JPS5965632A - Vibration-isolating rubber - Google Patents

Abstract

PURPOSE:To improve durability of an entire vibration-isolating rubber, by a method wherein, in a vibration-isolating rubber used in the engine mount of a car, the compression strain of a compression deforming part is decreased over the shearing strain of a shearing deforming part during static load. CONSTITUTION:An elastic rubber body 1 has a compression deforming part 1a and shearing deforming part 1b which are mainly deformed by compression and shearing, respectively, during static load, and is vulcanized for adhesion to a cylindrical inner tube 2 and 2-split outer tubes 3a and 3b. When the outer tubes 3a and 3b are fastened to a bracket 5, the outer tubes 3a and 3b are pulled from each other in the direction in which the compression deforming part 1a is stretched, and are secured in a condition, in which a preliminary load is applied, by means of nuts 12a and 12b. Thus, when a static load is applied, the compression deforming part 1a is reduced in a compression deforming amount to decrease the compression strain of the compression deforming part 1a, resulting in extension of the limit of endurance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to anti-vibration rubber used for automobile engine mounts and the like.

As a conventional anti-vibration rubber, the one shown in FIG. 1 is known, for example, and its structure is such that an inverted T-shaped rubber elastic body 1 is placed between an inner cylinder 2 and an outer cylinder 3. A compressive deformation section 1a that is vulcanized and adhesively deforms mainly due to the static load applied to the im elastic body 1 when the inner cylinder 2 is fixed to a vehicle body etc. and the outer cylinder 3 is connected to a power unit etc. and a compressive deformation section 1a that mainly undergoes shearing. Shear deformation section 1b that deforms.

1b in the rubber elastic body 1.

The load P applied to the rubber elastic body 1 and its displacement δ show the characteristics shown in FIG. Load-
The dotted line G represents the load-displacement characteristic of the shear deformation portion 1b. Further, it is shown that when a static load (IG) is applied by the power unit of an automobile, the displacement is m.

Generally speaking, if the same strain is generated during use when the same rubber is used in shrinkage and shearing, the durability when used in sheared form is 15 to 15 times higher than the durability when used in compressive deformation. We know it will double.

However, in the conventional anti-vibration rubber, the IIE shrinkage deformation ζ1 of the rubber elastic body 1 when a static load is applied.
Since the amount of deformation of the rubber elastic body IG and the amount of deformation of the shear deformation portion 1b are the same, the compressive strain and the shear strain are almost the same. This had the disadvantage of causing cracks, etc., and reducing the durability of the anti-vibration rubber.

The present invention was made to solve the above-mentioned problems, and its purpose is to make the E contraction strain of the compressive deformation part under static load smaller than the shear strain of the shear deformation part. The object of the present invention is to provide a vibration isolating rubber that has the same durability as the whole of the vibration isolating rubber.

That is, in order to achieve this object, the present invention provides an outer cylinder in which one end of each is divided into at least two parts, a compression deformation part which mainly takes the shape of Ei: and a contraction shape, and a shear deformation part which mainly deforms in shear. The other end is bonded to the inner part, and the outer cylinder is pulled in the direction in which the compressively deformed part extends ([F], and the outer cylinder divided into two parts in the pre-fI & load-applied state due to this separation is I fixed it to the bracket and made it bZ.

Is this the compressed 1R-shaped part of the rubber elastic body in the vibration isolator of the present invention? Because it has been deformed in tension in advance as opposed to compression, when a static load is applied, the amount of compression deformation in the compression deformation part becomes smaller, reducing the compressive strain in the compression deformation part and extending the durability limit. The durability of anti-corrosion rubber can be improved (111).

Hereinafter, one embodiment of the present invention Fl''J will be explained in detail.

In describing this embodiment, we will take as an example the anti-resistance rubber used in the engine mount of an automobile, and the same reference numerals will be given to the same 115 parts as in the conventional structure.

No. 31 (・1) This shows the state in which the anti-vibration rubber D of the first embodiment is installed. The bracket 5 of anti-vibration rubber D is fixed to the power unit side bracket 4, and the anti-vibration rubber D is fixed to the bracket 6 of the vehicle body 4u:1. The inner cylinder 2 made of rubber D is fixed with bolts 7 and nuts 8, and the power unit 9 and the vehicle body 10 are mounted so as to be supported through the rubber elastic body 1.

In other words, when the anti-vibration rubber D is installed, the weight of the power unit 9 is applied to the rubber elastic body 1 as a static load, and when the engine is started or running, a dynamic load is applied to the rubber elastic body 1 around the position of displacement due to the static load. It is added to.

Next, the structure of the vibration isolator D of the first embodiment shown in FIG. The inner cylinder 2 has a cylindrical shape and the outer cylinder 3a is divided into two, and has shear deformations 1plb and Ib.

3b is vulcanized and bonded. 3a and 3b are outer cylinders, and the compressive deformation part 1a and the shear deformation part 1b, 1 of the im elastic body 1 are
b are vulcanized and bonded, respectively, and male screw members 11&, llb are provided protruding from the end surfaces of the outer cylinders 3a, 3b.

As shown in Fig. 4 (4), in the no-load state, 4
As shown in FIG. 4(B), the entire length of the im elastic body 1 is separated in the direction in which the compression deformation portion 1a of the outer cylinders 3a and 3b'f is extended, and the preloading state due to this separation is state 2
Attach the divided outer cylinders 3a and 3b to the bracket 5 with the nut 12a.
, 12b, the total length of the rubber elastic body 1 is reduced to A(
>7. ).

Therefore, as shown in the load-displacement characteristic graph of FIG. 5, the compressive deformation portion 1a of the rubber elastic body 1 is already deformed in the tensile direction opposite to the compressive direction in the no-load state, as shown by the dashed line F. Therefore, when the inner cylinder 2 is fixed and a load is applied to the bracket 5, the deformation of the compressive deformation part 1a in the tensile direction due to the preload becomes smaller and becomes zero at 8 points. After that, it is compressed and deformed, and the static load (
When IG) is applied, the overall displacement is n, but the actual displacement of the compressive deformation portion 1a is q.

In this way, in the first embodiment, the compressive strain of the compressively deformable portion 1a, which suffers from significant durability deterioration, can be significantly reduced compared to the conventional method in which no preload is applied, and the load of the compressively deformable portion 1a can be significantly reduced. Because the burden can be reduced,
This can completely improve the durability of anti-vibration rubber.

However, since a preload is applied to the shear deformation parts 1b and 1b in the direction of shear deformation, the shear deformation parts 1b and lb already have a substantial shear displacement amount r even in the no-load state, as shown by the dotted line G in FIG. When a static load (1G) is applied,
While the overall displacement is n length, the shear deformation part 4
b, l b (7) Substantive love becomes n+r, and shear deformation part 1b.

Although the durability of 1b is worse than before, the value of shear tension of shear deformation part 1b, IL+ is [(More shrinkage deformation part 1
At 1゛, which does not exceed about twice the value of 1 + shrinkage strain of a, the durability of shear deformation part 1b, lb] E shrinkage picture sound 1! It cannot be lower than the durability of lla.

Next, the second embodiment shown in FIG. 6 will be explained. This embodiment is a plan to reduce the durability of the vulcanized adhesive part of the shear deformation parts 1b and 1b, and is shown in FIG. 6(A). As shown, the shear deformation parts 1b and lb are applied (i+if the outer cylinder 3
b is opened outward in advance, and after the shear deformation parts 1b and lb are vulcanized and bonded, the outer cylinder 3b is deformed inward.

Therefore, in this second embodiment,
Since a preload is applied to [
Not only can the durability be improved by reducing the shrinkage strain of the E-phase deformation part 1a, but also the shear IWf deformation and the vulcanization bonding part of [(Ib, lb) are provided with a spare cart in order to reduce the shear strain. Therefore, the durability of the shear deformation parts Ib and ib is improved compared to Example 91, and overall durability can be expected to be the same.

Next, the sixth embodiment shown in FIG. 7 will be explained.
This actual i=x example is basically the same as the second example (in terms of structure and function, the difference is that the rubber elastic body 1
Stoppers 1c+1d and Iti are formed on the sides, and when a certain amount of displacement occurs, the amount of displacement is regulated by mutual contact of the rubber.

Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment. If it has a shear deformation part that shear deforms to
It is not limited to the shape of the example.

Further, the outer cylinder divided into two parts may be fixed to the bracket using fixing means such as bolts and nuts, or by other fixing structures.

[Brief explanation of the drawing]

Figure 1 shows a half cross section of a conventional anti-vibration rubber IY4. m2 diagram is load-displacement\If graph graph 3 using conventional anti-vibration rubber.
The figure does not show the state in which the anti-vibration rubber of the present invention is used in the engine mount of an automatic transmission.
FIG. 5 is a half-sectional view showing the anti-vibration rubber of the example. graph,? J',
6 II Lll fr 2 actual fb example (7') l:#
Figure 1 (B IA, Figure 7 is a 1-half-white diagram showing the rubber of the third embodiment. 1...Rubber elastic body, 1a...Tatari) e!l-shaped part, 1b
... Shear deformation F section, 2... Inner cylinder, 3a, 3b... External, 5... Bracket. Patent applicant Nissan Motor Co., Ltd. No. 10 Whistle 3 mouth・-1'+ u-'+- 0/'

Claims (1)

[Claims] 1) In a vibration isolator in which a rubber elastic body is interposed between a cylinder and an outer cylinder, the rubber elastic body has a compression deformation part that mainly undergoes compression deformation and a shear deformation part that mainly undergoes shear deformation in response to a static load. The compression deformation part and the shear deformation part of the elastic body are each vulcanized and adhered to an outer cylinder divided into at least two parts, and the outer cylinder is separated in the direction in which the compression deformation part extends, and a preload is applied by this separation. Anti-vibration rubber characterized by a two-part outer cylinder fixed to a bracket.