JP2000346134A - Bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bush capable of securing enough durability, and securing an enough elastic support ability. SOLUTION: This bush comprises a spindle fitting 1, an outer cylinder fitting 2 coaxially disposed at a distance on the outside of the spindle fitting 1, and a rubber elastic body 3 interposed between the spindle fitting 1 and the outer cylinder fitting 2 to integratedly connect them, and having a pair of recesses 31, 32 provided on both sides of the spindle fitting 1 in a main vibration input direction in the radial direction and penetrated axially. The rubber elastic body 3 is provided on both sides in the circumferential direction of central spaces 33, 36 formed between surfaces opposed to each other in the main vibration input direction of in the recesses 31, 32, and having a pair of protruding parts (34a, 34b) (37a, 37b) protruded from the opposite surface on the side of the outer cylinder fitting 2 to abut on the opposite surface on the side of the spindle fitting 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bush suitably used as a differential mount, a suspension bush, a trailing bush, and the like in a vehicle.

[0002]

2. Description of the Related Art Conventionally, for example, when a differential is mounted on a vehicle, a bush has been used as a differential mount for supporting the differential on a vehicle body. As shown in FIGS. 5 and 6, the bush 4, an outer tube 5 coaxially arranged outside the main shaft 4 at a distance, and the main shaft 4 and the outer tube as such a bush. And a rubber elastic body 6 having a pair of axially penetrating fins 61 and 62 provided on both sides of the spindle metal fitting 4 in the radial main vibration input direction. Are known.

This bush is used by connecting and fixing the main shaft fitting 4 to one of the mounting portions of the vehicle body and the differential, and connecting and fixing the outer cylindrical fitting 5 to the other mounting portion. You. In this case, the rubber elastic body 6 is attached such that a pair of bulges are located at positions along the main vibration input direction (the load input direction of the differential) in the radial direction of the bush.
When vibration is input to the bush, the rubber elastic body 6 is elastically deformed, and the vibration is effectively attenuated.

[0004]

By the way, the conventional bush described above is provided with a pair of bulges 61, 62 on both sides of the main shaft fitting 4 in the main vibration input direction of the rubber elastic body 6, so that when the vibration is input. The compressive strain and tensile strain of the rubber elastic body 6 generated are reduced, and the durability is improved. Further, by providing the pair of threads 61 and 62, the spring constant ratio in two directions, that is, the main vibration input direction and the direction orthogonal thereto, is appropriately set. Therefore, a pair of curls 61 and 62 provided on the rubber elastic body 6 are provided.
The shape, size, etc. of the bush are selectively determined according to the durability and spring characteristics required for the bush.

However, in the above-described conventional bush, since a pair of bulges 61 and 62 are provided along the main vibration input direction, the spring constant in the main vibration input direction is reduced.
For this reason, there is a problem that a bush that elastically supports the differential mounted on the vehicle body cannot secure a sufficient elastic supporting ability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a bush capable of securing sufficient durability and sufficient elastic supporting ability. Is what you do.

[0007]

According to a first aspect of the present invention, there is provided a spindle fitting, an outer cylindrical fitting coaxially disposed outside the spindle fitting at a distance from the spindle fitting, and the main spindle fitting. And an outer cylinder fitting interposed therebetween to integrally connect them, and a rubber elastic body having a pair of axially penetrating holes provided on both sides of the main spindle fitting in a radial main vibration input direction. And the rubber elastic body is provided on both sides in the circumferential direction of a central space formed between opposing surfaces in the main vibration input direction of each of the beams, and protrudes from one of the opposing surfaces. Means having a pair of protruding portions each contacting the other opposing surface.

According to this means, since each of the rubber elastic members is provided with a pair of projecting portions projecting from one opposing surface and abutting on the other opposing surface, the spring in the main vibration input direction is provided. The constant is increased, and good elastic support capacity of the bush is secured.

Further, since a central space where the opposing surfaces do not come into contact with each other is formed in a portion between the pair of projecting portions of each beam, when vibration is input in the main vibration input direction, the main shaft of the rubber elastic body is formed. The compressive stress generated on the side where the metal fitting and the outer metal fitting approach each other is appropriately distributed to the pair of protrusions on both sides of the central space, and the compression strain of the rubber elastic body is effectively reduced. At this time, on the side where the main shaft metal fitting of the rubber elastic body and the outer cylindrical metal fitting are separated, the pair of projecting portions that have been in contact with each other are easily separated from the facing surface, so that no tensile strain is generated. Therefore, good durability of the rubber elastic body and, by extension, the bush is ensured.

Therefore, according to the bush of the present invention,
Sufficient durability and sufficient elastic support capacity can be ensured.

According to a second aspect of the present invention, in the first aspect of the present invention, each of the projecting portions is formed on the other facing surface by subjecting the outer cylindrical fitting to drawing and compressing the rubber elastic body. The means of contact is adopted.

According to this means, durability can be improved by pre-compressing the rubber elastic body, and at the same time, the state of contact between each protruding portion and the opposing surface can be easily formed. In this specification, the term “contact” refers to a state in which a gap is not formed between the protruding portion and the opposing surface facing the protruding portion. Including the state.

According to a third aspect of the present invention, in the first aspect of the present invention, each of the projecting portions extends over a portion overlapping the main spindle in the main vibration input direction and a portion outside the main spindle. Is adopted.

According to this means, even when vibration is input from a direction deviated to some extent from the main vibration input direction, a stable contact state between each protruding portion and their opposing surfaces can be obtained. The allowable range in the direction can be widened.

According to a fourth aspect of the present invention, in the first aspect of the present invention, each of the projecting portions is formed to have a tapered shape in an axial section.

According to this means, it is possible to easily realize the non-linear characteristic in the spring characteristic in the main vibration input direction.

According to a fifth aspect of the present invention, in the first aspect of the invention, at least one of the contact surfaces between each of the projecting portions and the other facing surface is provided with irregularities or embossments. Is adopted.

According to this means, it is possible to prevent abnormal noise caused by friction between each protruding portion and the opposing surface.
These irregularities and embossments can be easily formed by transferring from a mold surface of a vulcanization mold that forms a rubber elastic body. In addition, it is preferable that the unevenness and the grain have a height difference of 1 mm or less.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a bush according to the present embodiment, FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is a cross-sectional view of a portion corresponding to line III-III in FIG.

As shown in FIG. 1, the bush according to the present embodiment comprises a spindle metal fitting 1, an outer cylindrical metal fitting 2 arranged coaxially at a distance outside the main spindle metal fitting 1, a spindle metal fitting 1, and an outer cylindrical metal fitting. The two are integrally connected by being interposed between the metal fitting 2 and the first and second beams 31, 32 and the four projecting portions 34a, 34b, 3
And a rubber elastic body 3 having 7a and 37b as main components.

The spindle fitting 1 is formed in a pipe shape from a metal such as steel.

The outer tube fitting 2 is formed in a cylindrical shape by a metal plate such as steel, and is coaxially arranged outside the main shaft fitting 1 at a distance. The outer tube 2 has an inner diameter that is larger than the outer diameter of the main shaft 1 by a predetermined dimension, and is formed to be slightly shorter than the main shaft 1.

The rubber elastic body 3 is formed in a substantially cylindrical shape by vulcanizing and molding a rubber material together with the main shaft 1 and the outer tube 2. The rubber elastic body 3 is used for the main spindle 1
Are vulcanized and bonded to the inner peripheral surface of the outer tube fitting 2 and are interposed therebetween to integrally connect the two.
On both sides of the main spindle 1 in the main vibration input direction in the radial direction of the rubber elastic body 3, a pair of first and second beams 31 and 32 penetrating in the axial direction are provided so as to be axially symmetric. .

On both sides in the circumferential direction of a central space 33 formed between opposing surfaces of the first beam 31 in the main vibration input direction, the central space 33 protrudes from the opposing surface on the side of the outer cylinder fitting 2, and protrudes from the main shaft fitting 1 side. A pair of projecting portions 34a, 34b abutting on the opposing surface
Is provided. The protrusions 34a and 34b are formed in a tapered shape in an axial cross section, and formed in a mountain shape slightly extending in a circumferential direction. Each protrusion 34a,
Reference numeral 34b is provided at a position straddling a portion that overlaps with the main shaft 1 in the main vibration input direction and a portion that is outside the main shaft 1. The protrusions 34a and 34b are provided with protrusions and recesses having a height difference of 1 mm or less on the protrusion tip surfaces. It should be noted that side spaces 35a and 35b are formed on the outer sides in the circumferential direction of the protruding portions 34a and 34b, respectively, between opposing surfaces facing each other in the main vibration input direction.

A pair of projections 34 of the first beam 31 are provided on both sides in the circumferential direction of the central space 36 of the second beam 32.
a, a pair of protrusions 37 formed in the same shape as 34b
a and 37b are provided to be axially symmetric. Further, side spaces 38a and 38b are formed on the outer sides in the circumferential direction of the protruding portions 37a and 37b, similarly to the side spaces 35a and 35b of the first beam 31.

As shown in FIG. 4, this rubber elastic body 3 is formed by vulcanization molding together with the spindle metal fitting 1 and the outer cylindrical metal fitting 2, and then the outer cylindrical metal fitting 2 is subjected to drawing processing to form a whole. Are pre-compressed by reducing the diameter. By performing the drawing process, each of the protrusions 34a, 34
The distal end surfaces of b, 37a, and 37b are in contact with opposing surfaces thereof.

The bush of the present embodiment configured as described above is used as a differential mount for supporting a differential mounted on a vehicle on a vehicle body in a vibration-proof manner. That is, the spindle metal fitting 1 is connected and fixed to one of the mounting portions of the vehicle body and the differential with mounting bolts, and the external metal fitting 2 is press-fitted and connected and fixed to one of the other mounting portions. . In this case, the rubber elastic body 3 is mounted such that the pair of bulges 31 and 32 are located at positions along the main vibration input direction (the load input direction of the differential) in the radial direction of the bush. As a result, each of the curves 31 and 32 of the rubber elastic body 3 has a pair of protrusions (34a and 34) that are in contact with the opposing surfaces.
b) Since (37a, 37b) is provided, the spring constant in the main vibration input direction is increased, and a good elastic support capability of the bush is secured.

When vibration is input to the bush, the rubber elastic body 3 is elastically deformed, and the vibration is effectively attenuated. At this time, each curry 31,
32 pairs of protrusions (34a, 34b) (37a, 37
Since the central spaces 33 and 36 are formed in the portion between b), the compressive stress of the rubber elastic body 3 generated on the side of the rubber elastic body 3 where the main shaft metal fitting 1 and the outer cylindrical metal fitting 2 approach each other, A pair of protrusions (34a, 34b) on both sides of the spaces 33, 36
(37a, 37b), and the compressive strain of the rubber elastic body 3 is effectively reduced.

On the other hand, on the side of the rubber elastic body 3 where the main shaft 1 and the outer tube 2 are separated, a pair of projecting portions (3
4a, 34b) (37a, 37b) and the opposing surface are easily separated from each other, so that no tensile strain is generated. Therefore, good durability of the rubber elastic body 3 and thus the bush is secured.

As described above, according to the bush of this embodiment, each of the beams 31 and 32 of the rubber elastic body 3 has the central space 33 formed between the opposing surfaces in the main vibration input direction. A pair of protrusions (34a, 34b) (37a, 37b) are provided on both sides in the circumferential direction of 36 so as to protrude from the facing surface on the side of the outer cylindrical fitting 2 and abut on the facing surface on the side of the spindle fitting 1, respectively. Sufficient durability and sufficient elastic support capacity can be ensured.

In the present embodiment, a pair of protrusions (34a, 34b) (37a, 37b) are provided so as to protrude from the outer cylinder fitting 2 toward the main spindle fitting 1, respectively. They may be provided so as to protrude from the main shaft 1 toward the outer tube 2 so that their protruding directions are opposite.

Then, the respective projecting portions 34a, 3a of this embodiment
4b, 37a and 37b are made by pressing the rubber elastic body 3 by pressing the outer cylindrical metal fitting 2 and compressing the rubber elastic body 3 so that the rubber elastic body 3 comes into contact with the opposing surfaces thereof. At the same time, the contact between the projecting portions 34a, 34b, 37a, and 37b and the facing surface can be easily formed.

The projections 34a, 34 of the present embodiment
Since b, 37a, and 37b are provided at positions that straddle the portion that overlaps with the main spindle 1 and the part that is outside the main spindle 1 in the main vibration input direction, vibrations occur in directions somewhat deviated from the main vibration input direction. Even when an input is made, a stable state of contact between the protruding portions 34a, 34b, 37a, 37b and their opposing surfaces can be obtained, and the allowable range in the vibration input direction can be widened.

Further, each of the projecting portions 34a, 34 of this embodiment
Since b, 37a, and 37b are formed to have a tapered shape in the axial section, non-linear characteristics in the spring characteristics in the main vibration input direction can be easily realized.

Further, in the present embodiment, each projection 3
Since the protrusions 4a, 34b, 37a, and 37b are provided with protrusions and recesses, the protrusions 34a, 34b, 37
It is possible to prevent abnormal noise generated due to friction between the a and 37b and these opposing surfaces.

[Brief description of the drawings]

FIG. 1 is a front view of a bush according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a cross-sectional view of a portion corresponding to line III-III in FIG.

FIG. 4 is a front view showing a state before drawing processing is performed on an outer cylindrical metal fitting of the bush according to the embodiment of the present invention.

FIG. 5 is a front view of a conventional bush.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

[Explanation of symbols]

1,4 ... Spindle bracket 2,5 ... Outer tube bracket 3,6
... rubber elastic body 31 ... first curving 32 ... second curving 33,
36 ... central space 34a, 34b, 37a, 37b ... projecting part 35,
38: Side space 61, 62: Currant

Claims (5)

[Claims] 1. A spindle metal fitting, an outer cylinder metal arranged coaxially at a distance outside the main spindle metal, and interposed between the main spindle metal and the outer cylinder metal to integrally form the two. Concatenate,
A rubber elastic body having a pair of axially penetrating lugs provided on both sides of the main shaft fitting in the radial main vibration input direction, wherein the rubber elastic body has the main vibration of each of the lugs. It is provided on both sides in the circumferential direction of the central space formed between the opposing surfaces facing each other in the input direction, and has a pair of projecting portions projecting from one opposing surface and abutting on the other opposing surface. bush. 2. The method according to claim 1, wherein each of the protruding portions is in contact with the other facing surface by performing drawing processing on the outer cylinder and compressing the rubber elastic body.
The bush described. 3. The device according to claim 1, wherein each of the projecting portions is provided at a position straddling a portion overlapping with the main spindle in the main vibration input direction and a portion outside the main spindle. Bush. 4. The bush according to claim 1, wherein each of the protrusions is formed to have a tapered shape in an axial cross section. 5. The bush according to claim 1, wherein at least one of the contact surfaces between each of the projecting portions and the other facing surface is provided with irregularities or embossments.