JP5578055B2 - Grommet - Google Patents

Description

  The present invention relates to a grommet that is attached to a wire harness for an automobile and is attached to a through hole of a vehicle body panel, and particularly reduces noise transmitted from the outside of an engine room or the like through the through hole to the room.

Conventionally, the present applicant has provided a grommet described in Japanese Patent Application Laid-Open No. 2002-10451 shown in FIGS. 11A and 11B as a grommet having particularly improved sound insulation performance with this type of grommet.
The grommet 100 is provided with a small-diameter inner cylinder 101 to be in close contact with the wire harness, a sound-insulating air layer 102 that surrounds the inner cylinder 101 and a thickened tip end side, and a recess 103 for locking the vehicle body on the outer peripheral surface. A large-diameter outer cylinder 104 is provided. The opening 106 on the other end side of the inner cylinder 101 and the outer cylinder 104 is closed by winding an adhesive tape 110 around the outer peripheral surface of the outer cylinder 104, and the sound insulation air layer 102 is sealed to improve the sound insulation performance.

Japanese Patent Laid-Open No. 2002-10451

  In the grommet 100 described above, the adhesive tape 110 is tightly wound around the outer periphery of the end of the outer cylinder 104 and the opening 106 between the inner cylinder 101 is closed. As shown in FIG. Since the inner diameter of the outer cylinder 104 and the outer diameter of the inner cylinder 101 are different, the opening 106 cannot be completely closed even when the adhesive tape 110 is wound, and a gap G is generated. The sound insulation performance is improved when the space is closed without the gap G, but the sound insulation performance is considerably lowered when the gap G is generated. In addition, when the adhesive tape 110 is wound around the outer periphery of the outer cylinder 104, the grommet 100 is made of an elastic material such as EPDM. There is also.

  Thus, since it is difficult to close the opening 106 by winding the adhesive tape 110, the cross-sectional area of the opening 106 cannot be increased. The opening 106 is formed by a punched hole for forming the air layer 102 for sound insulation. Therefore, the fact that the opening 106 made of the punched hole cannot be made large makes it impossible to form the sound insulation air layer 102 having a large cross-sectional area, which is a restriction for improving sound insulation.

  The present invention intends to solve the above problem, and even when the cross-sectional area of the opening formed between the inner cylinder and the outer cylinder is large, the opening can be completely closed so that the inner cylinder and the outer cylinder are closed. An object of the present invention is to provide a grommet capable of improving the sound insulation performance by using the air space between the cylinders as a completely sealed space and improving the sound insulation performance by enlarging the sealed space itself.

In order to solve the above-mentioned problems, as a first invention , an inner cylinder through which a wire harness is closely inserted and an end of the inner cylinder are folded outward to cover the outer circumference of the inner cylinder to form a sound insulating air layer And a grommet made of an elastic material in which one end side of the outer cylinder is thick and a vehicle body locking recess is annularly provided,
An annular filler, which is a separate member, is filled from an opening formed between the other end of the outer cylinder and the inner cylinder , and the filler has a thick outer peripheral portion in the axial direction and an inner peripheral portion in the axial direction. and thin, or the outer peripheral portion and inner peripheral portion is the intermediate layer as well as the thick axially has a thin axially closes the front Symbol opening in the filler, the outer striking position of the filler A grommet is provided in which an adhesive tape is wound around an outer peripheral surface of a cylinder, the outer cylinder is closely fixed to the inner cylinder via a filler, and the air layer for sound insulation is used as a sealed space. .
Further, as a second invention, an inner cylinder that tightly inserts the wire harness, an outer cylinder that folds one end of the inner cylinder outward and covers the outer periphery of the inner cylinder to form a sound insulating air layer, In the grommet made of an elastic material in which the one end side of the outer cylinder is thick and the vehicle body locking recess is annularly provided,
An annular filler, which is a separate member, is filled from an opening formed between the other end of the outer cylinder and the inner cylinder, and the filler extends from the annular inner peripheral surface to the outer peripheral surface over the entire length in the radial direction. The slit has a shape having the entire length in the axial direction, and is provided with a fitting portion that overlaps with each other at the split edge that sandwiches the slit,
The fitting portion of the filler is overlapped to close the opening, and an adhesive tape is wound around the outer peripheral surface of the outer cylinder corresponding to the arrangement position of the filler, so that the outer cylinder is closely attached to the inner cylinder via the filler. There is provided a grommet which is fixed and has an air space for sound insulation as a sealed space.

  The annular filler is made of rubber, elastomer or resin, and its inner peripheral surface is in close contact with the outer peripheral surface of the inner cylinder, and its outer peripheral surface is in close contact with the inner peripheral surface of the outer cylinder.

  By inserting the filler from an opening formed between the inner cylinder and the outer cylinder, closing the opening with the filler, and supporting the outer cylinder with the filler, the outer peripheral surface of the outer cylinder Adhesive tape can be wound tightly on workability. Therefore, the sound insulation space formed between the inner and outer cylinders can be closed without any gap between the filling of the filler and the winding of the adhesive tape, and the sound insulation performance can be improved.

  Further, since the radial dimension of the filler is provided in accordance with the cross-sectional area of the opening, the sound insulation space can be sealed even when the cross-sectional area of the opening is large. Therefore, the sound insulation performance can be further enhanced by increasing the cross-sectional area of the sound insulation space. Further, since it is not necessary to reduce the cross-sectional area of the opening, it is possible to improve the die cutting workability at the time of grommet molding.

In the first invention, the filler has a thick outer peripheral portion in the axial direction and a thin inner peripheral portion . Thus, if the outer peripheral part of a filler is thick, an outer cylinder can be supported firmly. Moreover, if the inner peripheral portion is thin, it is easy to bend, and the inner periphery of the filler can be bent following the change in the outer diameter of the wire harness. Alternatively, the outer peripheral portion and the inner peripheral portion may be thick in the axial direction and a thin portion may be provided in the intermediate layer.

In the second aspect of the invention, the filler is a shape having a single slit extending in a radial direction the entire length, that have provided a fitting portion mutually overlapping in the divided edges sandwiching the slit.
When the slit is provided, the filler can be expanded and attached to the inner cylinder by being externally fitted from the lateral direction (a direction perpendicular to the axis of the inner cylinder). Therefore, workability | operativity becomes good when attaching a cyclic | annular filler with the wire harness inserted in the grommet.

Further, as described above, the one split end and the other split end sandwiching the slit are fitted to each other so that there is no gap between the slits .
Specifically, a concave portion may be provided at one divided end, a convex portion that fits into the concave portion may be provided at the other divided end, and the one divided end and the other divided end may be overlapped with each other.

  As described above, the grommet of the present invention is formed between the other end of the inner and outer cylinders by providing an outer cylinder by folding outward from one end of the inner cylinder, providing a space for sound insulation between the inner and outer cylinders. In order to make the sound insulation space a sealed space, an annular filler is inserted into the opening, the opening is closed, the outer cylinder is supported by the filler, and an adhesive tape is attached to the outer peripheral surface of the outer cylinder Can be wound firmly and firmly. In this way, the opening of the sound insulation space formed between the inner and outer cylinders can be closed without any gap between the insertion of the filler and the winding of the adhesive tape, and the sound insulation space can be a sealed space.

The grommet of reference embodiment of this invention is shown, (A) is sectional drawing, (B) is a perspective view of a filler. (A) (B) (C) is sectional drawing which shows the process of forming the air layer for sound insulation sealed with the grommet. It is sectional drawing of the state which attached the grommet to the through-hole of the vehicle body panel. It is a graph which shows the measurement result of the sound insulation effect by an air layer. Shows the filler embodiment of the present invention, (A) is a side view, (B) is a sectional view along line A-A of (A). (A) (B) (C ) is an explanatory diagram of the operation of charging and Hamazai of the embodiment. The shows a modification Katachirei filler, a B - B line sectional view of (A) is a side view, (B) is (A). Indicates Filling material according to another embodiment of the present invention, (A) is a side view, (B) is a front view. It is each part sectional drawing of FIG. 8 (A), (A) is CC sectional view taken on the line, (B) is DD sectional drawing, (C) is EE sectional drawing. It is a side view of the state where the slit of the filler was closed. (A) (B) is sectional drawing of a prior art example. It is drawing which shows the problem of a prior art example.

Hereinafter, a grommet of an embodiment of the present invention will be described with reference to the drawings.
1 to 3 show a grommet according to a reference embodiment.
The grommet 1 is a molded body made of rubber or elastomer, and is molded with an elastomer made of EPDM in this reference embodiment.

The grommet 1 includes a small-diameter inner cylinder 2 that is in close contact with the wire harness, and an outer cylinder 3 that is folded outward from one end side of the inner cylinder 2, and an air layer for sound insulation between the inner cylinder 2 and the outer cylinder 3. 4 is opened. The inner cylinder 2 and the outer cylinder 3 have a folded portion at one end bent into a U shape to form a thin expansion / contraction connection portion 5, and one end of the air layer 4 is closed by the expansion / contraction connection portion 5. The side becomes the opening 6 because it is necessary to perform die cutting at the time of molding. On the opening 6 side, the inner cylinder 2 protrudes outward from the outer cylinder 3.
One end side of the outer cylinder 3 connected to the telescopic connecting portion 5 is thick, and an annular recess 7 for locking the vehicle body is provided on the outer peripheral surface.

A separate annular filler 10 is inserted into the opening 6 formed between the other ends of the inner cylinder 2 and the outer cylinder 3, and the other ends of the inner and outer cylinders 2 and 3 adjacent to the opening 6 are inserted. Filled.
The filler 10 made of the ring-shaped plug body may be any of rubber, elastomer, and resin. However, in this embodiment, since the filler 10 is not provided with a slit, it is made of foamed rubber having elasticity.

  The inner diameter of the filler 10 is equivalent to the outer diameter of the inner cylinder 2, the outer diameter of the filler 10 is equivalent to the inner diameter of the outer cylinder 3, and the inner and outer cylinders 2, 3 are filled with the filler 10 in the air layer 4. The opening 6 is closed and the outer cylinder 3 is firmly supported.

Since the inner cylinder 2 is inserted through the wire harness W / H while being expanded by a diameter expansion jig (not shown), the outer diameter of the inner cylinder 2 at the time of molding is different from the outer diameter of the inner cylinder 2 in the inserted state of the wire harness. To do. In this reference embodiment, the filler 10 is molded with foamed rubber as described above, the outer diameter of the inner cylinder 2 and the inner diameter of the filler 10 at the time of molding are made equal, and the filler 10 is expanded to the diameter of the inner cylinder 2. The diameter can be increased by following.

  Therefore, the filler 10 can be filled between the inner and outer cylinders 2 and 3 before inserting the wire harness into the inner cylinder 2, but the wire harness W / H can be After passing through the inner cylinder 2, the filler 10 is filled between the inner cylinder 2 and the outer cylinder 3 while expanding the diameter.

That is, as shown in FIG. 2A, first, the wire harness W / H is passed through the inner cylinder 2. The adhesive tape 13 is wound around the tip of the inner cylinder 2 protruding after insertion and the wire harness W / H, and the grommet 1 is fixed to a predetermined position of the wire harness.
Next, as shown in FIG. 2B, the filler 10 is fitted into the outer peripheral surface of the inner cylinder 2 from the opening 6. At that time, the outer cylinder 3 is beaten.
In a state where the filler 10 is filled between the inner and outer cylinders 2 and 3, as shown in FIG. 2C, the adhesive tape 12 is strongly wound around the outer peripheral surface of the outer cylinder 3 at the filling position of the filler 10. Then, the filler 10 is fixed between the inner and outer cylinders 2 and 3.

When the adhesive tape 12 is wound, the outer cylinder 3 is firmly supported because the space between the outer cylinder 3 and the inner cylinder 2 is not a gap but is filled with the filler 10. Therefore, the adhesive tape 12 can be tightly wound, and there is a gap between the outer peripheral surface of the inner cylinder 2 and the inner peripheral surface of the filler 10, and between the outer peripheral surface of the filler 10 and the inner peripheral surface of the outer cylinder 3. It can be in a state where it does not occur.
Thereby, since the opening 6 formed between the inner and outer cylinders 2 and 3 is completely closed by the winding of the filler 10 and the adhesive tape 12 as described above, the air layer 4 for sound insulation is separated from the sealed space. can do.

As shown in FIG. 3, the wire harness W / H to which the grommet 1 is attached is routed in an automobile and mounted in a through hole H provided in a vehicle body panel P that partitions the engine room (X) and the passenger compartment (Y). The sound insulation air layer 4 is disposed on the engine room (X) side. In addition, you may arrange | position to a compartment (Y) side.
The noise in the engine room (X) is transmitted from the outer cylinder 3 of the grommet 1 to the vehicle compartment (Y) through the sound insulation air layer 4 and the expansion / contraction connecting portion 5.
By using the air layer 4 as a sealed space, the sound attenuation rate in the air layer 4 can be increased, and the noise transmitted to the passenger compartment (Y) via the telescopic connecting portion 5 can be greatly reduced.

  In addition, since the openings 6 of the inner and outer layers 2 and 3 are closed with the separate filler 10, the opening 6 can be enlarged to increase the cross-sectional area of the air layer 4 for sound insulation. When the cross-sectional area of the air layer 4 is increased, a sound insulation effect can be obtained as is apparent from the following experimental results. As a result, noise transmission to the vehicle interior can be reduced, and the vehicle interior can be kept quiet.

" Reference Example"
In Example 1, an air layer having a thickness of 2 mm was sealed with inner and outer wall materials made of EPDM having a thickness of 2 mm.
Example 2 is 〃 4 〃
Example 3 is 〃 6 〃
In Comparative Example 1, an air layer was not provided and a sound insulating material made of EPDM having a thickness of 4 mm was used.
The sound insulation evaluation of Examples 1 to 3 and Comparative Example 1 is shown in FIG.

  As shown in FIG. 4, Comparative Example 1 in which the air layer was not provided and the thickness was 4 mm was lower in sound insulation effect than Examples 1 to 3 in which the thickness of both side walls was 2 mm and the air layer was interposed. Further, in Examples 1 to 3, the sound insulation effect was higher when the thickness of the air layer was increased, and the sound insulation effect of Example 3 in which the air layer was 6 mm was the highest.

  From the measurement results, the cross-sectional width of the air layer 4 surrounded by the inner cylinder 2 and the outer cylinder 3 is preferably ½ or more of the total thickness of the inner cylinder 2 and the outer cylinder 3. Is preferably 1 or more. If the air layer 4 is made larger, the sound insulation effect can be enhanced, and the upper limit is not limited. However, if the air layer 4 becomes larger, the grommet 1 becomes larger and there is a greater possibility that it will come into contact with an external interference material.

5 and 6 show an actual施形condition.
In the embodiment, the shape of the filler 10 of the reference embodiment is not a simple annular body, and the filler 10 has the outer peripheral portion 10a thick in the axial direction and the inner peripheral portion 10b thin in the axial direction . Other configurations and operational effects are the same as those of the reference embodiment shown in FIGS.
Thus, if the outer peripheral part 10a of the filler 10 is thick, the outer cylinder 3 can be firmly supported.

  Further, since the inner peripheral portion 10b is thin and easy to bend, as shown in FIGS. 6A, 6B, and 6C, the filler 10 can be made to correspond to a change in the diameter of the wire harness W / H. it can. As shown in FIG. 6C, when the outer diameter of the wire harness W / H is large and the inner cylinder 2 follows and expands, the inner peripheral portion 10b of the filler 10 follows and bends and adheres closely to the inner cylinder 2. . As shown in FIG. 6B, when the wire harness W / H has a medium diameter, the inner peripheral portion 10b of the filler 10 is compressed and is brought into close contact with the inner cylinder 2. As shown in FIG. 6A, when the wire harness W / H has a small diameter, the inner peripheral surface of the inner peripheral portion 10b is not contracted and the inner peripheral surface thereof is in close contact with the outer peripheral surface of the inner cylinder 2.

Figure 7 (A) (B) shows a modification Katachirei filler of the embodiment.
In the modification, as well as thick as in the above-described embodiment the outer peripheral portion 10a of the filler 10. On the other hand, the inner peripheral portion 10b is also thick, and an intermediate portion sandwiched between the inner and outer peripheral portions is provided with a thin portion 10c with an interval in the circumferential direction.
If it is set as this structure, while being able to hold | maintain the adhesiveness with the inner and outer cylinders 2 and 3, radial followability can also be hold | maintained. Since other configurations are the same as those of the reference embodiment , the same reference numerals are given and description thereof is omitted.

It shows the other implementation form of the present invention in FIGS. 8 to 10.
In this embodiment , the slit-shaped filler 10 is provided with one slit 20 extending along the entire length in the radial direction from the inner peripheral surface to the outer peripheral surface . When the slit 20 is provided, the filler 10 can be opened in the circumferential direction, and can be fitted from the lateral direction perpendicular to the axis with respect to the outer circumferential surface of the inner cylinder 2.
Therefore, after passing the wire harness W / H through the inner cylinder 2 of the grommet 1, the filler 10 is attached to the outer peripheral surface of the inner cylinder 2 by winding the outer cylinder 3.
Since the filler 10 passes through the wire harness W / H through the inner cylinder 2 and is attached after the inner cylinder 2 has expanded in diameter, the filler 10 does not have to extend following the diameter expansion of the inner cylinder 2 and is therefore a resin molded product. And can be molded from a relatively hard rubber or elastomer. In the present embodiment, it is formed of a high-hardness elastomer in consideration of adhesion to the inner and outer cylinders 2 and 3.

Further, if the slit 20 remains open with the filler 10 attached to the grommet 1, the slit 20 becomes a gap, and the sound insulating air layer is not completely sealed.
Therefore, as shown in FIG. 10, after the filler 10 has opened the slit 20 and attached to the grommet 1, the slit 20 is closed so that no gap is generated.

Specifically, in the filler 10, basically, the outer peripheral portion 10a is thick in the axial direction , the inner peripheral portion 10b is thin, and the thickness of the outer peripheral portion 10a is similar to the embodiment shown in FIGS. The inner peripheral portion 10b protrudes from the central portion in the vertical direction.
A fitting convex portion 10h that continues from the center of the thick outer peripheral portion 10a to the protruding portion of the inner peripheral portion 10b is provided on the entire length of the one split end 10e across the slit 20. The other split end 10i sandwiching the slit 20 is provided with a fitting concave portion 10k into which the fitting convex portion 10h is inserted into the thick outer peripheral portion 10a, and the thin portion of the inner peripheral portion 10b is a bent portion 10j. It overlaps with the outer surface of the portion 10h.

By setting the split ends of the both sides of the filler 10 on both sides sandwiching the slit 20 to the above shape, the slit 20 is opened and attached to the outer periphery of the inner cylinder 2 of the grommet 1. As shown in FIG. 6, the fitting convex portion 10h is inserted into the fitting concave portion 10k and overlaps with the bent portion 10j, so that the slit 20 is reliably closed.
Other configurations are the same as those in the above-described reference embodiment, and the operational effects are also the same.

DESCRIPTION OF SYMBOLS 1 Grommet 2 Inner cylinder 3 Outer cylinder 4 Air layer for sound insulation 5 Telescopic connection part 6 Opening 10 Filler 12 Adhesive tape 20 Slit

Claims (3)

An inner cylinder through which the wire harness is closely inserted, an outer cylinder in which one end of the inner cylinder is folded outward and covered on the outer periphery of the inner cylinder to form a sound insulation air layer, and one end side of the outer cylinder is thickened In the grommet made of an elastic material provided with a body locking recess annularly as meat,
An annular filler, which is a separate member, is filled from an opening formed between the other end of the outer cylinder and the inner cylinder , and the filler has a thick outer peripheral portion in the axial direction and an inner peripheral portion in the axial direction. It is thin, or the outer peripheral part and the inner peripheral part are thick in the axial direction and the intermediate layer is thin in the axial direction.
The closed front Symbol opening with a filling material, the outer cylinder by winding adhesive tape on an outer peripheral surface of the outer cylinder impinging on the arrangement position of the filler without a gap in close contact and fixed to the inner cylinder through the filling material, the sound insulating Grommet characterized in that the air layer for use is a sealed space. An inner cylinder through which the wire harness is closely inserted, an outer cylinder in which one end of the inner cylinder is folded outward and covered on the outer periphery of the inner cylinder to form a sound insulation air layer, and one end side of the outer cylinder is thickened In the grommet made of an elastic material provided with a body locking recess annularly as meat,
An annular filler, which is a separate member, is filled from an opening formed between the other end of the outer cylinder and the inner cylinder, and the filler extends from the annular inner peripheral surface to the outer peripheral surface over the entire length in the radial direction. The slit has a shape having the entire length in the axial direction, and is provided with a fitting portion that overlaps with each other at the split edge that sandwiches the slit,
The fitting portion of the filler is overlapped to close the opening, and an adhesive tape is wound around the outer peripheral surface of the outer cylinder corresponding to the arrangement position of the filler, so that the outer cylinder is closely attached to the inner cylinder via the filler. A grommet which is fixed and has an air space for sound insulation as a sealed space . The grommet according to claim 1 or 2, wherein the filler is made of rubber, elastomer or resin .

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