JP2000072067A - Suspension of two-wheeler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat suspension or a front fork suspension which is excellent in slidability and in a rotation preventive characteristic, and small in play in the rotational direction. SOLUTION: In a seat suspension in which an inner cylinder is slidably moved relative to an outer cylinder through a polygonal surface, an outer circumference of an inner cylinder 4 comprises a pair of circumferential parts 4b, 4b in the longitudinal direction of a motor-cycle length, a pair of circumferential parts in the right-to-left direction, a rotation preventive part 3A which is formed in a polygonal surface comprising four plane parts 4d formed between these circumferential parts and in which the inner circumference of the outer cylinder 3 comprises a polygonal surface as that formed on the outer circumference of the inner cylinder, and a bearing holding part 3b formed in the axial direction on an opening part side of the inner circumference of the outer cylinder 3 over a specified length, and annular bushes 5, 6 to support the circumferential parts 4b, 4c of the outer circumference of the inner cylinder 4 are fixed to upper and lower parts in the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat suspension provided between a body frame and a seat of a motorcycle or the like, or a front fork which is interposed in a front head pipe of the body frame and supports a front wheel. The present invention relates to a front fork suspension capable of sliding a front fork relative to a head pipe in an axial direction and absorbing a shock from a front wheel.

[0002]

2. Description of the Related Art Conventionally, as described in Japanese Patent Publication No. 50-13541, a bottomed cylinder fitted to a seat frame of a bicycle, etc.
There is disclosed a cylinder in which a cylinder is slidably and non-rotatably fitted, a sheet is fixed to an upper end of the cylinder, and a shock absorber is provided between the cylinder and a bottomed cylinder. The cylinder and the bottomed cylinder are fitted via a hexagonal cross-section detent, and are slidable up and down with respect to each other.

[0003]

Such a shock absorbing device is provided in a seat frame which is arranged obliquely in the longitudinal direction of the vehicle body, and a seat attached to an upper end portion of a cylinder generally has a front portion having a rear portion. Since the cylinder and the bottomed cylinder have a large side force in the front-rear direction due to being mounted in a higher state, the cylinder does not slide with respect to the bottomed cylinder.

Further, when such a side force is received on a polygonal surface, the contact between the cylinder and the cylinder with a bottom becomes a line contact at a corner of the polygonal surface, and the surface pressure at the line contact portion becomes high. The wear at the line contact part becomes severe.

As a solution, it is conceivable to provide a polygonal bushing having the same shape as the detent portion at the detent portion to reduce friction, but the dimensional tolerance between the cylinder and the bottomed cylinder is added, and the rotation direction is increased. The backlash increases. Also,
It is difficult to manufacture a polygonal bush and to fix the bush to the bottomed cylinder.

SUMMARY OF THE INVENTION An object of the present invention is to provide a seat suspension or a front fork suspension which is excellent in slidability and anti-rotation characteristics and has less play in the rotation direction.

[0007]

According to the present invention, there is provided an outer cylinder having a polygonal surface formed on an inner periphery thereof, wherein the outer cylinder has a polygonal surface formed on an inner periphery thereof. In a seat suspension such as a motorcycle having an inner cylinder having a polygonal surface that is slidably fitted on the outer periphery and a shock absorber provided between the outer cylinder and the inner cylinder, the outer periphery of the inner cylinder is formed by a pair of vehicle front-rear directions. A circumferential portion, a pair of circumferential portions in the left-right direction, and four flat portions formed between these circumferential portions are formed on a polygonal surface, and an inner circumference of the outer cylinder is formed by the inner cylinder. A detent portion formed of the same polygonal surface as the polygonal surface formed on the outer periphery, and a bearing holding portion formed over a predetermined length in the axial direction on the inner peripheral opening side of the outer cylinder, and this bearing holding portion, An annular bush supporting the inner cylinder is fixed vertically in the axial direction.

According to a second aspect of the present invention, in the first aspect of the present invention, the length of a pair of circumferential portions of the outer cylinder and the inner cylinder in the front-rear direction is further reduced. It is longer than the length of a pair of circumferential portions in the left-right direction.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a gas is sealed in the inner cylinder, and a piston rod having a piston attached to a distal end in the inner cylinder is further provided. The piston-side chamber and the piston-rod-side chamber are hermetically sealed in the inner cylinder, and the base end of the piston rod is attached to the outer cylinder.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a passage is formed in the piston rod for communicating the chambers on both sides of the piston, and the communication passage is opened and closed in the piston rod. The operating rod is inserted.

According to a fifth aspect of the present invention, there is provided an outer cylinder which is rotatably inserted into a front head pipe of a vehicle body frame, has a handle fixed to an upper end portion, and has a polygonal surface formed on an inner periphery thereof; An inner cylinder having a polygonal surface that fits and slides on the inner polygonal surface and formed on the outer periphery, and a fork that supports the front wheel is attached to the lower end, and a shock absorber provided between the outer cylinder and the inner cylinder. In a front fork suspension of a motorcycle or the like, the outer periphery of the inner cylinder is at least a pair of circumferential portions in the vehicle body front-rear direction,
A detent portion formed of a polygonal surface formed of a flat portion formed between these circumferential portions, and a polygonal surface fitted to the polygonal surface formed on the outer periphery of the inner cylinder. An annular bushing formed on the inner peripheral opening side of the outer cylinder in the axial direction over a predetermined length in the axial direction, and supporting the outer peripheral part of the inner cylinder on the bearing retaining part. Are fixed vertically in the axial direction.

[0012]

According to the first aspect of the present invention, the following operations are provided. The outer periphery of the inner cylinder is formed into a polygonal surface including a pair of circumferential portions in the vehicle longitudinal direction, a pair of circumferential portions in the left-right direction, and four flat portions formed between these circumferential portions. The inner circumference of the cylinder
This bearing holding portion is formed from a detent portion formed of the same polygonal surface as the polygonal surface formed on the outer periphery of the inner cylinder, and a bearing holding portion formed over a predetermined length in the axial direction on the inner peripheral opening side of the outer cylinder. Then, an annular bush that supports the circumferential portion of the outer periphery of the inner cylinder was fixed vertically in the axial direction.

Therefore, the four cylinders formed on the inner cylinder and the outer cylinder, respectively,
The two flat portions act to prevent rotation of the outer cylinder and the inner cylinder, and the circumferential portion formed on the outer periphery of the inner cylinder slides on the upper and lower annular bushes provided on the inner periphery of the bearing holding portion of the outer cylinder. The sliding property between the cylinder and the outer cylinder is improved, and the inner cylinder does not stick to the outer cylinder.

According to the second aspect of the present invention, the following operations are provided. The length of the pair of circumferential portions in the front-rear direction among the circumferential portions of the outer tube and the inner tube is longer than the length of the pair of circumferential portions in the left-right direction. Since the side force load in the front-rear direction is higher than the side force load in the left-right direction, the surface pressure per unit received by the bush can be reduced, and the bush is less likely to be worn.

According to the third aspect of the invention, the following operation is provided. The gas in the piston side chamber sealed and partitioned by the piston in the inner cylinder is compressed to perform a shock absorbing action.

According to the fourth aspect, the following operation is provided. The relative position between the inner cylinder and the outer cylinder attached to the piston rod, that is, the height of the seat, is adjusted by opening the communication passage in the piston with the operating rod and changing the relative position of the piston rod with respect to the inner cylinder. Can be.

According to the fifth aspect, the following operations are provided. When the steering wheel fixed to the upper end of the outer cylinder is steered, the outer cylinder and the inner cylinder rotate integrally within the head pipe, and when impact is applied from the road surface via a fork attached to the lower end of the inner cylinder. The inner cylinder slides axially with respect to the outer cylinder to absorb the impact from the fork attached to the lower end of the inner cylinder. At least a pair of circumferential portions formed on the outer periphery of the inner cylinder in the longitudinal direction of the vehicle body and an annular bush provided on the bearing holding portion formed on the opening side of the outer cylinder receive a side force load in the longitudinal direction. And the shock absorption is improved.

[0018]

1 is an overall view showing a seat suspension, FIG. 2 is an enlarged view of a main part of the seat suspension,
3 is a schematic view showing the inner cylinder of FIG. 2, FIG. 4 is a sectional view taken along line AA of FIG. 2, and FIG. 5 is a sectional view taken along line BB of FIG.

The seat suspension 1 is a bicycle seat frame pipe 2 which is disposed inclining in the vehicle longitudinal direction.
An outer cylinder 3 inserted therein, an inner cylinder 4 slidably inserted into the outer cylinder 3 and inserted in a rotational direction through a rotation preventing portion to be described later, and a portion between the outer cylinder 3 and the inner cylinder 4. The outer cylinder 3 is fixed to the inside of the seat frame pipe 2 by a fastener 5 fitted around the outer periphery of the seat frame pipe 2. The seat 9 on which the occupant rides is attached. However, the outer cylinder 3 may be formed integrally with the seat frame pipe.
The outer periphery of the inner cylinder 4 is AA in FIG. 4 except for a cylindrical portion 4a (indicated by L1 in FIG. 3) into which a cylindrical jig for gas filling is fitted.
As shown in the cross-sectional view and the BB cross-sectional view of FIG. 4, a pair of circumferential portions 4b, 4b in the vehicle front-rear direction, a pair of circumferential portions 4c, 4c in the left-right direction, and 4 formed therebetween. A pair of circumferential portions 4b, 4b in the front-rear direction of the vehicle body and a pair of circumferential portions 4c, 4c in the left-right direction are symmetrical. However, the circumferential portion 4b on the rear side of the vehicle body may be longer than the circumferential portion 4b on the front side, of the pair of circumferential portions 4b, 4b in the vehicle front-rear direction. The length of the pair of circumferential portions 4b in the front-rear direction is the same as the length of the pair of circumferential portions 4 in the left-right direction.
c, 4c are formed longer than the length.

The inner circumference of the outer cylinder 3 has a detent part 3A having a length L2 in FIG. 2 and a bearing holding part L3. 3B,
The detent portion 3A includes four circumferential portions 3b and 3c corresponding to the four circumferential portions 4b and 4c on the outer periphery of the inner cylinder 4 as shown in the AA cross-sectional view of FIG. It is composed of four flat portions 3d corresponding to the portion 4d, and has the same polygonal shape as the outer periphery of the inner cylinder 4. The upper opening side of the outer cylinder 3 is
A bearing holding portion 3B cut into a larger diameter than the outer circumferential portions 4b and 4c is formed. Annular bushes 5 and 6 are fixed to the upper and lower inner circumferences of the bearing holder 3B, and a spacer collar 7 is interposed between the upper and lower annular bushes 5 and 6. A pair of circumferential portions 4b, 4b in the vehicle front-rear direction and a pair of left and right circumferential portions 4c, 4c on the outer circumference of the inner cylinder 4 are in sliding contact with the inner circumferences of the upper and lower annular bushes 5, 6. The upper and lower annular bushes 5, 6 receive side force loads in the vehicle longitudinal direction. Flat part 4d and annular bushes 5, 6
Is formed between them. Annular bush 5,
In this embodiment, the upper and lower annular bushes 5 and 6 are integrally formed as long as they are formed long enough to receive the front and rear side forces. Is also good.

Four flat portions 3d formed on the inner periphery of the outer cylinder 3
Are engaged with the four flat portions 4d on the outer periphery of the inner cylinder 4 to prevent mutual rotation, and the bearing holding portion 3B on the upper inner periphery of the outer cylinder 3
The annular bushes 5 and 6 fixed to the inner periphery support the circumferential portions 4 b and 4 c on the outer periphery of the inner cylinder 4 to improve the slidability between the outer cylinder 3 and the inner cylinder 4. Generally, since the detent action is performed at the corners of the polygonal surface, the effect of the detent is greater as the number of polygonal surfaces is larger, but in consideration of the fact that the circumferential portion constituting the sliding portion must be formed, A square surface is preferred as in this embodiment.

Between the inner cylinder 4 and the outer cylinder 3, there is provided a shock absorber composed of a gas spring described below.

A seat mounting member 8 is inserted and fixed to the upper inner periphery of the inner cylinder 4, and a cap 11 having an O-ring fitted to the outer periphery is brought into contact with the lower end of the seat mounting member 8.
Is inserted airtight.

A rod guide 13 having a bush 12 fitted on the inner periphery thereof is fixed to the opening side of the lower end of the inner cylinder 4, and a piston rod 15 having a piston 14 attached to the tip of the rod guide 13 penetrates the rod guide 13. It is slidably inserted. Gas is sealed in the inner cylinder 4, the piston 14 slides into the inner cylinder 4 via an O-ring and a piston ring, and the gas chamber in the inner cylinder 4 is divided into a piston side gas chamber A and a piston rod side gas chamber B. Place in a sealed compartment.

A washer 16, a gas seal 17, a sleeve 18, and a rebound seat 20 are interposed in order adjacent to the upper portion of the rod guide 13, and the rebound seat 20 is in contact with a stopper ring 21 fixed to the outer periphery of the piston rod. At the center of the piston 14, there is formed a hollow hole 20 penetrating in the axial direction and having a small-diameter stepped portion 14a at an intermediate portion. A hollow piston rod 15 is screwed to one side of the hollow hole 20. A hollow valve guide 22 having an annular groove 22a formed on the outer periphery is sandwiched between the distal end of the piston rod 15 and the small-diameter step portion 14a of the piston 14. The hollow hole 20 of the piston 14 formed on the piston side gas chamber A side includes a small diameter hole 20a on the inner circumference of the small diameter step portion 14a and a large diameter hole 20b on the upper part. The piston-side gas chamber A and the piston-rod-side gas chamber B are provided with the large-diameter hole 20 of the piston 14.
b, a small diameter hole 20a, an inner periphery of the hollow valve guide 22, a lateral hole 22b of the hollow valve guide 22, an annular groove 22a on the outer periphery, and a communicating passage formed by a lateral hole 14b of the piston.
A small diameter hole 20a of the piston 14, a hollow valve guide 22,
A spool-like on-off valve 2 is provided on the inner periphery of the hollow piston rod 15.
4 is slidably inserted in the axial direction via two upper and lower O-rings 25 and 26 interposed on the inner periphery of the small-diameter step portion 14 a of the piston 14 and the inner periphery of the hollow rod 15. On the outer periphery of the on-off valve 24, a lateral hole 22b of the hollow valve guide 22 is
4. An annular groove 2 long enough to communicate with the central large-diameter hole 20b.
4a are formed.

The upper end of the on-off valve 24 has a flange 24b.
Is formed, and the upper surface of the small-diameter stepped portion 14 a of the piston 14 serves as a downward movement stopper of the on-off valve 24. Also, the piston 14
A stopper ring 27 is provided in the upper inner periphery of the large-diameter hole 20b, and serves as an upward movement stopper of the on-off valve 24.

The lower end of the on-off valve 24 is
Further, an operating rod 31 is provided below the push rod 28 via a spring 30, and when the operating rod 31 is moved upward against the urging force of the spring 30,
The tip of the operating rod 31 contacts the push rod 28,
Push rod 28 and on-off valve 24 in contact with push rod 28
And the gas chambers on both sides of the piston 14 communicate with each other through the communication path. When the upward movement of the operating rod 31 is released, the on-off valve 24 moves downward by the gas pressure of the piston side chamber A to close the communication passage.

When the on-off valve 24 moves upward, the stopper ring 2
7, the annular groove 2 formed on the outer periphery of the on-off valve 24
4a communicates between the large-diameter hole 20b of the piston 14 and the lateral hole 22b of the hollow valve guide 22, and the upper O-ring 25 provided on the inner periphery of the piston small-diameter step portion 14a is located in the annular groove 24a on the outer periphery of the on-off valve 24. A gap is formed in the inner circumference of the O-ring 25, and the chambers A and B on both sides of the piston communicate with each other. On-off valve 2
4, the outer peripheral annular groove 24a moves to a position where the large-diameter hole 20a of the piston 14 and the lateral hole 22b of the hollow valve guide 22 do not communicate with each other, and the upper O-ring 25 becomes large in the upper part of the annular groove 24a of the on-off valve 24. The communication between the chambers A and B on both sides of the piston located at the radial portion is closed.

A cap 32 is fixed to the outer periphery of the base end of the piston rod 15 between a stopper ring 34 and a nut 33, and the lower end of the outer cylinder 3 is supported on the periphery of the cap 32. A bump rubber 35 is provided on the upper surface of the cap 32 to contact the lower end surface of the inner cylinder 4 at the time of maximum compression.

When a wheel of a motorcycle or the like rides on the projection and receives an impact, the outer cylinder 3 fixed to the seat frame pipe 2 and the piston rod 15 fixed to the outer cylinder 3 move upward with respect to the inner cylinder. Then, the gas in the piston side chamber A in the inner cylinder 4 is compressed to absorb the shock, and when the shock is released, the pressure of the gas causes the piston rod 15 to extend and return to the original state.

By operating the operating rod 31 to move the on-off valve 24 upward to communicate the chambers A and B on both sides of the piston and to change the relative position of the inner cylinder 4 with respect to the outer cylinder 3, the height of the seat 9 is increased. Can be adjusted.

In the above embodiments, the embodiment of the seat suspension has been described. However, the outer cylinder 3 is rotatably provided in the front head pipe (not shown) of the body frame, and the traveling handle is provided above the outer cylinder 3. (Not shown) is fixed, and a fork (not shown) for supporting a front wheel is attached to a lower end of an inner cylinder 4 which is fitted to the outer cylinder 3 so as to be non-rotatable and slidable in the axial direction. In this case, as in the case of a seat suspension, since the force in the rotational direction and the side force load in the front-rear direction of the vehicle body are not applied much, the circumference of the outer cylinder 3 and the inner cylinder 4 fitted to each other is not required. The part is a pair 4b, 4
A polygonal surface having a reduced number of plane portions may be used only as b.

Although the embodiment in which the shock absorber between the inner cylinder and the outer cylinder is a gas spring has been described, a coil spring may be disposed between the inner cylinder and the outer cylinder. May be provided with a hydraulic damper and used together with a coil spring.

Since four gaps 4e are formed between the flat portion 4d on the outer periphery of the inner cylinder 4 and the annular bushes 5, 6, dust between the outer periphery of the inner cylinder 4 and the outer periphery of the outer cylinder 3 on the opening side is formed. Boots may be provided to prevent dust from entering.

Therefore, according to the present embodiment, the following effects are obtained. Four flat portions 4d formed on the inner cylinder 4 and the outer cylinder 3, respectively.
And 3d are fitted to each other, so that the outer cylinder 3 and the inner cylinder 4 are prevented from rotating. At this time, since no bearing member such as a bush is interposed between the detent portions of the inner cylinder 4 and the outer cylinder 3, play in the rotation direction can be reduced. In addition, a bearing holding portion is provided on the opening side of the outer cylinder 3, an annular bush that receives a side force load is provided on the bearing holding portion, and the circumferential portions 4 b and 4 c are formed on the outer periphery of the inner cylinder 4. The slidability between the inner cylinder 4 and the outer cylinder 3 is improved, and the inner cylinder 4 does not stick to the outer cylinder 3. In addition, the contact between the circumferential portions 4b and 4c of the inner cylinder 4 and the annular bushes 5 and 6 is a surface contact at the circumferential portion and is not a line contact as in the case of using a polygonal bush. Less bush wear.

Since the side force load in the front-back direction is higher than the side force load in the left-right direction, the surface pressure per unit received by the annular bushes 5, 6 can be reduced, and the annular bushes 5, 6 are less likely to be worn.

The gas in the piston side chamber A partitioned and sealed by the piston 14 sliding on the inner circumference of the inner cylinder 4 is compressed to perform an impact absorbing action.

The communication passage in the piston 14 is opened by the operating rod 31 and the piston rod 15 with respect to the inner cylinder 4 is opened.
, The relative position of the inner cylinder 4 and the outer cylinder 3 attached to the piston rod 15, ie, the seat 9
The height of the can be adjusted.

[0039]

As described above, according to the present invention, it is possible to improve the slidability and the anti-rotation characteristics of the seat suspension or the front fork suspension and to reduce the play in the rotation direction.

[Brief description of the drawings]

FIG. 1 is an overall view showing a seat suspension.

FIG. 2 is an enlarged view of a main part of a seat suspension.

FIG. 3 is a schematic view showing the inner cylinder of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a sectional view taken along the line BB of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seat suspension 3 Outer cylinder 4 Inner cylinder 3b, 3c Circumferential part of outer cylinder 4b, 4c Circumferential part of inner cylinder 3d Flat part of outer cylinder 4d Flat part of inner cylinder 3A Detent part 3B Bearing holding part 5, 6 Annular bush

Claims (5)

[Claims] 1. An outer cylinder having a polygonal surface formed on an inner periphery thereof, and an inner cylinder having a polygonal surface formed on its outer periphery to be slidably fitted with the polygonal surface on the inner periphery of the outer cylinder. And a cushioning device provided between the outer cylinder and the inner cylinder. In a seat suspension for a motorcycle or the like, comprising: a pair of circumferential parts in the vehicle longitudinal direction, and a pair of circumferential parts in the left-right direction; 4 formed between these circumferential portions
Two flat parts, and formed on a polygonal surface consisting of: the inner periphery of the outer cylinder, a detent part consisting of the same polygonal surface as the polygonal surface formed on the outer periphery of the inner cylinder, and the inner peripheral opening side of the outer cylinder. A bearing holding portion formed over a predetermined length in the axial direction, and an annular bush that supports a circumferential portion of the outer circumference of the inner cylinder is fixed to the bearing holding portion vertically and vertically. Seat suspension for motorcycles. 2. The outer cylinder and the inner cylinder having a circumferential portion.
2. The seat suspension according to claim 1, wherein a length of the pair of circumferential portions in the front-rear direction is longer than a length of the pair of circumferential portions in the left-right direction. 3. A gas is sealed in the inner cylinder, and a piston rod having a piston attached to a tip thereof is slidably inserted into the inner cylinder to seal the piston side chamber and the piston rod side chamber in the inner cylinder. 3. The seat suspension according to claim 1, wherein the base end of the piston rod is attached to the outer cylinder. 4. The motorcycle according to claim 3, wherein a passage communicating with the chambers on both sides of the piston is formed in the piston rod, and an operation rod for opening and closing the communication passage is inserted into the piston rod. Seat suspension. 5. An outer cylinder which is rotatably inserted into a front head pipe of a vehicle body frame, has a handle fixed to an upper end portion, and has a polygonal surface formed on an inner periphery thereof, and is fitted to a polygonal surface on an inner periphery of the outer cylinder. A front fork suspension for a motorcycle or the like, comprising: an inner cylinder in which a sliding polygonal surface is formed on the outer periphery and a fork for supporting a front wheel is attached to a lower end portion; and a shock absorber provided between the outer cylinder and the inner cylinder. The outer periphery of the inner cylinder is formed in a polygonal surface including at least a pair of circumferential portions in the vehicle body front-rear direction and a flat portion formed between these circumferential portions. The bearing holding portion is formed from a detent portion formed of a polygonal surface fitted to a polygonal surface formed on the outer periphery, and a bearing holding portion formed over a predetermined length in the axial direction on the inner peripheral opening side of the outer cylinder. An annular bush that supports a peripheral portion of the outer periphery of the inner cylinder Front fork suspension motorcycles etc., characterized in that the axially fixed vertically.