Terminal structure of shield electric wire, electric wire with terminal, and electric wire with connector
The terminal structure for shielded electric wires addresses the issues of low tensile strength and complexity by using a tubular ferrule with slits and a ring-shaped sleeve, ensuring secure fixation and easy formation, enhancing the structural integrity and compactness.
Patent Information
- Application Number
- JP2024029708
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-02-29
- Publication Date
- 2025-09-10
AI Technical Summary
Conventional terminal structures for shielded electric wires suffer from low tensile strength, a bulky size, and complex formation due to the expansion and contraction of braided shield layers, which leads to ferrules that are not securely fixed in the axial direction and require multiple stripping steps.
A terminal structure featuring a tubular ferrule with slits and a ring-shaped sleeve, held by a holder, sandwiches the shield layer without folding it back, ensuring secure fixation and high tensile strength, while maintaining a compact design and easy formation.
The new structure enhances the tensile strength of the ferrule, reduces the overall size, and simplifies the formation process by allowing a single-step stripping and crimping operation, resulting in a robust and efficient terminal connection.
Smart Images

Figure 2025132273000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a terminal structure for 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 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] 12(a) and 12(b), the outermost outer sheath 103 of the shielded electric wire 100 is first cut and removed over a predetermined length from the end to expose the shield layer 105 of the inner braided wire.
[0005] 12(c), the 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 with a conductor covered with an insulating coating.
[0006] Next, as shown in Fig. 12(d), a predetermined length of inner ferrule 109 is placed near the end of the outer jacket 103. The inner ferrule 109 is a ring-shaped metal member. Thereafter, as shown in Fig. 12(e), the shielding layer 105 exposed from the outer jacket 103 is folded back toward the outer jacket 103 (toward the inner ferrule 109). As a result, the inner ferrule 109 is covered with the shielding layer 105.
[0007] 12(f), the outer ferrule 113 is disposed on the outer periphery of the 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. By compressing the outer ferrule 113 from the periphery in this state, the inner ferrule 109 and the outer ferrule 113 can be crimped together with the shield layer 105 sandwiched between them.
[0008] Thereafter, a terminal is connected to the core portion 107 and accommodated in the connector housing. At this time, the outer ferrule 113 is brought into contact with a metal member disposed 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. 12, the inner ferrule 109 and the outer ferrule 113 are fixed to the folded 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, because the inner ferrule 109 and the outer ferrule 113, which are fixed while sandwiching the shield layer 105, are formed on the outer sheath 103 of the shielded wire 100, they tend to significantly protrude from the outer periphery of the shielded wire 100, resulting in an increase in the size of the structure in question. Furthermore, because the required length of the shield layer 105 increases by the amount of folding, stripping cannot be performed in one go. In other words, before folding back the shield layer 105, it is necessary to expose the shield layer 105 by stripping, and after folding back the shield layer 105, it is necessary to perform stripping to expose the conductor from the core portion 107, so there is 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] An object of the present disclosure is to provide a terminal structure for a shielded electric wire that has a high tensile strength of a ferrule relative to the shielded electric wire, has a compact structure, and is easy to form, as well as a terminal-equipped electric wire and a connector-equipped electric wire that include the same. [Means for solving the problem]
[0012] [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 comprising: a tubular portion having an inner diameter larger than the outer diameter of the core portion and having one or more slits extending from an end portion, the tubular portion having an exposed portion of the shielding layer exposed when a predetermined length of the outer covering is peeled off, and a ferrule located between the tubular portion and the core portion; 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, with the exposed portion of the shielding layer sandwiched between the tubular portion and the ring-shaped sleeve; and a holder located between the inner periphery of the tubular portion and a portion of the outer periphery of the core portion located on the inner periphery side of the exposed portion of the shielding layer, and the inner periphery of the tubular portion, for holding the tubular portion pressed 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 slit is provided at the end of the cylindrical portion on the base side, and further includes an enlarged slit portion having a width larger than the slit width. [3] The terminal structure of a shielded electric wire according to [1] or [2] above, wherein the holder is ring-shaped. [4] The terminal structure of a shielded electric wire according to [1] or [2] above, wherein the holder is ring-shaped and has one dividing slit extending from one end to the other end. [5] An electric wire with terminal having the terminal structure of the shielded electric wire described in any one of [1] to [4] above, wherein 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. [6] An electric wire with a connector in which the electric wire with terminal described in [5] above is accommodated in a connector housing, and 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 connected. [Effects of the Invention]
[0013] According to the present disclosure, 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. [Brief explanation of the drawings]
[0014] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an example of an end structure of a shielded electric wire according to an embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view showing an example of a shielded electric wire used in the terminal structure of the shielded electric wire according to the embodiment. [Figure 3] FIG. 3 is an enlarged perspective view showing an example of a ferrule used in the terminal structure of the shielded electric wire according to the embodiment. [Figure 4] FIG. 4 is an enlarged perspective view showing another example of a ferrule used in the terminal structure of the shielded electric wire according to the embodiment. [Figure 5] FIG. 5 is an enlarged perspective view showing another example of a ferrule used in the terminal structure of the shielded electric wire according to the embodiment. [Figure 6] FIG. 6 is a perspective view showing an example of a holder used in the terminal structure of the shielded electric wire according to the embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing the state of the tip of the shielded electric wire after the stripping process. [Figure 8] FIG. 8 is a vertical cross-sectional view showing the state of the tip end of the shielded electric wire after the sleeve fitting step has been performed. [Figure 9] FIG. 9 is a vertical cross-sectional view showing the state of the tip end of the shielded electric wire after the ferrule arrangement step has been performed. [Figure 10] FIG. 10 is a vertical cross-sectional view showing the state of the tip end of the shielded electric wire after the sleeve arrangement step has been performed. [Figure 11] FIG. 11 is a schematic diagram showing a connector-attached electric wire in which a terminal-attached electric wire having the terminal structure of the shielded electric wire according to the embodiment is accommodated in a connector housing. [Figure 12]FIG. 12 is an explanatory diagram showing a process for forming a conventional terminal structure of a shielded electric wire. DETAILED DESCRIPTION OF THE INVENTION
[0015] Hereinafter, a detailed description will be given based on an embodiment.
[0016] As a result of extensive research into the terminal structure of a shielded electric wire, the inventors have discovered that when the cylindrical portion of the ferrule has a slit, the holder holds the cylindrical portion of the ferrule pressed and fixed to the sleeve via the exposed portion of the shielding layer, and the sleeve is fixed to the exposed portion of the shielding layer in a state where it sandwiches the exposed portion of the shielding layer together with the cylindrical portion of the ferrule without folding it over, the tensile strength of the ferrule against the shielded electric wire is high, the structure is compact, and it can be easily formed, and have completed the present disclosure based on this finding.
[0017] The shielded wire termination structure of the embodiment is a shielded wire termination structure 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. The shielded wire termination structure includes a tubular portion having an inner diameter larger than the outer diameter of the core portion and one or more slits extending from an end portion, the tubular portion including an exposed portion of the shield layer exposed when a predetermined length of the outer sheath is peeled off and a ferrule located between the tubular portion and the core portion, a ring-shaped sleeve having an inner diameter larger than the outer diameter of the shielded wire and fixedly disposed at a position facing the outer periphery of the tubular portion with the exposed portion of the shield layer sandwiched between the tubular portion and the ring-shaped sleeve, and a holder located between the inner periphery of the tubular portion and a portion of the outer periphery of the core portion located on the inner periphery side of the exposed portion of the shield layer, the holder holding the tubular portion pressed against the sleeve via the exposed portion of the shield layer.
[0018] Fig. 1 is a longitudinal sectional view showing an example of a terminal structure of a shielded electric wire according to an embodiment. Fig. 2 is a longitudinal sectional view showing an example of a shielded electric wire used in the terminal structure of a shielded electric wire according to an embodiment. Fig. 3 is an enlarged perspective view showing an example of a ferrule used in the terminal structure of a shielded electric wire according to an embodiment. As shown in Fig. 1, the terminal structure 1 of a shielded electric wire according to an embodiment (hereinafter also simply referred to as the terminal structure) includes a shielded electric wire 10, a ferrule 20, a sleeve 30, and a holder 50.
[0019] As shown in Fig. 2, the shielded wire 10 used in the terminal structure 1 has a core 11, a shield layer 14 arranged on the outer periphery of the core 11, and an outer sheath 15 that covers the outer periphery of the shield layer 14. The core 11 has a conductor 12 and an insulating layer 13, and the outer periphery of the conductor 12 is covered with the insulating layer 13. The shield layer 14 covers the outer periphery of the core 11. The outer sheath 15 is arranged on the outer periphery of the shield layer 14.
[0020] The conductor 12 of the shielded wire 10 is electrically conductive and 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. The insulating layer 13 and the outer jacket 15 are electrically insulating and made of an electrically insulating resin such as polyvinyl chloride or polyethylene.
[0021] 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 deformed by expansion and contraction.
[0022] In the terminal structure 1, as shown in FIG. 1 and FIG. 7 described later, the shielded wire 10 is stripped in a stepped manner from the tip 10e of the shielded wire 10 toward the base end (not shown) of the shielded wire 10 so that the outer periphery of the conductor 12, the outer periphery of the insulating layer 13, the outer periphery of the shielding layer 14, and the outer periphery of the outer jacket 15 each become the outermost periphery of the shielded wire 10.
[0023] 1 and 3, the ferrule 20 includes a cylindrical portion 22 having an inner diameter larger than the outer diameter of the core portion 11 of the shielded electric wire 10. The ferrule 20 is a component for terminating the electric wire.
[0024] As shown in Fig. 1, in the terminal structure 1, the tubular portion 22 is arranged so as to be located 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. The outer peripheral surface of the tubular portion 22 contacts the inner peripheral surface of the exposed portion of the shielding layer 14, and the inner peripheral surface of the tubular portion 22 contacts the outer peripheral surface of the holder 50. The shielding layer 14 (exposed portion of the shielding layer 14) is not arranged on the inner peripheral side of the tubular portion 22. For example, as shown in Fig. 1, the thickness of the tubular portion 22 is approximately the same as the thickness of the shielding layer 14.
[0025] The cylindrical portion 22 of the ferrule 20 has one or more slits 24 extending from the end 22e of the cylindrical portion 22 toward the base end of the cylindrical portion 22. Figures 1 and 3 show an example in which a plurality of slits 24 are provided in the cylindrical portion 22.
[0026] As will be described later, when the holder 50 holds the cylindrical portion 22 of the ferrule 20 pressed and fixed to the sleeve 30 via the exposed portion of the shield layer 14, the radially outward force from the holder 50 tends to deform the tip side of the cylindrical portion 22 radially outward along a line extending in the circumferential direction of the cylindrical portion 22 connecting the base-side ends of the cylindrical portion 22 in the slits 24, or in some cases around the base-side end of the cylindrical portion 22 in the slits 24. In other words, the radially outward force from the holder 50 efficiently acts on the cylindrical portion 22, and the tip side of the cylindrical portion 22 easily expands and deforms toward the inner circumferential surface of the sleeve 30, so that the cylindrical portion 22 of the ferrule 20 can sandwich the exposed portion of the shield layer 14 together with the sleeve 30 while sufficiently pressing the exposed portion of the shield layer 14 against the sleeve 30 from the inside.
[0027] From the viewpoint of the formability of the slit 24 and efficient radial expansion deformation of the tip side of the tubular portion 22 due to the slit 24, the length of the slit 24 is preferably at least 1 / 3 of the axial length of the tubular portion 22 and not more than 2 / 3 of the axial length of the tubular portion 22, and more preferably at least 1 / 3 of the axial length of the tubular portion 22 and not more than 1 / 2 of the axial length of the tubular portion 22.
[0028] Also, although an example is shown here in which the slit 24 extends parallel to the axial direction of the tubular portion 22, the extension direction of the slit 24 is not particularly limited, and may be, for example, oblique to the axial direction of the tubular portion 22.
[0029] The ferrule 20 also includes a connecting portion 21 that is connected to a connected portion (not shown) of an external electronic device. The connecting portion 21 and the cylindrical portion 22 may be connected via a connecting portion 23 as shown in FIGS. 1 and 3, or may be connected directly.
[0030] The connecting portion 21 of the ferrule 20 is connected to a connected portion (not shown) of an external electronic device. The external electronic device is an electronic device separate from the shielded electric wire 10 and the terminal structure 1 of the 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. The connected portion of the external electronic device may be, but is not limited to, a connector 60 (described later), and may be anything electrically connected to the external electronic device. For example, the connected portion may be directly provided on the external electronic device, or may be 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. 11 , the shape of the connecting portion 21 of the ferrule 20 preferably corresponds to the shape of the connector 60.
[0031] Furthermore, although the connecting portion 21 of the ferrule 20 has a shape with a rectangular opening in FIG. 3, this is not limited to this, and the shape of the opening may be, for example, circular, elliptical, other polygonal, or irregular, as long as it is a shape that can be connected to the connecting portion of the external electronic device.
[0032] The ferrule 20 is electrically conductive and 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, etc. The ferrule 20 also has a hardness that allows it to maintain a predetermined shape.
[0033] The sleeve 30 is ring-shaped and has an inner diameter larger than the outer diameter of the shielded wire 10. The thickness of the sleeve 30 is also larger than the thickness of the tubular portion 22 of the ferrule 20. In the terminal structure 1, the sleeve 30 is fixedly disposed in a position facing the outer peripheral surface of the tubular portion 22 of the ferrule 20, with the exposed portion of the shielding layer 14 sandwiched between the sleeve 30 and the tubular portion 22 of the ferrule 20. The inner peripheral surface of the sleeve 30 is in contact with the outer peripheral surface of the exposed portion of the shielding layer 14. The sleeve 30 may also be formed by wrapping a band-shaped (strip-shaped) object around it to form a ring. The thickness of the sleeve 30 is not particularly limited as long as it is larger than the thickness of the tubular portion 22, and is set appropriately depending on the application of the terminal structure 1, etc.
[0034] The sleeve 30 is fixed to the exposed portion of the shielding layer 14 in a state in which the exposed portion of the shielding layer 14 is sandwiched between the inner peripheral surface of the sleeve 30 and the outer peripheral surface of the tubular portion 22 of the ferrule 20. In the terminal structure 1, the state in which the exposed portion of the shielding layer 14 is sandwiched between the sleeve 30 and the tubular portion 22 of the ferrule 20 means that the exposed portion of the shielding layer 14 is not folded back, and the exposed portion extending from the base end (not shown) of the shielded electric wire 10 to the tip end 10e is sandwiched between the sleeve 30 and the tubular portion 22 of the ferrule 20.
[0035] The holder 50 is located between the outer peripheral surface portion of the insulating layer 13 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 tubular portion 22 of the ferrule 20, and maintains a state in which the tubular portion 22 of the ferrule 20 is pressed and fixed against the inner peripheral surface of the sleeve 30 via the exposed portion of the shielding layer 14. The holder 50 is preferably ring-shaped.
[0036] When the holder 50 holds the tubular portion 22 of the ferrule 20 pressed and fixed against the inner surface of the sleeve 30 via the exposed portion of the shielding layer 14, the slits 24 provided in the tubular portion 22 cause the tip side of the tubular portion 22 to expand in diameter toward the inner surface of the sleeve 30, and the tip side of the deformed tubular portion 22 is fixed together with the sleeve 30 in a state where it sufficiently sandwiches the exposed portion of the shielding layer 14.
[0037] The cylindrical portion 22 of the ferrule 20 is crimped onto the exposed portion of the shield layer 14 by the radially expanding pressing force from the holder 50, and is sufficiently fixed to the shielded wire 10 with the exposed portion of the shield layer 14 sandwiched between the outer surface of the cylindrical portion 22 and the inner surface of the sleeve 30.
[0038] The inner surface of the holder 50 faces the outer surface of the insulating layer 13. As shown in Fig. 1, the entire inner surface of the holder 50 may be in contact with the outer surface of the insulating layer 13, or a portion of the inner surface of the holder 50 may be in contact with the outer surface of the insulating layer 13, or the inner surface of the holder 50 may not be in contact with the outer surface of the insulating layer 13. In addition, the outer surface of the holder 50 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 50.
[0039] In the terminal structure 1, the cylindrical portion 22 of the ferrule 20 and the sleeve 30 are each crimped and fixed to the shielded wire 10 with the exposed portion of the shielding layer 14 sandwiched between the cylindrical portion 22 of the ferrule 20 from the inside and the sleeve 30 from the outside without folding it back. Furthermore, the shielding layer 14 is not provided inside the cylindrical portion 22 of the ferrule 20. Thus, the cylindrical portion 22 of the ferrule 20 and the sleeve 30 are crimped together with the shielding layer 14 sandwiched between them without folding back the exposed portion, and the shielding layer 14 is not disposed inside the cylindrical portion 22. Furthermore, the radially outward force from the holder 50 efficiently expands and deforms the cylindrical portion 22 having the slits 24, pressing the cylindrical portion 22 of the ferrule 20 against the sleeve 30 via the exposed portion of the shielding layer 14. This increases the tensile strength of the ferrule 20 relative to the shielded wire 10.
[0040] In addition, in the terminal structure 1, the tubular portion 22 of the ferrule 20, which sandwiches the exposed portion of the shielding layer 14 from the inside without folding it back, is provided on a holder 50 that is placed on the exposed portion of the insulating layer 13 after the shielding layer 14 and the outer jacket 15 have been removed. In addition, the sleeve 30, which sandwiches the exposed portion of the shielding layer 14 from the outside without folding it back, is provided on the exposed portion of the shielding layer 14 after the outer jacket 15 has been removed. In this way, the shielding layer 14 is crimped to the tubular portion 22 and the sleeve 30 of the ferrule 20 without folding back the exposed portion, and the tubular portion 22 and the sleeve 30 that sandwich the exposed portion of the shielding layer 14 are not provided on the outer periphery of the outer jacket 15 of the shielded electric wire 10. This allows the terminal structure 1 to be made compact.
[0041] Furthermore, the shielded wire 10 is stripped in a stepped pattern so that the outer circumferential surfaces of the conductor 12, insulating layer 13, shielding layer 14, and jacket 15 all become outermost from the tip 10e of the shielded wire 10 toward the base end (not shown) of the shielded wire 10. The ferrule 20 and sleeve 30 are fixed to the shielding layer 14 without folding back the shielding layer 14. This allows the termination structure 1 to be easily formed.
[0042] Furthermore, from the viewpoint of efficiently expanding the diameter of the tip side of the tubular portion 22 due to the slit 24, it is preferable that the slit 24 further include an expanded slit portion 24a, which is provided at the end portion on the base side of the tubular portion 22 and has a width larger than the slit width, as shown in Fig. 4. When the tubular portion 22 has such a configuration, the tubular portion 22 of the ferrule 20 can more efficiently press the exposed portion of the shielding layer 14 against the inner circumferential surface of the sleeve 30. Furthermore, as shown in Fig. 5, the slit width of the slit 24 may increase from the end portion of the tubular portion 22 toward the base portion of the tubular portion 22.
[0043] Furthermore, from the viewpoint of the holder 50 efficiently pressing the cylindrical portion 22 of the ferrule 20 radially outward, it is preferable that the holder 50 be ring-shaped and have one dividing slit 51 extending from one end to the other. By providing the ring-shaped holder 50 having the dividing slit 51 in a reduced diameter state between the insulating layer 13 and the ferrule 20, the holder 50 can continue to press the inner circumferential surface of the cylindrical portion 22 of the ferrule 20 radially outward with an even stronger force.
[0044] Next, a method for forming the terminal structure of the embodiment will be described. The method for forming the terminal structure 1 includes a stripping step, a sleeve fitting step, a ferrule arrangement step, a sleeve arrangement step, and a crimping step.
[0045] The stripping step is a step of stripping the tip of the shielded electric wire 10 shown in Fig. 2. Fig. 7 is a vertical cross-sectional view showing the state of the tip of the shielded electric wire 10 after the stripping step has been performed.
[0046] In the stripping process, as shown in FIG. 7 , stripping is performed so that the outer surface 12s of the conductor 12, the outer surface 13s of the insulating layer 13, the outer surface 14s of the shielding layer 14, and the outer surface 15s of the jacket 15 appear in a stepped pattern from the tip 10e of the shielded wire 10 toward the base end (not shown) of the shielded wire 10. Stripping can be completed in a single operation of stripping the jacket 15, shielding layer 14, and insulating layer 13 toward the tip 10e of the shielded wire 10. This improves the work efficiency when forming the termination structure 1. The stripping can be performed using conventionally known devices and tools, such as a measuring stripping device.
[0047] In the sleeve fitting process carried out after the stripping process, a sleeve 30 is fitted onto the tip 10e of the shielded electric wire 10 and left standing at the outer peripheral surface 15s of the jacket 15. Fig. 8 is a vertical cross-sectional view showing the state of the tip portion of the shielded electric wire 10 after the sleeve fitting process has been carried out.
[0048] 8, in the sleeve fitting step, the sleeve 30 is arranged so as to be retracted to the position of the outer peripheral surface 15s of the jacket 15 of the shielded electric wire 10. In this embodiment, a molded product made of metal and formed into a ring shape is used as the sleeve 30.
[0049] After the sleeve 30 is fitted onto the shielded wire 10, the shield layer 14 constituting the shielded wire 10 is expanded (expanded in diameter) into a horn-like shape (reference symbol 14f), and a gap 14g is provided between the shield layer 14 and the insulating layer 13. As will be described later, the cylindrical portion 22 of the ferrule 20 and the holder 50 are fitted into this gap 14g. Here, one method for expanding the shield layer 14 of the shielded 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 8 shows the shield layer 14 in the horn-shaped shape (reference symbol 14f).
[0050] The ferrule arrangement process, which is performed after the sleeve fitting process, is a process of fitting the cylindrical portion 22 of the ferrule 20 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 strictly speaking, between the shield layer 14 and the insulating layer 13. In the sleeve fitting process, the shield layer 14 is expanded to provide the gap 14g, so that the cylindrical portion 22 of the ferrule 20 can be smoothly fitted into the gap 14g.
[0051] 9 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. 9 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 insulating layer 13.
[0052] The sleeve placement process, which is performed after the ferrule placement process, is a process in which the sleeve 30 is moved to the area where the tubular portion 22 of the ferrule 20 is located and placed in a position facing the outer circumferential surface of the tubular portion 22, sandwiching the exposed portion of the shielding layer 14. In the sleeve placement process, the sleeve 30 moves in the direction indicated by arrow X in FIG.
[0053] 10 is a vertical cross-sectional view showing the state of the tip end of the shielded wire 10 after the sleeve placement process. In the sleeve placement process, 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.
[0054] The crimping process, which is performed after the sleeve arrangement process, is a process in which the tubular portion 22 is deformed and expanded outward to crimp the exposed portion of the shield layer 14. This allows the tubular portion 22 and the sleeve 30 to be crimped and fixed with the exposed portion of the shield layer 14 sandwiched between them, thereby fixing the ferrule 20 and the sleeve 30 to the shielded wire 10.
[0055] In the crimping process, the holder 50 is fitted into the gap 14g between the tubular portion 22 and the insulating layer 13 from the side of the tip 10e of the shielded wire 10 along the direction indicated by arrow Y in Fig. 10. As a result, at least the tip side of the tubular portion 22 is expanded in diameter due to the slits 24, and the tubular portion 22 and the sleeve 30 are crimped and fixed to the exposed portion of the shielding layer 14. In this way, the exposed portion of the shielding layer 14 sandwiched between the tubular portion 22 and the sleeve 30 can be crimped and fixed to the outer peripheral surface of the tubular portion 22 and the inner peripheral surface of the sleeve 30.
[0056] In this way, it is possible to form the shielded electric wire terminal structure 1 shown in Fig. 1. According to this method for forming the terminal structure 1, it is possible to complete the stripping process of the tip portion of the shielded electric wire 10 in one go so that the conductor 12, the insulating layer 13, the shielding layer 14, and the outer jacket 15 each form the outermost periphery, and it is also possible to eliminate the need for folding back the shielding layer 14, so that the shielded electric wire terminal structure 1 with excellent properties can be easily formed with a reduced amount of work.
[0057] Next, an electric wire with terminal of an embodiment will be described. The electric wire with terminal of the embodiment has a terminal structure 1 of a shielded electric wire, in which a predetermined length of insulating layer is peeled from the tip of the core part, and the part of the conductor exposed by the peeling is connected to a terminal.
[0058] Fig. 11 is a schematic diagram showing a connector-attached electric wire in which an electric wire with a terminal having the terminal structure of a shielded electric wire of the embodiment is accommodated in a connector housing. As shown in Fig. 11, the electric wire with terminal 4 has the terminal structure 1 of the shielded electric wire of the above embodiment, and a terminal 40 is connected to the end of a conductor wire 12, and the conductor wire 12 and the terminal 40 can be connected by, for example, 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 wire 12 exposed by the peeling to the terminal 40, thereby electrically connecting the terminal 40 and the conductor wire 12.
[0059] In the shielded electric wire termination structure 1, a predetermined length of the insulating layer 13 is peeled off from the tip of the core portion 11 of the shielded electric wire 10, so that the exposed conductor 12 in the shielded electric wire termination structure 1 can be connected to a terminal 40 to form an electric wire with terminal 4. This terminal 40 may be electrically connected to a connection terminal (not shown) provided on a connected portion of an external electronic device.
[0060] The electric wire with terminal 4 is formed by connecting the terminal 40 to the end of the conductor 12 in the shielded electric wire termination structure 1. The connection between the conductor 12 and the terminal 40 may be by welding, or by other connection methods such as soldering, crimping, or locking.
[0061] Next, a description will be given of an electric wire with a connector according to an embodiment. In the electric wire with a connector according to the embodiment, an electric wire with a terminal 4 is accommodated in a connector housing, and a metal member is disposed in the connector housing over an area facing the terminal and the ferrule, and the ferrule and the metal member are electrically connected.
[0062] As shown in Fig. 11, in the connector-attached electric wire 6, the terminal-attached electric wire 4 is 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. Here, 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. 11 shows a case where the shape of the metal member 61 is formed into a rectangular tube shape.
[0063] 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.
[0064] The connector-attached electric wire 6 is formed by attaching the terminal-attached electric wire 4 to a connector 60, more specifically, a connector housing 60a, to form the connector-attached electric wire 6. The connector 60 is formed by arranging a metal member 61 in the connector housing 60a over an area facing the terminal 40 and the ferrule 20, and the terminal 40 of the terminal-attached electric wire 4 is inserted into the terminal insertion portion of the connector housing 60a, and the shield layer 14 and the connection portion 21 of the ferrule 20 are brought into contact with each other. 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 ferrule 20 and the metal member 61 arranged on the inner surface of the terminal insertion portion of the connector housing.
[0065] According to the embodiment described above, the cylindrical portion of the ferrule has a slit, the holder holds the cylindrical portion of the ferrule pressed and fixed to the sleeve via the exposed portion of the shielding layer, and the sleeve is fixed to the exposed portion of the shielding layer in a state where it sandwiches the exposed portion of the shielding layer together with the cylindrical portion of the ferrule without folding it back, so that the terminal structure of the shielded electric wire has a high tensile strength of the ferrule against the shielded electric wire, a compact structure, and can be easily formed.
[0066] 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.
[0067] 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]
[0068] 1: Terminal structure of shielded wire (Terminal structure) 4: Wire with terminal 6: Wire with connector 10: Shielded wire 11: Core section 12: Conductor 13: Insulating layer 14: Shield layer 15:Outer cover 20: Ferrule 21: Connection 22: Cylindrical part 22e: End 23:Connection part 24: Slit 24a: Slit expansion section 30: Sleeve 40: Terminal 50: Holder 51: Divided slit 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 an inner diameter larger than the outer diameter of the core portion, the tubular portion having one or more slits extending from an end thereof, the tubular portion being located between the core portion and an exposed portion of the shielding layer exposed when a predetermined length of the outer jacket is stripped away; a ring-shaped sleeve having an inner diameter larger than an outer diameter of the shielded electric wire, the ring-shaped sleeve being fixedly disposed at a position facing an outer peripheral surface of the cylindrical portion in a state in which the exposed portion of the shielding layer is sandwiched between the cylindrical portion and the ring-shaped sleeve; a holder that is positioned between an outer peripheral surface of the core portion that is positioned on the inner peripheral surface side of the exposed portion of the shield layer and an inner peripheral surface of the tubular portion, and that holds the tubular portion in a state where it is pressed and fixed to the sleeve via the exposed portion of the shield layer; A terminal structure of a shielded electric wire comprising:
2. 2. The shielded wire terminal structure according to claim 1, wherein the slit is provided at an end of the cylindrical portion on the base side, and further includes an enlarged slit portion having a width greater than the slit width.
3. The shielded wire terminal structure according to claim 1 , wherein the holder is ring-shaped.
4. 2. The shielded wire terminal structure according to claim 1, wherein the holder is ring-shaped and has one dividing slit extending from one end to the other end.
5. An electric wire with a terminal having the terminal structure of the shielded electric wire according to any one of claims 1 to 4, The electric wire with terminal, wherein 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.
6. A connector-attached electric wire in which the terminal-attached electric wire according to claim 5 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 ferrule and the metal member are electrically connected to each other.
Citation Information
Patent Citations
Connection method and connection structure of braided shield layer of shield wire and drain wire
JP2013051141A
Attachment device for sleeve to coaxial cable, attachment method for sleeve to coaxial cable, and shield conducting path
JP2021182467A