JP2002027641A - Grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grommet which tightly seals up a soundproof annular hollow part of double-cylinder construction. SOLUTION: A soundproof approximately ring-shaped hollow part 4 is formed between a small-diameter cylindrical part 2, into which a sire harness is inserted, and an extended-diameter cylindrical part 3 having a car body locking recession 3a. An annular rib 5 continues so as to go around in the circumferential direction in the state of being thin and disconnected. The other-end opening 3b of the extended-diameter part 3 is stopped up, and the hollow part 4 is sealed hermetically, by winding a tape on the other-end side peripheral surface of the extended-diameter part 3 to fasten the annular rib 5 together. The annular rib 5 can shrink and reduce its diameter easily, since it is thin and disconnected over the whole periphery, and adheres closely to the surface of the small- diameter part 2.

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 mounted in a state in which a wire harness is inserted into a through hole of a vehicle body panel or the like, and more particularly, to a grommet having a double cylindrical structure having an annular hollow portion for sound insulation. The annular hollow portion for sound insulation can be tightly sealed, and a sufficient sound insulation effect can be achieved.

[0002]

2. Description of the Related Art Grommets are used for wiring, harnessing, waterproofing, dustproofing, soundproofing, etc., when wiring automobile wiring harnesses from an engine room to a room. The wire harness is inserted through the grommet, passes through the through hole of the vehicle body panel that separates the engine room and the room, and the grommet is attached to the through hole to seal the through hole. In recent years, in order to improve the sound insulation performance of the grommet, FIG.
A grommet 41 having a double cylinder structure with good sound insulation performance as shown in FIG.

The grommet 41 shown in FIG. 8 is made of a molded product of rubber or an elastomer, and has a small-diameter cylindrical portion 42 into which a wire harness W / H is inserted and inserted, and continuously extends outward from the small-diameter cylindrical portion 42. An annular hollow portion 44 for sound insulation is provided between the small-diameter cylindrical portion 42 and an opening 43b at the other end, having a vehicle-body locking concave portion 43a for attachment to the vehicle body panel P on the outer peripheral surface on one end side of the enlarged diameter. And an enlarged-diameter cylindrical portion 43 having Further, in the grommet 41, as shown in FIG. 9, a continuous rib 45 is formed on the inner peripheral surface on the other end side of the enlarged-diameter cylindrical portion 43 so as to make a complete round in the circumferential direction without breaks. Have been.

In the case of the grommet 41, as shown in FIG. 10, a continuous rib 45 is jointly fastened to the outer peripheral surface on the other end side of the enlarged diameter cylindrical portion 43 in a state where the wire harness W / H is inserted and inserted. The opening 43b of the enlarged diameter cylindrical portion 43 is closed by winding the tape T so that the annular hollow portion 4 for sound insulation is formed.
Seal 4 Due to the sealing of the annular hollow portion 44, a sealed air layer is generated, and the sound insulation performance is improved.

[0005]

However, the above-described grommet 41 provided conventionally has an annular hollow portion 44.
However, there is a problem that the sound insulation performance is not improved as expected because the sealing cannot be sufficiently performed (the sealing property is not sufficient). By winding the tape T so that the continuous rib 45 is fastened together, the winding force of the tape T is concentrated on the continuous rib 45 so that the space between the small-diameter tube portion 42 and the large-diameter tube portion 43 is completely closed. It is configured to be. However, as shown in FIG. 11, when the tape T is wound, the enlarged-diameter tube portion 43 escapes to the side as a whole, leaving a large space between the small-diameter tube portion 42 and the enlarged-diameter tube portion 43. The small-diameter cylindrical portion 42 may not be in close contact with the surface, or the enlarged-diameter cylindrical portion 43 may be folded and overlapped. As a result, the fastening force of the tape T is deviated from the center of the cylinder,
3, the gap G remains between the small-diameter tube portion 42 and the large-diameter tube portion 43, and the annular hollow portion 44 is not tightly sealed.

The present invention has been made in view of the above-mentioned problems, and in particular, has a grommet capable of exhibiting a sufficient sound insulating effect by being able to tightly seal an annular hollow portion for sound insulation having a double cylinder structure. The task is to provide.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a small-diameter cylindrical portion made of rubber or an elastomer, through which an electric wire is inserted and inserted, and continuously extending outward from the small-diameter cylindrical portion. A large-diameter cylindrical portion having a vehicle body locking concave portion on the outer peripheral surface at one end side and having an opening at the other end, and having an annular hollow portion for sound insulation between the small-diameter cylindrical portion; An annular rib is provided on the inner peripheral surface on the other end side of the enlarged-diameter tube portion so as to make a round in the circumferential direction in a cut state, and the outer peripheral surface on the other end side of the enlarged-diameter cylinder portion is the annular rib. Is provided with a grommet having a configuration in which the opening at the other end of the enlarged diameter cylindrical portion is closed by tape-wrapping so as to fasten together, and the annular hollow portion for sound insulation is closed.

In the grommet according to the present invention, the diameter of the annular rib is easily reduced because the annular rib is cut along the entire circumference, and when the tape for sealing the annular hollow portion for sound insulation is wound from the outside of the enlarged-diameter cylindrical portion, the annular shape is reduced. Since the ribs are quickly reduced in diameter and the enlarged-diameter tube does not escape sideways, it is difficult to make a clear gap between the small-diameter tube and the enlarged-diameter tube, and the annular rib comes into close contact with the surface of the small-diameter tube. In addition, the overlapping of the enlarged diameter cylindrical portion does not occur. As a result, the gap between the small-diameter tube portion and the large-diameter tube portion is closed without a gap, and the large-diameter tube portion is strongly tightened by the tape toward the center of the tube, so that the annular hollow portion for sound insulation is tightly sealed. Demonstrate sufficient sound insulation effect.

On the other hand, the conventional continuous rib is continuous without any breaks, so that it is difficult to reduce the diameter, and the enlarged-diameter cylinder is easy to escape sideways as a whole. The gap tends to be large, and the continuous rib does not adhere to the surface of the small-diameter cylindrical portion, and the enlarged-diameter cylindrical portion may be folded and overlapped.
In the case of the grommet of the present invention, the wire harness inserted into the small-diameter cylindrical portion is strongly fastened together with the tape, and the gaps between the electric wires constituting the wire harness are closed without any gap. Especially when the fluid sealing material is filled between the wires of the wire harness, the fluid sealing material sufficiently penetrates into the unfilled space between the wires as the wire harness is strongly tightened together. The gap between them is surely closed.

[0010] The annular rib of the grommet of the present invention has an angle of 5 ° to 1 °.
It is preferable to be in a chopped state in which one cut appears at every 5 ° angle. If the angle is less than 5 °, the number of cuts is too large and the ribs become weak, and the sealing function, which is the original role of the ribs, becomes insufficient. Conversely, if the angle exceeds 15 °, the number of cuts is too small, and the effect of reducing the diameter due to shredding becomes insufficient.

The shape of each of the rib pieces cut into small pieces in the annular rib in the grommet of the present invention is not limited to a specific shape, but may be an arc shape, a sawtooth shape, a triangular wave shape, or the like.
A rectangular thing is illustrated. Of course, rib pieces having different shapes may be mixed in one annular rib.

In the grommet of the present invention, the inner surface of the other end of the enlarged-diameter tube portion is continued on the side of the annular rib at a predetermined distance in the circumferential direction while being substantially parallel to the axial direction. It is preferable that a plurality of recessed grooves are formed. In the case where such a concave groove is provided, the diameter of the side of the annular rib is also easily reduced as compared with the form in which the concave groove is not provided, and the annular rib of the enlarged diameter cylindrical portion is more likely to be formed on the surface of the small diameter cylindrical portion. The tight fit makes the sealing of the sound-insulating annular cavity more secure.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a grommet according to a first embodiment. As shown in FIG. 2, the grommet 1 separates the engine room from the room in a state where a wire harness W / H is inserted and fitted into a small-diameter cylindrical portion 2. It is mounted in a through hole of the vehicle body panel P.

The grommet 1 of the first embodiment is a molded product of rubber or an elastomer. As shown in FIGS. 1 to 3, the grommet 1 is arranged such that the large-diameter cylindrical portion 3 is located outside the small-diameter cylindrical portion 2. It has a double cylinder structure in which both cylinder portions 2 and 3 are continuously formed. The thin cylindrical small-diameter cylindrical portion 2 has openings 2a and 2b for inserting a wire harness at one end and the other end.
Further, the large-diameter cylinder portion 3 which extends continuously from the surface near the one end side of the small-diameter cylinder portion 2 in a substantially conical shape and has an enlarged diameter has an annular vehicle body engaging concave portion 3a on the outer peripheral surface at one end side. Has a thin cylindrical portion 3c which extends while reducing the diameter toward the other end and has an opening 3b at the other end, and a substantially annular hollow for sound insulation between the small cylindrical portion 2 and the small cylindrical portion 2c. It has a configuration having a portion 4.

In the case of the grommet 1 of the first embodiment, an annular rib 5 is provided on the inner peripheral surface on the other end side of the cylindrical portion 3c of the enlarged diameter cylindrical portion 3 so as to make a round in the circumferential direction in a cut state. Have been. As shown in FIG. 4, the annular rib 5 has a large number of rib pieces 5 with cuts 5a at regular angle θ intervals.
b are arranged along the circumferential direction. The annular rib 5 is in a chopped state in which one cut 5a appears at every angle of 5 ° to 15 °. If the angle is less than 5 °, the number of cuts is too large, and the ribs are weak. The annular rib 5 having an angle of 5 ° or more and 15 ° or less has a sufficient sealing action and a sufficient diameter reducing action.

The shape of each of the rib pieces 5b constituting the annular rib 5 is rectangular in FIG. 4, but may be arc-shaped, saw-tooth-shaped, or triangular-wave-shaped.
The rib pieces 5b having different shapes may be mixed. Further, in FIG. 4, the lengths (dimensions in the circumferential direction) of the respective rib pieces 5 b are all the same, but the lengths of the respective rib pieces 5 b do not need to be all uniform. Rib pieces 5b of different sizes may be mixed.

In the case of the grommet 1, on the side of the annular rib 5, the inner surface of the cylindrical portion 3c of the enlarged diameter cylindrical portion 3 is kept substantially parallel to each other along the axial direction at a predetermined distance in the circumferential direction. There are provided six grooves 6 formed so as to continue to the opening 3b. These six grooves 6 are shown in FIG.
As shown in the figure, the grooves are arranged at intervals of 30 ° with a width corresponding to the angle of 30 ° in the circumferential direction, and the portion where the concave groove 6 of the cylindrical portion 3c is further thinned. In the grommet 1, the concave groove 6 is provided only on the other end side of the annular rib 5, but the concave groove 6 may be provided on one end side (opposite side) of the annular rib 5.

On the other hand, the inner surface of the small-diameter cylindrical portion 2 of the grommet 1 has, as shown in FIGS. 2 and 3, a position where the annular rib 5 is located, and a position slightly shifted left and right in the axial direction from the position where the annular rib 5 is located. In each of the above, three continuous ribs 7 are provided so as to make a complete continuous round in the circumferential direction.

In the grommet 1, the substantially annular hollow portion 4 for sound insulation is sealed as follows. That is,
As shown in FIG. 6, the wire harness W / H is
, And as shown in FIG.
The tape T is wound around the outer peripheral surface on the other end side of the cylindrical portion 3c so that the annular rib 5 is fastened together, so that the opening 3b at the other end of the enlarged diameter cylindrical portion 3 is closed to form a substantially annular hollow portion 4. Seal. Usually, an adhesive tape in which an adhesive is applied to the surface of a vinyl chloride resin tape is used as the tape T, and the tape T is stretched 5 to 6 so that the tape T extends between the small-diameter cylindrical portion 2 and the large-diameter cylindrical portion 3.
It is strongly wound about once.

Since the annular rib 5 of the grommet 1 is in a chopped state over the entire circumference, the diameter of the annular rib 5 is easily reduced.
, The space between the small-diameter tube portion 2 and the large-diameter tube portion 3 does not become large, and the large-diameter tube portion 3
No breaks will occur. As a result, the enlarged diameter cylindrical portion 3
Is strongly tightened with the tape T toward the center of the tube, and at the same time, the space between the small-diameter tube portion 2 and the large-diameter tube portion 3 is closed without a gap, and the substantially annular hollow portion 4 is tightly sealed. Therefore, the substantially annular hollow portion 4 for sound insulation can exhibit a sufficient sound insulation effect.

In the grommet 1, the diameter of the annular rib 5 is also easily reduced by six concave grooves 6 provided on the inner peripheral surface of the cylindrical portion 3c of the enlarged diameter cylindrical portion 3. Since the entire cylindrical portion 3c is brought into close contact with the surface of the small-diameter cylindrical portion 2, the substantially annular hollow portion 4 is more securely sealed.

Further, since the wire harness W / H inserted into the small-diameter cylindrical portion 2 is also fastened with the tape T via the continuous rib 7, the gap between the electric wires constituting the wire harness W / H is also closed. It is. In particular, when the fluid sealing material is filled between the wires of the wire harness W / H, the fluid sealing material is sufficiently filled into the unfilled space between the wires as the wire harness W / H is strongly tightened together. Because of the penetration, the gap between the electric wires is reliably closed.

In the grommet 1 of the first embodiment,
Although the small-diameter tube 2 protrudes from both ends in the axial direction of the large-diameter tube 3, the large-diameter tube 3 is expanded from one end edge of the small-diameter tube 2 as shown in a grommet shown in FIG. Then, the configuration may be such that the small-diameter cylinder 2 does not protrude toward one end of the large-diameter cylinder 3.

Further, in order to evaluate the hermeticity and the like of the substantially annular hollow portion 4 of the grommet 1 of the first embodiment, the following example was prepared.

Example 1 In Example 1, a grommet 1 was obtained by molding rubber as a molding material with a molding die corresponding to the shape of the grommet 1 of the first embodiment. In the case of the grommet 1 of Example 1, the small-diameter cylindrical portion 2 has an outer diameter of 31 mm and a thickness of 1.5 mm, and the cylindrical portion 3c of the large-diameter cylindrical portion 3 has an outer diameter of 18 m.
m, the thickness was 1 mm, and the annular rib 5 was 1 mm in height and 5 mm in width, and was in a finely cut state in which one cut 5a appeared at every 10 ° angle. Furthermore, the groove 6 is about 10 m long
m, depth 0.75 mm.

After the wire harness W / H is inserted through the small-diameter cylindrical portion 2 of the grommet 1 of the first embodiment,
The outer peripheral surface on the other end side of the cylindrical portion 3c is strongly fastened so that the annular rib 5 is fastened together and the adhesive tape is straddled five times between the small-diameter cylindrical portion 2 and the large-diameter cylindrical portion 3. When the annular hollow portion 4 for winding and sound insulation is sealed, the annular rib 5 closely adheres to the surface of the small-diameter tube portion 2, and the enlarged-diameter tube portion 3 does not overlap. The ring-shaped hollow portion 4 was tightly closed without any gap.

Example 2 In Example 2, except that an elastomer was used instead of rubber, a grommet 1 was obtained in the same manner as in Example 1, and an adhesive tape was wound similarly to form an annular hollow portion 4. When sealed, the grommet 1 of Example 2 was used.
However, the annular hollow portion 4 was in a tightly sealed state.

[0028]

As is apparent from the above description, according to the grommet according to the present invention, since the annular rib is in a chopped state over the entire circumference, it is easy to reduce the diameter and the tape for sealing the annular hollow portion for sound insulation. When the outer diameter of the enlarged diameter cylindrical part is wound around the annular rib, the diameter of the annular rib is reduced rapidly, the enlarged diameter cylindrical part does not escape sideways, and the annular rib is in close contact with the surface of the small diameter cylindrical part. Since the gap between the small-diameter tube portion and the large-diameter tube portion is difficult to be vacated, and the large-diameter tube portion does not bend or overlap, the small-diameter tube portion and the large-diameter tube portion are closed without any gap, and the tape is closed by tape. The diameter-enlarged cylindrical portion is sufficiently tightened toward the center of the frame, and the annular hollow portion for sound insulation is tightly sealed, so that a sufficient sound insulating effect is exhibited.

In addition, according to the grommet of the present invention, the wire harness inserted into the small-diameter tube portion is strongly fastened together by the fastening force of the tape toward the center of the tube, and the gap between the wires constituting the wire harness is reduced. Disappears. Therefore,
Grommets can fully demonstrate their function.

[Brief description of the drawings]

FIG. 1 is a front view illustrating an appearance of a grommet according to a first embodiment.

FIG. 2 is a longitudinal sectional view showing the inside of the grommet of the first embodiment.

FIG. 3 is a cross-sectional view showing the inside of the grommet of the first embodiment.

FIG. 4 is a cross-sectional view showing an annular rib provided on a cylindrical portion of the enlarged diameter cylindrical portion.

FIG. 5 is a cross-sectional view showing a concave groove provided in a cylindrical portion of the enlarged-diameter tube portion.

FIG. 6 is a sectional view of a double-cylinder structure portion of the grommet according to the first embodiment.

FIG. 7 is a cross-sectional view showing a closed state of an annular hollow portion for sound insulation of the grommet of the first embodiment.

FIG. 8 is a cross-sectional view showing the inside of a conventional grommet.

FIG. 9 is a cross-sectional view of a double cylinder structure portion of a conventional grommet.

FIG. 10 is a cross-sectional view showing a tape winding portion of an annular hollow portion for sound insulation of a conventional grommet.

FIG. 11 is a cross-sectional view showing a sealed state of a conventional annular hollow portion for sound insulation of a grommet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Grommet 2 Small-diameter cylindrical part 3 Large-diameter cylindrical part 3a Car body locking concave part 3b Opening 3c cylindrical part 4 Substantially annular hollow part for sound insulation 5 Annular rib 5a Cut 6 Recessed groove P Body panel T Tape W / H Wire harness

Claims (3)

[Claims] 1. A small-diameter tubular portion made of rubber or elastomer, into which an electric wire is inserted and inserted, and a vehicle body engaging concave portion formed on one end side of the small-diameter tubular portion which continuously extends outward and has an increased diameter. A large-diameter cylindrical portion having an opening at the other end and having an annular hollow portion for sound insulation between the small-diameter cylindrical portion and the small-diameter cylindrical portion; An annular rib is provided so as to make a round in the circumferential direction in the state, and the outer peripheral surface on the other end side of the enlarged diameter cylindrical portion is tape-wound such that the annular rib is co-tightened to expand the diameter. A grommet having a configuration in which an opening at the other end of the cylindrical portion is closed to seal the annular sound hollow portion. 2. The grommet according to claim 1, wherein the annular rib is in a chopped state in which one cut is formed at every angle of 5 ° to 15 °. 3. An annular rib is formed laterally on the other end side of the enlarged-diameter cylindrical portion so as to continue along the axial direction at a predetermined distance in the circumferential direction while keeping the inner surface substantially parallel to the annular rib. The grommet according to claim 1 or 2, wherein a plurality of concave grooves are provided.