JP6487802B2 - Shock absorber - Google Patents

Description

  The present invention relates to a shock absorber.

  Conventionally, a shock absorber is used to support a rear wheel of a saddle-type vehicle such as a two-wheeled vehicle or a three-wheeled vehicle. Among such shock absorbers, there is a shock absorber in which a spring support that supports one end of a suspension spring that is a coil spring is driven by a jack so that the vehicle height can be adjusted (for example, Patent Document 1).

JP 2010-149548 A

  Here, when increasing the vehicle height adjustment amount in the shock absorber, it is preferable to increase the vehicle height adjustment amount without changing the longitudinal dimension of the suspension spring. This is because the longitudinal dimension of the suspension spring has already been optimally designed, and it is complicated to redesign the suspension spring. However, in the conventional shock absorber, if the vehicle height adjustment amount is increased without changing the longitudinal dimension of the suspension spring, no load is applied to the suspension spring when the shock absorber is fully extended, and the suspension spring is not moved in the axial direction. There may be a state where it can move freely, that is, a state where the suspension spring is idle. For this reason, as shown in FIG. 6, the applicant proposes a shock absorber having an auxiliary spring 22 interposed between the jack 4 and the spring receiver 21, and adjusts the vehicle height without changing the longitudinal dimension of the suspension spring 2. Even if the amount is increased, the suspension spring 2 can be prevented from playing.

  However, in the proposed shock absorber, as shown in FIG. 6, if the spring receiver 21, the auxiliary spring 22, and the piston 40 of the jack 4 that supports the auxiliary spring 22 are arranged side by side in the axial direction of the shock absorber, There is a problem that the mounting length of the shock absorber is deteriorated because the total length of the shock absorber becomes long.

  Accordingly, an object of the present invention is to provide a shock absorber that can improve the mountability of the shock absorber even if an auxiliary spring is provided.

  The invention according to claim 1, which solves the above problem, includes a spring receiver that supports one end of the suspension spring and is movable in the axial direction of the shock absorber body, a base attached to the shock absorber body, and an outer periphery of the base. Provided on the outer periphery of the piston, one end of which is supported by the spring support and the other end of which is supported by the piston. An auxiliary spring, and the spring receiver is provided on the outer periphery of the piston. Therefore, even if an auxiliary spring is provided, the axial length of the shock absorber can be shortened.

  In the invention according to claim 2, in addition to the configuration according to claim 1, the piston includes a cylindrical portion that is in sliding contact with the outer periphery of the base, and a support portion that protrudes outward from the cylindrical portion, The auxiliary spring has a coil shape, the cylindrical portion is inserted inside, the other end is supported by the support portion, and the spring support is formed in an annular shape so as to be in sliding contact with the outer periphery of the piston. Therefore, it is possible to simplify the configuration for arranging the spring receiver and the auxiliary spring on the outer periphery of the piston while supporting one end of the auxiliary spring with the spring receiver and supporting the other end with the piston.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the auxiliary spring has a close contact height when mounted on a stopped vehicle. Therefore, even if an auxiliary spring is provided, the spring characteristic of the shock absorber when the vehicle is running can be approximated to the spring characteristic of the shock absorber without the auxiliary spring.

  According to a fourth aspect of the present invention, in addition to the configuration according to the first or second aspect, the spring receiver is restricted from moving in a direction in which the auxiliary spring is compressed in a state of being attached to a stopped vehicle. A stopper is provided. Therefore, even if an auxiliary spring is provided, the spring characteristic of the shock absorber when the vehicle is running can be approximated to the spring characteristic of the shock absorber without the auxiliary spring. Furthermore, the appearance failure of the auxiliary spring can be suppressed.

  According to the shock absorber of the present invention, even if an auxiliary spring is provided, the mountability of the shock absorber can be improved.

It is the side view which simplified and showed the vehicle which attached the buffer which concerns on one embodiment of this invention. It is the front view which notched and showed the unloaded state of the buffer concerning one embodiment of the present invention partially, shows the state which advanced the piston to the right of the centerline, and shows the piston on the left of the centerline Is shown in the state in which is fully retracted. It is the front view which showed partially the 1G state of the buffer concerning one embodiment of the present invention, shows the state which advanced the piston to the right of the center line, and shows the piston to the left of the center line to the maximum Shown in the retracted state. It is the figure which expanded a part of FIG. It is the figure which expanded a part of front view partially cut away and shown the modification of the shock absorber concerning one embodiment of the present invention. It is the figure which expanded a part of front view which notched and showed the conventional shock absorber partially.

  Embodiments 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, a shock absorber A according to an embodiment of the present invention is interposed between a vehicle body B and a rear wheel W of a vehicle V that is a motorcycle. As shown in FIG. 2, the shock absorber A includes a shock absorber main body 1, a suspension spring 2 provided on the outer periphery of the shock absorber main body 1, and a spring receiver 20 that supports the lower end of the suspension spring 2 in FIG. A spring receiver 21 that supports the upper end of the suspension spring 2 in FIG. 2, a jack 3 that adjusts the position of the spring receiver 21, and an auxiliary spring 22 that is interposed between the spring receiver 21 and the jack 3. .

  The shock absorber body 1 includes a cylindrical outer shell 10 and a rod 11 that is movably inserted into the outer shell 10, and has a damping force that suppresses relative movement of the outer shell 10 and the rod 11 in the axial direction. Demonstrate. Brackets 12 and 13 are fixed to the outer shell 10 and the rod 11, respectively. The bracket 12 on the outer shell 10 side is connected to the vehicle body B, and the swing arm that supports the rear wheel W is supported by the bracket 13 on the rod 11 side. It connects with b1 (FIG. 1) via the link which is not shown in figure. Therefore, when an impact due to road surface unevenness is input to the rear wheel W, the rod 11 enters and exits the outer shell 10 and the shock absorber main body 1 expands and contracts to exhibit a damping force. As a result of the expansion and contraction of the suspension spring 2 together with the shock absorber main body 1, the shock absorber A expands and contracts.

  The suspension spring 2 is a coil spring formed by winding a wire in a coil shape, and exhibits an elastic force against the compression when compressed. The spring receiver 20 that supports the lower end of the suspension spring 2 in FIG. 2 is formed in an annular shape and provided on the outer periphery of the rod 11, and the downward movement of the rod 11 in FIG. 2 is restricted by the lower bracket 13 in FIG. Is done. Further, the spring receiver 21 that supports the upper end of the suspension spring 2 in FIG. 2 is formed in an annular shape, and is provided on the outer periphery of a later-described piston 34 of the jack 3, and is supported by the piston 34 via the auxiliary spring 22.

  The jack 3 includes a jack body 30 provided on the outer periphery of the outer shell 10 and having the piston 34, a pump 31 that supplies hydraulic oil to the jack body 30, and a motor 32 that drives the pump 31. The pump 31 and the motor 32 may have any configuration, and a well-known configuration can be adopted, and detailed description thereof is omitted here. In the case where the pump 31 is a gear pump, the pump 31 is inexpensive and excellent in durability, and the hydraulic oil can be quickly supplied to the jack body 30.

  Further, a flange 14 protruding outward is fixed to the outer periphery of the upper end portion in FIG. 2 of the outer shell 10, and the outer periphery on the lower side in FIG. 2 with respect to the flange 14 of the outer shell 10 is covered with a cylindrical guide 15. Yes. The guide 15 is formed with annular grooves (not shown) extending in the circumferential direction at both ends in the axial direction, and snap rings 16 and 17 are fitted into the annular grooves. A jack body 30 is attached to the outer periphery of the guide 15 and is prevented from coming off by both snap rings 16 and 17.

  The jack body 30 includes an annular base 33 provided on the outer periphery of the guide 15 and a top cylindrical piston 34 slidably mounted on the outer periphery of the base 33. The base 33 has a small-diameter portion 33a on the lower side in FIG. 2 having a small outer diameter, and a large-diameter portion 33b that is connected to the upper side in FIG. 2 of the small-diameter portion 33a and whose outer diameter is larger than the outer diameter of the small-diameter portion 33a. . An annular step 33c is provided at the boundary between the small diameter portion 33a and the large diameter portion 33b. The other piston 34 includes an annular top 34a that is in sliding contact with the outer periphery of the guide 15, a cylindrical portion 34b that extends upward in FIG. 2 from the outer periphery of the top 34a, and that is in sliding contact with the outer periphery of the small-diameter portion 33a. 2 and an annular support portion 34c protruding outward from the upper end portion.

  An annular O-ring (not shown) is provided between the base 33 and the guide 15, between the top 34 a of the piston 34 and the guide 15, and between the cylindrical portion 34 b of the piston 34 and the small diameter portion 33 a of the base 33. It is blocked by. And the space enclosed by the top part 34a, the cylinder part 34b, the small diameter part 33a, and the guide 15 is the annular liquid chamber L, and is filled with hydraulic oil.

  The liquid chamber L is connected to the pump 31 via a hose or the like. When the hydraulic oil is supplied to the liquid chamber L by the pump 31, the piston 34 advances downward in FIG. On the contrary, when the hydraulic oil is discharged from the liquid chamber L by the pump 31, the piston 34 moves backward in FIG. 2 and the liquid chamber L is reduced.

  On the outer periphery of the piston 34, a spring receiver 21 and an auxiliary spring 22 that support the upper end of the suspension spring 2 in FIG. The spring receiver 21 is slidably in contact with the outer periphery on the lower side in FIG. 2 with respect to the support portion 34 c of the piston 34, and is movable in the axial direction of the shock absorber body 1. The auxiliary spring 22 is a coil spring formed by winding a wire in a coil shape, and exhibits an elastic force against the compression when compressed. The cylindrical portion 34b of the piston 34 is inserted into the auxiliary spring 22 and the lower end in FIG. 2 of the auxiliary spring 22 is supported by the spring receiver 21 and the upper end in FIG. 2 is supported by the support portion 34c of the piston 34. It has been.

  That is, in the shock absorber A, the auxiliary spring 22 is connected in series with the suspension spring 2 via the spring receiver 21. When the spring member S is composed of the suspension spring 2, the spring receiver 21 and the auxiliary spring 22 connected in series as described above, the elastic force of the spring member S acts on the piston 34, and the jack body 30 is It is pressed against the flange 14 by force. Further, the base 33 of the jack body 30 is secured against the guide 15 by the upper snap ring 17 in FIG. 2, and when the jack body 30 is pressed against the flange 14 by the elastic force, the outer shell 10 of the guide 15. The snap ring 17 and the flange 14 restrict the movement in the axial direction relative to. The elastic force of the spring member S also acts on the lower spring receiver 20 in FIG. 2, and the spring receiver 20 is pressed against the bracket 13 by the elastic force. Therefore, when the shock absorber body 1 expands and contracts, the spring member S expands and contracts, and the vehicle body B is elastically supported by the spring member S.

  FIG. 2 shows a state where the shock absorber A has a natural length and the shock absorber main body 1 is fully extended in a no-load state where the shock absorber A is not loaded. In FIG. 2, the right side of the center line shows a state where the piston 34 is advanced as much as possible, and the left side shows a state where the piston 34 is retracted as much as possible.

  As shown on the right side in FIG. 2, when the piston 34 is advanced to the maximum in the no-load state, the auxiliary spring 22 deflects the suspension spring 2 by a certain amount to give an initial deflection, and the suspension spring 2 has a predetermined initial load. multiply. The piston 34 does not interfere with the lower snap ring 16 in FIG. When the snap ring 16 is provided in this way, the piston 34 can be prevented from coming out of the guide 15 during the assembly process of the shock absorber A, so that the shock absorber A can be easily assembled. Further, after the assembly of the shock absorber A is completed, the snap ring 16 does not interfere with the piston 34 and does not hinder the movement of the piston 34.

  Further, as shown on the left side in FIG. 2, in the state where the piston 34 is retracted as much as possible in the no-load state, the piston 34 contacts the step 33c of the base 33, and the suspension spring 2 and the auxiliary spring 22 are of natural length (free Close to the height). At the upper end of the base 34a of the piston 34 in FIG. 2, an annular recess 34d is provided on the outer peripheral side (FIG. 4), and the recess 34d faces the opening of the flow path connecting the liquid chamber L and the hose. . Therefore, even if the top portion 34a of the piston 34 is abutted against the tip of the small diameter portion 33a of the base 33 at the time of the last retreat, the pressure receiving area of the piston 34 that receives the hydraulic oil pressure increases. In addition, you may provide the said dent 34d in the small diameter part 33a side.

  Subsequently, the natural length of the auxiliary spring 22 is determined by the initial deflection (compression) of the suspension spring 2 from the stroke length of the piston 34 (the distance traveled from the maximum advanced state to the maximum retracted state). It is more than the length minus (long).

  Here, for example, in the shock absorber A, the state where the initial load that gives the initial deflection X (mm) to the suspension spring 2 is applied to the suspension spring 2 while the piston 34 is advanced to the maximum is optimal, and the stroke of the piston 34 is optimized. The length is Y (mm). Considering the case where the auxiliary spring 22 is not provided, if the stroke length Y of the piston 34 is within a range that does not exceed the initial deflection X of the suspension spring 2, the suspension spring 2 can be operated even if the piston 34 is retracted to the maximum in an unloaded state. Does not play.

  However, when the stroke length Y exceeds the initial deflection X when the stroke length Y of the piston 34 is increased and the vehicle height adjustment amount is increased without changing the longitudinal dimension of the suspension spring 2 without the auxiliary spring 22, The suspension spring 2 may become idle. This is because, when the piston 34 is retracted to the maximum in an unloaded state, the suspension spring extends X (mm) to reach a natural length, and then the piston 34 further retracts YX (mm). This is because the suspension spring 2 can move in the axial direction by -X).

  On the other hand, the shock absorber A includes the auxiliary spring 22, and the natural length of the auxiliary spring 22 is longer than the length obtained by subtracting the initial deflection X from the stroke length Y of the piston 34, that is, (Y−X). Therefore, even if the vehicle height adjustment amount is increased without changing the longitudinal dimension of the suspension spring 2, the auxiliary spring 22 fills the gap that allows the suspension spring 2 to move in the axial direction (surplus retraction amount), and the suspension spring Prevent 2 from playing.

  Further, the spring constant of the auxiliary spring 22 is much smaller than the spring constant of the suspension spring 2. Specifically, in the state where the weight of the vehicle V stopped (still) on the horizontal ground is applied to the shock absorber A in the attached state, that is, in the 1G state, the auxiliary spring 22 is compressed to the maximum and the contact height is increased. become. FIG. 3 shows the shock absorber A in the 1G state, showing a state in which the piston 34 is advanced to the right of the center line in FIG. 3, and retracting the piston 34 to the left of the center line in FIG. Shows the state.

  The suspension spring 2 does not reach the contact height with respect to the auxiliary spring 22 even when the shock absorber A is in the most contracted state. That is, in the 1G state, since the auxiliary spring 22 has a close contact height as described above, the spring constant of the spring member S becomes the spring constant of the suspension spring 2, and the vehicle body B is substantially supported only by the suspension spring 2. It becomes a state.

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

  When the vehicle V starts traveling, the hydraulic oil is supplied to the liquid chamber L by the pump 31 to advance the piston 34. Then, since the piston 34, the spring member S, the lower spring receiver 20 in FIG. 3 and the bracket 13 move downward in FIG. 3 with respect to the outer shell 10, the rod 11 is retracted from the outer shell 10 and the shock absorber. As A extends, the vehicle height increases.

  On the other hand, when the speed is lowered to stop the vehicle V, the hydraulic oil is discharged from the liquid chamber L by the pump 31 and the piston 34 is moved backward. Then, the piston 34, the spring member S, the lower spring receiver 20 in FIG. 3 and the bracket 13 move upward in FIG. 3 with respect to the outer shell 10, so that the rod 11 enters the outer shell 10 and the shock absorber. As A contracts, the vehicle height decreases.

  In addition, during normal vehicle travel in which the vehicle weight, the weight of the passenger, the weight of the load, etc. are applied to the shock absorber A, the auxiliary spring 22 is compressed to the close contact height. Therefore, during normal vehicle travel, the spring member S behaves so as to consist only of the suspension spring 2. However, when the shock absorber A is fully extended, such as when climbing over a level difference, even if the piston 34 is in the last retracted state, the auxiliary spring 22 is prevented from extending and the suspension spring 2 is prevented from playing. Furthermore, since the vehicle weight or the like is applied to the shock absorber A even when the vehicle V stops, the auxiliary spring 22 is maintained at the contact height.

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

  In the present embodiment, the auxiliary spring 22 has a close contact height when attached to the stopped vehicle V. Therefore, the suspension spring 2 having the same longitudinal dimension can be used with the shock absorber A having the auxiliary spring 22 and the shock absorber without the auxiliary spring, and even if the auxiliary spring 22 is provided, The spring characteristic can be approximated to that of a shock absorber without an auxiliary spring.

  In addition, in order to acquire the said effect, you may provide the stopper which controls that the spring receiver 21 moves to the direction which compresses the auxiliary spring 22 in the attachment state to the vehicle V which stopped. For example, in the form shown in FIG. 5, a step 34 e that functions as the stopper is provided on the outer periphery of the piston 34, and the spring receiver 21 hits the step 34 e before the auxiliary spring 22 reaches the contact height. In this case, since the auxiliary spring 22 does not reach the close contact height, it is possible to suppress the appearance failure of the auxiliary spring 22 such that the coils constituting the auxiliary spring 22 are rubbed and the coating is peeled off. Furthermore, since the load applied to the auxiliary spring 22 can be reduced, the durability of the auxiliary spring 22 can be improved.

  Further, the auxiliary spring 22 may be brought into close contact height, or the step (stopper) 34e may prevent the auxiliary spring 22 from being compressed in the 1G state where the rider's weight is added to the 1G state. Also in this case, the spring characteristic of the shock absorber A when the vehicle is running can be approximated to the spring characteristic of the shock absorber without the auxiliary spring. In FIG. 5, the step 34e functions as a stopper, but the configuration of the stopper can be changed as appropriate. For example, although not shown, the stopper may be a cylindrical spacer, provided on the inner periphery or outer periphery of the auxiliary spring 22, and connected to one of the spring receiver 21 or the piston 34.

  Further, in the present embodiment, the piston 34 has a cylindrical portion 34 b that is in sliding contact with the outer periphery of the base 33, and a support portion 34 c that protrudes outward from the cylindrical portion 34. The auxiliary spring 22 has a coil shape, the cylindrical portion 34b is inserted inside, the upper end (the other end) in FIG. 2 is supported by the support portion 34c, and the spring receiver 21 is formed in an annular shape so that the outer periphery of the piston 34 Slid in contact.

  According to the above configuration, it is possible to simplify the configuration for arranging the spring receiver 21 and the auxiliary spring 22 on the outer periphery of the piston 34 while supporting the one end of the auxiliary spring 22 with the spring receiver 21 and supporting the other end with the piston 34. The configuration of the piston 34 is not limited to the above, and can be changed as appropriate. And such a change is possible irrespective of the presence or absence of a stopper.

  Further, in the present embodiment, the shock absorber A includes a shock absorber main body 1 and a spring receiver 21 that supports the upper end (one end) in FIG. 2 of the suspension spring 2 and is movable in the axial direction of the shock absorber main body 1. A base 33 attached to the shock absorber main body 1, a jack 3 that is movably mounted on the outer periphery of the base 33 and forms a liquid chamber L between the base 33, and an outer periphery of the piston 34. 2, the lower end (one end) is supported by the spring receiver 21, and the upper end (other end) in FIG. 2 is provided with the auxiliary spring 22 supported by the piston 34, and the spring receiver 21 is provided on the outer periphery of the piston 34.

  According to the above configuration, even if the vehicle height adjustment amount is increased without changing the axial length of the suspension spring 2, it is possible to prevent the suspension spring 2 from becoming idle. And if vehicle height adjustment amount is increased, the footing property at the time of a stop can be made favorable. Further, if the suspension spring 2 is not allowed to play by the auxiliary spring 22, even if the jack body 30 is supported by the elastic force of the suspension spring 2 as in the present embodiment, the jack body 30 may fall off. The jack body 30 and the flange 14 can be separated and contacted repeatedly to prevent abnormal noises from being generated or shifted.

  Further, according to the above configuration, even if the auxiliary spring 22 is provided to prevent play of the suspension spring 2, the spring receiver 21 and the auxiliary spring 22 are provided on the outer periphery of the piston 34. And the axial direction length which match | combined the auxiliary spring 22 can be shortened. Therefore, the axial length of the shock absorber A can be shortened, and the mountability of the shock absorber A can be improved.

  In the shock absorber A, the suspension spring 2 and the auxiliary spring 22 are coil springs. However, the suspension spring 2 and the auxiliary spring 22 may be square springs having a rectangular cross section. , And can be changed as appropriate according to the desired spring characteristics.

  In the shock absorber A, the guide 15 is provided on the outer periphery of the outer shell 10 and the piston 34 is slidably contacted with the guide 15, but the outer periphery of the outer shell 10 The piston 34 may be brought into sliding contact directly with the outer periphery.

  The jack 3 includes a jack body 30 having a piston 34 and a base 33, a pump 31 that supplies hydraulic oil to the jack body 30, and a motor 32 that drives the pump 31. It can be changed as appropriate. For example, the liquid used for the jack 3 may be other than hydraulic oil, and water, an aqueous solution, or the like may be used.

  In the shock absorber A, the outer shell 10 is connected to the vehicle body B and the rod 11 is connected to the rear wheel W, which is an inverted type, but the outer shell 10 is connected to the rear wheel W. At the same time, the rod 11 may be connected to the vehicle body B to be an upright type.

  The shock absorber A is interposed between the motorcycle body B and the rear wheel W of the motorcycle. However, the shock absorber A may be used for a straddle-type vehicle other than a motorcycle, an automobile, or the like. .

  The above-described change can be made regardless of the configuration of the piston 34, with or without the stopper, while supporting one end of the auxiliary spring 22 with the spring receiver 21 and supporting the other end with the piston 34.

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

A ... Shock absorber, L ... Liquid chamber, V ... Vehicle, 1 ... Buffer body, 2 ... Suspension spring, 3 ... Jack, 21 ... Spring receiver, 22. ..Auxiliary springs 33 ... base 34 ... piston 34b ... cylinder part 34c ... support part 34e ... step (stopper)

Claims (4)

The shock absorber body,
A spring receiver that supports one end of the suspension spring and is movable in the axial direction of the shock absorber body;
A jack having a base attached to the shock absorber main body and a piston that is movably mounted on an outer periphery of the base and forms a liquid chamber between the base and the base;
An auxiliary spring provided on the outer periphery of the piston, one end supported by the spring support and the other end supported by the piston;
The shock absorber, wherein the spring support is provided on an outer periphery of the piston. The piston has a cylindrical portion that is in sliding contact with the outer periphery of the base, and a support portion that protrudes outward from the cylindrical portion,
The auxiliary spring is coiled, the cylindrical part is inserted inside, and the other end is supported by the support part,
The shock absorber according to claim 1, wherein the spring support is formed in an annular shape and slidably contacts the outer periphery of the piston. The shock absorber according to claim 1 or 2, wherein the auxiliary spring has a close contact height when mounted on a stopped vehicle. The shock absorber according to claim 1 or 2, further comprising a stopper that restricts movement of the spring receiver in a direction in which the auxiliary spring is compressed in a state of being attached to a stopped vehicle.

Images