Terminal structure of shield electric wire, electric wire with terminal, and electric wire with connector

Abstract

To provide a terminal structure of a shield electric wire that has a high tensile strength of a ferrule relative to a shield electric wire, has a compact structure, and is formed easily.SOLUTION: A terminal structure of a shield electric wire comprises: a ferrule 20 that has a cylindrical part 22 having an inner diameter larger than the outer diameter of a core part 11 of a shield electric wire 10, wherein the cylindrical part 22 is located between the core part 11 and an exposed portion of a shield layer 14 that is exposed after a predetermined length of casing 15 is peeled off; a ring-shaped sleeve 30 that has an inner diameter larger than the outer diameter of the shield electric wire 10, and is arranged at a position facing an outer peripheral surface of the cylindrical part 22 of the ferrule 20, while sandwiching the exposed portion of the shield layer 14; and a holder 40 that is located between an inner peripheral surface of the cylindrical part 22 and a portion of an outer peripheral surface of the core part 11 located on the side of an inner peripheral surface of the exposed portion of the shield layer 14, and holds a state in which the cylindrical part 22 is increased in diameter and deformed toward an inner peripheral surface of the sleeve 30 and the cylindrical part 22 is crimped and fixed to the sleeve with the exposed portion of the shield layer 14 therebetween.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a terminal structure of a shielded electric wire, an electric wire with a terminal, and an electric wire with a connector. [Background technology]

[0002] BACKGROUND ART Conventionally, shielded electric wires have been used in electric wires used in, for example, wire harnesses in automobiles in order to prevent leakage of electromagnetic waves to the outside or to suppress the influence of electromagnetic waves from the outside on the electric wires.

[0003] As such a shielded electric wire, for example, a shielded electric wire has been proposed in which a shield layer made of a braided wire is formed on the outer periphery of an insulated coated electric wire, and an outer sheath is formed on the outer periphery of this shield layer. When a terminal or the like is connected to the tip of such a shielded electric wire to form a connector, it is necessary to form a terminal structure for grounding the shield layer.

[0004] Fig. 9 is an explanatory diagram showing the steps of forming a conventional terminal structure. First, as shown in Fig. 9(b), the outermost outer sheath 103 of the shielded electric wire 100 shown in Fig. 9(a) is cut and removed over a predetermined length from the end to expose the shield layer 105 of the inner braided wire.

[0005] 9(c), the exposed shield layer 105 is cut to a predetermined length to expose the internal core portion 107. That is, a predetermined length of the shield layer 105 is exposed from the tip of the outer jacket 103, and a predetermined length of the core portion 107 is exposed from the tip of the shield layer 105. The core portion 107 is an electric wire in which a conductor (conductor wire) is insulated with an insulating layer.

[0006] Next, as shown in Fig. 9(d), a predetermined length of inner ferrule 109 is placed on the tip end of the outer jacket 103. The inner ferrule 109 is a ring-shaped metal member. Thereafter, as shown in Fig. 9(e), the exposed portion of the shielding layer 105 exposed from the tip end of the outer jacket 103 is folded back toward the outer jacket 103 (the inner ferrule 109 side). As a result, the inner ferrule 109 is covered with the exposed portion of the shielding layer 105.

[0007] 9(f), an outer ferrule 113 is placed on the outer peripheral surface of the exposed portion of the folded-back shield layer 105. The outer ferrule 113 is a metal annular member similar to the inner ferrule 109, and has an inner diameter larger than the outer diameter of the inner ferrule 109. With the outer ferrule 113 placed on the outer peripheral surface of the exposed portion of the shield layer 105, the outer ferrule 113 is compressively deformed from the outer peripheral surface side, thereby crimping and fixing the inner ferrule 109 and the outer ferrule 113 together with the exposed portion of the shield layer 105 sandwiched between them, thereby forming the terminal structure of the shielded electric wire.

[0008] After the termination structure of the shielded electric wire is formed, for example, a terminal is connected to the core portion 107, and the terminal is accommodated in the connector housing. At this time, the outer ferrule 113 is brought into contact (conductive) with a metal member arranged in the connector housing, and the metal member is connected to a ground wire, thereby grounding the shield layer of the shielded electric wire 100.

[0009] However, in the conventional terminal structure shown in Fig. 9 , the inner ferrule 109 and the outer ferrule 113 are fixed to the folded-back portion of the shield layer 105, which is made of a braided wire that easily expands and contracts. Therefore, the inner ferrule 109 and the outer ferrule 113, which are fixed while sandwiching the braided wire, follow the expansion and contraction of the shield layer 105 and are therefore not sufficiently fixed in the axial direction of the shielded wire 100 and tend to move easily. This raises concerns about a decrease in the tensile strength of these ferrules relative to the shielded wire 100. Furthermore, the inner ferrule 109 and the outer ferrule 113, which are fixed while sandwiching the exposed portion of the folded-back shield layer 105, are formed on the outer sheath 103 of the shielded wire 100 and tend to significantly protrude outward from the outer periphery of the shielded wire 100, resulting in an increase in the size of the structure in question. Furthermore, the required length of the exposed portion of the shield layer 105 increases by the amount of folding, making it impossible to perform stripping all at once. In addition, since it is necessary to fold back the shield layer 105, there is also room for improvement in terms of ease of forming the terminal structure. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-51141 [Patent Document 2] Patent Publication No. 2021-182467 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, an object of the present invention is to provide a terminal structure for a shielded electric wire that has a high tensile strength of the ferrule for the shielded electric wire, has a compact structure, and is easy to form, and to provide an electric wire with a terminal and an electric wire with a connector that are equipped with the same. [Means for solving the problem]

[0012] As a result of extensive research into the termination structure of a shielded electric wire, the inventors discovered that by using a structure in which the exposed portion of the shield layer of the shielded electric wire is sandwiched and crimped and fixed between the tubular portion and sleeve that make up the ferrule, without folding back the exposed portion of the shield layer, and by using holder 40 to maintain the tubular portion and sleeve in a crimped and fixed state, it is possible to increase the tensile strength of the ferrule with respect to the shielded electric wire and also improve work efficiency when forming the termination structure, which led to the completion of the present invention.

[0013] That is, the gist of the present invention is as follows. (1) An end structure of a shielded electric wire having a core portion in which a conductor is covered with an insulating layer, a shielding layer disposed on the outer periphery of the core portion, and an outer covering covering the outer periphery of the shielding layer, the end structure of the shielded electric wire comprising: a tubular portion having an inner diameter larger than the outer diameter of the core portion, the tubular portion being located between the core portion and an exposed portion of the shielding layer that is exposed when a predetermined length of the outer covering is peeled off; a ring-shaped sleeve having an inner diameter larger than the outer diameter of the shielded electric wire and located opposite the outer periphery of the tubular portion of the ferrule, with the exposed portion of the shielding layer sandwiched between them; and a holder located between a portion of the outer periphery of the core portion that is located on the inner periphery side of the exposed portion of the shielding layer and the inner periphery of the tubular portion of the ferrule, the holder deforming the tubular portion toward the inner periphery of the sleeve to expand the diameter of the tubular portion toward the inner periphery of the sleeve, thereby maintaining the tubular portion in a state where it is crimped and fixed to the sleeve via the exposed portion of the shielding layer. (2) The terminal structure of the shielded electric wire according to (1) above, wherein the material constituting the sleeve and the holder is stronger than the material constituting the cylindrical portion of the ferrule. (3) The terminal structure of the shielded electric wire according to (1) or (2) above, wherein the thickness of the cylindrical portion of the ferrule is thinner than the thickness of the sleeve. (4) An electric wire with terminal having the terminal structure of the shielded electric wire described in any one of (1) to (3) above, characterized in that a predetermined length of the insulating layer is peeled off from the tip of the core portion, and the part of the conductor exposed by the peeling is connected to a terminal. (5) A connector-attached electric wire in which the terminal-attached electric wire described in (4) above is accommodated in a connector housing, characterized in that a metal member is arranged in the connector housing over an area facing the terminal and the ferrule, and the ferrule and the metal member are electrically conductive. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a terminal structure for a shielded electric wire that has a high tensile strength of the ferrule relative to the shielded electric wire, has a compact structure, and is easy to form, as well as an electric wire with a terminal and an electric wire with a connector that include the same.

[0015] Furthermore, the present invention can provide a method for forming a terminal structure of a shielded electric wire that can easily form a terminal structure of a shielded electric wire having these excellent properties while simplifying the working process. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a longitudinal sectional view showing an end structure of a shielded electric wire according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a connector-attached electric wire in which a terminal-attached electric wire having the terminal structure of a shielded electric wire according to an embodiment of the present invention is accommodated in a connector housing. [Figure 3] 1 is a longitudinal cross-sectional view of a shielded electric wire used to form a terminal structure of a shielded electric wire according to an embodiment. FIG. [Figure 4] FIG. 2 is an enlarged perspective view of a ferrule used in the terminal structure of the shielded electric wire according to the embodiment. [Figure 5] 1 is a longitudinal cross-sectional view showing the state of the tip of the shielded electric wire after a stripping step is performed in the production of the terminal structure of the shielded electric wire. FIG. [Figure 6] 10 is a longitudinal cross-sectional view showing the state of the tip end of the shielded electric wire after a sleeve fitting step is performed in the production of the terminal structure of the shielded electric wire. FIG. [Figure 7]10 is a longitudinal cross-sectional view showing the state of the tip end of the shielded electric wire after a ferrule arrangement step is performed in the production of the terminal structure of the shielded electric wire. FIG. [Figure 8] 10 is a longitudinal cross-sectional view showing the state of the tip end of the shielded electric wire after a sleeve arrangement step is performed in the production of the terminal structure of the shielded electric wire. FIG. [Figure 9] 10A and 10B are explanatory diagrams showing a process for forming a conventional terminal structure of a shielded electric wire. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shielded wire terminal structure and a method for forming the same according to an embodiment of the present invention will be described below with reference to the drawings.

[0018] [Shielded wire terminal structure] First, the terminal structure of the shielded electric wire according to this embodiment will be described.

[0019] 1 is a longitudinal cross-sectional view showing the terminal structure of a shielded electric wire according to this embodiment. As shown in Fig. 1, the terminal structure 1 of a shielded electric wire according to this embodiment (hereinafter, may be simply referred to as "terminal structure") includes a shielded electric wire 10, a ferrule 20, a sleeve 30, and a holder 40.

[0020] The shielded wire termination structure 1 according to this embodiment is an termination structure of a shielded wire 10 having a core portion 11 in which a conductor 12 is covered with an insulating layer 13, a shield layer 14 arranged on the outer periphery of the core portion 11, and an outer sheath 15 covering the outer periphery of the shield layer 14, and has a tubular portion 22 having an inner diameter larger than the outer diameter of the core portion 11, and the tubular portion 22 is provided with a ferrule 20 positioned between the core portion 11 and an exposed portion of the shield layer 14 exposed when a predetermined length of the outer sheath 15 is peeled off, and the sleeve 30 has a large inner diameter and is arranged opposite the outer peripheral surface of the cylindrical portion 22 of the ferrule 20, with the exposed portion of the shielding layer 14 sandwiched between them; and a holder 40 is arranged between the outer peripheral surface of the core portion 11 located on the inner peripheral side of the exposed portion of the shielding layer 14 and the inner peripheral surface of the cylindrical portion 22 of the ferrule 20, and deforms the cylindrical portion 22 toward the inner peripheral surface of the sleeve 30 to expand its diameter and maintain the cylindrical portion 22 in a state where it is crimped and fixed to the sleeve via the exposed portion of the shielding layer 14.

[0021] As a result, by adopting a configuration in which the tubular portion 22 of the ferrule 20 is crimped and fixed to the sleeve 30 with the exposed portion of the shielding layer 14 sandwiched therebetween and the holder 40 maintains the crimped and fixed state of the tubular portion 22 and the sleeve 30 with the exposed portion of the shielding layer 14 sandwiched therebetween, the ferrule 20 is firmly fixed to the shielded electric wire 10, thereby increasing the tensile strength of the ferrule with respect to the shielded electric wire compared to a conventional shielded electric wire termination structure that adopts a configuration in which the folded-back exposed portion of the shielding layer 14 is sandwiched between the ferrule 20 and the insulating layer 13 of the shielded electric wire 10. Furthermore, the tip portion of the shielded electric wire 10 is exposed in order from the tip 10e so that the outer circumferential surface of the conductor 12, the outer circumferential surface of the insulating layer 13, and the outer circumferential surface of the shielding layer 14 each become the outermost periphery, and then stripped in a stepped pattern, and then the ferrule 20 can be fixed to the exposed portion of the shielding layer 14 of the shielded electric wire 10 without folding back the exposed portion of the shielding layer 14, thereby improving work efficiency when forming the termination structure 1. Furthermore, since the ferrule 20 is fixed to the shielded electric wire 10 not on the outer peripheral surface of the outer sheath 15 of the shielded electric wire 10 but on the outer peripheral surface of the core portion 11, which has a smaller outer diameter than the shielded electric wire 10, the overall size of the terminal structure of the shielded electric wire to which the ferrule 20 is fixed can be reduced.

[0022] Therefore, it is possible to provide a terminal structure for a shielded electric wire that has a high tensile strength of the ferrule relative to the shielded electric wire, has a compact structure, and is easy to form, as well as an electric wire with a terminal and an electric wire with a connector that include the same.

[0023] 3 is a longitudinal cross-sectional view of a shielded electric wire 10. The terminal structure of the shielded electric wire 10 includes a core 11 in which a conductor 12 is covered with an insulating layer 13, a shield layer 14 disposed on the outer periphery of the core 11, and an outer sheath 15 that covers the outer periphery of the shield layer 14. Of these, the conductor 12 is made of a conductive metal or alloy, such as copper or a copper alloy, aluminum or an aluminum alloy, iron or an iron alloy (such as stainless steel), silver or a silver alloy, etc. The insulating layer 13 and the outer sheath 15 are made of an insulating resin, such as polyvinyl chloride or polyethylene.

[0024] The shield layer 14 is an electrically conductive layer made of a metal or alloy, such as copper or a copper alloy, aluminum or an aluminum alloy, iron or an iron alloy such as stainless steel, or silver or a silver alloy. Examples of the shield layer 14 include a braided wire made of these metal or alloy wires, a foil-wound wire made of unbraided metal or alloy foil wound in a spiral shape, or a layer made of a conductive polymer. The shield layer 14 may have any of these structures. It may also have a structure combining two or more of these layers (for example, a laminate of a braided wire layer and a foil-wound wire layer). The shield layer 14 is easily stretched and deformed.

[0025] The tip of the shielded electric wire 10 is stripped in a stepped manner, starting from the tip 10e, so that the outer periphery of the conductor 12, the outer periphery of the insulating layer 13, and the outer periphery of the shielding layer 14 are exposed, respectively, to form the outermost periphery.

[0026] In this specification, the "tip portion" of the shielded electric wire 10 refers to a portion of the shielded electric wire 10 including the tip 10e. More specifically, it refers to an area extending from the tip 10e of the shielded electric wire 10 to which the influence of various deformations, addition of members, and the like caused by the terminal structure 1 according to this embodiment extends.

[0027] FIG. 4 is an enlarged perspective view of a ferrule 20 used to form the shielded wire termination structure 1 according to this embodiment. As shown in FIGS. 1 and 4 , the ferrule 20 has a tubular portion 22 with an inner diameter larger than the outer diameter of the core portion 11 of the shielded wire 10. The tubular portion 22 is configured to be located between the core portion 11 and an exposed portion of the shield layer 14 that is exposed when a predetermined length of the outer jacket 15 is peeled off from the tip end of the shielded wire 10. Here, the ferrule 20 may include, in addition to the tubular portion 22, a connection portion 21 and a linking portion 23 that connects the connection portion 21 and the tubular portion 22. Furthermore, the ferrule 20 has the tubular portion 22 and the connection portion 21 integrally formed. The ferrule 20 is a component that terminates an electric wire. The ferrule 20 is a conductive member made of, for example, a metal, such as copper or a copper alloy, aluminum or an aluminum alloy, or iron or an iron alloy (e.g., stainless steel), and has a hardness that allows it to maintain a predetermined shape.

[0028] The connecting portion 21 of the ferrule 20 is connected to a connected portion (not shown) of an external electronic device. Here, the external electronic device refers to an electronic device separate from the shielded electric wire 10 and the terminal structure of the shielded electric wire according to this embodiment, and examples thereof include various ECUs (Electronic Control Units), control devices, various motors, monitors, meters, various lamps, various sensors, and various other electrical components installed in automobiles. In addition, the connected portion of the external electronic device may be, but is not limited to, a connector 60 described below. It may be anything electrically connected to the external electronic device, for example, a device directly provided on the external electronic device, or a device connected to the external electronic device via a cable or the like. In particular, when the connected portion of the external electronic device is a connector 60 as shown in FIG. 2, the shape of the connecting portion 21 of the ferrule 20 preferably corresponds to the shape of the connector 60.

[0029] In Figure 4, the connection portion 21 of the ferrule 20 has a shape with a rectangular opening, but this is not limited to this, and the shape of the opening is not particularly limited as long as it can be a shape that can be connected to the metal member 61 of the connector 60, such as a circle, an ellipse, another polygon, or an irregular shape.

[0030] The cylindrical portion 22 of the ferrule 20 has an inner diameter larger than the outer diameter of the core portion 11 of the shielded wire 10 and is positioned between the core portion 11 and an exposed portion of the shielding layer 14 that is exposed when a predetermined length of the outer jacket 15 is peeled off. Preferably, the cylindrical portion 22 is positioned adjacent to the inner circumferential surface of the shielding layer 14. Since the cylindrical portion 22 has an inner diameter larger than the outer diameter of the core portion 11, a gap is formed at least partially between the cylindrical portion 22 and the core portion 11. Therefore, a holder 40 can be inserted into this gap from the tip end of the shielded wire 10 to apply an outward force to the cylindrical portion 22 and the shielding layer 14, thereby crimping and fixing them to a sleeve 30 (described later). The thickness of the cylindrical portion 22 can be approximately the same as the thickness of the shielding layer 14, as shown in FIG. 1 , for example.

[0031] Here, it is preferable that the thickness of the tubular portion 22 of the ferrule 20 is thinner than the thickness of the sleeve 30, which will be described later. This makes it easier for the tubular portion 22 to undergo radial expansion and deformation when the tubular portion 22 is crimped and fixed to the sleeve 30, so that the tubular portion 22 and the shield layer 14 can be crimped and fixed to the sleeve 30 more reliably.

[0032] The sleeve 30 has a ring-like shape and an inner diameter larger than the outer diameter of the shielded wire 10. This makes it possible to arrange the ferrule 20 in a state in which the sleeve 30 is previously arranged at a position on the outer circumferential surface of the jacket 15 away from the tip of the shielded wire 10 when forming the termination structure 1 for the shielded wire, thereby making it easier to form the termination structure 1. On the other hand, it is preferable that the sleeve 30 have an inner diameter larger than the outer diameter of the cylindrical portion 22 of the ferrule 20, from the viewpoint of providing a space between the sleeve 30 and the cylindrical portion 22 for sandwiching the shielding layer 14 and more efficiently attaching the ferrule 20 and the sleeve 30.

[0033] The sleeve 30 is disposed at a position facing the outer peripheral surface of the tubular portion 22 of the ferrule 20, and is disposed so that when the tubular portion 22 is deformed by expanding its diameter using a holder 40 (described later), the tubular portion 22 is crimped and fixed with the exposed portion of the shielding layer 14 sandwiched between them. At this time, the sleeve 30 serves as a crimping receiving portion when the holder 40 (described later) crimps the tubular portion 22 from the inside at a position facing the outer peripheral surface of the tubular portion 22 with the shielding layer 14 sandwiched between them, thereby crimping the tubular portion 22 and the shielding layer 14. Therefore, the ferrule 20 is firmly attached to the shielded wire 10 with high tensile strength.

[0034] The holder 40 is positioned between the inner peripheral surface of the tubular portion 22 and a portion of the outer peripheral surface of the core portion 11 located on the inner peripheral surface side of the exposed portion of the shield layer 14, and deforms the tubular portion 22 of the ferrule 20 to expand in diameter toward the inner peripheral surface of the sleeve 30, thereby maintaining a state in which the tubular portion 22 is crimped and fixed to the sleeve 30 via the exposed portion of the shield layer 14. At this time, the holder 40 deforms and crimps the tubular portion 22 from the inside in the direction expanding in diameter, thereby enabling the tubular portion 22 to be crimped and fixed to the sleeve 30 with the end of the shield layer 14 sandwiched between them. At the same time, the holder 40 maintains a state in which the tubular portion 22 is crimped and fixed to the sleeve 30 via the exposed portion of the shield layer 14, thereby maintaining a state in which the ferrule 20 is firmly fixed to the shielded electric wire 10, thereby increasing the tensile strength of the ferrule relative to the shielded electric wire.

[0035] The shape of the holder 40 may be such that it can at least partially expand the diameter of the cylindrical portion 22 of the ferrule 20, and may be such that it expands the diameter of the entire cylindrical portion 22, like a cylindrical jig. Alternatively, it may be such that it expands the diameter of only a part of the cylindrical portion 22, like a jig with a partial cutout or a wedge.

[0036] The holder 40 preferably has a protrusion 40a on its outer peripheral surface facing the cylindrical portion 22 of the ferrule 20. As a result, when the holder 40 is fitted and disposed between the cylindrical portion 22 and the core portion 11 (gap 14g), a force that expands and deforms the cylindrical portion 22 acts more strongly on the portion of the inner peripheral surface of the cylindrical portion 22 that faces the protrusion 40a than on other portions, and therefore the cylindrical portion 22 can be more strongly crimped and fixed to the sleeve 30 at and near the protrusion 40a.

[0037] The protrusions 40a on the outer peripheral surface of the holder 40 preferably have a shape that exerts an elastic force toward the opposing tubular portion 22. Examples of such shapes include a shape in which an end of the holder 40 is folded back, or a shape in which at least a portion of the holder 40 is bent so as to be convex toward the tubular portion 22. By forming the protrusions 40a in such a shape in which at least a portion of the holder 40 is folded back or bent back, an elastic force similar to that of a leaf spring acts from the holder 40 toward the tubular portion 22 when the tubular portion 22 of the ferrule 20 is deformed and expanded in diameter, and therefore the holder 40 can more firmly maintain the state in which the tubular portion 22 is crimped and fixed to the sleeve 30 with the shield layer 14 sandwiched therebetween.

[0038] Here, when the shape of the convex portion 40a of the holder 40 is at least partially folded or bent, the holder 40 may have a partial notch along the extension direction of the shielded electric wire 10 in order to facilitate the formation of the holder 40 by the bending process.

[0039] The inner surface of the holder 40 faces the outer surface of the insulating layer 13. Here, as shown in Fig. 1, the entire inner surface of the holder 40 may be in contact with the outer surface of the insulating layer 13, or a portion of the inner surface of the holder 40 may be in contact with the outer surface of the insulating layer 13, or the inner surface of the holder 40 may not be in contact with the outer surface of the insulating layer 13. In addition, the outer surface of the holder 40 presses against the inner circumferential surface of the tubular portion 22 of the ferrule 20. The shield layer 14 (the exposed portion of the shield layer 14) is not disposed on the inner surface side of the holder 40.

[0040] The material constituting one or both of the sleeve 30 and the holder 40 is preferably stronger than the material constituting the tubular portion 22 of the ferrule 20. This makes it less likely for the sleeve 30 and the holder 40 to deform when the tubular portion 22 is crimped and fixed to the sleeve 30 using the holder 40, thereby making it possible to more reliably crimp and fix the tubular portion 22 (and the exposed portion of the shielding layer 14) to the sleeve 30. On the other hand, the material constituting one or both of the sleeve 30 and the holder 40 may be the same material as the ferrule 20. In cases where the sleeve 30 and the holder 40 are made of the same material as the ferrule 20, it is preferable that the thickness of the tubular portion 22 of the ferrule 20 be thinner than the sleeve 30 and the holder 40.

[0041] The thicknesses of the sleeve 30 and the holder 40 are set appropriately depending on the application of the termination structure 1, but are preferably greater than the thickness of the tubular portion 22 of the ferrule 20. In particular, when the sleeve 30 is made of the same material as the ferrule 20, it is more preferable that the thicknesses of the sleeve 30 and the holder 40 are greater than the thickness of the tubular portion 22 of the ferrule 20. In this way, the material making up the sleeve 30 and the holder 40 has a strength greater than or equal to that of the tubular portion 22 of the ferrule 20, thereby increasing the tensile strength of the ferrule 20 relative to the shielded wire 10, even compared to conventional shielded wire termination structures that employ a configuration in which the exposed portion of the folded-back shield layer 14 is sandwiched between the ferrule 20 and the insulating layer 13 or outer jacket 15 of the shielded wire 10.

[0042] [Wire with terminals] In this embodiment, an electric wire with terminal 5 can be configured having the above-described shielded electric wire termination structure 1. As shown in FIG. 2 , the electric wire with terminal 5 has a terminal 50 connected to an end of a conductor 12, and the conductor 12 and the terminal 50 can be connected by welding, such as ultrasonic welding. Here, the electric wire with terminal 5 is formed by peeling a predetermined length of the insulating layer 13 from the tip of the core portion 11 of the shielded electric wire 10, and connecting the portion of the conductor 12 exposed by the peeling to the terminal 50, thereby electrically connecting the terminal 50 and the conductor 12. In particular, when the electric wire with terminal 5 is formed from the above-described shielded electric wire termination structure 1, the shielded electric wire termination structure 1 is in a state in which a predetermined length of the insulating layer 13 is peeled from the tip of the core portion 11 of the shielded electric wire 10, exposing the conductor 12. Therefore, the electric wire with terminal 5 can be formed by connecting the exposed conductor 12 in the shielded electric wire termination structure 1 to the terminal 50. In particular, in this electric wire with terminal 5, the holder 40 holds the cylindrical portion 22 of the ferrule 20 in a crimped and fixed state to the sleeve 30 by sandwiching the exposed portion of the shielding layer 14, so that the terminal 50 connected to the ferrule 20 can be firmly fixed to the shielded electric wire 10. The terminal 50 may be electrically connected to another connection terminal or a connection terminal (not shown) provided on a connected portion of an external electronic device. Note that, in the electric wire with terminal 5, components other than the terminal 50 may be attached to the terminal 50 from the viewpoint of locking the terminal 50 at a predetermined position inside a connector 60 (described later) and from the viewpoint of ensuring electrical continuity of the shielding layer 14 of the shielded electric wire 10.

[0043] [Wire with connector] FIG. 2 is a schematic diagram showing a connector-attached electric wire in which a terminal-attached electric wire 5 having a shielded electric wire termination structure 1 according to an embodiment of the present invention is accommodated in a connector. As shown in FIG. 2, the terminal-attached electric wire 5 described above may constitute a connector-attached electric wire 6 accommodated in a connector 60, more specifically, a connector housing 60a. In this connector-attached electric wire 6, a metal member 61 is disposed in the connector housing 60a over an area facing the terminal 50 and the ferrule 20, and the ferrule 20 and the metal member 61 are configured to be electrically conductive. The shape of the metal member 61 is not particularly limited as long as it has a shape that roughly corresponds to the outer shape of the ferrule 20. Note that FIG. 2 shows a case in which the shape of the metal member 61 is formed into a rectangular tube shape.

[0044] The terminal 50 constituting the terminal-fitted electric wire 5 is disposed at the tip side of the connector 60, and by inserting another terminal to be connected, the terminals can be electrically connected to each other. Meanwhile, inside the connector 60, the ferrule 20 comes into contact with a metal member 61 for electrical continuity. The metal member 61 is connected to a ground wire (not shown), so that the shield layer 14 constituting the shielded electric wire 10 can be grounded.

[0045] [Example of a method for forming the terminal structure of a shielded electric wire] Next, an example of a method for forming the shielded electric wire termination structure 1 according to this embodiment will be described. The shielded electric wire termination structure 1 can be produced using a method including, for example, a stripping step, a sleeve fitting step, a ferrule arrangement step, a sleeve arrangement step, a crimping step, and a terminal connection step.

[0046] (Strip process) The stripping step is a step of stripping the tip of the shielded electric wire 10 shown in Fig. 3. Fig. 5 is a vertical cross-sectional view showing the state of the tip of the shielded electric wire 10 after the stripping step.

[0047] In the stripping process, as shown in Fig. 5, the shielded electric wire 10 is stripped starting from the tip 10e so that the outer peripheral surfaces (12s, 13s, 14s) of the conductor 12, insulating layer 13, and shielding layer 14 appear in a stepped pattern. This stripping process involves stripping and exposing the outer sheath 15, shielding layer 14, and insulating layer 13 sequentially from the side of the shielded electric wire 10 farthest from the tip 10e (the right side in Fig. 5) toward the tip 10e. This allows all stripping processes to be completed in a single operation, thereby improving work efficiency when forming the termination structure 1. The stripping process can be performed using conventionally known devices and tools, such as a measuring stripping device.

[0048] (Sleeve fitting process) The sleeve fitting step is a step of fitting the sleeve 30 from the tip 10e of the shielded electric wire 10 to a position above the outer sheath portion 15s of the shielded electric wire 10 where the outer sheath 15 has not been stripped in the stripping step. Fig. 6 is a vertical cross-sectional view showing the state of the tip portion of the shielded electric wire 10 after the sleeve fitting step has been performed.

[0049] 6, in the sleeve fitting step, the sleeve 30 is fitted onto the tip end of the shielded electric wire 10 from the tip end, and is disposed in advance at a position on the outer sheath portion 15s of the shielded electric wire 10 from which the outer sheath 15 has not been stripped in the stripping step. In this embodiment, a metal ring-shaped molded product is used as the sleeve 30.

[0050] Thereafter, the exposed portion of the shield layer 14 constituting the shielded electric wire 10 is expanded (expanded in diameter) to form a horn-like shape (reference numeral 14f), and a gap 14g is provided between the insulating layer 13 and the exposed portion. As will be described later, the cylindrical portion 22 of the ferrule 20 and the holder 40 are fitted into this gap 14g. Here, one method for expanding the shield layer 14 of the shielded electric wire 10 to form the gap 14g is to loosen the braid of the shield layer 14 and bend it outward to expand it into a horn-like shape. Figure 6 shows the shield layer 14 in the horn-shaped shape (reference numeral 14f).

[0051] (Ferrule placement process) The ferrule placement process is a process in which, after the stripping process and the sleeve fitting process, the cylindrical portion 22 of the ferrule 20 is fitted from the side of the tip portion 14e of the shield layer 14 into the gap 14g between the shield layer 14 and the core portion 11, more precisely, between the insulating layer 13. Before this process is performed, the shield layer diameter expansion process is performed to expand the shield layer 14 and provide the gap 14g, which allows the cylindrical portion 22 of the ferrule 20 to be fitted smoothly into the gap 14g.

[0052] 7 is a vertical cross-sectional view showing the state of the tip end of the shielded wire 10 after the ferrule arrangement step has been performed. Fig. 7 shows the state in which the trumpet-shaped portion 14f of the shielding layer 14 is further expanded (jumped up) when the cylindrical portion 22 of the ferrule 20 is fitted into the small gap 14g between the shielding layer 14 and the core portion 11.

[0053] (Sleeve placement process) In the forming method of this embodiment, the sleeve arrangement step is a step of moving the sleeve 30 along the axial direction of the shielded electric wire 10 toward the tip of the shielded electric wire 10, and arranging the sleeve 30 in a position facing the outer circumferential surface of the tubular portion 22 with the exposed portion of the shield layer 14 sandwiched between them. In the sleeve arrangement step, the sleeve 30 moves in the direction indicated by arrow X in FIG. 7 .

[0054] 8 is a vertical cross-sectional view showing the state of the tip end of the shielded wire 10 after the sleeve placement step. In the sleeve placement step, the trumpet-shaped portion 14f of the expanded (flung up) shield layer 14 is pressed down and placed over the outer circumferential surface of the tubular portion 22 when the sleeve 30 is moved to a position facing the outer circumferential surface of the tubular portion 22. In other words, the exposed portion of the shield layer 14 is sandwiched between the tubular portion 22 of the ferrule 20 and the sleeve 30.

[0055] (Holder placement process) The holder placement step is a step of placing the holder 40 by fitting it into the gap 14g between the tubular portion 22 and the core portion 11 from the side of the tip 10e of the shielded electric wire 10 along the direction indicated by arrow Y in Fig. 8. As a result, the tubular portion 22 of the ferrule 20 is at least partially expanded in diameter at a position facing the outer circumferential surface of the tubular portion 22 and is crimped onto the inner circumferential surface of the sleeve 30, so that the shield layer 14 sandwiched between the tubular portion 22 and the sleeve 30 can be crimped and fixed onto the inner circumferential surface of the sleeve 30 with the exposed portion of the shield layer 14 sandwiched therebetween, and as a result, the termination structure 1 for the shielded electric wire 10 shown in Fig. 1 can be formed.

[0056] By using this method of forming the terminal structure 1 of a shielded electric wire, the tip portion of the shielded electric wire 10 can be stripped in order from the tip 10e so that the outer surface of the conductor 12, the outer surface of the insulating layer 13, and the outer surface of the shielding layer 14 each become the outermost circumference, and since the work of folding back the shielding layer 14 is not required, the terminal structure 1 of a shielded electric wire with excellent properties can be easily formed by simplifying the work process.

[0057] [Example of a method for forming a terminal-attached wire] After forming the shielded electric wire termination structure 1, a terminal connecting step may be performed in which a terminal 50 is connected to the end of the conductor 12. By performing the terminal connecting step, the terminal-equipped electric wire 5 is formed. Here, the conductor 12 and the terminal 50 can be connected by welding, for example, ultrasonic welding. Of course, the conductor 12 and the terminal 50 may be connected by other connection methods than welding, such as soldering, crimping, or locking.

[0058] [Example of a method for forming a connector-attached electric wire] After the electric wire with terminal 5 is formed, a connector connecting step may be performed in which the electric wire with terminal 5 is attached to the connector 60, more specifically, to the connector housing 60a. In the connector connecting step, a connector 60 is used in which a metal member 61 is arranged in the connector housing 60a over an area facing the terminal 50 and the ferrule 20, and the terminal 50 of the electric wire with terminal 5 is inserted into the terminal insertion portion of the connector housing 60a, and the shielding layer 14 is brought into contact with the connection portion 21 of the ferrule 20. This prevents contact between the terminal 50 inserted into the terminal insertion portion and the metal member 61, and also enables electrical conduction between the shielding layer 14 and the metal member 61 arranged on the inner surface of the terminal insertion portion of the connector housing 60a.

[0059] The above-described embodiments merely show typical examples of the present invention, and the present invention is not limited to the above-described embodiments. For example, in the above-described embodiments, the shielded electric wire 10 is described as a shielded electric wire of a so-called coaxial cable, in which the core portion 11 is made of one conductor wire 12 covered with one insulating layer 13. However, in the present invention, the core portion may be a bundle of two or more electric wires (i.e., conductor wires covered with an insulating layer). Furthermore, in the above-described embodiments, the conductor wire 12 is described as a single wire, but the conductor wire 12 of the present invention may be a twisted wire in which two or more wires are twisted together.

[0060] In addition, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the gist of the present invention. As long as such modifications still provide the configuration of the shielded electric wire terminal structure, electric wire with terminal, and electric wire with connector of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0061] 1: Terminal structure of shielded wire 5: Wire with terminal 6: Wire with connector 10: Shielded wire 11: Core section 12: Conductor 13: Insulating layer 14: Shield layer 15:Outer cover 15s: outer sheath of shielded wire 20: Ferrule 21: Connection 22: Cylindrical part 23:Connection part 30: Sleeve 40: Holder 40a: Convex part of the holder 50: Terminal 60: Connector 61: Metal parts 100: Shielded wire 103:Outer cover 105: Shield layer 107: Core section 109: Inner ferrule 113: Outer ferrule

Claims

1. A terminal structure of a shielded electric wire having a core portion in which a conductor is covered with an insulating layer, a shield layer disposed on the outer periphery of the core portion, and an outer sheath covering the outer periphery of the shield layer, a ferrule having a cylindrical portion having an inner diameter larger than an outer diameter of the core portion, the cylindrical portion being positioned between the core portion and an exposed portion of the shielding layer exposed when a predetermined length of the outer jacket is stripped off; a ring-shaped sleeve having an inner diameter larger than an outer diameter of the shielded wire, the ring-shaped sleeve being disposed at a position facing an outer peripheral surface of the cylindrical portion of the ferrule in a state in which the exposed portion of the shielding layer is sandwiched between the sleeve and the exposed portion; a holder that is positioned between an outer peripheral surface of the core portion that is located on the inner peripheral surface side of the exposed portion of the shielding layer and an inner peripheral surface of the cylindrical portion of the ferrule, and that deforms the cylindrical portion to expand in diameter toward the inner peripheral surface of the sleeve, thereby maintaining a state in which the cylindrical portion is crimped and fixed to the sleeve via the exposed portion of the shielding layer; A terminal structure of a shielded electric wire comprising:

2. 2. The shielded wire terminal structure according to claim 1, wherein the material constituting the sleeve and the holder has a strength higher than that of the material constituting the cylindrical portion of the ferrule.

3. 2. The shielded wire terminal structure according to claim 1, wherein the cylindrical portion of the ferrule has a thickness smaller than a thickness of the sleeve.

4. A terminal-attached electric wire having the terminal structure of the shielded electric wire according to any one of claims 1 to 3, The electric wire with terminal is characterized in that a predetermined length of the insulating layer is peeled off from the tip of the core portion, and the portion of the conductor exposed by the peeling is connected to a terminal.

5. A connector-attached electric wire in which the terminal-attached electric wire according to claim 4 is accommodated in a connector housing, a metal member is disposed in the connector housing over an area facing the terminal and the ferrule; The connector-attached electric wire is characterized in that the ferrule and the metal member are electrically connected to each other.

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