JPH10257646A - Attaching structure for grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To incorporate a wiring harness by an insertion operation in one direction into a box, only without drawing back the wiring harness towards an engine room side. SOLUTION: A wiring harness is inserted into a box which is provided in the engine room of a car and has a built-in electronic controller through a grommet, attached to a piercing hole formed in the side wall of the box. A through-hole 12 forms a barring 13. The grommet 15 is composed of a small diameter cylindrical part through which the wiring harness is inserted, an expanded diameter cylindrical part 15b, retaining nails 15c made to be protruded from the tip part of the expanded diameter cylindrical part 15b and a sealing brim part 15d which is made to be protruded from the outer circumferential surface of an expanded diameter cylindrical part 15b, so as to be positioned on the outer circumferential surface of the barring 13 and has an L-shaped cross-section and those components are integrally molded. The grommet is pushed into a box from an engine room side to make the retaining nails 15c retain with the inner circumferential edge of the piercing hole and, further, the outer circumference of the sealing brim part 15d positioned on the outer circumferential surface of the barring 13 is tightened and fixed by a belt-type tightening member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case in which a wire harness is inserted through a grommet into a through hole provided in a side wall of a box in a box built in an electronic controller (computer) arranged in an engine room of an automobile. In this case, the grommet is attached to the box with good operability, and the sealing performance is improved.

[0002]

2. Description of the Related Art Boxes accommodating computers that are indispensable for controlling electrical components in automobiles have conventionally been arranged in a vehicle compartment, but recently, studies have been made to mount them in an engine room. In that case, it is necessary to insert the wire harness into the box containing the computer, but in the engine room, flooding becomes a problem, so attach a grommet to the wire harness and attach the grommet to a through hole of the box. It is necessary to seal.

[0003] As this type of grommet, various types of grommet to be attached to a wire harness through hole provided in a panel separating an engine room and a vehicle room have been proposed. FIGS. 5 (A) and 5 (B) show a case where a wire harness is inserted through the above-mentioned computer housing box (hereinafter abbreviated as an ECU box) by using a grommet of this kind.
A structure shown in (C) has been proposed.

[0004] The grommet 1 for sealing is provided with an enlarged-diameter tube portion 1b at the end of the electric-wire insertion tube portion 1a, and a locking groove 1c is formed on the outer periphery of the enlarged-diameter tube portion 1b. As shown in (1), the locking groove 1c is locked to the periphery of the through hole 2a of the ECU box 2 and attached in a sealed state.

[0006] As shown in FIG. 6, the grommet 1 is attached by first passing a wire harness W / H inserted through the grommet 1 as shown in FIG.
As shown in (B), the diameter of the enlarged-diameter tube portion 1b of the grommet 1 is reduced and passed through the through hole 2a to the small-diameter tube portion 1a side (X) in the box 2, and finally shown in (C). Thus, the wire harness W / H on the engine room side (Y) is pulled back to the engine room side as shown by the arrow, and is locked in the locking groove 1c of the enlarged diameter cylindrical portion 1b.

[0006]

However, various devices are densely arranged in the vicinity of the ECU box arrangement in the engine room, and a space for pulling back the wire harness shown in FIG. 6C is provided. There is a problem that is difficult to secure. Therefore, the workability of assembling the wire harness becomes extremely difficult, and as a result, the grommet can be reliably mounted on the ECU
There is a problem that it is difficult to lock the box.

The present invention has been made in view of the above-mentioned problem, and eliminates the need for inserting the wire harness from the engine room into the ECU box and then returning the wire harness to the engine room side. The problem is to improve the workability of assembling the wire harness, and to improve the sealability by securely pressing the grommet seal part against the ECU box so that the work can be done only in one direction from the ECU box to the ECU box. And

[0008]

In order to solve the above-mentioned problems, according to the present invention, in a box (ECU box) with a built-in electronic controller disposed in an engine room of an automobile, a side wall of the box is provided. The wire harness is inserted through a grommet through a through hole provided in the grommet, and the through hole has a burring protruding outward on the engine room side, while the grommet is inserted through the wire harness in close contact therewith. A small-diameter tube portion, a large-diameter tube portion expanding from one end of the small-diameter tube portion, a locking claw protruding from a tip of the large-diameter tube portion, and the large-diameter tube so as to be positioned on an outer peripheral surface of the burring. A sealing flange portion having an L-shaped cross section protruding from the outer peripheral surface of the cylindrical portion is integrally formed. The grommet is passed from the engine room side into the box, and the locking claw is formed on the inner peripheral edge of the through hole. To While stop, and provides a mounting structure of the grommet, characterized in that the outer circumference of the sealing flange portion positioned on the burring outer peripheral surface, are clamped by a member with the belt-shaped tightening.

In the above-described grommet, only one-way operation of inserting the wire harness from the engine room side into the ECU box is required, and after the insertion, the belt-like fastening member is attached to the grommet sealing flange by the operation from above. Just wind and tighten. As described above, since there is no need to pull the wire harness back to the engine room side, the workability of assembling the wire harness can be improved.

The belt-shaped fastening member is made of resin,
A metal tie belt that is fastened steplessly or a lock-type belt is preferably used (claim 2).
The material and the method of tightening the belt-shaped tightening member are not limited, and any material may be used as long as the grommet sealing flange can be tightened to the outer peripheral surface of the burring of the ECU box. preferable.

In the grommet, a first sealing rib which is in pressure contact with the inner peripheral surface of the burring is provided so as to protrude from the outer peripheral surface of the enlarged-diameter cylindrical portion, and a sealing flange at a position opposed to the belt-shaped tightening member. A second seal rib is provided on the inner peripheral surface,
The seal rib is pressed against the outer peripheral surface of the burring (claim 3). When the grommet sealing ribs are pressed against both the inner and outer peripheral surfaces of the burring in this manner, the sealing performance can be improved.

Further, it is preferable that the grommet is provided with an insertion groove for the belt-shaped tightening member on an outer peripheral surface of a sealing flange located on an outer peripheral surface of the burring. Providing the insertion groove as described above makes it difficult for the belt-shaped tightening member to be misaligned, and secures the seal by securely tightening the sealing flange to the outer peripheral surface of the burring.

Furthermore, it is preferable to fill a sealant into the inside of the enlarged-diameter cylindrical portion of the grommet.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 10 denotes a box with a built-in computer disposed in an engine room of an automobile. A through hole 12 formed in a side wall 11 of the box 10 protrudes from the periphery to the engine room side (Y). A burring 13 is provided.

A grommet 15 is attached to a wire harness W / H which is routed through the through hole 12 from the engine room side (Y) to the inside (X) of the box 10. The grommet 15 includes a small-diameter cylindrical portion 15a through which the wire harness W / H is inserted in close contact, a large-diameter cylindrical portion 15b expanding from one end of the small-diameter cylindrical portion 15a, and a large-diameter cylindrical portion 15b.
A locking claw 15c protruding radially outward from the tip of the burring 13; and a sealing flange having an L-shaped cross section protruding from the outer peripheral surface of the enlarged diameter cylindrical portion 15b so as to be located along the outer peripheral surface 13a of the burring 13. The portion 15d is integrally formed of rubber or elastomer.

Further, the outer diameter of the enlarged diameter cylindrical portion 15b is slightly smaller than the inner diameter of the burring 13 and the through hole 12, so that the enlarged diameter cylindrical portion 15b
The enlarged-diameter cylindrical portion 15 is set so as to pass through smoothly.
A first seal rib 15e, which comes into pressure contact with the inner peripheral surface 13b of the burring 13, projects annularly from the outer peripheral surface of the b.

The sealing flange portion 15d is thicker than the other portions, and projects a second sealing rib 15f from an inner peripheral surface opposed to the burring outer peripheral surface 13a. The second sealing rib 15f and the first sealing rib 15e are formed. Is positioned so that the burring 13 is pressed and held from both sides. The outer peripheral surface of the sealing flange 15d facing the second sealing rib 15f has an insertion groove 15 for a belt-shaped fastening member.
g is annularly recessed.

A tie belt 16 made of resin is attached to the insertion groove 15g. The tie belt has a well-known structure. The tie belt is provided with a locking portion 16a at one end, and a locking groove 16c is continuously provided in the belt portion 16b, and the locking groove 16c is inserted into a through hole of the locking portion 16a. It is locked at a required position by a locking piece 16d projecting into the through hole.

After the grommet 15 having the above structure is attached to the wire harness W / H in advance, the sealing agent 18 is filled into the small-diameter cylindrical portion 15c from the enlarged-diameter cylindrical portion 15b side and hardened, and the inner peripheral surface of the grommet 15 is set. And the wire harness W / H.

As described above, the wire harness W / H having the grommet 15 attached thereto and filled with the sealing agent 18 is as follows.
As shown in FIGS. 3A, 3B and 3C, the wire harness W / H is passed through the through hole 12 from the engine room side (Y). At that time, since the outer diameter of the enlarged diameter cylindrical portion 15b of the grommet 15 is slightly smaller than the inner diameter of the burring 13,
The protruding locking claws 15c can be smoothly inserted while being compressed.

When the locking claw 15c at the tip of the enlarged diameter cylindrical portion 15b comes out of the through hole 12 and protrudes into the box 10, it is locked to the inner peripheral edge of the through hole 12 to be in the state shown in FIG. In this state, the first sealing rib 15e of the enlarged diameter cylindrical portion 15b presses against the inner peripheral surface of the burring 13 and the sealing flange 1
5d is located on the outer peripheral surface of the burring 13, and the second seal rib 15f protruding from the inner peripheral surface of the sealing flange 15d contacts the outer peripheral surface of the burring 13.

In this state, as shown in FIG. 3C, the tie belt 16 is fastened and fixed in a state of being fitted into the insertion groove 15g of the sealing flange 15d. The tie belt 16
As a result, the second seal rib 15f is pressed against the outer peripheral surface 13b of the burring 13 and pressed against the outer peripheral surface 13b.

After the wire harness W / H is inserted in one direction from the engine room side (Y) into the box (X), the tie belt 16 is inserted from above.
, And there is no work to pull the wire harness W / H back to the engine room side (Y), so that the work of assembling the wire harness can be easily performed even if there is no space on the engine room side.

In addition, since the seal ribs on both the inner peripheral surface and the outer peripheral surface of the burring 13 protruding from the through hole 12 of the box 10 are pressed against each other, the sealing performance can be improved.

FIG. 4 shows a modification of the belt state tightening member, in which a lock type locking portion 16a 'is provided at one end of a metal annular band portion 16b', and a lock claw 16c 'is provided at the other end.
And the locking claw 16c 'is fixed to the locking type locking portion 16a'.
When it is inserted into the device, it is locked with one touch.

[0026]

As is apparent from the above description, according to the present invention, one-way operation from the engine room to the box is sufficient, and it is not necessary to perform the operation of pulling the engine room, which is difficult to pull. As a result, the mounting workability can be improved.

Further, since the seal rib is pressed against the inner and outer peripheral surfaces of the burring on the peripheral edge of the through hole on the box side, the waterproof performance of the grommet is improved, and the ingress of the box into the computer built-in box is reliably prevented. Can be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a mounted state of a grommet according to the embodiment of the present invention.

FIGS. 3A, 3B, and 3C are cross-sectional views illustrating an attachment process according to the embodiment of the present invention.

FIG. 4A is a perspective view showing a modification of the belt-shaped fastening member of the present invention, and FIG. 4B is a schematic sectional view showing a lock mechanism.

5A and 5B show a conventional example, in which FIG.
(B) is a principal part enlarged perspective view, (C) is a CC sectional view taken on the line (B).

FIGS. 6A, 6B, and 6C are cross-sectional views showing a mounting step of a conventional grommet.

[Explanation of symbols]

 10 ECU Box 12 Through Hole 13 Burring 15 Grommet 15a Small Diameter Cylindrical Part 15b Large Diameter Cylindrical Part 15c Engagement Claw 15d Sealing Cylindrical Part 15e First Seal Rib 15f Second Seal Rib 16 Belt Tightening Member W / H Wire Harness X Box Y engine room side

Claims (5)

[Claims] 1. A wire harness is inserted through a grommet into a through hole provided in a side wall of an electronic controller in a box with a built-in electronic controller disposed in an engine room of an automobile. The grommets are provided with a burring protruding outward on the engine room side, the grommet includes a small-diameter tubular portion through which a wire harness is brought into close contact and inserted, an enlarged-diameter tubular portion expanding from one end of the small-diameter tubular portion, A locking claw protruding from the tip of the cylindrical portion and a sealing flange having an L-shaped cross section protruding from the outer peripheral surface of the enlarged diameter cylindrical portion so as to be located on the outer peripheral surface of the burring are integrally formed. Passing the grommet from the engine room side into the box to lock the locking claw on the inner peripheral edge of the through hole, and tighten the outer periphery of the sealing flange located on the outer peripheral surface of the burring in a belt-like manner. A grommet mounting structure, wherein the grommet is fastened and fixed by an attaching member. 2. The grommet mounting structure according to claim 1, wherein the belt-shaped fastening member is formed of a resin or metal tie belt which is fastened in a stepless manner, or a lock type belt. 3. The grommet has a first sealing rib, which is in pressure contact with an inner peripheral surface of a burring, protruding from an outer peripheral surface of the enlarged-diameter cylindrical portion, and a sealing flange at a position facing the belt-shaped tightening member. The grommet mounting structure according to claim 1 or 2, wherein a second seal rib is provided on an inner peripheral surface of the portion, and the second seal rib is pressed against the outer peripheral surface of the burring. 4. The grommet according to claim 1, wherein an insertion groove of the belt-shaped tightening member is provided on an outer peripheral surface of a sealing flange located on an outer peripheral surface of the burring. The grommet mounting structure described in 1. 5. The grommet according to claim 1, wherein a sealing agent is filled inside the enlarged-diameter tube portion.
The grommet mounting structure described in the item.