JP3119179B2 - 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 to be attached to a wire harness for an automobile, and more particularly, to a back panel at both ends of a bellows-like cylindrical portion through which a wire harness to be routed from a back panel of an automobile to a back door is inserted. A flange for mounting both ends is provided in a wire harness through hole provided in the back door and the back door. When the back door is opened, the grommet is easily deformed so that the grommet can follow the opening operation.

[0002]

2. Description of the Related Art Conventionally, in a car, a back door provided on a back panel is provided with a motor for a wiper to drive the wiper and to turn on lamps. And back panel 1
The wiring harness W / H is routed from the rear door 2 to the rear door 2. The lower end of the back door 2 is lifted, and the hinge 3 between the upper back side panel 1 and the back panel 1 is used as a fulcrum.
Is opened, the portion of the wire harness W / H between the back panel 1 and the back door 2 is exposed to the outside. Therefore, the wire harness W / H of this portion is passed through the grommet 4 and the flanges 4a, 4
a is fixed to the periphery of the through hole provided in the back panel 1 and the back door 2 to cover the wire harness for waterproofing.

When one of these types is opened and closed with respect to the other, and a rotational force acts on the grommet during the opening operation, unreasonable deformation is prevented from occurring.
Grommets 4 having the shapes shown in FIGS. The grommet 4 has a cylindrical portion 4c between the flanges 4a and 4b at both ends in a bellows shape, and the bellows has a shape in which peaks 4d and valleys 4e are spirally connected.

The grommet having the bellows-like cylindrical portion having the spirally formed peaks and valleys continuously expands and contracts in the axial direction when rotating, and absorbs the rotational force so that unreasonable deformation does not occur. I have.

[0005]

However, the above-mentioned spiral peaks and valleys have a cross-sectional shape of a perfect circle as shown in FIG. 7 in the same manner as a tube provided with a normal spiral peak and valley. Due to its shape, it is difficult to deform. For this reason, when subjected to a torsional action due to the rotational force, as shown in FIG. 8, it is difficult to deform as a whole, and the torsion cannot be absorbed only by the bellows portion, and both ends of the bellows portion and the flanges 4a,
Twist occurs in portions 4f and 4g between 4b. In this way, when the side portions 4f and 4g are twisted, the grommet 4
Is shortened, and stress is transmitted to the flanges at both ends. Therefore, there is a problem that the flanges 4a and 4b are deformed and a gap is generated between the mounting side (the back panel and the back door, etc.), and the waterproof performance is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a bellows-like cylindrical portion provided with alternating peaks and valleys is easily twisted, and the torsion force generated during rotation is absorbed by the bellows-like cylindrical portion. It is another object of the present invention to provide a grommet that enhances waterproof performance by preventing stress from being applied to flanges at both ends.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a bellows-like cylindrical portion having alternately formed peaks and valleys, provided with flanges at both ends thereof. A grommet that has a pair of straight portions facing each other in a cross-sectional shape of a ridge, and a large arc portion that continues a wide portion on one side of both ends of the pair of straight portions. The grommet is characterized in that the narrow width portion on the other end side has a substantially oval shape formed by a continuous small arc portion and is deformed by the pair of linear portions to absorb torsion.

More specifically, for example, while the directions of the flanges at both ends are phased by 180 degrees, the cross-sectional shape of the peak of the bellows-like cylindrical portion is changed to a pair of straight portions facing each other in a C-shape. Each of the pair of straight portions has a generally oval shape formed by a pair of arc portions each having a wide portion and a narrow portion at both ends thereof, and each portion is continuous at a predetermined pitch from one end to the other end in the axial direction. The shapes of the peaks are sequentially shifted in the angle range of the number of peaks / 180 degrees.

If a straight portion is provided in each peak portion as described above, the straight portion is more easily deformed than the circular portion, so that it is easily deformed as a whole, and therefore, it is possible to smoothly absorb the twist. it can. Moreover, the direction of the flanges at both ends is 1
Since the orientation is 80 degrees, the number of peaks is 18 so that the orientation of the peaks is exactly 180 from one end to the other end.
Since 0 ° is equally divided and shifted by the same angle, the torsion is absorbed only by the bellows-like tubular portion, and the torsion is not generated in the flanges at both ends. Therefore, the flanges at both ends can be securely fixed to the fixed portion (the back panel and the back door, etc.)
The waterproof performance can be ensured without generating a gap.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

The grommet 10 shown in FIGS. 1 to 5 of the embodiment is a wire harness W which is routed from the center of the upper frame of the back panel 1 to the back door 2 in the same manner as the grommet 4 shown in FIG. / H, which is to be attached to the connection between the back panel 1 and the back door 2, wherein the flanges 11 and 12 fitted and fixed to the through hole on the back panel side and the through hole on the back door side are oriented 180 degrees. Instead, these flanges 11 and 12 are connected by a bellows-like cylindrical portion 13.

The grommet 10 is integrally formed of rubber or elastomer, and is continuous with flanges 11 and 12 having large diameters on both sides of a bellows-like cylindrical portion 13 through short non-bellows-like cylindrical portions 16 and 17. Let me. Locking grooves 11a, 12a are provided on the outer peripheral surfaces of the flanges 11, 12, and the locking grooves 11a, 12a are fitted to the peripheral edges of the through holes 1a, 2a (shown in FIG. 4) of the back panel 1 and the back door 2. In combination, the flanges 11 and 12 are closely fixed to each other.

The bellows-shaped cylindrical portion 13 has a peak portion 14 and a valley portion 1.
5 are alternately formed, and as shown in FIG. 2, the pitches P of the ridges 14 arranged in the axial direction when viewed from the front side are the same. In the present embodiment, eight peaks 14 are formed in parallel.

As shown in FIGS. 3 (A) to 3 (H), the sectional shapes of the eight peaks 14A to 14H which are sequentially arranged in parallel from the flange 11 side to the flange 12 side of the peak 14 are in a V-shape. A pair of straight portions 14a and 14b facing each other, a large arc portion 14c continuing the wide portion on one side of both ends of the pair of linear portions, and a small arc portion 14d continuing the narrow portion on the other end. The eight ridges 14A to 14H have the same shape.

The directions of the eight egg-shaped peaks 14A to 14H are changed by 22.5 degrees at a time so that the flange 11
The direction of the crest 14A at the tip on the side and the crest 14H at the other end on the side of the flange 12 are changed by exactly 180 degrees. That is, the ridge portion 14A has the small arc portion 14d projecting at an acute angle positioned on the axis L toward the left side in the drawing. The next peak 14B rises up the small arc 14d at α = 22.5 °,
The angle is sequentially changed clockwise by 22.5 ° from the ridges 14B to 14H, and the ridge 14H at the other end positions the small arc portion 14d to the right on the axis L. In addition, mountain part 1
The cross-sectional shape of the valley 15 between 4 is circular.

From the flange 11 at one end to the cylindrical portion 16,
Bellows-like cylindrical part 13, cylindrical part 17, and flange 1 at the other end
2, the hollow portion 20 is continuous, and the size of the hollow portion 20 is set to a size that allows the wire harness W / H to be passed through smoothly.

With the wire harness W / H inserted into the grommet 10 having the above structure, the grommet is disposed between the back panel 1 and the back door 2 as shown in FIG. 11 to back panel 1
And the other flange 12 is locked and fixed to the through hole 2a of the back door 2.

When the back door 2 is lifted up and opened upward with the hinge 3 at the upper end as a fulcrum, the grommet 10 interposed between the back panel 1 and the back door 2 is interlocked with the rotation of the back door 2. Then, since the flange 11 and 12 are rotated and the mounting positions of the flanges 11 and 12 are shifted in the left-right direction, torsion also occurs.

In the above operation, the peaks 14 and the valleys 13 are alternately provided on the bellows-like cylindrical portion 13 of the grommet 10, so that
Since the ridges 14 and the valleys 15 slide and rotate with respect to each other and are twisted, and the ridges 14 are provided with the straight portions 14a and 14b, the straight portions 14a and 14b are easily deformed and easily twisted, and the back door The torsion added at the time of the opening operation of No. 2 can be reliably absorbed by the bellows-like cylindrical portion 13. As a result, the cylindrical portions 1 on both sides as shown in FIG.
The back panel 1 and the back door 2 can be held in close contact with each other without causing any twist on the flanges 6 and 17 and without applying stress to the flanges 11 and 12 at both ends, thereby ensuring waterproof performance.

The number of the ridges 14 provided on the bellows-shaped cylindrical portion 13 is not limited, and the angle at which the ridges are deflected differs depending on the orientation of the flanges 11 and 12. That is, the angle between the flanges 11 and 12 is divided by the number of peaks, and they are sequentially shifted by the angle of the value.

The cross-sectional shape of the peak portion of the bellows-shaped cylindrical portion 13 is not limited to the substantially oval shape of the embodiment, but may be any shape having a pair of straight portions where deformation easily occurs.

[0022]

As is apparent from the above description, the grommet according to the present invention is provided with alternating peaks and valleys in a bellows-like cylindrical portion provided between both end flanges, and has a cross-sectional shape of the peaks. Since a pair of straight portions are provided and the directions of the ridges are sequentially changed at the same angle, each ridge is easily deformed, and as a result, is deformed as a whole to easily twist. Can be absorbed. Therefore, without applying stress to the flange,
It is possible to reliably prevent the deformation of the flange and the generation of a gap between the back panel and the fixed portion such as the back door, and as a result, it is possible to ensure waterproof performance.

[Brief description of the drawings]

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

FIG. 2 is a front view of the grommet.

FIGS. 3A to 3H are AA to H-lines of FIG. 2;
It is sectional drawing of the H line.

FIG. 4 is a schematic diagram in which the grommet is mounted between a back panel and a back door.

FIG. 5 is a perspective view showing the operation of the grommet when the back door is opened.

FIG. 6 is a schematic view showing a mounting location of a grommet.

7A and 7B show a grommet of a conventional example, wherein FIG. 7A is a perspective view, FIG. 7B is a front view, and FIG.
(D) is sectional drawing which shows the attachment state of a grommet.

FIG. 8 is a perspective view showing a problem of the grommet shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Back panel 2 Back door 3 Hinge 10 Grommet 11, 12 Flange 13 Bellows-like cylindrical part 14 Crest part 14a, 14b Linear part 14c, 14d Arc part 15 Valley part 16, 17 Cylindrical part

Claims (3)

(57) [Claims] 1. A grommet in which flanges are provided at both ends of a bellows-like cylindrical portion provided with alternating peaks and valleys, and the directions of the flanges at both ends are phased. A pair of straight portions facing each other in a C shape
Having a wide portion on one side at both ends of the pair of straight portions.
A continuous large arc and a small arc continuous with the narrow part on the other end
And an approximately oval shape, and deformed by the pair of straight portions.
A grommet characterized in that it is configured to absorb torsion . 2. The accordion-shaped cylindrical portion has a straight axis.
The large arc and small circle of the above-mentioned peak are located in the direction of the straight axis.
Connect both ends of the arc and sequentially set the direction of the peak defined by the axis
The grommet according to claim 1, wherein the grommet is changed by an angle . 3. A position in a direction of a ridge at both ends of the bellows-like cylindrical portion.
Assuming that the phase angle is the same as the phase angle of the flanges at both ends
The grommet according to claim 2, wherein