JPH07336067A - Grommet - Google Patents

Abstract

PURPOSE:To prevent the sealing material with which the inside of a grommet is filled from separating from the inner surface of the grommet and prevent the grommet from breaking when a wire harness is put through it. CONSTITUTION:A grommet 11 is composed of a cylindrical large-diameter part 11b with a retaining groove 11a, which engages with a through hole 1a of a car body panel 1, in the outer surface of the part 11b and a cylindrical small-diameter part 11c that is contiguous with an edge of the large-diameter part. A wire harness WH is put through a wire harness insertion hole 11d composed of hollow parts of the cylinders. In all the inner surface of the large- diameter part, many narrow width grooves 11e are made at specified spacing. At both ends of the grooves in the longitudinal direction and at the bottom of the grooves, spherically bulged retaining parts 11h and 11g are provided. The grooves 11a, 11b are filled with the sealing material 10 with which the gaps between the wires of the wire harness from the large-diameter part to the small-diameter part are filled. The sealing material in the grooves is prevented from coming off the grooves by the retaining parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grommet which is fitted with a wire harness inserted through a through hole of a vehicle, and more particularly to a grommet having a sealant filled therein for waterproofing, dustproofing and soundproofing. The external force prevents the sealant from peeling off from the inner surface of the grommet to form a gap therebetween.

[0002]

2. Description of the Related Art In a wire harness for a vehicle, when the wire harness is wired by penetrating a through hole of a vehicle body or equipment, the wire harness is previously inserted through a wire harness insertion hole provided in a rubber grommet. The grommet is attached to the through hole in this state to make it waterproof, dustproof and soundproof. However, even when the wire harness is inserted into the grommet, when a gap is generated between the wire harness and the wire harness insertion hole of the grommet, and between the electric wire groups forming the wire harness, the water is leaked through the gap. Occur.

Therefore, as shown in FIG. 5 (A), as a grommet to be attached to a place where water is likely to occur, a large diameter cylinder having an engaging groove 2a engaging with the through hole 1a of the vehicle body panel 1 as shown in FIG. Using a grommet 2 having a small diameter cylindrical reduced portion 2c continuous to the reduced diameter end of the enlarged diameter portion 2b, the hollow portion of the enlarged diameter portion 2b and the reduced diameter portion 2c After inserting the wire harness WH into the wire harness insertion hole 2d, the sealant 3 is placed inside the wire harness insertion hole 2d.
To improve the waterproof performance.

However, in the grommet 2 shown in FIG.
As shown in, when the wire harness WH is pulled in the wire harness insertion direction X when the wire harness WH is attached to the vehicle body panel 1,
Since the expanded diameter portion 2b is reduced in diameter toward the reduced diameter portion 2c, the hardened sealant 3 is easily separated from the peripheral wall of the wire harness insertion hole 2d. In this case, since a gap is created between the sealant 3 and the peripheral wall of the wire harness insertion hole 2d, there is a problem that water may be generated from this gap.

On the other hand, the grommet 5 shown in FIG. 6 is provided. (Refer to Japanese Utility Model Laid-Open No. 1-66713) In the grommet 5, the convex portion 5e projecting into the wire harness insertion hole is circumferentially spaced from the inner surface on the opening side of the peripheral wall 5b-1 of the expanded diameter portion 5b. The protrusion 5e
Recesses 5f are provided in the inner surface of the peripheral wall 5b-1 on the side of the reduced diameter portion at a predetermined interval in the circumferential direction, and the sealing agent 3 is applied to the reduced diameter portion 5c.
More up to the convex portion 5e is filled.

[0006]

According to the grommet 5 described above, the upper surface of the sealant 3 is adhered to the lower surface of the convex portion 5e, and the sealant 3 is filled in the concave portion 5f, so that the wire harness insertion hole 5d is formed. The adhesion area between the peripheral wall and the sealant 3 is increased. In addition, the cured sealant 3 has convex portions 5e.
When the wire harness WH is pulled in the insertion direction X, the lower surface of the convex portion 5e and the upper surface of the concave portion 5f are caught and the seal agent 3 is engaged with the lower end surface of the concave portion 5f and the inner surface of the concave portion 5f. Can be reduced.

However, the grommet 5 has a drawback that it is weak in the external force in the radial direction Y and the twisting direction of the grommet 5 which is orthogonal to the X direction. That is, when the wire harness WH is pulled in the radial direction Y of the grommet 5,
Alternatively, when the grommet 5 is pulled in the twisting direction, as shown in FIG. 7, the sealing agent 3 which is hardened inside the recess 5f is easily peeled off from the recess 5f and separated, and the wire harness insertion hole 5d There is a problem that a gap is generated between the peripheral wall and the sealant 3.

Further, as shown in FIG. 8A, when the wire harness WH is inserted into the grommet 5, the claw portion 6 of the grommet spreader is inserted into the wire harness insertion hole 5d and the claw portion 6 is inserted. The wire harness insertion hole 5d is expanded by expanding the grommet 5 in the radial direction, and the wire harness WH is inserted inside in this state. When the diameter of the wire harness insertion hole 5d is expanded as described above, the entire grommet is deformed, but when the peripheral wall 5b-1 of the expanded diameter portion 5b having the recess 5f is deformed, the deformation is caused as shown in FIG. As shown in FIG. 5, the force due to the deformation particularly concentrates on the edge portion 5f-1 of the recess 5f, and a crack may occur at the edge portion 5f-1 and the grommet 5 may be damaged.

The present invention has been made in view of the above problems, and increases the adhesive area between the grommet and the sealing agent filled inside the grommet to increase the fixing strength of the sealing agent to the grommet and to the wire harness. The purpose of the present invention is to provide a grommet that reliably prevents the sealant from peeling from the grommet regardless of the tensile force applied from any direction, and that cracks do not occur from the edge of the groove provided for filling the sealant. I am trying.

[0010]

In order to achieve the above object, according to the present invention, in claim 1, there is provided a cylindrical expanded portion having a locking groove for locking a through hole of a vehicle body panel formed on an outer peripheral surface thereof. A grommet having a continuous tubular reduced diameter portion at one end of the enlarged diameter portion, the wire harness being inserted through a wire harness insertion hole formed of these hollow portions, and the entire inner peripheral surface of the enlarged diameter portion. , A large number of narrow grooves are formed at required intervals, and spherically bulged locking portions are provided at both ends in the longitudinal direction of these grooves and the bottom surface of the groove. A grommet characterized in that the sealing agent filled between the electric wire groups of the wire harness is also filled inside each of the grooves to prevent separation of the sealing agent filled by the locking portion from the groove. It is provided. That is, a large number of grooves having a fine statless structure are provided on the inner peripheral surface of the expanded diameter portion.

The grooves of the enlarged diameter portion are arranged in the circumferential direction in the length direction of the groove, the groove width is set in the axial direction, and the length of the groove is about 5 mm.
The width of the groove is about 1 mm, the depth of the groove is about 1 mm, and the depth of the groove is about half the thickness of 2 mm of the grommet. It is preferable to provide. (Claim 2)

[0012]

In the grommet according to claim 1 of the present invention, since a large number of narrow grooves are provided, by filling these grooves with a sealant, the adhesive area between the sealant and the grommet is greatly increased. It can be done. In addition, the groove has a statless structure in which a spherically bulged locking portion is provided at both ends in the lengthwise direction and on the bottom surface of the groove, and the sealing agent filled in the locking portion does not easily peel off. The sealing agent is not easily peeled off from the grommet even when a tensile force acts on the fixed wire harness from any of the X, Y and twist directions. Therefore, it is possible to prevent a gap from being generated between the inner peripheral surface of the grommet and the sealant.

Further, when the groove provided on the inner peripheral surface of the expanded portion of the grommet has the shape described in claim 2, even if a large number of grooves are provided, the strength of the grommet is not lowered, and the sealing agent and the grommet are provided. The adhesion area with can be dramatically increased.

[0014]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. As shown in FIG. 1, the grommet 11 of the present invention includes a substantially conical cylindrical expanded portion 11b having a locking groove 11a for locking the through hole 1a of the vehicle body panel 1 formed on the outer peripheral surface thereof.
A cylindrical reduced diameter portion 11c continuous with the reduced diameter end portion of the enlarged diameter portion 11b is integrally formed from a rubber material or the like. Due to the continuous hollow portion of the expanded diameter portion 11b and the reduced diameter portion 11c,
A wire harness insertion hole 11d for inserting the wire harness WH is formed.

A narrow groove 11e having a statless structure is formed on the entire inner peripheral surface of the peripheral wall 11b-1 of the expanded diameter portion 11b so as to prevent the sealant 10 filling the inside of the wire harness insertion hole 11d from peeling off. Are recessed at a required interval.

The groove 11e is arranged such that the extending length direction thereof is arranged in the circumferential direction of the expanded diameter portion 11b, the width direction thereof is arranged in the axial direction of the expanded diameter portion 11b, and the depth direction thereof is expanded. Part 1
It is arranged in the radial direction of 1b. Further, the groove 11e is provided with locking portions 11h and 11g that are spherically expanded and have a diameter increased, at both ends in the longitudinal direction and the bottom surface in the depth direction of the elongated recess 11f. The depth of the groove 11b is set to half or less of the wall thickness of the expanded diameter portion 11b. In the present embodiment, the thickness of the expanded diameter portion 11b is 2 mm and the depth of the groove 11e is 1 mm, and The height is 5 mm and the width is 1 mm.

As shown in FIG. 1, with the wire harness WH inserted through the wire harness insertion hole 11d, a waterproof sealant 10 is provided from the reduced diameter portion 11c on the lower side to the vicinity of the opening side of the enlarged diameter portion 11b. Is filled. The sealant 10
Are filled between the peripheral wall of the wire harness insertion hole 11d including the inside of the groove 11e and the wire harness WH, and between the wire group of the wire harness WH.

The grommet 11 having the above structure is the molding die 1
2, the wire harness WH is inserted through the wire harness insertion hole 11d of the grommet 11, and then the wire harness insertion hole 11d is filled with the sealant 10 for manufacturing.

The molding die 12 is, as shown in FIG.
The wire harness insertion hole 1 is provided between the upper mold 13 and the lower mold 14.
The core mold 15 forming 1d is interposed, and the injection hole
The molten rubber material is injected into the cavities 13a and 14a from (not shown), and the rubber material is cured to form the grommet 11.

When removing the grommet 11 from the molding die 12, after removing the upper die 13 and the lower die 14,
Air is blown into the holes 15a of the core mold 15 to inflate the grommet 11, the outer peripheral surface of the core mold 15 and the inner peripheral surface of the grommet 11 are separated, and separated from each other.
1 is moved to the reduced diameter side and removed from the connection part of the core mold 15. At this time, since the grommet 11 bulges outward, the formed groove 11e is not damaged and can be easily peeled off.

The insertion work of the wire harness WH is the same as the conventional one, and the claw portion 6 (shown in FIG. 8A) of the grommet spreader is inserted into the wire harness insertion hole 11d, and the claw portion 6 is inserted into the grommet 11. The wire harness insertion hole 11d is expanded in the radial direction and the diameter of the wire harness insertion hole 11d is expanded to insert the wire harness WH.

At this time, as shown in FIG. 4, the expanded diameter portion 11b
The outer peripheral wall 11b-1 is also expanded and deformed, but the groove 11e disperses the force generated by the deformation because the engaging portions 11g and 11h at the outer ends are formed in a spherical shape to eliminate the edge portion. You can Therefore, the grommet 5 of the conventional example
As described above, there is no possibility that the force due to the deformation is concentrated on the edge portion and the grommet is damaged such as a crack. Also, groove 1
Since 1e is recessed with a length of 1/2 or less of the thickness of the expanded diameter portion 11b, it does not break due to deformation, and the strength can be reliably retained.

The sealant 10 is one that hardens with time and has permeability, and by injecting it from the opening of the enlarged diameter portion 11b, the peripheral wall of the wire harness insertion hole 11d including the inside of the groove 11e and the wire harness WH. And between the wire groups of the wire harness WH. Further, the sealant 10 also flows into the groove 11e, and the recess 11f
The locking portions 11g and 11h are filled in the entire area inside the groove 11e.

According to the grommet 11, the groove 11 is formed.
Since the sealant 10 is also filled inside e, the adhesive area between the sealant 10 and the grommet 11 can be greatly increased. Further, the grommet 11 has a wire harness insertion direction X with respect to the wire harness WH, and
When an external force is applied in the radial direction Y, the locking portion 1 of the groove 11e
It is possible to prevent the sealant 10a that has hardened inside 1g from moving at a step between the sealant 10a and the recess 11f. Furthermore, when an external force in the twisting direction is applied to the grommet 11, the locking portion 11h and the concave portion 1
The step of 1f can prevent the sealing agent 10b cured inside the locking portion 11h from moving in the circumferential direction. Therefore, it is possible to reliably prevent the cured sealant 10 from moving inside the groove 11e and to form a gap between the inner peripheral surface of the grommet 11 and the sealant 10.

[0025]

As is apparent from the above description, in the grommet according to claim 1 of the present invention, a large number of statless structure grooves are provided on the inner peripheral surface of the expanded diameter portion, and the sealing agent is also filled inside these grooves. Since it is configured such that it is possible to significantly increase the adhesive surface contact between the grommet and the sealant. Further, since the groove is provided with spherically bulged locking portions on both ends in the length direction and the bottom surface in the depth direction, a pulling force acts on the wire harness or the grommet from either direction. However, since the sealing agent that has hardened inside the groove is locked by the step of the locking portion, it is possible to prevent the sealing agent from moving. Therefore, it is possible to reliably prevent a gap from being generated between the sealant and the inner peripheral surface of the grommet.

Further, since the engaging portion formed at the end of the groove is spherical and has no corners, even if the grommet is deformed when expanding the diameter of the wire harness insertion hole, the force due to this deformation is It can be dispersed at the locking part. Therefore, it is possible to prevent the grommet from being damaged such as a crack when the wire harness is inserted.

Further, in the grommet according to claim 2, since the groove is extended to a depth not more than half the wall thickness of the expanded diameter portion, a large number of grooves are provided on the inner peripheral surface of the expanded diameter portion. Also, the adhesive area can be dramatically increased and the locking force between the sealant and the grommet can be improved without lowering the strength.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a grommet of the present invention.

FIG. 2 is a sectional perspective view showing a statless structure of a grommet.

FIG. 3 is a cross-sectional view showing a molding die that forms a grommet.

FIG. 4 is a sectional view of a main part of a grommet.

FIG. 5A is a sectional view showing a mounting state of a conventional grommet, and FIG. 5B is a sectional view showing a problem.

FIG. 6 is a sectional view showing another conventional example of a grommet.

7 is a sectional view showing a problem of the grommet of FIG.

8A and 8B are cross-sectional views showing another problem of the grommet of FIG.

[Explanation of symbols]

 1 Body Panel 1a Through Hole 10 Sealant 11 Grommet 11a Locking Groove 11b Expanding Part 11c Reduced Diameter 11d Wire Harness Insertion Hole 11e Groove 11g, 11h Locking Part

Claims (2)

[Claims] 1. A tubular expanded portion having a locking groove formed on an outer peripheral surface for engaging with a through hole of a vehicle body panel, and a tubular reduced diameter portion continuous to one end of the expanded portion, A grommet for inserting a wire harness into a wire harness insertion hole formed of these hollow parts, wherein a large number of narrow grooves are formed at required intervals over the entire inner peripheral surface of the expanded diameter part. Provide spherically bulged locking parts on both ends in the length direction and on the bottom of the groove, and seal the sealant filled between the wire groups of the wire harness from the expanded diameter part to the reduced diameter part inside each groove. A grommet characterized in that the grommet is configured so as to prevent the peeling of the sealing agent filled by the locking portion from the groove. 2. The plurality of grooves formed in the enlarged diameter portion are arranged in the circumferential direction in the groove length direction, and the groove width direction is the axial direction, and the groove length is about 5 mm and the groove width is About 1mm, groove depth about 1
2. The grommet according to claim 1, wherein the groove has a depth of about 0.5 mm and the depth of the groove is about half of a wall thickness of 2 mm of the grommet, and a large number of grooves having the above shape are provided at required intervals in the radial direction and the axial direction.