JP3678168B2 - Cracked corrugated tube for wire harness exterior - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a cracked corrugated tube for exterior of a wire harness, and more specifically, is fitted on a wire harness arranged in an automobile, and an axial slit provided in the corrugated tube has a corrugated tube. This prevents the mouth from opening when it is curved.
[0002]
[Prior art]
Conventionally, wire harnesses routed in automobiles have corrugated tubes made of synthetic resin in order to prevent damage to the wires of the wire harness due to interference when there are interferences such as protrusions and edges at the site of wiring. Was to protect the exterior.
[0003]
As shown in FIG. 5 and FIG. 6, the corrugated tube 1 is composed of a bellows-like cylindrical body in which annular crests 2 and troughs 3 are alternately provided in the axial direction, and is routed in a refraction place. Is bent freely according to it.
The corrugated tube 1 is provided with a slit 4 that can be expanded along the entire length in the axial direction so that the corrugated tube 1 can be attached to the wire harness so as to cover the wire harness from the side in the direction perpendicular to the axis. In many cases, the slit has a so-called cracked shape, which is an opening for mounting on a wire harness.
[0004]
In this type of broken corrugated tube, as shown in FIG. 7, there is a problem that the slit 4 is greatly opened at the bent portion and becomes a mouth opening, and the electric wire w of the wire harness W / H inserted through the inside is likely to protrude. When the electric wire w protrudes outside from the corrugated tube 1, there is a problem that the electric wire w is damaged due to the above-described interference or the like existing in the wiring site.
[0005]
Various countermeasures have been taken for the above-described problem. For example, in Japanese Patent Laid-Open No. 2000-115942, as shown in FIG. 8, a positioning protrusion that engages with one end or the other end of the slit. The corrugated tubes 1A and 1B having the shape 5 are provided and the corrugated tubes 1A and 1B are externally mounted on the wire harness as a double tube, and the slit position is phased by 180 degrees.
Further, in Japanese Patent Laid-Open No. 2000-115949, as shown in FIG. 9, movable walls 6a and 6b bent inward are provided on both side ends of the slit 4, and these movable walls 6a and 6b are wrapped. Has been proposed.
In general, as shown in FIG. 10, the tape T is wound around the outer surface of the corrugated tube 1 to deal with the opening phenomenon of the slit 4 in many cases.
[0006]
[Problems to be solved by the invention]
However, in the corrugated tube shown in FIG. 8 described above, first, two large and small corrugated tubes that are double cylinders are required, and there is a problem that it takes a lot of work because the slit positions are shifted by 180 degrees. Furthermore, since the positioning projection 5 is provided on any of the two large and small corrugated tubes, there is a problem that the shape of the corrugated tube itself is complicated.
Moreover, in the corrugated tube shown in FIG. 9, since it is necessary to insert an electric wire group while pushing the movable walls 6a and 6b open, workability is deteriorated and the inner ends of these movable walls 6a and 6b are wires of the wire harness. There is a risk of contact with the group and damage to the group of wires. Further, when the corrugated tube is bent at an acute angle, it is impossible to prevent the opening of the mouth even if the movable walls 6a and 6b are provided.
In addition, when a tape is wound around the outer peripheral surface of a corrugated tube that is generally used to prevent opening, it is a tape, so there is a risk that it will be cut by interferences, and the tape winding requires a lot of work. There is a problem to upload. Furthermore, since a vinyl chloride tape is usually used as the tape, the amount of chlorine increases at the time of disposal, which is not preferable from an environmental viewpoint.
[0007]
The present invention has been made in view of the above problems, and it is an object to prevent the opening of the slit when the corrugated tube is bent without significantly changing the shape of the corrugated tube and without requiring tape winding or the like. Yes.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention is externally fitted to a wire harness routed in an automobile, and is provided with annular crests and troughs alternately on the outer peripheral surface in the axial direction and continuous in the entire length in the axial direction. In a corrugated tube with a crack shape provided with a slit,
The pitch between the peak protruding in a trapezoidal shape and the valley between the peaks is the same pitch, and a recess is formed from the top end of the peak, and the depth of the recess is The wire harness exterior crack characterized in that the height of the top end part of the part and the bottom end face of the trough part is ½ or less, and the thickness of the peak part, trough part and hollow part is the same. We provide corrugated tubes.
[0009]
Thus, since the reinforcement part which consists of a hollow part is provided in the peak part, the intensity | strength of the longitudinal cross-section in a peak part is raised, and the opening phenomenon in the said slit at the time of a corrugate tube bending can be prevented. As a result, it is not necessary to increase the overall thickness of the corrugated tube in order to prevent opening of the corrugated tube, so that the overall thickness of the corrugated tube can be made thinner than before. In other words, it was possible to prevent the opening of the mouth even if the thickness was reduced by about 10 to 20%.
[0010]
In addition, the outer diameter of the corrugated tube can be made the same as that of the conventional one, and since the diameter is not increased, the corrugated tube can be arranged in a conventionally arranged space.
Moreover, by providing the depressions in the peaks, the flexibility and stretchability can be further improved, and the function of the corrugated tube itself can be improved.
Furthermore, since it is not necessary to wind a tape made of vinyl chloride after the corrugated tube is externally fitted to the wire harness as in the conventional case, it is possible to reduce the cost of parts and to prevent an increase in work man-hours. It is also preferable in terms of countermeasures.
[0011]
The recess is formed in the central portion at the top end of the peak, and the depth is ¼ or more and ½ or less of the height of the top end of the peak and the bottom end face of the valley. It is preferable to do.
That is, when the depth of the hollow portion is made larger than the above 1/2, the expansion and contraction in the axial direction at the peak portion increases, and the corrugated clamp attached by locking the trough portion to the outer peripheral surface of the corrugated tube is easily detached, If it is smaller than ¼, the effect of strengthening the rigidity by the indented portion becomes low, and it becomes impossible to reliably prevent the opening of the slit during bending. Therefore, as described above, the corrugated clamp attached to the outer peripheral surface of the corrugated tube can be kept stable by setting the depth of the recessed portion in the range of 1/2 to 1/4, and the opening of the slit can be opened. Can be prevented.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment.
The corrugated tube 10 is made of synthetic resin and has a bellows-like cylindrical shape in which annular crests 11 and troughs 12 are alternately provided at the same pitch in the axial direction, and the slit 13 extends along the entire length in the axial direction. The crack shape is cut out. The corrugated tube 10 has a uniform and uniform thickness as a whole, and is 10 to 20% thinner than a conventional corrugated tube. In addition, it is good also as the same thickness as the conventional corrugated tube.
The corrugated tube 10 has a slit 13 as an opening, and is attached to a wire harness routed in an automobile from the side perpendicular to the axis.
[0013]
As shown in FIG. 3, the top end portion 11a corresponding to the outer peripheral surface of the mountain portion 11 having a trapezoidal cross section is provided with a concave portion 11b having an annular concave shape at the center thereof. The recess 11b has a relationship of L1> L2, where L1 is the depth of the valley 12 and L2 is the depth of the recess 11b. In this embodiment, L2 = 1/2 × L1. .
[0014]
By setting it as the said structure, in the peak part 11, the recessed part 11b was provided in the top end part 11a which was the flat surface conventionally, and the reinforcement part of (L2x2) was provided, and the corrugated tube 10 The strength of the longitudinal section can be increased, and the strength equivalent to that when the thickness of the corrugated tube is increased can be provided.
[0015]
Therefore, even if the corrugated tube 10 is sheathed on the wire harness, routed along the car body, and the corrugated tube 10 is bent, the presence of the recess 11b increases the strength of the longitudinal section, thereby increasing the strength of the longitudinal section. Opening of the slit 13 can be prevented by strengthening the edges so as not to separate.
[0016]
Moreover, the corrugated clamp (not shown) attached to the outer peripheral surface of the corrugated tube 10 can be used as the conventional product by making the pitch width of the peak portion 11 and the trough portion 12 the same as the conventional one. Contribute to the sharing of
Furthermore, although the strength of the longitudinal section is increased by the depression 11b, the presence of the depression 11b in the transverse section exhibits the same function as the bellows pitch is reduced, and the stretchability and flexibility can be enhanced. .
[0017]
In addition, in this embodiment, although the hollow part 11b recessedly provided in each peak part 11 is provided with respect to one peak part, when a corrugated tube is large diameter and the top end part of a peak part is large, May be provided with a plurality of depressions.
[0018]
FIG. 4 shows a second embodiment.
In the present embodiment, the hollow portion 11b having an annular concave shape in the first embodiment has an annular V shape.
The corrugated tube of the present embodiment is made of the same synthetic resin as that of the first embodiment, and has a cylindrical shape in which annular crests 11 'and troughs 12 are alternately provided in the axial direction. A V-shaped depression 11b ′ is provided, and the depth L2 ′ of the depression 11b ′ is set to L2 ′ = 1/4 × L1 with respect to the depth L1 of the valley 12.
Further, the pitch width of the peak portion 11 'and the valley portion 12 is the same as that of the first embodiment, and the thickness of the corrugated tube is all constant.
Other configurations and operational effects are the same as those of the first embodiment, and thus the description thereof is omitted.
[0019]
【The invention's effect】
As is clear from the above description, according to the corrugated tube of the present invention, it is possible to reinforce the peak portion by providing a recess at the top end portion of the peak portion, and to increase the strength of the longitudinal section at the peak portion. The same strength as when the corrugated tube is thick can be provided. As a result, when the wire harness is sheathed with a corrugated tube and routed in the vehicle, even if a load in the opening direction acts on the slit at the bent portion, the both side edges of the slit are not separated against this, Opening can be prevented.
[0020]
Thus, since the opening of the slit can be prevented, the electric wire accommodated in the corrugated tube does not protrude to the outside at the bent portion, and the occurrence of damage to the electric wire can be prevented.
In addition, since the conventional winding of the vinyl chloride tape can be made unnecessary, it is possible to reduce the cost of parts and the number of work steps, thereby greatly reducing the cost. Furthermore, by not using vinyl chloride tape, the amount of chlorine generated at the time of disposal can be reduced, which can contribute to environmental measures.
[0021]
Furthermore, since the strength can be increased by providing a depression in the peak, it is possible to reduce the overall thickness of the corrugated tube, reducing the weight and reducing the outer diameter of the corrugated tube from the conventional one. Since it can be made the same diameter and does not increase in diameter, it can be routed in a conventionally routed space.
In addition, by providing the depressions in the peaks, the flexibility and stretchability can be further improved, and the function of the corrugated tube itself can be improved.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view of a corrugated tube according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line II of FIG.
FIG. 3 is an enlarged cross-sectional view of a main part of the corrugated tube of the first embodiment.
FIG. 4 is an enlarged cross-sectional view of a main part of a corrugated tube according to a second embodiment.
FIG. 5 is a side view of a conventional corrugated tube.
6 is a cross-sectional view taken along line II-II in FIG.
FIG. 7 is a perspective view showing a conventional problem.
FIG. 8 is a cross-sectional view showing a conventional example.
FIG. 9 is a perspective view showing another conventional example.
FIG. 10 is a perspective view showing another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Corrugated tube 11 Peak part 11a Top end part 11b Depression part 12 Valley part 13 Slit L1 Depth L2 of a valley part, L2 'Depth of a depression part

Claims (2)

A crack-shaped corrugated tube that is externally fitted to a wire harness that is routed to an automobile, and that is provided with annular crests and troughs alternately in the axial direction on the outer peripheral surface, and provided with slits that are continuous over the entire length in the axial direction. In
The pitch between the peak protruding in a trapezoidal shape and the valley between the peaks is the same pitch, and a recess is formed from the top end of the peak, and the depth of the recess is The wire harness exterior crack characterized in that the height of the top end part of the part and the bottom end face of the trough part is ½ or less, and the thickness of the peak part, trough part and hollow part is the same. Corrugated tube. 2. The recessed portion is formed in a central portion of a top end portion of a peak portion, and a depth thereof is set to ¼ or more of a height between a top end portion of the peak portion and a bottom end face of a valley portion. Cracked corrugated tube for wire harness exterior as described in 1.

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