JPH07161394A - Ground structure of shielded electric cable - Google Patents

Abstract

PURPOSE:To simplify the processing work by forming a grounding circuit by winding one end of a wound band which has a conductor in the rear side on a conductor layer of a sheath layer and conducting the other end with a wall plate of an automobile, etc., through a wall plate contacting part. CONSTITUTION:An attachment band 15 to which a conductive contact part 11 of a strip-like conductive sheet is stuck in the rear side is coiled on an earth contact part 6 formed by exposing a conductive layer 5 in the middle part of a shielded electric cable 1 by peeling an insulating outer coating 4 of a sheath layer 3. Meanwhile, a stopping head 13 to be fitted and fixed in a fixing hole 8 of a wall plate 7 of an automobile, etc., is formed in a band insertion stopping part 16 and a cramp 10 for earth is installed. A wall plate contacting part 12 in which a cantilever elastic arm 17 having a holding contact claw 20 at the free end is unitedly laid is put between a press contact piece 14 and a wall plate 7. When the band 15 is inserted into the stopping part 16 and fastened, the tip end of the claw 20 joined to a band stopping hole 21 is brought into contact with the contact part 11 by pressure and electrically conducted with the wall plate contacting part 12 through the arm 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for electric wiring of electronic devices and automobiles, and wraps a core wire of a signal conductor in a sheath layer to prevent adverse effects of external electromagnetic waves on the core wire. The present invention relates to a ground structure of a shielded electric wire that prevents leakage of electromagnetic waves from the core electric wire to the outside.

[0002]

2. Description of the Related Art A shielded wire 1 has a structure in which a core wire 2 of a signal wire is wrapped with a sheath layer 3 having a conductive layer 5 made of a conductive metal net such as an aluminum wire inside an insulating outer cover 4 as shown in FIG. And a ground circuit described below is formed at the end of the shielded electric wire 1. That is, by peeling off a part of the insulating outer cover 4 at the end of the shielded electric wire 1,
The exposed conductive layer 5 is twisted and collected to form a single wire drain wire 2
Processed to 0 and crimping the connector 22 to the drain wire 20 to provide the ground wire 21 and the connector 2 on the vehicle body / device side provided in advance.
2 is connected to form a ground circuit, or a shield wire 1 has a drain wire (not shown) made of a conductive mesh parallel to the core wire 2 provided therein. A part of the sheath layer 3 is peeled off, and the exposed drain wire is made into a single wire shape in the same manner as described above, and the connector 2
2 is crimped and similarly connected to a ground wire provided in advance to form a ground circuit. Then, the drain wire 20 in a single wire state formed at the end of the shielded electric wire 1 is subjected to an insulation treatment such as fitting of a heat shrink tube or tape winding.

On the other hand, as a grounding structure for a shielded electric wire disclosed in Japanese Utility Model Laid-Open No. 4-33268, a blade member having a blade portion for peeling off an insulating sheath of the shielded electric wire and bringing the exposed conductive layer into contact with the conductive layer. There is a publicly known example of a structure in which an earth wire is connected and a blade holding member which is combined with the blade member is mounted and grounded.

[0004]

The former one of the above-mentioned conventional grounding structures is such that the end portion of the shielded electric wire 1 is peeled off, the conductive layer 5 is twisted and gathered to form the drain wire 20 in a single wire state, and Insulating the drain wire 20 by fitting a heat-shrinkable tube to the drain wire 20 is extremely complicated and inferior in workability, resulting in inefficient work, which is contrary to the high productivity of electric wire mass production in recent years. When the conductive layer 5 is twisted and collected to form the drain wire 20 in a single wire state,
It is necessary to peel off the sheath layer 3 of a considerable length (usually about 20
In addition, even when crimping the connector 22 to the drain wire of the twisted wire, the drain wire length necessary for fixing and holding the drain wire lacking rigidity is required, and therefore the end portion of the shielded wire 1 is required. There is no choice but to lengthen the peeling. Therefore, the sheath layer 3 does not exist in these long peeled portions, and there is a quality problem in that the shield performance is lost.

On the other hand, the latter one has a drawback that the structure is complicated and the formability of the connecting member is poor, and in addition, the connecting connection between the ground wire and the connecting member requires labor and it is difficult to obtain sufficient connection strength. , Mass production and low cost are strongly required, and lack of practicability as a shielded electric wire for automobiles in which high durability against vehicle body vibration is essential. The present invention provides a grounding structure for a shielded electric wire which solves the above-mentioned drawbacks of the prior art.

[0006]

The grounding structure of the shielded wire of the present invention which solves the above technical problems is "grounding connection in which the insulating outer layer of the sheath layer of the shielded wire is peeled off to expose the conductive layer of the sheath layer. A wrapping band that can be wrapped around the part,
A locking head for the wall plate of the vehicle body / device is provided upright, and a grounding clamp having a pressure contact piece to the wall plate is attached to the grounding connection portion below the locking head, and The earthing clamp is a wall plate contact portion arranged on the pressure contact piece,
A conductive body having a conductive layer contact portion disposed on the back surface of the band of the winding band in conduction with the wall plate contact portion is mounted, and the conductive layer of the earth connection portion and the wall plate are connected via the conductive body. The structure is such that it conducts electricity to form a ground circuit. "

The conductor is "a conductive layer contact portion in which the band insertion locking portion is provided with a winding band penetrating the band fixing hole and a locking head, and the band fixing hole is closed. And a wall plate contact portion that is continuous with an elastic arm having locking contact claws that extend into the band insertion locking portion and engage with the band stop hole. The elastic arm has a structure in which the locking contact claw engaged with the band stop hole has a shape of elastically pressure-contacting the conductive layer contact portion, or the wall plate contact portion and the conductive layer contact portion are connected to each other. The one with the integrated structure is used.

[0008]

The above-described ground structure of the shielded wire of the present invention is
The complicated work of forming the ground circuit by long peeling off the end of the shielded wire in the above-mentioned conventional structure is unnecessary, and since the sheath layer at that end is effectively preserved, there is no missing part of the shield performance, Shield performance is improved. And, for the peeling of the insulating outer cover for providing the ground connection portion, a strip having a small width with which the winding band can be wound is sufficient.
The winding circuit can be formed simply by winding the winding band around the ground connection part and locking the locking head to the vehicle body / device, thus simplifying the formation process of the ground circuit. It

Further, in the earthing structure of the present invention, the earthing clamp is provided as a main portion, and the contact portion of the conductor disposed in the earthing clamp is pressed by the winding band and the pressure contact piece to make a mating member. Since it is contacted to the side, it has good conductivity as an earth circuit, and it has a stable structure and has a stable earth function even when used for electric wiring of automobiles that is structurally robust and continuously receives external force due to vehicle body vibration etc. You can secure the sex. Since the grounding clamp also has a function of holding the disposition posture of the shielded wire in the vehicle body / device, the conventional wiring clamp can be omitted.

[0010]

Embodiments will be described in detail below based on embodiments. First, referring to FIG. 1 showing a first embodiment of the present invention, an insulating outer sheath 4 of a sheath layer 3 is formed on an arbitrary intermediate portion of a shielded electric wire 1.
Is provided to expose the conductive layer 5 of the sheath layer 3 along the circumference, and a ground connecting portion 6 is provided.
The winding band 15 around the ground connection portion 6 and the vehicle body wall plate 7
The locking head 13 that is fitted and locked in the fitting hole 8 of FIG. 2 is erected on the band insertion locking portion 16, and the grounding clamp 10 provided with a conductor described below is attached to the locking head 13. When is fitted into and locked in the fitting hole 8, the ground connection portion 6 and the wall plate 7 are electrically connected by the conductor, and the ground circuit of the shielded electric wire 1 is formed.

More specifically, the grounding clamp 10 has the wall plate 7 when the locking head 13 is fitted and locked in the fitting hole 8.
A plate-shaped press-contact piece 14 for press-contacting with is provided below the locking head 13, and the winding band 15 is provided with band stop holes 21 continuous in the longitudinal direction of the band at a fine pitch. The conductors are a conductive layer contact portion 11 of a band-shaped conductive plate attached to the back surface of the band of the winding band 15, and a wall plate contact portion 12 disposed on the pressure contact surface of the pressure contact piece 14 to the wall plate 7. In this wall plate contact portion 12, a cantilever elastic arm 17 is inserted into the band insertion locking portion 16 and has a locking contact claw 20 at its free end. It has been extended.

That is, the wall plate contact portion 12 has a disk shape without a central hole which is placed on the upper surface of the pressure contact piece 14, and the locking head 13 is passed through the through hole 22 at the center thereof to be mounted on the pressure contact piece 14. Then, when the lock claw 19 on the back surface is inserted into the lock hole 24 of the pressure contact piece 14, the lock contact piece 14 is placed and locked on the pressure contact piece 14 and the pressure contact piece 1
The elastic arm 17 passing through the arm window 18 of No. 4 is inserted into the band insertion locking portion 16, and the elastic arm 1 in the insertion posture
7 extends in the insertion direction of the winding band 15 so that the locking contact claw 20 faces downward.

Then (see (C) and (D) of FIG. 1), when the winding band 15 wound around the ground connection portion 6 is passed through the band insertion locking portion 16 and tightened, the band stop of the winding band 15 is stopped. The locking contact claw 20 of the elastic arm 17 is engaged with the hole 21 to lock the tightening posture of the winding band 15, and at the same time, the tip of the locking contact claw 20 engaged with the band stop hole 21 is The structure is in pressure contact with the conductive layer contact portion 11 existing on the outlet side of the band stop hole 21, and the wall plate contact portion 12 and the conductive layer contact portion 11 are electrically connected via the elastic arm 17.
Then, the winding band 15 is wound around the earth connection portion 6, and the earth clamp 10 is attached to the shielded wire 1.
When the protruding locking head 13 is fitted and locked in the fitting hole 8,
The wall plate contact portion 12 is brought into pressure contact with the wall plate 7 by the pressure contact force of the pressure contact piece 14, and the conductive layer contact portion 11 is brought into contact with the conductive layer 5 of the ground connecting portion 6 and the conductor of the earth clamp 10 is interposed. As a result, an earth circuit is formed to the vehicle body of the shielded electric wire 1 in which the conductive layer 5 is electrically connected to the wall plate 7.

Reference numeral 23 in the figure denotes a looper portion in which the wall plate contact portion 12 is partially raised, and the conductive layer contact portion 11 is provided.
In order to arrange and fix the wrapping band 15 on the wrapping band 15, adhesion or insert molding to the wrapping band made of resin, or a locking means with a pin protruding on one side is used. The above-described ground structure of the embodiment shown in FIG.
Since 7 has both the conduction function and the band locking function described above,
There is an advantage that a dedicated locking means for the winding band 15 is unnecessary.

Next, another embodiment of the present invention will be described with reference to FIG. That is, similar to the embodiment of FIG. 1, in the earth structure having the earth clamp 10 as a main part, which disposes the conductor having the wall plate contact portion 12 and the conductive layer contact portion 11, the conductor of the embodiment of FIG. Is a band insertion locking portion 16
The wall plate contact portion 12 and the conductive layer contact portion 11 are integrated with each other through a connecting portion 26 attached to the side circumference of the. The wall plate contact portion 12 is arranged on the upper surface of the pressure contact piece 14, and the conductive layer contact portion 11 is attached to the band back surface of the winding band 15.

In the embodiment of FIG. 2, the band insertion locking portion 16 is provided with an elastic arm 17 exclusively for band locking, and the winding band 15 is engaged with the elastic arm 17 instead of the band stop hole 21. The locking groove 25 is continuously provided in small increments on the surface of the band.

[0017]

As described above, in the ground structure for a shielded electric wire according to the present invention, the long sheath layer absent portion at the end of the shielded electric wire is eliminated and the shielding performance is improved. Then, the structure of the earth circuit is simplified, the formation process of the earth circuit and the earth connection work are simplified, the cost of the shielded wire is reduced, and the demand for mass production and high productivity of electric wiring for automobiles is satisfied. Further, it has a great effect that it has a strong structure and has high durability against vibration and the like, and the ground circuit performance is excellently stabilized for a long period of time.

[Brief description of drawings]

FIG. 1 shows a grounding structure of a shielded electric wire according to a first embodiment of the present invention, in which (A) is a perspective view of the constituent members of the grounding clamp, and (B) is the whole grounding clamp. A perspective view and a perspective view showing a state of attachment to a shielded electric wire, (C) in the figure is a cross-sectional view of the shielded electric wire to which the grounding clamp is attached, and (D) in the figure shows the elastic arm and the winding band. Enlarged sectional view showing the engaged state of

2A and 2B show a ground structure of a shielded wire according to another embodiment of the present invention, in which FIG. 2A is a perspective view of the conductor, and FIG. 2B is a perspective view of the grounding clamp.

FIG. 3 is an illustration of a conventional ground structure for a shielded wire.

[Explanation of symbols]

 1 Shielded Wire 2 Core Wire 3 Sheath Layer 4 Insulating Skin 5 Conductive Layer 6 Ground Connection Part 7 Wall Plate 8 Fitting Hole 10 Grounding Clamp 11 Conductive Layer Contact Part 12 Wall Plate Contact Part 13 Locking Head 14 Pressure Contact Piece 15 Winding Band 16 Band insertion locking part 17 Elastic arm 18 Arm window 20 Locking contact claw 21 Band stop hole 22 Through hole 25 Locking groove 26 Connecting part

Claims (3)

[Claims] 1. A wrapping band for peeling off an insulating outer cover of a sheath layer of a shielded wire to wrap the conductive layer of the sheath layer around an exposed ground connection portion, and a head for locking to a wall plate of a vehicle body / device. A grounding clamp, which is erected upright and has a pressure contact piece to the wall plate, is attached to the ground connection portion below the locking head, and the ground clamp is disposed on the pressure contact piece. A wall plate contact portion and a conductor having a conductive layer contact portion which is electrically connected to the wall plate contact portion and is disposed on the back surface of the band of the winding band are mounted, and the ground connection portion of the ground connection portion is connected through the conductor. A grounding structure for a shielded electric wire, characterized in that a grounding circuit is formed by electrically conducting a conductive layer and the wall plate. 2. A band insertion locking portion is provided with a winding band having a band stop hole penetrating therethrough and a locking head, and a conductive layer contact portion disposed so as to close the band stop hole and the band insertion member. An elastic arm having a locking contact claw that extends into the stopper and engages with the band stopper is formed as a conductor separately combined with the wall plate contact portion, and the elastic arm is the band. The ground structure for a shielded electric wire according to claim 1, wherein the locking contact claw engaged with the stop hole has a shape that elastically presses the conductive layer contact portion. 3. The ground structure for a shielded electric wire according to claim 1, wherein the wall plate contact portion and the conductive layer contact portion are integrally made of a conductor via a connecting portion.