JPH10274298A - Attaching structure for chain guide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut off the transmission of a hitting sound generated with a chain guide to an attaching surface by providing an elastic buffer member between the large diameter outer peripheral surface of a shoulder bolt and the inner peripheral surface of a chain guide attaching hole. SOLUTION: A chain guide 1 is made of a nylon resin material having low friction and large strength, and one end surface thereof is a shoe surface 3 contacted with a chain 2. An annular groove 8 is formed in the peripheral edge part of an attaching hole 6 in the flange part 5D side of the chain guide 1, an annular elliptic buffer member 7 being fitted into the annular groove 8. Its inner peripheral surface adhered to the outer peripheral surface of the large diameter part 5B of a shoulder bolt 5, and an annular gap S is formed between the attaching hole 6 of the chain guide 5 and the large diameter part 5B. By this gap S, a generated hitting sound is absorbed by the elastic buffer member and also vibration generated by contact with the chain guide is attenuated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a chain guide on a mounting surface of an engine block or the like.
In particular, the present invention relates to a mounting structure applied when a linear expansion coefficient of a mounting surface is different from a linear expansion coefficient of a chain guide.

[0002]

2. Description of the Related Art Conventionally, in a chain transmission device used for an engine or the like, as shown in FIG. 4, tension of a chain A3 bridged between a driving sprocket A1 and a driven sprocket A2. A chain guide A4 for preventing run-out of the chain A3 during traveling is disposed outside the side portion, and a tensioner device A5 for removing the slack of the chain A3 outside the loose side portion. Are located.

The tensioner device A5 includes a tensioner lever A8 having one end supported on a mounting surface A6 of an engine block or the like by a pivot pin A7 and swingably provided, and the other end of the tensioner lever A8 connected to a chain A3. And the shoe surface A10 of the tensioner lever A8 presses the slack side surface of the chain A3 by the urging force of the tensioner A9 to apply an appropriate tension to the chain A3. Has been prevented.

[0004] The chain guide A4 is
3 is made of a nylon resin material in order to reduce the resistance and vibration noise when slidingly contacting the chain A3. Have been.

FIG. 5 is a sectional view taken along the line XX in FIG. 4 and viewed in the direction of the arrow. As shown in FIG. 5, the chain guide A4 has mounting holes formed at both ends in the longitudinal direction. The large diameter portion A13 of the shoulder bolt A12 is inserted into A11, and the screw portion A14 is attached to the mounting surface A6 of the engine block or the like.
Screwed into the screw hole A15 formed in the mounting surface A
6 attached.

At this time, when the temperature of the mounting surface A6 rises due to the difference in linear expansion coefficient between the mounting surface A6 and the resin-made chain guide A4, the mounting holes A11 at both ends of the chain guide A4.
The gap between the shoulder bolt A12 and the gap between the shoulder bolts A12 screwed to the mounting surface A6 is shifted due to the difference in thermal expansion between the two. Therefore, the chain guide A4 is mounted more than the outer diameter of the large diameter portion A13 of the shoulder bolt A12. The gap S11 is provided between the two by making the inner diameter of the hole A11 slightly larger to absorb the displacement.

[0007]

In the conventional chain guide as described above, the striking sound generated between the chain and the chain guide propagates to various components such as the engine block on the mounting surface side via the shoulder bolt. In addition, there is a gap between the mounting hole of the chain guide and the large-diameter portion of the shoulder bolt inserted into the mounting hole. There has been a problem that the outer peripheral surface of the diameter portion and the inner peripheral surface of the mounting hole collide and generate noise.

When the sound generated on the side of the chain guide propagates to the mounting surface via the shoulder bolt,
There is a problem that parts with low rigidity such as chain covers and head covers resonate and generate large abnormal noise.As a countermeasure, the shape of low-rigidity parts was changed to prevent resonance. There was a problem that the cost was high.

Therefore, the present invention solves the above-mentioned problems of the prior art, interrupts the transmission of a tapping sound generated between the chain guide and the mounting surface, and generates noise due to vibration of the chain guide. It is an object of the present invention to provide a chain guide mounting structure that can prevent the occurrence of the chain guide.

[0010]

In order to achieve the above object, the present invention relates to a shoulder bolt which is fastened and fixed to a screw hole formed on a mounting surface, and has a large diameter portion formed at both ends of a chain guide. A mounting structure for a chain guide, wherein the chain guide is supported on a mounting surface by penetrating through a mounting hole having an inner diameter larger than the outer diameter of the portion, wherein the outer peripheral surface of a large-diameter portion of the shoulder bolt and the chain guide are mounted. An elastic cushioning member is interposed between the inner peripheral surface of the hole and the outer peripheral surface of the large diameter portion and the inner peripheral surface of the mounting hole.

[0011]

When the running chain comes into sliding contact with the chain guide, the elastic cushioning member is provided between the inner peripheral surface of the mounting hole at both ends of the chain guide and the outer peripheral surface of the large diameter portion of the shoulder bolt penetrating therethrough. Is formed, the hitting sound generated between the chain and the chain guide during the traveling of the chain is absorbed by the elastic cushioning member,
Transmission to the mounting surface is blocked.

Further, vibration generated in the chain guide due to sliding contact with the running chain is attenuated by the elastic buffering member, and the elastic buffering member between the outer peripheral surface of the large diameter portion and the inner peripheral surface of the mounting hole is used. Collision between the inner peripheral surface of the mounting hole and the outer peripheral surface of the large-diameter portion due to the vibration of the chain guide is avoided, and the generation of collision noise is prevented.

Further, the temperature of the mounting surface rises while the chain is running, and the distance between the center of the mounting hole at both ends of the chain guide is determined by the difference in linear expansion coefficient between the chain guide and the mounting surface.
If there is a deviation from the distance between the centers of the two shoulder bolts, the elastic cushioning member is elastically deformed, and the deviation can be absorbed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 shows a first example of a chain guide mounting structure according to the present invention.
FIG. 4 is a cross-sectional view of a chain guide mounting portion showing the embodiment,
The chain guide 1 is formed of a nylon-based resin material having low friction and high strength, and has one end surface serving as a shoe surface 3 that comes into sliding contact with the chain 2, and one side surface formed on an engine block. The mounting surface 4.

A screw hole 4A is formed in the mounting surface 4, and a screw portion 5A of the shoulder bolt 5 is screwed into the screw hole 4A, and the mounting surface 4 and the end surface of the large diameter portion 5B are in contact with each other. The shoulder bolt 5 is fixed. The large diameter portion 5B of the shoulder bolt 5 penetrates a mounting hole 6 formed in the chain guide 1. The inner diameter of the mounting hole 6 is slightly larger than the outer diameter of the large diameter portion 5B of the shoulder bolt 5, and the length L of the large diameter portion 5B is formed slightly longer than the width W of the chain guide 1. ing.

The large diameter portion 5D is formed by a flange portion 5D having an outer diameter larger than the inner diameter of the mounting hole 6 formed between the large diameter portion 5B of the shoulder bolt 5 and the bolt head 5C.
The chain guide 1 is held so as not to come off from B.

An annular groove 8 into which an annular elastic cushioning member 7 is fitted is formed on the periphery of the mounting hole 6 on the flange 5D side of the chain guide 1. The elastic cushioning member 7 is made of rubber, and its inner peripheral surface has a large diameter portion 5 of the shoulder bolt 5.
An annular gap S is formed between the mounting hole 6 of the chain guide 1 and the large diameter portion 5B in close contact with the outer peripheral surface of B.

FIG. 2 is a cross-sectional view of a chain guide mounting portion showing a second embodiment of the chain guide mounting structure of the present invention, in which portions indicated by the same reference numerals as FIG. 1 in FIG. Has the same configuration as that in FIG.

In this embodiment, a mounting hole 6A on the side of the chain guide 1A facing the flange 5D of the shoulder bolt 5 is provided.
Is chamfered to a tapered surface 8A which is opened outward, and a rubber elastic cushioning member 7A whose outer peripheral surface is formed by a tapered surface which matches the tapered surface 8A is fitted therein.

When the shoulder bolt 5 is fastened to the mounting surface 4, the elastic cushioning member 7 A is pushed by the flange 5 D to form a tapered surface forming an outer peripheral surface of the chain guide 1.
A is slightly elastically deformed by being pressed against the tapered surface 8A of the peripheral portion of the mounting hole 6A of A, and the inner peripheral surface thereof closely adheres to the outer peripheral surface of the shoulder bolt 5, and the mounting hole 6A of the chain guide 1A is Centering and mounting hole 6A
And a large-diameter portion 5B to form an annular gap S.

FIG. 3 is a cross-sectional view of a chain guide mounting portion showing a third embodiment of the chain guide mounting structure of the present invention, in which portions indicated by the same reference numerals as FIG. 1 in FIG. Has the same configuration as that in FIG.

In this embodiment, an annular groove 8B is formed in the inner peripheral surface of the mounting hole 6B of the chain guide 1B, into which a rubber elastic cushioning member 7B formed annularly is fitted. The annular groove 8B has a U-shaped or U-shaped cross section in which the inner peripheral side of the mounting hole 6B is open.
The outer peripheral surface of the large diameter portion 5B is fitted and fixed, and the inner peripheral surface thereof is in close contact with the outer peripheral surface of the large diameter portion 5B of the shoulder bolt 5.
An annular gap S is formed between B and the mounting hole 6B.

In this embodiment, since the annular groove 8B is formed on the inner peripheral surface at a position away from the peripheral edge of the mounting hole 6B, before the chain guide 1B is assembled to the mounting surface 4 with the shoulder bolt 5, Even if the elastic cushioning member 7B is previously mounted in the annular groove 8B of the mounting hole 6B, there is no danger of falling off, and there is an advantage that the assembling work can be performed efficiently.

In each of the embodiments described above, only one elastic cushioning member is provided between the mounting hole of the chain guide and the shoulder bolt, but a plurality of elastic cushioning members may be provided in the axial direction.

In each embodiment, an annular groove or a tapered surface for fitting or positioning an annular elastic buffer member is formed on the chain guide side. However, an annular groove is formed on the outer peripheral surface of the large diameter portion of the shoulder bolt. Then, an annular elastic cushioning member may be fitted therein so that its outer peripheral surface is in close contact with the smooth inner peripheral surface of the mounting hole of the chain guide.

Further, the elastic cushioning member may be disposed at a plurality of positions in the circumferential direction between the inner peripheral surface of the mounting hole of the chain guide and the outer peripheral surface of the large diameter portion of the shoulder bolt. A key groove-like linear groove is formed in the surface and the inner peripheral surface of the mounting hole in the axial direction at several locations at equal intervals in the circumferential direction.
An elastic buffer member having a width and a length suitable for these linear grooves may be fitted so that the inner peripheral surface of the mounting hole does not directly contact the outer peripheral surface of the shoulder bolt.

[0027]

According to the mounting structure of the chain guide of the present invention, since the elastic buffer member is interposed between the mounting hole of the chain guide and the large diameter portion of the shoulder bolt penetrating the mounting hole, the chain The striking sound generated between the chain and the chain guide during traveling is absorbed by the elastic cushioning member, so that transmission of the striking sound to the mounting surface side can be interrupted, and the temperature of the mounting surface during traveling of the chain decreases. If the distance between the center of the mounting hole at both ends of the chain guide and the distance between the centers of the two shoulder bolts is raised due to the difference in linear expansion coefficient between the chain guide and the mounting surface, The elastic cushioning member is elastically deformed, so that the displacement can be absorbed.

Further, the vibration caused in the chain guide due to the sliding contact with the running chain is attenuated by the elastic buffer member, and the elastic buffer member is provided between the outer peripheral surface of the large diameter portion and the inner peripheral surface of the mounting hole. Since the annular gap is always formed, collision between the two is avoided even if the chain guide vibrates, and the generation of collision noise can be prevented.

Further, it is not necessary to increase the rigidity of a member which is likely to resonate on the mounting surface side of the chain guide, and an elastic cushioning member is added to the conventional chain guide, and details of the molding die of the chain guide are modified. This alone can prevent the generation of noise from the chain guide, and can greatly reduce costs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a chain guide mounting portion showing a first embodiment of a chain guide mounting structure of the present invention.

FIG. 2 is a sectional view of a chain guide mounting portion showing a second embodiment of the chain guide mounting structure of the present invention.

FIG. 3 is a cross-sectional view of a chain guide mounting portion showing a third embodiment of the chain guide mounting structure of the present invention.

FIG. 4 is a diagram showing an example of use of a conventional chain guide.

FIG. 5 is a diagram viewed in a direction of an arrow at a position of line XX in FIG. 5;

[Explanation of symbols]

 1, 1A, 1B Chain guide 2 Chain 3 Shoe surface 4 Mounting surface 4A Screw hole 5 Shoulder bolt 5A Screw portion 5B Large diameter portion 5C Bolt head 5D Collar portion 6, 6A, 6B Mounting hole 7, 7A, 7B Elastic cushioning member 8, 8B Annular groove 8A Tapered surface S Clearance

Claims (1)

[Claims] 1. A large-diameter portion of a shoulder bolt fastened and fixed to a screw hole formed in a mounting surface is connected to a mounting hole having an inner diameter larger than an outer diameter of the large-diameter portion formed at both ends of a chain guide. In the mounting structure of the chain guide, wherein the chain guide is penetrated to support the chain guide on the mounting surface, an elastic buffer member is interposed between the outer peripheral surface of the large diameter portion of the shoulder bolt and the inner peripheral surface of the mounting hole of the chain guide. Wherein the outer peripheral surface of the large diameter portion and the inner peripheral surface of the mounting hole are separated from each other.