JP2002010451A - Grommet, method of mounting and mounting structure for installation of wire harness to the grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grommet to maintain water and sound insulation and enable the wire harness to bend near a panel without deformation. SOLUTION: A grommet is composed of an inner tube 11, an outer tube 12 which is provided with a recess 14 formed on the outer periphery face as and an elastic connection part 13. The inner tube 11 is closely adhered to a wire harness W/H and has small diameter. The outer tube 12 surrounds the inner tube 11 with an air layer 20 and has large diameter, thicker part on the tip and a cavity 14 on the outer circumference. The elastic connection part 13 connects the tips of the inner tube 11 and the outer tube 12 and the elastic connection part 13 is displaced between a first position, a second position and a third position. In the first position, the elastic connection part 13 bends between the inner tube 11 and the outer tube 12 in the radial direction and another end of the inner tube 11 which projects from the outer tube 12. In the second position, the elastic connection part 13 extends from the outer tube 12 to the inner tube 11, inclined with respect to another end of the grommet and another end of the inner tube 11 projects from outer tube 12 by a large amount. The elastic connection 13 expands, extending to its tip and other ends of the inner tube 11 and the outer tube 12 which are to be displaced to the the third position with which they watch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grommet which is attached to a wire harness for an automobile and is attached to a through hole of a vehicle body panel, and a method and an attachment structure for the grommet.

[0002]

2. Description of the Related Art Conventionally, when a wire harness is routed from outside such as an engine room of an automobile to a vehicle interior, as shown in FIGS. 4 (A) and 4 (B), rubber or elastomer is added to the wire harness W / H. The grommet 1 made of steel is externally fitted. Wire harness W to which this grommet 1 is attached
/ H is passed through the through hole 3 of the vehicle body panel 2 that separates the exterior (X) and the passenger compartment (Y), and the grommet 1 is attached to the periphery of the through hole 3 to penetrate from the engine room side to the passenger compartment. Hole 3
Waterproof and dustproof to prevent water and dust from entering through.

In addition, noise (abnormal noise) transmitted from the outside of the engine room or the like to the vehicle interior through the wire harness penetration portion.
Therefore, a sound insulating grommet 1 ′ shown in FIG. 5 is provided. The sound-insulating grommet 1 'is formed by wrapping an end of an outer cylinder 6 with a tape 8a and providing an air reservoir 7 between the inner cylinder 5 and the outer cylinder 6, so that noise transmitted from outside to the grommet 1' is retained in the air reservoir. The part 7 absorbs sound to provide sound insulation. In addition, the electric wire of the wire harness W / H that passes through the inside of the inner cylinder 5 is filled with a waterproofing agent 9 in advance to enhance the sealing property. In the grommet 1 ′, after the wire harness is inserted through the inner cylinder 5, the end of the inner cylinder 5 is
Wrap with tape 8b and fix with wire harness W / H,
This makes the grommet excellent in both water stopping performance and sound insulation performance.

[0004]

However, when the sound insulating grommet 1 'is mounted in the through hole 3 of the vehicle body panel 2, the inner cylinder 5 projects more outward than the outer cylinder 6, so that the The protruding length L of the grommet 1 'to the outside on the engine room side becomes longer.

For this reason, as shown in FIG. 6, when there is an external interference member 50 near the panel 2 and it is necessary to bend the wire harness W / H near the panel 2, when the wire harness W / H needs to be bent, It is necessary to bend up to 5. The inside of the bent and protruding inner cylinder 5 is filled with the water-stopping agent 9, so that it is hard and hard to bend. Further, when the inner cylinder 5 is bent, the entire grommet 1 'is deformed, and a gap C is generated between the vehicle body locking portion of the grommet 1' and the panel, so that the sealing performance is deteriorated. In addition, due to the deformation of the grommet 1 ', the tape fixing the outer cylinder 6 and the inner cylinder 5 also shifts, and the outer cylinder 6 and the inner cylinder 5 are separated from each other, the air reservoir 7 is not sealed, and the sound insulation performance is reduced. There is also a problem of lowering.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to maintain a water stopping performance and a sound insulating performance of a grommet, and to allow a wire harness to be bent near a panel without deforming the grommet. Is an issue.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a grommet which is integrally formed of rubber or elastomer and is fitted to a through hole of a vehicle body panel while being externally fixed to a wire harness. A small-diameter inner cylinder that is brought into close contact with the harness, a large-diameter outer cylinder that surrounds the inner cylinder by opening an air layer, and has a thicker front end side and a concave portion for locking the vehicle body on the outer peripheral surface; The telescopic connecting portion connects the front end and the front end of the inner cylinder, and the telescopic connecting portion is in a contracted state in which the inner cylinder is contracted radially between the outer cylinder and the outer cylinder, and the other end of the inner cylinder projects from the outer cylinder. A second position where the other end of the inner cylinder protrudes larger than the outer cylinder in a state where the expandable connection portion is inclined and extended from the outer cylinder to the inner cylinder toward the other end, and The third in which the other end of the inner cylinder coincides with the other end of the outer cylinder by bulging to the distal end side
A grommet is provided which is adapted to be displaced into position.

[0008] By providing the telescopic connecting portion, the grommet can be displaced to the first position, the second position, and the third position, so that the position of the inner cylinder can be moved. Therefore, in order to obtain the water stopping performance and sound insulation performance of the grommet, when winding the inner cylinder and the outer cylinder end with tape, fix the inner cylinder to the panel side after fixing the tape at the position where the inner cylinder protrudes to the outside. To make the other end of the inner cylinder coincide with the other end of the outer cylinder. Thus, the length of the grommet projecting from the panel to the outdoor side can be shortened, and the wire harness can be bent near the panel even when there is an external interference material near the panel on the outdoor side.

The grommet can be attached to the wire harness by passing the wire harness through the inner cylinder at the first position, and then pulling the inner cylinder toward the other end to the second position. At the position, the inner cylinder and the wire harness are fixed by tape winding, and then, the inner cylinder is pushed into the outer cylinder, and the other end of the outer cylinder and the inner cylinder is in a third position where the elastic connection portion bulges to the distal end side. In this state, the other ends of the outer cylinder and the inner cylinder are tape-fixed, and the air layer between the outer cylinder and the inner cylinder is sealed, whereby the outer cylinder and the inner cylinder are attached to the wire harness.

As described above, when the inner tube of the grommet and the electric wire group of the wire harness are fixed by winding the tape, the inner tube is projected from the outer tube, so that the operation of fixing the tape can be easily performed. After that, when the inner cylinder is pushed in, the expansion / contraction connection part is thinned and bent, so that the expansion / contraction connection part can be smoothly expanded to push the inner cylinder.

The wire harness passed through the inner cylinder is in a state where a group of electric wires is coated in advance with a waterproofing agent and is roughly wound with tape, and is inserted into the inner cylinder in this state. Usually, the portion filled with the water blocking agent hardens after the filling, so that the degree of freedom with respect to the bending of the wire harness is low. However, since the inner cylinder and the wire harness are fixed by tape winding, and then the inner cylinder is pushed into the outer cylinder, the inner cylinder filled with the waterproofing agent is accommodated in the outer cylinder. The wire harness can be bent at a position protruding from the wire harness.

Further, since the other ends of the inner cylinder and the outer cylinder coincide with each other and are fixed by tape winding, a sealed air layer is provided between the inner cylinder and the outer cylinder, so that the sound insulation performance can be improved.

As the water stopping agent for stopping water between the wires of the wire harness, one-component silicone having a low viscosity is preferably used.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment, in which a grommet 10 is made of rubber or an elastomer, and has a small-diameter inner cylinder 11 which is in close contact with a wire harness;
A large-diameter outer cylinder 12 surrounding an air layer 20
The outer tube 12 has a thicker end portion and a concave portion 14 for locking the vehicle body on the outer peripheral surface. The telescopic connecting part 1
Numeral 3 is thin so that it can be easily deformed.

The grommet 10 is in a contracted state, as shown in FIG. 1A, in which the elastic connecting portion 13 is bent radially between the inner cylinder 11 and the outer cylinder 12, and the other end of the inner cylinder 11 is 1B, the other end of the inner cylinder 11 is extended from the outer cylinder 12 to the inner cylinder 11 in a state where the other end of the inner cylinder 11 is inclined and extended toward the other end. A second position that protrudes more;
As shown in FIG. 1 (C), the expansion / contraction connection side bulges toward the distal end side and is displaced to a third position where the other ends of the inner cylinder 11 and the outer cylinder 12 coincide.

At the second position, the dimension of the inner cylinder 11 projecting from the outer cylinder is about 30 mm. Therefore, when displacing from the second position to the third position, the inner cylinder 11
0mm is pushed in.

As described above, the grommet 10 can be displaced between the first position, the second position, and the third position by the expansion and contraction of the expansion and contraction connection portion 13, so that the position of the inner cylinder 11 can be moved.

The method of attaching the grommet to the wire harness will be described below. As shown in FIG. 2A, the wire harness W / H is passed through the inner cylinder 11 at the first position of the grommet 10. At this time, the waterproofing agent 15 is applied to the wire group 16 of the wire harness in advance by a water stopping method between lines, and is roughly wound by the tape 30c. Then, as shown in FIG. 2 (B), the inner cylinder 11 is pulled toward the other end to the second position, and the tip of the inner cylinder 11 and the wire harness W /
H is fixed by tape winding with a tape 30a. Thereafter, as shown in FIG. 2C, the inner cylinder 11 is pushed into the outer cylinder 12 together with the wire harness W / H. With this operation, the expansion / contraction connection portion 13 is deformed to the third position bulging to the distal end side, the inner cylinder 11 can be accommodated in the outer cylinder 12, and the other ends of the outer cylinder 12 and the inner cylinder 11 are matched. Can be. In this state, the other ends of the outer cylinder 12 and the inner cylinder 11 are fixedly wound with a tape 30b. Thereby, the air layer 20 between the outer cylinder 12 and the inner cylinder 11 is sealed.

When the inner cylinder 11 is pushed into the outer cylinder 12 as described above, the portion filled with the water-stopping agent 15 is accommodated in the outer cylinder 12, and the water-stopping filling position is set inside the grommet 10. it can.

When the wire harness W / H to which the grommet 10 is attached as described above is routed on the vehicle body, and as shown in FIG. 3, the grommet is mounted on the panel through the through hole 3 of the vehicle body panel 2, the grommet 10 Since the overall length of the panel is short, the amount of protrusion from the panel is also short. Therefore, when bending the wire harness in relation to the external interference member 50, the wire harness may be bent at a position where the wire harness protrudes from the grommet 10, and the grommet 10 does not need to be bent.

As a result, the wire harness can be easily bent, and the grommet is not bent, so that no deformation occurs and the water stopping performance and the sound insulation performance can be maintained.

The grommet is preferably used because the overall length of the grommet can be shortened even when the wire harness is not closed between lines.

[0023]

As is apparent from the above description, according to the present invention, a wire harness in which a sealed air layer is provided between an inner cylinder and an outer cylinder, and a waterproofing agent is applied to the inner cylinder. Since it is inserted, it becomes a grommet with excellent water stopping performance and sound insulation performance. Further, the inner cylinder through which the wire harness filled with the waterproofing agent is inserted can be accommodated inside the outer cylinder, so that the entire length of the grommet can be shortened and the waterproofing agent-filled portion can be located inside the grommet. Therefore, when wiring the wire harness to the vehicle body, when the wire harness needs to be bent near the grommet attached to the through hole of the vehicle body panel, only the wire harness is bent because the amount of protrusion of the grommet from the panel is small. This eliminates the necessity of forcibly deforming and bending the grommet. As a result, the wire harness can be smoothly bent, and the grommet can maintain the water stopping performance and the sound insulation performance.

[Brief description of the drawings]

1 shows an embodiment of the grommet of the invention,
(A) (B) (C) is sectional drawing in each deformation | transformation position of a grommet.

FIGS. 2A, 2B, and 2C are cross-sectional views showing a method of attaching a grommet to a wire harness.

FIG. 3 is a cross-sectional view showing a state in which a wire harness to which a grommet is attached is attached to a vehicle body.

FIG. 4A is a cross-sectional view of a conventional grommet, and FIG.
FIG. 2 is a schematic view showing a vehicle body attachment state.

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

6 is a view showing a problem of the grommet of FIG.

[Explanation of symbols]

 2 Panel 3 Through-hole 10 Grommet 11 Inner cylinder 12 Outer cylinder 13 Telescopic connection part 14 Depression for vehicle body locking 15 Waterproofing agent 16 Electric wire group 20 Air layer 30a, 30b Tape

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02G 3/38 H02G 3/28 F

Claims (4)

[Claims] 1. A grommet integrally formed of rubber or an elastomer mounted on a through hole of a vehicle body panel while being externally fitted and fixed to a wire harness, wherein a small-diameter inner cylinder is brought into close contact with the wire harness, and air is supplied to the inner cylinder. A large-diameter outer cylinder surrounding the layer by opening the layer and having a concave portion for locking the vehicle body on the outer peripheral surface with a thicker tip side, and a telescopic connecting portion connecting the tip of the outer cylinder and the tip of the inner cylinder. A first position at which the other end of the inner cylinder projects from the outer cylinder; and A second position in which the other end of the inner cylinder protrudes larger than the outer cylinder in a state where the other end of the inner cylinder protrudes from the outer cylinder in a state where the other end of the inner cylinder extends toward the other end of the inner cylinder and the outer cylinder; A grommet is adapted to be displaced to a third position where 2. A method of attaching the grommet according to claim 1 to a wire harness, wherein a wire harness is passed through the inner cylinder at a first position of the grommet, and then the inner cylinder is pulled toward the other end. The second position, and the inner tube and the wire harness are tape-fixed at the second position. Thereafter, the inner tube is pushed into the outer tube, and the telescopic connecting portion swells toward the distal end. The other end of the outer cylinder and the other end of the inner cylinder coincide with each other, and in this state, the other end of the outer cylinder and the other end of the inner cylinder are fixed by tape winding, and a grommet wire harness mounting that seals an air layer between the outer cylinder and the inner cylinder is provided. Method. 3. The method according to claim 2, wherein the wire group of the wire harness inserted into the inner cylinder is preliminarily coated with a waterproofing agent. 4. A structure in which the grommet according to claim 1 is attached to a wire harness, wherein the other ends of the inner cylinder and the outer cylinder coincide with each other and are fixedly wound with a tape, and are sealed between the inner cylinder and the outer cylinder. Air layer is provided, and the elastic connecting portion is bulged at the tip side of the inner cylinder and the outer cylinder, and the inner cylinder through which the wire harness is inserted is filled with a waterproofing agent. Grommet wire harness mounting structure.