JPH1182752A - Sealing device with sound insulating seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten sound insulating effect by constituting a sound insulating seal by installing first sound insulating members and second sound insulating members which are thin and have low rigidity and arranging the second insulating members in series with the first members in the axial direction while contacting the inner circumferences of the second sound insulating members with a movable axis in a manner the second sound insulating members can freely slide. SOLUTION: This sealing device with a sound insulating seal 1 comprises a seal main body 5 to seal a gap between the inner circumference of an axial hole 3 and a movable axis 4 and a sound insulating seal 60 fixed in the seal main body 5 to seal transmitted sound between the axial hole 3 of a housing 2 and the movable axis 4. The seal main body 5 is a dust seal and comprises an outer circumferential fixed part 51 fitted and fixed in the inner circumference of the axial hole 3 of the housing 2, a seal lip part 52 in the inner circumferential side which is air-tightly brought into contact with the movable axis 4 in a manner the part can slide, and a bellows part 53 which connects the seal lip part 52 and the outer circumferential fixed part 51 and the eccentricity of the axis is absorbed by deformation of the bellows part 53. The sound seal 60 comprises first sound insulating members 6 which are thick and have high rigidity and second sound insulating members 27 which are thin and arranged in series with the first sound insulating members 6 in the axial direction and have low rigidity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used for a shaft sealing portion having a large eccentricity or mounting eccentricity such as a dust seal of a steering shaft of an automobile, and more particularly to a sealing device provided with a sound insulating seal.

[0002]

2. Description of the Related Art FIG. 2 shows an example of such a conventional sealing device with a sound insulating seal.

That is, the shaft hole 101 of the housing 100
Seal body 1 for sealing the gap between the inner circumference and the moving shaft 102
03 and the housing 1 fixed to the seal body 103.
And a sound insulation seal 104 that blocks transmitted sound between the shaft hole 101 and the moving shaft 102.

[0004] The sound insulating seal 104 includes a cylindrical casing portion 105 fitted and fixed to the seal body 103, a sound insulating member 106 incorporated in the inner periphery of the casing portion 105,
It is composed of When the moving shaft 102 is eccentric, the sound insulating member 10 is not interfered with the sound insulating member 106.
6 The inner diameter of the moving shaft 102
A gap A is provided between the sound insulation member 106 and the sound insulation member 106.

[0005]

However, in the case of the above-mentioned conventional sealing device, the moving shaft 102 and the sound insulating member 1 are not provided.
The sound insulation was not sufficient because there was a gap A between 06.

[0006] It is sufficient to reduce the gap, but then,
Since there is a problem that the moving resistance of the moving shaft 102 such as the rotational torque increases due to interference with the moving shaft 102, the gap A cannot be reduced. Also, the sound insulating member 10
It is conceivable to reduce the contact resistance even if the moving shaft 102 interferes by reducing the rigidity of No. 6, but this will reduce the sound insulation effect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a sealing device with a sound insulating seal capable of enhancing a sound insulating effect.

[0008]

In order to achieve the above object, according to the present invention, there is provided a seal body for sealing a gap between an inner periphery of a shaft hole of a housing and a moving shaft, and a housing fixed to the seal body. A sound insulating seal that blocks transmitted sound between the shaft hole and the moving shaft, wherein the sound insulating seal has a first sound insulating member having a gap of a predetermined size between the moving shaft and the eccentricity of the moving shaft. In the sealing device with a seal, a thin, low-rigidity second sound insulating member arranged in series with the first sound insulating member in the axial direction is provided on the sound insulating seal, and the inner periphery of the second sound insulating member slides on the moving shaft. It is characterized by freely contacting.

In the present invention, the gap between the housing and the moving shaft is completely sealed by the second sound insulating member, and the sound insulating effect is enhanced. Since the second sound insulation member is thin and has a low rigidity, the sliding resistance with the moving shaft is small. Further, even if the moving shaft is eccentric, the second sound insulating member is deformed to follow the eccentricity, and does not hinder the eccentric movement of the moving shaft.

On the other hand, the sound absorbing performance can be maintained by the first sound insulating member, and the sound insulating effect can be enhanced in tandem with the sealing structure of the second sound insulating member.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 1 shows a sealing device with a sound insulating seal according to one embodiment of the present invention.

The sealing device 1 with a soundproof seal is provided with a seal body 5 for sealing a gap between the inner periphery of the shaft hole 3 of the housing 2 and the moving shaft 4, and moving with the shaft hole 3 of the housing 2 fixed to the seal body 5. A sound-insulating seal 60 for blocking transmitted sound between the shafts 4.

The seal body 5 is a dust seal, and has an outer peripheral fixing portion 51 fitted and fixed to the inner periphery of the shaft hole 3 of the housing 2.
A seal lip portion 52 on the inner peripheral side slidably and sealingly contacting the moving shaft 4;
And a bellows portion 53 connecting between them, and the shaft eccentricity is absorbed by deformation of the bellows portion 53. The seal body 5 is provided on the dust side D with respect to the sound insulation seal 60.
Placed in

On the other hand, the sound insulating seal 60 includes a first sound insulating member 6 having a large thickness and high rigidity, and a second sound insulating member 7 having a small thickness and a low rigidity arranged in series with the first sound insulating member 6 in the axial direction. Configuration. The sound insulation seal 60 is disposed on the side opposite to the dust E with respect to the seal lip portion 52 of the seal body 5, and is located on the noise source side in the present embodiment. Of course, the transmitted sound is blocked, and the dust side D may be the noise side.

The first and second sound insulating members 6 and 7 are incorporated in a casing 8 having a U-shaped cross section, and are formed on the non-dust side E of the outer peripheral fixing portion 51 of the seal body 5 via the casing 8. It is fitted and fixed to the inner periphery of the annular projection 54.
The annular projecting portion 54 is made of a rubber-like elastic material that projects annularly in the axial direction from a metal fixing flange 55 that engages with the opening end surface of the shaft hole 3 of the housing 2.

The casing 8 has a cylindrical fixed tubular portion 81.
A first inward flange portion 82 protruding radially inward from a dust-side end of the fixed cylindrical portion 81; and a radially inward protruding portion from a non-dust-side end of the fixed cylindrical portion 81. And a second inward flange portion 83 to be formed.
An annular projection 84 is provided on the outer periphery of the fixed cylindrical portion 81 near the dust-side end thereof so as to partially protrude outward in the radial direction.
4 is fitted and fixed in an annular groove provided on the inner periphery. The portion of the fixed cylindrical portion 81 closer to the dust side D than the annular convex portion 84 is partially fitted to the inner periphery of the outer peripheral fixed portion 51 of the seal body 5.

The casing 8 comprises a metal ring 9 having an L-shaped cross section, and a rubber-like elastic body 10 which is integrally baked on the metal ring 9. The metal ring 9 includes a cylindrical outer cylinder portion 91, an inward flange portion 92 protruding inward in the radial direction from an end of the outer cylinder portion 91 opposite the dust side,
The outer cylindrical portion 91 has a dust-side end extending up to the annular convex portion 84 of the fixed cylindrical portion 81 of the casing 8, and a fixed cylindrical portion fitted to the inner periphery of the outer peripheral fixed portion 51 of the seal body 5. An end of the casing 81 on the dust side D of 81 is composed of the rubber-like elastic body 10 alone.

The first sound insulating member 6 is a thick and highly rigid member whose outer periphery is closely fitted to the inner periphery of the fixed cylindrical portion 81 of the casing 8 and whose axial end face is the first and second inward flange portions. 8
2,83. On the other hand, the inner diameter is larger than the outer diameter of the moving shaft 4 and the moving shaft 4 is located between the first sound insulating member 6 and the moving shaft 4.
A gap A for releasing the amount of eccentricity is formed.

As shown in the figure, the first sound insulating member 6
It can be divided into a plurality of pieces 61, 62. Each of the two pieces 61 and 62 of the first sound insulating member 6 has a rectangular cross section and an outer periphery in a U-shape.
1, the first and second inward flange portions 82,
83 sandwiched in the axial direction. Although not shown, when there is a protrusion on the outer periphery of the moving shaft 4, interference with the protrusion can be avoided by making the inner diameters of the plurality of pieces 61 and 62 different.

As a material of the first sound insulating member 6, various sound absorbing materials such as a sponge-like foam material such as VD foam manufactured by Bridgestone Corporation can be used.

On the other hand, the second sound insulating member 7 is a thin and low rigid member. In the present embodiment, the second sound insulating member 7 is formed in a washer-like thin plate shape, and the two pieces 61 and 6 of the first sound insulating member 6 are formed.
It is mounted in the casing 8 while being sandwiched between the two in the axial direction. In the illustrated example, the outer diameter end of the second sound insulation member 7 is fitted to the inner periphery of the fixed cylindrical portion 81 of the casing 8, and the half of the outer diameter side is the piece 61 of the first sound insulation member 6,
62, and a half portion on the inner diameter side is the first sound insulating member 6.
Are exposed in the gap between the inner circumferences of the pieces 61 and 62 and the outer circumference of the moving shaft 4, and the inner diameter end portion is slidably in contact with the outer circumference of the moving shaft 4.

The material of the second sound insulating member 7 is the first
The same material as the sound insulating member 6 may be used, or various materials such as a fabric material such as rubber, resin bellows, and nonwoven fabric may be used. However, the second sound insulation member 7 is
Since it comes into sliding contact with the outer periphery, an inelastic material is preferable in consideration of the noise (unusual noise) during sliding.

In this embodiment, the second sound insulating member 7
Accordingly, the gap between the housing 2 and the moving shaft 4 is completely sealed, and the sound insulating effect by the first sound insulating member 6 is enhanced without causing the sliding resistance of the moving shaft 4 to increase. Since the second sound insulating member 7 is thin and has a low rigidity, even if the moving shaft 4 is eccentric, the second sound insulating member 7 is deformed to follow the eccentricity and does not hinder the eccentric movement of the moving shaft 4. .

On the other hand, the sound absorbing performance is maintained by the first sound insulating member 6, and the sound insulating effect can be enhanced in tandem with the sealing structure of the second sound insulating member 7. [Other Embodiments] In the sound insulation, if the width of the sound insulation seal in the axial direction is the same, the greater the number of the sound insulation layers of the second sound insulation member 7, the more effective. It is preferable that the set number be as large as possible.

FIG. 2 shows that each of the pieces 61 and 62 of the first sound insulating member 6 of FIG.
The second sound insulating members 7, 7 are provided between the members a, 61b, 62a, 62b to provide a total of three layers of second sound insulating members 7, 7, 7.

The other configuration and operation are the same as those of the above-described embodiment, and therefore, the same components will be denoted by the same reference characters and description thereof will be omitted.

The first and second sound insulating members 6 and 7 may be bonded and fixed.

[0029]

As described above, according to the present invention,
A thin, low-rigidity second sound insulating member that contacts the moving shaft is provided separately from the first sound insulating member that is not in contact with the moving shaft, so that the gap between the housing and the moving shaft is completely sealed, and the sliding of the moving shaft is achieved. The sound insulation effect can be enhanced in parallel with the sound insulation performance of the first sound insulation member without increasing the resistance.

Further, since the second sound insulating member is thin and has a low rigidity, even if the moving shaft is eccentric, the second sound insulating member is deformed to follow the eccentricity, so that the eccentric movement of the moving shaft is prevented. Absent.

[Brief description of the drawings]

FIG. 1 shows a sealing device with a sound insulating seal according to an embodiment of the present invention. FIG. 1 (a) is a longitudinal sectional view of a main part showing an entire structure, and FIG. 1 (b) is a sound insulating sealing part. Partial sectional view of
FIG. 13C is a partial cross-sectional view of a sound insulation seal portion according to another embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a conventional sealing device with a sound insulating seal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device with a sound insulating seal 2 Housing 3 Shaft hole 4 Moving shaft 5 Seal main body 51 Peripheral fixing part 52 Seal lip part 53 Bellows part 54 Annular projecting part 55 Fixed flange 60 Sound insulating seal 6 First sound insulating member 61, 62 piece 7 Second Sound insulation member 8 Casing 81 Fixed cylindrical portion 82, 83 First and second inward flange portions 84 Annular convex portion 9 Metal ring 91 Outer cylindrical portion 92 Inward flange portion 10 Rubber-like elastic body D dust side E Anti-dust side

Claims (1)

[Claims] 1. A seal body for sealing a gap between an inner periphery of a shaft hole of a housing and a moving shaft, and a sound insulating seal fixed to the seal body and blocking transmitted sound between the shaft hole of the housing and the moving shaft. A sealing device having a first sound insulating member having a gap of a predetermined size for allowing the eccentricity of the moving shaft to escape from the moving shaft, wherein the sound insulating seal is provided in the axial direction with the first sound insulating member. A thin, low-rigidity second sound-insulating member arranged in series with the movable member, wherein the inner periphery of the second sound-insulating member is slidably contacted with a moving shaft.