JP4172535B2 - Grommet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grommet, and more specifically, in a grommet for internally inserting a group of electric wires routed between a vehicle body (vehicle body) of an automobile and a door that is opened and closed with respect to a left and right door and a luggage door. It is intended to prevent disconnection or the like from occurring in the electric wire group that repeatedly receives the bending load together with the grommet according to the opening / closing operation.
[0002]
[Prior art]
In the automotive, as shown in FIG. 9, and a wiring harness W / H between the vehicle body 1 and the deck lid 2, transmits a signal to supply power to the lamp and the like of the attached to the luggage door 2 ing.
The wire harness W / H routed between the vehicle body 1 and the door 2 is inundated when the door is opened, and when exposed to the outside, the appearance is poor and damage is likely to occur. A grommet 3 formed of a material is packaged.
[0003]
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 the bellows-shaped cylindrical portion 3a. The illustrated grommet 3 has a resin on the large-diameter cylindrical portions 3b and 3c. This is a type in which an inner 4 is attached, and a locking claw 4a provided on the outer periphery of the resin inner 4 is locked to the periphery of a through hole formed in a vehicle body and a door panel.
[0004]
Grommet 3 passes through wire harness W / H composed of a large number of electric wire groups, and tape T is wound around tape-wrapped tongue piece 3b-1 projecting from one end of large-diameter cylindrical portion 3b to adhere to the wire harness. is doing. The grommet 3 attached to this wire harness is attached between the vehicle body 1 and the door 2 by bending the bellows-like tube portion 3a as shown in FIG. 9, and the bellows-like tube portion according to the opening / closing operation of the door 2 3a changes the bending angle and expands and contracts to follow the door.
[0005]
[Problems to be solved by the invention]
The space for housing the grommet 3 is a limited space S, as shown in FIG. 11A, and the bellows-shaped cylindrical portion 3a needs to be bent and stretched along the limited space S. The bellows-shaped cylindrical portion 3a is not necessarily bent or stretched along the space S. In the luggage door, as shown in FIG. 11 (B), the baggage is likely to be bent by the bellows-like cylindrical portion 3a that is continuous with the large-diameter cylindrical portion 3b on the door locking side. When such buckling occurs, there is a problem in that concentrated stress is generated in the electric wires in the buckling and disconnection is likely to occur.
This problem is not limited to between the body and the luggage door, and wiring between the rotation panel such as the body and the back door, it occurs at the site receiving the repeated bending action.
[0006]
In order to prevent buckling of the bellows-shaped tube portion, means such as increasing the thickness of a portion where buckling is likely to occur or embedding and reinforcing a valley portion can be considered. However, since the bellows-like cylindrical portion is also required to be stretchable, there arises a problem that the required stretchability cannot be obtained simply by reinforcing.
[0007]
The present invention has been made in view of the above problems, and in a grommet which is attached between a vehicle body and a door and repeatedly undergoes a bending action, prevents the occurrence of buckling in the bellows-like cylindrical portion and prevents disconnection. And it makes it a subject not to impair an expansion-contraction function.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is a grommet that is attached to a wire harness that is routed from the vehicle body side to the door side of an automobile, and receives a bending load repeatedly according to the opening and closing operation of the door ,
Between the large-diameter cylindrical portions that are locked to the through holes in the vehicle body panel and the door panel, the cylindrical portions on both sides that are not provided with the valleys that are continuous with the large-diameter cylindrical portions on both sides, and the cylindrical portions between these two cylindrical portions. And a bellows-shaped cylindrical portion,
Provided in the end region of the bellows- shaped tube portion is a bending-regulating rib that fills the valley on the outer peripheral side, and a plurality of ribs are provided at equal intervals in the entire circumferential direction of the valley, and the center of each rib setting the slit-like groove for expansion in the circumferential direction the entire length of each rib only, the width of the groove is a width of the end faces of the ribs facing each other across the groove can not be bent excessively in contact during the bending, the
There is provided a grommet characterized in that the height of the rib is lower than the apex of the peak portion of the bellows and is not less than ½ of the height from the apex of the valley portion to the apex of the peak portion.
[0009]
As described above, in the end region of the bellows-like tube portion where the bending stress is likely to be concentrated due to the complicated bending of the grommet, a rib for restricting the bending is provided to fill the valley portion, and the groove is formed in the rib. Therefore, when the end portion is to be bent, the ribs facing each other through the groove do not bend excessively. Therefore, local twisting and bending of the grommet are alleviated by avoiding stress concentration at the end portion, and buckling in a narrow space is eliminated, and damage such as disconnection of an electric wire inserted inside is prevented. be able to.
[0010]
Furthermore, since the rib provided in the end region of the bellows-like cylindrical portion is provided with an expansion / contraction groove at least in the center, the rib can be extended in the same manner as the region where the rib of the bellows-like cylindrical portion is not provided. Does not hinder the stretch performance.
[0011]
The ribs are provided on the entire circumference of the valley at intervals in the circumferential direction, and the grooves provided on the ribs are formed on the entire length in the circumferential direction.
[0012]
In this way, by arranging the plurality of ribs evenly around the entire circumference, the buckling can be prevented regardless of the direction in which the bellows-like cylindrical portion is bent, and the ribs are spaced apart in the circumferential direction. By providing it open, the material cost can be reduced compared to the case where it is provided continuously all around. Furthermore, the expansion and contraction performance of the bellows-shaped cylindrical portion can be favorably maintained by forming the groove provided in the rib over the entire length in the circumferential direction.
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.
[0013]
Further, as shown in the drawings of the embodiments described later, the height of the rib is lower than the apex of the peak portion of the bellows, so that the handleability and appearance are improved, and the height of the rib is set to the apex of the valley portion. It is preferable that the height from the top to the top of the peak portion is ½ or more, and that buckling can be effectively prevented when the end region of the bellows tube portion is bent.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
Grommet embodiment while the exterior to the wire harness, in which mounted between the vehicle body and luggage door shown in FIG. 9.
[0015]
A grommet 10 according to an embodiment of the present invention is shown in FIGS.
Similar to FIG. 9 , the grommet 10 has large-diameter cylindrical portions 12 and 13 continuously provided on both sides of the bellows-shaped cylindrical portion 11, and is integrally formed of rubber or elastomer.
[0016]
The bellows-shaped tube portion 11 is a large-diameter tube via tube portions 11d and 11e that are not provided with valleys at both ends in the length direction (axial direction) of the bellows portion 11c in which the valley portions 11a and the peak portions 11b are alternately continuous. It continues to parts 12 and 13.
Further, in the end region P of the bellows-like cylindrical portion 11 continuous to the large diameter cylindrical portion 12, as shown in FIG. 3, the valleys 11 a rib 11f for flexion limit so as to fill the outer peripheral side of the 11g An extending and contracting groove 11h is provided between the ribs 11f and 11g.
As shown in FIG. 4, the ribs 11f and 11g are provided at eight equal intervals in the circumferential direction of the bellows portion 11c, and have a mountain shape in cross section.
[0017]
The large-diameter cylindrical portions 12 and 13 are provided with annular recesses 12a and 13a for locking the vehicle inner locking resin inner 4 similar to FIG. 10 and seal lips 12b at the tips of the large-diameter cylindrical portions 12 and 13, 13b, and when mounted on the vehicle body, the sealing 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 protruded from the inner surface of the cylindrical portion 11 d and exposed to the outside through the opening of the large-diameter cylindrical portion 12.
[0018]
With the above configuration, even when force F is applied as shown in FIG. 5 in the end region P of the bellows-like tube portion 11 where the bending stress is likely to concentrate due to the complicated bending of the grommet 10, the opposing ribs 11f and 11g Since they come into contact with each other and interfere with each other, they will not bend excessively and will not buckle even if installed in a narrow 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.
[0019]
Further, since the ribs 11f and 11g provided in the end region P of the bellows part 11c are provided with the expansion and contraction groove 11h in the center, the same as the region where the ribs 11f and 11g of the bellows part 11c are not provided. It can be stretched and does not hinder the stretch performance.
[0020]
Further, by providing the ribs 11f and 11g on the entire circumference, buckling and the like can be prevented regardless of the direction in which the bellows portion 11c is bent, and the ribs 11f and 11g are provided at intervals in the circumferential direction. The material cost can be reduced as compared with the case where it is provided uniformly on the entire circumference.
[0021]
The ribs 11f and 11g have a mountain shape with the center of the rib protruding in the circumferential direction , but may have a rectangular shape.
[0022]
FIG. 6 shows a second embodiment.
The difference from the first embodiment is that the position where the rib is provided is not the outer peripheral side of the valley portion 11a but the inner peripheral side of the mountain portion 11b.
Bending restriction ribs 11f ′ and 11g ′ are protruded inwardly in an end region P of the bellows-like tube portion 11 continuous with the large-diameter tube portion 12 so as to fill the inner peripheral side of the peak portion 11b. An expansion / contraction groove 11h ′ is provided between the ribs 11f ′ and 11g ′.
With the above configuration, buckling and the like can be prevented while maintaining stretchability as in the first embodiment, although it is similar in appearance to a bellows-like cylindrical portion not provided with a normal rib.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0023]
FIG. 7 shows a third embodiment.
The difference from the first embodiment is that the position where the rib is provided is 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.
At the same time, the ribs 11f and 11g for bending regulation are projected outward so as to fill the outer peripheral side of the valley portion 11a in the end region P of the bellows-like cylindrical portion 11 continuous with the large-diameter cylindrical portion 12. The ribs 11f 'and 11g' for restricting the bending are projected inward so as to fill the inner peripheral side of the portion 11b, and are expanded and contracted between the ribs 11f and 11g and between the ribs 11f 'and 11g'. Grooves 11h and 11h ′ are provided respectively.
With the above configuration, the buckling resistance can be further improved as compared with the first embodiment, and the stretchability can be maintained by the presence of the grooves 11h and 11h ′.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0024]
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 trough portion 11 a ″ is a quadrangular cross section.
[0025]
As in the first embodiment, ribs 11g ″ (not shown) are provided at opposite positions on the paper surface depth side of the ribs 11f ″ shown in FIG. 8 via expansion / contraction grooves.
Further, the ribs 11f ″ and 11g ″ are provided at six locations at equal intervals in the circumferential direction of the bellows-like cylindrical portion 11.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0026]
【The invention's effect】
As is clear from the above description, according to the present invention, in the end region of the bellows-like tube portion where bending stress is likely to concentrate, the bending control is performed to fill the outer peripheral side of the valley portion and / or the peripheral side without the peak portion. Since the ribs are provided and grooves are provided in the ribs, when the end portions are bent, the opposing ribs are not brought into contact with each other via the grooves and are not excessively bent. Therefore, local bending of the grommet at the end portion is alleviated, buckling or the like in a narrow space is eliminated, and disconnection of an electric wire inserted inside can be prevented.
Further, since the rib provided in the end region of the bellows-like cylindrical portion is provided with the expansion / contraction groove, the expansion / contraction performance is not hindered.
[0027]
Further, by providing the ribs on the entire circumference, it is possible to prevent the buckling and the like regardless of the direction in which the bellows-like cylindrical portion is bent, and to provide the ribs at intervals in the circumferential direction. The material cost can be reduced as compared with the case where it is provided continuously around the circumference. Furthermore, the groove | channel provided in a rib can be formed in the full length of the circumferential direction, and can maintain the expansion-contraction performance of a bellows-shaped cylinder part favorably.
[0028]
In addition, the height of the rib is less than or equal to the peak of the peak, so that the handleability and appearance are good, and the height of the rib is 1/2 or more of the height from the peak of the valley to the peak of the peak By doing so, it is possible to effectively prevent buckling and the like.
[Brief description of the drawings]
FIG. 1 is a front view of a grommet according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II of the grommet in FIG.
FIG. 3 is a cross-sectional view of a main part of the grommet in FIG.
FIG. 4 is a cross-sectional view of the grommet in FIG. 1 taken along the line II-II.
5 is a cross-sectional view of the main part when an external force is applied to the grommet in FIG. 1. FIG.
FIG. 6 is a cross-sectional view of a main part of a grommet according to a second embodiment.
FIG. 7 is a cross-sectional view of a main part of a grommet according to a third embodiment.
FIG. 8 is a cross-sectional view of a grommet according to a fourth embodiment.
FIG. 9 is a perspective view showing an arrangement part of grommets.
FIG. 10 is a perspective view of a conventional grommet.
FIGS. 11A and 11B are cross-sectional views of main parts of a conventional grommet. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Grommet 11 Bellows-shaped cylinder part 11a Valley part 11b Mountain part 11c Bellows part 11f, 11g Rib 11h Groove 12, 13 Large diameter cylinder part W / H Wire harness

Claims (2)

A grommet that is attached to a wire harness that is routed from the vehicle body side to the door side of the automobile and receives a load of bending repeatedly according to the opening and closing operation of the door ,
Between the large-diameter cylindrical portions that are locked to the through holes in the vehicle body panel and the door panel, the cylindrical portions on both sides that are not provided with the valleys that are continuous with the large-diameter cylindrical portions on both sides, and the cylindrical portions between these two cylindrical portions. And a bellows-shaped cylindrical portion,
Provided in the end region of the bellows- shaped tube portion is a bending-regulating rib that fills the valley on the outer peripheral side, and a plurality of ribs are provided at equal intervals in the entire circumferential direction of the valley, and the center of each rib setting the slit-like groove for expansion in the circumferential direction the entire length of each rib only, the width of the groove is a width of the end faces of the ribs facing each other across the groove can not be bent excessively in contact during the bending, the
A grommet characterized in that the height of the rib is lower than the apex of the peak portion of the bellows and at least half the height from the apex of the valley portion to the apex of the peak portion.   The grommet according to claim 1, wherein the rib provided at intervals in the circumferential direction has a mountain shape or a rectangular shape in which a center of the rib protrudes in the circumferential direction.

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