JP4483767B2 - Grommet - Google Patents

Description

  The present invention relates to a grommet, and more particularly to a one-motion grommet that is externally mounted on a wire harness routed in an automobile, is pushed into a through hole of a vehicle body panel from one direction, and is attached to the periphery of the through hole. .

  Conventionally, a grommet made of rubber or elastomer is attached to a wire harness routed from an engine room of an automobile to a vehicle interior, and the grommet is attached to a through hole of a vehicle body panel that partitions the engine room and the vehicle interior. Protects the wire harness that passes through the vehicle and is waterproof, dustproof, and soundproofed from the engine compartment side to the vehicle compartment.

As this type of grommet, the present applicant provides grommet 1 shown in FIG. 7 in Japanese Patent Application Laid-Open No. 2003-125521 (Patent Document 1). Specifically, the grommet 1 includes a first small-diameter cylindrical portion 2, a large-diameter cylindrical portion 3 continuous to the first small-diameter cylindrical portion 2, and a closing portion 4 that closes the large-diameter side end surface of the large-diameter cylindrical portion 3. The wire harness W / H, which is composed of a second small-diameter cylindrical portion 5 protruding from the center of the closing portion 4 and penetrates the grommet 1, is taped to the first and second small-diameter cylindrical portions 2, 5 on both the front and rear sides. The wire harness W / H is wound around and fixed to the exterior.
In this state, the first small-diameter cylindrical portion 2 side of the grommet 1 is pushed into the through hole Pa of the vehicle body panel P from the outdoor (A) partitioned by the vehicle body panel P to the indoor (B), and at the indoor (B) side. The one-motion pulling of the wire harness W / H protruding from the first small-diameter cylindrical portion 2 fits the vehicle body locking recess 3a provided on the outer peripheral surface of the large-diameter cylindrical portion 3 to the periphery of the through hole Pa of the vehicle body panel P. The grommet 1 is attached to the vehicle body panel P.

In the grommet 1 of the above-mentioned patent document 1, since it is not mounted with a two-motion reciprocating operation in which the grommet 1 is pushed and pulled into the through hole Pa of the vehicle body panel P, it is mounted with one motion that moves in one direction. There is an advantage that the mounting workability is excellent. Thus, when attaching the grommet 1 to the vehicle body panel P, the first small diameter cylindrical portion 2 provided on the indoor side of the grommet 1 is taped and fixed to the wire harness W / H. When contacting the peripheral edge of the P through-hole Pa, the diameter-expanded cylindrical portion 3 can be smoothly reduced in diameter without being crushed in the axial direction, and the through-hole Pa can be passed therethrough.
However, in the grommet 1, the first small-diameter cylindrical portion 2 protrudes on the indoor side, and the first small-diameter cylindrical portion 2 and the wire harness W / H are fixed by tape. A region L that is rigid and difficult to bend extends to the inside. Therefore, when there is an external interference material near the vehicle body panel P and the wire harness W / H needs to be bent in the vicinity of the vehicle body panel P, the rigid region on the first small diameter cylindrical portion 2 side of the grommet 1 is bent. Although it is necessary, it is very difficult to bend, and if it is bent forcibly, the entire grommet 1 is deformed, and a gap is formed between the vehicle body locking recess 3a of the grommet 1 and the vehicle body panel P, resulting in poor sealing performance.

JP 2003-125521 A

  The present invention has been made in view of the above-described problems, and while maintaining the water stopping performance of the grommet while using a one-motion grommet, the wire harness can be bent in the vicinity of the vehicle body panel without deforming the grommet. It is a problem.

In order to solve the above-mentioned problem, the present invention is a grommet that is externally fixed to a wire harness routed in an automobile and is attached to a through-hole of a vehicle body panel,
An inner cylinder that allows the wire harness to adhere and penetrates;
An outer cylinder which is molded integrally with the front end of the inner tube serving as insertion end into the through-hole by return folded outward,
The outer cylinder is folded from the front end of the inner cylinder and is expanded toward the rear side, the enlarged diameter cylindrical part, the rear end face part on the large diameter side of the enlarged diameter cylinder part, and the inner side of the rear end face part A continuous straight pipe portion surrounding the inner cylinder continuously around the circumference ,
While providing a vehicle body locking recess on the outer peripheral surface on the large-diameter side of the enlarged-diameter cylindrical portion of the outer cylinder,
On the outer peripheral surface of the inner cylinder, a reinforcing portion that extends continuously to the inner surface of the front-end small-diameter side of the enlarged-diameter cylindrical portion and extends toward the rear-end surface portion is provided .
A plurality of the reinforcing portions are provided at predetermined intervals in the entire circumference or circumferential direction of the inner cylinder, and the reinforcing portions protrude in a step shape from the inner cylinder with a required thickness, and a rear end portion of the reinforcing portion Is provided in a stepped recess provided in the inner periphery of the rear end surface portion of the outer cylinder, and a grommet configured to restrict rearward movement of the reinforcing portion is provided.

In the grommet of the present invention having the above-described configuration, the insertion side into the through hole of the vehicle body panel is the small diameter side of the front end of the large diameter cylindrical portion, and the small diameter cylindrical portion described in Patent Document 1 is not provided so as to protrude from the opposite side. The grommet is attached to the vehicle body panel in one motion in which the grommet is passed through the through hole and the vehicle body locking recess is locked to the periphery of the through hole simply by pushing in from the small-diameter cylindrical portion side protruding.
In a state where the grommet is mounted on the vehicle body panel, only the diameter-enlarged cylindrical portion protrudes from the vehicle body panel to the vehicle compartment side, and the protruding length can be shortened. This makes it possible to easily bend only the wire harness protruding from the enlarged cylindrical portion in the vicinity of the vehicle body panel and to bend the grommet itself even if an external interference material is disposed near the vehicle body panel. Therefore, the water stopping performance can be maintained without deforming the grommet.

However, since the small-diameter cylindrical portion that protrudes toward the indoor side is not provided as in Japanese Patent Laid-Open Publication No. 2001-260, there is no pulling action from the indoor side, and only the push-in is performed from the outdoor side. The side is easy to roll up.
On the other hand, in the grommet of the present invention, as described above, the reinforcing portion is provided on the outer surface of the inner cylinder, and the reinforcing portion is continuously reinforced to the inner surface on the front end small diameter side of the enlarged diameter cylindrical portion. It is possible to prevent the front-end small-diameter side of the enlarged-diameter cylindrical portion from rolling up. Thereby, the pushing force from the outdoor side can be reliably applied to the grommet, and the grommet can be attached to the through hole of the vehicle body panel without any problem in one motion.

A plurality of the reinforcing portions are provided at predetermined intervals in the entire circumference or circumferential direction of the inner cylinder, and the reinforcing portions are protruded in a step shape from the inner cylinder with a required thickness.
That is, since the reinforcing portion prevents the insertion-side front end from being deformed when inserted into the through-hole, the reinforcing portion can be sufficiently reinforced in width, thickness, and length.
In the case where a plurality of reinforcing portions are provided at intervals in the circumferential direction of the inner cylinder, it is preferable that three or four reinforcing portions are provided at equal intervals.

Further, the rear end portion of the reinforcement portion, is positioned within the stepped recess portion provided on the inner periphery of the rear end surface of the outer cylinder, that has a structure for restricting the rearward movement of the reinforcing portion.
With this structure, even if the reinforcing part is urged in the backward direction by the reaction force generated when the grommet is pushed into the through hole, the rear end surface of the reinforcing part comes into contact with the inner surface of the recess and can be prevented from moving backward. The force can be reliably transmitted to the grommet and the insertion force can be reduced.
Furthermore, even after the grommet is attached to the through-hole, even if the grommet is pulled to the outdoor side by the wire harness, the reinforcing part can abut against the inner surface of the stepped depression, and the movement can be prevented. Can be prevented from falling off. That is, not only can the insertion force be reduced, but also the grommet holding force can be improved.

Furthermore, it is preferable that an annular groove surrounding the inner cylinder is provided on the small diameter side of the front end of the enlarged diameter cylindrical portion.
According to the above configuration, when the grommet is attached to the vehicle body panel, the outer surface of the enlarged diameter cylindrical portion comes into contact with the periphery of the through hole provided in the vehicle body panel, so that the load applied to the enlarged diameter cylindrical portion is increased by the annular groove. It is possible to make it difficult to transmit to the continuous position between the portion and the inner cylinder. As a result, the inner cylinder is further unlikely to be turned up from the wire harness, and the force for pushing the wire harness is easily transmitted to the grommet, so that the insertion force of the grommet can be reduced.

Further, a strip-shaped convex portion is provided radially on the outer peripheral surface of the enlarged diameter cylindrical portion from the front end small diameter side to the rear end large diameter side, and the straight tube portion of the outer cylinder and the rear end portion of the inner cylinder are inserted. A sealed space is provided between the inner cylinder and the outer cylinder by tape-fixing together with the wire harness to be made.
As described above, when the convex portion is provided on the outer peripheral surface of the enlarged diameter cylindrical portion, the contact area with the inner peripheral surface of the through hole of the vehicle body panel can be reduced, which can contribute to a reduction in the insertion force of the grommet.
Further, by providing a sealed space between the inner cylinder and the outer cylinder, it is possible to reduce or block the transmission of noise from the outside such as the engine room to the room.

  As described above, in the grommet according to the present invention, since the small-diameter cylindrical portion is not projected on the insertion end side of the through hole of the vehicle body panel, only the large-diameter cylindrical portion protrudes from the vehicle body panel to the vehicle compartment side. The protruding length can be shortened. This makes it possible to easily bend only the wire harness protruding from the enlarged cylindrical portion in the vicinity of the vehicle body panel and to bend the grommet itself even if an external interference material is disposed near the vehicle body panel. Therefore, the water stopping performance can be maintained without deforming the grommet.

  Further, since the reinforcing portion is provided on the outer surface of the inner cylinder and the reinforcing portion is connected to the inner surface on the small diameter side on the insertion end of the enlarged diameter cylindrical portion, the continuous position of the enlarged diameter cylindrical portion and the inner cylinder is deformed. Can be prevented. As a result, when the grommet is attached to the vehicle body panel, the insertion side front end can be prevented from coming into contact with the peripheral edge of the through-hole even if it is performed with one motion only by pushing from the outside, and the pushing force can be prevented. The grommet can be attached to the vehicle body panel.

Embodiments of the present invention will be described with reference to the drawings.
1 to 5 show an embodiment, and the grommet 10 is integrally formed of rubber or elastomer, and an inner cylinder 11 serving as an insertion end into the through hole Pa of the vehicle body panel P, and a front end of the inner cylinder 11 are arranged outside. The enlarged diameter cylindrical part 12 formed by folding back and expanding toward the rear side, the rear end face part 13 on the large diameter side of the enlarged diameter cylinder part 12, and the inner periphery of the rear end face part 13 And an outer cylinder 15 including a straight pipe portion 14 surrounding the cylinder 11. The large diameter side of the enlarged diameter cylindrical portion 12 is thick, and a vehicle body locking recess 16 is provided in an annular shape on the outer peripheral surface thereof.

The vehicle body locking recess 16 includes both side surfaces 16a and 16b and a bottom surface 16c continuous to the both side surfaces 16a and 16b, and is provided with a lip portion 16d protruding from the outer peripheral edge of the large-diameter side surface 16a.
A plurality of belt-like convex portions 20 extending in the axial direction are provided on the outer peripheral surface of the enlarged diameter cylindrical portion 12 so as to extend in the axial direction from the small diameter side to the large diameter side of the vehicle body locking concave portion 16 at intervals in the circumferential direction. Yes. The convex portion 20 has a so-called rib shape that protrudes from the outer peripheral surface of the diameter-enlarged cylindrical portion 12 in a stepped manner. A narrow groove 20a extending in the circumferential direction is provided on the outer surface of the convex portion 20 at the same height as the tip of the side surface 16b of the vehicle body locking concave portion 16.
In the present embodiment, the eight convex portions 20 are extended in the axial direction with the same width in the circumferential direction from the small diameter side to the large diameter side, and the eight convex portions 20 have the same shape.

  Since the width of each convex portion 20 is the same in the axial direction X, the convex portion 20 extends radially from the small diameter side to the large diameter side. The end portions 20b of the small-diameter side convex portions 20 are arranged closely adjacent to each other, and the end portions 20c of the large-diameter side convex portions 20 have a space between the adjacent convex portions. A triangular depression 21 formed on the outer peripheral surface of the portion 12 is generated in a direction extending from the small diameter side to the large diameter side.

  A central groove 22 in the axial direction is provided at the center in the circumferential direction of the recess 21. Further, both side grooves 23 are provided along the base of the convex portion 20. Even if the convex portion 20 is protruded by these grooves 22 and 23 to increase the rigidity of the enlarged diameter cylindrical portion 12, it can be easily bent in the reduced diameter direction when inserted into the through hole of the vehicle body panel. ing. That is, the grooves 22 and 24 guide the dent portion 21 in the direction in which it is folded, so that the diameter is reduced without difficulty.

As shown in FIG. 3, the inner cylinder 11 passes through an enlarged diameter cylindrical portion 12 and a straight pipe portion 14 provided on the larger diameter side of the enlarged diameter cylindrical portion 12, and the inner diameter of the inner cylinder 11 is adjusted to a grommet. 10 is set to be smaller than the outer diameter of the wire harness W / H that covers the exterior. A plurality of rib-shaped reinforcing portions 30 extending in the axial direction are provided on the outer peripheral surface of the inner cylinder 11 at intervals in the circumferential direction, and the front end of the reinforcing portion 30 is connected to the inner surface of the enlarged-diameter cylindrical portion 12. On the other hand, the rear end is provided at a position close to the stepped depression 17 provided on the inner surface of the continuous position of the rear end surface portion 13 and the straight tube portion 14. The stepped recess 17 includes an annular side surface 17a having a radial direction as a width direction and an annular side surface 17b continuing from the side surface 17a and having an axial direction as a width direction. The side surface 17a and the rear end surface 30a of the reinforcing portion 30 And the side surface 17b and the rear end side of the outer peripheral surface 30b of the reinforcing portion 30 are arranged to face each other, and the rear end portion of the reinforcing portion 30 is positioned inside the stepped recess portion 17. In the present embodiment, as shown in FIG. 4, four reinforcing portions 30 are provided at intervals of 90 degrees in the circumferential direction.
In addition, an annular groove 18 surrounding the inner cylinder 11 is provided at the small-diameter end of the enlarged cylinder part 12, which is a continuous position between the enlarged cylinder part 12 and the inner cylinder 11.

  With the inner cylinder 11 of the grommet 10 expanded in diameter, the wire harness W / H is penetrated, the inner cylinder 11 is returned to the original, and the inner peripheral surface of the inner cylinder 11 is brought into close contact with the outer peripheral surface of the wire harness W / H. Furthermore, the end portion of the straight pipe portion 14 is fixed to the wire harness W / H with a tape T, and the grommet 10 is externally mounted on the wire harness W / H as shown in FIG. At this time, a sealed sound insulation space S is formed between the inner cylinder 11 and the outer cylinder 15. In this state, the grommet 10 is attached to the through hole Pa of the vehicle body panel P formed of a dash panel that partitions the engine room side (A) and the vehicle compartment side (B).

The grommet mounting operation will be described below.
The diameter-enlarged cylindrical portion 12 is pushed into the through hole Pa of the vehicle body panel P from the engine room side (A). At this time, if the grommet 10 is inclined, a part of the convex portion 20 hits the inner peripheral surface of the through hole Pa to generate contact resistance. Thereby, the operator corrects the insertion posture of the grommet 10.
Moreover, since a large number of protrusions 20 are provided on the outer peripheral surface of the thin-walled enlarged diameter cylindrical portion 12, the rigidity of the enlarged diameter cylindrical portion 12 increases, and when the grommet 10 is inserted obliquely, It is possible to reliably prevent the diameter-expanded cylindrical portion 12 of the pressed portion from being deformed so as to be bent.

When the enlarged diameter cylindrical portion 12 of the grommet 10 is passed through the through hole Pa and reaches the contact point of the convex portion 20 that is the same as the inner diameter of the through hole Pa, the pressure contact between the outer surface of the convex portion 20 and the inner peripheral surface of the through hole A feeling of moderation is generated in the worker.
From this point of time, when the operator pushes the grommet 10 at a stroke and passes the through hole Pa so as to crush the convex portion 20, the vehicle body locking concave portion 16 of the enlarged diameter cylindrical portion 12 is formed on the periphery of the through hole Pa of the vehicle body panel P. The grommet 10 is attached to the vehicle body panel P by being fitted.

  When the grommet 10 is attached, the inner peripheral surface of the through hole interferes with the enlarged diameter cylindrical portion 12 of the grommet 10, but the reinforcing portion 30 connected to the inner surface of the enlarged diameter cylindrical portion 12 is provided to deform the inner cylinder 11. Since the annular groove 18 is provided at the tip of the small diameter side of the enlarged diameter cylindrical portion 12 so that the load applied to the enlarged diameter cylindrical portion 12 is not transmitted to the distal end of the inner cylinder 11, the inner cylinder 11 is connected to the wire harness. No worries from W / H. Therefore, the grommet 10 can be easily attached to the vehicle body panel P without providing a small-diameter cylindrical portion for tape-fixing the wire harness W / H on the small-diameter end side of the large-diameter cylindrical portion 12.

  Thus, since it is not necessary to provide a small-diameter cylindrical portion that is closely fitted to the wire harness from the small-diameter end side of the enlarged-diameter cylindrical portion 12 toward the vehicle interior side, the grommet 10 protrudes from the vehicle body panel P to the vehicle interior side. No. is only the enlarged diameter cylindrical portion 12, and the protruding length L of the grommet 10 from the vehicle body panel P can be shortened. Thereby, even if the external interference material is disposed near the vehicle body panel P, only the wire harness W / H protruding from the enlarged diameter cylindrical portion 12 in the vicinity of the vehicle body panel P can be easily bent, and Since it is not necessary to bend the grommet 10 itself, the water stop performance can be maintained without deforming the grommet 10.

  In addition, after the grommet 10 is attached to the vehicle body panel P, the rear end surface 30a and the outer periphery of the reinforcing portion 30 provided in the inner cylinder 11 even if a load is applied to the wire harness W / H in the direction opposite to the insertion direction. The surface 30 b interferes with the side surfaces 17 a and 17 b of the stepped recess portion 17 provided in the rear end surface portion 13. Thereby, deformation of the grommet 10 can be prevented, and the grommet 10 can be prevented from falling off the vehicle body panel Pa.

  As shown in FIG. 6, the number of reinforcing portions 30 provided in the inner cylinder 11 may be different from that in the above embodiment. In FIG. 6A, three reinforcing portions 30 are provided at intervals of 120 degrees in the circumferential direction. In FIG. 6A, the reinforcing portion 30 is provided on the entire circumference of the inner cylinder 11.

It is a perspective view of the grommet of an embodiment of the present invention. It is a front view of a grommet. It is an AA line sectional view of a grommet. It is a BB line sectional view of a grommet. (A) (B) is drawing which shows the attachment method to the vehicle body panel of a grommet. (A) (B) It is drawing which shows the modification of embodiment. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Grommet 11 Inner cylinder 12 Expanded diameter cylinder part 13 Rear end surface part 14 Straight pipe part 15 Outer cylinder 16 Car body latching recessed part 18 Annular groove 20 Convex part 30 Reinforcement part P Car body panel Pa Through hole

Claims (3)

A grommet that is externally fixed to a wire harness routed in an automobile and is attached to a through hole of a vehicle body panel,
An inner cylinder that allows the wire harness to adhere and penetrates;
An outer cylinder which is molded integrally with the front end of the inner tube serving as insertion end into the through-hole by return folded outward,
Said outer cylinder flare tube portion formed by the enlarged diameter toward the rear side by folding from the front end of the inner tube, and the rear end surface of the large diameter side of the enlarged diameter cylindrical portion, of the rear end face A continuous straight pipe portion surrounding the inner cylinder continuously around the circumference ,
While providing a vehicle body locking recess on the outer peripheral surface on the large-diameter side of the enlarged-diameter cylindrical portion of the outer cylinder,
On the outer peripheral surface of the inner cylinder, a reinforcing portion that extends continuously to the inner surface of the front-end small-diameter side of the enlarged-diameter cylindrical portion and extends toward the rear-end surface portion is provided .
A plurality of the reinforcing portions are provided at predetermined intervals in the entire circumference or circumferential direction of the inner cylinder, and the reinforcing portions protrude in a step shape from the inner cylinder with a required thickness, and a rear end portion of the reinforcing portion The grommet which is located inside the stepped depression provided on the inner periphery of the rear end surface portion of the outer cylinder and restricts the rearward movement of the reinforcing portion . The grommet according to claim 1 , wherein an annular groove surrounding the inner cylinder is provided on the small diameter side of the front end of the enlarged diameter cylindrical portion . A wire having a belt-like convex portion radially provided from the front end small diameter side to the rear end large diameter side on the outer peripheral surface of the enlarged diameter cylindrical portion, and through which the straight tube portion of the outer cylinder and the rear end portion of the inner cylinder are inserted The grommet according to claim 1 or 2, wherein a space sealed between the inner cylinder and the outer cylinder is provided by tape winding together with the harness .

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