JPH04292286A - Wheel suspension system for bicycle - Google Patents

Abstract

PURPOSE:To dispense with any installation of a cross-member mounting boss on top of a fork leg, thereby making any cutting work of the fork leg unnecessary and a tube usable for this leg by attaching a cross member to an upper part of the fork leg via a cross-member holder. CONSTITUTION:A suspension system of a bicycle 10 consists of a pair of retractable suspension assemblies 21. Each suspension assembly 21 is composed of a slide tube 22 being clamped to a steering bracket 15, a tubular fork leg 23 being fitted in this slide tube 22 free of slide motion and holding a front-wheel hub, and an unillustrated damping force generator being interposed between these elements. In the above constitution, a cross-member holder 26 is fitted in a lower outer circumference in an upper end diametral expanding part of each fork leg 23. Then, each cross-member holder 26 is connected by a U-shaped cross member 27 with constant swing rigidity. With this constitution, such a requirement that the cross-member mounting boss is installed on top of each fork leg 23 is eliminated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle wheel suspension system.

0002

[Prior Art] Conventionally, in mountain bicycles,
As described in Japanese Unexamined Patent Publication No. 2-231289, "a pair of left and right slide tubes fixed to a steering bracket rotatably supported on the front part of the bicycle body;
The cylindrical fork leg is configured to include a pair of left and right cylindrical fork legs that are slidably fitted into the slide tube and hold the front wheel axle, and a damping force generator provided between the slide tube and the fork leg. A "suspension system" is used. According to this suspension system, when the slide tube and the fork leg expand and contract, the damping force generating device operates to buffer the impact caused by unevenness of the road surface.

However, in the above-mentioned suspension system, the suspension member that supports the front wheel on the steering bracket is divided into two parts, the slide tube and the fork leg.
Low rigidity. In particular, when supporting the brake lever around the upper outer circumference of the fork leg, the brake reaction force applied to the brake lever acts as if twisting the fork leg when the brake is applied, so it is necessary to ensure sufficient rigidity to withstand this force. becomes.

[0004] Therefore, as described in Japanese Patent Application Laid-Open No. 2-231289, a system has been proposed in which the upper portions of the left and right fork legs are connected by a U-shaped cross member having a certain degree of torsional rigidity.

[0005]

However, in the prior art, in order to provide a cross member attachment boss on the upper part of the fork leg, the fork leg is manufactured by casting an aluminum alloy or the like and then cutting the fork leg. Therefore, tube materials such as extruded tubes and drawn tubes cannot be used as the fork leg material.

[0006] The present invention provides a suspension device in which a slide tube and a fork leg are slidably fitted together, and the upper parts of the left and right fork legs are connected by a cross member to ensure rigidity. The purpose is to make the pipe material usable.

[0007]

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a pair of left and right slide tubes fixed to a steering bracket rotatably supported on the front part of a bicycle body, and a pair of left and right slide tubes that are slidable on the slide tubes. A bicycle wheel suspension comprising a pair of left and right cylindrical fork legs that are movably fitted and hold a front wheel axle, and a damping force generator provided between the slide tube and the fork legs. In the device, a cross member holder is fitted around the upper outer periphery of the fork leg, and the left and right cross member holders are connected by a cross member having a certain torsional rigidity.

According to a second aspect of the present invention, in the present invention according to the first aspect, the cross member holder further includes front and rear attachment portions, and the front attachment portions of the left and right cross member holders are connected to the front cross member. The rear mounting portions of the left and right cross member holders are connected by the rear cross member.

According to a third aspect of the present invention, in the present invention according to the first or second aspect, the cross member holder further includes a concave-convex engagement that engages with the fork leg in an outer circumferential direction of the fork leg. It is designed to be engaged at the joint and fitted externally.

0010

[Function] According to the present invention as set forth in claim 1, there is the following function and effect.

(2) The cross member is attached to the upper part of the fork leg via a cross member holder. Therefore, there is no need to provide a cross member attachment boss on the upper part of the fork leg, and there is no need to cut the fork leg after casting. Therefore,
A tube material such as an extruded tube or a drawn tube can be used as the fork leg material.

According to the present invention as set forth in claim 2, the following
It has the function and effect of

(2) Front and rear cross members are provided on both front and rear sides of the upper portion of the fork leg via cross member holders. Therefore, the rigidity of the suspension system can be further improved.

According to the present invention as set forth in claim 3, the following
It has the function and effect of

(2) The cross member holder is fitted onto the upper portion of the fork leg through the concave and convex engaging portion in a completely prevented rotation state. Therefore, the torsional rigidity of the suspension system can be further improved.

[0016]

[Example] Fig. 1 is a cross-sectional view of a main part showing an example of a suspension assembly constituting the suspension system of the present invention, and Fig. 2 is a view showing the suspension assembly, (A) is an overall view, and (B) is a diagram showing the suspension assembly. 3 is a plan view showing the cross member holder, FIG. 4 is a view showing the piston body, (A) is a sectional view, (B) is a plan view, and FIG. 5 is a disk valve. 6 is a front view showing the main parts of the suspension system, FIG. 7 is a perspective view showing the main parts of the suspension system, and FIG. 8 is a plan view showing another example of the cross member holder.

As shown in FIGS. 6 and 7, the bicycle 10 has a steering shaft 13 mounted on bearings 13A and 13B provided above and below a head pipe 12 located at the front of a vehicle body 11.
is rotatably supported. A handlebar 14 is fixed to the upwardly projecting end of the steering shaft 13, and a steering bracket 15 is fixed to the downwardly projecting end of the steering shaft 13.
is fixed.

The suspension device 20 of the present invention includes a pair of left and right telescopic suspension assemblies 21. Each suspension assembly 21 includes a slide tube 22 fixed to the steering bracket 15, and a slide tube 22 fixed to the steering bracket 15.
The fork leg 23 is configured to include a cylindrical fork leg 23 that is slidably fitted into the fork leg 23 and holds the front wheel axle, and a damping force generator 24 that is provided between the slide tube 22 and the fork leg 23.

The fork leg 23 is formed by cold forging a tube material, and is provided with an axle support portion 23A at the reduced diameter lower end.

However, as shown in FIGS. 1, 2, 6, and 7, the suspension system 20 has a cross member holder 26 fitted around the lower outer periphery of the enlarged diameter portion 25 at the upper end of each of the left and right fork legs 23.
The left and right cross member holders 26 are connected by a U-shaped cross member 27 having a certain degree of torsional rigidity. As a result, the suspension system 20 compensates for the lack of rigidity due to being divided into two parts, the slide tube 22 and the fork leg 23, and also prevents the fork leg 23 from being damaged due to a brake reaction force applied to the brake lever 34, which will be described later, when the brake is applied. The rigidity of the fork leg 23 is ensured against torsion acting on the fork leg 23.

Here, the cross member holder 26 is an annular body as shown in FIG. 3, and has two cross member mounting bosses 2.
8 and two screw bosses 29. The cross member 27 has its proximal end attachment portion 31 attached to the cross member attachment boss 28 of the cross member holder 26 with an attachment screw 32 . Further, the cross member holder 26 is held by a retaining ring 26A attached to a portion corresponding to the lower end of the cross member holder 26 on the outer periphery of the fork leg 23, and the fork leg It is fixed to the outer periphery of 23.

As shown in FIG. 7, a brake lever 34 constituting a rim type brake system is mounted on one cross member mounting boss 28 of the cross member holder 26 together with the cross member 27 by means of a mounting screw 32. Tightened and held. 35 is a brake pad, and 36 is a brake wire.

The cross member holder 26 may be provided with a brake lever mounting boss separate from the cross member mounting boss 28, and the brake lever 34 may be independently held by the brake lever mounting boss.

Furthermore, the cross member holder 26 does not include the screw boss 29 but has a recess 37 on the inner periphery, so that the recess 37 is connected to the convex portion provided on the outer periphery of the fork leg 23 and the outer periphery of the fork leg 23. It may be prevented from rotating by engaging in the direction, and held by a retaining ring attached to a portion corresponding to the lower end of the cross member holder 26 on the outer periphery of the fork leg 23.

As shown in FIGS. 1 and 2, the suspension assembly 21 includes a retaining ring 41A on the outer periphery of the lower end of the slide tube 22.
Due to the sliding contact between the guide bush 41 installed at 41B and the inner periphery of the fork leg 23, and the sliding contact between the guide bush 42 press-fitted to the inner periphery of the upper end of the fork leg 23 and the outer periphery of the slide tube 22. , slide tube 2
2 and the fork leg 23 are slidable relative to each other. In addition, on the inner peripheral part of the above-mentioned upper end enlarged diameter part 25 of the fork leg 23,
Seal spacer 43, oil seal 44, retaining ring 45,
A dust seal 46 is attached to provide a seal with the slide tube 22.

[0026] Also, at the intermediate inner circumference of the fork leg 23,
An end member 48 having an O-ring 47 fitted thereon is press-fitted, and a bump rubber 49 is arranged on the upper end surface of the end member 48 . As a result, at the final end of the contraction stroke, the suspension assembly 21 connects the lower end surface of the piston body 61, which will be described later, connected to the lower inner circumference of the slide tube 22 with the bump rubber 49.
It is possible to abut and stop the end member 48 via.

Further, a rebound rubber 51 is installed and held below the guide bush 42 at the inner peripheral portion of the upper end of the fork leg 23. As a result, at the final end of the extension stroke of the suspension assembly 21, the rebound seat 53, which is secured to the intermediate outer circumference of the slide tube 22 by the retaining ring 52,
The upper end surface can be stopped by abutting against the guide bush 42 via the rebound rubber 51.

As shown in FIGS. 1 and 2, the damping force generating device 24 includes a piston body 61 connected to the inner periphery of the lower end of the slide tube 22. Incidentally, a retaining ring 62 is interposed at the upper part of the joint between the slide tube 22 and the piston body 61. As shown in FIGS. 4A and 4B, the piston body 61 defines an upper chamber 63A on the slide tube 22 side and a lower chamber 63B on the fork leg 23 side, and the upper chamber 63A and the lower chamber 63B, a long hole-shaped contraction side flow path 64 and a round hole-shaped expansion side flow path 65 are provided. The contraction side flow path 64 is located on the center side of the piston body 61, and the expansion side flow path 65 is located on the center side of the piston body 61.
is arranged on the outer peripheral side of the piston body 61.

Note that the upper chamber 63A is connected to the slide tube 22.
is fixed to the upper end of the O-ring 102 with a retaining ring 101.
The piston body 61 is defined by a closing member 103 that is fitted onto the outside of the piston body 61, and seals oil on the piston body 61 side and air on the closing member 103 side. Further, the lower chamber 63B is defined by the aforementioned end member 48 and the piston body 61, and is sealed against oil.

The damping force generating device 24 also moves a first valve 67 in the form of a slide valve, which is biased by a valve spring 66 in the direction of closing the contraction side flow path 64, to the piston body 6.
1 is placed on the upper chamber 63A side. Thereby, the damping force generating device 24 is activated in the lower chamber 63B when the suspension device 20 is compressed.
The rising pressure pushes the first valve 67 open against the biasing force of the valve spring 66, transfers the oil in the lower chamber 63B from the contraction side flow path 64 to the upper chamber 63A, and as a result, the oil in the upper chamber 6
A damping force is generated by compressing the air in 3A.

At this time, the center hole 61 of the piston body 61
A bolt 68 is attached to A, and the bolt 68 has a head 68A.
and the nut 69, a collar 71, a piston body 61,
The valve holding member 72 is sandwiched therebetween. Then, the spring receiver 73 on the head 68A side of the bolt 68 and the first valve 67 on the piston body 61 side are attached around the collar 71, and the valve spring 66 is inserted between the spring receiver 73 and the first valve 67. I am intervening. Spring receiver 73
is supported by the head 68A of the bolt 68, and its supporting position can be adjusted by an adjustment tool 81, which will be described later.

Further, the damping force generating device 24 is configured to generate a damping force in the lower chamber 63 during the extension stroke of the slide tube 22 and fork leg
A second valve 74 in the form of a disc valve that opens the extension side flow passage 65 by B negative pressure is arranged on the lower chamber 63B side of the piston body 61. Thereby, in the damping force generating device 24, when the suspension system 20 is extended, the second valve 74 changes the amount of deflection according to the negative pressure of the lower chamber 63B, and generates a damping force.

At this time, the second valve 74, as shown in FIG.
The inner annular portion 74A is fixed to the lower end surface of the piston body 61 with a nut 69 via the valve holding member 72, and the outer annular portion 74B is connected to the extension side flow path 65.
is arranged so that it can be closed. That is, the outer annular portion 74B can be largely displaced by the spring action of the connecting portion 74C, and the extension side flow path 65 can be opened and closed. Note that between the inner annular portion 74A and the outer annular portion 74B, elongated hole portions 74D facing the contraction side flow path 64 are provided on both sides of the connecting portion 74C.

Further, the damping force generating device 24 is connected to the upper and lower chambers 63.
A slit 75 and/or an orifice 76 are provided in the piston body 61 as a throttle communication path that constantly communicates between A and 63B. The slit 75 and orifice 76 are shown in FIG.
), (B), in the piston body 61, the first
A region on the extension side flow path 65 side which is not always blocked by the valve 67 and a region on the side of the contraction side flow path 64 which is not always blocked by the second valve 74 are communicated with each other. As a result, the damping force generating device 24 has the slit 75 and the orifice 76 in the upper chamber 63A and
The lower chamber 63B is constantly communicated with the lower chamber 63B to generate a damping force due to throttling resistance.

Furthermore, an operating member 82 of an adjusting tool 81 is rotatably inserted through the aforementioned closing member 103 provided at the upper end of the slide tube 22 via an O-ring 83. A width across flat portion for rotational operation is formed at the upper end of the operating member 82 located outside the slide tube 22, and a substantially semicircular section provided at the lower end of the operating member 82 located inside the slide tube 22. The upper end of the adjustment pipe 84 is integrated with the adjustment pipe 84 in the rotational direction, and is fitted so as to be movable relative to the adjustment pipe 84 in the axial direction. An adjustment nut 85 is fixed to the lower end of the adjustment pipe 84, and the nut 85 is screwed into a threaded portion screwed into the head 68A of the bolt 68 described above. The lower end surface of the nut 85 is connected to the head 68.
It can protrude downward from the lower end surface of A and can abut against the spring receiver 73 described above. That is, the adjustment tool 81 is
By screwing the adjustment nut 85 through the adjustment pipe 84, the spring receiver 73 is pushed down by the lower end surface of the adjustment nut 85, and the supporting position of the valve spring 66 by the spring receiver 73 is adjusted, and as a result, the suspension device 20 The damping force when compressed can be adjusted.

The operating member 82 of the adjusting tool 81 is provided with an air valve 86 at its center, making it possible to adjust the air pressure in the upper chamber 63A.

Next, the operation of the above embodiment will be explained.

■The cross member 27 is the cross member holder 26
It is attached to the upper part of the fork leg 23 via. Therefore, there is no need to provide a cross member attachment boss on the upper part of the fork leg 23, and there is no need to cut the fork leg 23 after casting. Therefore, as the material for the fork leg 23, a tube material such as an extruded tube or a drawn tube can be used.

(2) The cross member holder 26 can be fitted onto the upper part of the fork leg 23 in a state where it is completely prevented from rotating through the concave and convex engaging portion. As a result, the suspension device 20
torsional rigidity can be further improved.

[0040] Also, regardless of whether the brake lever 34 is held in the cross member holder 26 independently or together with the cross member 27, the mounting position of the brake lever 34 may change due to changes in the brake components. When changing, it is possible to cope with the change by changing only the cross member holder 26 without changing the fork leg 23 itself.

FIG. 8 is a plan view showing another example of the cross member holder.

The cross member holder 91 includes two cross member mounting bosses 92F and 92R at the front and rear, and two screw bosses 93, and is fixed to the outer periphery of the fork leg 23 by a fixing screw via the screw bosses 93. Ru. The left and right cross member holders 9 are fixed to the left and right fork legs 23.
The front cross member mounting boss 92F of 1 is the front cross member 9
4F, and the rear cross member attachment bosses 92R of each cross member holder 91 are connected at the rear cross member 94R.

According to this, the front and rear cross members 94F and 94R are provided on both front and rear sides of the upper part of the fork leg 23 via the cross member holder 91. Therefore, the suspension system 2
The rigidity of 0 can be further improved.

[0044]

[Effects of the Invention] As described above, according to the present invention, a suspension device is provided in which a slide tube and a fork leg are slidably fitted, and the upper parts of the left and right fork legs are connected by a cross member to ensure rigidity. In construction, tubing can be used as the fork leg material.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing an example of a suspension assembly constituting a suspension device of the present invention.

FIG. 2 is a diagram showing a suspension assembly, in which (A) is an overall view and (B) is a sectional view taken along the line BB.

FIG. 3 is a plan view showing the cross member holder.

FIG. 4 is a diagram showing a piston body, in which (A) is a sectional view and (B) is a plan view.

FIG. 5 is a plan view showing the disc valve.

FIG. 6 is a front view showing the main parts of the suspension system.

FIG. 7 is a perspective view showing the main parts of the suspension system.

FIG. 8 is a plan view showing another example of the cross member holder.

[Explanation of symbols]

10 Bicycle 11 Vehicle body 15 Steering bracket 20 Suspension device 22 Slide tube 23 Fork legs 24 Damping force generator 26 Cross member holder 27 Cross member 37 Recess 91 Cross member holder 92F, 92R Front and rear cross member mounting bosses (front and rear mounting portions) 94F Front cross member 94R Rear cross member

Claims (3)

[Claims] Claim 1: A pair of left and right slide tubes fixed to a steering bracket rotatably supported at the front of a bicycle body, and a pair of left and right slide tubes slidably fitted to the slide tubes to hold a front wheel axle. A bicycle wheel suspension device comprising a cylindrical fork leg and a damping force generating device provided between the slide tube and the fork leg, wherein a cross member holder is provided on the upper outer periphery of the fork leg. A bicycle wheel suspension device, characterized in that the cross member holders on the left and right are connected by a cross member fitted externally and having a certain torsional rigidity. 2. The cross member holder includes front and rear mounting portions, the front mounting portions of the left and right cross member holders are connected by a front cross member, and the rear mounting portions of the left and right cross member holders are connected to the rear. The bicycle wheel suspension device according to claim 1, wherein the bicycle wheel suspension device is connected by a cross member. 3. The bicycle wheel according to claim 1, wherein the cross member holder is externally fitted to the fork leg by being engaged with a concave-convex engaging portion that engages in the outer circumferential direction of the fork leg. Suspension system.