JP2005093198A - Grounding structure of shielded wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple grounding structure needing a small number of working manhours required for grounding a plurality of shielded wires. <P>SOLUTION: A shield layer 1b is exposed by peeling off a cover material 1c at an intermediate part of each shielded wire 1; and a fastening band 2 with a conductive layer 2f formed at least on the inside surface side of a band part 2b is wound around, fastened to and fixed to a splice part 5 formed by superimposing and bundling a terminal part of a grounding wire 4 on the exposed shield layer 1b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wire harness routed in an automobile, and more particularly to grounding of a plurality of shielded wires constituting the wire harness.

  In general, a wire harness is an electric wiring system in which a predetermined circuit is configured by a plurality of electric wires and electronic components and connectors connected to the electric wires. Among these, in-vehicle electrical components that are particularly required to shield noise, shielded wires are used as wires that connect the electronic components such as sensors. This shielded electric wire is of a type in which a sheath, which is a covering material, includes a plurality of or one signal line via a shield layer such as a braided wire, or a plurality of shielded wires via a shield layer such as a metal tape, or There is a type in which one signal line and a drain line conducted to the shield layer are included, and it is usually necessary to ground these braided lines and drain lines.

  As a configuration of a wire harness using a plurality of such shielded wires, for example, there are those shown in FIGS. As shown in the drawing, various sensors 21 in an engine room of an automobile and an indoor control circuit 22 are connected by a plurality of shield wires (three in this example).

  The shielded electric wire 1 in FIG. 8 is of a braided wire type shield layer, and the end of each shielded electric wire 1 is peeled off to expose the internal signal line 1a and the braided wire 1b as the shield layer. In this case, for the ground connection of the braided wire 1b of each shielded electric wire 1, the ground wire 29 is connected to the end of the braided wire 1b on the indoor side and twisted and connected in a concentrated manner by the crimping terminal 23. A braided wire 1b of each shielded electric wire 1 is grounded by attaching a ground terminal 30 connected to one end of the shielded wire to a vehicle body panel or the like.

  Further, in the case of a shielded electric wire including a drain wire, as shown in FIG. 9, the end portion of each shielded electric wire 7 is peeled to expose the internal signal wire 7a and the drain wire 7c. A lead wire 25 is connected to the tip of each drain wire 7 c on the inner side by a crimp terminal 24, and a terminal 26 attached to the tip of the lead wire 25 is inserted into the joint connector 27. The three drain lines 7c are intensively connected. By attaching a ground terminal 30 connected to one end of a ground wire 29 connected to the joint terminal 28 to a vehicle body panel or the like, the drain wire 7c of each shielded wire 7 is grounded.

  Generally, a shielded electric wire ensures shielding performance by connecting a braided wire or a drain wire to ground at one or both ends. If only one end is connected to ground, cut off the braided wire or drain wire on the opposite side, and connect the exposed braided wire to the ground by connecting the wires, and if the drain wire is far from the ground position, add the wires and connect to the ground. Connecting.

JP 2000-207946 A

  However, in the case of a braided wire type shielded wire as described above, in order to add a grounding wire, each braided wire is untwisted and twisted and processed by welding or a crimp terminal. In addition, in the case of a drain wire type shielded wire, a terminal can be crimped to each drain wire, so it is good for a circuit configuration in which the signal wire is connected to the same connector connected to the ground, but as shown in FIG. In order to connect to the ground at a distance from the cable, it is necessary to add an electric wire to the drain wire.

  Normally, grounding of shielded wires occurs at the computer-side end portion of the control circuit or the like. For example, in a configuration in which a large number of shielded wires are connected to the engine computer, as in the case of an engine harness, all of them are shielded wires. Since the grounding treatment as described above is performed, it is difficult to improve the work efficiency and reduce the cost.

  Further, in a configuration using a joint connector for grounding, it may be difficult to secure an installation space for the joint connector. In this case as well, there are problems in that the number of work steps is large because parts such as lead wires, joint connectors, and terminals are required, and there are terminal crimping and connector connection.

  Furthermore, if the shield wire is peeled off with the shield layer, the peeled portion becomes unshielded, so if the peel length is long, the end of the shield wire is the intended purpose of the shield wire. There is a problem that a good shielding effect cannot be achieved.

  The problem to be solved by the present invention is to provide a grounding structure with a simple configuration that requires a small number of work steps for grounding such a plurality of shielded wires.

  In order to solve this problem, the grounding structure for a shielded wire according to the present invention grounds a plurality of shielded wires formed by covering a signal line and a shield layer for shielding the signal wire with a covering material. It is a structure and peels off the covering material in the middle part of each shielded electric wire to expose the shield layer, and at least the band part at the splice part where the terminal part of the ground wire is overlapped and bundled on the exposed shield layer The gist of the present invention is to wind and squeeze and fix the band portion of a binding band having a conductor layer formed on the inner surface side thereof.

  Further, the signal line and a shield layer for shielding the signal line and a drain wire that is electrically connected to the shield layer are covered with a covering material, and a plurality of shielded electric wires are grounded together. Peel off the covering material at the middle of the shielded wire to expose the drain wire, and at the inner side of the band portion at least on the inner surface side of the band portion, the exposed drain wire is overlapped with the end portion of the ground wire and bundled The gist of the present invention is to wind and squeeze and fix the band portion of the binding band formed with the.

  In this case, the splice part may be configured to be provided with a conductive resin mold. Further, the binding band may be configured to have a cable fixing portion provided so as to be along the longitudinal direction of the shielded electric wire when wound.

  According to the grounding structure of the shielded electric wire having the above configuration, since the skinned portion of the covering material is an intermediate portion instead of the terminal portion of the shielded electric wire, it is possible to arbitrarily select the skinning position. The grounding position of the shielded wire can be set to an optimum position (for example, a position close to the grounding location on the vehicle body panel or the engine). In addition, it is possible to perform grounding simply by wrapping and squeezing a binding band with a conductor layer on the inner surface side of the band part around the splice part where the end part of the ground wire is overlapped with the part peeled off and bundled In addition, there is no crimping process for adding electric wires, and the number of work steps is reduced. Furthermore, since no joint connector is required, space efficiency is good. Since the stripping length is about the width of the band portion, there is little reduction in shielding performance, and there is a shielding effect due to the conductor layer formed in the band portion.

  In this case, if the splice part has a configuration in which a conductive resin mold is applied, the connection reliability between the conductors in the splice part is improved. Further, if the cable tie is formed on the binding band so as to extend along the longitudinal direction of the shielded electric wire when wound, the cable fixing portion is shielded by, for example, taping. Since the stress due to bending or the like to the shielded wire is prevented from being concentrated on the splice part to which each conductor is connected, the connection reliability is improved.

  Embodiments of a grounding structure for shielded wires according to the present invention will be described below with reference to the drawings. FIG. 1 shows a wire harness W1 composed of a plurality of shielded electric wires 1 and a binding band 2 used for grounding at each intermediate position of the shielded electric wires 1.

  In this case, the wire harness W1 is composed of a bundle of a plurality of (three in the present embodiment) braided wire type shielded electric wires 1 and the cross-sectional structure of each shielded electric wire 1 is an outer periphery of the braided wire 1b which is a shield layer. The three signal wires 1a, 1a, 1a wound around are encapsulated in a covering material 1c.

  As shown in the figure, the braided wire 1b is exposed by cutting and removing only the covering material 1c at the intermediate position of each shielded wire 1, and the end of the ground wire 4 connected to the separately prepared ground terminal 3 is exposed. A portion is placed on the exposed braided wire 1b to form a splice portion 5.

  The binding band 2 includes a flexible band portion 2b formed with a locking groove 2a and wound around the outer periphery of the splice portion 5 described above, and a locking portion 2c protruding from the rear end of the band portion 2b. Yes. The locking portion 2c is formed with a slit 2d for inserting the wound band portion 2b from the tip, and a locking claw 2e for locking the locking groove 2a of the band portion 2b in the slit 2d.

  A plurality of the locking grooves 2a are provided side by side in the longitudinal direction on the surface that becomes the outside when the band portion 2b is wound. In addition, a conductive metal foil 2f is attached to the inner surface of the band portion 2b on the inner surface of the band portion 2b.

  FIG. 2 shows a state in which the binding band 2 having such a configuration is wound around the above-described splice portion 5 and fixed. As a result, the braided wires 1b or the braided wire 1b and the ground wire 4 are pressed into contact with each other at the splice portion 5 and the outer peripheral surface of the splice portion 5 is in surface contact with the metal foil 2f on the inner peripheral surface of the band portion 2b. Then, grounding is performed.

  Next, the case where the above-described binding band 2 is applied to the grounding of the drain wire type shielded wire will be described. The wire harness W2 shown in FIG. 3 is composed of a bundle of a plurality of (three in this embodiment) drain wire type shielded electric wires 7, and the sectional structure of each shielded electric wire 7 is a shield tape 7b which is a shield layer. The signal lines 7a, 7a, 7a and the drain line 7c wound around the outer periphery are encapsulated in a covering material 7d. As shown in the drawing, the signal line 7a and the drain line 7c are exposed by cutting and removing only the covering material 7d and the shield tape 7b at an intermediate position between the shielded electric wires 7. Also in this case, the end portion of the ground wire 4 connected to the ground terminal 3 is placed on the exposed drain wire 7c to form the splice portion 8.

  FIG. 4 shows a state in which a resin mold 9 having conductivity is applied so as to cover the inside and outside of the splice portion 8 described above. The reason why the resin mold 9 is applied is that when the binding band 2 is wound and fixed around the splice portion 8 in the state of FIG. 3, the drain wire 7c is located at a position not in contact with the metal foil 2f on the inner peripheral surface of the band portion 2b. Because there is. Therefore, by applying the resin mold 9, each drain wire 7 c and the ground wire 4 are conductively connected through the conductive resin mold 9.

  FIG. 5 shows a state in which the band portion 2b of the binding band 2 is wound around the splice portion 8 to which the resin mold 9 is applied, and is squeezed and fixed. Even if the resin mold 9 is not applied to the splice 8, as shown in FIG. 6, the exposed three drain wires 7 c are positioned in the vicinity of the center inside the splice 8 and the end of the ground wire 4. And the band portion 2b is wrapped and fastened so that only the three drain wires 7c and the ground wire 4 are included, and the contact between the drain wires 7c and the drain wire 7c and the ground wire 4 is secured. .

  FIG. 7 shows a modification of the binding band. The locking portion 2c of the binding band 10 is formed with a cable fixing portion 10a that is provided along the longitudinal direction of the shielded electric wire when wound around the splice portion. Thereby, for example, by fixing the cable fixing portion 10a to the shielded electric wire by taping or the like, it is possible to prevent stress due to bending to the shielded electric wire from being concentrated on the splice portion to which each conductor is connected. Connection reliability will be improved.

  According to the grounding structure of the shielded electric wire described above, the skinned part of the covering material is not the terminal part of the shielded electric wire but the intermediate part, so the peeled part can be arbitrarily selected. The grounding position of the wire can be set to the optimum position, and furthermore, the stripping length is only about the width of the band part, so it is shorter than the case of end stripping as in the prior art, and the shielding performance is also degraded. Few. As described above, the grounding structure has a simple configuration in which the grounding process can be performed simply by winding and squeezing the band part of the binding band having the conductor layer formed on the inner surface around the splice part formed by peeling off the intermediate skin. Therefore, for example, if this grounding structure is applied to an engine harness, conventionally, the grounded wire is applied to the terminal portion on the computer side in the room and the added electric wire is returned to the engine room and connected to the ground point on the engine. However, in the shielded electric wire on the engine room side, the portion near the ground point on the engine is peeled off, and the grounding treatment can be performed only by binding the grounding wire with the binding band of the present invention.

  As mentioned above, although one Example of the earthing | grounding structure of the shielded wire which concerns on this invention was described, this invention is not limited to such an Example at all, In the range which does not deviate from the summary of this invention, in various aspects. Of course, it can be implemented. For example, the shielded electric wire can be applied to what is called a coaxial cable. Moreover, about the conductor layer formed in the band part inner surface of a binding band, you may form a conductor layer by insert molding of a conductive metal besides sticking of metal foil.

It is the figure which showed the state in which the splice part was formed in the wire harness which consists of a binding band before clamping | tightening and a shield electric wire without a drain wire. It is the figure which showed the state after the fastening of FIG. It is the figure which showed the state in which the splice part was formed in the wire harness which consists of a shield electric wire with a drain wire type. It is the figure which showed the state in which the resin band which has electroconductivity was given to the binding band before fastening, and the splice part of FIG. It is the figure which showed the state after the fastening of FIG. It is the figure which showed the winding state of the binding band in the case of not giving a resin mold. It is the figure which showed the binding band in which the cable fixing | fixed part along the longitudinal direction of a shielded electric wire was provided when it wound around the splice part. It is the figure which showed the earthing | grounding structure of the wire harness which consists of a shield wire without a drain wire used conventionally. It is the figure which showed the earth processing structure of the wire harness which consists of a shield wire with a drain wire type used conventionally.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield electric wire 1a Signal wire 1b Braided wire 1c Coating material 2 Binding band 2a Locking groove 2b Band part 2c Locking part 2d Slit 2e Locking claw 2f Metal foil 3 Grounding terminal 4 Grounding cable 5 Splice part 7 Shielding cable 7a Signal line 7b Shield tape 7c Drain wire 7d Cover material 8 Splice part 9 Resin mold 10 Binding band 10a Cable fixing part W1 Wire harness W2 Wire harness

Claims (4)

A structure in which a signal wire and a shield layer for shielding the signal wire are covered with a covering material, and a plurality of shielded wires are grounded together, and the covering material in the middle of each shielded wire is peeled off. The shield layer is exposed, and the band portion of the binding band in which the conductor layer is formed at least on the inner surface side of the band portion is wound around the splice portion in which the end portion of the ground wire is overlapped and bundled with the exposed shield layer. A grounding structure for shielded wires, characterized by tightening and fixing. A structure in which a plurality of shielded wires are formed by covering a signal line, a shield layer for shielding the signal line, and a drain wire connected to the shield layer with a covering material, and each shielded wire is grounded Peel off the cover of the middle part of the wire to expose the drain wire, and at the inner side of the band part at least on the inner surface side of the band part at the splice part where the end part of the ground wire is bundled with the exposed drain wire A grounding structure for a shielded wire, wherein the band portion of the binding band is wound and tightened and fixed. The grounding structure for a shielded wire according to claim 1 or 2, wherein the splice part is provided with a conductive resin mold. The cable tie according to any one of claims 1 to 3, wherein a cable fixing portion is formed on the binding band so as to be along a longitudinal direction of the shielded wire when wound. Grounding structure.

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