JP2023102114A - Electromagnetic shield structure - Google Patents

Abstract

To provide an electromagnetic shield structure etc. with good connection workability and reliability.SOLUTION: An electromagnetic shield structure 5 comprises a braided wire 1, a rigid pipe 3, etc. The braided wire 1 is a cylindrical member braided with metal element wires, having flexibility. The rigid pipe 3 may be a metal or a resin pipe. The rigid pipe 3 is formed in a shape according to an installation part, for example, in a vehicle. A single braided wire 1 is inserted into the rigid pipe 3 without being cut in the middle. The length of the braided wire 1 is longer than that of the rigid pipe 3. Therefore, the ends of the braided wire 1 protrude from both ends of the rigid pipe 3 by a prescribed length in the electromagnetic shield structure 5. The electromagnetic shield structure 5 allows a wire 7 to be inserted into it.SELECTED DRAWING: Figure 2

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic shield structure in which electric wires are passed and which is used, for example, in electric vehicles.

Electric vehicles such as BEVs (Battery Electric Vehicles) and HEVs (Hybrid Electric Vehicles) use wire harnesses arranged under floors. This wire harness, for example, uses a corrugated tube, a protector, and a rigid pipe-shaped exterior material, just like a conventional wire harness.

On the other hand, underfloor wire harnesses, which need to transmit a large amount of power, need to take measures to shield noise so that the noise does not affect the auxiliary equipment installed in the vehicle and the passengers.

As such an electromagnetic shield structure, an electromagnetic shield tube made of a metal pipe is used, and the end of the electromagnetic shield tube is covered with, for example, a tubular braided wire. By crimping the electromagnetic shield tube and the braided wire from the outer periphery with a crimping member, the electromagnetic shield tube and the braided wire can be electrically connected and the braided wire can be connected to the electromagnetic shield tube (for example, Patent Documents 1 to 3).

JP 2017-117863 A JP 2017-120917 A JP 2004-171952 A

As in Patent Documents 1 to 3, by using a braided wire, it is possible to cover the connection between the electric wire inserted inside the metal electromagnetic shield tube and the other electric device unit or the like with a conductor, so that the shielding performance of the connection can be ensured. In addition, since the braided wire has flexibility, it is possible to ensure the shielding performance between the electromagnetic shield tube and the electrical equipment unit or the like.

However, since it is necessary to use a crimping member to connect the electromagnetic shield tube and the braided wire, there is a problem that the number of parts increases. In addition, a special process is required for the crimping work, and braided wires must be connected to each end of the electromagnetic shield tube.

In addition, since pre-threading of the crimping member is required, if pre-threading is forgotten, it is necessary to go back to the process. Further, when the crimping member is a so-called ear clamp, the ear portion protrudes from the outer diameter of the electromagnetic shield tube after clamping. For this reason, there is a risk that the ear portion will interfere with routing to a vehicle or the like.

In addition, the connection between the electromagnetic shield tube and the braided wire requires low electrical resistance and high connection strength. For example, vibrations of automobiles may cause loosening of caulking members and corrosion of connecting portions, which may increase electrical resistance and reduce connection strength.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electromagnetic shielding structure and the like with good connection workability and reliability.

In order to achieve the aforementioned object, the present invention provides an electromagnetic shield structure into which an electric wire can be inserted, comprising: a rigid tube having a predetermined rigidity and capable of retaining its shape; and a braided wire inserted through the rigid tube, wherein the braided wire is longer than the rigid tube, and an end of the braided wire protrudes from an end of the rigid tube.

It is desirable that the rigid tube and the braided wire are fixed in the vicinity of both ends of the rigid tube.

The rigid tube and the braided wire may be secured with tape.

The rigid tube and the braided wire may be secured with a grommet secured to the end of the rigid tube.

The rigid pipe may be divided into a plurality of pieces, and the braided wire may be exposed for a predetermined length between the rigid pipes.

The rigid pipe may be a resin pipe.

A flexible tube may be arranged to cover at least a portion of the braided wire exposed from the rigid tube.

According to the present invention, since one braided wire passes through the rigid tube, there is no need to connect the braided wire at the end of the rigid tube. Therefore, no connecting work is required, and no crimping member or the like is required. In addition, since an electrical connection between the pipe and the braided wire is not required, there is no risk of deterioration in shielding performance at the connection, and substantially uniform and highly reliable shielding performance can be obtained over the entirety.

In addition, since the rigid pipe itself does not require shielding properties, there is no need to use an electromagnetic shield pipe such as a metal pipe or a composite pipe in which a metal layer and a resin layer are integrated. Moreover, since the metal is not exposed to the outside of the rigid pipe, no armor is required to protect the metal portion.

Further, by fixing the rigid pipe and the braided wire in the vicinity of both ends of the rigid pipe, displacement of the braided wire with respect to the rigid pipe can be suppressed. Even in this case, it is sufficient to fix the braided wire and the rigid tube to a degree that can suppress the positional deviation, so a conventional caulking member or strong joint is not required, and a simple fixation such as a tape or a grommet is sufficient.

In addition, since no crimping member is used, there is no protruding part unlike the ear clamp, and subsequent wiring work is easy. For example, since there is no large protruding portion on the outer peripheral portion of the shield structure, it is possible to wire in a space-saving manner when wiring to the vehicle. In addition, since the end portion of the rigid tube is not reduced in diameter by caulking, the inner diameter of the rigid tube is substantially constant, which does not interfere with the insertion of electric wires therein.

For example, in the conventional caulking method, the diameter of the electromagnetic shield tube at the connecting portion is reduced, so the diameter of the wire that can be passed through is determined in consideration of the inner diameter of the reduced diameter portion. For this reason, an unnecessary gap is formed between the electric wire and the electromagnetic shield tube at a portion other than the connecting portion. However, if there is no diameter-reduced portion, it is possible to use an electromagnetic shield tube of a size appropriate for the diameter of the internal electric wire even at locations other than the connection portion, so wiring in a vehicle can be done in a more space-saving manner.

In addition, by dividing the rigid pipe into a plurality of pieces and exposing a predetermined length of braided wire between the rigid pipes, the rigid pipe can be arranged only in a necessary portion, and other portions can be composed of the braided wire. Therefore, the degree of freedom in shape is high. In addition, it is easy to handle because it can be bent at the braided wire during transportation and storage.

Since a resin pipe can be used as such a rigid pipe, it is lightweight, easier to bend than a metal pipe, and has a high degree of freedom in shape.

In addition, by covering the braided wire exposed from the rigid tube with the flexible tube, it is possible to suppress the braided wire from being damaged by stones and ensure waterproofness.

Advantageous Effects of Invention According to the present invention, it is possible to provide an electromagnetic shield structure and the like with good connection workability and reliability.

FIG. 2 is an exploded perspective view of the braided wire 1 and the rigid tube 3; The figure which shows the electromagnetic shield structure 5. FIG. Sectional drawing of the electromagnetic shield structure 5. FIG. (a), (b) is a figure which shows the edge part of the rigid pipe|tube 3 in an electromagnetic shielding structure. (a), (b) is a figure which shows the use condition of the electromagnetic shielding structure 5. FIG. The figure which shows the use condition of the electromagnetic shield structure 5. FIG. The figure which shows the use condition of the electromagnetic shield structure 5. FIG.

An electromagnetic shield structure according to an embodiment of the present invention will be described below. FIG. 1 is an exploded perspective view of the electromagnetic shield structure, and FIG. 2 is a perspective view showing the electromagnetic shield structure 5. As shown in FIG.

The electromagnetic shield structure 5 is composed of the braided wire 1, the rigid tube 3, and the like. The braided wire 1 is a tubular member in which metal wires are woven, and has flexibility. The braided wire 1 is not entirely composed of metal wires, but may be a wire in which metal wires and resin wires are woven together as long as the desired shielding performance can be secured.

The rigid tube 3 may be made of metal, but a resin tubular body is applicable. The rigid pipe 3 is molded into a shape corresponding to an installation portion in a vehicle or the like, for example. The rigid tube 3 only needs to have a certain degree of rigidity so that its shape does not change due to its own weight or the like.

When the rigid tube 3 is made of resin, for example, it may be crosslinked in order to improve heat resistance, or a flame retardant such as a halogen-based, phosphorus-based, or metal hydrate may be added, or titanium oxide or the like may be added to improve weather resistance. Moreover, you may color resin as needed.

As shown in FIG. 2, one braided wire 1 is passed through one rigid tube 3 without being cut in the middle. The length of the braided wire 1 is longer than the length of the rigid tube 3. Therefore, in the electromagnetic shield structure 5 , the ends of the braided wire 1 protrude from both ends of the rigid tube 3 by a predetermined length. The total length of the braided wire 1 exposed from the rigid pipe 3 is shorter than the total length of the rigid pipe 3 with respect to the total length of the electromagnetic shield structure 5 .

FIG. 3 is a cross-sectional view of the electromagnetic shield structure 5. As shown in FIG. The electromagnetic shield structure 5 can have electric wires 7 inserted therein. At this time, since the rigid tube 3 has substantially the same inner diameter over the entire length, the work of inserting the electric wire 7 is easy. In addition, the outer diameter of the braided wire 1 is slightly smaller than the inner diameter of the rigid tube 3, and since there is no diameter change portion, the area ratio of the cross section occupied by the electric wire 7 can be increased. In the illustrated example, a gap is formed between the inner surface of the rigid tube 3 and the outer surface of the braided wire 1, but substantially the entire circumference of the braided wire 1 may be in contact with the inner surface of the rigid tube 3.

Although the braided wire 1 can be used in a state where it is only inserted into the rigid tube 3, the rigid tube 3 and the braided wire 1 may be fixed near both ends of the rigid tube 3 in order to suppress axial displacement between the braided wire 1 and the rigid tube 3.

FIG. 4(a) is a diagram showing a state in which the rigid tube 3 and the braided wire 1 are fixed with a tape 9 at the end of the rigid tube 3. FIG. The braided wire 1 and the rigid tube 3 can be fixed by using a tape 9 at the end of the rigid tube 3 . Thus, since it is not necessary to join the braided wire 1 to the tubular body by caulking or the like, both can be fixed with a simple structure.

As a fixing method, a grommet 11 may be used as shown in FIG. 4(b). By attaching the grommet 11 to the end of the rigid tube 3 and arranging the braided wire 1 so as to pass through the grommet 11 , it is possible to suppress the displacement between the braided wire 1 and the rigid tube 3 . In this way, since it is not necessary to establish continuity between the braided wire 1 and the rigid tube 3, it is possible to use the tape 9 or the grommet 11, and if necessary, the fixation can be released, and the position of the braided wire 1 can be adjusted and replaced easily. The braided wire 1 may be fixed only at one end of the rigid tube 3 instead of fixing the braided wire 1 at both ends of the rigid tube 3 .

Next, a usage example of the electromagnetic shield structure 5 will be described. FIG. 5( a ) is a diagram showing an example of the state of use of the electromagnetic shield structure 5 . An example in which the braided wire 1 is fixed by the grommet 11 is shown, but the tape 9 may be used, and the fixing structure may be omitted. As described above, the electromagnetic shield structure 5 has the electric wire 7 inserted therein. Note that the number and size of the electric wires 7 are not particularly limited.

Connectors 13 are connected to both ends of the electric wire 7 . The connector 13 can be connected to another connector provided on the electrical equipment unit (not shown). Although the connector 13 is exposed from the end of the braided wire 1 in the figure, the length of the braided wire 1 is set to such an extent that the entire connecting portion can be covered with the braided wire when connected to another electric device unit or the like. That is, the length of the braided wire 1 may be longer than the length of the electric wire 7 inside. In addition, the braided wire 1 is grounded to the body of the automobile or the like at least at one point, if necessary.

Alternatively, as shown in FIG. 5(b), the wire 7 may be directly connected to the electric equipment unit 15 without placing the connector 13 at the tip thereof. Also in this case, by connecting the braided wire 1 to the housing (shield connector or the like) of the electric device unit 15 and completely covering the electric wire 7 and the like, high shielding performance can be obtained.

As described above, according to the present embodiment, since the shielding effect of the braided wire 1 is utilized over the entire length, it is not necessary to use an electromagnetic shield tube such as a metal tube or a composite tube having a metal layer as the rigid tube 3 . Therefore, the rigid pipe 3 can be made of a resin pipe. In addition, since the resin pipe is easier to bend than metal pipes and composite pipes (the allowable range of bending radius and the like is wide), the rigid pipe 3 has a high degree of freedom in shape.

In addition, since the braided wire 1 is inserted through the rigid tube 3 , the rigid tube 3 functions as a protective tube (armor) for the metal wires forming the braided wire 1 . Therefore, as compared with the conventional case of using a metal electromagnetic shield tube, the exterior can be reduced.

In addition, since the braided wire 1 is used without being cut, there is no need to connect the end of the braided wire 1 and the end of the rigid tube 3 . For example, conventionally, when the braided wire 1 is connected to the end of an electromagnetic shield tube, a strong connection such as a crimping ring is required in consideration of connection strength and electrical contact resistance. For this reason, the work is easy and there is no formation of protrusions such as ear clamps.

Further, in the conventional method, when connecting the end of the electromagnetic shield tube and the end of the braided wire, the end of the braided wire (the end of the metal wire forming the braided wire) is exposed. Therefore, the end of the metal wire may damage peripheral devices. However, in the present embodiment, the ends (metal wire ends) of the braided wire 1 are not exposed in the vicinity of the ends of the rigid tube 3 . Therefore, it is possible to suppress damage to peripheral devices and the like due to the ends of the braided wire 1 .

Further, conventionally, the end of the braided wire is folded back at the connection between the electromagnetic shield tube and the braided wire, but such folding work is not required. Also, since the ends of the braided wire are not exposed, the work is safe.

Further, as described above, the electromagnetic shield structure 5 can obtain a shielding effect by the braided wire 1 over almost the entire length. For example, conventionally, there are discontinuous portions of the shielding effect, that is, the shielding portion by the electromagnetic shield tube, the shielding portion by the braided wire, and the connecting portion thereof, but in this embodiment, a uniform shielding effect can be obtained over the entire length. Therefore, a stable shielding effect can be obtained.

In the embodiment described above, an example in which one braided wire 1 is inserted through one rigid tube 3 has been described, but the present invention is not limited to this. FIG. 6 is a diagram showing another usage example using the electromagnetic shield structure 5. FIG.

In the example shown in FIG. 6, the rigid pipe 3 is divided into a plurality of pieces, and the internal braided wire 1 is exposed for a predetermined length between the rigid pipes 3 . That is, by inserting one braided wire 1 through a plurality of rigid pipes 3 and leaving a gap between the rigid pipes 3 , the internal braided wire 1 is exposed even in the intermediate portion of the electromagnetic shield structure 5 .

In addition, a separate protective tube (armor) may be arranged for the exposed portion of the braided wire 1 in order to protect the braided wire 1 . Alternatively, in order to protect the braided wire 1, at least the exposed portion may be coated with a resin or the like.

Moreover, when the rigid pipe 3 is divided into a plurality of pieces, the braided wire 1 does not have to be exposed at the abutting portions of the rigid pipes 3 . For example, by using two rigid pipes 3 butted against each other, only one rigid pipe 3 can be used, and the other rigid pipe 3 can be changed according to the type of vehicle. Even in this case, since the internal braided wire 1 is continuous, leakage of noise from the gaps of the rigid tube 3 can be suppressed.

Although the example shown in FIG. 6 shows an example in which the rigid pipe 3 is divided into two, it may be divided into three or more. Further, as described above, the grommet 11 or the like may be used to prevent the braided wire 1 from slipping from the rigid tube 3 only at one end of the rigid tube 3. Therefore, for example, the grommet 11 may be omitted at the central exposed portion of the braided wire 1.

By dividing the rigid tube 3 in this way, it is possible to obtain sufficient flexibility at the portion of the braided wire 1 and maintain the shape at the portion of the rigid tube 3, thereby facilitating the layout of the vehicle. In addition, by dividing the rigid tube 3 into a plurality of parts, it is easy to handle during transportation and storage.

Moreover, in the example shown in FIG. 7, the braided wire 1 exposed from the rigid tube 3 is covered with the flexible tube 17 . The flexible tube 17 is, for example, a corrugated tube made of resin. By arranging the flexible tube 17, it is possible to prevent the braided wire 1 from being damaged by a stone splash or the like, and to improve waterproofness. It is desirable that the flexible tube 17 cover the entire braided wire 1 exposed from the rigid tube 3, but it is sufficient if it can cover at least a part of it. Also, the end of the flexible tube 17 may be fixed to the grommet 11 or the rigid tube 3 . Also, the flexible tube 17 may be arranged over the entire length including the rigid tube 3 .

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not influenced by the above-described embodiments. It is clear that a person skilled in the art can conceive of various modifications or modifications within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention.

1 Braided wire 3 Rigid tube 5 Electromagnetic shield structure 7 Electric wire 9 Tape 11 Grommet 13 Connector 15 Electric equipment unit 17 Flexible tube

Claims (7)

An electromagnetic shield structure in which an electric wire can be inserted,
a rigid tube having a predetermined rigidity and capable of retaining its shape;
a braided wire inserted through the inside of the rigid tube;
and
The electromagnetic shield structure, wherein the braided wire is longer than the rigid tube, and an end of the braided wire protrudes from the end of the rigid tube. 2. The electromagnetic shield structure according to claim 1, wherein said rigid pipe and said braided wire are fixed near both ends of said rigid pipe. 3. The electromagnetic shield structure according to claim 2, wherein said rigid tube and said braided wire are fixed with tape. 3. The electromagnetic shield structure according to claim 2, wherein said rigid tube and said braided wire are fixed by a grommet fixed to an end of said rigid tube. 5. The electromagnetic shield structure according to claim 1, wherein said rigid pipe is divided into a plurality of pieces, and said braided wire is exposed for a predetermined length between said rigid pipes. 6. The electromagnetic shield structure according to claim 1, wherein said rigid pipe is a resin pipe. The electromagnetic shield structure according to any one of claims 1 to 6, wherein a flexible tube is arranged so as to cover at least part of the braided wire exposed from the rigid tube.

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