JPH0562543A - Method for forming flat wire harness - Google Patents

Abstract

PURPOSE:To manufacture a wire harness having a branch circuit excellent in the versatility easily and at a low cost. CONSTITUTION:A flat wire harness is formed by using an FPC 123 in a wiring region having a branch circuit and using FFCs 121, 122 in the wiring region without any branch circuit. The branching works for wirings are done easily by the use of branch wiring layers 111b, 111c of the FPC 123, and restricted use of costly FPC 123 should reduce the costs, and further a combination of the FFCs 121, 122 and FPC 123 allows accomplishing a variety of circuits to present excellent versatility.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a flat wire harness used for automobile wiring or the like.

[0002]

2. Description of the Related Art In recent years, with the multi-functionalization of automobiles, wire harnesses are required to have more circuits and be more complicated. This target includes so-called flexible flat circuits (hereinafter referred to as "FFC") and flexible printed circuits, which are described below.
A flexible wiring board called a circuit (hereinafter referred to as "FPC") is used, and there is an increasing movement to reduce weight and save space.

That is, the FFC is a flexible wiring board having no branch circuit, and has a structure in which a plurality of wiring layers, each extending linearly and arranged in parallel, are covered with a film. On the other hand, the FPC is a flexible wiring board having a branch circuit and is covered with a film in a state in which a plurality of wiring layers forming a trunk line and a branch wiring layer connected to the wiring layers are integrally formed. Have a structured structure.

[0004]

However, when the wire harness is composed of only FFC or FPC, the following problems occur.

In other words, in the case of the FFC only,
Wiring boards for branch circuits are separately prepared according to a large number of branch circuits existing in the wire harness, and the wiring layers of these wiring boards are ultrasonically welded, spot-welded, and caulked to the predetermined wiring layers of the FFC to be the main line. It is necessary to connect the terminals by crimping the terminals to form a branch circuit. As described above, since the work of connecting the wiring board for the branch circuit is separately required, there is a problem that the number of steps increases and the formation of the wire harness becomes complicated.

On the other hand, when the wire harness is constructed only by the FPC, the wiring connection work for forming the branch circuit is not required unlike in the case of the FFC, but the FPC is created according to each circuit pattern. , FPC that can be used only for a wire harness with a specific circuit configuration and has poor versatility, and is more expensive than FFC
There is a problem in that the cost is increased because the circuit is configured by only the above.

The present invention solves the above-mentioned problems of the prior art and provides a method for forming a flat wire harness having a branch circuit, which is easy to form, has excellent versatility, and can reduce the cost. To aim.

[0008]

SUMMARY OF THE INVENTION The present invention is a method for forming a flat wire harness comprising a wiring region having a branch circuit and a wiring region having no branch circuit. A first flexible wiring board in which a plurality of wiring layers arranged are covered with a film is prepared, and a second flexible wiring board in which a plurality of wiring layers having a branch wiring layer is covered with a film is prepared. A wiring region having the branch circuit is formed by a second flexible wiring board, and the first flexible wiring board is provided.
The flexible wiring board is used to form a wiring region having no branch circuit.

[0009]

According to the method of forming a flat wire harness of the present invention, the wiring region having the branch circuit is formed by the second flexible wiring board having the branch wiring layer, and the wiring region having no branch circuit is arranged in parallel. Since it is formed by the first flexible wiring board having a plurality of wiring layers arranged in, the branching work of the wiring can be easily performed using the branching wiring layer of the second flexible wiring board. In addition, since the second flexible wiring board such as an expensive FPC is only partially used, the cost can be reduced, and various types of circuits can be realized by combining the first and second flexible wiring boards. Excellent versatility.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. In the following description of the embodiment, a case of forming a flat wire harness for an automobile corresponding to the wiring diagram of FIG. 1 will be described.

In this wiring diagram, as shown in FIG.
To the fourth connectors 1 to 4 are electrically connected, and the plurality of wires 1 drawn out from the first connector 1 are connected.
Nine wires 10 out of 0 are connected to the second connector 2, and four wires 10 are connected to the third connector 3. Further, among the wirings 10 between the first and second connectors 1 and 2, three wirings 10 are connected with branch wirings 11, and the branch wirings 10 are connected to the fourth connector 4.

In such a wiring diagram, the wiring portion can be considered as a wiring region 23 having a branch circuit and wiring regions 21 and 22 having no branch circuit. Of these, the wiring region 21 connected to the second connector 2 has a linear circuit configuration, while the third connector 3
The wiring region 22 connected to is formed in a circuit so as to bend 90 degrees in the middle.

In this embodiment, in forming the flat wire harness, the wiring regions 21 and 22 having no branch circuit are made of FFC, and the wiring region 23 having a branch circuit is made of FPC.

That is, as shown in FIG. 2 and FIG.
The FFCs 121 and 122 used in the areas corresponding to the wiring areas 21 and 22 having no branch circuit are the wiring areas 21 and
The wiring layers 110 are provided in the same number as the wirings 10 respectively arranged in the line 22, and each wiring layer 110 is covered with a film material in a state where the wiring layers 110 are linearly arranged in parallel with each other. ing.

Further, as shown in FIG. 4, the FPC 123 used in the wiring region 23 has wiring layers 110, 111a, 11 arranged corresponding to the circuit pattern of the wiring region 23.
1b and 111c are formed by forming a strip-shaped flexible wiring board covered with a film material and partially cutting a non-wiring region on the outer periphery of the wiring board as shown in FIG. More specifically, in the three wiring layers 110 out of the plurality of wiring layers 110, the branch wiring layers 111a, 111b, and 111c branched from the wiring layers 110 are wired so as to extend in parallel to the respective wiring layers 110. Layer 110
It is formed integrally with. Then, the branch wiring layer 111
Of the branch wiring layers 111a and 111c arranged on both sides of the
The non-wiring region is cut out along the outer periphery of the, and the cut 200 is formed along the periphery of the branch wiring layer 111b arranged in the center.

One end of the FFC 121 (FIG. 2) on one side is connected to the center of the first connector 1 as shown in FIG. 7, and the other end is connected to the left half of the second connector 2. Connected. Also, the FFC 122 on the other side (FIG. 3)
Is bent 90 degrees in the middle as shown in FIG.
As shown in, one end is connected to the left end portion of the first connector 1 and the other end is connected to the third connector 3.

Further, as shown in FIG. 4 and FIG.
The branch wiring layer 111a of 123 is bent 90 degrees together with the non-wiring region around it. Furthermore, the branch wiring layer 11
1b is folded back together with the non-wiring region around it by 180 degrees, then bent by 90 degrees, and arranged in parallel with branch wiring layer 111a. In this case, the branch wiring layer 111b is 18
Although it is made to fold back at 0 degree, the end position of the branch wiring layer 111b is aligned with the end position of the branch wiring layer 111a by appropriately changing the folding position. Further, similarly, the branch wiring layer 111c is folded 180 degrees and then bent 90 degrees to form the branch wiring layer 111c.
It is arranged parallel to a and 111b.

As shown in FIG. 7, one end of the FPC 123 in which the branch wiring layer 111 is bent is connected to the right end portion of the first connector 1 and the other end is the right half of the second connector 2. Connected to the department. Further, each end of each branch wiring layer 111a, 111b, 111c is connected to the fourth connector 4.

As a result, a flat wire harness corresponding to the wiring diagram of FIG. 1 is formed.

According to this flat wire harness forming method, since the wiring region 23 having the branch circuit is formed by the FPC 123 integrally formed with the branch wiring layers 111a, 111b, 111c, the branch wiring layer 11 is formed.
The wiring work can be easily performed by using 1a, 111b, and 111c, and there is no need to separately connect a flexible wiring board for branch wiring as in the case of the conventional FFC, and a wire harness having a branch circuit. Can be easily formed.

Further, since the expensive FPC 123 is used only in the wiring region 23 having the branch circuit and the inexpensive FFCs 121 and 122 are used in the wiring regions 21 and 22 having no branch circuit, the FPC as in the conventional case is used. The cost can be reduced as compared with the case where the wire harness is formed only. Further, by combining FPC and FFC, various kinds of circuits can be realized and the versatility is excellent.

[0022]

As described above, according to the method for forming a flat wire harness of the present invention, the wiring region having the branch circuit is constituted by the second flexible wiring board having the branch wiring layer, and the branch circuit is formed. Since the wiring region that does not have is formed by the first flexible wiring board, the branching work of the wiring can be easily performed by using the branch wiring layer of the second flexible wiring board, and the expensive flexible printed circuit board (FPC) or the like can be used. Since the second flexible wiring board is only partially used, the cost can be reduced, and various kinds of circuits can be realized by combining the first and second flexible wiring boards, and the versatility is excellent.

[Brief description of drawings]

FIG. 1 is a wiring diagram of a flat wire harness.

FIG. 2 is a plan view showing an FFC used in an embodiment of the present invention.

FIG. 3 is a plan view showing another FFC used in one embodiment of the present invention.

FIG. 4 is a plan view showing an FPC used in an embodiment of the present invention.

FIG. 5 is a diagram for explaining a method for forming a flat wire harness that is an embodiment of the present invention.

FIG. 6 is a diagram for explaining a method for forming a flat wire harness that is an embodiment of the present invention.

FIG. 7 is a perspective view showing a flat wire harness formed according to an embodiment of the present invention.

[Explanation of symbols]

21, 22 Wiring area having a linear circuit 23 Wiring area having a branch circuit 110 Wiring layers 111a to 111c Branch wiring layers 121, 122 FFC (first flexible wiring board) 123 FPC (second flexible wiring board)

Claims (1)

[Claims] 1. A method for forming a flat wire harness comprising a wiring region having a branch circuit and a wiring region having no branch circuit, wherein a plurality of wiring layers arranged in parallel are covered with a film. Of the flexible wiring board, a second flexible wiring board in which a plurality of wiring layers having branch wiring layers are covered with a film is prepared, and a wiring area having the branch circuit is formed by the second flexible wiring board. A method for forming a flat wire harness, characterized in that a wiring area having no branch circuit is formed by the first flexible wiring board while being formed.