Rotating electric machine and manufacturing method thereof

Abstract

To sufficiently improve complete roundness in a rotary member including projections used for obtaining a trigger signal.SOLUTION: Totally 16 pieces of trigger projections 33a protruding radially outside of a cylindrical wall 33 and used for obtaining a trigger signal indicating a rotational state of a crankshaft are provided in a first area AR1 of the cylindrical wall 33. Totally 2 pieces of correction recesses 33c provided radially inside of the cylindrical wall 33 and recessed radially outside of the cylindrical wall 33 are provided in a second area AR2 of the cylindrical wall 33. The correction recesses 33c are provided, thereby correcting the cylindrical wall 33 close to be complete round. As a result, complete roundness of a rotor main body 31 comprising the trigger projections 33a used for obtaining the trigger signal can be sufficiently improved.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine including a stator and a rotor, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, an ACG starter, for example, has been used to start engines of motorcycles and the like. ACG stands for "Alternating Current Generator." An ACG starter operates as a starter motor that rotates the crankshaft when starting the engine, and as a generator that charges the vehicle battery after the engine has started. The ACG starter is also used to detect the rotation state of the crankshaft. This allows the vehicle controller to determine the spark plug ignition timing and fuel injection timing.

[0003] For example, Patent Document 1 describes a flywheel (rotating member) used in a rotating electric machine. This flywheel has a cylindrical yoke (ferromagnetic material) with a bottom, and multiple permanent magnets are fixed to the inner peripheral surface of the cylindrical portion that forms the yoke. In addition, multiple trigger protrusions that protrude outward and are axially elongated are provided circumferentially on the outer peripheral surface of the cylindrical portion.

[0004] These trigger protrusions are used to detect the rotational state of the crankshaft fixed to the flywheel. Specifically, a sensor (magnetic sensor) located opposite the trigger protrusion on the flywheel detects the magnetism of the magnetized trigger protrusion. As a result, the on-board controller electrically connected to the sensor detects the rotational state of the crankshaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2006 / 022392 Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology described in Patent Document 1, a shaving die is used to perform shaving to improve the roundness of the flywheel (rotating member) and the molding accuracy of the trigger protrusions (protrusions). However, there are regions around the circumferential direction of the flywheel where multiple trigger protrusions are formed and regions where these trigger protrusions are not formed. Therefore, it has been difficult to sufficiently correct (achieve high roundness) a flywheel that has been distorted by forming the trigger protrusions using shaving alone.

[0007] An object of the present invention is to provide a rotating electrical machine and a manufacturing method thereof that can sufficiently improve the roundness of a rotating member having a protrusion used to obtain a trigger signal. [Means for solving the problem]

[0008] The rotating electric machine of the present invention is a rotating electric machine including a stator and a rotor that rotates relative to the stator and has a plurality of permanent magnets arranged so that N poles and S poles appear alternately in the direction of rotation, wherein the rotor includes a rotating member having a bottom wall portion to which a rotating shaft is fixed and a cylindrical wall portion provided on the bottom wall portion and to which the plurality of permanent magnets are fixed, the cylindrical wall portion having a first region portion and a second region portion arranged in its circumferential direction, the first region portion having a plurality of convex portions that protrude radially outward from the cylindrical wall portion and are used to obtain a trigger signal that indicates the rotation state of the rotating shaft, and the second region portion having at least one first concave portion that is provided radially inward from the cylindrical wall portion and recessed radially outward from the cylindrical wall portion. a second recess having a depth dimension deeper than that of the first recess, provided on a radially inner side of the cylindrical wall portion and at a portion corresponding to the protrusion; There are.

[0009] A manufacturing method for a rotating electric machine of the present invention is a manufacturing method for a rotating electric machine including a stator and a rotor that rotates relative to the stator and has a plurality of permanent magnets arranged so that N poles and S poles appear alternately in the direction of rotation, and includes the following steps: a first step of preparing a rotating member that has a bottom wall portion to which a rotating shaft is fixed and a cylindrical wall portion that is provided on the bottom wall portion and to which the plurality of permanent magnets are fixed, and setting the rotating member in a press machine; a second step of forming, in a first region provided on the cylindrical wall portion, a plurality of convex portions that protrude radially outward from the cylindrical wall portion and are used to obtain a trigger signal that indicates the rotation state of the rotating shaft; and a third step of forming, in a second region provided on the cylindrical wall portion, at least one first concave portion that is provided radially inside the cylindrical wall portion and is recessed radially outward from the cylindrical wall portion. In the second step, a second recess having a depth dimension deeper than that of the first recess is formed on the radially inner side of the cylindrical wall portion and in a portion corresponding to the protrusion. do. [Effects of the Invention]

[0010] According to the present invention, the first region of the cylindrical wall is provided with a plurality of protrusions that protrude radially outward from the cylindrical wall and are used to obtain a trigger signal that indicates the rotation state of the rotating shaft, and the second region of the cylindrical wall is provided with at least one first recess that is provided radially inward from the cylindrical wall and recessed radially outward from the cylindrical wall. By providing the first recess, the cylindrical wall is corrected to approach a perfect circle, and therefore it is possible to sufficiently improve the roundness of the rotating member having the protrusions that are used to obtain the trigger signal. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing an ACG starter according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view illustrating the internal structure of the ACG starter of FIG. [Figure 3] FIG. 2 is a perspective view showing a rotor body of the ACG starter of FIG. 1. [Figure 4] 4 is a plan view of the rotor body of FIG. 3 as viewed from above. [Figure 5] FIG. 5 is a view taken along the arrow A in FIG. 4. [Figure 6] FIG. 6 is a cross-sectional view taken along line BB in FIG. 5. [Figure 7] FIG. 7 is an enlarged view of a portion C circled by a dashed line in FIG. [Figure 8] FIG. 7 is an enlarged view of a portion D circled by a dashed line in FIG. 6. [Figure 9] FIG. 10 is a cross-sectional view of the first press apparatus illustrating the workpiece setting step. [Figure 10] FIG. 10 is a cross-sectional view of a first press machine illustrating the trigger protrusion forming step. [Figure 11] FIG. 11 is a cross-sectional view taken along line EE in FIG. [Figure 12] FIG. 12 is a cross-sectional view corresponding to FIG. 11 of the second pressing device, illustrating the corrective recess forming step. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0013] FIG. 1 is a perspective view showing an ACG starter according to the present invention, FIG. 2 is a cross-sectional view illustrating the internal structure of the ACG starter of FIG. 1, FIG. 3 is a perspective view showing the rotor body of the ACG starter of FIG. 1, FIG. 4 is a plan view of the rotor body of FIG. 3 seen from above in the figure, FIG. 5 is a view as seen from the arrow A in FIG. 4, FIG. 6 is a cross-sectional view along line BB in FIG. 5, FIG. 7 is an enlarged view of part C circled in dashed line in FIG. 6, FIG. 8 is an enlarged view of part D circled in dashed line in FIG. 6, FIG. 9 is a cross-sectional view of a first press device illustrating the "work setting process", FIG. 10 is a cross-sectional view of the first press device illustrating the "trigger protrusion forming process", FIG. 11 is a cross-sectional view along line EE in FIG. 10, and FIG. 12 is a cross-sectional view corresponding to FIG. 11 of a second press device illustrating the "corrective recess forming process".

[0014] [ACG Starter Overview] 1 and 2 corresponds to the rotating electric machine of the present invention and is used as a starter and generator for a motorcycle or the like (not shown). Specifically, the ACG starter 10 employs the same structure as an outer rotor brushless motor. When starting an engine (not shown), the ACG starter 10 operates as a starter motor by receiving a drive current from an on-board battery (not shown), and after the engine has started, it operates as a generator by the driving force of the engine.

[0015] The ACG starter 10 is formed in a generally flat, disk-like shape and is provided at the axial end of a crankshaft (rotating shaft) CS that forms the rotating part of the engine. Specifically, the ACG starter 10 includes a stator 20 fixed inside a crankcase (not shown), and a rotor 30 fixed to the crankshaft CS and rotating relative to the stator 20.

[0016] Additionally, a plurality of trigger protrusions 33a are provided radially outward of the rotor 30, aligned in the circumferential direction. These trigger protrusions 33a are used to obtain trigger signals indicating the rotation state of the crankshaft CS, and a magnetic sensor MS is provided radially outward of the trigger protrusions 33a. The magnetic sensor MS is, for example, a Hall element, fixed inside the crankcase, and electrically connected to an on-board controller (not shown).

[0017] The multiple trigger protrusions 33a are magnetized by multiple permanent magnets MG provided radially inside the rotor 30, causing the magnetic sensor MS to generate a pulse signal (rectangular wave) each time it faces the trigger protrusion 33a. Therefore, when operating as a starter, a drive current is supplied to the ACG starter 10, which rotates the crankshaft CS as the rotor 30 rotates, and the plug and fuel pump operate at predetermined ignition and fuel injection timings to start the engine. On the other hand, when operating as a generator, the plug and fuel pump operate at predetermined ignition and fuel injection timings to continuously drive the engine, and the rotor 30 rotates as the crankshaft CS rotates, generating electricity.

[0018] [stator] The stator 20 includes a core 21 formed by laminating multiple steel plates (ferromagnetic material). The core 21 includes a ring-shaped main body 21a and multiple teeth 21b protruding radially outward from the main body 21a. In FIG. 2, dashed lines indicate boundaries between the main body 21a and the teeth 21b. Specifically, a total of 18 teeth 21b are provided (see FIG. 1), and the base ends of the teeth 21b are integrally connected to the main body 21a. In other words, the core 21 includes a total of 18 slots SL (see FIG. 1).

[0019] Coils CL corresponding to the U, V, and W phases (three phases) are arranged in the slots SL in order in the circumferential direction of the core 21. Specifically, the coils CL corresponding to the U, V, and W phases are wound around the teeth 21b in concentrated winding. Conductive wires CD are electrically connected to the coils CL corresponding to the U, V, and W phases, respectively, so that drive currents are sequentially supplied from the vehicle controller to the three-phase coils CL. Note that in FIG. 1, the coils CL are shaded to make the arrangement of the coils CL easier to understand.

[0020] Each tooth 21b is fitted with an insulator 22 made of an insulating material such as plastic. The insulators 22 are thin and cover the periphery of the teeth 21b and the outer periphery of the main body 21a. This insulates the teeth 21b from the coil CL. That is, the coil CL is wound around the tooth 21b via the insulator 22.

[0021] [Rotor] The rotor 30 includes a rotor body 31. The rotor body 31 corresponds to the rotating member of the present invention, and as shown in Figures 2 to 6, is formed into a roughly bowl shape by pressing a relatively thick steel plate (ferromagnetic material) or the like. Specifically, the rotor body 31 includes a bottom wall portion 32 formed in a roughly disk shape, and a cylindrical wall portion 33 that is integral with the bottom wall portion 32 and stands vertically from the outer periphery of the bottom wall portion 32.

[0022] A large diameter hole 32a is provided in the approximate center of the bottom wall portion 32. A boss portion 34b of the crankshaft fixing member 34 is inserted into the large diameter hole 32a. A total of six insertion holes 32b are provided around the large diameter hole 32a, and rivets RV (see FIG. 2) are inserted into these insertion holes 32b. A plurality of other holes are also provided in the bottom wall portion 32 for the purpose of weight reduction, etc.

[0023] A crankshaft fixing member 34, to which an axial end of the crankshaft CS is fixed, is fixed to the side of the bottom wall portion 32 opposite to the stator 20 side. In other words, the crankshaft CS is fixed to the bottom wall portion 32 via the crankshaft fixing member 34. The crankshaft fixing member 34 includes an annular main body 34a formed in a substantially annular shape and a boss portion 34b formed in a substantially cylindrical shape.

[0024] The annular body 34a is fixed to the bottom wall 32 with a plurality of rivets RV. The boss 34b is inserted into the large-diameter hole 32a, and the axial end of the crankshaft CS is fixed to the boss 34b so as not to rotate relative to the boss 34b. As a result, the crankshaft CS rotates in conjunction with the rotation of the rotor body 31, and the rotor body 31 rotates in conjunction with the rotation of the crankshaft CS.

[0025] The crankshaft fixing member 34 is thicker than the rotor body 31, and is relatively heavy. This ensures sufficient fixing strength between the ACG starter 10 and the crankshaft CS. Furthermore, this prevents rotational irregularities during high-speed rotation and reduces the load on both the crankshaft CS and the ACG starter 10. In this way, the crankshaft fixing member 34, together with the rotor body 31, functions as a flywheel.

[0026] [Permanent magnet] 1 and 2, a total of eight permanent magnets MG (not shown in detail) are attached to the radially inner side of the cylindrical wall portion 33, i.e., on the core 21 side of the cylindrical wall portion 33. These permanent magnets MG are made of ferrite magnets and are arranged so that the north and south poles appear alternately in the direction of rotation of the rotor body 31. However, the permanent magnets MG are not limited to ferrite magnets, and other types of magnets such as neodymium magnets can also be used. Each permanent magnet MG is formed in a roughly arc-like shape (roughly tile-like) following the shape of the inside of the cylindrical wall portion 33, and is firmly fixed to the cylindrical wall portion 33 with an adhesive or the like (not shown).

[0027] Furthermore, the total of eight permanent magnets MG are pressed against the cylindrical wall portion 33 from the radially inner side of the rotor body 31 by magnet holders HD formed in a substantially cylindrical shape. This more reliably prevents each permanent magnet MG from falling off the cylindrical wall portion 33. The magnet holders HD are formed from flexible thin stainless steel plates, SP material (cold-rolled steel plates), or the like.

[0028] [Trigger protrusion] 6, a first area AR1 and a second area AR2 are provided side by side in the circumferential direction of the cylindrical wall portion 33. Specifically, eight-ninths (an angular range of 320°) of the cylindrical wall portion 33 is the first area AR1, and one-ninth (an angular range of 40°) of the cylindrical wall portion 33 is the second area AR2.

[0029] A total of 16 trigger protrusions 33a are provided in the first region AR1 of the cylindrical wall portion 33. These trigger protrusions 33a correspond to the convex portions of the present invention and are provided to protrude radially outward from the cylindrical wall portion 33. The trigger protrusions 33a are used to obtain a trigger signal that indicates the rotation state of the crankshaft CS, and as shown in FIG. 2, face the magnetic sensor MS in the radial direction of the rotor main body 31.

[0030] A minute gap δS (approximately 0.5 mm) is provided between the trigger protrusion 33a and the magnetic sensor MS. This allows the magnetic sensor MS to reliably detect the magnetism of the magnetized trigger protrusion 33a while avoiding contact between the trigger protrusion 33a and the magnetic sensor MS. Each trigger protrusion 33a is magnetized by the magnetic force of a permanent magnet MG attached to the radially inner side of the cylindrical wall portion 33.

[0031] 3 and 5, the total of 16 trigger protrusions 33a are all formed in the same shape (approximately rectangular parallelepiped shape) that is short in the circumferential direction of the cylindrical wall portion 33 and long in the axial direction of the cylindrical wall portion 33. Furthermore, as shown in FIG. 6, these trigger protrusions 33a are arranged at equal intervals (20° intervals) in the circumferential direction of the cylindrical wall portion 33 within the range of the first region AR1 of the cylindrical wall portion 33. Furthermore, all of the trigger protrusions 33a are arranged in a portion of the cylindrical wall portion 33 near the bottom wall portion 32 in the axial direction, as shown in FIG.

[0032] 7, the trigger protrusions 33a protrude radially outward from the cylindrical wall portion 33, and the protrusion height H is approximately the same as the thickness T of the cylindrical wall portion 33 (H≈T). The total of 16 trigger protrusions 33a are formed by a first pressing device 40 shown in FIGS. 9 to 11.

[0033] 7, a recess 33b having a depth dimension d1 is provided on the radially inner side (lower side in the drawing) of a portion of the cylindrical wall portion 33 corresponding to the trigger protrusion 33a. The recess 33b corresponds to the second recess in the present invention and is recessed toward the radially outer side (upper side in the drawing) of the cylindrical wall portion 33. The depth dimension d1 of the recess 33b is deeper than the depth dimension d2 of the correction recess 33c (see FIG. 8) provided in the second region AR2 (d1>d2).

[0034] Here, the recess 33b is a portion that is depressed by being pressed by the tip 44a of the punch 44 of the first press device 40 (see FIGS. 9 to 11), thereby forming the trigger protrusion 33a so as to protrude radially outward from the cylindrical wall portion 33. The protruding height H of the trigger protrusion 33a is adjusted by adjusting the depth dimension d1 of the recess 33b (adjusting the pressing amount of the punch 44).

[0035] [Correction recess] 6, a total of two corrective recesses 33c are provided in the second region AR2 of the cylindrical wall portion 33. These corrective recesses 33c correspond to the first recesses of the present invention, and are provided on the radially inner side of the cylindrical wall portion 33 and recessed toward the radially outer side of the cylindrical wall portion 33. The pair of corrective recesses 33c are provided to remove (correct) distortion of the cylindrical wall portion 33 that occurs when the trigger protrusion 33a is formed in the first region AR1, and by providing the corrective recesses 33c in the second region AR2, high circularity of the cylindrical wall portion 33 is ensured.

[0036] In addition, in the present embodiment, the trigger protrusion 33a (recess 33b) and the correction recess 33c are both arranged at equal intervals (20° intervals) in the circumferential direction of the cylindrical wall portion 33. This enables the cylindrical wall portion 33 to approach a perfect circle with higher accuracy. However, depending on the accuracy (roundness) required for the cylindrical wall portion 33, one correction recess 33c may be provided, or three or more correction recesses 33c may be provided.

[0037] As shown in FIGS. 3 and 8, the total of two correction recesses 33c are both formed in the same shape, and have a shape that is short in the circumferential direction of the cylindrical wall portion 33 and long in the axial direction of the cylindrical wall portion 33 (substantially rectangular parallelepiped shape). Further, as shown in FIG. 6, these correction recesses 33c are arranged at 20° intervals from each other in the circumferential direction of the cylindrical wall portion 33 within the range of the second region portion AR2 of the cylindrical wall portion 33. Furthermore, as shown in FIG. 3, the pair of correction recesses 33c are arranged at a portion closer to the bottom wall portion 32 in the axial direction of the cylindrical wall portion 33, similar to the trigger protrusion 33a.

[0038] Also, as shown in FIG. 8, the depth dimension d2 of the correction recess 33c is a shallow dimension (d2 < d1) such that the cylindrical wall portion 33 does not protrude outward in its radial direction. Specifically, the depth dimension d2 of the correction recess 33c is set to be half or less of the depth dimension d1 of the recess 33b. As a result, the outer diameter dimension OD1 of the portion of the cylindrical wall portion 33 corresponding to the correction recess 33c is the same as the outer diameter dimension OD2 of the portion of the cylindrical wall portion 33 where the trigger protrusion 33a and the correction recess 33c are not provided (OD1 = OD2).

[0039] In this way, the correction recess 33c is formed only for the purpose of enhancing the roundness of the cylindrical wall portion 33, and the portion of the cylindrical wall portion 33 corresponding to the correction recess 33c does not protrude outward in the radial direction of the cylindrical wall portion 33 like the trigger protrusion 33a. Therefore, in the portion of the cylindrical wall portion 33 where the correction recess 33c is provided (the portion of the second region portion AR2), the magnetic sensor MS does not detect magnetism and does not generate a pulse signal (rectangular wave).

[0040] The two correction recesses 33c in total are formed by the second press device 50 shown in Fig. 12. Specifically, the correction recesses 33c are recessed portions pressed by the tip end 44a of the punch 44 of the second press device 50, and the depth dimension d2 of the correction recesses 33c is adjusted by adjusting the pressing amount of the punch 44 of the second press device 50.

[0041] [Rotor body manufacturing method] Next, a method for manufacturing the ACG starter 10 formed as above, in particular a method for manufacturing the rotor body 31 that forms the ACG starter 10, will be described in detail with reference to the drawings.

[0042] Prior to describing the manufacturing method of the rotor body 31, we will describe the structures of the first press device 40 and the second press device 50 used to manufacture the rotor body 31. Here, the first and second press devices 40 and 50 both correspond to the press device in the present invention.

[0043] [First press device] 9 to 11 is a device for forming the trigger protrusion 33a (recess 33b) in the first region AR1 (see FIG. 6) of the cylindrical wall portion 33. The first press device 40 includes a bottom base 41 fixed to a factory floor or the like (not shown), and an upper base 42 disposed above the bottom base 41.

[0044] A punch holder 43 is movably provided on the bottom base 41. The punch holder 43 moves toward or away from the upper base 42 by the driving force of a drive mechanism (not shown). A punch 44 that forms the trigger protrusion 33a (recess 33b) is fixed to the punch holder 43. The punch 44 has a tip 44a that forms the recess 33b, and the punch holder 43 holds the punch 44 so that the tip 44a faces the upper base 42.

[0045] A workpiece set member 45 formed in a substantially disk shape is attached to the front side (left side in FIG. 9) of the punch holder 43. The workpiece set member 45 is a part that supports the cylindrical wall portion 33 of the rotor body 31 (workpiece W) before the trigger protrusion 33a (recess 33b) and the correction recess 33c are formed. The punch 44 is able to slide against the workpiece set member 45, and the workpiece set member 45 has the function of guiding the movement of the punch 44.

[0046] Furthermore, a location plate 46 formed in a substantially disk shape is rotatably provided further forward of the work set member 45. The location plate 46 is a part that rotates relative to the punch 44 by the driving force of a drive mechanism (not shown). The work W supported by the work set member 45 can be fixed to the location plate 46 by a pin (not shown). The location plate 46 has the function of rotating the work W at predetermined angle intervals (at each pitch of the trigger protrusion 33a).

[0047] A stripper member 47 is provided on the upper base 42 side of the punch holder 43. A coil spring (not shown) is provided between the stripper member 47 and the punch holder 43. As a result, the stripper member 47 is biased toward the upper base 42 side by the spring force of the coil spring. After forming the trigger protrusion 33a (recess 33b), the stripper member 47 rises by the spring force of the coil spring and has the function of releasing (disengaging) the workpiece W (rotor main body 31) biting into the tip portion 44a of the punch 44.

[0048] A backing plate 48 is fixed to the bottom base 41 side of the upper base 42. A slotted die 49 is fixed to the bottom base 41 side of the backing plate 48. The backing plate 48 is a part that receives a processing load when the first press device 40 is in operation, and is a high-strength component. The slotted die 49 is provided with a hole 49a that extends in the movement direction of the punch 44, and the hole 49a faces the tip end 44a of the punch 44 in the movement direction of the punch 44. This makes it possible to form a trigger protrusion 33a that protrudes radially outward from the cylindrical wall portion 33.

[0049] As shown in FIG. 9, in the initial state of the first press device 40 (a state in which the workpiece W can be set), a first gap L1 is formed between the workpiece W and the holed die 49. In addition, a second gap L2 that is slightly narrower than the first gap L1 is formed between the punch holder 43 and the stripper member 47 (L2 <L1)。

[0050] [Second press device] The second press device 50 shown in Fig. 12 is a device for forming a correction recess 33c in the second region AR2 (see Fig. 6) of the cylindrical wall portion 33. That is, the second press device 50 has a function of correcting the cylindrical wall portion 33 (rotor main body 31) that has been distorted through processing by the first press device 40 so that it approaches a perfect circle.

[0051] The second press device 50 differs from the first press device 40 in that it is provided with a die 51 that does not have a hole. The other structures are the same as those of the first press device 40. Therefore, in FIG. 12, the same parts as those of the first press device 40 are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0052] In addition, the second press device 50 is controlled so that the feed amount (push amount) of the punch 44 is smaller than that of the first press device 40. This makes it possible to form the correcting recess 33c having a depth dimension d2 shallower than the recess 33b (depth dimension d1) on the radially inner side of the cylindrical wall portion 33 (d2 <d1)。

[0053] [Workset Operation] The "workpiece setting step" corresponds to the first step in the present invention. In the "workpiece setting step," first, a workpiece W that has been manufactured in advance in a separate manufacturing step is prepared. The workpiece W refers to the rotor body 31 before the trigger protrusion 33a (recess 33b) and the correction recess 33c (see FIG. 6) are formed.

[0054] Next, the prepared workpiece W is placed on the workpiece setting member 45 so that it faces the front side of the location plate 46 of the first press device 40, as shown by arrow M1 in Figure 9. Then, the bottom wall portion 32 of the workpiece W is fixed to the location plate 46 by pinning.

[0055] As a result, the workpiece W, which will later become the rotor body 31, is held by the workpiece setting member 45 and the location plate 46, completing the setting of the workpiece W in the first press device 40. This completes the "workpiece setting step."

[0056] [Trigger protrusion forming process] The "trigger protrusion forming process" corresponds to the second process in the present invention. In the "trigger protrusion forming process," first, as shown by arrow M2 in Fig. 9, the first press device 40 is operated to raise the punch holder 43 by the amount of the first gap L1. This causes the outer peripheral portion of the cylindrical wall portion 33 of the workpiece W to abut against the lower surface of the holed die 49 (the surface on the bottom base 41 side).

[0057] Next, the punch holder 43 is raised as shown by arrow M3 in FIG. 10. Specifically, the punch holder 43 is further raised by the amount of the second gap L2 shown in FIG. 9. Then, as shown in FIGS. 10 and 11, the tip 44a of the punch 44 bites into a predetermined location on the radially inner side of the cylindrical wall portion 33, causing the cylindrical wall portion 33 to plastically deform and form a recess 33b. The portion of the cylindrical wall portion 33 pushed out by the tip 44a escapes into the hole 49a of the holed die 49. As a result, the trigger protrusion 33a is formed so as to protrude radially outward from the cylindrical wall portion 33.

[0058] The above-described molding operation of the trigger protrusions 33a (recesses 33b) is repeated the number of times equal to the required number of trigger protrusions 33a. Specifically, as shown in Fig. 11, the location plate 46 rotates in 20° increments in the direction of the arrow RT, and a total of 16 trigger protrusions 33a are formed at 20° intervals in the first area AR1 (see Fig. 6) provided in the cylindrical wall portion 33.

[0059] At this time, the tip 44a of the punch 44 is pressed toward the cylindrical wall portion 33 with a strong force and forms a recess 33b with a depth d1, so that the tip 44a bites into the cylindrical wall portion 33. However, when the punch holder 43 descends, the stripper member 47 presses the cylindrical wall portion 33 upward by the spring force of the coil spring. Therefore, the tip 44a of the punch 44 easily comes out of the recess 33b of the cylindrical wall portion 33.

[0060] In this way, the formation of the trigger protrusion 33a (recess 33b) in the first region AR1 of the cylindrical wall portion 33 is completed, and the "trigger protrusion forming step" is finished.

[0061] [Corrective recess forming process] The "corrective recess forming step" corresponds to the third step in the present invention. Before proceeding to the "corrective recess forming step," the workpiece W that has been through the "trigger protrusion forming step" is first set in the second press device 50 either manually by an operator or automatically by an arm robot (see FIG. 12). At this time, the workpiece W is held by the workpiece set member 45 and location plate 46 (not shown) of the second press device 50 so that the second area AR2 provided in the cylindrical wall portion 33 faces the die 51.

[0062] 12, the second press device 50 is operated to raise the punch holder 43, whereby the tip 44a of the punch 44 forms a corrective recess 33c that is recessed radially outward of the cylindrical wall portion 33 on the radially inner side of the second region AR2 of the cylindrical wall portion 33. Thereafter, in the same manner as described above, the location plate 46 rotates by 20° in the direction of the arrow RT, and another corrective recess 33c is continuously formed.

[0063] As a result, the distortion of the cylindrical wall portion 33 (particularly the distortion concentrated in the second region AR2) caused by forming the trigger protrusion 33a (recess 33b) in the first region AR1 of the cylindrical wall portion 33 is corrected by forming the correction recess 33c in the second region AR2 of the cylindrical wall portion 33, thereby improving the circularity of the cylindrical wall portion 33 (workpiece W).

[0064] Therefore, the outer diameter dimension OD1 of the portion of the cylindrical wall portion 33 corresponding to the corrective recess 33c and the outer diameter dimension OD2 of the portion of the cylindrical wall portion 33 where the trigger protrusion 33a and the corrective recess 33c are not provided are made the same dimensions (OD1 = OD2), and the [corrective recess molding process] is completed, and ultimately, the rotor body 31 with improved circularity is completed.

[0065] As described above in detail, according to this embodiment, the first region AR1 of the cylindrical wall portion 33 is provided with a total of 16 trigger protrusions 33a that protrude radially outward from the cylindrical wall portion 33 and are used to obtain trigger signals that indicate the rotation state of the crankshaft CS, and the second region AR2 of the cylindrical wall portion 33 is provided with a total of two correcting recesses 33c that are provided radially inward from the cylindrical wall portion 33 and recessed radially outward from the cylindrical wall portion 33. By providing the correcting recesses 33c, the cylindrical wall portion 33 is corrected so that it approaches a perfect circle, and therefore it is possible to sufficiently improve the roundness of the rotor body 31 that has the trigger protrusions 33a that are used to obtain trigger signals.

[0066] Furthermore, according to this embodiment, a recess 33b having a depth d1 that is deeper than the depth d2 of the correcting recess 33c is provided at a portion corresponding to the trigger protrusion 33a on the radially inner side of the cylindrical wall portion 33. This makes it possible to form both the trigger protrusion 33a and the correcting recess 33c by pressing the punch 44 from the radially inner side to the radially outer side of the cylindrical wall portion 33, thereby improving work efficiency.

[0067] Furthermore, according to this embodiment, the outer diameter OD1 of the portion of the cylindrical wall portion 33 corresponding to the correcting recess 33c is the same as the outer diameter OD2 of the portion of the cylindrical wall portion 33 where the trigger protrusion 33a and the correcting recess 33c are not provided. This improves the roundness of the rotor body 31, suppresses the occurrence of rotational irregularities of the rotor body 31, and suppresses increases in the rotational resistance of the crankshaft CS, making it possible to improve the fuel efficiency of motorcycles, etc.

[0068] Furthermore, according to this embodiment, while improving the working efficiency as described above, the roundness of the rotor body 31 can be sufficiently improved, and furthermore, the fuel efficiency of motorcycles and the like can be improved, which makes it possible to achieve the Sustainable Development Goals (SDGs) established by the United Nations, particularly Goal 7 (Affordable and clean energy) and Goal 13 (Climate action).

[0069] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, the ACG starter 10 having a total of eight permanent magnets MG and a total of 18 teeth 21b (slots SL) has been described as an example, but the present invention is not limited to this, and the numbers of permanent magnets MG and teeth 21b (slots SL), as well as the numbers of trigger protrusions 33a and corrective recesses 33c, can be set as desired according to the specifications required for the ACG starter.

[0070] Furthermore, in the above embodiment, the trigger protrusion 33a and the corrective recess 33c are formed using two presses (the first press 40 and the second press 50). However, the present invention is not limited to this. For example, both the trigger protrusion 33a and the corrective recess 33c can be formed using a single first press 40 by precisely controlling the feed rate of the punch 44. In this case, when forming the corrective recess 33c, efforts are made to avoid forming a protrusion on the radially outer side of the cylindrical wall portion 33 as much as possible. Even if a protrusion is formed, its protruding height is kept low so that the magnetic field of that portion is not detected by the magnetic sensor MS (see FIG. 2).

[0071] Furthermore, in the above embodiment, the ACG starter 10 has been described as being used as an example for a starter and generator for a motorcycle or the like, but the present invention is not limited to this and can also be applied to ACG starters used, for example, in agricultural machinery such as cultivators, outboard motors for small boats, etc.

[0072] Furthermore, the material, shape, size, number, installation location, etc. of each component in the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited to the above-described embodiments. [Explanation of symbols]

[0073] 10: ACG starter (rotating electric machine), 20: stator, 21: core, 21a: main body, 21b: teeth, 22: insulator, 30: rotor, 31: rotor main body (rotating member), 32: bottom wall, 32a: large diameter hole, 32b: insertion hole, 33: cylindrical wall, 33a: trigger protrusion (convex portion), 33b: recess (second recess), 33c: correction recess (first recess), 34: crankshaft fixing member, 34a: annular main body, 34b: boss portion, 40: first press device (press device), 41: bottom base, 42: upper base, 43: punch holder, 44 : Punch, 44a: Tip, 45: Workpiece set member, 46: Location plate, 47: Stripper member, 48: Backing plate, 49: Die with hole, 49a: Hole, 50: Second press device (press device), 51: Die, AR1: First area, AR2: Second area, CD: Conductive wire, CL: Coil, CS: Crankshaft (rotating shaft), HD: Magnet holder, L1: First gap, L2: Second gap, MG: Permanent magnet, MS: Magnetic sensor, OD1, OD2: Outer diameter, RV: Rivet, SL: Slot, W: Workpiece, δS: Minute gap

Claims

1. A stator; a rotor that rotates relative to the stator and has a plurality of permanent magnets arranged so that N poles and S poles appear alternately in the direction of rotation; A rotating electric machine comprising: The rotor is a bottom wall portion to which the rotation shaft is fixed; a cylindrical wall portion provided on the bottom wall portion and to which the plurality of permanent magnets are fixed; a rotating member having the cylindrical wall portion has a first region portion and a second region portion arranged in a circumferential direction thereof, the first region is provided with a plurality of protrusions that protrude radially outward from the cylindrical wall portion and are used to obtain a trigger signal that indicates a rotation state of the rotating shaft, The second region includes at least one first recess provided radially inside the cylindrical wall portion and recessed radially outside the cylindrical wall portion, a second recess having a depth dimension deeper than a depth dimension of the first recess is provided at a radially inner side of the cylindrical wall portion and at a portion corresponding to the protrusion; Rotating electric motor.

2. an outer diameter dimension of a portion of the cylindrical wall portion corresponding to the first recessed portion is the same as an outer diameter dimension of a portion of the cylindrical wall portion where the convex portion and the first recessed portion are not provided; The rotating electric machine according to claim 1 .

3. A stator; a rotor that rotates relative to the stator and has a plurality of permanent magnets arranged so that N poles and S poles appear alternately in the direction of rotation; A manufacturing method of a rotating electric machine comprising: a first step of preparing a rotating member having a bottom wall portion to which a rotating shaft is fixed and a cylindrical wall portion provided on the bottom wall portion and to which the plurality of permanent magnets are fixed, and setting the rotating member in a press device; a second step of forming a plurality of protrusions in a first region provided in the cylindrical wall portion, the protrusions protruding radially outward from the cylindrical wall portion and used to obtain a trigger signal indicating a rotation state of the rotating shaft; a third step of forming at least one first recess in the second region provided in the cylindrical wall portion, the first recess being provided radially inside the cylindrical wall portion and recessed radially outside the cylindrical wall portion; and In the second step, a second recess having a depth dimension deeper than a depth dimension of the first recess is formed on a radially inner side of the cylindrical wall portion and in a portion corresponding to the protrusion. A manufacturing method for a rotating electric machine.

4. In the third step, an outer diameter dimension of a portion of the cylindrical wall portion corresponding to the first recess is set to be the same as an outer diameter dimension of a portion of the cylindrical wall portion where the convex portion and the first recess are not provided. The method for manufacturing a rotating electric machine according to claim 3 .

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