JP4253948B2 - Method for manufacturing U-shaped coated conductor wire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a U-shaped coated conductor wire, in which a conductor wire on which an insulating coating is formed is bent into a U-shape.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a coated conductor wire corresponding to each application is used in various electric appliances, and the coated conductor wire may be processed into a U shape for convenience of assembly. Thus, the coated conductor wire processed into a U shape is hereinafter referred to as a “U-shaped coated conductor wire”. The U-shaped coated conductor wire is manufactured, for example, by bending a rod-shaped coated conductor wire. FIG. 6 is a diagram illustrating an example of a manufacturing process of a conventional U-shaped coated conductor wire. In the conventional manufacturing process shown in FIG. 6, first, the predetermined positions on both sides of the rod-shaped coated conductor wire 1 are grasped by the clamps 3 and 4 (step 1), and then the bent portion 2 of the coated conductor wire 1 is removed. While pressing against the cored bar 6, each of the clamp tools 3, 4 is rotated around the bent portion 2 in a predetermined direction to wind the coated conductor line around the cored bar 6 (step 2), thereby forming the coated conductor line 1. A U-shaped coated conductor wire was manufactured by bending it into a U-shape.
[0003]
[Problems to be solved by the invention]
By the way, in the U-shaped coated conductor wire manufactured by the above-described conventional manufacturing process, when the radius of curvature of the bent portion is to be reduced, the insulating coating on the outer diameter side of the bent portion is greatly extended, Since the insulating coating is strongly compressed, there is a problem that the insulating coating in this portion is likely to be cracked. As described above, if a crack occurs in the insulating coating, the conductor wire under the insulating coating is exposed to cause insulation failure, which is not preferable.
[0004]
The present invention was created in view of the above points, and an object of the present invention is to provide a method for manufacturing a U-shaped coated conductor wire capable of preventing the occurrence of cracks in the insulating film at the bent portion. It is in.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, in the method of manufacturing a U-shaped coated conductor wire according to the present invention, a step of gripping both ends of the conductor wire on which the coating is formed with the first and second clamping tools, A step of heating by including at least the bent portion, and a step of bending the conductor wire by rotating at least one of the first and second clamps around the bent portion as a rotation center. In general, since the material used for the insulating coating formed on the conductor wire increases flexibility by heating, the resistance to the elongation and compression of the insulating coating at the bent portion can be improved by using this, Therefore, it is possible to prevent the insulating coating from cracking even when the radius of curvature of the bent portion is reduced.
The step of bending the conductor wire includes a step of bending the conductor wire with a large curvature radius and a step of bending the conductor wire with a small curvature radius, and the step of heating the conductor wire with a large radius of curvature. It is desirable to carry out between the step of bending and the step of bending with a small radius of curvature. In this way, by first bending the conductor wire with a large radius of curvature, heating can be performed after protruding the bent portion to some extent, so when considering a production line, a heating means such as a heater is arranged. There is an advantage that it becomes easy.
[0006]
In particular, it is desirable that the step of bending the conductor wire described above bends the conductor wire while pressing the conductor wire against a core member whose surface facing the conductor wire is formed in a predetermined curved shape. By using the core member as a guide when bending the conductor wire in this way, the curvature radius of the bent portion can be determined corresponding to the curvature radius of the curved surface-shaped portion formed on the core member. The radius of curvature can be formed with high accuracy.
[0007]
Further, when the conductor wire is bent using the core member as described above, the core member is preferably heated to a predetermined temperature. By heating the core member to a predetermined temperature, the temperature of the inner peripheral surface of the conductor wire in contact with the core member does not decrease even while the conductor wire is bent. It can hold | maintain and it can prevent more reliably that a crack generate | occur | produces in the insulating film of a bending part.
[0008]
[0009]
Moreover, in the process of bending the above-described conductor wire, it is desirable to reduce the bending speed as the curvature of the bent portion decreases. Usually, the smaller the radius of curvature of the bent part, the more easily the cracks occur because the insulating film is greatly stretched on the outer diameter side. However, the insulating film on the outer diameter side of the bent part is reduced by lowering the bending speed. In this case, since the elongation of the insulation coating caused by creep deformation can be used in addition to the elongation of the insulation coating that normally occurs, cracks can be prevented from occurring in the insulation coating at the bent portion even when the radius of curvature is small. .
[0010]
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the manufacturing method of the U-shaped coat conductor wire of one embodiment to which the present invention is applied is explained in detail, referring to drawings.
[0012]
FIG. 1 is a diagram illustrating a manufacturing process of a U-shaped coated conductor wire as a basis of an embodiment of the present invention . In FIG. 1, the same components as those used in the conventional manufacturing process shown in FIG. 6 described above are given the same reference numerals for description. A coated conductor wire 1 shown in FIG. 1 is a rod-shaped conductor member having a predetermined cross-sectional shape, and an insulating coating for electrical insulation is formed on the outside thereof. Further, the vicinity of the midpoint of the coated conductor wire 1 becomes a bent portion 2 when the coated conductor wire 1 is processed into a U shape. The clamp tools 3 and 4 are for grasping and fixing the both end portions of the coated conductor wire 1 respectively, and are rotatable around a predetermined position.
[0013]
The heater 5 is for heating the bent portion 2 included in the coated conductor wire 1 to a predetermined temperature. The temperature at which the bent portion 2 is heated by the heater 5 can be arbitrarily set within a temperature range in which the insulating film of the bent portion 2 does not cause quality deterioration due to heat. The cored bar 6 as a core member is a rod-shaped member having a predetermined diameter, and is used as a guide when the coated conductor wire 1 is bent. Accordingly, the radius of curvature of the bent portion 2 is determined corresponding to the diameter of the cored bar 6. Further, the cored bar 6 is not limited to the case where the cross-sectional shape is formed in a circular shape because only the facing surface with which the coated conductor wire 1 comes into contact has only to be formed in a curved shape having a predetermined diameter. Only the part may be formed to have a predetermined diameter, and the other part may be formed in an arbitrary shape.
[0014]
Next, a method for manufacturing a U-shaped coated conductor wire as the basis of the embodiment will be described in detail with reference to FIG. As shown in FIG. 1, first, the vicinity of both ends of the coated conductor wire 1 is grasped by the clamps 3 and 4 (step 1). Next, the predetermined range including the bent portion 2 is heated by the heater 5 until a predetermined temperature is reached (step 2). The temperature control of the bent portion 2 in step 2, that is, whether or not the predetermined temperature has been reached is determined based on the heating time or the surface temperature of the bent portion 2 is directly measured using a temperature sensor such as a thermocouple. The case where it carries out by doing is considered. Moreover, the heating range of the coated conductor wire 1 by the heater 5 should just include the bending part 2 at least, and you may make it heat the whole coated conductor wire 1. FIG. Thereafter, the coated conductor wire 1 is wound around the cored bar 6 by rotating the clamps 3 and 4 in a predetermined direction while pressing the bent part 2 against the cored bar 6 (step 3). In this embodiment, the coated conductor wire 1 is wound around the core metal 6 by rotating the clamp tool 3 counterclockwise with respect to the core metal 6 and the clamp tool 4 by approximately 90 degrees clockwise. Thereby, the rod-shaped coated conductor wire 1 is formed into a U shape, and a U-shaped coated conductor wire is manufactured.
[0015]
Thus, in the manufacturing method of the U-shaped coated conductor wire as the basis of the embodiment , when the coated conductor wire 1 is bent into a U shape at a predetermined position, the bent portion 2 is insulated by heating to a predetermined temperature. The flexibility of the coating is increased to improve the resistance to elongation and compression, and when the coated conductor wire 1 is bent with a small radius of curvature, it is possible to prevent the insulating coating of the bent portion 2 from cracking.
[0016]
In addition, this invention is not limited to the manufacturing method of the U-shaped coat conductor wire as the foundation of the said embodiment , A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the manufacturing method of the U-shaped coated conductor wire as the basis of the above-described embodiment, the bent portion 2 included in the coated conductor wire 1 is heated to a predetermined temperature by the heater 5. The bent portion 2 may be heated by heating 6 to a predetermined temperature. By heating the cored bar 6, the coated conductor which contacts the cored bar 6 while the coated conductor wire 1 is bent in the process 3 shown in FIG. Since the temperature of the inner peripheral surface of the wire 1 is not lowered, the insulating coating flexibility at the contact portion can be maintained, and the insulating coating of the bent portion 2 can be more reliably prevented from cracking. can do.
[0017]
Moreover, in the manufacturing method of the U-shaped coated conductor wire as the basis of the above-described embodiment, the cored bar 6 is used as a guide when the coated conductor wire 1 is bent. However, the accuracy of the radius of curvature of the bent portion 2 is reduced so much. In a case where it is not required, the coated conductor wire 1 may be bent without using the cored bar 6 in the step 3 shown in FIG. In this case, the cored bar 6 is not required, and the replacement work of the cored bar 6 is not required. Therefore, the process can be simplified, and the cost can be reduced accordingly.
[0018]
Moreover, in the manufacturing method of the U-shaped coated conductor wire as the basis of the above-described embodiment, in the step 3 shown in FIG. 1, each of the clamp tools 3, 4 is rotated in a predetermined direction to form the coated conductor wire 1. Although it was bent, only one of the clamps 3 or 4 may be rotated in a predetermined direction. For example, if only one clamp tool 3 is rotated, the other clamp tool 4 is fixed, and if the clamp tool 3 is rotated about 180 ° , the U-shape as the basis of the above-described embodiment. A U-shaped coated conductor wire can be produced in the same manner as the method for producing a coated conductor wire.
[0019]
Moreover, in the manufacturing method of the U-shaped coated conductor wire as the basis of the above-described embodiment, the bending speed at the time of bending the bent portion 2 is not particularly limited, but this bending speed is determined by the curvature of the bent portion 2. You may make it slow, so that a radius becomes small. Here, the “bending speed” represents the amount of change per unit time when each of the clamp tools 3 and 4 rotates in a predetermined direction in the step 3 shown in FIG. FIG. 2 is a diagram illustrating an example of the relationship between the radius of curvature of the bent portion 2 and the bending speed. 3 and 4 show examples of U-shaped coated conductor wires having different curvature radii. FIG. 3 shows a U-shaped coated conductor wire having a bent portion 2 with a small curvature radius A in FIG. 1 shows U-shaped coated conductor wires each having a bent portion 2 having a radius of curvature B larger than A. As shown in FIG. 4, when forming the bending part 2 in the curvature radius B, the bending speed is set to V2. Further, as shown in FIG. 3, when the bent portion 2 is formed into A smaller than the curvature radius B, the bending speed is set to V1 which is slower than V2.
[0020]
In general, the smaller the radius of curvature of the bent portion 2 is, the more easily the crack is caused by the insulating film on the outer diameter side being greatly stretched. However, as the radius of curvature of the bent portion becomes smaller, as shown in FIG. By slowing down the speed, the insulation coating on the outer diameter side of the bent portion can utilize the elongation of the insulation coating caused by creep deformation in addition to the elongation of the insulation coating that normally occurs, so when the radius of curvature is small In addition, it is possible to prevent cracks from occurring in the insulating coating at the bent portion.
[0021]
Further, in the manufacturing method of the U-shaped coated conductor wire as the basis of the above-described embodiment, when the U-shaped coated conductor wire having a predetermined radius of curvature is manufactured, the bent portion 2 is predetermined by a single bending operation. The bending operation is divided into two or more times, and the bending radius of the bent portion 2 is gradually reduced to finally obtain a predetermined radius of curvature. You may do it.
[0022]
FIG. 5 is a diagram illustrating an embodiment of the present invention . First, grasp both sides of the bent portion 2 included in the coated conductor wire 1 with the clamps 3 and 4 (step 1, not shown), and from a predetermined curvature radius to finally obtain the bent portion 2. Is bent to a larger radius of curvature (step 2). As a specific method of obtaining a radius of curvature larger than a predetermined radius of curvature in the step 2, a method using a metal core having a diameter corresponding to the radius of curvature to be obtained, or the bending portion 2 by the clamp tools 3 and 4 are used. A method of devising how to apply a force when bending, or a jig having a concave portion whose cross section is an arc shape is disposed on the outer diameter side of the bent portion 2, and the bent portion 2 is pressed against the jig. Although a method etc. can be considered, any method may be used. Next, the bent portion 2 is heated by the heater 5 until it reaches a predetermined temperature (step 3), and then the bent portion 2 is brought into contact with the cored bar 6 and the coated conductor wire 1 is wound along the cored bar 6 (step 4). ). As described above, the bending portion 2 of the coated conductor wire 1 is heated only when the bending radius of the bending portion 2 is reduced stepwise and the bending step with a small curvature radius is performed. Therefore, since it can heat after making the bending part 2 protrude to some extent, there exists an advantage which becomes easy to arrange | position the heater 5 on a manufacturing line.
[0023]
In the above-described embodiment of the present invention, the case where the bending operation is divided into two or more times and the radius of curvature of the bent portion 2 is reduced stepwise has been described. When the radius of curvature to be applied is reduced stepwise, the relationship between the radius of curvature and the bending speed described with reference to FIG. 2 may be applied to decrease the bending speed as the radius of curvature at each stage decreases.
[0024]
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a method for manufacturing a U-shaped coated conductor wire as a basis of an embodiment of the present invention .
FIG. 2 is a diagram showing an example of a relationship between a radius of curvature to be given to a bent portion and a bending speed.
FIG. 3 is a diagram showing an example of a U-shaped coated conductor wire having a different radius of curvature.
FIG. 4 is a diagram showing an example of a U-shaped coated conductor wire having a different radius of curvature.
FIG. 5 is a diagram illustrating a manufacturing process of a U-shaped coated conductor wire as an embodiment of the present invention .
FIG. 6 is a diagram showing an example of a manufacturing process of a conventional U-shaped coated conductor wire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Coated conductor wire 2 Bending part 3, 4 Clamping tool 5 Heater 6 Core metal

Claims (4)

Gripping both ends of the conductor wire on which the film is formed with the first and second clamps,
Heating the conductor wire including at least a bent portion of the conductor wire ;
A step of bending the conductor wire by rotating at least one of the first and second clamps with the bent portion as a rotation center;
Equipped with a,
The step of bending the conductor wire includes
Bending the conductor wire with a large radius of curvature;
Bending the conductor wire with a small radius of curvature,
A method for producing a U-shaped coated conductor wire , wherein the step of heating the conductor wire is performed between the step of bending with the large radius of curvature and the step of bending with the small radius of curvature . In claim 1,
The method of manufacturing a U-shaped coated conductor wire, wherein the step of bending the conductor wire comprises bending the conductor wire while pressing the conductor wire against a core member having a surface facing the conductor wire formed in a predetermined curved surface shape. In claim 2,
A method of manufacturing a U-shaped coated conductor wire, wherein the core member is heated. 4. The method of manufacturing a U-shaped coated conductor wire according to claim 1, wherein in the step of bending the conductor wire, a bending speed is decreased as the radius of curvature of the bent portion decreases. 5.

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