JP5471908B2 - Sound insulation structure of grommet mounting part - Google Patents

Description

  The present invention relates to a sound insulation structure for a grommet mounting portion, and more specifically, a grommet fitted to the through-hole, with the grommet being externally mounted on a wire harness routed from a vehicle engine compartment to a vehicle compartment through a through-hole of a vehicle body panel. It is intended to improve the sound insulation of the mounting portion.

In order to achieve the sound insulation performance of the grommet mounting part, as shown in FIG. 4, a sound insulation material having a sound absorbing property at the periphery of the through hole H is provided on the side surface of the dash panel P that partitions the engine room X and the vehicle compartment Y. A silencer 100 is attached.
In JP-A-8-308067 (Patent Document 1), as shown in FIG. 5, a grommet 110 that is externally mounted on a wire harness W / H is attached to a through hole H, and a seal lip 111 provided on the grommet 110 is provided. The through hole H is passed through and pressed against the silencer 100 from the passenger compartment side.
By bringing the seal lip 111 into contact with the silencer 100, no gap is formed between the through hole H and the silencer 100, and noise on the engine room X side is prevented from entering the vehicle compartment Y, and On the side of the passenger compartment, the silencer 100 absorbs the noise on the engine compartment side to keep the passenger compartment Y quiet.

  In Japanese Patent Laid-Open No. 2002-44839 (Patent Document 2), there is a case where a silencer is attached to the grommet, and the sound is insulated by closing the inner circumference of the grommet and the wire harness penetrating through the grommet with the silencer.

  In addition, as shown in FIG. 4, when a two-piece grommet 150 in which a grommet main body 151 made of an elastic body such as rubber and a resin inner 152 made of a resin molded product are used, the grommet main body 151 is provided. The seal lip 155 is pressed against the side of the engine room of the dash panel P.

Japanese Patent Laid-Open No. 8-308067 Japanese Patent Laid-Open No. 2002-44839

In Patent Document 1 shown in FIG. 5, the seal lip 111 is attached to the insertion-side tip of the grommet 110.
There is a problem in that the workability of inserting the through hole H is very poor because the outer diameter of the enlarged diameter tube 112 is larger than the inner diameter of the through hole H.
Further, even if a silencer is provided inside the grommet, the sound insulation performance from the periphery of the through hole on the outer periphery of the grommet cannot be improved.

  In the structure shown in FIG. 4, there are four routes (1) to (4) through which noise leaks from the engine room X to the vehicle compartment Y. Among these, the sound insulation from the routes (2) to (4) in the region surrounded by the portion where the seal lip of the grommet 150 is in contact with the dash panel can be highly enhanced. However, the sound leakage of the route (1) passing through the portion surrounded by the through hole 100h of the silencer 100 from the outer engine room side away from the grommet cannot be reduced, which causes indoor noise.

  If the seal lip of the grommet can be brought into contact with the silencer 100 attached to the passenger compartment side with respect to the problem, the sound insulation of the route (1) can be achieved. However, if the hole provided in the silencer 100 is made smaller than the panel through hole and protrudes into the hollow from the periphery of the through hole, the workability of inserting the wire harness is deteriorated, while the annular seal lip provided in the grommet has a larger diameter than the through hole. Then, there is a problem that it becomes difficult to insert the grommet provided with the seal lip into the through hole.

  This invention is made | formed in view of the said problem, and makes it the subject to aim at the improvement of sound insulation performance, without impairing the attachment property to the through-hole of a grommet.

In order to solve the above problems, as a first invention,
A soft silencer surrounding the through hole is attached to the vehicle body side surface of the vehicle body provided with a through hole for inserting a wire harness with a burring projecting from the periphery, and the burring is attached to the side surface of the soft silencer in the vehicle compartment. A hard silencer with the tip protruding inward from the inner peripheral surface of the
A two-piece grommet consisting of a grommet main body made of rubber or elastomer and a resin inner fitted inside the grommet main body is externally mounted on the wire harness inserted through the through hole of the vehicle body,
The grommet body protrudes from the outer periphery of a small-diameter cylindrical portion through which the wire harness is closely inserted and protrudes in the outer diameter direction, and a burring and a vehicle body abut on the outer surface of the resin inner fit locking portion. While the sealing lip for
The resin inner has a cylindrical shape that is inserted through the small-diameter cylindrical portion of the grommet body, and is inserted into the resin inner fitting engagement portion from the base end of the cylindrical portion that is inserted along the inner peripheral surface of the burring. The sound insulation of the grommet mounting portion, characterized in that a locking collar portion having an L-shaped cross section that protrudes and an extended cylinder portion provided at the tip with a seal portion that contacts the hard silencer is provided on the cylinder portion. Provide structure.

The soft silencer that is attached to the side of the vehicle compartment is a relatively thick silencer that is conventionally attached to the vehicle compartment and is made of foam or the like. A hard silencer made of a leather sheet, a flexible resin sheet, or the like is further attached to the vehicle compartment surface side of the soft silencer as a skin.
The through hole for the wire harness provided in the hard silencer is made smaller than the through hole of the soft silencer and further smaller than the through hole of the vehicle body, and the tip of the extension cylinder portion provided in the resin inner is abutted against the hard silencer. As a result, the periphery of the vehicle body through hole that was not surrounded by the soft silencer is closed by the hard silencer, so that sound leakage from the engine room or the like can be reduced or prevented.
The extended cylindrical portion provided in the resin inner is projected at a position along the inner peripheral surface of the burring of the vehicle body through hole, and the extended cylindrical portion is positioned on the outer peripheral side of the small diameter cylindrical portion through which the wire harness is inserted. Therefore, the grommet can be inserted with a single touch of pushing the wire harness without impairing the insertion workability of the grommet, and the leakage of sound can be reduced or prevented by abutting the extended cylindrical portion of the resin inner against the hard silencer.

As a second invention,
A soft silencer surrounding the through hole is attached to the vehicle body side surface of the vehicle body provided with a through hole for inserting a wire harness with a burring projecting from the periphery, and the burring is attached to the side surface of the soft silencer in the vehicle compartment. A hard silencer with an inner diameter equivalent to the inner diameter of
The wire harness that is inserted into the through-hole is covered with a grommet body made of rubber or elastomer, and a two-piece grommet made of a resin inner fitted inside the grommet body,
The grommet body has a resin inner fitting engagement portion protruding in an outer diameter direction from an outer periphery of a small diameter cylinder portion through which the wire harness is closely attached, and the small diameter cylinder is disposed on the inner circumference side of the resin inner fitting engagement portion. While providing an extension cylinder part so as to surround the part, provided with a seal part bent from the tip of the extension cylinder part to the outer peripheral side and brought into contact with the hard silencer,
The resin inner has a cylindrical shape that is inserted through the small-diameter cylindrical portion of the grommet body, and is inserted into the resin inner fitting engagement portion from the base end of the cylindrical portion that is inserted along the inner peripheral surface of the burring. A locking collar portion having a L-shaped cross section that protrudes is projected, and the cylindrical portion is an extended cylindrical portion that presses against a bent portion toward the outer peripheral side along the outer peripheral surface of the extended cylindrical portion of the grommet body,
There is provided a sound insulation structure for a grommet mounting portion in which a distal end position of the extended cylindrical portion of the resin inner is a position surrounded by the hard silencer.

In the second invention, the through hole of the hard silencer is substantially the same diameter as the through hole of the vehicle body, and is larger than the through hole of the hard silencer of the first invention. Therefore, since the extension cylinder part of the resin inner that is inserted along the inner peripheral surface of the burring cannot be brought into contact with the hard silencer, the extension cylinder part that the front end bends outward and expands is provided on the grommet body, and the outer side is bent outward. A seal part is provided at the tip, and it is brought into contact with the hard silencer to prevent sound leakage.
And since the extension cylinder part provided in the grommet main body has low rigidity and is easy to fall down, it is easy to bite between a burring and a grommet. Therefore, in order to reinforce the extension cylinder part of the grommet body and prevent it from falling, an extension cylinder part is provided in the resin inner, and the part bent outward from the tip of the extension cylinder part of the grommet body is securely pressed against the hard silencer. I am trying to do it.

  The resin inner fitting engagement portion of the grommet body includes a radial protrusion projecting from the outer periphery of the small diameter cylindrical portion, an outer peripheral wall continuous to the outer peripheral end of the radial protrusion, and a tip of the outer peripheral wall. A stepped folded portion that forms a hollow portion that is folded inward to engage and lock the locking collar portion of the resin inner, a burring seal lip that includes a tip end surface of the stepped folded portion, and the stepped folded portion The shape is provided with a seal lip that protrudes from the outer surface of the part and contacts the outer surface of the vehicle body.

  Moreover, you may make the said grommet main body protrude the cylindrical part for wire rod penetration in the inner peripheral side of the said radial direction protrusion part. A hose for supplying washer cleaning water and an opener cable for opening the bonnet are inserted into the tubular portion for penetrating the wire.

  In the sound insulation structure of the grommet mounting portion of the first invention having the above-described configuration, in order to press the tip of the extension cylinder portion provided in the resin inner to the hard silencer protruding inward from the through hole of the vehicle body and the through hole of the soft silencer, Sound leakage from the engine room through the through hole of the soft silencer can be reduced or prevented.

  In the sound insulation structure for the grommet mounting portion according to the second aspect of the invention, the tip of the extension cylinder provided in the grommet body is bent outwardly and pressed against a hard silencer having the same diameter as the vehicle body through hole. Sound leakage from the engine room through the through hole can be reduced or prevented.

It is sectional drawing which shows 1st Embodiment of this invention. It is sectional drawing which shows 2nd Embodiment of this invention. It is a principal part expanded sectional view of 2nd Embodiment. It is drawing which shows a prior art example. It is drawing which shows another prior art example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment.
As shown in FIG. 1, a grommet that passes through a wire harness W / H through a through hole H with a burring provided in a dash panel P of a vehicle body that partitions an engine room X and a vehicle compartment Y of an automobile, and is externally attached to the wire harness. 1 is attached to the inner peripheral edge of the through hole H, and the seal portion 23 provided in the grommet 1 is passed through the through hole 3a of the soft silencer 3 attached to the indoor side surface Pi of the dash panel P. Further, the soft silencer 3 is in contact with the peripheral edge of the through hole 4a of the hard silencer 4 attached to the side surface of the room 3 from the engine room side.

  The soft silencer 3 is made of foamed resin or foamed rubber and has excellent sound absorption, and is thicker than the hard silencer 4. The soft silencer 3 is provided with a through hole 3a communicating with the through hole H of the vehicle body, and the through hole 3a has a larger diameter than the through hole H of the vehicle body.

The hard silencer 4 is made of leather or a flexible resin sheet and has excellent sound insulation, and the thickness is about ½ to ¼ that of the soft silencer 3.
The through hole 4a provided in the hard silencer 4 has a smaller diameter than the through hole H provided in the dash panel P, but is larger than the outer diameter of the small diameter cylindrical portion 11 through which the wire harness W / H of the grommet body 10 described later is inserted. .
The burring Hb that is bent from the periphery of the through hole H of the dash panel P protrudes toward the engine room X side, and the soft silencer 3 is attached to the side of the passenger compartment opposite to the dash panel P and the passenger compartment of the soft silencer 3 A hard silencer 4 is attached to the side. The hard silencer 4 protrudes inward from the through hole H of the dash panel P, but does not protrude to a position that obstructs the insertion of the small diameter cylindrical portion 11 through which the wire harness is inserted.

  The grommet 1 includes a grommet main body 10 made of rubber or an elastomer, and a resin inner 20 that is fitted into the grommet main body 10.

  The grommet body 10 has a small-diameter cylindrical portion 11 through which the wire harness is closely inserted and a resin inner fitting engagement portion 12 protruding from the outer periphery of the small-diameter cylindrical portion 11 in the outer diameter direction. The resin inner fitting engagement portion 12 includes a radial protruding portion 12a protruding from the outer periphery of the small diameter cylindrical portion 11, an outer peripheral wall 12b continuous to the outer peripheral end of the radial protruding portion 12a, and an outer peripheral wall 12b. It consists of a step-like folded portion 12c that folds the tip inward to form a hollow portion that engages and locks the locking collar portion of the resin inner 20. A burring tip seal portion 13 composed of the tip end surface of the stepped folded portion 12c and a seal lip portion 15 projecting from the outer surface of the stepped folded portion 12c and contacting the dash panel P are provided.

  The resin inner 20 has a cylindrical shape that is assembled by penetrating the small-diameter cylindrical portion 11 of the grommet main body 10, and the resin inner inner fitting locking portion 12 is inserted from the base end of the cylindrical portion 21 that is inserted along the inner peripheral surface of the burring Hb. A locking collar portion 22 having an L-shaped cross section that is inserted into and locked to protrudes. The cylinder part 21 is provided with an extension cylinder part 24 provided at the tip with a seal part 23 to be brought into contact with the hard silencer 4. The protruding amount of the extension cylinder 24 is such that the grommet 1 is locked to the through hole H, passes through the through hole H and the through hole 3a of the soft silencer 3, and seals at the tip of the through hole 4a of the hard silencer 4 It is set as the dimension which the part 23 presses.

Next, the attachment process to the through-hole H of the grommet 1 attached to the wire harness W / H will be described.
The grommet 1 has a resin inner 20 assembled in advance on the grommet body 10. That is, the locking collar portion 22 of the resin inner 20 is inserted and locked to the resin inner fitting locking portion 12 of the grommet body 10.

  The small diameter cylindrical portion 11 provided on the grommet main body 10 of the grommet 1 is expanded with a jig so as to penetrate the wire harness W / H, and both ends in the length direction of the small diameter cylindrical portion 11 are wound with the wire harness W / H and an adhesive tape. It is stuck.

  In this way, the wire harness W / H with the grommet 1 is inserted and locked into the through hole H of the dodge panel P from the engine room X side to the vehicle compartment Y side. Specifically, the distal end seal portion 23 of the extension cylinder portion 24 of the resin inner 20 is inserted in the direction of the arrow in FIG.

  The extended cylindrical portion 24 of the resin inner 20 is inserted into the through hole H provided in the dash panel P while the inner peripheral surface of the burring Hb is in contact with it. Since the through hole 3a of the soft silencer 3 affixed to the side surface of the through hole H has a larger diameter than the through hole H, the extension cylinder portion 24 is inserted through the through hole 3a without difficulty. A stage in which the locking collar portion 22 of the resin inner 20 is locked to the tip of the burring Hb, the burring tip seal portion 13 of the grommet body 10 contacts the tip of the burring Hb, and the seal lip portion 15 contacts the dash panel P. Thus, the seal part 23 at the tip of the extension cylinder part 24 is pressed against the periphery of the through hole 4 a of the hard silencer 4.

  As described above, when the seal lips 13 and 15 are brought into contact with the burring Hb and the dash panel P, the seal portion 23 at the tip of the extension cylinder portion 24 of the resin inner 20 abuts against the hard silencer 4. Sound leakage through the through hole 3a of the silencer 3 can be reduced or prevented.

2 and 3 show a second embodiment.
In the second embodiment, similarly to the first embodiment, the soft silencer 3 surrounding the through hole H of the dash panel P is attached, and the through hole 3a of the soft silencer 3 has a larger diameter than the through hole H. The through hole 4a of the hard silencer 4 attached to the side surface of the soft silencer 3 is assumed to have an inner diameter equivalent to the through hole H. That is, the hard silencer 4 is not protruded inward from the through hole H.

In the grommet 1 of the second embodiment, an extension cylinder part 30 protrudes on the inner peripheral side of the radial protrusion 12 a of the grommet body 10, and extends along the inner peripheral side of the extension cylinder part 24 of the resin inner 20.
The projecting end of the extension cylinder part 30 is bent outward with the projecting end of the extension cylinder part 24 of the resin inner as a fulcrum 30p to provide an umbrella part 32, and the inner peripheral surface of the hard silencer 4 at the tip of the umbrella part 32 There is provided a seal portion 33 to be brought into contact with.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  In the second embodiment, since the through hole 4a of the hard silencer 4 that presses the seal part of the grommet 1 is enlarged, the extension cylinder part 30 is provided in the grommet body instead of the resin inner, and the tip thereof is umbrella-shaped outward. The seal portion 33 is provided by bending, and the seal portion 33 is pressed against the hard silencer 4. And since the grommet body 10 is made of rubber, it is easy to bend and fall down. Therefore, the extension cylinder part 30 of the grommet body is externally fitted with the extension cylinder part 24 of the resin inner 20 so that the protruding extension cylinder part 30 does not fall down. It does not bite between the burring Hb and the grommet 1. In addition, by supporting the bending position of the distal end of the extension cylinder portion 30 and, in other words, determining the opening position of the umbrella, the sealing portion 33 at the distal end is reliably pressed against the hard silencer 4.

  Further, wire rod penetrating tube portions 45 </ b> A and 45 </ b> B project from the inner peripheral side of the radially projecting portion 12 a of the grommet body 10. The tips of the wire penetrating tube portions 45A and 45B are closed, and when the washer hose or the opener cable is inserted, the closed end is cut and penetrated. Since other configurations and operations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

1 Grommet 3 Soft silencer 3a Through hole 4 Hard silencer
4a Through hole 10 Grommet body 20 Resin inner 24 Extension cylinder part 23 Seal part P Dash panel H Through hole Hb Burring W / H Wire harness

Claims (3)

A soft silencer surrounding the through hole is attached to the vehicle body side surface of the vehicle body provided with a through hole for inserting a wire harness with a burring projecting from the periphery, and the burring is attached to the side surface of the soft silencer in the vehicle compartment. A hard silencer with the tip protruding inward from the inner peripheral surface of the
A two-piece grommet consisting of a grommet main body made of rubber or elastomer and a resin inner fitted inside the grommet main body is externally mounted on the wire harness inserted through the through hole of the vehicle body,
The grommet body protrudes from the outer periphery of a small-diameter cylindrical portion through which the wire harness is closely inserted and protrudes in the outer diameter direction, and a burring and a vehicle body abut on the outer surface of the resin inner fit locking portion. While the sealing lip for
The resin inner has a cylindrical shape that is inserted through the small-diameter cylindrical portion of the grommet body, and is inserted into the resin inner fitting engagement portion from the base end of the cylindrical portion that is inserted along the inner peripheral surface of the burring. The sound insulation of the grommet mounting portion, characterized in that a locking collar portion having an L-shaped cross section that protrudes and an extended cylinder portion provided at the tip with a seal portion that contacts the hard silencer is provided on the cylinder portion. Construction. A soft silencer surrounding the through hole is attached to the vehicle body side surface of the vehicle body provided with a through hole for inserting a wire harness with a burring projecting from the periphery, and the burring is attached to the side surface of the soft silencer in the vehicle compartment. A hard silencer with an inner diameter equivalent to the inner diameter of
The wire harness that is inserted into the through-hole is covered with a grommet body made of rubber or elastomer, and a two-piece grommet made of a resin inner fitted inside the grommet body,
The grommet body has a resin inner fitting engagement portion protruding in an outer diameter direction from an outer periphery of a small diameter cylinder portion through which the wire harness is closely attached, and the small diameter cylinder is disposed on the inner circumference side of the resin inner fitting engagement portion. While providing an extension cylinder part so as to surround the part, provided with a seal part bent from the tip of the extension cylinder part to the outer peripheral side and brought into contact with the hard silencer,
The resin inner has a cylindrical shape that is inserted through the small-diameter cylindrical portion of the grommet body, and is inserted into the resin inner fitting engagement portion from the base end of the cylindrical portion that is inserted along the inner peripheral surface of the burring. A locking collar portion having a L-shaped cross section that protrudes is projected, and the cylindrical portion is an extended cylindrical portion that presses against a bent portion toward the outer peripheral side along the outer peripheral surface of the extended cylindrical portion of the grommet body,
A sound insulation structure for a grommet mounting portion in which a distal end position of the extended cylindrical portion of the resin inner is a position surrounded by the hard silencer.   The resin inner fitting engagement portion of the grommet body includes a radial protrusion projecting from the outer periphery of the small diameter cylindrical portion, an outer peripheral wall continuous to the outer peripheral end of the radial protrusion, and a tip of the outer peripheral wall. A stepped folded portion that forms a hollow portion that is folded inward to engage and lock the locking collar portion of the resin inner, a burring seal lip that includes a tip end surface of the stepped folded portion, and the stepped folded portion The sound insulation structure for a grommet mounting portion according to claim 1 or 2, wherein the structure is provided with a seal lip that protrudes from the outer surface of the portion and contacts the outer surface of the vehicle body.

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