Connector-equipped wire

Abstract

To provide a connector-equipped wire that is not affected by electromagnetic noise radiation due to bias in current density in an electric wire and that does not leak electromagnetic noise to the outside from a shield shell that is connected and fixed to an external object to be connected.SOLUTION: A connector-equipped wire 1 includes: an electric wire 7; and a connector 3 having at least a conductive shield shell 5 that houses an end of the electric wire 7. The shield shell 5 has a side wall that surrounds the end of the electric wire 7 and is connected and fixed to an object to be connected 10. The shield shell 5 has a conductive coating 52 on at least a portion of an end surface 51 of the side wall 50 that comes into contact with the object to be connected 10 when the shield shell is connected and fixed to the object to be connected 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a connector-attached electric wire. [Background technology]

[0002] Conventionally, electric wires used to connect electronic devices or control boards, etc., installed in vehicles, etc., often use high-voltage and high-frequency currents. However, it is known that the electric wires used in these vehicles, etc., generate electromagnetic noise (electromagnetic noise) due to the high-voltage current flowing through them and the difference in distance to the electric wire or connection terminal within the connector, which causes uneven current density. To prevent this electromagnetic noise from being superimposed on the signal lines of other electronic devices or control boards, etc., and causing adverse effects, there is a demand for electric wires with connectors that can block electromagnetic noise.

[0003] For example, Patent Document 1 discloses a compact electric wire with a connector. The electric wire is provided with a braided body, which is a cylindrical member that covers the outer surface of the electric wire. The braided body is made of conductive wires braided into a cylindrical, mesh-like shape, and is described as preventing electromagnetic noise generated by current flowing through the core wire from affecting electronic devices and other devices located nearby. Patent Document 2 also discloses a wire harness that can prevent a decrease in electromagnetic shielding performance. The document describes a first shielding member that is electrically connected to a cylindrical member in contact with a plurality of first exposed portions of a plurality of electric wire members. However, both Patent Documents 1 and 2 are insufficient in shielding electromagnetic noise, and it is difficult to ignore the effects of electromagnetic noise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-038823 [Patent Document 2] Japanese Patent Application Publication No. 2023-146269 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide an electric wire with a connector that can significantly improve shielding characteristics by optimizing the shielding shell, thereby stably reducing the contact resistance between the shielding shell and the object to be connected and suppressing unevenness in the current density flowing through the electric wire. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention is as follows. (1) An electric wire with a connector, comprising an electric wire and a connector having at least a conductive shield shell that houses an end of the electric wire, the shield shell having a side wall that surrounds the end of the electric wire and is connected and fixed to an object to be connected, the shield shell having a conductive coating on at least a portion of the end surface of the side wall that comes into contact with the object to be connected when the shield shell is connected and fixed to the object to be connected. (2) The electric wire with connector according to (1) above, wherein the shield shell has the conductive coating on the entire end surface of the side wall that contacts the connection object. (3) The electric wire with connector described in (2) above, wherein the shield shell has a pair of flange portions, each having a lower surface extending on the same plane as the end surface of the side wall from the outer surfaces of both side walls positioned symmetrically across the width of the end of the electric wire to be housed, and a through hole is formed in the flange portions for inserting a fastening member to connect them. (4) The electric wire with connector according to (3) above, wherein the shield shell has the conductive coating on the flange portion. (5) The electric wire with connector according to (1) or (3) above, wherein the shield shell is made of aluminum. (6) The electric wire with connector according to (5) above, wherein the conductive coating has a tin-plated coating. (7) The electric wire with connector according to (6) above, wherein the shield shell is subjected to a zincate treatment between the shield shell and the tin-plated coating. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a connector-equipped electric wire that can significantly improve shielding characteristics by stably reducing the contact resistance between the shield shell and the object to be connected and suppressing unevenness in the current density flowing through the electric wire. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the configuration of an electric wire with a connector according to one embodiment of the present invention, in a separated state before being connected and fixed to an object to be connected. [Figure 2] FIG. 2(a) is a diagram explaining the shielded shell of conventional example 1, and is a side view when the flange portion is located at one location on the front side wall of the shielded shell; FIG. 2(b) is a diagram explaining the shielded shell of conventional example 2, and is a side view when the flange portion is located at one location on the front side wall of the shielded shell and the bottom surface of the shielded shell is lowered; and FIG. 2(c) is a diagram explaining the shielded shell of conventional example 3, and is a top view when the flange portion is located at one location on the side wall of the shielded shell. [Figure 3] FIG. 3(a) is a diagram for explaining the fastening state of the shield shell of conventional example 1, and is a side view showing the fastening state when the flange portion is located at one location on the front side wall of the shield shell; FIG. 3(b) is a diagram for explaining the fastening state of the shield shell of conventional example 2, and is a side view showing the fastening state when the flange portion is located at one location and the bottom surface of the shield shell is lowered; and FIG. 3(c) is a diagram for explaining the shield shell of conventional example 3, and is a front view showing the fastening state when the flange portion is located at one location on the side wall of the side of the shield shell. [Figure 4] 4A to 4C are diagrams illustrating the fastened state of the shield shell of the present invention, where FIG. 4A is a top view, FIG. 4B is a side view, and FIG. 4C is a bottom view. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A connector-attached electric wire according to an embodiment of the present invention will be described below. Note that the following description is an example of an embodiment of the present invention and does not limit the scope of the claims.

[0010] <Wire with connector> FIG. 1 is a perspective view showing the configuration of an electric wire with a connector according to one embodiment of the present invention, in a separated state before being connected and fixed to an object to be connected. The electric wire with connector 1 of the present invention comprises an electric wire 7 and a connector 3 having at least a conductive shield shell 5 that houses an end of the electric wire 7, the shield shell 5 having a side wall 50 that surrounds the end of the electric wire 7, and the electric wire with connector 1 is connected and fixed to an object to be connected 10, and the shield shell 5 has a conductive coating 52 on at least a part of an end face 51 of the side wall 50 that comes into contact with the object to be connected 10 when the shield shell 5 is connected and fixed to the object to be connected 10, preferably on the entire end face 51, and further preferably on the bottom face of the flange portion 6. Since it is preferable that the end faces of the shield shell 5 and the flange portion 6 are on the same plane without any steps, it is preferable that the conductive coating 52 is also provided at the same time.

[0011] <Connector> The electric wire with connector 1 of the present invention has a connector 3 that fixes and holds a connection terminal (not shown) that mates with a connection terminal provided on an electronic device, a control board, or the like. The shape of the connection terminal is not particularly limited. For example, it is fixedly connected or fitted to a metal housing of the electronic device, and the connection terminal provided at the end of the electric wire 7 drawn into the connector 3 is electrically connected to a connection terminal on the device body inside the housing. Also, the connector 3 that holds the connection terminal is fitted and connected to a connector provided on the control board and connected to an electronic component, thereby achieving an electrical connection. Therefore, the connector 3 provided in the electric wire with connector 1 of the present invention is not particularly limited.

[0012] <Electric wire> The electric wire 7 used in the connector-attached electric wire 1 of the present invention is not limited to a specific type. For example, the electric wire 7 may include a conductor consisting of a plurality of strands or wires made of aluminum or aluminum alloy (hereinafter referred to as "aluminum material"), copper, copper alloy, or silver, and an insulating layer that provides an insulating coating around the conductor. Examples of insulating materials that can be used to form the insulating layer include various resin compositions, such as styrene-based resins and ABS-based resins. The thickness of the insulating layer can be appropriately selected within a range that satisfies the desired insulating properties. At the end of the electric wire 7, the insulating layer is peeled off to expose a portion, which is then connected to a connection terminal (not shown) that can be fixed to the connector 3. Examples of the electric wire 7 include a PN line that supplies high-voltage power from a power source via a power supply terminal provided on a control board or the like.

[0013] <Shield Shell> The shield shell 5 has a box shape with an open back side, holds connection terminals (not shown) provided at the ends of electric wires inside, and forms side walls 50 that surround the terminals. The connection terminals of the shield shell 5 fit into connection terminals (not shown) of a connector provided on the object 10 to be connected. The shield shell 5 is electrically conductive and is made of, for example, aluminum. Furthermore, by using a conductive material for the shield shell 5, it is possible to prevent electromagnetic noise generated from the electric wires 7 from leaking to the outside.

[0014] <Flange part> The shielding shell 5 has flat flange portions 6 on the side walls 50 thereof in order to be connected and fixed to the connection object 10. The flange portions 6 have lower surfaces that extend from the outer surfaces of the side walls 50 of the shielding shell 5, which are positioned symmetrically about the width center around the ends of the electric wires 7 to be housed, on the same plane as the end faces 51 of the side walls 50, and form pairs symmetrically about the width center around the electric wires 7. While FIG. 1 shows one pair of flange portions 6, two or more pairs can be provided along the side walls 50, each at positions symmetrical about the width center. By connecting and fixing these pairs of flange portions 6 to the connection object with fastening members 8 such as bolts, it is possible to maintain a state in which the end faces 51 of the shielding shell 5 are in contact with the connection object 10 with a relatively uniform contact pressure, and as a result, it is possible to effectively improve the shielding characteristics. Furthermore, the flange portion 6 is provided with through holes 61 for inserting fastening members 8 that connect and fix the connector 3 to a connection object 10, such as a wall surface or a control board of an electronic device. The fastening members 8 are not particularly limited, but it is preferable to use bolts and nuts, or screws (not shown). The fastening members 8 ensure an axial force during connection and fixation, and can connect and fix the shield shell 5 to the connection object 10.

[0015] The flange portion 6 mechanically and electrically connects the shield shell 5, and the shield shell 5 can be connected to the ground by using fastening members 8 in the through holes 61. Therefore, like the shield shell 5, the flange portion 6 is conductive and is preferably made of aluminum. Furthermore, when the shield shell 5 is connected and fixed to the object to be connected 10, the shield shell 5 has a conductive coating 52 on at least a part of the end surface 51 of the side wall 50 that comes into contact with the object to be connected 10. Furthermore, the shield shell 5 is provided with the conductive coating 52 on the entire end surface 51 of the side wall 50 that comes into contact with the object to be connected 10.

[0016] <Conductive coating> The conductive coating 52 provided on the shield shell 5 improves adhesion when connected and fixed to the connection object 10, and by eliminating gaps between the shield shell 5 and the connection object 10, it is possible to prevent electromagnetic noise generated by the electric wires 7 inside from leaking to the outside. The conductive coating 52 preferably has ductility such that it is crushed when the shield shell 5 is connected and fixed to the connection object 10, thereby increasing the effective contact area with the connection object 10. Furthermore, the conductive coating 52 can be formed using a plating method, which requires fine processing. A tin plating coating is particularly preferable as the conductive coating 52. Metallic tin has low hardness and a low melting point, and therefore has excellent ductility. Furthermore, tin oxide has high conductivity, which can prevent deterioration over time.

[0017] <Plating> To impart conductivity, gold plating, nickel plating, tin plating, etc. are used. The plating method is not particularly limited, and either dry or wet methods can be used, with wet plating being preferred due to its ease of use. Wet plating may be either electrolytic plating or electroless plating. To partially plate the end surface 51 of the side wall 50 of the shield shell 5, the portions not to be plated may be masked with, for example, masking tape, a rubber insulator, or a polymer resist, and then plating is performed.

[0018] The shielding shell 5 is required to have high conductivity in order to electrically connect electronic devices, control boards, etc., and is made of aluminum or an aluminum alloy (hereinafter referred to as "aluminum material"). The aluminum material used in the present invention preferably has a tensile strength of 100 MPa or more when tempered. However, aluminum materials have an insulating oxide film on the aluminum surface, which can cause low conductivity and poor conduction. Therefore, simply providing a conductive tin plating film may not provide high conductivity.

[0019] <Zincate treatment> When aluminum is tin-plated, aluminum and tin do not form an alloy, and even if a tin-plated film is formed on the aluminum, the adhesion between the two is insufficient. To improve this insufficient adhesion, zincate treatment can be used on aluminum. For example, an alkaline degreasing agent is used to remove oil from the aluminum material on the end surface 51 of the shield shell 5, and then an alkaline etching solution is used to remove the aluminum oxide film on the surface. After that, a tin-plated film is formed on the aluminum material by a wet tin plating method.

[0020] <Tin plating film> The tin plating film on the aluminum material can be formed by electrolytic plating or electroless plating. The thickness of the tin plating film is preferably 1.0 μm or more and 10.0 μm or less, and more preferably 1.0 μm or more and 5.0 μm or less. If the thickness of the tin plating film is less than 1.0 μm, pinholes where plating is not formed may occur, and if it exceeds 10.0 μm, variations in the thickness of the plating layer may occur.

[0021] <Securing and connecting shield shells> The shield shell 5 is connected and fixed to the connection object 10 as follows. FIG. 2(a) is a diagram illustrating the shield shell 5 of conventional example 1, and is a side view when the flange portion 6 is located at one location on the front side wall 50 of the shield shell 5; FIG. 2(b) is a diagram illustrating the shield shell 5 of conventional example 2, and is a side view when the flange portion 6 is located at one location on the front side wall 50 of the shield shell 5, lowering the bottom surface of the shield shell; and FIG. 2(c) is a diagram illustrating the shield shell 5 of conventional example 3, and is a top view when the flange portion 6 is located at one location on the side wall 50 of the side of the shield shell 5. FIG. 3(a) is a diagram for explaining the fastening state of the shield shell 5 of conventional example 1, and is a side view showing the fastening state when there is one flange portion; FIG. 3(b) is a diagram for explaining the fastening state of the shield shell of conventional example 2, and is a side view showing the fastening state when there is one flange portion and the bottom surface of the shield shell is lowered; and FIG. 3(c) is a front view for explaining the fastening state of the shield shell of conventional example 3. 4A to 4C are diagrams illustrating the fastened state of the shield shell 5 of the present invention, where FIG. 4A is a top view, FIG. 4B is a side view, and FIG. 4C is a bottom view.

[0022] As shown in FIG. 2(a), in Conventional Example 1, the flange portion 6 of the shielded shell 5 is connected to a single connector-attached electric wire 1 on the front side wall 50 of the shielded shell 5. FIG. 3(a) shows a state in which the flange portion 6 of the shielded shell 5 is connected and fixed with a fastening member 8. Connecting and fixing with the fastening member 8 causes a portion of the end surface 51 of the side wall 50 of the shielded shell 5, which is away from the flange portion 6, to float and separate from the connection object 10, forming a gap. Electromagnetic noise leaks from this gap and may affect electronic circuits, such as a control board, located near the shielded shell 5, causing malfunction. Furthermore, even if the flange portion 6 is made of an elastic material or the shielded shell 5 is connected and fixed at a single flange portion 6, it is difficult to completely connect and fix the shielded shell 5 to the connection object 10 without forming a gap. As a result, the contact pressure with the shielding shell 5 is small except in the vicinity of the flange portion 6, and contact resistance increases when electrical conduction is established with the connection object 10 via the flange portion 6 of the shielding shell 5 and the end face 51. As a result, the current path to the vicinity of the flange portion 6 becomes dominant, resulting in a large bias in current density and increased electromagnetic noise. Furthermore, forming a gap with the connection object 10 increases the leakage of electromagnetic noise, which has an adverse effect on electronic devices, etc.

[0023] Furthermore, as shown in FIG. 2(b), Conventional Example 2 uses a connector-attached electric wire 1 in which the bottom surface of the shielded shell is lowered at one flange portion. This example shows a case in which the end surface (bottom surface) of the shielded shell is inclined so that the further away from the flange portion where the fastening member 8 is fastened, the closer it is to the object to be connected. As shown in FIG. 3(b), a conventional example shows a fastening state in which a portion of the bottom surface of the shielded shell 5 is lowered and the shielded shell 5 is fastened with the fastening member 8 at one flange portion 6 of the shielded shell 5. Since the shielded shell 5 is fastened at one flange portion 6, the position away from the flange portion 6 is lowered and the bottom surface of the shielded shell 5 is inclined. However, even in this case, even if the shielded shell is fastened at one flange portion 6, it is difficult to completely fasten the shielded shell 5 to the object to be connected 10 without forming a gap. Furthermore, even if there is no significant gap between the shielded shell 5 and the object to be connected 10, it is not possible to prevent electromagnetic noise from leaking to the outside.

[0024] Furthermore, as shown in FIG. 2(c), in Conventional Example 3, the flange portion 6 of the shielded shell 5 is connected to the side wall 50 of the shielded shell 5 at one location, and the connector-attached electric wire 1 is used. FIG. 3(a) is a front view showing a fastened state in which the flange portion 6 is connected to the side wall 50 of the shielded shell 5 at one location with a fastening member 8. Connecting and fixing with the fastening member 8 causes a portion of the end surface 51 of the side wall 50 of the shielded shell 5, which is away from the flange portion 6, to float and separate from the connection object 10, forming a gap. Electromagnetic noise leaks from this gap and may affect electronic circuits, such as a control board, located near the shielded shell 5, resulting in malfunction. Furthermore, even if the flange portion 6 is made of an elastic material or the shielded shell 5 is connected and fixed at one location with the flange portion 6, it is difficult to completely connect and fix the shielded shell 5 to the connection object 10 without forming a gap. As a result, the contact pressure with the shielded shell 5 is small and the contact resistance is high except in the vicinity of the flange portion 6. As a result, the current path near the flange portion 6 becomes dominant, causing a large bias in current density and increasing electromagnetic noise. Furthermore, forming a gap with the connection object 10 increases the leakage of electromagnetic noise, which has an adverse effect on electronic devices, etc.

[0025] Therefore, as shown in FIG. 4( a), the shielded shell 5 of the present invention is provided with a pair of flange portions 6 symmetrically arranged about the center of the width of the shielded shell 5 in the direction in which current flows through the electric wires 7, and fastening members 8 are arranged thereon. In this example, the electric wires 7 extend from the right side to the left side of the shielded shell 5. Therefore, the flange portions 6 are provided with fastening members 8 arranged symmetrically above and below the center of the width, indicated by the dashed-dotted line in FIG. 4( a). By connecting and fixing the flange portions 6 with these fastening members 8, the entire shielded shell can be connected and fixed evenly to the connection object 10. Here, one pair of flange portions 6 is shown, but two or more pairs may be provided. This allows the shielded shell 5 to be connected and fixed to the connection object 10 without any gaps, thereby preventing electromagnetic noise from leaking to the outside. Furthermore, as shown in Figures 4(b) and (c), by applying a tin-plated coating as conductive coating 52 to part, the entire circumference, or the bottom surface of flange portion 6 of end face 51 with which shielding shell 5 comes into contact, even if there are areas where the surface pressure is low in the connected and fixed state fastened by fastening members 8, the tin-plated coating, which has low hardness, will collapse, lowering the contact resistance of shielding shell 5 with connected object 10, reducing the electrical resistance when connected to ground, and preventing the formation of gaps through which electromagnetic noise leaks. Furthermore, since the shield shell 5 is uniform across the entire contact area, the inclination of the shield shell 5 is eliminated, the bias in the current density of the electric wires 7 stored inside the shield shell 5 is reduced, and the generation of electromagnetic noise can be suppressed.

[0026] As explained above, the shielding characteristics were compared between the electric wire with connector 1 of the present invention and the electric wire with connector of Conventional Examples 1 to 3. It was confirmed that, compared to Conventional Examples 1 to 3, the electric wire with connector 1 of the present invention comes into contact with the object to be connected 10 over the entire flange portion 6 and end face 51, and therefore the contact resistance decreases in inverse proportion to the contact area, improving the shielding characteristics. [Explanation of symbols]

[0027] 1. Wire with connector 3 Connectors 5 Shield Shell 50 side wall 51 End face of side wall 52 Conductive coating 6 Flange 61 Through hole 7 Electric wire 8 Fastening members 10 Connected Objects

Claims

1. Electric wires and a connector having at least a conductive shield shell that accommodates an end of the electric wire; Equipped with The shield shell has a side wall surrounding an end of the electric wire, and is connected and fixed to an object to be connected, and is a connector-attached electric wire, The shield shell has a conductive coating on at least a part of an end surface of the side wall that comes into contact with the object to be connected when the shield shell is connected and fixed to the object to be connected.

2. The electric wire with connector according to claim 1 , wherein the shield shell is provided with the conductive coating on the entire end surface of the side wall that contacts the connection object.

3. 3. The electric wire with connector according to claim 2, wherein the shield shell has a pair of flange portions, each of which has a lower surface extending flush with the end surface of the side wall from the outer surfaces of both side walls positioned symmetrically across the width of the shield shell with the end of the electric wire to be housed as the center, and the flange portions have through holes formed in which fastening members are inserted to connect the flange portions.

4. The electric wire with connector according to claim 3 , wherein the shield shell has the conductive coating on the flange portion.

5. The electric wire with connector according to claim 1 or 3, wherein the shield shell is made of an aluminum material.

6. The connector-attached electric wire according to claim 5 , wherein the conductive coating comprises a tin-plated coating.

7. The electric wire with connector according to claim 6 , wherein a zincate treatment is applied between the shield shell and the tin-plated coating.

Images