JPH0628738Y2 - Wire harness grommet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a wire harness grommet used for fixing a wire harness electric wire to a panel of a vehicle or the like.

[Conventional technology]

FIG. 10 is a perspective view showing a conventional wire harness grommet (hereinafter, simply referred to as a grommet), and FIG. 11 is a sectional view showing a state in which the wire harness is fixed to a single-side panel.

That is, the grommet main body 22 has a tubular portion 23 into which the wire harness 2 is inserted and a cup portion 24 fitted into the panel hole 4 which are integrally formed of a rubber material, and the outer periphery of the tubular portion 23 is tapered. None, the ring 26 formed of a metal or a synthetic resin material is fitted into the tapered surface 25 to tighten the wire harness 2. Further, a concave groove 27 is formed on the outer peripheral edge of the cup portion 24,
The groove 27 is fitted and fixed in the panel hole 4.

However, in the above-mentioned conventional grommet, since the ring 26 is fitted into the tapered surface 25 of the tubular portion 23 to obtain the tightness of the wire harness 2, the inner diameter of the tubular portion 23 is substantially the same as the outer diameter of the wire harness 2. The diameter is set so that it is difficult to insert the wire harness 2, and when the rubber elasticity of the fitting portion (23) is lost due to aging, the ring 26 moves to the taper small diameter side and the tension of the wire harness 2 is reduced. There is a problem that the wire harness 2 is weakened and the wire harness 2 cannot be held.

Further, because of the structure in which the concave groove 27 of the cup portion 24 is fitted into the panel hole 4, it is difficult to insert it by setting a large fitting tightening allowance, but if the tightening allowance is made small, it easily comes off when an external force is applied. There was also a problem.

[Problems to be solved by the device]

In view of the above-mentioned problems, the present invention makes it easy to insert a wire harness, maintain the tightness of the wire harness even with age, and easily fit the panel to an external force. It is intended to provide a wire harness grommet that is hard to come off.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a wire harness grommet in which a small-diameter portion through which a wire harness is inserted and a large-diameter portion into which a panel hole is inserted are integrally formed by an elastic body. A wire harness grommet characterized by being fitted with a ring body of a shape memory alloy that reduces its diameter to a bellows shape on the circumference, and a ring groove is provided inside the large diameter part for the wire harness grommet, A wire harness grommet formed by fitting a ring body of a shape-memory alloy having a bellows shape that expands to a ring shape by heating in a ring groove, and between the small diameter portion and the large diameter portion. The wire harness grommet is characterized in that a bellows portion is provided.

[Action]

Since a ring body made of a shape memory alloy is used for the small-diameter portion, the diameter of which is restored to a bellows shape on the circumference by heating, so that the tense force can be obtained even if the inner diameter of the small-diameter portion is set sufficiently larger than that of the wire harness. Therefore, it is easy to insert the wire harness.

In addition, since a ring body of a shape memory alloy that has a bellows-like shape that expands to a ring shape on the circumference by heating is used for the ring groove of the large diameter part, sufficient fixing is possible without an initial tightening margin with the panel. The force is obtained and thus easy to set on the panel.

Further, by providing a bellows portion between the small diameter portion and the large diameter portion, the bellows portion absorbs the bending at the time of tightening and fixing, so that the small diameter portion and the large diameter portion are arranged on one plane (one-dimensionally). Arranged configurations are possible.

〔Example〕

FIG. 1 (a) is a perspective view showing an embodiment of a wire harness grommet (hereinafter simply referred to as a grommet) according to the present invention.

In the grommet main body 1 in this embodiment, a tubular portion (small diameter portion) 3a through which the wire harness 2 is inserted and a cup portion (large diameter portion) 5 that fits into the panel hole 4 on the vehicle body side are integrally formed of a rubber material. The inner diameter of the tubular portion 3a is set sufficiently larger than the diameter of the wire harness 2, and a flange portion 6 protruding in the outer peripheral direction is provided at the end edge of the tubular portion 3a.

Then, overcoming the flange portion 6, a small ring 7a made of an irreversible shape memory alloy is fitted to the outer periphery of the cylindrical portion 3a. As shown in FIG. 1 (b), the small ring 7a has the property of being deformed (restored) into a bellows shape on the circumference by heating to reduce its inner diameter. Therefore, the wire harness 2 can be firmly tightened by the small ring 7a. Further, even if the small ring 7a is misaligned due to a strong pulling force or the like, the small ring 7a is locked by the flange portion 6 and does not come off.

If there is a risk of rainwater or the like entering, it is sufficient to cover the opening 8 of the grommet with a vinyl tape or the like not shown.

FIG. 2 (a) is a perspective view showing an embodiment in which the cup portion is fixed to the panel hole on the vehicle body side, and FIG. 2 (b) is a sectional view thereof.

As shown in FIG. (B), on the cup large diameter portion 5a, a flange portion 8a is projected on the outer circumference of the cup large diameter portion 5a, and a flexible portion 10a forming a step portion 9 is raised on the flange portion 8a and the flexible portion 10a is raised. An annular slit 12 is formed between the portion 10a and the cup outer peripheral surface 11, and
The annular slit 12 is formed inside the flexible portion 10a and the collar portion 8a.
Is provided with a ring groove 13a. The ring groove 13a
Is set so that the stepped portion 9 is located substantially at the center in the height direction.

Reference numeral 14a in the figure is a large ring made of a shape memory alloy having a bellows-like shape which has a property of returning to a circumferential annular shape by heating and expanding its outer diameter.

Then, as shown in FIG. 3, the large ring 14a is fitted into the ring groove 13a through the annular slit 12 of the grommet body 1a. Further, in this state, the step portion 9 of the grommet main body 1a is engaged with the panel hole 4 on the vehicle body side, but at this time, it is not necessary to press-fit and the engaging work is easy. Then, by heating the large ring 14a with a dryer (heater) or the like (not shown), as shown in FIG.
Since 4a is restored to an annular shape on the circumference and expands to the outside, the step portion 9 of the grommet body 1a is pressed against the panel 4 ', and the flexible portion 10a is bent to form the raised portion 15 on the panel 4'. . And the grommet main body 1a by the raised portion 15
Fits tightly on the panel 4 '. Therefore, a reliable fixing force can be obtained.

FIG. 5 shows an embodiment in which the large ring is formed in a U-shaped cross section. According to this example, the U-shaped ends 16 and 16 'of the large ring 14b are in line contact with the ring groove 13b. Since the flexible portion 10b and the brim portion 8b of the grommet body 1b are pressed at the same time, a stronger fixing force can be exerted.

Further, FIG. 6 is an example in which the large ring is formed in an inverted L-shaped cross section, and is set by abutting the L-shaped end 17 of the large ring 14c on the flexible portion 10c side of the grommet body 1c. Is. According to this example, compared to the example shown in FIG.
The large ring 14c can be easily fitted into the ring groove 13c, and a strong fixing force can be obtained.

FIG. 7 is a vertical sectional view showing another embodiment of the grommet according to the present invention.

The grommet body 1d in this embodiment has a small-diameter portion 3d for tightening the wire harness 2 and a large-diameter portion 5d that fits into the panel hole 4 formed concentrically in a one-dimensional direction, and has a large diameter with the small-diameter portion 3d. The bellows portion 18 is provided between the diameter portions 5d. Reference numeral 19 is a cylindrical extension for coating.

Ring grooves 20 and 13d are formed on the outer circumference of the small diameter portion 3d and the inner circumference of the large diameter portion 5d, respectively, and the large diameter portion 5d is provided with a step portion 9d similar to that of the embodiment (FIG. 2). It is provided.

Then, as shown in FIG. 8, with respect to the ring groove 20 of the small-diameter portion 3d, as in the above-described embodiment, the small ring 7 of a shape memory alloy is restored to a bellows shape by heating and the inner diameter thereof is reduced.
At the same time as setting d, a large ring 14d of shape memory alloy having a bellows shape is set in the ring groove 13d of the large diameter portion 5d, which is restored to a circumferential annular shape by heating and expands its outer diameter.

Then, by heating each ring 7d, 14d with a dryer (heater) or the like, as shown in FIG.
The diameter of d is reduced and the small diameter portion 3d tightens the wire harness 2, while the diameter of the large ring 14d is enlarged and the step portion 9d strongly presses the panel 4 ', so that the grommet main body 1d is firmly fixed to the panel.

In the figure, reference numeral 21 is a sealing (vinyl tape or the like) for preventing rainwater intrusion.

[Effect of device]

As described above, the wire harness grommet according to the present invention makes it easy to insert the wire harness, does not loosen the wire harness due to aging, and can be easily fitted to the mating panel, and is difficult to remove. The workability of assembling is improved, and there is an effect of preventing accidents such as breakage of the wire harness during use and electrical short circuit and leakage due to intrusion of rainwater.

[Brief description of drawings]

1 (a) is an exploded perspective view showing a wire harness grommet of the present invention, FIG. 1 (b) is a perspective view showing its assembled state, and FIG. 2 (a) is an exploded perspective view showing another embodiment. 2 (b) is a longitudinal sectional view thereof, FIG. 3 is a sectional view showing a state before deformation of the large ring, FIG. 4 is a sectional view showing a state after the deformation, and FIGS. Is a sectional view showing another embodiment of the large ring in the present invention, FIG. 7 is an exploded vertical sectional view showing another embodiment of the present invention, FIG. 8 is a vertical sectional view showing the set state, and FIG. Is a vertical sectional view showing its assembled state, FIG. 10 is a perspective view showing a conventional wire harness grommet, and FIG. 11 is a sectional view showing its assembled state. 1, 1a to d ... Grommet body, 2 ... Wire harness, 3a, 3d ... Small diameter portion (cylindrical portion), 4 ... Panel hole,
5, 5a, 5d ... Large diameter part, 7a, 7d ... Small ring,
13a to d, 20 ... Ring groove, 14a to d ... Large ring, 18 ... Bellows portion.

Claims (3)

[Scope of utility model registration request] 1. A wire harness grommet in which a small-diameter portion for inserting a wire harness and a large-diameter portion for fitting in a panel hole are integrally formed by an elastic body, and the small-diameter portion is restored to a bellows shape by heating. A wire harness grommet characterized by being fitted with a ring body of a shape memory alloy having a diameter. 2. A ring groove is provided inside the large-diameter portion, and a ring body of a shape memory alloy having a bellows-like shape which is expanded into a ring-like shape by heating is fitted into the ring groove. The wire harness grommet according to claim (1). 3. The wire harness grommet according to claim 2, wherein a bellows portion is provided between the small diameter portion and the large diameter portion.