JPH0742878A - Grommet - Google Patents

Abstract

(57) [Summary] [Purpose] When mounting the grommet to the panel mounting hole, it can be mounted with a low insertion force by positioning it in the correct posture, which can reduce the number of work steps and ensure accurate mounting. [Structure] An annular step which is fitted to an opening edge 8a of a panel mounting hole 8 by reducing the diameter of the large-diameter tubular portion on the outer peripheral surface of an intermediate portion 4 connecting the large-diameter tubular portion 2 and the small-diameter tubular portion 3. After the portion 5 is provided and the opening edge is temporarily locked to the annular step, the grommet 1
Is inserted into the panel mounting hole and fitted into the mounting hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents contact between a mounting hole and a wire harness when inserting a wire harness or the like into a mounting hole formed in a panel or the like, and allows water to penetrate into the panel through a gap. The present invention relates to a grommet for preventing the above, and more particularly, to a grommet that can be easily assembled in a panel mounting hole.

[0002]

2. Description of the Related Art Conventionally, this type of grommet is usually made of rubber,
It is made of an elastic material such as synthetic resin and has a substantially donut shape. It is elastically deformed so as to reduce the diameter when the wire harness etc. is inserted, and the annular groove formed on the outer periphery is engaged with the mounting hole of the panel etc. By doing so, it is attached to the panel or the like. However, when mounting, for example, if the peripheral wall thickness around the annular groove is large, the reaction force at the time of elastic deformation is strong and it is difficult to obtain a sufficient amount of bending, so there is a problem that it is very difficult to insert it into the panel mounting hole. It was For this reason,
In the grommet disclosed in Japanese Patent No. 56919, a thin notch that is easily deformed by insertion is formed on the outer periphery of the insertion portion of the grommet into the panel mounting hole, so that the grommet can be easily inserted into the panel mounting hole. Good ones have been proposed.

Referring to FIG. 4, the grommet 21 will be described below. The grommet 21 is made of an elastic material such as rubber or synthetic resin. The grommet 21 is composed of the collar portion 22 and the collar portion 22. Also has an insertion portion 23 having a small diameter, and further has an annular groove 29 fitted into a mounting hole 28 of a dash panel 27 or the like.
And a wire harness, for example, is inserted into and supported by a through hole 24 provided in the shaft core. In order to make it easy to insert the grommet 21 into the mounting hole 28, the insertion portion 23 has a tip portion 23b slightly smaller than the inner diameter of the mounting hole 28, and a diameter gradually increasing from the tip portion 23b for mounting. It is formed in a truncated cone shape having a base portion 23a having a diameter larger than the inner diameter of the hole 28, and the base portion 23a is provided with an annular groove 29 having a diameter close to the inner diameter of the mounting hole 28.

The grommet 21 has the tip 2
3b is inserted into the mounting hole 28, and further, the base portion 23a is elastically deformed so as to reduce the diameter and inserted into the panel surface, so that the annular groove 29 fits with the mounting hole 28 and is in close contact with the dash panel 27. It is attached. But its base 2
In order to facilitate elastic deformation of 3a, as shown in FIG. 4 (B), a plurality of notches 30 are provided in the outer peripheral surface of the insertion portion 23 at appropriate intervals, and the base portion 23a is arranged along the axis. A remaining portion 31 that reduces the wall thickness is provided between the notches 30.
As a result, the grommet 21 is press-fitted in the axial direction at the time of mounting the same, and at the same time, a torsional force is applied in the circumferential direction, so that the remaining portion 31 is easily deformed in the circumferential direction due to the presence of the notch 30, and thus, is substantially It was possible to easily reduce the diameter and insert it into the mounting hole 28 easily. Furthermore, the grommet is
By mounting with such a low insertion force, breakage such as tearing could be avoided.

As another conventional example, as shown in FIG. 5, a rear edge portion 49a of an annular groove 49 corresponding to the base portion in the conventional example shown in FIG. 4 is thin-walled so as to be easily elastically deformed in the axial direction. Some are formed in a shape.

[0006]

However, in each of the above-mentioned conventional examples, in the former one, since the mold shape is complicated according to the grommet shape, the mold cost increases and the manufacturing cost increases. There was a drawback that it would end up. Further, as described above, when mounting on a dash panel or the like, it is required to perform work to apply axial twisting and circumferential twisting at the same time, which requires extra labor. In particular, the addition of such work complicates the robot structure when automating the mounting work.

In the latter case, when the grommet 41 is inserted into the mounting hole 48, the grommet 41 supports the large-diameter cylindrical portion 42 having the annular groove 49 and the wire harness 50 as shown in FIG. Since the tapered surface 44 is formed between the small diameter cylindrical portion 43 and the small diameter cylindrical portion 43, which is in contact with the mounting hole opening edge 47a of the panel 47, the tapered surface 44 is difficult to keep in a horizontal state before insertion, and thus is unnatural. The insertion was made in such a way that it could not be expected to be inserted with low insertion force. The inevitability of positioning the grommet in the correct position prior to insertion is similar with the former, and this problem remains unsolved.

The present invention has been made in order to solve such drawbacks and difficulties, and the purpose thereof is to obtain a low insertion force by positioning and inserting the grommet in a correct posture when mounting it. , It is to provide a grommet that can reduce the working time and realize an accurate mounting work.

[0009]

In order to achieve the above object, a grommet according to the present invention has a large diameter tubular portion, a small diameter tubular portion,
A grommet for gradually reducing the diameter of the large-diameter tubular portion and including an intermediate portion for integrally connecting the large-diameter tubular portion and the small-diameter tubular portion, and at least reducing the diameter of the large-diameter tubular portion and inserting it into the panel mounting hole. In the above, an annular step portion that temporarily locks with the panel mounting hole before reducing the diameter of the large diameter cylindrical portion is provided on the outer peripheral surface of the intermediate portion reaching the large diameter cylindrical portion.

[0010]

[Function] Since the grommet is temporarily locked in the panel mounting hole by the annular step portion abutting against the panel surface before it is inserted into the dash panel, etc., positioning at the time of insertion is facilitated and the grommet is inserted in the correct posture. It can be carried out. As a result, the grommet portion that elastically deforms can be brought into uniform contact with the entire circumference of the rim of the mounting hole, and thus a low insertion force can be obtained, and the work man-hours at the time of mounting work can be reduced, and at the same time, accurate Can be installed.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a vertical sectional view showing an embodiment of the grommet of the present invention, showing a state before panel mounting. FIG. 2 is a vertical cross-sectional view of the grommet shown in FIG. 1 and shows a panel mounting completed state. FIG. 3 is an enlarged sectional view taken along the circle A of FIG.
In addition, in each of the above drawings, a wire harness or the like inserted into the grommet is omitted.

In FIG. 1, the grommet 1 of the present invention is
One end is made up of a large-diameter tubular portion 2, and the other end is made up of a small-diameter tubular portion 3 having an inner diameter such that a wire harness or the like can be inserted. The large-diameter tubular portion 2 and the small-diameter tubular portion 3 are larger than the large-diameter tubular portion 2. The diameter is gradually reduced,
In addition, it has a structure integrally connected by the intermediate portion 4 formed in a bellows shape. Further, this grommet 1 is formed as a molded product of an elastic member such as rubber, and as in the conventional case,
It is elastically deformable. In particular, the intermediate portion 4 can be easily elastically deformed in the axial direction and the circumferential direction due to the characteristics of the shape in combination with the characteristics of the material.

On the outer peripheral surface of the large-diameter cylindrical portion 2, an annular groove 9 for mounting in a panel mounting hole 8 described later is provided in a ring shape. On the rear side of the annular groove 9 and on the outer peripheral surface of the intermediate portion 4 reaching the large-diameter tubular portion 2, an annular step portion 5 cut in the circumferential direction is formed. The dash panel 7 is provided with a panel mounting hole 8 for mounting the grommet 1 at a predetermined position, and the mounting hole 8 has an opening edge 8a slightly bent in a specific direction to be burred.

The annular groove 9 and the annular stepped portion 5 will be further described with reference to FIG. 3. The annular groove 9 has a diameter substantially equal to that of the panel mounting hole 8, and the width dimension is the opening edge 8a. It is formed somewhat wider than the width of. Further, a lip-shaped locking piece 2a that can be tightly engaged with the panel surface is formed on the peripheral edge of the front side wall forming the large-diameter cylindrical portion 2 among the side walls forming the annular groove 9.

A rear side wall 9a of the side walls forming the annular groove 9 is formed in a thin flange-like shape, and a grommet 1 is provided on the rear side through the side wall 9a. The annular step portion 5 for temporarily locking the grommet 1 to the panel 7 when it is mounted in the mounting hole 8 is formed. The annular step portion 5 is provided with a diameter slightly smaller than that of the mounting hole 8 and has a flat locking surface 5a. The grommet 1 is inserted into the panel mounting hole 8 and the annular step portion 5 is further attached to the panel. Fitting in the mounting hole 8 and engaging surface 5a
When these are arranged so as to be inscribed in the opening edge 8a, the grommet 1 can be temporarily locked to the panel 7 (see FIG. 1).

As shown in FIG. 1, the inner wall surface and the rear end portion of the small-diameter cylindrical portion 3 are in contact with an outer peripheral surface of a wire harness (not shown) so as to improve the adhesion.
a is provided.

Next, the panel 7 of the grommet 1 having the above structure
The work of attaching to is explained. The grommet 1 is inserted into the mounting hole 8 from the small-diameter cylindrical portion 3 of the grommet 1 with the wire harness inserted therethrough. Further, when the grommet 1 is inserted and inserted until it abuts against the surface of the panel 7, the locking surface 5a is arranged in an inscribed state with respect to the opening edge 8a as shown by the imaginary line in FIG. Be stopped. After being positioned in such a state, when the grommet 1 is further pulled in the direction of the arrow in FIG. 1, the side wall 9a is pressed by the surface of the panel 7 and elastically deforms easily toward the large-diameter cylindrical portion 2 side. The large-diameter cylindrical portion 2 is formed by the fact that 8a gets over this side wall 9a.
In a reduced diameter state and moved into the annular groove 9. Then, when the surface of the panel 7 is provided in a state where the side wall on the side of the large-diameter tubular portion 2 forming the annular groove 9 is strongly pressed, the side wall 9a is restored, and the grommet 1 is attached to the mounting hole as shown in FIG. 8 is inserted. Further, in this state, the lip-shaped locking piece 2
The a is in close contact with the surface of the panel 7 and can prevent water from entering from the large-diameter cylindrical portion 2 side.

[0018]

As described above, the grommet according to the present invention is positioned and inserted in the correct posture by the locking step before being mounted in the panel mounting hole, so that the predetermined insertion force is low. Can be obtained. Therefore, the mounting workability is improved, the working time can be shortened, and the accurate mounting work can be realized.

[Brief description of drawings]

FIG. 1 is a vertical sectional view according to an embodiment of a grommet of the present invention, showing a state before panel mounting.

FIG. 2 is a vertical sectional view of the grommet shown in FIG. 1 in a panel-mounted state.

FIG. 3 is an enlarged cross-sectional view of a portion indicated by a circular frame A in FIG.

FIG. 4 is a grommet according to a conventional example, in which (A) is a longitudinal sectional view thereof and (B) is a plan view thereof.

FIG. 5 is a sectional view of a grommet according to another conventional example.

[Explanation of symbols]

 1 Grommet 2 Large-diameter cylindrical part 3 Small-diameter cylindrical part 4 Intermediate part 5 Annular step 5a Locking surface 7 Dash panel 8 Panel mounting hole 8a Opening edge 9 Annular groove

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[Procedure amendment]

[Submission date] November 4, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

Next, the panel 7 of the grommet 1 having the above structure
The work of attaching to is explained. The grommet 1 is inserted into the mounting hole 8 from the small-diameter cylindrical portion 3 of the grommet 1 with the wire harness inserted therethrough. Further, when the grommet 1 is inserted and inserted until it abuts against the surface of the panel 7, the locking surface 5a is arranged in an inscribed state with respect to the opening edge 8a as shown by the imaginary line in FIG. Be stopped. When the grommet 1 is further pulled in the direction of the arrow after being positioned in such a state, the side wall 9a is pressed by the surface of the panel 7 and elastically deforms easily toward the large-diameter cylindrical portion 2 side, whereby the opening edge 8a is formed. By moving over the side wall 9a, the large-diameter cylindrical portion 2 is moved into the annular groove 9 with the diameter reduced. When the surface of the panel 7 is provided in a state where the side wall on the side of the large-diameter tubular portion 2 forming the annular groove 9 is strongly pressed, the side wall 9a is restored, and the grommet 1 is attached to the mounting hole as shown in FIG. 8 is inserted. Further, in this state, the lip-shaped locking piece 2
The a is in close contact with the surface of the panel 7 and can prevent water from entering from the large-diameter cylindrical portion 2 side.

Claims (1)

[Claims] 1. A large-diameter tubular portion, a small-diameter tubular portion, and an intermediate portion that gradually reduces the diameter of the large-diameter tubular portion to integrally connect the large-diameter tubular portion and the small-diameter tubular portion, and at least the large-diameter tubular portion. In the grommet that reduces the diameter of the tubular portion and inserts it into the panel mounting hole, the annular step portion that temporarily locks with the panel mounting hole before reducing the diameter of the large diameter tubular portion reaches the large diameter tubular portion. Grommet characterized by being provided on the outer peripheral surface of the part.