JP5794899B2 - Shield braiding - Google Patents

Description

  The present invention relates to a shield braid.

  Conventionally, shielded electric wires have been proposed as countermeasures against external noise. In such a shielded electric wire, a shield braid formed by braiding a strand such as a copper wire is provided on the outer periphery of the conductor, and noise is shielded from the shield braid (for example, Patent Document 1). reference).

  In recent years, electric wires having a small diameter, light weight, and bending resistance have been demanded for robot applications and the like, and accompanying this, the demand for shield braiding of electric wires has increased. In response to this requirement, a shield braid obtained by braiding a metal-coated fiber obtained by winding a copper foil on a fiber, and a shield braid obtained by braiding a metal-coated fiber subjected to copper plating have been proposed. Since this metal-coated fiber has a small diameter, light weight, and high bending properties, and has excellent shielding performance, a shield braid obtained by braiding the metal-coated fiber is suitable as a shield member for a robot.

JP 2006-164830 A

  Here, it is necessary to connect a ground wire to the shield braid. However, in the shield braid described above, there is a possibility that a connection failure may occur when the ground wire is connected. For example, soldering may be performed when connecting the ground wire. In this case, since a metal film is provided on the fiber in the shield braid described above, the number of metal portions is small as compared with the case where the braid is configured with a conductor wire. For this reason, for example, when the metal film is copper, the copper layer is diffused into the tin layer of the solder by the soldering process, which causes a connection failure.

  In addition, the metal-coated fibers at the end of the electric wire may be converged to form a bundle, and a terminal may be crimped on the bundle to perform grounding. However, even in such a case, since the brazing property of the fiber itself is poor, it is difficult to converge and form a bundle, and it is difficult to crimp the terminal, which may cause poor connection.

  The present invention has been made in order to solve such a conventional problem. The object of the present invention is to provide a shield that has a small diameter, light weight, and high bending characteristics, and reduces the possibility of poor connection. It is an object of the present invention to provide a shield braid capable of preventing a decrease in performance.

The shield braid of the present invention is composed of a plurality of metal-coated fibers formed by forming a metal film on the outer periphery of a heat-resistant fiber and a copper material made of copper or a copper alloy , or another conductor different from the copper material And a linear body composed of the copper material coated on the conductor, and a braided shield braid, wherein the linear body has a pitch of 20 mm to 150 mm in the longitudinal direction. in is disposed, and the thickness of the copper material is 150 micrometers from 10 micrometers.

  According to the shield braid of the present invention, since the copper material is disposed between the plurality of metal-coated fibers, the possibility of poor connection can be reduced by using this copper material. In particular, since the copper material exceeds 10 micrometers in thickness, the thickness is not too thin and the possibility of copper erosion can be reduced. Moreover, since the copper material is less than 150 micrometers in thickness, it can suppress the situation where the flexibility of a shield braiding is inhibited without being too thick. Moreover, since a copper material is arrange | positioned in the longitudinal direction over pitch 20mm, it can suppress the situation where a copper material is arrange | positioned densely and a shield braiding becomes difficult to unravel and it becomes difficult to crimp a terminal. Furthermore, since the copper material is arranged with a pitch of less than 150 millimeters in the longitudinal direction, it is possible to prevent a situation where the pitch becomes large and the locations where solder connection is made are too limited. Therefore, it has a small diameter, light weight, and high bending characteristics, and can reduce the possibility of connection failure.

  According to the present invention, it has a small diameter, a light weight, and a high bending property, and can reduce the possibility of poor connection and prevent a decrease in shielding performance.

It is a schematic block diagram of the shielded electric wire containing the shield braid which concerns on embodiment of this invention, Comprising: (a) has shown the perspective view, (b) has shown sectional drawing. It is a detailed sectional view of the metal-coated fiber shown in FIG. It is a detailed top view which shows the shield braid concerning this embodiment. It is sectional drawing which shows the detail of a copper material, (a) shows a 1st example, (b) shows a 2nd example, (c) has shown the 3rd example. It is sectional drawing which shows the other example of copper material.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a shielded electric wire including a shield braid according to an embodiment of the present invention, where (a) shows a perspective view and (b) shows a cross-sectional view. As shown in FIG. 1, the shielded electric wire 1 includes a conductor 10, an insulating layer 20, and a shield braid 30.

  The conductor 10 is composed of, for example, an annealed copper wire, a tin-plated annealed copper wire, and a tin-plated copper alloy wire. In the present embodiment, the number of conductors 10 is one, but a plurality of conductors may be used. The diameter of the conductor 10 may be changed as appropriate according to the specifications. The insulating layer 20 is a member coated on the conductor 10 and is constituted by a non-conductive member.

  The shield braid 30 is configured by braiding metal-coated fibers 31. FIG. 2 is a detailed cross-sectional view of the metal-coated fiber 31 shown in FIG. As shown in FIG. 2, the metal-coated fiber 31 is formed by forming a metal film 31b on the outer periphery of the heat-resistant fiber 31a. The reason for using the heat resistant fiber 31a is to cope with soldering.

  Here, the heat-resistant fibers 31a correspond to, for example, para-aramid fibers, PBO (poly (p-phenylenebenzobisoxazole) fibers, polyarylate fibers, and polymer polyethylene fibers.) The heat-resistant fibers 31a are meta-aramid fibers. Also applicable are polyphenylene sulfide fiber, polyimide fiber, fluorine fiber, and the like.

  The metal film 31b is made of copper such as annealed copper or pure copper or a copper alloy containing these. The metal film 31b is formed by, for example, forming the heat-resistant fiber 31a on the heat-resistant fiber 31a by immersing the heat-resistant fiber 31a in the plating tank, or winding a metal foil made of copper or a copper alloy on the heat-resistant fiber 31a. Or

  Furthermore, in the shield braid 30 according to this embodiment, a copper wire 32 made of copper or a copper alloy is interposed between a plurality of metal-coated fibers 31 constituting the braid. FIG. 3 is a detailed top view showing the shield braid 30 according to the present embodiment. In FIG. 3, the conductor 10 and the insulating layer 20 are also illustrated for convenience of explanation.

  The copper material 32 shown in FIG. 3 is made of copper such as annealed copper or pure copper or a copper alloy containing these, and the shield braid 30 is obtained by replacing a part of the metal-coated fibers 31 with the copper material 32. The copper material 32 is interposed between the metal-coated fibers 31.

  FIG. 4 is a cross-sectional view showing details of the copper material 32, in which (a) shows a first example, (b) shows a second example, and (c) shows a third example. . As shown in FIG. 4A, the copper material 32 has a substantially circular cross section. Further, the copper material 32 is not limited to a circular cross section, but may be an elliptical cross section or a substantially flat plate shape as shown in FIGS.

  Here, in the present embodiment, the copper material 32 is arranged with a pitch of 20 mm to 150 mm in the longitudinal direction of the shielded electric wire 1. That is, the pitch P shown in FIG. 3 is greater than 20 millimeters and less than 150 millimeters. Thus, since the copper material 32 is arrange | positioned with the pitch P exceeding 20 millimeters in the longitudinal direction, the copper material 32 is arrange | positioned densely, the shield braiding 30 becomes difficult to unravel, and it becomes difficult to crimp a terminal. Can be suppressed. In addition, since the copper material 32 is disposed with a pitch P of less than 150 millimeters in the longitudinal direction, it is possible to prevent a situation in which the pitch P becomes large and the locations where solder connection is made are too limited.

  In the present embodiment, the copper material 32 has a thickness T shown in FIG. 4 of 10 to 150 micrometers. Here, since the thickness T of the copper material 32 exceeds 10 micrometers, the thickness T is not too thin and the possibility of copper erosion can be reduced. Further, since the thickness T of the copper material 32 is less than 150 micrometers, it is possible to suppress the situation where the flexibility of the shield braid 30 is hindered and it becomes difficult to crimp the terminal.

  As shown in FIG. 4, the thickness T of the copper material 32 is a diameter portion when the copper material 32 has a substantially circular cross section, and has a long diameter when the copper material 32 has an elliptical shape. This is the same as the general concept of thickness when the copper material 32 is substantially flat. That is, the thickness T of the copper material 32 is a concept indicating the longest length in the thickness direction (the radial direction of the shielded electric wire 1).

  Next, a method for manufacturing the shield braid 30 according to the present embodiment will be described. The shield braid 30 according to the present embodiment is manufactured using a braiding machine in the same manner as a conventional shield braid. At this time, in the shield braid 30 according to the present embodiment, at least one of the plurality of hits is for the copper material 32 and the other hit is for the metal-coated fiber 31. Thereby, the shield braiding 30 according to the present embodiment is manufactured by the braiding machine.

  In the shielded electric wire 1 using the shield braid 30 according to the present embodiment, the ground wire is connected by the following method.

  First, when soldering to connect the ground wire, the operator only has to solder the ground wire to the copper material 32 of the shield braid 30. Thereby, even if copper erosion occurs in the metal-coated fiber 31, copper erosion does not occur with respect to the copper material 32, and connectivity between the shield braid 30 and the ground wire is ensured.

  In addition, when performing terminal crimping when connecting the ground wire, first, the shield braid 30 is unwound at the end portion of the shielded electric wire 1, and the unfolded portion is converged to form a bundle. At this time, the metal coated fiber 31 is wound with the copper material 32. As a result, the bundle is difficult to unravel. And the bundle wound by the copper material 32 is crimped by the terminal connected to a ground wire. Thereby, the situation where it becomes difficult to crimp the terminal due to the poor brazing property of the fiber can be prevented, and the possibility of causing poor connection can be reduced.

  In this way, according to the shield braid 30 according to the present embodiment, the copper material 32 is disposed between the plurality of metal-coated fibers 31, so that the possibility of poor connection can be obtained by using the copper material 32. Can be reduced. In particular, since the thickness T of the copper material 32 exceeds 10 micrometers, the thickness T is not too thin and the possibility of copper erosion can be reduced. Moreover, since the thickness T is less than 150 micrometers, since the copper material 32 is not too thick, the situation where the flexibility of the shield braid 30 is inhibited can be suppressed. Further, since the copper material 32 is arranged with the pitch P in the longitudinal direction exceeding 20 millimeters, the situation where the copper material 32 is densely arranged and the shield braid 30 is difficult to be unwound and the terminal is difficult to crimp is suppressed. can do. Furthermore, since the copper material 32 is arranged with a pitch P in the longitudinal direction of less than 150 millimeters, it is possible to prevent a situation in which the pitch P becomes large and the locations where solder connection is made are too limited. Therefore, it has a small diameter, light weight, and high bending characteristics, and can reduce the possibility of connection failure.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention.

  For example, in the shield braid 30 according to the present embodiment, the metal-coated fibers 31 and the copper material 32 are formed in a single layer, but the present invention is not limited thereto, and may be multilayered. That is, it may have a multilayer structure in which another shield braid 30 is stacked on the shield braid 30 according to the present embodiment.

  Further, the copper material 32 is not limited to the one shown in FIG. 4 or the like, and may be the one shown in FIG. FIG. 5 is a cross-sectional view showing another example of the copper material 32. As shown in FIG. 5, the copper material 32 may have a structure (copper clad) covered on the outer periphery of an aluminum layer 33 having a circular cross section. Even with this structure, as described above, if the pitch P is arranged from 20 millimeters to 150 millimeters and the thickness T is 10 micrometers to 150 micrometers, the same effect can be obtained. is there. In the example shown in FIG. 5, the thickness T corresponds to the thickness of the copper film coated on the outer periphery of the aluminum layer 33. Also, the copper clad is not limited to the aluminum layer 33 and may be constituted by another conductor.

  In addition, although the copper material 32 according to the present embodiment is manufactured by using one punch for the copper material 32, the present invention is not limited thereto, and two or more punches are manufactured for the copper material 32. May be.

DESCRIPTION OF SYMBOLS 1 ... Shield electric wire 10 ... Conductor 20 ... Insulator 30 ... Shield braiding 31 ... Metal coating fiber 31a ... Heat-resistant fiber 31b ... Metal film 32 ... Copper material P ... Pitch T ... Thickness

Claims (1)

It is composed of a plurality of metal-coated fibers formed by forming a metal film on the outer periphery of the heat-resistant fiber and a copper material made of copper or a copper alloy , or is coated on the conductor and another conductor different from the copper material. And a shield braid configured by braiding a linear body composed of the copper material,
Braided shield the linear member are arranged in 150 millimeters pitch 20 mm in the longitudinal direction, characterized in that the thickness of the copper material is 150 micrometers from 10 micrometers.

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