JP2019062738A - Grommet - Google Patents

Abstract

To provide a grommet with improved waterproofness.SOLUTION: The grommet coated over a corrugated tube 5 includes: a tubular corrugated end portion 9 which can be connected to an outer circumferential side of the corrugated tube 5 in a sealed state; and a plurality of sealing lips 20-1 to 20-4 provided so as to be in close contact with valley portions of the corrugated tube 5 at an inner circumferential surface of the corrugated end portion 9. At a tip end portion of an outer peripheral surface of the corrugated end portion 9, a tapered relief surface 17 is formed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a grommet.

   Conventionally, in a hybrid car or an electric car, a wire harness wired between a battery and an inverter or between an inverter and a motor is often inserted through a metal pipe and wired. The metal pipe is disposed along the longitudinal direction under the floor of the vehicle body. This metal pipe has the function of shielding the electric wire and the function of protection from stepping stones and the like. After the metal pipe is introduced into the engine room, it may be connected to the inverter side via a metal braid. The metal braided portion is a mesh of metal wire braided, is attached to the end of a metal pipe, and is connected by caulking using a caulking ring. Furthermore, a waterproof grommet made of a rubber material may be fitted to a connection portion between the metal pipe and the metal braided portion.

JP-A-2006-311699: FIG.

  By the way, the situation where high pressure cleaning water is sprayed also on the part where grommet is installed is assumed. However, the above-described conventional structure can not sufficiently cope with such a situation, and there is a concern that the seal between the corrugated tube and the grommet and between the pipe and the grommet may deteriorate with time.

  This invention is completed based on the above situations, Comprising: It aims at providing the grommet which can improve waterproofness.

The grommet according to the present invention is a grommet to be attached to at least one cylindrical member for accommodating an electric wire therein, and the first end which can be connected in a sealing state to the outer peripheral side of the at least one cylindrical member. A second end which is provided on the side opposite to the first end and which can be connected in a sealed state on the outer peripheral side of the at least one tubular member; and the outer periphery of the second end The tip of the surface is characterized in that a tapered relief surface is formed.
A wire harness assembly according to the present invention includes the above-described grommet and a wire housed inside the at least one tubular member, and the at least one tubular member includes a peak and a valley. Are alternately repeated to include a flexible corrugated tube having a corrugated shape.
Furthermore, another wire harness assembly according to the present invention includes the above-described grommet and a wire housed inside the at least one tubular member, the at least one tubular member including a pipe and a mountain portion. And a valley portion are alternately repeated, and the corrugated tube having a flexible bellows shape is formed, and the first end of the grommet is connected to the pipe, and the second of the grommet is formed. Is characterized in that the end of the is connected to the corrugated tube.

  The effects and advantages of the present invention are as follows. For example, assuming that high-pressure washing water is poured on the end face of the end of the grommet, if the end face is formed upright, the pressure of the high-pressure washing water is likely to be received. For this reason, there is a possibility that the end face portion may go up and the washing water may enter the inside of the grommet. In that respect, according to the present invention, high pressure cleaning water can be released along the taper of the relief surface, so that the rolling up of the end face portion of the end of the grommet is effectively alleviated, thereby enhancing the sealing function of the grommet. Can.

An exploded perspective view showing the periphery of the grommet mounting site Grommet cross section Cross section of the grommet at the attachment site Cross section showing a modification of the grommet

A preferred embodiment of the present invention will be described.
(1) A grommet is provided with a mounting groove for positioning a tightening band formed on the outer peripheral surface of the second end, and a plurality of grommets formed over the entire inner peripheral surface of the second end. The plurality of sealing lips may include at least a first sealing lip formed at a position corresponding to the mounting groove. According to such a configuration, the sealing function at the second end can be improved.
(2) The grommet may be configured such that the mounting groove and the escape surface are separated from each other.

(3) The grommet may have a configuration in which the plurality of sealing lips have at least a second sealing lip formed at a position corresponding to the opening edge of the second end. According to such a configuration, the sealing function at the second end can be further improved.
(4) In the wire harness assembly according to the present invention, the end of the pipe is fixed to the metal braided portion by a caulking ring, and the grommet is between the first end and the second end. It may have a base, and the base may have a receptacle which is formed by bulging a part thereof radially outward, and the receptacle may receive the caulking part of the caulking ring.

Example 1
Next, a first embodiment of the grommet according to the present invention will be described with reference to the drawings.
In this embodiment, in the hybrid vehicle, the grommet G1 provided in the wiring path of the wire harness WH for connecting between the battery mounted in the rear vehicle compartment and the inverter mounted in the engine room will be described. .

  The wire harness WH is made of a plurality of electric wires as shown in FIG. A portion of the wire harness WH is inserted into the conductive metal shield pipe 1. The shield pipe 1 is made of aluminum or an aluminum alloy, and is disposed under the floor of the vehicle body. Further, as shown in FIG. 3, the end of the shield pipe 1 is expanded in a trumpet shape to form an expanded portion 2.

  One end of the metal braided portion 3 is connected to one end of the shield pipe 1. The metal braided portion 3 is formed by, for example, braiding a copper-based metal wire, the surface of which is tin-plated, into a mesh shape and a long cylindrical shape. An electric wire drawn from the shield pipe 1 is inserted into the metal braid portion 3. The metal braided portion 3 is attached to the outer peripheral surface of the shield pipe 1 and is caulked and fixed by a caulking ring 4.

  The caulking ring 4 is known. In the natural state, the caulking ring 4 is configured such that a part of the ring-shaped main body 4A bypasses radially outward and protrudes as a caulking part 4B. When the caulking ring 4 is tightened, the main body portion 4A can be shifted to a diameter-reduced state by pinching the root portion of the caulking portion 4B and approaching, whereby the metal braid portion 3 is caulked and fixed to the shield pipe 1 .

  The metal braided portion 3 is inserted into the corrugated tube 5 except for a partial range on the side to be connected to the shield pipe 1, and the end portion of the metal braided portion 3 extends to a connecting portion with an inverter not shown. . Thus, the wire harness WH is shielded over the length range in which the shield pipe 1 and the metal braid portion 3 are provided.

  The corrugated tube 5 is integrally formed of a synthetic resin material into a long cylindrical shape. The circumferential surface of the corrugated tube 5 is formed in a bellows shape in which the mountain portion 5A and the valley portion 5B are repeated, and has a good flexibility. A grommet G1 accommodating the metal braided portion 3 exposed from the corrugated tube 5 is mounted so as to be bridged between the corrugated tube 5 and the shield pipe 1.

  The grommet G1 is integrally formed of a rubber material (for example, EPDM). A central portion in the axial direction of the grommet G1 is a base portion 6, and a part of the grommet G1 is formed with a housing portion 7 which expands radially outward and circumferentially over a predetermined length range. The internal space of the accommodation portion 7 is a space for accommodating the caulking portion 4B of the caulking ring 4.

  The pipe side end 8 is formed on one end side of the grommet G1, and the corrugated side end 9 is formed on the other end side. The pipe side end 8 and the corrugated side end 9 are both formed in a cylindrical shape, and the pipe side end 8 is capable of inserting the end of the shield pipe 1 inward, and the side of the corrugated tube 5 is the corrugated tube 5 It can be inserted to the outer peripheral side.

  At the position near the end of the outer peripheral surface of the pipe end 8, two ridges 10 are formed over the entire circumference at intervals. A mounting groove 11 for positioning the clamping band 12 is formed between the two flanges 10. The groove width of the mounting groove 11 is set to be slightly wider than the width of the tightening band 12.

  The description will be simplified since the clamping band 12 is known. The fastening band 12 is formed integrally with a synthetic resin material and formed in a band shape at one end of the fastening band 12 with a lock 13 which can be inserted at the other end, and at the other end in the length direction A large number of serrated locking edges (not shown) are formed along. Further, a locking claw (not shown) is formed in the lock portion 13 so as to be flexible, and the other end side passed through the lock portion 13 is pulled to be selectively locked with each locking edge. As a result, the pipe end 8 can be tied and fastened to the shield pipe 1.

  On the other hand, as shown in FIG. 2, a plurality of (four in the drawing) pipe side sealing lips are provided on the inner peripheral surface of the pipe side end portion 8. Each of the pipe side sealing lips 14-1 to 14-4 is integrally formed along the entire circumference, and can be in close contact with the outer peripheral surface of the shield pipe 1 for sealing. In the present embodiment, each of the pipe side sealing lips 14-1 to 14-4 is provided at the opening edge of the pipe side end 8 (first lip 14-1), and the axial center portion of the mounting groove 11 The second lip 14-2 provided immediately below the first lip, the second lip 14-2), the second lip 14-2), the second lip 14-2), the second lip 14-2); And the third lip 14-3 (fourth lip 14-4). Thus, in the present embodiment, only the second lip 14-2 is located within the width area (area indicated by W in FIG. 2) to be tightened by the tightening band 12, and the others are offset from the width area. Are arranged to function as an auxiliary lip. Further, the protruding heights of the pipe side sealing lips 14-1 to 14-4 are all uniform.

  Further, at the end of the outer peripheral surface of the pipe side end portion 8, a tapered pipe side relief surface 15 is formed. That is, on the end face of the pipe side end portion 8, an annular rising surface 18 is formed which is substantially perpendicular to the axis. And, the above-mentioned pipe side relief surface 15 is formed over the entire circumference from the outer peripheral edge of the rising surface 18 to the top of the flange 10 located on the tip side.

  On the other hand, a mounting groove 16 for positioning the clamping band 12 is also formed in the center in the axial direction on the outer peripheral surface of the corrugated end 9 along the entire circumference. A tapered corrugated corrugated relief surface 17 is also formed at the end of the outer peripheral surface of the corrugated end 9. That is, the end face of the corrugated end portion 9 is formed with an annular rising surface 19 which is cut substantially at right angles to the axis. The above-mentioned corrugated side relief surface 17 is formed from the outer peripheral edge of the rising surface 19 over the entire circumference at a predetermined locking angle. In the present embodiment, the inclination angle α1 of the pipe side relief surface 15 is set smaller than the inclination angle α2 of the corrugated side relief surface 17 (α1 <α2).

  On the inner peripheral surface of the corrugated end portion 9, as shown in FIG. 2, a plurality of corrugated sealing lip portions 20-1 to 20-4 are provided. These are provided at a uniform pitch in the order from the one provided at the opening edge of the corrugated end 9 to the far side. This pitch is the same as the pitch of the ridges 5A and the valleys 5B of the corrugated tube 5. The protruding height of each corrugated side sealing lip 20-1 to 20-4 is set higher than each pipe side sealing lip 14-1 to 14-4, and the end of the corrugated tube 5 is the corrugated side end. In the state of being inserted into the inside 9, the protruding end of each corrugated seal lip is in close contact with the bottom surface of the valley portion 5 B of the corrugated tube 5 so that the seal is taken.

  In addition, with regard to the two strips (20-2, 20-3) positioned at the center among the corrugated side sealing lips 20-1 to 20-4, a tightening band 12 for tightening the corrugated side end portion 9 in the mounting groove 16 However, both the corrugate-side sealing lip 20-1 provided at the opening edge and the corrugate-side sealing lip 20-4 provided at the deepest portion It is located outside the width area W and functions as an auxiliary lip.

  Furthermore, one peak 5A of the corrugated tube 5 is positioned in the width area W of the tightening band 12 at the corrugated end 9 and in FIG. 3 the peak 5A is located almost directly under the tightening band 12 The ridge portion 5A abuts on a portion of the inner peripheral surface of the corrugated end portion 9 between the corrugated side sealing lips 20-2 and 20-3 located in the width area W. . Thus, at the same portion, there is a restriction that prevents excessive crushing of the corrugated lip for sealing 20-1 to 20-4 contained in the width area W when the tightening band 12 is likely to be excessively tightened. It can function as the unit 21.

  In the first embodiment, for example, the grommet G1 is attached as follows. First, a part of the metal braided portion 3 inserted into the inside of the corrugated tube 5 is drawn to the outside, and is put on the outer peripheral surface of the end of the shield pipe 1. Then, move the caulking ring 4 fitted in advance to the shield pipe 1 side to this covered part, and caulking the caulking part 4B of the caulking ring 4 in this state, the metal braided part 3 becomes It is caulked and fixed to the shield pipe 1.

  Thereafter, the grommet G1 previously fitted to the side of the shield pipe 1 or the corrugated tube 5 is moved toward the crimped portion of the metal braid portion 3. And, while accommodating the caulking portion 4B of the caulking ring 4 in the housing portion 7 of the grommet G1, the corrugated end 9 is on the outer peripheral side of the end of the corrugated tube 5 and the pipe end 8 is outer peripheral of the shield pipe 1 Cover each side. Thus, the grommet G1 is mounted so as to straddle the shield pipe 1 and the corrugated tube 5.

  At this time, at the pipe side end 8, the pipe side sealing lips 14-1 to 14-4 are in close contact with the outer peripheral surface of the shield pipe 1, and at the corrugated side end 9 each corrugated side sealing lip 20-1. To 20-4 enter the corresponding valleys 5B of the corrugated tube 5 and are in close contact with the bottom of each.

  Finally, the clamping band 12 is clamped in the mounting groove 11 of the pipe end 8 and the clamping band 12 is clamped in the mounting groove 16 at the corrugated end 9 to complete the mounting of the grommet G1.

  According to the grommet G1 attached as described above, the pipe-side sealing lip 14-1 to 14-4 and the corrugate-side sealing lip 20-1 to 20-4 make a gap with the shield pipe 1 or a corrugate Water can be prevented from entering between the tubes 5.

  By the way, the pipe side sealing lip 14-2 and the corrugated side sealing lips 20-2 and 20-3 are included in the width area W of the tightening band 12 at the pipe side end 8 and the corrugated side end 9 Or right below, so as long as the tightening band 12 is properly tightened, appropriate sealing pressure is applied to the pipe side sealing lip 14-2 and the corrugated side sealing lip 20-2, 20-3. It can be granted. In addition, even if the tightening band 12 is excessively tightened on the corrugated tube 5 side, the peak portion 5A of the corrugated tube 5 is positioned directly below the tightening band 12, and Since the contact is made, the corrugated side sealing lips 20-2 and 20-3 are not crushed excessively, and the sealing performance is secured.

  In addition, since the pipe side sealing lip 14-2 and the corrugated side sealing lips 20-2 and 20-3 included in the width area of the clamping band 12 are always subjected to clamping pressure from the clamping band 12, they deteriorate with time. It is conceivable that the sealing function is reduced. However, in the present embodiment, the pipe side sealing lips 14-1, 14-3 and 14-4 and the corrugated side sealing lip 20-1 are disposed so as to sandwich the same area W outside the width area W of the tightening band 12, Position each of 20-4. The lip outside these width regions W has a slow progress of deterioration with time, and is effective for long-term holding of the sealing property. In particular, the significance of providing such a structure at the pipe end 8 where the high pressure cleaning water is likely to be sprayed is significant.

  Furthermore, when the sealability is taken into consideration, the most severe situation is when high pressure cleaning water is sprayed to the end face of the pipe end 8 (also to the end face of the corrugated end 9). Possible). In the prior art, since the end face had a large area of the rising face which was perpendicular to the axis, the end face might be rolled up to allow entry of water. However, in the present embodiment, by providing the corrugated side relief surface 17 in addition to the pipe side relief surface 15, the area of the rising surfaces 18 and 19 becomes sufficiently smaller than before, and both pressure relief surfaces 15 , 17 and the end faces of the end portions 8 and 9 of the grommet G1 can be reliably relieved and the sealing performance can be maintained.

  Further, at the corrugated end 9, the corrugated sealing lip 20-1 to 20-4 formed at the opening edge is in the valley portion 5 </ b> B of the corrugated tube 5. It has become. Based on this point, in the present embodiment, even if the inclination angle α2 of the corrugated side escape surface 17 is set larger than the inclination angle α1 of the pipe side escape surface 15, it is difficult to cause the rolling up. Therefore, the wall thickness of the corrugated end 9 can be increased more than that of the pipe end 8 by that amount. Since the side of the corrugated tube 5 is a side on which the wiring direction of the electric wire is appropriately changed, the corrugate tube 5 is required to secure a certain thickness at the corrugated end 9 to increase rigidity. It is significant in ensuring the ability to follow the situation.

  Conventionally, at the corrugated end 9, the corrugated tube 5 is connected to the corrugated tube 5 by tape winding without using the clamping band 12. However, it has been pointed out that such tape winding has many variations in operation and poor connection reliability, but if it is tightening by the tightening band 12 as in this embodiment, use of a jig etc. The connection reliability is enhanced because a constant clamping force can be obtained relatively easily. Furthermore, in the case of tape winding, there is a concern that the tape will deteriorate with age, but in the present embodiment there is no such concern.

FIG. 4 shows a modification of the corrugated side sealing lips 20-1 to 20-4 and the pipe side sealing lips 14-1 to 14-4. In the grommet G2 shown in the figure, among the lip 20-1 to 20-4 for sealing on the corrugated side and the lip 14-1 to 14-4 for sealing on the pipe side, one located at the opening edge 14-1, 20 The projection height of -1 is higher than the others. The reason for doing this is that when the tightening band 12 is tightened, the entire opening edge of the pipe side end 8 and the corrugated side end 9 becomes expanded, and the corrugated lip 20-1 for sealing and the pipe located at the opening edge This is to cope with the possibility that the sealing function of the side sealing lip 14-1 may be degraded.
This also contributes to the improvement of the sealing performance of the grommet G2.

Other Embodiments
The present invention is not limited to the embodiments described above with reference to the drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) Although the metal braided portion 3 and the corrugated tube 5 are separately formed in the above embodiment, the metal braided portion 3 may be inserted into the corrugated tube 5 to be integrally formed.
(2) In the above embodiment, the shield pipe 1 is formed of only a metal material, but a metal cylindrical body may be inserted and formed in a resin pipe.

(3) In the above embodiment, the shield pipe 1 and the metal braid portion 3 are provided along the wiring area of the wire harness WH to secure the shield function, but the present invention is used under the condition that the shield is not required. In the case, the pipe does not necessarily have to be a conductive metal, and the metal braid 3 may be omitted.

DESCRIPTION OF SYMBOLS 1 ... Shield pipe 3 ... Metal braided part 5 ... Corrugated tube 5A ... Peak part 5B ... Valley part 8 ... Pipe side end part 9 ... Corrugated side end part 12 ... Clamping band 14-1 to 14-4 ... Lip for pipe side seal DESCRIPTION OF SYMBOLS 15 ... Pipe side relief surface 17 ... Corrugated side relief surface 20-1-20-4 ... Corrugation side seal lip 21 ... Regulation receiving part G1, G2 ... Grommet WH ... Wire harness W ... Width area

Claims (7)

A grommet which is placed over at least one tubular member which accommodates a wire therein;
A first end connectable in a sealed state to the outer peripheral side of the at least one cylindrical member, and a side opposite to the first end are provided, and the outer peripheral side of the at least one cylindrical member is sealed Having a second end connectable in the state;
A grommet characterized in that a tapered relief surface is formed at an end of an outer peripheral surface of the second end. A mounting groove for positioning a clamping band formed on an outer peripheral surface of the second end;
And a plurality of sealing lips formed over the entire circumference of the inner peripheral surface of the second end,
The grommet according to claim 1, wherein the plurality of sealing lips have at least a first sealing lip formed at a position corresponding to the mounting groove.   The grommet according to claim 2, wherein the mounting groove and the escape surface are provided apart from each other.   The plurality of sealing lips have at least a second sealing lip formed at a position corresponding to the opening edge of the second end. Grommet described. A grommet according to any one of claims 1 to 4;
And a wire housed inside the at least one tubular member,
The wire harness assembly according to claim 1, wherein the at least one tubular member includes a corrugated tube having a flexible bellows shape by alternately repeating a peak and a valley. A grommet according to any one of claims 1 to 4;
And a wire housed inside the at least one tubular member,
The at least one tubular member includes a flexible bellows-shaped corrugated tube by alternately repeating a pipe and a peak and a valley.
The first end of the grommet being connected to the pipe;
A wire harness assembly, wherein the second end of the grommet is connected to the corrugated tube. A wire harness assembly according to claim 5 or 6, wherein
A metal braid is fixed to the end of the pipe by a caulking ring,
The grommet has a base between the first end and the second end,
The base portion has a housing portion formed by bulging a part thereof radially outward,
A wire harness assembly characterized in that the accommodating portion accommodates the caulking portion of the caulking ring.

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