Shielded cable assembly

Abstract

To provide a shield wire assembly capable of preventing a wire seal from being damaged due to movement of a ferrule and capable of preventing the ferrule from being displaced excessively.SOLUTION: A shield wire assembly 1 comprises: a shield wire 10 including a braided wire 15; a ferrule 40 which is assembled to the shield wire 10 and is composed of a conductive material relating to the ground of the braided wire 15; a wire seal 60 which is assembled to the shield wire 10 and is in charge of waterproofing; and a stopper 50 which is assembled between the ferrule 40 and the wire seal 60 and is composed of an electrical insulation material. The stopper 50 includes a first stopper 51 which suppresses the displacement of the ferrule 40 to the inside in a radial direction D and a second stopper 55 which suppresses the displacement of the ferrule 40 toward the wire seal 60.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a shielded electric wire assembly including a wire seal which is a sealing member for waterproofing.

Background Art

[0002] Regarding the grounding method of a shielded electric wire used for an electric connector, for example, as disclosed in Patent Document 1 (FIG. 1), a structure using a shield contact (contact (61)) that can be crimped to a braided wire is known. Specifically, a terminal (53), a contact (61) that is crimp-connected to a shield braid (59) of a shield wire (57) whose core wire is connected to the terminal (53) and contacts a metal shell (55), and a waterproof sealing member (65) that is inserted around the outer periphery of the shield wire (57) and seals the shield wire (57) are provided.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the structure disclosed in Patent Document 1 is applied to a waterproof connector, it is necessary to arrange a contact (ferrule) near a waterproof sealing member (wire seal) for the purpose of reducing the size. However, depending on how the electric wire is handled, such as pulling the electric wire, the ferrule may move and contact the wire seal, damaging the wire seal and impairing the waterproof performance. Further, although the ferrule is grounded elastically by the metal shell and the spring piece, a space is generated between the ferrule and the electric wire due to structural reasons. The spring piece of the ferrule is displaced in the direction of this space to generate a contact load, but due to the posture at the time of inserting the terminal and the quality of the parts, excessive displacement may occur in the ferrule, which may impair the connection reliability.

[0005] Therefore, the present invention aims to provide a shielded wire assembly that can prevent damage to the wire seal due to the movement of the ferrule and prevent excessive displacement of the ferrule. [Means for solving the problem]

[0006] The shielded wire assembly of the present invention comprises a shielded wire including a braided wire, a ferrule made of a conductive material related to grounding the braided wire and assembled to the shielded wire, a wire seal responsible for waterproofing and assembled to the shielded wire, and a stopper made of an electrical insulating material and assembled between the ferrule and the wire seal. The stopper comprises a first stopper that suppresses radial inward displacement of the ferrule and a second stopper that suppresses displacement of the ferrule toward the wire seal.

[0007] In a shielded wire assembly, preferably, the first stopper and the second stopper are integrally formed, and the first stopper is cylindrical, and the second stopper is flange-shaped and protrudes radially outward from one end of the first stopper.

[0008] The first stopper preferably comprises a displacement-allowing portion that allows radial inward displacement of the elastic piece of the ferrule and a displacement-restricting portion that restricts radial inward displacement of the ferrule, wherein the outer diameter D52 of the displacement-allowing portion is formed to be smaller than the outer diameter D53 of the displacement-restricting portion.

[0009] The second stopper preferably includes a flange protruding radially outward from one end of the first stopper, such that if the radial dimension of the flange is D55 and the radial dimension of the ferrule is D43, then D55 ≥ D43.

[0010] In a shielded wire assembly, preferably, a ring-shaped rib is provided extending parallel to the first stopper from the radial end of the flange, and a ferrule is sandwiched between the rib and the displacement restricting portion. [Effects of the Invention]

[0011] The wire assembly of the present invention includes a stopper having a first stopper and a second stopper, the first stopper preventing excessive displacement radially inward of the ferrule, and the second stopper preventing damage to the wire seal. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view showing a shielded wire according to an embodiment. [Figure 2] Figure 1 is a perspective view showing the components of the seal section of a shielded wire separated. [Figure 3] Figure 2 shows a three-view and a longitudinal cross-sectional view of the stopper. [Figure 4] This is a cross-sectional view showing the shielded wire shown in Figure 1 attached to an electrical connector. [Figure 5] This is a magnified view of a portion of Figure 4. [Modes for carrying out the invention]

[0013] Hereinafter, an embodiment of the shielded wire assembly 1 of the present invention will be described with reference to the attached drawings. As shown in Figure 1, the shielded wire assembly 1 comprises a shielded wire 10, a grounding element 20 attached to the shielded wire 10 for grounding the braided wire, and a wire seal 60 that is attached to an electrical connector, for example, to provide waterproofing. The shielded wire assembly 1 includes a stopper 50 interposed between the grounding element 20 and the wire seal 60. By including the stopper 50, the shielded wire assembly 1 provides a scratch prevention effect that prevents damage to the wire seal 60. In addition, the stopper 50 provides an excessive displacement prevention effect that prevents excessive displacement exceeding the elastic limit from occurring in the elastic piece 44 of the ferrule 40. The components of the shielded wire assembly 1 will be described in order below, followed by a description of the mounting state of the shielded wire assembly 1 to the housing 100 of the electrical connector to which it is attached, and two functions of the shielded wire assembly 1: the scratch prevention function and the excessive displacement prevention function.

[0014] [Shielded wire 10: Figures 1 and 4] As shown in Figures 1 and 4, the shielded wire 10 comprises a conductive core wire 11, an inner layer covering 13 made of an electrically insulating material that surrounds the core wire 11, a braided wire 15 that surrounds the inner layer covering 13, and an outer layer covering 17 that surrounds the braided wire 15. The shielded wire 10 is equipped with a terminal 19 that is electrically connected to the core wire 11. In the shielded wire 10, as shown in Figure 1 and other figures, the side with the terminal 19 is defined as the front (F), and the side opposite the terminal 19 is defined as the rear (R). This definition has a relative meaning. For example, the wire seal 60 is assembled to the shielded wire 10 at the rear (R) of the stopper 50, and the stopper 50 is assembled to the shielded wire 10 at the front (F) of the wire seal 60.

[0015] [Core wire 11] The core wire 11 can be, for example, a stranded wire made by twisting together multiple metal strands, a conductor consisting of a single solid structure, or a combination of these conductors. The material constituting the core wire 11 can be a metal material with excellent conductivity, such as copper or copper alloy, or aluminum or aluminum alloy. The same applies to the metal strands of the braided wire 15 described later.

[0016] [Inner layer coating 13] The inner layer coating 13 covers the entire outer surface of the core wire 11, for example. The inner layer coating 13 is made of an electrical insulating material such as a synthetic resin, and specifically, a synthetic resin mainly composed of polyolefin resins such as cross-linked polyethylene and cross-linked polypropylene is used. The inner layer coating 13 may be made of a single type of insulating material, or it may be made by appropriately combining multiple types of insulating materials in multiple layers, for example.

[0017] [Stranded wire 15] The stranded wire 15 has a cylindrical form covering the outer periphery of the inner coating 13. As the stranded wire 15, a stranded wire formed by braiding a plurality of metal wires or a stranded wire formed by combining a metal wire and a resin wire can be used. At the front (F) end, the portion of the stranded wire 15 exposed from the outer coating 17 is folded back toward the rear (R). This folded-back portion 15A is sandwiched between the ferrule 40 and the fixing body 30. Thus, the stranded wire 15 is electrically connected to the ferrule 40.

[0018] [Outer coating 17] The outer coating 17 covers the entire circumferential direction of the outer peripheral surface of the stranded wire 15. The outer coating 17 is composed of, for example, the same electrical insulating material as the inner coating 13.

[0019] [Terminal 19] The terminal 19 is connected to the tip of the core wire 11 exposed from the inner coating 13. The terminal 19 includes a core wire connection portion 19A responsible for connecting to the core wire 11 and a mating connection portion 19B that is integrally formed with the core wire connection portion 19A and is connected to a mating terminal (not shown). In the terminal 19, the core wire connection portion 19A and the mating connection portion 19B are integrally formed by punching and bending a plate material made of a metal material with excellent conductivity as an example.

[0020] The core wire connection portion 19A is mechanically connected to the core wire 11 in addition to being electrically connected by means such as crimping and welding. The mating connection portion 19B has a fastening hole 19C penetrating in the plate thickness direction for connection by fastening to a mating terminal. For example, it is electrically and mechanically connected to a mating terminal (not shown) by a bolt (not shown) inserted into the fastening hole 19C.

[0021] [Grounding element 20: Figures 2, 4, 5] As shown in Figures 2, 4, and 5, the grounding element 20 electrically connects the braided wire 15 of the shielded wire 10 to the housing 100, which will be described later. The grounding element 20 includes a fixing body 30 that crimps the folded portion 15A of the braided wire 15 to the ferrule 40 and fixes the ferrule 40 to a predetermined position on the shielded wire 10, and a ferrule 40 that sandwiches the folded portion 15A of the braided wire 15 between itself and the fixing body 30.

[0022] [Fixed body 30] The fixing body 30 is fitted to the crimping portion 41 of the ferrule 40 from the outside, and by applying a load radially inward at an appropriate position in the circumferential direction, the crimping portion 41 is crimped and mechanically restrained with the braided wire 15 sandwiched in between. This crimping ensures a stable electrical connection between the braided wire 15 and the ferrule 40, and in addition, the crimping portion 41 is crimped to the outer layer coating 17 of the shielded wire 10, fixing the ferrule 40 in a predetermined position on the shielded wire 10. The materials constituting the fixing body 30 are not limited as long as they achieve their purpose, and are composed of metallic materials such as iron-based, aluminum-based, and copper-based materials. The fixing body 30 is typically composed of a cylindrical member and includes a fitting hole 31 in which the crimping portion 41 is located, and a crimping ring 33 surrounding the fitting hole 31. Here, a crimping ring 33 is given as an example of the fixing body 30, but the form of the fixing body 30 is not limited as long as it can fix the crimping portion 41 to the shielded wire 10 and also make an electrical connection with the braided wire 15.

[0023] [Ferrule 40] The ferrule 40 comprises a crimping portion 41 that is crimped to the shield wire 10 at a predetermined position on the shield wire 10 by being crimped by the fixing body 30, and a connecting portion 43 that is electrically connected to the housing 100. The crimping portion 41 and the connecting portion 43 are each formed in an annular shape, but the diameter of the crimping portion 41 is small, and the crimping portion 41 and the connecting portion 43 are integrally formed from a metal material having the same conductivity as the fixing body 30. The ferrule 40 can be manufactured, for example, by bending a flat plate into an annular shape. Alternatively, the ferrule 40 can be manufactured by preparing a circular tube of the same shape as the crimping portion 41 and expanding the diameter of the portion corresponding to the connecting portion 43.

[0024] The crimping portion 41 is, for example, a simple cylindrical shape. The connecting portion 43 comprises a front support end 43A, a rear support end 43B provided at intervals in the direction of the axis (C), and a plurality of elastic pieces 44 and a plurality of stationary pieces 45 provided between the front support end 43A and the rear support end 43B.

[0025] When the ferrule 40 is attached to the shielded wire 10, the elastic piece 44 is positioned on the front (F) side and the rear support end 43B is positioned on the rear (R) side. Both the front support end 43A and the rear support end 43B are formed to be continuous in the circumferential direction.

[0026] Each elastic piece 44 has a cantilevered shape, with the front support end 43A being the free end 44A and the rear support end 43B being the fixed end 44B connected to the rear support end 43B. Each elastic piece 44 has a contact point 44C that is responsible for direct connection with the housing 100. The contact point 44C is formed to protrude radially outward from the elastic piece 44. In the elastic piece 44, the cross-section excluding the contact point 44C, that is, the plane perpendicular to the axis (C), has an arc shape. The stationary piece 45 is similar.

[0027] Each stationary piece 45 has a cantilevered beam shape, with the side facing the front support end 43A forming a fixed end 45A connected to the front support end 43A, and the side facing the rear support end 43B forming a fixed end 45B connected to the rear support end 43B. The stationary pieces 45 are plate-shaped members made of an elastic metal material and can deform, but are called stationary pieces 45 from the viewpoint that they remain stationary in contrast to the elastic pieces 44.

[0028] Multiple elastic pieces 44 and multiple stationary pieces 45 are arranged alternately in the circumferential direction between the front support end 43A and the rear support end 43B. Furthermore, the elastic pieces 44 and stationary pieces 45 are formed to have equal radial dimensions from the axis (C), and the multiple elastic pieces 44 and multiple stationary pieces 45 are arranged alternately on a circular arc.

[0029] [Stopper 50: Figures 2, 3, 4, 5] Next, the stopper 50, which is positioned between the fixing body 30 and the wire seal 60 and provides scratch prevention and excessive displacement prevention effects, will be described with reference to Figures 2 to 5. The stopper 50 comprises a cylindrical first stopper 51 extending in the direction of the axis (C), and a second stopper 55 that is connected to the first stopper 51 at the rear (R) and protrudes radially (D) outward in a flange-like manner. The first stopper 51 and the second stopper 55 are integrally formed from, for example, rubber or an electrically insulating resin material.

[0030] [Daiichi Stoppa 51] The first stopper 51 is positioned between the outer layer coating 17 of the shielded wire 10 and the ferrule 40, with the aim of preventing the elastic piece 44 of the ferrule 40 from undergoing excessive inward displacement in the radial direction (D). The first stopper 51 comprises an inner circumferential surface 51A and an outer circumferential surface 51B. The first stopper 51 comprises a displacement-allowing portion 52 located on the front (F) side and a displacement-restricting portion 53 located on the rear (R) side of the displacement-allowing portion 52. An elastic piece 44 of the ferrule 40 is positioned in the displacement-allowing portion 52 with a gap on the radially (D) outward side. The rear support end 43B of the ferrule 40 is positioned in the displacement-restricting portion 53 with a gap on the radially (D) outward side.

[0031] The outer diameter D52 of the displacement-allowing portion 52 is formed to be smaller than the outer diameter D53 of the displacement-restricting portion 53 (see Figures 3 to 5). As described above, by making the outer diameter of the first stopper 51 in two stages, excessive radial (D) movement of the ferrule 40 is suppressed in the displacement-restricting portion 53, while the displacement-allowing portion 52 allows for a necessary and sufficient amount of inward deflection of the elastic piece 44 in the radial (D) direction. Note that in Figures 4 and 5, the elastic piece 44 is depicted as not deflecting. The difference ΔD between the outer diameter D53 and the outer diameter D52 (ΔD = outer diameter D53 - outer diameter D52) is set to correspond to a necessary and sufficient displacement applied to the elastic piece 44.

[0032] Multiple protrusions 54 extending in the axial direction (C) are arranged at equal intervals in the circumferential direction on the inner circumferential surface 51A of the first stopper 51. The tips of the protrusions 54 that face inward in the radial direction (D) are pointed. When the shielded wire 10 is fitted inside the stopper 50, the protrusions 54 bite into the outer layer coating 17 of the shielded wire 10, thereby preventing relative displacement of the shielded wire 10 and the stopper 50 in the circumferential direction.

[0033] [Second Stopper 55] The second stopper 55 is positioned between the rear (R) end of the connection portion 43 of the ferrule 40 and the wire seal 60, thereby preventing the ferrule 40 from moving toward the wire seal 60 and providing a scratch prevention function to prevent the connection portion 43 of the ferrule 40 from contacting and damaging the wire seal 60. To this end, if the radial dimension (D) of the second stopper 55 (flange 55A) is D55 and the radial dimension of the connection portion 43 is D43, the second stopper 55 is formed such that D55 ≥ D43 (see Figure 5).

[0034] The second stopper 55 comprises a flange 55A that protrudes radially (D) outward from the rear (R) end of the first stopper 51, and a ring-shaped rib 55B that extends forward (F) from the radial (D) end (tip) of the flange 55A and parallel to the first stopper 51. Flange 55A protects the wire seal 60 by colliding with ferrule 40 as it moves toward the wire seal 60. The rib 55B restrains the radial (D) displacement of the ferrule 43 by sandwiching the ferrule 40's connection portion 43 between itself and the displacement restricting portion 53, thereby positioning the connection portion 43.

[0035] [Wire seal 60] The wire seal 60 is provided between the housing 100 and the outer layer coating 17 of the shielded wire 10, and by being in close contact with both the housing 100 and the outer layer coating 17, it prevents moisture from entering the inside of the housing 100 via the outer layer coating 17. The wire seal 60 has a wire seal portion 61 that is in close contact with the outer circumferential surface of the outer layer coating 17 of the shielded wire 10, and a housing seal portion 63 that is in close contact with the inner circumferential surface of the housing 100. The wire seal 60 is made of a rubber material such as silicone rubber, nitrile rubber, and fluororubber.

[0036] [Housing 100: Figures 4 and 5] As shown in Figures 4 and 5, the housing 100 has a wire housing space 101 extending from the front (F) to the rear (R), and the shielded wire assembly 1 is housed in this wire housing space 101, forming one element of the electrical connector. The housing 100 is, for example, made of the conductive metal material mentioned above, typically an aluminum alloy.

[0037] The wire housing space 101 includes, as an example, a small space 101A located at the front (F) and a large space 101B located behind (R) the small space 101A. Both the small space 101A and the large space 101B consist of cylindrical voids, but the large space 101B has a larger diameter than the small space 101A. A step 101C is formed at the boundary between the small space 101A and the large space 101B. The inner circumferential surface of the housing 100 facing the small space 101A constitutes the electrical contact surface 101D to which the contact 44C of the elastic piece 44 of the ferrule 40 is electrically connected. The inner circumferential surface of the housing 100 facing the large space 101B constitutes the sealing surface 101E to which the housing sealing portion 63 of the wire seal 60 is tightly attached. The rear (R) end of the large space 101B is an opening 101F that connects to the outside, but this opening 101F is closed by a fastener 103.

[0038] [Installation status of shielded wire assembly 1 in housing 100: Figures 4 and 5] As shown in Figures 4 and 5, the shielded wire assembly 1 is mounted in the wire housing space 101 of the housing 100. The grounding element 20 (fixing body 30, ferrule 40) and stopper 50 are housed inside, spanning the small space 101A and the large space 101B.

[0039] In the small space 101A, the folded portion 15A is sandwiched between the braided wire 15 between the crimping portion 41 of the ferrule 40 and the crimping ring 31 of the fixed body 30, thereby electrically connecting the braided wire 15 and the ferrule 40. In addition, in the small space 101A, a necessary and sufficient radial (D) inward displacement (D) of the elastic piece 44 around the displacement-allowing portion 52 is permitted.

[0040] In the large space 101B, the rear support end 43B is constrained from inward radial (D) displacement by a displacement restricting portion 53 provided on its inside. In addition, the rear support end 43B is constrained from outward radial (D) displacement by a rib 55B. The contact point 44C of the elastic piece 44 contacts the electrical contact surface 101D. Furthermore, a flange 55A is positioned rearward (R) from the rear support end 43B. The rib 55B, which is connected to the radial (D) tip of the flange 55A, has its front (F) end abut against the step 101C, constraining the forward (F) displacement of the stopper 50. The rearward (R) displacement of the stopper 50 is constrained by a fastener 103 via a wire seal 60.

[0041] [Effects of Shielded Cable Assembly 1] The shielded wire assembly 1, by being equipped with a stopper 50, provides the following effects. The stopper 50 includes a first stopper 51 provided inside the ferrule 40. Therefore, the shielded wire assembly 1 can provide an excessive displacement prevention effect, preventing the ferrule 40 from being excessively displaced inward in the radial direction (D). Furthermore, the stopper 50 includes a second stopper 55 behind (R) the rear support end 43B of the ferrule 40. Therefore, the shielded wire assembly 1 can provide a scratch prevention effect, preventing the ferrule 40 from being displaced backward (R) and hitting the wire seal 60, thus preventing damage to the wire seal 60. Moreover, since the shielded wire assembly 1 can provide both the excessive displacement prevention effect and the scratch prevention effect by providing the stopper 50, which is a single, integrally formed component, it also offers cost advantages.

[0042] Although preferred embodiments of the present invention have been described above, it is possible to select or replace the configurations listed in the above embodiments, or to modify them to other configurations as appropriate, without departing from the spirit of the present invention. For example, in a preferred embodiment, the stopper 50 is integrally formed with a first stopper 51 that has an excessive displacement prevention function and a second stopper 55 that exhibits a scratch prevention function, but the present invention is not limited thereto. For example, a member corresponding to the first stopper 51 and a member corresponding to the second stopper 55, which are manufactured separately, may be placed in the positions in the shielded wire assembly 1 corresponding to the first stopper 51 and the second stopper 55, respectively.

[0043] Furthermore, the connecting portion 43 of the ferrule 40 preferably includes a cantilever-shaped elastic piece 44, but it may also be in a simple cylindrical shape. In that form as well, it is preferable to include a contact 44C or a portion equivalent to a contact 44C in order to ensure reliable electrical connection with the electrical contact surface 101D of the housing 100. [Explanation of Symbols]

[0044] 1 Wire assembly 10 Shielded Cables 11 core wires 13. Inner layer coating 15 Braided wire 15A Folded part 17. Outer layer coating 19 terminals 19A Core wire connection 19B Mutual connection section 19C fastening hole 20 Grounding elements 30 Fixed body 31 Fitting hole 33 Crimping ring 40 ferrules 41 Crimping section 43 Connection part 43A Front support end 43B Rear support end D43 Outer diameter 44 Elastic pieces 44A free end 44B fixed end 44C contact 45 Stationary piece 45A,45B Fixed end 50 Stoppers 51 First Stopper 51A Inner surface 51B Outer surface 52 Displacement allowable section D52 outer diameter 53 Displacement Control Section D53 outer diameter 54 protrusion 55 Second Stopper 55A Flange 55B Rib D55 outer diameter 60 Wire Seals 61 Wire sealing section 63 Housing seal section 100 Housing 101 Cable storage space 101A Small Space 101B Large Space 101C Step 101D Electric contact surface 101E sealing surface 101F opening 103 Fasteners C axis D radial direction F forward R rear

Claims

1. A shielded wire assembly (1) comprising: a shielded wire (10) including a braided wire (15); a ferrule (40) made of a conductive material related to grounding the braided wire (15) and assembled to the shielded wire (10); a wire seal (60) responsible for waterproofing and assembled to the shielded wire (10); and a stopper (50) made of an electrical insulating material and assembled between the ferrule (40) and the wire seal (60), wherein the stopper (50) comprises: a first stopper (51) that suppresses inward displacement of the ferrule (40) in the radial direction (D); and a second stopper (55) that suppresses displacement of the ferrule (40) toward the wire seal (60).

2. The shielded wire assembly (1) according to claim 1, comprising: the first stopper (51) and the second stopper (55) being integrally formed, the first stopper (51) being cylindrical, and the second stopper (55) being flange-shaped and protruding outward in the radial direction (D) from one end of the first stopper (51).

3. The first stopper (51) comprises a displacement-allowing portion (52) that allows inward displacement of the elastic piece (44) of the ferrule (40) in the radial direction (D), and a displacement-restricting portion (53) that restricts the inward displacement of the ferrule (40) in the radial direction (D), wherein the outer diameter D52 of the displacement-allowing portion (52) is formed to be smaller than the outer diameter D53 of the displacement-restricting portion (53), as described in claim 1 or claim 2.

4. The shielded wire assembly (1) according to claim 3, wherein the second stopper (55) is provided with a flange (55A) that protrudes radially (D) outward from one end of the first stopper (51), and if the radial dimension (D) of the flange (55A) is D55 and the radial dimension of the ferrule (40) is D43, then D55 ≥ D43.

5. The shielded wire assembly (1) according to claim 4, comprising a ring-shaped rib (55B) extending parallel to the first stopper (51) from the radial end (tip) of the flange (55A), wherein the ferrule (40) is sandwiched between the rib (55B) and the displacement restricting portion (53).

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