JP2025094969A - Valve and Cylinder Devices - Google Patents

Abstract

To provide a valve and a cylinder device suitable for the use of the valve which applies resistance to one flow and does not apply resistance to the other flow at the time of opening the valve without increasing the number of components and costs.SOLUTION: A valve V of the present invention includes: a valve sea member 20 having an annular valve seat 20d; a valve body 21 having an annular seat part 21b which can be seated to and removed from the valve seat 20d; a coil spring (urging member) 22 that urges the valve body 21 against the valve seat member 20; and a restriction flow path Pr formed in a state where the valve body 21 is inserted into the valve seam member 20. In a valve-opening state where the seat part 21b is away from the valve seat 20d, the valve body 21 is released from the valve seat member 20 to be fully opened in a flow from the valve seat member side to the valve body side, and in a flow from the valve seat side to the valve seat member side, a resistance is applied by the restriction flow path Pr in a state where at least a part of the valve body 21 is inserted into the valve seat member 20.SELECTED DRAWING: Figure 3

Description

The present invention relates to a valve and cylinder device.

Valves are used, for example, in cylinder devices such as shock absorbers and gas springs, and are installed in passages that connect working chambers in the cylinder devices to each other or to a tank that stores liquid.

For example, such a valve includes a valve seat, a valve body that can be seated on and removed from the valve seat, a spring that urges the valve body in the direction of seating on the valve seat, and a spool that uses hydraulic pressure to move the valve body away from the valve seat against the urging force of the spring; when the valve body is pushed by the spool and moves away from the valve seat to open, the working chamber is connected to the tank (see, for example, Patent Document 1).

JP 2021-134906 A

Conventional valves connect the working chambers or the working chambers to the tank when open, but provide almost no resistance to the flow of liquid regardless of the direction of the liquid flow. Therefore, conventional valves cannot provide resistance according to the direction of the liquid flow passing through the valve when open.

On the other hand, depending on the cylinder device, there may be cases where it is desired to make the operation slower during either the extension or contraction operation, while making the operation quicker during the other operation. To achieve this, it is necessary to provide resistance to the flow of liquid from the working chamber to the tank, and not provide resistance to the flow of liquid from the tank to the working chamber. However, conventional valves cannot provide resistance according to the direction of the liquid passing through the valve when the valve is open, so it is necessary to provide a valve that provides resistance to the flow of liquid from the working chamber to the tank in parallel with the conventional valve, which increases the number of parts and costs.

The present invention aims to provide a valve that provides resistance to flow in one direction but not the other when open, without increasing the number of parts or costs, and a cylinder device suitable for use with the valve.

In order to solve the above problems, the valve of the present invention comprises a cylindrical valve seat member having an annular valve seat at one axial end, a valve body having an annular seat portion that can be seated on and removed from the valve seat, a biasing member that biases the valve body toward the valve seat member, and a restricting flow path that is formed when the valve body is inserted into the valve seat member. When the seat portion separates from the valve seat and the valve is opened, the entire valve body leaves the valve seat member and is fully open against the flow from the valve seat member side to the valve body side, and the restricting flow path provides resistance against the flow from the valve body side to the valve seat member side with at least a part of the valve body inserted into the valve seat member.

A valve constructed in this way can function independently as a check valve to prevent liquid flow in one direction, and as a valve that provides resistance to liquid flow in the other direction.

The valve element in the valve may have a head that can move in and out of the valve seat member, and the restricted flow path in the valve may be formed by an annular gap between the outer periphery of the head of the valve element and the inner periphery of the valve seat member. With a valve configured in this way, an annular gap is formed between the head and the valve seat member, so they do not come into contact with each other. Therefore, when the valve element moves axially relative to the valve seat member to move in and out of the valve seat member of the head, the head does not interfere with the valve seat member, allowing the valve to be opened and closed smoothly.

The valve may further comprise an aligning member that aligns the valve disc with respect to the valve seat member while allowing the valve disc to move in the axial direction. With a valve thus equipped with an aligning member that aligns the valve disc, the valve disc can move in the axial direction without axial wobble when the head of the valve disc moves in and out of the valve seat member, so there is no risk of the head scraping the inner peripheral surface of the valve seat member, and smooth axial movement of the valve disc is ensured, allowing the valve to be opened and closed smoothly.

The cylinder device includes a cylinder, a piston movably inserted into the cylinder and dividing the cylinder into an extension side chamber and a compression side chamber, and a rod movably inserted into the cylinder and connected to the piston. One of the extension side chamber and the compression side chamber is open to the atmosphere, and the other of the extension side chamber and the compression side chamber is filled with liquid. The cylinder device includes a tank divided into an air chamber and a liquid chamber, a communication passage that connects the liquid chamber to the other of the extension side chamber and the compression side chamber, and a valve provided in the communication passage. With the cylinder device configured in this way, it is possible to slow down either the extension or contraction operation, and it is possible to give polarity to the operation speed depending on the operation direction, and since only one valve is required, it is possible to suppress an increase in the number of parts and costs.

The cylinder device may be used with the telescopic body spanning the body of the saddle-riding vehicle and a swing arm that can swing relative to the body of the saddle-riding vehicle and holds the rear wheel. With a cylinder device configured in this way, the vehicle height of the rear wheel side of the saddle-riding vehicle can be adjusted by opening and closing the valve.

Furthermore, the cylinder device may be such that the compression side chamber is open to the atmosphere, the extension side chamber is filled with liquid, and the valve is installed in a communication passage with the valve body facing the extension side chamber and the valve seat member facing the liquid chamber, so that the flow of liquid is resisted by the restricted flow passage when the telescopic body is extended, and is fully open when the telescopic body is contracted. With a cylinder device configured in this way, when the vehicle height of the rear wheel side is lowered during acceleration of a saddle-type vehicle, the valve is operated to open, and the valve provides resistance to the flow of liquid when the vehicle height is lowered by lowering the rear wheel side during acceleration of the saddle-type vehicle, reducing the speed at which the vehicle height falls and improving handling stability. When the vehicle height rises during braking, the valve does not provide resistance to the flow of liquid, and the telescopic body quickly contracts, quickly raising the vehicle height, improving vehicle stability during braking.

The valve of the present invention can function as a valve that provides resistance to flow in one direction when open, and does not provide resistance to flow in the other direction, without increasing the number of parts or costs. In addition, the cylinder device is optimal for use with the valve.

FIG. 2 is a cross-sectional view of a cylinder device according to the embodiment. 1 is a side view of a saddle-type vehicle equipped with a cylinder device according to an embodiment. FIG. 2 is an enlarged cross-sectional view of a valve according to one embodiment. FIG. 4 is a partially enlarged cross-sectional view of a valve according to a first modified example of the embodiment. FIG. 11 is a partially enlarged cross-sectional view of a valve according to a second modified example of the embodiment.

The present invention will be described based on the embodiment shown in the figures. As shown in Figure 1, a cylinder device C equipped with a valve V in one embodiment includes a telescopic body 1, a tank 10, a communication passage 16 that connects the inside of the telescopic body 1 with the tank 10, and a valve V provided in the communication passage 16.

As shown in FIG. 2, the telescopic body 1 in the cylinder device C is spanned between the lower end of the shock absorber D interposed between the body B and the wheel W of the saddle-riding vehicle M, a link plate P rotatably connected to the body B of the saddle-riding vehicle M, and a swing arm S that can swing relative to the body B of the saddle-riding vehicle M and holds the wheel W.

The shock absorber D is a telescopic shock absorber, and although not shown in detail, it is equipped with a cylinder and a rod that can enter and exit the cylinder, and exerts a damping force that prevents the shock absorber itself from expanding and contracting when the rod moves axially relative to the cylinder. The upper end of the shock absorber D is attached to the vehicle body B so as to be rotatable in the fore-and-aft direction of the vehicle body B, and the lower end of the shock absorber D is attached to the link plate P so as to be rotatable in the fore-and-aft direction of the vehicle body B. The link plate P has a triangular shape, and the vicinity of each vertex is hinged to the vehicle body B, the lower end of the shock absorber D, and one end of the telescopic body 1, respectively. Specifically, the front connection point of the link plate P is hinged to the vehicle body B, the rear connection point of the link plate P is hinged to the lower end of the shock absorber D, and the central connection point of the link plate P is hinged to one end of the telescopic body 1. The front end of the swing arm S is hinged to the vehicle body B so as to be rotatable in the vertical direction, and the rear end holds a wheel W so as to be rotatable, so that the swing arm S can swing in the vertical direction relative to the vehicle body B. The other end of the telescopic body 1 is hinged to the middle part of the swing arm S.

Therefore, when the telescopic body 1 is rod-shaped and does not extend or retract, if the swing arm S rotates upward in FIG. 2 relative to the vehicle body B and the wheel W approaches the vehicle body B, the link plate P rotates upward relative to the vehicle body B and compresses the shock absorber D, so the movement of the wheel W relative to the vehicle body B is suppressed by the damping force generated by the shock absorber D. Also, when the telescopic body 1 is rod-shaped and does not extend or retract, if the swing arm S rotates downward in FIG. 2 relative to the vehicle body B and the wheel W approaches the vehicle body B, the link plate P rotates downward relative to the vehicle body B and expands the shock absorber D, so the movement of the wheel W relative to the vehicle body B is suppressed by the damping force generated by the shock absorber D. Therefore, the shock absorber D suppresses the relative movement between the wheel W and the vehicle body B due to vibrations input while the saddle-type vehicle M is traveling, improving the ride comfort of the vehicle.

In contrast, when the cylinder device C extends the telescopic body 1, it rotates the swing arm S toward the upper side in FIG. 2 around the connection point to the vehicle body B as a fulcrum, so that the wheel W approaches the vehicle body B and the vehicle height of the saddle-type vehicle M is lowered, and when the telescopic body 1 is contracted, it rotates the swing arm S toward the lower side in FIG. 2 around the connection point to the vehicle body B as a fulcrum, so that the wheel W moves away from the vehicle body B and the vehicle height of the saddle-type vehicle M is raised.

The valve V and the cylinder device C will be described in detail below. The telescopic body 1 includes a cylinder 2, a piston 3 that is movably inserted into the cylinder 2 and divides the inside of the cylinder 2 into an extension side chamber R1 and a compression side chamber R2, and a rod 4 that is movably inserted into the cylinder 2 and connected to the piston 3.

As shown in FIG. 1, the cylinder 2 is a cylindrical shape with a bottom, and has an eye-shaped bracket 2b at the bottom 2a that is hinged to the link plate P, and an annular rod guide 5 is attached to the open end at the right end in FIG. 1. The piston 3 has an annular seal ring 3a and an annular piston ring 3b on its outer periphery that slide against the inner periphery of the cylinder 2, dividing the inside of the cylinder 2 into an expansion side chamber R1 and a compression side chamber R2, and can move smoothly inside the cylinder 2 in the axial direction, which is the left-right direction in FIG. 1.

The rod 4 is inserted into the cylinder 2 by being inserted through the inner circumference of the rod guide 5, with its tip end (left end in FIG. 1) connected to the piston 3 and its base end (right end in FIG. 1) protruding outside the cylinder 2. The cylinder 2 is provided with a hole 2c that connects the compression side chamber R2 on the left side of the piston 3 inside the cylinder 2 to the outside of the cylinder 2, and the compression side chamber R2 is open to the atmosphere. In addition, a connection hole 2d is provided on the side of the open end of the cylinder 2 to which a joint 6 facing the extension side chamber R1 is attached.

The tank 10 is composed of a bottomed, cylindrical tank body 11 with a bottom 11a, a cap 12 that closes the open end of the tank body 11, and a free piston 13 that is housed within the tank body 11 and can move axially to divide the inside of the tank body 11 into a liquid chamber L on the bottom side and an air chamber G on the open side.

The tank body 11 has a valve hole 11b that penetrates the bottom 11a in the vertical direction in FIG. 1, which is a direction perpendicular to the axial direction, and a port 11c that connects the inside of the valve hole 11b to the liquid chamber L. As shown in FIG. 3, the inner diameter of the valve hole 11b is smaller on the lower side, and a step 11b1 is provided below the port 11c in FIG. 3.

A joint 14 is attached to the open end at the lower end of the valve hole 11b, connecting the pipe 15 to the tank body 11. One end of the pipe 15 is connected to the cylinder 2 via a joint 6, and the other end is connected to the tank 10 via a joint 14, connecting the expansion-side chamber R1 to the valve hole 11b. In this manner, in this embodiment, the pipe 15, the valve hole 11b, and the port 11c form a communication passage 16 that connects the expansion-side chamber R1 to the liquid chamber L of the tank 10.

The cap 12 includes a cylindrical mounting portion 12a that is screwed to the inner circumference of the right end of the tank body 11 in FIG. 1, a cylindrical valve case 12b that is arranged on the inner circumference of the mounting portion 12a, an annular lid portion 12c that connects the right ends of the mounting portion 12a and the valve case 12b in FIG. 1, and an air valve 12d that is attached to the inner circumference of the valve case 12b and allows gas to be injected into the air chamber G from the outside, and closes the open end of the tank body 11.

The mounting portion 12a has a seal ring 12e on its outer periphery and a screw portion 12f provided to the right of the seal ring 12e in FIG. 1. When the cap 12 is inserted into the inner periphery of the open end of the tank body 11 and screwed to the tank body 11 using the screw portion 12f, the seal ring 12e is brought into close contact with the inner periphery of the tank body 11, sealing the tank 10 and preventing gas from leaking from the tank 10.

The free piston 13 is housed in the tank body 11 so as to be movable in the axial direction, dividing the tank body 11 into a liquid chamber L and an air chamber G, and transmits the pressure in the air chamber G to the liquid chamber L. Compressed gas is sealed in the air chamber G, and the pressure in the air chamber G is always equal to or higher than atmospheric pressure.

The valve V is accommodated in the valve hole 11b of the tank body 11. In this embodiment, as shown in FIG. 3, the valve V includes a valve seat member 20 accommodated in the valve hole 11b, a valve body 21 that can be seated on and removed from the valve seat member 20, a coil spring 22 as a biasing member that biases the valve body 21 toward the valve seat member 20, an alignment member 23 that aligns the valve body 21, a push rod 24 that, when operated externally, presses the valve body 21 against the biasing force of the coil spring 22 to separate the valve body 21 from the valve seat member 20, and an annular nut member 25 that is screwed to the open end of the valve hole 11b at the upper end in FIG. 3.

The valve seat member 20 is cylindrical and has a large diameter portion 20a with a large outer diameter that fits into the valve hole 11b, a small diameter portion 20b with a small outer diameter on the lower side of the large diameter portion 20a in FIG. 3, and a hole 20c that penetrates the large diameter portion 20a in the radial direction, and the valve seat 20d is formed by the annular lower end surface of the lower end of the small diameter portion 20b, which is one end in the axial direction. In addition, a seal ring 20e is attached to the outer periphery of the large diameter portion 20a and above the hole 20c in FIG. 3, which seals between the valve seat member 20 and the tank body 11 by coming into close contact with the wall surface that forms the valve hole 11b of the tank body 11 when the valve seat member 20 is accommodated in the valve hole 11b.

The aligning member 23 is cylindrical and includes a fitting portion 23a that fits around the outer periphery of the small diameter portion 20b of the valve seat member 20 and into the valve hole 11b, a housing tube 23b that extends axially from the lower end of the fitting portion 23a in FIG. 3, has an outer diameter smaller than that of the fitting portion 23a, and houses the valve body 21 and the coil spring 22 inside, and an aligning portion 23c that is provided in the shape of a brim from the lower end of the housing tube 23b in FIG. 3 toward the inner periphery.

The aligning member 23 is inserted into the valve hole 11b until the outer periphery of the lower end of the fitting portion 23a in FIG. 3 abuts against the step 11b1 in the valve hole 11b. When the valve seat member 20 is accommodated in the valve hole 11b with the small diameter portion 20b of the valve seat member 20 fitted into the inner periphery of the fitting portion 23a of the aligning member 23 and the step portion of the outer periphery at the boundary between the large diameter portion 20a and the small diameter portion 20b abutting against the upper end of the fitting portion 23a in FIG. 3, the port 11c and the hole 20c of the tank body 11 face each other, and the inside of the valve seat member 20 communicates with the liquid chamber L of the tank 10.

The housing tube 23b has a stopper 23b1, which is an annular step formed on the inner circumference by reducing the inner diameter on the lower side in FIG. 3, and a hole 23b2 that penetrates radially above the stopper 23b1 in FIG. 3. The outer diameter of the housing tube 23b is smaller than the inner diameter of the valve hole 11b below the step 11b1 in FIG. 3. Therefore, when the aligning member 23 is accommodated in the valve hole 11b as described above, an annular gap is formed between the housing tube 23b and the wall surface of the valve hole 11b. The inside of the aligning member 23 is connected to the liquid chamber L through the valve seat member 20, and is connected to the expansion side chamber R1 through the hole 23b2, the valve hole 11b, and the piping 15.

The inner diameter of the housing tube 23b is slightly smaller than the outer diameter of the small diameter portion 20b of the valve seat member 20, but can be set arbitrarily as long as it does not interfere with the movement of the valve body 21 described below and its seating on and off the valve seat 20d.

The valve body 21 has a cylindrical head 21a that can move in and out of the small diameter portion 20b of the valve seat member 20, an annular seat portion 21b that is connected to the rear of the head 21a at the bottom in FIG. 3 and can be seated on and removed from the valve seat 20d, a cylindrical spring fitting portion 21c that extends from the bottom of the seat portion 21b in FIG. 3, and a cylindrical shaft portion 21d that extends from the bottom end of the spring fitting portion 21c in FIG. 3, has an outer diameter smaller than that of the spring fitting portion 21c, and slides against the inner circumference of the alignment portion 23c of the alignment member 23.

The outer diameter of the head 21a is smaller than the inner diameter of the small diameter portion 20b, and when the head 21a is inserted into the small diameter portion 20b, the valve body 21 forms a restricted flow path Pr in the annular gap between the outer periphery of the head 21a and the inner periphery of the small diameter portion 20b.

The seat portion 21b has an outer diameter larger than the outer diameter of the head portion 21a and the inner diameter of the valve seat 20d, and has a tapered surface in which the outer diameter decreases toward the top in FIG. 3, and the tapered surface faces the valve seat 20d. The outer diameter of the seat portion 21b is also larger than the inner diameter of the stopper 23b1 of the storage tube 23b, and is smaller than the inner diameter of the stopper 23b1 of the storage tube 23b above the stopper 23b1 in FIG. 3.

Therefore, the valve body 21 can move in the axial direction, which is the vertical direction in FIG. 3, while being accommodated in the accommodation tube 23b, and when the seat portion 21b is seated on the valve seat 20d, the tapered surface abuts against the inner peripheral edge of the valve seat 20d, and the valve body 21 closes the communication passage 16. Also, when the valve body 21 moves downward in FIG. 3 from the position where the seat portion 21b is seated on the valve seat 20d and the lower end of the seat portion 21b in FIG. 3 abuts against the stopper 23b1, the entire head portion 21a is completely removed from the valve seat member 20, and the communication passage 16 is fully opened. In this state, the head portion 21a of the valve body 21 is completely removed from the small diameter portion 20b, so that no restrictive flow path Pr is formed between the valve body 21 and the valve seat member 20, and the valve V does not provide much resistance to the flow of liquid passing between the valve body 21 and the valve seat 20d.

Even if the seat portion 21b is separated from the valve seat 20d, if the head portion 21a is partially inserted into the small diameter portion 20b, the valve body 21 forms a restricted flow path Pr between itself and the valve seat member 20, providing resistance to the flow of liquid passing through the restricted flow path Pr.

The outer diameter of the spring fitting portion 21c is smaller than the inner diameter of the housing tube 23b, and forms an annular space between the spring fitting portion 21c and the housing tube 23b to accommodate the coil spring 22 as a biasing member, and fits around the inner circumference of the coil spring 22 to guide the expansion and contraction of the coil spring 22. The coil spring 22 is interposed between the lower end of the seat portion 21b in FIG. 3 and the upper end of the alignment portion 23c of the alignment member 23 in FIG. 3, and constantly biases the valve body 21 in a direction to seat it on the valve seat 20d. Therefore, when no external force is acting on the valve body 21, the valve body 21 is biased by the coil spring 22 and positioned at a position where it sits on the valve seat 20d. In addition, since the coil spring 22 is fitted into the spring fitting portion 21c, a stable biasing force can be applied to the valve body 21 without eccentricity.

The shaft portion 21d at the rear end of the valve body 21 is slidably inserted into the inner circumference of the alignment portion 23c of the alignment member 23, and the valve body 21 can move toward or away from the valve seat member 20, which is fitted into the fitting portion 23a of the alignment member 23, without axial deviation. Therefore, the head portion 21a of the valve body 21 can smoothly move in and out of the small diameter portion 20b of the valve seat member 20 without interfering with the small diameter portion 20b.

The push rod 24 is rod-shaped and includes a body 24a with a flange 24b that can abut against the end face of the large diameter portion 20a of the valve seat member 20 in the middle, and a pressing shaft 24c that extends axially from the lower end of the body 24a and faces the upper end of the head 21a of the valve body 21 in FIG. 3. The body 24a does not face the hole 20c even if it enters the large diameter portion 20a until the flange 24b abuts against the upper end of the large diameter portion 20a of the valve seat member 20 in FIG. 3, so that the hole 20c is not blocked. The pressing shaft 24c has an outer diameter sufficiently smaller than the outer diameter of the head 21a of the valve body 21 so as not to provide resistance when liquid passes between the pressing shaft 24c and the small diameter portion 20b when it enters the small diameter portion 20b.

When the push rod 24 enters the large diameter portion 20a of the valve seat member 20 until the flange 24b abuts against the upper end of the large diameter portion 20a in FIG. 3, it abuts against the head 21a of the valve body 21 and pushes the valve body 21 downward in FIG. 3, and the valve body 21 moves away from the valve seat 20d while leaving a part of the head 21a in the small diameter portion 20b.

The nut member 25 is cylindrical and has a threaded portion 25a on its outer periphery. It is screwed to the inner periphery of the upper end of the valve hole 11b in FIG. 3 and attached to the tank body 11. When the nut member 25 is attached to the valve hole 11b, it abuts against the outer periphery of the upper end of the large diameter portion 20a of the valve seat member 20 in FIG. 3, sandwiching the valve seat member 20 and the alignment member 23 together with the step portion 11b1 to fix the valve seat member 20 and the alignment member 23 in the valve hole 11b. The nut member 25 also has a flange 25b on its inner periphery that faces the flange 24b of the push rod 24 in the axial direction. Therefore, the push rod 24 can move in the axial direction, which is the up-down direction in FIG. 3, from the uppermost position where the flange 24b abuts against the flange 25b of the nut member 25 to the lowermost position where the flange 24b abuts against the upper end of the large diameter portion 20a of the valve seat member 20 in FIG. 3.

The push rod 24 is connected via a wire (not shown) to a lever switch (not shown) provided near the handle of the saddle riding vehicle M. When the driver of the saddle riding vehicle M operates the lever switch to push the push rod 24 downward in Fig. 3, the push rod 24 pushes the valve body 21 downward in Fig. 3 against the biasing force of the coil spring 22, the valve body 21 moves away from the valve seat 20d, and the valve V opens. When the driver of the saddle riding vehicle M operates the lever switch to move the push rod 24 upward in Fig. 3, the push rod 24 moves away from the valve body 21, and the valve body 21 is pushed upward in Fig. 3 by the biasing force of the coil spring 22 and seats on the valve seat 20d, closing the valve V. In this way, valve V is a normally closed valve that opens when valve body 21 is pushed by operating push rod 24, but closes when the pushing force of push rod 24 is not acting, with valve body 21 seated on valve seat 20d by the biasing force of coil spring 22.

The valve V and cylinder device C are configured as described above, and the operation of the valve V and cylinder device C will be described below. In the cylinder device C, as described above, the compression side chamber R2 is open to the atmosphere, and the extension side chamber R1 is connected to the liquid chamber L pressurized by the air chamber G of the tank 10 via the communication passage 16. When the push rod 24 in the valve V is not operated and the push rod 24 does not exert a force to separate the valve body 21 from the valve seat 20d, and the valve V is closed, the communication between the extension side chamber R1 and the liquid chamber L is cut off, and liquid cannot be exchanged between the extension side chamber R1 and the liquid chamber L. As a result, the cylinder device C cannot be extended or retracted, and becomes rod-shaped. On the other hand, when the push rod 24 in the valve V is operated to separate the valve body 21 from the valve seat 20d by the push rod 24 to open the valve V, the expansion side chamber R1 and the liquid chamber L are connected, allowing liquid to flow between the expansion side chamber R1 and the liquid chamber L, so that the cylinder device C is in an expandable and contractible state. Also, when the valve V is open, the compression side chamber R2 is open to the atmosphere, and the pressure of the air chamber G is transmitted to the expansion side chamber R1, pushing the piston 3 toward the compression side chamber R2. Therefore, the cylinder device C tries to contract while the valve V is open in a state where no external force is acting.

Based on the above, the operation of the cylinder device C applied to the saddle-type vehicle M will be explained. First, when the valve V is closed, the cylinder device C becomes rod-shaped and cannot be extended or retracted. Therefore, when the swing arm S swings in the vertical direction in FIG. 2 relative to the vehicle body B due to vibration input from the road surface while the saddle-type vehicle M is traveling, the cylinder device C transmits the swing of the swing arm S to the link plate P, so that the shock absorber D expands and contracts to generate a damping force, thereby suppressing the vibration of the vehicle body B.

On the other hand, when the valve V is opened, a force in the extension direction acts on the telescopic body 1 due to the weight of the vehicle body B, and the pressure in the extension side chamber R1 becomes greater than the pressure in the tank 10, so the cylinder device C extends to its maximum extent and liquid moves from the extension side chamber R1 to the liquid chamber L of the tank 10 via the communication passage 16 and the valve V. When the cylinder device C extends, the swing arm S rotates in a direction approaching the vehicle body B, shortening the vertical distance between the vehicle body B and the wheel W, and the vehicle height of the saddle-type vehicle M decreases by the amount of the shortened distance.

Here, when the valve V is opened, the push rod 24 separates the valve body 21 from the valve seat 20d, but does not allow the head 21a to completely come out from inside the small diameter portion 20b of the valve seat member 20, so that a restricted flow path Pr is formed between the head 21a and the small diameter portion 20b. When the cylinder device C extends and liquid flows from the extension side chamber R1 to the liquid chamber L, the high-pressure liquid pressed by the piston 3 passes between the valve body 21 and the valve seat 20d from the valve body 21 side to the valve seat member 20 side and moves to the low-pressure side liquid chamber L. Therefore, if the side facing the valve seat 20d is the front side and the opposite side is the back side, the valve body 21 is pressed against the valve seat 20d side by the pressure of the extension side chamber R1, which is high pressure on the back side, and the valve body 21 does not move from the position pushed by the push rod 24, and the head 21a is maintained in a state in which it has entered the small diameter portion 20b. Therefore, the liquid flowing from the expansion-side chamber R1 to the liquid chamber L passes through the restrictor flow path Pr, and the restrictor flow path Pr provides resistance to the flow of liquid from the expansion-side chamber R1 to the liquid chamber L.

In this way, when the valve V is opened, the cylinder device C receives the vehicle weight and the telescopic body 1 performs the extension operation, but since the flow restriction flow path Pr provides resistance to the flow of liquid, the extension speed becomes slow and the cylinder device extends slowly, and the vehicle height of the saddle-riding vehicle M also slowly decreases. When the vehicle height of the rear wheel side of the saddle-riding vehicle M is lowered, the center of gravity of the vehicle is lowered and the lift of the front wheel during acceleration is suppressed, improving the acceleration performance. Therefore, when accelerating, the driver can intentionally lower the vehicle height and improve the acceleration performance by operating the lever switch to open the valve V. When the vehicle height is lowered, the valve V provides resistance to the flow of liquid and the extension operation of the cylinder device C is slowed down, so that the handling stability can be improved by suppressing abrupt changes in the vehicle body posture. When the valve V is closed while the cylinder device C is extended and the vehicle height is lowered, the liquid cannot move between the extension side chamber R1 and the liquid chamber L, and the cylinder device C becomes a rod-shaped body and the vehicle height can be maintained in the lowered state.

In addition, when the saddle-type vehicle M decelerates with the valve V open, the vehicle body B pitches forward and separates from the wheel W, and the force in the extension direction acting on the telescopic body 1 decreases, causing the pressure in the tank 10 to exceed the pressure in the extension-side chamber R1, resulting in a force in the contraction direction acting, and the cylinder device C contracts, causing the liquid to move from the liquid chamber L to the extension-side chamber R1 via the communication passage 16 and the valve V. As the cylinder device C contracts, the swing arm S rotates in a direction away from the vehicle body B, increasing the vertical distance between the vehicle body B and the wheel W, and the vehicle height of the saddle-type vehicle M increases by the amount of this increase in distance.

When the cylinder device C contracts and liquid flows from the liquid chamber L to the extension side chamber R1, the liquid in the liquid chamber L, which is under pressure from the air chamber G, passes between the valve body 21 and the valve seat 20d from the valve seat member 20 side toward the valve body 21 side and moves to the low-pressure extension side chamber R1. Therefore, the valve body 21 receives pressure from the high-pressure side liquid chamber L from the front side and retreats from the valve seat 20d to a position restricted by the stopper 23b1, and the head 21a completely comes out of the small diameter portion 20b, maximizing the opening area of the valve V. When the head 21a comes out of the valve seat member 20, no restrictive flow path Pr is formed between the head 21a and the valve seat member 20, and the valve V provides almost no resistance to the flow of liquid from the liquid chamber L to the extension side chamber R1 and allows the flow.

In this way, when the liquid flows from the liquid chamber L to the extension-side chamber R1, unlike when the liquid flows from the extension-side chamber R1 to the liquid chamber L, there is almost no resistance to the flow of the liquid, so the cylinder device C contracts quickly and the vehicle height of the saddle-type vehicle M rises quickly. Raising the vehicle height of the rear wheel side of the saddle-type vehicle M suppresses the rear wheel from lifting off the road surface during braking and improves vehicle stability during braking, so when braking, the driver can operate the lever switch to open the valve V to intentionally raise the vehicle height and improve vehicle stability during braking.

When raising the vehicle height, the valve V offers almost no resistance to the flow of liquid, allowing the cylinder device C to contract quickly, immediately preventing the wheel W from lifting off the road surface during braking. If the valve V is closed while the cylinder device C is contracted and the vehicle height is raised, liquid cannot pass between the expansion side chamber R1 and the liquid chamber L, and the cylinder device C becomes rod-shaped, allowing the vehicle height to be maintained at the raised state.

As described above, the valve V of this embodiment comprises a cylindrical valve seat member 20 having an annular valve seat 20d at one axial end, a valve body 21 having an annular seat portion 21b that can be seated on and removed from the valve seat 20d, a coil spring (biasing member) 22 that biases the valve body 21 toward the valve seat member 20, and a restricting flow path Pr that is formed when the valve body 21 is inserted into the valve seat member 20. When the seat portion 21b separates from the valve seat 20d and the valve is opened, the entire valve body 21 leaves the valve seat member 20 and is fully open against the flow from the valve seat member side to the valve body side, and the restricting flow path Pr provides resistance against the flow from the valve body side to the valve seat member side with at least a part of the valve body 21 inserted into the valve seat member 20.

With the valve V configured in this way, when the valve is open, the head 21a completely leaves the valve seat member 20 and does not form a restricting flow path Pr, providing almost no resistance to the flow of liquid passing through it from the valve seat member side to the valve body side, while the restricting flow path Pr provides resistance to the flow of liquid passing through it from the valve body side to the valve seat member side. In this way, the valve V can function independently as a check valve for the flow of liquid in one direction and as a valve that provides resistance to the flow of liquid in the other direction. Therefore, with the valve V of this embodiment, the check valve and the valve that provides resistance must be provided in parallel in a conventional valve, but the valve V of this embodiment can independently achieve the functions of both a check valve and a valve that provides resistance. As described above, with the valve V of this embodiment, a valve that provides resistance to the flow in one direction but does not provide resistance to the flow in the other direction when the valve is open can be realized without increasing the number of parts and costs.

As described above, the valve seat member 20 has a large diameter portion 20a and a small diameter portion 20b, but the design of the other structures of the valve seat member 20 can be changed as desired as long as it has at least the small diameter portion 20b that has the valve seat 20d at one axial end and allows the head 21a of the valve body 21 to move in and out. Also, the biasing member is a coil spring 22, but it may be a spring or elastic body other than a coil spring as long as it can bias the valve body 21 in the direction of seating it on the valve seat 20d.

In addition, in the valve V of this embodiment, the valve body 21 has a head 21a that can move in and out of the valve seat member 20, and the restricting flow path Pr is formed by an annular gap between the outer periphery of the head 21a of the valve body 21 and the inner periphery of the valve seat member 20. With the valve V configured in this manner, an annular gap is formed between the head 21a and the valve seat member 20, so they do not come into contact with each other. Therefore, when the valve body 21 moves axially relative to the valve seat member 20 and the head 21a moves in and out of the valve seat member 20, the head 21a does not interfere with the valve seat member 20, and the valve can be opened and closed smoothly.

Furthermore, the valve V of this embodiment is provided with an aligning member 23 that aligns the valve body 21 with respect to the valve seat member 20 while allowing the valve body 21 to move in the axial direction. With a valve V equipped with an aligning member 23 that aligns the valve body 21 in this manner, the valve body 21 can move in the axial direction without axial wobble when the head 21a of the valve body 21 moves in and out of the valve seat member 20, so there is no need to worry about the head 21a scraping the inner surface of the valve seat member 20, and smooth axial movement of the valve body 21 is guaranteed, allowing the valve to be opened and closed smoothly.

In the valve V of this embodiment, the shaft portion 21d is provided on the side opposite the valve seat of the valve body 21, and the aligning member 23 is provided with an annular aligning portion 23c into which the shaft portion 21d is slidably inserted. Alternatively, a hole may be provided along the axial direction on the valve body 21 side, and a shaft that is inserted into the hole in the valve body 21 may be provided on the aligning member 23 side to align the valve body 21 with respect to the valve seat member 20, or the aligning member 23 may be provided on the tank body 11. Also, a hole may be provided along the axial direction at the tip of the head 21a, and a shaft that is inserted into the hole in the head 21a may be provided at the tip of the push rod 24, and the shaft may be used as the aligning member.

However, as mentioned above, if the aligning member 23 is cylindrical and fits into the small diameter portion 20b of the valve seat member 20 to house the valve body 21, and the aligning portion 23c of the aligning member 23 aligns the valve body 21 and functions as a spring receiver for the coil spring (biasing member) 22 that biases the valve body 21, the components that make up the valve V can be assembled and housed in the valve hole 11b in advance, making it easier to assemble the valve V, and the aligning member 23 and valve body 21 can be assembled using the valve seat member 20 as a base, making it easier to align the valve body 21 with the valve seat member 20.

As described above, the restriction flow path Pr is formed by an annular gap between the outer periphery of the head 21a of the valve body 21 and the inner periphery of the valve seat member 20. However, as in the valve V1 of the first modified example of one embodiment shown in Figure 4, the outer periphery of the head 21a may be brought into sliding contact with the inner periphery of the small diameter portion 20b of the valve seat member 20, and a groove 21a1 may be provided along the axial direction on the outer periphery of the head 21a, so that the restriction flow path Pr is formed by the groove 21a1 provided in the head 21a until the seat portion 21b separates from the valve seat 20d and the head 21a completely comes out from within the small diameter portion 20b. In this case, the valve body 21 is aligned with the valve seat member 20 by the aligning member 23, so even if the head 21a comes out of the inner circumference of the valve seat member 20, the head 21a can enter the valve seat member 20 again and close the valve V. Therefore, when the aligning member 23 is provided, the restriction flow path Pr may be provided by a groove 21a1 formed on the outer circumference of the head 21a. In this case, as in the valve V2 of the second modified example shown in FIG. 5, instead of the groove 21a1, a passage 21a2 that opens from the tip of the head 21a to the base end of the head 21a may be formed to form the restriction flow path Pr by the passage 21a2. When the restriction flow path Pr is formed by the passage 21a2 in this way, the flow path length of the restriction flow path Pr does not change until the head 21a completely comes out of the small diameter portion 20b, and the resistance that the restriction flow path Pr provides to the flow of the liquid does not change.

The cylinder device C of this embodiment further includes a cylinder 2, a piston 3 movably inserted into the cylinder 2 and dividing the cylinder 2 into an extension side chamber R1 and a compression side chamber R2, a rod 4 movably inserted into the cylinder 2 and connected to the piston 3, an expandable body 1 in which the compression side chamber R2 is open to the atmosphere and the extension side chamber R1 is filled with liquid, a tank 10 whose interior is divided into an air chamber G and a liquid chamber L, a communication passage 16 that connects the liquid chamber L to the extension side chamber R1, and a valve V provided in the communication passage 16.

In this embodiment, the cylinder device C has the compression side chamber R2 open to the atmosphere, and when the valve V is opened, the pressure of the air chamber G acts on the extension side chamber R1, so that a spring force that contracts the telescopic body 1 can be exerted. In addition, when the valve V is opened, the cylinder device C provides resistance to the flow of liquid from the extension side chamber R1 to the liquid chamber L through the restrictor flow path Pr, and provides almost no resistance to the flow of liquid from the liquid chamber L to the extension side chamber R1. Therefore, when the telescopic body 1 is extended by an external force, the operation is slow, allowing the telescopic body 1 to be extended slowly, and when the telescopic body 1 is contracted spontaneously or by an external force, the operation is quick, allowing the telescopic body 1 to be contracted quickly.

In addition, if the compression side chamber R2 is opened to the atmosphere, the extension side chamber R1 and the liquid chamber L are connected by the communication passage 16, and the installation direction of the valve V relative to the communication passage 16 is reversed, the cylinder device C exerts a spring force that contracts the telescopic body 1 when the valve V is opened, and the valve V provides resistance to the flow of liquid from the liquid chamber L to the extension side chamber R1 through the restrictor flow path Pr, and provides almost no resistance to the flow of liquid from the extension side chamber R1 to the liquid chamber L. Therefore, when contracting spontaneously or due to an external force, the operation is slow, causing the telescopic body 1 to contract slowly, and when expanding due to an external force, the operation is quick, causing the telescopic body 1 to expand quickly.

Alternatively, the expansion side chamber R1 may be opened to the atmosphere, the compression side chamber R2 and the liquid chamber L may be connected by a communication passage 16, and the flow of liquid from the compression side chamber R2 to the liquid chamber L may be resisted by the restricting flow passage Pr when the valve V is open, so that the flow of liquid from the liquid chamber L to the compression side chamber R2 is hardly resisted. In this way, the cylinder device C exerts a spring force that extends the telescopic body 1 when the valve V is open, and when contracting due to an external force, the operation is slow, so that the telescopic body 1 is contracted slowly, and when expanding spontaneously or due to an external force, the operation is quick, so that the telescopic body 1 is expanded quickly.

Furthermore, the expansion side chamber R1 may be opened to the atmosphere, the compression side chamber R2 and the liquid chamber L may be connected by a communication passage 16, and the flow of liquid from the liquid chamber L to the compression side chamber R2 may be resisted by the restricting flow passage Pr when the valve V is open, so that the flow of liquid from the compression side chamber R2 to the liquid chamber L may be almost completely resisted. In this way, the cylinder device C exerts a spring force that extends the telescopic body 1 when the valve V is open, and operates slowly to slowly extend the telescopic body 1 when the telescopic body 1 is extended spontaneously or by an external force, and operates quickly to quickly contract the telescopic body 1 when the telescopic body 1 is contracted by an external force.

In this way, the cylinder device C can slow down either the extension or contraction operation, and not only can the operating speed be polarized depending on the operating direction, but it also prevents an increase in the number of parts and costs, making the valve V ideal for application to cylinder devices C that require the operating speed to be polarized.

Furthermore, the telescopic body 1 in the cylinder device C of this embodiment is spanned between the body B of the saddle-riding vehicle M and a swing arm S that can swing relative to the body B of the saddle-riding vehicle M and holds the wheel W. The cylinder device C configured in this way can adjust the vehicle height of the rear wheel side of the saddle-riding vehicle M by opening and closing the valve V.

In addition, in the cylinder device C of this embodiment, the compression side chamber R2 is open to the atmosphere, and the extension side chamber R1 is filled with liquid. The valve V is installed in the communication passage 16 with the valve body 21 facing the extension side chamber R1 and the valve seat member 20 facing the liquid chamber L, and the restricting flow path Pr provides resistance to the flow of liquid when the telescopic body 1 is extended, and is fully opened when the telescopic body 1 is contracted. With the cylinder device C configured in this way, when the vehicle height of the rear wheel side is lowered during acceleration of the saddle-type vehicle M, the valve V provides resistance to the flow of liquid when the vehicle height is lowered by opening the valve V, reducing the speed at which the vehicle height decreases, thereby improving the handling stability. When the vehicle height rises during braking, the valve V does not provide resistance to the flow of liquid, and the telescopic body 1 quickly contracts, quickly raising the vehicle height, improving the vehicle stability during braking.

The valve V can be used as a valve for various hydraulic circuits other than the cylinder device C described above, and the cylinder device C can also be used for purposes other than adjusting the vehicle height of the saddle-type vehicle M.

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

1: Telescopic body, 2: Cylinder, 3: Piston, 4: Rod, 10: Tank, 16: Communication passage, 20: Valve seat member, 20d: Valve seat, 21: Valve body, 21a: Head, 21b: Seat portion, 22: Coil spring (biasing member), 23: Alignment member, B: Vehicle body, C: Cylinder device, G: Air chamber, L: Fluid chamber, M: Saddle-type vehicle, P: Link plate, Pr: Restriction flow path, R1: Expansion side chamber, R2: Compression side chamber, S: Swing arm, V, V1, V2: Valve, W: Wheel

Claims (6)

a valve seat member having a cylindrical shape and an annular valve seat at one axial end;
a valve body having an annular seat portion that can be seated on and removed from the valve seat;
a biasing member that biases the valve body toward the valve seat member;
a restricting flow path formed when the valve body is inserted into the valve seat member,
when the seat portion separates from the valve seat and the valve is opened, the entire valve body comes out of the valve seat member and fully opens against a flow from the valve seat member side to the valve body side, and resistance is provided against a flow from the valve body side to the valve seat member side by the restricting flow path with at least a part of the valve body being inserted into the valve seat member. The valve body has a head portion that is movable within the valve seat member,
2. The valve of claim 1, wherein the restrictor flow passage is defined by an annular gap between an outer periphery of the head of the valve disc and an inner periphery of the valve seat member. 3. The valve according to claim 2, further comprising an aligning member that aligns the valve body with respect to the valve seat member while allowing the valve body to move in the axial direction. an expansion/contraction body including a cylinder, a piston movably inserted into the cylinder and dividing the inside of the cylinder into an extension-side chamber and a compression-side chamber, and a rod movably inserted into the cylinder and connected to the piston, wherein one of the extension-side chamber and the compression-side chamber is open to the atmosphere and the other of the extension-side chamber and the compression-side chamber is filled with a liquid;
a tank whose interior is divided into an air chamber and a liquid chamber;
a communication passage communicating the fluid chamber with the other of the expansion-side chamber and the compression-side chamber;
A cylinder device comprising: a valve according to claim 1 provided in the communication passage. The cylinder device according to claim 4, wherein the telescopic body is spanned between a body of a saddle-ride type vehicle and a swing arm that is swingable relative to the body of the saddle-ride type vehicle and holds the rear wheel. The compression-side chamber is open to the atmosphere and the expansion-side chamber is filled with liquid,
The cylinder device according to claim 5, characterized in that the valve is installed in the communication passage with the valve body facing the extension side chamber and the valve seat member facing the liquid chamber, and the restricting flow passage provides resistance to the flow of liquid when the telescopic body is extended, and is fully open when the telescopic body is contracted.

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