JP6447381B2 - Grommet and wire harness with grommet - Google Patents

Description

  The present invention relates to a grommet, and more particularly, to a technique for assembling a wire harness arranged in an automobile and mounting it in a through hole of a vehicle body panel to protect the wire harness at a through hole insertion portion and to provide waterproofing and dustproofing.

  A grommet formed of rubber or elastomer is attached to the wire harness routed from the engine room of the automobile to the vehicle interior, and the grommet is attached to a through hole of a vehicle body panel that partitions the engine room and the vehicle interior. . With such a structure, protection of the wire harness inserted through the through hole, prevention of intrusion of water and dust from the engine room side to the vehicle compartment side, and sound insulation are achieved.

  In Patent Document 1, as shown in FIG. 6, a pair of semicircular closed surface portions 914 and 915 projecting from the inner peripheral surface at the distal end on the large diameter side of the enlarged diameter cylindrical portion 913 provided with the vehicle body locking recess 912. And a pair of semi-annular tube portions 916 and 917 respectively protruding from the peripheral edges of the circular notches at the center of the opposed ends of the pair of closed surface portions 914 and 915, and the outer circumferences of the pair of semi-annular tube portions 916 and 917 There is disclosed a grommet 910 that is wound around an adhesive tape.

  The pair of closing surface portions 914 and 915 are thinner than the diameter-expanded cylindrical portion 913, and the peak portion 920 and the valley portion 921 extending in the semicircular direction surrounding the roots of the semi-annular cylindrical portions 916 and 917 in the radial direction. It has the bellows part 950 provided alternately. When the semicircular cylindrical portions 916 and 917 protruding from the center of the closing surface portions 914 and 915 are deformed according to the outer diameter of the wire harness 901 to which the tape winding is fixed and the bending direction of the wire harness 901, the closing surface portions 914 and 915 These deformations are absorbed by the expansion and contraction of the bellows, and the deformation of the vehicle body engaging recess 912 of the enlarged diameter cylindrical portion 913 connected to the outer peripheral side of the closing surface portions 914 and 915 is prevented.

JP 2009-225509 A

  However, as shown in FIG. 7, when the wire harness 901 held by the grommet 910 is largely bent and the path is restricted, for example, when a large compressive force acts on the bellows portion of the closing surface portion 915, the closing surface portion 915 There was a risk that the shape could not be maintained, and the inside (side of the enlarged diameter cylindrical portion 913) could enter. In this case, the sound insulation performance of the grommet 910 is reduced by narrowing the air tank 922 formed by the enlarged diameter cylindrical portion 913 and the closed surface portion 915.

  Then, an object of this invention is to provide the technique which reduces the fall of the sound insulation performance of a grommet by the bending of the hold | maintained wire harness.

  In order to solve the above-mentioned problem, a first aspect is a grommet attached to a through hole formed in a vehicle body panel through which a wire harness is inserted, and a small-diameter cylindrical portion that forms an insertion hole through which the wire harness is inserted And an enlarged diameter cylindrical portion that is formed so as to extend outward from the small diameter cylindrical portion and to extend in the axial direction of the small diameter cylindrical portion, and an annular groove is formed on the outer peripheral portion thereof so that the peripheral edge portion of the through hole can be fitted thereinto. A closing surface portion extending radially inward from an inner peripheral surface of the diameter-enlarging cylinder portion and closing the diameter-enlarging cylinder portion; and extending from the closing surface portion to the one axial side, and the wire harness is inserted therethrough. An auxiliary cylinder part that forms an insertion hole, and the closing surface part extends in the circumferential direction surrounding the auxiliary cylinder part and protrudes in the axial direction, and extends in the circumferential direction and the peak part In the direction opposite to the direction in which the The troughs that come out have bellows portions that are alternately provided in the radial direction of the diameter-expanded cylindrical portion, and the bellows portions are adjacent to each other in the two protruding heights in the axial direction. Has a mountain.

  Moreover, a 2nd aspect is a grommet which concerns on a 1st aspect, Comprising: The said bellows part has three or more of the said peak parts, Of the three said continuous peak parts, it is the said radial direction. The two crests located on the outer side and the inner side protrude from the central crest portion on one side in the axial direction.

  Moreover, a 3rd aspect is a grommet which concerns on a 2nd aspect, Comprising: The said axial direction one side is a direction away from the said enlarged diameter cylinder part.

  Moreover, a 4th aspect is a wire harness with a grommet, Comprising: It hold | maintained in the insertion state by the grommet which concerns on the aspect of any one of 1st to 3rd, the said small diameter cylinder part, and the said auxiliary | assistant cylinder part. The wire harness is provided.

  According to the grommets according to the first to third aspects, when the bellows part is compressed by bending the wire harness inserted through the small diameter cylinder part and the auxiliary cylinder part, the peak part having the higher protrusion height. However, they can overlap so as to cover the lower peak. This makes it possible to compress and deform the bellows portion thinner. Therefore, it can suppress that the bellows part collapse | crumbles, and it can suppress entering into the air tank formed of an enlarged diameter cylinder part and a closed surface part, and can suppress that the sound-insulation performance of a grommet falls.

  Moreover, according to the grommet which concerns on a 2nd aspect, when a bellows part is compressed, two peak parts located in an outer side and an inner side can approach and overlap over a center peak part. As a result, the bellows portion can be thinly compressed and deformed, and the bellows portion can be more effectively suppressed from entering the air tank.

  Moreover, according to the grommet which concerns on a 3rd aspect, the volume of an air tank can be expanded by projecting the two peak parts which protrude rather than the center peak part in the direction away from an enlarged diameter cylinder part. Thereby, the sound insulation effect of the grommet can be enhanced.

  Moreover, according to the wire harness with a grommet which concerns on a 4th aspect, when a bellows part is compressed by bending the wire harness penetrated by the small diameter cylinder part and the auxiliary cylinder part, the one where protrusion height is higher The ridges can overlap so as to cover the lower ridges. This makes it possible to compress and deform the bellows portion thinner. Therefore, it can suppress that the bellows part collapse | crumbles, and it can suppress entering into the air tank formed of an enlarged diameter cylinder part and a closed surface part, and can suppress that the sound-insulation performance of a grommet falls.

It is sectional drawing which shows the wire harness with a grommet which concerns on embodiment. It is a fragmentary sectional view showing a closed face part of a grommet concerning an embodiment. It is a rear view which shows the grommet which concerns on embodiment. It is a schematic sectional drawing which shows the bellows part of the state compressed. It is a schematic sectional drawing which shows the bellows part which concerns on a comparative example. It is sectional drawing which shows the conventional wire harness with a grommet. It is a schematic sectional drawing which shows the conventional wire harness with a grommet.

<1. Embodiment>
Hereinafter, the grommet 20 according to the embodiment will be described. Drawing 1 is a sectional view showing wire harness 10 with a grommet concerning an embodiment. FIG. 2 is a partial cross-sectional view showing the closing surface portion 40 of the grommet 20 according to the embodiment. FIG. 3 is a rear view showing the grommet 20 according to the embodiment.

  The vehicle body panel 16 is a substantially plate-like member that partitions a space in the vehicle. As the vehicle body panel 16, for example, a panel that partitions a vehicle compartment and an engine room is assumed. The vehicle body panel 16 is formed with mounting holes 18 (through holes) penetrating both sides thereof. Here, the mounting hole 18 has a substantially circular shape, but it does not necessarily have to be a circular shape, and may have a rectangular shape or the like. The peripheral portion of the mounting hole 18 may be appropriately subjected to a processing process (burring process) or the like that bends to one of the main surface sides of the vehicle body panel 16.

  The wire harness with grommet 10 includes a wire harness 12 and a grommet 20.

  The wire harness 12 includes a plurality of bundled electric wires. The wire harness 12 is a member that is disposed through the mounting hole 18 of the vehicle body panel 16 to electrically connect the electrical devices installed in each of the two spaces defined by the vehicle body panel 16. is there.

  The grommet 20 is attached to an attachment hole 18 formed in the vehicle body panel 16 in a state of being attached to the intermediate portion in the longitudinal direction of the wire harness 12. In this state, the grommet 20 protects from the peripheral edge portion of the mounting hole 18 of the wire harness 12. In addition, the grommet 20 has a function of preventing the passage of water, dust, or the like between the two spaces defined by the vehicle body panel 16 and blocking sound.

  The grommet 20 is made of, for example, an elastomer (elastic material such as rubber or synthetic resin material), and includes a small-diameter cylindrical portion 22, an enlarged-diameter cylindrical portion 30, and a closing surface portion 40.

  The small diameter cylindrical portion 22 is formed in a cylindrical shape, and an insertion hole 24 through which the wire harness 12 is inserted is formed. A plurality of annular protrusions 25 are arranged on the inner peripheral surface forming the insertion hole 24 of the small diameter cylindrical portion 22 with a predetermined interval in the axial direction. The innermost circumference of each annular protrusion 25 is slightly smaller than the cross section of the wire harness 12. That is, the wire harness 12 can be inserted into the insertion hole 24 by elastically deforming the small-diameter cylindrical portion 22 so as to widen the diameter of the insertion hole 24. After the wire harness 12 is inserted, the small diameter cylindrical portion 22 contracts, so that the wire harness 12 is fastened and fixed to the small diameter cylindrical portion 22. By providing the plurality of annular protrusions 25, the contact area with the wire harness 12 in the insertion hole 24 of the small-diameter cylindrical portion 22 is reduced, so that it is easy to insert and high sealing performance can be obtained. . However, the plurality of annular protrusions 25 is not an essential configuration and can be omitted.

  Cut along the axial direction of the insertion hole 24 from the end on the other axial side of the small-diameter cylindrical portion 22 to a position in front of the one of the plurality of annular projections 25 positioned on the other side in the axial direction. May be formed. By forming such a cut, the diameter of the small diameter cylindrical portion 22 can be easily increased, and the wire harness 12 can be easily inserted.

  A tape retaining rib 26 that protrudes radially outward along the circumferential direction is provided at the end on the other axial side of the small diameter cylindrical portion 22. Even when the adhesive tape is wound around the outer end portion of the small-diameter cylindrical portion 22 and the wire harness 12 in a state where the wire harness 12 is inserted and held in the small-diameter cylindrical portion 22, the wire harness 12 is attached to the small-diameter cylindrical portion 22. Is fixed.

  The enlarged diameter cylindrical portion 30 is formed so as to expand outward from the smaller diameter cylindrical portion 22. Here, the enlarged diameter cylindrical portion 30 includes an umbrella-shaped portion 32, a thick portion 34 provided on the open end side of the umbrella-shaped portion 32, and a connecting portion that connects the umbrella-shaped portion 32 and the thick portion 34. 35. The umbrella-shaped portion 32 is a portion that extends in the synthesis direction of the radially outer side and one of the small-diameter cylindrical portions 22 in the axial direction, and the connecting portion 35 is a portion that extends in the axial direction of the small-diameter cylindrical portion 22.

  An annular groove 36 into which the peripheral edge of the mounting hole 18 can be fitted is formed on the outer peripheral portion between the umbrella-shaped portion 32 and the thick portion 34. The connecting part 35 is located on the bottom side of the annular groove 36 and connects the umbrella-like part 32 and the thick part 34.

  The groove width of the annular groove 36 is set to a width that allows the peripheral edge of the mounting hole 18 of the vehicle body panel 16 to be fitted, and specifically, is set to be the same as or slightly larger than the thickness of the vehicle body panel 16. Is done. The outer diameter of the bottom portion of the annular groove 36 (the outer diameter of the connecting portion 35) is set to be approximately the same as the inner diameter of the mounting hole 18.

  Since the annular groove 36 itself is a circular groove that opens outward, the mounting posture with respect to the mounting hole 18 is free.

  Moreover, the closed surface part 40 is formed so that it may protrude toward the inner peripheral side (diameter direction inner side) from the inner peripheral part of the connection part 35. As shown in FIG. The closing surface portion 40 is formed in a disk shape that is relatively thin (for example, thinner than the umbrella-shaped portion 32), and an inner space formed by the umbrella-shaped portion 32 and the connecting portion 35 of the diameter-expanded cylindrical portion 30 is formed. It is configured to close. Thus, the air tank 41 is formed by the enlarged diameter cylindrical portion 30 and the closed surface portion 40. By forming such an air tank 41, the sound insulation performance of the grommet 20 is enhanced.

  The closing surface portion 40 has a bellows portion 50. The bellows part 50 extends in a circumferential direction surrounding an auxiliary cylinder part 42 to be described later, and has a peak part 51 protruding in one axial direction and the other side in the axial direction extending in the circumferential direction (the peak part 51 protrudes). The valley portions 53 projecting in the direction opposite to the direction) are alternately provided in the radial direction of the diameter-enlarging cylindrical portion 30. The bellows part 50 has a substantially uniform thickness in the radial direction, and in a cross-sectional view including the central axis, the top part of the peak part 51 and the inner angles of the side wall parts thereof, and the bottom part of the valley part 53 and the bottom part thereof It is configured to expand and contract in the extending direction (radial direction) by changing the inner angle with the side wall portions on both sides (see FIG. 2).

  In this example, the bellows part 50 is composed of three continuous peak parts 51 (peak parts 51a, 51b, 51c) and two valley parts 53 (53a, 53b) arranged between the peak parts 51. Has been.

  Of the three continuous ridges 51, the ridge 51a on the inner side in the radial direction (the direction orthogonal to the central axis of the enlarged diameter cylindrical portion 30) and the outer ridge 51c on the one side in the axial direction than the central ridge 51b. Protruding. In other words, each top part of each peak part 51a, 51c is set to one axial side rather than the top part of peak part 51b. One ridge 51a of two adjacent ridges 51a and 51b protrudes in the axial direction from the other ridge 51b, and among the two adjacent ridges 51b and 51c, the ridge 51c is a ridge. It protrudes on one side in the axial direction from 51b.

  Further, the projecting heights of the valley portions 53a and 53b toward the other side in the axial direction are substantially the same. In other words, the tops of the valleys 53a and 53b are set at positions that are substantially aligned in the axial direction. Note that the protruding heights of the adjacent valley portions 53 may be different.

  An auxiliary cylinder portion 42 protrudes from the central portion of the closing surface portion 40 so as to protrude outward (one side in the axial direction). The auxiliary cylinder part 42 is formed in a cylindrical shape into which the wire harness 12 can be inserted. Then, with the wire harness 12 inserted through the auxiliary cylinder part 42, the auxiliary tape part 42 is fixed to the wire harness 12 by winding the adhesive tape around the auxiliary cylinder part 42 and the wire harness 12.

  The closed surface portion 40 and the auxiliary cylinder portion 42 are formed with a partial division slit 40S. When the grommet 20 is molded, the partial division slit 40S plays a role of facilitating the die removal by easily elastically deforming each of these portions.

  FIG. 4 is a schematic sectional view showing the bellows portion 50 in a compressed state. When the wire harness 12 is arranged perpendicular to the vehicle body panel 16, as shown in FIG. 1, the bellows portion 50 is maintained in its original shape with almost no expansion and contraction.

  However, when the path of the wire harness 12 is restricted in a bent state (see FIG. 7), a part of the bellows portion 50 is compressed by the wire harness 12. In the case of this example, since the protruding height of the central peak 51b is low, the adjacent peaks 51a and 51c cover the peak 51b, and they overlap each other beyond the peak 51b. The overlapping thickness of the peaks 51a and 51c is D1.

  FIG. 5 is a schematic cross-sectional view showing a bellows portion 50A according to a comparative example. The bellows portion 50A has three peak portions 51, and the protruding heights thereof are the same. When such an accordion portion 50A is employed instead of the accordion portion 50, as shown in FIG. 5, the accordion portion 50A is compressed so that the three peak portions 51 overlap each other. The thickness of the overlap of the three peaks 51 at this time is defined as D2.

  The bellows portion 50A can be compressed and deformed up to the thickness D2, but if it is compressed and deformed beyond that, the shape collapses and enters the air tank 41 (see FIG. 7). On the other hand, the bellows portion 50 according to the present embodiment can be compressed and deformed to a thickness D1 that is smaller than the thickness D2 by the thickness of the peak portion 51b. That is, since the grommet 20 according to the present embodiment can be deformed thinner, it is possible to reduce the accordion portion 50 from entering the air tank 41. Therefore, it can reduce that a sound insulation function falls.

  In addition, the quantity of the peak part 51 and the trough part 53 is not limited to the thing of illustration, It can set arbitrarily. That is, the bellows portion 50 may include at least two peak portions 51 and one valley portion 53 arranged between them. By projecting either one of the two peak portions 51 to the one side in the axial direction from the other, it becomes difficult to collapse when the bellows portion 50 contracts, and the air tank 41 can be prevented from becoming smaller. Of course, four or more mountain parts 51 may be provided. Furthermore, you may make it the position of each top part of the some peak part 51 differ in an axial direction.

  Further, in the present embodiment, the direction in which each peak 51 protrudes is a direction facing one side in the axial direction, and this direction is a direction away from the diameter-enlarged cylindrical portion 30. That is, the direction in which the peak portions 51 a and 51 c protrude is a direction in which the volume of the air tank 41 configured by the enlarged diameter cylindrical portion 30 and the closed surface portion 40 is expanded. Thus, the sound-insulating effect can be enhanced by projecting the peaks 51a and 51c in the direction of expanding the volume of the air tank 41.

  Moreover, you may make it the some peak part 51 from which protrusion height differs protrude in the axial direction other side.

  As described above, the present invention has been described in detail. However, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Wire harness with grommet 12 Wire harness 16 Car body panel 18 Mounting hole 20 Grommet 22 Small diameter cylindrical part 24 Insertion hole 30 Expanded cylindrical part 32 Umbrella-shaped part 34 Thick part 35 Connecting part 36 Annular groove 40 Closing surface part 41 Air tank 42 Auxiliary Tube part 50, 50A Bellows part 51, 51a, 51b, 51c Mountain part 53, 53a, 53b Valley part

Claims (4)

A grommet attached to a through hole formed in a vehicle body panel through which a wire harness is inserted,
A small-diameter cylindrical portion that forms an insertion hole through which the wire harness is inserted;
An expanded diameter cylindrical portion formed to extend outward from the small diameter cylindrical portion and to extend in the axial direction of the small diameter cylindrical portion, and an annular groove in which a peripheral edge portion of the through hole can be fitted on the outer peripheral portion;
A closed surface portion extending radially inward from an inner peripheral surface of the expanded diameter cylindrical portion to close the expanded diameter cylindrical portion;
An auxiliary cylinder portion that extends from the closed surface portion to the one side in the axial direction and forms an insertion hole through which the wire harness is inserted;
With
The closed surface portion extends in the circumferential direction surrounding the auxiliary cylinder portion and protrudes in the axial direction, and the valley extends in the circumferential direction and protrudes in a direction opposite to the direction in which the peak portion protrudes. And a bellows part configured to be alternately provided in the radial direction of the enlarged diameter cylindrical part,
The said bellows part is a grommet which has two said adjacent peak parts from which the protrusion height to the said axial direction differs. The grommet according to claim 1,
The bellows part has three or more peak parts,
Of the three consecutive crests, the two crests positioned on the outer side and the inner side in the radial direction protrude in the axial direction from the central crest. The grommet according to claim 2,
The grommet in which the projecting direction of the peak portion is a direction away from the enlarged diameter cylindrical portion. A grommet according to any one of claims 1 to 3,
The wire harness held in an inserted state in the small-diameter cylinder part and the auxiliary cylinder part; and
A wire harness with a grommet.

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