JPH1191671A - Support structure of link type front suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce size and weight of an installation part of a buffer. SOLUTION: This link type front suspension 2 is a quadrangle link comprising a fork pipe 20, a pushrod 21 and a double link coupling the parts, and the top end of the pushrod 21 is coupled with a buffer 22 and an axle 29. Upper bracket 28 which supports the top end of the buffer 22 is composed separately from a top bridge 3, and split-clamped to the fork pipe 20 under the top bridge 3. The top bridge 3 couples the top ends of the right and left fork pipes 20, allowing a steering stem 4 to penetrate to the backside to be clamped with a cap nut 76. The elastic support of the buffer 22 for the upper bracket 28 is divided into upper and lower parts; an expansion side mount rubber 61 and a push-up side mount rubber 63 arranged with the upper bracket 28 in-between and pinched by a nut 66.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a link type front suspension device for a motorcycle.

[0002]

2. Description of the Related Art U.S. Pat. No. 4,775,163 shows a front link type suspension for a motorcycle. This front link type suspension has a pair of front forks extending to the left and right of the front wheel, a pivot link having one end pivotally attached to the front fork and supporting the front wheel at the other end, and one end pivotally attached to an intermediate portion of the pivot link. , The other end of which has a push rod connected to a shock absorber composed of a damper and a damper spring.

[0003]

In this front suspension device, the load receiving member of the damper is a top bridge to which a front fork can be attached, and the structure is not clear in this known example. Since the top bridge is connected to the upper end of the stem pipe through which the head pipe of the body frame penetrates, the mounting of the front fork and the shock absorber to the vehicle body side for each upper end must be shared by one top bridge become.

However, when the load of the shock absorber is received by the top bridge, the top bridge must be made rigid to withstand the heavy load of the shock absorber. As a result, the size of the top bridge is increased and the weight is increased. Also, to support the shock absorber, front fork and stem pipe with one top bridge,
Replacement can only be performed on the entire top bridge, which makes maintenance difficult.

Although it is not clear in the above-mentioned known examples, generally, such a top bridge is attached to the front fork and the stem pipe by providing front fork mounting holes on the left and right sides of the top bridge in advance, and forming the hole in the center of the rear part. Stem pipe mounting holes are provided respectively, and they are mounted from above and the upper ends of the front fork and the stem pipe are passed through these front fork mounting holes and the stem pipe mounting holes. The protruding portions are fixed by fastening them with nuts.

However, if a slant type in which the stem pipe and the front fork are angled is adopted, it is necessary to assemble the steering stem in the middle of the front fork and to assemble sequentially from the bottom, and finally attach the top bridge to complete the assembly. And the steering stem and the top bridge must be fastened prior to mounting the top bridge, which complicates assembly.

Further, the mounting portion of the damper to the top bridge side is generally elastically supported by a rubber bush or a ring bush.
Since these members have an annular shape in which the circular surface is used sideways, the rubber volume is reduced, and the member can cope only with the movement in the rotation direction. In addition, the push-up side requires a larger rubber volume than the extension side, but it is not possible to make the rubber volume and hardness suitable for such requirements of the push-up side and the extension side.

[0008]

According to a first aspect of the present invention, there is provided a link type front suspension support structure, which comprises a pair of left and right front forks extending vertically with a front wheel interposed therebetween. A lower link that is pivotally connected at one end to the front wheel at the other end, a push rod that is pivotally connected at one end to an intermediate portion of the lower link and the other end is connected to a shock absorber, and the push rod and front fork. 2 with a front link suspension having an upper link connected between the two
The wheel is characterized in that a top bridge connecting the upper ends of the front fork and the stem pipe and an upper bracket connecting the upper ends of the front fork and the shock absorber are formed separately.

[0009] The second invention is the above-mentioned first invention, wherein:
When the front fork and the stem pipe have different axes, and the top bridge is mounted from above the front fork and the stem pipe from above, the stem pipe and the front fork are inserted into both the stem pipe mounting hole and the front fork mounting hole provided in the top bridge. The stem pipe mounting hole of the top bridge has a large diameter so that each end of the fork is fitted simultaneously, and the upper end of the stem pipe is fastened to the top bridge via a collar.

In a third aspect, in the first aspect,
A mounting shaft provided at the upper end of the shock absorber is passed through a mounting hole provided in the upper bracket, and a pair of mounting rubbers which are divided in advance into upper and lower sides of the upper bracket around the mounting hole. It is characterized by having been concluded.

[0011]

According to the first aspect of the present invention, the top bridge and the upper bracket are separated from each other, and the large load of the shock absorber is received only by the upper bracket, and the top bridge is used only for the turning operation. Can be

Further, since the front suspension can be assembled without the top bridge until the final assembly stage, the front suspension can be assembled sequentially from the bottom, and the top bridge can be finally attached to complete the assembly, thereby facilitating the assembly. In addition, since the replacement can be performed separately on the front suspension side and the steering system, maintenance is improved, and the size of each unit can be reduced.

According to the second invention, when the top bridge is mounted from above with the front fork being angled to the stem pipe, the diameter of the stem pipe mounting hole is larger than that of the stem pipe. And the stem pipe can be simultaneously fitted into the stem pipe mounting hole and the front fork mounting hole, respectively.

Thereafter, if a collar is inserted into the stem pipe mounting hole, there is no play, so that the stem pipe can be mounted on the top bridge by fastening the upper part of the stem pipe. Therefore, even if the slant type is adopted,
The top bridge can be mounted from above with the front fork and stem pipe fixed by the steering stem, facilitating assembly work.

According to the third aspect of the present invention, since a pair of mount rubbers are provided above and below the upper bracket, rubber volumes, materials, and materials of the extension rubber and the push-up rubber are provided.
The hardness and the like can be varied, and the configuration can be optimized for the performance required for each. In addition, it can cope with a load direction other than the rotation direction, can obtain a large rubber volume in a small space, and can simplify the structure near the top bridge.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 1 is an overall side view of a motorcycle to which the present invention is applied, FIG. 2 is an enlarged side view of a part of a link type front suspension, FIG. 3 is a front view of a front fork, and FIG. FIG. 5 is a top view of the top bridge and the upper bracket, FIG. 6 is a top view of the steering stem (in the direction of arrow A in FIG. 4), and FIG. 7 is FIG.
8 is a sectional view taken along line 8-8 of FIG. 8, FIG. 9 is a schematic sectional view illustrating a method of attaching the top bridge, and FIG.
0 is a view of another embodiment in which the structure of FIG. 6 is partially modified.

First, in FIG. 1, a link type front suspension 2 supporting a front wheel 1 is rotatably connected to a head pipe 5 by a stem pipe 4 via a top bridge 3 and is steerable by a handle 6. I have.

The head pipe 5 includes a main pipe 8 disposed in the front-rear direction above the V-type four-cycle engine 7;
The front down pipe 9 is attached to each front end of the front down pipe 9 obliquely descending forward of the engine 7.

The rear portion of the main pipe 8 is connected to a pivot plate 10 extending long in the vertical direction in a pair of right and left, and a rear swing arm 12 having a front end supported by a pivot portion 11 of the pivot plate 10 extends rearward, and a rear end. The rear wheel 13 is supported. Rear swing arm 12
Is swingable up and down around the pivot portion 11 to form a rear suspension.

A seat rail 14 extends rearward from a rear portion of the main pipe 8, and a rear cowl 15 and a seat 16 are supported thereon. A fuel tank 17 is supported on the main pipe 8 in front of the seat 16.

The lower ends of the front down pipe 9 and the pivot plate 10 are connected by a lower frame 18 which passes under the engine 7 in the front-rear direction, and a radiator 19 is supported on the front down pipe 9.

As shown in FIGS. 2 and 3, the link type front suspension 2 is composed of a fork pipe 20, a push rod 21 and a shock absorber 22 parallel to the fork pipe 20, an upper link 23 for connecting these intermediate parts in the vertical direction, and these. A pair of left and right pivot links 24 for connecting the lower ends are provided.

The fork pipe 20 on the right side of the vehicle body has a fender link 25 having one end connected to a vertically intermediate portion between the connection portions of the upper link 23 and the pivot link 24 and the other end connected to a front fender (described later). It has.

The left and right fork pipes 20 are connected at their upper ends by a top bridge 3 and at their intermediate portions to a steering stem 26. The top bridge 3 and the steering stem 26 are connected to the stem pipe 4 at each central portion, and the stem pipe 4 is rotatably supported in the head pipe 5.

The fork pipe 20 is a tapered pipe member whose upper part and its lower part also have a tapered shape which changes upward and downward similarly to the connection with the steering stem 26. It can be manufactured by a known method such as swaging the extruded pipe member into a tapered shape. The lower end of the fork pipe 20 is pivotally connected to one end of a pivot link 24 and a shaft 27.

The shock absorber 22 is composed of a known hydraulic damper having a built-in damper spring. The upper end is supported by the front of an upper bracket 28, and the lower end is connected to the upper end of the push rod 21 by a shaft 29. Is being worn.

The push rod 21 is fork pipe 20
The lower end of the pipe member extends downward substantially in parallel with the shaft member, and the lower end of the pipe member is axially attached to the intermediate portion of the pivot link 24 by the shaft 30. The other end of the pivot link 24 is connected to the axle 31 of the front wheel 1.
It is attached to the shaft.

The upper link 23 is disposed in the vicinity of a front fender 32 disposed between the left and right fork pipes 20 and the push rod 21, and has one end connected to the shaft 3.
3, the shaft is attached to the fork pipe 20, and the intermediate portion is attached to the push rod 21 by the shaft 34. The length of the upper link 23 between the shafts 33 and 34 and the length of the pivot link 24 between the shafts 27 and 31 are substantially equal.

Therefore, the fork pipe 20, push rod 21, upper link 23 and pivot link 24 constitute a substantially parallelogram link mechanism, and the front wheel 1
The push rod 21 moves substantially parallel to the fork pipe 20 in response to the vertical movement of the push rod 21.

The front ends of the left and right upper links 23 are:
It extends further forward than the push rod 21, and its extended end is mounted on a stay 35 that projects downward from the front fender 32 with a shaft 36.

On the right side of the vehicle body, the fender link 2
5 is disposed substantially parallel to a position lower than the mounting position of the upper link 23, and one end of a shaft 38 is attached to a stay 37 that extends downward longer from a stay 35 on the right side of the vehicle body of the front fender 32, The other end is attached to the fork pipe 20 by a shaft 39.

A line connecting the shafts 36 and 37 of the stays 35 and 37 is substantially parallel to the axis of the fork pipe 20. The front fender includes the upper link 23 on the left side of the vehicle body, the fender link 25 on the right side of the vehicle body, and the stays 35 and 37. A substantially parallelogram link mechanism is constituted by the fork pipe 32 and the fork pipe 20, and the front fender 32 is moved up and down substantially in parallel in response to the vertical movement of the front wheel 1.

The caliper bracket 4 is provided around the axle 31.
0 is rotatably supported at one end and a caliper 4 is provided at the other end.
1 is supported, and can be slidably contacted with the brake disc 42 during braking to directly receive a braking force.

A stay 43 projecting rearward is formed integrally with the caliper 41, and one end of a torque link 46 is axially attached to the stay 43 by a shaft 45, and the other end is axially attached to the fork pipe 20 by a shaft 47. I have.

In FIG. 4, the shock absorber 22 is provided with a damper 5.
0, a cushion spring 51 is provided, a lower end of the cushion spring 51 is in contact with a lower flange 52, and a lower end of the shock absorber 22 is attached to the push rod 21 by a shaft 29 by an elastic attachment portion 53.

The upper end of the cushion spring 51 is in contact with an upper flange 55 provided around the piston rod 54, and the upper flange 55 is provided with a stopper rubber 56.
And the washer 57.

The upper end of the piston rod 54 projects upward through a washer 57, and passes through a through hole 59 formed in the bottom of a bowl-like portion 58 formed on the upper bracket 28 and projecting upward.

An annular concave portion 60 having a small diameter is formed on the upper surface of the bowl-shaped portion 58 in the vicinity of the through hole 59, and the extension-side mount rubber 61 is accommodated therein.

A large-diameter annular concave portion 62 is also formed on the lower surface in the vicinity of the through hole 59, and also accommodates a large-diameter push-up mount rubber 63.

The extension-side mount rubber 61 and the push-up side mount rubber 63 are formed so as to have optimum bar volumes, materials, hardness and the like required respectively. The rubber 63 protrudes downward in a spherical shape.

The extension mount rubber 61 contacts the upper washer 64 with a spherical surface, the push-up mount rubber 63 contacts the washer 57 with a spherical surface, and the bowl-shaped portion 58 and the push-up mount rubber 6 via the collar 65.
3. By projecting upward through the extension-side mount rubber 61 and the upper washer 64 and fastening the nut 66 to the tip, the elastic member is elastically supported by the upper bracket 28. Reference numeral 67 denotes a cap.

As is apparent from FIGS. 5 and 7, through holes 68 are formed on the left and right portions of the upper bracket 28 overlapping the top bridge 3, and a slit 69 is formed in a part thereof. It is split fastened by a bolt 70 that penetrates the upper part of the fork 20 and crosses the slit 69. The central portion between the left and right through holes 68 is a step 71 that falls downward.

The top bridge 3 has a front portion overlapping the rear portion of the upper bracket 28, and a front fork mounting hole 72 through which the upper end of the front fork 20 penetrates is formed coaxially with the through hole 68 on the left and right sides of the overlapping portion. At the middle part, the mounting hole 7 of the handlebar mounting stay 73 (FIG. 8)
4 are formed as a pair of left and right, and a stem pipe mounting hole 75 is provided in the center of the rear end.

The upper end of the stem pipe 4 is fitted into the stem pipe mounting hole 75 and fastened with a cap nut 76.

A slit 77 is also formed in the front fork mounting hole 72 in the same manner as the upper bracket 28, and the slit 77 is split and fastened with a bolt 78 crossing the slit 77. Accordingly, the top bridge 3 and the upper bracket 28 are separately fastened to the front fork 20 by the bolts 78 and 70, respectively.

As shown in FIG. 6, the steering stem 2
6, a stem pipe 4 is provided to protrude upward.
The front fork 20 is fixed by tightening bolts 82 in a direction crossing the slits 81 formed in the front forks.

When the left and right front forks 20 are fixed by the steering stem 26, as shown in FIG. 9, the axis C1 of the stem pipe 4 and the axis C2 of the front fork 20 open upward by a slight angle θ. ,
It is a slant type.

As shown in FIGS. 7 and 9, the front fork mounting hole 72 of the top bridge 3 is formed along the axis C 2 and has a diameter capable of closely adhering to the outer periphery of the front fork 20.

On the other hand, as shown in FIGS. 8 and 9, the stem pipe mounting hole 75 is formed along the axis C1, and at the same time when the front fork 20 enters the front fork mounting hole 72, the stem pipe 4 is connected to the stem pipe mounting hole. The diameter of the stem pipe 4 is larger than the outer diameter of the stem pipe 4 so as to be able to enter the space 75.

The resulting gap between the steering stem 4 and the stem pipe mounting hole 75 is fitted with a collar 85 with a collar, and the collar 86 is supported by the bottom of an annular recess 87 around the stem pipe mounting hole 75. . Code 88
Is a male screw portion at the upper end of the stem pipe 4.

Numeral 89 in FIG. 8 is a nut for fastening the lower end of the handlebar mounting stay 73. The nut is fastened from below using the space formed by the step 71 of the upper bracket 28.

Next, the operation of this embodiment will be described. The upper support structure of this link type front suspension device is
Since the top bridge 3 and the upper bracket 28 are separately provided, the large load of the shock absorber 22 is received only by the upper bracket 28, and the top bridge 3 is used only for steering operation, so that the size and weight can be reduced.

Further, since the front suspension can be assembled without using the top bridge 3 until the final assembly stage, the top bridge 3 can be assembled sequentially from the bottom, and the top bridge 3 can be finally mounted to complete the assembly. become. In addition, since the replacement can be performed separately on the front suspension side and the steering system, maintenance is improved, and the size of each unit can be reduced.

Even if the fork pipe 20 is angled to the stem pipe 4, if the top bridge 3 is mounted from above, the stem pipe mounting hole 75 has a larger diameter than the stem pipe 4. , The fork pipe 20 and the stem pipe 4 can be simultaneously fitted into the stem pipe mounting hole 75 and the front fork mounting hole 72, respectively.

After that, if the collar 85 with a collar is inserted into the stem pipe mounting hole 75, there is no play. Therefore, the male thread 88 formed on the upper part of the stem pipe 4 is fastened with the cap nut 76, so that the stem pipe is removed. 4 and top bridge 3 can be attached. Therefore, even if the slant type is adopted or the fork pipe 20 and the stem pipe 4 are fixed in an angled state by the steering stem 26 in advance, the top bridge 3 can be mounted from above thereafter, and the assembling work is easy. become.

Further, since a pair of vertically divided mount rubbers (61, 63) are provided above and below the through hole 59 of the upper bracket 28, the rubber volume, material, and hardness of the extension rubber 61 and the push-up rubber 63 are provided. And so on, and can be optimally configured for the performance required for each. In addition, it can cope with a load direction other than the rotation direction, and a large rubber volume can be obtained in a small space, and the structure near the top bridge 3 can be simplified.

FIG. 10 shows another embodiment relating to the attachment of the stem pipe to the top bridge 3.
A slit 90 is formed around the periphery of the stem pipe mounting hole 7.
After inserting the stem pipe 4 into the
It is designed to be split. Thereby, the cap nut 76 can be omitted.

[Brief description of the drawings]

FIG. 1 is an overall side view of a motorcycle to which the present invention is applied.

FIG. 2 is a partially enlarged side view of a link type front suspension.

FIG. 3 is a front view of a front fork.

FIG. 4 is a partially cutaway side view of the upper structure of the front suspension.

FIG. 5 is a top view of the top bridge and the upper bracket.

FIG. 6 is a top view of the steering stem (in the direction indicated by the arrow A in FIG. 4).

FIG. 7 is a sectional view taken along line 7-7 of FIG. 5;

FIG. 8 is a sectional view taken along line 8-8 of FIG.

FIG. 9 is a schematic sectional view illustrating a method of mounting the top bridge.

FIG. 10 is a diagram corresponding to FIG. 6 of another embodiment.

[Explanation of symbols]

1: front wheel, 2: link type front suspension, 3:
Top bridge, 5: Head pipe, 20: Fork pipe, 21: Push rod, 22: Shock absorber, 23: Upper link, 24: Pivot link, 25: Fender link, 26: Steering stem, 28: Upper bracket, 61: Extension side mount rubber, 63: Push-up side mount rubber, 72: Front fork mounting hole,
75: stem pipe mounting hole, 85: collar with collar

Claims (3)

[Claims] A pair of left and right front forks extending vertically with a front wheel interposed therebetween, a lower link having one end pivotally attached to the front fork and the other end supporting a front wheel, and one end connected to an intermediate portion of the lower link. A motorcycle provided with a front link type suspension having a push rod mounted on a shaft and having the other end connected to the shock absorber, and an upper link connected between the push rod and the front fork. A support structure for a link-type front suspension, wherein a top bridge connecting upper ends of stem pipes and an upper bracket connecting upper ends of a front fork and a shock absorber are formed separately. 2. The front fork and the stem pipe have different axes, and the top bridge is mounted from above on the front fork and stem pipe from above.
The stem pipe mounting hole of the top bridge has a large diameter so that both ends of the stem pipe and the front fork are simultaneously fitted into both the stem pipe mounting hole and the front fork mounting hole provided in the top bridge, and the stem is inserted through the collar. The support structure for a link type front suspension according to claim 1, wherein an upper end of the pipe is fastened to a top bridge. 3. A pair of mounting shafts provided at the upper end of the shock absorber penetrate through mounting holes provided in the upper bracket, and are vertically divided in advance with both surfaces of the upper bracket surrounding the mounting holes interposed therebetween. 2. The support structure for a link type front suspension according to claim 1, wherein the support structure is fastened via a mount rubber.