Corrugated tube and wire harness

Abstract

To provide a corrugated tube and a wire harness capable of easily securing bending performance in a short axis direction and suppressing cracking of a rib.SOLUTION: The corrugated tube (10) is formed into a tubular shape with an oval cross-section and is capable of accommodating a wire inside the tube, crest portions (11) and trough portions (12) are alternately continuous in a tube axis direction, a rib (13) continuous in the tube axis direction is formed on at least one of both ends in a long axis direction of the oval shape, the rib (13) protrudes outward from the trough portion (12) within a range not exceeding the crest portion (11), and a thickness T2 of the rib (13) is larger than a thickness T1 on both end sides in a short axis direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a corrugated tube and a wire harness. [Background technology]

[0002] A corrugated tube has been proposed that is cylindrical, can house electric wires, and has alternating peaks and valleys in the axial direction of the tube. This corrugated tube protects the electric wires inside while allowing a certain degree of bending due to the bellows structure formed by the continuous peaks and valleys.

[0003] Furthermore, such corrugated tubes have also been proposed, such as those for sliding doors, that have an elliptical cross section that allows bending in a specific direction (minor axis direction) but does not allow sagging in a direction perpendicular to the specific direction (major axis direction). In particular, corrugated tubes with an elliptical cross section have ribs formed on both ends of the elliptical shape in the major axis direction that continue in the axial direction of the tube, and the rigidity of the ribs is used to further suppress sagging (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4606275 Summary of the Invention [Problem to be solved by the invention]

[0005] The corrugated tube described in Patent Document 1 is used, for example, for a sliding door. Because the corrugated tube for a sliding door is installed near the feet so as not to get in the way of the occupant, there is a possibility that the occupant may step on it while opening or closing the door. If the occupant does step on the corrugated tube, excessive load may be applied to the ribs, potentially causing them to crack. To address this issue, the corrugated tube can be made less likely to crack by increasing its overall wall thickness, but this makes it difficult to bend in the minor axis direction due to the increased wall thickness.

[0006] This problem is not limited to corrugated tubes for sliding doors, but is also common to corrugated tubes for other applications in which a rib that continues in the axial direction of the tube is formed on at least one of the longitudinal ends of the oval shape and in which the rib may be subjected to load depending on the usage environment.

[0007] The present invention has been made to solve these conventional problems, and an object of the present invention is to provide a corrugated tube and a wire harness that can easily ensure bending performance in the minor axis direction and can suppress rib cracking. [Means for solving the problem]

[0008] The corrugated tube according to the present invention is a cylindrically formed corrugated tube with an elliptical cross section, capable of accommodating electric wires inside the tube, with alternating peaks and valleys in the axial direction of the tube, and with a rib formed on at least one of both ends of the elliptical shape in the major axis direction that continues in the axial direction of the tube, the rib protruding outward from the valley portion within an area not exceeding the peaks, and the thickness of the rib is greater than the thickness at both ends in the minor axis direction.

[0009] A wire harness according to the present invention includes the corrugated tube described above and electric wires housed inside the cylindrical interior of the corrugated tube. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a corrugated tube or the like that can easily ensure bending performance in the minor axis direction and can suppress cracking of ribs. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a top view showing a wire harness including a corrugated tube according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the corrugated tube shown in FIG. [Figure 3] 3A and 3B are cross-sectional views taken along the line AA in FIG. 2, where (a) shows the entire cross section of the corrugated tube, (b) shows an enlarged cross section of the corrugated tube near the end in the minor axis direction, and (c) shows an enlarged cross section of the corrugated tube near the end in the major axis direction. [Figure 4] 3A and 3B are cross-sectional views taken along the line B-B in FIG. 2, where (a) shows the entire cross section of the corrugated tube, (b) shows an enlarged cross section of the corrugated tube near the end in the minor axis direction, and (c) shows an enlarged cross section of the corrugated tube near the end in the major axis direction. [Figure 5] 1 is a first table showing an experimental example of the corrugated tube according to the present embodiment. [Figure 6] 10 is a second table showing experimental examples of the corrugated tube according to the present embodiment. [Figure 7] 10 is a graph showing the amount of sagging relative to the thickness of the rib and the thickness of the bellows. [Figure 8] FIG. 10 is a partial cross-sectional view showing a modified example of the corrugated tube according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below in accordance with preferred embodiments. Note that the present invention is not limited to the embodiments shown below and can be modified as appropriate without departing from the spirit of the present invention. In addition, in the embodiments shown below, some components are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are applied as appropriate to the details of the omitted technologies within the scope of the content described below.

[0013] Fig. 1 is a top view showing a wire harness including a corrugated tube according to an embodiment of the present invention. As shown in Fig. 1, the wire harness 1 is composed of a corrugated tube 10 and at least one electric wire W (two in the example shown in Fig. 1) housed inside the corrugated tube 10. The electric wire W may be a solid wire or a stranded wire, or may be a bundle of multiple wires wrapped in tape or the like. Furthermore, the electric wire W may have a flattened shape to match the shape of the corrugated tube 10 (an oval shape described below).

[0014] Fig. 2 is a side view of the corrugated tube 10 shown in Fig. 1, Fig. 3 is a cross-sectional view taken along line AA in Fig. 2, and Fig. 4 is a cross-sectional view taken along line BB in Fig. 2. In Fig. 3 and Fig. 4, (a) shows the entire cross-section of the corrugated tube 10, (b) shows an enlarged cross-section of the corrugated tube 10 near the end in the minor axis direction, and (c) shows an enlarged cross-section of the corrugated tube 10 near the end in the major axis direction.

[0015] 3 and 4, the corrugated tube 10 is formed into a cylindrical shape with an oval cross section, and is capable of storing an electric wire W (see FIG. 1) inside the cylindrical shape. The corrugated tube 10 is made of a resin (such as polypropylene, polyvinyl chloride, polyethylene, or polyamide) having a predetermined rigidity sufficient to protect the electric wire W.

[0016] The corrugated tube 10 shown in FIGS. 1 to 4 has a bellows structure in which peaks 11 and valleys 12 are alternately arranged in the axial direction. The corrugated tube 10 also has ribs 13 formed on both ends of the oval shape in the axial direction, extending continuously in the axial direction. Due to this structure, the corrugated tube 10 according to this embodiment is allowed to be bent in the minor axis direction of the oval shape, but sagging in the major axis direction is suppressed. That is, the bellows structure allows the corrugated tube 10 to be bent in the minor axis direction, while the ribs 13 further suppress sagging in the major axis direction, while the oval shape provides a basic structure that is difficult to bend in the major axis direction. The side walls of the ribs 13 are curved walls 13a that are curved with a radius that protrudes inward, as shown in FIG. 1. These curved walls 13a contribute to improving the impact resistance of the corrugated tube 10.

[0017] Furthermore, in the corrugated tube 10 according to this embodiment, the ribs 13 protrude outward from the valley portions 12 within a range that does not exceed the peak portions 11. In other words, the ribs 13 do not exceed the peak portions 11, and are configured such that, for example, when a load is applied from the outside of the longitudinal axis of the corrugated tube 10, the load is unlikely to be directly applied to the ribs 13. Note that in the example shown in Figures 1 to 4, the ribs 13 are flush with the peak portions 11, but this is not a limitation, and the ribs 13 may be formed lower than the peak portions 11.

[0018] In addition, the ribs 13 shown in Figures 3 and 4 have a thickness greater than the thickness at both ends in the minor axis direction. Explaining in more detail, first, as shown in Figures 3(a) and 3(b), the side portions 14 of the corrugated tube 10, which are at both ends in the minor axis direction, have a thickness (thickness in the minor axis direction) of T1. On the other hand, as shown in Figures 3(a) and 3(c), a rib 13 is formed at the center of the semicircular portions 15 of the corrugated tube 10, which are at both ends in the major axis direction, and this rib 13 has a thickness (thickness in the major axis direction) of T2, which is greater than T1.

[0019] The same is true when referring to the cross section of Fig. 4. That is, as shown in Fig. 4(a) and Fig. 4(b), the side portion 14 of the corrugated tube 10 has a thickness of T1, and the rib 13 has a thickness of T2 which is larger than T1.

[0020] As described above, in the corrugated tube 10 according to this embodiment, the thickness T2 of the rib 13 is greater than the thickness T1 of the side portion 14. This increases the impact resistance of the rib 13, making it difficult for the rib 13 to crack even if a large force acts on the rib 13.

[0021] As shown in Figures 3(a) and 3(c), it is preferable that the thickness T3 of the curved wall 13a, which forms the side wall of the rib 13, is also larger than T1. This is because the impact resistance of the rib 13 can be further improved. Furthermore, although the semicircular portions 15, which are on both ends in the longitudinal direction, may be thickened only in the rib 13, it is preferable that the thickness gradually increases from the side portion 14 to the position of the rib 13, as shown in Figure 4(a). This is because the impact resistance of the periphery of the rib 13 can also be improved.

[0022] In this embodiment, as shown in Figures 3 and 4, the thicknesses T1, T2 of the side portions 14 and the ribs 13 are the same at the peak portions 11 and the valley portions 12, but they may be different. In this case, it is sufficient that the thickest portion of the rib 13 is thicker than the thinnest portion of the side portions 14. This is because a minimum improvement in impact resistance can be achieved. Of course, the thinnest portion of the rib 13 may also be thicker than the thickest portion of the side portions 14. This is because a further improvement in impact resistance can be achieved.

[0023] To explain the thicknesses T1 and T2 in more detail, it is preferable that the ratio of the thickness T2 of the rib 13 to the thickness T1 of the side portion 14 of the corrugated tube 10 is 2.10 or more and 2.80 or less. This is because a certain level of impact resistance and bendability can be ensured, making the corrugated tube suitable for use in a sliding door.

[0024] 5 and 6 are diagrams showing experimental examples of the corrugated tube 10 according to this embodiment. In the diagrams, the numbers 1 to 182 indicate the experimental example numbers, and the numerical value adjacent to the experimental example numbers indicates the wall thickness (mm) of the side portion. Experimental Examples 1 to 182 are explained below. In the following experimental examples, corrugated tubes suitable for use in sliding doors were evaluated. All numerical values ​​for each experimental example are shown with two significant digits. The corrugated tubes used in Experimental Examples 1 to 182 were of a standard size for use in general sliding doors, with the distance between the side walls of the ribs (the distance indicated by reference symbol L1 in FIG. 3(c)) being 1.5 mm and the distance between the valleys (the distance indicated by reference symbol L2 in FIG. 1) being 0.6 mm.

[0025] First, the rib thickness was standardized to 0.35 mm for Experimental Examples 1 to 14. The side thicknesses were 0.19 mm, 0.18 mm, 0.18 mm, 0.17 mm, 0.16 mm, 0.15 mm, 0.15 mm, 0.14 mm, 0.13 mm, 0.13 mm, 0.13 mm, 0.12 mm, 0.12 mm, and 0.11 mm, respectively, for Experimental Examples 1 to 14. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 1 to 14 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0026] Furthermore, the rib thickness was uniformly set to 0.40 mm for Experimental Examples 15 to 28. The side thicknesses were 0.22 mm, 0.21 mm, 0.20 mm, 0.19 mm, 0.18 mm, 0.17 mm, 0.17 mm, 0.16 mm, 0.15 mm, 0.15 mm, 0.14 mm, 0.14 mm, 0.13 mm, and 0.13 mm, respectively, for Experimental Examples 15 to 28. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 15 to 28 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0027] Furthermore, the rib thickness was uniformly set to 0.45 mm for Experimental Examples 29 to 42. The side thicknesses were 0.25 mm, 0.24 mm, 0.23 mm, 0.21 mm, 0.20 mm, 0.20 mm, 0.19 mm, 0.18 mm, 0.17 mm, 0.17 mm, 0.16 mm, 0.16 mm, 0.15 mm, and 0.15 mm, respectively, for Experimental Examples 29 to 42. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 29 to 42 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0028] The rib thickness was uniformly set to 0.50 mm for Experimental Examples 43 to 56. The side thicknesses were 0.28 mm, 0.26 mm, 0.25 mm, 0.24 mm, 0.23 mm, 0.22 mm, 0.21 mm, 0.20 mm, 0.19 mm, 0.19 mm, 0.18 mm, 0.17 mm, 0.17 mm, and 0.16 mm, respectively, for Experimental Examples 43 to 56. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 43 to 56 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0029] The rib thickness was uniformly set to 0.55 mm for Experimental Examples 57 to 70. The side thicknesses were 0.31 mm, 0.29 mm, 0.28 mm, 0.26 mm, 0.25 mm, 0.24 mm, 0.23 mm, 0.22 mm, 0.21 mm, 0.20 mm, 0.20 mm, 0.19 mm, 0.18 mm, and 0.18 mm, respectively, for Experimental Examples 57 to 70. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 57 to 70 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0030] The rib thickness was uniformly set to 0.60 mm for Experimental Examples 71 to 84. The side thicknesses were 0.33 mm, 0.32 mm, 0.30 mm, 0.29 mm, 0.27 mm, 0.26 mm, 0.25 mm, 0.24 mm, 0.23 mm, 0.22 mm, 0.21 mm, 0.21 mm, 0.20 mm, and 0.19 mm, respectively, for Experimental Examples 71 to 84. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 71 to 84 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0031] The rib thickness was uniformly set to 0.65 mm for Experimental Examples 85 to 98. The side thicknesses were 0.36 mm, 0.34 mm, 0.33 mm, 0.31 mm, 0.30 mm, 0.28 mm, 0.27 mm, 0.26 mm, 0.25 mm, 0.24 mm, 0.23 mm, 0.22 mm, 0.22 mm, and 0.21 mm, respectively, for Experimental Examples 85 to 98. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 85 to 98 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0032] For Experimental Examples 99 to 112, the rib thickness was uniformly set to 0.70 mm. The side thicknesses were 0.39 mm, 0.37 mm, 0.35 mm, 0.33 mm, 0.32 mm, 0.30 mm, 0.29 mm, 0.28 mm, 0.27 mm, 0.26 mm, 0.25 mm, 0.24 mm, 0.23 mm, and 0.23 mm, respectively, for Experimental Examples 99 to 112. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 99 to 112 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0033] The rib thickness was uniformly set to 0.75 mm for Experimental Examples 113 to 126. The side thicknesses were 0.42 mm, 0.39 mm, 0.38 mm, 0.36 mm, 0.34 mm, 0.33 mm, 0.31 mm, 0.30 mm, 0.29 mm, 0.28 mm, 0.27 mm, 0.26 mm, 0.25 mm, and 0.24 mm, respectively, for Experimental Examples 113 to 126. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 113 to 126 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0034] The rib thickness was uniformly set to 0.80 mm for Experimental Examples 127 to 140. The side thicknesses were 0.44 mm, 0.42 mm, 0.40 mm, 0.38 mm, 0.36 mm, 0.35 mm, 0.33 mm, 0.32 mm, 0.31 mm, 0.30 mm, 0.29 mm, 0.28 mm, 0.27 mm, and 0.26 mm, respectively, for Experimental Examples 127 to 140. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 127 to 140 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0035] The rib thickness was uniformly set to 0.85 mm for Experimental Examples 141 to 154. The side thicknesses were 0.47 mm, 0.45 mm, 0.43 mm, 0.40 mm, 0.39 mm, 0.37 mm, 0.35 mm, 0.34 mm, 0.33 mm, 0.31 mm, 0.30 mm, 0.29 mm, 0.28 mm, and 0.27 mm, respectively, for Experimental Examples 141 to 154. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 141 to 154 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0036] The rib thickness was uniformly set to 0.90 mm for Experimental Examples 155 to 168. The side thicknesses were 0.50 mm, 0.47 mm, 0.45 mm, 0.43 mm, 0.41 mm, 0.39 mm, 0.38 mm, 0.36 mm, 0.35 mm, 0.33 mm, 0.32 mm, 0.31 mm, 0.30 mm, and 0.29 mm, respectively, for Experimental Examples 155 to 168. As a result, the ratios of the rib thickness to the side thickness for Experimental Examples 155 to 168 were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively.

[0037] In Experimental Examples 169 to 182, the rib thickness was uniformly set to 0.95 mm. The side thicknesses were 0.53 mm, 0.50 mm, 0.48 mm, 0.45 mm, 0.43 mm, 0.41 mm, 0.40 mm, 0.38 mm, 0.37 mm, 0.35 mm, 0.34 mm, 0.33 mm, 0.32 mm, and 0.31 mm, respectively, in Experimental Examples 169 to 182. As a result, the ratios of the rib thickness to the side thickness were 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, and 3.10, respectively, in Experimental Examples 169 to 182.

[0038] Impact resistance tests and bending load tests were conducted on the corrugated tubes of these experimental examples. For the impact resistance test, the fabricated corrugated tube was placed between two platforms spaced 200 mm apart, so that it bridged the ground, and a 100-g steel ball was dropped from a height of 1 m (height from the corrugated tube) onto the rib near the center of the part that was above the ground. Products that did not develop cracks or breaks in the rib upon impact with the steel ball were deemed to have passed the test, while products that developed cracks or breaks were deemed to have failed the test. The tests were conducted at temperatures of -10°C and -20°C, low enough to easily cause cracks in corrugated tubes. Products that developed cracks or breaks at either temperature were deemed to have failed the test.

[0039] The bending load test was carried out by measuring the load when the corrugated tube was bent in the minor axis direction to R25. A product was deemed to have passed if the load was 10N or less, and failed if the load exceeded 10N. The test was carried out at low temperatures of -10°C and -20°C, at which the corrugated tube tends to harden, and a product was deemed to have failed if the load exceeded the limit at either temperature.

[0040] Both tests were conducted using three types of corrugated tube material: polypropylene, polyvinyl chloride, and polyethylene. However, the test results did not change depending on the material. Therefore, Experimental Examples 1 to 182 summarize the experimental results for each material.

[0041] Among the corrugated tubes according to Experimental Examples 1 to 182, all those with a ratio of 2.10 or more and 2.80 or less and a rib thickness of 0.45 mm or more and 0.85 mm or less passed both the impact resistance test and the bending load test. Although outside the above ranges, Experimental Examples 29 to 31, 43 to 45, 54 to 59, 68 to 73, 82 to 87, 96 to 101, 110 to 112, 114, 115, 124 to 126, 129, 138 to 140, and 152 to 154 also passed both tests.

[0042] On the other hand, among the corrugated tubes according to Experimental Examples 1 to 182, Experimental Examples 1 to 28, 40 to 42 failed the impact resistance test. The product failed the bending load test.

[0043] As described above, it was found that corrugated tubes with a ratio between 2.10 and 2.80 are more likely to pass the test. Similarly, for corrugated tubes for standard-sized sliding doors, it was found that a rib thickness between 0.45 mm and 0.85 mm is more likely to pass the test.

[0044] Conversely, if the ratio is below 2.10, the rib thickness relative to the side is insufficient, making it more likely to break or crack, and it is therefore more likely to fail the impact resistance test. Also, if the ratio is above 2.80, the rib thickness relative to the side becomes too thick, making it more difficult to bend in the minor axis direction.

[0045] From the above, we found that the ratio is crucial for impact resistance and bending load, and that a ratio of at least 2.10 to 2.80 ensures a certain level of impact resistance and ease of bending, making it suitable for use in sliding doors. From the perspective of reducing load, a ratio of 2.60 or less is preferable, with 2.50 or less being more preferable. Furthermore, while the corrugated tubes in the above experimental examples employ a structure in which the side walls of the ribs are not curved, curved side walls are expected to provide even greater impact resistance, and a ratio slightly below 2.10 may be acceptable. Furthermore, since the size of corrugated tubes for sliding doors is somewhat fixed, the wall thickness of the ribs is preferably 0.45 mm to 0.85 mm.

[0046] Corrugated tubes with rib thicknesses of 0.45 mm or more also meet the sagging standard. Figure 7 is a graph showing the sagging amount as a function of rib thickness and bellows thickness. The sagging amount was measured by preparing a 500 mm long corrugated tube, supporting both ends, and applying a load of 1.3 N, equivalent to the load of an electric cable, to the center. The amount of sagging at the center was measured from a straight state. As shown in Figure 7, the rib thicknesses were 0.45 mm, 0.65 mm, and 0.85 mm, while the bellows thickness (i.e., the thickness at both ends in the minor axis direction) varied from 0.15 mm to 0.40 mm. The sagging amount did not exceed 5 mm in any of these cases, meeting the standard. On the other hand, when there were no ribs, the sagging amount significantly exceeded 5 mm, failing to meet the standard.

[0047] In this way, in the corrugated tube 10 according to this embodiment, the ribs 13 protrude outward from the valley portions 12 within a range not exceeding the peak portions 11, thereby making it difficult for excessive force to be applied only to the ribs 13. Furthermore, because the thickness T2 of the ribs 13 is greater than the thickness T1 at both ends in the minor axis direction, even if a large force acts on the ribs 13, the ribs 13 can be protected, and the thickness T1 at both ends in the minor axis direction can be kept small, making it easier to ensure bending performance in the minor axis direction. Therefore, it is possible to provide a corrugated tube 10 that can easily ensure bending performance in the minor axis direction and suppress cracking in the ribs 13.

[0048] In addition, the ratio of the thickness T2 of the rib 13 to the thickness T1 at both ends in the short axis direction is 2.10 or more and 2.80 or less, ensuring a certain level of impact resistance and ease of bending, making it suitable for use in sliding doors.

[0049] Furthermore, since the thickness of the rib is set to 0.45 mm or more and 0.85 mm or less, it is possible to further ensure bending performance and more easily prevent cracking of the rib 13 for the corrugated tube 10 for a standard sliding door.

[0050] Furthermore, the wire harness 1 according to this embodiment includes the corrugated tube 10 and the electric wires W housed inside the cylindrical interior of the corrugated tube 10, and therefore it is possible to provide a wire harness 1 having the corrugated tube 10 that can easily ensure bending performance in the minor axis direction and suppress cracking in the ribs 13.

[0051] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and modifications may be made within the scope of the spirit of the present invention, and if possible, publicly known or well-known technologies may be combined.

[0052] For example, in this embodiment, the corrugated tube 10 is assumed to have alternating peaks 11 and valleys 12 over the entire length. However, this is not particularly limited, and the corrugated tube 10 may have a straight pipe structure in which the peaks 11 and valleys 12 alternately continue only in the portions that require bending, and the remaining portions do not have peaks 11 or valleys 12.

[0053] Furthermore, the corrugated tube 10 according to this embodiment has been described assuming that it does not have a slit extending in the axial direction of the tube, but this is not particularly limited, and it may also have a slit and the electric wire W may be inserted from the side portion 14, etc.

[0054] Furthermore, the corrugated tube 10 may be configured as shown in Fig. 8. Fig. 8 is a partial cross-sectional view showing a modified example of the corrugated tube 10 according to this embodiment. As shown in Fig. 4, the semicircular portion 15 of the corrugated tube 10 according to this embodiment is configured so that its thickness gradually increases from the side portion 14 toward the position of the rib 13. However, this is not limiting, and the corrugated tube 10 may be configured so that its thickness increases only above the rib 13, as shown in Fig. 8.

[0055] Additionally, although the corrugated tube 10 according to this embodiment is provided with the ribs 13 at both ends in the longitudinal direction, the present invention is not limited to this, and the ribs may be provided at at least one of the ends. [Explanation of symbols]

[0056] 1: Wire harness 10: Corrugated tube 11: Yamabe 12: Valley 13: Rib 13a: Curved wall 14: Side 15: Semicircular section T1~T3: Wall thickness W: Electric wire

Claims

1. A corrugated tube having an elliptical cross section, formed in a cylindrical shape, capable of accommodating an electric wire inside the cylindrical body, having peaks and valleys alternately continuing in a cylindrical axis direction, and having a rib formed on at least one of both ends of the elliptical shape in the longitudinal direction, the rib continuing in the cylindrical axis direction, the rib protrudes outward from the valley portion within a range not exceeding the peak portion, The thickness of the rib is greater than the thickness at both ends in the minor axis direction of the oval shape. A corrugated tube characterized by:

2. The ratio of the thickness of the rib to the thickness at both ends in the minor axis direction is set to 2.10 or more and 2.80 or less. The corrugated tube according to claim 1 .

3. The thickness of the rib is set to be 0.45 mm or more and 0.85 mm or less. The corrugated tube according to claim 1 .

4. The corrugated tube according to any one of claims 1 to 3; an electric wire housed inside the corrugated tube; A wire harness comprising:

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