JP5818203B2 - Hydraulic shock absorber - Google Patents

Description

  The present invention relates to a hydraulic shock absorber, and more particularly to an improvement of a hydraulic shock absorber as a front fork that is provided on the front wheel side of a motorcycle and absorbs vibration.

  There have been various proposals for a hydraulic shock absorber as a front fork that is provided on the front wheel side of a two-wheeled vehicle and absorbs vibration. For example, in the proposal disclosed in Patent Document 1, a hydraulic shock absorber is mainly used. In addition to having a damping mechanism, an auxiliary damping mechanism is provided.

  That is, in the hydraulic shock absorber disclosed in Patent Document 1, the vehicle body side tube and the wheel side tube are connected to a telescopic type and have a damper set in an inverted type in a fork body that can be expanded and contracted.

  This hydraulic shock absorber has a main damping mechanism in the damper, and has a damping mechanism that assists the reservoir outside the damper, that is, in the fork body, that is, an auxiliary damping mechanism. Become.

  Therefore, in the hydraulic shock absorber disclosed in Patent Document 1, when the fork main body expands and contracts, the rod enters and exits the cylinder in the damper, and a predetermined damping action is performed by the main damping mechanism.

  In particular, when the fork main body contracts, the fluid surface of the working fluid in the reservoir rises, and this rising fluid surface, that is, the working fluid passes through the auxiliary damping mechanism, thereby performing an auxiliary damping action. The

Japanese Patent No. 3351826

  However, in the proposal disclosed in Patent Document 1 described above, even if the auxiliary damping mechanism is provided, it may be pointed out that a more preferable damping action cannot be achieved in the hydraulic shock absorber.

  That is, in the hydraulic shock absorber disclosed in Patent Document 1 described above, the throttle member that constitutes the auxiliary damping mechanism has a single throttle channel, so that the auxiliary damping action performed by this throttle member is fixed. It becomes a thing.

  However, in a two-wheeled vehicle, the expansion and contraction state of the front fork differs depending on the posture, and although it is auxiliary, the above-described fixed damping action cannot provide a more favorable riding comfort in the two-wheeled vehicle.

  The present invention has been made in view of the above-described present situation, and an object of the present invention is to provide a hydraulic shock absorber that can obtain a more favorable riding comfort in a vehicle by an auxiliary damping action.

To achieve the above object, the configuration of a hydraulic shock absorber according to the present invention, a cylinder which is the lower end side member by accommodating the working fluid within, it is inserted freely and out to the cylinder is the upper side member that has a upright-type damper having a rod, in a hydraulic shock absorber formed by the outside of the damper reservoir, an auxiliary damping mechanism in the reservoir, the auxiliary damping mechanism is movable up and down on the outer circumference of the cylinder an annular valve forming an annular gap which forms the damping action upon the passage of hydraulic fluid between the inner and the periphery of the opposing cylindrical body with provided, and a biasing means for biasing the lowering direction the annular valve Suppose you have it.

  Therefore, in the present invention, the main damping mechanism provided in the damper during the expansion / contraction operation of the fork main body can provide a predetermined main damping action, and the auxiliary damping mechanism provided in the reservoir outside the damper can provide the predetermined assistance. Therefore, the degree of freedom in setting the damping action in the hydraulic shock absorber is increased.

  At this time, in the auxiliary damping mechanism, since the elements constituting the auxiliary damping mechanism include the annular valve, the biasing means, the annular gap, and the fluid surface, the mass in the annular valve, the biasing means By setting the urging force, the size of the annular gap, and the position of the fluid surface, the damping action of this auxiliary damping mechanism can be changed in various ways. In addition to the damping action of the main damping mechanism in the damper, Therefore, it is possible to realize a further effective damping action that is varied.

  In the auxiliary damping mechanism, when the position of the fluid surface of the working fluid in the reservoir is positioned below the annular valve in the auxiliary damping mechanism, for example, a predetermined damping action is performed.

  That is, for example, when the fork main body is in a neutral state, if the fork main body is compared, the contraction operation is performed at a low speed and the fluid surface below the annular valve is increased at a low speed when compared, so that the working fluid is Passes through the annular gap between the vehicle and the wheel side tube and flows into the upper part of the annular valve, and the working fluid passes through the annular gap, whereby a predetermined damping action is performed.

  When the fork main body in the neutral state is compared, the contraction operation is performed at a high speed, and the fluid surface below the annular valve is increased at a high speed, so that the working fluid pushes up the annular valve.

  At this time, the annular valve rises against the urging force of the coil spring as the urging means, and the energy loss at this time becomes a damping action and does not withstand the urging force of the coil spring as the urging means. A damping action different from the damping action is performed.

  As a result, according to the present invention, a more favorable riding comfort in the vehicle can be obtained by the auxiliary damping action of the auxiliary damping mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. It is a semi-longitudinal longitudinal cross-sectional view which shows the intermediate part in the hydraulic shock absorber by one Embodiment of this invention. FIG. 6 is a half-longitudinal longitudinal sectional view showing a state in which an auxiliary damping mechanism is provided in the reservoir.

  The present invention will be described below with reference to the drawings. In the illustrated embodiment, the hydraulic shock absorber according to the present invention is provided on the front wheel side of a motorcycle serving as a vehicle and absorbs vibration during traveling. It is said.

Then, the front fork, as shown in FIG. 1, has a fork body and a car body side tube 1 and the vehicle wheel side tube 2 is a retractable coupled to telescopic (not Shimese marks).

  And this fork body has a damper (not shown) set upright on the shaft core part, and this damper has a main damping mechanism (not shown) inside, and is operated to extend and contract. Sometimes, a predetermined damping action is performed, and an auxiliary damping mechanism 10 is provided outside to perform a predetermined damping action during the contraction operation.

  Incidentally, in this fork main body, the opening end portion which is the lower end portion of the vehicle body side tube 1 is used as a seal case portion (not shown), and a seal member on the inner peripheral side portion, that is, in the place shown in FIG. The seal 11 and the dust seal 12 are provided. The oil seal 11 prevents the working fluid represented by the hydraulic oil from the inside of the fork main body from leaking out of the fork main body, and the dust adhered to the outer periphery of the wheel side tube 2 by the dust seal 12. Is prevented from entering the inside of the fork main body, that is, the oil seal 11 side.

  In addition, the fork main body has a lower bearing 13 whose inner periphery is in sliding contact with the outer periphery of the wheel side tube 2 on the inner peripheral side portion at the opening end of the vehicle body side tube 1, and the upper end portion of the wheel side tube 2. 1 has an upper bearing 21 (see FIG. 1) whose outer periphery is in sliding contact with the inner periphery of the vehicle body side tube 1, and the concentricity and sliding of the wheel side tube 2 with respect to the vehicle body side tube 1 by both bearings 13, 21. Ensures mobility.

  A gap formed between both the bearings 13 and 21 and the vehicle body side tube 1 and the wheel side tube 2 is defined as a lubrication gap S, and a communication hole opened in the wheel side tube 2 in the lubrication gap S. The lubricating fluid between the vehicle body side tube 1 and the wheel side tube 2 is guaranteed by the working fluid from the inside of the wheel side tube 2 flowing as a lubricant through 2a (see FIG. 1).

  By the way, the fork main body shown in the figure does not have a suspension spring in the air chamber A (see FIG. 1) separated from the reservoir R in the fork main body by the fluid surface O (see FIG. 1) of the working fluid. 1), that is, when the fork main body is in the most extended state, the air pressure that is equal to or higher than the atmospheric pressure is energized in the air chamber A to be urged in the extending direction.

  Therefore, this fork main body does not have a suspension spring as an urging element in the extending direction, which contributes to a reduction in the overall weight of the front fork.

  In the fork main body, the air spring force based on the air pressure in the air chamber A overcomes the contraction operation, and the fork main body expands by the air spring force, and the damper expands and contracts in synchronization with the expansion and contraction operation of the fork main body. .

  Returning to FIG. 1, the fork main body is set to be an inverted type in which the vehicle body side tube 1 is made of a large diameter outer tube and the wheel side tube 2 is made of a small diameter inner tube.

However, from where the present invention is intended, set in place of the fork main body is set in an inverted, the inner tube on the car body side tube 1, the upright type to the outer tube in the vehicle wheel side tube 2 May be.

  Further, the lower end portion of the wheel side tube 2 is a bottom portion (not shown) that closes the lower end opening of the wheel side tube 2 as shown in FIG. 1, and an oil lock mechanism 6 described later is provided at the upper end of the bottom portion. An oil lock case 62 is seated.

  At this time, although not shown, a seal member is appropriately provided between the lower end portion of the wheel side tube 2 and the oil lock case 62 to ensure liquid tightness between the two.

  Although not shown, the vehicle body side tube 1 has a cap member that detachably closes the upper end opening of the vehicle body side tube 1 at the upper end portion, and this cap member has a later-described damper at the shaft core portion. The upper end portion of the rod 4 to be configured is connected so as to be separable.

  Therefore, in this fork body, when the cap member is separated from the upper end of the vehicle body side tube 1, the vehicle body side tube 1 can be lowered, and the rod 4 and the wheel side tube in the damper connected to the cap member. 2 can be exposed, and for example, the amount of working fluid accommodated in the fork body, that is, the height position of the fluid surface O separating the air chamber A can be adjusted. Become.

  On the other hand, as shown in FIG. 1, the damper is installed on the shaft core portion of the wheel-side tube 2, and is provided on the shaft core portion of the vehicle body-side tube 1. A rod 4 that is suspended and serves as an upper end side member, and a tip end side that is the lower end side in the drawing is inserted into the cylinder 3 so as to be freely inserted and removed, and a lower end of the rod 4 that is slidably inserted into the cylinder 3 in the drawing. The cylinder 3 has a piston 5 which is held by a leading end (not shown) as a part and separates the upper chamber R1 and the lower chamber R2.

  At this time, as shown in the figure, a piston nut (not shown) that connects the piston 5 to the tip of the rod 4 constitutes an oil lock piece 61 in an oil lock mechanism 6 described later. This will be described later. .

  In this damper, the cylinder 3 has a rod guide 31 at the head end (not shown) which is the upper end in FIG. 1, and the rod guide 31 closes the upper end opening of the cylinder 3. The rod 4 is passed through the shaft core.

  At this time, the upper end portion of the rod guide 31 shown in FIG. 1 suspends the upper end portion of the coil spring 101 as an urging means in the auxiliary damping mechanism 10 described later, and the upper end portion of the rod guide 31 is on the outer peripheral side. The protruding flange portion 31 a is used to lock the upper end of the coil spring 101.

  The cylinder 3 has a spring holder 32 formed in an annular shape between the rod guide 31 and an inner peripheral step (not shown) in the cylinder 3 below the rod guide 31. An extension spring S1 provided so as to be wound around the rod 4 with a side arrangement, and a balance spring S2 provided so as to be arranged on the outer periphery side and provided on the inner circumference of the cylinder 3 are suspended. .

  Note that the lower end of the extension spring S1 is carried by a spring receiver 41 that is held fixed on the outer periphery of the rod 4 on the lower side, that is, in a snap ring 41a that is fitted to the rod 4 as shown in FIG. It faces the spring receiver 41.

  On the other hand, as shown in FIG. 1, an annular spring sheet 33 is held at the lower end of the balance spring S2, and this spring sheet 33 is placed at the upper end of the lower piston 5, that is, as shown in FIG. Is opposed to a spring stopper 34 carried on a portion constituting a damping mechanism in the piston 5 described later.

  Therefore, when the rod 4 rises in the cylinder 3 with a large stroke and reaches the maximum extension state, the extension spring S1 contracts by the contact of the spring receiver 41 to exert a spring force, and the damper is extended most. Mitigates shock during operation.

  The balance spring S2 is contracted by the contact of the spring stopper 34 to the spring seat 33 and contracts the spring force, that is, the damper, when the rod 4 rises in the cylinder 3 with a large stroke and reaches the maximum extension state. Demonstrate the spring force biased in the direction.

  That is, the illustrated front fork is energized in the extending direction by enclosing a pressure higher than atmospheric pressure in the air chamber A in the reservoir R when the fork main body is in the most extended state, thereby providing a reaction force. Therefore, the reaction force during the contraction operation in the predetermined stroke region from the maximum extension state can be reduced by suppressing the reaction force in the predetermined stroke region in which the fork main body contracts from the maximum extension state by the balance spring S2. It becomes possible.

  Returning, the rod guide 31 closes the upper end opening of the cylinder 3 and allows the rod 4 to pass through the shaft core portion. Therefore, as shown in FIG. 3, an annular recess is formed on the inner peripheral side of the lower half. (Not shown), and a backup member 35 is inserted into the recess.

  The backup member 35 has a seal 35a made of an O-ring on the back side which is the side of the rod guide 31 to ensure liquid-tightness with the rod guide 31 and is adjacent to the inner periphery. The inner periphery of the bush 35b is slidably contacted with the outer periphery of the rod 4 to ensure the slidability with respect to the rod 4, that is, the rod guide 31 with respect to the rod 4.

  Also, as shown in FIG. 3, the rod guide 31 has an annular groove (not shown) that opens laterally on the inner circumferential side of the upper half, and the inner circumference of the rod 4 is the annular groove. A seal 36 made of an O-ring that is in sliding contact with the outer periphery is provided to ensure liquid tightness between the rod guide 31 and the rod 4.

  By the way, in the damper, the lower end portion of the cylinder 3 is a bottom end portion (not shown), and an oil lock case 62 constituting an oil lock mechanism 6 described later is provided at the bottom end portion. Close the bottom opening.

  A communication hole 3 a that allows communication between the lower chamber R 2 inside the cylinder 3 and the reservoir R outside the cylinder 3 is provided slightly above the bottom end portion to which the oil lock case 62 is connected in the cylinder 3. .

  The communication hole 3a may have a damping action when the working fluid passes through, for example, an orifice, depending on the configuration of a damping mechanism in the piston 5 to be described later, and may not be a noticeable damping action. It may be a hole.

  Therefore, in the cylinder 3 having the communication hole 3a described above, an amount of working fluid corresponding to the rod intrusion volume that becomes redundant in the lower chamber R2 when the damper 5 in which the piston 5 descends in the cylinder 3 is contracted. The outflow to the reservoir R outside the cylinder 3 through the communication hole 3a is allowed.

  In the cylinder 3 having the communication hole 3a, an amount of working fluid corresponding to the rod withdrawal volume integral that is insufficient in the lower chamber R2 when the damper 5 in which the piston 5 moves up in the cylinder 3 is operated. Is allowed to flow into the lower chamber R2, that is, from the reservoir R outside the cylinder 3.

  If the oil lock case 62 is provided at the bottom end portion of the cylinder 3, the replenishment of the working fluid from the reservoir R to the lower chamber R2 is as shown in FIG. 62 may be realized by including the check valve C.

  That is, a check valve C that prevents the working fluid from passing from the oil lock case 62 toward the reservoir R, but allows the working fluid from the reservoir R to flow into the oil lock case 62 in the opposite direction. May be provided in the oil lock case 62.

  In this case, even when the communication hole 3a provided in the cylinder 3 is an orifice and restricts the passage of the working fluid, it does not cause a problem of insufficient suction of the working fluid in the lower chamber R2 when the damper is extended. There is an advantage that becomes possible.

  The rod 4 basically only needs to connect the piston 5 slidably inserted into the cylinder 3 to the tip portion which is the lower end portion, and therefore may be formed of a solid body. However, it may be formed of a hollow body, that is, a pipe.

  When the rod 4 is formed of a pipe, it is possible to increase the bending strength while reducing the weight as compared with the case where the rod 4 is formed of a solid body. A control rod can be arranged, which is advantageous in that the control rod can be used to adjust the damping action of the damping mechanism by the control valve.

  Incidentally, the control rod itself is also made of a pipe, so that the weight of the control rod can be reduced and the bending strength can be improved.

  In addition, the control valve has a rear end adjacent to the lower end of the control rod. However, the tip end, that is, the front end of the control valve bypasses the damping mechanism and bypasses the lower chamber R2 and the upper chamber R1 in the cylinder 3. It arrange | positions in the bypass path which connects.

  Therefore, when a bypass path is provided in the damping mechanism and a control valve is provided in this bypass path, the flow rate of the working fluid passing through the bypass path can be made somewhat. It is possible to adjust the damping action by the damping mechanism.

  Note that when a control valve is provided in the bypass passage, the damping action that the control valve adjusts is adjusted by the expansion side damping valve 51 or the pressure side damping valve provided in the piston 5 constituting the main damping mechanism described later. 52 is a damping action.

  That is, as will be described later, in the present invention, the auxiliary damping mechanism 10 is provided in addition to the main damping mechanism. However, according to the concept of the main damping mechanism, the control valve described above is provided in the present invention. It can be said that it constitutes the main damping mechanism.

  As shown in FIG. 1, the piston 5 is slidably inserted into the cylinder 3. As shown in FIG. 2, the piston 5 is interposed in the tip member 44 of the rod 4 and has an upper chamber R 1 and a lower chamber in the cylinder 3. Separated from R2.

  The piston 5 has damping means that performs a predetermined damping action when the piston 5 slides in the cylinder 3 to allow communication between the upper chamber R1 and the lower chamber R2, and this damping means is shown in the figure. Has an extension side damping valve 51 (see FIG. 2) and a compression side damping valve 52 provided on the piston 5.

  By the way, in the present invention, the auxiliary damping mechanism 10 is provided in addition to the main damping mechanism. However, in the illustrated case, the main damping mechanism is provided in the piston 5. The extension-side damping valve 51 and the compression-side damping valve 52 provided in the above form the main damping mechanism.

  In FIG. 2, the compression side damping valve 52 is composed of a laminated annular leaf valve, which closes the piston 5 so that the downstream end of the opening of the pressure side passage 5a can be opened, and the extension side damping valve 51 is also laminated. It consists of a leaf valve, and closes the piston 5 so that the downstream end of the open side passage (not shown) opened can be opened.

  In addition, although said piston 5 is hold | maintained at the front-end | tip part of the rod 4 with a piston nut (not shown), it exists in illustration and a piston nut comprises the oil lock piece 61 in the oil lock mechanism 6. Therefore, in this piston nut, a portion screwed into the tip end portion of the rod 4 is a nut portion (not shown), and a portion fitted into the oil lock case 62 is a tip portion (not shown). This tip portion substantially constitutes an oil lock case.

  From this point of view, the tip of the oil lock piece 61 may be provided with a taper 61a along the axial direction of the cylinder 3 on the outer periphery as shown in FIG. 1, and as shown in FIG. Alternatively, it may be formed in a substantially cylindrical shape or a cylindrical shape having no taper.

  Therefore, in the damper having the cylinder 3, the rod 4 and the piston 5 formed as described above, the damping mechanism in which the working fluid in the upper chamber R1 is mainly used during the extension operation in which the piston 5 ascends in the cylinder 3 is provided. The gas flows out into the lower chamber R2 through the expansion side damping valve 51 provided in the piston 5 to be configured, and a predetermined damping action is performed.

  At this time, an amount of working fluid corresponding to the rod withdrawal volume deficient in the lower chamber R2 is replenished from the reservoir R to the cylinder 3 through the open communication hole 3a, and the communication hole 3a is made an orifice. The extension side is dampened.

  In this damper, when the piston 5 descends in the cylinder 3, the working fluid in the lower chamber R2 enters the upper chamber R1 via the compression side damping valve 52 provided in the piston constituting the main damping mechanism. Inflow and a predetermined damping action are performed.

  At this time, an amount of working fluid that is excessive in the lower chamber R2 and corresponding to the rod intrusion integral flows out to the reservoir R through the communication hole 3a, and when the communication hole 3a is an orifice, the pressure side damping action Is made.

  Incidentally, according to the concept of the main damping mechanism in the present invention, it can be said that the communication hole 3a constitutes the main damping mechanism in the present invention as long as the communication hole 3a is orificed and performs a predetermined damping action.

  Further, as described above, when the control valve is provided in the bypass path bypassing the expansion side damping valve 51 and the pressure side damping valve 52 constituting the main damping mechanism, it can be said that this control valve also constitutes the main damping mechanism in the present invention. .

  As shown in FIG. 1, the oil lock mechanism 6 includes an oil lock piece 61 including a piston nut that connects a piston 5 to a tip end of a rod 4 that is removably inserted into the cylinder 3, and a bottom end portion of the cylinder 3. And an oil lock case 62 provided on the front side.

  Therefore, in the oil lock mechanism 6, the oil lock piece 61 is composed of a piston nut, and the oil lock case 62 is provided at the bottom end portion of the cylinder 3. And the position of the fluid surface O (see FIG. 1) in the working fluid that causes the oil lock mechanism 6 to function as compared with the case where it is provided between the base end of the rod 4 and the vicinity of the base end. 3 can be positioned below the head end portion of the head 3, and the amount of the working fluid to be accommodated can be reduced, thereby reducing the weight of the front fork.

  In the oil lock mechanism 6, the oil lock piece 61 is composed of a piston nut that connects the piston 5 to the tip of the rod 4. However, although not shown, an oil lock case in the oil lock mechanism is provided at the head end of the cylinder. Therefore, as compared with the case where the oil lock piece in the oil lock mechanism is provided independently at or near the base end portion of the upper rod 4, the piston nut and the oil lock piece are separate parts. The number of parts can be reduced without forming.

  In addition, in the present invention, the reservoir R has an auxiliary damping mechanism 10 to be described later. In the operation of the auxiliary damping mechanism 10, the fluid surface O of the working fluid is below the auxiliary damping mechanism 10. Therefore, it can be said that it is meaningful to reduce the amount of the working fluid stored.

  On the other hand, in the oil lock mechanism 6, the oil lock case 62 has a sealing means (not shown) on an inner peripheral side portion of an opening end portion that forms an opening for introducing the oil lock piece 61.

  The sealing means confines the working fluid in the oil lock case 62 when the oil lock piece 61 comes into the oil lock case 62, and also when the oil lock piece 61 comes out of the oil lock case 62. The hydraulic fluid from the lower chamber R2 is allowed to flow into the oil lock case 62.

  At this time, the sealing means includes an annular groove (not shown) formed in the inner peripheral side portion of the opening end portion of the oil lock case 62, and an oil lock case in the radial direction and the axial direction of the rod 4 in the annular groove. An annular seal 63 (see FIG. 1) is inserted in 62 so as to be movable in the axial direction and allows the oil lock case 61 to be fitted to the inner peripheral side.

  In this sealing means, the annular seal 63 has a passage (not shown) including a notch that allows communication between the inner peripheral side and the outer peripheral side of the annular seal 63 on the end surface facing the lower chamber R2. When the opposite end surface is seated on the inner wall of the annular groove, communication between the inner peripheral side and the outer peripheral side of the annular seal 63 is prevented.

  Therefore, in the oil lock mechanism 6, since the oil lock case 62 has a sealing means on the inner peripheral side portion of the opening end portion that forms the opening through which the oil lock piece 61 is introduced, the oil lock piece 61 has the oil lock case 62. When it fits in, the working fluid from the oil lock case 62 passes through the annular gap that appears between the oil lock piece 61 and the sealing means, and at this time, a cushion effect is obtained.

  In this oil lock mechanism 6, since the oil lock case 62 has a sealing means on the inner peripheral side of the opening end portion that forms the opening through which the oil lock piece 61 is introduced, the oil lock piece 61 is placed in the oil lock case 62. The sealing means traps the working fluid in the oil lock case 62 when fitting into the oil lock case 62, and the oil lock function is exerted so that the oil lock piece 61 does not fit further into the oil lock case 62. A bottom butt is avoided in the front fork.

  Further, in this oil lock mechanism 6, when the oil lock piece 61 fitted in the oil lock case 62 comes out of the oil lock case 62, the seal means moves downward from the side wall of the annular groove. Since the inflow of the working fluid from the chamber R2 into the oil lock case 62 is allowed, it is possible to avoid a damper that prevents the oil lock piece 61 from coming out of the oil lock case 62, that is, an inoperable state of the front fork.

  In the present invention, as described above, the auxiliary damping mechanism 10 is provided in addition to the main damping mechanism.

  In the present invention, when the main damping mechanism is provided in the piston 5, that is, in the damper, the auxiliary damping mechanism 10 is provided outside the damper, that is, in the reservoir R. To do.

As will be described below, the auxiliary damping mechanism 10 is, as shown in FIGS. 1 and 3, an annular valve 102 that is wound around the outer periphery of the cylinder 3 so as to move up and down, in addition to the coil spring 101 as the biasing means. The annular valve 102 has a lower end opposed to the outside of the cylinder 3, that is, a lower portion of the reservoir R outside the damper, and an outer periphery of the annular valve 102 is disposed on the inner periphery of the wheel side tube 2 as a cylindrical body . It is made to oppose with the annular clearance S3 which accept | permits passage.

  The annular valve 102 connects the lower end of the coil spring 101 to the upper end side, and the upper end portion of the coil spring 101 is suspended on the outer periphery of the upper end portion of the rod guide 31 included in the cylinder 3 as described above. Further, the upper end of the rod guide 31 is locked to the flange portion 31a.

  Therefore, in the present invention, the main damping mechanism provided in the damper during the expansion / contraction operation of the fork main body can perform a predetermined main damping action, and at the same time, the auxiliary damping mechanism 10 provided in the reservoir R outside the damper has the predetermined damping function. An auxiliary damping action can be performed, and the degree of freedom in setting the damping action in the hydraulic shock absorber is increased.

  At this time, in the auxiliary damping mechanism 10, the elements constituting the auxiliary damping mechanism 10 include the annular valve 102, the coil spring 101, the annular gap S 3, and a plurality of fluid surfaces O. By arbitrarily setting the mass in the coil spring 101, the spring force in the coil spring 101, the size of the annular gap S3, and the position of the fluid surface O, the damping action by the auxiliary damping mechanism 10 can be changed in various ways. In addition to the damping action in the main damping mechanism, even if compared with the proposal disclosed in Patent Document 1, it is possible to realize a more effective damping action that is rich in changes.

  In the auxiliary damping mechanism 10, when the position of the fluid surface O of the working fluid in the reservoir R is positioned below the annular valve 102 in the auxiliary damping mechanism 10, for example, a predetermined damping action is performed. It will be.

  That is, for example, when the fork main body is in a neutral state, if the fork main body is compared, the contraction operation is performed at a low speed, and the fluid surface O below the annular valve 102 is increased at a low speed when compared. It passes through the annular gap S3 between the annular valve 102 and the wheel side tube 2 and flows into the upper part of the annular valve 102. By passing the working fluid through the annular gap S3, a predetermined damping action is performed. Will be.

  Then, if the fork main body in the neutral state is compared, the contraction operation is performed at a high speed, and if the fluid surface O below the annular valve 102 is compared, the fluid surface O is increased at a high speed, so that the working fluid pushes up the annular valve 102. .

  At this time, the annular valve 102 rises against the urging force of the coil spring 101 as the urging means, and the energy loss at this time becomes a damping action, and the urging force of the coil spring 101 as the urging means described above. Attenuating action different from that when not resisting is performed.

  As a result, according to the present invention, a more preferable riding comfort in the vehicle can be obtained by the auxiliary damping action of the auxiliary damping mechanism 10.

  By the way, in the place shown in the figure, the annular valve 102 has a passage 102a made of a notch at the lower end corner on the outer peripheral side, and this passage 102a communicates with the annular gap S3. When the working fluid rising to the lower end surface comes into contact, when the flow velocity is relatively slow, the fluid flows into the so-called upper part of the annular valve 102 via the passage 102a and the annular gap S3. By passing through the passage 102a and the annular gap S3, it becomes possible to perform a predetermined linear damping action.

  As described above, in the front fork as the hydraulic shock absorber according to the present invention, the fork main body accommodates the working fluid therein and serves as the lower end side member, and the cylinder 3 is inserted into the cylinder 3 so as to freely enter and exit. It has a rod 4 which is an upper end side member, and a piston 5 which is held by the rod 4 and is slidably inserted into the cylinder 3 and separates the upper chamber R1 and the lower chamber R2 into the cylinder 3. Therefore, a predetermined damping action can be performed by the main damping mechanism when the damper is extended or contracted.

  In the front fork according to the present invention, since the auxiliary damping mechanism 10 is provided in the fork main body, that is, the reservoir R outside the damper, the damping action that cannot be completely guaranteed by the main damping mechanism in the damper. Can be made.

  That is, for example, when the two-wheeled vehicle after the jump landings from the front wheel or the two-wheeled vehicle suddenly brakes and the front fork, that is, the fork main body contracts with a large stroke under high speed, The auxiliary damping mechanism 10 can be burdened with the damping action exceeding the capacity of the main damping mechanism, so that the riding comfort in a two-wheeled vehicle can be further improved.

  In the above description, the operation condition of the auxiliary damping mechanism 10 is that the position of the fluid surface O of the working fluid is below the auxiliary damping mechanism 10, but considering the function of the auxiliary damping mechanism 10, the fluid surface Even if the position of O is above the auxiliary damping mechanism 10, that is, even if the auxiliary damping mechanism 10 is in the working fluid, it can be said that the functioning position is not different.

DESCRIPTION OF SYMBOLS 1 Car body side tube 2 Wheel side tube 2a, 3a Communication hole 3 Cylinder 4 Rod 5 Piston 5a Pressure side passage 6 Oil lock mechanism 10 Auxiliary damping mechanism 11 Oil seal 12 Dust seal 13 Lower bearing 21 Upper bearing 22 Axle holder 23 Seal holder 23a, 23b Seal 31 Rod guide 31a Flange portion 32 Spring holder 33 Spring seat 34 Spring stopper 35 Backup member 35a, 36 Seal 35b Bushing 41 Spring support 41a Snap ring 44 Tip member 51 Extension side damping valve 52 Pressure side damping valve 61 Oil lock piece 61a taper composed of piston nut 62 Oil lock case 63 Annular seal 101 Coil spring as urging means 102 Annular valve 102a Passage A Air chamber O Fluid surface R Reservoir R1 Upper Chamber R2 Lower chamber S Lubrication gap S1 Stretch spring S2 Balance spring S3 Annular gap

Claims (4)

A cylinder that is the lower end side member by accommodating the working fluid within, has an erecting type damper having a rod that is in and out freely inserted has been upper side member to the cylinder, the outside of the damper In the hydraulic shock absorber as a reservoir,
An auxiliary damping mechanism is provided in the reservoir,
The auxiliary damping mechanism includes an annular valve forming an annular gap which forms the damping action upon the passage of hydraulic fluid between the inner periphery of the cylindrical body opposite with provided vertically movably on the outer circumference of the cylinder, the annular hydraulic shock absorber, characterized by chromatic and biasing means for biasing the valve in the down direction. It said annular valve you have a passage communicating with the annular gap becomes from notches on the lower end side outer peripheral portion
The hydraulic shock absorber according to claim 1. The urging means comprises a coil spring, the lower end is carried by the annular valve, and the upper end is locked to the upper end of the rod guide that closes the upper end opening of the cylinder .
The hydraulic shock absorber according to claim 1 or 2 , wherein The cylinder is erected in the shaft core portion of the vehicle wheel side tube, the rod is vertically to the shaft core portion of the vehicle body side tube which is connected to the telescopic type the wheel side tube, the wheel side tube the cylindrical body Was
Hydraulic shock absorber according to any one of claims 1 3, characterized in that.

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