JP3613946B2 - Sealing device with sound insulation seal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device used for a shaft seal portion having a large shaft eccentricity or mounting eccentricity such as a dust seal of a steering shaft of an automobile, and more particularly to a sealing device with a sound insulating seal provided with a sound insulating seal.
[0002]
[Prior art]
An example of such a conventional sealing device with a sound insulation seal is shown in FIG.
[0003]
That is, the seal body 103 that seals the gap between the inner periphery of the shaft hole 101 of the housing 100 and the moving shaft 102, and the sound insulation that is fixed to the seal body 103 and blocks the transmitted sound between the shaft hole 101 of the housing 100 and the moving shaft 102. And a seal 104.
[0004]
The sound insulation seal 104 includes a cylindrical casing portion 105 that is fitted and fixed to the seal main body 103, and a sound insulation member 106 that is incorporated into the inner periphery of the casing portion 105. The inner diameter of the sound insulating member 106 is made larger than that of the moving shaft 102 so as not to interfere with the sound insulating member 106 when the moving shaft 102 is eccentric, and a gap A is provided between the moving shaft 102 and the sound insulating member 106. .
[0005]
[Problems to be solved by the invention]
However, in the case of the conventional sealing device described above, the sound insulation is not sufficient because there is a gap A between the moving shaft 102 and the sound insulation member 106.
[0006]
The gap may be reduced. However, if this occurs, there arises a problem that the movement resistance such as the rotational torque of the movement shaft 102 increases due to interference with the movement shaft 102, and therefore the gap A cannot be reduced. Further, it is conceivable to reduce the contact resistance even if the moving shaft 102 interferes by reducing the rigidity of the sound insulating member 106, but this will reduce the sound insulating effect.
[0007]
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a sealing device with a sound insulation seal capable of enhancing the sound insulation effect.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a seal body that seals the gap between the inner periphery of the shaft hole of the housing and the moving shaft, and a transmission between the shaft hole of the housing and the moving shaft that is fixed to the seal body. A sound-insulating seal that blocks sound, and the sound-insulating seal is used for a dust seal of a steering shaft of an automobile having a first sound-insulating member having a gap of a predetermined dimension for escaping the eccentricity of the moving shaft with the moving shaft. In a sealing device with a sound insulation seal,
The sound insulation seal is provided with a thin, low-rigidity second sound insulation member arranged in series in the axial direction with the first sound insulation member at least on the anti-dust side of the first sound insulation member, and an inner periphery of the second sound insulation member is provided. The movable shaft is slidably brought into contact with the moving shaft.
[0009]
In the present invention, the gap between the housing and the moving shaft is completely sealed by the second sound insulation member, and the sound insulation effect is enhanced. Since the second sound insulating 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 following the movement, and the moving movement of the moving shaft is not hindered.
[0010]
On the other hand, the sound absorbing performance is maintained by the first sound insulating member, and the sound insulating effect can be enhanced in combination with the sealing configuration of the second sound insulating member.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below based on the illustrated embodiments.
[0012]
FIG. 1 shows a sealing device with a sound insulating seal according to an embodiment of the present invention.
[0013]
This sealing device 1 with a sound insulation seal includes a seal body 5 that seals a gap between the inner periphery of the shaft hole 3 of the housing 2 and the moving shaft 4, and a space between the shaft hole 3 of the housing 2 and the moving shaft 4 that is fixed to the seal body 5. And a sound insulation seal 60 for blocking the transmitted sound.
[0014]
The seal body 5 is a dust seal, an outer peripheral fixing portion 51 that is fitted and fixed to the inner periphery of the shaft hole 3 of the housing 2, an inner peripheral seal lip portion 52 that is in sliding contact with the moving shaft 4 slidably, and this seal An accordion portion 53 that connects the lip portion 52 and the outer periphery fixing portion 51 is provided, and the shaft eccentricity is absorbed by deformation of the accordion portion 53. The seal body 5 is disposed on the dust side D with respect to the sound insulation seal 60.
[0015]
On the other hand, the sound insulation seal 60 includes a thick and highly rigid first sound insulation member 6 and a thin and low rigidity second sound insulation member 7 arranged in series with the first sound insulation member 6 in the axial direction. It has become. The sound-insulating seal 60 is disposed on the anti-dust E side with respect to the seal lip portion 52 of the seal body 5 and is on the noise source side in the present embodiment. Of course, the transmission sound is blocked, and the dust side D may be the noise side.
[0016]
The first and second sound insulation members 6, 7 are incorporated in a casing 8 having a U-shaped cross section, and are annular protrusions formed on the anti-dust side E of the outer periphery fixing portion 51 of the seal body 5 via the casing 8. 54 is fitted and fixed to the inner periphery. 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.
[0017]
The casing 8 includes a cylindrical fixed cylinder portion 81, a first inward flange portion 82 that protrudes radially inward from the dust side end portion of the fixed cylinder portion 81, and the anti-dust side of the fixed cylinder portion 81. A second inward flange portion 83 projecting radially inward from the end portion. On the outer periphery of the fixed cylindrical portion 81, an annular convex portion 84 that partially projects outward in the radial direction is provided near the dust side end portion, and this annular convex portion 84 is provided inside the annular projecting portion 54 of the seal body 5. It is fitted and fixed in an annular groove provided on the periphery. Further, the portion on the dust side D from the annular convex portion 84 of the fixed cylindrical portion 81 is partially fitted to the inner periphery of the outer peripheral fixed portion 51 of the seal body 5.
[0018]
The casing 8 includes a metal ring 9 having an L-shaped cross section and a rubber-like elastic body 10 that is integrally baked on the metal ring 9. The metal ring 9 includes a cylindrical outer tube portion 91 and an inward flange portion 92 that protrudes inward in the radial direction from the opposite dust end of the outer tube portion 91. The outer tube portion The dust side end portion of 91 is up to the annular convex portion 84 of the fixed cylinder portion 81 of the casing 8, and the casing side end portion of the dust side D of the fixed cylinder portion 81 fitted to the inner periphery of the outer periphery fixing portion 51 of the seal body 5. Is composed of a rubber-like elastic body 10 alone.
[0019]
The first sound insulating member 6 is a thick and highly rigid member, and its outer periphery is closely fitted to the inner periphery of the fixed cylinder portion 81 of the casing 8, and the axial end surfaces are the first and second inward flange portions 82 and 83. Abut. On the other hand, the inner diameter is larger than the outer diameter of the moving shaft 4, and a gap A for releasing the eccentric amount of the moving shaft 4 is formed between the first sound insulating member 6 and the moving shaft 4.
[0020]
As shown in the figure, the first sound insulating member 6 can be divided into a plurality of pieces 61 and 62. Each of the two pieces 61, 62 of the first sound insulating member 6 has a rectangular cross section, and the outer periphery is fitted to the inner periphery of the fixed cylinder portion 81 of the casing 8, and the first and second inward flange portions 82, 83 is held in the axial direction. Although not shown, when there are protrusions on the outer periphery of the moving shaft 4, interference with the protrusions can be avoided by making the inner diameters of the plurality of pieces 61 and 62 different.
[0021]
As the 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.
[0022]
On the other hand, the second sound insulating member 7 is a thin and low-rigidity member, which is formed into a washer-like thin plate shape in the present embodiment, and is axially disposed between the two pieces 61 and 62 of the first sound insulating member 6. It is mounted in the casing 8 in a sandwiched state. In the illustrated example, the outer diameter end of the second sound insulation member 7 is fitted to the inner periphery of the fixed cylinder portion 81 of the casing 8, and the outer diameter side half is between the pieces 61 and 62 of the first sound insulation member 6. The inner half is exposed in the gap between the inner periphery of the pieces 61 and 62 of the first sound insulation member 6 and the outer periphery of the moving shaft 4, and the inner end is slidably in contact with the outer periphery of the moving shaft 4. ing.
[0023]
As the material of the second sound insulation member 7, the same material as that of the first sound insulation member 6 may be used, and various materials such as a fabric material such as rubber, resin bellows, and nonwoven fabric may be used. However, since the second sound insulating member 7 is slidably contacted with the outer periphery of the moving shaft 4, an inelastic material is preferable in consideration of squealing (abnormal noise) during sliding.
[0024]
In the present embodiment, the gap between the housing 2 and the moving shaft 4 is completely sealed by the second sound insulating member 7, and the first sound insulating member 6 does not cause an increase in sliding resistance of the moving shaft 4. The sound insulation effect is enhanced in combination with the sound insulation performance. Since the second sound insulating member 7 is thin and has a low rigidity, even if the moving shaft 4 is decentered, the second sound insulating member 7 is deformed following the eccentricity, and the eccentric movement of the moving shaft 4 is not hindered. .
[0025]
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 combination with the sealing configuration of the second sound insulating member 7.
[Other embodiments]
In terms of sound insulation, if the width of the sound insulation seal in the axial direction is the same, it is effective to increase the number of sound insulation layers of the second sound insulation member 7, so that the number of second sound insulation members 7 to be set is as large as possible. preferable.
[0026]
In FIG. 1 (c) , each piece 61, 62 of the first sound insulation member 6 in FIG. 1 (b) is further divided into two parts, and the second sound insulation member 7, between the divided pieces 61a, 61b, 62a, 62b. 7 and a total of three layers of second sound insulation members 7, 7, and 7 are provided.
[0027]
Since other configurations and operations are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and the description thereof is omitted.
[0028]
The first and second sound insulation members 6 and 7 may be bonded and fixed.
[0029]
【The invention's effect】
As described above, according to the present invention, the thin and low-rigidity second sound insulation member that comes into contact with the movement shaft is provided in addition to the movement shaft and the non-contact first sound insulation member. The gap is completely sealed, and the sound insulation effect can be enhanced in combination with the sound insulation performance by the first sound insulation member without causing an increase in sliding resistance of the moving shaft.
[0030]
In addition, since the second sound insulating member is thin and has a low rigidity, even if the moving shaft is decentered, the second sound insulating member is deformed following the moving shaft and does not hinder the eccentric movement of the moving shaft.
[Brief description of the drawings]
FIG. 1 shows a sealing device with a sound insulation seal according to an embodiment of the present invention, in which FIG. 1 (a) is a longitudinal sectional view of an essential part showing the overall configuration, and FIG. 1 (b) is a sound insulation seal portion. FIG. 4C is a partial cross-sectional view of a sound-insulating seal portion according to another embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of an essential part of a conventional sealing device with a sound insulation seal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sealing device 2 with a sound insulation seal Housing 3 Shaft hole 4 Moving shaft 5 Seal main body 51 Outer periphery fixed part 52 Seal lip part 53 Bellows part 54 Annular protrusion 55 Fixed flange 60 Sound insulation seal 6 First sound insulation member 61, 62 Piece 7 Second Sound insulating member 8 Casing 81 Fixed cylinder parts 82, 83 First and second inward flange parts 84 Annular convex part 9 Metal ring 91 Outer cylinder part 92 Inward flange part 10 Rubber elastic body D Dust side E Anti dust side

Claims (1)

A seal body that seals a gap between the inner periphery of the shaft hole of the housing and the moving shaft, and a sound insulating seal that is fixed to the seal body and blocks transmitted sound between the shaft hole of the housing and the moving shaft. In a sealing device with a sound insulation seal used for a dust seal of a steering shaft of an automobile, having a first sound insulation member having a gap of a predetermined dimension for releasing the eccentricity of the movement shaft between the movement shaft,
The sound insulation seal is provided with a thin, low-rigidity second sound insulation member arranged in series in the axial direction with the first sound insulation member at least on the anti-dust side of the first sound insulation member, and an inner periphery of the second sound insulation member is provided. A sealing device with a sound-insulating seal, which is slidably brought into contact with a moving shaft.

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