JP3881053B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used for a steering rod of an automobile and the like, and particularly relates to a sealing device with improved sound insulation.
[0002]
[Prior art]
Conventionally, this type of sealing device is used as shown in FIG.
[0003]
That is, 101 is a steering rod of an automobile, and is disposed so as to penetrate the front dash panel 102 between the vehicle interior side I and the engine room side O.
[0004]
Reference numeral 103 denotes a steering dust seal as a sealing device, which seals a gap between the front dash panel 102 and the through hole 102a.
[0005]
The steering dust seal 103 takes into account the movement of the steering rod 101 in the eccentric direction with respect to the through hole 102a, the fixed ring portion 103a for fixing to the through hole 102a, the seal portion 103b that contacts the surface of the rotating steering rod 101, and the steering rod 101. And a bellows portion 103c for causing the seal portion 103b to follow the steering rod 101.
[0006]
As a function of the steering dust seal 103, dust and rainwater from the engine room side O are prevented from entering the vehicle interior side I, and engine sound and vehicle running sound are prevented from entering the vehicle interior side I. Is.
[0007]
However, the bellows portion 103c has a thin shape in order to improve the followability of the seal portion 103b to the steering rod 101. The bellows portion 103c passes through the bellows portion 103c without reducing the noise on the engine room side O. This was a factor that increased the noise level in the room interior I.
[0008]
FIG. 5 is an example of a prior art employed to solve the above problem. In this sealing device 201, a thick washer-shaped sound insulating plate 203 made of an elastic member is disposed on the vehicle interior side I of the sealing device 103 described in FIG. The sound insulating plate 203 is fitted into a mounting portion 202 that protrudes toward the vehicle compartment side I or the engine room side O of the fixed ring portion 103a. And the noise which passed through the bellows part 103c with this sound insulation board 203 was absorbed, and a noise level was reduced.
[0009]
[Problems to be solved by the invention]
However, in the sealing device 201 having the above-described configuration, if the size of the inner diameter portion of the sound insulating plate 203 is the same as the outer diameter size of the steering rod 101, although the sound insulating plate 203 is made of an elastic member, its followability The inner diameter portion is damaged due to the eccentric motion of the steering rod 101.
[0010]
Therefore, in the conventional sound insulating plate 203, a gap is provided between the inner diameter portion and the outer diameter of the steering rod 101 to prevent damage to the inner diameter portion of the sound insulating plate 203.
[0011]
However, since the noise on the engine room side O passes through this gap, there is a limit to the reduction of the noise level, which hinders further noise reduction on the vehicle interior side I.
[0012]
The present invention has been made in order to solve the above-described problems of the prior art, and the object of the present invention is to provide sound insulation that has high tracking performance with respect to the shaft and can effectively prevent transmission of noise from the engine room side. It is in providing a high sealing device.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a first fixed ring that seals between two members of an opening that moves relative to each other and a shaft that passes through the opening is fixed to the opening. And a first seal portion that is in sealing contact with the surface of the shaft, and seals between the first fixed ring portion and the first seal portion and allows relative movement of the first seal portion with respect to the first fixed ring portion. A first sealing device including a first bellows portion, a fitting portion formed on an inner diameter side of the first fixed ring portion, and a second sealing device attached to the fitting portion, The second sealing device seals a space between the second fixed ring portion attached to the fitting portion, the second seal portion in sealing contact with the surface of the shaft, and the second fixed ring portion and the second seal portion. , While allowing relative movement of the second seal part with respect to the second fixed ring part, the first fixed ring part and the first fixed ring part The roots at both ends of the second bellows part connected to the second fixed ring part and the second seal part are separated in the axial direction with respect to the roots at both ends of the first bellows part connected to the seal part. And a second bellows between the first and second bellows of each of the first sealing device and the second sealing device and the second bellows at both ends of the first bellows. Since the roots at both ends of the part are separated in the axial direction, a thick sealed region is formed in the axial direction.
[0014]
Therefore, the space between the opening and the shaft is double-sealed by the bellows, and a sealed region is formed to improve sound insulation. Moreover, the followability with respect to the axis | shaft of a seal part is also favorable.
[0016]
In addition, it is preferable that a lip for partitioning a sealed space between the first bellows portion of the first sealing device and the second bellows portion of the second sealing device is provided, and the sealing region is divided into a plurality of regions. According to this, the shape of the sealed region formed by the bellows is stably maintained, and at the same time, the transmitted sound is reduced.
[0017]
In addition, it is also preferable to provide a sound absorbing member formed of a sound absorbing material having elasticity in the sealed region, so that the shape of the sealed region is stabilized and transmitted sound is reduced.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 1 shows a first embodiment of a sealing device to which the present invention is applied. The sealing device 1 is mainly used as a sealing device for sealing a gap between the steering rod 4 of an automobile and the opening 5a of the front dash panel 5 as described in the section of the prior art.
[0019]
The sealing device 1 has a configuration in which two sealing devices 2 and 3 having substantially the same shape are combined.
[0020]
The sealing device 2 includes a fixed ring portion 2a that is fixed to the opening 5a, and includes a bellows portion 2b that protrudes from the engine room side O of the fixed ring portion 2a. The bellows portion 2b is connected to a seal portion 2c that is in sealing contact with the surface of the steering rod 4 after forming a loop so as to allow the steering rod 4 to move in the eccentric direction.
[0021]
The seal portion 2c includes a lip tip portion 2d and a sliding guide portion 2e parallel to the surface of the steering rod 4, and the lip tip portion 2d prevents intrusion of dust and rainwater from the engine room side O, and the sliding guide The portion 2e receives the rotation of the steering rod 4, the axial movement, and the eccentric movement.
[0022]
On the other hand, the sealing device 3 has substantially the same shape as the sealing device 2, and the fixing ring portion 3 a is fitted to the fitting portion formed on the inner diameter side of the fixing ring portion 2 a of the sealing device 2. 2 includes a bellows portion 3b and a seal portion 3c.
[0023]
In the present embodiment, the bellows portion 2b and the bellows portion 3b are separated so as not to interfere with each other. And the sealing area | region M is formed among them.
[0024]
Therefore, the space between the opening 5a and the steering rod 4 is double-sealed by the bellows 2b and 3b, and the sealing region M is formed, so that the sound insulation is improved. Further, the followability of the seal portions 2c and 3c to the steering rod 4 is also good.
[0025]
(Embodiment 2)
FIG. 2 shows a second embodiment to which the present invention is applied. FIG. 2A is a cross-sectional explanatory diagram for explaining the configuration of the sealing device 11, and FIG. 2B is formed of, for example, foaming urethane as an elastic sound-absorbing material loaded in the sealing region M1. It is a partially cutaway view of the sound absorbing member.
[0026]
In the second embodiment, the sealing device 11 includes two sealing devices 12 and 13 as in the first embodiment.
[0027]
Explaining only the configuration different from the first embodiment described above, the bellows portion 13b of the sealing device 13 penetrates inside the loop of the bellows portion 12b of the sealing device 12.
[0028]
As the coupling means, a rear end portion 12f of the seal portion 12c and a front end portion 13d of the seal portion 13c are formed with fitting portions configured to fit each other, and the seal portion 12c and the seal portion 13c are coupled. is doing.
[0029]
With this configuration, the behavior of the seal portion is stabilized with respect to the movement of the seal portions 12c and 13c in the axial direction of the steering rod 4, and the shape of the sealing region M1 is also kept constant.
[0030]
Moreover, the sound insulation is further improved by loading the sound absorbing member 16 having substantially the same shape as the shape of the sealed region M1. The sound absorbing member 16 is held between the bellows portions 12b and 13b because the seal portions 12c and 13c are coupled to each other, and the interval between the bellows portions 12b and 13b is maintained even if the steering rod 4 is decentered.
[0031]
(Embodiment 3)
FIG. 3 shows a sealing device 31 according to the third embodiment. In this figure, the same reference numerals are attached to the same components as those of the sealing device 1 shown in FIG. As a characteristic configuration of the sealing device 31, a connecting lip 32 is provided on the bellows 3 b of the second sealing device 3 as a connecting means for connecting the bellows 3 b and the bellows 2 b of the sealing device 2 to each other. .
[0032]
The sealing lip 32 divides the sealed region into M1 and M2. Therefore, the shape of the sealing regions M1 and M2 formed between the bellows portions 3b and 2b is stably held by the connection lip 32, and sound transmitted through the engine or the like is attenuated in the respective sealing regions. Improves.
[0033]
Further, in this embodiment, one connecting lip is provided as a connecting means, but it can be increased to two or three, and can also be provided in each of the bellows portions 3b and 2b. .
[0034]
【The invention's effect】
The present invention has the above-described configuration and action, and the space between the opening and the shaft is double sealed by the bellows, and a sealed region is formed to improve sound insulation. Moreover, the followability with respect to the axis | shaft of a seal part is also favorable.
[0035]
In addition, when the seal portions are coupled, the axial movement of the seal portions is stable, and the shape of the sealed region is also kept constant.
[0036]
Moreover, what divided | segmented the sealing area into plurality stabilizes the shape of each sealing area, and a sound attenuate | damps effectively.
[0037]
The sound insulating property is further improved by loading the sound absorbing member in the sealed region.
[Brief description of the drawings]
FIG. 1 is a cross-sectional explanatory view of a sealing device to which the present invention is applied (Embodiment 1).
FIG. 2 is an explanatory cross-sectional view of a sealing device to which the present invention is applied (Embodiment 2).
FIG. 3 is a cross-sectional explanatory view of a sealing device to which the present invention is applied (Embodiment 3).
FIG. 4 is a diagram for explaining a usage form of a conventional sealing device.
FIG. 5 is a cross-sectional explanatory view of a conventional sealing device.
[Explanation of symbols]
1, 2, 3 Sealing device 2a, 3a Fixed ring part 2b, 3b Bellow part 3c, 3c Seal part 4 Steering rod (shaft)
5 Front dash panel 5a Opening I Car interior side M, M1 Sealing area O Engine room side

Claims (3)

Sealing between the two members of the opening that moves relative to and the shaft that passes through the opening,
A first fixed ring portion fixed to the opening; a first seal portion that is in sealing contact with the surface of the shaft; and a seal between the first fixed ring portion and the first seal portion and a first seal portion. A first sealing device comprising a first bellows part that allows relative movement of the first stationary ring part;
A fitting portion formed on the inner diameter side of the first fixed ring portion;
A second sealing device attached to the fitting portion;
The second sealing device seals between a second fixed ring portion attached to the fitting portion, a second seal portion in sealing contact with the surface of the shaft, and the second fixed ring portion and the second seal portion. In addition, while allowing relative movement of the second seal portion with respect to the second fixed ring portion, with respect to the roots at both ends of the first bellow portion connected to the first fixed ring portion and the first seal portion, The second fixed ring portion and the second bellows portion, the roots of both ends of the second bellow portion connected to the second seal portion are separated in the axial direction,
Between the first and second bellows portions of the first sealing device and the second sealing device, the roots at both ends of the first bellows portion and the roots at both ends of the second bellows portion are separated in the axial direction. Therefore, a sealing device having a thick sealing region in the axial direction is formed. Claim 1, characterized in that comprises a lip partitioning the sealed space between the second bellows portion of the first bellows unit and the second sealing device of the first sealing device, to divide the seal area into a plurality of regions sealing device as claimed in. Wherein the sealing area, the sealing apparatus according to claim 1 or 2 characterized in that it comprises a sound absorbing member formed of sound absorbing material having elasticity.

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