JP5904155B2 - Grommet and wire harness with grommet - Google Patents

Description

  The present invention relates to a grommet and a wire harness with a grommet.

  In a vehicle such as an automobile, an engine room and a cabin are partitioned by a vehicle panel. A grommet is attached to the wire harness extending over the engine room and the cabin. The grommet is attached to a through hole formed in the vehicle panel. The grommet protects the wire harness, suppresses intrusion of water, dust and the like from the engine room to the cabin, and suppresses sound leakage from the engine room to the cabin.

  Double walls are formed in the grommets of Patent Documents 1 to 3. An air layer is interposed between the double walls. The air layer improves the sound insulation of the grommet.

JP 2012-125082 A JP 2010-88217 A JP 2002-171646 A

  The grommet shown in Patent Document 1 has an undercut that becomes an obstacle to mold release. When the grommet shown in Patent Document 1 is molded using a mold, it is necessary to use a mold having a slide mechanism or to forcefully remove the grommet. It is difficult to improve the productivity of the grommet shown in Patent Document 1.

  The grommet shown in Patent Document 2 is composed of two parts. When the grommet is composed of two or more parts, there is a possibility that an undercut that becomes an obstacle to mold release can be eliminated from the grommet. However, when the grommet is composed of two or more parts, it is difficult to improve the productivity of the grommet.

  The grommet shown in Patent Document 3 has an undercut. In order to facilitate mold release, a slit is formed in the grommet of Patent Document 3. However, the slit causes sound leakage and reduces the sound insulation of the grommet.

  The present invention is made to solve these problems. The problem to be solved by the present invention is to provide a grommet and a wire harness with a grommet having high sound insulation and high productivity.

  The grommet includes first to fourth cylindrical structures. The second cylindrical structure follows the first cylindrical structure. The third cylindrical structure follows the second cylindrical structure. The fourth cylindrical structure follows the third cylindrical structure. First to fourth through holes are formed in the first to fourth cylindrical structures, respectively. The second through hole follows the first through hole. The third through hole continues to the second through hole. The fourth through hole continues to the third through hole. Panel grooves are formed in the second cylindrical structure. The cross section of the second through hole and the cross section of the third through hole are larger than the cross section of the first through hole. The third cylindrical structure and the fourth cylindrical structure have flexibility. The fourth cylindrical structure includes a thin part and a thick part. The thin portions and the thick portions are alternately arranged in the circumferential direction. The thin wall portion projects radially inward from the thick wall portion.

  The wire harness with grommets includes a grommet, a wire harness, a first adhesive tape, and a second adhesive tape. The grommet includes first to fourth cylindrical structures. The second cylindrical structure follows the first cylindrical structure. The third cylindrical structure follows the second cylindrical structure. The fourth cylindrical structure follows the third cylindrical structure. First to fourth through holes are formed in the first to fourth cylindrical structures, respectively. The second through hole follows the first through hole. The third through hole continues to the second through hole. The fourth through hole continues to the third through hole. Panel grooves are formed in the second cylindrical structure. The cross section of the second through hole and the cross section of the third through hole are larger than the cross section of the first through hole. The fourth through hole is recessed and the fourth cylindrical structure is pushed toward the third through hole. The first adhesive tape is wound over the first tubular structure and the wire harness. The second adhesive tape is wound over the fourth tubular structure and the wire harness.

  In the wire harness with grommets, desirably, the third cylindrical structure is thinned away from the second cylindrical structure, and the fourth cylindrical structure includes a thin part and a thick part. The thin portions and the thick portions are alternately arranged in the circumferential direction. The thin wall portion projects radially inward from the thick wall portion.

  According to this invention, a double wall is comprised by the 2nd cylindrical structure and the 3rd cylindrical structure, and an air layer is interposed between double walls. The sound insulation of the grommet is improved.

  Looseness is easily formed in the vicinity of the boundary between the third cylindrical structure and the fourth cylindrical structure, and the grommet easily adapts to the curvature of the wire harness. Even if the wire harness is curved, the sound insulation of the grommet is maintained.

  When the grommet is molded using a mold, it is possible to avoid an undercut that becomes an obstacle to mold release. Grommet productivity is improved.

  These and other objects, features, aspects and advantages of the invention will become more apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

It is a perspective view of a grommet. It is sectional drawing of a grommet. It is a top view of a grommet. It is sectional drawing of a grommet. It is a top view of a grommet. It is sectional drawing, such as a wire harness with a grommet.

  The perspective view of FIG. 1, the cross-sectional view of FIG. 2, and the top view of FIG. 3 schematically show the grommet 1000 of this embodiment.

  The grommet 1000 shown in FIGS. 1 to 3 is preferably made of rubber or elastomer. When the grommet 1000 is made of rubber or elastomer, the grommet 1000 is easily integrally formed, and the productivity of the grommet 1000 is improved. However, the grommet 1000 may be made of a material other than rubber and elastomer. For example, the grommet 1000 may be made of an elastic material other than rubber and elastomer, and a part of the grommet 1000 may be made of a material other than the elastic material. For example, a part of grommet 1000 may be made of a resin such as polypropylene or polyamide, or may be made of metal, ceramics, or the like.

  Grommet 1000 has a cylindrical structure as a whole. The grommet 1000 includes a first cylindrical structure 1020, a second cylindrical structure 1021, a third cylindrical structure 1022, and a fourth cylindrical structure 1023. The grommet 1000 may include components other than the first cylindrical structure 1020, the second cylindrical structure 1021, the third cylindrical structure 1022, and the fourth cylindrical structure 1023. The structures of the first cylindrical structure 1020, the second cylindrical structure 1021, the third cylindrical structure 1022, and the fourth cylindrical structure 1023 may be changed. For example, all or part of the first cylindrical structure 1020, the second cylindrical structure 1021, the third cylindrical structure 1022, and the fourth cylindrical structure 1023 may include ribs.

  The first tubular structure 1020, the second tubular structure 1021, the third tubular structure 1022, and the fourth tubular structure 1023 extend in the axial direction 9000 of the grommet 1000 and are in the order described. It is arranged in 1000 axial directions 9000. Accordingly, the second cylindrical structure 1021 follows the first cylindrical structure 1020. The third cylindrical structure 1022 follows the second cylindrical structure 1021. The fourth cylindrical structure 1023 follows the third cylindrical structure 1022.

  In the first cylindrical structure 1020, the second cylindrical structure 1021, the third cylindrical structure 1022, and the fourth cylindrical structure 1023, a first through hole 1040, a second through hole 1041, A third through hole 1042 and a fourth through hole 1043 are formed. It is planned to pass the wire harness through the first through hole 1040, the second through hole 1041, the third through hole 1042, and the fourth through hole 1043.

  The first through hole 1040, the second through hole 1041, the third through hole 1042, and the fourth through hole 1043 extend in the axial direction 9000 of the grommet 1000, and the axial direction of the grommet 1000 in the order described. It is arranged in 9000. Accordingly, the second through hole 1041 continues to the first through hole 1040. The third through hole 1042 continues to the second through hole 1041. The fourth through hole 1043 continues to the third through hole 1042.

  A panel groove 1060 is formed on the outer peripheral surface of the second cylindrical structure 1021. It is planned that a vehicle panel is fitted in the panel groove 1060.

  The cross sections of the first through hole 1040, the second through hole 1041, the third through hole 1042, and the fourth through hole 1043 described below are respectively the first through hole 1040, the second through hole 1041, This is a surface (cross section) obtained by cutting the third through-hole 1042 and the fourth through-hole 1043 along a plane perpendicular to the axis of the grommet 1000. The cross section of the wire harness described below is a surface (cross section) obtained by cutting the wire harness on a plane perpendicular to the direction in which the wire harness extends. When the fourth through-hole 1043 is not depressed, the cross-sections of the first through-hole 1040, the second through-hole 1041, the third through-hole 1042, and the fourth through-hole 1043 are typically circular. Shape. When the cross section is circular, the size of the cross section is also expressed by the size of the diameter. However, the cross sections of the first through hole 1040, the second through hole 1041, the third through hole 1042, and the fourth through hole 1043 may not be circular.

  The cross section of the first through hole 1040 is desirably smaller than the cross section of the wire harness when the wire harness is not passed through the first through hole 1040, and the wire harness is passed through the first through hole 1040. If so, it will be spread out to fit the cross section of the wire harness.

  The cross section of the second through hole 1041 is larger than the cross section of the first through hole 1040 and larger than the cross section of the wire harness that is passed therethrough. The cross section of the second through-hole 1041 increases as the distance from the first through-hole 1040 increases in the section 1180 near the first through-hole 1040, and is constant in the section 1181 near the third through-hole 1042. However, the cross-sectional size distribution may be changed.

  The second cylindrical structure 1021 is desirably thicker than the first cylindrical structure 1020, the third cylindrical structure 1022, and the fourth cylindrical structure 1023. Thereby, even if all or a part of the first cylindrical structure 1020, the third cylindrical structure 1022, and the fourth cylindrical structure 1023 are deformed, the second cylindrical structure 1021 is hardly deformed. The rigidity of the second cylindrical structure 1021 may be ensured by a method other than increasing the thickness of the second cylindrical structure 1021. For example, the rigidity of the second cylindrical structure 1021 may be ensured by adding reinforcement made of a hard material to the second cylindrical structure 1021.

  The third cylindrical structure 1022 has flexibility and can be bent. The third tubular structure 1022 is thinned away from the second tubular structure 1021 and is likely to be deformed as it is separated from the second tubular structure 1021.

  The cross section of the third through hole 1042 is larger than the cross section of the first through hole 1040 and larger than the cross section of the wire harness that is passed therethrough. The cross section of the third through hole 1042 decreases as the distance from the second through hole 1041 increases.

  The fourth cylindrical structure 1023 has flexibility and can be bent. The fourth cylindrical structure 1023 includes a thin portion 1200 and a thick portion 1201. The number of thin portions 1200 and the number of thick portions 1201 may be increased or decreased. The thin portion 1200 is easier to deform than the thick portion 1201. The thin portions 1200 and the thick portions 1201 are alternately arranged in the circumferential direction 9001. The thin portion 1200 protrudes inward in the radial direction 9002 from the thick portion 1201. A circumferential direction 9001 is a direction around the axis of the grommet 1000. The inner side in the radial direction 9002 is a direction approaching the axis of the grommet 1000.

  The cross section of the fourth through hole 1043 is larger than the cross section of the first through hole 1040 and larger than the cross section of the wire harness that is passed therethrough. The cross section of the fourth through hole 1043 increases as the distance from the third through hole 1042 increases.

  The cross-sectional view of FIG. 4 and the top view of FIG. 4 and 5 show a state in which the fourth through-hole 1043 has been depressed and the fourth cylindrical structure 1023 has been pushed toward the third through-hole 1042.

  As shown in FIGS. 4 and 5, when stress toward the inner side in the radial direction 9002 is applied to the fourth tubular structure 1023, the relatively thin thin portion 1200 is crushed in the circumferential direction 9001, The thick part 1201 is moved inward in the radial direction 9002. Thereby, the 4th through-hole 1043 is easily depressed. The thick part 1201 is also slightly deformed. The thin portion 1200 may be deformed more complicatedly.

  In addition, when stress is applied to the fourth cylindrical structure 1023 in the downward direction in the axial direction 9000, the fourth cylindrical structure 1023 is coupled to the second cylindrical structure 1021 that is difficult to deform out of the third cylindrical structure 1022. The portion near the second tubular structure 1021 that is difficult to deform is hardly deformed, but the portion near the fourth tubular structure 1023 that is easily deformed is curved inward in the radial direction 9002 of the grommet 1000. For this reason, the vicinity of the boundary between the third cylindrical structure 1022 and the fourth cylindrical structure 1023 is curved in a zigzag manner, and the fourth cylindrical structure 1023 is easily pushed toward the third through hole 1042. A bump 1220 is formed in the vicinity of the boundary between the third cylindrical structure 1022 and the fourth cylindrical structure 1023.

  Grommet 1000 does not have an undercut that becomes an obstacle to mold release when molding using a mold. Although the vicinity of the boundary between the third cylindrical structure 1022 and the fourth cylindrical structure 1023 slightly protrudes inward in the radial direction 9002, the vicinity of the boundary between the third cylindrical structure 1022 and the fourth cylindrical structure 1023 Is easy to deform and does not become an obstacle to mold release. For this reason, the grommet 1000 is easily integrally formed and has high productivity.

  The cross-sectional view of FIG. 6 schematically shows the wire harness 1240 with grommet. FIG. 6 shows a state where the vehicle panel 1241 is fitted to the wire harness 1240 with grommet.

  As shown in FIG. 6, the wire harness with a grommet 1240 includes a grommet 1000, a wire harness 1260, a first adhesive tape 1261, and a second adhesive tape 1262.

  The wire harness 1260 is passed through the first through hole 1040, the second through hole 1041, the third through hole 1042, and the fourth through hole 1043, and the vehicle panel 1241 is fitted in the panel groove 1060. The vehicle panel 1241 partitions the engine room and the cabin. The first tubular structure 1020 is disposed on the cabin side from the vehicle panel 1241, and the third tubular structure 1022 and the fourth tubular structure 1023 are disposed on the engine room side from the vehicle panel 1241.

  When the wire harness 1260 is passed through the first through hole 1040, the first tubular structure 1020 is deformed in conformity with the wire harness 1260, and the first through hole 1040 is expanded. The first tubular structure 1020 tightens the wire harness 1260, and the grommet 1000 is fixed to the wire harness 1260. A gap between the wire harness 1260 and the first tubular structure 1020 is reduced, and water immersion, sound leakage, and the like are suppressed.

  When the wire harness 1260 is passed through the second through hole 1041, a first space 1280 is formed between the wire harness 1260 and the second tubular structure 1021.

  When the wire harness 1260 is passed through the third through hole 1042, the second space 1300 is formed between the wire harness 1260 and the third cylindrical structure 1022.

  The fourth through hole 1043 is depressed, and the fourth cylindrical structure 1023 is pushed toward the third through hole 1042. In order to facilitate this deformation, as described above, the third cylindrical structure 1022 is thinned away from the second cylindrical structure 1021, and the fourth cylindrical structure 1023 has a thin portion 1200 and a thickness. A meat part 1201 is provided. However, even when the third cylindrical structure 1022 and the fourth cylindrical structure 1023 do not have the structure, the fourth through-hole 1043 is recessed and the fourth cylindrical structure 1023 is changed to the third through-hole 1042. It is possible to push in.

  The fourth tubular structure 1023 fastens the wire harness 1260 and the grommet 1000 is fixed to the wire harness 1260. The gap between the wire harness 1260 and the fourth cylindrical structure 1023 is reduced, and water immersion, sound leakage, and the like are suppressed.

  The first adhesive tape 1261 is wound over the first tubular structure 1020 and the wire harness 1260. Thereby, the wire harness 1260 is fixed to the first tubular structure 1020, and the gap between the first tubular structure 1020 and the wire harness 1260 is closed.

  The second adhesive tape 1262 is wound over the fourth tubular structure 1023 and the wire harness 1260. Thereby, the state where the fourth tubular structure 1023 is tightening the wire harness 1260 is maintained, and the gap between the fourth tubular structure 1023 and the wire harness 1260 is closed.

  The second cylindrical structure 1021 and the third cylindrical structure 1022 are double walls. A first space 1280 and a second space 1300 filled with air are interposed between the double walls. Thereby, the sound insulation of the grommet 1000 improves.

  Since the bump 1220 is formed in the vicinity of the boundary between the third cylindrical structure 1022 and the fourth cylindrical structure 1023, the grommet 1000 easily adapts to the curvature of the wire harness 1260. Thereby, even if the wire harness 1260 curves, the sound insulation of the grommet 1000 is maintained.

  The grommeted wire harness 1240 is typically attached to an automobile. The wire harness 1260 electrically connects two or more devices mounted on the automobile. The wire harness 1240 with a grommet may be attached to a device other than an automobile. For example, the wire harness 1240 with grommet may be attached to a vehicle such as a motorcycle, a copying machine, or the like.

  The wire harness 1260 typically has a branch and electrically connects three or more devices. In some cases, the wire harness 1260 does not have a branch and electrically connects two devices.

  While the invention has been shown and described in detail, the above description is illustrative in all aspects and not restrictive. Accordingly, it is understood that numerous modifications and variations can be devised without departing from the scope of the present invention.

1000 Grommet 1020 1st cylindrical structure 1021 2nd cylindrical structure 1022 3rd cylindrical structure 1023 4th cylindrical structure 1040 1st through-hole 1041 2nd through-hole 1042 3rd through-hole 1043 1st 4 through-hole 1200 Thin part 1201 Thick part 1240 Wire harness with grommet 1260 Wire harness 1261 First adhesive tape 1262 Second adhesive tape

Claims (2)

A first tubular structure in which a first through hole is formed;
Following the first cylindrical structure, a second through hole and a panel groove are formed, the second through hole follows the first through hole, and a cross section of the second through hole is the first through hole. A second cylindrical structure larger than the cross section of one through hole;
It has flexibility, is thinned as it moves away from the second cylindrical structure following the second cylindrical structure, a third through hole is formed, and the third through hole is the second cylindrical structure. A third cylindrical structure in which the cross-section of the third through-hole is larger than the cross-section of the first through-hole,
It has flexibility and is provided with a thin part and a thick part following the third cylindrical structure, the thin part and the thick part are alternately arranged in the circumferential direction, and the thin part is the thick part. Projecting radially inward from the portion, a fourth through-hole is formed, and the fourth through-hole follows the third through-hole,
Grommet with. A first cylindrical structure, a second cylindrical structure, a third cylindrical structure, and a fourth cylindrical structure, wherein the second cylindrical structure follows the first cylindrical structure; 3 cylindrical structure follows the second cylindrical structure, the fourth cylindrical structure follows the third cylindrical structure, the first cylindrical structure, the second cylindrical structure, A first through hole, a second through hole, a third through hole, and a fourth through hole are formed in the third cylindrical structure and the fourth cylindrical structure, respectively, and the second through hole Continues to the first through hole, the third through hole continues to the second through hole, the fourth through hole continues to the third through hole, and the second cylindrical structure is formed. A groove for a panel is formed, and a cross section of the second through hole and a cross section of the third through hole are larger than a cross section of the first through hole, and the third cylindrical structure and the fourth cylindrical shape are formed. Flexible structure The a, said fourth through-hole is deflated, grommet the fourth tubular structure is pushed toward the third through hole,
A wire harness passed through the first through hole, the second through hole, the third through hole, and the fourth through hole;
A first adhesive tape wound over the first tubular structure and the wire harness;
A second adhesive tape wound over the fourth tubular structure and the wire harness;
Equipped with a,
The third cylindrical structure is thinned away from the second cylindrical structure, the fourth cylindrical structure includes a thin part and a thick part, and the thin part and the thick part are in the circumferential direction. The wire harness with a grommet which is alternately arranged and the thin-walled portion projects radially inward from the thick-walled portion .

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