JP2008236921A - Magnetic circuit component, electric motor, fuel pump, and manufacturing methods for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic circuit component aimed at improving manufacturing speed, an electric motor, a fuel pump, and manufacturing methods for them. <P>SOLUTION: A stator 30 as the magnetic circuit component is manufactured through a cylinder arrangement process, in which a cylindrical core is formed by placing split cores with winding coiled in the rotating direction of a rotor; then a molding die arranging process, in which a core M3 for resin molding at the inside circumferential side of the cylindrical core; and then a molding process, in which the cylindrical core 32K is molded with a resin in a state that end portions in the circumferential direction of adjacent split cores can move freely, in such a manner that the pressure of molten resin is given in the direction of pressing the split cores toward the core M3. According to this method, the split cores are pressed toward the molding die by the pressure of the molten resin, while moving freely. As a result, the circularity at the cap side of the cylindrical core 32K can be dependent on the circularity of the core M3, so that it is less apt to be affected by the machining accuracy of the split cores. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic circuit component such as a stator and a rotor provided in an electric motor used for a fuel pump, for example.

  2. Description of the Related Art Conventionally, as this type of magnetic circuit component, a structure in which a cylindrical core is configured by arranging a plurality of divided cores wound with windings in a rotation direction is known. When this magnetic circuit component is applied to, for example, a stator, a rotor is disposed inside the cylindrical core. For example, when applied to a rotor, the rotating shaft is fixed inside the cylindrical core and the cylindrical core is fixed. The stator will be arranged on the outer peripheral side of the.

In such a type of magnetic circuit component having a plurality of divided cores, it is necessary to connect and hold the divided cores. Therefore, conventionally, an engaging portion is provided in the split core, and the engaging portions of the adjacent split cores are engaged with each other (see, for example, Patent Documents 1 to 3).
JP 2005-204369 A JP 2001-103690 A JP 2002-58181 A

  Here, managing the gap between the stator and the rotor with high accuracy greatly affects the performance of the electric motor. Therefore, it has been conventionally required to improve the roundness of a cylindrical core composed of a plurality of magnetic circuit components.

  However, in the structures described in Patent Documents 1 to 3 in which the engaging portions of the adjacent split cores are engaged with each other, the processing accuracy of the split cores, particularly the processing accuracy of the engaging portions, is improved in order to improve the roundness. Therefore, there is a limit to improving the roundness by improving the processing accuracy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a magnetic circuit component, an electric motor, a fuel pump, and a method for manufacturing the same, in which roundness is improved.

  Another object of the present invention is to provide a magnetic circuit component, an electric motor, a fuel pump, and a manufacturing method thereof for improving the manufacturing speed.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The inventors of the present invention have conceived the invention by paying attention to the following points. In other words, when improving the roundness of a cylindrical core composed of a plurality of magnetic circuit components, the roundness of the surface on the side where the gap between the stator and the rotor is located is improved on the inner and outer peripheral sides of the cylindrical core. If it can be made, the gap can be managed with high accuracy, and the performance of the electric motor can be improved.

  Focusing on this point, in the invention according to claim 1, in the method of manufacturing a magnetic circuit component, a cylindrical arrangement step of forming a cylindrical core by arranging a plurality of divided cores in a state where the winding is wound in the rotation direction of the rotor Then, a molding die arranging step of arranging a molding die for resin mold on the side on which the gap between the stator and the rotor is located among the inner peripheral side and the outer peripheral side of the cylindrical core, and then the adjacent division A molding step of resin-molding the cylindrical core so that the pressure of the molten resin is applied in a direction in which the split core is pressed against the mold while the circumferential ends of the core are relatively movable. Features.

  According to this, since the plurality of split cores are integrally held by the resin, the engaging portions described in Patent Documents 1 to 3 can be made unnecessary. When the resin molding is performed, the split core is pressed against the mold by the pressure of the molten resin while moving freely. As a result, the surface on the side on which the molding die is arranged among the inner peripheral side and the outer peripheral side of the cylindrical core, that is, the surface on which the gap between the stator and the rotor is located is positioned by the molding die. The roundness of the surface of the cylindrical core on the side where the gap is formed is less affected by the processing accuracy of the split core. For example, the radial dimensional accuracy of the split core does not affect the roundness of the surface of the cylindrical core that forms the gap.

  As described above, according to the present invention, the roundness on the gap side of the magnetic circuit component can be improved, so that the gap between the stator and the rotor can be managed with high accuracy, and the performance of the electric motor can be improved.

  As in the second aspect of the invention, the magnetic circuit component constitutes a stator, and in the molding die arrangement step, a core as a molding die is preferably inserted and arranged on the inner peripheral side of the cylindrical core. In this case, a magnetic circuit component is preferably used as a stator of a brushless motor having a rotor as a permanent magnet.

  In the invention described in claim 3, a groove extending in the direction of the rotation axis is formed on the surface on the opposite side of the inner peripheral side and outer peripheral side of the split core on which the molding die is arranged. Resin molding is performed so that molten resin flows into the groove. According to this, since the split core is pressed against the mold by the molten resin flowing into the groove, it is possible to easily realize resin molding so as to press the split core against the mold.

  In the invention according to claim 4, in the cylindrical arrangement step, a jig is used that grips the divided cores and moves them in the rotational direction so as to become a cylindrical core, and the division is performed by engaging the engaging portion of the jig with the groove. The core is held by a jig. According to this, when using the jig for gripping and moving the split core, the groove used for injecting the resin as described above is also used as the groove for engaging the engaging portion of the jig. Therefore, it is possible to eliminate the need for forming a groove dedicated to jig holding.

  In the invention described in claim 5, the jig is provided corresponding to each of the split cores and includes a holder unit having an engaging portion, and the plurality of holder units are connected to each other in a relatively rotatable state. In the cylindrical arrangement step, the cylindrical core is formed by moving the holder unit from a state in which the holder units are arranged in a row while holding the divided cores to a state in which the holder units are arranged in the rotational direction. According to this, it is possible to easily form the cylindrical core in the cylindrical arrangement step.

  Here, in the conventional manufacturing method, a wire is individually wound around a split core to form a winding, and a plurality of split cores in a state where the winding is formed are arranged in a cylindrical shape, and then split cores that are in phase Connect the windings between each other with a saddle line. As a result, the work of winding the winding and the work of connecting the saddle line are separate work, which is a troublesome work and causes a problem that the work speed is slow.

  With respect to this problem, in the invention according to claim 6, a planar arrangement step of arranging a plurality of divided cores in a line, a winding step of winding a wire around the divided cores to form a winding, and a winding around the divided cores. In the planar arrangement process, the winding process of winding the wound wire to other divided cores that are in phase to form a wound part, and continuously winding the process for each phase of the split core, The adjacent split cores are arranged apart from each other by a predetermined gap, and in the scooping step, the wire is wound so that no slack occurs in the winding part.

  In this way, if the divided cores adjacent to each other are arranged apart from each other by a predetermined gap in the plane arrangement step and wound so that no slack is generated in the winding portion in the continuous winding step, the cylinder in the cylinder arrangement step The inventors have found that excessive tension is not applied to the wound part in the process of forming the core, and that slack in the wound part can be avoided in the state where the cylindrical core is formed. . Therefore, according to the present invention, the work of winding the winding and the wire connection work can be performed continuously in the continuous winding process, so that the work time can be reduced and the work speed can be increased.

  In invention of Claim 7, the plane arrangement | positioning process which arranges a several division | segmentation core in a line, the winding process which winds a wire around a division | segmentation core, and forms the said coil | winding after that, and the wire wound around the division | segmentation core A continuous winding process in which the winding process of forming a wound portion by winding the other cores in the same phase is repeated for each phase of the split core, and then the plurality of split cores are rotated in the rotor direction. A cylindrical arrangement step of forming a cylindrical core side by side, and in the plane arrangement step, the adjacent divided cores are arranged apart from each other by a predetermined gap so that no slack occurs in the winding portion in the scooping step. It is characterized by scooping the wire.

  According to this, as described above, it is possible to avoid applying excessive tension to the winding part in the process of forming the cylindrical core in the cylinder arranging step, and further, the winding part is slack in the state where the cylindrical core is formed. Can also be avoided. Therefore, since the work of winding the winding and the wire connection work can be performed continuously in the continuous winding process, the work time can be reduced and the work speed can be increased.

  As described in claim 8, when the magnetic circuit component manufacturing method described above is applied to an electric motor manufacturing method, the same effect as described above is exhibited. According to the ninth aspect of the present invention, the method for manufacturing the electric motor is applied to a method for manufacturing a fuel pump in which the pressurized fuel is circulated through the gap between the stator and the rotor. In this case, since the gap is also used as the fuel passage, it is possible to manage the flow path cross-sectional area of the fuel passage with high accuracy because the gap can be managed with high accuracy.

  In the invention according to claim 10, in the magnetic circuit component constituting one of the stator and the rotor provided in the electric motor, the plurality of divided cores arranged in the rotation direction to constitute the cylindrical core, and wound around the divided core The adjacent split cores are resin-molded and held without being fastened to each other.

  According to this, since the plurality of split cores are integrally held by the resin, the engaging portions described in Patent Documents 1 to 3 can be made unnecessary. When the resin molding is performed, the split core can be pressed against the mold by the pressure of the molten resin while moving freely. As a result, the surface on the side on which the molding die is arranged among the inner peripheral side and the outer peripheral side of the cylindrical core, that is, the surface on which the gap between the stator and the rotor is located is positioned by the molding die. The roundness of the surface of the cylindrical core on the side where the gap is formed is less affected by the processing accuracy of the split core. As described above, according to the present invention, the roundness on the gap side of the magnetic circuit component can be improved, so that the gap between the stator and the rotor can be managed with high accuracy, and the performance of the electric motor can be improved.

  In the invention according to claim 11, a groove extending in the direction of the rotation axis is formed on the surface on the opposite side to the side where the gap between the stator and the rotor is located, on the inner peripheral side and the outer peripheral side of the split core. The groove has a shape in which a cross-sectional area expands from the opening of the groove toward the bottom so that the engaging portion of the jig that moves the cylindrical core by gripping the split core can be engaged. And is filled with a mold resin.

  According to this, since the split core is pressed against the mold by the molten resin flowing into the groove, it is possible to easily realize resin molding so as to press the split core against the mold. In addition, when using a jig for gripping and moving the split core, the groove used for injecting the resin as described above can also be used as a groove for engaging the engaging portion of the jig. It is not necessary to form a groove dedicated to gripping the jig.

  As described in claim 12, when the magnetic circuit component described above is applied to an electric motor, the same effect as described above is exhibited. According to a thirteenth aspect of the present invention, the electric motor is applied to a fuel pump that causes the boosted fuel to flow through the gap between the stator and the rotor. In this case, since the gap is also used as the fuel passage, it is possible to manage the flow path cross-sectional area of the fuel passage with high accuracy because the gap can be managed with high accuracy.

  Hereinafter, an embodiment in which a magnetic circuit component, an electric motor, and a fuel pump manufacturing method according to the present invention are applied to a fuel pump mounted on a vehicle will be described with reference to the drawings.

  First, the structure of the fuel pump 10 will be described with reference to FIGS. 1 and 2.

  1 is a cross-sectional view of the fuel pump 10, and FIG. 2 is a cross-sectional view taken along the line II of FIG. The fuel pump 10 according to the present embodiment is an in-tank type pump installed in a fuel tank of a two-wheeled vehicle, for example. As shown in FIG. 1, the fuel pump 10 includes a pump unit 12, a motor unit 13 that rotationally drives the impeller 20 of the pump unit 12, and an end support cover 28. The housing 14 surrounds the outer periphery of the pump unit 12 and the motor unit 13 and is a common housing for the pump unit 12 and the motor unit 13. The end support cover 28 covers the opposite side of the motor unit 13 from the pump unit 12 and forms a fuel discharge port 60.

  The pump unit 12 is a Wesco pump having a pump cover 16, a pump casing 18, and an impeller 20. The pump cover 16 and the pump casing 18 accommodate the impeller 20 rotatably. The fuel sucked from the suction port 17 formed in the pump cover 16 is pressurized by the rotation of the impeller 20 and passes through the fuel passage 62 formed between the inner peripheral surface of the stator 30 and the outer peripheral surface of the rotor 50. As described above, the liquid is discharged from the discharge port 60 formed in the end support cover 28.

  The motor unit 13 is a brushless motor (electric motor), and includes a stator 30 (magnetic circuit component), a winding 42, a rotor 50, and the like. As shown in FIG. 2, the stator 30 is configured by arranging six divided cores 32 in the circumferential direction. Each split core 32 generates a magnetic pole on the facing surface facing the rotor 50 by energizing the winding 42. That is, the gap between the inner peripheral surface of the stator 30 and the outer peripheral surface of the rotor 50 functions as the fuel passage 62 as described above, and also functions as the gap 62 on the magnetic circuit between the stator 30 and the rotor 50.

  Each divided core 32 has an outer peripheral portion 34 and a tooth 36, and is integrally formed by laminating magnetic steel plates provided with an insulating film in the rotation axis direction (perpendicular to the plane of FIG. 2). The outer peripheral portion 34 is formed in an arc shape having the same width in the circumferential direction, and is formed in an annular shape by the six outer peripheral portions 34. The teeth 36 protrude from the central part of the outer peripheral part 34 toward the rotor 50 on the inner peripheral side. A resin insulator 40 is assembled to each divided core 32 so as to be separated from the winding space. Further, a slit-like groove 35 extending in the stacking direction (perpendicular to the plane of FIG. 2) is formed at the center of the arc of the outer peripheral portion 34.

  The windings 42 are concentrated on the outer periphery of the insulator 40 for each of the split cores 32, and are electrically connected to the terminals 44 taken out of the end support cover 28 on the end support cover 28 side shown in FIG. Connected. The windings 42 are divided into three types, U-phase, V-phase, and W-phase. The drive current supplied to the windings 42 of each phase is switched by a control device (not shown), whereby the windings 42 of each phase. Is controlled. In order to switch the drive current supplied to the winding 42 and rotate the rotor 50, it is necessary to detect the rotational position of the rotor 50. Therefore, for example, it is preferable that the rotational position of the rotor 50 is detected by a detection element such as a Hall element and the drive current is switched based on the detection signal.

  The rotor 50 includes the shaft 24 and the permanent magnet 54, and is rotatably installed on the inner periphery of the stator 30. The shaft 24 is rotatably supported by bearings 26 and 27. As shown in FIG. 2, the permanent magnet 54 is formed of a single member in a cylindrical shape, and forms eight magnetic poles in the rotation direction. The eight magnetic poles are magnetized so as to form different magnetic poles alternately in the rotational direction on the outer peripheral surface facing the stator 30.

  Next, a method for manufacturing the stator 30 (magnetic circuit component) will be described.

  <1. Split Core Assembly Step> First, the split core 32 is formed by stacking and assembling press-formed magnetic steel sheets in the direction of the rotation axis (vertical direction in FIG. 3A). Thereafter, as shown in FIG. 3A, the insulator 40 is fitted from one end side and the other end side of the split core 32. In this way, six divided cores 32 into which the insulator 40 is fitted are prepared.

  <2. Planar Arrangement Step> Next, using the jig M1 shown in FIG. 4, six divided cores 32 are arranged in a line and arranged in a plane as shown in FIG. The split cores 32 arranged in a plane are arranged so that the arc end of the outer peripheral portion 34 faces the arc end of the outer peripheral portion 34 of the adjacent split core 32 and the outer peripheral portion 34 faces downward. In addition, illustration of the insulator 40 is abbreviate | omitted in FIG.3 (b) and FIG.

  As shown in FIG. 4, the jig M <b> 1 has six holder units 90, and the holder unit 90 includes a stopper member 91, a holder 92, a rod 93, and an elastic member 94. In the planar arrangement step, the six stopper members 91 are fixed in a line on the main body (not shown) of the jig M1. A holder 92 is accommodated in the stopper member 91 so as to be slidable. The holder 92 is connected to the rod 93 and slides integrally.

  FIG. 5A is a partially enlarged view of FIG. 4, and an engagement portion 92 a is formed on the holder 92. The engaging portion 92 a can engage with the groove 35 formed in the outer peripheral portion 34 of the split core 32. Specifically, the groove 35 is formed in a shape in which a cross-sectional area increases from the groove opening 35a toward the bottom 35b, and is engaged from the end surface in the longitudinal direction (perpendicular to the paper surface of FIG. 5) of the groove 35. The engaging portion 92a can be engaged with the groove 35 by inserting the portion 92a. It should be noted that the shapes of the engaging portion 92a and the groove 35 are not limited to the circular shape shown in FIG. 5A, but may be a trapezoidal shape shown in FIG. 5B, for example.

  The elastic member 94 applies an elastic force in a direction in which the holder 92 is accommodated in the stopper member 91. When the rod 93 is pushed against the elastic force by an external device (not shown), the engaging portion 92a of the holder 92 protrudes from the stopper member 91 to the outside.

  In the planar arrangement step, first, the rod 93 is pushed by an external device to project the engaging portion 92a, and the groove 35 is engaged with the engaging portion 92a in this state. Next, the external device is separated from the rod 93, and the holder 92 is pulled into the stopper member 91 by the elastic member 94. Then, the split core 32 is drawn together with the holder 92, and the outer peripheral portion 34 of the split core 32 abuts while being pressed against the stopper surface 91 a of the stopper member 91. Thereby, the split core 32 is fixed at a predetermined position.

  Specifically, the six divided cores 32 are planarly arranged in a row so that the adjacent divided cores 32 are separated from each other by a predetermined gap CL (see FIGS. 4 and 6). Specifically, the clearance CL is a clearance between the arc end of the outer peripheral portion 34 and the arc end of the outer peripheral portion 34 of the adjacent split core 32.

  <3. Continuous Winding Step> Next, using the winding machine M2 shown in FIG. 3B, a winding step of winding the wire 42N around the insulator 40 assembled to the split core 32 to form the winding 42 is performed. . Thereafter, a winding process is performed in which the wire 42N wound around the split core 32 is wound to another split core 32 having the same phase to form a wound portion 42a. Then, the winding step and the scooping step are continuously repeated for each phase (U phase, V phase, W phase) of the split core 32.

  In this continuous winding process, while the wire rod 42N is fed from the nozzle 95 provided in the winding machine M2, the position of the nozzle 95 is moved to wind the wire rod 42N to a desired position and to turn it. For example, if the nozzle 95 is swung around the split core 32 as indicated by the arrow Y1, the wire 42N is wound around the insulator 40. The wound portion 42 a is wound along the outer peripheral surface of the insulator 40.

  3 (c) and 6 are two views showing a state in which the winding process is completed, FIG. 6 (a) is a front view corresponding to FIG. 4, and FIG. 6 (b) is a view of FIG. 6 (a). FIG. As described above, the winding 42 is divided into three types of U-phase, V-phase, and W-phase, and the divided cores 32 are arranged in a line so as to be in the order of U-phase, V-phase, and W-phase. Yes. In FIG. 3C, only the U-phase winding 42 is shown. 3C and 6A, the symbol Us indicates the winding start portion of the wire 42N that is the U phase, and the symbol Ue indicates the winding end portion of the wire 42N that is the U phase.

  The function of each part located between the winding start part Us and the winding end part Ue in the U-phase wire 42N will be described below. That is, the winding start portion Us that starts to be wound around one of the split cores 32 of the pair of U phases, the portion that forms the winding 42 that is wound around one of the split cores 32, and the end of the insulator 40. A curled part 42b wound around the protrusion 40a and fixed, a wound part 42a, a curled part 42b fixed to the protrusion 40a related to the other split core 32, and a coil wound around the other split core 32 A part forming the line 42 and a winding end part Ue drawn out from the other split core 32 are formed in order.

  In other words, the nozzle 95 is moved so that the U-phase wire 42N has such a structure. Of the movement of the nozzle 95, the movement when forming the winding 42 corresponds to the winding process, and the movement when forming the winding portion 42a corresponds to the winding process. That is, the winding process and the scooping process for the U phase described above are continuously performed. Then, after winding the U-phase wire 42N as shown in FIG. 3 (c), the wire 42N is cut, and then the V-phase and W-phase wire 42N is wound by the same procedure as the U-phase. The scooping process is performed continuously.

  In the winding process in the continuous winding process, the nozzle 95 is moved while applying a predetermined tension to the wire 42N. Similarly, in the winding process, the nozzle 95 is moved while applying a predetermined tension to the wire 42N so that no slack is generated in the winding part 42a. In addition, since the bulge part 42b located in the both ends of the winding part 42a is being fixed to the protrusion part 40a, it can suppress that sagging arises in the winding part 42a after a continuous winding process is complete | finished.

  <4. Cylindrical Arrangement Step> Next, the six stopper members 91 fixed to the main body portion of the jig M1 in the planar arrangement step are removed from the main body portion, so that the six holder units 90 are movable. Here, FIG. 7 is a plan view of the jig M1 viewed from the direction of arrow III in FIG. 6B, and shows the back side of the jig M1 shown in FIG. As shown in FIG. 7, the six holder units 90 are connected in a rotatable state via a connecting shaft 96a by a link member 96 provided in the jig M1.

  In the cylindrical arrangement step, the six holder units 90 are moved in an annular shape as shown in FIG. As a result, as shown in FIG. 9, a plurality of the six divided cores 32 are arranged in the circumferential direction to form a cylindrical cylindrical core 32K.

  <5. Mold Die Arrangement Step> Next, a mold for applying a resin mold to the cylindrical core 32K is arranged. FIG. 10 is a cross-sectional view taken along the line IV-IV in FIG. 8, and the mold is mainly composed of a resin core M3 and a metal outer ring mold M4. The core M3 has a cylindrical shape, and the outer diameter of the core M3 is set to a size obtained by adding the gap 62 to the outer diameter of the rotor 50. The core M3 is inserted and disposed on the cylindrical inner peripheral surface side of the cylindrical core 32K, and the outer ring mold M4 is disposed on the cylindrical inner peripheral surface side of the cylindrical core 32K.

  Specifically, the core M3 is inserted into the cylindrical core 32K while the six holder units 90 are held by the jig M1, and the jig M1 is moved downward while being held by the jig M1. The cylindrical core 32K is inserted into the outer ring mold M4. Thereafter, the rod 93 is pushed out against the elastic force of the elastic member 94 by an external device (not shown), the outer peripheral portion 34 of the split core 32 pressed against the stopper surface 91a is opened, and the engaging portion 92a of the holder 92 is grooved. 35 is extracted from the upper end side (upper side in FIG. 10). Thereby, the jig M1 is removed from the cylindrical core 32K, and the core M3 and the outer ring mold M4 are arranged at predetermined positions with respect to the cylindrical core 32K.

  <6. Molding Process> As shown in FIG. 10, the injection gate 97 for injecting the molten resin into the mold is provided in a portion of the outer ring mold M4 that faces the groove 35 of each divided core 32, and also in the axial direction. Is located at the center of the groove 35. That is, the injection gates 97 are provided at six locations, and melt into the mold from the outer peripheral surface side of the cylindrical core 32K, as indicated by the arrow Y2 in FIG. 11 and FIG. Press-fit the resin. At this time, the circumferential end portions of the adjacent split cores 32 are not fastened and are freely movable. In other words, the six divided cores 32 are disposed in a space 97a (see FIG. 10) between the core M3 and the outer ring mold M4 so as to be freely movable in both the radial direction and the circumferential direction. Has been. The split core 32 is restricted from moving in the axial direction (vertical direction in FIG. 10).

  The molten resin injected from the injection gate 97 flows in preference to the groove 35 of the split core 32 having a low flow resistance. Therefore, each divided core 32 is pushed toward the radial center by the pressure of the molten resin in the groove 35. At this time, each divided core 32 can be freely moved both in the radial direction and in the circumferential direction, and is therefore pressed against the outer peripheral surface M3a (see FIGS. 10 and 11) of the core M3. Movement toward the center of the direction is restricted. Accordingly, since the six divided cores 32 are molded while being pressed against the outer peripheral surface M3a of the core M3, the roundness of the inner peripheral surface 32Ka (see FIG. 12) of the cylindrical core 32K is the core M3. It becomes equivalent to the roundness of the outer peripheral surface M3a.

  In addition, since the electrically conductive parts such as the winding 42 and the winding portion 42a are covered with the mold resin, damage and a short circuit of the winding 42 and the winding portion 42a are prevented. In addition, since the winding 42 and the winding portion 42a can be avoided from being immersed in the fuel, for example, even when a metal foreign matter is mixed in the fuel, the winding 42 and the winding portion 42a due to the metal foreign matter are mixed. Short circuit is prevented.

  As shown in FIG. 11, a protruding portion M3b that protrudes outward in the radial direction is provided on a portion of the outer peripheral surface M3a of the core M3 that is located between the adjacent split cores 32. As a result, the fuel passage 62 formed between the inner peripheral surface of the stator 30 and the outer peripheral surface of the rotor 50 is formed with a passage expanding portion 62a (see FIG. 2) that expands the passage radially outward. It becomes.

  <7. Demolding Step> Next, the outer ring mold M4 and the core M3 are removed from the molded cylindrical core 32K and demolded. FIG. 12 is a cross-sectional view showing the cylindrical core 32K in a removed state. In this state, the six divided cores 32 are integrally held by the mold resin. In FIG. 2, black portions indicate mold resin, and the mold resin portions constitute the end support cover 28 described above. When the cylindrical core 32K formed as described above is assembled so as to come into contact with the inside of the housing 14, the cylindrical core 32K including the six divided cores 32 and the windings 42 functions as a magnetic circuit component.

  As described above, according to the present embodiment, the following effects are exhibited.

  (1) When resin molding is performed, the split core 32 is pressed against the outer peripheral surface M3a of the core M3 by the pressure of the molten resin while freely moving, and movement toward the radial center is restricted. Therefore, the roundness of the inner circumferential surface 32Ka of the cylindrical core 32K is equal to the roundness of the outer circumferential surface M3a of the core M3 regardless of the machining accuracy of the split core 32. Specifically, the roundness of the inner peripheral surface 32Ka of the cylindrical core 32K can be ensured regardless of the press working accuracy of the magnetic steel plates arranged in a stack constituting the split core 32. That is, even if the radial dimension of the split core 32 varies, the roundness of the inner peripheral surface 32Ka of the cylindrical core 32K can be secured without being affected by the variation. Therefore, the gap 62 on the magnetic circuit, which is a gap between the inner peripheral surface of the stator 30 and the outer peripheral surface of the rotor 50, can be managed with high accuracy, and the performance of the motor unit 13 can be improved.

  Further, in the conventional manufacturing method in which the split cores 32 are fastened together by welding, there is a possibility that spatter generated during welding may be mixed into the resin mold as a metal foreign object. It will cause a short circuit. On the other hand, according to this embodiment, since the fastening of each divided core 32 is abolished, it is possible to prevent the occurrence of the metallic foreign matter as described above, and to avoid a short circuit of the electrically conductive component.

  (2) In the cylindrical arrangement step, a jig M1 that grips and moves the split core 32 to become the cylindrical core 32K is used, and the engaging portion 92a of the jig M1 is engaged with the groove 35 of the split core 32. As a result, the split core 32 is held by the jig M1. According to this, when using the jig M1 for gripping and moving the split core 32, the groove 35 used for injecting the resin as described above is engaged with the engaging portion 92a of the jig M1. Therefore, it is possible to eliminate the need for forming a dedicated groove for holding the jig.

  (3) In the present embodiment, in the plane arranging step, the adjacent divided cores 32 are arranged apart from each other by a predetermined gap CL, and in the step of turning, the wire 42N is scooped so that no slack occurs in the winding portion 42a. turn. According to this, it is possible to avoid applying excessive tension to the winding portion 42a in the process of forming the cylindrical core 32K in the cylinder arranging step, and further, the winding portion 42a is slack in the state where the cylindrical core 32K is formed. It can also be avoided. Therefore, since the work of winding the winding 42 and the work of forming the winding part 42a can be performed continuously, the labor of the work can be reduced and the work speed can be increased.

  (4) Here, since the resin insulator 40 is immersed in the fuel, it may swell, and when the insulator 40 swells, the passage sectional area of the fuel passage 62 becomes small. To solve this problem, if the gap between the inner circumferential surface of the stator 30 and the outer circumferential surface of the rotor 50 is simply enlarged in the radial direction to secure a passage cross-sectional area, this gap is a magnetic circuit between the stator 30 and the rotor 50. Since it functions as the upper gap 62, the amount of magnetic flux passing through the magnetic circuit is reduced, and the performance of the motor unit 13 is reduced.

  On the other hand, according to the present embodiment, since the passage enlarged portion 62a is formed as described above, a sufficient passage sectional area of the fuel passage 62 can be ensured even when the insulator 40 swells. Moreover, since the channel | path expansion part 62a is located between the adjacent split cores 32, it can suppress that the magnetic flux amount which passes a magnetic circuit falls.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and the characteristic structures of the above embodiments may be arbitrarily combined. For example, you may implement as follows.

  In the above embodiment, a permanent magnet is adopted for the rotor 50. However, when the rotor 50 is constituted by a plurality of divided cores 32, windings 42 and the like in the same manner as the stator 30, the rotor 50 is related to the present invention. You may make it apply as a magnetic circuit component. In this case, the shaft 24 is inserted and arranged on the inner peripheral surface side of the rotor 50.

  And when resin-molding the cylindrical core 32K comprised by the division | segmentation core 32 of the rotor 50, molten resin is press-fit in a shaping | molding die from the inner peripheral surface side of the cylindrical core 32K. At this time, each divided core 32 can be freely moved both in the radial direction and in the circumferential direction. Therefore, the divided core 32 is pressed against the inner circumferential surface of the outer ring mold M4, and the molding is performed while the movement outward in the radial direction is restricted. Is done. Thereby, the roundness of the outer peripheral surface of the cylindrical core 32K becomes equal to the roundness of the inner peripheral surface of the outer ring mold M4. Therefore, the gap 62 on the magnetic circuit, which is a gap between the inner peripheral surface of the stator 30 and the outer peripheral surface of the rotor 50, can be managed with high accuracy, and the performance of the motor unit 13 can be improved.

  In this case, if the groove 35 is formed on the inner peripheral surface of the teeth 36 of the split core 32, the split core 32 is pressed against the inner peripheral surface of the outer ring mold M4 by the molten resin flowing into the groove 35. It is easy to realize and is preferable.

  In the above embodiment, the winding portion 42 a is wound along the outer peripheral surface of the insulator 40, but may be wound along the inner peripheral surface of the insulator 40.

  Moreover, in the said embodiment, although the electric motor provided with a magnetic circuit component is applied to the motor part 13 of a fuel pump, the electric motor which concerns on this invention is not restricted to the electric motor for fuel pumps.

Sectional drawing which shows the fuel pump which concerns on one Embodiment of this invention. II sectional drawing of FIG. The perspective view explaining the manufacturing procedure of the stator shown in FIG. The top view which shows the manufacturing apparatus for manufacturing the stator of FIG. The elements on larger scale of FIG. FIG. 4 is a two-side view illustrating a state where the winding process of FIG. 3 is completed. The top view which looked at the jig | tool of FIG. 4 from the arrow III direction of FIG.6 (b). The perspective view which shows the state which moved the holder unit of the jig | tool of FIG. 4 cyclically | annularly. The perspective view which shows the state of the cylindrical core formed by the movement of the holder unit of FIG. IV-IV sectional drawing of FIG. The V arrow directional view of FIG. Sectional drawing which shows the state which carried out resin molding of the cylindrical core of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel pump, 13 ... Motor part (electric motor)
DESCRIPTION OF SYMBOLS 20 ... Impeller, 28 ... End support cover by mold resin part, 30 ... Stator, 32K ... Cylindrical core, 32 ... Split core, 35b ... Bottom part, 35 ... Groove, 35a ... Opening part, 42 ... Winding, 42N ... Wire, 42a ... winding portion, 50 ... rotor, 62 ... gap (fuel passage) between the inner peripheral surface of the stator and the outer peripheral surface of the rotor, 92a ... engagement portion, CL ... a predetermined gap between the split cores in the plane arranging step, M1 ... jig, M2 ... winding machine, M3 ... core (mold), M4 ... outer ring mold (mold).

Claims (13)

In a method of manufacturing a magnetic circuit component comprising one of a stator and a rotor provided in an electric motor, and having a plurality of divided cores arranged in a rotation direction and windings wound around the divided cores,
A cylindrical arrangement step of forming a cylindrical core by arranging a plurality of the divided cores in a state in which the winding is wound in the rotation direction of the rotor;
Thereafter, a molding die arranging step of arranging a molding die for a resin mold on a side where a gap between the stator and the rotor is located among the inner circumferential side and the outer circumferential side of the cylindrical core,
Thereafter, the cylindrical core is resin molded so that the pressure of the molten resin is applied in a direction in which the divided core is pressed against the mold while the circumferential ends of the adjacent divided cores are relatively movable. A molding process,
A method of manufacturing a magnetic circuit component comprising: The magnetic circuit component constitutes the stator,
2. The method of manufacturing a magnetic circuit component according to claim 1, wherein in the molding die arrangement step, a core as the molding die is inserted and arranged on an inner peripheral side of the cylindrical core. A groove extending in the direction of the rotation axis is formed on the surface on the side opposite to the side on which the molding die is arranged, of the inner peripheral side and the outer peripheral side of the split core,
3. The method of manufacturing a magnetic circuit component according to claim 1, wherein in the molding step, resin molding is performed so that molten resin flows into the groove.   In the cylindrical arrangement step, a jig that grips the divided cores and moves them so as to be arranged in the rotation direction to become the cylindrical cores is used, and the divided cores are engaged by engaging the engaging portions of the jigs with the grooves. The method of manufacturing a magnetic circuit component according to claim 3, wherein the jig is held by the jig. The jig includes a holder unit provided corresponding to each of the divided cores and having the engaging portion.
The plurality of holder units are coupled to each other in a relatively rotatable state,
5. The cylindrical core is formed by moving the holder unit from a state in which the holder units are arranged in a row while holding the divided cores to a state in which the holder units are arranged in a rotational direction. The manufacturing method of the magnetic circuit component of description. A planar arrangement step of arranging a plurality of the divided cores in a row;
Thereafter, a winding step of winding the wire around the split core to form the winding, and winding the wire wound around the split core to another split core in the same phase to form a wound portion A continuous winding step of repeating the turning step continuously for each phase of the split core;
Including
In the planar arrangement step, the adjacent divided cores are arranged apart by a predetermined gap,
6. The method of manufacturing a magnetic circuit component according to claim 1, wherein, in the winding step, the wire is wound so that no slack occurs in the winding portion. In a method of manufacturing a magnetic circuit component comprising one of a stator and a rotor provided in an electric motor, and having a plurality of divided cores arranged in a rotation direction and windings wound around the divided cores,
A planar arrangement step of arranging a plurality of the divided cores in a row;
Thereafter, a winding step of winding the wire around the split core to form the winding, and winding the wire wound around the split core to another split core in the same phase to form a wound portion A continuous winding step of repeating the turning step continuously for each phase of the split core;
Thereafter, a cylindrical arrangement step of forming a cylindrical core by arranging a plurality of the divided cores in the rotation direction of the rotor;
Including
In the planar arrangement step, the adjacent divided cores are arranged apart by a predetermined gap,
In the scooping step, the wire material is scooped so that no slack is generated in the winding part. A step of manufacturing one of a stator and a rotor provided in the electric motor by the method according to any one of claims 1 to 7,
Producing the other of the stator and the rotor;
Assembling the rotor to the stator;
The manufacturing method of the electric motor characterized by including. In a method for manufacturing a fuel pump, wherein an impeller is rotated by an electric motor to boost the fuel, and the boosted fuel is circulated through a gap between the stator and the rotor.
Producing an electric motor by the method according to claim 8;
Assembling an impeller for boosting fuel to the rotating shaft of the rotor;
A method for manufacturing a fuel pump, comprising: In a magnetic circuit component constituting one of a stator and a rotor provided in an electric motor,
A plurality of split cores arranged in a rotational direction to form a cylindrical core;
A winding wound around the split core;
With
Adjacent divided cores are held by being resin-molded without being fastened to each other. Of the inner peripheral side and the outer peripheral side of the split core, a groove extending in the rotation axis direction is formed on the surface opposite to the side where the gap between the stator and the rotor is located.
The groove is
It is formed in a shape in which the cross-sectional area expands from the opening of the groove toward the bottom so that it can be engaged with the engaging part of the jig that moves the gripping core to become the cylindrical core.
The magnetic circuit component according to claim 10, wherein the magnetic circuit component is filled with a mold resin. The magnetic circuit component according to claim 10 or 11, constituting one of a stator and a rotor,
The other of the stator and the rotor;
An electric motor comprising: An electric motor according to claim 12,
An impeller that rotates with the rotating shaft of the electric motor to boost the fuel;
With
A fuel pump, wherein the pressurized fuel is circulated through a gap between a stator and a rotor of the electric motor.

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