JP2012005261A - Grommet for wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve water stop performance in a grommet of two body objects, in which a resin inner is assembled in a grommet body.SOLUTION: The grommet includes the grommet body made of rubber or elastomer and the resin inner of a resin molding assembled to the grommet body. The grommet body includes: a small diameter cylinder to which a wire group of a wire harness closely adheres and are inserted; a large diameter cylinder projecting from an outer peripheral face of the small diameter cylinder; a circular groove for inserting a bar ring thereto, which is protrusively arranged at a tip of the large diameter cylinder; and a pair of seal lips bent toward an inner part of the groove from tips of both side walls of the circular groove. The pair of seal lips abut on both side faces of the bar ring and spaces are formed between the bar ring and both the side walls. The resin inner includes a cylinder which is internally engaged with the large diameter cylinder of the grommet body and an elastic lock piece in a folding shape in a protrusive manner from the tip of the cylinder to the outer peripheral face. A lock claw protrusively arranged on the outer face of the elastic lock piece is locked to a peripheral edge of a through hole.

Description

  TECHNICAL FIELD The present invention relates to a grommet for a wire harness, and more specifically, in a grommet that is externally mounted on a wire harness routed in a vehicle and attached to a through hole of a vehicle body to achieve waterproof, dustproof, and sound insulation, particularly from an elastic body such as rubber. It is intended to improve the waterproof performance of a two-piece grommet in which an inner made of a resin molded product is combined with a grommet body.

The wire harness routed from the engine room of the automobile through the through hole in the vehicle body panel to the passenger compartment is fitted with a grommet and installed in the through hole to provide waterproof, dustproof, and sound insulation from the engine compartment to the passenger compartment. ing.
As this type of grommet, a single-piece grommet made of only an elastic body such as rubber or elastomer and a two-piece grommet in which a resin inner of a resin molded product is combined with a grommet body made of an elastic body are widely used.

  The present applicant provides the two-piece grommet in JP-A-10-257647, JP-A-2004-265788, and the like. Further, as two-piece grommets used when the through hole of the vehicle body is a burring hole, grommets shown in FIGS. 4A, 4B, and 4C are widely used. The grommet 100 includes a grommet main body 101 having a large-diameter cylindrical portion 101b at the tip of a small-diameter cylindrical portion 101a through which the wire harness is closely inserted, and a resin inner 105 that is fitted into the large-diameter cylindrical portion 101b of the grommet main body 101. It consists of. The grommet body 101 is provided with a folded portion 101c from the distal end of the large-diameter cylindrical portion 101b, the axially protruding portion on the distal end side of the folded portion 101c is used as a seal portion 101d, and the seal rib 101d has a semicircular seal rib. 101e is projected. As shown in FIG. 4C, the seal portion 101d is brought into contact with the inner peripheral surface of the burring 201 protruding from the peripheral edge of the through hole 200 of the vehicle body B. On the other hand, the resin inner 105 has an elastic lock piece 105b protruding from the tip of the cylindrical portion 105a to the outer peripheral side. A lock claw 105c is provided on the elastic lock piece 105b, and a burring contact portion 105e is further extended from the position of the front end locking surface 105d of the lock claw 105c.

  The grommet 100 is attached to the through hole 200 with a burring of the vehicle body B as shown in FIG. With the grommet attached, the outer peripheral surface of the seal portion 101d of the grommet body 101 and the inner peripheral surface of the burring 201 are wrapped, and the burring contact portion 105e of the resin inner 105 is wrapped with the burring 201. Surface pressure is generated to ensure waterproof performance.

  However, as shown in FIG. 5, when the grommet 100 is inserted, the tip of the seal portion 101d of the grommet body 101 may be caught by the tip edge 201a of the burring 201, and the seal portion 101d may be turned over. In that case, there is a problem that the sealing rib 101e of the sealing portion 101d of the grommet body does not contact the burring 201 and the water stopping performance is deteriorated.

JP-A-10-257647, JP 2004-265788 A

  The present invention is to solve the above problem, and in a two-piece grommet that is fixed to the periphery of the through hole with a resin inner lock claw, the seal part of the grommet body at the edge of the burring protruding from the periphery of the through hole It is set as the structure which does not get caught by catching, and, therefore, makes the subject to improve the water stop performance of a grommet.

In order to solve the above-mentioned problem, the present invention is a grommet that is mounted on a through-hole with a burring of a vehicle body that is externally mounted on a wire harness routed in a vehicle,
It consists of a grommet body made of rubber or elastomer, and a resin inner of a resin molded product assembled to the grommet body,
The grommet body includes a small-diameter cylindrical portion that allows the electric wire group of the wire harness to be closely inserted, a large-diameter cylindrical portion that protrudes from the outer peripheral surface of the small-diameter cylindrical portion, and a burring that protrudes from the tip of the large-diameter cylindrical portion An annular groove for insertion, and a pair of seal lips bent toward the inside of the groove from the tips of both side walls of the annular groove, and the pair of seal lips are brought into contact with both side surfaces of the burring and the burring While providing a space between each side wall,
The resin inner includes a cylindrical portion that fits inside the large-diameter cylindrical portion of the grommet body, and an elastic lock piece that protrudes from the tip of the cylindrical portion toward the outer peripheral surface, and protrudes from the outer surface of the elastic lock piece. A grommet for a wire harness is provided in which the lock claw provided is configured to be engaged with the periphery of the through hole.

  As described above, an annular groove for inserting a burring is provided in the grommet main body, and a seal lip provided at the tip of both side walls of the annular groove is bent toward the inside of the groove to make it easy to fall into the inside of the groove. In order to contact the inner and outer surfaces of the burring. Therefore, when the burring is inserted into the annular groove, even if the tip edge of the burring is caught by the seal lip, it does not fall in the direction of detaching from the burring, just by falling down in the groove insertion direction where the seal lip is bent, The seal lip can be kept in contact with the burring. Thus, the seal lip can be prevented from curling, and the sealing lip is brought into contact with the inner and outer peripheral surfaces of the burring for reliable sealing, so that the water stop performance can be improved.

  As described above, the seal lip provided on the grommet body is bent at the tip of both side walls of the annular groove into which the burring is inserted into the groove, so that even if the tip edge of the burring contacts the seal lip, the groove Since it does not fall into the interior and leave the burring, the contact area with the burring increases, so that the water stop performance can be prevented from being lowered and further the water stop performance can be improved.

It is sectional drawing of the grommet of this invention. It is a principal part enlarged view of the said grommet. It is drawing which shows the process in which the burring which protruded from the through hole is inserted in the annular groove of a grommet main body. (A)-(C) are drawings which show a prior art example. It is drawing which shows the problem of a prior art example.

Hereinafter, an embodiment of a grommet for a wire harness of the present invention will be described with reference to FIGS.
A grommet 1 according to the present invention is a grommet that is mounted on a through hole 51 with a burring that is provided in a dash panel 50 of a vehicle body, which is externally mounted on a wire harness W / H routed from an engine room of a vehicle to a vehicle compartment. .

  The grommet 1 is a two-piece grommet comprising a grommet body 2 made of rubber or elastomer and a resin inner 10 of a resin molded product assembled to the grommet body 2.

  The grommet body 2 includes a small-diameter cylindrical portion 3 through which a wire group of the wire harness W / H is closely inserted and a large-diameter cylindrical portion 4 protruding from an outer peripheral surface at an intermediate position in the length direction of the small-diameter cylindrical portion 3. A pair of inner and outer seal lips 6 provided at the tips of both side walls comprising an annular groove 5 for inserting a burring provided at the tip of the large-diameter cylindrical portion 4, and an outer peripheral wall 5a and an inner peripheral wall 5b of the annular groove 5. , 7 are provided.

  The annular groove 5 for inserting the burring is formed by projecting an L-shaped refracting wall 4b in an annular shape from an inner peripheral surface at an intermediate position of the outer peripheral wall 4a of the large-diameter cylindrical portion 4, thereby forming an annular groove 5 having a U-shaped cross section. Provided. An outer peripheral wall 5a formed from the tip of the outer peripheral wall 4a protrudes from an inner peripheral wall 5b formed from the refracting wall 4b. A space 5 c sandwiched between the outer peripheral wall 5 a and the inner peripheral wall 5 b becomes a burring insertion space, and the radial dimension of the space 5 c is larger than the thickness of the burring 52. Therefore, spaces 5c1 and 5c2 are secured between the burring 52, the outer peripheral wall 5a, and the inner peripheral wall 5b in a state where the burring 52 is inserted into the space 5c.

The outer peripheral seal lip 6 protruding from the tip of the outer peripheral wall 5 a of the annular groove 5 is bent so as to incline downward toward the inner space 5 c of the annular groove 5. An inner peripheral seal lip 7 protruding from the tip of the inner peripheral wall 5 b is bent so as to incline toward the inner space 5 c of the annular groove 5. And since the outer peripheral wall 5a protrudes from the inner peripheral wall 5b, the outer peripheral seal lip 6 and the inner peripheral seal lip 7 are in a position shifted in the axial direction so that they do not come into contact with each other and interfere with each other. , And can be deformed in the spaces 5c1 and 5c2, respectively.
As a result, as shown in FIG. 3, the seal lips 6 and 7 contacting the burring 52 inserted into the annular groove 5 fall into the groove, and the seal lip 7 contacts the inner peripheral surface of the protruding end of the burring 52. The seal lip 6 is in contact with the outer peripheral surface on the base side.

  Further, a resin inner fitting portion 8 is provided in a portion surrounded by an end surface wall 4c of the large diameter cylindrical portion 4 continuing to the small diameter cylindrical portion 3 of the grommet body 2 and a refractive wall 4b protruding from the outer peripheral wall 4a. Yes.

The resin inner 10 includes an annular mounting plate 11 that is set to overlap the end surface wall 4 c of the large-diameter cylindrical portion 4 of the grommet body 2, and a fitting protrusion 11 a is provided on the outer peripheral edge of the annular mounting plate 11. The fitting protrusion 11a is provided in the outer peripheral edge part through the hole 18 in the location which provides the elastic lock piece 14 mentioned later. The fitting protrusion 11 a is fitted into the resin inner fitting portion 8 of the grommet body 2, and the resin inner 10 is assembled to the grommet body 2.
The inner diameter of the central hole 11 b of the annular mounting plate portion 11 is larger than the small diameter cylindrical portion 3 of the grommet body 2, and the small diameter cylindrical portion 3 is passed through the resin inner 10.

Further, a cylindrical portion 12 is projected from one surface of the annular mounting plate portion 11 and protruded from the protruding end of the large diameter cylindrical portion 4 of the grommet body 2.
An elastic lock piece 14 protrudes from the tip of the cylindrical portion 12 in a folded manner toward the outer peripheral surface with an interval of 90 degrees in the circumferential direction. A triangular lock claw 15 projects from the outer surface of the intermediate portion in the protruding direction of the elastic lock piece 14, and a burring contact portion 16 extends from the lock claw 15.

The locking surface 15 a of the lock claw 15 provided on the elastic lock piece 14 is positioned outside the tip opening of the annular groove 5 of the grommet body 2.
With this shape, when the burring 52 gets over the lock claw 15, the burring 52 is inserted into the annular groove 5 of the grommet body 2, and the seal lip 6 is formed on the outer peripheral surface of the burring 52 inside the annular groove 5. The seal lip 7 is in contact with the inner peripheral surface, and the locking surface 15 a of the lock claw 15 is locked to the peripheral edge of the through hole 51. Further, the burring contact portion 16 protruding from the lock claw 15 of the elastic lock piece 14 is brought into contact with the inner peripheral surface of the burring 52.

  Next, the grommet 1 is attached to the wire harness W / H, the wire harness W / H is routed to the automobile and passed through the through hole 51 with the burring 52 of the dash panel 50, and the grommet 1 is inserted into the through hole 51. The effect | action to mount | wear is demonstrated.

  First, the grommet 1 is completed by assembling the resin inner 10 to the grommet body 2. That is, the annular mounting plate portion 11 of the resin inner 10 is overlaid on the end surface wall 4 c of the large diameter cylindrical portion 4 of the grommet body 2 and the fitting protrusion 11 a is fitted into the resin inner fitting portion 8 of the grommet body 2.

  The wire harness W / H is penetrated while the small diameter cylindrical portion 3 of the grommet 1 assembled as described above is expanded with an expansion jig (not shown). After the penetration, the adhesive tape T is wound around both ends of the small diameter cylindrical portion 3 in the length direction and the wire harness W / H, and the grommet 1 is fixed to the wire harness W / H.

  The wire harness W / H to which the grommet 1 is attached as described above is routed in the automobile. As shown in FIG. 1, a burring 52 projects toward the engine room (X) from the periphery of a through hole 51 formed in the dash panel 50. The wire harness W / H is inserted through the through hole 51 from the engine room (X) side toward the vehicle compartment (Y).

  When the grommet 1 reaches the protruding end of the burring 52 protruding from the through hole 51, the annular burring 52 comes into contact with the outer peripheral surface of the elastic lock piece 14 and reaches the protruding position of the lock claw 15. Since the burring 52 gets over the lock claw 15, each elastic lock piece 14 bends inward. Thereby, the burring 52 gets over the lock claw 15 and is inserted into the annular groove 5 of the grommet body 2 while being in contact with the burring contact portion 16 of the elastic lock piece 14.

  As shown in FIG. 3, the protruding end of the seal lip 6 of the grommet body 2 first contacts the outer peripheral surface of the burring 52 inserted into the annular groove 5, and then the seal of the grommet main body 2 contacts the inner peripheral surface of the burring 52. The protruding end of the lip 7 contacts. In response to the insertion of the burring 52, the sealing lips 6 and 7 bent toward the inside of the annular groove 5 are deformed so as to fall into the inside of the annular groove 5 while being in contact with the burring 52. When the tip 52a of the burring 52 comes into contact with the bottom wall of the annular groove 5, the seal lip 6 is in pressure contact with the outer peripheral surface of the burring 52 and the seal lip 7 is in pressure contact with the inner peripheral surface.

  Further, when the burring 52 is inserted into the annular groove 5, even if the leading edge of the burring 52 comes into contact with the seal lip 6 or 7, the burring 52 simply falls down into the annular groove 5 by insertion of the burring 52. It does not droop further away and does not degrade the water stop performance.

  Further, since the seal lip 6 is pressed against the outer peripheral surface of the burring 52 and the seal lip 7 is pressed against the inner peripheral surface at a position separated in the axial direction, the burring 52 can be held so as not to be displaced. Moreover, since the seal lips 6 and 7 are bent in the insertion direction of the burring 52, the insertion force when inserting the grommet can be reduced.

  The grommet of the present invention is not limited to the above embodiment, and a resin inner attachment portion may be provided at one end in the length direction of the small diameter cylindrical portion of the grommet main body, and the resin inner may be attached to the tip of the small diameter cylindrical portion of the grommet main body. .

DESCRIPTION OF SYMBOLS 1 Grommet 2 Grommet main body 3 Small diameter cylindrical part 4 Large diameter cylindrical part 5 Annular groove for inserting burring 5a Outer peripheral wall 5b Inner peripheral wall 5c Space 6, 7 Seal lip 10 Resin inner 11 Annular mounting plate 12 Cylindrical part 14 Elastic locking piece 15 Lock claw 16 Burring contact 50 Dash panel 51 Through hole 52 Burring W / H Wire harness

Claims (1)

A grommet that is attached to a through-hole with a burring of a vehicle body that is externally mounted on a wire harness routed in a vehicle,
It consists of a grommet body made of rubber or elastomer, and a resin inner of a resin molded product assembled to the grommet body,
The grommet body includes a small-diameter cylindrical portion that allows the electric wire group of the wire harness to be closely inserted, a large-diameter cylindrical portion that protrudes from the outer peripheral surface of the small-diameter cylindrical portion, and a burring that protrudes from the tip of the large-diameter cylindrical portion An annular groove for insertion, and a pair of seal lips bent toward the inside of the groove from the tips of both side walls of the annular groove, and the pair of seal lips are brought into contact with both side surfaces of the burring and the burring While providing a space between each side wall,
The resin inner includes a cylindrical portion that fits inside the large-diameter cylindrical portion of the grommet body, and an elastic lock piece that protrudes from the tip of the cylindrical portion toward the outer peripheral surface, and protrudes from the outer surface of the elastic lock piece. A grommet for a wire harness, characterized in that a lock claw provided is locked to the periphery of the through hole.

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