Corrugated tube holding structure and electric wire protecting component

Abstract

To suppress reduction in holding force of a corrugated tube.SOLUTION: A pair of holding members 2030, for holding a terminal of a corrugated tube 10 in an assembled state are provided, the pair of holding members respectively have holding parts 2232, for holding the terminal of the corrugated tube by sandwiching it from an outer peripheral surface side, and the pair of holding parts are projections projected from respective inner wall surfaces for each of a plurality of recessed parts 11 on the outer peripheral surface side of the corrugated tube. A holding rib 2434 provided with a semi-arc portion 24a and a semi-arc portion 34a which are concentrically inserted into a recessed portion on an outer peripheral surface side is provided, and a tube expanding protrusion 25 which is inserted into the slit 13 of the corrugated tube in an assembled state and expands one end portion and the other end portion of the corrugated tube in a circumferential direction when viewed from the slit to expand the end of the corrugated tube is provided on an internal wall surface of one holding portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a corrugated tube holding structure and a wire protection component. [Background technology]

[0002] Conventionally, wire protection components include a housing and a cover that accommodate and allow multiple wires pulled out from the end of a cylindrical corrugated tube. The housing and the cover are provided with retaining ribs for holding the end of the corrugated tube. Each retaining rib has a semicircular arc portion that forms an arc when the housing and cover are fully assembled, and the semicircular arc portion is inserted into a recess in the bellows portion of the corrugated tube to hold the end of the corrugated tube (see Patent Document 1 listed below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-164390 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a conventional corrugated tube holding structure uses a corrugated tube with slits, when the corrugated tube is pulled in the axial direction and the side wall surface of the recess catches on the retaining rib, the corrugated tube is squeezed radially inward, reducing the amount of engagement of the retaining rib within the recess. Therefore, the conventional corrugated tube holding structure may reduce the holding force of the corrugated tube, and there is room for improvement in this regard.

[0005] Therefore, an object of the present invention is to provide a corrugated tube holding structure and a wire protection component that can prevent a decrease in the holding force of the corrugated tube. [Means for solving the problem]

[0006] The corrugated tube holding structure of the present invention comprises a pair of holding members that hold a terminal of the corrugated tube in an assembled state, the corrugated tube being formed in a bellows tube shape having annular recesses and protrusions alternately arranged in the tube axis direction and slits cut in the tube axis direction, the pair of holding members each having a holding portion that holds the terminal of the corrugated tube by sandwiching it from the outer surface side, the pair of holding portions being protrusions that protrude from their inner wall surfaces for each of the plurality of recesses on the outer surface side, and each having a holding rib with a semicircular arc portion that is inserted concentrically into the recesses on the outer surface side, and the inner wall surface of one of the holding portions is provided with an expanding protrusion that is inserted into the slit in an assembled state and pushes apart one end and the other end of the terminal of the corrugated tube in the circumferential direction as seen from the slit, thereby expanding the terminal of the corrugated tube.

[0007] Moreover, a wire protection component according to the present invention includes: a corrugated tube having annular recesses and protrusions alternately arranged in a tube axis direction and slits cut in the tube axis direction, the corrugated tube having a bellows-like shape and through which a plurality of electric wires are inserted; a housing that accommodates the plurality of electric wires pulled out from an end of the corrugated tube and pulls them outward; and a cover that holds the end of the corrugated tube between itself and the housing in an assembled state and that covers and conceals the plurality of electric wires pulled out from the end of the corrugated tube between itself and the housing in an assembled state; The covers each have a retaining portion that clamps and holds the terminal of the corrugated tube from the outer surface side, and the pair of retaining portions are protrusions that protrude from the inner wall surface of each of the plurality of recesses on the outer surface side, and have retaining ribs with semicircular arc portions that are inserted concentrically into the recesses on the outer surface side, and the inner wall surface of one of the retaining portions is provided with an expanding protrusion that is inserted into the slit in the assembled state and pushes apart one end and the other end of the terminal of the corrugated tube in the circumferential direction as seen from the slit, thereby expanding the terminal of the corrugated tube. [Effects of the Invention]

[0008] In the corrugated tube holding structure and wire protection component according to the present invention, the expanding protrusions expand the end of the corrugated tube, increasing the engagement allowance of the pair of semicircular arc portions within the recesses on the outer peripheral surface. Therefore, even if the corrugated tube is pulled in the axial direction and narrows radially inward, the pair of holding portions can reduce the amount of narrowing compared to before, ensuring the engagement allowance of the semicircular arc portions within the recesses. Therefore, the corrugated tube holding structure and wire protection component according to the present invention can prevent a decrease in the holding force of the corrugated tube. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an exploded perspective view showing a corrugated tube holding structure and a wire protection component according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the corrugated tube holding structure and the wire protection component according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line XX in FIG. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view taken along line YY in FIG. [Figure 5] FIG. 5 is a partially enlarged cross-sectional view taken along line ZZ in FIG. [Figure 6] FIG. 6 is a plan view showing the main parts inside the housing. [Figure 7] FIG. 7 is a plan view showing the main parts inside the cover. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a corrugated tube holding structure and a wire protection component according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments.

[0011] [Embodiment] One embodiment of a corrugated tube holding structure and a wire protection component according to the present invention will be described with reference to FIGS. 1 to 7. FIG.

[0012] 1 to 5, reference numeral 1 denotes a wire protection component of this embodiment. This wire protection component 1 includes a cylindrical corrugated tube 10 and a housing 20 and a cover 30 as a pair of holding members that hold the end of the corrugated tube 10 in an assembled state (FIGS. 1 to 5). A corrugated tube holding structure 100 of this embodiment is constituted by the housing 20 and the cover 30 as a pair of holding members.

[0013] The corrugated tube 10 is formed in the shape of a bellows tube having annular recesses 11 and protrusions 12 alternately arranged in the axial direction of the tube, and slits 13 cut in the axial direction of the tube (FIGS. 1 to 5). A plurality of electric wires (not shown) are inserted through this corrugated tube 10.

[0014] The housing 20 and cover 30, which serve as a pair of holding members, are molded from an insulating material such as synthetic resin, and are assembled together.

[0015] The housing 20 accommodates and allows the plurality of electric wires drawn out from the end of the corrugated tube 10. The cover 30 holds the end of the corrugated tube 10 between itself and the housing 20 in the assembled state, and also covers and conceals the plurality of electric wires drawn out from the end of the corrugated tube 10 between itself and the housing 20 in the assembled state.

[0016] The housing 20 has a housing main body 21 that houses multiple electric wires pulled out from the end of the corrugated tube 10 (FIGS. 1 to 5). The cover 30 has a cover main body 31 that covers and conceals the multiple electric wires pulled out from the end of the corrugated tube 10 between the housing 20 in the assembled state (FIGS. 1 to 4). The housing main body 21 and the cover main body 31 form an internal space in which the multiple electric wires pulled out from the end of the corrugated tube 10 are routed when the assembled state is complete.

[0017] The housing 20 and the cover 30 each have holding portions 22, 32 that sandwich and hold the end of the corrugated tube 10 from the outer peripheral surface side (FIGS. 1 to 4).

[0018] The housing 20 and cover 30 are maintained in their mutually assembled state by locking mechanisms at multiple locations. The locking mechanisms maintain the assembled state by engaging the first engagement portion 23 provided on the housing 20 with the second engagement portion 33 provided on the cover 30 in the assembled state (FIGS. 1, 3, and 5). For example, in this locking mechanism, the first engagement portion 23 is formed as a claw-shaped protrusion, and the second engagement portion 33 is formed as a groove that hooks onto this protrusion. This locking mechanism is provided at one location between the housing main body 21 and the cover main body 31, and at two locations between the pair of retaining portions 22, 32.

[0019] The pair of retaining portions 22, 32 are cylindrical in the assembled state and hold the end of the corrugated tube 10 therein. The pair of retaining portions 22, 32 are protrusions that protrude from their respective inner wall surfaces for each of the plurality of recesses 11 on the outer circumferential surface of the corrugated tube 10. The pair of retaining portions 22, 32 have retaining ribs 24, 34 that fit into the recesses 11 to hold the end of the corrugated tube 10 ( FIGS. 1 and 3 to 7 ). The pair of retaining ribs 24, 34 are provided with semicircular arc portions 24a, 34a that are concentrically inserted into the plurality of recesses 11 on the outer circumferential surface of the corrugated tube 10 ( FIGS. 1 , 3 , 6 , and 7 ). The pair of semicircular arc portions 24a, 34a form annular portions when the pair of retaining portions 22, 32 are assembled and are arranged concentrically within the recesses 11. Therefore, the pair of semicircular arc portions 24a, 34a can engage the side wall surfaces of the recesses 11 in the axial direction of the corrugated tube 10. Therefore, the end of the corrugated tube 10 is held by a plurality of pairs of holding ribs 24, 34 at the pair of holding portions 22, 32.

[0020] However, as mentioned above, if the corrugated tube 10 is pulled in the axial direction, the side wall surface of the recess 11 will get caught on the semicircular arc portions 24a, 34a of the pair of retaining ribs 24, 34, causing the corrugated tube 10 to be constricted radially inward, reducing the engagement allowance of the semicircular arc portions 24a, 34a within the recess 11.

[0021] Therefore, an expansion protrusion 25 is provided on the inner wall surface of one of the holding portions 22 (32) which is inserted into the slit 13 in the assembled state and pushes apart one end and the other end in the circumferential direction as seen from the slit 13 at the end of the corrugated tube 10 to expand the end of the corrugated tube 10 (FIGS. 1 and 3 to 6). Here, the expansion protrusion 25 is provided on the holding portion 22 of the housing 20.

[0022] The tube expansion projections 25 expand the end of the corrugated tube 10, increasing the engagement allowance of the pair of semicircular arc portions 24a, 34a within the recess 11 on the outer peripheral surface side. Therefore, in the pair of holding portions 22, 32, even if the corrugated tube 10 is pulled in the tube axial direction and narrows radially inward, the amount of narrowing can be reduced compared to before, ensuring the engagement allowance of the semicircular arc portions 24a, 34a within the recess 11. Therefore, the wire protection component 1 and corrugated tube holding structure 100 of this embodiment can prevent a decrease in the holding force of the corrugated tube 10.

[0023] Here, it is desirable that the expansion protrusion 25 be inserted into the slit 13 at the convex portion 12 on the outer surface side of the corrugated tube 10 in order to efficiently increase the engagement allowance of the semicircular arc portions 24a, 34a within the recess 11 as the corrugated tube 10 is expanded.

[0024] In the wire protection component 1, multiple electric wires are pulled out from the corrugated tube 10, whose ends are held in this manner, into the internal space of the housing main body 21 and the cover main body 31. The housing 20 has an electric wire pull-out portion 26 that pulls out the multiple electric wires in the internal space (FIGS. 1 to 3). The electric wire pull-out portion 26 is formed in a cylindrical shape with its own cylindrical axis perpendicular to the cylindrical axis formed by the pair of holding portions 22, 32.

[0025] For example, the multiple electric wires shown here connect a torque sensor and an electronic control unit of an electric power steering. Wire protection component 1 is attached to the housing of the torque sensor and is provided to ensure a waterproof function between the housing and the wire protection component. Wire lead-out portion 26 of this wire protection component 1 is fitted into a circular through-hole in the housing.

[0026] Therefore, a cylindrical mat seal 41 with a lip on its outer circumferential surface is housed inside the electric wire pull-out portion 26 (FIG. 3). This mat seal 41 has a cylindrical through-hole (hereinafter referred to as "electric wire insertion hole") 41a with a lip on its inner circumferential surface formed for each electric wire (FIG. 3). The electric wire pulled out from the end of the corrugated tube 10 passes through the internal space formed by the housing main body 21 and the cover main body 31 and is pulled out through the electric wire insertion hole 41a. In this way, the mat seal 41 is provided to ensure a waterproof function inside the electric wire pull-out portion 26.

[0027] In the wire protection component 1, a mat seal cover 50 attached to the wire pull-out portion 26 prevents the mat seal 41 from falling off from the wire pull-out portion 26 (FIGS. 1 to 3). The mat seal cover 50 has a wire insertion hole 51 formed coaxially with the wire insertion hole 41a (FIG. 3). The wire that passes through the wire insertion hole 41a of the mat seal 41 is pulled out through the wire insertion hole 51.

[0028] In addition, an annular sealing member 42 is provided on the outer peripheral surface of the electric wire pull-out portion 26 (FIGS. 1 to 3). This sealing member 42 fills the gap between the outer peripheral surface of the electric wire pull-out portion 26 and the inner peripheral surface of the through-hole in the housing of the torque sensor, thereby ensuring a waterproof function outside the electric wire pull-out portion 26. [Explanation of symbols]

[0029] 1. Wire protection parts 10 Corrugated tube 11 Recess 12 Convex part 13 Slit 20 Housing (retaining member) 22 Holding part 24 Retaining rib 24a Semicircular arc section 25 Expanding protrusion 30 Cover (retaining member) 32 Holding part 34 Retaining rib 34a Semicircular arc section 100 Corrugated tube holding structure

Claims

1. a pair of holding members for holding the ends of the corrugated tube in an assembled state; The corrugated tube is formed into a bellows tube shape having annular recesses and protrusions alternately arranged in a tube axis direction and slits cut in the tube axis direction, the pair of holding members each have a holding portion that sandwiches and holds the end of the corrugated tube from an outer peripheral surface side, The pair of holding portions are protrusions that protrude from the inner wall surfaces of the respective ones of the plurality of recesses on the outer peripheral surface side, and each have a holding rib provided with a semicircular arc portion that is inserted concentrically into the recesses on the outer peripheral surface side, a corrugated tube holding structure characterized in that an expansion protrusion is provided on the inner wall surface of one of the holding portions, which is inserted into the slit in an assembled state and pushes apart one end and the other end of the corrugated tube in the circumferential direction as seen from the slit, thereby expanding the end of the corrugated tube.

2. 2. The corrugated tube holding structure according to claim 1, wherein the expansion protrusion expands the end of the corrugated tube to increase the engagement allowance of the pair of semicircular arc portions within the recess on the outer surface side.

3. 3. The corrugated tube holding structure according to claim 1, wherein the tube expanding projection is inserted into the slit at the convex portion on the outer circumferential surface side.

4. a corrugated tube having a bellows-like shape, which has annular recesses and protrusions alternately arranged in a tube axis direction and slits cut in the tube axis direction, and through which a plurality of electric wires are inserted; a housing for accommodating and allowing the plurality of electric wires drawn out from the end of the corrugated tube to be drawn outward; a cover that holds the end of the corrugated tube between itself and the housing in an assembled state, and that covers and conceals the plurality of electric wires drawn out from the end of the corrugated tube between itself and the housing in an assembled state; Equipped with the housing and the cover each have a holding portion that sandwiches and holds the end of the corrugated tube from an outer peripheral surface side, The pair of holding portions are protrusions that protrude from the inner wall surfaces of the respective ones of the plurality of recesses on the outer peripheral surface side, and each have a holding rib provided with a semicircular arc portion that is inserted concentrically into the recesses on the outer peripheral surface side, a tube expansion protrusion is provided on the inner wall surface of one of the holding portions, which is inserted into the slit in an assembled state and pushes apart one end and the other end of the corrugated tube in the circumferential direction as seen from the slit, thereby expanding the end of the corrugated tube.

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