JP2012152045A - Shield cable, installation structure of shield cable, and method for inserting wire into shield tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield cable and an installation structure of the shield cable which obtain substantially uniform shield properties relative to a circumferential direction of a shield tube when an electric wire is inserted into the shield tube.SOLUTION: A shield cable 1 is composed mainly of a shield tube 3, an electric wire 5, and the like. The shield tube 3 is formed by a flexible corrugate tube made of a resin. A shield layer, which is a metal layer, is formed on at least an outer surface of the shield tube 3, and the electric wire 5 is inserted into the shield tube 3. Centering members 7a are provided on an outer periphery of the electric wire 5 at the inner side of the shield tube 3 so as to be spaced a predetermined distance away from each other. Further, centering members 7b, which serve as end part centering members, are provided near both end parts of the shield cable 1 (near both openings of the shield tube 3) as necessary.

Description

  The present invention relates to a shielded cable in which an electric wire is passed through a shield tube, a shield cable laying structure using the shielded cable, and the like.

  Conventionally, in the laying place where there is a risk of damaging the electric wires in underground burial, indoor wiring, vehicle wiring, and other various equipment wiring, a metal tube or resin tube is used as the protective tube for the wire. Prevents trauma. Furthermore, in order to shield noise generated from the inserted wire or prevent noise from entering the wire from the external environment, use a shielded wire or insert the wire into a metal tube or the like to ground the metal tube. To prevent noise.

  For example, metal pipes such as steel pipes and aluminum pipes are used as protective pipes for cables used for automobiles and the like for vehicles. The metal tube is usually provided at the lower part of the vehicle body. Since the protective tube is a metal tube, the protective tube itself has a shielding property against external noise, and is not easily affected by noise. However, since the metal tube is processed into a predetermined shape, the processing cost is high, and the degree of freedom in layout and arrangement of the electronic device or the like is low. Moreover, since it is metal, there also exists a problem of weight. Therefore, a resin pipe having shielding properties has been studied.

  As such a shield tube, for example, a metal layer is formed by using an electroless plating method on a resin corrugated tube, or a metal layer is formed by winding a metal tape around the corrugated tube, There are methods for forming a corrugated tube having shielding properties (Patent Document 1, Patent Document 2, and Patent Document 3).

JP 9-298382 A Japanese Patent Laid-Open No. 10-185015 JP 2010-246296 A

  On the other hand, when a shield cable is formed by inserting an electric wire through the shield tube as described above, the electric wire is positioned so as to contact the inner surface of the shield tube inside the shield tube. That is, the electric wire is positioned so as to come into contact with the lower part of the inner surface of the shield tube by gravity in the cross section of the shield tube.

  However, the shield characteristic of the shield layer formed in the shield tube varies depending on the distance from the electric wire. For this reason, when the electric wire is arranged so as to be biased to one side in the cross section of the shield tube, the shield characteristics of the shield layer are different on the side closer to and far from the electric wire. That is, it has non-uniform shield characteristics in the circumferential direction of the shield tube.

  The present invention has been made in view of such problems, and a shielded cable and a shield capable of obtaining a substantially uniform shield characteristic with respect to the circumferential direction of the shield tube when an electric wire is inserted through the shield tube. The purpose is to provide a cable laying structure.

  In order to achieve the above-mentioned object, the first invention comprises a corrugated tube having a shield layer and an electric wire inserted through the corrugated tube, and a centering which is an elastic body on the outer periphery of the electric wire The members are arranged at a predetermined interval, the outer diameter of the centering member is larger than the inner diameter of the small-diameter portion of the corrugated tube, and the outer peripheral portion of the centering member fits into the large-diameter portion of the inner surface of the corrugated tube The shielded cable is characterized in that the electric wire can be held substantially at the center of the corrugated tube.

  End centering members are provided in the vicinity of both ends of the shielded cable, the end centering members have higher rigidity than the centering members in other portions, and the outer peripheral surfaces of the end centering members are You may contact with the internal peripheral surface of the large diameter part of a corrugated pipe. As described above, the shield cable can be sealed by using a disc-shaped centering member and bringing it into contact with the entire inner peripheral surface of the large-diameter portion of the corrugated tube. Here, the thickness of the centering member is made thin as it goes from the center toward the outer periphery, or only the outer peripheral portion is made thinner, so that the insertion property when inserting the cable equipped with the centering member into the corrugated tube is improved. Can be improved.

  According to 1st invention, when an electric wire is penetrated inside the corrugated pipe | tube which has a shield layer, an electric wire is hold | maintained by the centering member at the cross-sectional approximate center of a shield pipe | tube. Therefore, the distance between the shield layer formed on the corrugated tube and the electric wire is substantially constant over the entire circumference in the cross section of the corrugated tube. For this reason, the shield characteristic of a shielded cable can be made substantially constant in the circumferential direction of the shielded cable.

  In addition, since the outer diameter of the centering member is larger than the inner diameter of the small-diameter portion of the corrugated tube and can be fitted into the large-diameter portion, the electric wire with the centering member attached is inserted into the corrugated tube. Can be prevented from moving in the axial direction of the corrugated tube. For this reason, it is not necessary to fix an electric wire to a corrugated pipe with a tape etc. during conveyance of a shielded cable.

  The outer diameter of the centering member is the center of the centering member when the position farthest from the center of the centering member is the outer diameter of the centering member with the electric wire inserted through the centering member and fixed. The distance from the outer diameter portion to the outer diameter portion refers to the diameter of the centering member.

  In addition, an end centering member is disposed at the end of the shielded cable, and the end centering member is disposed so as to contact the inner surface of the large-diameter portion of the corrugated tube, thereby functioning as a sealing material for the shielded cable. Play. That is, it is possible to prevent water or the like from entering the shielded cable.

  In order to surely obtain a sealing effect, it is desirable that the end centering member has higher rigidity than the centering members in other portions. Thus, although the end centering member has higher rigidity than the centering members of other parts, the centering member is made rigid so that the outer diameter portion of the centering member can be inserted into the large diameter portion of the corrugated tube. No gap is formed between the inner surface of the corrugated tube after the member is inserted. Even in this case, since the end centering member can be installed from the end of the shielded cable after the electric wire is inserted, there is no influence on the electric wire inserting operation.

  According to a second aspect of the present invention, the shielded cable according to the first aspect of the present invention is partially laid and formed with a bent portion, and the bent portion of the shielded cable with respect to the arrangement interval of the centering member in the straight portion of the shielded cable. The shield cable laying structure is characterized in that a plurality of the centering members are arranged on an outer periphery of the electric wire so that an arrangement interval of the centering members in the is small. The third invention is a method for inserting an electric wire into a shield tube, wherein a step a in which centering members, which are elastic bodies, are arranged on the outer periphery of the electric wire at a predetermined interval; and the electric wave having a shield layer. The centering member has an outer diameter larger than an inner diameter of the small diameter portion of the corrugated tube, and an outer peripheral portion of the centering member is a large diameter of the inner surface of the corrugated tube. Can be fitted into the portion, and the electric wire can be held in the approximate center of the corrugated tube in a state where the electric wire is inserted through the corrugated tube. The centering members are arranged such that the arrangement interval of the centering members in the portion corresponding to the bent portion of the shielded cable after installation is smaller than the arrangement interval of the centering members in the portion corresponding to the straight portion of the shielded cable. It is inserted method of the wire to the shield tube, characterized by placing the timber on the outer periphery of the electric wire.

  According to the second and third inventions, since the shield tube is a corrugated tube, the bent portion can be easily formed and the shield cable can be laid. Further, by making the arrangement interval of the centering members in the bent portion of the shield cable narrower than the arrangement interval in the straight portion, the inner electric wire can be reliably held at the center of the cross section of the shield tube even in the bent portion.

  Moreover, in the straight part of the shielded cable, the amount of use of the centering member can be reduced by reducing the installation of the centering member. For this reason, while enabling cost reduction, the insertion resistance at the time of inserting an electric wire through a corrugated tube can be made small.

  According to the present invention, it is possible to provide a shielded cable, a shielded cable laying structure, and the like capable of obtaining a substantially uniform shield characteristic with respect to the circumferential direction of the shield tube when an electric wire is inserted through the shield tube. it can.

It is a figure which shows the shielded cable 1, (a) is a front view, (b) is front sectional drawing. It is an enlarged view of the centering member 7a vicinity, (a) is the A section enlarged view of FIG.1 (b), (b) is the EE sectional view taken on the line of (a). It is an enlarged view of centering member 7b vicinity, (a) is the B section enlarged view of FIG.1 (b), (b) is the HH sectional view taken on the line of (a). The figure which shows the state which penetrates the electric wire 5 in the shield tube 3. FIG. It is a figure which shows the state which inserts the electric wire 5 in the shield tube 3, Comprising: The enlarged view of the centering member 7a vicinity. The figure which shows the shield cable laying structure 17. FIG.

  Hereinafter, a shielded cable 1 according to an embodiment of the present invention will be described. 1A and 1B are diagrams showing a shielded cable 1, FIG. 1A is a front view of the shielded cable 1, and FIG. 1B is an axial sectional view of FIG. 1A. The shield cable 1 is mainly composed of a shield tube 3, an electric wire 5, and the like.

  The shield tube 3 is composed of a resin corrugated tube having flexibility. A shield layer, which is a metal layer, is formed on at least the outer surface of the shield tube. As the shield layer, for example, metal plating (double structure of electroless plating and electrolytic plating) may be provided on the surface of the resin tube, and metal tape or metal mesh is wound around the outer periphery of the resin tube May be. In any case, the shield tube 3 may be a corrugated tube having flexibility in a state where a shield layer is formed.

  An electric wire 5 is inserted into the shield tube 3. Terminals (not shown) are connected to both ends of the electric wire 5 that is a covered wire. In the present invention, the state before the terminal is connected to the electric wire 5 (the state shown in FIG. 1A) is also referred to as a shielded cable.

  As shown in FIG. 1B, centering members 7 a are provided at predetermined intervals on the outer periphery of the electric wire 5 inside the shield tube 3. Further, a centering member 7b, which is an end centering member, is provided near both ends of the shielded cable 1 (near both openings of the shield tube 3) as necessary.

  2 is an enlarged view of the vicinity of the centering member 7a, FIG. 2 (a) is an enlarged view of a portion A in FIG. 1 (b), and FIG. 2 (b) is a sectional view taken along the line EE of FIG. 2 (a). is there. The centering member 7 a is fixed to the outer periphery of the electric wire 5. For example, a hole having an inner diameter slightly smaller than the outer diameter of the electric wire 5 may be formed, the electric wire 5 may be inserted into the hole, and the electric wire 5 and the centering member 7a may be fixed. In this case, it becomes easy to insert the electric wire 5 into the centering member 7a by providing the end surface of the centering member 7a with a taper shape.

  The frictional force between the centering member 7a and the electric wire 5 is made larger than the resistance force generated in the centering member 7a when the electric wire 5 described later is inserted into the shield tube 3, so that the electric wire 5 is inserted into the shield tube 3. At this time, the centering member 7 a does not move in the axial direction of the electric wire 5. Moreover, you may fix the centering member 7a in the predetermined position of the electric wire 5 using an adhesive agent. In this case, the adhesive force between the centering member 7a and the electric wire 5 is made larger than the resistance force generated in the centering member 7a when the electric wire 5 described later is inserted into the shield tube 3, so that the electric wire 5 is inserted into the shield tube 3. In doing so, the centering member 7 a does not move in the axial direction of the electric wire 5.

  Further, the outer shape of the centering member 7a may be a plurality of tongue pieces formed radially around the electric wire 5, as in the cross shape shown in the figure, or a polygon such as a rectangle or a triangle, or a shield tube It is good also as a circle etc. according to the shape. Anyway, the electric wire 5 should just be hold | maintained in the approximate center in the cross section of the shield tube 3 by the centering member 7a.

  Here, the inner diameter of the small-diameter portion 11 of the shield tube 3 that is a corrugated tube (the inner diameter at the valley of the corrugated tube and the minimum inner diameter of the shield tube 3) is D, and the outer diameter of the centering member 7a (centering member 7a). C is larger than D, where C is the maximum outer diameter centered on the electric wire 5 in a state where is fixed to the electric wire 5. That is, a relationship of C> D is established.

  The thickness of the centering member 7a (F in the figure) is smaller than the width of the large-diameter portion 9 in the wave shape of the shield tube 3 (the length in the axial direction of the shield tube 3 and G in the figure). Therefore, the centering member 7 a is fitted into the large-diameter portion 9 of the shield tube 3 and is held against the shield tube 3. Note that the outer periphery of the centering member 7a does not necessarily need to be in contact with the inner surface of the large-diameter portion 9 of the shield tube 3 over the entire periphery.

  The centering member 7a is made of a resin that can be elastically deformed. The centering member 7a is formed of a member that can be easily deformed as long as the electric wire 5 can be held without the centering member 7a being crushed by the weight of the electric wire 5.

  In the example shown in FIG. 2A, the centering member 7a is configured with a substantially constant thickness (F in the figure) throughout, but the present invention is not limited to this. As the distance from the electric wire 5 is increased, the thickness may be gradually reduced, and only the outer peripheral portion of the centering member 7a (for example, the outside of the range corresponding to the small diameter portion D) may be a thin portion. In this case, as a matter of course, only the thickness F of the centering member 7a that fits into the large-diameter portion 9 needs to be smaller than the width G of the large-diameter portion. Further, the length of the contact portion with the electric wire 5 is set to a length that can provide a necessary frictional force (or adhesive force) between the electric wire and the centering member, and the thickness between the contact portion and the outer peripheral portion of the centering member is It may be the same.

  3 is an enlarged view of the vicinity of the centering member 7b, FIG. 3 (a) is an enlarged view of a portion B of FIG. 1 (b), and FIG. 3 (b) is a cross-sectional view taken along the line HH of FIG. 3 (a). is there. The centering member 7b has substantially the same configuration as the centering member 7a. The centering member 7b is in close contact with the outer periphery of the electric wire 5, and further contacts the inner surface of the large diameter portion 9 of the shield tube 3 over the entire periphery. That is, the centering member 7 b has an outer shape corresponding to the shape of the shield tube 3, and has an outer diameter slightly larger than the inner diameter of the large diameter portion 9.

The centering member 7b has higher rigidity than the centering member 7a. For example, the centering member 7b is formed thicker than the centering member 7a. For this reason, even if tension etc. are given to electric wire 5, centering member 7b is fixed to shield tube 3, and electric wire 5 does not move easily in the axial direction. In addition, no gap is formed between the centering member 7 b and the inner surface of the large-diameter portion 9 of the shield tube 3.
Note that the centering member 7b may be disposed in the small diameter portion 11 of the shield tube 3 if the coefficient of friction between the outer periphery of the centering member 7b and the inner peripheral surface of the shield tube 3 is sufficiently large.

  Next, a method for manufacturing the shielded cable 1 will be described. First, the shield tube 3 and the electric wire 5 are cut to a required length, and centering members 7a are installed on the outer periphery of the electric wire 5 at a predetermined interval. At this time, in a predetermined portion of the electric wire 5, a narrow pitch portion 15 in which the interval between adjacent centering members is narrow (J in the drawing) and a wide pitch portion 13 in which the interval between adjacent centering members is wide (I in the drawing). And are formed. The positions of the narrow pitch portion 15 and the wide pitch portion 13 will be described later.

  Next, the electric wire 5 to which the centering member 7a is fixed is inserted from the end of the shield tube 3 into the inside (in the direction of arrow K in the figure).

  FIG. 5 is a view showing the vicinity of the centering member 7 a when the electric wire 5 is inserted through the shield tube 3. As described above, the outer diameter of the centering member 7 a is larger than the inner diameter of the small diameter portion 11 of the shield tube 3. For this reason, when the centering member 7a moves the small diameter portion 11 in the axial direction, the vicinity of the outer peripheral portion of the centering member 7a is deformed (FIG. 5A).

  When the electric wire 5 is further pushed in the axial direction in this state (arrow L in the figure), the centering member 7a moves to the position of the large diameter portion 9 and returns to the original shape (FIG. 5B). Is fitted into the large-diameter portion 9. When the electric wire 5 is further pushed in the axial direction from this state (arrow L in the figure), the centering member 7a moves again to the position of the small-diameter portion 11 while being elastically deformed (FIG. 5 ( a)) While repeating the above, the electric wire 5 to which the centering member 7a is fixed is inserted into the shield tube 3.

  When the electric wire 5 is inserted over the entire length of the shield tube 3, finally, the centering member 7 b is attached from both ends of the shield tube 3. For example, the electric wire 5 may be inserted into the center hole of the centering member 7b and the centering member 7b may be pushed into the large diameter portion 9 near the opening of the shield tube 3. Although the centering member 7b has high rigidity, the centering member 7b and the shield tube 3 are elastically deformed by being strongly pressed into the end portion of the shield tube 3, and the centering member 7b can be fitted into the large diameter portion 9.

  By providing centering members 7b on both sides of the shield tube 3, the shield cable 1 is completed. In the shielded cable 1, all the centering members 7 a fixed to the electric wires 5 do not necessarily have to be fitted into the large-diameter portion 9 of the shield tube 3. That is, approximately half of the centering members 7 a are fitted into the large diameter portion 9. On the other hand, the remaining centering member 7a is positioned on the small diameter portion 11 in a deformed state. Even in this state, the movement of the electric wire 5 in the axial direction is suppressed by the centering member 7 a fitted into the large-diameter portion 9.

  Next, a shielded cable laying structure using the shielded cable 1 of the present invention will be described. FIG. 6 is a view showing the shielded cable laying structure 17. In addition, the form of the shielded cable to be laid is not limited to the illustrated example.

  The shielded cable 1 is laid in a predetermined layout, for example, at the lower part of an automobile, and is fixed to a vehicle body or the like at predetermined intervals. At this time, the shielded cable 1 is formed with a straight part 19 that is partially linear and a bent part 21 where the shielded cable 1 is bent and laid with a predetermined curvature. In addition, the bending part 21 is not necessarily limited to the bending form shown in figure, A bending angle and a bending radius are suitably set according to a layout.

  As described above, the centering member 7a is provided at a predetermined interval in the electric wire 5 inserted inside. Further, as the arrangement interval of the centering member 7a, a wide pitch portion 13 and a narrow pitch portion 15 are provided. Here, the centering member 7 a is disposed so that the wide pitch portion 13 is located at a portion corresponding to the straight portion 19 and the narrow pitch portion 15 is located at the bent portion 21.

  That is, since the electric wire 5 is bent at the bent portion 21, the position of the electric wire 5 in the cross section of the shield tube 3 is likely to change. For this reason, many centering members 7 a are arranged to securely hold the electric wire 5 at the center of the cross section of the shield tube 3.

  On the other hand, in the linear part 19, the electric wire 5 should just consider the position change by the bending accompanying self weight. For this reason, even if the arrangement density of the centering members 7a is reduced, the electric wires 5 can be held at the center of the cross section of the shield tube 3.

  In addition, in this embodiment, although divided into the two states of the linear part 19 and the bending part 21, and each site | part was made into the wide pitch part 13 and the narrow pitch part 15, this invention is not limited to this. For example, the pitch of the centering member 7a may be set finely according to the bending radius of the bent portion. That is, the centering member 7a can be arranged at a higher density than the straight portion at a portion where the bending radius is large, and the centering member 7a can be arranged at a higher density at a portion where the bending radius is smaller.

  As described above, according to the present embodiment, the electric wire 5 can be held at the approximate center of the cross section of the shield tube 3 inside the shield tube 3. For this reason, the distance between the electric wire 5 and the shield layer of the shield tube 3 is substantially constant in any direction. Therefore, substantially uniform shielding characteristics can be obtained over the entire circumference of the shielded cable 1.

  Further, the outer diameter of the centering member 7 a is larger than the inner diameter of the small diameter portion 11 of the shield tube 3. For this reason, the movement of the electric wire 5 in the axial direction with respect to the shield tube 3 is suppressed by the centering member 7a. For this reason, the end of the electric wire 5 does not enter the inside of the shield tube 3 during transportation or laying, and the electric wire 5 does not fall out of the shield tube 3.

  Further, since the centering member 7a can be easily deformed, when the electric wire 5 is inserted into the shield tube 3, the outer peripheral portion of the centering member 7a is easily deformed and repeatedly fitted into the large diameter portion 9. Can move in the axial direction. For this reason, the electric wire 5 can be easily inserted into the shield tube 3.

  Further, centering members 7 b are provided at both ends of the shielded cable 1, and the outer peripheral portion of the centering member 7 b is in contact with the inner surface of the large diameter portion 9. Further, the centering member 7b and the electric wire 5 are in close contact with each other. For this reason, both ends of the shielded cable 1 are sealed by the shield member 7b. Therefore, the centering member 7b can prevent water or the like from entering the shielded cable without sealing with a separate sealing member or the like.

  The centering member 7b has higher rigidity than the centering member 7a, but unlike the centering member 7a, the centering member 7b is not inserted into the shield tube 3 together with the electric wires 5. For this reason, the insertion workability of the electric wire 5 is not adversely affected by the centering member 7b.

  The centering member 7b is provided only at both ends of the shielded cable 1. For this reason, the centering member 7b can be pushed in from the opening of the shield tube 3. Further, since the centering member 7b has high rigidity, it does not move easily even when tension or the like is applied to the electric wire 5, and is always pressed against the inner surface of the shield tube 3. Therefore, it is possible to ensure the sealing performance.

  Further, in the state where the shielded cable 1 is laid, the centering members 7a are arranged at a high density (narrow spacing) in the portion corresponding to the bent portion 21, so that the electric wire 5 can be surely placed at substantially the center of the cross section of the shield tube 3. Can be held. In addition, in the state where the shielded cable 1 is laid, the centering member 7a is disposed at a small density (wide interval) in a portion corresponding to the straight portion 19, and thereby the insertion property of the electric wire 5 may be deteriorated more than necessary. The number of used parts can be reduced.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Shielded cable 3 ......... Shield tube 5 ......... Electric wire 7a, 7b ......... Centering member 9 ......... Large diameter part 11 ......... Small diameter part 13 ......... Wide pitch part 15 ......... Narrow Pitch part 19 ......... Linear part 21 ......... Bending part

Claims (4)

A corrugated tube having a shield layer;
An electric wire inserted into the corrugated tube;
A shielded cable comprising a centering member,
On the outer periphery of the wire,
The centering members that are elastic bodies are arranged at predetermined intervals,
The outer diameter of the centering member is larger than the inner diameter of the small-diameter portion of the corrugated tube, and the outer peripheral portion of the centering member can be fitted into the large-diameter portion of the inner surface of the corrugated tube. A shielded cable that can be held substantially in the center of the corrugated tube.   End centering members are provided in the vicinity of both ends of the shielded cable, the end centering members have higher rigidity than the centering members in other portions, and the outer peripheral surfaces of the end centering members are The shielded cable according to claim 1, wherein the shielded cable is in contact with the inner peripheral surface of the large-diameter portion of the corrugated tube. The shielded cable according to claim 1 or 2 is partially laid to form a bent portion,
The plurality of centering members are arranged on the outer periphery of the electric wire so that the arrangement interval of the centering members in the bent portion of the shield cable is smaller than the arrangement interval of the centering members in the straight portion of the shielded cable. Characteristic shield cable laying structure. A method of inserting an electric wire into a shield tube,
A step a in which centering members, which are elastic bodies, are arranged at predetermined intervals on the outer periphery of the electric wire;
Inserting the wire into a corrugated tube having a shield layer; and b.
Comprising
An outer diameter of the centering member is larger than an inner diameter of a small diameter portion of the corrugated tube, an outer peripheral portion of the centering member can be fitted into a large diameter portion of an inner surface of the corrugated tube, and the electric wire In a state of being inserted through the corrugated tube, the electric wire can be held at the approximate center of the corrugated tube,
In the step (a), the arrangement interval of the centering members in the portion corresponding to the bent portion of the shielded cable after installation is smaller than the arrangement interval of the centering member in the portion corresponding to the straight portion of the shielded cable after installation. A method of inserting a wire into a shield tube, wherein the plurality of centering members are arranged on an outer periphery of the wire.

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