JP4276100B2 - Shock absorber - Google Patents

Description

  The present invention relates to a shock absorber in which a sliding guide tube for an inner tube is provided on the inner periphery of an opening of an outer tube, and grease is filled between the inner periphery of the sliding guide tube and the inner tube.

  A front wheel shock absorber used for a small displacement scooter is provided with a piston made of a hard synthetic resin such as Duracon (registered trademark) on the outer periphery of the tip of the inner tube on the wheel side in terms of cost. In addition, a sliding guide tube made of hard synthetic resin such as Duracon (registered trademark) is provided on the inner periphery of the opening of the outer tube on the vehicle body side, and the inner tube on the wheel side is guided by this piston and the sliding guide tube, A simple shock absorber (so-called grease damper) filled with lubricating grease is attached between the outer periphery of the piston and the inner periphery of the outer tube and between the inner periphery of the sliding guide tube and the inner tube.

This shock absorber generates a damping force by the friction between the piston and the outer tube, and the inner tube and the sliding guide tube, and also between the piston and the outer tube and keeps a proper lubrication. A lubricating grease is filled between the guide tube and the inner tube (Patent Document 1).
46-14809

  In the shock absorber of the type of Patent Document 1, when the grease is consumed over time, the sliding guide tube made of synthetic resin and the iron inner tube are in direct contact unless the grease is replenished. The guide tube is worn and the shock absorber is destroyed. Usually, the life of the shock absorber is exhausted when the grease has run out, so there is no other way than replacing the shock absorber with a new one.

  Although it is conceivable to attach a grease nipple or the like to the outer tube, there is a problem in terms of structure and cost, and a simpler and less expensive structure is required.

  An object of the present invention is to slidably insert an inner tube into an outer tube via a sliding guide tube provided in an opening of the outer tube, and to lubricate between the sliding guide tube and the inner tube. It is an object of the present invention to provide a shock absorber having a simple and inexpensive sliding guide tube having a structure capable of holding a grease for a long time in a shock absorber filled with grease.

According to the first aspect of the present invention, the inner tube is slidably inserted into the outer tube via the sliding guide tube provided in the opening of the outer tube, and the sliding guide tube and the inner tube are In a shock absorber filled with lubricating grease in the middle, a grease reservoir hole is provided in the middle of the sliding guide cylinder in the axial direction so that the inner and outer circumferences communicate with each other. An annular seal member that is slidably in contact with the outer periphery of the inner tube is provided on the periphery, and grease inside the axial direction of the seal member is supplied to the slide guide tube via the outer periphery of the slide guide tube. A circulation path communicating with the hole is formed , and an annular inner circumferential groove for fitting the annular seal member is formed at both ends of the sliding guide cylinder, and the seal member in the inner circumferential groove is formed. On the inner side of the sliding guide tube A circulation hole that communicates with the circumference is formed, a circulation groove that communicates the circulation hole with the grease reservoir hole is formed on the outer periphery of the sliding guide cylinder, and the circulation path is configured by the circulation hole and the circulation groove. Is .

According to a second aspect of the present invention, in the first aspect of the present invention, an annular outer peripheral groove in which the grease retaining hole is opened is formed on the outer periphery of the sliding guide tube, and the sliding is formed in the inner peripheral grooves at both ends. A plurality of circulation holes that communicate the inner and outer circumferences of the guide cylinder are formed, and a plurality of circulation grooves that communicate the plurality of circulation holes with the annular outer circumferential groove are formed on the outer circumference of the sliding guide cylinder in the axial direction. is there.

According to a third aspect of the invention, in the first or second aspect of the invention, the seal member is an O-ring .

(Claim 1)
a. “An annular seal member that slides in contact with the outer periphery of the inner tube is provided on the inner periphery of both ends in the axial direction of the sliding guide tube, and grease on the inner side in the axial direction of the seal member is provided on the sliding guide tube. By forming a circulation path that communicates with the grease reservoir hole through the outer periphery of the grease, the grease adhering to the outer periphery of the inner tube is scraped off by the annular seal member and leaks to the outside in the axial direction of the sliding guide cylinder To prevent. Further, the scraped grease passes through the hole in the circulation path formed on the inner side in the axial direction of the seal member, is pushed out to the outer peripheral side, and further passes through the outer periphery of the sliding guide tube to return to the grease reservoir hole. . In other words, the grease circulates through the circulation path of the sliding guide cylinder to the grease reservoir hole and prevents the grease from leaking outside as much as possible.
Therefore, the life of the shock absorber can be extended with a simple and inexpensive configuration.

b . “At both ends of the sliding guide tube, an annular inner circumferential groove for fitting an annular sealing member is formed, and the inner and outer circumferences of the sliding guide tube are formed on the inner side of the inner circumferential groove in the axial direction of the sealing member. A circulation hole is formed on the outer periphery of the sliding guide cylinder, and a circulation path is formed by the circulation hole and the circulation groove. The grease on the outer periphery of the inner tube that has been dropped accumulates in the annular inner peripheral groove, and is further pushed out from the circulation hole on the inner side in the axial direction of the seal member to the outer peripheral side, and returns to the grease reservoir hole through the circulation groove on the outer periphery.

  As a result, the grease can be held also in the inner circumferential groove, so that the sealing member is lubricated, and there are a plurality of lubrication points, so that the slidability is increased. Also, grease circulation is ensured.

(Claim 2 )
c. “On the outer circumference of the sliding guide cylinder, an annular outer circumferential groove with a grease reservoir hole is formed, and on the inner circumferential grooves at both ends, a plurality of circulation holes communicating the inner and outer circumferences of the sliding guide cylinder are formed. On the outer periphery of the cylinder, a plurality of circulation grooves are formed in the axial direction to communicate the plurality of circulation holes with the annular outer circumferential groove. Circulates through the plurality of circulation holes and further through the plurality of circulation grooves to the annular outer circumferential groove where the grease reservoir hole opens.

  As a result, the total cross-sectional area of the circulation path is increased, and the grease can be smoothly circulated.

(Claim 3 )
d. By using an O-ring as the seal member, the seal member can be made inexpensive.

  1 is a front view showing the shock absorber partially broken, FIG. 2 is a cross-sectional view showing the suspension spring support structure of FIG. 1, FIG. 3 is a cross-sectional view showing the lower spring support, and FIG. FIG. 5 shows a lower spring receiver, (A) is a sectional view, (B) is a side view, FIG. 6 shows an upper spring receiver, (A) is a sectional view, (B) is a plan view, (C) is a side view, FIG. 7 is a sectional view showing the periphery of the sliding guide tube of FIG. 1, FIG. 8 is a perspective view of the sliding guide tube, FIG. 9 shows the sliding guide tube, and (A) is a front view. FIG. 5B is a cross-sectional view taken along line BB, and FIG. 5C is a cross-sectional view taken along line CC.

  A shock absorber 10 in FIG. 1 is used as a front wheel shock absorber such as a small displacement scooter, and an outer tube 11 on the vehicle body side is attached to a steering shaft 1 supported on the vehicle body side via upper and lower brackets 2 and 3. It is. The shock absorber 10 is provided with a sliding guide tube 13 made of a hard synthetic resin such as engineering plastic such as Duracon (trademark of Polyplastics) on the inner periphery of the opening of the outer tube 11, and the inner tube inserted into the outer tube 11. 12 is guided by the sliding guide tube 13.

  Further, as shown in FIG. 2, the shock absorber 10 is provided with a synthetic resin piston 14 that slides on the inner periphery of the outer tube 11 on the outer periphery of the upper end portion of the inner tube 12. 11, two air chambers 15A and 15B are defined above and below the piston 14.

  The shock absorber 10 includes a piston 14 provided on the outer periphery of the distal end portion of the inner tube 12, an inner periphery of the outer tube 11, and an inner periphery of the sliding guide tube 13 provided on the outer tube 11 and an outer periphery of the inner tube 12. A grease damper filled with lubricating grease is formed between them. That is, the shock absorber 10 generates a damping force due to the friction between the outer periphery of the piston 14 and the inner periphery of the outer tube 11 and the friction between the inner tube 12 and the sliding guide cylinder 13, and the outer periphery of the piston 14 and the inner tube 11. The proper lubrication is maintained by the grease filled between the circumference and the inner tube 12 and the sliding guide tube 13.

  The shock absorber 10 abuts the base end large-diameter portion 13A of the sliding guide tube 13 inserted into the inner periphery of the opening portion of the outer tube 11 against the step portion on the inner periphery of the opening end large-diameter portion of the outer tube 11, The backup ring 15 seated on the end surface of the base end large diameter portion 13A is locked by a stopper ring 16 engaged with the inner periphery of the large diameter portion of the open end of the outer tube 11, and the open end of the outer tube 11 is closed. The dust seal 17 is attached to the outer periphery of the large diameter portion, and the oil seal lip 17A and the dust seal lip 17B of the dust seal 17 are brought into close contact with the outer periphery of the inner tube 12 (FIG. 7).

  The shock absorber 10 is provided with cylindrical spring receivers 21 and 22 on the upper end portion of the inner tube 12 and the upper portion of the outer tube 11, respectively, and each end of the suspension spring 23 is arranged on the outer periphery of the spring receivers 21 and 22. Each part is wound and attached.

  Hereinafter, (A) an air vent structure for the upper air chamber 15A of the outer tube 11 and (B) a grease circulation structure of the sliding guide cylinder 13 will be described.

(A) Air vent structure for the upper air chamber 15A of the outer tube 11 As shown in FIG. 3, the shock absorber 10 forms an air vent passage 31 in the lower spring receiver 21 at the upper end portion of the inner tube 12, and the piston 14 The upper air chamber 15 </ b> A communicates with the outside through the air vent passage 31 and the inner tube 12.

  As shown in FIG. 5, the spring receiver 21 inserts the fitting shaft 33 at the lower part of the annular flange 32 into the upper end inner diameter portion of the inner tube 12, butts the flange 32 against the upper end surface of the inner tube 12. The lower end portion of the suspension spring 23 is wound around a spiral groove 34A provided in a part in the circumferential direction of the upper spring winding portion 34 (two arc portions opposed in the diameter direction).

  The spring receiver 21 forms a hollow portion 31A extending over the entire length of the fitting shaft 33 to the spring winding portion 34, and communicates the inner and outer circumferences with the upper end surface of the fitting shaft 33 facing the upper air chamber 15A of the outer tube 11. A groove-like communication part 31B (or a hole-like communication part is acceptable) is formed, and the air vent passage 31 is formed by the hollow part 31A and the communication part 31B. The upper air chamber 15 </ b> A of the outer tube 11 is connected to an air vent passage 31 (hollow portion 31 </ b> A, communication portion 31 </ b> B) of the spring receiver 21, a drain hole 12 </ b> A provided in the inner tube 12, and a lower portion of the inner tube 12. Communicate to the outside.

  In addition, 12B is a guide stay of a brake wire, 12C is a stay for protector attachment, 12D is a brake stopper, and each is fixed to the outer periphery of the lower part of the inner tube 12 by welding.

  A metal collar 24 having a smaller outer diameter than the inner periphery of the outer tube 11 is attached to the upper outer periphery of the inner tube 12, and the fitting shaft 33 of the spring receiver 21 inserted into the upper end inner diameter portion of the inner tube 12, and the inner A fixing pin 25 is inserted like a skewer into a through hole provided in each of the tube 12 and the collar 24. The spring receiver 21 is fixed in both the axial direction and the rotational direction by the fixing pin 25 with the flange 32 abutted against the upper end surface of the inner tube 12. The piston 14 is fitted on the outer periphery of the upper end portion of the inner tube 12 and is sandwiched between the flange 32 of the spring receiver 21 and the collar 24. An annular recess into which the flange 32 is fitted is formed on the upper end surface of the piston 14, and the lower end surface of the piston 14 is seated on the upper end surface of the collar 24.

  A bump rubber 27 is provided on the upper end surface of the spring receiver 21 via a collar 26 made of synthetic resin. The bump rubber 27 abuts on the end surface of the upper spring receiver 22 and makes it possible to regulate the maximum compression stroke of the outer tube 11 and the inner tube 12.

  As shown in FIG. 4, the shock absorber 10 has the outer periphery of the cap 28 fixed to the upper end portion of the outer tube 11 by welding, and the upper spring receiver 22 on the upper portion of the outer tube 11 is supported on the back surface of the cap 28. An air vent passage 41 is formed between the upper spring receiver 22 and the cap 28, and the upper air chamber 15 </ b> A of the outer tube 11 communicates with the outside through the air vent passage 41.

  As shown in FIG. 6, the spring receiver 22 includes a protrusion 43 </ b> A provided on a part of the outer periphery of the head 43 by inserting the upper head 43 of the annular flange 42 into the inner diameter of the cap 28 via a gap 41 </ b> A. Is engaged with an anti-rotation recess 28A (not shown) provided on the inner periphery of the cap 28 to prevent the rotation. Further, the spring receiver 22 has a circumferential portion of the spring winding portion 44 at the lower portion of the flange 42 (two arc portions opposed in the diameter direction) in a state where the flange 42 is abutted against the lower end surface of the cap 28. The upper end portion of the suspension spring 23 is wound around the provided spiral groove 44A.

  The spring receiver 22 extends radially outward from the outer peripheral side of the head 43 at a plurality of circumferential positions (for example, three positions) on the upper surface of the flange 42, and on the outer periphery of the flange 42 facing the inner periphery of the outer tube 11. A vent groove 41B is provided. The spring receiver 22 forms an air vent passage 41 by the gap 41A and the ventilation groove 41B. The upper air chamber 15A of the outer tube 11 communicates with the outside through an air vent passage 41 (gap 41A, ventilation groove 41B) of the spring receiver 22.

  A fixing screw 4 inserted through the upper bracket 2 is screwed to the center of the head 43 to the spring winding portion 44 of the spring receiver 22, and the upper bracket 2 is fixed to the upper end surface of the cap 28 of the outer tube 11. Is done.

  In addition, the mounting tube 11A is welded and fixed to a part (intermediate portion) of the outer tube 11 in the axial direction, and the lower bracket 3 is welded and fixed to the intermediate portion of the outer periphery of the mounting tube 11A. The presence of the attachment tube 11 </ b> A prevents welding distortion for attaching the lower bracket 3 to the outer tube 11 on the inner periphery of the outer tube 11 on which the piston 14 slides.

  The suspension spring 23 wound around each of the lower spring receiver 21 and the upper spring receiver 22 functions as a rebound spring that regulates the maximum extension stroke of the outer tube 11 and the inner tube 12, and at the time of maximum extension, the sliding guide cylinder. 13 prevents the upper end surface of 13 from colliding with the lower end surface of the collar 26.

Therefore, according to the present embodiment, the following operational effects can be obtained.
a. “By forming an air vent passage 31 in the spring receiver 21 at the upper end of the inner tube 12 and allowing the upper air chamber 15A of the piston 14 to communicate with the outside via the air vent passage 31 and the inner tube 12” When the inner tube 12 is retracted from the outer tube 11 when the shock absorber 10 is extended, the upper air chamber 15A of the piston 14 in the outer tube 11 expands and depressurizes. Outside air is replenished to the upper air chamber 15 </ b> A in the outer tube 11 through the air vent passage 31 of the spring receiver 21 from the gap of the axle mounting portion at the tip.

  As a result, the upper and lower air chambers 15 and 15B of the piston 14 in the outer tube 11 are not depressurized, and mud or the like is formed on the inner peripheral surface of the sliding guide cylinder 13 provided on the inner periphery of the open end of the outer tube 11. No longer inhale.

  b. Since the air vent passage 31 is formed by the hollow portion 31A and the communication portion 31B of the spring receiver 21, the pressure reduction in the shock absorber 10 can be achieved with a simple structure in which the hollow portion 31A and the communication portion 31B are formed in the spring receiver 21. Can be prevented. In addition, since the cylindrical spring receiver 21 is formed by zinc die casting, it does not require additional processing man-hours, and the cost can be reduced by reducing the amount of material used. Become.

  c. By “the upper air chamber 15A of the piston 14 is made to reach the outside through the drain hole 12A provided in the lower part of the inner tube 12”, the water accumulated in the inner tube 12 due to condensation in the inner tube 12 or the like. Since the air vent passage 31 is formed using the existing drain hole 12A for discharging, it is not necessary to process the air vent passage 31 separately. Therefore, the air vent passage 31 can be formed at a low cost without causing an increase in cost.

  d. “Bump rubber 27 is provided on the spring receiver 21 at the upper end of the inner tube 12 via a collar 26 made of synthetic resin, and this bump rubber 27 is brought into contact with the end face of the spring receiver 21 provided on the upper portion of the outer tube 11. By doing so, the bump rubber 27 abuts against the end face of the spring receiver 22 on the outer tube 11 side, thereby buffering at the time of maximum compression. Further, the collar 26 made of synthetic resin defines an air vent passage 31 between the upper end surface of the spring receiver 21 on the inner tube 12 side and also serves as a guide for the suspension spring 23.

  e. “The air vent passage 41 is provided between the spring receiver 22 on the outer tube 11 side and the cap 28 provided at the upper end portion of the outer tube 11”, whereby the inner circumference of the upper end portion of the spring receiver 22 and the outer tube 11 is provided. A gap 41A is provided between the cap 28 and the cap 28, and the gap 41A is added as an air vent passage 41, so that the pressure reducing effect of the air chambers 15A and 15B in the outer tube 11 can be increased.

(B) Grease circulation structure of the sliding guide tube 13 As shown in FIG. 7, the shock absorber 10 allows the inner tube 12 to slide freely on the sliding guide tube 13 provided on the inner periphery of the opening of the outer tube 11. invite.

  As shown in FIGS. 8 and 9, the sliding guide cylinder 13 is provided with a grease reservoir hole 51 communicating with the inner and outer circumferences in an axial intermediate portion, and the grease loaded in the grease reservoir hole 51 is disposed on the outer periphery of the inner tube 12. Adhere. On the inner periphery of both the upper and lower ends in the axial direction of the sliding guide tube 13, there are provided upper and lower annular seal members 60 slidably contacting the outer periphery of the inner tube 12, for example, O-rings, and the outer tube 11 and the inner tube 12. During the expansion / contraction stroke, the grease adhering to the outer periphery of the inner tube 12 is scraped off by the seal member 60. The grease on the inner side in the axial direction of the seal member 60 scraped off by the upper and lower seal members 60 passes through the outer periphery of the sliding guide cylinder 13 through the upper and lower circulation paths 53 as shown by arrows in FIG. 51 is communicated.

  Specifically, the sliding guide tube 13 is formed with upper and lower inner peripheral grooves 52 and 52 into which the upper and lower seal members 60 are fitted on the inner periphery of the upper and lower ends in the axial direction. The grease on the inner side in the axial direction of the sealing member 60 is accumulated in the inner circumferential grooves 52. The sliding guide cylinder 13 is formed with upper and lower circulation holes 53A communicating with the inner and outer circumferences of the sliding guide cylinder 13 in the axially inner portion of the seal member 60 in each inner circumferential groove 52, and each circulation hole 53A. The upper and lower circulation grooves 53 </ b> B extending in the axial direction so as to communicate with the grease reservoir hole 51 are formed on the outer periphery of the sliding guide cylinder 13. A circulation path 53 is constituted by the circulation hole 53A and the circulation groove 53B.

  Furthermore, the sliding guide tube 13 forms a wide annular outer peripheral groove 54 in which the grease reservoir hole 51 is opened on the outer periphery of the intermediate portion in the axial direction. A plurality of circulation holes 53 </ b> A communicating the inner and outer circumferences of the sliding guide cylinder 13 are formed in the inner peripheral grooves 52 at both the upper and lower ends of the sliding guide cylinder 13. A plurality of circulation grooves 53B that communicate the plurality of circulation holes 53A with the annular outer circumferential groove 54 are formed in the axial direction.

Therefore, according to the present embodiment, the following operational effects can be obtained.
a. “An annular seal member 60 slidably contacting the outer periphery of the inner tube 12 is provided on the inner periphery of both end portions in the axial direction of the sliding guide tube 13, and grease on the inner side in the axial direction of the seal member 60 is applied to the sliding guide tube 13. The circulation path 53 communicating with the grease reservoir hole 51 is formed via the outer periphery of the sliding guide cylinder 13 ”, whereby the grease adhering to the outer periphery of the inner tube 12 is scraped off by the annular seal member 60, Leakage to the outside of the moving guide cylinder 13 in the axial direction is prevented. Further, the scraped grease passes through the hole 53A of the circulation path 53 formed on the inner side in the axial direction of the seal member 60, is pushed out to the outer peripheral side, and further passes through the outer periphery of the sliding guide tube 13 to be grease. Return to the pool hole 51. That is, the grease circulates through the circulation path 53 of the sliding guide cylinder 13 to the grease reservoir hole 51 and prevents the grease from leaking outside as much as possible.
Therefore, the life of the shock absorber can be extended with a simple and inexpensive configuration.

  b. “An annular inner circumferential groove 52 into which the annular sealing member 60 is fitted is formed at both ends of the sliding guide tube 13, and the sliding is performed on the axially inner side of the sealing member 60 in the inner circumferential groove 52. A circulation hole 53A that connects the inner and outer periphery of the guide cylinder 13 is formed, and a circulation groove 53B that communicates the circulation hole 53A with the grease reservoir hole 51 is formed on the outer periphery of the sliding guide cylinder 13, and the circulation hole 53A and the circulation groove 53B are formed. The grease on the outer periphery of the inner tube 12 scraped off by the seal member 60 is accumulated in the annular inner peripheral groove 52 and further from the circulation hole 53A on the axially inner side of the seal member 60 to the outer peripheral side. To the grease reservoir hole 51 through the circulation groove 53B on the outer periphery.

  As a result, the grease can be held also in the inner circumferential groove 52, so that the seal member 60 is lubricated and a plurality of lubrication points are provided, so that the slidability is increased. Also, grease circulation is ensured.

  c. “On the outer periphery of the sliding guide tube 13, an annular outer peripheral groove 54 in which the grease retaining hole 51 is opened is formed, and a plurality of circulation holes 53 </ b> A communicating the inner and outer periphery of the sliding guide tube 13 with the inner peripheral grooves 52 at both ends. The inner tube scraped off by the seal member 60 is formed on the outer periphery of the sliding guide tube 13 and the plurality of circulation grooves 53B are formed in the axial direction to communicate the plurality of circulation holes 53A with the annular outer periphery groove 54 ". The outer circumferential grease 12 is formed in the inner circumferential grooves 52 at both ends, passes through the plurality of circulation holes 53A, and further circulates through the plurality of circulation grooves 53B to the annular outer circumferential groove 54 where the grease reservoir hole 51 is opened. .

  As a result, the total cross-sectional area of the circulation path 53 is increased, and the grease can be smoothly circulated.

  d. By making the seal member 60 an O-ring, the seal member 60 can be made inexpensive.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration of the present invention is not limited to these embodiments, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

FIG. 1 is a front view of the shock absorber partially cut away. FIG. 2 is a cross-sectional view showing the suspension spring support structure of FIG. FIG. 3 is a cross-sectional view showing the lower spring support. FIG. 4 is a cross-sectional view showing the periphery of the upper spring bearing. 5A and 5B show a lower spring receiver, where FIG. 5A is a sectional view and FIG. 5B is a side view. 6A and 6B show an upper spring support, FIG. 6A is a sectional view, FIG. 6B is a plan view, and FIG. 6C is a side view. FIG. 7 is a sectional view showing the periphery of the sliding guide cylinder of FIG. FIG. 8 is a perspective view showing a sliding guide tube. 9A and 9B show a sliding guide tube, where FIG. 9A is a front view, FIG. 9B is a cross-sectional view taken along line BB, and FIG. 9C is a cross-sectional view taken along line CC.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Shock absorber 11 Outer tube 12 Inner tube 13 Sliding guide cylinder 51 Grease reservoir hole 52 Inner peripheral groove 53 Circulating path 53A Circulating hole 53B Circulating groove 54 Outer peripheral groove 60 Seal member

Claims (3)

The inner tube is slidably inserted into the outer tube through a sliding guide tube provided in the opening of the outer tube, and lubricating grease is inserted between the sliding guide tube and the inner tube. In the filled shock absorber,
A grease reservoir hole that communicates the inner and outer circumferences is provided in the axial middle portion of the sliding guide cylinder, and the annular circumference that slides in contact with the outer circumference of the inner tube is provided at the inner circumference of both axial ends of the sliding guide cylinder. Providing a sealing member,
A circulation path is formed in the sliding guide cylinder to allow grease on the inner side in the axial direction of the seal member to communicate with the grease reservoir hole via the outer periphery of the sliding guide cylinder .
An annular inner circumferential groove for fitting the annular seal member is formed at both ends of the sliding guide tube,
A circulation hole communicating with the inner and outer circumferences of the sliding guide cylinder is formed in the axially inner portion of the seal member in the inner circumferential groove,
A circulation groove for communicating the circulation hole with the grease reservoir hole is formed on the outer periphery of the sliding guide cylinder,
A shock absorber characterized in that the circulation path is constituted by the circulation hole and the circulation groove . On the outer periphery of the sliding guide tube, an annular outer peripheral groove in which the grease reservoir hole opens is formed,
Forming a plurality of circulation holes communicating with the inner and outer peripheries of the sliding guide tube in the inner peripheral grooves of the both ends
2. The shock absorber according to claim 1 , wherein a plurality of circulation grooves that communicate the plurality of circulation holes with the annular outer circumferential groove are formed in an outer periphery of the sliding guide cylinder in an axial direction. The shock absorber according to claim 1 or 2 , wherein the seal member is an O-ring.

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