JP2013113315A - Suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an increase in cost for improving a suspension which lubricates a sliding surface of a vehicle body-side bearing.SOLUTION: The suspension includes: a suspension body F having an outer tube 1 on a vehicle body-side and an inner tube 2 on a wheel-side movably inserted in the outer tube 1; a liquid chamber R1 which is formed in the suspension body F and houses a working fluid; a vehicle body-side bearing 3 which is held by the inner tube 2 and is in slide-contact with an inner circumferential surface of the outer tube 1; a wheel-side bearing 4 which is held by the outer tube 1 and is in slide-contact with an outer circumferential surface of the inner tube 2; and a cylindrical clearance T formed between the vehicle body-side bearing 3 and the wheel-side bearing 4. The suspension includes: a communication hole 21 which is formed on the inner tube 2 to always connect the cylindrical clearance T and the liquid chamber R1; and a check valve 5 which is arranged on the inside of the communication hole 21, allows communication between the cylindrical clearance T and the liquid chamber R1 when the cylindrical clearance T is reduced, and prevents the communication between the cylindrical clearance T and the liquid chamber L when the cylindrical clearance T is enlarged.

Description

  The present invention relates to an improvement of a suspension device.

  Generally, in a transport device such as an automobile or a motorcycle, a suspension device is interposed between a vehicle body and a wheel, and the suspension device suppresses an impact caused by road surface unevenness from being transmitted to the vehicle body.

  For example, as shown in FIG. 6, the suspension device disclosed in Patent Document 1 is a front fork that suspends a front wheel of a motorcycle, an outer tube 1 connected to the vehicle body side, and an outer tube connected to the wheel side. The suspension apparatus main body F which consists of the inner tube 2 inserted so that a movement is possible in 1 is provided, and can be expanded-contracted.

  Further, between the overlapping portions of the outer tube 1 and the inner tube 2, a vehicle body side bearing 3 that is held by the inner tube 2 and is in sliding contact with the inner peripheral surface of the outer tube 1, and an inner tube 2 that is held by the outer tube 1. A wheel-side bearing 4 slidably in contact with the outer peripheral surface is disposed, and a cylindrical gap T is formed between the bearings 3 and 4. A working fluid for lubricating the sliding surfaces of the bearings 3 and 4 is accommodated in the cylindrical gap T.

  The suspension device main body F accommodates a damper D that generates a predetermined damping force as the suspension device main body F expands and contracts. The damper D closes the cylinder 7 in which the working fluid is accommodated, the rod 8 inserted into the cylinder 7 so as to be movable in the axial direction, and the vehicle body side opening (the upper opening in FIG. 6) of the cylinder 7. A rod guide 90 that pivotally supports the rod 8.

  Further, a reservoir R is formed outside the damper D in the suspension device main body F. The reservoir R is composed of a liquid chamber R1 that stores a working fluid and an air chamber R2 that is formed above the liquid surface O of the liquid chamber R1 and stores gas. Compensates for changes in cylinder volume.

  As shown in FIG. 7, the liquid chamber R1 is divided into upper and lower liquid chambers R10 and R11 by an outer peripheral portion 90a of the rod guide 90. The upper and lower liquid chambers R10 and R11 are separated from the rod guide. Communicating through a through hole 91 formed in 90.

  The inner tube 2 has a communication hole at a position facing the flow path L10 formed between the outer peripheral surface of the rod guide 90 and the inner peripheral surface of the inner tube 2 and always facing the cylindrical gap T. 21 is formed, and the lower liquid chamber R11 can communicate with the cylindrical gap T via the flow path L10 and the communication hole 21.

  Further, the upper side of the flow path L10 in FIG. 7 is closed with a seal 92, so that the flow path L10 does not directly communicate with the upper liquid chamber R10. On the other hand, the lower side of the flow path L10 in FIG. 7 is closed by an annular check valve 5A loosely fitted in an annular groove 90b formed in a U-shaped cross section on the outer peripheral surface of the rod guide 90. ing.

  The check valve 5A is in sliding contact with the inner peripheral surface of the inner tube 2. Further, a notch 51 is formed in the radial direction on the inner side surface (upper surface in FIG. 7) of the check valve 5A.

  With the above configuration, when the vehicle body side bearing 3 and the wheel side bearing 4 approach when the front fork is extended, the flow path L10 is pressurized together with the cylindrical gap T, and the check valve 5A is closed. For this reason, the working fluid in the cylindrical gap T passes between the vehicle body side bearing 3 and the outer tube 1 and moves to the reservoir R.

  On the other hand, when the vehicle body side bearing 3 and the wheel side bearing 4 are separated during compression of the front fork, the flow path L10 is decompressed together with the cylindrical gap T, and the check valve 5A is opened. For this reason, the working fluid in the lower liquid chamber R11 is supplied into the cylindrical gap T through the flow path L10 and the communication hole 21.

JP-A-4-31221

  Therefore, a conventional suspension device such as a front fork can be provided with the above-described configuration to smoothly extend and contract the suspension device main body F by lubricating the sliding surface of the vehicle body side bearing 3 when the suspension device is extended. However, the following improvements are demanded.

  That is, in the above-described conventional form, the communication hole 21 that communicates the liquid chamber R1 formed in the suspension device main body F and the cylindrical gap T faces the flow path L10 formed outside the rod guide 90, And it is necessary to arrange | position between the vehicle body side bearing 3 and the wheel side bearing 4. FIG.

  However, if a hole is formed in the inner tube 2 to form the communication hole 21, the strength of that portion is reduced. Therefore, it is required to support the inner tube 2 with the wheel bearing 4 while avoiding the vicinity of the communication hole 21. It is done.

  Therefore, in the conventional form, even when the suspension system in which the wheel-side bearing 4 and the communication hole 21 are closest to each other is extended most, the cylinder 7 is provided in order to ensure a sufficient distance between the wheel-side bearing 4 and the communication hole 21. The rod guide 90 must be extended and moved to the vehicle body side (upper side in FIG. 6), which increases the cost.

  Accordingly, an object of the present invention is to lubricate the sliding surface of the vehicle body side bearing 3, and the cost between the wheel side bearing 4 and the communication hole 21 is sufficiently high when the suspension device is fully extended. It is to provide a suspension system that does not become.

  Means for solving the above-mentioned problems include a suspension device body comprising an outer tube disposed on the vehicle body side and an inner tube disposed on the wheel side and movably inserted into the outer tube, and the suspension device body. A liquid chamber that is formed inside and contains a working fluid; a vehicle body-side bearing that is held at the vehicle body side end of the inner tube and that is in sliding contact with the inner peripheral surface of the outer tube; and a wheel side end of the outer tube. In a suspension system that includes a wheel side bearing that is held in sliding contact with the outer peripheral surface of the inner tube, and a cylindrical gap that is formed between the vehicle body side bearing and the wheel side bearing, the suspension is always formed on the inner tube. A communication hole that communicates the cylindrical gap and the liquid chamber, and the cylindrical gap and the liquid chamber are disposed when the cylindrical gap is reduced by being disposed on the inner side of the communication hole. It is to include a check valve for blocking the communication of the cylindrical gap and the liquid chamber when the cylindrical gap is expanded while permitting passage.

  According to the present invention, the sliding surface of the vehicle body side bearing can be lubricated irrespective of the length of the cylinder and the position of the rod guide. Therefore, the cost does not increase even if the distance between the wheel-side bearing and the communication hole is sufficient when the suspension device is fully extended.

It is a front view which partially cuts and shows the principal part of the front fork which is a suspension apparatus concerning 1st embodiment of this invention. It is the longitudinal cross-sectional view which expanded the check valve periphery part of FIG. 1, and was seen from the front side. It is the longitudinal cross-sectional view which expanded the check valve peripheral part of the front fork which is a suspension apparatus which concerns on 2nd embodiment of this invention, and was seen from the front side. It is the longitudinal cross-sectional view which expanded the check valve periphery part of the front fork which is a suspension apparatus concerning 3rd embodiment of this invention, and was seen from the front side. The modification of 1st embodiment of this invention (FIG. 2) is shown, It is the longitudinal cross-sectional view which expanded the check valve periphery part of the front fork which is a suspension apparatus which concerns on this modification, and was seen from the front side. It is a front view which partially cuts and shows the main part of the front fork which is the conventional suspension apparatus. It is the longitudinal cross-sectional view which expanded the check valve periphery part of FIG. 6, and was seen from the front side.

  A suspension device according to a first embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, the suspension device according to the present embodiment is arranged on the vehicle body side (upper side in FIG. 1) and on the wheel side (lower side in FIG. 1) and the outer tube 1. A suspension device main body F comprising an inner tube 2 that is movably inserted therein, a liquid chamber R1 that is formed in the suspension device main body F and accommodates a working fluid, and a vehicle body side end portion 20 of the inner tube 2 A vehicle body side bearing 3 held in contact with the inner peripheral surface of the outer tube 1 and a wheel side bearing 4 held in the wheel side end portion 10 of the outer tube 1 and slidably contacted with the outer peripheral surface of the inner tube 2. A cylindrical gap T formed between the vehicle body side bearing 3 and the wheel side bearing 4 is provided.

  Further, the suspension device according to the present embodiment is formed in the inner tube 2 and always communicates with the cylindrical gap T and the liquid chamber R1, and the inner side of the communication hole 21 (see FIG. When the cylindrical gap T is arranged and the cylindrical gap T is reduced, the cylindrical gap T and the liquid chamber R1 are allowed to communicate with each other, and the cylindrical gap T is enlarged when the cylindrical gap T is enlarged. And a check valve 5 for preventing communication of the chamber R1.

  Hereinafter, in detail, the suspension device according to the present embodiment is a front fork that suspends a front wheel of a motorcycle. The outer tube 1 is connected to the steering shaft of the motorcycle via a vehicle body side bracket (not shown), and the inner tube 2 is connected to the axle of the front wheel via a wheel side bracket (not shown).

  Moreover, the suspension apparatus main body F which consists of the outer tube 1 and the inner tube 2 is obstruct | occluded with the cap member 6 attached to the outer tube 1 at the vehicle body side opening which becomes the upper side in FIG. The opening on the wheel side is closed by the wheel side bracket (not shown) attached to the inner tube 2.

  Further, a suspension spring S and a damper D are accommodated in the suspension apparatus main body F, and a reservoir R is formed outside the damper D. The reservoir R includes a liquid chamber R1 that stores the working fluid, and an air chamber R2 that is formed on the upper side via the liquid level O of the liquid chamber R1 and stores a gas that generates a reaction force when the suspension device main body F is compressed. It consists of. In the present embodiment, the working fluid stored in the reservoir R is oil, and the gas is an inert gas such as nitrogen.

  Subsequently, the suspension spring S accommodated in the suspension apparatus main body F is formed of a coil spring, and always urges the front fork in the extending direction to elastically support the vehicle body. And the front fork can absorb the impact by road surface unevenness by providing this suspension spring S.

  The damper D accommodated in the suspension apparatus main body F together with the suspension spring S is arranged in parallel with the suspension spring S. The structure of the damper D is well known, and is not shown in detail. However, the damper D is suspended from the cylinder 7 and the cap member 6 which are erected on the axial center of the inner tube 2 and fixed to the inner tube side. A rod 8 that moves in the axial direction in the cylinder 7 as the front fork expands and contracts, and an annular rod guide 9 that closes the vehicle body side opening (the upper opening in FIG. 1) of the cylinder 7 and supports the rod 8. With.

  The inside of the cylinder 7 is divided into two chambers by a piston (not shown) that is held at the tip of the rod 8 and slidably contacts the inner peripheral surface of the cylinder 7, and these chambers are filled with working fluid. ing. Further, assuming that the upper chamber in FIG. 1 is one chamber and the lower chamber in FIG. 1 is the other chamber, the other chamber is a base member (not shown) attached to the bottom portion (lower portion in FIG. 1) of the cylinder 7. It is partitioned from R1.

  Further, the one chamber and the other chamber communicate with each other via a flow path formed in a piston (not shown), and the other chamber and the liquid chamber R1 pass through a flow path formed in a base member (not shown). Communicate.

  Thereby, when the front fork in which the piston moves upward in FIG. 1 is extended, the one chamber is pressurized, the working fluid in the one chamber moves to the other chamber through the flow path of the piston, and the rod volume that has left the cylinder 7 Minute working fluid moves from the liquid chamber R1 to the other chamber through the flow path of the base member.

  On the other hand, when the front fork in which the piston moves downward in FIG. 1 is compressed, the other chamber is pressurized, and the working fluid in the other chamber moves to the one chamber via the flow path of the piston and enters the cylinder 7. The volume of working fluid moves from the other chamber to the liquid chamber R1 through the channel of the base member.

  Furthermore, the damper D is provided with known damping force generating means (not shown) such as a leaf valve and an orifice that give a predetermined resistance to the working fluid passing through the flow paths formed in the piston and the base member. In addition, a damping force due to resistance when the working fluid passes through each of the flow paths is generated, and the expansion and contraction movement of the front fork accompanying the shock absorption of the suspension spring S is suppressed.

  Subsequently, between the overlapping portion of the outer tube 1 and the inner tube 2, the vehicle body side bearing 3 that is held by the vehicle body side end portion 20 of the inner tube 2 and slidably contacts the inner peripheral surface of the outer tube 1, and the outer tube 1. A wheel-side bearing 4 that is held by the wheel-side end 10 and slidably contacts the outer peripheral surface of the inner tube 2 is disposed, and a cylindrical gap T that accommodates the working fluid is formed between the bearings 3 and 4. ing.

  In addition, the inner periphery of the outer tube 1 on the wheel side end 10 has an annular shape that is in sliding contact with the outer peripheral surface of the inner tube 2 on the outside air side (wheel side), which is the lower side in FIG. An oil seal C1 and a dust seal C2 are attached in series to prevent the working fluid from flowing out of the cylindrical gap T.

  Further, an annular groove 22 is formed on the outer periphery of the vehicle body side end portion 20 of the inner tube 2 on the inner side (vehicle body side) which is the upper side in FIG. As shown in FIG. 2, the annular groove 22 includes an annular outside air side surface 22a, a vertical surface 22b rising from the inner peripheral end of the outside air side surface 22a, and the inner peripheral end facing the outside air side surface 22a. It consists of an annular inner side surface 22c continuous with 22b and is formed in a U-shaped cross section.

  Further, an annular check valve 5 is loosely fitted on the outer side of the annular groove 22 while being in sliding contact with the inner peripheral surface of the outer tube 1, and the inner peripheral surface of the check valve 5 and the vertical surface 22 b of the annular groove 22 are A cylindrical flow path L is formed between the two. Further, the check valve 5 has a notch 50 formed in the radial direction on the inner side surface 22c side which is the upper side in FIG. 2, and when the check valve 5 comes into contact with the outside air side surface 22a of the annular groove 22. The communication between the cylindrical gap T and the reservoir R is prevented, and when the check valve 5 is separated from the outside air side surface 22a, the communication between the cylindrical gap T and the reservoir R is allowed.

  Further, the inner tube 2 is always provided with a communication hole 21 at a position facing the cylindrical gap T and always disposed in the liquid chamber R1. Accordingly, the communication hole 21 always communicates the cylindrical gap T and the liquid chamber R1.

  Next, the effect of the front fork as a suspension device according to the present embodiment will be described. When the front fork withdraws the inner tube 2 from the outer tube 1 is extended, the vehicle body side bearing 3 and the wheel side bearing 4 come close to pressurize the cylindrical gap T. At this time, as shown in FIG. 2, the check valve 5 communicates with the cylindrical gap T and the reservoir R away from the outside air side surface 22 a of the annular groove 22.

  Thereby, the working fluid in the cylindrical gap T passes through the communication hole 21 and moves to the liquid chamber R1, and between the vehicle body side bearing 3 and the outer tube 1, the cylindrical flow path L, the notch 50, the air It passes through the chamber R2 and moves to the liquid chamber R1.

  On the other hand, when the front fork in which the inner tube 2 enters the outer tube 1 is compressed, the vehicle body side bearing 3 and the wheel side bearing 4 are separated from each other and the cylindrical gap T is decompressed. At this time, although not shown, the check valve 5 abuts on the outside air side surface 22a of the annular groove 22 to prevent communication between the cylindrical gap T and the reservoir R.

  As a result, the working fluid in the liquid chamber R1 moves so as to be sucked into the cylindrical gap T through the communication hole 21 while the liquid level of the working fluid in the cylindrical gap T is maintained at the position of the check valve 5. To do.

  That is, the front fork as the suspension device according to the present embodiment lubricates the sliding surface of the vehicle body side bearing 3 when extended, and prevents the working fluid level in the cylindrical gap T from decreasing during compression. Thus, the suspension device main body F can be smoothly expanded and contracted.

  Further, in the present embodiment, the communication hole 21 that always communicates the cylindrical gap T and the liquid chamber R1 only needs to be disposed so as to be always in the liquid chamber R1, and the length of the cylinder 7 and the rod guide 9 Since the communication hole 21 can be arranged regardless of the position, the distance between the wheel-side bearing 4 and the communication hole 21 when the front fork is fully extended does not increase the cost.

  In particular, in the suspension device in which the suspension spring S is accommodated in the suspension device main body F like the front fork of the present embodiment or the conventional embodiment, the suspension spring S is interposed between the cylinder 7 and the cap member 6. Therefore, when the cylinder 7 is extended as in the conventional form shown in FIGS. 6 and 7, the space for accommodating the suspension spring S is reduced.

  Thereby, in the conventional form, the design of the suspension spring S becomes difficult, or the spring case 60 that supports the vehicle body side end (upper end in the figure) of the suspension spring S is shortened, causing noise. However, in the present embodiment, it is not necessary to extend the cylinder 7, so that the design freedom of the suspension spring S can be increased and the length of the spring case 60 can be secured.

  Further, in the conventional configuration, since the check valve 5A and the seal 92 are disposed, it is necessary to reduce the distance between the rod guide 90 and the inner tube 2. However, according to the present invention, the rod guide 9 Since the communication hole 21 can be arranged regardless of the position, the distance between the rod guide 9 and the inner tube 2 can be made wider than before, and the structure of the rod guide 9 is not complicated.

  Moreover, in this Embodiment, it becomes possible to reduce the number of parts of a suspension apparatus by attaching the check valve 5 to the inner tube 2 without providing a new member for attaching the check valve 5. .

  Further, in the present embodiment, the check valve 5 is formed in an annular shape, has a notch 50 on the inner side surface (upper surface in FIG. 2), and has a U-shaped cross section formed on the outer peripheral surface of the inner tube 2. Since the annular groove 22 is attached, the structure of the check valve 5 and the structure for attaching the check valve 5 can be simplified.

  Next, a front fork which is a suspension device according to a second embodiment of the present invention will be described with reference to FIG. This embodiment differs from the first embodiment in the position where the check valve is provided, and the configuration of the peripheral portion of the check valve is different accordingly, but the basic configuration is the same as in the first embodiment. It is the same.

  Accordingly, only the parts different from the first embodiment will be described here, and the detailed description and drawings about the same configuration as the first embodiment omitted in FIG. 3 are the same as those of the first embodiment. The description and reference to FIGS.

  In the present embodiment, the front end of the inner tube 2 on the vehicle body side end portion 20 is in sliding contact with the inner peripheral surface of the outer tube 1 and communicates with the cylindrical clearance T through the sliding surface of the vehicle body side bearing 3. The inner side opening of L1 on the upper side in FIG. 3 is closed.

  An annular groove 23 is formed on the inner peripheral surface of the inner tube 2 at a position corresponding to the gap L 1, and an annular check valve 500 is attached to the annular groove 23. The annular groove 23 includes an annular outside air side surface 23a, a vertical surface 23b rising from an outer peripheral end of the outside air side surface 23a, an annular inner side surface 23c facing the outside air side surface 23a and having an outer peripheral end continuous with the vertical surface 23b. And has a U-shaped cross section.

  Further, the inner tube 2 is formed with a through hole 2a that penetrates from the annular groove 23 to the outside of the inner tube 2 and communicates with the gap L1.

  The inner peripheral surface (upper side in FIG. 3) of the check valve 500 is in sliding contact with the vertical surface 23b of the annular groove 23, and the outer peripheral surface of the check valve 500 (lower side in FIG. 3) A notch 501 is formed at a position facing the through hole 2a.

  Further, the end surface 502 of the inner peripheral portion on the outside side of the check valve 500 is formed in an annular shape so as to prevent communication between the through hole 2a and the reservoir R when contacting the outside air side surface 23a of the annular groove 23. It has become.

  With the above-described configuration, when the front fork as the suspension device according to the present embodiment is extended, the two bearings 3 and 4 approach each other, whereby the gap L1 is pressurized together with the cylindrical gap T, as shown in FIG. Thus, the check valve 500 moves to the inner side, which is the upper side in FIG. 3, and leaves the outside air side surface 23 a of the annular groove 23.

  On the other hand, when the front fork is compressed, the bearings 3 and 4 are separated from each other, so that the pressure in the cylindrical gap T and the gap L1 decreases, and the check valve 500 moves to the outside air side, which is the lower side in FIG. It contacts the outside air side surface 23 a of the groove 23.

  That is, the check valve 500 in the present embodiment also allows the communication between the cylindrical gap T and the liquid chamber R1 when the cylindrical gap T is reduced, and the cylindrical gap T is the same as the check valve 5 in the first embodiment. When expanding, the communication between the cylindrical gap T and the liquid chamber R1 is prevented.

  As a result, the front fork as the suspension device according to the present embodiment also lubricates the sliding surface of the vehicle body side bearing 3 when extended, and the liquid level in the cylindrical gap T during compression is similar to that of the first embodiment. It is possible to prevent the lowering and smoothly extend and contract the suspension device main body F.

  Also in the present embodiment, the communication hole 21 that always communicates the cylindrical gap T and the liquid chamber R1 only needs to be disposed so as to be always in the liquid chamber R1. Since the communication hole 21 can be disposed regardless of the position of the front fork, the distance between the wheel-side bearing 4 and the communication hole 21 when the front fork is fully extended does not increase the cost.

  In the present embodiment, the inner tube 2 is provided with the annular groove 23 and the through hole 2a, and the annular check valve 500 is provided inside the annular groove 23. The configuration for providing the valve 500 can be simplified.

  Next, a front fork which is a suspension device according to a third embodiment of the present invention will be described with reference to FIG. This embodiment differs from the first embodiment in the position where the check valve is provided, and the configuration of the peripheral portion of the check valve is different accordingly, but the basic configuration is the same as in the first embodiment. It is the same.

  Therefore, only the parts different from the first embodiment will be described here, and the detailed description and drawings about the same configuration as the first embodiment omitted in FIG. 4 are the same as those of the first embodiment. The description and reference to FIGS.

  The check valve 510 in the present embodiment is attached to the annular groove 24 of the inner tube 2 formed near the outside air side of the vehicle body side bearing 3. The annular groove 24 is formed on the inner peripheral surface of the inner tube 2, and has an annular outer air side surface 24a, a vertical surface 24b standing from the outer peripheral end of the outer air side surface 24a, and the outer peripheral end facing the outer air side surface 24a. Comprises an annular inner side surface 24c continuous with the vertical surface 24b, and is formed in a U-shaped cross section.

  Further, the inner tube 2 is formed with a through hole 2 b that penetrates from the annular groove 24 to the outside of the inner tube 2 and communicates with the cylindrical gap T.

  The inner peripheral surface (upper side in FIG. 4) of the check valve 510 is in sliding contact with the vertical surface 24b of the annular groove 24, and the outer peripheral surface of the check valve 510 (lower side in FIG. 4) A notch 511 is formed at a position facing the through hole 2b.

  Further, the end surface 512 of the outside air side inner peripheral portion of the check valve 510 is formed in an annular shape so as to prevent the communication between the through hole 2b and the reservoir R when contacting the outside air side surface 24a of the annular groove 24. It has become.

  By providing the above configuration, when the front fork as the suspension device according to the present embodiment is extended, both the bearings 3 and 4 approach to pressurize the cylindrical gap T, and as shown in FIG. The check valve 510 moves to the inner side which is the upper side in FIG. 4 and leaves the outside air side surface 24a of the annular groove 24.

  On the other hand, when the front fork is compressed, the bearings 3 and 4 are separated from each other, so that the pressure in the cylindrical gap T decreases, and the check valve 510 moves to the outside air side, which is the lower side in FIG. It contacts the outside air side surface 24a.

  That is, the check valve 510 in the present embodiment also allows the communication between the cylindrical gap T and the liquid chamber R1 when the cylindrical gap T is reduced, and the cylindrical gap T is similar to the check valve 5 in the first embodiment. When expanding, the communication between the cylindrical gap T and the liquid chamber R1 is prevented.

  Further, in the present embodiment, although the check valve 510 is disposed on the outside air side from the vehicle body side bearing 3, the liquid level in the cylindrical gap T does not fall below the check valve 510.

  Therefore, even if the liquid level in the cylindrical gap T is lowered to the position of the check valve 510, the distance between the liquid level and the vehicle body side bearing 3 can be shortened, and the outer tube 1 is extended when the front fork is extended. It is possible to make sliding contact with the vehicle body side bearing 3 in a state where the inner peripheral surface of the suspension is lubricated with the working fluid in the cylindrical gap T, and the suspension device main body F can be smoothly expanded and contracted.

  Also in the present embodiment, the communication hole 21 that always communicates the cylindrical gap T and the liquid chamber R1 only needs to be disposed so as to be always in the liquid chamber R1. Since the communication hole 21 can be disposed regardless of the position of the front fork, the distance between the wheel-side bearing 4 and the communication hole 21 when the front fork is fully extended does not increase the cost.

  Further, in the present embodiment, since the annular groove 24 and the through hole 2b are provided in the inner tube 2 and the annular check valve 510 is provided inside the annular groove 24, the structure of the check valve 510 and the check valve 500 are provided. The structure for providing the can be simplified.

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

  For example, in the above embodiment, the suspension device according to the present invention is a front fork that suspends a front wheel of a motorcycle. However, the rear cushion unit for the rear wheel of a motorcycle, and other transportation equipment such as an automobile may be used. Of course, it may be used for a suspension system.

  In the above embodiment, the damper D and the suspension spring S are accommodated in the suspension apparatus main body F. However, if the liquid chamber L is formed in the suspension apparatus body F, the damper D and the suspension spring S are accommodated. The damper D and the suspension spring S may be accommodated in any form.

  In the above embodiment, the check valves 5, 500, 510 are attached to the inner tube 2. However, a member other than the inner tube 2 may be provided, and the check valves 5, 500, 510 may be attached to this member. .

  In the first embodiment, as shown in FIG. 5, the annular groove 22 may be formed near the outside air side of the vehicle body side bearing 3, and the check valve 5 may be attached to the inner periphery of the annular groove 22. Even in this case, it is possible to prevent the liquid level in the cylindrical gap T from being lowered below the check valve 5 during compression, and to smoothly expand and contract the suspension device F.

  In the second embodiment, the through hole 2a may be directly communicated with the cylindrical gap T instead of the gap L1, and the configuration of the flow path that connects the cylindrical gap T and the liquid chamber R1 may be The configuration of the check valve that allows communication of the flow paths can be selected as appropriate.

C1 Oil seal C2 Dust seal D Damper F Suspension device main body L Cylindrical flow path L1 Clearance L10 Flow path O Liquid level R Reservoir R1 Liquid chamber R2 Air chamber S Suspension spring T Cylindrical clearance 1 Outer tube 2 Inner tubes 2a, 2b Through hole 3 Car body side bearing 4 Wheel side bearing 5, 500, 510, 5A Check valve 6 Cap member 7 Cylinder 8 Rod 9, 90 Rod guide 10 Wheel side end 20 of outer tube Inner body side end 21 of inner tube Communication hole 22, 23, 24, 90b annular groove 50, 51 notch

Claims (4)

A suspension device body composed of an outer tube disposed on the vehicle body side and an inner tube disposed on the wheel side and movably inserted into the outer tube, and formed in the suspension device body to contain the working fluid A liquid chamber, a vehicle body side bearing that is held at the vehicle body side end of the inner tube and is in sliding contact with the inner peripheral surface of the outer tube, and a wheel side end portion of the outer tube that is held at the outer peripheral surface of the inner tube. In a suspension device comprising a wheel side bearing that is in sliding contact, and a cylindrical gap formed between the vehicle body side bearing and the wheel side bearing,
A communication hole that is formed in the inner tube and always communicates the cylindrical gap and the liquid chamber, and the cylindrical gap and the liquid are disposed when the cylindrical gap is reduced by being disposed on the inner side of the communication hole. A suspension device comprising: a check valve that allows communication between chambers and prevents the communication between the cylindrical gap and the liquid chamber when the cylindrical gap is enlarged.   The suspension apparatus according to claim 1, wherein the check valve is attached to the inner tube. An annular groove having a U-shaped cross section is formed on the inner peripheral surface of the inner tube, and the annular check valve is attached to the annular groove, and a through hole communicates from the annular groove to the cylindrical gap. The annular groove includes an annular outside air side surface, a vertical surface rising from an outer peripheral end of the outside air side surface, and an annular inner side surface facing the outside air side surface and having an outer peripheral end continuous to the vertical surface. Become
In the check valve, the inner peripheral surface is in sliding contact with the vertical surface, the outer air outer peripheral surface is formed with a notch facing the through hole, and the end surface of the outer air inner peripheral portion is formed in an annular shape to form the outer air side surface. The suspension device according to claim 2, wherein the suspension device is separated from the seat. An annular groove having a U-shaped cross section is formed on the outer peripheral surface of the inner tube, and the annular check valve is attached to the annular groove. The annular groove includes an annular outside air side surface and an inside of the outside air side surface. It consists of a vertical surface rising from the peripheral end, and an annular inner side surface facing the outside air side surface and the inner peripheral end continuing to the vertical surface,
The check valve is in sliding contact with the inner peripheral surface of the outer tube, and a cylindrical flow path is formed between the inner peripheral surface and the vertical surface. The suspension device according to claim 2, wherein a notch is formed.

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