JP2003087945A - Grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent buckling from occurring in a bellows cylindrical portion and expanding and contracting function from being impaired in a grommet subjected to bending action. SOLUTION: The grommet is intended to be attached to a wiring harness run from the vehicular body side to the door side of an automobile. The grommet comprises larger-diameter portions 12 and 13 which are provided with anchoring portions anchored at through holes in a body panel and door panels and are positioned on both ends of the grommet, and the bellows cylindrical portion 11 connecting the larger-diameter portions 12 and 13. The bellows cylindrical portion 11 in the area P connecting to the larger-diameter portion 12 on the door panel side is provided with ribs 11f and 11g for controlling buckling which fill the outer circumferential side of valley portions 11a and/or the inner circumferential side of peak portions 11b, and a groove 11h for expansion and contraction is formed at the center of the ribs 11f and 11g.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to grommets,
Specifically, in a grommet for internally inserting a wire group arranged between a vehicle body (vehicle body) of an automobile and doors that are opened and closed with respect to left and right doors and a luggage door body, a grommet according to the opening / closing operation of the door. At the same time, the wire group which is repeatedly subjected to bending load is prevented from being broken.

[0002]

2. Description of the Related Art In an automobile, as shown in FIG.
Wire harness W / H between the vehicle body 1 and the luggage door 2
Is installed, and power is supplied to the lamps and the like attached to the language door 2 and signals are transmitted. The car body 1
The wire harness W / H installed between the door and the door 2 is formed of an elastic material such as rubber, because water is generated when the door is opened, and if exposed to the outside, the appearance is bad and damage is likely to occur. The grommet 3 that has been used is exteriorly coated.

As shown in FIG. 10, the grommet 3 has a shape in which large-diameter cylindrical portions 3b and 3c for locking the vehicle body are provided on both sides of a bellows-shaped cylindrical portion 3a. Three
This is a type in which a resin inner 4 is attached to c, and a locking claw 4a provided on the outer periphery of the resin inner 4 is locked to the peripheral edge of a through hole formed in a vehicle body and a door panel.

The grommet 3 has a wire harness W / H composed of a large number of electric wires passed through the inside thereof, and one end thereof has a large-diameter cylindrical portion 3
The tape T is wound around the tape winding tongue piece 3b-1 protruding from b, and is fixed to the wire harness. As shown in FIG. 9, the grommet 3 attached to the wire harness is installed between the vehicle body 1 and the door 2 by bending the bellows-like tubular portion 3a, and the bellows-like tubular portion is opened or closed according to the opening / closing operation of the door 2. 3a changes the bending angle and expands and contracts to follow the door.

[0005]

The space for accommodating the grommet 3 is a limited space S, as shown in FIG. 11 (A), and the bellows-shaped tubular portion 3a extends along the limited space S. Although it is necessary to bend and expand / contract, the bellows-shaped tubular portion 3a is not always bent / extended / contracted along the space S. In a luggage door, as shown in FIG. 11 (B), the bellows-like tubular portion 3a, which is continuous with the large-diameter tubular portion 3b on the door locking side, is likely to be bent and buckled. When such buckling occurs, there is a problem that concentrated stress is generated in the electric wire in the buckling and the wire is easily broken. This problem occurs not only between the vehicle body and the language door, but also in a portion that is repeatedly routed between the vehicle body such as the vehicle body and the back door and the rotating panel such as the door.

In order to prevent buckling of the bellows-shaped tubular portion, it is conceivable to increase the thickness of the portion where buckling is likely to occur or to embed a valley portion for reinforcement. However,
Since the bellows-shaped tubular portion is also required to have elasticity, there is a problem that the required elasticity cannot be obtained by simply reinforcing it.

The present invention has been made in view of the above problems, and in a grommet mounted between a vehicle body and a door and repeatedly subjected to a bending action, the bellows-like tubular portion is prevented from buckling, and a wire breakage occurs. It is an object to prevent this and to prevent the expansion and contraction function from being impaired.

[0008]

In order to solve the above problems, the present invention is a grommet mounted on a wire harness routed from the vehicle body side of an automobile to an opening / closing panel of a door or a luggage door. A large-diameter cylindrical portion that is locked in the through-hole and a bellows-shaped cylindrical portion that is continuous with the large-diameter cylindrical portion, and that is continuous with the large-diameter cylindrical portion on the vehicle body panel and / or door panel side. The above-mentioned bellows-shaped tubular portion is provided with a bending-regulating rib that fills a valley portion on the outer peripheral side and / or the inner peripheral side, and a groove for expansion and contraction is provided at least at the center of the rib. Are offered.

As described above, in the end region of the bellows-shaped tubular portion, which is a portion where bending stress is likely to concentrate due to the complicated bending of the grommet, the bending regulating rib for filling the valley portion is provided, and Since the rib is provided with the groove, when the end portion tries to bend, the ribs facing each other through the groove do not excessively bend. Therefore, local stress and bending of the grommet are mitigated by avoiding stress concentration at the end portion, buckling in a narrow space is eliminated, and damage such as disconnection of the electric wire inserted inside is prevented. be able to.

Further, since the rib provided in the end portion region of the bellows-like tubular portion has a groove for expansion and contraction at least in the center, it is extended in the same manner as the region of the bellows-like tubular portion without the rib. It is possible and does not hinder the expansion and contraction performance.

The ribs are provided at intervals in the circumferential direction on the entire circumference of the valley, and the grooves provided in the rib are formed over the entire length in the circumferential direction.

By thus disposing the plurality of ribs evenly around the entire circumference, the buckling and the like can be prevented even if the bellows-shaped tubular portion bends in any direction, and the ribs are circumferentially arranged. By providing them at intervals, it is possible to reduce the material cost as compared with the case where they are provided continuously over the entire circumference. Furthermore, by forming the groove provided in the rib over the entire length in the circumferential direction, it is possible to maintain excellent expansion and contraction performance of the bellows-shaped tubular portion. The ribs provided at intervals in the circumferential direction have a mountain shape or a rectangular shape with the center in the circumferential direction protruding.

Further, by setting the height of the rib to be less than or equal to the apex of the ridge of the bellows, the handleability and appearance are improved, and the height of the rib is set from the apex of the valley to the apex of the ridge. It is preferable that it is set to 1/2 or more of that because buckling or the like can be effectively prevented when the end region of the bellows-shaped tubular portion is bent.

[0014]

DETAILED DESCRIPTION OF THE INVENTION A first embodiment of the present invention will be described below with reference to the drawings. The grommet according to the embodiment is mounted between the vehicle body and the language door shown in FIG.

FIG. 1 shows a grommet 10 according to an embodiment of the present invention.
Through FIG. The grommet 10 is one in which large-diameter cylindrical portions 12 and 13 are continuously provided at both ends of a bellows-shaped cylindrical portion 11 similar to that shown in FIG. 7, and is integrally molded of rubber or elastomer.

The bellows-shaped tubular portion 11 includes a valley portion 11a and a mountain portion 11
b and b are continuously connected to the large-diameter cylindrical portions 12 and 13 via cylindrical portions 11d and 11e having no peaks and valleys at both ends in the length direction (axial direction) of the bellows portion 11c. Further, in the end region P of the bellows-shaped tubular portion 11 which is continuous with the large-diameter tubular portion 12,
As shown in FIG. 3, bending restriction ribs 11f and 11g are projected so as to fill the outer peripheral side of the valley portion 11, and a stretchable groove 11h is provided between the ribs 11f and 11g. . As shown in FIG. 4, the ribs 11f and 11g are provided at eight locations at equal intervals in the circumferential direction of the bellows portion 11c and have a mountain-shaped cross section.

The large-diameter cylindrical portions 12, 13 have annular recesses 12a, 13a for locking the resin inner 4 for locking the vehicle body similar to FIG. The lips 12b and 13b are provided, and when attached to the vehicle body, the seal lips 12b and 13b are pressed against the panel surface to ensure waterproofness. Further, the tape winding tongue piece 14 for fixing the wire harness is projected from the inner surface of the tubular portion 11d and is exposed to the outside through the opening of the large diameter tubular portion 12.

With the above construction, in the end region P of the bellows-shaped tubular portion 11 where the bending stress is likely to be concentrated due to the complicated bending of the grommet 10, even if a force F is applied as shown in FIG. Since 11f and 11g come into contact with each other and interfere with each other, they do not bend excessively and do not buckle even when installed in a place with a small space. Therefore, local twisting and bending of the grommet 10 are alleviated, and damage such as disconnection of the electric wire inserted inside can be prevented.

Further, since the ribs 11f and 11g provided in the end region P of the bellows portion 11c have a groove 11h for expansion and contraction at the center, they are regions where the ribs 11f and 11g of the bellows portion 11c are not provided. It can be stretched in the same way and does not hinder the stretch performance.

By providing the ribs 11f and 11g on the entire circumference, buckling and the like can be prevented even if the bellows portion 11c bends in any direction, and the ribs 11f and 11g are circumferentially spaced. By providing it, the material cost can be reduced as compared with the case where it is provided uniformly over the entire circumference.

The ribs 11f and 11g have a mountain shape with the center in the circumferential direction protruding, but may have a rectangular shape.

FIG. 6 shows a second embodiment. The difference from the first embodiment is that the position where the rib is provided is not on the outer peripheral side of the valley 11a but on the inner peripheral side of the mountain 11b. In the end region P of the bellows-shaped tubular portion 11 which is continuous with the large-diameter tubular portion 12,
Rib 1 for bending control so as to fill the inner peripheral side of the mountain portion 11b
The ribs 11f 'and 11g' are projected inward.
A groove 11h 'for expansion and contraction is provided between f'and 11g'. With the above-described configuration, although it is similar in appearance to the bellows-shaped tubular portion not provided with a normal rib, it is possible to prevent buckling while maintaining elasticity as in the first embodiment. Since other configurations are similar to those of the first embodiment, description thereof will be omitted.

FIG. 7 shows a third embodiment. The difference from the first embodiment is that the ribs are provided not only on the outer peripheral side of the valley portion 11a but also on the inner peripheral side of the mountain portion 11b. In the end region P of the bellows-shaped tubular portion 11 which is continuous with the large-diameter tubular portion 12, bending limiting ribs 11f and 11g are projected outward so as to fill the outer peripheral side of the valley portion 11a, and at the same time, the ridges are formed. Bending restriction ribs 11f 'and 11g' are projected inward so as to fill the inner peripheral side of the portion 11b, and between the ribs 11f and 11g and between the ribs 11f 'and 11g'.
Grooves 11h and 11h 'for expansion and contraction are respectively provided between them. With the above configuration, the buckling resistance can be further improved as compared with the first embodiment, and the groove 11
The presence of h and 11h ′ can maintain the elasticity.
Since other configurations are similar to those of the first embodiment, description thereof will be omitted.

FIG. 8 shows a fourth embodiment. The difference from the first embodiment is that the shape of the bending restricting rib 11f ″ protruding so as to fill the outer peripheral side of the valley 11 ″ is a quadrangular cross section.

As in the first embodiment, ribs 11g "(not shown) are provided at the opposite positions of the ribs 11f" shown in FIG. 8 on the depth side of the drawing, as in the first embodiment. Also,
The ribs 11f ″ and 11g ″ are provided at six locations at equal intervals in the circumferential direction of the bellows-shaped tubular portion 11. Note that the other configurations are similar to those of the first embodiment, and thus the description thereof will be omitted.

[0026]

As is apparent from the above description, according to the present invention, in the end region of the bellows-shaped tubular portion where bending stress is likely to concentrate, the outer peripheral side of the valley portion and / or the peripheral side without the crest portion. Since a rib for bending control that fills the groove is provided and a groove is provided in the rib, when the end portion is bent, the ribs facing each other through the groove do not come into contact with each other and bend excessively. . Therefore, local bending of the grommet at the end portion is alleviated, buckling in a narrow space is eliminated, and breakage of the electric wire inserted inside can be prevented. Further, since the rib provided in the end region of the bellows-shaped tubular portion is provided with the groove for expansion and contraction, the expansion and contraction performance is not impaired.

By providing the ribs on the entire circumference, it is possible to prevent the buckling and the like regardless of the direction of bending of the bellows-shaped tubular portion, and to provide the ribs at intervals in the circumferential direction. Thus, the material cost can be reduced as compared with the case where the material is continuously provided on the entire circumference. Furthermore, by forming the groove provided in the rib over the entire length in the circumferential direction, the expansion and contraction performance of the bellows-shaped tubular portion can be maintained well.

Further, by setting the height of the rib to be equal to or lower than the apex of the crest, the handleability and appearance are improved, and the height of the rib is set to be 1 from the height of the trough to the apex of the crest. / 2
By setting it as the above, buckling etc. can be prevented effectively and it is suitable.

[Brief description of drawings]

FIG. 1 is a front view of a grommet according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the grommet of FIG. 1 taken along the line I-I.

FIG. 3 is a cross-sectional view of a main part of the grommet shown in FIG.

4 is a sectional view of the grommet of FIG. 1 taken along the line II-II.

5 is a cross-sectional view of essential parts when an external force is applied to the grommet of FIG.

FIG. 6 is a sectional view of a main part of a grommet according to a second embodiment.

FIG. 7 is a sectional view of a main part of a grommet according to a third embodiment.

FIG. 8 is a sectional view of a grommet according to a fourth embodiment.

FIG. 9 is a perspective view showing an arrangement portion of a grommet.

FIG. 10 is a perspective view of a conventional grommet.

11 (A) and (B) are cross-sectional views of a main part of a conventional grommet.

[Explanation of symbols]

10 Grommet 11 Bellows tube 11a Tanibe 11b Yamabe 11c bellows 11f, 11g rib 11h groove 12, 13 Large diameter cylinder W / H wire harness

Claims (4)

[Claims] 1. A grommet to be mounted on a wire harness routed from a vehicle body side to a door side of an automobile, which has large-diameter cylindrical portions on both sides locked in through holes of the vehicle body panel and the door panel. A bellows-shaped tubular portion continuous between the large-diameter tubular portions, and the bellows-shaped tubular portion in a region continuous with the large-diameter tubular portion on the vehicle body panel and / or door panel side,
A grommet, characterized in that a rib for restricting bending is provided to fill a valley portion on the outer peripheral side and / or the inner peripheral side, and a groove for expansion and contraction is provided at least at the center of the rib. 2. The grommet according to claim 1, wherein a plurality of the ribs are provided in the valley portion at intervals in the circumferential direction, and the groove provided in each rib is provided along the entire circumferential length of each rib. 3. The rib according to claim 1, wherein the height of the rib is less than or equal to the apex of the ridge of the bellows, and is ½ or more of the height from the apex of the valley to the apex of the ridge. Grommet. 4. The grommet according to claim 2 or 3, wherein the ribs provided at intervals in the circumferential direction have a mountain shape or a rectangular shape with a center in the circumferential direction protruding.