JP7342751B2 - Method of manufacturing conductive wire - Google Patents

Description

The present invention relates to a method for manufacturing a conductive wire whose end coating layer is peeled off.

BACKGROUND ART Conventionally, a motor connection member that connects a motor winding and a terminal block is known (see, for example, Patent Document 1). In the motor connection member, a conductor wire having electrical conductivity is coated with an insulating member (hereinafter also referred to as an "insulating coating") made of resin.

The insulating coating is peeled off from the ends of the motor connection member that connect to the windings and the ends that connect to the terminal block. As a method of peeling off an insulating coating, a method of mechanically peeling it off using a cutting tool is known (see, for example, Patent Document 2).

Patent No. 6075174 Japanese Patent Application Publication No. 2007-151285

In the method of peeling off using a cutting tool, in order to prevent the insulation coating from remaining after removal, when the insulation coating is scraped off, a part of the conductor wire is also scraped off at the same time. Therefore, variations in the external dimensions of the conductor wire from which the insulating coating has been peeled off using the method of peeling using a cutting tool depend on the processing accuracy in the peeling using the cutting tool.

For example, the accuracy of the external dimensions required for the conductor wire from which the insulation coating has been peeled may be higher than the processing accuracy in peeling using a cutting tool. In this case, there was a problem in that the external dimensions of the conductor wire from which the insulating coating was peeled varied widely.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a conductive wire that easily suppresses variations in external dimensions of a conductor wire from which an insulating coating has been peeled off.

In order to achieve the above object, the present invention provides the following means.
The method for manufacturing a conductive wire of the present invention provides a conductive wire having a columnar conductor wire and an insulating coating formed from an insulating material covering the circumferential surface of the conductor wire, the conductive wire having a predetermined length. a preparation step of preparing a conductive wire, and a first slit for forming a first notch portion extending in the circumferential direction, which is a cut from which the insulation coating is removed, at a position that separates the end portion of the conductive wire from other parts; a forming step; a pressing step in which at least a portion of the end portion is pressed to plastically deform it so that at least a portion of the insulating coating at the end portion is lifted from the conductor wire; and the end portion in which at least a portion of the end portion is plastically deformed. and a peeling step of peeling the insulating coating from the portion.

According to the method for manufacturing a conductive wire of the present invention, at least a portion of the insulation coating is lifted from the conductor wire in the pressing process, and the insulation coating is peeled off in the peeling process, so that the external dimensions of the conductor wire from which the insulation coating has been peeled off. This has the effect of easily suppressing variations in

1 is a schematic diagram illustrating a conductive wire used in a manufacturing method according to an embodiment of the present invention. 1 is a flowchart illustrating a manufacturing method according to an embodiment of the present invention. It is a schematic diagram explaining the state where the 1st cut part and the 2nd cut part were formed in the conductive wire. It is a schematic diagram explaining the shape of the conductive wire after a press process. FIG. 3 is a schematic diagram illustrating the distance between two press surfaces. It is a schematic diagram explaining the shape of a conductive wire after a cutting process. It is a schematic diagram explaining the shape of the conductive wire after a peeling process. It is a flow chart explaining other embodiments of the manufacturing method concerning the present invention.

A method for manufacturing a conductive wire according to an embodiment of the present invention will be described with reference to FIGS. 1 to 8. The conductive wire 10 manufactured by the manufacturing method of this embodiment is an enamelled wire, and is a motor connection member (also referred to as "FEED coil") that connects between the windings of the motor and the terminal block.

A plurality of manufactured conductive wires 10 (for example, three conductive wires) are assembled into one resin molded body by injection molding. A resin molded body containing this conductive wire 10 is attached to a motor. For example, an end 15 of a conductive wire 10, which will be described later, is TIG welded (tungsten-inert gas welding) to a connection part of a motor winding or a connection part of a terminal block.

FIG. 1 is a diagram showing the shape of a conductive wire 10 during manufacture. In the manufacturing method of this embodiment, at least the insulating coating 25 of the end portion 13 of the conductive wire 10 shown in FIG. 1 is peeled off. Note that the method for manufacturing the conductive wire 10 shown in FIG. 1 can be any known method and is not particularly limited.

The conductor wire 10 is provided with a conductor wire 21 and an insulating coating 25. The conductor wire 21 is a member formed into a single cylindrical shape using oxygen-free copper. The insulating film 25 is a one-layer film made of aminoimide that covers the conductor wire 21 . Note that the conductor wire 21 may be formed in a cylindrical shape or a prismatic shape.

Next, a method for manufacturing the conductive wire 10 of this embodiment will be described with reference to FIG. 2 and the like. Although the manufacturing method of this embodiment is applied to two ends 13 of the conductive wire 10 in the following description, it may be applied to only one end 13.

First, a conductive wire 10 having a predetermined length is prepared. Specifically, a preparation step (S11) is performed in which a conductive wire 10 manufactured by a known method is prepared and cut into a predetermined length (S11).

The predetermined length is determined depending on the size, shape, standard, etc. of the motor to which the conductive wire 10 is attached. A known method can be used to cut into a predetermined length.

When the conductive wire 10 is cut into a predetermined length, a slit formation step (first slit formation step, second slit formation Step S13) is performed.

As shown in FIG. 3, the first cut portion 31 and the second cut portion 33 are formed by removing the insulating coating 25 in a groove shape and exposing the conductor wire 21. The first notch portion 31 is an annular notch that partitions the end portion and the center (other portions) of the conductive wire 10 and extends in the circumferential direction of the conductive wire 10 .

The second notch 33 is a notch that extends in the longitudinal direction on the circumferential surface of the conductive wire 10 , and extends from the first notch 31 to the end of the conductive wire 10 . Note that the second notch portion 33 is provided in a region different from the press surface 35, which will be described later.

As a method for forming the first cut portion 31 and the second cut portion 33, a method of removing (burning) the insulating coating 25 by irradiating a laser can be used. Note that a method of removing (scraping) the insulating coating 25 using a cutting tool, a method of removing (melting) using chemicals, etc. may be used.

Once the first notch 31 and the second notch 33 are formed in the end 13, a pressing step (S15) is performed in which the end 15 of the end 13 is pressed, in other words crushed, and plastically deformed. The distal end 15 is the end portion of the conductive wire 10 at the end portion 13 . In other words, this is the part where the above-mentioned TIG welding is performed.

In the pressing step S15, the distal end 15 of the end portion 13 is plastically deformed into a crank shape, and the cross-sectional shape of the distal end 15 is plastically deformed from a circle to a shape having two flat press surfaces 35. At least a portion of the insulating coating 25 at the end 15 is lifted from the conductor wire 21.

The press surface 35 is a flat surface formed by being pressed by a mold used in the press step S15, and is used to weld objects (for example, connections of motor windings and terminal blocks) when performing the above-mentioned TIG welding. This is the surface that comes into contact with the connector (such as a connection part). Note that known molds and press machines can be used in the press process.

As shown in FIG. 5, the distance (spacing) LP between the two pressing surfaces 35 at the end 15 is 20% compared to the diameter (external dimension) D of the conductive wire 10 (in other words, the end 15 before the pressing process). 70% or less. More preferably, it is 30% or more and 60% or less. In this embodiment, an example in which a conductive wire 10 having a diameter D of 2.8 mm is plastically deformed by a pressing process to an end 15 with a distance LP of 1.5 mm between two pressing surfaces 35 will be described.

When the pressing step is performed, a cutting step (S17) is performed in which the end 15 is cut into a predetermined length LT. The predetermined length LT is determined depending on the shape of the connection with the windings of the motor or the shape of the connection with the terminal block. A known method can be used for cutting.

When the end 15 is cut to a predetermined length LT, a peeling step (S19) is performed to peel off the insulating coating 25. Specifically, the work of peeling off the insulation coating 25 from the conductor wire 21 is performed by blowing air to the end portion 13 . FIG. 7 shows the state after the insulating coating 25 has been peeled off from the end portion 13.

Note that a known device can be used as a device for performing air blowing in the peeling process. Moreover, air may be used to peel off the insulating coating 25 in the peeling process, or other gas such as nitrogen may be used.

According to the above method for manufacturing a conductive wire, at least a portion of the insulating coating 25 is lifted from the conductor wire 21 in the pressing step S15, making it easier to peel off the insulating coating 25 in the peeling step S19. Further, since the first notch portion 31 is provided, only the insulating coating 25 on the end portion 13 can be easily peeled off. The external dimensional accuracy of the conductor wire 21 depends on the processing accuracy in at least one of the forming process and the pressing process of the conductor wire 21. The processing accuracy of these steps is higher than the processing accuracy of the method of peeling off the insulating coating 25 using a cutting tool, so it is easy to suppress variations in the outer diameter dimension of the conductor wire 21. In other words, it is easy to improve shape stability and reproducibility. In other words, it is easier to improve quality.

The terminal end 15 of the conductive wire 10 is TIG welded to a motor winding connection or a terminal block connection. In this case, if impurities such as oil are present at the end 15 to be welded, the strength of the welded portion is likely to decrease. Therefore, in the method of peeling off the insulating coating 25 using a cutting tool, cutting oil that suppresses friction or performs cooling during cutting is not used.

Compared to the time required to peel off the insulation coating 25 using a cutting tool without using cutting oil, the time required to peel off the insulation coating 25 through the slit forming step S13, pressing step S15, and peeling step S19 can be easily shortened. Further, wear and tear on equipment such as cutting tools used to peel off the insulating coating 25 can be easily suppressed, and equipment costs can be easily reduced.

By providing the second notch 33, the insulating coating 25 can be peeled off from the conductor wire 21 more easily than in the case where the second notch 33 is not provided. For example, the insulating coating 25 can be peeled away from the second notch 33 starting from the second notch 33, making it easier to peel off the insulating coating 25.

By providing the second cut portion 33 in a region different from the press surface 35 on the end portion 13, the insulating coating 25 can be easily peeled off from the conductor wire 21. A region of the end portion 13 that is different from the press surface 35 may undergo a larger change in shape due to plastic deformation than the press surface 35 . If it is difficult for the insulating coating 25 to follow this change in shape, the insulating coating 25 will float away from the conductor wire 21 in areas where the shape change is large. By providing the second notch 33 in this region, the insulating coating 25 floats around the second notch 33, making it easier to peel the insulating coating 25 from the conductor wire 21 from the second notch 33.

By setting the distance LP between the two opposing press surfaces 35 to 70% or less with respect to the diameter D of the conductive wire 10, the insulating coating 25 is more easily lifted off the conductor wire 21 than when it exceeds 70%. . Furthermore, by setting the ratio to 20% or more, defects due to excessive plastic deformation are less likely to occur in the conductor wire 21, compared to a case where the ratio is less than 20%. Furthermore, by setting the ratio to 30% or more and 60% or less, the insulating coating is more likely to be lifted off the conductor wire, and problems due to excessive plastic deformation are less likely to occur in the conductor wire, compared to the case where the ratio is 20% or more and 70% or less.

By blowing air to peel off the insulation coating 25 from the conductor wire 21, the insulation coating 25 can be peeled off more easily than when the insulation coating 25 is grabbed and peeled off, and a part of the insulation coating 25 is removed from the conductor wire 21. becomes less likely to remain.

Note that the technical scope of the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention.
For example, as shown in FIG. 8, a drying step S10 for drying the conductive wire 10 may be provided. Examples of the drying method include a method of heating the conductive wire 10 to reduce the moisture contained in the insulating coating 25. Note that the drying step S10 may be a step before the pressing step S15.

By providing the drying step S10, it becomes easier to peel off the insulating coating 25 compared to the case where the drying step is not provided. For example, when comparing cases where the amount of water contained in the insulating coating 25 is large and cases where the amount of water is small, a portion of the insulating coating 25 tends to remain on the conductor wire 21 during the peeling step S19 when the amount of water is large. By providing the drying step S10 to reduce the moisture contained in the insulating coating 25, the insulating coating 25 is less likely to remain on the conductor wire in the peeling step S19.

Further, the second cut portion 33 may be provided in a region of the end portion 13 that corresponds to the press surface 35 .
By providing the second cut portion 33 on the press surface 35 at the end portion 13, the insulating coating 25 can be easily peeled off from the conductor wire 21. The press surface 35 at the end portion 13 is a surface to which a larger force is applied in the press step S15 compared to a region different from the press surface 35. The insulating coating 25 may lift off the conductor wire 21 in areas where a large force is applied. By providing the second notch 33 in this region, the insulating coating 25 floats around the second notch 33, making it easier to peel the insulating coating 25 from the conductor wire 21 from the second notch 33.

Furthermore, either the slit forming step S13 or the pressing step S15 may be performed first. As in the above embodiment, the slit forming step S13 may be performed first and the pressing step S15 may be performed later, or the pressing step S15 may be performed first and the slit forming step S13 may be performed later. Note that when the slit forming step S13 is performed before the pressing step S15, it is easier to form cuts that extend linearly.

Further, in the slit forming step S13, only the first cut portion 31 may be provided and the second cut portion 33 may not be provided. For example, if the insulating coating 25 is lifted off the conductor wire 21 over a wide range in the pressing step S15, the insulating coating 25 can be peeled off from the end portion 13 even if the second notch 33 is not provided.

Further, in the peeling step S19, the insulation coating 25 may be peeled off from the conductor wire 21 by air blowing, or the insulation coating 25 may be peeled off by other methods. For example, the insulation coating 25 floating from the conductor wire 21 may be pinched and peeled off by pulling the pinched insulation coating 25.

DESCRIPTION OF SYMBOLS 10... Conductive wire, 13... End part, 21... Conductor wire, 25... Insulating coating, 31... First notch part, 33... Second notch part, 35... Press surface, LP... Distance (interval), D... Diameter ( external dimensions), S10... Drying process, S11... Preparation process, S13... Slit forming process (first slit forming process, second slit forming process), S15... Pressing process, S19... Peeling process

Claims (3)

a preparation step of preparing a conductive wire having a predetermined length, the conductive wire having a conductor wire and an insulating coating formed from an insulating material covering the circumferential surface of the conductor wire;
a first slit forming step of forming a first notch extending in the circumferential direction in the insulating coating at a position separating the end of the conductive wire from other parts;
a pressing step of plastically deforming at least a portion of the end portion;
a peeling step of peeling off the insulating coating from the end portion where at least a portion has been plastically deformed;
has
Prior to the pressing step, the method further includes a second slit forming step of forming at least one second notch extending in the longitudinal direction of the conductive wire in the insulating coating at the end portion,
The method for manufacturing a conductive wire, wherein the second cut portion is provided in a region different from at least one press surface formed by pressing when the end portion is plastically deformed in the pressing step. a preparation step of preparing a conductive wire having a predetermined length, the conductive wire having a conductor wire and an insulating coating formed from an insulating material covering the circumferential surface of the conductor wire;
a first slit forming step of forming a first notch extending in the circumferential direction in the insulating coating at a position separating the end of the conductive wire from other parts;
a pressing step of plastically deforming at least a portion of the end portion;
a peeling step of peeling off the insulating coating from the end portion where at least a portion has been plastically deformed;
has
In the method for manufacturing a conductive wire, the peeling step includes spraying gas between the conductor wire and the insulation coating to peel the insulation coating from the conductor wire. a preparation step of preparing a conductive wire having a predetermined length, the conductive wire having a conductor wire and an insulating coating formed from an insulating material covering the circumferential surface of the conductor wire;
a first slit forming step of forming a first notch extending in the circumferential direction in the insulating coating at a position separating the end of the conductive wire from other parts;
a pressing step of plastically deforming at least a portion of the end portion;
a peeling step of peeling off the insulating coating from the end portion where at least a portion has been plastically deformed;
has
A method for manufacturing a conductive wire, further comprising a drying step of drying the conductive wire before the pressing step.

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