Manufacturing method of enameled wire

Abstract

The present invention provides a method for manufacturing enameled wire that can suppress blistering of the enamel coating and prevent insulation defects in the enameled wire. [Solution] The method for manufacturing the enameled wire 1 comprises a wire drawing step of drawing a wire 10, a recovery step of forming the wire 10 after the wire drawing step into a coil and recovering it in a spindle 36, a spin-out discharge step of feeding out the wire 10 recovered in the spindle 36 while rotating the spindle 36, and a coating formation step of forming an enamel coating on the outer circumference of the wire 10 fed out in the spin-out discharge step.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing enameled wire.

Background Art

[0002] In a conventional method for manufacturing enameled wire, after a wire rod drawn to a predetermined outer diameter is wound around a bobbin, an enamel coating is formed on the outer circumference of the wire rod fed out from the bobbin to manufacture enameled wire. As a wire winding device for winding the wire rod around the bobbin, a wire winding device using a traverser capable of reciprocating in the axial direction of the bobbin, as shown in Patent Document 1, has been used. The traverser is for guiding the wire rod and winding the wire rod in a plurality of stages in alignment around the bobbin while repeatedly reversing the moving direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, winding wire using a traverser had the problem that it was difficult to adjust the reversal position of the traverser's movement. If the reversal position was misaligned for any reason, an excessive gap could be created between the wire wound on the bobbin and the bobbin flange, or the wire could be damaged by friction between the wire wound on the bobbin and the bobbin flange. Also, if the winding pitch on the bobbin and the wire diameter did not match, the wire could be damaged. For example, if the winding pitch was small, the next wire could overlap the wound wire as it was wound, causing the wires to rub against each other and be damaged. Conversely, if the winding pitch was large, a gap could be created between adjacent wires, causing a step drop when the next section was wound, which could cause the wires to rub against each other and be damaged. When the wire was damaged, bulging could occur when the enamel coating was formed on that wire, potentially leading to poor insulation of the enameled wire.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a method for manufacturing enameled wire that can suppress blistering of the enamel coating and suppress insulation defects in the enameled wire. [Means for solving the problem]

[0006] To achieve the above objective, the present invention provides a method for manufacturing enameled wire, comprising: a wire drawing step of drawing a wire; a collection step of forming the wire after the wire drawing step into a coil and collecting it in a spindle; a rotational discharge step of feeding out the wire collected in the spindle while rotating the spindle; and a coating formation step of forming an enamel coating on the outer circumference of the wire fed out in the rotational discharge step. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a method for manufacturing enameled wire that can suppress blistering of the enamel coating and suppress insulation defects in the enameled wire. [Brief explanation of the drawing]

[0008] [Figure 1]This is a schematic diagram of a peeling device used in the peeling process in the embodiment. [Figure 2] This is a schematic diagram of a wire drawing apparatus used in the wire drawing process in the embodiment. [Figure 3] This is a schematic diagram of an enamel forming apparatus used in the enamel forming process in the embodiment. [Figure 4] This is a front view of a spool used in the final step of the peeling process or wire drawing process in the embodiment. [Figure 5] Figure 4 is a cross-sectional view taken along the VV line. [Figure 6] This is a front view showing a cross-sectional view of a part of the dance wheel in a modified example of the embodiment. [Figure 7] This is a plan view of a dance wheel in a modified example of the embodiment. [Modes for carrying out the invention]

[0009] [Embodiment] Embodiments of the present invention will be described with reference to Figures 1 to 5. The embodiments described below are presented as preferred specific examples for carrying out the present invention, and while some parts specifically illustrate various technically preferable technical matters, the technical scope of the present invention is not limited to these specific embodiments.

[0010] (Method of manufacturing enameled wire) This embodiment relates to a method for manufacturing enameled wire. The method for manufacturing enameled wire comprises a stripping process for stripping the outer layer of a wire, a wire drawing process for drawing the stripped wire, and an enamel forming process for forming an enamel coating on the outer circumference of the drawn wire. Figure 1 is a schematic diagram of a stripping apparatus 2 used in the stripping process. Figure 2 is a schematic diagram of a wire drawing apparatus 3 used in the wire drawing process. Figure 3 is a schematic diagram of an enamel forming apparatus 4 used in the enamel forming process.

[0011] (Skinning process) As shown in Figure 1, the deskinning process involves using a deskinning device 2 to deskin a wire 10 made of pure copper or a copper alloy while it is running, and then recovering it in a spindle 25. The deskinning device 2 comprises a supply unit 21, a pulley 22, a deskinning machine 23, a coiler 24, and a spindle 25.

[0012] The supply unit 21 is a winding of wire 10, which is the raw material for enameled wire, and can be in the form of a coil, bobbin, or spindle. The wire 10 drawn out from the supply unit 21 (i.e., the starting wire) is made of, for example, pure copper or a copper alloy, has a circular cross-section, and a diameter of 8.0 mm. The wire 10 drawn out from the supply unit 21 is guided by a pulley 22 and supplied to the stripping machine 23.

[0013] The stripping machine 23 performs a stripping process to remove the thin outer layer from the surface of the wire 10 by passing it through a stripping die (not shown). The diameter of the stripped wire 10 is, for example, 6.3 mm. The wire 10 that has passed through the stripping machine 23 is guided by a pulley 22 and supplied to the coiler 24.

[0014] The coiler 24 winds the wire 10 to create a coil shape and performs a pre-recovery process by dropping the coiled wire 10 onto the spindle 25. The coiler 24 does not wind the wire 10 in multiple layers like a bobbin, for example, but winds the wire 10 into a single coil shape. The coiler 24 repeats a cycle of winding the wire 10 a predetermined number of turns and dropping it onto the spindle 25. A general coiler used in the wire manufacturing process can be used as the coiler 24. The wire 10, which has been coiled by the coiler 24, is dropped onto the spindle 25.

[0015] Figure 4 is a front view of the wheel 25 (or the wheel 36 described later). Figure 5 is a cross-sectional view taken along the line VV in Figure 4. As shown in Figures 1, 4, and 5, the wheel 25 comprises a frame 251 and a cover 252.

[0016] The frame 251 is made of a pipe material such as iron and includes leg portions 251a and a core portion 251b. The leg portions 251a support the coiled wire 10 dropped onto the dancing ring 25 from below. Although not shown in the figure, a protective plate along the horizontal direction may be arranged on the leg portions 251a, and the wire 10 may be arranged on the upper surface of the protective plate. The core portion 251b stands upright upward from the leg portions 251a and passes through the center of the coiled wire 10 dropped onto the dancing ring 25. The core portion 251b includes vertical portions 251c formed in the vertical direction from a plurality of locations (specifically, four locations) of the leg portions 251a, and a connecting portion 251d formed in a direction intersecting in the vertical direction so as to connect the upper ends of these vertical portions 251c.

[0017] The cover 252 covers the surface of the core portion 251b on the side where the wire 10 is arranged (in this embodiment, the radially outer side of the dancing ring 25). That is, the cover 252 is interposed between the wire 10 and the core portion 251b. In this embodiment, the cover 252 has a shape like a half-cut cylindrical body and covers a part of the vertical portions 251c and the connecting portion 251d of the core portion 251b from the outer peripheral side of the dancing ring 25. In this embodiment, the dancing ring 25 has a plurality of covers 252 that cover each of all the vertical portions 251c. The inner radius of curvature of the cover 252 is greater than or equal to the radius of curvature of the outer peripheral surface of the core portion 251b. Thereby, when the wire 10 is dropped from the coiler 24 onto the dancing ring 25, it is suppressed that the wire 10 interferes with the cover 252 in the vertical direction. In this embodiment, the cover 252 is made of a material softer than the core portion 251b (specifically, iron), for example, resin. When the wire 10 is dropped from the coiler 24 onto the dancing ring 25, the coiled wire 10 can move in a random direction, so there is a possibility that the wire 10 hits the core portion 251b and the wire 10 is damaged. Also, after the wire 10 is collected on the dancing ring 25 and during transportation, friction may occur between the wire 10 and the dancing ring 25 due to vibration or the like, and it is also conceivable that the wire 10 is damaged. Therefore, by covering the core portion 251b with the cover 252, it is suppressed that the wire 10 hits the core portion 251b and the wire 10 is damaged.

[0018] In addition, in this embodiment, although an example in which the cover 252 is attached to the core portion 251b by a plurality of members having a shape like a half-divided cylindrical body is shown, the present invention is not limited to this. FIG. 6 is a front view showing a modified example of the dancing wheel 25, and FIG. 7 is a plan view showing a modified example of the dancing wheel 25. In FIG. 6, the cover 252 is shown in cross section. The cover 252 may be configured to be formed in upper and lower cylindrical shapes as shown in FIGS. 6 and 7, for example, and arranged to surround the entire core portion 251b (specifically, the vertical portion 251c) from the outer peripheral side.

[0019] Note that in the dancing wheel 25, it is also possible to omit the cover 252. Even when the wire 10 is recovered using the dancing wheel 25 without the cover 252, the occurrence of damage to the wire 10 is reduced as compared with the case where the wire 10 is wound in a plurality of stages by applying tension, such as a bobbin or the like.

[0020] (Wire drawing process) As shown in FIG. 2, the wire drawing process is a process in which the wire 10 that has undergone the skin peeling process is run using the wire drawing device 3, the wire 10 is drawn, and is recovered by the dancing wheel 36. The wire drawing device 3 includes a dancing wheel 25, a pulley 31, a wire drawing machine 32, a capstan 33, a dancer 34, a coiler 35, and a dancing wheel 36.

[0021] The dancing wheel 25 is one that has recovered the wire 10 in the skin peeling process and has been moved to the wire drawing device 3. The wire 10 drawn from the dancing wheel 25 is guided by the pulley 31 and supplied to the wire drawing machine 32.

[0022] The wire drawing machine 32 performs a wire drawing process of squeezing the wire 10 to a desired diameter by passing the wire 10 through a wire drawing die (not shown). The wire drawing machine 32 may have a plurality of wire drawing dies with smaller inner diameters as it is closer to the downstream side in the running direction of the wire 10, for example. In this embodiment, the cross section of the wire 10 after wire drawing is circular, and the diameter is 2.0 mm or more, specifically, for example, 3.0 mm. The wire 10 that has passed through the wire drawing machine 32 is taken up by the capstan 33.

[0023] The capstan 33 is rotated by winding the wire 10 that has passed through the wire drawing machine 32 around it. As a result, the frictional force between the outer surface of the capstan 33 and the wire 10 pulls the wire 10 out of the wire drawing machine 32 and sends it downstream (to the dancer 34 in this embodiment).

[0024] The dancer 34 includes, for example, a fixed roll 341 whose rotation axis is fixed, and a movable roll 342 that can move radially relative to the fixed roll 341. The dancer 34 maintains a constant tension in the wire 10 by moving the movable roll 342 in accordance with the tension of the wire 10 fed out from the capstan 33. The wire 10 that has passed through the dancer 34 is supplied to the coiler 35.

[0025] The coiler 35 is the same as the coiler 24 used in the debarking process, and performs a recovery process in which it coils the wire 10 and drops the coiled wire 10 into the spindle 36. As shown in Figures 4 and 5, the spindle 36 also has the same configuration as the spindle 25 used in the debarking process, and comprises a frame 361 with legs 361a and a core 361b, and a cover 362 surrounding the core 361b. The core 361b, like the spindle 25, comprises a vertical part 361c and a connecting part 361d.

[0026] As shown in Figure 2, by recovering the wire 10 after drawing using the coiler 35 and the winding wheel 36, the occurrence of damage to the wire 10 is reduced compared to cases where the wire 10 is wound in multiple stages under tension, such as on a bobbin. If the wire 10 is damaged after drawing, swelling may occur when the enamel coating is formed on the wire 10 in the subsequent enamel formation process, potentially leading to poor insulation of the enamel wire. Therefore, it is desirable to suppress the occurrence of damage to the wire 10 after drawing, and from this viewpoint, it is important to recover the wire 10 after drawing using the winding wheel 36. In particular, when the wire 10 after drawing is an extra-thick wire with a diameter of 2.0 mm or more, as in this embodiment, if the wire 10 is wound under tension on a bobbin, it is prone to damage due to friction between wires, friction between the wire and the flange of the bobbin, and stepping into the gaps between wires, so using the winding wheel 36 is especially effective. When winding thin wires onto a bobbin, irregular winding can suppress friction between wires, friction between wires and the bobbin flange, and stepping into gaps between wires, thus reducing damage to the wire. However, with thicker wires, irregular winding can cause wire bending, which can lead to problems in the enamel process, making irregular winding difficult.

[0027] (Enamel formation process) As shown in Figure 3, the enamel forming process is a process in which an enamel coating is formed on the wire 10 while the wire 10 is running using an enamel forming apparatus 4. The enamel forming apparatus 4 comprises a wheel 36 mounted on a turntable 41, a pulley 42, an annealing furnace 43, an enamel forming section 44, a take-up machine 45, and a winding machine 46.

[0028] The wire wheel 36 is formed by moving the wire rod 10 recovered during the wire drawing process and placing it on the turntable 41 of the enamel forming apparatus 4. The turntable 41 rotates integrally with the mounted wire wheel 36, around the central axis of the coiled wire rod 10 recovered in the wire wheel 36. The turntable 41 performs a round-trip discharge process, feeding out the wire rod 10 recovered in the wire wheel 36 while rotating the wire wheel 36. When the wire rod 10 is fed out of the wire wheel 36, the turntable 41 rotates the wire wheel 36 in the direction in which the wire rod 10 is fed out (i.e., the direction in which the wire rod 10 unravels from the wire wheel 36). By feeding out the wire rod 10 while rotating the wire wheel 36 in this way, it is suppressed that the wire rod 10 will come off the pulley 42 or become entangled due to twisting that occurs as the wire rod 10 is fed out. The rotation speed of the turntable 41 is matched to the travel speed of the wire rod 10. The wire 10 drawn from the spindle 36 is guided by a plurality of pulleys 42 and supplied to the annealing furnace 43. The spindle 25 may also be rotated in the same manner when the wire 10 is fed out during the wire drawing process.

[0029] The annealing furnace 43 anneals and softens the wire 10. As the wire 10 passes through the annealing furnace 43, twisting and processing distortion of the wire 10 are reduced. The annealed wire 10 is supplied to the enamel forming section 44 via a plurality of pulleys 42.

[0030] The enamel forming unit 44 performs a coating process to form an enamel coating on the outer circumference of the wire 10. The enamel forming unit 44 has a coating unit 441, a baking furnace 442, and a plurality of turn pulleys 443. The coating unit 441 applies enamel paint to the outer circumference of the wire 10. The wire 10 coated with enamel paint is supplied to the baking furnace 442. The baking furnace 442 heats the wire 10 to dry and harden the enamel paint on the outer circumference of the wire 10 by baking. The wire 10 that has passed through the baking furnace 442 is returned to the coating unit 441 via the plurality of turn pulleys 443, and the application of enamel paint in the coating unit 441 and the baking of enamel paint in the baking furnace 442 are repeated until the enamel coating reaches the desired thickness.

[0031] The enameled wire 1, which is the wire material 10 that has passed through the enamel forming section 44, is then pulled by the take-up machine 45 and wound up by a winding machine 46 such as a bobbin. In this manner, enameled wire 1 is manufactured.

[0032] (Operation and Effects of the Embodiment) The manufacturing method for the enameled wire 1 in this embodiment includes a recovery step in which the wire 10 after the wire drawing process is coiled and recovered using a winding wheel 36. By recovering the wire 10 after drawing using the winding wheel 36 in this way, damage to the wire 10 is suppressed compared to when the wire 10 is wound on a bobbin while tension is applied to the wire 10 in multiple layers. In addition, recovering the wire 10 using the winding wheel 36 allows for a larger amount of wire 10 to be recovered in one go (i.e., the amount per lot) compared to when the wire 10 is wound on a bobbin. This reduces the number of lot changes and leads to improved productivity. Furthermore, it reduces the amount of waste that may be generated during lot changes and leads to improved yield.

[0033] Furthermore, the manufacturing method of the enameled wire 1 in this embodiment includes a rotating discharge step in which the wire 10 after drawing is fed to the coating formation step for forming the enamel coating, while the wheel 36 is rotated. This prevents twisting of the wire 10 when it is fed out after drawing, which can cause the wire 10 to come off or get tangled in the pulley 42.

[0034] Furthermore, in the retrieval process, the wire 10 after the wire drawing process is coiled and dropped into the winding wheel 36. This further reduces the tension applied to the wire 10 during retrieval, thereby further reducing damage to the wire 10.

[0035] Furthermore, the winding wheel 36 includes a core 361b made of pipe material that passes through the center of the coiled wire 10, and a cover 362 that covers the side of the core 361b where the wire 10 is placed. In the recovery process, the coiled wire 10 is recovered on the outer circumference side of the cover 362. Therefore, damage to the core 361b due to interference between the wire 10 and the core 361b is suppressed during the recovery and transportation of the wire 10.

[0036] Furthermore, the cover 362 is made of a softer material than the core 361b. Therefore, damage to the wire 10 during collection and transportation is further suppressed.

[0037] Furthermore, the diameter of the manufactured enameled wire 1 exceeds 2.0 mm. When manufacturing such thick wires, if tension is applied to the drawn wire material 10 and it is wound onto a bobbin, it is prone to damage due to friction between the wires themselves and between the wire and the flange of the bobbin, etc. Therefore, when manufacturing such thick wires, using a spindle 36 to recover the drawn wire material 10 is particularly effective in suppressing damage to the wire material 10.

[0038] Furthermore, the manufacturing method of the enameled wire 1 in this embodiment further comprises a stripping step in which the outer layer of the wire 10 is stripped before the wire drawing step, and a pre-recovery step in which the stripped wire 10 is recovered using a spindle 25. If the wire 10 has scratches after the stripping step, small scratches may disappear in the subsequent wire drawing step, but large scratches may remain even after the wire drawing step. Therefore, by using the spindle 25 in the pre-recovery step as well, the remaining scratches on the wire 10 are suppressed.

[0039] As described above, this embodiment makes it possible to suppress the occurrence of damage to the wire. This provides a method for manufacturing enameled wire that can suppress blistering of the enamel coating and suppress insulation defects in the enameled wire.

[0040] (Summary of the embodiments) Next, the technical concept understood from the embodiments described above will be described using the reference numerals and other symbols from the embodiments. However, the reference numerals and other symbols in the following description are not limited to the components in the claims that are specifically shown in the embodiments.

[0041] [1] A method for manufacturing an enameled wire 1, comprising: a wire drawing step of drawing a wire 10; a recovery step of forming the wire 10 after the wire drawing step into a coil and recovering it in a spindle 36; a spin-out discharge step of feeding out the wire 10 recovered in the spindle 36 while rotating the spindle 36; and a coating formation step of forming an enamel coating on the outer circumference of the wire 10 fed out in the spin-out discharge step.

[0042] [2] In the recovery step, the wire material 10 after the wire drawing step is coiled and dropped into the spindle 36, the method for manufacturing enameled wire 1 as described in [1].

[0043] [3] The method for manufacturing enameled wire 1 according to [1] or [2], wherein the wheel 36 comprises a core portion 361b made of pipe material that is passed through the center of the coiled wire 10, and a cover 362 that covers the side of the core portion 361b on which the wire 10 is placed, and in the recovery step, the coiled wire 10 is recovered on the outer circumference side of the cover 362.

[0044] [4] The method for manufacturing the enameled wire 1 according to [3], wherein the cover 362 is made of a material softer than the core portion 361b.

[0045] [5] A method for manufacturing enameled wire 1 according to any one of [1] to [4], wherein the diameter of the enameled wire 1 manufactured is greater than 2.0 mm.

[0046] [6] A method for manufacturing an enameled wire 1 according to any one of [1] to [5], further comprising a stripping step of stripping the outer layer of the wire 10 before the wire drawing step, and a pre-recovery step of recovering the stripped wire 10 in a spindle 25.

[0047] (Note) Although embodiments of the present invention have been described above, the embodiments described herein do not limit the invention as defined in the claims. Furthermore, it should be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. Moreover, the present invention can be implemented with appropriate modifications without departing from its spirit. [Explanation of Symbols]

[0048] 1... Enamel wire 10...Wire rod 25...Maiwa 36…Maiwa 361b…core part 362...cover

Claims

1. The wire drawing process, which involves drawing wire material, A recovery step is to recover the wire material after the wire drawing process by forming it into a coil and using a winding wheel. The process of transferring and ejecting the wire material collected on the aforementioned wheel while rotating the wheel, The process includes a coating formation step of forming an enamel coating on the outer circumference of the wire material that was fed out in the aforementioned transfer and discharge step. A method for manufacturing enameled wire.

2. In the recovery process, the wire material after the wire drawing process is shaped into a coil and dropped into the wheel. The method for manufacturing enameled wire according to claim 1.

3. The aforementioned dance wheel comprises a core made of pipe material that passes through the center of the coiled wire, and a cover that covers the side of the core on which the wire is placed. In the recovery process, the coiled wire is recovered on the outer circumference of the cover. A method for producing enameled wire according to claim 1 or 2.

4. The cover is made of a material softer than the core. The method for manufacturing enameled wire according to claim 3.

5. The diameter of the enameled wire produced exceeds 2.0 mm. A method for producing enameled wire according to claim 1 or 2.

6. A stripping step in which the wire material is stripped before the wire drawing process, The system further comprises a pre-recovery step in which the stripped wire material is recovered using a spool. A method for producing enameled wire according to claim 1 or 2.

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