JP2011211806A - Method of manufacturing motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a motor which has a stacked core that is easy to cover with an insulating film by suppressing an increase in a manufacturing time.SOLUTION: This method is for manufacturing a motor, where the thickness in the direction of a rotating shaft, of the body 43 of a plate is one and a half times or over the thickness in the direction of the rotating shaft of another magnetic plate 22, and the topside 64 of the body 43 of the plate is continuous to a slot face 53 via a curved convex, and the radius of curvature of the curved convex is 0.4 or more and 0.8 or less for and the thickness of the body 43 of the plate, and the ratio of the thickness of the insulating film in a section, which covers the curved convex, to the thickness of the insulating film in a section, which covers the topside 64 of the body 43 of the plate, is 0.5 or over. This includes a press process for forming the body 43 of the plate and forming the curved convex simultaneously by pressing a plate material with a thickness of 0.8 mm or over so as to manufacture an end part magnetic plate 25.

Description

  The present invention relates to an electric motor manufacturing method for manufacturing an electric motor used for a drive source of a pump, for example.

  As a prior art, a fuel pump is known in which the pump unit is driven by the rotation of the armature of the motor unit to boost the fuel (for example, see Patent Document 1). The armature used for such a fuel pump has a laminated core and a coil wound around the laminated core.

  If the winding is wound directly around the slot of the laminated core when manufacturing the armature, there is a problem that the winding is damaged by the edge of the laminated core and a winding failure occurs. In order to solve such a problem, the edge of the laminated core is covered with an insulating film made of an insulating material to prevent the winding from being damaged during the winding.

  The insulating film is formed by heat curing a paint electrodeposited on the surface of the laminated core. Since the paints pull each other when the paint is heated and cured, if there is an edge in the laminated core, the paint on the edge is pulled from both sides with the edge as a boundary. As a result, the thickness of the insulating film formed on the edge is reduced, and there is a problem that the edge cannot be reliably covered with the insulating film having a predetermined thickness. In order to solve such a problem, a technique for chamfering an edge is disclosed (see Patent Document 2). By chamfering the edge, the force generated at the edge when the coating is heat-cured is reduced, and the thickness is prevented from being reduced.

JP 2007-104890 A Japanese Patent Laid-Open No. 9-247876

  Examples of the method of R-chamfering the edge of the laminated core include barrel processing, shot blasting, cutting processing, and filing. When the edge of the laminated core is chamfered by such a processing method, there is a problem that the manufacturing time of the laminated core increases.

  Accordingly, the present invention has been made in view of the above-described problems, and an object thereof is to provide a method for manufacturing an electric motor having a laminated core that can be easily covered with an insulating film while suppressing an increase in manufacturing time. To do.

  The present invention employs the following technical means in order to achieve the aforementioned object.

  The invention according to claim 1 includes a core that rotates around the rotation axis, forms a plurality of slots in the rotation direction, and accommodates a coil in each slot, and the core includes a plurality of layers stacked in the rotation axis direction. A magnetic plate and an insulating film that covers the laminated magnetic plates, and a plurality of slots are formed so as to be recessed radially inward from the outer peripheral surface of the core and to extend in the direction of the rotation axis of the core. Of the magnetic plates, the end magnetic plate forming the end of the core in the rotation axis direction has a plate main body that overlaps with the adjacent magnetic plate adjacent to the inner side of the rotation axis, and the thickness of the plate main body in the rotation axis direction. Is 1.5 times or more the thickness of the other magnetic plate in the direction of the rotation axis, and the surface on the outer side of the plate body portion in the direction of the rotation axis is connected to the surface facing the slot of the plate body portion by a curved convex surface. The radius of curvature of the convex surface is 0.4 to 0.8 times the thickness of the plate body. The ratio of the thickness of the insulating film covering the curved convex surface to the thickness of the insulating film covering the outer surface in the rotation axis direction of the plate body is 0.5 or more. A method comprising: a step of pressing a plate material having a thickness of 0.8 mm or more to form a plate main body portion and simultaneously forming a curved convex surface in order to manufacture an end magnetic plate. This is a method for manufacturing an electric motor.

  According to the first aspect of the present invention, the core is formed by laminating a plurality of magnetic plates in the rotation axis direction. A plurality of slots are formed in the core so as to be recessed radially inward from the outer peripheral surface and extend in the rotation axis direction. Accordingly, each magnetic plate is formed with a recess that is recessed radially inward to form a slot. By stacking the magnetic plates with the recesses, slots extending in the rotation axis direction can be formed on the outer peripheral surface of the core. Of the plurality of magnetic plates, an end magnetic plate that forms an end of the core in the rotation axis direction has a plate body that overlaps with an adjacent magnetic plate adjacent to the inner side in the rotation axis direction. The surface on the outer side in the rotation axis direction of the plate body portion is continuous with the surface facing the slot of the plate body portion and the curved convex surface. Although the laminated magnetic plates are covered with an insulating film, the curved convex surface can reduce the force generated at the edge of the plate main body when the paint for forming the insulating film is heat-cured. Accordingly, it is possible to suppress the thickness of the insulating film from being reduced.

  In order to manufacture such an end magnetic plate, a plate material having a thickness of 0.8 mm or more is pressed in a pressing step. A curved convex surface is formed simultaneously with the plate body. Therefore, since the process of forming only the curved convex surface is unnecessary, an increase in manufacturing time for forming the curved convex surface can be suppressed. Moreover, since the plate material having a thickness of 0.8 mm or more is pressed, the possibility that the curved convex surface cannot be formed due to the plate material being too thin can be reduced. Moreover, since the curvature radius of a curved convex surface is 0.4 times or more and 0.8 times or less of the thickness of a board main-body part, a curved convex surface can be formed in a board main-body part by press work.

  Furthermore, the ratio of the thickness of the insulating film in the portion covering the curved convex surface to the thickness of the insulating film in the portion covering the outer surface in the rotation axis direction of the plate body portion is 0.5 or more. By setting it as such a dimension, it can prevent that it becomes an insulation defect because the insulating film of the part which covers a curved convex surface becomes thin.

  In the invention according to claim 2, the end magnetic plate further has a protruding portion protruding outward from the outer peripheral edge portion of the plate main body portion in the rotation axis direction. In the pressing step, the protruding portion is formed at the same time as forming the curved convex surface. It is characterized by forming.

  According to the second aspect of the present invention, the end magnetic plate further has a protruding portion that protrudes outward in the rotational axis direction from the outer peripheral edge portion of the plate main body portion. Such a protrusion can be formed by bending a plate material by press working. Further, since the curved convex surface and the protruding portion are simultaneously formed in the pressing step, processing only for the protruding portion is unnecessary. Therefore, it can suppress that the manufacturing time of the core which has a protrusion part increases. Moreover, since it has a protrusion part, when a permanent magnet exists in the position facing the outer peripheral surface of a core, the area facing a permanent magnet becomes large. As a result, the amount of magnetic flux in the core can be increased without increasing the axial length of the core.

  Furthermore, in invention of Claim 3, the thickness of a board | plate material is 1.5 mm or less, It is characterized by the above-mentioned.

  According to invention of Claim 3, since thickness is 1.5 mm or less, it can suppress that thickness is too thick and the magnetic resistance in an edge part magnetic plate increases. Further, since the thickness is 1.5 mm or less, the plate material can be formed by a bending press in order to form the protruding portion.

  Furthermore, the invention described in claim 4 is characterized in that the thickness of the insulating film covering the curved convex surface is not less than 100 μm and not more than 300 μm.

  According to the invention described in claim 3, the thickness of the insulating film covering the curved convex surface is not less than 100 μm and not more than 300 μm. When the thickness of the insulating film is less than 100 μm, there is a high possibility that an insulation failure will occur. On the other hand, if the thickness of the insulating film is larger than 300 μm, the insulating film is too thick, so that the area that occupies the insulating film in the slot increases, and the coil cannot be reliably accommodated in the slot. In the present invention, since the thickness of the insulating film covering the curved convex surface is not less than 100 μm and not more than 300 μm, it is possible to prevent insulation failure and accommodate the coil in the slot.

  Further, the invention according to claim 5 is characterized in that the radius of curvature of the curved convex surface is not less than 0.4 mm and not more than 0.8 mm.

  According to invention of Claim 4, the curvature radius of a curved convex surface is 0.4 mm or more and 0.8 mm or less. If the radius of curvature of the curved convex surface is less than 0.4 mm, when the insulating film is formed, the insulating film becomes thin at the edge, and there is a high possibility that insulation failure will occur. If the radius of curvature of the curved convex surface is larger than 0.8 mm, the processed width may be large, and the curved convex surface may not be formed by press working. In the present invention, since the radius of curvature of the curved convex surface is 0.4 mm or more and 0.8 mm or less, it is possible to prevent a poor insulation and to form the curved convex surface on the plate material.

It is sectional drawing which shows the fuel pump 10 of 1st Embodiment. It is a front view which shows the state of the motor part 12 except the permanent magnet 16. FIG. 2 is a front view showing a state in which a shaft 18 is assembled to a laminated core 21. FIG. It is a perspective view which shows the state of the motor part 12 except the resin molding part 20. FIG. 3 is a front view showing an end magnetic plate 25. FIG. FIG. 6 is a cross-sectional view seen from a section line VI-VI in FIG. 5. 3 is an enlarged plan view showing a part of a laminated core 21. FIG. FIG. 8 is a cross-sectional view seen from the section line VIII-VIII in FIG. 7. It is a graph which shows an example of the relationship between the thickness of the insulating film 60, a withstand voltage, and a space factor. It is a graph which shows an example of the relationship between the radius R1 and an edge coverage.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a fuel pump 10 according to a first embodiment of the present invention. The fuel pump 10 is an in-tank type turbine pump accommodated in a fuel tank (not shown) such as a two-wheel or four-wheel vehicle. The fuel pump 10 includes a pump unit 11 and a motor unit 12 that drives the pump unit 11. The pump unit 11 is a turbine pump having a pump cover 13, a pump case 14, and an impeller 15. The motor unit 12 is an electric motor that rotationally drives the impeller 15. The motor unit 12 includes a permanent magnet 16, an armature 17, a shaft 18, a commutator 19, and a resin molding unit 20.

  First, the motor unit 12 will be described. FIG. 2 is a front view showing a state of the motor unit 12 excluding the permanent magnet 16. FIG. 3 is a front view showing a state in which the shaft 18 is assembled to the laminated core 21 constituting the armature 17. FIG. 4 is a perspective view showing a state of the motor unit 12 excluding the permanent magnet 16 and the resin molding unit 20.

  As shown in FIG. 1, the permanent magnet 16 has a cylindrical shape and alternately forms different magnetic poles in the circumferential direction. The permanent magnet 16 is made of a ferrite magnet, for example. The permanent magnet 16 has a cylindrical shape as a whole by arranging a plurality of arc-shaped magnet members in the circumferential direction. Two arc-shaped magnet members are attached to the inner peripheral wall of the housing in the circumferential direction. As a result, the permanent magnet 16 forms magnetic poles having different poles alternately in the circumferential direction on the inner circumferential side facing the armature 17.

  The armature 17 has a cylindrical shape and is rotatably disposed on the inner peripheral side of the permanent magnet 16, and includes a laminated core 21 having a plurality of slots 23 and a coil 24 accommodated in the slots 23. The laminated core 21 includes a plurality of magnetic plates 22. As shown in FIG. 3, the laminated core 21 is formed by laminating a plurality of magnetic plates 22 in the rotation axis direction Z (vertical direction in FIG. 1). The magnetic plate 22 is formed, for example, by pressing a silicon steel plate. Moreover, you may form the magnetic plate 22 using cold rolled steel plates, such as SPCC other than a silicon steel plate, for example.

  Of the plurality of magnetic plates 22, the two end magnetic plates 25 disposed at the end Z in the rotation axis direction of the laminated core 21 are other magnetic plates (hereinafter also referred to as “intermediate magnetic plates”). 39 and the configuration is different. FIG. 5 is a front view showing the end magnetic plate 25. FIG. 6 is a cross-sectional view seen from the section line VI-VI in FIG. In FIG. 5, the right half is omitted. The end magnetic plate 25 includes a plate main body 43 that overlaps with a magnetic plate adjacent to the inner side in the rotation axis direction Z (hereinafter also referred to as “adjacent magnetic plate 50”), and a rotation axis from the outer peripheral edge of the plate main body 43. And a protruding portion 26 protruding outward in the direction Z. Accordingly, the protruding portion 26 extends outward in the rotation axis direction Z so as to face the magnetic pole surface of the permanent magnet 16 on the outer peripheral side, that is, on the outer peripheral side, that is, on the outer peripheral side.

  Each magnetic plate 22 is formed with a plurality of slot recesses 27 that are recessed inward in the radial direction X from the outer peripheral surface of each magnetic plate 22 with a gap in the circumferential direction Y. In the present embodiment, eight slot recesses 27 are formed. By stacking the magnetic plates 22 so that the slot recesses 27 coincide with each other, a plurality of slots 23 extending in the rotation axis direction Z are formed in the laminated core 21. Therefore, by laminating the magnetic plate 22 having the slot recesses 27, the slot 23 is recessed inward in the radial direction X from the outer peripheral surface 51 of the laminated core 21, extends in the rotation axis direction Z of the laminated core 21, and is laminated. Are formed at intervals in the circumferential direction Y. Each magnetic plate 22 is formed with a shaft through hole 28 that penetrates each magnetic plate 22 in the rotation axis direction Z. The shaft 18 is press-fitted into the shaft through hole 28. An insulating layer (not shown) that suppresses electrical conduction is provided between adjacent magnetic plates 22. An insulating film 60 is formed on the portion of the laminated core 21 that contacts the coil 24, for example, the surface facing the slot 23.

  The coil 24 is wound using spaces 29 at both ends in the rotation axis direction Z of the armature 17 shown by a two-dot chain line in FIG. 1 (see FIG. 4). Such a space 29 is defined by the coil plate 30 provided on the shaft 18 and the end surface of the end magnetic plate 25 outside the rotation axis direction Z. The coil plate 30 is formed in a mortar shape. The coil plate 30 is provided to define the arrangement state of the coils 24 at both ends of the armature 17 in the rotation axis direction Z. In the armature 17 of this embodiment, the coil 24 is wound around the slot 23 by distributed winding.

  The shaft 18 is a rotating shaft of the armature 17 and is press-fitted into the shaft through hole 28 of the magnetic plate 22. Both ends of the shaft 18 in the rotation axis direction Z are respectively supported by two bearings 31. Each bearing 31 is supported by the pump case 14 and the bearing holder 32, respectively.

  The commutator 19 is formed in a disk shape, and is assembled to one end of the shaft 18 on the opposite side of the impeller 15 with respect to the armature 17. The commutator 19 has a plurality of segments 33 installed in the circumferential direction Y. The segment 33 is made of carbon, for example. The segments 33 adjacent to each other in the circumferential direction Y are electrically insulated by a gap and an insulating resin material. Each segment 33 of the commutator 19 is electrically connected to the commutator terminal 34. A winding 25a of the coil 24 is wound around the commutator terminal 34. The commutator terminal 34 and the coil 24 are electrically connected by fusing on the outer peripheral side of the commutator 19. As the armature 17 rotates, the end surface of each segment 33 on the opposite side in the axial direction with respect to the armature 17 is sequentially brought into contact with a brush (not shown), so that the drive current supplied to the coil 24 is rectified. .

  The resin molding portion 20 is made of an insulating resin and is filled so as to cover a fusing portion which is an electrical connection portion between the commutator terminal 34 and the winding 25a of the coil 24 except for a contact surface with the brush. Further, the resin molding portion 20 is filled in the end portion on the opposite side to the end portion where the commutator 19 of the armature 17 is provided, and the slot 23. By providing the resin molding part 20 in these parts, the armature 17 can be formed in a smooth columnar shape with no irregularities on the outer peripheral surface, and the rotational resistance of the armature 17 can be reduced. Further, the resin molded portion 20 can prevent the coil 24 and the electrical connection portion from being corroded.

  Next, the pump unit 11 will be described. The pump portion 11 is installed at the other end portion in the rotation axis direction Z with respect to the armature 17, and an impeller 15 as a rotation member is assembled to the shaft 18. The pump cover 13 and the pump case 14 accommodate the impeller 15 rotatably. The pump cover 13 is formed with a suction port 36 for sucking fuel into the pump passage 35. The pump passage 35 is formed in a C shape between the pump cover 13 and the pump case 14 and the outer peripheral edge of the impeller 15. The impeller 15 is formed in a disk shape, and a plurality of blade grooves (not shown) are formed on the outer peripheral edge in the rotation direction. When the impeller 15 rotates together with the shaft 18 due to the rotation of the armature 17, the fuel turns into a swirl flow by repeating the outflow and inflow of the fuel from the blade groove at the front in the rotation direction toward the blade groove at the rear in the rotation direction. The pressure is increased in the passage 35.

  The fuel whose pressure is increased by the rotation of the impeller 15 is pressure-fed from the discharge port (not shown) provided in the pump case 14 to the motor unit 12 side. The fuel pumped to the motor unit 12 side passes between the permanent magnet 16 and the armature 17 and is supplied from the discharge port 37 to the engine side. A check valve 38 is accommodated in the discharge port 37, and the check valve 38 prevents a back flow of fuel discharged from the discharge port 37.

  Next, the configuration of the laminated core 21 will be described in more detail. FIG. 7 is an enlarged plan view showing a part of the laminated core 21. FIG. 8 is a cross-sectional view seen from the section line VIII-VIII in FIG. In FIG. 7, the insulating film 60 constituting the laminated core 21 is omitted. As shown in FIGS. 7 and 8, the slot surface 53 facing the slot 23 in the plate main body 43 is continuous with the slot surface 63 facing the slot 23 in the adjacent magnetic plate 50.

  A T-shaped portion sandwiched between slots 23 adjacent to each other in the circumferential direction Y when viewed in the rotation axis direction Z is a portion called a tooth 62. The teeth 62 have a teeth main body 62a extending in the radial direction X when viewed in the rotation axis direction Z, and a teeth outer peripheral 62b extending in the circumferential direction Y connected to the outside in the radial direction X of the teeth main body 62a. Therefore, the outer peripheral surface of the teeth outer peripheral portion 62 b is a portion constituting the outer peripheral surface 51 of the laminated core 21.

  As shown in FIG. 8, the upper surface 64 on the outer side in the rotation axis direction Z of the plate main body 43 is connected to the slot surface 53 facing the slot of the plate main body 43 by a curved convex surface. The upper surface 64 on the outer side in the rotation axis direction Z of the plate main body 43 is opposite to the surface (surface on the inner side in the rotation axis direction Z) laminated on the adjacent magnetic plate 50 in the plate main body 43 in the rotation axis direction Z. It is a surface to be located. The curved convex surface is an arcuate curved surface having a radius R1 in the present embodiment. The curved convex surface does not protrude outward in the rotation axis direction Z from a virtual plane including the upper surface 64. Further, the curved convex surface does not protrude outward in the circumferential direction Y from a virtual plane including the slot surface 53.

  An edge 65 in the rotational direction of the upper surface 64 of the plate main body 43 is rounded by pressing and formed into a curved convex surface. Specifically, the edge 65 is formed into a curved convex surface by pressing the edge 65 in a press die. Surface pressing is to make the cutting edge by punching process a smooth curved surface. Further, the protruding portion 26 of the end magnetic plate 25 is formed by bending the outer peripheral edge portion in the radial direction X of the disk-shaped plate material such as a bending press. The step of forming the protrusion 26 and the step of forming the curved convex surface are performed by the same pressing step. Therefore, the edge 65 of the plate material is R-chamfered in the bending press process of the protruding portion 26. In other words, the protrusion 26 and the curved convex surface are simultaneously formed by pressing in the pressing process.

  The thickness t1 of the plate main body 43 is larger than the thickness t2 of the intermediate magnetic plate 39. The thickness t1 of the plate main body 43 is, for example, 1.0 mm, and the thickness t2 of the intermediate magnetic plate 39 is, for example, 0.5 mm. Therefore, the thickness t1 of the plate main body 43 is not less than 1.5 times and not more than 3.0 times the thickness t2 of the intermediate magnetic plate 39.

  The thickness t1 of the plate main body 43 is set to a dimension that can be pressed by pressing, and is set to 0.8 mm or more. Moreover, since the magnetic resistance increases as the thickness t1 of the plate body 43 increases, the amount of magnetic flux of the laminated core decreases. As a result, the torque of the motor unit 12 may decrease. Therefore, the thickness t1 of the plate body 43 is set to be 1.5 mm or less.

  Further, the curvature radius R1 of the curved convex surface is set to be not less than 0.4 times and not more than 0.8 times the thickness t1 of the plate body 43. A curved convex surface can be formed on the plate main body 43 by pressing when the ratio is 0.8 times or less. The grounds for 0.4 times or more will be described later. Here, the curvature radius R1 of the curved convex surface is a radius in a virtual plane parallel to the rotation axis.

  The laminated core 21 is provided with the insulating film 60 on the slot surface 53 facing at least the slot 23 as described above. The insulating film 60 is provided to insulate the laminated core 21 and the coil 24 from each other. The insulating film 60 also has a function of preventing the winding 25 a from being damaged by contacting the laminated core 21 when the winding 25 a is wound to accommodate the coil 24 in the slot 23 in the laminated core 21. . In order to form such an insulating film 60, first, powder that is a precursor of the insulating film 60 is applied to the slot surface 53 facing the slot 23 of the laminated body (see FIG. 3) in which the magnetic plates 22 are laminated. . Next, when the coated powder is heated, it hardens and becomes the insulating film 60. For example, epoxy powder is used as the powder to be coated. As the powder, not only epoxy powder but also fused silica, for example, is added as a material for adjusting the linear expansion coefficient. The powder coating is performed by, for example, an electrostatic powder coating method.

  Next, the thickness (film thickness) of the insulating film 60 will be described with reference to FIG. FIG. 9 is a graph showing an example of the relationship between the thickness of the insulating film 60, the withstand voltage, and the space factor. The withstand voltage on the left vertical axis in FIG. 9 is an index indicating whether insulation is ensured by the insulating film 60. The space factor on the right vertical axis in FIG. 9 is the ratio of the coil 24 in the slot 23.

  First, the withstand voltage will be described. The greater the withstand voltage value, the better the insulation. In this embodiment, in order to ensure insulation, the withstand voltage is preferably 1000 V or higher. The greater the thickness of the insulating film 60, the better the insulation. Therefore, the withstand voltage increases as the thickness of the insulating film 60 increases. In the present embodiment, since the withstand voltage of 1000 V is 100 μm, the thickness of the insulating film 60 is formed to be 100 μm or more.

  Next, the space factor will be described. As the thickness of the insulating film 60 increases, the area in the slot 23 decreases. Therefore, the space factor decreases as the thickness of the insulating film 60 increases. If the space factor is small, the coil 24 may not be reliably accommodated in the slot 23, and the coil 24 may protrude to the outer peripheral side of the laminated core 21. Therefore, the space factor is preferably 45% or less. In the present embodiment, since the thickness of the space factor of 45% is 300 μm, the thickness of the insulating film 60 is formed to be 300 μm or less.

  Therefore, the insulating film 60 is formed to have a thickness of 100 μm or more and 300 μm or less. As a result, it is possible to prevent insulation failure and to accommodate the coil 24 in the slot 23.

  Next, the radius R1 of the curved convex surface will be described with reference to FIG. FIG. 10 is a graph showing an example of the relationship between the radius R1 and the edge coverage. In FIG. 10, the vertical axis represents the edge coverage, and the horizontal axis represents the radius R1. The edge coverage is a ratio of the thickness t4 of the edge 65 to the thickness t3 of the upper surface 64 or the slot surface 53 when the insulating film 60 is formed. The thickness of the edge 65 is the thickness of the insulating film 60 that covers the curved convex surface. FIG. 10 shows the distribution of the formation results when 10 samples n are used for each of three cases where the radius R1 is 0.2 mm, 0.5 mm, and 0.8 mm. As the radius R1 increases, the edge cover ratio increases. This is because, when the coated powder is heated and cured, the powders are pulled from each other, and are pulled from both sides with the edge 65 of the plate main body 43 as a boundary. In the present embodiment, the edge 65 is rounded to be a curved convex surface, so that the force acting on the edge 65 is smaller, but the larger the radius R1, the smaller the acting force. Therefore, the edge coverage is preferably 0.5 or more. When the thickness t1 of the end magnetic plate is 1.0 mm, the radius R1 of the edge 65 is set to 0.4 mm or more and 0.8 mm or less. The upper limit of the radius R1 is 0.8 mm because a curved convex surface exceeding 0.8 mm, which is 0.8 times the thickness (plate thickness) t1, is formed on a plate material having a thickness t1 of 1.0 mm. This is because the processing width is large and difficult. When the radius R1 is 0.5 mm, for example, and the thickness t3 of the upper surface 64 is 300 μm, the edge cover ratio is 0.5 or more, so the thickness t4 of the edge 65 is 150 μm or more, and the insulating film 60 described above. Can meet the thickness requirement.

  As described above, the upper surface 64 on the outer side in the rotation axis direction Z of the plate main body 43 of the present embodiment is connected to the slot surface 53 of the plate main body 43 by the curved convex surface. The laminated magnetic plate 22 is covered by the insulating film 60, but the curved convex surface reduces the force generated at the edge 65 of the plate main body 43 when the paint for forming the insulating film 60 is heat-cured. Can do. Accordingly, it is possible to suppress the thickness of the insulating film 60 from being reduced.

  As a manufacturing method for manufacturing such a motor unit 12, a plate material having a thickness of 0.8 mm or more is pressed in the end magnetic plate 25 by a pressing process. The curved convex surface is formed during the pressing process. Therefore, among the steps of forming the end magnetic plate 25, for example, the step of forming the protrusion 26, the step of forming the slot recess 27, the step of forming the shaft through hole 28, and the step of forming the curved convex surface Can be formed by the same pressing process. This eliminates the need for the step of forming only the curved convex surface, so that an increase in manufacturing time for forming the curved convex surface can be suppressed. Further, since the plate material having a thickness of 0.8 mm or more and 1.5 mm or less is pressed, the possibility that the curved convex surface cannot be formed due to the plate material being too thin can be reduced. Moreover, when a board | plate material is too thick, it can suppress that a magnetic resistance increases.

  The curvature radius R1 of the curved convex surface is not less than 0.5 times and not more than 0.8 times the thickness of the plate body portion 43, and is relative to the thickness t3 of the insulating film 60 in the portion covering the upper surface 64 of the plate body portion 43. The ratio of the thickness t4 of the insulating film 60 that covers the curved convex surface is 0.5 or more. By setting it as such a dimension, it can prevent that the insulation film 60 of the part which covers a curved convex surface becomes thin and becomes insulation failure.

  Moreover, in this Embodiment, the thickness of the insulating film 60 of the part which covers a curved convex surface is 100 micrometers or more and 300 micrometers or less. When the thickness of the insulating film 60 is less than 100 μm, there is a high possibility that an insulation failure will occur. On the other hand, if the thickness of the insulating film 60 is larger than 300 μm, the insulating film 60 is too thick, so that the area that occupies the insulating film 60 in the slot 23 increases, and the coil 24 can be reliably accommodated in the slot 23. Disappear. In the present embodiment, since the thickness t4 of the insulating film 60 that covers the curved convex surface is 100 μm or more and 300 μm or less, it is possible to prevent insulation failure and to accommodate the coil in the slot 23. .

  Furthermore, in this Embodiment, the curvature radius of a curved convex surface is 0.4 mm or more and 0.8 mm or less. When the curvature radius of the curved convex surface is less than 0.4 mm, when the insulating film 60 is formed, the insulating film 60 becomes thin at the edge 65, and there is a high possibility that an insulation failure occurs. If the radius of curvature of the curved convex surface is larger than 0.8 mm, the processed width may be large, and the curved convex surface may not be formed by press working. In the present embodiment, since the radius of curvature of the curved convex surface is 0.4 mm or more and 0.8 mm or less, it is possible to prevent poor insulation and to form the curved convex surface on the plate material.

  Further, in the present embodiment, since the end magnetic plate 25 is formed with the protruding portion 26 facing the magnetic pole surface of the permanent magnet 16, the area of the laminated core 21 facing the magnetic pole surface of the permanent magnet 16 is widened. . Thereby, the magnetic flux amount of the laminated core 21 can be increased without increasing the axial length of the laminated core 21.

  Further, since the thickness of the plate material is 1.5 mm or less, it is possible to suppress an increase in the magnetic resistance in the end magnetic plate 25 due to the thickness being too thick. Further, since the thickness is 1.5 mm or less, bending press is possible, so that the protruding portion 26 and the curved convex surface can be simultaneously formed in the same pressing step.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the first embodiment described above, powder is applied to the slot surface 53 of the laminated core 21 in order to form the insulating film 60. However, the present invention is not limited to powder, and liquid paint may be applied. Good.

  In the first embodiment described above, the end magnetic plate 25 has the protruding portion 26, but may be a plate-shaped end magnetic plate 25 that does not have the protruding portion 26.

DESCRIPTION OF SYMBOLS 10 ... Fuel pump 11 ... Pump part 12 ... Motor part (electric motor)
17 ... Armature 18 ... Shaft 19 ... Commutator 20 ... Resin molding part 21 ... Laminated core (core)
22 ... Magnetic plate 23 ... Slot 24 ... Coil 25 ... End magnetic plate 26 ... Projection 39 ... Intermediate magnetic plate 43 ... Plate body 50 ... Adjacent magnetic plate 53 ... Slot surface 60 ... Insulating film 62 ... Teeth 65 ... Edge

Claims (5)

A core that rotates around a rotation axis, forms a plurality of slots in the rotation direction, and accommodates a coil in each slot;
The core has a plurality of magnetic plates stacked in the rotation axis direction, and an insulating film covering the stacked magnetic plates,
The slot is recessed radially inward from the outer peripheral surface of the core, and is formed in a plurality so as to extend in the rotation axis direction of the core,
Of the plurality of magnetic plates, the end magnetic plate that forms the rotation axis direction end of the core has a plate body that overlaps with an adjacent magnetic plate adjacent to the rotation axis direction inside,
The thickness in the direction of the rotation axis in the plate body is 1.5 times or more the thickness in the direction of the rotation axis in the other magnetic plate,
The surface of the plate body portion on the outer side in the rotation axis direction is continuous with a surface facing the slot of the plate body portion, and a curved convex surface,
The radius of curvature of the curved convex surface is not less than 0.4 times and not more than 0.8 times the thickness of the plate body part,
A motor in which the ratio of the thickness of the insulating film in the portion covering the curved convex surface to the thickness of the insulating film in the portion covering the outer surface in the rotation axis direction of the plate main body is 0.5 or more is manufactured. A method for manufacturing an electric motor,
In order to manufacture the end magnetic plate, an electric motor comprising a pressing step of pressing a plate material having a thickness of 0.8 mm or more to form the curved main surface at the same time as forming the plate main body portion. Manufacturing method. The end magnetic plate further has a protrusion that protrudes outward from the outer peripheral edge of the plate main body in the direction of the rotation axis,
The method of manufacturing an electric motor according to claim 1, wherein in the pressing step, the protruding portion is formed simultaneously with the formation of the curved convex surface.   The thickness of the said board | plate material is 1.5 mm or less, The manufacturing method of the electric motor of Claim 2 characterized by the above-mentioned.   4. The method of manufacturing an electric motor according to claim 1, wherein a thickness of the insulating film covering the curved convex surface is not less than 100 μm and not more than 300 μm.   The method of manufacturing an electric motor according to any one of claims 1 to 4, wherein a radius of curvature of the curved convex surface is not less than 0.4 mm and not more than 0.8 mm.

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