To provide a manufacturing method of a harness by a flat cable and a semi-finished product of the harness.

Abstract

To provide a flat cable capable of changing a direction to a predetermined angle direction in the same plane.SOLUTION: In a flat cable 1, a plurality of electric wires 2 in which a core wire is covered with an insulator are drawn out from bobbins 6 respectively and arranged in parallel. The electric wire 2 is straightly advanced through a direction changing part C, and in the direction changing part C, the electric wire 2 is formed with an arc-shaped extra length part 2' for each electric wire 2, and this extra length part 2' is put in a state of swelling upward from a plane of the flat cable 1. The length is determined so that the length of the extra length part 2' of the electric wire 2 around the outside is the largest and becomes shorter toward the inside. In the first step, since the flat cable 1 can be manufactured while maintaining the linearity of the flat cable 1, the first step can be performed in a narrow place. In the second step, the extra-length portion 2 ' formed in the first step is expanded into a planar shape, so that the electric wire 2 can be stretched in a direction to which the direction of the electric wire 2 is to be changed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a harness using a flat cable that allows a direction change within the same plane in a flat cable in which a plurality of electric wires are arranged in parallel, and to a semi-finished product of the harness. [Background technology]

[0002] For example, in automobiles, harnesses made up of a large number of bundled electric wires are used to supply power and send and receive signals. In particular, in the case of autonomous driving, which has become common in recent years, where multiple image sensors and the like are used, several times more electric wires are required for signal transmission and the like than in the past.

[0003] In automotive harnesses, electric wires must be bundled and routed under the floor or in the ceiling, making it difficult to route a large number of electric wires. Conventionally, flexible flat cables, which use copper foil as the conductor and change direction by folding, as in Patent Document 1, have been used in some cases, but this has problems such as a large amount of material waste and troublesome terminal processing, making it difficult to handle a large number of circuits.

[0004] Another option is to use a flat cable, in which multiple electric wires, each with an insulating core, are arranged in parallel on a plane. This offers advantages in terms of efficiency and convenience when wired in a straight line on a plane. However, automotive harnesses often require wiring in narrow spaces or along complex vehicle body shapes. To meet these requirements using a flat cable, it is essential to be able to change the direction of the wires within the same plane. However, changing the direction of multiple electric wires simultaneously within the same plane as the flat cable would result in a large bulkiness, which would diminish the advantages of using a flat cable.

[0005] Furthermore, even if an existing flat cable is used or a flat cable is being created, it is difficult to change the direction of the flat cable in the same plane as the flat cable. For example, it is possible to draw a wiring diagram of the harness on a large table and then form a harness using the flat cable by placing the electric wires W one by one according to the wiring diagram, but this would require an enormous amount of time and effort. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-125310 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to solve the above-mentioned problems and to provide a method for manufacturing a harness using a flat cable that allows the direction of a flat cable having a large number of electric wires to be changed in a predetermined angular direction within the same plane, and a semi-finished product of such a harness. [Means for solving the problem]

[0008] To achieve the above object, the present invention provides a method for manufacturing a harness using a flat cable, comprising: a first step of forming an excess portion in a linear middle portion of a flat cable in which a plurality of electric wires are arranged in parallel, for each electric wire whose direction is to be changed within the same plane, the excess portion having a length required for the change of direction; and a second step of spreading the excess portion out in a plane and extending the electric wire whose direction is to be changed in a predetermined direction.

[0009] Furthermore, a semi-finished flat cable harness according to the present invention is characterized in that, in the straight intermediate section of the flat cable in which a plurality of electric wires are arranged in parallel, an excess section of the length required for the direction change of the electric wires to be changed in the same plane is formed for each of the electric wires. [Effects of the Invention]

[0010] According to the method for manufacturing a harness using a flat cable and the semi-finished product of the harness of the present invention, an excess length of the wire is formed at the direction change portion, making it possible to change the direction at a predetermined angle within the same plane as the flat cable. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a plan view of a flat cable for a harness whose direction is changed within the same plane. [Figure 2] 10 is an explanatory diagram of a flat cable provided with a direction change portion in a first step. FIG. [Figure 3] 10A and 10B are explanatory diagrams of a direction change portion of a flat cable. [Figure 4] FIG. 2 is a perspective view of a direction change portion of the flat cable in a first step. [Figure 5] FIG. 10 is a plan view of the flat cable whose direction has been changed in the second step. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail based on the illustrated embodiment.

[0013] Figure 1 is a plan view of a flat cable 1 for a harness that has been created. For example, it shows a state in which a branch wire B consisting of four straight electric wires 2 and a branch wire B' consisting of six electric wires 2 that change direction at a direction change section C within the same plane are provided from a main wire M consisting of ten electric wires 2. The insulating covering 3 is stripped from the end of each electric wire 2 to expose the core wire 4 in order to secure a connecting member. Furthermore, laminate sheets 5 are adhered to the top and bottom surfaces of the main wire M and the branch wires B and B' to fix the relative positions of the electric wires 2 relative to each other.

[0014] 2 is an explanatory diagram of a case where a direction change section C is provided in the first step of manufacturing the flat cable 1. Several electric wires 2 are drawn out from bobbins 6 and arranged in parallel to form the flat cable 1. Generally, in a flat cable 1, for example, 8, 12, 24, or the like electric wires 2 are arranged in parallel in a plane, but for convenience of explanation, the number of electric wires 2 in FIG. 1 is shown to be fewer than the actual number.

[0015] In this state, the flat cable 1 is intended to change the direction of the electric wires 2 at the direction change section C in the second step, in the same plane as the flat cable 1, in an orthogonal direction, i.e., toward the front side as indicated by the dashed line. For this reason, in the first step, the electric wires 2 are made to go straight through the direction change section C, and at the direction change section C, the electric wires 2 are expanded, for example, into a semi-cylindrical shape to form excess lengths 2' for each electric wire 2, and these excess lengths 2' are made to bulge upward from the plane of the flat cable 1.

[0016] 3 is an explanatory diagram of a case where the direction of this flat cable 1 is changed by 90 degrees perpendicularly to the center point O by a direction change section C within the same plane. For the sake of convenience, in this explanation, it is assumed that the flat cable 1 is composed of three electric wires 2a, 2b, and 2c.

[0017] The electric wires 2a, 2b, and 2c at the direction change section C are formed as arc-shaped excess lengths 2a', 2b', and 2c' at the direction change section C. The length of the excess length 2a' of the outer electric wire 2a is the longest and decreases toward the inside. For example, if the diameter of the electric wires 2 is 2r and the distance between the electric wires 2 is r, to change direction at a right angle around point O, the center length of the excess length 2a' of the outer electric wire 2a is calculated to be 2π·8r / 4=4πr, the center length of the excess length 2b' of the central electric wire 2b is calculated to be 2π·5r / 4=5πr / 2, and the center length of the excess length 2c' of the inner electric wire 2c is calculated to be 2π·2r / 4=πr.

[0018] The lengths of the excess portions 2a', 2b', 2c' of the electric wires 2a, 2b, 2c at the direction change portion C can be determined by, for example, forming grooves in the surface of a semi-cylindrical mold and aligning the lengths along the grooves. That is, in the first step, as shown in Figure 4, the excess portions 2a', 2b', 2c' are bulged upward by the mold while the flat cable 1 remains straight.

[0019] In this first step, the angle at which the direction is changed is not 90 degrees as in the embodiment, but the direction can be changed at an angle greater or less than 90 degrees, and the length of the excess part 2' should be adjusted to correspond to that angle. In this case, the required length of the excess part 2' can be easily calculated geometrically as described above.

[0020] In the embodiment shown in FIG. 3, the direction of the electric wire 2 is changed at a sharp angle. However, even if the direction is changed in a large, gentle arc shape, this can be achieved by adjusting the lengths of the excess portions 2a', 2b', and 2c' according to the radius of curvature.

[0021] In the illustrated embodiment, these excess portions 2' are bulged out, for example, in a kamaboko shape, but if there is space available, the excess portions 2' can be formed by extending out to the side in the same plane as the flat cable 1.

[0022] In the first step, after forming the direction change section C using the excess length section 2', as shown in Figure 4, a laminate sheet 5 is adhered to both sides of the electric wires 2a, 2b, and 2c in the areas where the positions of the electric wires 2 have been determined other than the direction change section C, thereby fixing the adjacent electric wires 2 so that they do not shift.

[0023] In this way, the first step can be carried out even in a narrow space because it is possible to form the direction change portion C while maintaining the linearity of the flat cable 1. Furthermore, once the wiring of one harness, for example, with a maximum length of 5 to 6 m, is completed in this way, the wires 2 are cut from the bobbin 6, and the production of the next harness can be started.

[0024] The harness manufactured in the first process can be subsequently subjected to the second process. In this case, the harness can be stored as a semi-finished product and subsequently, or when needed, completed as a harness suitable for use in the second process. It is also possible to sell the semi-finished product.

[0025] In the above description of the first step, we have exemplified a case where some of the electric wires 2 of the flat cable 1 are simply changed in direction to the side as branch wires B. However, even when multiple branch wires B are branched off in any direction to the left or right from the trunk line M of the flat cable 1, or when branch wires B are further branched off from each other, by forming excess lengths 2' of the electric wires 2 at each direction change section C, the direction of the electric wires 2 can be changed in any angular direction even in a complex branched state. In addition, the length of the branch wires B can be set to any length by selecting the length of the electric wires 2 drawn out from the bobbin 6.

[0026] If the wires 2 are automatically pulled out from the bobbin 6 by a predetermined length and the excess wires 2' are formed, the wires 2 can be laid out almost automatically in the flat cable 1. In this case, it may become unnecessary to use a mold for forming the excess wires 2'.

[0027] As described above, in this embodiment of the present invention, the bulged excess length portion 2' formed in the first step is expanded in the second step into a flat state within the same plane as shown in Fig. 5, thereby enabling the wire 2 to be changed in direction to be stretched in the perpendicular direction. Then, by adhering the laminate sheet 5 to both sides of the flattened direction change portion C and fixing the excess length portions 2' at the direction change portion C together, a flat cable 1 that can be used as a harness is obtained.

[0028] In order to use it as a harness, it is usually necessary to strip the insulation from the end of each electric wire 2 and fix a connecting member such as a crimp connection terminal to the core wire, but fixing this connecting member can be performed during the first process or the second process. [Explanation of symbols]

[0029] 1 flat cable 2, 2a, 2b, 2c wire 2', 2a', 2b', 2c' extra length 3. Insulators 4-core wire 5. Laminated sheet 6 bobbins M Main Line B branch line C Direction change section r Radius of the wire, spacing between wires

Claims

1. a first step of forming an extra length portion for each of the electric wires to be changed in direction within the same plane in a linear intermediate portion of a flat cable in which a plurality of electric wires are arranged in parallel, the extra length portion being equal to the length required for the change in direction; a second step of spreading the excess length out flat and extending the wires to be changed in a predetermined direction.

2. 2. The method for manufacturing a flat cable harness according to claim 1, wherein the length of the excess portion is determined in accordance with the angle and radius of curvature of the direction change.

3. 3. The method for manufacturing a flat cable harness according to claim 1, wherein the length of the excess portion is determined using a mold.

4. 3. The method for manufacturing a harness using flat cables according to claim 1, wherein the excess length portion bulges out from a planar portion of the flat cable.

5. 3. The method for manufacturing a harness using flat cables according to claim 1, further comprising the step of fixing a connecting member to an end of the electric wire.

6. A semi-finished flat cable harness is characterized in that a flat cable has a plurality of parallel electric wires arranged in a straight intermediate portion thereof, and an excess portion of the length required for the electric wires to be changed in direction within the same plane is formed for each of the electric wires in the straight intermediate portion of the flat cable.

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