JP2000092647A - Corrugated tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sticking-out of wires from a slit portion at the time of bending or tensioning a corrugated tube. SOLUTION: In the corrugated tube 1 comprising a slit portion 2 formed in a longitudinal direction, the portion 2 is bent to alternately form ridge parts 4 and trough parts 5. The portion 2 is bent in a zigzag manner. The part 2 may be bent in a rectangular wave state. The parts 4 and the parts 5 absorb a tensile force at an outside and a compression force at an inside at the time of bending the tube. Since the parts 4 are extended and disposed in a direction of opening the slit portion, a large craze does not occur at the portion 2, and ejection of the wire or breakage or damage of the wire at the time of the ejection is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated tube having a slit through which a wire harness is inserted, and prevents the slit from being opened due to bending or pulling when the vehicle is assembled.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional corrugated tube installed on a vehicle panel. The corrugated tube 21 is formed in a bellows cylindrical shape using a synthetic resin as a material. A wire harness 28 (FIG. 8) is inserted into the corrugated tube 21, and the wire harness 28 is protected by the corrugated tube 21 from external interference, rainwater, dust, and the like.

The corrugated tube 21 has a slit portion 22 formed straight in the longitudinal direction, and a wire harness 28 is inserted into the corrugated tube 21 from the slit portion 22. For example, a resin tape is turbulently wound (wound at a large pitch) around the wire harness 28, or a binding band (not shown) is wound at intervals.

However, in the above-described conventional corrugated tube 21, the corrugated tube 21 is bent at, for example, a substantially right angle at the bent portion (the corner portion 31 or the corner portion 32) of the vehicle panel 30 in FIG. In this case, as shown in FIG. 8 (perspective view) and FIG.
A crack occurs in the slit portion 22 at the first bent portion 23, and the electric wire 28 a (FIG. 8) constituting the wire harness 28 protrudes outside from the crack portion 29, causing interference or biting with peripheral devices. There was a concern. The crack portion 29 is likely to occur when the slit portion 22 is located above or below the corrugated tube 21.

On the other hand, FIGS. 10 (a) and 10 (b) show another conventional example (Japanese Patent Laid-Open No. Hei 7-245844), in which a spiral slit
1 shows a corrugated tube 41 having the following. The slit portion 42 is spirally cut out around the entire corrugated tube 41. The wire harness 48 is inserted from the slit portion 42 into the corrugated tube 41.

However, this corrugated tube 4
1, the corrugated tube 4 shown in FIG.
When 1 is pulled in the longitudinal direction as shown by the arrow d, the corrugated tube 41 extends in the longitudinal direction to form a gap 49 in the spiral slit portion 42, and the electric wire 4 extends from the gap 49.
There is a concern that the protrusion 8a may protrude to the outside, causing interference with peripheral devices or biting.

[0007] When the corrugated tube 41 is bent at the bent portions 31 and 32 of the vehicle panel 30 as shown in FIG.
There is also a concern that the electric wire 48a will protrude.
In particular, when the corrugated tube 41 is bent while being pulled, a large gap 49 is formed in the slit portion 42, and there is a concern that the electric wire 48a is likely to protrude.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention does not allow the electric wire to protrude from the slit portion even when the corrugated tube is largely bent or pulled strongly in the longitudinal direction, so that the electric wire is not damaged. An object of the present invention is to provide a corrugated tube that does not cause damage or damage.

[0009]

In order to achieve the above object, the present invention relates to a corrugated tube having a slit formed in a longitudinal direction, wherein the slit is bent so that peaks and valleys are alternately formed. (Claim 1). It is also effective that the slit portion is bent in a meandering shape (claim 2). It is also effective that the slit is bent in a rectangular wave shape.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show one embodiment of a corrugated tube according to the present invention.

The corrugated tube 1 has a meandering slit portion 2 as shown in FIG. The slit portion 2 is curved in a substantially S-shaped or sinusoidal wave shape and is continuous in the longitudinal direction of the corrugated tube 1. The slit portion 2 may be formed only on the bent portion 3 (FIG. 2) of the corrugated tube 1 or may be formed over the entire length of the corrugated tube 1.

The slit portion 2 extends in the longitudinal direction of the corrugated tube 1 at a meandering height (wave height or amplitude) H (FIG. 1) smaller than the outer diameter of the corrugated tube 1.
For example, when the corrugated tube 1 is viewed from directly above as shown in FIG. 1, the position of the slit portion 2 is such that the virtual center line m of the meandering slit portion 2 overlaps the virtual center line of the corrugated tube 1. It is set as follows.

In the free state of the corrugated tube 1, the slits 2 are in close contact with each other without any gap. That is, the curved ridges (convex portions) 4 on one side of the corrugated tube 1 and the curved valleys (concave portions) 5 on the other side of the corrugated tube 1 are separated from the slit portion 2 in the circumferential direction of the corrugated tube 1. Joined to each other. In one side of the corrugated tube 1 followed by curved valleys 5 ₁ on both sides of the curved ridges 4,
Is curved ridges 4 ₁ is followed on both sides of the curved valleys 5 in the other side.

As in the prior art, in the circumferential direction of the corrugated tube 1, a number of ridges 6 are formed in a bellows shape at an equal pitch, and a circumferential groove 7 is formed between the ridges 6. The inner surface side of the ridge 6 is a space (peripheral groove) not shown. The corrugated tube 1 can be easily bent by the bellows shape.

FIGS. 2 and 3 show a wire harness 8 (FIG. 2).
Are a perspective view and a plan view showing a state in which the corrugated tube 1 accommodating the vehicle panel is bent substantially at right angles along the bent portions 31 and 32 (see FIG. 7) of the vehicle panel.

In this embodiment, the meandering slit 2 is located above the corrugated tube 1 (upper half). As shown in FIG. 3, the outer bent portion 3 a accompanies the bending of the corrugated tube 1.
A tensile force acts as shown by the arrow A, and a compressive force acts on the inner bent portion 3b as shown by the arrow B. In the conventional corrugated tube 21 (FIG. 9), a linear slit portion 22 is formed in the bent portion 23 in the radial direction (arrow C direction) of the corrugated tube 21 by the tensile force in the direction of arrow A and the compressive force in the direction of arrow B. It opens greatly.

On the other hand, according to the present embodiment, as shown in FIGS. 2 and 3, a force in the opening direction (direction of arrow C) acts on the bent portion 3 of the corrugated tube 1 by the tensile force and the compressive force. However, since the slit portion 2 is curved in a meandering shape, the curved peak portions 4 and the valley portions 5 absorb the force in the opening direction, and the peak portions 4 project toward the valley portions 5. In addition, the opening gap of the slit portion 2 is minimized.

That is, the inner ridge 4 is compressed in the direction of action of the compressive force to absorb the force in the opening direction, and the ridge 4 projects toward the valley 5 to minimize the gap between the slits 2. Limit. If crests 4 ₁ of the outer is at the bending center,
Crest 4 spread to ₁ tensile force in the direction (arrow i direction) absorbs mouth opening force, and the mountain portion 4 ₁ protrudes toward the troughs 5 _1, minimize the clearance of the slit portion 2 To keep. Thus, the electric wires 8a (FIG. 2) in the corrugated tube 1 are prevented from jumping out.

In contrast to the conventional example (FIG. 10), even when a strong tensile force acts on the corrugated tube 1 in the longitudinal direction, the ridges 4 opposing each other on both sides of the meandering slit 2.
The valley 5 and the valley 5 are strongly adhered to each other using the tensile force while being pulled in the longitudinal direction, so that the generation of the gap is prevented and the electric wire 8a (FIG. 2) does not jump out.

4 to 6 show another embodiment of the corrugated tube according to the present invention. The corrugated tube 11 has a slit portion 12 having a rectangular wave shape in the longitudinal direction.
Is formed. The rectangular wave-shaped slit portion 12 forms a rectangular peak portion (convex portion) 14 and a valley portion (concave portion) 15. The position, size, and the like of the slit portion 12 are the same as those in the previous example, and thus detailed description is omitted.

As shown in FIG. 6, even if a force in the opening direction (direction of arrow C) acts on the bent portion 13 of the corrugated tube 11 due to the tensile force in the direction of arrow A and the compressive force in the direction of arrow B, the slit portion is not affected. Since 12 is bent in a rectangular wave shape,
The peaks 14 and the valleys 15 absorb the force in the opening direction, and the peaks 14 protrude toward the valleys 15 to form the slits 1.
Minimize gap 2

That is, in the bent portion 13, the inner ridge 14 expands substantially in a fan shape to absorb the force in the opening direction, and the ridge 14 projects toward the valley 15. Outer peak 14
₁ when in a bent central, crest 14 ₁ absorbs the mouth opening force spreads the reverse fan shape substantially, and the mountain portion 14 ₁ protrudes toward the valleys 15 _1.

Further, even when a strong tensile force acts in the longitudinal direction of the corrugated tube 11, the crests 14 and the valleys 15 facing each other with the meandering slit 12 as a boundary are pulled in the longitudinal direction of the corrugated tube. The wires 18a (FIG. 5) do not jump out because they tightly adhere to each other to prevent the generation of a gap.

In each of the above embodiments, the slit portion 2 bent in a meandering shape and the slit portion 12 bent in a rectangular wave shape are used.
Although the corrugated tubes 1 and 11 formed with are shown,
The slit portion is not limited to the meandering shape or the rectangular wave shape. For example, a slit portion (not shown) having an intermediate shape (approximately trapezoidal shape) between the meandering shape and the rectangular wave shape has the same effect as described above.

[0025]

As described above, according to the first aspect of the present invention, the peaks and the valleys absorb the tensile force on the outside and the compressive force on the inside when the corrugated tube is bent, and the peaks are formed. Since it is positioned so as to protrude in the opening direction of the slit portion, a large crack does not occur in the slit portion, so that jumping out of the electric wire and accompanying damage or breakage of the electric wire are prevented. Also, even when the corrugated tube is strongly pulled, the crests and valleys facing the slits are tightly adhered in the joining direction using the tensile force, so that no gap is generated in the slits, It is possible to prevent the electric wires from jumping out and the accompanying electric wires from being damaged or damaged. According to the second aspect of the present invention, the outer tensile force and the inner compressive force at the time of bending the corrugated tube according to the first aspect are smoothly and reliably absorbed, thereby preventing the slit from cracking. The effect is more reliably exhibited. In addition, the contact between the crest and the valley when the corrugated tube is pulled is more reliably performed, and the effect of preventing the gap in the slit is more reliably exhibited. Further, according to the third aspect of the present invention, the bonding force between the peak and the valley facing the slit is strong, and the corrugated tube exerts strong shape retention against bending and tension. Thereby, the opening of the mouth and the generation of a gap in the slit portion are prevented.

[Brief description of the drawings]

FIG. 1 is a plan view partially showing an embodiment of a corrugated tube according to the present invention.

FIG. 2 is a perspective view showing a state in which the corrugated tube is bent.

FIG. 3 is a plan view (explanatory diagram) showing a state where the corrugated tube is bent.

FIG. 4 is a plan view partially showing another embodiment of the corrugated tube.

FIG. 5 is a perspective view showing a state where the corrugated tube is bent.

FIG. 6 is a plan view (explanatory diagram) showing a state in which the corrugated tube is bent.

FIG. 7 is a perspective view showing a state in which a corrugated tube is attached to a vehicle.

8 is an enlarged perspective view of a portion A of FIG. 7 showing a conventional example.

FIG. 9 is a plan view (explanatory view) showing a conventional example.

FIG. 10 shows another conventional example, in which (a) is a normal state,
(b) is a plan view showing a state where a tensile force is applied.

[Explanation of symbols]

 1,11 Corrugated tube 2,12 Slit part 4,14 Mountain part 5,15 Valley part

Claims (3)

[Claims] 1. A corrugated tube having a slit formed in a longitudinal direction, wherein the slit is bent so as to alternately form peaks and valleys. 2. The corrugated tube according to claim 1, wherein the slit is bent in a meandering manner. 3. The corrugated tube according to claim 1, wherein said slit portion is bent in a rectangular wave shape.