JP4839201B2 - Buffer valve structure - Google Patents

Description

  The present invention relates to an improved valve structure of a shock absorber.

  Conventionally, this kind of shock absorber valve structure is embodied in, for example, a piston portion of a shock absorber for a vehicle, and an annular leaf valve is laminated on the outlet end of a port provided in the piston portion. A valve that opens and closes a port is known.

  In particular, in the above-described shock absorber valve structure in which the inner periphery of the leaf valve is fixedly supported and the port is opened and closed by bending the outer peripheral side, the damping force in the medium and high speed regions becomes too large in the vehicle. In order to solve this problem, the inner periphery of the leaf valve L may not be fixedly supported and the inner periphery of the leaf valve L may be connected to the piston rod R or the piston P as shown in FIG. Has been proposed in which a valve structure of a shock absorber is slidably brought into contact with the outer periphery of a cylindrical piston nut N fixed to the piston rod R and the back surface of the leaf valve L is urged by a spring S through a main valve M. In the figure, it is embodied in the expansion side damping valve of the shock absorber (see, for example, Patent Document 1).

In the shock absorber to which this valve structure is applied, as shown in the figure, when the piston speed when the piston P moves upward is in the low speed region, the outer peripheral side of the leaf valve L is stacked on the leaf valve L. Since it bends with the contact part as a fulcrum, as shown in FIG. 5, it exhibits substantially the same damping characteristics as the valve structure in which the inner periphery is fixedly supported. The pressure of the hydraulic oil passing through the valve acts on the leaf valve L, and the leaf valve L lifts and retreats in the axial direction from the piston P together with the main valve M against the urging force of the spring S. Compared with the valve structure of the shock absorber supported by the vehicle, the flow passage area is increased and the damping force is suppressed from being excessive, so that the riding comfort in the vehicle can be improved.
JP-A-9-291196 (FIG. 1)

  However, in the proposed valve structure as described above, although it is a useful technique in terms of improving riding comfort in a vehicle, it may be pointed out that there are the following problems.

  Here, in the conventional valve structure of the shock absorber, when the piston speed is in the low speed region, the damping coefficient indicating the rate of increase of the damping force with respect to the increase of the piston speed is relatively large, while the piston speed is Is in the middle and high speed range, it is preferable to make the damping coefficient as small as possible. In order to realize this, the spring constant of the spring S is maintained without changing the initial load that the spring S biases the leaf valve L. Needs to be set small.

  However, in order to satisfy this condition, that is, the condition of reducing the spring constant while keeping the initial load of the spring S as it is, it is necessary to set the free length of the spring S long and set the filament diameter small. Then, as the natural length of the spring S is increased, the entire length of the piston part including the valve is increased, and the stroke length that is the extendable range of the shock absorber is reduced by that length, so that the above stroke length is secured. As a result, the overall length of the shock absorber becomes longer, and the mountability on the vehicle deteriorates.

  Furthermore, the strength of the spring S is weakened by reducing the diameter of the filament S.

  Therefore, the present invention was devised to improve the above problems, and the object of the present invention is to provide a shock absorber capable of satisfying both the riding comfort in a vehicle and the stroke length in the shock absorber. It is to provide a valve structure.

In order to solve the above-described object, the problem-solving means in the present invention includes a valve disk in which a port is formed, a shaft member rising from the shaft center portion of the valve disk, and an inner peripheral side inserted through the outer periphery of the shaft member. with the sliding contact is laminated on the valve disc Te annular valve laminated annular leaf valve for closing the port, the inner peripheral side to the leaf valve with sliding contact is inserted to the outer periphery of the shaft member and the member is suppressed, in the valve structure of the damper provided with a biasing means for biasing the leaf valve via the valve restraining member in a direction for closing the port, the valve restraining the leaf valve outer diameter of the member together with set larger than the outer diameter, the bar an annular portion having an inner diameter larger than the outer diameter of the leaf valve to the valve disc end of the valve restraining member Is projected on the subdisk side, it in the low speed range of the piston speed deflects only the outer peripheral edge of the leaf valve, which the leaf valve and the valve restraining member is in the high speed range in the piston velocity is lifted against the biasing means It is characterized by.
In this case, an annular valve seat projecting toward the leaf valve side is provided on the outer peripheral side from the port of the valve disk, and the leaf valve is set so as to close the port by being seated on the valve seat. It is preferable to protrude from the front end of the valve seat toward the valve disc.
Similarly, the inner peripheral surface of the annular portion may be inclined so that the tip of the annular portion is tapered.
Similarly, the valve disc is a piston through which a piston rod is inserted into the shaft center, and the shaft member is formed into a cylindrical shape and is a piston nut that is screwed to the tip of the piston rod to fix the piston to the piston rod. The urging member may be a coil spring interposed between the valve holding member and the piston nut.

According to the valve structure of the shock absorber of the present invention, only the outer peripheral edge of the leaf valve is bent at the low speed region of the piston speed, so that the hydraulic oil passes through the clearance only on the outer peripheral side of the leaf valve. Since the leaf valve and the valve holding member are lifted against the urging means, the gap through which the hydraulic oil passes can be made larger than the gap in the low speed region of the piston speed. In particular, the action of the annular part makes it easy to retract the entire leaf valve from the valve disc in the axial direction. Therefore, while increasing the damping coefficient in the low speed region, the piston speed increases the damping coefficient in the medium to high speed region. Since it can be made smaller than the valve structure of a conventional shock absorber, the riding comfort in the vehicle can be improved.

  Further, since the damping coefficient when the piston speed is in the middle and high speed region can be reduced as compared with the valve structure of the conventional shock absorber without reducing the spring constant of the biasing means, the valve structure The axial length of the piston part including the valve structure can be maintained equivalent to the valve structure of the conventional shock absorber, and the entire piston part including each part constituting the valve structure is not lengthened. There is no inconvenience that the stroke length, which is the extendable range of the device, is shortened, and the mountability to the vehicle does not deteriorate.

  In addition, there is no need to reduce the spring constant of the urging means, and there is no risk of lowering the strength of the urging means, so there is no fear of strength, and the mountability and ride comfort of the shock absorber are satisfied. In addition, the reliability and practicality of the valve structure of the shock absorber can be improved.

  Hereinafter, the valve structure of the shock absorber of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a piston portion of a shock absorber in which a valve structure of the shock absorber according to an embodiment is embodied. FIG. 2 is a diagram illustrating a damping characteristic in a shock absorber in which the valve structure of the shock absorber according to the embodiment is embodied. FIG. 3 is a longitudinal sectional view of a part of a piston portion in which a valve structure of a shock absorber according to a modification of the embodiment is embodied.

As shown in FIG. 1, the valve structure of the shock absorber in one embodiment is embodied as an extension side damping valve of the piston portion of the shock absorber, and includes a piston 1 as a valve disk in which a port 2 is formed, and a piston A piston nut 4 that is a shaft member that rises from the shaft center portion of 1 and an annular leaf valve 10 that is slidably contacted by inserting the inner peripheral side into the outer periphery of the piston nut 4 and that is stacked on the piston 1 and closes the port 2; The inner peripheral side is inserted into the outer periphery of the piston nut 4 to be in sliding contact with the annular valve pressing member 11 stacked on the leaf valve 10, and the leaf through the valve pressing member 11 in the direction of closing the port 2. And a coil spring 15 as an urging means for urging the valve 10.

  On the other hand, a shock absorber in which the valve structure is embodied is well known and will not be described in detail, but specifically, for example, a cylinder 40 and a head member (not shown) that seals the upper end of the cylinder 40. ), A piston rod 5 slidably passing through a head member (not shown), the piston 1 provided at the end of the piston rod 5, and two pressures separated by the piston 1 in the cylinder 40 The upper chamber 41 and the lower chamber 42, which are chambers, a sealing member (not shown) for sealing the lower end of the cylinder 40, and a cylinder internal volume change corresponding to the volume of the piston rod 5 protruding and retracting from the cylinder 40 are not shown. A cylinder or an air chamber is provided, and the cylinder 40 is filled with a fluid, specifically, hydraulic oil.

  In the above valve structure, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the pressure in the upper chamber 41 rises, and the port 2 passes from the upper chamber 41 to the lower chamber 42. When the hydraulic oil moves, the leaf valve 10 provides resistance to the movement of the hydraulic oil to cause a predetermined pressure loss, thereby functioning as a damping force generating element that generates a predetermined damping force in the shock absorber.

  Hereinafter, the valve structure will be described in detail. The piston 1 serving as a valve disk is formed in a bottomed cylindrical shape, and an insertion hole 1b through which a piston rod 5 of a shock absorber is inserted into an axial center portion of the bottom portion 1a, , A window 3 communicating with the port 2, an annular valve seat 1c formed on the outer peripheral side of the window 3 serving as an outlet end of the port 2 and projecting from the bottom 1a of the piston 1 toward the leaf valve 10, and extending to the outer peripheral side It is provided with a cylindrical portion 1f.

  The piston 1 is provided with a pressure-side port 1d that allows a flow of hydraulic oil from the lower chamber 42 to the upper chamber 41 when the shock absorber contracts, on the outer peripheral side from the port 2 on the extended side of the bottom 1a. It has been.

  The piston rod 5 is inserted into the insertion hole 1b of the piston 1 as described above, and the tip of the piston rod 5 is projected downward in FIG. The outer diameter of the tip 5a of the piston rod 5 is set to be smaller than the outer diameter on the upper side in FIG. 1 from the tip 5a, and a step portion 5b is formed at a portion where the outer diameters of the upper side and the tip are different. Yes.

  Subsequently, the piston nut 4 serving as a shaft member is configured to include a cylindrical portion 4a and a flange 4b extending from the outer periphery of the lower end in FIG. 1, and the upper end outer periphery of the cylindrical portion 4a has a small diameter, and the small diameter portion 4c. Is formed.

  The tip of the piston rod 5 is inserted into the insertion hole 1b of the piston 1 together with the pressure-side leaf valve 100, the spacer 101 and the valve stopper 102, and the piston nut 4 is inserted into the piston rod 5 from below in FIG. The piston 1 is clamped between the stepped portion of the piston rod 5 and the upper end of the piston nut 4 so as to be fixed to the piston rod 5.

  In addition, the lower end opening part in the insertion hole 1b provided in the bottom part 1a of the piston 1 is expanded in diameter, and the enlarged diameter part 1e is provided, and a step part is formed, and FIG. 1 of the small diameter part 4c in the cylinder part 4a is formed in this step part. The middle and upper ends can be inserted.

  A plurality of annular spacers 7 having a smaller diameter than the leaf valve 10 are stacked on the bottom portion 1a of the piston 1 so as to be in sliding contact with the outer periphery of the small diameter portion 4c of the cylindrical portion 4a of the piston nut 4 from below the spacer 7. A leaf valve 10 slidably contacting the outer periphery of the small diameter portion 4c is stacked, and a plurality of annular spacers 8 having a smaller diameter than the leaf valve 10 and slidably contacting the outer periphery of the small diameter portion 4c are stacked from below the leaf valve 10. In addition, a valve holding member 11 that is slidably contacted with the outer periphery of the small-diameter portion 4c from below the spacer 8 is laminated.

  The leaf valve 10 is configured as a laminated leaf valve by laminating a plurality of annularly formed plates. The upper surface in FIG. 1 is brought into contact with the valve seat 1c to close the port 2 of the piston 1. Can be done. In this embodiment, the leaf valve 10 is configured as a laminated leaf valve. However, the number of the annular plates can be arbitrarily determined depending on the damping characteristic (relationship of the damping force with respect to the piston speed) realized by the valve structure. Depending on the attenuation characteristics generated in the shock absorber, there may be a plurality of sheets or only one sheet, and the outer diameter of each leaf can be set differently depending on the attenuation characteristics generated in the shock absorber. Further, although not shown in detail, a notch formed on the outer periphery of the leaf valve 10 seated on the valve seat 1c or a known orifice formed by being stamped on the valve seat 1c is provided.

  Incidentally, by providing the enlarged diameter portion 1e, the piston nut 4 can be positioned in the radial direction with respect to the piston 1, and the above-described leaf valve 10, spacers 7 and 8, and valve restraining member 11 are attached to the piston nut 4. After assembly, these members can be attached together with the piston 1 to the tip 5a of the piston rod 5, which is convenient for manufacturing. However, the enlarged diameter portion 1e may be omitted.

  Further, as described above, by forming the piston 1 in the shape of a bottomed cylinder, a member constituting the valve structure such as a leaf valve can be accommodated in the piston 1, and the piston 1 shown in FIG. The length from the middle upper end to the lower end in FIG. 1 of the piston nut 4 can be shortened, and the piston portion can be reduced in size.

  Further, the valve holding member 11 stacked at the lowest position in FIG. 1 is set to have an outer diameter larger than the outer diameter of the leaf valve 10 with the inner peripheral side slidably contacting the outer periphery of the small diameter portion 4c of the piston nut 4 described above. An annular main body 11a, a cylindrical part 11b that hangs downward from the lower end in FIG. 1 of the annular main body 11a and has an inner peripheral side slidably contacting the outer periphery of the small diameter part 4c, and a piston side end 11c of the annular main body 11a And an annular portion 12 provided so as to protrude toward the piston 1 while having an inner diameter larger than the diameter.

  The inner peripheral surface 12a of the annular portion 12 is inclined so that the tip 12b of the annular portion 12 is tapered, and the tip 12b of the annular portion 12 is a tip A that is the lower end of the valve seat 1c in FIG. Further, the front end 12b is positioned on the piston 1 side, which is above the front end A of the valve seat 1c in FIG.

  A coil spring 15 as an urging means is interposed between the annular main body 11a and the flange 4b of the piston nut 4. The leaf spring 10 is pressed against the valve seat 1c by the coil spring 15.

  Although the cylindrical portion 11b can be omitted, the cylindrical portion 11b exhibits a function of centering the coil spring 15, and the biasing force of the coil spring 15 is not biased to the valve restraining member 11 by this centering function. Since it can be made to act, it is desirable to provide it.

  With the above configuration, the urging force of the coil spring 15 is applied to the inner peripheral side of the leaf valve 10 via the valve holding member 11, and the leaf valve 10 is urged in the direction of closing the port 2 with the coil spring 15. is doing.

  Therefore, the leaf valve 10 and the valve restraining member 11 resist the urging force when the piston 1 moves upward in FIG. 1 and the difference between the pressure in the upper chamber 41 and the pressure in the lower chamber 42 increases. Thus, the coil spring 15 is compressed so that the entire leaf valve 10 moves backward in the axial direction from the piston 1, that is, lifts downward in FIG.

  The leaf in which the axial thickness of the entire spacer 7 is set shorter than the axial length from the bottom 1a of the piston 1 to the tip A of the valve seat 1c, and the urging force acts on the inner peripheral side. An initial deflection is given to the valve 10.

  By setting the deflection amount of the initial deflection, the valve opening pressure when the leaf valve 10 leaves the valve seat 1c and opens the port 2 can be adjusted. The deflection amount of the initial deflection is the entire amount of the spacer 7. The thickness is set so as to be optimal for a vehicle to which a shock absorber is applied. The spacer 7 can be omitted depending on the axial length from the bottom 1a of the piston 1 to the lower end of the valve seat 1c.

  Further, in the above description, the urging means is the coil spring 15. However, since a predetermined urging force may be applied to the leaf valve 10, this may be, for example, a disc spring or a leaf spring, or an elastic material such as rubber. It may be a body.

  Next, the operation of the valve structure in the embodiment will be described. As described above, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the pressure in the upper chamber 41 increases, and the upper chamber 41 is increased. The hydraulic fluid inside passes through the port 2 and tries to move into the lower chamber 42.

  When the piston speed, which is the expansion / contraction speed of the shock absorber, is in the low speed region, the leaf valve 10 cannot be lifted back from the piston 1 against the urging force of the coil spring 15, and the leaf valve 10 is Since the spring 15 is urged by the spring 15 so as to close the port 2, the outer peripheral edge of the leaf valve 10 bends with the outer peripheral edge of the spacer 8 as a fulcrum, and the hydraulic oil flows through the port 2 to the leaf valve. 10 passes through a gap between the leaf valve 10 and the valve seat 1c formed by separating from the valve seat 1c.

  When the piston speed, which is the expansion / contraction speed of the shock absorber, is in the low speed region, the hydraulic oil is notched or valve provided on the outer periphery of the leaf valve 10 seated on the valve seat 1c when the piston speed is extremely low. The orifice passes through the orifice formed by stamping the seat 1c, and then the outer periphery of the leaf valve 10 is bent as the speed increases, and passes through the gap between the leaf valve 10 and the valve seat 1c. The valve 10 cannot be lifted back from the piston 1 against the urging force of the coil spring 15, and the leaf valve 10 is urged by the coil spring 15 to be pressed so as to close the port 2, and is a spacer. Only the outer periphery of 8 is bent as a fulcrum.

  Accordingly, the damping characteristic (relationship of the damping force to the piston speed) at this time is as shown by the solid line in FIG. 2, and the damping coefficient is relatively large in this low speed region.

  On the other hand, when the speed of the piston 1 reaches the middle-high speed region, the difference between the pressure in the upper chamber 41 and the pressure in the lower chamber 42 increases, and the force that pushes down the hydraulic oil leaf valve 10 downward in FIG. At the same time, the force overcomes the urging force of the coil spring 15, and the entire leaf valve 10 is retracted in the axial direction from the piston 1, that is, moved downward in FIG.

  Here, in the valve restraining member 11, even if the leaf valve 10 is separated from the valve seat 1c and the port 2 is opened, the flow direction of the hydraulic oil passing through the port 2 from the upper chamber 41 is circular. The portion 12 can be forcibly directed toward the piston 1, and the dynamic pressure of the hydraulic oil can be positively applied to the valve restraining member 11 by the annular portion 12.

  That is, due to the above action of the annular portion 12, the force for pushing the valve holding member 11 downward in FIG. 1 becomes larger than that of the conventional shock absorber.

  Thus, when the entire leaf valve 10 is separated from the bottom 1a of the piston 1, the gap between the valve seat 1c and the leaf valve 10 is larger than when the piston speed is in the low speed region, and the piston speed is increased. The gap increases proportionally.

  In other words, the damping characteristic when the piston speed is in the medium-high speed region is as shown by the solid line in FIG. 2 and is proportional to the increase in piston speed, but the damping coefficient is smaller than the low speed region, and the slope of the damping characteristic Becomes smaller.

  As is clear from the above description, in the valve structure of the present embodiment, the entire leaf valve 10 is separated from the piston 1 by the above action of the annular portion 12 as compared with the valve structure of the conventional shock absorber. Since it is easy to retract in the axial direction, the damping coefficient when the piston speed is in the middle and high speed range is smaller than that of the conventional shock absorber valve structure without setting the spring constant of the coil spring 15 small. Is possible.

  Further, the initial load of the coil spring 15, that is, the urging force of the coil spring 15 in a state where the leaf valve 10 is in contact with the piston 1, is also set in the same manner as the spring S in the conventional shock absorber valve structure. , While the piston coefficient increases the damping coefficient in the low speed region, the damping coefficient in the medium and high speed region can be reduced compared with the valve structure of the conventional shock absorber, improving the riding comfort in the vehicle It can be done.

  Further, since the damping coefficient when the piston speed is in the middle and high speed range can be reduced as compared with the valve structure of the conventional shock absorber without reducing the spring constant of the coil spring 15, the valve structure The axial length of the piston part including the valve structure can be maintained equivalent to the valve structure of the conventional shock absorber, and the entire piston part including each part constituting the valve structure is not lengthened. There is no inconvenience that the stroke length, which is the extendable range of the device, is shortened, and the mountability to the vehicle does not deteriorate.

  Further, since the wire diameter of the coil spring 15 is not reduced, there is no fear of strength, and the reliability of the valve structure of the shock absorber is satisfied while satisfying the mountability and riding comfort of the shock absorber in the vehicle. And the practicality can be improved. Even when the biasing means is an elastic body other than the coil spring, for example, an elastic body such as a cylindrical rubber, the spring constant tends to decrease in order to reduce the spring constant because the cross-sectional area is reduced. However, in the present invention, since it is not necessary to reduce the spring constant of the urging means, the strength of the urging means is not reduced.

  Further, since the tip 12b of the annular portion 12 protrudes toward the piston 1 from the tip A of the valve seat 1c, the direction of the hydraulic oil flow can be greatly changed, so that a larger dynamic pressure is suppressed by the valve. Since the valve restraining member 11 can be easily retracted with a smaller hydraulic oil pressure, the damping coefficient when the piston speed is in the middle / high speed region can be set smaller, and can be further reduced. Riding comfort in the vehicle can be improved.

  Furthermore, since the inner peripheral surface 12a of the annular portion 12 is inclined so that the tip 12b is tapered as described above, the gap between the valve seat 1c and the annular portion 12 is set to be small. A throttling effect due to the gap between the annular portion 12 and the valve seat 1c can be expected. By this throttling effect, the pressure in the space B surrounded by the valve restraining member 11, the bottom 1a of the piston 1 and the valve seat 1c is increased. be able to.

  Therefore, in this case as well, a large force can be applied to the valve restraining portion 11 due to the pressure increase in the space B, so that the valve restraining member 11 can be easily moved backward with a smaller hydraulic oil pressure. The damping coefficient when the piston speed is in the medium to high speed region can be reduced, and the riding comfort in the vehicle can be further improved.

  Note that the piston speed at which the valve restraining member 11 starts to retract in the axial direction from the piston 1, that is, the boundary between the low speed region and the medium to high speed region may be set to about 0.2 m / s, for example. When the piston speed is in the middle to high speed range, the damping coefficient is kept relatively small, the damping force does not become too large, and the riding comfort in the vehicle can be secured, making it practical. Will improve.

  In the above-described embodiment, the piston 1 is fixed by the piston nut 4. However, when the piston 1 can be fixed to the piston rod 5 by another means, the lower end of the coil spring 15 in FIG. The leaf valve 10 and the valve holding member 11 may be in direct sliding contact with the outer periphery of the piston rod 5, and the piston 1 is provided with an insertion hole 1a. The piston rod 5 is projected so as to be inserted into the tip end portion of the piston 5. However, a shaft member that is integral with or separate from the piston 1 that is a valve disk may be provided in the shaft center portion of the piston 1.

  Further, in the case where the outer peripheral diameter of the valve restraining member 11 is large and the annular portion 12 narrows the inlet of the compression side port 1d, the distal end 12b forms the outer peripheral surface of the annular portion 12 as shown in FIG. It is preferable to prevent the annular portion 12 from narrowing the inlet of the port 1d by inclining the taper so that the outer diameter of the piston 1 is not increased. .

  This is the end of the description of the embodiment of the valve structure, but the valve structure of the present invention can be embodied in the compression side damping valve of the piston portion of the shock absorber, or in the base valve portion. Of course, the present invention can be applied to a valve of a shock absorber that functions as a damping force generating element that generates a damping force.

  It should be noted that the scope of the present invention is not limited to the details shown or described.

It is a longitudinal cross-sectional view in the piston part of the buffer which actualized the valve structure of the buffer in one Embodiment. It is a figure which shows the damping characteristic in the buffer which embodied the valve | bulb structure of the buffer of one Embodiment. It is a longitudinal cross-sectional view in a part of piston part in which the valve | bulb structure of the shock absorber in the modification of one Embodiment was actualized. It is a longitudinal cross-sectional view of the piston part of the buffer which actualized the valve structure of the conventional buffer. It is a figure which shows the damping characteristic in the buffer which actualized the valve structure of the conventional buffer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston 1a which is a valve disc Bottom part 1b Insertion hole 1c Valve seat 1d, 2 Port 1e Expanded diameter part 1f, 4a, 11b Cylindrical part 3 Window 4 Piston nut 4b which is a shaft member 4c Small diameter part 5 Piston rod 5a Piston rod tip 5b Stepped portion 5c Screw portion 7, 8, 101 Spacer 10 Leaf valve 11 Valve restraining member 11a Annular body 11c Piston end portion 12 of annular body Annular portion 12a Inner circumferential surface 12b of annular portion Tip 15 of annular portion Coil spring 100 Pressure side leaf valve 102 Valve stopper A Tip of valve seat B Space

Claims (4)

A valve disc which port is formed, is laminated and the shaft member rising from the axial center of the valve disc, the inner circumferential side with the sliding contact is inserted to the outer periphery of the shaft member to said valve disc closes said port through an annular leaf valve, an annular valve restraining member which is laminated on the leaf valve with an inner peripheral side sliding contact is inserted to the outer periphery of the shaft member, the valve restraining member in a direction for closing the port in the valve structure of the damper provided with a biasing means for biasing the leaf valve Te, the outer diameter of the valve restraining member and sets larger than the outer diameter of the leaf valve, the valve restraining valve disc side of the member an annular portion having an inner diameter larger than the outer diameter of the leaf valve to the end portion is projected into the valve disk side, the leaf in the low-speed range of the piston speed Alone with the bent outer peripheral edge of the lube valve structure of the damper of the leaf valve and the valve restraining member is in the high speed range in the piston speed, characterized in that to lift against the biasing means. An annular valve seat that protrudes toward the leaf valve is provided on the outer peripheral side from the port of the valve disc, and the leaf valve is set to close the port when seated on the valve seat. The shock absorber valve structure according to claim 1, wherein the shock absorber protrudes toward the valve disk from the tip. The shock absorber valve structure according to claim 1 or 2, wherein an inner peripheral surface of the annular portion is inclined so that a tip of the annular portion is tapered. The valve disc is a piston in which a piston rod is inserted into an axial center portion, and the shaft member is formed in a cylindrical shape and is a piston nut that is screwed to the tip of the piston rod to fix the piston to the piston rod. 4. The valve structure for a shock absorber according to claim 1, wherein the biasing member is a coil spring interposed between the valve holding member and the piston nut.

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