic oil opens the valve V and moves from the pressure side chamber R2 to the expansion side chamber R1, but the valve V is located between the valve body 20 and the spring receiver 21 in the dashpot chamber 23. Since the movement of the valve body 20 in the axial direction with respect to the piston 3 can be suppressed, it is possible to suppress the sudden opening of the valve V and a sudden change in the damping force. In addition, in the damper D, by providing the dashpot chamber 23, the movement of the valve body 20 in the axial direction with respect to the piston 3 can be suppressed, so that the valve V is suddenly opened and the pressure in the pressure side chamber R2 is suddenly reduced. The pressure is lowered below the opening pressure of the valve V, the valve V immediately closes, and the pressure in the pressure side chamber R2 rises again than the valve opening pressure to open the valve V. This operation is repeated, and the pressure side is closed. It is possible to prevent pressure fluctuations in the chamber R2 from becoming vibratory. Therefore, vibration of the valve body 20 in the valve V can be suppressed, and vibrational changes in the magnitude of the damping force of the damper D can be prevented.

As described above, the valve V of this embodiment comprises a hollow piston (housing) 3 having an annular valve seat 3b on its inner circumference, a valve body 20 housed within the piston (housing) 3 so as to be movable in the axial direction and capable of being seated on and removed from the annular valve seat 3b, a spring retainer 21 provided within the piston (housing) 3, a spring 22 interposed between the valve body 20 and the spring retainer 21 for biasing the valve body 20 in a direction in which the valve body 20 is seated on the annular valve seat 3b, and a spring 22 for biasing the valve body 20 in the axial direction. The dashpot chamber 23 increases or decreases the volume by movement, suppressing the movement of the valve body 20. The valve body 20 has a valve portion 24 that has a seating portion 24c that seats and releases from the annular valve seat 3b and is restricted from moving radially relative to the piston (housing) 3, and a spring bearing portion 25 that has a valve body side spring bearing 25a that supports one end of the spring 22 and is allowed to move radially relative to the valve portion 24 while abutting against it. The dashpot chamber 23 is formed between the spring bearing portion 25 and the spring bearing 21.

The valve V thus constructed includes a dashpot chamber 23, which provides resistance to the axial movement of the valve body 20 relative to the piston 3, thereby suppressing sudden displacement and vibration of the valve body 20. The valve V of this embodiment is composed of two parts: a valve portion 24 in which the valve body 20 is seated on and released from the annular valve seat 3b and whose radial movement is restricted by the piston 3 as a housing, and a spring receiving portion 25 that is allowed to move radially relative to the valve portion 24 and supports one end of the spring 22. Therefore, even if the valve portion 24 is aligned with the piston 3 as a housing, the spring receiving portion 25 can move radially relative to the valve portion 24, so that the spring receiving portion 25 can be aligned by the spring receiving portion 21 without being restricted by the valve portion 24 that is aligned with the piston 3. Therefore, with the valve V of this embodiment, there is no longer the restriction that the valve body must be concentrically positioned with both the housing and the case that forms the dashpot chamber, as in conventional valves, so high machining precision is not required for the valve body 20, piston (housing) 3, and spring retainer 21, and the valve V can be easily assembled even if there is a large dimensional error.

In the valve V of this embodiment, the valve seat is annular valve seat 3b, and the seating portion 24c that seats and leaves the annular valve seat 3b is annular, but the valve seat and seating portion 24c are not limited to being annular, and may have any shape that is created when the valve seat seats on the seating portion 24c.

Further, in the valve V of this embodiment, one of the valve portion 24 and the spring receiving portion 25 has a convex protruding in the axial direction from the abutting end that abuts the other of the valve portion 24 and the spring receiving portion 25. The other of the valve part 24 and the spring receiving part 25 opens at the abutting end that contacts one of the valve part 24 and the spring receiving part 25, so that the convex part 25e can move in the radial direction. It has a recess 24d into which it is inserted. In the valve V of this embodiment, by inserting the convex portion 25e into the concave portion 24d when assembling the valve body 20 of the valve V, the spring receiving portion 25 can be positioned to some extent in the radial direction with respect to the valve portion 24. This makes it easier to assemble the valve V.

In the valve V of this embodiment, the spring 22 is a coil spring, the spring receiver 21 protrudes toward the valve body 20, and has a case 21b disposed on the inner circumferential side of the spring 22. The spring receiving portion 25 in the body 20 has a rod 25d that is inserted into the case 21b so as to be movable in the axial direction, and the dashpot chamber 23 is formed by the case 21b and the rod 25d. According to the valve V configured in this way, the dashpot chamber 23 is provided inside the spring 22, so even if the dashpot chamber 23 is provided, the spring receiving portion 25 of the valve body 20 can be made small. The inertia of the valve body 20 can be reduced to improve valve opening responsiveness.

As in the first modified valve V1 of the embodiment shown in FIG. 4, the case 26b may be provided on the spring receiving portion 26 and brought into sliding contact with the inner circumference of the large diameter portion 3a2 of the valve hole 3a to form the dashpot chamber 23. In the first modified valve V1, the valve body 20 is composed of two parts: a valve portion 24 having the same configuration as the valve V, and a spring receiving portion 26 that abuts against the valve portion 24.

The spring bearing portion 26 includes a disk-shaped valve body side spring bearing 26a that abuts against the end face of the flange 24b of the valve portion 24 on the opposite tip side, a cylindrical case 26b that protrudes in the axial direction from the outer periphery of the left end of the valve body side spring bearing 26a in FIG. 4 and is disposed on the outer periphery of the spring 22 and faces the inner periphery of the large diameter portion 3a2 of the valve hole 3a via an annular gap, and a protrusion 26c that is provided in the center of the valve portion side end of the valve body side spring bearing 26a and protrudes in the axial direction toward the valve portion 24. The axial length of the protrusion 26c is shorter than the axial length of the recess 24d, so that the entire protrusion 26c can be inserted into the recess 24d. Therefore, when the valve body side spring receiver 26a of the spring receiver 26 faces the flange 24b of the valve portion 24 and the protrusion 26c is inserted into the recess 24d, the end face of the valve body side spring receiver 26a comes into contact with the end face of the spring receiver side of the flange 24b. In addition, since the outer diameter of the protrusion 26c is smaller than the inner diameter of the recess 24d, the protrusion 26c can be inserted into the recess 24d so as to be movable in the radial direction, and the spring receiver 26 can be displaced in the radial direction with respect to the valve portion 24 with the spring receiver 26 and the valve portion 24 in contact by the gap formed between the outer periphery of the protrusion 26c and the inner periphery of the recess 24d. In this way, the valve portion 24 and the spring receiver 26 are allowed to move in the radial direction with respect to each other, although there is a restriction due to the protrusion 26c and the recess 24d.

The spring bearing 27 is cylindrical and has a screw portion 27a with a screw groove on its outer periphery that screws into the screw portion 3a21 provided on the left end side of the large diameter portion 3a2 of the valve hole 3a of the piston 3 in FIG. 4, and a fitting protrusion 27b that protrudes axially from the right end of the screw portion 27a toward the valve body 20 in FIG. 4 and fits into the inner periphery of the spring 22. When the spring bearing 27 is screwed into the large diameter portion 3a2 of the valve hole 3a, it closes the opening of the valve hole 3a on the expansion side chamber side.

The spring 22 is compressed and interposed between the valve body side spring receiver 26a and the spring receiver 27 of the spring receiver 26 of the valve body 20, and biases the valve body 20 toward the annular valve seat 3b. The right end of the spring 22 in FIG. 4 is inserted into the case 26b of the spring receiver 26 and supported by the valve body side spring receiver 26a. The inner diameter of the inner circumference of the case 26b on the valve body side spring receiver side is smaller than the other parts of the inner circumference of the case 26b, and the outer circumference of the right end of the spring 22 in FIG. 4 is fitted into the small diameter part of the inner circumference of the case 26b. Furthermore, the fitting protrusion 27b of the spring receiver 27 is fitted into the inner circumference of the left end of the spring 22 in FIG. 4. The case 26b is arranged on the outer circumference side of the spring 22, so that interference with the inner circumference of the large diameter part 3a2 of the spring 22 is prevented. The spring 22 may be interposed between the spring bearing 27 and the end of the case 26b, and may be a spring other than a coil spring as long as it does not block the restricted flow path.

As described above, since the valve body 20 is provided with the spring receiving part 26 including the case 26b, the inside of the case 26b passes through the restricted flow path formed between the case 26b and the large diameter part 3a2 of the valve hole 3a, and the outside of the case 26b. The interior of the case 26b is closed by the spring receiver 27 attached to the valve hole 3a, except for communication with the valve hole 3a, and a dashpot chamber 28 is formed between the spring receiver 26 and the spring receiver 27.

The valve V1 in this embodiment is composed of two parts: a valve portion 24 in which the valve body 20 is seated on and off the annular valve seat 3b and whose radial movement is restricted by the piston 3 as a housing; and a spring receiving portion 26 which is allowed to move radially relative to the valve portion 24 and supports one end of the spring 22. Therefore, even if the valve portion 24 is aligned with the small diameter portion 3a1 in the valve hole 3a of the piston 3 which is the housing, the spring receiving portion 26 can move radially relative to the valve portion 24, and therefore the spring receiving portion 26 can be aligned with the large diameter portion 3a2 in the valve hole 3a of the piston 3 without being restrained by the valve portion 24 which is aligned with the small diameter portion 3a1. Thus, according to the valve V1 of this embodiment, even if the valve portion 24 and the spring receiving portion 26 of the valve body 20 are separately aligned by different parts of the piston 3, which is the housing, the spring receiving portion 26 can move radially relative to the valve portion 24, eliminating the restriction that the valve body must be concentrically positioned with both the housing and the case that forms the dashpot chamber, as in conventional valves. Therefore, according to the valve V1 of the first modified example, high machining precision is not required for the valve body 20 and the piston (housing) 3, and the valve V can be easily assembled even if there is a large dimensional error.

In the valve V1, the valve body 20 is provided with a case 26b, and a restricted flow path is provided between the large diameter portion 3a2 of the valve hole 3a and the case 26b, so it is difficult to ensure a flow path area for the large diameter portion 3a2 of the valve hole 3a as a relief path. Therefore, a port 3c that opens from the inner circumference of the piston 3 to the large diameter portion 3a2, a groove 3d provided at the end of the piston 3 on the side of the extension side chamber, and a piston rod passage 2a provided in the piston rod 2 that communicates the port 3c and the groove 3d are provided to ensure communication between the compression side chamber R2 and the extension side chamber R1 through the valve hole 3a. Note that if there is space only in the piston 3 to provide a passage that communicates the large diameter portion 3a2 of the valve hole 3a with the extension side chamber R1, the piston rod passage 2a does not need to be provided in the piston rod 2.

In addition, if it is desired to guide the axial movement of the spring bearing portion 26 by the inner circumference of the large diameter portion 3a2 of the valve hole 3a, the outer circumference of the case 26b may be brought into sliding contact with the inner circumference of the large diameter portion 3a2, and a groove may be provided on the outer circumference of the case 26b or the inner circumference of the large diameter portion 3a2 to function as a restricting flow path that connects the dashpot chamber 28 to the outside of the case 26b, or a hole may be provided in the spring bearing 27 to function as a restricting flow path that connects the dashpot chamber 28 to the extension side chamber R1.

Although the preferred embodiments of the present invention have been described in detail above, modifications, variations, and changes can be made without departing from the scope of the claims.

3... Piston (housing), 3b... Annular valve seat, 20... Valve body, 21, 27... Spring receiver, 22... Spring, 23, 28... Dashpot chamber, 24 ...Valve part, 24c...Seating part, 24d...Concave part, 25, 26...Spring receiver part, 25a, 26a...Valve body side spring receiver, 25e, 26c...Convex part, V , V1... valve

Claims (2)

a hollow housing having a valve seat on its inner periphery;
a valve body accommodated within the housing so as to be axially movable and seated on and separated from the valve seat;
A spring bearing provided in the housing;
a spring interposed between the valve body and the spring bearing for biasing the valve body in a direction to seat on the valve seat;
a dashpot chamber whose volume is increased or decreased by axial movement of the valve disc to suppress movement of the valve disc,
the valve body has a valve portion having a seat portion which seats on and separates from the valve seat and is restricted in its radial movement with respect to the housing, and a spring bearing portion which has a valve body side spring bearing which supports one end of the spring and is allowed to move radially with respect to the valve portion and abuts against the valve body,
The dashpot chamber is formed between the spring receiving portion and the spring receiving portion. One of the valve part and the spring receiving part has a convex part that projects in the axial direction from a contact end that contacts the other of the valve part and the spring receiving part,
The other of the valve part and the spring receiving part has a recess that opens at a contact end that contacts one of the valve part and the spring receiving part and into which the convex part is inserted so as to be movable in a radial direction. The valve according to claim 1, characterized in that:

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