Connection structure of shielded electric wire and connector

Abstract

The purpose of the present invention is to provide a technique with which it is possible to reduce the size of a connector while securing a creepage distance. A connection structure between a shielded electric wire and the connector includes: a first insulation layer covering the outer periphery of the conductor; a shield braid provided on the outer peripheral side of the first insulation layer; and a second insulation layer covering the outer periphery of the shield braid. The connector includes a shield connection cylinder arranged on the outer peripheral side of the first insulation layer extending from an end of the second insulation layer while providing an annular space with the first insulation layer. The shield braid extending from the end of the second insulation layer is electrically connected to the shield connection cylinder.

Description

Connection structure between shielded wire and connector

[0001] The present disclosure relates to a connection structure between a shielded wire and a connector.

[0002] Shielded electric wires are sometimes used in wire harnesses and the like installed in vehicles. In a shielded electric wire, a shield braid is provided on the outer periphery of an insulated electric wire including a conductor and an insulating layer (first insulating layer) covering the conductor, and an insulating layer (second insulating layer) is provided on the outer periphery of the shield braid. By grounding the shield braid, leakage of electromagnetic waves from the conductor to the outside is suppressed, and the influence of electromagnetic waves from the outside on the conductor is also suppressed.

[0003] At the tip (front end) of the shielded wire, the second insulating layer is stripped, and the first insulating layer is stripped distally (forward) from the stripped portion of the second insulating layer. For example, in Patent Document 1, the shielding braid extending from the end of the second insulating layer is folded back to the opposite side (rear side) and crimped to a grounding terminal fitting on the outer periphery of the second insulating layer. For example, in Patent Document 2, the shielding braid extending from the end of the second insulating layer is welded to a shielding conductive member without being folded back, while still covering the outer periphery of the first insulating layer.

[0004] JP 2009-117286 A JP 2022-134504 A

[0005] Shielded electric wires are sometimes used, for example, as power supply cables. The size of the connector connected to the end of such shielded electric wires tends to be large. This is because, in such shielded electric wires, the conductor voltage is expected to be high, and therefore, a considerable creepage distance must be ensured between the conductor exposed from the first insulating layer and the shield braid exposed from the second insulating layer in the connector.

[0006] Therefore, an object of the present disclosure is to provide a technique that can reduce the size of a connector while ensuring the creepage distance.

[0007] The connection structure between a shielded electric wire and a connector disclosed herein is a connection structure between a shielded electric wire and a connector, the connection structure between a shielded electric wire including a conductor, a first insulating layer covering the outer periphery of the conductor, a shield braid provided on the outer periphery of the first insulating layer, and a second insulating layer covering the outer periphery of the shield braid, wherein the connector includes a shield connection tube that is arranged on the outer periphery of the first insulating layer extending from an end of the second insulating layer, with an annular space formed between the connector and the first insulating layer, and the shield braid extending from the end of the second insulating layer is electrically connected to the shield connection tube.

[0008] According to the present disclosure, it is possible to reduce the size of the connector while ensuring the creepage distance.

[0009] Fig. 1 is a perspective view of a connection structure according to an embodiment. Fig. 2 is a perspective view of the connection structure, showing the cap in a transparent state. Fig. 3 is a side cross-sectional view of the connection structure. Fig. 4 is a perspective view showing a shielded electric wire and a connector in an exploded state. Fig. 5 is a schematic diagram for explaining the relationship between the connection structure and the size of the connector. Fig. 6 is a side view of a connection structure according to a modified example, showing the cap in a cross-sectional state.

[0010] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0011] The connection structure of the present disclosure between a shielded electric wire and a connector is as follows.

[0012] (1) A connection structure between a shielded electric wire and a connector, the connection structure comprising a conductor, a first insulating layer covering the outer periphery of the conductor, a shield braid provided on the outer periphery of the first insulating layer, and a second insulating layer covering the outer periphery of the shield braid, wherein the connector comprises a shield connection tube disposed on the outer periphery of the first insulating layer extending from an end of the second insulating layer, with an annular space formed between the connector and the first insulating layer, and the shield braid extending from the end of the second insulating layer is electrically connected to the shield connection tube.

[0013] By providing the annular space, the portion of the first insulating layer that overlaps with the shield connection tube in the axial direction can be included in (counted as) the creepage distance, thereby ensuring the creepage distance and reducing the size of the connector.

[0014] (2) In the connection structure between a shielded electric wire and a connector of (1), the connector may include a shield housing whose one axial end portion constitutes the shield connection tube. In this case, the shield braid can be grounded through the shield housing.

[0015] (3) In the connection structure between a shielded electric wire and a connector of (2), the connector may include a terminal to which the conductor is connected, and an inner housing made of an insulating material that is housed in the shield housing and supports the terminal coaxially with the shield housing. In this case, the terminal, and therefore the shielded electric wire connected to the terminal, are arranged coaxially with the shield housing, so that the annular space can be stably maintained.

[0016] However, "on the same axis" as used here does not only include cases where the axes of the two members are exactly aligned, but also cases where the axes of the two members are separated by a tolerance or within a range that allows for similar functionality (for example, cases where the separation is a dimension that is sufficiently small relative to the radial dimension of the annular space). The same applies hereinafter.

[0017] (4) In the connection structure between a shielded electric wire and a connector according to (2) or (3), the connector may include a cylindrical cap connected to the shielding housing, and the portion of the shielded electric wire that is covered with the second insulating layer may be inserted into the cap, thereby arranging the shielded electric wire coaxially with the shielding housing. In this case, the shielded electric wire is arranged coaxially with the shielding housing by being inserted into the cap, and therefore the annular space can be stably maintained.

[0018] (5) In the connection structure between a shielded electric wire and a connector according to any one of (1) to (4), the connector may include a crimping tube provided to sandwich the shielding braid between the connector and the shielding connecting tube, and the shielding braid may be crimped and fixed between the shielding connecting tube and the crimping tube. In this case, the state in which the shielding braid and the shielding connecting tube are electrically connected can be easily achieved.

[0019] (6) In the connection structure between a shielded electric wire and a connector according to any one of (1) to (4), the shield braid and the shield connection tube may be welded by laser welding, which reduces the number of parts required to electrically connect the shield braid and the shield connection tube.

[0020] [Details of the embodiment of the present disclosure] Specific examples of the connection structure between a shielded electric wire and a connector according to the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0021] [Embodiment] <1. Connection Structure> A connection structure 100 between a shielded electric wire 1 and a connector 2 according to an embodiment will be described with reference to Figs. 1 to 4. Fig. 1 is a perspective view of the connection structure 100. Fig. 2 is a perspective view of the connection structure 100, in which the cap 24 is shown in a transparent state (two-dot chain line). Fig. 3 is a side cross-sectional view of the connection structure 100. Fig. 4 is a perspective view showing the shielded electric wire 1 and the connector 2 in a disassembled state. Note that, hereinafter, the axial direction of the shielded electric wire 1 and the connector 2 will be referred to as the "front-rear direction," and the tip side of the shielded electric wire 1 will be referred to as the "front side." This is for convenience of explanation and does not limit the usage posture, etc.

[0022] (I) Shielded Wire 1 As shown in FIG. 4 , the shielded wire 1 includes a conductor 11, a first insulating layer 12, a shield braid (braid) 13, and a second insulating layer 14. The conductor 11 is a core wire (e.g., a solid wire, a twisted wire formed by twisting multiple strands, etc.) made of a conductive material (e.g., a conductive metal). The conductor 11 is provided on the axial side (the radial center side) of the shielded wire 1. The first insulating layer 12 is a coating that covers the outer periphery of the conductor 11 and is made of an insulating material (e.g., an insulating synthetic resin). The shield braid 13 is formed into a tubular shape by weaving (e.g., weaving into a mesh) thin wires made of a conductive material (e.g., a conductive metal). The shield braid 13 is provided on the outer periphery of the first insulating layer 12. The second insulating layer 14 is a coating that covers the outer periphery of the shield braid 13 and is made of an insulating material (e.g., an insulating synthetic resin). At the front end portion of the shielded wire 1, the second insulating layer 14 is stripped and removed. That is, the shield braid 13, the first insulating layer 12, and the conductor 11 extend forward from the end of the second insulating layer 14. Furthermore, at a position forward of the end of the second insulating layer 14, the first insulating layer 12 is stripped and removed. That is, the conductor 11 extends forward from the end of the first insulating layer 12.

[0023] (ii) Connector 2 The connector 2 includes a terminal 21, an inner case 22, a shield case 23, a cap 24, a crimp tube 25, and a seal member 26.

[0024] (Terminal 21) As shown in Fig. 4, the terminal 21 includes, for example, a front connection portion 211 and a rear connection portion 212 provided on the rear side thereof. Here, for example, the front connection portion 211 and the rear connection portion 212 are both tubular (e.g., cylindrical) and arranged on the same axis. Furthermore, the outer diameter of the front connection portion 211 is larger than the outer diameter of the rear connection portion 212. Therefore, the rear end surface of the front connection portion 211 protrudes outward from the rear connection portion 212. The terminal 21 is formed of a conductive material (e.g., a conductive metal).

[0025] 3, the conductor 11 is connected to the terminal 21. Specifically, for example, the tip portion of the conductor 11 is inserted into the rear connection portion 212, and the rear connection portion 212 and the inserted tip portion of the conductor 11 are fixed to each other while being electrically connected by an appropriate method (such as crimping or laser welding).

[0026] 4, the internal housing 22 includes, for example, a cylindrical (e.g., cylindrical) peripheral wall 221 and a rear wall 222 provided at the rear end of the peripheral wall 221. A circular through-hole 222a is provided at the center of the rear wall 222. The internal housing 22 is formed of an insulating material (e.g., insulating resin).

[0027] As shown in FIG. 3 , the internal housing 22 supports the terminal 21. Specifically, the terminal 21 is arranged so that the front connection portion 211 is housed within the internal housing 22 and the rear connection portion 212 extends rearward through the through-hole 222a. In this state, the rear end portion of the front connection portion 211 housed within the internal housing 22 is housed in a recess 222b provided in the front surface of the rear wall 222. The recess 222b is arranged to surround the through-hole 222a, and the inner diameter of the recess 222b is approximately the same as the outer diameter of the front connection portion 211. Therefore, the rear end portion of the front connection portion 211 is housed in the recess 222b while contacting the circumferential surface and front surface of the recess 222b. As a result, the terminal 21 is positioned coaxially with the internal housing 22 and supported by the internal housing 22.

[0028] 4, the shield housing 23 includes, for example, a shield shell 231 and a shield connection tube 232. Here, the front end portion of the shield housing 23 forms the shield shell 231, and the rear end portion of the shield housing 23 forms the shield connection tube 232. The shield shell 231 and the shield connection tube 232 are both tubular (for example, cylindrical) and arranged on the same axis. The shield housing 23 is made of a conductive material (for example, a conductive metal).

[0029] As shown in FIG. 3 , the shield shell 231 accommodates the internal housing 22. Specifically, for example, the inner peripheral surface of the shield shell 231 is provided with a large-diameter surface 231a at the front end and a small-diameter surface 231b at the rear end. The inner diameter of the large-diameter surface 231a is substantially the same as the outer diameter of the internal housing 22. The inner diameter of the small-diameter surface 231b is smaller than the inner diameter of the large-diameter surface 231a, and an inclined surface 231c that decreases in diameter toward the rear is provided between the large-diameter surface 231a and the small-diameter surface 231b. The internal housing 22 is accommodated in the shield shell 231 such that the outer peripheral surface of the peripheral wall 221 contacts the large-diameter surface 231a and the rear surface of the rear wall 222 contacts the inclined surface 231c. As a result, the internal housing 22 is accommodated in the shield shell 231, positioned coaxially with the shield shell 231 (and thus the shield housing 23). As described above, the inner housing 22 supports the terminal 21 coaxially therewith. Therefore, by arranging the inner housing 22 coaxially with the shield housing 23, the terminal 21 (and thus the shielded electric wire 1 connected to the terminal 21) is supported coaxially with the shield housing 23.

[0030] As shown in FIG. 3 , the shield connecting tube 232 extends rearward from the rear edge of the small-diameter surface 231b. The shielded electric wire 1 is inserted into the connector 2 to a position where the end of the second insulating layer 14 is close to the rear end of the shield connecting tube 232 in the front-rear direction, and the exposed portion of the first insulating layer 12 of the shielded electric wire 1 is inserted into the shield connecting tube 232. In other words, the shield connecting tube 232 is disposed on the outer circumferential side (outer side in the radial direction) of the first insulating layer 12 extending from the end of the second insulating layer 14. The inner diameter of the shield connecting tube 232 is larger than the outer diameter of the first insulating layer 12. The shielded electric wire 1 and the shield housing 23 are disposed on the same axis. Therefore, an annular space (annular gap extending in the entire circumferential direction) G is provided between the inner circumferential surface of the shield connecting tube 232 and the outer circumferential surface of the first insulating layer 12. That is, the shield connecting tube 232 is disposed on the outer circumferential side of the first insulating layer 12 while providing an annular space G between the shield connecting tube 232 and the first insulating layer 12 .

[0031] As shown in FIGS. 2 and 3 , the shield braid 13 extending from the end of the second insulating layer 14 is electrically connected to the shield connecting tube 232. The electrically connected state between the shield braid 13 and the shield connecting tube 232 can be achieved, for example, as follows: First, a crimping tube 25 is prepared (Step 1). The crimping tube 25 is, for example, a cylindrical member made of a conductive material (e.g., a conductive metal). Then, the crimping tube 25 is provided so as to sandwich the shield braid 13 between itself and the shield connecting tube 232 (Step 2). Specifically, for example, the shield braid 13 extending forward from the end of the second insulating layer 14 is expanded radially outward and placed over the outer peripheral surface of the shield connecting tube 232, and the crimping tube 25 is provided on the outer peripheral side of the shield braid 13 placed over the outer peripheral surface of the shield connecting tube 232. Next, an applicator having a pair of pressing portions is prepared (Step 3). As an example, an applicator is prepared in which each pressing portion has a pressing surface that is shaped like half of a polygon (e.g., a hexagon) in cross section. Then, a crimping tube 25 (i.e., a crimping tube 25 provided on the outer periphery of the shield braid 13 that covers the outer periphery of the shield connecting tube 232) is disposed between a pair of pressing portions of the applicator, and the pair of pressing portions are moved toward each other (fourth step). This causes the crimping tube 25 to deform and be crimped to the shield connecting tube 232 (so-called square crimping). As a result, the shield braid 13 is crimped and fixed between the shield connecting tube 232 and the crimping tube 25, and the shield braid 13 and the shield connecting tube 232 are fixed while being electrically connected to each other.

[0032] (Cap 24) As shown in Fig. 4, the cap 24 includes, for example, a connecting portion 241 and an insertion portion 242. Here, the front end portion of the cap 24 forms the connecting portion 241, and the rear end portion of the cap 24 forms the insertion portion 242. The connecting portion 241 and the insertion portion 242 are both tubular (for example, cylindrical) and arranged on the same axis. The cap 24 may be made of a conductive material or an insulating material.

[0033] 1 and 3 , the cap 24 is connected to the shield housing 23 from the rear side. Specifically, for example, the inner diameter of the connecting portion 241 is approximately the same as the outer diameter of the shield shell 231, and the cap 24 is connected to the shield housing 23 so that the inner peripheral surface of the connecting portion 241 contacts the outer peripheral surface of the shield shell 231. As a result, the cap 24 is disposed coaxially with the shield housing 23 and connected to the shield housing 23. Meanwhile, the inner diameter of the insertion portion 242 is smaller than the inner diameter of the connecting portion 241, and a connecting tube portion 243 whose diameter decreases toward the rear is provided between the insertion portion 242 and the connecting portion 241. When the cap 24 is connected to the shield housing 23, the shield connecting tube 232 and the crimping tube 25, which are provided so as to sandwich the shield braid 13 between them, are housed inside the connecting tube portion 243. Here, when the cap 24 is connected to the shield housing 23, the front end face of the connection part 241 abuts against a stepped surface 231d provided on the outer peripheral surface of the shield shell 231, thereby restricting the front-rear position of the cap 24. This maintains the connecting tube part 243 in a positional relationship where it is not in contact with the shield connecting tube 232 and the like housed therein.

[0034] 1 and 3 , with the cap 24 connected to the shield housing 23, the portion of the shielded wire 1 that is covered with the second insulating layer 14 is inserted into the insertion portion 242. Here, the inner diameter of the insertion portion 242 is slightly larger than the outer diameter of the second insulating layer 14, and a gap is provided between the inner circumferential surface of the insertion portion 242 and the outer circumferential surface of the second insulating layer 14. A seal member 26 (e.g., a cylindrical seal member 26 made of an insulating material) is provided to fill this gap. As described above, the cap 24 is disposed coaxially with the shield housing 23 and connected to the shield housing 23. Therefore, by inserting the shielded wire 1 through the insertion portion 242, the shielded wire 1 is disposed coaxially with the shield housing 23.

[0035] <2. Usage State> In usage state, for example, a mating connector is connected to the connector 2 from the front side. In this state, terminals and the like provided on the mating connector are inserted into the front connection portions 211 of the terminals 21 and are electrically connected to the terminals 21. In addition, a shielding housing and the like provided on the mating connector are in contact with the shielding housing 23 (specifically, the shield shell 231) and are electrically connected to the shielding housing 23. The shielding braid 13 is grounded through the shielding housing 23. By grounding the shielding braid 13, leakage of electromagnetic waves from the conductor 11 to the outside is suppressed, and the influence of electromagnetic waves from the outside on the conductor 11 is also suppressed.

[0036] <3. Creepage Distance> The shielded wire 1 may be used, for example, as a power supply cable. In such a case, it is expected that the voltage of the conductor 11 will increase, and therefore, in the connector 2, a considerable creepage distance must be ensured between the conductor 11 exposed from the first insulating layer 12 and the shield braid 13 exposed from the second insulating layer 14. The connection structure 100 allows the size of the connector 2 to be reduced while ensuring the required creepage distance. This point will be explained with reference to FIG. 5. FIG. 5 is a schematic diagram illustrating the relationship between the connection structure 100 and the size of the connector 2.

[0037] As described above, in the connection structure 100, the shield connection tube 232, to which the shield braid 13 is electrically connected, is disposed with an annular space G between it and the first insulating layer 12. With this configuration, the creepage distance D between the conductor 11 and the shield braid 13 (hereinafter simply referred to as the "creepage distance") is determined by the distance in the front-to-rear direction from the end of the first insulating layer 12 to the end of the second insulating layer 14 (i.e., the length of the first insulating layer 12 exposed from the second insulating layer 14 in the front-to-rear direction; hereinafter referred to as the "exposed length of the first insulating layer 12"). That is, it is sufficient that the exposed length of the first insulating layer 12 is equal to or greater than the required creepage distance value. In other words, in the connection structure 100, by providing the annular space G, the portion T of the first insulating layer 12 that overlaps with the shield connection tube 232 in the front-to-rear direction can be included in the creepage distance D (counted as the creepage distance D). In other words, the annular space G increases the creepage distance D. Therefore, the size of the connector 2 can be reduced while ensuring the creepage distance D.

[0038] For comparison, consider a connection structure 900a according to a first comparative example in which the annular space G is not provided (i.e., the shield braid 13 and the conductive tubular member 91a electrically connected thereto are provided in contact with the first insulating layer 12). In this connection structure 900a, the portion Ta of the first insulating layer 12 that overlaps with the tubular member 91a in the front-to-rear direction cannot be counted as the creepage distance D. That is, the distance obtained by subtracting the length of the portion Ta that overlaps with the tubular member 91a from the exposed length of the first insulating layer 12 must be equal to or greater than the required creepage distance value. From another perspective, the exposed length of the first insulating layer 12 is the sum of the required creepage distance value and the length Ta of the tubular member 91a in the front-to-rear direction. Therefore, the size (front-to-rear direction size) of the connector 92a is larger than when the annular space G is provided. That is, in the connection structure 900 a according to the first comparative example, it is difficult to reduce the size of the connector 92 a to the same extent as the connector 2 of the connection structure 100 .

[0039] For further comparison, consider a connection structure 900b according to a second comparative example in which the shielding braid 13 is folded back and electrically connected to the conductive tubular member 91b on the outer periphery of the second insulating layer 14. In this connection structure 900b, similar to the connection structure 100, the creepage distance D is determined by the exposed length of the first insulating layer 12. That is, it is sufficient that the exposed length of the first insulating layer 12 is equal to or greater than the desired creepage distance value. However, in the connection structure 900b, the tubular member 91b is located behind the end of the second insulating layer 14 without overlapping with the first insulating layer 12 in the front-to-rear direction. Therefore, in order to accommodate the tubular member 91b, the size (front-to-rear dimension) of the connector 92b needs to be extended rearward by the length Tb of the tubular member 91b in the front-to-rear direction compared to when the shielding braid 13 is not folded back. That is, even in the connection structure 900 b according to the second comparative example, it is difficult to reduce the size of the connector 92 b to the same extent as the connector 2 of the connection structure 100 .

[0040] 4. Effects In the connection structure 100 between the shielded electric wire 1 and the connector 2 configured as described above, the connector 2 includes the shield connecting tube 232, which is disposed on the outer circumferential side of the first insulating layer 12 extending from the end of the second insulating layer 14, with an annular space G formed between the connector 2 and the first insulating layer 12. The shield braid 13 extending from the end of the second insulating layer 14 is electrically connected to the shield connecting tube 232. With this configuration, the annular space G is provided, so that the portion T of the first insulating layer 12 that overlaps with the shield connecting tube 232 in the front-to-rear direction can be included in the creepage distance D (counted as the creepage distance D). Therefore, the size of the connector 2 can be reduced while ensuring the creepage distance D.

[0041] Furthermore, in the connection structure 100, one axial end (rear side) of the shield housing 23 included in the connector 2 constitutes the shield connecting tube 232. That is, the connector 2 includes the shield housing 23 whose one axial end (rear side) constitutes the shield connecting tube 232. Therefore, the shield braid 13 can be grounded through the shield housing 23.

[0042] Furthermore, in the connection structure 100, the connector 2 includes a terminal 21 to which the conductor 11 is connected, and an inner housing 22 made of an insulating material that is housed in the shield housing 23 and supports the terminal 21 coaxially with the shield housing 23. In this case, the terminal 21, and therefore the shielded electric wire 1 connected to the terminal 21, are arranged coaxially with the shield housing 23, so that the annular space G can be stably maintained.

[0043] Moreover, in the connection structure 100, the connector 2 includes a cylindrical cap 24 that is connected to the shield housing 23. The portion of the shield wire 1 that is covered with the second insulating layer 14 is inserted into the cap 24, thereby arranging the shield wire 1 coaxially with the shield housing 23. In this case, because the shield wire 1 is arranged coaxially with the shield housing 23 by being inserted into the cap 24, the annular space G can be stably maintained.

[0044] Furthermore, in the connection structure 100, the shielded electric wire 1 is supported so as to be disposed on the same axis as the shield housing 23 at both a position forward of the shielded connecting tube 232 (a portion connected to the terminal 21) and a position rearward of the shielded connecting tube 232 (a portion inserted into the cap 24). Therefore, the annular space G can be maintained particularly stably.

[0045] Furthermore, in the connection structure 100, the connector 2 includes a crimping tube 25 that is provided so as to sandwich the shielding braid 13 between the connector 2 and the shielding connecting tube 232. The shielding braid 13 is then crimped and fixed between the shielding connecting tube 232 and the crimping tube 25. Therefore, it is possible to easily achieve a state in which the shielding braid 13 and the shielding connecting tube 232 are electrically connected.

[0046] [Modification] In the above embodiment, the state in which the shielding braid 13 and the shield connecting tube 232 are electrically connected may be formed, for example, as follows. That is, first, the shielding braid 13 extending forward from the end of the second insulating layer 14 is expanded radially outward and placed over the outer peripheral surface of the shield connecting tube 232. Next, a laser beam is irradiated onto the shielding braid 13 and the shield connecting tube 232 over which it is placed, and the shielding braid 13 and the shield connecting tube 232 are welded together by laser welding. As a result, as shown in FIG. 6 , a welded portion 27 is formed where the shield connecting tube 232 and the shielding braid 13 are welded together, and the shielding braid 13 and the shield connecting tube 232 are electrically connected and fixed together. When the shielding braid 13 and the shield connecting tube 232 are electrically connected together by laser welding, the crimping tube 25, which was required when connecting them by crimping, is not required. That is, the number of parts required to establish an electrical connection between the shield braid 13 and the shield connecting tube 232 can be reduced.

[0047] In the above embodiment, the role of arranging the shielded electric wire 1 and the shield housing 23 on the same axis may be played by only one of the internal housing 22 and the cap 24. For example, if the internal housing 22 supports the terminal 21 in a position on the same axis as the shield housing 23, thereby arranging the shielded electric wire 1 connected to the terminal 21 on the same axis as the shield housing 23, the cap 24 may be omitted. Furthermore, for example, if the shielded electric wire 1 is inserted through the cap 24 and thereby arranged on the same axis as the shield housing 23, the internal housing 22 may only play the role of insulating the terminal 21 from the shield housing 23.

[0048] In the above embodiment, the shield housing 23 and the cap 24 may be connected to each other to form an external housing (outer case). For example, if the connector 2 is a waterproof connector, the seal member 26 may serve as a stopper (e.g., a rubber stopper) to prevent water or the like from entering the interior of the external housing. That is, the seal member 26 may be in liquid-tight contact at its outer peripheral surface with the inner peripheral surface of the insertion portion 242 and in liquid-tight contact at its inner peripheral surface with the outer peripheral surface of the second insulating layer 14, thereby liquid-tightly sealing the gap between the insertion portion 242 and the shielded electric wire 1 inserted therethrough. On the other hand, if the connector 2 is not a waterproof connector, the seal member 26 may be omitted. Even if the seal member 26 is omitted, as long as the dimensional difference between the inner diameter of the insertion portion 242 and the outer diameter of the second insulating layer 14 is sufficiently small (e.g., sufficiently small relative to the radial dimension of the annular space G), the shielded electric wire 1 is positioned coaxially with the shield housing 23 when inserted through the insertion portion 242.

[0049] In the above embodiment, the shield housing 23 includes the shield shell 231 and the shield connecting tube 232. Here, the shield shell 231 may be formed integrally with the shield connecting tube 232, as in the above embodiment. Alternatively, the shield shell 231 may be formed separately from the shield connecting tube 232 and connected to the shield connecting tube 232 via a connecting member made of a conductive material. Furthermore, the shield shell 231 is not an essential element and may be omitted.

[0050] In the above embodiment, the shape and dimensions of each part of the connector 2 can be specified as appropriate. For example, the front connection part 211 of the terminal 21 may be pin-shaped. The rear connection part 212 of the terminal 21 may be open-barrel shaped. Furthermore, at least one of the inner casing 22, the shield casing 23, and the cap 24 may have a shape other than a cylinder (for example, a polygonal tube) on either or both of the inner and outer circumferential sides.

[0051] The configurations described in the above embodiments and modifications can be combined as appropriate as long as they are not mutually contradictory.

[0052] REFERENCE SIGNS LIST 1 shielded wire 11 conductor 12 first insulating layer 13 shield braid 14 second insulating layer 2 connector 21 terminal 211 front connection portion 212 rear connection portion 22 inner housing 221 peripheral wall 222 rear wall 222a through hole 222b recess 23 shield housing 231 base portion 231a large diameter surface 231b small diameter surface 231c inclined surface 231d step surface 232 shield connection tube 24 cap 241 connection portion 242 insertion portion 243 connecting tube portion 25 crimping tube 26 seal member 27 welded portion 100 connection structure G annular space D creepage distance

Claims

1. A connection structure between a connector and a shielded electric wire, the connection structure comprising a conductor, a first insulating layer covering the outer periphery of the conductor, a shielding braid provided on the outer periphery of the first insulating layer, and a second insulating layer covering the outer periphery of the shielding braid, wherein the connector comprises: a shield connection tube that is disposed on the outer periphery of the first insulating layer extending from the end of the second insulating layer, with an annular space formed between the first insulating layer and the shielding braid; and the shielding braid extending from the end of the second insulating layer is electrically connected to the shield connection tube.

2. A connection structure between a shielded electric wire and a connector as described in claim 1, wherein the connector comprises a shield housing, the portion of one end in the axial direction of which constitutes the shield connection tube.

3. A connection structure between a shielded electric wire and a connector as described in claim 2, wherein the connector comprises: a terminal to which the conductor is connected; and an internal housing made of an insulating material that is housed in the shielding housing and supports the terminal on the same axis as the shielding housing.

4. A connection structure between a shielded electric wire and a connector as set forth in claim 2 or 3, wherein the connector comprises a cylindrical cap connected to the shielded housing, and the portion of the shielded electric wire that is covered with the second insulating layer is inserted into the cap, thereby arranging the shielded electric wire on the same axis as the shielded housing.

5. A connection structure between a shielded electric wire and a connector as set forth in any one of claims 1 to 3, wherein the connector comprises a crimping tube provided so as to sandwich the shield braid between the shield connecting tube and the crimping tube, and the shield braid is crimped and fixed between the shield connecting tube and the crimping tube.

6. A connection structure between a shielded electric wire and a connector according to any one of claims 1 to 3, wherein the shield braid and the shield connection tube are welded together by laser welding.

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