JP2019168094A - Buffer - Google Patents

Abstract

To provide a buffer capable of easily adjusting secondary attenuation force occurring in elongation and secondary attenuation force occurring in contraction individually.SOLUTION: A buffer comprises a partition wall member P partitioning a liquid reservoir R formed between an expandable buffer body D and a tube member 1 provided on the outer periphery thereof into an upper chamber r1 and a lower chamber r2, having a through-hole 7d communicating between the upper chamber r1 and the lower chamber r2, and moving relative to a liquid level Rs of the liquid reservoir R when the buffer body D expands and contracts. The partition wall member P has a first member 7 and a second member 8 that changes the opening area of the through-hole 7d by relative movement with the first member 7. The direction of relative movement of the first member 7 and the second member 8 is switched according to a direction in which liquid flows through the through-hole 7d.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an improved shock absorber.

  Conventionally, a shock absorber has a cylinder and a rod that is inserted into the cylinder so as to be movable in the axial direction. The shock absorber body that expands and contracts and exhibits a main damping force during the expansion and contraction, and the shock absorber. A tube member that is provided on the outer periphery of the container body and forms a liquid storage chamber for storing liquid between the shock absorber main body, the liquid storage chamber is divided into an upper chamber and a lower chamber, and the upper chamber and the lower chamber are communicated with each other. And a truncated cone-shaped partition wall member in which an aperture hole is formed.

  In such a shock absorber, the shock absorber body expands and contracts when the shock absorber expands and contracts, and exhibits a main damping force. Further, the liquid surface of the liquid storage chamber and the partition member move relative to each other as the shock absorber expands and contracts. When the shock absorber expands and contracts while the partition member is immersed in the liquid, the liquid is throttled. Move between the upper and lower chambers through. In addition, a resistance is applied to the flow of the liquid by the throttle hole, thereby generating a secondary damping force in addition to the main damping force (for example, Patent Document 1). .

JP 2010-261477 A

  Here, for example, when the shock absorber is used as a vehicle suspension and is interposed between the vehicle body and the axle, etc., when the amount of shrinkage of the shock absorber increases, the pressure side that resists the shrinkage is reduced. There are cases where it is desired to increase the damping force to alleviate the impact at the time of the most contraction.

  In such a case, the partition member may be installed so that the partition member is immersed in the liquid when the amount of contraction of the shock absorber becomes a predetermined amount or more. In this way, when the amount of contraction of the shock absorber exceeds a predetermined value, a secondary damping force is generated in addition to the main damping force, and the compression side damping force of the entire shock absorber can be increased.

  The characteristics of the damping force required for the shock absorber as shown in the above example vary depending on the purpose of use of the shock absorber, etc., but the stroke amount of the shock absorber (compression amount from the no-load state) or the operation direction There may be a case where a secondary damping force is additionally generated according to (when extended or compressed) and the damping force of the entire shock absorber at that time is increased.

  In the conventional shock absorber, if the position where the partition member is provided is changed, the stroke amount (position) where the secondary damping force starts to be generated can be changed. Can be adjusted. However, in the conventional shock absorber, the throttle hole of the partition member is always opened regardless of the expansion / contraction direction, and the opening area (flow path area) is constant. It is difficult to make adjustments such as increasing only the secondary damping force generated at the time of contraction without changing the value.

  Accordingly, the present invention has an object to provide a shock absorber capable of solving such problems and easily and independently adjusting a secondary damping force generated during expansion and a secondary damping force generated during contraction. .

  A shock absorber that solves the above problems partitions a liquid reservoir chamber formed between a shock absorber main body having a cylinder and a rod and extending and contracting, and a tube member provided on the outer periphery thereof into an upper chamber and a lower chamber. A partition member having a passage communicating the chamber and the lower chamber and changing the position of the liquid reservoir chamber with respect to the liquid level when the shock absorber main body expands and contracts is provided. And the partition member has a first member and a second member that changes the flow passage area of the passage by relative movement with the first member, and the first member according to the direction in which the liquid flows through the passage The direction of relative movement of the second member is switched.

  According to the above configuration, for example, when it is desired to increase only the secondary damping force generated when the shock absorber is contracted, the first member and the second member are arranged in the direction of decreasing the passage area of the passage when the shock absorber body is contracted. What is necessary is just to arrange | position a partition member so that two members may move relatively, and the flow-path area at the time of expansion-contraction can be set separately. For this reason, the secondary damping force generated when the shock absorber extends and the secondary damping force generated when the shock absorber contracts can be easily adjusted individually.

  Further, in the shock absorber, the first member and the second member are both cylindrical, the shock absorber body is inserted into the inner peripheral side of the first member, and the passage passes through the thickness of the first member. The second member, which is mounted on the inner peripheral side or the outer peripheral side of the first member so as to be movable in the axial direction, moves in the axial direction with respect to the first member. The opening area may be changed.

  According to the said structure, it is easy to switch the direction of relative movement of a 1st member and a 2nd member according to the direction where a liquid flows through a channel | path. Furthermore, since the through hole can be enlarged, the secondary damping force generated when the passage area of the passage is maximized can be reduced, and the adjustment range of the secondary damping force can be increased.

  In the shock absorber, the first member has an annular small-diameter portion that is in contact with the outer periphery of the shock-absorber body, and a truncated cone cylinder that is connected to one end of the small-diameter portion and gradually increases in inner diameter and outer diameter as the distance from the small-diameter portion increases. And a ring-shaped body portion and an annular large-diameter portion that is connected to the end of the body portion on the side opposite to the small-diameter portion and contacts the inner periphery of the tube member. According to this configuration, it is easy to secure a space for mounting the second member on the inner peripheral side or the outer peripheral side of the first member while partitioning the liquid reservoir chamber into the upper chamber and the lower chamber with the first member.

  In the shock absorber, the second member may include a shutter portion that opens and closes the through hole, and the inner and outer diameters of the shutter portion may be gradually reduced toward the tip in the shape of a truncated cone. According to this configuration, the outer peripheral surface and the inner peripheral surface of the shutter portion are directed from the pressure of the upper chamber or the lower chamber and from the upper chamber or the lower chamber to the other chamber through the through hole. It can be a pressure-receiving surface that receives the fluid force of the flowing liquid. For this reason, according to the said structure, it is easy to switch the direction of the relative movement of a 1st member and a 2nd member according to the direction through which a liquid flows through a channel | path.

  In the shock absorber, a rib may be formed along the axial direction on the inner periphery or outer periphery of the first member, and movement of the second member toward the upper chamber side or the lower chamber side may be limited by the rib. . According to the said structure, it is easy to change the shape of a 2nd member, and tuning of secondary damping force can be made easy.

  In the above shock absorber, the first member is arranged with the large-diameter portion directed toward either the upper chamber or the lower chamber, and the second member is an annular slide that is in sliding contact with the inner periphery of the large-diameter portion. And the second member has a notch formed on the outer periphery of the slide member in a state where movement of the second member to one chamber side is restricted at one end in the axial direction of the second member. An end groove that communicates the gap formed along the axial direction with the one member and the one chamber may be formed. According to the said structure, it can prevent that a liquid is confined between a 1st member and a 2nd member, and can ensure the opening / closing operation | movement of the channel | path by the relative movement of a 1st member and a 2nd member.

  In the shock absorber, the tube member has an outer tube and an inner tube that is slidably inserted into the outer tube, the cylinder is connected to the outer tube, and the rod is connected to the inner tube. The first member is mounted on the outer periphery of the cylinder and is slidably inserted inside the inner tube, and a coil spring is interposed between the first member and a lid portion that closes one end of the inner tube. It is good to be.

  According to the said structure, since a 1st member functions also as a spring receiving member which supports the end of a coil spring, the number of components of a buffer can be reduced compared with the case where the spring receiving member and a partition member are provided separately. .

  According to the shock absorber of the present invention, the secondary damping force generated at the time of expansion and the secondary damping force generated at the time of contraction can be easily adjusted individually.

It is the longitudinal cross-sectional view which showed the shock absorber which concerns on one embodiment of this invention in principle. (A) is the front view which showed the state when the partition member of the buffer which concerns on one embodiment of this invention maximized the opening area of a through-hole. (B) is sectional drawing which notched and showed a part of partition member of (a) to the vertical direction. (A) is the front view which showed the state when the partition member of FIG. 2 minimized the opening area of the through-hole. (B) is sectional drawing which notched and showed a part of partition member of (a) to the vertical direction. It is the fragmentary sectional view which showed the modification of the 2nd member in the partition member of the buffer which concerns on one embodiment of this invention. The modification of the partition member of the buffer which concerns on one embodiment of this invention is shown. (A) is the front view which showed the state when the partition member which concerns on the modification maximized the opening area of a through-hole. (B) is sectional drawing which notched and showed a part of partition member of (a) to the vertical direction. (A) is the front view which showed the state when the partition member of FIG. 5 minimized the opening area of the through-hole. (B) is sectional drawing which notched and showed a part of partition member of (a) to the vertical direction. It is the perspective view which looked at the 2nd member of the partition member shown to FIG. It is the longitudinal cross-sectional view which showed the modification of the buffer which concerns on one embodiment of this invention, and showed the buffer which concerns on the said modification in principle.

  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.

  The shock absorbers A and A1 according to the embodiment of the present invention shown in FIGS. 1 and 8 are each used in a vehicle suspension device. In the following description, the upper and lower sides of the shock absorbers A and A1 in a state where the shock absorbers A and A1 are attached to the vehicle are simply referred to as “upper” and “lower” of the shock absorbers A and A1, unless otherwise specified.

  A shock absorber A according to an embodiment of the present invention shown in FIG. 1 is used in a front fork that is a suspension device for suspending front wheels of a saddle-ride type vehicle. The shock absorber A includes a telescopic tube member 1 having an outer tube 10 and an inner tube 11 slidably inserted into the outer tube 10. A shock absorber body D and a suspension spring S.

  In the present embodiment, the tube member 1 is an inverted type, and is attached to a straddle-type vehicle with the outer tube 10 facing upward (vehicle body side) and the inner tube 11 facing downward (axle side). Thus, in the present embodiment, the outer tube 10 is a vehicle body side tube, and the inner tube 11 is a wheel side tube.

  The outer tube 10 is connected to the vehicle body of the saddle riding type vehicle via a vehicle body side bracket (not shown), and the inner tube 11 is connected to the front wheel axle via the wheel side bracket 12. In this way, the shock absorber A is interposed between the vehicle body and the axle, and when the front wheel vibrates up and down, for example, when the straddle-type vehicle travels on an uneven road surface, the inner tube 11 is moved to the outer tube 10. The shock absorber A expands and contracts.

  Further, the upper end of the outer tube 10 which is the upper end of the tube member 1 is closed with a cap 13. On the other hand, the lower end of the inner tube 11 serving as the lower end of the tube member 1 is closed by the wheel side bracket 12. Furthermore, the lower end of the cylindrical gap formed between the overlapping portions of the outer tube 10 and the inner tube 11 is closed with a seal member 14. In this way, the inside of the tube member 1 is sealed.

  The shock absorber body D and the suspension spring S are accommodated in the tube member 1. More specifically, the suspension spring S of the present embodiment is a coil spring and is disposed in a liquid reservoir chamber R formed between the tube member 1 and the shock absorber body D. In the liquid storage chamber R, a liquid such as hydraulic oil is stored on the lower side, and a gas such as air is sealed above the liquid level Rs.

  Subsequently, the shock absorber body D includes a cylinder 2, a piston 3 slidably inserted into the cylinder 2, a piston rod 4 having one end connected to the piston 3 and the other end protruding outside the cylinder 2. An annular rod guide 20 that is attached to one end of the cylinder 2 and slidably supports the piston rod 4, and a valve case 5 that is fixed to the opposite side of the rod guide 20 when viewed from the piston 3 in the cylinder 2. The free piston 6 is slidably inserted to the opposite side of the piston 3 when viewed from the valve case 5 in the cylinder 2, and the biasing member 60 biases the free piston 6 toward the piston 3.

  The shock absorber body D of the present embodiment is an inverted type, and is disposed in the tube member 1 with the piston rod 4 protruding outside the cylinder 2 facing downward (axle side). The cylinder 2 is connected to the outer tube 10 via the cap 13, and the piston rod 4 is connected to the inner tube 11 via the wheel side bracket 12.

  Thus, the shock absorber body D is interposed between the outer tube 10 and the inner tube 11. When the shock absorber A expands and contracts and the inner tube 11 enters and exits the outer tube 10, the piston rod 4 enters and exits the cylinder 2, the shock absorber body D expands and contracts, and the piston 3 moves up and down in the cylinder 2.

  The upper end of the cylinder 2 is closed with a cap 13. On the other hand, the lower end of the cylinder 2 is closed by the rod guide 20. Thus, the inside of the cylinder 2 whose both ends in the axial direction are closed is partitioned into the liquid chamber L and the air chamber G by the free piston 6. The liquid chamber L is filled with the same liquid as the liquid reservoir chamber R, and the gas chamber G is filled with the same gas as the liquid reservoir chamber R.

  The liquid chamber L is divided vertically by the piston 3 and the valve case 5. The piston rod 4 side of the piston 3 is on the expansion side chamber L1, and the space between the piston 3 and the valve case 5 is the pressure side chamber L2 and the valve case 5 is free. The piston 6 side is a pressurizing chamber L3. In other words, the expansion side chamber L1 and the pressure side chamber L2 are partitioned by the piston 3, the pressure side chamber L2 and the pressurizing chamber L3 are partitioned by the valve case 5, and the pressurizing chamber L3 and the air chamber G are partitioned by the free piston 6. ing.

  Further, the urging member 60 is accommodated in the air chamber G. The biasing member 60 is a coil spring in the present embodiment, and is interposed between the cap 13 and the free piston 6 in a compressed state. For this reason, the urging member 60 pressurizes the pressurizing chamber L <b> 3 via the free piston 6. The pressure in the pressurizing chamber L3 is transmitted to the pressure side chamber L2 and the extension side chamber L1 through passages described later formed in the valve case 5 and the piston 3, respectively. For this reason, when the pressurizing chamber L3 is pressurized using the biasing member 60 and the free piston 6, the entire liquid chamber L can be pressurized.

  Further, a communication hole 2a is formed in the upper part of the cylinder 2, so that gas can freely move between the gas chamber G and the liquid reservoir chamber R through the communication hole 2a. However, the communication hole 2a is eliminated and compressed gas is sealed in the air chamber G, and an air spring configured with the air chamber G is used as an urging member, or the elasticity of rubber or the like accommodated in the air chamber G is used. The member may be used as an urging member.

  Subsequently, the piston 3 is formed with an extension side passage 3a and a pressure side passage 3b communicating the extension side chamber L1 and the pressure side chamber L2. An extension side valve 30 is provided in the extension side passage 3a. The extension side valve 30 is an extension side damping element, and opens when the shock absorber A is extended, and provides resistance to the flow of liquid from the extension side chamber L1 toward the compression side chamber L2. On the other hand, a pressure side valve 31 is provided in the pressure side passage 3b. The pressure side valve 31 is a check valve, and opens only when the shock absorber A contracts, and allows the flow of liquid from the pressure side chamber L2 toward the extension side chamber L1.

  Further, the valve case 5 is formed with a suction passage 5a and a discharge passage 5b that connect the pressure side chamber L2 and the pressurization chamber L3. A suction valve 50 is provided in the suction passage 5a. The suction valve 50 is a check valve that opens only when the shock absorber A is extended and allows the flow of liquid from the pressurizing chamber L3 toward the pressure side chamber L2. On the other hand, a damping valve 51 is provided in the discharge passage 5b. The damping valve 51 is a pressure side damping element, and opens when the shock absorber A contracts, and provides resistance to the flow of liquid from the pressure side chamber L2 toward the pressure chamber L3.

  According to the above configuration, when the shock absorber A is extended so that the inner tube 11 is retracted from the outer tube 10, the piston rod 4 is retracted from the cylinder 2 and the shock absorber body D is extended, and the piston 3 is moved downward in the cylinder 2. It moves and compresses the extension side chamber L1. When the shock absorber A is extended, the liquid in the expansion side chamber L1 pushes open the expansion side valve 30 and moves to the compression side chamber L2 through the expansion side passage 3a. Resistance is given to the flow of the liquid by the expansion side valve 30. For this reason, when the shock absorber A extends, the pressure in the expansion side chamber L1 rises, and the shock absorber main body D exhibits the main expansion side damping force that prevents the expansion operation.

  Further, when the shock absorber A is extended, the suction valve 50 is opened, and the liquid corresponding to 4 volumes of the piston rod retreated from the cylinder 2 is supplied from the pressurizing chamber L3 to the pressure side chamber L2 through the suction passage 5a. When the liquid in the pressurizing chamber L3 decreases in this way, the free piston 6 is pushed down by the urging force of the urging member 60 and moves forward, the volume of the pressurizing chamber L3 is reduced and the volume of the air chamber G is expanded. To do. Thus, in the present embodiment, even if the volume in the volume integrating cylinder 2 of the piston rod 4 that has retreated from the cylinder 2 when the shock absorber A is extended increases, the volume change is compensated for the pressurizing chamber L3 and the air chamber G. Can compensate.

  On the other hand, when the shock absorber A contracts in which the inner tube 11 enters the outer tube 10, the piston rod 4 enters the cylinder 2, the shock absorber body D contracts, and the piston 3 moves upward in the cylinder 2. Then, the compression side chamber L2 is compressed. When the shock absorber A is contracted, the pressure side valve 31 is opened, and the liquid in the pressure side chamber L2 moves to the expansion side chamber L1 through the pressure side passage 3b. As described above, since the pressure side valve 31 is a check valve, the pressure in the extension side chamber L1 and the pressure side chamber L2 becomes substantially the same when the shock absorber A contracts.

  Further, when the shock absorber A contracts, the liquid in the pressure side chamber L2 pushes open the damping valve 51, and the volume of the piston rod 4 volume that has entered the cylinder 2 passes through the discharge passage 5b from the pressure side chamber L2 to the pressure chamber L3. Is discharged. Resistance is given to the flow of the liquid by the damping valve 51. For this reason, when the shock absorber A contracts, the pressure in the expansion side chamber L1 and the compression side chamber L2 rises, and the shock absorber main body D exhibits the main compression side damping force that hinders the contraction operation.

  When the shock absorber A contracts, the liquid moves from the pressure side chamber L2 to the pressurizing chamber L3 and the liquid in the pressurizing chamber L3 increases. As a result, the free piston 6 is pushed up against the urging force of the urging member 60. The volume of the pressurizing chamber L3 is increased and the volume of the air chamber G is reduced. Thus, in the present embodiment, even if the volume in the volumetric cylinder 2 of the piston rod 4 that has entered the cylinder 2 when the shock absorber A contracts decreases, the volume change is detected by the pressurizing chamber L3 and the air chamber. G can compensate.

  Further, in the present embodiment, a pressurizing mechanism that pressurizes the liquid chamber L by including the urging member 60 and the free piston 6 is configured. For this reason, the liquid column rigidity in the cylinder 2 can be increased to improve the damping force generation response. Furthermore, in this embodiment, although not shown, when the retraction amount of the free piston 6 (the movement amount in the direction away from the valve case 5) increases, the liquid in the pressurizing chamber L3 is transferred to the liquid reservoir chamber R through the communication hole 2a. A relief mechanism is provided. For this reason, even if it has a pressurizing mechanism, it can prevent that the pressure in the cylinder 2 becomes excessive.

  In the present embodiment, the expansion side valve 30 functions as an expansion side damping element for generating an expansion side damping force, and the attenuation valve 51 functions as a compression side damping element for generating a compression side damping force. Since the passages provided with the expansion side and compression side damping elements are each one-way, the expansion side damping force and the compression side damping force can be set independently. As such a damping element, a leaf valve, a poppet valve or the like can be employed.

  However, the damping element may be an orifice, a choke passage or the like, and in this case, bidirectional flow of the passage provided with the damping element may be allowed. Further, the pressure side valve 31 may be replaced with a pressure side damping element, and resistance may be given to the flow of liquid in the pressure side passage 3b from the pressure side chamber L2 toward the extension side chamber L1. Thus, the configuration and arrangement of the attenuation element can be changed as appropriate.

  Further, the style of the shock absorber body D can be changed as appropriate. For example, with the shock absorber body D upright, the piston rod 4 protruding outside the cylinder 2 is directed upward (vehicle body side), the piston rod is connected to the vehicle body side tube, and the cylinder is connected to the axle side tube. Also good. In such a case, the pressurizing chamber L3, the gas chamber G, the free piston 6, and the urging member 60 in the cylinder 2 are eliminated, and the pressure side chamber L2 and the liquid reservoir chamber R are formed by the suction passage 5a and the discharge passage 5b. You may communicate with.

  Further, the liquid or gas may not move between the cylinder 2 and the liquid reservoir chamber R. In this case, different liquids or gases may be accommodated in the cylinder 2 and the liquid reservoir chamber R.

  Subsequently, the shock absorber A includes a partition member P that is provided between the tube member 1 and the shock absorber body D and partitions the liquid reservoir chamber R into an upper chamber r1 and a lower chamber r2. The partition member P has a cylindrical first member 7 mounted on the outer periphery of the cylinder 2 and a second member 8 inserted on the inner peripheral side of the first member 7 so as to be movable in the axial direction. Configured.

  As shown in FIGS. 2 and 3, the first member 7 is a divergent cylindrical member whose end is thicker than the tip, and an annular small-diameter portion 7a provided at the tip, and the small-diameter portion 7a It includes a truncated cone-shaped barrel portion 7b that is continuous with the end and gradually increases with increasing distance from the small-diameter portion 7a, and an annular large-diameter portion 7c that is continuous with the end opposite to the small-diameter portion 7a. As shown in FIG. 1, the first member 7 is mounted on the outer periphery of the cylinder 2 with the small diameter portion 7a facing upward and the large diameter portion 7c facing downward.

  As shown in FIGS. 2 (b) and 3 (b), the inner diameter of the small diameter portion 7a is smaller than the inner diameter of the large diameter portion 7c, and the inner periphery of the small diameter portion 7a is in contact with the outer periphery of the cylinder 2 (FIG. 1). Touch. As shown in FIG. 1, a stopper member 21 such as a snap ring is mounted on the outer periphery of the cylinder 2 so that the upper end of the small diameter portion 7 a abuts against the stopper member 21. For this reason, the upward movement of the first member 7 relative to the cylinder 2 is restricted by the stopper member 21.

  2B and 3B, the outer diameter of the large diameter portion 7c is larger than the outer diameter of the small diameter portion 7a, and the outer periphery of the large diameter portion 7c is the inner tube 11 (FIG. 1). ) An annular spring seat 9 is attached to the lower end of the large diameter portion 7c, and the upper end of the suspension spring S abuts on the spring seat 9 as shown in FIG. Further, the lower end of the suspension spring S is supported by the wheel side bracket 12.

  Therefore, when the shock absorber A contracts and the cylinder 2 enters the inner tube 11, the first member 7, which is prevented from moving upward with respect to the cylinder 2 by the stopper member 21, approaches the wheel side bracket 12 and is suspended. The spring S is compressed. In this way, when the suspension spring S is compressed, an elastic force is exerted to urge the shock absorber A in the extending direction. For this reason, the vehicle body can be elastically supported by the suspension spring S.

  In the present embodiment, the wheel side bracket 12 functions as a lid portion that closes the lower end of the inner tube 11, and the wheel side bracket 12 supports one end of the suspension spring S. However, the lower end of the suspension spring S may be supported by a lid formed separately from the wheel side bracket 12. In this way, the configuration of the lid that closes one end of the inner tube 11 and supports one end of the suspension spring S is not limited to the wheel-side bracket 12 and can be changed as appropriate.

  Next, as shown in FIGS. 2B and 3B, the body portion 7b is in the shape of a truncated cone as described above, and the inner diameter and outer diameter thereof are the upper ends (ends on the small diameter portion 7a side), respectively. Gradually increases toward the lower end (end on the large diameter portion 7c side). And as shown in FIG. 1, when the 1st member 7 exists in an attachment state, a clearance gap is made in the inner peripheral side and outer peripheral side of the trunk | drum 7b, respectively.

  A gap formed on the inner peripheral side (cylinder 2 side) of the body portion 7b opens to the lower chamber r2, and the upper side is closed by the small diameter portion 7a. On the other hand, a gap formed on the outer peripheral side (inner tube 11 side) of the body portion 7b opens to the upper chamber r1 and the lower side is closed by the large diameter portion 7c.

  The trunk portion 7b is formed with a through hole 7d that penetrates the thickness of the trunk portion 7b and communicates the upper chamber r1 and the lower chamber r2. As shown in FIGS. 2 and 3, the through holes 7d are vertically long holes extending in the axial direction of the body portion 7b, and a plurality of the through holes 7d are formed in the circumferential direction of the body portion 7b.

  Further, as shown in FIGS. 2B and 3B, a rib 7e is formed along the axial direction on the inner periphery of the body portion 7b. The ribs 7e are provided in the same number as the through holes 7d, and the through holes 7d and the ribs 7e are alternately arranged in the circumferential direction of the body portion 7b.

  In this embodiment, four through holes 7d and four ribs 7e are formed, but the number can be changed as appropriate. Furthermore, the numbers of the through holes 7d and the ribs 7e are not necessarily the same, and the shapes and arrangement of the through holes 7d and the ribs 7e can be changed as appropriate.

  Subsequently, the second member 8 to be inserted on the inner peripheral side of the first member 7 includes a truncated cone-shaped cylindrical shutter portion 8a that is provided at the distal end portion thereof and tapers toward the distal end portion, and the shutter portion 8a. And an annular slide portion 8b connected to the end. The second member 8 is inserted into the first member 7 with the shutter portion 8a facing upward and the sliding portion 8b facing downward, and the sliding portion 8b is slid onto the inner periphery of the large-diameter portion 7c. The first member 7 is moved in the axial direction (vertical direction) while being in contact.

  A groove 8c is formed from the upper end of the second member 8 to the middle of the slide portion 8b, and the lower portion of the rib 7e is inserted into the groove 8c. When the second member 8 moves upward (upper chamber side) relative to the first member 7, the lower end of the rib 7e hits the bottom of the groove 8c, and the second member 8 moves further upward. Is blocked (FIG. 3). Thus, in the present embodiment, the rib 7e functions as an upper chamber side stopper that restricts the upward movement (upper chamber r1 side) of the second member 8 relative to the first member 7.

  As described above, the position where the second member 8 hits the rib (upper chamber side stopper) 7e and the further upward movement is prevented is defined as the upper limit position. Then, when the second member 8 is in its upper limit position, the tip of the shutter portion 8a is at a position higher than the lower end of the through hole 7d, the shutter portion 8a covers a part of the through hole 7d, and the through hole 7d The opening area is narrowed (FIG. 3A).

  In the present embodiment, the lower end of the rib 7e is lower than the lower end of the through hole 7d, so that the upper end of the second member 8 can move upward beyond the lower end of the through hole 7d. A groove 8c is formed in the member 8. However, when the lower end of the rib 7e is at a position higher than the lower end of the through hole 7d, the groove 8c is eliminated, the upper end of the second member 8 is abutted against the lower end of the rib 7e, and the position is set to the second member. An upper limit position of 8 may be used.

  On the other hand, when the second member 8 moves downward (lower chamber r2 side) with respect to the first member 7, the lower end of the slide portion 8b hits the spring seat 9, and further below the second member 8. Is prevented from moving to (Fig. 2 (b)). Thus, in the present embodiment, the spring seat 9 functions as a lower chamber side stopper that restricts the downward movement of the second member 8 relative to the first member 7 (lower chamber r2 side).

  As described above, the position where the second member 8 hits the spring seat (lower chamber side stopper) 9 and the further downward movement is prevented is defined as the lower limit position. Then, when the 2nd member 8 exists in the lower limit position, the front-end | tip of the shutter part 8a exists in a position lower than the lower end of the through-hole 7d, and the through-hole 7d is opened fully (FIG. 2 (a)). ). When the second member 8 is at the lower limit position, the through hole 7d does not necessarily have to be fully opened.

  Hereinafter, the operation of the shock absorber A of the present embodiment will be described.

  When the shock absorber A shown in FIG. 1 contracts and the cylinder 2 enters the inner tube 11, the partition member P moves in the inner tube 11 together with the cylinder 2 and approaches the liquid level Rs of the liquid storage chamber R. When the amount of penetration of the cylinder 2 into the inner tube 11 further increases, the cylinder 2 enters the liquid in the liquid storage chamber R, the liquid level Rs rises, and the partition member P is immersed in the liquid. Thus, in this Embodiment, when the shrinkage | contraction amount (stroke amount) of the buffer A becomes more than predetermined, it will move in a liquid in the state in which the partition member P was immersed.

  When the shock absorber A exhibits a contraction operation with the partition wall member P immersed therein, the liquid in the lower chamber r2 moves from the inner peripheral side of the large diameter portion 7c of the first member 7 to the inner peripheral side of the trunk portion 7b. The liquid level Rs rises while moving to the upper chamber r1 through the through hole 7d. At this time, the second member 8 is moved upward in the first member 7 by receiving the pressure of the lower chamber r2 and the fluid force of the liquid flowing from the lower chamber r2 to the upper chamber r1 through the through hole 7d. The opening area of the through hole 7d is narrowed.

  For this reason, when the shock absorber A contracts within a predetermined stroke range in which the amount of contraction of the shock absorber A is greater than or equal to a predetermined amount, a large resistance is imparted to the flow of liquid from the lower chamber r2 to the upper chamber r1 by the through hole 7d. Is done. Thereby, in addition to the main compression side damping force due to the resistance of the damping valve (pressure side damping element) V4, a large secondary damping force due to the resistance of the through hole 7d is generated.

  On the other hand, when the shock absorber A exhibits an extension operation with the partition wall member P immersed, the liquid in the upper chamber r1 moves from the outer peripheral side of the trunk portion 7b to the lower chamber r2 through the through hole 7d. The liquid level Rs is lowered. At this time, the second member 8 is moved downward in the first member 7 by receiving the pressure of the upper chamber r1 and the fluid force of the liquid flowing from the upper chamber r1 to the lower chamber r2 through the through hole 7d. The opening area of the through hole 7d is increased.

  For this reason, when the shock absorber A extends in a predetermined stroke range in which the amount of contraction of the shock absorber A is equal to or greater than a predetermined amount, resistance is imparted to the flow of liquid from the upper chamber r1 to the lower chamber r2 through the through hole 7d. However, its resistance is smaller than when it contracts. As a result, the secondary damping force caused by the resistance of the through hole 7d generated in addition to the main elongation side damping force caused by the resistance of the expansion side valve (extension side damping element) V1 is reduced.

  Further, when the partition member P is located above the liquid level Rs of the liquid reservoir R, the gas freely passes between the upper chamber r1 and the lower chamber r2 through the through hole 7d. For this reason, in the stroke range in which the amount of contraction of the shock absorber A is less than a predetermined amount, no secondary damping force is generated, and the damping force generated by the shock absorber A is only the main damping force.

  As described above, in the present embodiment, the secondary damping force generated is increased only when the amount of contraction of the shock absorber A exceeds a predetermined value and the shock absorber A contracts, and the shock absorber is increased. A damping force as a whole can be increased. For this reason, even when a large thrust input is applied when the damping force in the normal stroke range in which the contraction amount of the shock absorber A is not so large, the shock at the time of the maximum contraction of the shock absorber A is sufficiently obtained. Can be relaxed.

  Hereinafter, the function and effect of the shock absorber A according to the present embodiment will be described.

  The shock absorber A according to the present embodiment includes a shock absorber body D that has a cylinder 2 and a piston rod 4 that is inserted into the cylinder 2 so as to be movable in the axial direction, and the shock absorber body D. A tube member 1 that forms a liquid reservoir chamber R with the shock absorber body D, and partitions the liquid reservoir chamber R into an upper chamber r1 and a lower chamber r2, and an upper chamber r1 and a lower chamber r2. And a partition wall member P having a through-hole 7d communicating therewith. Thus, in the present embodiment, the through hole 7d is a passage that communicates the upper chamber r1 and the lower chamber r2.

  Further, in the present embodiment, the partition wall member P is moved with respect to the liquid level Rs of the liquid storage chamber R when the shock absorber body D is expanded and contracted, and the partition wall member P includes the first member 7, The second member 8 changes the opening area (flow passage area) of the through hole (passage) 7d by relative movement with the first member 7. The direction of relative movement of the first member 7 and the second member 8 is switched according to the direction in which the liquid flows through the through hole (passage) 7d.

  For this reason, when it is desired to reduce the secondary damping force generated during expansion of the shock absorber A and increase the secondary damping force generated during contraction as in the present embodiment, for example, FIG. The partition member P is arranged in such a way that when the shock absorber body D contracts, when the liquid flows through the through hole (passage) 7d, the opening area (flow passage area) of the through hole (passage) 7d is reduced. The one member 7 and the second member 8 may be moved relative to each other. On the other hand, when it is desired to increase the secondary damping force generated when the shock absorber A is extended and to reduce the secondary damping force generated when the shock absorber A is contracted, for example, the partition member P is set upside down in FIG. What is necessary is just to arrange.

  As described above, according to the above configuration, when the liquid flows through the through hole (passage) 7d, the opening area (flow channel area) of the through hole (passage) 7d can be changed according to the expansion / contraction direction of the shock absorber body D. Therefore, the secondary damping force generated when the shock absorber A extends and the secondary damping force generated when the shock absorber A contracts can be easily adjusted individually.

  Moreover, in this Embodiment, both the 1st member 7 and the 2nd member 8 are cylindrical. The shock absorber body D is inserted on the inner peripheral side of the first member 7, and the passage that communicates the upper chamber r 1 and the lower chamber r 2 has a through hole 7 d that penetrates the thickness of the first member 7. Is formed. Further, when the second member 8 is inserted on the inner peripheral side of the first member 7 so as to be movable in the axial direction, and the second member 8 moves in the axial direction with respect to the first member 7, The opening area is changed.

  According to the said structure, it is easy to switch the direction of the relative movement of the 1st member 7 and the 2nd member 8 according to the direction through which the liquid flows through the through-hole (passage | path) 7d. Furthermore, according to the said structure, the through-hole 7d is formed in the cylindrical 1st member 7 so that the thickness may be penetrated, and the through-hole 7d can be enlarged. In addition, a passage having the through hole 7d and communicating the upper chamber r1 and the lower chamber r2 is formed, and the flow area of the passage can be changed by changing the opening area of the through hole 7d.

  For this reason, according to the said structure, the opening area at the time of the maximum opening of the through-hole (passage | path) 7d can be enlarged, and the secondary damping force generate | occur | produced at that time can be made small. In other words, according to the above configuration, the adjustment range in the direction of decreasing the secondary damping force can be increased, so that the adjustment range of the secondary damping force can be increased.

  Further, the first member 7 of the present embodiment has an annular small diameter portion 7a whose inner periphery is in contact with the outer periphery of the shock absorber main body D, and an inner diameter and an outer diameter that are connected to one end of the small diameter portion 7a and move away from the small diameter portion 7a. An annular shape in which the outer periphery is in contact with the inner periphery of the tube member 1 and is connected to an end (anti-small diameter portion side end) opposite to the small diameter portion 7a of the truncated cone portion 7b. Large-diameter portion 7c.

  For this reason, it is easy to secure a space for mounting the second member 8 on the inner peripheral side of the first member 7 while partitioning the liquid reservoir chamber R up and down by the first member 7. Note that the second member 8 may be mounted on the outer peripheral side of the first member 7, and even in such a case, according to the above configuration, a space for mounting the second member 8 can be easily secured.

  Further, the second member 8 of the present embodiment includes a shutter portion 8a that opens and closes the through hole 7d, and the inner diameter and the outer diameter are gradually reduced as the shutter portion 8a is in the shape of a truncated cone and toward the tip. . Here, opening and closing the through hole 7d means to increase or decrease the opening area of the through hole 7d.

  According to the above configuration, the outer peripheral surface and the inner peripheral surface of the shutter portion 8a are respectively connected to the pressure in the upper chamber r1 or the lower chamber r2 and either the upper chamber r1 or the lower chamber r2 through the through hole 7d. The pressure receiving surface can receive the fluid force of the liquid flowing from the chamber toward the other chamber. For this reason, according to the said structure, it is easy to switch the direction of the relative movement of the 1st member 7 and the 2nd member 8 according to the direction through which the liquid flows through the through-hole (passage | path) 7d.

  Furthermore, as shown in FIG. 4, a pressure receiving portion 8d having a gentle inclination angle (small bottom angle) may be provided at the tip of the shutter portion 8a. In this case, the pressure receiving area can be increased. However, the pressure receiving surface of the second member 8 may be formed other than the shutter portion 8a. In this case, the outer diameter or inner diameter of the shutter portion 8a may be constant.

  Moreover, in this Embodiment, the rib 7e is formed along the axial direction in the inner periphery of the 1st member 7, and the movement to the upper chamber r1 side of the 2nd member 8 is restrict | limited by the rib 7e. According to this configuration, the first member 7 can be reinforced with the ribs 7e, and the shape of the second member 8 can be easily changed, and the secondary damping force can be easily tuned.

  This is because, for example, the tip of the second member 8 (the upper end of the portion other than the groove 8c) is abutted against a portion other than the inner rib 7e of the first member 7 to move the second member 8 toward the upper chamber r1. In this case, if the shape of the tip of the second member 8 is changed by providing a pressure receiving portion 8d as shown in FIG. 4, the upper limit position of the second member 8 is shifted, and the upper limit position is reached. It will be necessary to adjust. For this reason, the shape of the 2nd member 8 cannot be changed simply.

  On the other hand, according to the above configuration, the upper limit position can be adjusted by changing the position of the portion (abutting portion) that abuts against the rib 7e of the second member 8, and of course, the abutting portion (in this embodiment) If the bottom of the groove 8c is not changed, the upper limit position does not change even if the shape of the other part is changed. For this reason, even if the shape of the second member 8 is changed, it is not necessary to adjust the upper limit position. Therefore, it is easy to change the shape of the second member 8 such as by providing the pressure receiving portion 8d, and secondary damping force tuning is possible. Can be easily done.

  In addition, such an effect is a case where the 2nd member 8 is attached to the outer periphery of the 1st member 7 so that a movement to an axial direction is possible, Comprising: The rib formed in the outer periphery of the 1st member 7 is the 2nd member 8's outer periphery. Even when the movement to the upper chamber r1 side is restricted, the partition member P is attached in the reverse direction so that the movement to the lower chamber r2 side of the second member 8 is restricted by the rib 7e. You may do this.

  Furthermore, like the partition member P1 shown in FIGS. 5 and 6, the upper end (tip) of the second member 8A is abutted against the inner periphery of the first member 7A to restrict the upward movement of the second member 8A in the drawing. You may do it (FIG.5 (b)). In this case, the rib 7e can be omitted, and when the first member 7A is provided with a rib, the length and arrangement of the rib can be freely changed. For example, you may provide a rib in the outer periphery of the 1st member 7A which inserted the 2nd member 8A in the inner peripheral side.

  Further, in the partition member P1 shown in FIGS. 5 and 6, the first member 7A is arranged with the large diameter portion 7c facing the lower chamber r2 as in the partition member P shown in FIGS. Furthermore, as shown in FIG. 7, the outer peripheral shape of the slide portion 8b of the second member 8A is a rounded quadrangular shape as viewed in the axial direction, and an end portion at the lower end (one axial end) of the second member 8A. A groove 8e is formed. Then, the curved portion 8f whose outer periphery is formed in a curved shape is brought into sliding contact with the inner periphery of the large-diameter portion 7c of the first member 7A.

  As described above, in the partition member P1 shown in FIGS. 5 and 6, the outer peripheral shape of the slide portion 8b is a shape in which a part of the outer periphery of the annular member is notched in the axial direction, and the notched portion (notch A gap is formed along the axial direction between the portion 8g) and the first member 7A.

  Furthermore, the end groove 8e is formed in each of the curved portion 8f and the cutout portion 8g. Therefore, as shown in FIG. 5B, even when the second member 8A is seated on the spring seat 9 (the state where movement of the second member 8A toward the lower chamber r2 side is restricted), A gap is formed between the two member 8A and the spring seat 9 by the end groove 8e, and a gap formed between the notch 8g and the first member 7A and the lower chamber r2 is an end groove of the notch 8g. 8e communicates.

  According to the above configuration, the second member 8A can be prevented from sticking to the spring sheet (lower chamber side stopper) 9, and the liquid can be prevented from being confined between the first member 7A and the second member 8A. Thereby, the opening / closing operation of the through hole (passage) 7d by the relative movement of the first member 7A and the second member 8A (operation to increase or decrease the flow passage area of the passage) can be ensured.

  Such a configuration for ensuring operation may naturally be applied to the second member 8 shown in FIGS. 5 and 6, the partition member P1 is attached upside down, and the large diameter portion 7c of the first member 7A is arranged toward the upper chamber r1 side, and toward the upper chamber r1 side of the second member 8A. In a state where the movement of the first member 7A is restricted, the gap between the notch 8g and the first member 7A and the upper chamber r1 may be communicated with each other by the end groove 8e.

  Further, the number and shape of the notches 8g can be changed as appropriate. For example, when the flat surface is formed on the outer periphery of the second member 8A by the notch portion 8g as in the present embodiment, the slide portion 8b has one notch portion 8g, and the outer peripheral shape of the slide portion 8b. May be D-shaped when viewed in the axial direction, the slide portion 8b has three or five or more cutout portions 8g, and the outer peripheral shape of the slide portion 8b is rounded polygonal when viewed in the axial direction. It may be. Further, a groove having a U-shaped section or a U-shape may be provided on the outer periphery of the slide portion 8b along the axial direction, and a portion where the groove is formed may be used as a notch portion 8g.

  In the partition member P1 shown in FIGS. 5 and 6, an annular step 7f is formed at the boundary between the body portion 7b and the large diameter portion 7c on the inner periphery of the first member 7A. Furthermore, an annular step 8h facing the step 7f of the first member 7A is formed on the outer periphery of the second member 8A and at the boundary between the shutter portion 8a and the slide portion 8b. In such a case, the step 8h of the second member 8A may be abutted against the step 7f of the first member to limit the upward movement of the second member 8A in the drawing.

  According to the above configuration, similarly to the case where the movement of the second member 8 is restricted by the rib 7e, the shape of the second member 8A can be easily changed, and the secondary damping force can be easily tuned. In addition, according to the above configuration, the rib 7e can be omitted, and when the rib is provided on the first member 7A, the length and arrangement of the rib can be freely changed.

  In each of the partition members P and P1, the first members 7 and 7A and the second members 8 and 8A are both cylindrical, and they are relatively moved in the vertical direction. However, the shapes of the first member 7, 7A and the second member 8, 8A are not necessarily cylindrical, and the direction in which these members move relative to each other is not limited to the top and bottom.

  In the present embodiment, the tube member 1 includes an outer tube 10 and an inner tube 11 that is slidably inserted into the outer tube 10. The cylinder 2 of the shock absorber body D is connected to the outer tube 10, and the piston rod 4 is connected to the inner tube 11. Further, the first member 7 is mounted on the outer periphery of the cylinder 2 and is slidably inserted inside the inner tube 11, and a wheel side bracket (lid portion) that closes one end of the first member 7 and the inner tube 11. A suspension spring (coil spring) S is interposed between the two.

  For this reason, the suspension spring S or the spring seat 9 with which the upper end of the suspension spring S abuts can be used as a lower chamber side stopper that restricts the movement of the second member 8 toward the lower chamber r2. Furthermore, since the first member 7 also functions as a spring receiving member that supports the upper end of the suspension spring S, the number of parts of the shock absorber A can be reduced as compared with the case where the spring receiving member and the partition member P are provided separately. .

  Moreover, in this Embodiment, the spring seat 9 with which the 1st member 7 was mounted | worn is utilized as a lower chamber side stopper which restrict | limits the movement to the lower chamber r2 side with respect to the 1st member 7 of the 2nd member 8. FIG. For this reason, if the spring member 9 is attached to the first member 7 in which the second member 8 is inserted inside, the second member 8 is attached to the first member 7 so that it can be assembled to the shock absorber body D. The assembly work of the shock absorber A can be facilitated.

  However, the spring seat 9 may be eliminated, and the upper end of the suspension spring S may be directly abutted against the lower end of the first member 7. In this case, the suspension spring S may be used as a lower chamber side stopper. Furthermore, a compressed gas may be sealed above the liquid level Rs of the liquid reservoir chamber R, and an air spring configured with an air chamber in the liquid reservoir chamber R may be used as a suspension spring. That is, the partition member P does not necessarily have a function as a spring receiving member. In this case, the spring seat 9 may be used only as a lower chamber side stopper.

  The shock absorber A of the present embodiment is used as a front fork that suspends the front wheels of a saddle-ride type vehicle, and the tube member 1 is a telescopic member having an outer tube 10 and an inner tube 11. . Further, in the present embodiment, the tube member 1 is an inverted type, the outer tube 10 is a vehicle body side tube, and the inner tube 11 is a wheel side tube.

  However, the tube member 1 may be upright, the outer tube 10 may be a wheel side tube, and the inner tube 11 may be a vehicle body side tube, and the purpose of use of the shock absorber A is not limited to the front fork. For example, the shock absorber according to the present invention may be used in a rear cushion unit for suspending a rear wheel of a saddle-ride type vehicle or a suspension device for an automobile provided with a vehicle compartment. In these cases, the tube member 1 may be replaced with a single outer shell 15 disposed on the outer periphery of the cylinder 2 as in the shock absorber A1 shown in FIG.

  Further, in the shock absorber A shown in FIG. 1, the cylinder 2 of the shock absorber body D is connected to the vehicle body, and the piston rod 4 is connected to the axle. When the shock absorber body D expands and contracts, the partition wall member P mounted on the outer periphery of the cylinder 2 moves up and down with respect to the liquid level Rs, and when the shock absorber body D contracts and the cylinder 2 is immersed in the liquid. The liquid level Rs rises.

  However, like the shock absorber A1 shown in FIG. 8, the cylinder 2 and the outer shell 15 are connected to the axle and the piston rod 4 is connected to the vehicle body, and the suction passage 5a and the discharge passage 5b formed in the valve case 5 are compressed. The chamber L2 and the liquid reservoir chamber R may be communicated with each other. In this case, the liquid corresponding to 4 volumes of the piston rod entering and exiting the cylinder 2 when the shock absorber body D1 expands and contracts moves back and forth between the pressure side chamber L2 and the liquid reservoir chamber R, so that the liquid level Rs of the liquid reservoir chamber R is changed. Move up and down.

  In the shock absorber A1 shown in FIG. 8, the partition member P is fixed to the outer periphery of the cylinder 2. When the liquid level Rs moves up and down during expansion and contraction of the shock absorber body D1, the liquid level Rs and the partition member P Moves up and down relative to each other. Thus, also in the shock absorber A1, the partition wall member P moves relative to the liquid level Rs of the liquid reservoir chamber R when the shock absorber body D1 expands and contracts.

  Furthermore, also in the shock absorber A1 shown in FIG. 8, the partition member P is configured to include the first member 7 and the second member 8, and the first is formed according to the direction in which the liquid flows through the through hole (passage) 7d. The direction of relative movement between the member 7 and the second member 8 is switched. For this reason, also in the shock absorber A1, the opening area (flow channel area) of the through hole (passage) 7d is changed according to the expansion and contraction direction of the shock absorber A1, and secondary attenuation that occurs when the shock absorber A1 extends. The force and the secondary damping force generated when the shock absorber A1 contracts can be easily adjusted individually.

  In the shock absorber A1 shown in FIG. 8, the partition member P shown in FIGS. 2 and 3 is adopted, but the partition member P may be changed to the partition member P1 shown in FIGS. It is.

  Further, in the shock absorbers A and A1 shown in FIGS. 1 and 8, the partition members P and P1 are immersed in a predetermined stroke range in which the shrinkage amount of the shock absorbers A and A1 is equal to or larger than a predetermined value, so that a secondary damping force is obtained. Will occur. However, the stroke range for generating the secondary damping force can be changed as appropriate. For example, the partition members P and P1 may always be immersed so that a secondary damping force is generated during expansion and contraction of the shock absorbers A and A1 over the entire stroke range from the most extended state to the most contracted state. .

  Further, in the shock absorbers A and A1 shown in FIGS. 1 and 8, the shock absorber bodies D and D1 are of a single rod type, and the piston rod 4 protrudes from one side of the piston 3 to the outside of the cylinder 2. However, if the partition members P and P1 and the liquid level Rs of the liquid storage chamber R move relative to each other when the shock absorber main body is expanded and contracted, the shock absorber main body is on one rod side, and the piston rod 4 is a piston. 3 may project out of the cylinder 2 from both sides. In addition, in the shock absorber main body, the rod entering and exiting the cylinder 2 is not necessarily the piston rod 4 connected to the piston 3.

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

A, A1 ... buffer, D, D1 ... buffer body, P, P1 ... partition member, R ... liquid reservoir, Rs ... liquid level, r1 ... upper chamber, r2 ... lower chamber, S ... suspension spring (coil spring), 1 ... tube member, 2 ... cylinder, 4 ... piston rod (rod), 7, 7A ... first member 7a: small diameter portion, 7b: body portion, 7c: large diameter portion, 7d: through hole (passage), 7e ... rib, 8, 8A ... second member, 8a ... Shutter part, 8b ... Slide part, 8d ... End groove, 8f ... Notch part, 10 ... Outer tube, 11 ... Inner tube, 12 ... Wheel side bracket (Cover), 15 ... Outer shell (tube member)

Claims (7)

A shock absorber body having a cylinder and a rod inserted into the cylinder so as to be movable in the axial direction;
A tube member that is provided on the outer periphery of the shock absorber body and forms a liquid storage chamber with the shock absorber body;
A partition wall that partitions the liquid reservoir chamber into an upper chamber and a lower chamber and has a passage that communicates the upper chamber and the lower chamber, and moves relative to the liquid level of the liquid reservoir chamber when the shock absorber body is expanded or contracted With members,
The partition member has a first member and a second member that changes a flow area of the passage by relative movement with the first member,
The shock absorber according to claim 1, wherein a direction of relative movement between the first member and the second member is switched according to a direction in which the liquid flows in the passage. The first member and the second member are both cylindrical,
The shock absorber body is inserted on the inner peripheral side of the first member,
The passage is formed with a through hole penetrating the thickness of the first member,
The second member is mounted on the inner peripheral side or the outer peripheral side of the first member so as to be movable in the axial direction.
The shock absorber according to claim 1, wherein when the second member moves in the axial direction with respect to the first member, an opening area of the through hole is changed. The first member includes an annular small-diameter portion whose inner periphery is in contact with the outer periphery of the shock absorber main body, and a truncated cone that is connected to one end of the small-diameter portion and whose inner diameter and outer diameter are gradually increased as the distance from the small-diameter portion increases. The shock absorber according to claim 2, further comprising: a cylindrical body portion; and an annular large diameter portion that is connected to an end of the body portion on the side opposite to the small diameter portion and has an outer periphery contacting the inner periphery of the tube member. The second member includes a shutter portion that opens and closes the through hole,
The shock absorber according to claim 2 or 3, wherein the inner diameter and the outer diameter are gradually reduced as the shutter portion is in the shape of a truncated cone and toward the tip. Ribs are formed along the axial direction on the inner periphery or outer periphery of the first member,
The shock absorber according to any one of claims 2 to 4, wherein movement of the second member toward the upper chamber side or the lower chamber side is restricted by the rib. The first member is arranged with the large-diameter portion facing either the upper chamber or the lower chamber,
The second member includes an annular slide portion that is in sliding contact with the inner periphery of the large diameter portion,
On the outer periphery of the slide portion, a notch portion that forms a gap along the axial direction between the first member and the first member is formed,
One end of the second member in the axial direction is formed with an end groove that communicates the gap with the one chamber in a state where movement of the second member toward the one chamber is restricted. The shock absorber according to any one of claims 4 and 5 depending on claim 3 and claim 3. The tube member has an outer tube and an inner tube that is slidably inserted into the outer tube,
The cylinder is connected to the outer tube;
The rod is connected to the inner tube;
The first member is mounted on the outer periphery of the cylinder and is slidably inserted inside the inner tube.
The shock absorber according to any one of claims 1 to 6, wherein a coil spring is interposed between the first member and a lid portion that closes one end of the inner tube.

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