JP2013122255A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a shock absorber capable of adjusting a damping force while pressing the inner periphery side of a leaf valve.SOLUTION: A shock absorber D includes a piston 1 which is partitioned into one chamber A and the other chamber B, a pressure side flow path 11 which is formed in the piston 1 and makes one chamber A communicate with the other chamber B, an annular plate-like leaf valve 21 which blocks an outlet of the pressure side flow path 11 so as to be openable and closable while being laminated at the one-chamber side of the piston 1, a piston rod 3 which stands up at the one-chamber side of the piston 1, and an energizing spring 4 which energizes the leaf valve 21 to the piston side, and also includes a jack chamber J1, a jack member 5 which can be separated from and approximate the leaf valve 21 accompanied by the expansion and contraction of the jack chamber J1 while one end of which contacts with the energizing spring 4, a flow path J2 for a jack which always communicates with the jack chamber J1 while being formed at a piston rod 3, and an adjuster 7 which supplies and discharges fluid for the jack to the jack chamber J1 through the flow path J2 for the jack while being attached to the piston opposite side of the piston rod 3.

Description

  The present invention relates to an improvement of a shock absorber.

  In general, a shock absorber is used to suppress a vibration by generating a damping force in a transportation device such as an automobile or a motorcycle, a building, or the like.

  For example, a shock absorber D1 disclosed in Patent Document 1 shown in FIG. 4 includes a cylinder 6 that contains a working fluid, a piston rod (shaft member) 3 that is movably inserted in the cylinder 6 in the axial direction, A piston (valve disk) 1A held at the tip of the piston rod 3;

  The cylinder 6 is partitioned by the piston 1A into one chamber A and the other chamber B filled with the working fluid, and these chambers A and B pass through the flow path 100 formed in the piston 1A. It is communicated through.

  An annular plate-like leaf valve 200 is fixed to the one chamber side (piston rod side) of the piston 1A with the inner periphery as a fixed end, and the outer periphery of the leaf valve 200 is formed on the piston 1A. The valve seat 101 is seated on and off to close the outlet of the flow path 100 so that it can be opened and closed, and resistance is given to the working fluid passing through the flow path 100.

  On the other hand, since the inlet of the flow path 100 is open to the other chamber side, when the other chamber B on the piston side is pressurized by the piston 1A when the shock absorber D1 is compressed, the working fluid in the other chamber B flows. The leaf valve 200 is opened, passes through the gap between the outer periphery of the leaf valve 200 and the valve seat 101 and moves to the one chamber A. The shock absorber D1 includes a bypass passage 102 that bypasses the flow passage 100 and communicates the one chamber A and the other chamber B, and a needle valve 103 that restricts the bypass passage 102 and forms an orifice. .

  With the above configuration, when the piston speed is in the low speed region, the shock absorber D1 generates a damping force having a square characteristic due to the resistance of the orifice when the working fluid passes through the bypass 102. When the piston speed leaves the low speed range and reaches the middle high speed range, the shock absorber D1 generates a proportional damping force because the leaf valve 200 is opened.

  Further, the shock absorber D1 is movable along a pressing member 201 that contacts the outer peripheral portion of the leaf valve 200 on the side opposite to the piston, and a guide hole 300 that is formed long in the axial direction on the piston side of the piston rod 3. A movable seat 202, a biasing spring (biasing member) 4 interposed between the movable sheet 202 and the pressing member 201 and biasing the leaf valve 200 toward the piston, and a piston rod formed in a cylindrical shape 3 is movably inserted into the push rod 301 that contacts the anti-piston side of the moving sheet 202, and is attached to the anti-piston side of the piston rod 3 to drive the moving sheet 202 via the push rod 301. And an adjusting member (not shown).

  And by providing the said structure, the buffer D1 operates this adjustment member, changes the reaction force by the said urging | biasing spring 4 by moving the moving sheet 202 to the leaf valve 200, and in the buffer D1. The damping force at the time of compression can be adjusted.

JP 2007-225066 A

  However, in the conventional shock absorber D1, since the outer peripheral portion of the leaf valve 200 is pressed by the pressing member 201, the damping characteristic shown by the solid line in FIG. The change at the time of switching to the proportional characteristic damping force P2 by 200 is abrupt, which may give the user an impression that the ride is uncomfortable.

  Therefore, by pressing the inner peripheral side of the leaf valve 200, the change at the time of switching from the damping force P1 of the square characteristic to the damping force P2 of the proportional characteristic is smoothed, and the damping as shown by the two-dot chain line in FIG. It is preferable to use force characteristics.

  However, the amount of change on the inner peripheral side of the leaf valve 200 when the valve is opened is smaller than the amount of change on the outer peripheral side. The damping force cannot be adjusted unless the spring force of the biasing member 4 is increased.

  When the spring force of the urging spring 4 is increased, the conventional long and small diameter push rod 301 and the moving sheet 202 are insufficient in strength and may be deformed. Further, when the push rod 301 is increased in diameter or the moving sheet 202 is formed thick so that the push rod 301 or the moving sheet 202 can be strengthened to withstand the spring force of the urging spring 4, There is a problem that the weight of the container D1 is increased.

  Accordingly, an object of the present invention is to ensure sufficient strength to hold the inner peripheral side of the leaf valve without increasing the weight of the shock absorber, and to attenuate when the working fluid moves from the other chamber to the one chamber. It is to provide a shock absorber capable of adjusting the force.

  Means for solving the above-described problems include a valve disc that is divided into one chamber and the other chamber, a flow passage that is formed in the valve disc and communicates the one chamber and the other chamber, and one of the valve discs. An annular plate-like leaf valve that is stacked on the chamber side so as to close the outlet of the flow path so as to be openable and closable, a shaft member that stands on one chamber side of the valve disc, and a bias member that biases the leaf valve toward the valve disc side In the shock absorber including a biasing member, a jack chamber, a jack member whose one end abuts against the leaf valve side of the biasing member and can be moved closer to the leaf valve as the jack chamber expands or contracts, and the shaft member A jack flow path that is always formed and communicated with the jack chamber, and is attached to the jack chamber through the jack flow path that is attached to the opposite side of the valve disk of the shaft member. It is to comprise an adjustment member for supplying and discharging Yakki fluid.

  ADVANTAGE OF THE INVENTION According to this invention, sufficient intensity | strength to hold down the inner peripheral side of a leaf valve can be ensured, without making a buffer weight, damping force adjustment when a working fluid moves from one chamber to one chamber Can do.

It is a left half longitudinal cross-sectional view which shows the principal part of the front fork which is a suspension apparatus using the buffer which concerns on one embodiment of this invention. It is a longitudinal cross-sectional view which expands and shows the front-end | tip member part of the buffer which concerns on one embodiment of this invention. It is a left half longitudinal cross-sectional view which shows the adjuster part of the front fork which is a suspension apparatus using the buffer which concerns on one embodiment of this invention. It is a left half longitudinal cross-sectional view which shows the principal part of the conventional shock absorber. It is a graph which shows the damping force characteristic in the conventional shock absorber.

  A shock absorber according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, the shock absorber D according to the present embodiment includes a piston (valve disk) 1 that is divided into one chamber A and the other chamber B, and the one chamber A and the above-described one formed on the piston 1. A pressure side flow path (flow path) 11 communicating with the other chamber B, an annular plate-shaped leaf valve 21 stacked on one chamber side of the piston 1 and closing the outlet of the pressure side flow path 11 so as to be openable and closable; A piston rod (shaft member) 3 standing on one chamber side of the piston 1 and an urging spring (urging member) 4 for urging the leaf valve 21 toward the piston are provided.

  Further, the shock absorber D includes a jack chamber J1 and a jack member whose one end abuts on the side opposite to the leaf valve 21 of the biasing spring 4 and can be moved closer to the leaf valve 21 as the jack chamber J1 expands or contracts. 5, the jack passage J2 formed in the piston rod 3 and always communicating with the jack chamber J1, and the jack chamber attached to the opposite piston side of the piston rod 3 via the jack passage J2. J1 is provided with an adjuster (adjusting member) 7 (FIG. 3) for supplying and discharging the jack fluid.

  The shock absorber D according to the present embodiment is used for a front fork that is a suspension device for suspending a front wheel of a motorcycle, and includes an outer tube T1 and an inner tube T2 that appears and disappears in the outer tube T1. It is accommodated in the suspension device main body F.

  Although the structure of the front fork is well known and not shown in detail, a suspension spring S that constantly biases the suspension device main body F in the extending direction is accommodated in parallel with the shock absorber D in the suspension device main body F. Yes. Thereby, the front fork absorbs the impact caused by the road surface unevenness by the suspension spring S, and the shock absorber D suppresses the expansion and contraction movement of the front fork accompanying this absorption.

  In the suspension device main body F, a reservoir R is formed outside the shock absorber D, and contains working fluid and gas. The upper and lower openings in FIG. 1 of the suspension device main body F are closed by the cap member 8 (FIG. 3) and a bottom member (not shown), and a cylinder formed between the overlapping portions of the outer tube T1 and the inner tube T2. A gap T3 is attached to the inner periphery of the lower open end of the outer tube T1 in FIG. 1 and is closed by an annular dust seal s1 and an oil seal s2 that are in sliding contact with the outer peripheral surface of the inner tube T2. The working fluid and gas are prevented from leaking to the atmosphere side.

  Hereinafter, the shock absorber D according to the present embodiment housed in the suspension apparatus main body F will be described in detail. The shock absorber D includes a cylinder 6 that stands on the shaft center of the suspension device main body F and accommodates a working fluid, a piston rod (shaft member) 3 that protrudes and retracts in the cylinder 6 as the front fork expands and contracts, A piston (valve disk) 1 is provided which is held at the tip of the piston rod 3 and slidably contacts the inner peripheral surface of the cylinder 6 and is filled with the working fluid inside the cylinder 6 and the other chamber B. In the present embodiment, the working fluid stored in the cylinder 6 or the reservoir R is made of a liquid such as water, an aqueous solution, or oil, and the shock absorber D is a hydraulic pressure shock absorber.

  Further, in the shock absorber D, an annular rod guide 60 is attached to the one chamber side opening end of the cylinder 6, and the annular bearing 60 a fitted to the inner periphery of the rod guide 60 is used to The piston rod 3 is pivotally supported.

  A cushion member 61 made of a coil spring is provided between the rod guide 60 and the piston 1, and the cushion member 61 is in contact with the rod guide 60 and compressed when the front fork is fully extended. The reaction force can absorb the impact when the front fork is fully extended.

  Subsequently, as shown in FIG. 2, the piston 1 held at the tip of the piston rod 3 mainly allows the working fluid to move from one chamber A on the piston rod side to the other chamber B on the piston side. An extension-side flow path 10 and a pressure-side flow path 11 that mainly allows movement of the working fluid from the other chamber B to the one chamber A are formed, and the working fluid in the one chamber A and the other chamber B passes through the flow path. You can go back and forth via 10,11.

  Also, on the one chamber side and the other chamber side of the piston 1, there are a plurality of leaf valves 21 and 20 that are fixed to the piston 1 with the inner periphery as a fixed end and the outer periphery can be bent to the anti-piston side, respectively. Are stacked. Hereinafter, each leaf valve stacked on one chamber side of the piston 1 is referred to as a pressure side leaf valve 21, and each leaf valve stacked on the other chamber side of the piston 1 is referred to as an extension side leaf valve 20.

  The outlet of the extension side flow passage 10 formed in the piston 1 is closed so as to be opened and closed by the extension side leaf valve 20, and the inlet is not blocked by the pressure side leaf valve 21. One side opens to the chamber side. On the other hand, the outlet of the pressure side channel 11 is closed by the pressure side leaf valve 21 so as to be openable and closable, and the inlet is not blocked by the extension side leaf valve 20 and opens to the other chamber side.

  Further, of the leaf valves 20 and 21 on the expansion side and the pressure side, notches 20a and 21a functioning as orifices are respectively formed on the outer periphery of the leaf valves 20 and 21 on the most piston side. , 21a can be given resistance to the working fluid.

  And by providing the said structure, when the piston speed is in the low speed region at the time of extension of the front fork in which the piston rod 3 retracts from the cylinder 6 and the one chamber A is pressurized by the piston 1, the one chamber A The working fluid moves to the other chamber B through the notches 20a and 21a. Further, when the front fork extends, when the piston speed goes out of the low speed range and reaches the middle high speed range, the working fluid moves from the one chamber A to the other chamber B by bending the outer peripheral portion of the leaf valve 20 on the extension side. To do.

  On the other hand, when the piston speed is in the low speed region during compression of the front fork in which the piston rod 3 enters the cylinder 6 and the other chamber B is pressurized by the piston 1, the working fluid in the other chamber B is notched. It moves to one chamber A through 20a and 21a. When the front fork is compressed, when the piston speed leaves the low speed range and reaches the middle high speed range, the working fluid moves from the other chamber B to the one chamber A by bending the outer peripheral portion of the pressure side leaf valve 21. .

  That is, in the shock absorber D, when the piston speed is in the low speed range, the working fluid generates a square characteristic damping force due to the orifice, and when the piston speed reaches the middle high speed range, the proportional characteristics are attenuated by the leaf valves 20 and 21. Can generate power. Each threshold value in the piston speed region (low speed region, medium speed region, and high speed region) can be set as appropriate.

  Further, the shock absorber D according to the present embodiment compensates for a change in the cylinder volume corresponding to the volume of the piston rod retreating into the cylinder 6 and a change in the volume of the working fluid due to a temperature change. A well-known base member having a flow path that communicates the other chamber B and the reservoir R is provided at the bottom part in the lower side of FIGS. However, other well-known configurations may be selected as the configuration for volume compensation and temperature compensation. Similarly, although not shown, an air chamber partitioned by the other chamber B and the free piston is provided at the bottom of the cylinder 6. The air chamber may be expanded and contracted by moving the free piston.

  By the way, in the present embodiment, the piston rod 3 stands on the one chamber side of the piston 1 via the tip member 9, and the tip member 9 is in order from the rod guide side which is the upper side in FIG. It has a coupling portion 90 formed in a cylindrical shape with a screw groove 90a on the inner periphery, a cylindrical cylindrical portion 91, a bottomed cylindrical barrel portion 92, and a rod-shaped holding portion 93. These are arranged continuously in series on the same axis.

  The holding portion 93 is formed with an outer diameter smaller than the outer diameter of the body portion 92, and a screw groove is formed on the outer peripheral surface of the distal end portion (anti-piston rod side end portion) 93a. . As a result, the tip member 9 inserts the holding portion 93 into the mounting hole 1a of the piston 1 and screwes the nut N into the tip portion 93a, thereby holding the piston 1 between the trunk portion 92 and the nut N. Can be held.

  Also, a plurality of leaf valves 21, a small-diameter annular plate spacer 23, and a cylindrical spacer 24 are laminated in order from the piston side on the one chamber side, which is the upper side in FIG. On the other chamber side, a plurality of leaf valves 20, a small-diameter annular plate spacer 25 and an annular valve stopper 26 are laminated in order from the piston side. It is held between the nut N and held by the tip member 9.

  Further, a moving spring receiver 27 formed in an annular shape is slidably contacted with the outer peripheral surface of the spacer 24, and the moving spring receiver 27 is moved from the position in contact with the spacer 23 on the one chamber side to the tip member 9. It is possible to move to a position where the body 92 abuts. Further, the moving spring receiver 27 is urged to the piston side by the urging spring 4 and presses the inner peripheral side of the pressure-side leaf valve 21 via the one-side chamber spacer 23.

  Returning, the cylindrical portion 91 of the distal end member 9 is formed to have the same outer diameter as the coupling portion 90 and the inner diameter is substantially the same as the coupling portion 90, and the distal end portion 3a of the piston rod 3 is inserted. The In addition, annular grooves 91a and 91b having a U-shaped cross section are formed on the outer peripheral surface and the inner peripheral surface of the cylindrical portion 91, respectively, and the annular seals r1 and r2 are engaged with the annular grooves 91a and 91b, respectively. doing. The inner peripheral side seal r2 is in close contact with the outer peripheral surface of the tip portion 3a of the piston rod 3, and seals between the tip member 9 and the piston rod 3.

  Further, the trunk portion 92 is formed so that the outer diameter is smaller than the outer diameters of the coupling portion 90 and the cylindrical portion 91, and the inner diameter of the cylindrical end portion 92a formed on the cylindrical member side which is the upper side in FIG. Is formed smaller than the inner diameter of the cylindrical portion 91, and when the piston rod 3 is screwed into the coupling portion 90, the tip of the piston rod 3 abuts against the cylindrical end portion 92a. Further, the body 92 is formed with a hole 92 b that communicates the inside of the cylindrical end 92 a and the outside of the body 92.

  Subsequently, a cylindrical jack member 5 is provided on the outer periphery of the tip member 92. The jack member 5 is coaxially connected to the large inner diameter portion 50 on the rod guide side which is the upper side in FIG. 2 and the piston side of the large inner diameter portion 50 and has an inner diameter smaller than the inner diameter of the large inner diameter portion 50. And a small inner diameter portion 51 to be formed. An annular groove 51a having a U-shaped cross section is formed on the inner peripheral surface of the end portion on the large inner diameter portion side of the small inner diameter portion 51, and an annular seal r3 is engaged with the inner periphery of the annular groove 51a. doing.

  Further, the jack member 5 is configured such that the large inner diameter portion 50 is in sliding contact with the outer peripheral surface of the cylindrical portion 91 of the tip member 9 via a seal r1 attached to the tip member 9, and the small inner diameter portion 51 is the trunk of the tip member 9. The outer peripheral surface of the portion 92 is in sliding contact with a seal r3 attached to the jack member 5. For this reason, the jack member 5 can move along the piston rod 3 while being in sliding contact with the tip member 9, and can move closer to the leaf valve 21 on the compression side.

  Further, one end of the biasing spring (biasing member) 4 made of a coil spring on the side opposite to the leaf valve 21 is in contact with the piston side end of the jack member 5. The other end of the biasing spring 4 is in contact with a moving spring receiver 27 stacked on the pressure-side leaf valve 21. For this reason, when the jack member 5 approaches the pressure-side leaf valve 21, the reaction force by the biasing spring 4 increases, and when the jack member 5 moves away from the pressure-side leaf valve 21, the reaction force by the biasing spring 4 decreases.

  Subsequently, a jack chamber J1 is formed between the cylindrical portion 91 of the tip member 9 and the small inner diameter portion 51 of the jack member 5 so as to accommodate the fluid for jack. The jack fluid in the jack chamber J1 is caused by the seal r1 that engages with the cylindrical portion 91 and slidably contacts the jack member 5, and the seal r3 that engages with the small inner diameter portion 51 and slidably contacts the tip member 9. It does not flow into the cylinder 6.

  The jack chamber J1 expands when the jack member 5 moves to the piston side (pressure side leaf valve side) and the cylindrical portion 91 and the small inner diameter portion 51 are separated from each other. When the cylinder portion 91 and the small inner diameter portion 51 approach each other, the pressure is reduced. The expansion and contraction of the jack chamber J1 is performed by supplying and discharging the jack fluid into the jack chamber J1 through the jack flow path J2.

  The jack flow path J2 is formed in the axial center portion of the piston rod 3 formed in a cylindrical shape, and through the axial center portion of the cylindrical end portion 92a and the hole 92b in the body portion 92 of the tip member 9. It communicates with the jack room J1. The hole 92b is formed at a position that is not completely blocked by the small inner diameter portion 51 of the jack member 5, and is set so as not to prevent communication between the jack flow path J2 and the jack chamber J1.

  Further, the anti-jack chamber side of the jack flow path J2 is closed by a plug member 70 attached to the inner periphery of the end portion of the piston rod 3 on the anti-piston side as shown in FIG. An annular groove 70a having a U-shaped cross section is formed on the outer peripheral surface of the plug member 70, and an annular seal r4 is engaged with the outer periphery of the annular groove 70a. Thereby, the plug member 70 closes the anti-jack chamber side of the jack flow path J <b> 2, is brought into sliding contact with the inner peripheral surface of the piston rod 3 via the seal r <b> 4, and is movable along the piston rod 3.

  Subsequently, the tip of an adjuster (adjusting member) 7 is in contact with the anti-jack fluid side that is the upper side in FIG. 3 of the plug member 70, and the adjuster 7 causes the cap member 8 to hold the piston rod 3. A cylindrical rod holding member 80 is threadably engaged with the inner periphery.

  That is, in the present embodiment, it is a single room filled with the jack fluid from the jack flow path J2 to the jack chamber J2, and is sealed with the seals r1, r2, r3, r4. Since the plug member 70 and the jack member 5 located at both ends of the room are movable along the piston rod 3, the jack member 5 is interlocked by moving the plug member 70 with the adjuster 7. be able to. Further, the jack fluid in the present embodiment may be made of gas or liquid and can be selected from a wide variety, but the same fluid as the working fluid stored in the cylinder 6 or the reservoir R is employed. It is also good.

  Below, the effect of the shock absorber D which concerns on this Embodiment is demonstrated. In this embodiment, when the adjuster 7 serving as the adjustment member is moved to the piston rod side and the plug member 70 is moved into the piston rod 3, the jack fluid corresponding to the volume of the plug member that has entered enters the jack flow path J2. Move to room J1. For this reason, the jack member 5 moves forward to the piston side, the reaction force of the biasing spring (biasing member) 4 increases, and the force for biasing the pressure side leaf valve 21 to the piston side increases.

  On the other hand, when the adjuster 7 as the adjusting member is moved to the side opposite to the piston rod and the plug member 70 is retracted from the piston rod 3, the jack fluid corresponding to the volume of the retracted plug member moves from the jack chamber J1 to the jack flow path J2. To do. For this reason, the jack member 5 moves backward from the piston side, and the reaction force of the biasing spring (biasing member) 4 becomes small, and the force for biasing the pressure side leaf valve 21 toward the piston side becomes weak.

  That is, according to the present embodiment, the damping force (pressure side pressure) when the working fluid passes through the pressure side flow path 11 of the piston 1 and moves from the other chamber B to the one chamber A by the operation of the adjuster 7 as the adjusting member. The damping force can be adjusted.

  In this embodiment, since the biasing spring 4 presses the inner peripheral side of the pressure side leaf valve 21, the proportional characteristic of the leaf valve 21 is obtained from the damping force of the square characteristic of the orifice (notches 20a and 21a). It is possible to smooth the change when switching to the damping force, and to prevent the ride comfort from deteriorating.

  Further, in the shock absorber D of the present embodiment, even if the spring force of the biasing spring 4 is increased in order to hold down the inner peripheral side of the leaf valve 21, the jack member 5 is driven using the jack fluid. Therefore, it is possible to ensure a sufficient strength that can withstand the spring force of the urging spring 4, and the shock absorber D is not increased in weight.

  Further, in the present embodiment, the piston rod 3 is formed in a cylindrical shape, and the jack flow path J2 is formed in the axial center portion, and the anti-jack chamber side of the jack flow path J2 is disposed opposite to the piston rod 3. The stopper member 70 is attached to the piston side end portion so as to be movable in the axial direction, and the stopper member 70 is driven by an adjuster 7 as an adjusting member.

  Therefore, the plug member 70 and the jack member 5 can be interlocked while simplifying the configuration for closing the anti-jack chamber side of the jack flow path J2, and the configuration for adjusting the damping force can be simplified.

  The distal end member 9 includes a cylindrical portion 91 and a trunk portion 92 that is coaxially connected to the piston side of the cylindrical portion 91 and has an outer diameter smaller than the outer diameter of the cylindrical portion 91. A cylindrical jack member 5 provided on the outer periphery includes a large inner diameter portion 50 and a small inner diameter portion 51 that is coaxially connected to the piston side of the large inner diameter portion 50 and has an inner diameter smaller than the inner diameter of the large inner diameter portion 50. Since the jack chamber J1 is formed between the cylindrical portion 91 and the small inner diameter portion 51, the jack member 5 can be easily moved in the axial direction as the jack chamber J1 expands and contracts. It becomes.

  Further, in the present embodiment, the biasing spring 4 biases the pressure side leaf valve 21 stacked on the one chamber side of the piston 1 to the piston side via the spacer 23, so that the spacer 23 having a different outer shape is used. By using this, the position for energizing the leaf valve 21 can be easily changed.

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

  For example, in the above embodiment, the shock absorber according to the present invention is used for a front fork, but even if it is used for a rear cushion unit that suspends the rear wheel of a motorcycle, It may be used for suspension equipment for transport equipment and buildings.

  The shock absorber of the above embodiment is a single rod type hydraulic pressure shock absorber, but it may be a double rod type shock absorber or a pneumatic pressure shock absorber that uses gas as a working fluid.

  In the above embodiment, the present invention is embodied in the piston portion of the shock absorber. However, the working fluid is provided with a base member that communicates the other chamber and the reservoir, and is excessively insufficient in the cylinder via the base member. The present invention may be embodied in the base member portion of the shock absorber that compensates for this from the reservoir.

A One chamber B Other chamber D, D1 Shock absorber F Suspension device body J1 Jack chamber J2 Jack flow path T1 Outer tube T2 Inner tube R Reservoir r1, r1, r3, r4 Seal S Suspension spring 1, 1A Piston (valve disk)
3 Piston rod (shaft member)
4 Energizing spring (urging member)
5 Jack member 6 Cylinder 7 Adjuster (Adjustment member)
8 Cap member 9 Tip member 10 Stretch side channel 11, 100 Pressure side channel (channel)
20, 21 Leaf valve 50 Large inner diameter portion 51 Small inner diameter portions 51a, 91a, 91b, 70a Annular groove 60 Rod guide 70 Plug member 90 Connecting portion 91 Tube portion 92 Body portion 93 Holding portion

Claims (5)

A valve disc partitioned into one chamber and the other chamber; a flow passage formed in the valve disc to communicate the one chamber and the other chamber; and laminated on one chamber side of the valve disc to In a shock absorber comprising an annular plate-like leaf valve that closes the outlet in an openable and closable manner, a shaft member that stands on one side of the valve disc, and a biasing member that biases the leaf valve toward the valve disc.
A jack chamber, a jack member whose one end abuts on the side opposite to the leaf valve of the urging member and can be moved closer to the leaf valve as the jack chamber expands or contracts, and the jack chamber formed on the shaft member, A jack flow path that is always in communication, and an adjustment member that is attached to the shaft member on the side opposite to the valve disk and feeds and discharges the jack fluid to and from the jack chamber via the jack flow path. Shock absorber.   The shaft member is formed in a cylindrical shape, and the jack flow path is formed in the axial center portion. The anti-jack chamber side of the jack flow path is axially connected to the end of the shaft member on the anti-valve disk side. The shock absorber according to claim 1, wherein the stopper member is closed by a stopper member that is movably attached, and the stopper member is driven by the adjusting member.   The valve disc is held by the shaft member via a tip member, and the tip member is coaxially connected to the cylinder portion and the valve disc side of the cylinder portion so that the outer diameter is outside the cylinder portion. The jack member is formed in a cylindrical shape and provided on the outer periphery of the tip member, and is coaxially connected to the large inner diameter portion and the valve disk side of the large inner diameter portion. 3. The jack chamber according to claim 1, further comprising a small inner diameter portion having an inner diameter smaller than an inner diameter of the large diameter portion, wherein the jack chamber is formed between the cylindrical portion and the small inner diameter portion. The shock absorber described.   A spacer is provided on a side of the leaf valve opposite to the valve disc, and the biasing member biases the leaf valve toward the valve disc via the spacer. 4. The shock absorber according to any one of 3.   A shock absorber comprising: a cylinder that contains a working fluid; a piston rod that is movably inserted into the cylinder; and a piston that is held by the piston rod and that is in sliding contact with the inner peripheral surface of the cylinder. The rod and the piston are the shaft member and the valve disc, respectively, and the one chamber and the other chamber are formed in the cylinder. Shock absorber.

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