The present invention relates to a processing method and a processing apparatus for a round metallic wire provided as a conductor in a predetermined position of an electric device, and a method for manufacturing a power distribution component formed by integrating a resin member with the round metallic wire.
A round metallic wire formed of a solid wire in a cross-section circular shape is used as conductors of various electric devices. The round metallic wire is inexpensive as compared with a square wire in a cross-section square shape, and excellent in strength against tension and bending, and further has such an advantage as easier bending in a desired direction than the square shape when attached to the electric device. In focusing attention on such an advantage, for example, in Japanese Patent Application Laid-open No. 2014-128095, the round metallic wire is used as a power line for supplying electric power to a three-phase rotary electric machine such as a motor. On the other hand, connecting three power lines to terminals individually brings about a problem such that flexibility of the power line causes a displacement at the time of fastening to the terminal, and Japanese Patent Application Laid-open No. 2014-128095 proposes that to prevent such a displacement, a power-line fixing member including three insertion holes through which the three power lines are inserted is used. By using such a power-line fixing member, the displacement is securely suppressed, but due to the circular cross section of the power line, it rotates centered at an axial center in the insertion hole of the power-line fixing member. As a result, difficulty of positioning at the time of fastening with the terminal and a displacement due to vibrations have been unable to be completely eliminated. In consideration of this point, Japanese Patent Application Laid-open No. 2017-55486 discloses a technique in which a jig crushes a predetermined portion of a power line to a cross-section non-circular shape and a resin member which is a power-line fixing member is molded integrally with this portion. Since the resin member is integrated with the cross-section non-circular portion, relative rotation between the power line and the resin member is suppressed.
However, Japanese Patent Application Laid-open No. 2017-55486, the cross-section non-circular portion is formed on the power line by the jig before the resin member as the power-line fixing member is integrated therewith. The round metallic wire made of copper or the like has flexibility, and hence can be bent to some extent to be fitted to a shape of an attachment portion when assembled to the motor or the like as described above, but actually, a power line formed in a three-dimensional shape, whose bending angle, length, and the like are specified beforehand to be fitted to the attachment portion, is used. The power line in Japanese Patent Application Laid-open No. 2017-55486 is also similar, and the predetermined portion of the three-dimensionally shaped power line processed to given design specifications is crushed by the jig through additional processing, and the resin member is integrated therewith.
Subjecting such a round metallic wire processed to/with the given design specifications and accuracy to the processing of partial crushing with the jig affects the bending angle, a bend position, and the like of the round metallic wire formed in the three-dimensional shape, and even though an aim to stop the rotation by using the resin member can be attained, there is a possibility that dimensional accuracy and accuracy of form of the round metallic wire itself are inferior against the design specifications.
The present invention was made in consideration of the above and has an object to provide a method for processing a round metallic wire and a round metallic wire processing apparatus which make it possible to process a three-dimensionally shaped round metallic wire having a cross-section non-circular portion in a predetermined portion without performing additional processing, and having specified dimensional accuracy and accuracy of form, and a method for manufacturing a power distribution component.
To solve the above problems, a method for processing a round metallic wire of the present invention, the method for processing the round metallic wire formed of a cross-section circular solid wire, and subjected to bending in a predetermined three-dimensional shape and provided as a conductor in a predetermined position of an electric device, the method includes:
a correction step of linearly correcting a coiled material of the round metallic wire;
a cross-section non-circular portion forming step of forming a cross-section non-circular portion having a non-circular cross-sectional shape in a diameter direction in at least one position of the round metallic wire linearly corrected by the correction step; and a bending step of holding the cross-section non-circular portion in a wire holding portion of a bending machine and performing bending in the three-dimensional shape.
Preferably, in the cross-section non-circular portion forming step, the cross-section non-circular portion is processed in a shape including a flat surface which comes into surface contact with an abutting surface of the wire holding portion of the bending machine.
Preferably, at either timing after the correction step and before the cross-section non-circular portion forming step or timing after the cross-section non-circular portion forming step, the round metallic wire is cut in a predetermined length.
Further, a round metallic wire processing apparatus of the present invention for subjecting a cross-section circular solid wire provided as a conductor in a predetermined position of an electric device to bending in a predetermined three-dimensional shape, the apparatus includes:
a straightening machine which linearly corrects a coiled material of the round metallic wire;
a cross-section non-circular portion forming machine which forms a cross-section non-circular portion having a non-circular cross-sectional shape in a diameter direction in at least one position of the round metallic wire linearly corrected by the straightening machine;
a bending machine which holds the cross-section non-circular portion in a wire holding portion and performs bending in the three-dimensional shape; and a cutting machine which cuts the round metallic wire.
Preferably, the cross-section non-circular portion forming machine includes a pressing portion which forms a flat surface which makes the cross-section non-circular portion in surface contact with an abutting surface of the wire holding portion of the bending machine.
Further, a cutting machine control unit which at either timing after the correction and before the formation of the cross-section non-circular portion or timing after the formation of the cross-section non-circular portion and before the bending, controls the cutting machine to cut the round metallic wire in a predetermined length is included.
Further, a method for manufacturing a power distribution component of the present invention,
the method for manufacturing the power distribution component including a processed product of a round metallic wire formed of a cross-section circular solid wire and subjected to bending in a predetermined three-dimensional shape and a resin member attached integrally with the processed product, and provided in a predetermined position of an electric device,
On an outer periphery of the cross-section non-circular portion of the processed product of the round metallic wire processed by the method for processing the round metallic wire, the resin member is fixed.
According to the present invention, in an intermediate step in which the round metallic wire is processed in the predetermined three-dimensional shape, in at least one position, the cross-section non-circular portion having a non-circular cross-sectional shape is formed. At the time of bending, this cross-section non-circular portion is held by the wire holding portion of the bending machine, and the bending is performed in the predetermined three-dimensional shape. Holding the cross-section non-circular portion causes relative rotation centered at an axial center between the cross-section non-circular portion and the wire holding portion to be suppressed as compared with a case of the cross-section circular shape. In particular, processing this cross-section non-circular portion in a shape including the flat surface which comes into surface contact with the abutting surface of the wire holding portion of the bending machine causes the relative rotation between the cross-section non-circular portion and the wire holding portion to be further suppressed. As a result, bending accuracy in the three-dimensional shape is improved. Further, a displacement is eliminated in a holding position of the wire holding portion of the bending machine, which also reduces an error among processed products. Further, normally, after the bending, dimensional measurement is performed on the processed products by using an optical microscope or the like. At this time, the cross-section circular shape makes it difficult to focus on a tangent along a longitudinal direction, and makes positioning relative to a reference line of the optical microscope difficult, but having the cross-section non-circular portion, preferably having the flat surface makes a visible line clear, which makes it easy to focus on it and makes the positioning easy, resulting in improvement also in dimensional measurement accuracy.
Hence, according to the present invention, after obtaining the processed product of the three-dimensionally shaped round metallic wire having high dimensional accuracy and accuracy of form, the round metallic wire can be combined with the member such as a rotation stopper as it is while maintaining the high dimensional accuracy and the like without a need to perform additional processing for forming the cross-section non-circular portion. Further, the power distribution component integrated with the resin member by insert molding can also be manufactured easily by using the cross-section non-circular portion as it is without performing the additional processing.
An embodiment of the present invention will be hereinafter described using the drawings.
The wire processed product 100A is set in a metal mold, and a resin member 200 is integrated by insert molding (refer to
Next, a processing method and a processing apparatus for the round metallic wire 100 used as described above will be described.
The straightening machine 10 includes, for example, a plurality of straightening rollers 11 disposed to be opposed, as illustrated in
A cross-section non-circular portion forming machine 20 forms a predetermined portion of the round metallic wire 100 processed linearly by the straightening machine 10 in a non-circular shape in the cross-sectional shape in the diameter direction of the round metallic wire 100. A concrete structure of the cross-section non-circular portion forming machine 20 is not limited, but for example, is constituted of a pressing machine having pressing portions 21 which sandwiches the round metallic wire 100 on both sides along the diameter direction as illustrated in
In this embodiment, both the facing surfaces 21a, 21a of the pressing portions 21, 21 on both 180-degree opposed sides of the cross-section non-circular portion forming machine 20 are formed as the flat surfaces. Accordingly, when these pressing portions 21, 21 approach each other, one pair of the opposing flat surfaces 105a, 105c serving as the cross-section non-circular portion 105 are formed, and next, by turning the round metallic wire 100 by 90 degrees centered at an axial center and making the pressing portions 21, 21 approach each other again, the other pair of the opposing flat surfaces 105b, 105d are formed, and the cross-section non-circular portion 105 having a substantially rectangular cross section in the diameter direction is formed.
However, the cross-sectional shape of the cross-section non-circular portion 105 is applicable unless circular, and for example, the flat surface may be formed only on one surface, or the flat surfaces may be formed only on two opposing surfaces. They may be formed on three or five surfaces or more. However, the closer the cross-sectional shape is to a circle, the more likely relative rotation between the cross-section non-circular portion 105 and the wire holding portion 31 of the bending machine 230 and the relative rotation, when the resin member 200 illustrated in
As the bending machine 30, for example, the one provided with the wire holding portion (chuck) 31 at a tip of a three-dimensionally movable robot arm 32 as illustrated in
In
The cutting machine 40 cuts the round metallic wire 100 in a predetermined length in accordance with the design specifications. As long as the round metallic wire 100 can be cut, its structure is not limited at all. In this embodiment, a cutting machine control unit 50 which automatically operates the cutting machine 40 is included (refer to
The timing of cutting by using the cutting machine 40 can be optionally set depending on the kind of the three-dimensional shape to be imparted to the round metallic wire 100, the required dimensional accuracy, and the like. As illustrated in
As illustrated in
Next, one example of a method for processing the round metallic wire 100 will be described based on
Next, for example, the linearly corrected round metallic wire 100 is cut in a predetermined length by the cutting machine 40 (S2 in
Next, the cross-section non-circular portion 105 is held by the wire holding portion 31 of the bending machine 30, and a three-dimensional shape in accordance with the design specifications is imparted (S4 in
This completes the wire processed product 100A. Note that the timing of the cutting step is thus not limited to before the formation of the cross-section non-circular portion after the correction, but as illustrated in
According to this embodiment, with respect to the round metallic wire 100, the cross-section non-circular portion 105 is formed before the bending. Therefore, by holding the cross-section non-circular portion 105 in the wire holding portion 31, the bending can be performed, which allows the prevention of the movement in the rotation direction centered at the axial center at the time of bending, or the like, resulting in enabling an increase of bending accuracy. Further, making a holding position of the wire holding portion 31 stable reduces variations in processing accuracy among products. Further, the round metallic wire 100 is transferred between the machines by feed rollers (not illustrated), and after the formation of the cross-section non-circular portion 105, a slide with respect to the feed rollers is suppressed, which also enables suppression of a deterioration of the processing accuracy caused by variations in feed rate.
Further, when dimensions of the processed wire processed product 100A are measured using an optical microscope, a visible outline of the cross-section non-circular portion 105, in particular, a surface processed in the flat surface is easy to observe. That is, in a circular cross section, it is difficult to focus on a tangent of the circular cross section when it is observed by the optical microscope, which sometimes affects dimensional measurement accuracy, but according to this embodiment, it becomes easy to focus on the visible outline of the flat surface or the like, which increases the dimensional measurement accuracy.
Next, when to use the wire processed product 100A of this embodiment as, for example, a power distribution component, it is integrated with the resin member 200 which functions as a rotation stopper for an attachment portion, or the like, the resin member 200 is integrated with the cross-section non-circular portion 105 by the insert molding (S10) to obtain a power distribution component 300 (refer to
According to the above, the wire processed product 100A and the power distribution component 300 of the round metallic wire 100 obtained by the present invention are particularly suitable for uses requiring high dimensional accuracy, accuracy of form, and the like despite an inexpensive round wire as compared with a square wire.
Number | Date | Country | Kind |
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2019-193979 | Oct 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/036121 | 9/24/2020 | WO |