JPH0710064A - Rear cushion unit for bicycle - Google Patents

Abstract

(57) [Summary] [Object] The present invention makes it possible to easily adjust the mounting dimensions of a vehicle body frame to improve the degree of freedom of mounting, and to realize sharing of parts of the rear cushion unit. According to the present invention, a swing arm supporting a rear wheel is swingably supported by a body frame of a bicycle, and a rear cushion unit 31 for a bicycle in which the swing arm is buffer-suspended on the body frame. A unit side mounting bracket 59 that supports the unit on the vehicle body frame is configured to be movable in the axial direction of the rear cushion unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle rear cushion unit mounted on a bicycle rear suspension, which has an improved mounting structure.

[0002]

2. Description of the Related Art In recent bicycles, especially mountain bicycles, a rear wheel is supported by a swing arm, the swing arm is pivotally supported by a body frame, and the swing arm is mounted on a vehicle body through a rear cushion unit. There is a frame that is designed to be suspended. As a result, the ground contact of the rear wheels is improved, and the cranking power of the rider can be effectively transmitted to the road surface.

[0003]

However, there are many types of mountain bicycles as described above, and the body frame has various specifications and dimensions. For this reason, if the dimensions of the rear cushion unit were changed for each different body frame, this rear cushion unit also has many types,
The cost will rise.

The present invention has been made in consideration of the above-mentioned circumstances, and a bicycle in which the size of attachment to the vehicle body frame can be easily adjusted to improve the degree of freedom of attachment and the parts can be shared. The purpose of the present invention is to provide a rear cushion unit.

[0005]

According to the present invention, a swing arm supporting a rear wheel is swingably supported by a body frame of a bicycle, and a rear cushion unit for a bicycle suspending the swing arm on the body frame. The mounting bracket for supporting the rear cushion unit on the vehicle body frame is configured to be movable in the axial direction of the rear cushion unit.

[0006]

Therefore, according to the bicycle rear cushion unit of the present invention, the mounting bracket for supporting the rear cushion unit on the vehicle body frame is configured to be axially movable on the rear cushion unit. Even if the specifications and dimensions of the body frame are changed due to an abundance of vehicles, the mounting dimensions of the rear cushion unit can be changed by moving the mounting bracket in the axial direction of the rear cushion unit, even if this rear cushion unit has the same standard. Easy to adjust. As a result, the degree of freedom in mounting the rear cushion unit is improved, the rear cushion unit of the same standard can be mounted on each of the vehicle body frames, and the parts of the rear cushion unit can be shared.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a body frame of a mountain bicycle equipped with a bicycle rear cushion unit according to the present invention. FIG. 2A is a side view showing the rear cushion unit of FIG. 1 in a half-section state.
(B) and (C) are the IIB arrow line views and IIC arrow line views of FIG. 2 (A), respectively. FIG. 3A is shown in FIG.
FIG. 3B is a cross-sectional view taken along line III A-III A in FIG.
It is a front view which shows the lock nut of FIG. 2 (A). Figure 4
FIG. 4 is a sectional view taken along line IV-IV in FIG.

As shown in FIG. 1, a body frame 11 of a mountain bicycle 10 has a head tube 12 to which a top tube 13 and a down tube 14 are welded, and the top tube 13 and the down tube 14 are respectively joined to an upper tube joint. A seat main tube 17 is fixedly attached via 15 and a lower tube joint 16.

A front fork 18 is rotatably supported by the head tube 12. This front fork 1
A front wheel 19 is rotatably supported at the lower end of the front fork 18, and a handle bar 20 is provided at the upper end of the front fork 18.
Is fixed. A seat sub tube 21 is inserted through the seat main tube 17, and a saddle 22 is installed on the seat sub tube 21. By adjusting the position of the seat sub tube 21 with respect to the seat main tube 17, the height of the saddle 22 is changed.

A swing arm 23 is swingably supported by the lower tube joint 16. The rear wheel 25 is rotatably supported by a rear tube joint 24 fixed to the free end of the swing arm 23. Rear wheel 2
A sprocket 26 is attached to 5. On the other hand, a chain wheel 27 is rotatably supported by the lower tube joint 16, and a pedal (not shown) is installed on the chain wheel 27 via a crank (not shown). These sprocket 26 and chain wheel 2
A chain 28 is stretched between 7 and the stepping force of the rider acting on the pedal is transmitted to the rear wheel 26 via the chain wheel 27 and the sprocket 26.

Now, in the rear tube joint 24,
One end of the push rod 29 is rotatably supported, and the other end of the push rod 29 is P of a triangular link 30.
It is rotatably supported by the end 30P. Q of this link 30
The end is swingably supported by the upper tube joint 15. Therefore, by swinging the swing arm 23 in the arrow M direction, the link 30 is provided so as to be swingable in the arrow N direction around the Q end 30Q. The connecting medal 32 of the rear cushion unit 31 is connected to the R end 30R of the link 30. The rear cushion unit 31 absorbs the impact from the rear wheel 25 and damps the swing of the swing arm 23 and the link 30.

The rear cushion unit 31 is shown in FIG.
As shown in (A), a coil spring 34 is combined with the oil damper 33. Oil damper 33
In the cylinder 35, a piston 36 is accommodated in a reciprocating manner, and a base end portion of a piston rod 37 is fixed to the piston 36. A rod end 38 is screwed to the tip of the piston rod 37. On the rod end 38, as shown in FIG.
2 is fixed using a nut 39. Reference numeral 40 indicates a lock nut, and reference numeral 50 indicates a stop rubber.

A spring seat 41 is locked on the tip side of the cylinder 35 of the oil damper 33 shown in FIG. 2 (A). Further, a spring adjuster 42 is screwed on the outer circumference of the rod end 38. These spring seats 41
And the coil spring 3 between the spring adjuster 42.
4 is interposed in a compressed state, and the coil spring 34 absorbs the impact from the rear wheel 25 acting on the connected medal 32. By moving the spring adjuster 42 in the axial direction of the piston rod 37, the coil spring 34
The initial load of is adjusted.

A rod guide 43 and a cap 44 are fixed to the cylinder 35 of the oil damper 33 on the tip end side. The rod guide 43 inserts and guides the piston rod 37. An oil seal 45 is provided on the rod guide 43 to seal the sliding surface with the piston rod 37. Further, a retainer 46 is fixedly attached to the base end side of the cylinder 35, and the diaphragm 4 is attached to the retainer 46.
7 is inserted. A cap 48 is further attached to the base end of the cylinder 35 in an airtight state.

With the diaphragm 47, the cylinder 3
A gas chamber 49 is defined within 5. The other chamber of the cylinder 35 is filled with oil.
To define an oil chamber A and an oil chamber B.

The piston rod 37 of the oil damper 33 is provided with a first valve 51 and a second valve 52 on both sides of the piston 36, and a valve retainer 53 on both sides of the first valve 51 and the second valve 52. It is arranged. The first valve 51, the second valve 52, the valve retainer 53, and the piston 36 are integrally fixed to the small diameter portion of the piston rod 37 using a nut 56. 54 is a stopper and 55 is a stopper rubber.

As shown in FIGS. 2 (A), (B) and (C), the piston 36 is provided with an expansion side oil flow path 57 and a contraction side oil flow path 58. These expansion side oil flow paths 5
Four 7 and contraction side oil flow paths 58 are alternately provided along the circumferential direction of the piston 36. The second valve 52 can close the contraction side oil flow path 58, and the first valve 5
1 makes it possible to close the extension side oil flow path 57.

When a force in the direction of compressing the coil spring 34 acts on the connecting medal 32 by the impact from the rear wheel 25, the piston 36 moves to the oil chamber A side, and the oil in this oil chamber A flows in the contraction side oil flow. Flowing through the passage 58, the second valve 52 is flexibly deformed and reaches the oil chamber B. A contraction-side damping force is generated due to the fluid resistance while the oil flows by flexing and deforming the second valve 52.

When a force for extending the coil spring 34 acts on the piston rod 37, the oil damper 3
The oil from the oil chamber B of No. 3 flows through the extension side oil flow path 57, and bends and deforms the first valve 51 to make the oil chamber A
To The extension side damping force is generated due to the fluid resistance while the oil flexibly deforms the first valve 51 and flows.

Here, the first valve 51 is replaced by the second valve 52.
Since it is configured so as not to be flexibly deformed more than that, the extension side damping force is set to be larger than the contraction side damping force. Therefore, the oil damper 33 suppresses the extension of the coil spring 34 and suppresses the swing of the swing arm 23 and the link 30.

The maximum stroke of the piston 36 when the oil damper 33 is compressed is defined by the stop rubber 50 contacting the cap 44. Also,
The maximum stroke of the piston 36 when the oil damper 33 extends is determined by the stopper rubber 55 when the rod guide 43
It is specified by abutting against. Further, when the oil damper 33 is compressed, the piston rod 37 enters the oil chamber A, so that the diaphragm 47 moves toward the cap 48 side by the intrusion volume of the piston rod 37, and the gas chamber 49 functions as a volume compensation chamber. .

By the way, the above-mentioned rear cushion unit 31 is rotatably attached to the vehicle body frame 11 through the unit side mounting bracket 59 and the frame side mounting bracket 60 using the mounting bolts 61 (FIG. 3). Of these, the frame side mounting bracket 60 is shown in FIG.
As shown in, the top tube 13 of the body frame 11
One pair is welded on both sides of the.

Further, as shown in FIGS. 2 (A) and 3 (A), a screw portion 62 is engraved on the outer circumference of the cylinder 35 of the oil damper 33 in the rear cushion unit 31. The unit side mounting bracket 5 is attached to the screw portion 62.
9 is screwed so as to be movable in the axial direction of the cylinder 35.

Therefore, when mounting the rear cushion unit 31 to the vehicle body frame 11, the unit side mounting bracket 59 is screwed onto the threaded portion 62 of the cylinder 35 and moved in the axial direction of the cylinder 35, and the lock nut is placed at an appropriate position. Positioning is performed by using 63 (FIG. 3B). After that, attach the mounting bolt 61 to the unit side mounting bracket 5
9 and the frame-side mounting bracket 60 are inserted through the respective insertion holes 64 and 65, and fixed using mounting nuts 66.

According to the above embodiment, the unit side mounting bracket 59 for supporting the rear cushion unit 31 on the top tube 13 of the vehicle body frame 11 is the cylinder 3 in the oil damper 33 of the rear cushion unit 31.
Because it is configured to be movable in the axial direction of 5, the mountain bicycle 1
Even if the vehicle model of 0 is different and the specifications and dimensions of the body frame 11 are changed, the unit side mounting bracket 59 is attached to the cylinder 35
If it is moved in the axial direction of, the rear cushion unit 31
Even if the standards are the same, this rear cushion unit 3
The mounting dimensions of 1 can be easily adjusted. As a result, the degree of freedom in attaching the rear cushion unit 31 is improved, and the rear cushion unit 31 of the same standard can be attached to each of the vehicle body frames 11 described above.
Can be shared.

Further, after the rear cushion unit 31 is mounted on the top tube 13 of the vehicle body frame 11 via the unit side mounting bracket 59 and the frame side mounting bracket 60, the cylinder 3 of the oil damper 33 is mounted.
5 can be rotated to move the rear cushion unit 31 relative to the unit side mounting bracket 59 in the axial direction. Therefore, since the suspension dimension of the swing arm 23 via the link 30 and the push rod 29 can be changed, the vehicle height of the bicycle 10 can be adjusted. Further, by adjusting the vehicle height, the caster angle θ of the front fork 18 can be optimally adjusted according to the rider's physique and taste, and as a result, the steering stability of the mountain bicycle 10 can be improved.

In the above embodiment, the rear cushion unit 31 is described as being arranged substantially horizontally, but the rear cushion unit 31 may be changed by changing the length of the push rod 29 or the support point of the link 30. It may be installed vertically.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific structure of the present invention is not limited to this embodiment, and changes in design within the scope not departing from the gist of the present invention can be made. Even if it exists, it is included in the present invention.

[0029]

As described above, according to the bicycle rear cushion unit of the present invention, the mounting dimension to the vehicle body frame can be easily adjusted to improve the degree of freedom of mounting, and the parts of the rear cushion unit. Can be shared.

[Brief description of drawings]

FIG. 1 is a side view showing a body frame and the like of a mountain bicycle equipped with a bicycle rear cushion unit according to the present invention.

FIG. 2 (A) is a side view showing the rear cushion unit of FIG. 1 in a half cross-sectional state, and FIGS. 2 (B) and 2 (C) are views taken along the line IIB of FIG. 2 (A). , And IIC
FIG.

3 (A) is a sectional view taken along the line III A-III A in FIG. 2 (A), and FIG. 3 (B) is a front view showing the lock nut of FIG. 2 (A). .

FIG. 4 is a sectional view taken along line IV-IV in FIG.

[Explanation of symbols]

 10 Mountain Bicycle 11 Body Frame 23 Swing Arm 25 Rear Wheel 29 Push Rod 30 Link 31 Rear Cushion Unit 33 Oil Damper 34 Coil Spring 35 Cylinder 59 Unit Side Mounting Bracket 62 Cylinder Screw 63 63 Lock Nut

Claims (2)

[Claims] 1. A bicycle rear cushion unit in which a swing arm supporting a rear wheel is swingably supported by a body frame of a bicycle, and the swing arm is buffer-suspended on the body frame. A rear cushion unit for a bicycle, wherein a mounting bracket supported on the vehicle body frame is configured to be movable in the axial direction of the rear cushion unit. 2. The rear cushion unit has a screw engraved on the outer periphery thereof, and a mounting bracket is screwed onto the screw so that the mounting bracket is movable in the axial direction of the rear cushion unit. The bicycle rear cushion unit described in 1.