JP3355105B2 - Grommet with bellows - 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 with a bellows which is installed between a vehicle body and a door and through which a wire harness is inserted.

[0002]

2. Description of the Related Art Wire harnesses for electrically connecting electrical components disposed on a door side of an automobile to a vehicle body side include a tube which is stretched between the vehicle body side and the door side near a joint portion between a vehicle body and a door. Protects by inserting through the grommet. As this type of grommet, a bellows-type grommet is used because it is required to have elasticity that follows door opening and closing. For example, in a grommet disclosed in Japanese Utility Model Laid-Open No. 5-20952, two types of bellows having different diameters are combined, and when reduced in the longitudinal direction, a small-diameter bellow enters the inner diameter side of a large-diameter bellow. To increase the elasticity of the bellows. Further, in the grommet disclosed in Japanese Utility Model Application Laid-Open No. 63-126150, when the mounting position on the door-side panel to which one end is mounted is different from the mounting position on the vehicle body-side panel to which the other end is mounted, the height is different. The elasticity of the bellows is enhanced by forming the bellows of the grommet parallel to the panel surfaces of both mounting portions.

FIG. 3 shows the upper edge of the back door opening of the vehicle body 1,
This shows a structure generally used as a grommet connecting the upper end of a flip-up type back door 2 hinged to the grommet. The grommet 3 has attachment portions 34, 35 formed at both ends of a bellows-like cylindrical portion 30. One of the mounting portions 34 is fitted into a mounting hole of the vehicle body, the other mounting portion 35 is fitted into a mounting hole of the door 2, and a wire harness is inserted through the fitting hole.

[0004]

In this case, if both ends are attached to the vehicle body and the door at positions opposed to each other in the front-rear direction, the expansion and contraction of the cylindrical portion 30 when opening and closing the door becomes excessive, and wire harnesses inserted through the inside of the tube portion 30 become large. Since the wire harnesses and the bellows rub against each other, the mounting position on the vehicle body and the mounting position on the door are offset and the grommet is arranged in the vehicle width direction, so that expansion and contraction does not become excessive. Length. However, with this structure, a twist of about 90 ° occurs between both ends of the cylindrical portion 30 of the grommet 3 when the door is opened.
For this reason, there is a problem that the cylindrical portion 30 is crushed and deformed, and the mounting portions 34 and 35 are disengaged from the mounting holes due to a torsion force, and the wire harnesses may be damaged.

However, the conventional grommet disclosed in the above-mentioned literature is effective in improving the stretchability in the linear direction, but does not solve the above-mentioned problem due to the twist of the grommet.

SUMMARY OF THE INVENTION Accordingly, the present invention realizes a grommet with a bellows excellent in followability to expansion and contraction and torsion, particularly torsion accompanying opening and closing of a door, thereby preventing crushing of the grommet and detachment of a mounting portion, and a wire harness. The object of the present invention is to improve the protection performance.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a mounting portion formed at one end of a bellows-like cylindrical portion is locked to a vehicle body side.
A grommet that locks the mounting part formed at the other end to the door side, and protects the wire harnesses from the vehicle body side to the door side by passing them through. The resulting bellows grommet has a long
Crests and valleys on one semi-peripheral side of the cylinder extending in the hand direction
Is higher than the height difference between the peaks and valleys on the other semi-peripheral side.
Is large, and the one semi-peripheral surface side and the other semi-peripheral surface side
Beforehand, along the torsion direction of the cylinder when the door is fully open.
Thus, the structure is arranged spirally in the longitudinal direction (claim 1). When the grommet is twisted when the door is opened, the grommet is mainly formed on one half-peripheral surface side of the grommet whose extensibility is increased by increasing the height difference between the peak and the valley, so that the resistance to twisting is small. In addition, the ridges and valleys on one half-peripheral surface side where the extensibility is increased are arranged in advance in the twisting direction at the time of maximum twisting of the door fully open, so resistance is further reduced, and each ridge and valley does not fall down. The grommets do not collapse.

The present invention also provides a bellows-shaped cylindrical portion formed at one end.
With the attached part on the vehicle body side, and formed on the other end.
The mounting part is locked to the door side, from the vehicle body side to the door side
Grommet that protects by passing through wire harnesses
The door is opened and closed, and is stretched and twisted between both ends.
The longitudinal direction of the accordion grommet
The pitch of the peaks and valleys on one semi-peripheral side of the cylindrical portion is
It is denser than the pitch of the peaks and valleys on the other semi-peripheral side, and
The one semi-peripheral surface side and the other semi-peripheral surface side
When the door is fully open, the longitudinal direction is
The structure is arranged spirally (claim 2). With this, the same operation and effect as described above can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. The grommet 3A is connected to the upper edge of the back door opening of the vehicle body 1 shown in FIG. 3 and to the upper end of the flip-up type back door 2 which is hinged to the upper edge and pivots about 90 ° upward about the hinge axis to open. Is a grommet that spans the vehicle in the vehicle width direction. Fig. 1 (A) shows the grommet 3A in the mounted state.
(When the door is closed) viewed from above, FIGS. 1 (B), (C),
(D) is a figure which shows the cross section of each part of grommet 3A.
1 (B), (C) and (D) show the paper of FIG. 1 (A).
The direction perpendicular to the plane is shown as the vertical direction.

The grommet 3A is an integrally formed body made of a rubber material. As shown in FIG. 1 (A), the cylindrical portion 30 has a mountain portion 311 and a valley portion 31 at an intermediate portion while leaving the cylindrical portions 32 and 33 at both ends.
2 are alternately formed as a bellows portion 31 and a cylindrical portion 3
2, 33 are provided with mounting portions 34, 35, respectively. The attachment portions 34 and 35 are oval plates having a diameter larger than that of the cylindrical portions 32 and 33. Inside the engagement portions 34 and 35, engagement members are engaged with opening edges of oval through holes (not shown) of the vehicle body 1 and the back door 2. 36, 37
Are mounted, and flanges 342 and 352 which are in close contact with the opening edges of the through holes are provided on the peripheral edges of the mounting portions 34 and 35, respectively.
Are integrally formed. The through hole on the vehicle body 1 side is formed in the horizontal end face of the rear end of the roof having a Z-shaped cross section that forms the upper edge of the back door opening, and the through hole on the back door 2 side is the upper edge of the back door opening of the vehicle body 1. And formed on the upper frame portion of the door frame of the back door 2 hinged to the rear door 2. Both through holes are at positions offset in the vehicle width direction.

The mounting portion 34 is fitted downward into the through hole of the vehicle body 1. The cylindrical portion 32 on the mounting portion 34 rises upward, bends by approximately 90 ° and extends in the vehicle width direction, the bellows portion 31 is arranged in the vehicle width direction, and the cylindrical portion 33 on the mounting portion 35 side is a door of the back door 2. The mounting portion 35 is bent rearward so as to face the frame surface, and the mounting portion 35 is fitted into a through hole of the door frame 2.

The back door 2 is flipped upward by about 90 ° when it is opened. Thus, the bellows portion 31 of the grommet 3A attached in the vehicle width direction has a twist of approximately 90 ° between both ends thereof. Since the mounting portions 34 and 35 have an elliptical shape, they do not rotate with respect to the fitted through holes.

The structure of the bellows portion 31 will be described. Bellows 31
In FIG. 1A, the axis F of the valley 312 is a straight line as shown in FIG. On the other hand, as shown in FIG. 1B, the peak 311 has its axis E at the end on the one attachment portion 34 side (the vehicle body side). Eccentric. At the other end on the side of the mounting portion 35 (back door side), as shown in FIG.
The axis E of the line 9 is in the direction twisted when the back door is fully opened.
It is displaced by 0 ° and is eccentric in the lateral direction with respect to the axis F of the valley 312. FIG. 1 (C) shows the center of the bellows 31 in the longitudinal direction.
As shown in the figure, the axis E of the peak 311 is 45 ° on the twist side.
It is displaced and eccentrically deviated from the axis F of the valley 312. Therefore, the entire axis E of the peak 311 extends spirally from one end to the other end. Thereby, one half circumferential surface 3 of the bellows portion 31 extending in the longitudinal direction and spirally
The height difference between the peak 311 and the valley 312 on the 1a side is larger than that on the other half circumferential surface 31b side. The height difference at the center in the circumferential direction of one half-peripheral surface 31a is about 1.5 to 2.5 times the height difference at the other half-peripheral edge 31b.

In the grommet 3A having the above-described structure, when the back door is rotated and opened upward by 90 ° when the back door is opened, the entire bellows portion 31 is twisted by 90 ° between both ends while extending. This twist is the peak 311 and the valley 31
2 is absorbed by the elongation on the half-peripheral surface 31a side where the extensibility is further improved by increasing the height difference, so that the resistance is smaller than the whole being twisted. Moreover, the peak 311 and the valley 312 having a large difference in height are twisted in advance (spiral direction).
, The resistance to twisting when the back door is opened is further reduced, the peaks 311 and the valleys 312 do not fall down, and the bellows 31 is not bent or deformed.

Next, a second embodiment of the present invention will be described with reference to FIG. 2, focusing on differences from the first embodiment.
In the bellows portion 31 of the grommet 3B, the height of each peak and the depth of each valley are the same over the entire length, and the axis G of the ridge and the valley is common. Then, the peak portions 311a and valley portions 312a of one of the half surface 31a side extending helically in the longitudinal direction along the direction is twisted at the back door opening, and the peak portions 311b and valleys 312b of the other half face 31b side Are different in pitch, and the pitch of the peak 311a and the valley 312a on the one semi-peripheral surface 31a side is different from the pitch of the peak 311b and the valley 3 on the other half peripheral surface 31b side.
It is denser than the pitch of 12b. The difference in pitch density is about 1.2 to 1.8 times. Other structures are substantially the same as those of the grommet 3A, and the same portions are denoted by the same reference numerals and description thereof will be omitted.

In the grommet 3B, one half circumferential surface 31a
The pitch of the side of the mountain portions 311a and valley portions 312a, because the dense than the pitch of the other half face 31b side of the crests 311b and troughs 312b, is greater extensibility is more of one half face 31a side, The same operation and effects as those of the grommet 3A are obtained.

In each of the above embodiments, the arrangement of the peaks and valleys having a large difference in height and the arrangement of the peaks and valleys having a close pitch are determined by adjusting the twist angle at both ends of the bellows to 90 °. The torsional direction is determined by the opening when the back door is fully opened. For example, when the opening is 90 degrees or more, the torsional direction is also 90 degrees or more.

[0018]

According to the grommet of the present invention, the ability to follow the expansion and contraction and torsion of the grommet due to opening and closing of the door is improved, the deformation of the grommet and the detachment of the mounting portion do not occur, and the protection performance of wire harnesses is improved. I do.

[Brief description of the drawings]

[1] shows the grommet of the present invention, (A) is de
(A) A view of the grommet when closed from above , (B), (C),
(D) is the IB-IB line, IC-IC line, ID-ID of (A), respectively.
It is sectional drawing in the position along a line.

FIG. 2 shows another grommet of the present invention, wherein (A)
Is a top view of the grommet with the door closed , (B),
(C) and (D) are the IIB-IIB lines and (IIC) of (A), respectively.
-IIC line, IID It is sectional drawing in the position along the -IID line.

FIG. 3 shows a mounting state of a conventional grommet.
(A) is a perspective view when the back door is closed, and (B) is a perspective view when the back door is opened.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2 Back door 3, 3A, 3B Grommet 30 Cylindrical part 31 Bellows part 31a One half peripheral surface 31b The other half peripheral surface 311, 311a, 311b Mountain part 312, 312a, 312b Valley part 34, 35 Mounting part

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-148279 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01B 17/58 H02G 3/22

Claims (2)

(57) [Claims] An attachment portion formed at one end of a bellows-shaped cylindrical portion is locked to a vehicle body side, and a mounting portion formed at the other end is locked to a door side, and extends from the vehicle body side to the door side. A grommet for protecting a wire harness by inserting the wire harness, wherein the grommet with a bellows in which expansion and contraction and torsion occur between both ends in accordance with opening and closing of a door is provided.
The height difference between the peaks and valleys on one half of the circumference is
Is greater than the height difference between the peak and valley on the
When the half-peripheral side and the other half-peripheral side are
Spirally arranged in the longitudinal direction along the torsion direction of the cylindrical portion
A grommet with a bellows, characterized by a lined structure . 2. A mounting portion formed at one end of a bellows-shaped cylindrical portion is locked to a vehicle body side, and a mounting portion formed at the other end is locked to a door side, and extends from the vehicle body side to the door side. A grommet for protecting a wire harness by inserting the wire harness, wherein the grommet with a bellows in which expansion and contraction and torsion occur between both ends in accordance with opening and closing of a door is provided.
The pitch of the peaks and valleys on one semi-peripheral surface is
The pitch of the peaks and valleys on the side
The peripheral side and the other half peripheral side
Arranged spirally in the longitudinal direction along the torsion direction of the cylindrical part
A grommet with a bellows, characterized in that it has a structure that does .