JP3098217B2 - Grounding structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a grounding structure for bonding a shielding layer of a wire to be grounded to a grounding conductor.

[0002]

2. Description of the Related Art Conventionally, as a measure against radio noise interference (hereinafter referred to as "EMI"), a shielded electric wire or a conduit is grounded. That is, the shield layer of the electric wire such as the copper braided jacket of the shielded electric wire or the metal tube of the electric conduit is connected to the ground electrode with a low-impedance conductor (hereinafter referred to as "bonding"). The work of grounding the shielding layer of such an electric wire is a very expensive and time-consuming work.

Conventionally, an electric wire is laid near a ground conductor,
Generally, natural grounding is performed by bonding a wire and a grounding conductor with a hanging bracket or the like, or bonding is performed at both ends of the wire to an outer casing of the device. In order to further ensure the bonding, there has been a method using a grounding metal band. In these methods, the shield layer of the electric wire is crimped by mechanical tightening so that the contact resistance is low and the electric resistance is not changed by vibration. In addition, soldering is sometimes used for electric wires to which such a mechanical fastening method is difficult to apply.

[0004]

However, in the method of mechanically tightening using a hanging bracket or the like, when the tightening is loosened, for example, when the screw is loosened, play is generated. Therefore, there has been a problem that grounding is not reliably performed and contact resistance is increased. Further, the electric wires themselves may be damaged by mechanical tightening. On the other hand, bonding using soldering has a problem that a huge amount of work time is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to surely ground a shielding layer of an electric wire,
It is another object of the present invention to provide a grounding structure that reduces contact resistance and does not damage the electric wire itself.

[0006]

Means for Solving the Problems and Effects of the Invention In order to achieve the above-mentioned object, the grounding structure according to claim 1, wherein the shielding layer of an electric wire having a shielding layer on the outermost periphery is used as a grounding conductor. A grounding structure to be bonded, comprising: an elastic material as a core material; and a conductive coating layer laminated on the elastic material , wherein the electric wire is sandwiched by the conductive coating layer.
The conductive coating layers are opposed to each other by being bendable in parallel to the length direction of the wire, and at least a part of the conductive coating layer located on the outside while sandwiching and enclosing the electric wire is pressed against the ground conductor. It is characterized by being arranged so that

In this grounding structure, the outermost shielding layer of the electric wire is bonded to the grounding conductor. "Shielding layer" is, for example,
It is a copper braided jacket or a metal tube which further covers the outside of an insulator such as vinyl which covers a conductor transmitting an electric signal. Also,
The “ground conductor” is a conductor bonded to a ground pole. Therefore, if the shield layer of the electric wire is bonded to the ground conductor, the shield layer of the electric wire will be grounded.

The grounding structure is obtained by laminating a conductive coating layer on an elastic material as a core material. Then, the wire is flattened in the length direction of the wire so that the wire is sandwiched by the conductive coating layer.
The conductive coating layers were opposed by being foldable into rows .

The grounding structure is arranged such that at least a portion of the conductive coating layer laminated outside the conductor is pressed against the ground conductor with the electric wire sandwiched and enclosed by the opposing conductive coating layers. . According to this grounding structure, the electric wire is sandwiched and included in the conductive coating layer, and a part of the conductive coating layer laminated on the outside presses against the ground conductor. Are in contact with the conductive coating layer laminated on the elastic material as the core material, and the shield layer and the ground conductor are bonded via the conductive coating layer. At this time, since the present grounding structure sandwiches and includes the electric wire between the opposing conductive coating layers, it is grounded continuously in the length direction of the electric wire. In other words, the grounding area of the shield layer of the electric wire is larger than in the case where only a predetermined portion of the electric wire is partially bonded with a fitting or the like. As a result, the shield layer of the electric wire can be reliably grounded.

[0010] The elastic material as the core material is elastically deformed by the force acting on the electric wire held between the opposing conductive coating layers. Therefore, the conductive coating layer is pressed against the electric wire by the elastic action of the elastic material. On the other hand, the grounding structure itself is arranged so that the conductive covering layer is pressed against the grounding conductor, so that the contact resistance between the shield layer of the electric wire and the conductive covering layer and the contact resistance between the conductive covering layer and the grounding conductor can be kept low. it can. Thereby, stable grounding of the shield layer of the electric wire can be realized. Further, since the electric wires are not mechanically tightened with screws or the like, the electric wires are not damaged.

Furthermore, since the electric wire is sandwiched and included in the conductive coating layer, the present grounding structure can be used as a shield material for EMI countermeasures, in addition to the above-described effect of reliably grounding the shield layer of the electric wire. . By the way, when the electric wire is clamped, it is conceivable to make the entire outer peripheral surface of the electric wire shielding layer abut on the conductive coating layer so as to further increase the ground area of the electric wire shielding layer. There is also.

That is, there is a high possibility that the contact portion between the shielding layer and the conductive coating layer of the electric wire is corroded. When a contact portion is corroded, an intense repetitive pulse is generated from the contact portion, and this pulse is known to be the most significant high-frequency noise.

In view of this, it is conceivable to adopt the configuration described in claim 2. That is, in addition to the structure shown in claim 1, when the electric wire is sandwiched and included, at least a part of the outer peripheral surface of the shield layer of the electric wire is configured not to contact the conductive coating layer. It is characterized by the following.

[0014] In this case, at least a part of the outer peripheral surface of the shield layer of the electric wire is sandwiched and included by the opposing conductive coating layer without contacting the conductive coating layer. Therefore, air can flow in a portion where the shield layer of the electric wire does not contact the conductive coating layer of the grounding structure due to an elastic deformation of the elastic material due to an external force. As a result, corrosion of the shielding layer of the electric wire can be prevented, and the occurrence of repetitive pulses due to the corrosion is eliminated, so that the occurrence of high-frequency noise can be prevented.

The state in which the electric wire is sandwiched between and contained in the opposing conductive coating layers is a state in which the electric wire is pressed against the conductive coating layer, and the electric wire is also pressed from the conductive coating layer by the elastic deformation of the core elastic material. A force is acting on. Therefore, for example, when the grounding structure formed on the plate-like body is bent as described above to hold the electric wire, and when the external force is not continuously applied to the grounding structure, the state where the electric wire is held cannot be maintained. Can be considered. Therefore, for example, by arranging the main grounding structure so as to sandwich the main grounding structure in a housing or the like, so as to continue to apply an external force to the main grounding structure,
It is conceivable to keep the state where the wire is sandwiched,
For example, as set forth in claim 3, a configuration may be provided that further includes a state holding unit that holds a state in which the electric wire is sandwiched and included.

Here, as the state holding means, for example,
It is possible to use a double-sided adhesive tape, a hook-and-loop fastener, and a slide fastener. For example, when the ground structure formed on the plate-like body is bent as described above to sandwich an electric wire, a configuration in which a state holding unit is provided at the end of the opposing conductive coating layer may be considered. In other words, the ends of the conductive coating layer facing each other when bent are not separated from each other. Accordingly, the state in which the electric wire is sandwiched can be maintained without continuously applying an external force by something other than the main grounding structure, so that it is not necessary to form a housing or the like in accordance with the main grounding structure. As a result, the present grounding structure can be used in various places.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a grounding structure 10 according to the present embodiment. FIG. 1 shows a state in which the grounding structure 10 in a state of holding and including the electric wire 20 is disposed in a concave portion 32 a formed in the housing 32.

The grounding structure 10 includes an elastic material 11 as a core material.
And a conductive coating layer 12 laminated on the elastic material 11. Here, it is conceivable to use a urethane foam material, an elastomer material, or the like as the elastic material 11. The conductive coating layer 12 may be formed as a metal foil such as a copper foil or an aluminum foil, a metal plating layer, a metal coding layer, a wire mesh layer, or the like. It is assumed that the conductive coating layer 12 is sufficiently thinly laminated so as to be smoothly deformed according to the elastic deformation of the elastic material 11.

The electric wire 20 is made of a conductor 2 for transmitting an electric signal.
3, the insulator 22 covering the conductor 23, and the insulator 22
Is formed of the outermost shielding layer 21 covering the outermost layer. The shielding layer 21 is a copper foil or a copper braided jacket or the like.
EMI can be prevented by grounding 1.

As shown in FIG. 2, the grounding structure 10 according to the present embodiment has a lengthwise direction (direction indicated by an arrow A) on an electric wire 20.
It is formed long. Further, as shown in the cross-sectional view of FIG. 3, the grounding structure 10 of the present embodiment can be bent at a portion indicated by a symbol B in parallel with the longitudinal direction. Therefore, by folding in two, as shown in FIG. 2, the conductive coating layers 12 face each other, and the electric wires 20 are sandwiched and included by the facing conductive coating layers 12.

At this time, since a force is applied to the elastic member 11 of the grounding structure 10 from the electric wire 20 via the conductive coating layer 12, the elastic member 11 undergoes elastic deformation. Due to the elastic action of the elastic member 11, the conductive coating layer 12 comes into pressure contact with the electric wire 20 (see FIG. 2). Further, in the grounding structure 10 of the present embodiment, when the opposing conductive coating layer 12 sandwiches and includes the electric wire 20, a portion of the outer peripheral surface of the shielding layer 21 of the electric wire 20 that does not contact the conductive coating layer 12 is formed. I can do it. That is, as shown in FIG. 2, a portion of the outer peripheral surface of the shielding layer 21 of the electric wire 20 that does not contact the conductive coating layer 12 creates a space C between the conductive coating layer 12 (see FIG. 2). ).

In order to maintain the state in which the electric wire 20 is sandwiched and enclosed by the opposing conductive coating layers 12 as described above, in the grounding structure 10 of the present embodiment, the electric wire 20 is sandwiched and folded in two. A double-sided pressure-sensitive adhesive tape (not shown) was continuously provided in the longitudinal direction at the contact portion 10a between the opposing conductive coating layers 12. Thus, the state in which the electric wire 20 is sandwiched and contained can be maintained without applying an external force to the grounding structure 10. Note that the double-sided pressure-sensitive adhesive tape corresponds to “state holding means”. It is also conceivable to use a hook-and-loop fastener instead of the double-sided adhesive tape, or to use a slide fastener.

Here, the relationship between the housing 32 and the grounding structure 10 in the present embodiment will be described with reference to FIG. 1 again.
The housing 32 of the present embodiment is formed of plastic, and the housing 32 has a concave portion 32a having a width slightly smaller than the width of the ground structure 10 in a state of being folded in two. The housing 3 including the surface forming the recess 32a
On the surface of 2, a ground conductor 31 which is a metal foil bonded to a ground electrode is laminated.

The grounding structure 10 of the present embodiment is arranged by being pushed into the concave portion 32 a where the grounding conductor 31 is laminated. As described above, since the recess 32a of the housing 32 is slightly narrower than the width of the grounding structure 10,
Receives an external force from the inner side surface of the concave portion 32a of the housing 32, and the elastic member 11 of the grounding structure 10 undergoes elastic deformation. Therefore,
Due to the elastic action of the elastic member 11, the conductive coating layer 12 of the ground structure 10 comes into pressure contact with the ground conductor 31 laminated in the concave portion 32a. The grounding structure 10 according to the present embodiment
In other words, the outer peripheral conductive coating layer 12 having a substantially rectangular cross section corresponds to the “outer conductive coating layer”. FIG.
Are arranged such that the contact portion 10a of the opposing conductive coating layer 12 is located on the back side of the concave portion 32a. Conversely, the contact portion 10a is You may arrange | position by rotating 180 degrees with respect to the housing | casing 32 so that it may be located in the opening side.

According to such a grounding structure 10 of the present embodiment, the shielding layer 21 of the electric wire 20 is pressed against the conductive coating layer 12, and the conductive coating layer 12 is grounded on the recess 32 a of the housing 32. It is pressed against the conductor 31. Therefore, the electric wire 20
The shielding layer 21 is bonded to the ground conductor 31 of the housing 32 by the conductive coating layer 12. Ground conductor 3
1 is bonded to the ground electrode, that is, the shielding layer 21 of the electric wire 20 is grounded by the conductive coating layer 12.

In addition, the grounding structure 10 of the present embodiment
As shown in FIG. 2, since the electric wire 20 is sandwiched and included over the entire length, continuous grounding is performed in the longitudinal direction of the electric wire 20. Therefore, compared to the conventional case where only a predetermined portion of the electric wire is bonded with a hanging metal fitting or the like, the electric wire 2
The ground area of the zero shielding layer 21 increases. As a result, the shielding layer 21 of the electric wire 20 can be reliably bonded to the ground conductor 31.

Also, in the grounding structure 10 of the present embodiment, the conductive coating layer 12
Is pressed against the electric wire 20, while the ground structure 10 itself is also pressed against the ground conductor 31 by the elastic action of the elastic material 11. Therefore, both the contact resistance between the shielding layer 21 and the conductive coating layer 12 of the electric wire 20 and the contact resistance between the conductive coating layer 12 and the ground conductor 31 can be kept low. As a result, wire 2
The stable grounding of the 0 shielding layer 21 can be realized.

Further, the grounding structure 10 of the present embodiment
The electric wire 20 is disposed in the concave portion 32 a of the housing 32 in a state where the electric wire 20 is sandwiched and enclosed by the opposing conductive coating layers 12. That is, since the electric wire 20 itself is not mechanically fastened, safe grounding can be realized without damaging the electric wire 20.

In addition, the grounding structure 10 of the present embodiment
Since the electric wire 20 is sandwiched and contained, not only the above-described secure, stable and safe grounding of the shielding layer 21 of the electric wire 20 but also a role as a shielding material for EMI measures is achieved. In addition, the grounding structure 10 of the present embodiment
When the electric wire 20 is sandwiched, the shielding layer 2 of the electric wire 20
1 does not come into contact with the conductive coating layer 12 and the space C
(See FIG. 2). Therefore, when the volume of the space C changes due to the elastic deformation of the elastic member 11 due to an external force, a flow of air occurs in the space C. As a result, corrosion of the shielding layer 21 can be prevented. Therefore, generation of high frequency noise due to corrosion of the shielding layer 21 can also be prevented.

As described above, the present invention is not limited to such embodiments at all, and can be implemented in various forms without departing from the gist of the present invention. Although the grounding structure 10 of the above embodiment is formed as a plate-like body that can be folded in two,
Any configuration may be used as long as the configuration can be sandwiched and included. For example, various configurations are illustrated as cross-sectional views in FIG.

The grounding structure 100 shown in FIG. 4A is an example in which a concave portion 100x is formed so as to oppose a conductive coating layer 102 laminated on an elastic material 101 as a core material. The concave portion 100x has a curved surface portion 100y that contacts the outer peripheral surface of the shielding layer 21 of the electric wire 20.
By arranging the electric wire 20 in the space shown in the drawing from the opening 100a of 00x and closing the opening 100a, the electric wire 20 is sandwiched and contained by the conductive coating layer 102 of the curved surface portion 100y. In this case, the entire outer peripheral surface of the shielding layer 21 of the electric wire 20 is pressed against the conductive coating layer 102 and the shielding layer 2 of the electric wire 20 is pressed.
1 can increase the contact area. Thereby, the shielding layer 21 of the electric wire 20 can be grounded more reliably.

The grounding structure 110 shown in FIG. 4B is also an example in which the concave portions 110x and 110y are formed so as to face the conductive coating layer 112 laminated on the elastic material 111 as a core material. Two concave portions 110x and 110y are formed so as to oppose two pairs of conductive coating layers 112. Openings 110a, 1 of these recesses 110x, 110y
The electric wire 20 is inserted from 10b and arranged in the space shown in the figure, and the electric wire 20 is sandwiched and contained by the opposing conductive coating layers 112 in the respective concave portions 110x and 110y. In this case, if the electric wire 20 is sandwiched between the two concave portions 110x and 110y, the two electric wires can be grounded together, so that the time required for the grounding work can be further reduced. It is also conceivable that a plurality of electric wires 20 are sandwiched between the two formed recesses 110x and 110y.

The grounding structure 120 shown in FIG. 4C is obtained by laminating a conductive coating layer 122 on an elastic material 121, and has an arm α at one end D of its cross section. The other end of the cross section has a substantially U-shaped arm portion β. The arm α can be bent at the end D, and an opening 12 is formed in a space inside the arm β (the space shown in the figure).
0a, the electric wire 2 is formed by the inner surface 120y of the U-shaped arm β and the surface 120x of the tip of the arm α.
0 is pinched. In this case, since the bent arm part α can be held by the arm part β and held in a bent state, the state where the electric wire 20 is sandwiched is maintained without using the double-sided adhesive tape or the like which is the state holding means described above. be able to.

In the above embodiment, the ground conductor 31 made of metal foil is laminated on the housing 32 made of plastic. However, if the housing 32 is made of metal, for example, The housing 32 may be used as a “ground conductor” by bonding itself to a ground electrode.

Further, in the above embodiment, the grounding structure 10 is sandwiched between the concave portions 32a of
However, the present invention is not limited to this, and any configuration may be used as long as the ground structure 10 is pressed against the ground conductor bonded to the ground electrode.

For example, the arrangement of the grounding structure 10 is illustrated in the cross-sectional view of FIG. Also, in FIG. 5, in order to avoid complication, the electric wire 20 sandwiched between the grounding structures 10 is shown.
Are not shown. FIG. 5A shows an example in which the installation member 301 as a “ground conductor” is cut and raised, and the ground structure 10 is sandwiched from both sides.

FIG. 5B shows an example in which two projections are formed on the installation member 312, and the grounding structure 10 is held between these projections. In this case, the grounding conductor 311 is attached to the installation member 312.
Are laminated. FIG. 5C shows an example in which the ground structure 10 is sandwiched between an upper housing member 331u and a lower housing member 331d as “ground conductors”. In this case, for example, when the lower housing member 331d is a case and the upper housing member 331u is a lid of the case, the upper housing member 331u may be removed. Therefore, in such a case, it is conceivable to provide a double-sided adhesive tape at the contact portion 331s between the grounding structure 10 and the lower housing member 331d, and fix the grounding structure 10 to the lower housing member 331d with the double-sided adhesive tape. Can be

FIG. 5D shows a grounding structure in a closed space formed by a recess 341s formed in the lower housing member 341d as a “grounding conductor” and an upper housing member 341u as a “grounding conductor”. This is an example in which the body 10 is arranged. Also in this case, for example, the lower housing member 341d is a case and the upper housing member 3
It is conceivable that 41u is the lid of the case. At this time, in a state where the upper housing member 341u is removed, FIG.
As in the relationship between the grounding structure 10 and the concave portion 32a of the housing 32 shown in FIG. 7, the grounding structure 10 partially protrudes from the concave portion 341s. Accordingly, the grounding structure 10 receives a force from the upper housing member 341u in a state of being covered with the upper housing member 341u, and the elastic material 11 of the grounding structure 10 undergoes elastic deformation. Therefore, the conductive coating layer 12 is pressed against the upper housing member 341u by the elastic action of the elastic material 11. Therefore, the grounding structure 10 also has an effect as an EMI shielding gasket provided between the case and the lid.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a grounding structure, an electric wire, and a housing according to an embodiment.

FIG. 2 is an explanatory diagram illustrating a cross section and an appearance of a grounding structure according to the embodiment.

FIG. 3 is a cross-sectional view illustrating a grounding structure according to the embodiment.

FIG. 4 is a cross-sectional view illustrating a grounding structure.

FIG. 5 is a cross-sectional view illustrating an arrangement of a grounding structure.

[Explanation of symbols]

10, 100, 110, 120 ... grounding structure 10a ... contact portion 100a, 110a, 110b, 120a ... opening 11, 101, 111, 121 ... elastic material 12, 102, 112, 122 ... conductive coating layer 20 ... electric wire 21 ... shielding layer 22 ... insulating layer 23 ... signal line 31 ... ground conductor 32 ... housing 32a ... recessed part 301 ... installation member 311 ... ground conductor 312 ... installation member 331u, 341u ... upper housing member 331d, 3
41d: lower housing member 331s: contact portion 341s: concave portion

Claims (3)

(57) [Claims] A grounding structure for bonding a shielding layer of an electric wire having a shielding layer on the outermost periphery to a grounding conductor, comprising: an elastic material as a core material; and a conductive coating layer laminated on the elastic material. In order for the electric wire to be sandwiched by the conductive coating layer, the conductive coating layer can be bent in parallel with the length direction of the electric wire so that the conductive coating layer faces each other, and the electric wire is positioned outside in a state where the electric wire is sandwiched and included. A grounding structure, wherein at least a part of the conductive coating layer is pressed against the grounding conductor. 2. The grounding structure according to claim 1, wherein When sandwiching and enclosing the wire, the shielding layer of the wire
At least a portion of the outer peripheral surface does not contact the conductive coating layer
A grounding structure characterized by being configured as described above. 3. The grounding structure according to claim 1 or 2,
hand, Further, a state in which the electric wire is held in a state of being sandwiched and included.
A grounding structure comprising a holding means.