Method for manufacturing motor coil and motor coil

Abstract

To provide a coil having suitable insulation even at high temperatures.SOLUTION: A manufacturing method of a motor coil includes a coating step (S104) of forming an insulating coating on the surface of a long, flat metal plate member, and a winding step (S106) of winding a flat plate member into a cylindrical shape to form a cylindrical body in which flat plates are stacked. During the winding step, gaps are formed between the flat plates at the bent portions at both longitudinal ends of the cylindrical body.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a motor coil and a motor coil. [Background technology]

[0002] Patent Document 1 below discloses a motor having a coil wound in a spiral shape, with an insulating coating formed on the surface of the coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-149930 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, as motors have become faster in rotation, heat generation has increased, and so there is a demand for increasing the temperature of the coil to improve the cooling efficiency of the coil using a refrigerant.However, because the insulating coating in Patent Document 1 is formed after the linear member is wound spirally, the insulating coating cannot be formed properly on the coil, and there is a risk that the insulating coating will deteriorate when the coil becomes hot.

[0005] The present invention has been made in view of these points, and has an object to provide a coil that has appropriate insulation even at high temperatures. [Means for solving the problem]

[0006] In a first aspect of the present invention, there is provided a method for manufacturing a motor coil, comprising a coating step of forming an insulating coating on the surface of a long, flat metal plate member, and a winding step of winding the flat plate member into a cylindrical shape to form a cylindrical body in which flat plates are stacked, wherein, during the winding step, gaps are formed between the flat plates at the bent portions at both longitudinal ends of the cylindrical body.

[0007] In addition, in the winding step, the flat plate member may be wound into a cylindrical shape so that three or more of the bent portions face each other, and gaps between the three or more bent portions may be different from one another.

[0008] In addition, in the winding step, the flat plate member may be wound into a cylindrical shape such that the gaps between the three or more bent portions become larger toward the outside in the longitudinal direction.

[0009] In addition, during the winding step, the flat plate member may be wound into a cylindrical shape so that the flat plates of the straight portions connecting the bent portions at both ends of the cylindrical body in the longitudinal direction are in contact with each other.

[0010] In a second aspect of the present invention, there is provided a motor coil that forms a cylindrical body by winding a flat plate member with an insulating coating on its surface, and that comprises a first side wall portion in which flat plates are stacked along the longitudinal direction, a second side wall portion opposite the first side wall portion and in which flat plates are stacked along the longitudinal direction, and a plurality of bent portions connecting the longitudinal ends of each flat plate of the first side wall portion to the longitudinal ends of each flat plate of the second side wall portion, with gaps formed between the plurality of bent portions.

[0011] The flat plates of the first side wall portion may be in contact with each other, and the flat plates of the second side wall portion may be in contact with each other.

[0012] The gaps between the three or more bent portions may become larger outward in the longitudinal direction. [Effects of the Invention]

[0013] The present invention has the effect of realizing a coil that has appropriate insulation even at high temperatures. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing a stator 1 to which a coil 10 is attached. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a coil 10. [Figure 3] FIG. 3 is an enlarged schematic view of a portion A of FIG. 2. [Figure 4] 2 is a schematic diagram showing a state in which the coil 10 is fitted to the teeth. FIG. [Figure 5] 3 is a flowchart showing the flow of manufacturing the coil 10. [Figure 6] 1 is a schematic diagram showing a long flat plate member 100. FIG. [Figure 7] FIG. 2 is a schematic diagram showing a cylindrical body 200. DETAILED DESCRIPTION OF THE INVENTION

[0015] <Coil Overview> The coil according to this embodiment is a motor coil that is attached to a motor mounted on a vehicle such as a truck. The motor includes a stator and a rotor, and the coil is attached to the stator. Specifically, the coil is provided on the inner peripheral surface of the stator and surrounds the rotor.

[0016] FIG. 1 is a schematic diagram showing a stator 1 to which a coil 10 is attached. As shown in FIG. 1, a plurality of coils 10 are provided on the inner peripheral surface of the stator 1. The plurality of coils 10 are provided at predetermined intervals along the circumferential direction. The coils 10 are attached so as to surround teeth protruding from the inner peripheral surface of the stator 1. Specifically, a through-hole is provided in the center of the coil 10, and the through-hole is fitted into the tooth.

[0017] The multiple coils 10 are arranged so as to surround the rotor 5 shown by the dashed line in FIG. 1. A refrigerant (specifically, cooling oil or cooling water) is filled between the rotor 5 and the coils 10. When the rotor 5 rotates, the refrigerant comes into contact with the coils 10 and cools them. An insulating coating is formed on the coils 10 to ensure insulation from the rotor 5. The coils 10 are cylindrical bodies wound around a flat plate member whose surface is coated with an insulating coating. The coils 10 are wound in a strip shape in a so-called flatwise manner.

[0018] However, as the rotational speed of the motor increases, heat generation increases, and there is a demand to increase the temperature of the coil 10 in order to improve the cooling efficiency of the refrigerant for the coil 10. This is because when the temperature of the coil 10 is high, the temperature difference with the refrigerant increases, and therefore the cooling efficiency of the coil 10 by the refrigerant increases.

[0019] Unlike the present embodiment, in the case of coils in which a linear material is wound around the teeth, a resin-based insulating coating is usually formed, but resin-based insulating coatings deteriorate more rapidly as the temperature increases, so the coil temperature cannot be raised. Forming an insulating coating on the coil using an inorganic material that can withstand high temperatures could be considered, but in the case of coils in which a linear material is wound around the teeth, bending the coil wire could cause cracks or peeling, which could impair the insulation.

[0020] In contrast, when manufacturing the coil 10 according to this embodiment, as will be described in detail later, a flat plate member coated with an insulating coating is wound into a cylindrical shape to form a cylinder of overlapping flat plates. The flat plate member is wound so as to form gaps between the flat plates at both longitudinal ends. This ensures insulation even if cracks or peeling of the insulating coating occur at the bent portions at both longitudinal ends during winding. As a result, an insulating coating that has adequate insulation properties even at high temperatures can be formed on the coil 10.

[0021] <Detailed coil configuration> Fig. 2 is a schematic diagram showing the configuration of the coil 10. Fig. 3 is a schematic diagram showing an enlarged view of part A in Fig. 2. Fig. 4 is a schematic diagram showing the fitted state of the coil 10 and the teeth.

[0022] As shown in Fig. 2, the coil 10 is a cylinder having a through-hole 12 in the center. As shown in Fig. 4, the through-hole 12 can be fitted into the teeth 2 of the stator 1. The coil 10 is attached to the stator 1 by fitting the through-hole 12 into the teeth 2.

[0023] The shape of the coil 10 in plan view is, but is not limited to, a long, thin cylinder. Because the coil 10 is attached to the stator of a high-speed motor, it is desirable for the number of turns of the coil 10 to be small. For this reason, the number of turns of the coil 10 is three here, but is not limited to this and may be four or more.

[0024] 2, the coil 10 has a first side wall portion 20, a second side wall portion 30, a one-end bent portion 40, an other-end bent portion 50, a first connecting portion 60, and a second connecting portion 65. The first side wall portion 20, the second side wall portion 30, the one-end bent portion 40, the other-end bent portion 50, the first connecting portion 60, and the second connecting portion 65 are connected to each other. The coil 10 is formed by winding a flat plate member whose opposite ends become the first connecting portion 60 and the second connecting portion 65.

[0025] The first side wall portion 20 is a side wall along the longitudinal direction of the coil 10. The first side wall portion 20 is formed by stacking a plurality of flat plates (here, three flat plates 21 to 23). The plurality of flat plates 21 to 23 are parallel to each other in the longitudinal direction. The flat plates 21 to 23 are in contact with each other as shown in FIG. 3. Specifically, the flat plates 21 to 23 are in surface contact with each other.

[0026] An insulating coating is applied to the surfaces of the flat plates 21 to 23 of the first side wall portion 20. The surfaces of the flat plates 21 to 23 that are covered with the insulating coating are in surface contact with each other, so that insulation between the flat plates 21 to 23 is ensured by the insulating coating. The thickness of the flat plates 21 to 23 is 1 mm or less here, and preferably 0.5 mm. When the flat plates 21 to 23 having such a thickness are arranged perpendicular to one another, the width (0.5 mm) of the flat plates 21 to 23 in the direction perpendicular to the magnetic flux generated by the coil 10 is small, and therefore eddy current loss can be reduced.

[0027] The second side wall portion 30 is a side wall along the longitudinal direction of the coil 10, and faces the first side wall portion 20. Similar to the first side wall portion 20, the second side wall portion 30 is formed by stacking a plurality of flat plates (here, three flat plates 31 to 33). The plurality of flat plates 31 to 33 are parallel to the longitudinal direction and are in contact with each other.

[0028] Similar to the flat plates 21 to 23, the surfaces of the flat plates 31 to 33 of the second side wall portion 30 are also coated with an insulating film. The surfaces of the flat plates 31 to 33 coated with the insulating film are in surface contact with each other. Therefore, the insulating film ensures insulation between the flat plates 31 to 33.

[0029] The one-end bent portion 40 is a bent portion provided on one end side in the longitudinal direction of the coil 10. The one-end bent portion 40 is formed by bending a flat plate member when manufacturing the coil 10. The one-end bent portion 40 connects one end in the longitudinal direction of each of the flat plates 21 to 23 of the first side wall portion 20 and one end in the longitudinal direction of each of the flat plates 31 to 33 of the second side wall portion 30.

[0030] As shown in Fig. 3, the one-end bending portion 40 has bending portion 41, bending portion 42, and bending portion 43. Bending portion 41 is connected to one end of the flat plate 21 of the first side wall portion 20 and one end of the flat plate 31 of the second side wall portion 30. Bending portion 42 is connected to one end of the flat plate 22 of the first side wall portion 20 and one end of the flat plate 32 of the second side wall portion 30. Bending portion 43 is connected to one end of the flat plate 23 of the first side wall portion 20 and one end of the flat plate 33 of the second side wall portion 30. Bending portion 43 is located on the outermost side, and bending portion 41 is located on the innermost side.

[0031] Unlike the flat plates of the first side wall portion 20 and the second side wall portion 30, the bent portions 41 to 43 are not in contact with each other. Specifically, as shown in FIG. 3, gaps are formed between the bent portions 41 to 43. The gaps are larger than the thicknesses of the flat plates of the bent portions 41 to 43, for example. The size of the gap between the bent portions 41 and 42 is different from the size of the gap between the bent portions 42 and 43. The gaps between the bent portions 41 to 43 become larger outward in the longitudinal direction. In other words, the gap between the bent portions 42 and 43 is larger than the gap between the bent portions 41 and 42.

[0032] Forming gaps between the bent portions 41 to 43 ensures insulation between the bent portions 41 to 43. In particular, when the coil 10 is formed by winding a flat plate member having an insulating coating on its surface, even if the insulating coating cracks or peels off at the bent portions 41 to 43 during winding, for example, insulation between the bent portions 41 to 43 can be ensured. Furthermore, by forming gaps between the bent portions 41 to 43, the refrigerant can enter the gaps, which makes it easier for the bent portions 41 to 43 to come into contact with the refrigerant, and makes it easier for heat to be dissipated from the bent portions 41 to 43. As a result, the cooling efficiency of the refrigerant is improved.

[0033] The other-end bent portion 50 is a bent portion provided on the other end side in the longitudinal direction of the coil 10. The other-end bent portion 50 is formed by bending a flat plate member when manufacturing the coil 10. The other-end bent portion 50 connects the other end in the longitudinal direction of each flat plate of the first side wall portion 20 and the other end in the longitudinal direction of each flat plate of the second side wall portion 30.

[0034] The other-end bending portion 50 has bending portion 51, bending portion 52, and bending portion 53. Bending portion 51 has a configuration similar to bending portion 41 of one-end bending portion 40, bending portion 52 has a configuration similar to bending portion 42, and bending portion 53 has a configuration similar to bending portion 43. Gaps are formed between bending portions 51 to 53, similar to bending portions 41 to 43. These gaps not only ensure insulation between bending portions 51 to 53, but also improve the cooling efficiency of the refrigerant.

[0035] As shown in Fig. 4, the first connecting portion 60 and the second connecting portion 65 are portions that connect to the stator 1. One of the first connecting portion 60 and the second connecting portion 65 serves as an inlet for current to the coil 10, and the other serves as an outlet for current from the coil 10.

[0036] <Coil manufacturing method> A method for manufacturing the coil 10 according to this embodiment will be described with reference to FIG. Fig. 5 is a flowchart showing the flow of manufacturing the coil 10. As shown in Fig. 5, the manufacturing of the coil 10 is performed in the order of a preparation step, a coating step, and a winding step. Each step will be described below.

[0037] (preparation process) First, as a preparation step, the worker prepares a metal flat plate member (step S102). For example, the worker prepares a long flat plate member 100 shown in FIG.

[0038] FIG. 6 is a schematic diagram showing a long flat plate member 100. Here, the flat plate member 100 is made of copper or aluminum, but is not limited to these and may be made of other metals. The length of the flat plate member 100 is set according to the number of turns of the coil 10. The thickness of the flat plate member 100 is set according to the number of turns of the coil 10, and is 0.5 mm in this example. The width of the flat plate member 100 is the same as the height of the coil 10.

[0039] (Coating process) Next, in a coating process, the worker forms an insulating coating on the surface of the flat plate member 100 (step S104). For example, the worker forms an inorganic insulating coating on the entire surface of the flat plate member 100 by thermal spraying.

[0040] Specifically, the worker forms an insulating coating by spraying molten ceramic onto the entire surface of the flat plate member 100. By forming an inorganic insulating coating, it is possible to prevent the insulating properties of the insulating coating from being impaired, compared to a resin-based insulating coating, even if the temperature of the coil 10 becomes high.

[0041] (winding process) Next, in the winding process, the worker winds the flat plate member 100 having the insulating coating formed on its surface into a cylindrical shape (step S106). By winding the flat plate member 100, a cylindrical body in which flat plates are stacked is formed. At this time, the worker forms gaps between the flat plates at the bent portions at both ends of the longitudinal direction of the cylindrical body 200. Specifically, the cylindrical body 200 shown in FIG. 7 is formed.

[0042] 7 is a schematic diagram showing a cylindrical body 200. The shape of the cylindrical body 200 is the same as that of the coil 10 shown in FIG. 2. The worker forms the cylindrical body 200 so that the flat plates 221-223 and the flat plates 231-233 of the straight portions along the longitudinal direction of the cylindrical body 200 are in contact with each other. The flat plates 221-223 correspond to the flat plates 21-23 of the first side wall portion 20 of the coil 10, and the flat plates 231-233 correspond to the flat plates 31-33 of the second side wall portion 30.

[0043] The worker also winds the flat plate member 100 so that the bent portions 241 to 243 connected to one longitudinal end of the flat plates 221 to 223 and the flat plates 231 to 233 face each other. Similarly, the worker winds the flat plate member 100 so that the bent portions 251 to 253 connected to the other longitudinal end of the flat plates 221 to 223 and the flat plates 231 to 233 face each other. At this time, the worker forms gaps between the flat plates of the bent portions 241 to 243 and between the flat plates of the bent portions 251 to 253. The bent portions 241 to 243 correspond to the bent portions 41 to 43 of the coil 10, and the bent portions 251 to 253 correspond to the bent portions 51 to 53.

[0044] The gaps between the bent portions 241 to 243 are different from one another. Similarly, the gaps between the bent portions 251 to 253 are different from one another. Specifically, the worker winds the flat plate member 100 so that the gaps between the bent portions 241 to 243 and the bent portions 251 to 253 become larger toward the outside in the longitudinal direction.

[0045] <Effects of this embodiment> In the above-described method for manufacturing the coil 10, the flat plate member 100 on which the insulating coating is formed is wound into a cylindrical shape to form the overlapping flat plates of the cylindrical body 200. At this time, the flat plate member 100 is wound so as to form gaps between the flat plates at the bent portions 241-243 and 251-253 at both ends in the longitudinal direction. As a result, even if cracks or peeling occur in the insulating coating of the flat plates of the bent portions 241-243, 251-253 at both ends in the longitudinal direction during winding of the flat plate member 100, insulation can be ensured by forming gaps between the flat plates. As a result, an insulating coating that has appropriate insulating properties even at high temperatures can be formed on the coil 10. Furthermore, the cooling efficiency of the refrigerant increases as the refrigerant enters the gaps.

[0046] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0047] 10 coils 20 First side wall portion 30 Second side wall 40 One end bent part 50 Other end bent part 100 Flat plate member 200 cylinder 241~243 Bending section 251~253 Bending section

Claims

1. a coating step of forming an insulating coating on the surface of a long, flat metal member; a winding step of winding the flat plate member into a cylindrical shape to form a cylindrical body in which flat plates are stacked; and A method for manufacturing a motor coil, wherein during the winding process, gaps are formed between the flat plates at the bent portions at both longitudinal ends of the cylindrical body.

2. During the winding step, the flat plate member is wound into a cylindrical shape so that three or more of the bent portions face each other; The gaps between the three or more bent portions are different from each other. A method for manufacturing a coil of the motor according to claim 1.

3. During the winding step, the flat plate member is wound into a cylindrical shape such that gaps between the three or more bent portions become larger toward the outside in the longitudinal direction. A method for manufacturing a coil of the motor according to claim 2.

4. During the winding step, the flat plate member is wound into a cylindrical shape so that the flat plates of the straight portions connecting the bent portions at both ends of the longitudinal direction of the cylindrical body are in contact with each other. A method for manufacturing a coil of the motor according to claim 1.

5. A motor coil having a cylindrical body formed by winding a flat plate member having an insulating coating on its surface, a first side wall portion formed by overlapping flat plates along the longitudinal direction; a second side wall portion facing the first side wall portion and overlapping a flat plate along the longitudinal direction; a plurality of bent portions connecting longitudinal ends of the flat plates of the first side wall portion and longitudinal ends of the flat plates of the second side wall portion; Equipped with A coil for a motor, wherein gaps are formed between the plurality of bent portions.

6. the flat plates of the first side wall portion are in contact with each other, The flat plates of the second side wall portion are in contact with each other. A coil for a motor according to claim 5.

7. The gaps between the three or more bent portions become larger outward in the longitudinal direction. A coil for a motor according to claim 5.

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