JP5457878B2 - Fluid pressure buffer - Google Patents

Description

  The present invention relates to an improvement of a fluid pressure shock absorber used in a saddle-ride vehicle such as a two-wheeled vehicle.

  A fluid pressure shock absorber, such as a front fork, used in a saddle-riding vehicle such as a two-wheeled vehicle dampens road surface vibrations input to the front wheel by suspending the front wheel of the two-wheeled vehicle.

  For example, the front fork disclosed in Patent Literature 1 generates a predetermined damping force by being accommodated in the fork main body including an outer tube and an inner tube that can be inserted into and retracted into the outer tube. And a suspension spring serving as a biasing means for constantly biasing the fork main body in the extending direction.

  The damper includes a cylinder that rises at the axial center portion of the inner tube and accommodates a working fluid, a rod that stands at the axial center portion of the outer tube and protrudes and retracts in the cylinder, Accordingly, a damping force generating means for generating a predetermined damping force is provided.

  The fork body is set upside down with the outer tube disposed on the vehicle body side and the inner tube disposed on the wheel side.

  Further, a reservoir chamber is formed between the fork body and the damper, and the reservoir chamber stores a working fluid for making up for the working fluid that becomes excessive or insufficient due to the protrusion / depression of the rod or a temperature change. An air chamber is formed above the oil level of the working fluid.

  Further, the suspension spring is provided in the reservoir chamber, and the suspension spring is interposed between an upper spring receiver fixed to the outer tube side and a lower spring receiver fixed to the inner tube side. .

  The suspension spring is usually made of a metal coil spring.

  Therefore, in order to reduce the weight of the front fork, the applicant replaces the urging means consisting of the suspension spring and encloses the air chamber while compressing gas, and always urges the fork main body in the extending direction. It was invented to be used as

  However, if the gas is simply compressed and sealed in the air chamber, the spring reaction force of the air chamber acts even when the fork body is fully extended, so that the contraction stroke in the vicinity of the maximum extension is not quickly started and the ride comfort is increased. There is a risk of worsening.

  Therefore, as shown in FIG. 5, the applicant urges the fork main body F in the contracting direction within a predetermined stroke range from when the fork main body F is fully extended, and also air chambers when the fork main body F is fully extended. A front fork with a balance spring T7 that cancels the spring reaction force of A was proposed.

  In the proposed front fork, the inverted damper T3, the air chamber A functioning as a suspension spring, and the fork body F in the fork body F composed of the outer tube 1 and the inner tube 2 are urged in the extending direction. The balance spring T7 is accommodated.

  The damper T3, together with the air chamber A, constitutes a so-called single-cylinder fluid pressure shock absorber. The cylinder T4 stands on the axial center of the outer tube 1 and the cylinder T4 stands on the axial center of the inner tube 2. A rod T5 protruding and retracting inside, a piston T6 provided at the tip of this rod T5 and having an extension side damping force generation valve V2, and a base provided on the upper side of the cylinder T4 in the drawing and having a compression side damping force generation valve V1 A member T41 and a free piston T9 that separates the air chamber A and is movable in the axial direction are provided.

  The balance spring T7 is interposed between an upper spring receiving member TA fixed to the inner periphery of the upper end portion of the inner tube 2 in the drawing and a lower spring receiver TB fixed to the outer periphery of the lower end portion of the cylinder T4 in the drawing. In addition, the fork body F is urged in the contraction direction within a predetermined stroke range from the time when the fork body F is fully extended as shown in FIG. 5 and the spring reaction force of the air chamber A when the fork body F is fully extended. Offset.

JP 2009-156359 A (FIG. 1)

  The proposed front fork is provided with the balance spring T7 so that the ride comfort of the vehicle in the vicinity of the maximum extension of the fork main body F is not deteriorated. The balance spring T7 has a spring constant as compared with the conventional suspension spring. Is set to be smaller than the conventional suspension spring.

  Therefore, the proposed front fork is useful in that it can be formed lighter than the front fork disclosed in Patent Document 1, but the following problems may be pointed out.

  In other words, when the upright type front fork accommodates the upright damper T3, the cylinder T4 and the inner tube 2 do not move relative to each other as the fork body F expands and contracts. The fork main body F cannot be urged in the contraction direction.

  Further, in order to urge the fork main body F in the contracting direction, a balance spring T7 can be interposed between the rod guide T40 and the piston T6. In this case, the balance spring T7 is connected to the inner periphery of the cylinder T4. There is a risk of damaging the sliding surface of the piston T6.

  Accordingly, an object of the present invention is to dispose a balance spring outside a cylinder in a fluid pressure shock absorber such as a front fork and attach a balance spring regardless of a damper accommodation form (upright type or inverted type). And providing a balance spring mounting structure.

Means for solving the above problems include a shock absorber body comprising an outer tube and an inner tube that can be freely inserted and retracted into the outer tube, and a predetermined damping force generated in the shock absorber body. And a biasing means for constantly biasing the shock absorber body in the extending direction,
The damper is erected on one axial center portion of the outer tube or the inner tube and accommodates a working fluid, and is erected on the other axial center portion of the outer tube or the inner tube. A rod that moves in and out, and a damping force generating means that generates a predetermined damping force as the rod protrudes and retracts, wherein the biasing means is a fluid comprising an air chamber that encloses gas and generates a predetermined spring reaction force In the pressure buffer,
A spring receiving member comprising an extension piece fixed to the other of the outer tube or the inner tube via the rod and extending toward the cylinder;
A balance spring interposed between one spring receiver provided protruding outward from the cylinder and the other spring receiver disposed on the opposite rod side of the one spring receiver. It equipped with a door,
The spring receiving member is formed in an annular shape so that an inner periphery thereof is coupled to the rod outer periphery, the extending piece formed in a cylindrical shape extending from the base portion, and the inside and the outside of the spring receiving member are communicated with each other. It comprises a case provided with the communication means to do.

According to the present invention, since one spring receiver on which the balance spring is interposed is fixed to the cylinder side and the other spring receiver is fixed to the rod side, the balance spring is arranged outside the cylinder and the damper is accommodated. It becomes possible to attach a balance spring that urges the shock absorber body in the contraction direction regardless of whether it is an upright type or an inverted type.
In particular, when the shock absorber body contracts, the extended piece and the inner tube overlap, making it difficult for hydraulic oil to flow out of the spring receiving member via the communication means, and the hydraulic oil in the spring receiving member passes through the communication means. Therefore, it is possible to exert a damping force by the communication means.
Therefore, it is not necessary to provide a conventionally known oil lock mechanism or elastic body for absorbing the impact, and the configuration of the fluid pressure shock absorber can be simplified.

It is a longitudinal cross-sectional view which shows in principle the most extended state of the front fork which is a fluid pressure buffer which concerns on one embodiment of this invention. It is a longitudinal half sectional view showing the maximum extension state of a front fork which is a fluid pressure shock absorber according to an embodiment of the present invention. It is a longitudinal half sectional view showing the most contracted state of a front fork which is a fluid pressure shock absorber according to an embodiment of the present invention. (A) (b) (c) It is a longitudinal cross-sectional view which respectively shows the Example of the spring receiving member of the front fork which is a fluid pressure buffer which concerns on one embodiment of this invention. It is a longitudinal cross-sectional view which shows in principle the most extended state of the front fork which is a fluid pressure buffer of the previous proposal.

  Hereinafter, a mounting structure of a balance spring in a fluid pressure shock absorber according to an embodiment of the present invention will be described in detail with reference to the drawings.

  The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  In the present embodiment, the present invention is embodied in a front fork that suspends a front wheel of a two-wheeled vehicle, and the front fork functions as a fluid pressure buffer that attenuates road surface vibration input to the front wheel. .

  As shown in FIG. 1, the front fork includes a fork main body F that is a shock absorber body including an outer tube 1 and an inner tube 2 that is inserted and retracted into the outer tube 1. The damper 3 is accommodated and generates a predetermined damping force, and the urging means for always urging the fork main body F in the extending direction.

  The damper 3 rises at the axial center portion of the inner tube 2 and accommodates hydraulic oil as a working fluid, and rises at the axial center portion of the outer tube 1 and protrudes into and out of the cylinder 4. The rod 5 is provided with a damping force generating means for generating a predetermined damping force when the rod 5 is projected and retracted.

  The urging means includes an air chamber A in which a gas is enclosed to generate a predetermined spring reaction force.

  The front fork includes a spring receiving member 8 including an extended piece 80 that is fixed to the outer tube 1 and extends toward the cylinder.

  Further, the front fork is provided on one side of the spring receiver 40s that protrudes outward from the cylinder 4 and the other spring formed on the extended piece 80 by being disposed on the opposite rod side of the one spring receiver 40s. A balance spring 7 is provided between the receptacle 80s.

  Below, each component of the front fork in the embodiment of the present invention will be described.

  The front fork is composed of a pair of left and right shock absorber bodies F standing on both sides of the front wheel of the two-wheeled vehicle. The fork main body F is disposed on the vehicle body side of the two-wheeled vehicle and on the wheel side, and the above described It consists of the inner tube 2 that appears and disappears in the outer tube 1 and is set upside down.

  Although not shown, the upper end side of the outer tube 1 in the drawing is connected to the handle side of the two-wheeled vehicle via an upper bracket, and the lower end side of the inner tube 2 in the drawing is connected to the axle of the front wheel of the two-wheeled vehicle.

  The fork main body F is sealed at its upper and lower ends with a cap member 11 and a bottom member 21, respectively.

  Further, a cylindrical gap formed between the inner periphery of the outer tube 1 and the outer periphery of the inner tube 2 is attached to the inner periphery of the opening on the lower end side of the outer tube 1 in the figure, and is an annular shape that is in sliding contact with the outer periphery of the inner tube 2. The seal 12 is used.

  The fork main body F accommodates a damper 3 that generates a predetermined damping force inside, and a reservoir chamber R that accommodates hydraulic oil is formed outside the damper 3.

  In the reservoir chamber R, an air chamber A is formed above the boundary of the oil level O of the stored hydraulic oil. The air chamber A is filled with gas and exhibits a predetermined spring reaction force. Thus, the fork main body F functions as a biasing means that always biases the fork main body F in the extending direction.

  That is, the air chamber A is set to an internal pressure that urges the fork main body F in the extending direction even when the fork main body F has the maximum volume, and is always maintained in a compressed state.

  As shown in FIGS. 2 and 3, by providing an air valve E on the cap member 11, the internal pressure of the air chamber A can be appropriately adjusted to obtain a desired spring reaction force.

  The damper 3 housed inside the fork main body F rises at the axial center portion of the inner tube 2 and accommodates hydraulic oil, and rises at the axial center portion of the outer tube 1 and enters the cylinder 4. The rod 5 includes a rod 5 into which the tip can be freely inserted and retracted, and a damping force generating means for generating a predetermined damping force as the rod 5 moves in and out, and is set upright.

  As shown in FIGS. 2 and 3, the rod 5 is fixed to the cap member 11 via a nut N at the base end portion located at the upper end in the drawing.

  On the other hand, the front end side of the rod 5 protrudes and retracts into the cylinder 4 while being supported by the inner periphery of the annular rod guide 40 coupled to the inner periphery of the upper end portion of the cylinder 4 in the drawing, and the piston 6 through the tip member 50. Hold.

  An extension spring S is provided on the lower side of the rod guide 40 in the figure, and this extension spring S absorbs the impact of the piston 6 and the rod guide 40 coming into contact when the fork body F is fully extended.

  The cylinder 4 is fixed to the inner tube 2 via the bottom member 21 and is partitioned by the piston 6 into an extension side working chamber P2 located at the upper side in the figure and a pressure side working chamber P1 located at the lower side in the figure.

  The pressure side working chamber P1 communicates with the reservoir chamber R through a flow path of a base member 41 provided in the bottom member 21 (FIG. 1), and inside the cylinder 4 as the rod 5 moves in and out through the flow path. It becomes possible to supplement the reservoir chamber R with excess or insufficient hydraulic oil.

  The base member 41 includes a compression side damping force generation valve V1 that generates a damping force when the fork main body F contracts in the flow path, and a check valve C1 that allows only the flow of hydraulic oil from the reservoir chamber R to the compression side working chamber P1. And comprising.

  The compression-side damping force generation valve V1 generates a predetermined damping force when the hydraulic oil that is the surplus volume of the rod 5 that is immersed in the cylinder 4 as the fork body F contracts flows into the reservoir chamber R. .

  Further, the check valve C1 quickly compensates the hydraulic fluid from the reservoir chamber R for the insufficient volume of the rod 5 that retreats as the fork main body F extends.

  On the other hand, the piston 6 includes an extension side damping force generation valve V2 that generates a damping force when the fork main body F extends, and a check valve C2 that allows only the flow of hydraulic oil from the pressure side operation chamber P1 to the extension side operation chamber P2. And comprising.

  The extension side damping force generation valve V2 generates a predetermined damping force when hydraulic oil flows out from the extension side working chamber P2 to the pressure side working chamber P1 as the rod 5 is retracted when the fork main body F is extended.

  Further, the check valve C2 quickly causes the working oil to flow out from the compression side working chamber P1 to the extension side working chamber P2 when the fork main body F contracts.

  In the present embodiment, the compression-side damping force generation valve V1 and the extension-side damping force generation valve V2 constitute a damping force generation means. However, the configuration of the damping force generation means is not limited to that shown in the drawings. A well-known configuration can be selected as appropriate.

  The fork main body F urges the fork main body F in a contracting direction within a predetermined stroke range from the time when the fork main body F is fully extended, and the spring reaction of the air chamber A when the fork main body F is fully extended. A balance spring 7 for canceling the force is provided.

  The balance spring 7 is fixed to the cylinder 4 via the rod guide 40 and protrudes outwardly from the cylinder 4. The other spring receiver 80 s is fixed to the outer tube 1 via the rod 5. It is inserted between.

  The other spring receiver 80s is disposed on the opposite rod side of the one spring receiver 40s, that is, on the lower side in the drawing, and the balance spring 7 attaches the fork main body F in the extending direction by providing this configuration. It will be possible to

  Further, by providing the above configuration, one spring receiver 40 s on which the balance spring 7 is interposed is fixed to the cylinder side and the other spring receiver 80 s is fixed to the rod side, and the other spring receiver 80 s is one spring receiver 40 s. Therefore, the balance spring 7 can bias the fork main body F in the contracting direction regardless of the accommodation form (upright type or inverted type) of the damper 3.

  As in the present embodiment, the damper 3 is formed upright and is set so that the oil level O in the reservoir chamber R is positioned above the rod guide 40 even when the fork body F is fully extended. Thus, the front fork according to the present embodiment can easily keep the inside of the cylinder 4 liquid-tight as compared with the front fork shown in FIG. 5 that houses the inverted damper 3.

  Further, the balance spring 7 is provided outside the cylinder 4 so that the inner peripheral surface of the cylinder 4 is not damaged, and thus the sliding surface of the piston 6 can be kept smooth.

  Further, as shown in FIGS. 2 and 3, even when the front fork includes the extension spring S, the balance spring 7 and the extension spring S interfere with each other because the balance spring 7 is provided outside the cylinder 4. There is nothing to do.

  The predetermined stroke range from the maximum extension of the fork main body F may be set as appropriate according to the desired spring reaction force of the front fork, and when the balance spring 7 is not loaded with respect to the entire stroke length of the fork main body F. The spring length (hereinafter simply referred to as spring length) can be set.

  The operation of the balance spring 7 will be described below.

  As shown in FIG. 2, when the fork main body F is fully extended, the distance between the spring receivers 40s and 80s is the shortest. At this time, the balance spring 7 is compressed most, so that the spring reaction force is maximum.

  When the fork main body F starts to contract, the spring receivers 40s and 80s are separated from each other, and the spring reaction force of the balance spring 7 is reduced, and the distance between the spring receivers 40s and 80s and the spring length of the balance spring 7 coincide with each other. Then, the spring reaction force of the balance spring 7 becomes zero.

  Further, when the fork main body F continues to contract, the upper end of the balance spring 7 in the drawing and one spring receiver 40s are separated from each other, and when the fork main body F shown in FIG. Is the longest distance.

  That is, until the balance spring 7 is fully extended from the maximum extension of the fork main body F where the balance spring 7 is most compressed and the distance between the spring receivers 40 s and 80 s matches the spring length of the balance spring 7, The fork body F is urged in the extending direction.

  Therefore, by appropriately setting the spring length of the balance spring 7 with respect to the entire stroke of the fork main body F, it becomes possible to arbitrarily set the stroke range from the maximum extension of the fork main body F on which the balance spring 7 acts.

  The balance spring 7 described above cancels the spring reaction force of the air chamber A when the fork main body F is fully extended. The air chamber A that urges the fork main body F in the extending direction when the fork main body F is fully extended. And the spring reaction force of the balance spring 7 that urges the fork main body F in the contracting direction, and the spring reaction force of the air chamber A does not act on the fork main body F. .

  By providing the above configuration, the fork main body F can quickly contract within a predetermined stroke range of the fork main body F on which the balance spring 7 acts, and deterioration of the riding comfort of the fork main body F can be prevented. Become.

  A spring receiving member 8 carrying the lower end of the balance spring 7 in the figure is inserted between the base 81 fixed to the rod 5 and the outer periphery of the cylinder 4 and the inner periphery of the inner tube 2 extending from the base 81. And a communication means for communicating between the inside and outside of the spring receiving member 8.

  The base portion 81 is formed in an annular shape and is fixed to the outer periphery of the rod 5, and the extended piece 80 is formed in a cylindrical shape, and the upper end portion in the figure is coupled to the outer periphery of the base portion 81, and The other spring receiver 80s is provided.

  As shown in FIGS. 2, 3, and 4 (a), the communication means includes a throttle 81a that penetrates the thickness of the base 81 and a communication hole 80a that penetrates the thickness of the extended piece 80. The hydraulic oil passes through the inside and outside of the spring receiving member 8 through the restrictor 81a and the communication hole 80a.

  By arranging a plurality of the communication holes 80a side by side in the axial direction of the extending piece 80, the inner and outer oil surfaces O of the spring receiving member 8 can be made to coincide, but this is not restrictive.

  For example, as shown in FIG. 4B, a slit 80b formed by notching the extending piece 80 in the axial direction may be used in place of the communication hole 80a. The same effect as that of the hole 80a can be obtained.

  The base 81 is formed in an annular shape, and the inner periphery is coupled to the outer periphery of the rod 5 to hold the extended piece 80 on the outer periphery. The base 81 is positioned above the oil level O when the fork main body F shown in FIG. 2 is fully extended, and is set to be immersed in the hydraulic oil when the fork main body F shown in FIG.

  Therefore, when the hydraulic oil passes through the restriction 81a of the base 81 when the fork main body F contracts, resistance is generated, and the contraction motion of the fork main body F can be attenuated.

  2 and 3, when the fork main body F contracts, the extension piece 80 and the inner tube 2 overlap (FIG. 3), and the hydraulic oil flows through the communication hole 80a of the extension piece 80. It becomes difficult for oil to flow out of the spring receiving member 8, and the hydraulic oil in the spring receiving member 8 flows out of the spring receiving member 8 through the restrictor 81 a of the base portion 81, so that a compression-side damping force is exhibited by the restrictor 81 a. It becomes possible.

  Therefore, it is not necessary to provide a conventionally known oil lock mechanism or elastic body for absorbing an impact when the fork main body F is contracted most, and the configuration of the front fork can be simplified.

  As shown in FIG. 4 (c), the base 81 is not provided with the throttle 81a, and the communication hole 80a of the extended piece 80a is used as the throttle 80c to absorb the impact when the fork main body F is contracted most. You may do that.

  Although not shown, in the spring receiving member 8 in FIG. 4A, the base 81 may not be provided with the throttle 81a, and only the communication hole 80a on the base 81 side may be used as the throttle 80c.

  In this embodiment, the spring receiving member 8 is fixed to the outer tube 1 via the rod 5, but the spring receiving member 8 may be fixed to the outer tube 1 via the cap member 11.

  In this case, it is possible to make the spring receiving member 8 simpler by configuring the spring receiving member 8 only by the extended piece 80.

  The shape and configuration of the spring receiving member 8 are not limited to those described above, and the front fork may be provided with a conventionally known oil lock mechanism or elastic body for absorbing the impact when the fork main body F is most contracted. In the case where it is not necessary to absorb the impact when the fork main body F is contracted due to the other configuration, the shape of the spring receiving member 8 is such that the other spring receiver 80s is fixed to the rod 5 and more than the one spring receiver 40s. As long as it can be arranged on the side opposite the rod, it can be set appropriately.

  In the present embodiment, the other spring receiver 80s protrudes inward from the tip of the extended piece 80 of the spring receiving member 8, so that the configuration of the front fork is not complicated, but this is not limited. Instead, the other spring receiver 80 s may be coupled to the spring receiver 8.

  In the present embodiment, one spring receiver 40 s is provided integrally with the rod guide 40, and protrudes outward from the cylinder 4 from the rod side end of the rod guide 40. A spring receiver can be provided without processing.

  The configuration of one spring receiver 40s can be selected as appropriate. For example, the one spring receiver 40s may be coupled to the outer periphery of the cylinder 4 as in FIG.

  While the preferred embodiment of the present invention has been described 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-described embodiment, the configuration according to the present invention is embodied in the front fork. However, the present invention is not limited to this, and it is needless to say that the configuration may be embodied in a rear cushion unit or another shock absorber.

  In the above embodiment, an inverted front fork that accommodates an upright damper is adopted. However, an upright front walk may be used, and the accommodation form of the damper 3 to be accommodated is not limited.

  In the present embodiment, the working oil is accommodated as the working fluid inside the fork main body. However, the present invention is not limited to this, and an aqueous working fluid may be used.

A Air chamber C1, C2 Check valve F Fork body O Oil level P1 Pressure side working chamber P2 Stretch side working chamber R Reservoir chamber V1 Pressure side damping force generating valve V2 Stretching side damping force generating valve S Stretching spring 1 Outer tube 2 Inner tube 3 , T3 damper 4, T4 cylinder 5, T5 rod 6, T6 piston 7, T7 balance spring 8 spring receiving member 11 cap member 12 seal member 21 bottom member 40, T40 rod guide 41, T41 base member 80 extending piece 81 base

Claims (4)

A shock absorber body composed of an outer tube and an inner tube that can be freely inserted and retracted in the outer tube, a damper that is housed in the shock absorber body and generates a predetermined damping force, and the shock absorber body are always attached. An urging means for urging in the extending direction,
The damper is erected on one axial center portion of the outer tube or the inner tube and accommodates a working fluid, and is erected on the other axial center portion of the outer tube or the inner tube. A rod that moves in and out, and a damping force generating means that generates a predetermined damping force as the rod protrudes and retracts, wherein the biasing means is a fluid comprising an air chamber that encloses gas and generates a predetermined spring reaction force In the pressure buffer,
A spring receiving member comprising an extension piece fixed to the other of the outer tube or the inner tube via the rod and extending toward the cylinder;
A balance spring interposed between one spring receiver provided protruding outward from the cylinder and the other spring receiver disposed on the opposite rod side of the one spring receiver. It equipped with a door,
The spring receiving member is formed in an annular shape so that an inner periphery thereof is coupled to the rod outer periphery, the extending piece formed in a cylindrical shape extending from the base portion, and the inside and the outside of the spring receiving member are communicated with each other. A fluid pressure shock absorber comprising a case having a communicating means . The fluid pressure shock absorber according to claim 1, wherein the communication means includes a throttle that generates resistance when the working fluid passes through . The one spring receiver is provided at an opening on the rod side of the cylinder and is provided integrally with an annular rod guide for guiding the rod into the cylinder, and from the rod side end of the rod guide to the outside of the cylinder. The fluid pressure shock absorber according to claim 1 or 2 , wherein the fluid pressure shock absorber projects outward. In the shock absorber body, the outer tube is arranged on the vehicle body side, the inner tube is arranged on the wheel side, the rod is fixed to the outer tube, and the cylinder is fixed to the inner tube. The reservoir chamber formed between the shock absorber body and the damper is configured as an inverted type that accommodates the damper, and a working fluid that supplements the working fluid that is excessive or insufficient in the cylinder is stored. The fluid pressure shock absorber according to claim 1, 2, or 3 , wherein the air chamber is formed above the oil surface .

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