JPH0228083A - Axle supporting structure for rear arm - Google Patents

Abstract

PURPOSE:To suppress a surface pressure of contact to not more than the fixed value with surface contact always generated by forming either one of the recessed or protruded part engaging surfaces into a curved surface in an axle supporting part which forms a V-shaped recessed part in the outer side surface of an axle insertion hole in the rear end of a rear arm and a V-shaped protruded part in a chain puller. CONSTITUTION:An insertion hole of an axle 5 is formed in a rear end part 4 of a rear arm swivelable with a car body pivot part serving as the center, while a V-shaped recessed part 11 is provided in the outer side surface. A chain puller 10, having a V-shaped protruded part 14 opposed facing to the recessed part 11, is inserted interposing, and the axle 5 is mounted by a nut 18. Either one of an engaging surface 11a of the V-shaped recessed part 11 or an engaging surface of the V-shaped protruded part 14 is flexed to the outside, forming a circular curved surface. In tightening by the nut 18, an engaging part is always brought into surface contact, enabling a surface pressure of the contact to be suppressed to the fixed value or less.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an axle support structure for a rear arm in a motorcycle or the like.

(Prior art) For example, in a motorcycle, the rear wheel is rotatably supported at the rear end of the rear arm via a rear axle that passes through the rear axle, or within the support structure of the rear east axle of the rear arm. The metal member has a V-shaped recess formed on the outer surface of the rear end of the metal arm that constitutes the rear end of the two left and right arms that extend rearward from the pivot part of the rear arm.
The axle is supported between the rear end portions of the rear arm by engaging the letter-shaped convex portions and tightening a nut that is threaded onto the end of the axle that is inserted through the rear end portions of these arms and the metal member. There is.

(Problems to be Solved by the Invention) ■ In the conventional axle support structure, what are the V-shaped recess at the rear end of the rear arm and the V-shaped protrusion on the metal member? Since they were engaged at the surface, it was possible to keep the contact surface pressure of the engagement surface low, but due to the assembly error book, there were cases where the two parts came into line contact without surface contact. Excessive surface pressure is generated in the line contact area, causing plastic deformation in that area,
Deformation occurs in both members due to insufficient surface pressure strength.

The present invention has been made in view of the above problems, and its object is to ensure that the rear end of the rear arm and the metal member that engages with the rear arm are in surface contact with each other in any case. Therefore, it is an object of the present invention to provide a vehicle support structure for a rear arm in which the contact surface pressure between both members is suppressed to a certain value or less.

(Means for Solving the Problems) In order to achieve the object described in E, the present invention provides a metal arm rear end portion that constitutes the rear end portions of the two left and right arm portions extending rearward from the pivot portion of the rear arm. The V-shaped protrusion of the metal member is engaged with the V-shaped recess formed on the outer surface of the arm, and the nut that is threaded onto the rear end of these arms and the end of the axle that is inserted through the metal member is tightened. In a vehicle support structure for a rear arm that supports the axle between the rear ends of the rear arms, one of the engagement surfaces of the V-shaped recess at the rear end of the arm and the V-shaped protrusion of the metal member are tilted. It is characterized by a convex curved surface.

(Function) Therefore, when tightening the nut, even if the metal member at the front is tilted relative to the rear end of the rear arm due to an assembly error, both members will not line up at any point on the curved surface. Contact. And if you tighten the nuts.

Both members receive an axial force, and the member with the convex curved engagement surface is elastically deformed at its line contact portion, and the contact between the two members changes from line contact to surface contact, and as a result, one car The contact pressure of parts can be kept below a certain value.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

Fig. 1 is a side view showing a rear arm vehicle support structure according to the present invention; Fig. 2 is a cross section taken along line II-II in Fig. 1 [L Fig. 3 is an enlarged view of part A in Fig. 2; Fig. 4 5 is a plan view showing the axle support structure, and FIG. 5 is an exploded perspective view thereof.

[In A, l is the rear arm of the motorcycle, and the front end of the rear arm l has a pipe 2 constituting the bibout part.
The pipe 2 is welded in the left and right direction (vehicle width direction).
From there, two square pipe-shaped arm portions 3.3 on the left and right extend integrally to the rear.

A metal end piece 4.4, which is a separate member constituting the rear end of the gloss arm l, is welded to the rear ends of these arms 111g3, 3, and between these end pieces 4.4 is an axle shaft. 5, and is rotatably supported via the axle 5 by a rear wheel 6 or the rear end of the gloss arm l. The front end of the rear arm l is rotatably connected to the vehicle body frame (not shown) via a bibout shaft 7 inserted into the pipe 2. Therefore, the rear arm l pivots rearward about the pivot shaft 7. It can swing up and down together with the wheels 6, and is suspended on the side of the heavy body via a rear suspension (not shown).

By the way, each of the end pieces 4 is made of an extruded material or a pultruded material obtained by extrusion molding or pultrusion molding using an aluminum material as a raw material.
An oval axle insertion hole 8 and through holes 9, which penetrate in the left-right direction (vehicle width direction), are formed in the axle. In addition, through holes 9, 9
is formed for the purpose of reducing the weight of the end piece 4 and making machining easier.

Further, as shown in detail in FIG. 5, a V-shaped recess 11 to be engaged with a chain buller lO, which is a metal member, is formed by machining on the outer surface of the end piece 4. One long side of the recess 11 in the front-rear direction constitutes a flat tapered surface 11a, lla that opens outward. Further, the width shaft insertion hole 8 opens into this V-shaped recess 11, and an adjustment bolt 12 is screwed into the end face 11b of the V-shaped recess 11. 13 are screwed together.

The chain buller 10 is also made of extruded or drawn material, and is provided with a V-shaped protrusion 14 to engage with the V-shaped recess 11 formed in the end piece 4. The upper surface of the letter-shaped convex portion 14 is a convex arcuate surface 14a having a predetermined curvature.

14a. A groove 15 having a rectangular cross section is formed on the outer surface of the chain buller 10 and extends in the front-rear direction, and a circular hole 16 is opened in the groove 15. Incidentally, above and below the groove 15 of this chain puller IO, circular holes 17° 17 are provided in the front-rear direction to reduce weight.

Further, the axle 5 is made of a hollow bolt material as shown in detail in FIG. 5, and the head 5a has a cut surface 5a-
1, 5a-1 are formed, and a wedge portion 5b is formed at the tip.

Thus, the L vehicle distribution shaft 5 is inserted into the circular hole 16 of the chain puller lO, and the cut surface 5a-1 of the head 5a,
5a-1 is fitted into the groove 15 of the chain puller IO to prevent the axle 5 from rotating. Then, this axle 5 is inserted into the axle insertion hole 8 of one end piece 4 and the axle insertion hole 8 of the other end piece 4. V of the end piece 4
The nut 1 is sequentially passed through the circular hole 16 of the other chain puller lO that engages with the letter-shaped recess 11, and is screwed into the threaded portion 5b thereof.
8, the axle 5 is supported at both ends by the end piece 4.4 via chain pullers 10.10. The hub 6a of the rear heavy wheel 6 is inserted through the axle 5, and the rear heavy wheel 6 is rotatably supported by the -V shaft 5 as described above.

In the above axle support structure, the V of the chain puller lO
The engagement surfaces of the letter-shaped convex portions 14 are particularly convex arcuate surfaces 14a, 14a.
Therefore, before tightening the nut 18, even if the chain puller 10 is tilted with respect to the end piece 4 due to an assembly error, each arcuate surface 14a of the chain puller 10 and the tapered surface 11a of the end piece 4 What is the third
Line contact is made at point a, as shown by the jO line in the figure. However, when the nut 18 is subsequently tightened, the chain puller lO and the end piece 4 receive an axial force, and the chain puller lO is elastically deformed at the m contact portion of each curved surface 14a, causing the chain puller lO and the end piece 4 to contact each other. As shown by the solid line in FIG. 3, the width of the chain puller 10 is in surface contact with the end piece 4, and as a result, the contact pressure between the chain puller 10 and the end piece 4 is suppressed to a certain value or less. In this embodiment, since the circular holes 17, 17 are provided through the chain puller 10, which is a member that is elastically deformed, the rigidity of the chain puller 10 decreases and its elastic deformation increases. The contact width shown in the figure is expanded, and as a result, the contact pressure can be kept lower. Furthermore, since the chain puller lO has arcuate surfaces 14a, 14a, the chain puller lO
O sometimes performs a self-aligning function when assembled.

By the way, in the above embodiment, a convex curved surface is provided on the chain puller side, or a convex curved surface (arc surface) is provided on the end piece 104 side as shown in FIG.
, l1la are provided and the engaging surfaces 114a, 114a of the chain puller 110 are made into flat tapered surfaces, and the same effect as described above can be obtained. (Effects of the Invention) As is clear from the above description, according to the present invention, the outer surface of the rear end portion of the metal arm that constitutes the rear end portion of the two left and right arm portions extending rearward from the pivot portion of the rear arm. The V-shaped protrusion of the metal member is engaged with the V-shaped recess formed in the metal member, and the nut that is threaded onto the rear end of these arms and the end of the axle that is inserted through the metal member is tightened. In an axle support structure for a rear arm that supports an axle between rear end portions of the rear arm, the engaging surface of either the V-shaped recess at the rear end of the arm or the V-shaped convex portion of the metal member is a convex curved surface. Therefore, the rear end of the rear arm and the metal member that engages with the rear end of the rear arm are always in surface contact under any circumstances.

As a result, it is possible to suppress the contact surface pressure between the two members to a certain value or less.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the rear arm axle support structure according to the present invention, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 11A, Fig. 3 is an enlarged view of section A in Fig. 2, and Fig. 4 is the same. FIG. 5 is a top view showing the axle support structure, FIG. 5 is an exploded perspective view of the same, and FIG. 6 is a view similar to FIG. 2 showing a modified embodiment of the present invention. l...Rear arm, 2...Pipe (pivot part),
3... Arm part, 4,104... End piece (rear end of arm), 5... Axle, 10,110... Chain puller (metal member), 11... V-shaped recess ,1
1a. 14a...Tapered surface (engaging surface), l4...V-shaped convex portion, 14a. la...Arc surface (engaging surface) Patent applicant Yamaha Motor Co., Ltd.

Claims (1)

[Claims] A V-shaped protrusion of a metal member is formed in a V-shaped recess formed on the outer surface of the rear end of the metal arm that constitutes the rear end of the two left and right arms that extend rearward from the pivot part of the rear arm. In the axle support structure for the rear arm, the axle is supported between the rear end parts of the rear arm by engaging the rear end parts of the rear arms and tightening a nut threaded onto the end of the axle that is inserted through the rear end parts of these arms and the metal member. An axle support structure for a rear arm, characterized in that either the V-shaped concave portion at the rear end of the arm or the V-shaped convex portion of the metal member has a convexly curved engagement surface.