JP7832065B2 - Grommets and wire harnesses - Google Patents

Description

This invention relates to grommets and wire harnesses.

As a conventional grommet for use in vehicles, Patent Document 1 discloses a grommet that is attached to a through-hole formed in a vehicle body panel through which a wire harness is inserted. This type of grommet has a main body portion that fits into the through-hole and a cylindrical portion through which wiring materials such as electric wires are inserted. A fitting groove is formed on the outer circumferential surface of the main body portion to fit onto the periphery of the through-hole in the vehicle body panel. Here, a gripping portion is provided on the main body portion, and the process of fitting the periphery of the through-hole into the fitting groove is performed by gripping this gripping portion and pulling the main body portion.

Japanese Patent Publication No. 2021-016286

Incidentally, some grommets have an oval shape in their main body, which includes both straight lines and arcs. When such an oval-shaped body is used, there is a risk of a partial fit where the fitting groove in the straight section and the through-hole do not fully engage, leaving room for improvement in terms of workability.

This invention has been made in view of the above circumstances, and aims to provide a grommet and a wire harness that can ensure proper workability when fitting the oval-shaped main body into a through hole.

To achieve the above objective, the grommet according to the present invention comprises a main body portion that fits into a through hole penetrating the object to be mounted along the axial direction and has an oval shape including a straight portion and an arc portion when viewed from the axial direction, a cylindrical portion penetrating the main body portion, and a gripping portion erected on the main body portion, wherein the gripping portion extends along the arc portion, and both ends of the gripping portion are located within areas demarcated by a pair of the straight portions.

To achieve the above objective, the wire harness according to the present invention comprises a conductive cable guide and a grommet through which the cable guide is inserted. The grommet fits into a through-hole that penetrates the mounting object axially and comprises a main body portion that, when viewed from the axial direction, has an oval shape including a straight portion and an arc portion, a cylindrical portion that penetrates the main body portion, and a gripping portion erected on the main body portion. The gripping portion extends along the arc portion, and both ends of the gripping portion are located within areas demarcated by a pair of the straight portions.

According to the grommet and wire harness of the present invention, the gripping portion extends along an arc, and both ends of the gripping portion are located within a region demarcated by a pair of straight sections. Therefore, the force applied to the gripping portion is transmitted within this region, allowing the oval-shaped main body to be securely fitted into the through-hole. Thus, the grommet and wire harness have the effect of ensuring proper workability when fitting the main body into the through-hole.

Figure 1 is a perspective view showing a schematic configuration of a wire harness to which a grommet according to the embodiment is applied. Figure 2 is an exploded perspective view of the wire harness shown in Figure 1. Figure 3 is a plan view showing the grommet according to this embodiment attached to the mounting panel. Figure 4 is a cross-sectional view taken along line A-A in Figure 3.

The embodiments of the present invention will be described in detail below with reference to the drawings. However, the invention is not limited to these embodiments. Furthermore, some of the components in the following embodiments are easily substituted or substantially identical to those that are easily substituted by those skilled in the art.

Figure 1 is a perspective view showing a schematic configuration of a wire harness to which the grommet according to this embodiment is applied. Figure 2 is an exploded perspective view of the wire harness of Figure 1. Figure 3 is a plan view showing the grommet according to this embodiment mounted on a mounting panel. Figure 4 is a cross-sectional view taken along line A-A in Figure 3. The grommet 1 of this embodiment is incorporated into a wire harness WH routed in a vehicle or the like. Here, the wire harness WH is, for example, a bundle of multiple wiring materials W used for power supply and signal communication to connect various devices mounted in a vehicle, and the multiple wiring materials W are connected to each device with connectors or the like. As shown in Figure 1, the wire harness WH comprises, for example, two conductive wiring materials W and a grommet 1 through which these wiring materials W are inserted. The wire harness WH may also include various other components such as corrugated tubing, resin tape, protectors and other exterior members, electrical connection boxes, and fasteners.

The wiring harness W is composed of, for example, metal rods, electric wires, and wire bundles. A metal rod consists of a conductive rod-shaped member covered with an insulating coating. An electric wire consists of a conductor (core wire) made up of multiple conductive metal strands, covered with an insulating coating. A wire bundle is a bundle of these electric wires. A wire harness WH bundles and integrates multiple wiring harnesses W, and various devices are electrically connected via connectors provided at the ends of the bundled wiring harnesses W.

As shown in Figure 2, the grommet 1 is attached to a through-hole 101 formed in the mounting panel 100, and is used to route the cable routing material W across two spaces separated by the mounting panel 100 via this through-hole 101.

The mounting panel 100 is, for example, a metal plate that constitutes the body of a vehicle, and the through-hole 101 is formed in an oval shape and penetrates the mounting panel 100 along the thickness direction. Here, an oval shape refers to a shape that includes a pair of opposing straight sections along the long axis and a substantially arc-shaped arc section connecting these pairs of straight sections. In this embodiment, the mounting panel 100 is also provided with a peripheral wall 102 that rises along the thickness direction on the inner periphery of the through-hole 101. By providing this peripheral wall 102, the strength of the mounting panel 100 including the through-hole 101 can be increased. This peripheral wall 102 is formed, for example, by burring.

Furthermore, the two spaces partitioned by the mounting panel 100 are typically the interior space (e.g., the cabin) and the exterior space (e.g., the engine compartment). The grommet 1 is installed in the through-hole 101 with the wire harness WH's routing material W inserted through it and the grommet surrounding the routing material W. This protects the routing material W passing through the through-hole 101 and also seals (watersproofs) the through-hole 101. In addition to waterproofing the through-hole 101, the grommet 1 also has functions such as dustproofing and sound insulation. The configuration of the grommet 1 will be described in detail below with reference to the figures.

In Figures 1 to 4, the mounting panel 100 shows only a portion of the area surrounding the through-hole 101. Also, in Figures 3 and 4, the cable routing material W inserted into the grommet 1 is omitted. Furthermore, in the following explanation, of the three intersecting directions, the first direction is referred to as the "axial direction X," the second direction as the "width direction Y," and the third direction as the "depth direction Z." The axial direction X, width direction Y, and depth direction Z are typically mutually orthogonal. Here, the axial direction X corresponds to the thickness direction of the mounting panel 100 described above, and corresponds to the insertion direction of the cable routing material W and grommet 1 into the through-hole 101. The width direction Y and depth direction Z correspond to the extension direction of the mounting panel 100. Furthermore, in this embodiment, the grommet 1 has an oval shape similar to the through-hole 101, with the width direction Y corresponding to the direction along the major axis Y1 (Figure 3) of the grommet 1, and the depth direction Z corresponding to the direction along the minor axis of the grommet 1.

For the sake of clarity, this explanation assumes that the cable routing material W is routed linearly along the axial direction X. However, it is not limited to this configuration. The axial direction X may be a bent direction when the grommet 1 is attached to the mounting panel 100, and the grommet 1 and cable routing material W may be partially bent. Furthermore, unless otherwise specified, the directions used in the following explanation refer to the directions when the grommet 1 is assembled to the mounting panel 100.

As shown in Figure 1, the grommet 1 of this embodiment is a sealing member capable of sealing water between the grommet and the through-hole 101 (see Figure 2) of the mounting panel 100, with a cable guide W inserted through it along the axial direction X. The grommet 1 comprises a main body portion 10, a cylindrical portion 20, and a gripping portion 30, which are integrally formed as an elastic body. The grommet 1 is made of an insulating elastic resin material with low rigidity and high flexibility, such as rubber or thermoplastic elastomer (for example, ethylene-propylene-diene rubber (EPDM)).

The main body portion 10 is the part that fits into the through hole 101, sealing the through hole 101 and through which the cable material W is inserted along the axial direction X. Here, the main body portion 10 is formed as a portion through which two cable materials W can be inserted. As shown in Figure 2, the main body portion 10 is composed of a partition wall portion 11, an annular base portion 12, and a fitting groove portion 13.

As shown in Figure 3, the partition wall 11 is a plate-like member formed in an oval shape when viewed from the axial direction X. Specifically, the partition wall 11 is formed in an oval plate shape including a pair of opposing straight sections 11A that extend along the long axis Y1, and a substantially arc-shaped arc section 11B connecting these pair of straight sections 11A.

The annular base 12 is a thick annular member that is continuous with the periphery (straight portion 11A and arc portion 11B) of the partition wall 11. This annular base 12 is larger than the partition wall 11 and, like the partition wall 11, is formed in an oval annular shape when viewed from the axial direction X. The annular base 12 is integrated with the periphery of the partition wall 11, and both the partition wall 11 and the annular base 12 are formed in a hollow dome shape, with the annular base 12 side opening in the axial direction X. The partition wall 11 is provided with a cylindrical portion 20 and a gripping portion 30 on the side opposite to the annular base 12 side in the axial direction X.

Furthermore, the fitting groove 13 is an oval-shaped groove formed on the outer circumference of the annular base 12. When the main body 10 (grommet 1) is attached to the through hole 101 of the mounting panel 100, the fitting groove 13 elastically adheres to the peripheral wall 102 of the through hole 101 and is fitted into the through hole 101.

Furthermore, in this embodiment, the annular base 12 has a first annular base 14 located on the axial direction X side of the partition wall 11 relative to the fitting groove 13, and a second annular base 15 located on the opposite side of the axial direction X from the partition wall 11 relative to the fitting groove 13. Both the first annular base 14 and the second annular base 15 are formed in an oval shape, with the second annular base 15 having a larger external dimension than the first annular base 14. Also, one of the first annular base 14 and the second annular base 15 is positioned in the interior space of the vehicle, while the other is positioned in the exterior space.

The cylindrical portion 20 is formed integrally with the main body portion 10 in a cylindrical shape, and is the portion through which the cable material W is inserted along the axial direction X. Each cylindrical portion 20 allows for the insertion of the cable material W along the axial direction X.

The cylindrical portion 20 is formed to protrude from the partition wall portion 11 along the axial direction X to one side (opposite to the annular base portion 12). The cylindrical portion 20 is formed in a cylindrical shape centered on a central axis (not shown) along the axial direction X, and extends along the axial direction X. The cylindrical portion 20 is formed in a cylindrical shape with a smaller diameter than the partition wall portion 11. One end of the cylindrical portion 20 in the axial direction X is open, and the other end is connected to the partition wall portion 11. In this embodiment, the pair of cylindrical portions 20 are connected to the partition wall portion 11 at positions aligned in the width direction Y on the long axis Y1.

The cylindrical portion 20 has multiple lip portions 20a formed on its inner circumferential surface (see Figure 4). Each of the multiple lip portions 20a is a pleated, annular water-sealing portion formed along the circumferential direction, and is positioned at intervals along the axial direction X. Each lip portion 20a is configured to adhere tightly to the outer surface of the cable material W inserted inside through elastic deformation, sealing the entire circumference of the cable material W.

The gripping portion 30 is formed integrally with the main body portion 10 in an arc shape and is the part that is gripped and pulled by the worker when attaching the main body portion 10 (grommet 1) to the through hole 101 of the mounting panel 100. The pair of gripping portions 30 are positioned at both ends in the direction along the long axis Y1 and are erected to protrude from the partition wall portion 11 along the axial direction X to one side (opposite side from the annular base portion 12).

Furthermore, the gripping portion 30 is an arc-shaped wall portion extending along the arc portion 11B of the partition wall portion 11, and has a base end 30A connected to the partition wall portion 11 and a tip end 30B located on the opposite side from the partition wall portion 11 along the axial direction X. The gripping portion 30 is formed symmetrically with respect to the long axis Y1, and is formed to be wider in the depth direction Z, sloping from the tip end 30B towards the base end 30A. Both ends 30A1 on the base end 30A side of the gripping portion 30 are each located within a region 50 demarcated by a pair of straight portions 11A of the partition wall portion 11. This region 50 is a region demarcated by a pair of straight portions 11A and a pair of imaginary lines Z1 connecting the connection point 11C between the arc portion 11B and the straight portion 11A. In other words, the gripping portion 30 extends from the arc portion 11B side of the partition wall portion 11 along the arc portion 11B toward a pair of straight portions 11A, and both ends 30A1 on the base end 30A side of the gripping portion 30 extend beyond the aforementioned connection point 11C into the region 50 (towards the straight portions 11A).

In this configuration, both ends 30A1 on the base end 30A side of the gripping portion 30 are located within the region 50 demarcated by the pair of straight sections 11A of the partition wall portion 11. Therefore, when attaching the grommet 1 (main body portion 10) to the through hole 101, the force applied to the gripping portion 30 is transmitted within the region 50. This allows the oval-shaped straight section 11A to be effectively pulled, enabling the fitting groove portion 13 corresponding to this straight section 11A to be assembled with the peripheral wall 102 of the through hole 101. Consequently, partial fitting between the fitting groove portion 13 and the peripheral wall 102 of the through hole 101 is suppressed, ensuring that the grommet 1 (main body portion 10) is securely fitted into the through hole 101.

Furthermore, as shown in Figure 4, the gripping portion 30 is provided with a handle portion 30B1 at its tip 30B in the axial direction X, which is thicker than the rest of the portion. This handle portion 30B1 is the part that the operator actually grasps the gripping portion 30. This handle portion 30B1 is formed so as to protrude along the width direction Y from both the surface where the gripping portions 30 face each other and the opposite surface at the tip 30B of the gripping portion 30. This allows the operator to firmly grasp the gripping portion 30, and enables easy fitting of the grommet 1 (main body portion 10) into the through hole 101.

Furthermore, as shown in Figure 3, the handle portion 30B1 is formed on the long axis Y1 of the main body portion 10. This allows the force applied to the gripping portion 30 to be evenly transmitted to the base end 30A of the gripping portion 30 via the handle portion 30B1, thus enabling easy fitting of the grommet 1 (main body portion 10) into the through hole 101.

The grommet 1 and wire harness WH of this embodiment, as described above, are fitted into a through hole 101 that penetrates the mounting panel 100 along the axial direction X. The grommet 1 and wire harness WH comprise a main body 10 that, when viewed from the axial direction X, has an oval shape including an arc portion 11B and a straight portion 11A, a cylindrical portion 20 through which the wiring material W is inserted, and a gripping portion 30 erected on the main body 10. The gripping portion 30 extends along the arc portion 11B, and both ends 30A1 on the base end 30A side of the gripping portion 30 are located within a region 50 partitioned by a pair of straight portions 11A. Therefore, when attaching the main body 10 to the through hole 101, the force applied to the gripping portion 30 is transmitted into the region 50, which effectively pulls the straight portion 11A of the oval-shaped main body 10, allowing the main body 10 to be securely fitted into the through hole 101. Therefore, the grommet 1 and the wire harness WH have the effect of ensuring proper workability when fitting the main body 10 into the through hole 101.

Furthermore, in the grommet 1 and wire harness WH of this embodiment, the gripping portion 30 has a handgrip portion 30B1 formed thicker than other parts at its tip 30B in the axial direction X. Therefore, the worker can firmly grip the gripping portion 30, and the grommet 1 (main body portion 10) can be easily fitted into the through hole 101.

Furthermore, in the grommet 1 and wire harness WH of this embodiment, since the grip portion 30B1 is formed on the long axis Y1 of the main body portion 10, the force applied to the grip portion 30 is transmitted evenly to the base end 30A of the grip portion 30 via the grip portion 30B1, allowing the grommet 1 (main body portion 10) to be easily fitted into the through hole 101.

Furthermore, the grommets and wire harnesses according to the embodiments of the present invention described above are not limited to the embodiments described above, and various modifications are possible within the scope of the claims.

In the above explanation, the wiring material W was described as being a conductive wire or the like, but it is not limited to this; at least one of the wiring material W may be, for example, a washer hose through which fluid can flow.

1 Grommet 10 Main body 11 Partition wall 11A Straight section 11B Arc section 11C Connection point 12 Annular base 13 Fitting groove 14 First annular base 15 Second annular base 20 Cylindrical section 30 Gripping section 30A Base end 30A1 Both ends 30B Tip 30B1 Handle 50 Area 100 Mounting panel (to be mounted)
101 Through hole 102 Peripheral wall W Cable material WH Wire harness X Axis direction Y1 Long axis Z1 Imaginary line

Claims (4)

A main body portion that fits into a through hole that penetrates the object to be mounted along the axial direction and has an oval shape including an arc portion and a straight portion when viewed from the axial direction,
A cylindrical portion through which the cable material is inserted,
The main body is provided with a gripping portion erected on the main body,
The grommet is characterized in that the gripping portion extends along the arc portion, and both ends of the gripping portion are located within a region demarcated by a pair of straight portions. The gripping portion includes a handle portion formed with a thicker tip in the axial direction.
The grommet according to claim 1. The handle portion is formed on the long axis of the main body portion.
The grommet according to claim 2. It comprises a conductive cable guide and a grommet through which the cable guide is inserted,
The grommet is fitted into a through hole that penetrates the object to be mounted along the axial direction, and has a main body that is oval in shape including a straight portion and an arc portion when viewed from the axial direction,
A cylindrical portion through which the cable material is inserted,
The main body is provided with a gripping portion erected on the main body,
The wire harness is characterized in that the gripping portion extends along the arc portion, and both ends of the gripping portion are located within a region demarcated by a pair of straight portions.