JP2001351449A - Manufacturing method of coated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply manufacture a coated wire of a given length. SOLUTION: A conductor 11 cut in the given length is put through a heat contraction tube 12, and is directly coated with the heat contraction tube 12 by heating and shrinking the contraction tube 12. By setting the length of the conductor 11 longer than that of the heat contraction tube 12, a coated wire 10 having exposed conductor parts at both ends is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a covered electric wire suitable for making, for example, a wire harness for an automobile.

[0002]

2. Description of the Related Art An electric wire mainly used in a wire harness for an automobile has an outer periphery of a conductor coated with an insulating coating by extrusion molding.

FIG. 4A shows a production line for such a covered electric wire. The conductor 2 sent from the conductor drum 1 is
It is introduced into an extruder 3, where an insulating coating is provided on the outer periphery of the conductor 2. The coated electric wire 5 coated by the extruder 3 is wound around the electric wire drum 6 after diving through the cooling water tank 4.

A covered electric wire 5 wound around an electric wire drum 6
Is then transferred to a wire harness manufacturing process, where it is cut into various lengths as needed and peeled as shown in FIG.

[0005]

By the way, conventionally,
In order to obtain wires of various lengths for assembling wire harnesses, a continuous long insulated wire is produced at a wire manufacturing plant, and then the coated wires are cut to a predetermined length at a wire harness manufacturing plant. To cut off. Therefore, the intermediate stock had to be held in the form of the electric wire drum 6 as the electric wires were moved between the factories. Further, since the coated electric wire 5 is supplied as a long object, the loss tends to increase, and it is difficult to produce a small lot. In addition, since a specialized electric wire production line equipped with the extruder 3 is required, there is a problem that the production equipment becomes large.

According to the present invention, in consideration of the above circumstances, it is possible to reduce the intermediate stock of electric wire drums and the like, and to achieve a reasonable production with a small loss even in a small lot.
Moreover, an object of the present invention is to provide a method of manufacturing a covered electric wire capable of manufacturing a covered electric wire of a predetermined length suitable for assembling a wire harness with simple equipment.

[0007]

According to the first aspect of the present invention, a conductor cut to a predetermined length is inserted into a heat-shrinkable tube and heated to shrink the heat-shrinkable tube.
The conductor is directly covered with the heat-shrinkable tube. The conductor in this case may be a single conductor or a bundle of strands.

According to the present invention, since the conductor which has been cut into a predetermined length in advance is directly covered with the heat-shrinkable tube, there is no need to hold an intermediate stock like a wire drum. Also, if you cut the conductor and heat shrink tubing to the length required to assemble the wire harness, you can prepare wires of the required length for the wire harness without any loss, Reasonable production is possible. Further, since only a simple means for heating the heat-shrinkable tube is required as equipment, a dedicated electric wire production line including an extruder is not required, and equipment cost can be reduced.

According to a second aspect of the present invention, a large number of conductors cut to a predetermined length are inserted into a heat-shrinkable tube at a distance from each other, and heated to shrink the heat-shrinkable tube. The conductor is directly covered with a heat-shrinkable tube, and the distance between the conductors is kept constant.

According to the present invention, it is possible to easily manufacture a covered electric wire in which a plurality of conductors are arranged at intervals, such as a flat electric wire (flat cable). In this case, similarly to the first aspect of the present invention, since the conductor cut to a predetermined length in advance is directly covered with the heat-shrinkable tube, there is no need to hold an intermediate stock in the form of an electric wire drum. . In addition, if the conductor and heat shrink tube are cut to the required length, a coated wire of the required length can be easily prepared without any loss, and reasonable production is possible. . Further, since only a simple means for heating the heat-shrinkable tube is required as equipment, a dedicated electric wire production line including an extruder is not required, and equipment cost can be reduced.

According to a third aspect of the present invention, there is provided the method for manufacturing a covered electric wire according to the first or second aspect, wherein the length of the conductor is set to be longer than the heat-shrinkable tube, and the conductor is inserted into the heat-shrinkable tube. In this state, both ends of the conductor are exposed from both ends of the heat-shrinkable tube, and in this state, the heat-shrinkable tube is heated to shrink the heat-shrinkable tube, thereby obtaining an electric wire having conductor exposed portions at both ends. And

According to the present invention, a covered electric wire having exposed conductors at both ends can be obtained, so that the step of removing the covering can be omitted.

According to a fourth aspect of the present invention, there is provided the method for manufacturing a covered electric wire according to any one of the first to third aspects, wherein at least one of the conductors is connected to a heat roller when the conductor is inserted into a heat-shrinkable tube. The heat-shrinkable tube is brought into close contact with the conductor by heating and pressing when passing through the pair of rollers.

As a method of heating the heat-shrinkable tube,
Although a simple method such as blowing hot air can be adopted, in the present invention, the heat-shrinkable tube is brought into close contact with the conductor by heating and pressing by a roller through a heat-shrinkable tube between the pair of rollers. As a result, the degree of adhesion between the conductor and the heat-shrinkable tube can be increased. The present invention is suitable for making the inner surfaces of the heat-shrinkable tubes tightly pressed together without any gaps, and for reliably insulating the conductors, especially when flat electric wires are produced.

According to a fifth aspect of the present invention, there is provided the method of manufacturing a covered electric wire according to the fourth aspect, wherein the roller pair is provided in multiple stages, and the conductor is passed through a heat-shrinkable tube, and the rollers are sequentially provided in multiple stages. It is characterized in that the heat-shrinkable tube is gradually increased in the degree of adhesion to the conductor and the cross section is made smaller by passing between the pair.

According to the present invention, heating and heating are performed by a multi-stage roller pair.
Since the pressure welding is performed, the degree of adhesion of the heat-shrinkable tube can be further increased. Therefore, it is particularly suitable for making a flat electric wire, and the inner surfaces of the heat-shrinkable tubes can be press-bonded without any gap, so that the conductors can be reliably insulated.

According to a sixth aspect of the present invention, there is provided the method for producing a covered electric wire according to any one of the first to fifth aspects, wherein the inner surface of the heat-shrinkable tube before the heat-shrinkage is coated with a hot melt. Features.

In the present invention, since the inner surface of the heat-shrinkable tube is coated with the hot melt in advance, the hot-melt melts when the heat-shrinkable tube is shrunk by heating, and fills the gap between the heat-shrinkable tube and the conductor. When the conductor is made of a bundle of wires, the hot melt penetrates into the gaps between the wires, so that waterproofness can be secured.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The first feature of the present invention is to use a heat-shrinkable tube as an insulating coating material. Each embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a process explanatory view of the manufacturing method of the first embodiment.

In the manufacturing method of the first embodiment, (a) First, the conductor 11 and the heat-shrinkable tube 12 are cut to a required length. The length of the conductor 11 is set longer than the heat-shrinkable tube 12.

(B) Next, the conductor 11 cut to a predetermined length
Is inserted into the heat-shrinkable tube 12 so that both ends of the conductor 11 are exposed from both ends of the heat-shrinkable tube 12.

(C) Next, this is heated. The simplest method of heating is to blow hot air.

(D) Then, heat and heat shrink the tube 1
By shrinking 2, the outer periphery of the conductor 11 is directly covered by the heat-shrinkable tube 12, and a covered wire 10 having a predetermined length having conductor exposed portions at both ends is obtained.

After that, the coated electric wire 10 having the predetermined length is directly flowed to a wire harness processing step and processed to form a wire harness.

In the case of manufacturing in this way, it is only necessary to prepare the conductor 11 and the heat-shrinkable tube 12, so that it is not necessary to keep the intermediate stock like a wire drum as in the conventional case. In addition, it is possible to prepare the required length of the covered electric wire 10 having the conductor exposed portions at both ends for the wire harness in a state where no loss is generated. Production is possible.

The equipment includes a heat shrink tube 12
Since only a simple means for heating the wire is required, a dedicated electric wire production line including an extruder is not required, and equipment costs can be reduced.

Next, a method of manufacturing a multi-core covered electric wire is shown in FIG.
This will be described with reference to FIG.

In this case, (a) First, the plurality of conductors 21 and one heat-shrinkable tube 22 are cut to a required length. The length of each conductor 21 is set longer than the heat-shrinkable tube 22.

(B) Next, a plurality of conductors 21 cut to a predetermined length are inserted into the heat-shrinkable tube 22 at a certain interval from each other, and both ends of the conductor 21 are connected to both ends of the heat-shrinkable tube 22. More exposed.

(C) Next, this is heated. The simplest method of heating is to blow hot air.

(D) Then, heat and heat shrink the tube 2
2 is contracted to directly cover the outer periphery of the conductor 21 with the heat-shrinkable tube 22 and to keep the distance between the conductors 21 constant. Get 20.

As described above, the multi-core covered electric wire 20 suitable for modularization can be easily manufactured, and the same effect as described above can be produced even when a multi-core electric wire is manufactured. .

As a heating method, a method using a pair of heat rollers can be adopted in addition to blowing hot air.

An example will be described with reference to FIG. Here, the case where the multi-core covered electric wire 20 of FIG. 2 is made is taken as an example.

The equipment to be prepared is a two-stage heat roller pair 31, 32 in which heat rollers 31A, 31B, 32A, 32B with grooves 35, 36 are vertically combined. The heat roller pairs 31 and 32 at the front and rear stages have different compression ratios.

At the stage when the conductor 21 is inserted into the heat-shrinkable tube 22, the heat-shrinkable tube is sequentially passed between the heat-roller pairs 31 and 32 and heated and pressed when passing through the heat-roller pairs 31 and 32. 22 is brought into close contact with the conductor 21. The positions of the grooves 35 and 36 correspond to the positions of the conductor 21.

By doing so, the degree of adhesion of the heat shrinkable tube 22 to the conductor 21 is sequentially increased, and
The cross section can be reduced. As a result, the inner surfaces of the heat-shrinkable tubes 22 are pressed together without any gap, and
Insulation between them can be ensured. In addition, the conductor 21 can be prevented from moving after the heat-shrinkable tube 22 is cooled and shrunk, and the external shape can be satisfactorily adjusted.

The heat roller pair 31, 32 can also be used to make the single-core covered electric wire 10 shown in FIG. In that case, a pair of heat rolls 31 having different compression ratios,
As the wire passes through the gap 32, the coated electric wire 10 can be processed into a desired diameter.

If the inner surfaces of the heat-shrinkable tubes 12 and 22 are coated with a hot melt as needed, the hot-melt is melted when the heat-shrinkable tubes 12 and 22 are shrunk by heating. 22 and conductor 1
The gap between the conductors 11 and 21 can be filled, and the conductors 11 and 21 can be prevented without play. Also, waterproof performance can be secured. In particular, when the conductors 11 and 21 are made of strands, the hot melt penetrates into the gaps between the strands, so that the waterproof performance between the strands can also be secured.

[0041]

As described above, according to the first aspect of the present invention, it is not necessary to keep an intermediate stock of wire drums and the like, and a short wire of a required length for a wire harness can be easily prepared. Therefore, even in a small lot, rational production with little loss is possible. In addition, equipment can be simplified, so that equipment costs can be reduced.

According to the second aspect of the present invention, it is possible to easily manufacture a multi-core covered electric wire while exhibiting the same effects as the first aspect of the present invention.

According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, the step of removing the coating can be omitted, so that a more rational production is possible.

According to the fourth aspect of the present invention, in addition to the effects of any one of the first to third aspects, an effect is provided that the degree of adhesion between the conductor and the heat-shrinkable tube can be increased.

According to the fifth aspect of the present invention, the degree of adhesion between the conductor and the heat-shrinkable tube can be further increased,
In particular, when producing a multi-core covered electric wire, the insulation performance between conductors can be improved.

According to the invention of claim 6, according to claim 1,
In addition to the effects of any one of the above inventions, it is possible to ensure waterproofness by melting the hot melt.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of the present invention, and is a view showing each step (a) to (d) of manufacturing.

FIG. 2 is an explanatory view of a second embodiment of the present invention, and is a view showing each step (a) to (d) of manufacturing.

FIG. 3 is a diagram illustrating an example of a heating method according to a second embodiment of the present invention.

4A and 4B are explanatory diagrams of a conventional method of manufacturing a covered electric wire, wherein FIG. 4A is a configuration diagram of a wire manufacturing line, and FIG. 4B is a process explanatory diagram until a wire is cut and a wire for a wire harness is prepared. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Insulated electric wire 11 Conductor 12 Heat-shrinkable tube 20 Insulated electric wire 21 Conductor 22 Heat-shrinkable tube 31, 32 Roller pair 31A, 31B, 32A, 32B Heat roller

Claims (6)

[Claims] 1. A conductor cut to a predetermined length is inserted into a heat-shrinkable tube, and heated to shrink the heat-shrinkable tube, thereby directly covering the conductor with the heat-shrinkable tube. Manufacturing method of coated electric wire. 2. A plurality of conductors cut to a predetermined length are inserted into a heat-shrinkable tube at a distance from each other, and heated to shrink the heat-shrinkable tube. A method for manufacturing a covered electric wire, wherein a conductor is directly covered and a distance between conductors is kept constant. 3. The method for producing a covered electric wire according to claim 1, wherein the length of the conductor is set to be longer than a heat-shrinkable tube, and the conductor is inserted through the heat-shrinkable tube. The insulated wire is characterized in that both ends of the conductor are exposed from both ends of the heat-shrinkable tube and heated in that state to shrink the heat-shrinkable tube, thereby obtaining an electric wire having exposed portions at both ends. Production method. 4. The method of manufacturing a covered electric wire according to claim 1, wherein the conductor is inserted into a heat-shrinkable tube, and at least one of the heat-shrinkable tubes is a heat roller. Through
A method for producing a covered electric wire, wherein a heat-shrinkable tube is brought into close contact with a conductor by heating and pressing when passing through the pair of rollers. 5. The method for manufacturing a covered electric wire according to claim 4, wherein the roller pairs are provided in multiple stages, and the conductors are passed through a heat-shrinkable tube and sequentially passed between the roller pairs provided in multiple stages. A method for manufacturing a covered electric wire, wherein the degree of adhesion of the heat-shrinkable tube to the conductor is gradually increased and the cross section is reduced. 6. The method for producing a covered electric wire according to claim 1, wherein a hot melt is coated on an inner surface of the heat-shrinkable tube before the heat-shrinkage. Manufacturing method.