阅读说明：本技术 电磁屏蔽部件及线束 (Electromagnetic shielding member and wire harness ) 是由 木本裕一 于 2018-06-11 设计创作，主要内容包括：金属管(31)具有半分割筒状的一对半割筒部(41、42)、和半割筒部(41)的周向两端部(41a)和半割筒部(42)的端部(43a)被焊接的焊接部位(P)。在半割筒部(42)(主体部(43))的内周面(43b)形成有延出部(44),延出部(44)从该内周面(43b)向金属管(31)的径向内侧延出,并且朝向半割筒部(41)侧延出,延出部(44)中与焊接部位(P)在径向上对置的部分以与焊接部位(P)之间具有空隙(S)的方式设置。(The metal pipe (31) has half-divided cylindrical portions (41, 42) of a half-divided cylindrical portion () and a welding part (P) where both circumferential end portions (41a) of the half-divided cylindrical portion (41) and an end portion (43a) of the half-divided cylindrical portion (42) are welded, an extension portion (44) is formed on an inner circumferential surface (43b) of the half-divided cylindrical portion (42) (main body portion (43)), the extension portion (44) extends from the inner circumferential surface (43b) to the radial inner side of the metal pipe (31) and extends toward the side of the half-divided cylindrical portion (41), and a part of the extension portion (44) that is opposed to the welding part (P) in the radial direction is provided with a gap (S) between the extension portion and the welding part (P).)

1, electromagnetic shielding members, comprising a cylindrical member having conductivity, wherein a wire is inserted into the cylindrical member,

the tubular member has a 1 st half-cut tubular portion in a half-cut tubular shape, a 2 nd half-cut tubular portion in a half-cut tubular shape, and a welding portion where both circumferential end portions of the 1 st half-cut tubular portion and both circumferential end portions of the 2 nd half-cut tubular portion are welded,

an extension portion extending from the inner peripheral surface toward the inside in the radial direction of the tubular member and extending toward the 2 nd half-cut tube portion side is formed on the inner peripheral surface of the 1 st half-cut tube portion,

a portion of the extension portion that faces the welding portion in the radial direction is provided with a gap from the welding portion.

2. The electromagnetic shielding component of claim 1,

the extending portions are formed at both ends of the 1 st half-cut cylinder portion in the circumferential direction,

each of the extending portions has a tip end surface facing radially outward at a tip end portion in an extending direction thereof,

at least parts of the tip end surface abut against the inner peripheral surface of the 2 nd half-cut tube portion.

3. The electromagnetic shielding component of claim 2,

a tip end portion of the extended portion in an extending direction thereof has a tip end surface facing the inner peripheral surface of the 2 nd half-cut cylinder portion,

the distal end surface is formed along the inner peripheral surface of the 2 nd half-cut tube portion facing each other.

4. The electromagnetic shielding component of any of claims 1-3,

the extending portion extends so as to curve from the inner peripheral surface of the 1 st half-cut tube portion toward the inner peripheral surface of the 2 nd half-cut tube portion.

5, wire harness comprising the electromagnetic shielding member according to any of claims 1 to 4, and at least wires inserted into the electromagnetic shielding member.

6. The wire harness according to claim 5,

the at least wires are a plurality of wires inserted through the electromagnetic shielding component,

the extending portion is located in a direction intersecting with an arrangement direction of the plurality of electric wires.

Technical Field

The invention relates to an electromagnetic shielding member and a wire harness.

Background

Conventionally, a wire harness mounted on a vehicle includes: as a countermeasure against electromagnetic noise, the periphery of the electric wire is covered with an electromagnetic shield member (see, for example, patent document 1).

Such an electromagnetic shield member includes a conductive cylindrical member, and the cylindrical member is bent into a predetermined shape in accordance with a wiring path of an electric wire, and the cylindrical member is formed by welding halves of the cylindrical member.

Disclosure of Invention

Problems to be solved by the invention

By using the half-split cylindrical member, the electric wire can be arranged in the internal space of the cylindrical member formed by the two half-split cylindrical members before the half-split cylindrical member is welded. However, when the two half-divided cylindrical members are welded in a state in which the electric wire is surrounded by the two half-divided cylindrical members before welding, the electric wire inside may be damaged.

The present invention has been made to solve the above problems, and an object thereof is to provide an electromagnetic shielding member and a wire harness that suppress damage to electric wires.

Means for solving the problems

An electromagnetic shield component that solves the above-described problems includes a tubular member that has electrical conductivity and in which a wire is inserted, the tubular member having a 1 st half-cut tubular portion that is a half-cut tubular shape, a 2 nd half-cut tubular portion that is a half-cut tubular shape, and a welding portion where both circumferential end portions of the 1 st half-cut tubular portion and both circumferential end portions of the 2 nd half-cut tubular portion are welded, an extension portion that extends from the inner circumferential surface toward the inside in the radial direction of the tubular member and toward the 2 nd half-cut tubular portion side being formed on the inner circumferential surface of the 1 st half-cut tubular portion, and a portion of the extension portion that faces the welding portion in the radial direction being provided with a space between the extension portion and the welding portion.

According to this configuration, the 1 st semi-divided cylindrical portion has an extension portion extending from the inner peripheral surface toward the inside in the radial direction of the cylindrical member and extending toward the 2 nd semi-divided cylindrical portion side, and a portion of the extension portion that faces the welding portion in the radial direction has a gap between the extension portion and the welding portion. This can suppress direct application of heat (energy) applied from a heat source (energy source) to the electric wire when welding between the circumferential end portions, and can suppress damage to the electric wire. In addition, since the extension portion can receive spatter that may be generated during welding, damage to the electric wire due to spatter can be suppressed.

In the electromagnetic shielding member, it is preferable that the extended portions are formed at both ends in the circumferential direction of the 1 st half-cut tube portion, each of the extended portions has a distal end surface facing radially outward at a distal end portion in an extending direction thereof, and at least portions of the distal end surface abut against an inner circumferential surface of the 2 nd half-cut tube portion.

In this configuration, since the portions of the distal end surfaces of the extending portions formed at the respective circumferential end portions of the 1 st half-cut tube portion abut against the inner circumferential surface of the 2 nd half-cut tube portion, the extending portions provided in the 1 st half-cut tube portion can restrict the movement of the 2 nd half-cut tube portion in a state where the circumferential end portions of the respective half-cut tube portions abut against each other, and displacement during welding can be suppressed.

In the electromagnetic shielding member, it is preferable that the extended portion has a distal end surface facing the inner peripheral surface of the 2 nd half-cut tube portion at a distal end portion in an extending direction thereof, and the distal end surface is formed along the inner peripheral surface of the 2 nd half-cut tube portion facing each other.

According to this configuration, the extending portion has a distal end surface facing the inner peripheral surface of the 2 nd half-cut tube portion at a distal end portion in the extending direction thereof, and the distal end surface is formed along the inner peripheral surface of the 2 nd half-cut tube portion facing each other. Therefore, when the 1 st half-cut tubular portion and the 2 nd half-cut tubular portion are opposed to each other and both end portions in the circumferential direction are made to approach each other, the end portions in the circumferential direction of the 2 nd half-cut tubular portion where the extending portions are not provided can be guided radially outward with the end portions in the circumferential direction of the 2 nd half-cut tubular portion in contact with the distal end surface of the extending portion provided in the 1 st half-cut tubular portion.

In the electromagnetic shielding member, it is preferable that the extended portion is extended so as to be bent from the inner peripheral surface of the 1 st half-cut tube portion toward the inner peripheral surface of the 2 nd half-cut tube portion.

According to this configuration, since the extending portion is formed so as to be bent, deterioration in workability in bending the cylindrical member can be suppressed.

Further, a wire harness for solving the above problems includes the electromagnetic shield member according to any one of items above, and at least electric wires inserted into the electromagnetic shield member.

With this configuration, a wire harness can be provided which achieves the same effects as those described in any of the above.

In the above-described wire harness, it is preferable that the at least electric wires are a plurality of electric wires inserted into the electromagnetic shield member, and the extending portion is located in a direction intersecting with an arrangement direction of the plurality of electric wires.

According to this configuration, by providing the extending portion in the direction intersecting the direction in which the plurality of wires are arranged, interference with the wires can be suppressed as compared with, for example, a case where the extending portion is provided in the direction in which the wires are arranged. That is, when the cylindrical member is formed in a substantially circular shape, the space in the cylindrical member can be effectively used, and therefore, the increase in size of the cylindrical member can be suppressed.

Effects of the invention

According to the electromagnetic shielding member and the wire harness of the present invention, damage to the electric wire can be suppressed.

Drawings

Fig. 1 is a schematic configuration diagram of a wire harness according to an embodiment.

Fig. 2 is a sectional view of the wire harness taken along line 2-2 in fig. 1.

Fig. 3 is a sectional view for explaining a method of manufacturing a metal pipe according to the embodiment.

Fig. 4 is a sectional view for explaining a metal pipe according to a modification.

Detailed Description

Hereinafter, a embodiment of a wire harness will be described with reference to the drawings, and in each of the drawings, portion of the structure may be enlarged or simplified for convenience of description.

As shown in fig. 1, a wire harness 10 of the present embodiment is wired so as to pass under the floor of a vehicle or the like in order to connect, for example, a high-voltage battery 11 provided at the rear of the vehicle and an inverter 12 provided at the front of the vehicle in a hybrid vehicle, an electric vehicle, or the like. The inverter 12 is connected to a drive wheel motor (not shown) serving as a power source for running the vehicle, generates an alternating current from the direct current of the high-voltage battery 11, and supplies the alternating current to the motor. The high-voltage battery 11 is a battery capable of supplying a voltage of several hundred volts.

The wire harness 10 includes two high-voltage electric wires 13a and 13b connected to the positive electrode terminal and the negative electrode terminal of the high-voltage battery 11, respectively, and a tubular electromagnetic shield member 14 surrounding the high-voltage electric wires 13a and 13b .

As shown in fig. 2, the high-voltage electric wires 13a and 13b are coated electric wires in which a core wire 21 formed of a conductor is covered with an insulating coating layer 22 formed of a resin material. The insulating coating layer 22 is formed by extrusion coating on the outer peripheral surface of the core wire 21, and coats the outer peripheral surface of the core wire 21 in a close contact state.

The high-voltage electric wires 13a and 13b are unshielded electric wires having no shielding structure and are electric wires that can respond to high voltage and large current, the high-voltage electric wires 13a and 13b are inserted into the electromagnetic shielding member 14, and ends of the high-voltage electric wires 13a and 13b are connected to the high-voltage battery 11 via a connector C1, and ends are connected to the inverter 12 via a connector C2.

The electromagnetic shield member 14 has an elongated cylindrical shape as a whole. The electromagnetic shield member 14 includes: a metal pipe 31 located at a middle portion in the longitudinal direction of the electromagnetic shield member 14; and a braided member 32 located in a range including both longitudinal end portions of the electromagnetic shielding member 14 except for a portion constituted by the metal pipe 31.

The metal pipe 31 is formed of, for example, an aluminum-based metal material, the metal pipe 31 is routed through the underfloor of the vehicle, and bent into a predetermined shape corresponding to the underfloor configuration, and the metal pipe 31 serves as an electromagnetic shield for the high-voltage electric wires 13a and 13b inserted therein, and protects the high-voltage electric wires 13a and 13b from flying stones and the like.

As shown in fig. 2, the metal pipe 31 of the present embodiment has a half-split cylindrical portion 41 and a half-split cylindrical portion 42.

The half-cut cylindrical portions 41 and 42 are formed of an aluminum-based metal material.

The half-cut cylindrical portion 41 has a half-cut cylindrical shape and a shape opening in the direction , and the cross-sectional shape of the half-cut cylindrical portion 41 perpendicular to the extending direction is formed, for example, in a semicircular shape.

The half-cut tube portion 42 has a half-cut tube-shaped main body portion 43, and extending portions 44 extending from the vicinity of end portions 43a on both sides in the circumferential direction of the main body portion 43 on the inner circumferential surface 43b of the main body portion 43. The body portion 43 has a cross-sectional shape perpendicular to the extending direction, for example, a semicircular shape. The half- cut tube portions 41 and 42 are formed by, for example, extrusion molding.

the half-split tubular portions 41, 42 are joined together so that the ends 41a on both sides in the circumferential direction of the half-split tubular portion 41 and the ends 43a on both sides in the circumferential direction of the main body portion 43 of the half-split tubular portion 42 are joined together . more specifically, the half-split tubular portions 41, 42 are joined together by welding the ends 41a on both sides in the circumferential direction of the half-split tubular portion 41 and the ends 43a on both sides in the circumferential direction, a welding point P where these ends 41a and 43a are welded together is formed over the entire length in the extending direction of the half-split tubular portions 41, 42. the ends 41a, 43a of the half-split tubular portions 41, 42 are closed by this welding point P, . thus, the substantially right circular tubular metal pipe 31 is formed.

As shown in fig. 2, each extending portion 44 is formed so as to have a curved shape from the half-cut tube portion 42 (main body portion 43) side toward the inner peripheral surface 41b of the half-cut tube portion 41. That is, the extended portion 44 has an arc-shaped cross-sectional shape (cross-sectional shape of the half- cut cylinder portions 41 and 42 perpendicular to the extending direction). Each extended portion 44 is formed over the entire length of the half-cut tube portion 42 in the extending direction.

Each extending portion 44 is formed to have a gap S at a portion facing the welding point P on the radial inner side of the metal pipe 31. Each extending portion 44 is configured to: in a state where the half- cut tube portions 41 and 42 are welded, the distal end surface 44a of the extending portion 44 extends to abut against the inner peripheral surface 41b of the half-cut tube portion 41. The distal end surface 44a of each extending portion 44 having a curved shape is formed along the inner peripheral surface 41b of the half-cut tube portion 41 facing (abutting) each other. In this example, the shape along the inner peripheral surface 41b includes a curved surface shape and a planar surface shape.

Further, the distal end surface 44a is configured to: the inner peripheral surface 41b of the half-cut cylindrical portion 41 is directed radially outward of the metal pipe 31. The distal end surface 44a of each extending portion 44 is a plane extending in a direction intersecting the direction D1 facing the half- cut tube portions 41 and 42 and a direction intersecting the direction D2, and the direction D2 is orthogonal to the direction D1 facing the half- cut tube portions 41 and 42. The distal end surface 44a of each extending portion 44 is configured to: the half- cut tube portions 41 and 42 are located closer to the half-cut tube portion 41 side in the facing direction D1, and are located farther from the end portion 41a side of the half-cut tube portion 41 extended by the extending portion 44 in the direction D2 which is the direction orthogonal to the facing direction D1 and orthogonal to the insertion direction of the electric wires 13a and 13 b.

The thickness of the extending portion 44 is preferably set in a range from approximately half of the thickness of the main body portion 43 to approximately the same level as the thickness of the main body portion 43, for example, when the thickness of the extending portion 44 is thicker than the thickness of the main body portion 43 or is approximately half of the thickness of the main body portion 43, wrinkles or the like may occur in an inner portion of the metal pipe 31 during bending processing, and when the radius of curvature of the extending portion 44 is made extremely small or large, wrinkles or the like may occur during bending processing of the metal pipe 31.

The extending portion 44 is located in a direction (the same direction as the direction D1) orthogonal to the arrangement direction (the same direction as the direction D2) of the two high-voltage electric wires 13a and 13 b. This enables effective use of the space in the metal pipe 31.

As shown in fig. 1, the outer periphery of each braided member 32 is surrounded by an outer member 34 such as a bellows. Further, a rubber grommet 35 is attached to a connection portion between the metal pipe 31 and the braided member 32, and the grommet 35 covers the outer periphery of the connection portion to prevent water from entering.

The high-voltage electric wires 13a, 13b may have portions (outer tube portions X) that are led out from both ends of the metal tube 31 and are not covered with the metal tube 31, and the outer tube portions X of the high-voltage electric wires 13a, 13b are electromagnetically shielded by the braided members 32 by the outer tube portions X of the high-voltage electric wires 13a, 13b being surrounded by the outer peripheries of the outer tube portions X of the high-voltage electric wires 13a, 13 b.

Next, a method for manufacturing the wire harness 10 (the metal pipe 31) according to the present embodiment will be described.

As shown in fig. 3, the circumferential ends 41a of the half-cut tube portion 41 and the circumferential ends 43a of the body portion 43 of the half-cut tube portion 42 are arranged to face each other.

Next, the end 41a of the half-cut tube portion 41 and the end 43a of the body portion 43 of the half-cut tube portion 42 are relatively moved in the direction D1 until they come into contact with each other. At this time, for example, when the end 41a of the half-cut cylindrical portion 41 and the distal end surface 44a of the extension portion 44 are in contact with each other, the end 41a of the half-cut cylindrical portion 41 is guided by the distal end surface 44a to the outside in the radial direction of the metal pipe 31. In a state where the end portions 41a and 43a are in contact with each other in the direction D1, the distal end surface 44a of the extended portion 44 on the half-cut tube portion 42 side is in contact with the inner peripheral surface 41b of the half-cut tube portion 41. Thus, even when a force is applied to move the half-cut tube portion 41 and the half-cut tube portion 42 relative to each other in the direction D2 perpendicular to the direction D1, the extending portion 44 (the distal end surface 44a) and the inner peripheral surface 41b abut against each other, and the relative displacement in the direction D2 can be suppressed.

Then, in a state where the end portion 41a of the half-cut tube portion 41 and the end portion 43a of the main body portion 43 of the half-cut tube portion 42 are in contact with each other, heat (energy) such as laser light is applied (irradiated) between the end portions 41a, 43a, and welding is performed, thereby completing the metal pipe 31. At this time, when heat is applied so that the end portions 41a and 43a are integrally welded to each other, the heat reaches the radially inner side than the end portions 41a and 43a, but the heat is received by the extending portion 44, and therefore the high-voltage electric wires 13a and 13b reaching the inside can be suppressed. Similarly, although spatter or the like may be generated during welding, the extended portion 44 receives the spatter even when the spatter is generated. Thus, the extending portion 44 can suppress damage to the high-voltage electric wires 13a and 13 b.

Next, the effects of the present embodiment are described.

(1) An extended portion 44 is formed on an inner peripheral surface 43b of the half-cut cylindrical portion 42 (main body portion 43), the extended portion 44 extends from the inner peripheral surface 43b to the inside in the radial direction of the metal pipe 31 and extends toward the half-cut cylindrical portion 41 side, and a portion of the extended portion 44 that faces the welding point P in the radial direction has a space S between the welding point P and the extended portion 44. This can suppress direct application of heat (energy) such as laser light applied from a heat source to the electric wires 13a and 13b when welding the end portions 41a and 43 a. This can suppress damage to the high-voltage electric wires 13a and 13 b. In addition, since the extension portion 44 can receive spatters that may be generated during welding, damage to the high-voltage electric wires 13a and 13b due to spatters can be suppressed.

(2) The distal end surfaces 44a of the extending portions 44 formed at the end portions 43a on both sides in the circumferential direction of the half-cut tube portion 42 (body portion 43) abut against the inner circumferential surface 41b of the half-cut tube portion 41. Therefore, in a state where the end portions 41a, 43a on both sides in the circumferential direction of the half- cut cylinder portions 41, 42 are in contact with each other, the movement of the half-cut cylinder portion 41 can be restricted by the extending portion 44 provided in the half-cut cylinder portion 42, and displacement during welding can be suppressed.

(3) The extending portion 44 has a distal end surface 44a facing the inner peripheral surface 41b of the half-cut tube portion 41 at a distal end portion in the extending direction thereof, and the distal end surface 44a is formed along the inner peripheral surface 41b of the opposing half-cut tube portion 41. Therefore, when the half-cut tube portion 41 and the half-cut tube portion 42 are opposed to each other and the end portions 41a and 43a on both sides in the circumferential direction are brought close to each other, the end portion 41a of the half-cut tube portion 41 where the extending portion 44 is not provided can be guided radially outward with the end portion 41a of the extending portion 44 provided in the half-cut tube portion 42 (main body portion 43) in contact with the distal end surface 44 a.

(4) By forming the extending portion 44 in a bending manner, deterioration in workability in bending the metal pipe 31 can be suppressed.

(5) By providing the extending portions 44 in the direction intersecting the direction in which the plurality of high-voltage electric wires 13a, 13b are arranged, interference with the high-voltage electric wires 13a, 13b can be suppressed as compared with the case where the extending portions are provided in the direction in which the high-voltage electric wires 13a, 13b are arranged. That is, when the metal pipe 31 is formed in a substantially circular shape, the space in the metal pipe 31 can be effectively used, and therefore, the increase in size of the tubular member can be suppressed.

The above embodiment may be modified as follows.

In the above-described embodiment, the extending portions 44 are provided in the vicinity of the end portions 43a on both sides in the circumferential direction of the half-cut tube portion 42, but the present invention is not limited to this, and for example, the extending portions 44 may be provided in the vicinity of the end portions 41a on both sides in the circumferential direction of the half-cut tube portion 41, and as shown in fig. 4, extending portions 44 may be provided in each of the half-cut tube portion 41 and the half-cut tube portion 42.

In the above embodiment, the distal end surface 44a of the extending portion 44 is configured to abut against the inner circumferential surface 41b of the half-cut tube portion 41, but the present invention is not limited thereto. For example, the distal end surface 44a of the extended portion 44 may be configured to be spaced apart from the inner circumferential surface 41b, such as being close to the inner circumferential surface 41b of the half-cut tube portion 41.

In the above embodiment, the distal end surface 44a of the extending portion 44 is formed in a shape along the inner peripheral surface 41b of the half-cut tube portion 41, but is not limited thereto. For example, the distal end surface 44a may be formed to face radially inward, or may be formed to face in a direction parallel to the direction D1 or in a direction parallel to the direction D2.

In the above embodiment, the distal end surface 44a is formed in a planar shape, but other shapes such as a curved surface shape may be adopted.

In the above embodiment, the extending portion 44 is formed in a curved shape (circular arc shape), but the extending portion 44 is not limited to this, and may be formed in a cross-sectional shape having a straight line portion such as an L shape or a V shape.

In the above embodiment, the half-cut tube portion 41 and the half-cut tube portion 42 (body portion 43) are formed in a semi-cylindrical shape, and the metal pipe 31 is formed in a substantially circular shape, but the invention is not limited thereto. The half-cut cylinder portion 41 and the half-cut cylinder portion 42 may be appropriately changed to: the metal pipe 31 is formed in a shape other than a perfect circle such as an ellipse or an oblong.

In the above embodiment, both circumferential ends of each of the half-cut tubular portions 41 and 42 are configured to face each other, but a configuration in which both circumferential ends are radially overlapped may be adopted.

In the wire harness 10 of the above embodiment, the two high-voltage electric wires 13a and 13b are inserted into the electromagnetic shield member 14, but the configuration of the electric wires inserted into the electromagnetic shield member 14 may be changed as appropriate depending on the vehicle configuration. For example, the following may be configured: as the electric wire inserted through the electromagnetic shield member 14, a low-voltage electric wire for supplying electric power for connecting a low-voltage battery having a rated voltage of, for example, 12V or 24V and various low-voltage devices (for example, a lamp, a car audio, and the like) to drive the various low-voltage devices is added.

The arrangement relationship between the high-voltage battery 11 and the inverter 12 in the vehicle is not limited to the above embodiment, and may be appropriately changed according to the vehicle configuration. In the above embodiment, the high-voltage battery 11 is connected to the inverter 12 via the high- voltage wires 13a and 13b, but may be connected to a high-voltage device other than the inverter 12.

Although the above embodiment is applied to the wire harness 10 that connects the high-voltage battery 11 and the inverter 12, the present invention may be applied to a wire harness that connects the inverter 12 and a motor for driving wheels, for example.

The above embodiments and modifications may be combined as appropriate.

The half-cut cylindrical portion 42 is preferably an piece including the main body portion (half cylindrical body) 43 and the extended portion 44, and the half-cut cylindrical portion 42 may be formed by fixing the extended portion 44 to the main body portion 43 in advance before the half-cut cylindrical portions 41 and 42 are joined by welding.

The end portions 41a, 43a of the half- cut cylinder portions 41, 42 are sometimes referred to as joint portions. The welding point P may be a welding point or a welding seam.

The extending portion 44 functions as a blocking portion: the welding portion P is covered in a non-contact manner, and the wires 13a and 13b are protected from spattering which may occur during welding. The extending portion 44 can be configured as a protruding portion having a base end 44b and a free end 44 a. The extending portion 44 can have a base end 44b at a 1 st position offset from an end 43a of the half-cut tube portion 42 in the inner peripheral surface 43b of the half-cut tube portion 42. The extending portion 44 may have a sputter receiving surface so as to cover the end portion 43a of the half-cut tube portion 42, i.e., the welding portion P, without contact, and the sputter receiving surface may be a concave curved surface 44c extending from the base end 44b toward the distal end surface 44 a.

The distal end surface 44a of the extending portion 44 functions as a positioning surface: when the two half-cut tubular portions 41 and 42 are combined, the two half-cut tubular portions 41 and 42 are positioned with each other by temporarily or intermittently contacting the inner peripheral surface 41b of the half-cut tubular portion 41. The half- cut tube portions 41 and 42 can be stably combined by the distal end surface 44a, and the combination is facilitated. The tip end surface 44a of the extension 44 is sometimes referred to as a free end.