JPH06249282A - Vibrationproof rubber - Google Patents

Abstract

PURPOSE:To provide a vibrationproof rubber without necessity of rustproofing treatment on a mechanical connected part formed out of Al die casting. CONSTITUTION:This vibrationproof rubber is constituted of a main body rubber part 41, and a mechanical connected part 51 vulcanizedly jointed with a main body rubber part 41. It is featured that the whole or the one part of the mechanical connected part is formed out of Al alloy die casting, and the Al alloy is Al-Mg series alloy containing Mg: 3.0-5.0%, Mn: 0.2-0.6%, Si: 0.5-1.0%, Be: 0.002-0.004%, as essential components except Al.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration rubber having a main body rubber portion and a mechanical connecting portion vulcanized and adhered to the main body rubber portion. In particular, anti-vibration rubber that requires a high degree of corrosion-resistant adhesiveness between the mechanical coupling part made of metal and the rubber part of the main body, such as engine mounts of automobiles that are susceptible to salt damage due to coastal running and snowy road running. Is a suitable invention. As used herein, the term "corrosion resistance" means the durability of adhesion between the rubber part and the mechanically bonded part in a metal corrosive atmosphere.

Although a liquid-sealed engine mount will be mainly described as an example of the vibration-proof rubber, the present invention is also applicable to other vibration-proof rubbers such as engine mounts, strut mounts, bumper rubbers, and bush rubbers. It is possible.

In the present specification, "parts" and "%" are weight units unless otherwise specified.

[0004]

2. Description of the Related Art FIG. 1 shows an example of a conventional liquid ring engine mount.

A partition plate 15 having a conduction groove 13 and a diaphragm 17 are provided in a cavity C for the upper liquid chamber formed in the lower central portion of the main body rubber portion 11, and a lower mounting plate portion (cap) 19 is provided. Assemble by. Here, the upper mounting plate portion 21 and the cylindrical main body insert portion 23 are integrated with the main rubber portion 11 by vulcanization adhesion. And
The partition plate 15 and the diaphragm 17 have flange portions 1
5a and 17a are engagement step portions 23 of the body insert portion 23.
a and the receiving step portion 19a of the lower mounting plate portion 19, and the upper liquid sealing chamber 2 is provided above and below the partition plate 15 respectively.
5 and the lower liquid sealing chamber 27 are formed. In addition, the upper and lower mounting plate portions 21 and 19 have mounting bolts 29 and 31 respectively.
It is equipped with. Further, the upper mounting plate portion 21 is provided with a stopper fitting 33 that interferes with the upper mounting plate portion 19 when assembled to the engine. In addition, each liquid sealing chamber 25, 2
A glycol-based fluid is usually enclosed in 7.

[0006]

However, in the case of the engine mount having the above-mentioned structure, the mechanical connecting portions such as the upper and lower mounting plate portions 21 and 19 and the main body insert portion 25 are usually iron-based from the viewpoint of strength. Since the sheet metal is pressed or cast from an iron-based casting, it is necessary to rust preventive treatment such as zinc plating and painting on each component, and the weight is increased.

Therefore, it is considered and proposed to form all or a part of the parts of the mechanical coupling portion by an Al alloy die casting which is lighter in weight than an iron-based material (Japanese Utility Model Publication No. 2-21348). etc). However, ADC12 (Al-Si-) having mechanical strength required for engine mounts is used.
With Cu-based alloys for die casting, it has been difficult to satisfy the characteristics required for engine mounts in terms of corrosion resistance (see Tables 1 and 2).

For this reason, it is necessary to subject the parts of the mechanical coupling portion to rust prevention treatment such as zinc plating and painting.

In view of the above, the present invention provides a main body rubber portion and a vibration isolating rubber which is a mechanical joint portion that is vulcanized and adhered to the main body rubber portion. In the mechanical joint portion formed by Al die casting, The purpose is to provide a vibration-proof rubber that does not require rust treatment.

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention, in the process of diligently developing the Al-Mg-based Al alloy for die casting, which has a specific composition, mechanically In addition to strength, it was found that the anti-vibration rubber satisfies the required properties in terms of corrosion resistance, and the present invention has the following constitution.

In the anti-vibration rubber to be a main body rubber portion and a mechanical joint portion capable of being vulcanized and bonded to the main body rubber portion, all or a part of the mechanical joint portion is formed by Al alloy die casting, and an Al alloy However, Mg: 3.
0-5.0%, Mn: 0.2-0.6%, Si: 0.5
To 1.0%, Be: 0.002 to 0.004%, and is an Al-Mg system.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIG.

(1) A partition plate 45 having a conduction groove 43 formed in a cavity C for the upper liquid chamber formed in the lower central portion of the main body rubber portion 41, and a diaphragm 47 are attached to a lower mounting block (cap). ) Assemble with 49. here,
An upper mounting block 51 and a main body insert portion 53 are integrated with the main rubber portion 41 by vulcanization adhesion. The flanges 45a and 47a of the partition plate 45 and the diaphragm 47 are sandwiched between the engaging step 53a of the body insert 53 and the receiving step 49a of the lower mounting block 49, and the partition plate 45 An upper liquid sealing chamber 55 and a lower liquid sealing chamber 57 are formed above and below, respectively. Further, mounting stud bolts 59 and 61 are screwed into the upper and lower mounting blocks 51 and 49, respectively. Further, the upper mounting block 51 includes a vibration-proof rubber main body (upper mounting block 51 + main body rubber portion 41 + main body insert portion 53).
The lower mounting block 49 and the lower mounting block 49 are engaged and integrated with each other, and a stopper-cum-assembly metal fitting 63 that interferes with the upper mounting block 49 when mounted on the engine is mounted. Up to this point, the basic configuration is similar to the above-mentioned conventional example.

(2) In the above structure, in this embodiment, the upper mounting block 51 and the lower mounting block 49, which are a part of the mechanical coupling portion requiring high strength, are formed by Al alloy die casting. The upper mounting block 51 is
From the viewpoint of vulcanization adhesive bondability with the main body rubber portion 41, etc., it has an uneven shape.

The Al alloy, which is a die casting material, contains Mg: 3.0 to 5.0 as an essential component in addition to Al.
%, Mn: 0.2 to 0.6%, Si: 0.5 to 1.0
%, Be: 0.002-0.004%, Al containing
-Mg system. This Al alloy usually contains Fe, Cu, Zn, Ni, etc. in an amount of less than 1% as an impure component, although it is desirable that the amount is small (see Table 1). The action of each of the above essential components is presumed to be as follows.

[0016] Mg has a function of forming a solid solution with Al and increasing mechanical strength without impairing corrosion resistance. If it is less than 3.0%, the mechanical strength tends to have a problem, and if it exceeds 5.0%, the fluidity (die casting property) tends to have a problem.

Like Mg, Mn also has a function of forming a solid solution with Al to increase the mechanical strength, but here, the addition of a small amount thereof has the function of preventing the occurrence of stress corrosion.
If it is less than 0.2%, it is difficult to prevent the stress corrosion from occurring.
On the other hand, when it exceeds 0.6%, a problem tends to occur relatively in fluidity (die casting property).

Si has the function of imparting fluidity (die casting property) to the alloy material. If it is less than 0.5%, it is difficult to secure the die casting property, and if it exceeds 1.0%, the corrosion resistance and the mechanical strength are likely to be adversely affected.

Be added with a very small amount has an antioxidant effect, and has the effect of improving the corrosion resistance without adversely affecting the mechanical strength and the like. If Be is less than 0.002%, the effect of Be addition is hard to be exerted, and even if it exceeds 0.004%, the effect of addition is not significantly increased.

(3) Then, in the vibration-proof rubber main body, the upper mounting block 49 and the main body insert portion 53 are set in the product cavity of the molding die (not shown), and the vibration-proof rubber material is injected into the cavity. And mold. As the molding material for the main rubber portion, natural rubber having good vibration damping properties or ethylene propylene rubber having good heat resistance is used.

At this time, the upper mounting block 49 is subjected to a surface roughening treatment by sandblasting or the like and then a primer treatment as in the conventional case. As the primer, a phenol type can be preferably used.

Since the main body insert portion 53 which is another mechanical coupling portion is not required to have a large mechanical strength,
In the illustrated example, it is formed of a rough surface molded body of inorganic fiber reinforced plastic, but it may be formed of the Al alloy material used for the upper mounting block.

Also, the stopper-fitting metal fitting 63 is
Although it is made of sheet metal as in the conventional example, it may be made of the aluminum die casting material used in the present invention.

(4) Physical properties tests were performed on the molded items (test pieces) die-cast with the Al alloy materials having the respective compositions shown in Table 1 for the items shown in Table 2, and the results are shown in Table 2. . The physical property test methods were as follows.

Mechanical strength: Using JIS Z 2201 No. 4 test piece, the tensile strength was measured and evaluated according to the method of JIS Z 2241.

Corrosion Resistance Adhesion Test: A pair of die cast moldings whose adhesive surface is treated with a phenolic primer (25
A cylindrical rubber molding having a length of φ12 mm × 10 mm was molded integrally by vulcanization adhesion (vulcanization condition: 150 ° C. × 5 minutes) during a period of × 35 × 3 mmt) to prepare a test piece. Regarding the test piece,
Keep the rubber molded part stretched 20% JIS Z2371
The salt spray test was carried out in accordance with the above, and the time until the rubber molding part peeled from the die-cast molding was measured and evaluated.

From Table 2, Al--Mg-- used in the present invention
It can be seen that the Si-based alloys (Examples 1 and 2) have high mechanical strength and also have good corrosion resistance. On the other hand, it can be seen that the ADC 12 has no problem in mechanical strength, but has a problem in corrosion resistance. ADC6
Shows that the corrosion resistance is not a problem, but there is a problem in mechanical strength.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

The vibration-proof rubber of the present invention is a vibration-proof rubber which is a main body rubber part and a mechanical connection part capable of being vulcanized and bonded to the main body rubber part. To
By forming the Al alloy die-cast with the above-mentioned specific composition, the following actions and effects are exhibited.

The die-casting material of the Al alloy die-casting forming all or part of the mechanical joint portion of the present invention has a sufficiently high mechanical strength and a high degree of corrosion resistance.

Therefore, the rustproofing treatment of the mechanical joint formed by the Al die casting is unnecessary. Therefore, it is possible to reduce the number of manufacturing steps and costs of the vibration proof rubber as a whole.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a conventional example of a liquid ring engine mount (anti-vibration rubber).

FIG. 2 is a sectional view showing an embodiment of a liquid ring engine mount to which the present invention is applied.

[Explanation of symbols]

 11 main body rubber part 21 upper mounting plate part (mechanical coupling part) 23 main body insert part (mechanical coupling part) 41 main body rubber part 45 partition plate 47 diaphragm 49 lower mounting block (mechanical coupling part) 51 upper mounting block (machine 53) Main body insert part (mechanical connection part)

Claims (1)

[Claims] 1. A vibration-proof rubber comprising a main body rubber portion and a mechanical joint portion vulcanized and adhered to the main body rubber portion, wherein all or a part of the mechanical joint portion is formed of an Al alloy die cast. , The Al alloy as an essential component other than Al Mg: 3.0 to 5.0%, Mn: 0.2 to 0.6%, Si: 0.5 to 1.0%, Be: 0.002 The anti-vibration rubber is an Al-Mg system containing 0.004% to 0.004%.