JP2003180021A - Grommet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide high sound insulation for a grommet having a structure of two hard and soft parts. <P>SOLUTION: In this grommet 50 in which a grommet outer 60 formed of a soft material is fitted in a grommet inner 70 formed of a hard material, a tubular body 72 which has an engagement part with a through hole Pa in a panel P at an outer periphery and inserted in the through hole from the top end is provided at the grommet inner 70, and an outer flange 71 is integrally provided at a base end of the tubular body 72. An annular flange wall 61 which has an adhesive seal part 63 to a panel P and a bag-shaped outer periphery 61a with which the outer flange 71 of the grommet inner 70 is engaged is provided at the grommet outer 60. A tubular part 65 in which a wire harness W is inserted in an inner part is jointed with the inner periphery end of the flange wall 61, and an outer collar part 66 which forms a sealed space 81 with the tubular body of the grommet inner, the tubular part of the grommet outer, and the flange wall by being brought into close contact with the inner periphery of the tubular body of the grommet inner is provided at the tope end of the tubular part of the grommet outer inserted in the tubular body 72 of the grommet inner 70 with a clearance. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grommet having a two-part structure in which a grommet inner made of a hard material and a grommet outer made of a soft material are combined, and more particularly, to a grommet having improved sound insulation.

[0002]

2. Description of the Related Art As a grommet which can be easily attached to and detached from a vehicle panel, an engaging portion for the peripheral edge of a through hole of the panel is made of hard resin, and a grommet inner formed of the hard resin is made of rubber or the like. There is known a two-part structure grommet that is fitted to a grommet outer formed of a soft material. This grommet has an advantage that it has better workability for attachment / detachment than a grommet made of only ordinary rubber.

FIG. 5 is a sectional view showing a grommet having a two-part structure disclosed in Japanese Patent Laid-Open No. 6-349366.
The grommet 1 is a combination of a grommet outer 2 made of rubber (soft material) and a grommet inner 3 made of a hard resin, and is attached to the peripheral edge of the through hole Pa of the panel P by the engaging portion 6 of the grommet inner 3. To be The grommet outer 2 is provided with a close contact seal part 4 that comes into pressure contact with the surface of the panel P, and a wire harness fitting part 5 that fits tightly around the outer periphery of the wire harness W, and the grommet inner 3 is attached to the panel P. By fixing, the panel penetration part of the wire harness W is sealed with the grommet 1.

[0004]

By the way, when the grommet is used by being attached to a dash panel of an automobile, for example, a sound insulation property is particularly required in order to prevent the sound from the engine room from entering the vehicle interior. But
In the conventional grommet 1 having the two-part structure of the outer and the inner of this type, sufficient sound insulation (transmission sound insulation) has not been ensured.

Generally, in the case of the grommet 11 made of only rubber as shown in FIG. 6, the wire harness fitting portions 14 and 15 for closely fitting to the wire harness are provided at both axial ends of the grommet 11 to penetrate the panel P. A technique is known in which a sealed space 16 is secured in the large-diameter portion 12 of the grommet 11 having the fitting groove 13 for the hole Pa, and the sealed space 16 blocks the transmitted sound through the grommet 11. As it is, it is difficult to apply it to a grommet having a soft and hard two-part structure.

In view of the above circumstances, an object of the present invention is to provide a grommet having a hard and soft two-part structure with improved sound insulation.

[0007]

According to a first aspect of the present invention, a grommet outer made of a soft material having a tight sealing portion for a panel is made into a grommet inner made of a hard material having an engaging portion with a peripheral edge of a through hole of the panel. In a grommet formed by fitting, the grommet inner is provided with a cylindrical body having an engaging portion with respect to the peripheral edge of the through hole of the panel on the outer periphery and inserted into the through hole from the distal end, and the base end of the cylindrical body. An outer flange is integrally provided to the grommet outer, and an annular flange wall having a bag-shaped outer peripheral portion having an outer seal of the grommet inner to which the outer flange of the grommet inner fits is provided on the grommet outer. The cylinder connected to the inner peripheral end of the wall, into which the wire harness is inserted, and inserted into the cylinder of the grommet inner at a distance. An outer flange portion that forms a sealed space together with the tubular body of the grommet inner, the tubular portion of the grommet outer, and the flange wall is provided at the tip of the portion by closely contacting with the inner circumference of the tubular body of the grommet inner. And

According to the present invention, since the sealed space (air layer) can be secured in the front part of the flange wall of the grommet outer, it is possible to reduce the sound transmitted through the grommet (improve the sound insulation). In addition, an air layer (gap) can be secured between the grommet outer cylinder and the grommet inner cylinder, so the flexibility of the grommet outer made of soft material can be fully demonstrated without any loss. Can be made. Therefore, although the grommet inner made of a hard material is used for mounting in the panel through hole to improve the mounting workability, the panel penetrating portion of the wire harness is suppressed while keeping the restraining force on the wire harness small (while having high flexibility). It is possible to improve the sealing property and sound insulation property of.

According to a second aspect of the present invention, in the grommet according to the first aspect, the cylindrical portion of the grommet outer is formed to have a diameter that secures a marginal space with the outer periphery of the wire harness. An annular wall is provided at the tip of the tubular portion so as to be in close contact with the outer periphery of the wire harness, and a wire harness fitting portion is provided at the base end of the tubular portion for closely fitting to the outer periphery of the wire harness.

According to the present invention, the tubular portion is not directly and closely fitted to the outer periphery of the wire harness, but an extra space is secured between the tubular portion and the outer periphery of the wire harness. The sound insulation of the grommet can be maintained while maintaining the property.

A third aspect of the present invention is the grommet according to the second aspect, wherein a bellows tube is extended at a base end of the tubular portion, and the wire harness fitting portion is provided at an end of the bellows tube. It is characterized by that.

According to the present invention, since the bellows tube is extended to the base end side of the tubular portion of the grommet outer and the wire harness fitting portion is provided at the end portion thereof, the grommet is allowed while allowing the axial displacement of the wire harness. It is possible to maintain the sealing property and the sound insulation property.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a used state of the grommet of the embodiment, and FIG. 2 is a sectional view showing a state when an external pulling force acts on the grommet in the state of FIG. Also,
3A and 3B are configuration diagrams of a grommet outer forming the grommet of the embodiment, where FIG. 3A is a front view and FIG. 3B is an I in FIG.
IIb-IIIb arrow sectional drawing, FIG. 4 is a block diagram of the grommet inner which comprises the grommet of embodiment, (a) is a front view, (b) is a side view, (c) is IVc- of (a) figure.
FIG. 4 is a sectional view taken along line IVc.

As shown in FIG. 1, the grommet 50 has a close contact seal portion (seal lip, etc.) with respect to the panel P.
Grommet outer 6 made of soft material (rubber) having 63
0 is an engaging portion 75 for the peripheral edge of the through hole Pa of the panel P.
The grommet inner 70 is made of a hard material (for example, resin) and has a half-divided structure having [see FIGS. 4A and 4B].

As shown in FIG. 4, the grommet inner 70 has a double-walled cylinder having an engaging portion 75 on the outer periphery for engaging the peripheral edge of the through hole Pa of the panel P and being inserted from the tip into the through hole Pa. A body 72 is provided, and an outer flange 71 having a substantially S-shaped cross section is integrally provided at the base end of the tubular body 72.

On the other hand, as shown in FIG. 3, the grommet outer 60 has an annular flange wall having the above-mentioned close contact seal portion 63 and a bag-shaped outer peripheral portion 61a with which the outer flange 71 of the grommet inner 70 is fitted. 61 is provided. Grommet outer 60 and grommet inner 70
As shown in FIG. 1, the outer peripheral portion of the outer flange 61 of the grommet outer 60 is fitted into the fitting groove 62 provided in the outer peripheral portion 61a of the flange wall 61 of the grommet inner 70, thereby being integrally combined. .

A cylindrical portion 65 into which the wire harness W is inserted is integrally connected to an inner peripheral end of the flange wall 61 of the grommet outer 70. Grommet inner 7
The tip of the tubular portion 65 that is inserted into the tubular body 72 of 0 at a distance is in close contact with the inner periphery of the tubular body 72 of the grommet inner 70, and thus the tubular body 72 of the grommet inner 70 and the grommet outer 60. An outer flange portion 66 that forms a sealed space 81 is integrally provided with the cylindrical portion 65 and the flange wall 61.

The tubular portion 65 of the grommet outer 60
Is formed with a diameter large enough to secure a margin space 82 with the outer periphery of the wire harness W, and the inner peripheral end of the cylindrical portion 65 is closely attached to the outer periphery of the wire harness W. An annular wall 67 is provided. Further, a bellows tube 68 is extended at the base end of the tubular portion 65, and a wire harness fitting section 69 that is closely fitted to the outer periphery of the wire harness W is provided at the end of the bellows tube 68.

The relationship between the outer diameter D of the outer collar portion 66 of the grommet outer 60 and the inner diameter D1 of the cylindrical body 72 of the grommet inner 70 is D ≧ D so that the sealed space 81 can be reliably formed.
1 and the flange wall 61 of the grommet outer 60
The distance L from the outer flange portion 66 to the outer flange portion 66 and the length L1 of the cylindrical body 71 of the grommet inner 70 are set to L <L1.

Next, the operation will be described.

When using the grommet 50, first, the wire harness W is inserted into the grommet outer 60, and the grommet inner 70 is fitted into the grommet outer 60. Then, the wire harness W is inserted from the right side of FIG. 1 into the through hole Pa of the panel P, and the tip of the tubular body 72 of the grommet inner 70 is attached to the panel P.
Through the through hole Pa. Engaging portion 7 provided on the outer periphery of the cylindrical body 72
When the cylindrical body 72 is inserted into the through hole Pa while elastically deforming 5 (see FIG. 4), the engaging portion 75 elastically restores at a certain position and engages with the peripheral portion of the through hole Pa. In this state,
The close contact seal portion 63 of the grommet outer 60 comes into close contact with the surface of the panel P, and the grommet 50 seals the through hole Pa.

At this time, as shown in FIG. 1, the outer collar portion 66 provided at the tip of the tubular portion 65 of the grommet outer 60 is
By closely contacting the inner periphery of the cylinder body 72 of the grommet inner 70, the cylinder body 72 of the grommet inner 70, the cylindrical portion 65 of the grommet outer 60, and the flange wall 61 form a sealed space (air layer) 81. Therefore, this sealed space 81
Is secured to the front side of the flange wall 61 to reduce the sound transmitted through the grommet 50 (improve the sound insulation).
Is planned.

The cylindrical portion 65 of the grommet outer 60
By ensuring the space (gap) 81 between the grommet inner 70 and the cylindrical body 72 of the grommet inner 70, the flexibility of the grommet outer 60 made of a soft material can be sufficiently exerted without impairing the flexibility at all. Therefore, although the grommet inner 70 made of a hard material that is convenient at the time of mounting is used to mount the grommet inner 70 in the through hole Pa of the panel P, while restraining the binding force to the wire harness W to be small (while having high flexibility), The sealability and sound insulation of the panel penetration portion of the wire harness W can be improved.

In addition, the tubular portion 65 of the grommet outer 60 is not directly and closely fitted to the outer periphery of the wire harness W, but a margin space 82 sealed between the tubular portion 65 and the outer periphery of the wire harness W is provided. Since it is ensured, the grommet 5 is maintained while maintaining sufficient flexibility of the wire harness W.
A sound insulation property of 0 can be maintained. Particularly, in the case of this grommet 50, since the bellows tube 68 is extended to the base end side of the tubular portion 65 of the grommet outer 60 and the wire harness fitting portion 69 is provided at the end portion thereof, the wire harness W is in the axial direction. It is possible to maintain the sealing property and the sound insulating property by the grommet 50 while allowing the displacement of.

Further, as shown in FIG. 2, even when the grommet outer 60 is deformed by being pulled by the wire harness W, the tip of the outer flange portion 66 comes into close contact with the inner peripheral surface of the cylindrical body 72 of the grommet inner 70. As such, the sound insulation performance does not deteriorate.

[0027]

As described above, according to the invention of claim 1, the grommet outer is provided with the outer brim portion which is in close contact with the inner circumference of the cylindrical body of the grommet inner. It is possible to secure a sealed space (air layer) in the front part of the flange wall, and the presence of the sealed space can reduce the sound transmitted through the grommet (improve the sound insulation). Therefore, when this grommet is used for the wire harness penetrating portion of the dash panel, it is possible to reduce the transmitted sound from the engine room to the vehicle interior.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, a sufficient space is secured between the tubular portion of the grommet outer and the outer periphery of the wire harness, so that the wire harness is sufficiently secured. The sound insulation of the grommet can be maintained while maintaining the flexibility.

According to the invention of claim 3, in addition to the effect of the invention of claim 2, the bellows tube is extended to the base end side of the tubular portion of the grommet outer, and the wire harness fitting portion is provided at the end portion. Since it is provided, it is possible to maintain the sealing property and the sound insulation property by the grommet while allowing the axial displacement of the wire harness.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a usage state of a grommet according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state when an external pulling force acts on the grommet in the state of FIG.

3A and 3B are configuration diagrams of a grommet outer constituting a grommet according to an embodiment of the present invention, FIG. 3A is a front view, and FIG. 3B is a sectional view taken along the line IIIb-IIIb in FIG.

FIG. 4 is a configuration diagram of a grommet inner forming the grommet according to the embodiment of the present invention, in which (a) is a front view, (b) is a side view, and (c) is a sectional view taken along the line IVc-IVc in (a). It is a figure.

FIG. 5 is a sectional view of a conventional grommet having a hard and soft two-part structure.

FIG. 6 is a cross-sectional view of a conventional grommet formed only of rubber.

[Explanation of symbols]

50 grommets 60 grommet outer 61 flange wall 61a outer peripheral portion 63 Close seal part 65 Cylindrical part 66 Outer collar part 67 Ring wall 68 bellows tube 69 Wire harness fitting part 70 Grommet Inner 71 outer flange 72 cylinder 81 sealed space 82 extra space P panel Pa through hole W wire harness

Claims (3)

[Claims] 1. A grommet formed by fitting a grommet outer made of a soft material having a tight sealing portion to a panel to a grommet inner made of a hard material having an engaging portion with respect to a peripheral edge of a through hole of the panel. In the outer periphery, a cylindrical body having an engaging portion for the peripheral edge of the through hole of the panel and inserted from the tip into the through hole is provided, and an outer flange is integrally provided at the base end of the cylindrical body, The grommet outer is provided with a ring-shaped flange wall having a bag-shaped outer peripheral portion having an outer seal of the grommet inner and having a close contact seal portion for the panel, and the inner peripheral end of the flange wall is internally provided. The grommet is connected to a tubular part through which the wire harness is inserted, and the grommet is attached to the tip of the tubular part that is inserted into the tubular body of the grommet inner at a distance. By close contact with the inner periphery of Toin'na cylindrical body, the grommet, characterized in that a outer collar portion which forms a sealed space together with the tubular portion and the flange wall of the cylindrical body and the grommet outer Gros helmet housing Na. 2. The grommet according to claim 1, wherein the tubular portion of the grommet outer is formed to have a diameter that secures a marginal space with the outer periphery of the wire harness,
A grommet characterized in that an annular wall that closely adheres to the outer periphery of the wire harness is provided at the tip of the tubular portion, and a wire harness fitting portion that closely fits to the outer periphery of the wire harness is provided at the proximal end of the tubular portion. . 3. The grommet according to claim 2, wherein a bellows tube is extended at a base end of the tubular portion, and the wire harness fitting portion is provided at an end of the bellows tube. Grommet to do.