JPH11351385A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sound insulating performance while preventing the transmission of noise, and improve a sealing property by providing plural second sealing devices in a sealing device on the inner diameter side of a fixed ring, and forming a sealing area between each bellow part of the sealing device and the plural second sealing devices. SOLUTION: A sealing device 1 is formed of three of a sealing device 2 and second sealing devices 3, 4 having the nearly the same structure. The second sealing devices 3, 4 are provided with fixed rings 3a, 4a, bellow parts 3b, 4b and seal parts 3c, 4c fitted on the inner diameter side of the fixed ring 2a of the sealing device 2. The bellow parts 2b, 3b and 4b are separated from each other so as to avoid the interference with each other, and two sealing areas M1, M2 are formed between them. Consequently, triple sealing by the bellows 2b, 3b, 4b is performed, and while since the sealing areas M1, M2 are formed, sound insulating performance is improved. Furthermore, a following property of the seal parts 2c, 3c, 4c to the shaft is excellent, and the sealing performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device which is used for a steering rod or the like of an automobile, and more particularly to a sealing device having improved sound insulation.

[0002]

2. Description of the Related Art Conventionally, this type of sealing device is used as shown in FIG.

[0003] That is, reference numeral 101 denotes a steering rod of an automobile, which is disposed so as to penetrate a front dash panel 102 between a vehicle interior side I and an engine room side O.

[0004] Reference numeral 103 denotes a steering dust seal as a sealing device, which seals a gap between the through hole 102a of the front dash panel 102 and the steering rod 101.

[0005] The steering dust seal 103 is
A fixed ring portion 103a for fixing to the through hole 102a, a seal portion 103b abutting on the surface of the rotating steering rod 101, and a seal portion 1 in consideration of the eccentric movement of the steering rod 101 with respect to the through hole 102a.
A bellows portion 103c for causing the steering rod 03 to follow the steering rod 101 is provided.

The steering dust seal 103
Functions to prevent intrusion of dust and rainwater from the engine room side O into the vehicle interior side I and to prevent engine noise and vehicle running noise from entering the vehicle interior side I. .

However, the bellows portion 103c is
The bellows portion 3b has a thin shape in order to improve the followability of the bellows portion 3b to the steering rod 101.
From 3c, the noise in the engine room O is passed through without being reduced, which is a factor of increasing the noise level in the vehicle room side I.

FIG. 3 shows an example of the prior art employed to solve the above problem. This sealing device 200
In this embodiment, thick cylindrical sound insulation members 203 and 204 made of an elastic member are arranged inside a housing 202 on the vehicle interior side I of a sealing device 103 'similar to that described with reference to FIG.

The noise insulation members 203 and 204 absorb noise passing through the bellows portion 103c to reduce the noise level.

FIG. 4 is a schematic diagram of Japanese Patent Application Laid-Open No.
No. 242880 discloses a sealing device 300 which is similar to the sealing devices 301 and 30 described with reference to FIG.
2 are arranged so as to be overlapped in the axial direction.

Both sealing devices 301 and 302 have sealing portions 301 a and 3 abutting against the surface of the steering rod 101.
02a, fixed ring portions 301b and 302b, bellows portion 301
c, 302c, and the bellows 301c, 30
A sealed area (air layer) 303 is formed between 2c.

The seal portions 301a and 302a prevent entry of dust and the like from outside, the bellows portions 301c and 302c function as an eccentric follow-up and sound insulating film for the steering rod 101, and the sealed region 303 functions as a sound insulating layer.

[0013]

However, in the sealing device 200 having the above structure, if the inner diameter of the sound insulating member 203 is set to be the same as the outer diameter of the steering rod 101, the elastic members of the sound insulating members 203 and 204 will be distorted. However, there is a limit in its followability, and there is a concern that the eccentric motion of the steering rod 101 may damage the inner diameter portion.

Therefore, in the conventional sound insulating members 203 and 204, gaps G101 and G102 are provided between the inner diameter portion and the outer diameter of the steering rod 101, and the sound insulating members 20 and 204 are provided.
3, 204 was prevented from being damaged.

However, since the noise on the engine room O side passes through the gaps G101 and G102, there is a limit to the reduction of the noise level, which hinders further reduction of the noise on the vehicle interior side I.

In the sealing device 300, the sealing region 303 functioning as a sound insulating layer can be provided, but a further sound insulating effect is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to effectively prevent the transmission of noise from the engine room side so as to enhance the sound insulation and improve the sealing performance. An object of the present invention is to provide a sealing device capable of improving the performance.

[0018]

According to the present invention, in order to achieve the above object, there is provided a method for sealing between two members of an opening which moves relatively and a shaft which passes through the opening. A fixed ring portion fixed to the portion, a seal portion sealingly contacting the surface of the shaft, and a bellows portion for sealing between the fixed ring portion and the seal portion and allowing relative movement of the seal portion relative to the fixed ring portion. A fitting portion formed on the inner diameter side of the fixed ring portion, and a plurality of second sealing devices attached to the fitting portion in the axial direction. A sealing ring attached to the fitting portion, a sealing portion sealingly contacting the surface of the shaft, a seal between the fixed ring portion and the sealing portion, and a fixed ring of the sealing portion. And a bellows portion allowing relative movement with respect to the portion. Characterized in that the formation of the sealing area between each of the bellows portion of the sealing device and a plurality of second sealing device.

According to this, the space between the opening and the shaft is sealed at least three times by the bellows portion, and at least two sealing regions are formed, so that the sound insulation is improved. Also,
The followability of the seal portion to the shaft is also good, and it is also preferable that the seal portion of the sealing device and the seal portion of the second sealing device include a seal lip.

The seal lip prevents the entry of dust and the like, and the sealing performance is further improved.

[0021]

FIG. 1 shows an embodiment of a sealing device to which the present invention is applied. This sealing device 1 is mainly used as a sealing device for sealing a gap between a steering rod 101 of an automobile and an opening 102a of a front dash panel 102 as described in the section of the prior art.

The sealing device 1 has a form in which three sealing devices 2, 3 and 4 having substantially the same configuration are combined.

The sealing device 2 has a fixed ring portion 2a fixed to the opening 102a, and a bellows portion 2b protruding from the engine room side O of the fixed ring portion 2a. And
The bellows portion 2b forms a loop so as to allow the steering rod 101 to move in the eccentric direction, and is connected to a seal portion 2c that comes into sealing contact with the surface of the steering rod 101.

The seal portion 2c includes a lip tip 2d and a sliding guide 2 parallel to the surface of the steering rod 101.
e, the lip tip 2d prevents dust and rainwater from entering from the engine room side O, and the sliding guide 2
By e, the rotation, the axial movement, and the eccentric movement of the steering rod 101 are received.

An auxiliary lip 2f serving as a grease reservoir is provided on the vehicle interior side I of the sliding guide portion 2e.

The sliding guide portion 2e has a large number of arc-shaped concave portions 2g formed on the peripheral wall surface so that a large number of lips 2h protrude, and a large number of lips 2h are in contact with the surface of the steering rod 101.

On the other hand, the sealing devices 3 and 4 as the second sealing device have substantially the same shape as the sealing device 2, and the fitting portion 2 formed on the inner diameter side of the fixed ring portion 2a of the sealing device 2 is provided.
Fixed ring portions 3a and 4a are fitted to i and 2j in the axial direction, and have bellows portions 3b and 4b and seal portions 3c and 4c, similarly to the sealing device 2.

Lip portions 3d, 4d slidingly contacting the surface of the steering rod 101 are provided on the seal portions 3c, 4c.
And sliding guide portions 3e and 4e for receiving rotation, axial movement, and eccentric movement of the steering rod 101.

The sliding guide portions 3e, 4e have a large number of convex portions 3f, 4f formed on the peripheral wall surface.
4f is in contact with the surface of the steering rod 101.

In this embodiment, the bellows 2b, 3b,
4b are spaced apart so as not to interfere with each other. Then, two sealed areas M1 and M2 are formed between them.

Therefore, the space between the opening 102a and the steering rod 101 is reduced by the bellows 2b, 3b and 4b.
While being heavily sealed, the sealed areas M1 and M2 are formed, and the sound insulation is improved. Also, the followability of the seal portions 2c, 3c, 4c to the steering rod 101 is good.

The lip tip 2d and the lips 3d, 4d make it possible to improve the sealing performance against the entry of dust and the like. Further, since each lip is a thin lip having low rigidity, the sliding torque can be reduced. Can be.

In this embodiment, the second sealing device is constituted by the two-stage sealing devices 3 and 4.
If a space can be secured, it is possible to arrange a larger number of sealing devices, and further improvement in sound insulation can be obtained.

[0034]

According to the present invention, the opening and the shaft are sealed at least three times by the bellows, and at least two sealing areas are formed to improve the sound insulation. I do. Further, the followability of the seal portion to the shaft is good. Further, the provision of the seal lip in the seal portion of the second sealing device prevents entry of dust and the like, and further improves the sealability.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a sealing device to which the present invention is applied.

FIG. 2 is a view for explaining a usage form of a conventional sealing device.

FIG. 3 is an explanatory sectional view of a conventional sealing device.

FIG. 4 is an explanatory sectional view of a conventional sealing device.

[Explanation of symbols]

 1, 2, 3, 4 Sealing device 2a, 3a, 4a Fixed ring portion 2b, 3b, 4b Bellows portion 3c, 3c, 4c Seal portion 101 Steering rod (shaft) 102 Front dash panel 102a Opening I Inside of vehicle interior M1, M2 Sealed area O Engine room side

Claims (2)

[Claims] 1. A seal for sealing between two members of an opening that moves relatively and a shaft that passes through the opening, and a sealing ring that is fixed to the opening and a sealing contact with a surface of the shaft. A sealing device comprising: a seal portion, and a bellows portion that seals between the fixed ring portion and the seal portion and allows relative movement of the seal portion with respect to the fixed ring portion, wherein the sealing device is formed on an inner diameter side of the fixed ring portion. And a plurality of second sealing devices attached to the fitting portion in the axial direction, wherein the plurality of second sealing devices are fixed ring portions attached to the fitting portion. A sealing portion that comes into sealing contact with the surface of the shaft;
And a bellows portion that seals between the fixed ring portion and the seal portion and allows relative movement of the seal portion with respect to the fixed ring portion, wherein each of the sealing device and the plurality of second sealing devices is provided. A sealing device wherein a sealing region is formed between bellows portions. 2. The sealing device according to claim 1, wherein the sealing portion of the sealing device and the sealing portion of the second sealing device are provided with a sealing lip.