JP3362383B2 - 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 fitted in a panel hole of a vehicle or the like.

[0002]

2. Description of the Related Art Grommets are made of a flexible material such as rubber, and are fitted into a panel hole when a wire harness is arranged in a vehicle or the like for soundproofing and waterproofing inside and outside, and a wire bundle forming the wire harness. Is used to protect the. Conventionally, since the shape of the grommet is thick, a large pressing force has been required to fit the grommet into the panel hole. Therefore, as a grommet that can be easily fitted into the panel hole with a small pressing force, for example, a grommet a described in Japanese Utility Model Laid-Open No. 2-81988 as shown in FIG. 6 has been proposed.

That is, in FIG. 6, the grommet a has an annular groove d fitted around a panel hole c formed in a partition b of a vehicle or the like, which is provided around an outer peripheral surface of a grommet body e. The flanges f and f'on both sides of the annular groove d are formed so as to gradually increase the groove width of the annular groove d from the opening d'to the bottom d ". Then, the grommet a is pressed in the p direction. Then, the partition wall b bends the left flange f in the direction opposite to the pressing direction (p direction), and the annular groove d is fitted into the panel hole c.

However, the flange f, 'in order to facilitate bending and its root portion f _1, f' f because has ₁ shape thin, the grommet a which is fitted into the panel hole c
Has a drawback that it is easily disengaged from the flange f '. Therefore, there has been proposed a grommet as shown in FIG. 7, which is easily fitted into the panel hole and does not easily come off from the panel hole after the fitting.
That is, in FIG. 7, the grommet g has an annular groove h fitted in a panel hole c of a partition wall b of a vehicle or the like, which is provided around the outer peripheral surface of a funnel-shaped grommet main body j to form a front flange portion k and a back flange portion. m and.

A case where the grommet g is fitted in the panel hole c will be described. As shown in FIG. 8A, when the grommet g is pressed in the p ′ direction, the panel hole c hits the front flange portion k and the front flange portion k starts to bend in the direction opposite to the p ′ direction. When further pressed, as shown in FIG. 8, the partition wall b abuts the annular protrusion q of the back flange portion m in a state where the front flange portion k is bent in the annular groove h.

When it is further pressed, as shown in FIG. 8 (c), the partition wall b pushes the annular projection q in the direction opposite to the p'direction, and the back flange portion m also bends. When the partition b passes through the lip n of the front flange k in a bent state and the distance between the lip n and the back flange m becomes larger than the panel thickness (thickness of partition), FIG. As shown in, the front flange portion k and the back flange portion m are restored by the elastic force and returned to the original state. The tip n'of the lip n and the tip q'of the annular protrusion q are in close contact with the partition b, and the panel hole c is fitted in the annular groove h.

However, the grommet g is replaced with the panel hole c.
When it is fitted to the grommet body g, it is necessary to bend the front flange portion k and the back flange portion m which are erected on both sides of the annular groove h of the grommet body j formed to have a large thickness.
There is a drawback that a large pressing force is required to press.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a grommet which can be easily fitted into a panel hole with a small pressing force.

[0009]

In order to achieve the above object, the present invention has an annular shape which is fitted into a panel hole formed in a partition wall on the outer peripheral surface of a grommet body which is funnel-shaped and has a thick wall. in grommet which the grooves are circumferentially, the circumferential wall of the grommet body central axis side of the annular groove is hollowed from the inner peripheral surface of the grommet body facing up to the circumferential wall surface vicinity is recessed portions formed At the same time , a thin-walled stretchable portion that is stretchable in the panel hole fitting direction is provided around the stretchable portion.
When it is in the normal state, the elastic part is folded into the annular groove.
When it is returned, a bent portion is formed and the stretchable portion is stretched.
When the bent portion is bent toward the central axis,
The shape is substantially parallel to the central axis (claim
Item 1). In addition, the shape of the lightening portion is usually the stretchable portion.
When it is brought into a state, it is made to have an isosceles triangular cross section,
A grommet having an isosceles trapezoidal cross section when the portion is extended is also effective (claim 2). Further, when the stretchable portion is extended, the lightening portion is formed into a trapezoidal shape in cross section, and the width of the facing wall surface of the lightening portion facing the peripheral wall surface is smaller than the width of the peripheral wall surface, and the meat is formed. the width of the opening face of the recessed portions is set larger than the width of the peripheral wall, even together employ grommet which is set substantially parallel to the circumferential wall surface and said opposing wall surface (claim
3) .

According to the present invention, since the expandable portion formed in the thick grommet body is expandable in the direction of fitting into the panel hole and has a thin shape, the grommet is pressed to press the panel hole. The expandable portion expands as the annular groove enters, and after the annular groove enters the panel hole, the expandable portion contracts and returns to its original state. Further, since the expandable portion has the bent portion that is folded back into the annular groove, the width of the annular groove can be easily changed.

Further, when the expanding / contracting portion is extended, the lightening portion has an isosceles trapezoidal shape in cross section, the peripheral wall surface and the opposed wall surface are set substantially parallel to each other, and the width of the peripheral wall surface is larger than the width of the opposed wall surface and the opening surface. Since the opposing wall surface and the opening surface are formed to be smaller than the width of
The elastic force generated in the stretchable portion when the stretchable portion is extended acts on the stretchable portion evenly.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show one embodiment of the grommet according to the present invention. The same members as those in the conventional example are given the same names. In FIG. 1, a grommet 1 is a grommet main body 2 that is funnel-shaped and has a thick wall.
On the outer peripheral surface of the large-diameter portion, a circular groove 5 having a concave cross-section that fits in a panel hole 4 formed in a partition wall 3 of a vehicle or the like is provided around, and a small-diameter portion of the grommet body 2 has a wire bundle (not shown). The insertion portion 6 for inserting and holding is formed in a thin shape.

[0013] As shown in FIG. 2, the insertion portion 6 side front flange portion 7, and on the opposite side of the insertion portion 6 is formed back flange 8 respectively. A lip portion 7a is formed at the tip of the front flange portion 7, and an annular projection 8a standing upright in the insertion portion 6 direction is provided around the tip of the back flange portion 8. The lip portion 7a has an inner peripheral lip 7b on the annular groove 5 side,
An outer peripheral lip 7c is formed on the opposite side. A projection 6a for preventing lateral displacement of the tape when the insertion part 6 and the electric wire bundle are wound with a tape (not shown) is provided at the tip of the insertion part 6 on the outer peripheral surface of the tip of the insertion part 6. It is installed around.

A peripheral wall surface 5a is formed in the annular groove 5 on the side of the central axis 2c of the grommet body 2. From the inner peripheral surface 2b of the grommet main body 2 facing the peripheral wall surface 5a, a wall-thinned portion 9 is provided around the peripheral wall surface 5a to the vicinity of the peripheral wall surface 5a.
A thin-walled stretchable portion 10 is formed that can be stretched in the direction of fitting to. In a normal state, the expandable part 10 has a bent part 10a folded back into the annular groove 5, and when the expandable part 10 extends, the bent part 10a bends toward the central axis 2c, and the shape of the expandable part 10 becomes the central axis 2c. Becomes almost parallel to.

As shown in FIGS. 2 and 3, the lightening portion 9 has an isosceles triangular cross-section when the expandable portion 10 is in a normal state. Further, in the stretched state, the shape thereof is an isosceles trapezoidal shape in cross section, and the lightening portion 9 opposed to the peripheral wall surface 5a.
The opposite wall 9a substantially in parallel with the cross-section of the peripheral wall 5a, and the width D of the width D ₁ of the opposing wall surfaces 9a circumferential wall surface 5a ₂
It is smaller and the width D ₃ of the opening surface 9b of the lightening portion 9 is larger than the width D ₂ of the peripheral wall surface 5a, that is, D ₁ <D ₂ <D
Set to ₃ .

It should be noted that the lightening portion when the expansion / contraction portion 10 is extended
The shape of 9 may be polygonal, but the case of the present embodiment is most preferable. In addition, the peripheral wall surface 5a and the opposing wall surface 9
Although it is possible that a and a are not set substantially parallel, it is most preferable that they are substantially parallel.

Next, the operation of the expansion / contraction part 10 when the grommet 1 is fitted in the panel hole 4 will be described. Figure 4
As shown in (a), when the grommet 1 is pressed in the P direction, the peripheral edge 4a of the panel hole 4 hits the front flange portion 7, and the front flange portion 7 begins to bend in the Q direction opposite to the P direction by the peripheral edge 4a. At the same time, the bent portion 10a starts to become flat.

When the pressing is continued, as shown in FIG. 4 (b), the bent portion 10a becomes completely flat (10b), and the front flange portion 7 becomes Q until the inner peripheral lip 7b abuts on the elastic portion 10. Bends in the direction. Then, the grommet main body 2 moves in a state where the inner wall surface 4a in the panel hole 4 and the front flange portion 7 are in close contact with each other. When the outer peripheral lip 7c reaches the inside of the inner wall surface 4a, one side wall surface 3a of the partition wall 3 has an annular projection 8a.
Hit against.

When it is further pressed, as shown in FIG. 4 (c), the annular projection 8a is moved by the action / reaction to cause the one side wall surface 3 to move.
The elastic portion 10 is pushed in the Q direction by a and the elastic portion 10 begins to expand in the Q direction until the lip portion 7a passes through the inner wall surface 4a.
0 grows (the stretchable part in the stretched state is 10 '). When the lip portion 7a passes through the inner wall surface 4a,
As shown in (d), the expansion / contraction portion 10 'begins to shrink with the annular projection 8a and one side wall surface 3a in contact with each other, and the front flange portion 7 starts to approach the other side wall surface 3b.

[0020] As shown in FIG. 4C, the inner peripheral lip 7b is not
The side wall surface 3b on one side, and the elastic portion 10 'is substantially
The state returns to 10 (the stretchable portion in that state is 10). Obey
The side wall surface 3a of the partition wall 3 and the annular projection 8a come into contact with each other.
And the other side wall surface 3b is brought into contact with the other side wall surface to form an annular shape.
The panel hole 4 can be fitted in the groove 5.

Further, since the expandable part 10 is expandable and contractible,
As shown in FIG. 5A, when the partition wall 3 is in a thin state D ₄ , the expansion portion 10 is bent into the annular groove 5 to form the bent portion 10a, and the partition wall 3 is divided into the inner peripheral lip 7b and the annular protrusion 8a. The width D ₂ of the annular groove 5 is adjusted so that and are close to each other. As shown in FIG. 5B, in the case where the partition wall 3 is in a thick state D ₅ , the bent portion 10a becomes flat and the stretchable portion 10 extends (stretchable portion 10 '), so that the partition wall 3, the width D ₂ of the annular groove 5 is adjusted so that the inner peripheral lip 7b and the annular protrusion 8a come into close contact with each other. Therefore, the expansion / contraction portion 10 expands / contracts according to the thickness D ₂ of the partition wall 3, so that the partition wall 3 and the annular groove 5 are fitted to each other.

Further, when the grommet 1 is pressed in the P direction to be fitted into the panel hole 4, the expansion / contraction portion 10 can be expanded / contracted in the P or Q direction, so that the pressing force can be made smaller than before. Besides, the width D ₁ of the facing wall surface 9a, the peripheral wall surface 5a
Between the width D ₂ and the width D ₃ of the opening surface 9b, D ₁ <D ₂ <D
_Since there is a relationship of ₃ , since the elastic force generated in the expanding and contracting portion 10 acts uniformly on the expanding and contracting portion 10 and the elastic force is dispersed, when the grommet 1 is fitted into the panel hole 4, the expanding and contracting portion 10 Never breaks.

[0023]

As described above, according to the present invention, the thick walled grommet body is thinned from the inner peripheral surface thereof to form a thin-walled stretchable portion that is stretchable in the direction of fitting into the panel hole. From
When the grommet is fitted into the panel hole, the expansion / contraction part expands as the annular groove enters the panel hole, and after the expansion, the expansion / contraction part contracts and returns to its original state. As a result, the grommet can be easily bent, so that the fitting work can be performed with a pressing force smaller than in the past.

Further, since the expandable portion has the bent portion folded back into the annular groove, the width of the annular groove can be easily changed. Thus, when the partition wall is thin, a bent portion is formed in the expansion / contraction portion, when the partition wall is thick, the bent portion is flattened, and the expansion / contraction portion is extended to form the panel hole and the annular groove. Since it is fitted, the panel holes formed in the partition walls having various thicknesses can be accommodated.

Further, when the expanding / contracting portion is extended, the lightening portion has an isosceles trapezoidal shape in cross section, the peripheral wall surface and the opposed wall surface are set substantially parallel to each other, and the width of the peripheral wall surface is larger than the width of the opposed wall surface and the opening is formed. Since the opposing wall surface and the opening surface are formed so as to have a width smaller than the width of the surface, the elastic force generated when the expansion portion expands acts on the expansion portion evenly. As a result, the elastic force is dispersed in the expansion / contraction portion, so that when the annular groove is fitted in the panel hole, the expansion / contraction portion is less likely to break.

[Brief description of drawings]

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

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a diagram showing a state in which the expandable portion of FIG. 2 is extended.

FIG. 4 is a vertical cross-sectional view for explaining a case where an annular groove is fitted in a panel hole. (A) shows a state where a grommet starts to be pressed, (b) shows a state where a bent portion is flat, (c) ) Is a state in which the elastic portion has begun to expand, (d) is a state before the elastic portion is contracted,
(E) is a state in which the expandable portion contracts and returns to the original state.

5A and 5B are vertical cross-sectional views showing a state in which an annular groove is fitted in a panel hole, where FIG. 5A is a case where the partition wall is thin, and FIG. 5B is a case where it is thick.

FIG. 6 is a vertical sectional view showing a conventional grommet.

FIG. 7 is a vertical sectional view showing another conventional grommet.

8A and 8B are vertical cross-sectional views for explaining a case where an annular groove is fitted in a panel hole. FIG. 8A is a state in which a grommet starts to be pressed, FIG. 8B is a state in which a front flange portion starts to bend, and FIG. ) Is a completely bent state, and (d) is a fitted state.

[Explanation of symbols]

1 Grommet 2 Grommet body 2b Inner peripheral surface 2c Center axis 3 Partition wall 4 Panel hole 5 Annular groove 5a Surrounding wall surface 9 Thinned portion 9a Opposing wall surface 9b Opening surface 10 , 10 ' Expansion / contraction portion 10a Bending portion D ₁ Width of opposing wall surface (width) ) D ₂ Width of wall surface (width) D ₃ Width of opening surface (width)

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Claims (3)

(57) [Claims] To 1. A peripheral surface of the grommet body formed thickly in the funnel, the grommet annular groove is fitted into the panel hole formed in the partition wall is circumferentially provided, the grommet body of said annular groove the peripheral wall of the central axis side are lightened up from the inner peripheral surface of the grommet body which faces the circumferential wall surface vicinity with the recessed portions are formed, freely a thin-walled expansion into the panel hole fitting direction the stretchable part of circumferentially, the stretchable portion
When it is in the normal state, the elastic part is folded into the annular groove.
When it is returned, a bent portion is formed and the stretchable portion is stretched.
When the bent portion is bent toward the central axis,
A grommet characterized in that the shape is substantially parallel to the central axis . 2. The shape of the lightening portion is usually the stretchable portion.
When it is brought into a state, it is made to have an isosceles triangular cross section,
The grommet according to claim 1, wherein the grommet has an isosceles trapezoidal cross section when the portion is in an extended state . 3. When the expanding / contracting portion is extended, the lightening portion is formed into an isosceles trapezoidal shape in cross section, and a width of a facing wall surface of the lightening portion facing the peripheral wall surface is smaller than a width of the peripheral wall surface. , the width of the opening surface of the meat the recessed portions is set larger than the width of the peripheral wall, the grommet according to claim 1 or 2, characterized in that the peripheral wall and said opposing wall surface is set substantially parallel to .