JP2545070B2 - Rear wheel shock absorber for motorcycles - Google Patents

Description

The present invention relates to a rear wheel shock absorber for a motorcycle.

(Prior Art) As a rear wheel shock absorber for a motorcycle, for example, Japanese Patent Laid-Open No. 58-
As disclosed in No. 20585, the front end of the rear fork is pivotally attached to the center frame, and the other end of the first link (bell crank lever) pivotally attached to the rear fork is pivotally attached to the lower part of the shock absorber. , The rear end of the second link (tension arm) whose front end is pivotally attached to the center frame is pivotally attached to the first link, and the increase amount of the cushioning force of the shock absorber with respect to the swing amount of the rear fork is represented by a curved curve. There is one that has been increased and made its characteristics progressive.

(Problems to be Solved by the Invention) However, in such a rear wheel shock absorber, since the upper ends of the first links are pivotally attached to the left and right fork members, the upper ends of the first links are bifurcated. Since it has to be formed, there is a problem that the first link becomes large and the shape becomes complicated.

Further, considering the rigidity of the first link, it is desirable that the first link is formed in a plate shape having a substantially triangular shape in a side view. However, in the above-described structure, this requires two first links. However, this causes problems such as an increase in the number of parts.

Therefore, it is conceivable that the first link is constituted by one link by pivotally connecting the upper end of the first link to the middle portion of the cross member. Since a large load is always applied, such a structure has a problem that the cross member has to be upsized and the crossmember is upsized and the weight is increased.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a rear wheel shock absorber of a motorcycle that is lightweight, compact, and has high rigidity.

(Means for Solving the Problems) In order to solve the above problems, the present invention comprises left and right rear fork members 3, 3 and a cross member 5 connecting the left and right rear fork members 3, 3. The front end is the body frame 50
A rear fork 1 pivotally attached to the rear fork, and a link mechanism 62 provided between the rear fork 1 and the body frame 50,
A shock absorber 52 provided between the vehicle body frame 50 and the link mechanism 62 is provided. One end of the link mechanism 62 is pivotally attached to the rear fork 1 and the other end is pivotally attached to a lower end of the shock absorber 52. First link 18 and one end pivotally attached to body frame 50,
In a rear wheel shock absorber of a motorcycle, the other end of which is composed of a second link 58 pivotally attached to the first link 18, and the first link 18 is formed in a substantially triangular shape extending downward. ,
The cross member 5 is formed in a substantially H shape in a plan view, and an upper wall 70 of an intermediate portion in the left-right direction of a bridge portion connecting the left and right of the cross member 5 is located above the left and right fork members 3, 3. In the lower wall 101 of the bridge portion of the cross member 5 which is bulged, the left and right side walls 102, 102 extending upward from the lower surface of the lower wall 101 and the left and right side walls connecting the upper ends of the left and right side walls 102, 102 are connected. The lower surface 104 of the portion 103 forms an inverted concave storage recess 16 having an open bottom, and the storage recess
The wall portion 103 forming the upper surface of 16 and the upper wall 70 of the bridge portion are configured to be vertically separated from each other.
Rib portions 24, 24 are provided vertically between the upper wall 70 and the upper wall 70, and this portion is formed into a hollow closed cross section, and the upper portion of the first link 18 described above is accommodated in the accommodating recessed portion 16, The upper end of the link member 18 is pivotally attached to the cross member 5 of the rear fork 1 by a shaft 20 penetrating the storage recess 16 in the left-right direction. .

Further, according to the present invention, a reinforcing portion is provided at a pivotal portion of the first link 18 of the cross member 5, and the reinforcing portion extends from the left and right side walls 102, 102 of the accommodating recess 16 outward in the left and right directions. The left and right rear fork members 3 and 3 are fitted together, and the pipe members 22 and 22 are integrated with the left and right rear fork members.

(Operation) According to the means described above, the cross member 5 of the rear fork 1 has a structure in which the upper and lower members 7.8 are joined and integrated, and the left and right fork members 3, 3 are joined and integrated in the cross member 5 to form the rear fork 1. And a storage recess that opens downward in the lower portion 8 of the base portion arranged in the left-right direction of the cross member 5.
16 on the other hand, on the other hand, the upper wall of the middle portion of the base upper part 30
70 is bulged upward and the upper end of the first link 18 connected to the lower end of the shock absorber 52 in the storage recess 16 is pivotally attached to the cross member 5 by the shaft 20 penetrating in the left-right direction. It is not necessary to form a bifurcated shape, and the structure thereof can be simplified. Further, the rear fork 1 has the upper end of the first link 18 accommodated in the accommodating recess 16 and pivotally attached by the shaft 20. It is possible to prevent the increase in size and reduce the weight while ensuring the rigidity of the.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

Sakae FIG. 1 is a side view of a rear wheel shock absorber for a motorcycle according to the present invention, FIG. 2 is an exploded perspective view of a rear fork, FIG. 3 is the same plan view, FIG. 4 is the same side view, and FIG. Is V-V in FIG.
FIG. 6 is a side view of the first link, FIG. 7 is a bottom view of the first link partially cut along the line VII-VII of FIG. 6, and FIG. The front view of the 1st link fractured | ruptured by the VIII-VIII line of FIG. 6 is shown.

As shown in FIG. 1, the rear wheel shock absorber includes a rear fork 1 and a first link whose upper end is pivotally supported by the rear fork 1.
18, a shock absorber 52 in which an upper portion is attached to an appropriate portion of the vehicle body frame 50 and a lower portion is pivotally attached to the link 18 first, and a front end is pivotally attached to the vehicle body frame 50, and a rear end is attached to the first link 18. A second link 58 pivotally attached to said first link 18
And the second link 58 constitutes a link mechanism 62.

The rear fork 1 is composed of left and right fork members 3, 3 and a cross member 5 connecting the left and right fork members 3, 3 as shown in FIG. Cross member 5 is second
As shown in FIG. 3 and FIG. 3, the bridge portion 5a is provided at the middle portion in the front-rear direction, and has a substantially H shape in plan view.

The rear fork 1 is substantially H-shaped in a plan view, and has a structure in which the upper member 7 and the lower member 8 are integrally joined by welding in the embodiment. After the upper member 7 of the rear fork 1, the bridge portion 5a
The middle portion of the upper wall 70 of the base portion 30, which is the upper side of the, is bulged above the left and right fork members 3, 3 (see FIG. 5).

The lower member 8 is an intermediate portion in the front-rear direction, and a base portion 10 of the intermediate portion that is below the bridge portion 5a after being arranged in the left and right (width direction).
And front arm portions 12 and 12 formed in a bifurcated shape from the front portions of the left and right side portions of the base portion 10, and rear arm portions 14 and 14 formed in a bifurcated shape from the rear portions of the left and right sides of the base portion 10 to the front. .
Pivot pipes 12a for pivotally supporting the rear fork 1 on the vehicle body frame 50 by a shaft 48 are formed at the front ends of the front arm portions 12, 12, respectively.

The central portion of the lower wall 101 of the base portion 10 is recessed upward to accommodate the storage portion 1
Forming 6 The storage portion 16 is composed of left and right side walls 102, 102 extending upward from the lower wall 101 and a wall portion 103 extending in the left-right direction connecting the upper ends of the left and right side walls 102, 102.
The upper ends of 02 and 102 and the lower surface 104 of the wall portion 103 are formed in an inverted concave shape whose lower side is opened.

The storage section 16 forms a space S1 for storing the upper portion of the first link 18 opened downward, and the left and right sides of the storage section 16 are provided with shafts 20 for pivotally supporting the first link 18. Shaft hole 16
form a. Further, pipe members 22 and 22 are provided so as to project from the both ends of the storage portion 16 toward the left and right, respectively.
Buds 24, 24 connected to the upper wall 70 are provided in a protruding manner, and the rib portions 24, 24 are laterally separated from each other and project upward.

As will be described later, the rib portions 24, 24 form an intermediate closed cross section between the upper upper wall 70 and the wall portion 103 of the lower storage recess 16, and the rib portions 24, 24 extend vertically within the hollow closed cross section. It is arranged vertically and functions as a rib between the upper wall 70 of the bridge portion and the upper wall of the storage recess, and in the embodiment, the bridge portion is arranged above and below the bases 30 and 10 of the upper and lower members 7 and 8. Since it is composed of the lap joint, it also functions as a connecting member between the upper wall 70 of the bridge portion and the upper wall of the storage recess.

Among these, the pipe members 22, 22 and the wall portion of the storage portion 16 constitute a reinforcing portion.

Standing piece-shaped walls 26, 26 are formed from the front side of the storage section 16 to the front arm sections 12, 12, and the standing piece-shaped walls are formed from the rear side of the storage section 16 to the inner surfaces of the rear arms 14, 14. The parts 28, 28 are formed respectively.

In the above, all the lower members 8 are integrally formed.

The upper member 7 having an H-shape in plan view includes a base portion 30 which forms a bridge portion at an intermediate portion in the front-rear direction, and extending portions 32, 32 formed in a bifurcated shape from front portions on both sides in the left-right direction of the base portion 30 to the front. The base portion 30 includes extension portions 34, 34 formed rearward from the rear portions on both sides in the left-right direction. The front and rear extending portions 32, 32, 34, 34 have their upper surfaces positioned downward with respect to the base portion 30, and the front and rear extending portions 3
2, 32, 34, 34 have a chain (not shown) extending above them, and on the upper surface of the base portion 30, there are long holes 36, 3 in the front-rear direction that are separated from each other in the left-right direction.
Forming 6

Downward wall portions 38 are provided so as to hang down from the inner portions of the extending portions 34, 34 and the rear portion of the base portion 30. Also, for the inner parts of the extension parts 32, 32 and the front part of the base part 30,
Similarly, downwardly extending wall portions 40 are provided so as to hang down.
A notch 41 is formed from below in a portion of each wall 40 located at the front of the base 30.

The lower surface 40a of the wall portion 40 is the upper surface 26a of the wall portion 26 of the lower member 8.
Is formed in a shape that matches with the lower surface 38a of the wall 38.
Is formed in a shape that matches the upper surface 28a of the wall portion 28 of the lower member 8. The notch portion 41 is the front peripheral edge of the storage portion 16 of the lower member 8.
It is formed in a shape that fits into 16b. All of the above upper members 7 are integrally formed.

Reference numerals 3 and 3 denote a pair of left and right rear fork members, which have the same structure, so only one rear fork member 3 will be described.

The rear fork member 3 comprises an upper member 3a and a lower member 3b, which are integrally joined by welding or the like. The central portion 3c of the rear fork member 3 has a square pipe shape with a square cross section, and the front portion 3d has a U-shaped cross section in which the inner side surface is open. Further, the rear wheel 42 has an opening at the rear portion 3e of the rear fork member 3,
The bracket 43 for supporting is fitted and the fitted portion is welded. In FIG. 2, reference numeral 44 is a hole into which the pipe member 22 is fitted.

In the above, the rear fork 1 is assembled as follows.

First, the long holes provided with the ribs 24, 24 of the lower member 8 in the front-rear direction on the upper wall 70 of the base portion 30 of the upper member 7 and separated left and right
36, 36, the upper surface 26a of the wall 26 of the lower member 8 and the upper member 7
The lower surface 40a of the wall portion 40 of the lower member 8, the upper surface 28a of the wall portion 28 of the lower member 8, the lower surface 38a of the wall portion 38 of the upper member 87, the front peripheral edge 16b of the storage portion 16 and the cutout portion 41 are brought into contact with each other. The upper member 7 and the lower member 8 are integrally connected by welding fitting portions such as the above and abutting portions.

As described above, as shown in FIG. 3, in a state in which the cross member 5 having the bridge portion 5a in the front-rear direction and having a substantially H-shape in plan view is formed, and the upper member 7 and the lower member 8 are joined together. A space S2 is formed between the upper member 7 and the lower member 8.

Next, the front openings of the left and right fork members 3,3 are fitted from the side of the upper member 7 and the lower member 8, and the pipe members 22,22 are fitted in the holes 44 of the fork members 3,3. The rear fork members 3, 3 are integrally joined to the upper member 7 and the lower member 8 by welding the fitting peripheral portions thereof (see FIG. 5).

FIG. 6 shows a side view of the first link 18, FIG. 7 is a bottom view of the first link 18 with a part cut along the line VII-VII in FIG. 6, and FIG. The front view of the 1st link fractured | ruptured by the VIII-VIII line of FIG. 6 is shown. The first link 18 has a substantially triangular shape that spreads downward in a side view, and the front lower end portion 18h is
It is formed in a bifurcated shape.

The upper end portion 18i of the first link 18 is provided so as to penetrate in the width direction of the hole portion 18a, and the left and right lower end front portions 18h are provided with hole portions 18b and 18b, respectively.
Are provided so as to penetrate coaxially in the width direction, and the hole 1
8c is provided so as to penetrate in the width direction. Collar 18d in hole 18a
And the collar 18e is fitted in the hole 18c. Another hole 18
A recess 18f is provided between a and the hole 18c, and the hole 18c and the hole 18b are formed.
Recesses 18g are formed between them.

As shown in FIGS. 1 and 5, the upper end portion 18i of the first link 18 is connected to the link storage space S1 of the rear fork 1 described above.
Is fitted from below, and the shaft 20 is inserted through the hole 18a of the link 18 and the shaft hole 16a of the accommodating portion 16, the upper part of the first link 18 is accommodated in the space S1, and the upper end of the link 18 is accommodated. Pivot.

The upper end of the shock absorber 52 is attached to an appropriate portion of the vehicle body frame 50, and the lower end 52a of the shock absorber 52 is sandwiched between the lower end front portions 18h, 18h of the first link 18 to connect the lower end front portions 18h, 18h. Hole 18b,
It is rotatably supported by a shaft 54 that passes through 18b.

The second link 58 has a front end pivotally attached to the vehicle body frame 50 by a shaft 56, and a rear end thereof by a shaft 60 at a lower end rear portion 18j of the first link 18.
Pivot to.

By the way, a large load acts on the pivotally-attached portion of the upper end of the first link 18, but since these loads are received by the pipe members 22 and 22 which are reinforcing portions and the wall portion of the storage portion 16,
It is not necessary to increase the rigidity of the cross member 5 as a whole to increase its rigidity, and the structure is compact.

In this embodiment, the upper end of the first link 18 is arranged so as to face the accommodating recess 16 provided in the lower portion of the bridge portion 5a in the substantially middle portion of the cross member 5 and is pivotally attached to this portion. The first link 18 can be configured by one link, and the upper portion of the first link 18 does not need to be bifurcated as in the conventional case, and the structure can be simplified.
Further, since the first link 18 has a substantially triangular shape in a side view, the rigidity can be increased, and further, the rear fork 1 is provided with the reinforcing portion at the pivotal connection portion at the upper end of the first link 18, so that the cross member 5 is provided. Can be prevented from increasing in size.

(Effects of the Invention) As described above, according to the present invention, the first link can be configured by one link, and the structure thereof can be simplified. In addition, the rigidity of the first link can be increased, the cross member can be prevented from becoming large, and the rear wheel shock absorber can be made compact and lightweight.

According to the present invention, since the accommodating recess is formed in the lower surface of the middle portion of the cross member, and the upper part of the first link is accommodated and pivotally mounted in the accommodating recess, the mounting position of the upper part of the first link is seen from the horizontal direction. It is inside the cross member, and therefore, the mounting position of the first link does not deviate upward or downward from the cross member. As a result, no bending moment is applied to the cross member, and it is possible to reduce the weight of the cross member while ensuring the rigidity required for the cross member.

Particularly, in the present invention, since the cross member has a hollow closed cross-section structure and the ribs are vertically provided in the hollow portion, it is possible to obtain a lightweight cross member having high rigidity, high strength, and high rigidity including the cross member as a whole, It is possible to obtain a rear fork with high strength and light weight.

Further, according to such a structure, the shock absorber can be installed at a lower position as compared with a structure in which the first link is eccentrically mounted above the cross member, and the center of gravity of the vehicle body can be lowered. You can

Further, since the middle portion of the upper wall of the bridge portion of the cross member is bulged upward, the distance between the upper wall of the bridge portion of the cross member and the wall portion of the storage recess disposed below the upper wall is increased. The cross member can have a large cross-sectional area, and the closed cross-sectional structure can structurally increase the strength and rigidity of the entire cross member, and can also reduce the weight as a whole.

Further, since the rib portion is provided in the wall portion of the storage recess between the upper wall of the bridge portion and the wall portion of the storage recess disposed below the upper wall, the left and right side walls of the storage recess are separated from the first link. The load to be received can be transmitted to the upper portion of the rib portion bridge portion, whereby the load of the first link can be shared and received above and below the bridge portion of the cross member.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a side view of a rear wheel shock absorber of a motorcycle according to the present invention, Fig. 2 is an exploded perspective view of a rear fork, and Fig. 3 is a plan view of the same. FIG. 4 is a side view of the same, FIG. 5 is a sectional view taken along line VV of FIG. 3, FIG. 6 is a side view of the first link, and FIG.
-VII shows a bottom view of the first link taken along the line VII, and FIG. 8 shows a front view of the first link partially cut along the line VIII-VIII of FIG. In the drawing, 1 is a rear fork, 3 and 3 are rear fork members,
5 is a cross member, 5a is a bridge portion, 70 is an upper surface, 10 is a base portion which is an upper side of the bridge portion, 101 is a lower wall, 102 and 102 are side walls, 104 is a lower surface, 16 is a storage recess, 18 is a first link, and 20 is Shaft, 22 and 22 are pipe members, 24 and 24 are connecting portions, 30 is a base portion below the bridge portion, 50 is a vehicle body frame, 52 is a shock absorber,
52 is a second link and 62 is a link mechanism.

Claims (2)

(57) [Claims] 1. A rear fork 1 comprising left and right rear fork members 3,3 and a cross member 5 connecting the left and right rear fork members 3,3, the front end of which is pivotally attached to a vehicle body frame 50. The link mechanism 62 is provided between the rear fork 1 and the vehicle body frame 50, and the shock absorber 52 is provided between the vehicle body frame 50 and the link mechanism 62. A first link 18 pivotally attached to the fork 1 and the other end pivotally attached to the lower end of the shock absorber 52, and one end pivotally attached to the vehicle body frame 50, the other end being the first link.
In a rear wheel shock absorber of a motorcycle, which is composed of a second link 58 pivotally attached to 18, the first link 18 is formed in a substantially triangular shape extending downward, and the cross member 5 is viewed in a plan view. Is formed in a substantially H shape, and the upper wall 70 of the middle portion in the left-right direction of the bridge portion connecting the left and right of the cross member 5 is bulged above the left and right fork members 3, 3 and On the lower wall 101 of the bridge part of the member 5,
Left and right side walls 102, 102 extending upward from the lower surface of the lower wall 101,
With the lower surface 104 of the wall portion 103 in the left-right direction connecting the upper ends of the left and right side walls 102, 102, an inverted concave type storage recess is opened downward.
The wall portion 103 forming the upper surface of the storage recess 16 and the upper wall 70 of the bridge portion are formed so as to be vertically separated from each other, and the space between the wall portion 103 and the upper wall 70 is formed. Ribs 24, 24 are vertically provided on the upper end of the first link member 18. The upper part of the first link member 18 is accommodated in the accommodating recess 16 by forming the rib portion 24, 24 in a hollow closed cross section. The rear wheel shock absorber for a motorcycle according to claim 1, wherein the storage recess 16 is pivotally attached to the cross member 5 of the rear fork 1 by a shaft 20 penetrating in the left-right direction. 2. The first link of the cross member 5
The pivot portion of 18 is provided with a reinforcing portion, and the reinforcing portion extends laterally outward from the left and right side walls 102, 102 of the storage recess 16 and is fitted with the left and right rear fork members 3, 3 to The rear wheel shock absorber for a motorcycle according to claim 1, wherein the rear wheel fork member is formed of pipe members 22, 22 integrated with the rear fork member.