JPH09259672A - Grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grommet which can sufficiently absorb external force even when it is applied to a flow pipe part, by forming a first stress absorbing part of almost U-shaped section between the flow pipe part and a grommet mounting part, and forming a second stress absorbing part of almost U-shaped section in one end of the grommet mounting part. SOLUTION: A stress absorbing part 20 comprising a first/second stress absorbing part 21, 22 is provided between a flow pipe part 10 and a grommet mounting part 30. In this first stress absorbing part 21, one end of the flow pipe part 10 is folded back in a peripheral direction, a section is formed in almost U shape, in the second stress absorbing part 22, one end of the grommet mounting part 30 is folded back in an internal peripheral direction, a section is formed in almost U shape. In this way, even when external force is applied to the flow pipe part 10 of a grommet, stress by the external force is sufficiently absorbed by the stress absorbing part 20, deformation of the grommet mounting part 30 is prevented, the grommet improving a waterproof and dustproof effect is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grommet used for arranging a wire harness penetrating a mounting hole of a vehicle body or the like.

[0002]

2. Description of the Related Art A conventional grommet will be described below with reference to the drawings. FIG. 2 is a cross-sectional view showing a conventional grommet (a cross section passing through the central axis of the conduit portion 10 in the longitudinal direction). In the conventional grommet, as shown in FIG. 2, the conduit portion 10, the stress absorbing portion 40, and the grommet mounting portion 30 are integrally formed of a rubber material or the like. The conduit portion 10 is formed in a tubular shape having a certain thickness, and a wire harness or the like is passed through the conduit portion 10 so that an adhesive tape is wound between the open end of the conduit portion 10 and the wire harness to externally A waterproof and dustproof seal is applied. The grommet mounting portion 30 has a wall thickness that is relatively hard to be deformed even when an external force is applied manually, and a fixing groove 31 that can be mounted in a grommet mounting hole of the vehicle body is formed on the outer periphery. The edge of the grommet mounting hole and the fixing groove 31 are brought into close contact with each other, so that the grommet mounting hole is waterproof and dustproof. Further, the stress absorbing portion 40 is located between the conduit portion 10 and the grommet mounting portion 30,
It has a shape that is folded back only once in the outer peripheral direction of the conduit portion 10, and has a linear cross section near the grommet mounting portion 30.

[0003]

However, in the conventional grommet, when an external force is applied to the wire harness attached to the grommet, the external force is transmitted to the grommet mounting part without being sufficiently absorbed by the stress absorbing part, and the grommet mounting part There is a problem in that the waterproof and dustproof effects are attenuated due to the formation of a gap between the grommet mounting hole and the fixing groove of the grommet by deforming.

The present invention has been made in view of the above points, and an object thereof is to provide a grommet in which the waterproof and dustproof effects are not attenuated even when an external force is applied to the wire harness attached to the grommet.

[0005]

The grommet of the present invention comprises:
In a grommet in which a stress absorbing portion is formed between a conduit portion and a grommet mounting portion, the stress absorbing portion has a U-shaped cross section, and one end of the grommet mounting portion has a substantially inward cross section. It is characterized in that it is formed of a second stress absorbing portion that is folded back in a U shape.

In this way, the stress absorbing portion formed by folding back the conduit section into a substantially U shape and the second portion formed by folding the grommet mounting portion in the inner circumferential direction into a substantially U shape.
By forming the stress absorbing portion, for example, when an unexpected external force is applied to the wire harness attached to the grommet, the external force is first absorbed by the deformation of the stress absorbing portion, and then the second stress absorbing portion. It is absorbed by the deformation of.
By providing such a stress absorbing part and the second stress absorbing part, even if an unexpected external force is applied to the conduit part of the grommet, the deformation of the grommet mounting part can be prevented, and thus the waterproof and dustproof effects are attenuated. There is no.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a grommet according to the present invention (a section passing through a central axis in the longitudinal direction of the conduit portion 10). As shown in FIG. 1, the grommet of the present invention includes a stress absorbing portion 20 between the conduit portion 10 and the grommet mounting portion 30.
The grommet in which the stress absorbing portion 20 is formed.
The cross section is folded back in a substantially U shape, and one end of the grommet mounting portion 30 is formed by the second stress absorbing section 22 in which the cross section is folded back in a substantially U shape in the inner circumferential direction. It is characterized by. In FIG. 1, 21 is the first
A stress absorption part is shown.

In the grommet of the present invention, the conduit portion 10, the stress absorbing portion 20, and the grommet mounting portion 30 are integrally formed of an elastic insulating material such as a rubber material. Although not shown, the conduit portion 10, the stress absorbing portion 20,
The grommet attachment portions 30 are arranged so that their central axes are the same. Further, the external shape is axisymmetric with the central axis as an axis (for example, a circle, an ellipse, an oval, etc. when viewed in the axial direction). The conduit portion 10 has a tubular shape with a certain thickness, and a wire harness or the like is passed through the conduit portion 10 to wind an adhesive tape between the open end of the conduit portion 10 and the wire harness. Waterproof and dustproof seals are applied from the outside. Further, the grommet mounting portion 30 is provided at a certain distance in the outer peripheral direction of the conduit portion 10 and has a wall thickness that is relatively hard to be deformed even when an external force is manually applied,
A fixing groove 31 that can be mounted in a grommet mounting hole of the vehicle body is formed on the outer periphery. The edge of the grommet mounting hole and the fixing groove 31 are brought into close contact with each other, so that the grommet mounting hole is waterproof and dustproof. Further, the stress absorbing portion 20 is provided on the outer peripheral side of the conduit portion 10 and on the inner peripheral side of the grommet mounting portion 30, has the same thickness as the conduit portion 10, and one end of the conduit portion 10 is in the outer peripheral direction. The cross section is folded back into a substantially U shape, and one end of the grommet mounting portion 30 is formed into a second stress absorbing section 22 in which the cross section is folded back in a substantially U shape in the inner circumferential direction. The second
Since the stress absorbing portion 22 is a connection point between portions having large differences in wall thickness, it is preferable that the stress absorbing part 22 is formed so that the wall thickness gradually changes for the purpose of avoiding stress concentration.

The stress absorbing portion 20 and the second stress absorbing portion 2
It is preferable that the portion formed by folding back the cross section of 2 in a substantially U shape has a radius of curvature and a thickness capable of absorbing stress. Needless to say, in order to obtain the aforementioned radius of curvature capable of absorbing stress, the outer peripheral surface of the conduit portion 10 and the grommet mounting portion 3
It is advisable to provide sufficient spaces (thickened portions) 23 and 24 between the 0 inner peripheral surfaces. Thereby, even if an unexpected external force acts on the wire harness attached to the grommet, the elastic stress absorbing portion 20 is easily deformed by receiving the external force, and the stress absorbing function can be sufficiently exhibited. Further, since the grommet of the present invention has a simple shape, the cost does not increase as compared with the conventional example.

[0010]

As described above, according to the grommet of the present invention, in the grommet in which the stress absorbing portion is formed between the conduit portion and the grommet mounting portion, the stress absorbing portion has a substantially U-shaped cross section. Since the grommet mounting portion is formed by the second stress absorbing portion which is formed by folding back one end of the grommet mounting portion in a generally U-shaped cross section in the inner circumferential direction, an external force is applied to the conduit portion of the grommet. However, since the stress absorbing portion and the second stress absorbing portion sufficiently absorb the stress to prevent deformation of the grommet mounting portion, it is possible to provide the grommet in which the waterproof and dustproof effects are not attenuated.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a conventional grommet.

[Explanation of symbols]

 10 conduit part 20 stress absorption part 21 1st stress absorption part 22 2nd stress absorption part 30 grommet attachment part

Claims (1)

[Claims] 1. A grommet in which a stress absorbing portion is formed between a conduit portion and a grommet mounting portion, wherein the stress absorbing portion has a U-shaped cross section, and one end of the grommet mounting portion is an inner circumference. A grommet characterized by being formed of a second stress absorbing portion formed by folding back a section in a substantially U shape in the direction.