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 1 of a shield electric wire 10 has a core part 11 in which a conducting wire 12 is covered with an insulating layer 13, a shield layer 14 that is arranged on the outer periphery of the core part 11, and a casing 15 that covers the outer periphery of the shield layer 14, and comprises: a ferrule 20 that has a cylindrical part 22 having an inner diameter larger than the outer diameter of the core part 11, wherein the cylindrical part 22 is located between the core part 11 and an exposed portion of the shield layer 14 that is exposed after a predetermined length of casing 15 is peeled off; and a ring-shaped sleeve 30 that has an inner diameter larger than the outer diameter of the shield electric wire 10, is arranged at a position facing an outer peripheral surface of the cylindrical part 22 of the ferrule 20, and is crimped and fixed at the cylindrical part 22, with the cylindrical part 22 being increased in diameter and deformed and sandwiching the exposed portion of the shield layer 14.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. 13 is an explanatory diagram showing the steps of forming a conventional terminal structure. First, as shown in Fig. 13(b), the outermost outer sheath 103 of the shielded electric wire 100 shown in Fig. 13(a) is cut and removed over a predetermined length from the end to expose the shield layer 105 of the inner braided wire.

[0005] 13(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. 13(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. 13(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] 13(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, like 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. 13 , 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, is compact in 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 terminal 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 between a cylindrical portion and a sleeve that make up the ferrule, without folding back the exposed portion of the shield layer, it is possible to increase the tensile strength of the ferrule relative to the shielded electric wire and also improve work efficiency when forming the terminal structure, and thus completed 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 arranged on the outer periphery of the core portion, and an outer covering covering the outer periphery of the shielding layer, the end structure of a shielded electric wire comprising: a tubular portion having an inner diameter larger than the outer diameter of the core portion, the tubular portion being an exposed portion of the shielding layer exposed when a predetermined length of the outer covering is peeled off, a ferrule positioned between the tubular portion and the core portion, and a ring-shaped sleeve having an inner diameter larger than the outer diameter of the shielded electric wire, positioned at a position facing the outer periphery of the tubular portion of the ferrule, and crimping and fixing the tubular portion while sandwiching the exposed portion of the shielding layer by expanding and deforming the tubular portion. (2) The terminal structure of the shielded electric wire according to (1) above, wherein the material constituting the sleeve 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]10 is a longitudinal cross-sectional view showing the state of the tip of the shielded electric wire when a pressing tool is inserted between a cylindrical portion and a core portion in a crimping step in the manufacture of the terminal structure of the shielded electric wire. FIG. [Figure 10] 10(a) and 10(b) are plan views showing the main parts of a pressing tool having a shape in which the diameter of a protruding portion is substantially constant, as another example of a pressing tool used to fabricate a terminal structure of a shielded electric wire, where FIG. 10(a) is a view showing the state before the protruding portion protrudes, and FIG. 10(b) is a view showing the state in which the protruding portion protrudes. [Figure 11] FIG. 10 is a perspective view showing a main part of a pressing tool that can make a protruding part protrude from a base part by the rotational force of a rotating part, as another example of a pressing tool used to fabricate an end structure of a shielded electric wire. [Figure 12] FIG. 10 is a cross-sectional view showing the main part of a pressing tool that is another example of a pressing tool used to fabricate a terminal structure of a shielded electric wire, and that can cause a protrusion to protrude from a base in the direction indicated by arrow Z when the base is moved along the direction indicated by arrow S. [Figure 13] 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, and a sleeve 30.

[0020] The terminal structure 1 of the shielded electric wire 10 in this embodiment is an terminal structure of the shielded electric wire 10 having a core portion 11 in which a conductor 12 is covered with an insulating layer 13, a shielding layer 14 arranged on the outer periphery of the core portion 11, and an outer sheath 15 covering the outer periphery of the shielding layer 14, and is equipped with a tubular portion 22 having an inner diameter larger than the outer diameter of the core portion 11, the tubular portion 22 being an exposed portion of the shielding layer 14 exposed when a predetermined length of the outer sheath 15 is peeled off, a ferrule 20 positioned between the core portion 11 and the tubular portion 22, and a ring-shaped sleeve 30 having an inner diameter larger than the outer diameter of the shielded electric wire 10, positioned opposite the outer peripheral surface of the tubular portion 22 of the ferrule 20, and which is expanded and deformed to crimp and fix the tubular portion 22 while sandwiching the exposed portion of the shielding layer 14.

[0021] This configuration in which the cylindrical 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 makes it possible to increase the tensile strength of the ferrule 20 relative to the shielded wire 10, particularly the tensile strength when the ferrule 20 is pulled in the direction toward the tip of the shielded wire 10 (to the left in FIG. 1 ), compared to a conventional shielded wire termination structure that employs a configuration in which the folded-back exposed portion of the shielding layer 14 is sandwiched between the insulating layer 13 or the outer jacket 15 of the shielded wire 10 and the ferrule 20. Furthermore, the tip portion of the shielded wire 10 is exposed from the tip 10e in order so that the outer peripheral surfaces of the conductor 12, the insulating layer 13, and the shielding layer 14 become the outermost peripheries, and then stripped in a stepped pattern. After that, the ferrule 20 can be fixed to the exposed portion of the shielding layer 14 of the shielded 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, it is possible to reduce the overall size of the termination structure of the shielded electric wire to which the ferrule 20 is fixed. Therefore, it is possible to provide a termination structure of a shielded electric wire in which the tensile strength of the ferrule relative to the shielded electric wire is high, the structure is compact, and it is easy to form, as well as an electric wire with a terminal and an electric wire with a connector that include the same.

[0022] 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 around the core 11, and an outer sheath 15 that covers 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), or silver or a silver alloy. The insulating layer 13 and the outer sheath 15 are made of an insulating resin, such as polyvinyl chloride or polyethylene.

[0023] 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 such 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.

[0024] 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.

[0025] 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.

[0026] 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, in addition to the tubular portion 22, the ferrule 20 may also include a connecting portion 21 and a linking portion 23 that connects the connecting portion 21 and the tubular portion 22. In addition, the ferrule 20 has the tubular portion 22 and the connecting portion 21 integrally formed. The ferrule 20 is a component that terminates an electric wire. The ferrule 20 is an electrically 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.

[0027] 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.

[0028] 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.

[0029] The tubular 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 tubular portion 22 is positioned adjacent to the inner circumferential surface of the shielding layer 14. Since the tubular 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 tubular portion 22 and the core portion 11. Therefore, a pressing tool 50 (described later) can be inserted into this gap from the tip end of the shielded wire 10 to apply an outward force to the tubular portion 22 and the shielding layer 14, thereby crimping and fixing them to a sleeve 30 (described later). The thickness of the tubular portion 22 can be approximately the same as the thickness of the shielding layer 14, as shown in FIG. 1 , for example.

[0030] 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.

[0031] The inner peripheral surface of the cylindrical portion 22 of the ferrule 20 has a recess 24, and the outer surface of the cylindrical portion 22, which is the back surface of the recess 24, preferably protrudes toward the sleeve 30, which will be described later. This allows a greater force to crimp and fix the cylindrical portion 22 to the sleeve 30 near the recess 24, making it possible to crimp and fix the cylindrical portion 22 to the sleeve 30 more strongly.

[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 the tubular portion 22 of the ferrule 20 is deformed to expand in diameter, thereby crimping and fixing the tubular portion 22 with the exposed portion of the shielding layer 14 sandwiched between them. At this time, the sleeve 30 serves as a crimping receiving portion, and the end of the shielding layer 14 is sandwiched between the sleeve 30 and the tubular portion 22, thereby crimping and fixing 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 material constituting the sleeve 30 is preferably stronger than the material constituting the tubular portion 22 of the ferrule 20. This makes it less likely for the sleeve 30 to deform when the tubular portion 22 is crimped and fixed to the sleeve 30, thereby enabling the tubular portion 22 (and the exposed portion of the shielding layer 14) to be more reliably crimped and fixed to the sleeve 30. On the other hand, the material constituting the sleeve 30 may be the same as the material constituting the ferrule 20. The thickness of the sleeve 30 is set appropriately depending on the application of the terminal structure 1, but is preferably greater than the thickness of the tubular portion 22 of the ferrule 20. In this case, the thickness of the tubular portion 22 is thinner than the thickness of the sleeve 30. In particular, when the sleeve 30 is made of the same material as the ferrule 20, it is more preferable that the thickness of the sleeve 30 be greater than the thickness of the tubular portion 22 of the ferrule 20. In this way, the material constituting the sleeve 30 has a strength greater than or equal to that of the material constituting the tubular portion 22 of the ferrule 20, and therefore the tensile strength of the ferrule 20 relative to the shielded wire 10 can be increased compared to the terminal structure of a conventional shielded wire, which employs a configuration in which the exposed portion of the folded-back shield layer 14 is sandwiched between the insulating layer 13 or outer sheath 15 of the shielded wire 10 and the ferrule 20.

[0035] [Terminal-attached wire] In this embodiment, an electric wire with terminal 4 can be configured having the above-described shielded electric wire termination structure 1. As shown in FIG. 2 , the electric wire with terminal 4 has a terminal 40 connected to an end of a conductor 12, and the conductor 12 and the terminal 40 can be connected by welding, such as ultrasonic welding. Here, the electric wire with terminal 4 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 40, thereby electrically connecting the terminal 40 and the conductor 12. In particular, when the electric wire with terminal 4 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 4 can be formed by connecting the exposed conductor 12 in the shielded electric wire termination structure 1 to the terminal 40. The terminal 40 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 the terminal-attached wire 4 may have components other than the terminal 40 attached to it from the viewpoint of locking the terminal 40 at a predetermined position inside a connector 60 (described later) or from the viewpoint of ensuring electrical continuity of the shielding layer 14 of the shielded wire 10.

[0036] [Wire with connector] Fig. 2 is a schematic diagram showing a connector-attached electric wire in which a terminal-attached electric wire 4 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 4 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 40 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.

[0037] The terminal 40 constituting the terminal-fitted wire 4 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 the shield layer 14 constituting the shielded wire 10 can be grounded.

[0038] [Example of a method for forming the terminal structure 1 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.

[0039] (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.

[0040] 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.

[0041] (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.

[0042] 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.

[0043] 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 a pressing tool 50 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).

[0044] (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.

[0045] 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.

[0046] (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 .

[0047] 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.

[0048] (Crimping process) The crimping process is a process of deforming the cylindrical portion 22 of the ferrule 20 so as to expand its diameter outward at a position facing the outer circumferential surface of the cylindrical portion 22. This allows the cylindrical portion 22 to be crimped and fixed to the sleeve 30 with the exposed portion of the shield layer 14 sandwiched between them.

[0049] In the crimping step, the pressing tool 50 is inserted 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 is at least partially expanded in diameter at a position facing the outer circumferential surface of the tubular portion 22 of the ferrule 20 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. As a result, the terminal structure 1 for the shielded electric wire 10 shown in Fig. 1 can be formed.

[0050] The pressing tool 50 used in the crimping step is a diameter expanding jig that has the effect of expanding the diameter of the tubular portion 22. Here, the pressing tool 50 may be one that expands the diameter of at least a portion of the tubular portion 22 of the ferrule 20, such as a cylindrical jig, or one that expands the diameter of only a portion of the tubular portion 22, such as a wedge.

[0051] FIG. 9 is a longitudinal cross-sectional view showing the state of the tip end of the shielded electric wire 10 when a pressing tool 50 is fitted between the tubular portion 22 and the core portion 11 in the crimping process. The pressing tool 50 fitted between the tubular portion 22 and the core portion 11 preferably forms the recess 24 by causing a protruding portion 51, which constitutes a part of the portion facing the tubular portion 22, to protrude from the base portion 52. At this time, the protruding portion 51 moves in the direction indicated by arrow Z in FIG. 9. This further expands the diameter of the portion of the inner circumferential surface of the tubular portion 22 that faced the protruding portion 51, thereby more firmly crimping and fixing the tubular portion 22 to the sleeve 30 at and near the recess 24. Furthermore, further expanding the diameter of the tubular portion 22 with the pressing tool 50 having the protruding portion 51 makes it possible to use a ferrule 20 having a thicker tubular portion 22.

[0052] The pressing tool with a protrusion is not limited to the pressing tool 50 shown in FIG. 9 , in which the entire portion facing the cylindrical portion 22, including the protrusion, has a shape that tapers toward the tip. Tools with other shapes may also be used. For example, a pressing tool 50a shown in FIG. 10(a) may be used, in which the diameter of the protrusion 51a is substantially constant. The pressing tool 50 shown in FIG. 9 may include a mechanism that causes the protrusion 51 to protrude from the base 52 by applying external pressure, such as hydraulic pressure, and returns the protrusion 51 to its original position by releasing the external pressure. The pressing tool 50a shown in FIG. 10(a) may also have the same mechanism as the pressing tool 50 shown in FIG. 9 , and may form a recess 24 in the cylindrical portion 22 by causing the protrusion 51a to protrude from the base 52a in the direction indicated by arrow Z, as shown in FIG. 10(b).

[0053] 11, a pressing tool 50b may be used as the pressing tool having a protruding portion. The pressing tool 50b can be configured to cause the protruding portion 51b to protrude from the base portion 52b in the direction indicated by the arrow Z by the rotational force R of the rotating portion 53b, and can return the protruding portion 51b from the base portion 52b by rotating the rotating portion 53b in the opposite direction. Also, as shown in FIG. 12, a pressing tool 50c may be used that can cause the protruding portion 51c to protrude from the base portion 52c in the direction indicated by the arrow Z when the base portion 52c is moved in the direction indicated by the arrow S along the extending direction of the shielded electric wire 10 (to the right in FIG. 12), and can return the protruding portion 51c from the base portion 52c when the base portion 52c is moved in the direction opposite to the arrow S (to the left in FIG. 12).

[0054] The pressing tool 50 inserted between the tubular portion 22 and the core portion 11 uses the protruding portion 51 to expand and deform the tubular portion 22 of the ferrule 20 as needed, and then returns the protruding portion 51 from the base portion 52, and then pulls it out toward the tip 10e of the shielded electric wire 10 to remove it, thereby forming the terminal structure 1 of the shielded electric wire 10 shown in Figure 1.

[0055] 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.

[0056] [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 40 is connected to the end of the conductor 12. By performing the terminal connecting step, the terminal-equipped electric wire 4 is formed. Here, the conductor 12 and the terminal 40 can be connected by welding, for example, ultrasonic welding. Of course, the conductor 12 and the terminal 40 may be connected by other connection methods than welding, such as soldering, crimping, or locking.

[0057] [Example of a method for forming a connector-attached electric wire] After the electric wire with terminal 4 is formed, a connector connection step may be performed in which the electric wire with terminal 4 is attached to the connector 60, more specifically, to the connector housing 60a. In the connector connection 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 40 and the ferrule 20, and the terminal 40 of the electric wire with terminal 4 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 40 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.

[0058] 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.

[0059] 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]

[0060] 1: Terminal structure of shielded wire 4: Wire with terminal 6: Wire with connector 10: Shielded wire 10e: Tip of shielded wire 11: Core section 12: Conductor 12s: outer surface of the conductor 13s: Outer surface of insulating layer 14s: Outer surface of the shield layer 13: Insulating layer 14: Shield layer 14e: Tip of the shield layer 14f: Trumpet-shaped part of the shield layer 14g: gap 15:Outer cover 15s: outer sheath of shielded wire 20: Ferrule 21: Connection 22: Cylindrical part 23:Connection part 24: Recess 30: Sleeve 40: Terminal 50, 50a to 50c: Pressing tools 51, 51a~51c: Projection part 52, 52a~52c: base 53: Rotating part 60: Connector 60a: Connector housing 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, disposed at a position facing an outer peripheral surface of the cylindrical portion of the ferrule, and configured to crimp and fix the cylindrical portion while sandwiching the exposed portion of the shielding layer by expanding and deforming the cylindrical portion; 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 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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