JP3085190B2 - Grommet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grommet for an automobile, and more particularly, to a grommet mounted on a wire harness penetrating a body panel or the like for partitioning an engine room from the interior of the vehicle. In the case of waterproofing, dustproofing, etc. by interposing, the sound insulation performance is also improved.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a grommet of this type has a small-diameter cylindrical reduced diameter portion 1 made of rubber or an elastomer and is in close contact with the outer peripheral surface of a wire harness. It has a configuration in which the enlarged diameter portion 2 expanding in a conical tube shape is integrally formed. A wire harness W in which the wire group w is bundled with the tape T1 for the grommet 3
/ H, and is wound tightly around the outer peripheral surface of the reduced diameter portion 1 with a tape T2. Grommet 3
The wire harness W / H to which is attached is passed through the grommet 3 through the through hole 4a of the vehicle body panel 4 at the time of wiring to the automobile,
A locking recess 2a provided on the outer peripheral surface of the enlarged diameter portion 2 is locked and attached to the through hole 4a.

[0003]

The above-mentioned wire harness W
/ H is routed from the engine room side X to the room side Y, so that the grommet 3 once inserts the entire enlarged diameter portion 2 into the room side Y, then pulls it back to the engine room side X, and The stop recess 2a needs to be locked in the through hole 4a of the vehicle body panel 4. Therefore, the enlarged diameter portion 2 is bent and the through hole 4
a, the inclined portion 2b of the enlarged diameter portion 2 is made thin.

[0004] Therefore, an incident sound (shown by a solid arrow in the figure) including noise on the engine room X side is transmitted through the thin-walled enlarged portion 2 into the grommet 3, and the transmitted sound (shown by a dotted arrow in the figure). (Shown) enters the indoor side Y through the space S between the inner peripheral surface of the grommet 3 and the outer peripheral surface of the wire harness W / H inside the enlarged diameter portion 2 of the grommet 3. As described above, the conventional general grommet does not pay particular attention to the sound insulation performance, so that the sound insulation performance is low, the noise leaks from the wire harness insertion portion into the room, and the comfort performance in the vehicle interior is reduced. there were.

In order to improve the sound insulation performance, as shown in FIG. 5, a solid body 6 made of a rigid body is inserted into the inner space of the enlarged diameter portion 2 of the grommet 3 to seal the space. Is inserted, there is a problem that the work of penetrating the wire harness W / H is not easy and the workability is impaired. Further, a configuration in which the space is filled with a sealant has been proposed, but there is a problem that the work of filling the sealant is troublesome. In addition, the grommet is hardly bent by the solid body 6 or the hardened sealant, so that the workability of inserting the grommet into the vehicle body panel is deteriorated. There is also a problem that the cable workability is deteriorated. As described above, when the sound insulation performance is to be improved, the workability is deteriorated, and the compatibility cannot be easily achieved.

In Japanese Utility Model Application Laid-Open No. 63-20590, as shown in FIGS. 6A and 6B, a seal wall 7 is provided from the inner surface of the enlarged diameter portion 2 to the reduced diameter portion 1 side. And a grommet body is provided with a space 8 between the grommet and the grommet. The grommet bends the enlarged diameter portion 2 in the direction of the arrow even when the sealing agent 9 filling the electric wire w is hardened. The grommet 10 is provided for easily passing the grommet 10 through the panel through hole 4a. However, when this seal wall is provided, when the electric wire w is inserted from the reduced-diameter portion 2 side, the seal wall is folded back to the enlarged-diameter portion side, so that the electric wire insertion operation is difficult, and the seal wall 7 is turned over. Therefore, there is a drawback that it is troublesome because it is necessary to extend to the reduced diameter portion side.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a grommet which does not impair the flexibility of the grommet and the bendability of the wire harness, and which can improve the sound insulation performance without requiring any labor. It is intended to provide.

[0008]

In order to achieve the above object, according to the present invention, there is provided a fuel cell system comprising: a small-diameter cylindrical reduced-diameter portion; and a conical-tube-shaped enlarged diameter portion extending from one end of the reduced-diameter portion. And a wire harness, in which a group of electric wires is bundled, is passed through an electric wire insertion hole provided along the axis of the reduced diameter portion and the enlarged diameter portion, and a vehicle body locking recess is provided on an outer peripheral portion of the enlarged diameter portion. In the grommet, a small-diameter cylindrical inner circumferential partition wall extending along the axis wire insertion hole of the diameter-increased portion from the diameter-reduced portion after being turned radially inward from the opening-side tip of the diameter-reduced portion. The inner peripheral partition wall portion is radially outwardly expanded at the position of the leading end opening of the enlarged diameter portion, and a locking portion is protruded in the vicinity of the leading end portion, while a locking groove is formed on the distal end surface of the enlarged diameter portion. The above-mentioned locking portion is locked in the locking groove to form a closed space for sound insulation with an air layer inside. It provides a grommet to be.

With the above structure, even if noise enters the grommet from the engine room side into the thin-walled reduced-diameter portion and the thin-walled inclined portion of the enlarged-diameter portion constituting the outer peripheral wall portion of the grommet, the sound is not transmitted inside. It is absorbed by an air layer in a space formed tightly between the partition wall and the surrounding partition wall, and transmission to the indoor side can be suppressed, so that sound insulation performance can be improved. In addition, since only a sealed air layer is provided, the grommet does not impair flexibility, does not reduce the workability of mounting on the vehicle body panel, and does not impair the bendability of the wire harness inserted into the grommet. The workability of wiring the harness is not reduced. Furthermore, the locking portion provided at the tip of the inner peripheral partition wall portion formed by projecting from the opening tip of the enlarged diameter portion of the grommet can be easily locked simply by locking the locking groove in the end face on the opening side of the enlarged diameter portion. A closed space can be formed, and workability is good.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in FIGS. 1 to 3 will be described below. The grommet 10 has an outer peripheral wall portion 16 including a small-diameter cylindrical reduced-diameter portion 11 and an enlarged-diameter portion 12 expanding from one end of the reduced-diameter portion 11 into a conical cylindrical shape, and a tip on the opening side of the reduced-diameter portion 11. A substantially small-diameter cylindrical inner peripheral partition wall portion 13 formed to extend further inside is integrally formed of rubber.

The enlarged diameter portion 12 includes a conical thin portion 12a and a cylindrical thick portion 12b continuous with the thin portion 12a.
A vehicle body locking concave portion 14 having a concave cross section is provided in an annular shape on the outer periphery of the thick portion 12b. Thick cabin side locking portion 1 protruding radially outward from the vehicle body locking concave portion 14 toward the tip opening side.
2c is provided, and a locking groove 12d formed of a spherical groove is provided on the distal end surface of the locking portion 12c. Further, a protrusion 14a protrudes from the bottom surface of the vehicle body locking recessed portion 14, and as shown in FIG.
The protrusion 14a is pressed against the outer peripheral surface of the flange portion 4b which is bent to the side.

The inner peripheral partition wall portion 13 has a reduced thickness so as to be easily bent, and has a radially folded portion 13a folded radially inward from an opening end of the reduced diameter portion 11, and a folded portion 13a. The small-diameter cylindrical portion 13b extending along the electric wire insertion hole 17 of the axis inside the smaller-diameter portion 11 and the larger-diameter portion 12 and at the opening end of the large-diameter portion 12 continuous with the small-diameter cylindrical portion 13b. A flange 13c is formed radially outward, and a locking portion 13d is provided near the tip of the flange 13c. The locking portion 13d and the locking groove 12d may be provided in an annular shape, or may be formed at appropriate intervals.

The grommet 10 is formed in the state shown in FIG. 1. After the formation, the locking portion 13d of the flange portion 13c is locked as shown in FIG. An annular air chamber 20 sealed by the inner peripheral wall 16 and the inner peripheral partition 13 is formed. As shown in FIG. 3, after the wire harness W / H is inserted through the grommet 10, the locking portion 13d may be locked in the locking groove 12d.

The wire harness W / H is passed through the grommet 10 from the reduced diameter portion 11 side to the inside of the inner peripheral partition wall portion 13 using a grommet enlarger. At that time, since the inner peripheral partition wall portion 13 of the grommet 10 contains only air inside, it has flexibility and elasticity, easily spreads, and impairs the workability of inserting the wire harness W / H. There is no.

After passing the wire harness W / H through the grommet 10 in the above state, as shown in FIG.
2 is wound around the outer peripheral surface of the reduced diameter portion 11 to the outer surface of the wire harness W / H, and the wire harness W / H is positioned and fixed to the grommet 10.

When the wire harness W / H to which the grommet 10 is attached is inserted into the through hole 4a of the vehicle body panel 4, the entire enlarged portion 12 of the grommet 10 is once inserted from the engine room side X to the indoor side Y. At this time, it is necessary to bend the enlarged diameter portion 12 so as to have a small diameter. However, this operation can be performed without any problem because the grommet is easily bent. After inserting the enlarged diameter portion 12 into the indoor side Y, it is pulled back to the engine room side X, and the vehicle body locking concave portion 14 is locked in the through hole 4a. At that time, the protrusion 14a is pressed by the flange 4b, and the sealing property is improved.

The grommet 10 attached to the vehicle body panel 4 as described above is provided between the thin-walled reduced-diameter portion 11 and the enlarged-diameter portion 12 and the wire harness W / H even when noise enters from the engine room side X. There is an air layer in the air chamber 20 partitioned by the inner peripheral partition wall portion 13, and the incident sound is absorbed by the air layer, and transmission of noise to the indoor side Y is suppressed.

[0018]

As is apparent from the above description, in the grommet according to the present invention, the inner peripheral partition is provided inside the conventional grommet, and the sealing between the inner peripheral partition and the outer peripheral wall is performed. Due to the presence of an air layer in the space, the thickness of the outer peripheral wall of the grommet is thin, so even if noise enters the grommet, sound transmission is suppressed, and noise is transmitted from the engine room side to the indoor side. And the sound insulation performance can be improved.

Furthermore, since only the sealed air layer is provided, the grommet does not impair flexibility, and the workability of inserting the wire harness into the grommet and the workability of inserting the grommet into the through hole of the vehicle body panel. In any case, both sound insulation and workability can be achieved.

Further, the sealed air layer can be formed extremely simply by locking the locking portion provided at the distal end of the inner peripheral partition wall into the locking groove at the distal end surface of the enlarged diameter portion.
Since it is formed by folding back from the reduced diameter part side to the enlarged diameter part side through which the wire is inserted and the folding direction is the same direction as the wire insertion direction with respect to the grommet, there is a problem that the inner peripheral partition wall part is folded back when inserting the wire. This has the advantage that it does not occur.

In particular, in a car, it is very important to prevent noise from entering the cabin in order to improve the comfortable performance of the living space in the cabin. In that case, the noise from the engine room side is important. The point is to eliminate or suppress leakage. By using the grommet of the present invention, it is possible to almost completely block low noise and suppress loud noise as well, thereby preventing and suppressing sound leakage into the vehicle interior and improving comfort performance. This has a specific effect that can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a grommet of the present invention.

FIG. 2 is a cross-sectional view showing a state where a sealed air layer is provided on the grommet of FIG.

FIG. 3 is a cross-sectional view showing a state in which a wire harness is inserted into a grommet of the present invention and locked to a vehicle body.

FIG. 4 is a cross-sectional view showing a state where a wire harness is inserted through a conventional grommet.

FIG. 5 is a cross-sectional view showing another conventional grommet.

FIGS. 6A and 6B are cross-sectional views showing another conventional grommet.

[Explanation of symbols]

 Reference Signs List 4 body panel 4a through hole 10 grommet 11 reduced diameter section 12 enlarged diameter section 12d locking groove 13 inner peripheral partition wall section 13d locking section 14 vehicle body locking concave section 16 outer peripheral wall section 20 air chamber w electric wire W / H wire harness

Claims (1)

(57) [Claims] 1. A small-diameter cylindrical reduced-diameter portion, and a large-diameter portion expanding from one end of the reduced-diameter portion into a conical cylindrical shape, provided along the axis of the reduced-diameter portion and the large-diameter portion. In a grommet provided with a vehicle body locking concave portion on the outer periphery of the enlarged diameter portion, the wire harness in which the group of electric wires was bundled was passed through the electric wire insertion hole, and the grommet was folded radially inward from the opening end of the reduced diameter portion. Later, a small-diameter cylindrical inner peripheral partition wall extending from the reduced diameter portion along the electric wire insertion hole of the axis of the enlarged diameter portion is provided, and the inner peripheral partition wall portion is positioned radially outward at the opening end of the enlarged diameter portion. And a locking portion is protruded in the vicinity of the distal end thereof, while a locking groove is provided on the distal end surface of the enlarged diameter portion, and the locking portion is locked in the locking groove to form an air space. A grommet characterized by forming an enclosed sound-insulating enclosed space.