JP2021004610A - Valve and shock absorber - Google Patents

Abstract

To provide a valve which can improve the durability of a leaf valve, and can prevent that a portion which is insufficient in rigidity is formed at a valve disc, and a shock absorber.SOLUTION: A valve disc 5 of a valve includes: an opposing part 5d formed with an annular opposing face f2 which can face an annular end face of a free end of a leaf valve at an internal periphery with a clearance; one or more first protrusions 5g protruding to one side in an axial direction from the opposing part 5d; and one or more second protrusions 5h protruding to the other side in the axial direction from the opposing part 5d. Both end parts of the first protrusion 5g in the circumferential direction are overlapped on any of the second protrusions 5h in the axial direction with the opposing part 5d sandwiched therebetween, and both end parts of the second protrusion 5h in the circumferential direction are overlapped on any of the first protrusions 5g in the axial direction with the opposing part 5d sandwiched therebetween.SELECTED DRAWING: Figure 3

Description

The present invention relates to a valve and an improvement of a shock absorber provided with the valve.

Conventionally, valves have been used, for example, to resist the flow of liquid generated when the shock absorber expands and contracts to generate damping force. Further, such a valve includes a valve disc and a leaf valve in which one of the inner circumference and the outer circumference is fixed to the valve disc and the other is a free end to allow bending to both sides in the axial direction. , A facing portion including an annular facing surface that projects toward the end face of the free end of the leaf valve on the valve disc and forms a minute gap between the valve disc and the end face of the free end. Some are provided (for example, Patent Document 1).

According to the above configuration, even when the end face of the free end of the leaf valve and the facing surface of the facing portion face each other, a minute gap is formed between them, so that the end on the free end side of the leaf valve is the same. It can move to both sides in the axial direction from the position where the end face faces the facing surface of the facing portion to the position where it does not face. As a result, when the expansion / contraction speed (piston speed) of the shock absorber increases, the end portion on the free end side of the leaf valve bends, and the end face thereof and the facing surface of the facing portion do not face each other. When the amount of deflection of the leaf valve increases as the piston speed increases, the gap formed between the free end and the facing portion increases, and the flow rate of the liquid passing through the leaf valve increases.

JP-A-2-76937

Here, in order to improve the durability of the leaf valve, it is preferable to reduce the amount of deflection of the leaf valve while ensuring the flow rate of the liquid passing through the leaf valve. Then, in order to reduce the amount of bending while ensuring the flow rate of the liquid passing through the leaf valve, the facing surface at the facing portion is such that the end face of the free end does not face the facing surface even if the amount of bending of the leaf valve is small. It is necessary to shorten the axial length of and its vicinity.

However, if this is done, a thin-walled portion is formed on the facing portion, and the rigidity of the thin-walled portion is insufficient, which may cause another problem such as deformation. In this way, with conventional valves, in order to ensure the durability of the leaf valve, if an attempt is made to reduce the amount of deflection while ensuring the flow rate, there is a possibility that the valve disk will have a portion with insufficient rigidity. It is difficult to improve the durability of the leaf valve.

Therefore, an object of the present invention is to provide a valve and a shock absorber that can improve the durability of the leaf valve and prevent the valve disc from having a portion having insufficient rigidity.

In a valve that solves the above problems, the valve disc has an annular facing portion in which an annular facing surface that is annular and has an annular facing surface that can face each other with a gap from the end surface of the free end of the leaf valve is formed on the inner circumference or the outer circumference, and the facing portion. Includes one or more first protrusions protruding from one of the axial directions and one or more second protrusions protruding from the opposite portion to the other in the axial direction, and both ends of the first protrusion in the circumferential direction face each other. It overlaps with any of the second protrusions in the axial direction across the portion, and both ends of the second protrusion in the circumferential direction overlap with any of the first protrusions in the axial direction with the facing portion in between.

According to the above configuration, if the axial length of the facing surface is shortened, even if the amount of bending of the leaf valve is small, the end face of the free end and the facing surface do not face each other, and at this time, the liquid is the shaft of the facing portion. It can pass through a portion without a first protrusion on one side in the direction or a portion without a second protrusion on the other side in the axial direction of the opposite portion. Therefore, if the axial length of the facing surface is shortened, the flow rate of the liquid passing through the leaf valve can be secured even if the amount of deflection of the leaf valve is small, and the durability of the leaf valve can be improved.

Further, according to the above configuration, even if the axial length of the facing surface is shortened in order to improve the durability of the leaf valve, the facing portion on which the facing surface is formed is the first protrusion and the second protrusion. Since it is reinforced at least on one side, it is possible to prevent the valve disc from having a portion having insufficient rigidity. That is, according to the above configuration, the axial length of the facing surface can be shortened in order to improve the durability of the leaf valve.

Further, in the valve, the first protrusion and the second protrusion may be provided alternately in the circumferential direction of the facing portion. In this way, the valve disc can be easily formed.

Further, in the valve, one or both of the first protrusion and the second protrusion may be formed with an inclined surface that inclines in the direction of approaching the leaf valve as it approaches the facing surface. In such a case, if the inclined surface is formed on the protrusion of the valve disc located on the leaf valve insertion side of the first protrusion and the second protrusion, the leaf valve is assembled. At that time, the leaf valve can be guided to the inside or the outside of the facing portion on the inclined surface, so that the valve assembly property can be improved.

Further, in the valve, an extension surface that is connected to the facing surface and flush with the facing surface may be formed on one or both of the first protrusion and the second protrusion. In this way, even if the leaf valve moves a little in the process of assembling the valve, the free end of the leaf valve does not run on an inclined surface or the like, and the assembling property of the valve can be further improved.

Further, in the above valve, the valve disc is provided with a disc portion in which a port is formed, a tubular portion having a facing portion, a first protrusion portion, and a second protrusion on the inner circumference, and is joined to the outer peripheral portion of the disc portion. It may have a tubular portion to be formed. In this way, the disk portion on which the port is formed and the tubular portion provided with the facing portion, the first protrusion, and the second protrusion can be individually formed and then integrated by joining, and the disk portion and the tubular portion can be integrated. Each of these can be easily molded by sintering.

Further, the valve is provided in a shock absorber, and the shock absorber includes a cylinder and a rod that is movably inserted into the cylinder in addition to the valve, and the cylinder and the rod are The valve may provide resistance to the flow of liquid generated during relative movement in the axial direction. In this way, a damping force due to the resistance of the valve can be generated when the shock absorber expands and contracts.

According to the valve of the present invention and the shock absorber provided with the valve, the durability of the leaf valve can be improved, and it is possible to prevent the valve disc from having a portion having insufficient rigidity.

It is a vertical sectional view which showed the shock absorber provided with the damping valve which is the valve which concerns on one Embodiment of this invention. It is a partially enlarged view which showed the piston part of FIG. 1 enlarged. (A) is a cross-sectional view taken along the line ZOZ of (c). (B) is a partially enlarged view showing the Y2 portion of (a) in an enlarged manner. (C) is a bottom view of a valve disc on the lower side of a damping valve, which is a valve according to an embodiment of the present invention. It is a developed view of the part including the facing part, the 1st protrusion part, and the 2nd protrusion part of the damping valve which is a valve which concerns on one Embodiment of this invention. A first modification of the damping valve which is the valve according to the embodiment of the present invention is shown, and a developed view of a portion including the facing portion, the first protrusion, and the second protrusion of the damping valve according to this modification. Is. It is a vertical sectional view which showed the 2nd modification of the damping valve which is the valve which concerns on one Embodiment of this invention, and showed the piston part of the shock absorber provided with the damping valve which concerns on this modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same reference numerals attached throughout several drawings indicate the same part (part) or the corresponding part (part).

As shown in FIG. 1, the valve according to the embodiment of the present invention is a damping valve V embodied in the piston portion of the shock absorber D. The shock absorber D is interposed between the vehicle body of a vehicle such as an automobile and the axle. In the following description, for convenience of description, the top and bottom of the shock absorber D shown in FIG. 1 are simply referred to as "top" and "bottom" unless otherwise specified.

The attachment target of the shock absorber provided with the valve according to the present invention is not limited to the vehicle and can be appropriately changed. Of course, the top and bottom of the shock absorber in the mounted state can be appropriately changed according to the mounting target. Specifically, the shock absorber D of the present embodiment may be attached to the vehicle in the same direction as in FIG. 1, or may be attached to the vehicle in the upside down direction.

Subsequently, the specific structure of the shock absorber D will be described. As shown in FIG. 1, the shock absorber D includes a bottomed cylinder-shaped cylinder 1, a piston 2 slidably inserted into the cylinder 1, a lower end connected to the piston 2, and an upper end outside the cylinder 1. It is provided with a piston rod 3 that protrudes toward.

A bracket (not shown) is provided at the upper end of the piston rod 3, and the piston rod 3 is connected to one of the vehicle body and the axle via the bracket. On the other hand, a bracket (not shown) is also provided on the bottom portion 1a of the cylinder 1, and the cylinder 1 is connected to the other of the vehicle body and the axle via the bracket.

In this way, the shock absorber D is interposed between the vehicle body and the axle. Then, when the wheels vibrate up and down with respect to the vehicle body, such as when the vehicle travels on an uneven road surface, the piston rod 3 moves in and out of the cylinder 1, the shock absorber D expands and contracts, and the piston 2 moves inside the cylinder 1. Move up and down (axial direction).

Further, the shock absorber D includes an annular cylinder head 10 that closes the upper end of the cylinder 1 and slidably supports the piston rod 3. On the other hand, the lower end of the cylinder 1 is closed by the bottom portion 1a. In this way, the inside of the cylinder 1 is a closed space. Then, the free piston 11 is slidably inserted on the side opposite to the piston rod 3 when viewed from the piston 2 in the cylinder 1.

In the cylinder 1, a liquid chamber L filled with a liquid such as hydraulic oil is formed above the free piston 11. On the other hand, a gas chamber G in which a compressed gas such as air or nitrogen gas is sealed is formed below the free piston 11 in the cylinder 1. In this way, the inside of the cylinder 1 is partitioned into a liquid chamber L and a gas chamber G by a free piston 11.

Then, when the piston rod 3 retracts from the cylinder 1 when the shock absorber D is extended and the volume of the volume integral cylinder of the retracted piston rod 3 increases, the free piston 11 moves upward in the cylinder 1 and the gas chamber G To expand. On the contrary, when the piston rod 3 invades the cylinder 1 when the shock absorber D contracts and the volume of the invading piston rod 3 in the volume integral cylinder decreases, the free piston 11 moves downward in the cylinder 1. The gas chamber G is reduced.

As described above, in the present embodiment, the shock absorber D is a single-rod, single-cylinder type, and the volume integral of the piston rod 3 entering and exiting the cylinder 1 is compensated by the gas chamber G. However, the configuration of the shock absorber D is not limited to this. For example, a reservoir for accommodating liquid and gas may be provided in place of the gas chamber G, and the piston rod volume integral that exchanges liquid between the cylinder and the reservoir when the shock absorber expands and contracts may be compensated. Further, the shock absorber may be of the double rod type, and the piston rods may be provided on both sides of the piston. In this case, the configuration itself for compensating the piston rod volume integral can be omitted.

Subsequently, the liquid chamber L in the cylinder 1 is divided by the piston 2 into an extension side chamber L1 on the piston rod 3 side and a compression side chamber L2 on the opposite side (anti-piston rod side). The piston 2 is sandwiched between a step 3a formed on the outer periphery of the piston rod 3 and a nut 30 screwed to the tip of the piston rod 3, and two valve discs 4 are held vertically on the outer periphery of the piston rod 3. , 5 is included.

Of the two valve discs 4 and 5, the valve disc 4 on the upper side (extension side chamber L1 side) is equipped with main valves 6 and 7 on the extension side and the compression side. On the other hand, the extremely low speed valve 8 is mounted on the valve disc 5 on the lower side (compression side chamber L2 side). A damping valve V is configured including two valve discs 4 and 5, main valves 6 and 7 on the extension side and compression side, and an extremely low speed valve 8. Hereinafter, each member constituting the damping valve V will be described in detail.

As shown in FIG. 2, the upper valve disc 4 has an annular main body portion 4b in which a mounting hole 4a allowing insertion of the piston rod 3 is formed in the central portion, and the lower end outer peripheral portion of the main body portion 4b downward. Includes a protruding tubular skirt portion 4c. Further, the main body portion 4b is formed with ports 4d and 4e on the extension side and the compression side which are opened on the inner peripheral side of the skirt portion 4c and penetrate the main body portion 4b in the axial direction. Then, the extension side port 4d is opened and closed by the extension side main valve 6 laminated on the lower side of the main body 4b, and the compression side port 4e is opened and closed by the compression side main valve 7 laminated on the upper side of the main body 4b. To.

Further, the lower valve disc 5 has a mounting hole 5a formed in the center portion for allowing the piston rod 3 to be inserted, and an annular disc portion fitted to the inner circumference of the skirt portion 4c in the upper valve disc 4. 5b, a tubular portion 5c that fits on the outer periphery of the lower end of the disk portion 5b and projects downward from the disk portion 5b, and an annular facing portion 5d that projects radially inward from the lower end of the tubular portion 5c. The cylinder portion 5c and the disc portion 5b are integrated by press fitting.

Then, the space between the disc portion 5b and the skirt portion 4c of the upper valve disc 4 is closed by the seal 5e, and the disc portion 5b has a port 5f that communicates the inside of the skirt portion 4c and the inside of the tubular portion 5c. It is formed. Further, a valve stopper 9 and an extremely low speed valve 8 are laminated on the lower side of the disk portion 5b, and the extremely low speed valve 8 closes the opening of the facing portion 5d located at the lower end portion of the tubular portion 5c. It is provided.

As a result, the liquid flowing from the main valves 6 and 7 to the compression side chamber L2 is extremely low speed at the inside of the skirt portion 4c of the upper valve disc 4 and the inside of the ports 5f and the cylinder portion 5c of the lower valve disc 5. It flows through the valve 8 in this order. On the contrary, the liquid flowing from the compression side chamber L2 to the main valves 6 and 7 flows in the opposite direction in the above path. As described above, the ultra-low speed valve 8 of the present embodiment is provided in series with the main valves 6 and 7 in the middle of the passage connecting the extension side chamber L1 and the compression side chamber L2. Hereinafter, the space from the inside of the skirt portion 4c located between the main valves 6 and 7 and the extremely low speed valve 8 to the inside of the tubular portion 5c is referred to as an intermediate chamber L3.

The extension side and compression side main valves 6 and 7 each have one or more leaf valves. This leaf valve is a thin annular plate having elasticity, and each of the main valves 6 and 7 is fixed to the valve disc 4 on the inner peripheral side in a state where the deflection on the outer peripheral side is allowed, and the outer peripheral portion is fixed to the valve disc 4. The outlets of the corresponding ports 4d and 4e are opened and closed by taking off and sitting.

The inlet of the extension side port 4d is open to the extension side chamber L1, and the pressure of the extension side chamber L1 bends the outer peripheral portion of the extension side main valve 6 downward and acts in the direction of opening the extension side port 4d. .. On the other hand, the inlet of the port 4e on the compression side is open to the intermediate chamber L3, and the pressure in the intermediate chamber L3 bends the outer peripheral portion of the main valve 7 on the compression side upward and acts in the direction of opening the port 4e on the compression side. To do.

Further, of the leaf valves constituting the extension side and compression side main valves 6 and 7, notches 6a and 7a are formed on the outer peripheral portion of the first leaf valve located closest to the valve disc 4 side, respectively. ing. As a result, even if the main valves 6 and 7 on the extension side and the compression side are closed, an orifice is formed by the notches 6a and 7a, and the liquid passes through the orifice between the extension side chamber L1 and the intermediate chamber L3. Go back and forth.

The orifice formed by the notches 6a and 7a allows bidirectional flow of liquid. Therefore, one of the notches 6a and 7a formed in the main valves 6 and 7 on the extension side and the compression side may be omitted. Further, the method of forming the orifice can be changed as appropriate. For example, a stamp may be formed on the valve seat on which the main valves 6 and 7 on the extension side or the compression side are separated and seated, and an orifice may be formed by this stamp. Further, the orifice may be replaced with a choke. Further, the main valve may be a valve other than the leaf valve such as a poppet valve.

Subsequently, the ultra-low speed valve 8 includes a leaf valve 8a and first and second sub-leaf valves 8b and 8c laminated above and below the leaf valve 8a. The leaf valve 8a and the first and second sub-leaf valves 8b and 8c are thin annular plates having elasticity, respectively, and the outer diameters of the first and second sub-leaf valves 8b and 8c are the leaf valves 8a. Smaller than the outer diameter.

Further, one or more spacers (not shown) having an outer diameter smaller than the outer diameters of the leaf valves 8a and the sub-leaf valves 8b and 8c are laminated above and below the extremely low speed valve 8, and the extremely low speed is extremely low. The inner peripheral portion of the valve 8 is sandwiched between the spacers and fixed to the valve disc 5. On the other hand, the outer peripheral side of the spacer 8 of the extremely low speed valve 8 is allowed to bend to both the upper and lower sides. As described above, in the present embodiment, the inner circumferences of the leaf valve 8a and the first and second sub-leaf valves 8b and 8c are fixed ends, and the outer circumference is a free end.

Further, the leaf valve 8a is provided at a position where the outer peripheral surface f1 which is the end surface of the free end thereof is opposed to the inner peripheral surface of the facing portion 5d in a non-bent state. In other words, the facing portion 5d of the valve disc 5 projects toward the outer peripheral surface (end face of the free end) f1 of the leaf valve 8a in a non-flexible state, and the inner peripheral surface of the facing portion 5d is not bent. The facing surface f2 faces the outer peripheral surface f1 of 8a. In addition, the "non-flexible state" means that the state is maintained in the state when there is no load (the state where the natural length is reached).

As shown in FIG. 3, the facing portion 5d has an annular shape, and projecting portions that project alternately are provided above and below the facing portion 5d so as to be arranged in the circumferential direction. Of these protrusions, if the protrusion protruding upward from the facing portion 5d is the first protrusion 5g and the protrusion protruding downward from the facing portion 5d is the second protrusion 5h, the first protrusion 5g and the second The two protrusions 5h are alternately arranged in the circumferential direction of the facing portions 5d while overlapping the ends thereof.

As a result, both ends of the first protrusion 5g in the circumferential direction are arranged vertically so as to overlap each other in the axial direction with the second protrusion 5h and the facing portion 5d in between, respectively, and the circumference of the second protrusion 5h. Both ends in the direction are arranged vertically so as to overlap each other in the axial direction with the first protrusion 5g and the facing portion interposed therebetween. Therefore, at least one of the first protrusion 5g and the second protrusion 5h is connected to the facing portion 5d on which the facing surface f2 is formed. Further, in the portion where the first protrusion 5g and the second protrusion 5h overlap, the end portion of the first protrusion 5g, the facing portion 5d, and the end portion of the second protrusion 5h are arranged in the axial direction (vertically). line up.

FIG. 4 is a developed view of a portion including the facing portion 5d, the first protrusion 5g, and the second protrusion 5h, as viewed from the central axis X of the valve disc 5. In FIG. 4, the region sandwiched between the straight line s1 connecting the upper ends of the facing portion 5d without the first protrusion 5g and the straight line s2 connecting the lower ends of the facing portion 5d without the second protruding portion 5h is the facing surface f2. The facing surface f2 is a continuous band-shaped annular surface. In the present embodiment, the axial length (width) of the facing surface f2 is substantially equal to the thickness of the leaf valve 8a and is very short.

Further, the first protrusion 5g and the second protrusion 5h are connected to the facing surface f2 and are connected to the extension surfaces f3 and f5 which are flush with the facing surface f2 and the extension surfaces f3 and f5 to extend. Inclined surfaces f4 and f6 are formed, which are inclined in a direction away from the central axis X as the distance from the surface f3 increases. The term "floating" as used herein means that there is no step between one surface and the other surface, or there is almost no step, and when the member moves from one surface to the other surface while sliding, it does not get caught. A state in which it can be moved. Further, it can be said that the inclined surfaces f4 and f6 are inclined toward the central axis X as they approach the facing surfaces f2.

According to the above configuration, when assembling the leaf valve 8a at the time of assembling the damping valve V, if the leaf valve 8a is installed so that the lower end in the drawing of the valve disc 5 faces upward and the leaf valve 8a is dropped inside the facing portion 5d, the leaf The valve 8a is guided by the inclined surface f6 and the extension surface f5, and the outer peripheral surface f1 of the leaf valve 8a moves to a position facing the facing surface f2. Further, since there are extension surfaces f3 and f5 flush with the opposite portion 5d above and below the facing portion 5d, the leaf valve 8a can be used when the damping valve V is transferred from the needle thread to the piston rod 3 or when the nut 30 is tightened. Even if it moves a little, the outer circumference of the leaf valve 8a does not ride on the inclined surfaces f4 and f6.

As shown in FIG. 2, when the leaf valve 8a is assembled and no hydraulic pressure is applied to the damping valve V, the leaf valve 8a is not bent and its outer peripheral surface f1 faces the facing portion 5d. Facing surface f2. At this time, a minute gap is formed between the outer peripheral surface f1 of the leaf valves 8a facing each other and the facing surface f2 of the facing portion 5d. Then, this gap allows the leaf valve 8a to move up and down with respect to the facing portion 5d on the outer circumference (free end). However, since the gap formed between the outer peripheral surfaces f1 and the facing surfaces f2 facing each other is very narrow, the movement of the liquid through the gap hardly occurs.

The pressure of the compression side chamber L2 acts in the direction of bending the outer peripheral portion of the leaf valve 8a upward. Then, in response to the pressure of the compression side chamber L2, the outer peripheral portion of the leaf valve 8a bends upward while bending the outer peripheral portion of the first sub-leaf valve 8b, and the outer peripheral surface (end surface of the free end) f1 of the leaf valve 8a becomes. When they are displaced upward from the facing surface f2 of the facing portion 5d and they do not face each other, the liquid in the compression side chamber L2 passes between the inside of the facing portion 5d and the adjacent first protrusions 5g and 5g to the intermediate chamber L3. Head to.

Further, when the amount of upward deflection of the leaf valve 8a and the first sub-leaf valve 8b becomes large to some extent, one or both of the leaf valve 8a and the first sub-leaf valve 8b abuts on the valve stopper 9, and more than that. Deflection is blocked. In this way, the valve stopper 9 limits the amount of upward deflection of the leaf valve 8a and the first sub-leaf valve 8b.

On the other hand, the pressure of the intermediate chamber L3 acts in the direction of bending the outer peripheral portion of the leaf valve 8a downward. Then, in response to the pressure of the intermediate chamber L3, the outer peripheral portion of the leaf valve 8a bends downward while bending the outer peripheral portion of the second sub-leaf valve 8c, and the outer peripheral surface (end surface of the free end) f1 of the leaf valve 8a becomes. When they are displaced downward from the facing surface f2 of the facing portion 5d and they do not face each other, the liquid in the intermediate chamber L3 passes between the inside of the facing portion 5d and the adjacent second protrusions 5h and 5h to the compression side chamber L2. Head to.

Further, when the amount of downward bending of the leaf valve 8a and the second sub-leaf valve 8c becomes large to some extent, one or both of the leaf valve 8a and the second sub-leaf valve 8c abut on the nut 30, and further bending occurs. Is blocked. In this way, the nut 30 functions as a valve stopper that limits the amount of downward bending of the leaf valve 8a and the second sub-leaf valve 8c.

Needless to say, apart from the nut 30, a valve stopper that limits the amount of downward bending of the leaf valve 8a and the second sub-leaf valve 8c may be provided. Further, the number of leaf valves and sub-leaf valves constituting the extremely low speed valve 8 can be changed as appropriate.

Hereinafter, the operation of the shock absorber D provided with the damping valve (valve) V according to the present embodiment will be described.

When the shock absorber D is extended, the piston 2 moves upward in the cylinder 1 to compress the extension side chamber L1, and the liquid in the extension side chamber L1 moves to the compression side chamber L2 through the damping valve V. Resistance is imparted to the flow of the liquid by the main valve 6 on the extension side, the orifice formed by the notches 6a and 7a of the main valves 6 and 7, or the extremely low speed valve 8, so that the extension side chamber L1 has resistance. The pressure rises and the shock absorber D exerts an extension damping force that hinders the extension operation.

On the contrary, when the shock absorber D contracts, the piston 2 moves downward in the cylinder 1 to compress the compression side chamber L2, and the liquid in the compression side chamber L2 passes through the damping valve V and moves to the extension side chamber L1. .. Resistance is applied to the flow of the liquid by the main valve 7 on the compression side, the orifice formed by the notches 6a and 7a of the main valves 6 and 7, or the extremely low speed valve 8, so that the pressure in the compression side chamber L2 is applied. Ascends, and the shock absorber D exerts a compression side damping force that hinders the contraction operation.

Then, in the shock absorber D, the main valves 6 and 7 on the extension side and the compression side are opened according to the piston speed, and the outer peripheral portion of the leaf valve 8a of the extremely low speed valve 8 is bent vertically to reduce the damping force. The characteristics (characteristics of damping force with respect to piston speed) change.

More specifically, when the speed of the piston 2 (piston speed) such as the start of movement of the shock absorber D is extremely low and the piston speed is in an extremely low speed range close to 0 (zero), the main valves 6 and 7 on the extension side and the compression side Is closed. On the other hand, the outer peripheral portion of the leaf valve 8a of the ultra-low speed valve 8 bends downward when the shock absorber D is extended and upward when the shock absorber D contracts, and the outer peripheral surface f1 of the leaf valve 8a and the facing surface f2 of the facing portion 5d move up and down. It shifts and does not face each other.

In this case, the liquid flowing back and forth between the extension side chamber L1 and the compression side chamber L2 is the orifice formed by the notches 6a and 7a of the main valves 6 and 7, the intermediate chamber L3, and the leaf valve 8a displaced vertically. It passes between the outer circumference of the surface and the inner circumference of the facing portion 5d, and passes through a gap formed between the adjacent first protrusions 5g and 5g or the second protrusions 5h and 5h. When this gap is hereinafter referred to as the opening of the extremely low speed valve 8, the opening area of the opening of the extremely low speed valve 8 increases as the piston speed increases in the extremely low speed region, but the main valves 6 and 7 respectively. It is smaller than the opening area of the total orifice formed by the notches 6a and 7a of.

Therefore, when the piston speed is in the extremely low speed region, the pressure loss when the liquid moves between the extension side chamber L1 and the compression side chamber L2 is dominated by the pressure loss due to the opening of the extremely low speed valve 8. The damping characteristic in the extremely low speed region is a characteristic peculiar to the valve that is proportional to the piston speed. As described above, even when the outer peripheral surface f1 of the leaf valve 8a and the facing surface f2 of the facing portion 5d face each other, a minute gap is formed between them. Therefore, the liquid may pass through the minute gap in the low speed region in the extremely low speed region. In such a case, in the region on the low speed side in the extremely low speed region, the pressure loss due to the minute gap becomes dominant and the damping characteristic becomes the characteristic peculiar to the orifice proportional to the square of the piston speed, and in the extremely low speed region. It becomes a characteristic peculiar to the valve in the high speed side region.

Subsequently, when the piston speed increases and the piston speed deviates from the extremely low speed region and is in the low speed region, the main valves 6 and 7 on the extension side and the compression side are closed as in the case of being in the extremely low speed region. On the other hand, the amount of deflection of the outer peripheral portion of the leaf valve 8a in the ultra-low speed valve 8 became large, and the opening area of the opening of the ultra-low speed valve 8 was formed by the notches 6a and 7a of the main valves 6 and 7. It is larger than the opening area of all orifices.

Therefore, when the piston speed is in the low speed range, the pressure loss when the liquid moves between the extension side chamber L1 and the compression side chamber L2 is dominated by the pressure loss due to the orifice formed by the notches 6a and 7a. Become. The damping force characteristic in the low speed range is a characteristic peculiar to the orifice that is proportional to the square of the piston speed.

Subsequently, when the piston speed is further increased to escape from the low speed range and are in the medium and high speed range, the main valve 6 on the extension side opens when the shock absorber D extends, and the main valve 7 on the compression side opens when the shock absorber D contracts. Further, the amount of deflection of the leaf valve 8a of the extremely low speed valve 8 becomes larger than that in the low speed region, and the opening of the extremely low speed valve 8 expands vertically.

In this case, the liquid flowing back and forth between the extension side chamber L1 and the compression side chamber L2 is a gap (opening) formed between the outer peripheral portion and the valve disc 4 by opening the main valves 6 and 7 on the extension side or the compression side. Then, it passes through the intermediate chamber L3 and the opening of the extremely low speed valve 8. In the medium to high speed range, the opening area of the opening of the extremely low speed valve 8 is large, and the liquid passes through the opening with relatively no resistance.

Therefore, when the piston speed is in the medium to high speed range, the pressure loss when the liquid moves between the extension side chamber L1 and the compression side chamber L2 is the pressure loss due to the openings of the main valves 6 and 7 on the extension side or the compression side. Becomes dominant. The damping force characteristic in the medium and high speed range is a characteristic peculiar to the valve that is proportional to the piston speed, and the inclination is further reduced as compared with the low speed range. Further, when the main valves 6 and 7 are fully opened in the middle of the middle and high speed range, the damping force characteristic becomes a characteristic peculiar to the port at the fully opened speed, and the inclination becomes large again.

Hereinafter, the action and effect of the damping valve (valve) V according to the present embodiment and the shock absorber D provided with the damping valve V will be described.

The damping valve (valve) V according to the present embodiment has a valve disc 5 and a leaf that is annular and has an inner circumference fixed to the valve disc 5 and is allowed to bend to both sides in the axial direction with the outer circumference as a free end. It is equipped with a valve 8a. Further, the valve disc 5 has an annular shape, and an annular facing surface f2 is formed on the inner circumference thereof so as to face the outer peripheral surface (end surface of the free end) f1 of the leaf valve 8a with a gap. It includes one or more first protrusions 5g protruding from the facing portion 5d in one direction in the axial direction, and one or more second protrusions 5h protruding from the facing portion in the other in the axial direction. Then, both ends of the first protrusion 5g in the circumferential direction overlap with any second protrusion 5h in the axial direction with the facing portion 5d interposed therebetween, and both ends of the second protrusion 5h in the circumferential direction are facing portions. It overlaps with any first protrusion 5g in the axial direction with 5d in between.

According to the above configuration, if the axial length of the facing surface f2 is shortened, the outer peripheral surface (end surface of the free end) f1 and the facing surface f2 do not face each other even if the amount of deflection of the leaf valve 8a is small. At this time, according to the above configuration, the liquid faces from between the adjacent first protrusion 5g and the first protrusion 5g, or between the adjacent second protrusion 5h and the second protrusion 5h. Since the liquid can flow into the inside of the leaf valve 8a, the flow rate of the liquid passing through the leaf valve 8a can be secured even if the amount of deflection of the leaf valve 8a is small, and the durability of the leaf valve 8a can be improved.

Further, according to the above configuration, in order to improve the durability of the leaf valve 8a, even if the axial length of the facing surface f2 is shortened, the facing portion 5d on which the facing surface f2 is formed is the first protrusion 5g. At least one of the second protrusions 5h is reinforced. Therefore, even if the axial length of the facing surface f2 is shortened in order to improve the durability of the leaf valve 8a, it is possible to prevent the valve disc 5 from having a portion having insufficient rigidity. As a result, according to the damping valve (valve) V having the above configuration and the shock absorber D provided with the valve, the durability of the leaf valve 8a can be improved, and the valve disc 5 has a portion having insufficient rigidity. Can be prevented.

Further, in the present embodiment, the first protrusion 5g and the second protrusion 5h are alternately provided in the circumferential direction of the facing portion 5d. Thereby, the valve disc 5 can be easily formed. However, the first protrusion 5g and the second protrusion 5h do not necessarily have to be arranged alternately. For example, three or more first protrusions 5g having a short circumferential length may be arranged on the upper side (one side in the axial direction) of one second protrusion 5h having a long circumferential length. ..

Further, as shown in FIG. 4, the distance between the adjacent first protrusions 5g and 5g and the distance between the adjacent second protrusions 5h and 5h are the portions where the first protrusion 5g and the second protrusion 5h overlap, respectively. If the width is set shorter than the width of (the portion where the first protrusion 5g, the facing portion 5d, and the second protrusion 5h are vertically aligned), the opening amount of the leaf valve 8a can be increased to increase the flow rate of the liquid. The durability of the leaf valve 8a can be further improved. The intervals between the first protrusions 5g and 5g, the intervals between the second protrusions 5h and 5h, and the widths of the portions where the first protrusions 5g and the second protrusions 5h overlap do not have to be constant. Any of the intervals may be shorter than any of the above widths.

Further, the first protrusion 5g and the second protrusion 5h of the present embodiment are formed with inclined surfaces f4 and f6 that incline toward the central axis X as they approach the facing surface f2, respectively. In the inclined surfaces f4 and f6, the direction approaching the central axis X is the direction approaching the leaf valve 8a. According to the above configuration, when assembling the damping valve V, the leaf valve 8a can be guided to the inside of the facing portion 5d by the inclined surface f6 of the second protrusion 5h on the leaf valve insertion side in the valve disc 5, so that the damping valve V Can be assembled well.

Further, the first protrusion 5g and the second protrusion 5h of the present embodiment are formed with extension surfaces f3 and f5 which are connected to the facing surface f2 and are flush with the facing surface f2, respectively. According to this configuration, even if the leaf valve 8a moves slightly when the damping valve V is transferred from the needle thread to the piston rod 3 or when the nut 30 is tightened, the outer circumference of the leaf valve 8a is on the inclined surfaces f4 and f6. Never run on. Therefore, according to the above configuration, the assembling property of the damping valve V can be further improved.

Further, as shown in FIG. 4, the extension surfaces f3 and f5 and the inclined surfaces f4 and f6 of the present embodiment are each rectangular, but their shapes can be changed as appropriate. For example, as shown in FIG. 5, the shape of the surface obtained by combining the extension surfaces f3 and f5 and the inclined surfaces f4 and f6 may be triangular. In such a case, the leaf valve 8a bends and its outer peripheral surface. When f1 no longer faces the facing surface f2, it is easier to secure the flow rate of the liquid passing through the leaf valve 8a.

Further, when the extension surfaces f3 and f5 and the inclined surfaces f4 and f6 are formed on both the first protrusion 5g and the second protrusion 5h as in the present embodiment, the amount of deflection of the leaf valve 8a is the same in the upper and lower directions. In some cases, it is easy to make the flow rate of the passing liquid the same, but if you focus on the function of guiding the leaf valve 8a to the inside of the facing portion 5d, the protrusion (this) on the leaf valve insertion side in the valve disc 5 In the embodiment, it is sufficient that the inclined surface f6 is provided only on the second protrusion 5h), and the inclined surface f6 may be directly connected to the facing surface f2.

Further, in the first protrusion 5g and the second protrusion 5h of the present embodiment, the leaf valve 8a is guided into the facing portion 5d, and the leaf valve 8a is displaced from a predetermined position in the assembly process of the damping valve V. It functions as a guide to prevent. However, the first protrusion 5g and the second protrusion 5h do not necessarily function as guides, and in this case, both the extension surfaces f3 and f5 and the inclined surfaces f4 and f6 may be eliminated.

Further, the valve disc 5 of the present embodiment is provided with a disc portion 5b on which a port 5f is formed, a tubular portion 5d, a first protrusion 5g, and a second protrusion 5h on the inner circumference. It has a tubular portion 5c joined to the outer peripheral portion of the disc portion 5b. According to this configuration, the disk portion 5b on which the port 5f is formed and the tubular portion 5c provided with the facing portion 5d, the first protrusion 5g, and the second protrusion 5h are individually formed and then integrated by joining. Therefore, each of the disc portion 5b and the cylinder portion 5c can be easily formed by sintering.

In the present embodiment, the disc portion 5b is press-fitted into the cylinder portion 5c, but the method of joining the disc portion 5b and the cylinder portion 5c can be appropriately changed. For example, the disk portion 5b may be provided with an annular joint portion, and the tubular portion 5c may be press-fitted into the joint portion. Further, the disc portion 5b and the cylinder portion 5c may be integrated by bonding or screwing.

Further, in the present embodiment, the inner circumferences of the leaf valve 8a and the first and second sub-leaf valves 8b and 8c are fixed ends, and the outer circumference is a free end. Therefore, as described above, it is preferable to divide the valve disc 5 into a disc portion 5b and a cylinder portion 5c, and provide a facing portion 5d, a first protrusion 5g, and a second protrusion 5h on the inner circumference of the cylinder portion 5c. .. However, the outer circumference of the leaf valve 8a is a fixed end and the inner circumference is a free end, and the facing surface f2 may be formed on the outer circumference of the facing portion, and the division position of the valve disc can be changed accordingly. Of course, the valve disc may be formed of a single component.

Further, in the present embodiment, the leaf valve 8a whose free end surface can face the facing surface f2 is used for the extremely low speed valve 8 connected in series with the main valves 6 and 7. However, as shown in FIG. 6, only the valve disc 5 may function as a piston, and the leaf valve 8a may be used as a main valve that bends in the medium to high speed range. In the above description, the piston speed region is divided into an extremely low speed region, a low speed region, and a medium high speed region, but the threshold value of each region can be arbitrarily set.

Further, the damping valve (valve) V of the present embodiment is used for the shock absorber D. The shock absorber D includes a cylinder 1 and a piston rod 3 movably inserted into the cylinder 1 in the axial direction, and the liquid generated when the cylinder 1 and the piston rod 3 move relative to each other in the axial direction. The flow is resisted by the damping valve V. Therefore, when the shock absorber D expands and contracts and the cylinder 1 and the piston rod 3 move relative to each other in the axial direction, a damping force due to the resistance of the damping valve (valve) V can be generated.

The damping valve (valve) V according to the present embodiment is embodied in the piston portion mounted on the piston rod 3 of the shock absorber D. However, the rod that goes in and out of the cylinder 1 does not necessarily have to be the piston rod to which the piston is attached, and the position where the damping valve V is provided is not limited to the piston portion. For example, as described above, when the shock absorber includes a reservoir, the valve according to the present invention may be provided in the middle of the passage connecting the cylinder and the reservoir.

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

D ... shock absorber, f1 ... outer peripheral surface (end surface of free end), f2 ... facing surface, f3, f5 ... extension surface, f4, f6 ... inclined surface, V ... damping Valve (valve), 1 ... Cylinder, 3 ... Piston rod (rod), 5 ... Valve disc, 5b ... Disc part, 5c ... Cylinder part, 5d ... Opposite part, 5f・ ・ ・ Port, 5g ・ ・ ・ First protrusion, 5h ・ ・ ・ Second protrusion, 8a ・ ・ ・ Leaf valve

Claims (6)

Valve disc and
It is provided with a leaf valve which is annular and one of the inner circumference and the outer circumference is fixed to the valve disc, and the other is a free end and allows bending to both sides in the axial direction.
The valve disc
An opposing portion that is annular and has an annular facing surface that can be opposed to the end surface of the free end on the inner or outer circumference with a gap.
One or more first protrusions protruding in one axial direction from the facing portion,
Including one or more second protrusions protruding from the facing portion to the other in the axial direction.
Both ends of the first protrusion in the circumferential direction overlap with any of the second protrusions in the axial direction with the facing portion in between.
A valve characterized in that both ends of the second protrusion in the circumferential direction overlap with any of the first protrusions in the axial direction with the facing portion interposed therebetween. The valve according to claim 1, wherein the first protrusion and the second protrusion are alternately provided in the circumferential direction of the facing portion. Claim 1 or claim 1, wherein one or both of the first protrusion and the second protrusion are formed with an inclined surface that inclines in a direction approaching the leaf valve as it approaches the facing surface. The valve according to 2. Any of claims 1 to 3, wherein an extension surface is formed on one or both of the first protrusion and the second protrusion so as to be connected to the facing surface and flush with the facing surface. The valve described in one item. The valve disc
The disk part where the port is formed and
It is tubular and has a tubular portion having the facing portion, the first protruding portion, and the second protruding portion provided on the inner circumference and joined to the outer peripheral portion of the disk portion. The valve according to any one of claims 1 to 4. Cylinder and
A rod that is movably inserted into the cylinder in the axial direction,
The valve according to any one of claims 1 to 5 is provided.
The valve is a shock absorber that provides resistance to the flow of liquid generated when the cylinder and the rod move relative to each other in the axial direction.

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