JP4771137B2 - MOTOR MANUFACTURING METHOD AND FUEL PUMP USING THE MOTOR - Google Patents

Description

The present invention relates to an inner rotor type brushless motor manufacturing method and a fuel pump using the same.

  Conventionally, a fuel pump using an inner rotor type brushless motor as a drive source is known (see, for example, Patent Documents 1 and 2). The brushless motor has a sliding resistance between the commutator and the brush like the brush motor, an electric resistance between the commutator and the brush, and a fluid resistance received by a groove provided to divide the commutator into each segment. There is no loss problem. As a result, the motor efficiency of the brushless motor is higher than that of the brush motor, and as a result, the efficiency of the fuel pump is improved. Here, the fuel pump efficiency is expressed by (motor efficiency) × (pump efficiency). Motor efficiency and pump efficiency are: I for drive current supplied to the motor of the fuel pump, V for applied voltage, T for motor torque, N for motor rotation speed, P for fuel pressure discharged by the fuel pump, and fuel discharge. When the quantity is Q, (motor efficiency) = (T × N) / (I × V), (pump efficiency) = (P × Q) / (T × N). That is, (fuel pump efficiency) = (motor efficiency) × (pump efficiency) = (P × Q) / (I × V).

And if it is equivalent motor efficiency, since a motor can be reduced in size rather than using a brush motor, the fuel pump using a brushless motor can be reduced in size.
The inventor of the present application, in such an inner rotor type brushless motor, by forming a stator core that surrounds the outer periphery of the rotor with a plurality of coil cores installed in the circumferential direction, a limited winding of each coil core with the miniaturization of the motor. We are studying a structure that easily winds a coil winding in a space with a high space factor. Here, the space factor is the ratio of the cross-sectional area of the winding occupying the winding space. That is, when the space factor is high, the number of windings that can be wound in the winding space increases, so that the motor efficiency can be improved while miniaturizing the motor.

  By the way, in the coil core 300 having the shape shown in FIG. 6 constituting the stator core, the inner peripheral surface 305 of the outer peripheral core 304 extending in the circumferential direction on the radially outer side of the teeth 302 of the coil core 300 has both ends in the circumferential direction of the inner peripheral surface 305. Is substantially located on an imaginary straight line 330 passing through. A coil winding surface 312 on the outer peripheral core 304 side of the insulator 310 around which the coil 320 is wound is along a virtual straight line 330. Thus, when the coil winding surface 312 on the outer peripheral core 304 side of the insulator 310 is along the virtual straight line 330, the winding can be easily wound in the winding space of the insulator 310.

  However, with the miniaturization of the motor, when the winding is wound a predetermined number of times in a limited winding space, the coil 320 reaches the vicinity of the opening of the insulator 310 and the coils adjacent in the circumferential direction approach or come into contact with each other. There is a risk of causing insulation failure between each other. In order to improve the motor efficiency, it is conceivable to increase the number of windings. However, for this purpose, a larger winding space is required. Therefore, it is required to increase the winding space of the winding while reducing the size of the motor.

JP 2005-110477 A JP 2005-110478 A

The present invention has been made to solve the above problems, while downsizing the motor, and an object thereof is to provide a fuel pump using the manufacturing method and its motor of the motor to increase the winding space.

According to the first aspect of the present invention, in the motor manufacturing method, a plurality of coil cores having teeth extending in the radial direction and outer peripheral cores extending in the circumferential direction on the radial outer side of the teeth are installed in the circumferential direction. A stator core;
An insulator that covers the coil core and that is at least partially disposed radially outward from a virtual straight line connecting the circumferential ends of the inner peripheral surface of the outer peripheral core;
A coil that is formed by winding a winding around the outer periphery of the insulator and switches a magnetic pole formed in the circumferential direction radially inward of the coil core by controlling energization;
A rotor that is rotatably installed on the inner peripheral side of the stator core and has magnetic poles that are alternately different in the rotation direction formed on the outer peripheral surface facing the stator core, and a method of manufacturing a motor,
A first step of placing the coil core fitted with the insulator on a base of a winding device with the outer peripheral core down;
After the first step, the winding is brought into contact with the guide surfaces at the upper ends of the guides positioned at both ends in the circumferential direction of the coil core and the guide surfaces at the upper ends of the guides positioned at both ends in the axial direction of the coil core. A second step of winding the winding around the insulator by moving a nozzle for supplying a wire in an axial direction and a circumferential direction of the coil core,
The guide surfaces at the upper ends of the guides positioned at both ends in the circumferential direction of the coil core extend linearly in the axial direction of the coil core, and the guide surfaces at the upper ends of the guides positioned at both ends in the axial direction of the coil core are The shape is almost along the inner coil winding surface,
In the second step, the nozzle applies tension to the winding toward the outer side in the radial direction of the coil core, guide surfaces at the upper ends of guides positioned at both ends in the circumferential direction of the coil core, and both ends in the axial direction of the coil core. The winding is brought into contact with the guide surface at the upper end of the guide located at the position, and when moving from one end side in the circumferential direction of the coil core toward the tooth side, by stopping or slowing down near the teeth , The winding is pushed into a coil winding surface of the insulator located on the radially outer side.
In the invention described in claims 1 to 4, at least a part of the insulator is disposed radially outside the imaginary straight line connecting the circumferential ends of the inner peripheral surface of the outer core. According to this structure, the winding space of a coil can be formed in the radial direction outer side rather than the circumferential direction both ends of an insulator, and winding space can be increased. Therefore, if the number of turns is the same, both circumferential positions of the coils wound around the coil cores can be recessed toward the teeth. Thereby, since the clearance gap between the coils adjacent to the circumferential direction becomes large, the insulation failure of the coils adjacent to the circumferential direction can be prevented. Further, since the winding space is increased, the number of winding turns can be increased while preventing the adjacent coils in the circumferential direction from being too close to each other, so that the motor efficiency is improved.

Here, in FIG. 6, the teeth 302 side of the outer peripheral core 304 of the coil core 300 is thicker than both sides in the circumferential direction of the outer peripheral core 304, but this thick portion is an unnecessary portion as a magnetic circuit.
Therefore, in the invention according to claim 2, since the teeth side of the inner peripheral surface of the outer peripheral core is located radially outside the virtual straight line connecting the circumferential ends of the inner peripheral surface of the outer core, the thickness is reduced. Yes. And the winding space is increasing because the teeth side of the coil winding surface by the side of the outer periphery core of an insulator is located in the diameter direction outside rather than a virtual straight line. Thus, by reducing the thickness of the unnecessary portion of the magnetic circuit, the winding space can be increased without deteriorating the magnetic performance.

In the invention according to claim 3, the teeth side of the coil winding surface on the outer peripheral core side of the insulator is a plane along a virtual straight line connecting both circumferential ends of the inner peripheral surface of the outer peripheral core. Therefore, the winding can be easily wound on the back side of the insulator along the plane of the coil winding surface.
In the invention according to claim 4, since the motor according to claims 1 to 3 is used, the fuel pump can be miniaturized.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A fuel pump using the motor according to the first embodiment of the present invention is shown in FIG. The fuel pump 10 of the present embodiment is an in-tank type turbine pump installed in a fuel tank of a two-wheeled vehicle having a displacement of 150 cc or less, for example.
The fuel pump 10 includes a pump 12 and a motor 14 that rotationally drives the pump 12. The housing of the fuel pump 10 is composed of housings 16 and 18. The housings 16 and 18 are each formed in a cylindrical shape by pressing a metal thin plate, and the housing 18 is press-fitted and fixed in the housing 16. The housing 16 also serves as a housing for the pump 12 and the motor 14 and has a thickness of about 0.5 mm. The pump case 20 and the stator core 30 are caulked and fixed at both axial ends of the housing 16. The pump case 22 and the stator core 30 are axially positioned by being abutted against both ends of the housing 18 in the axial direction.

  The pump 12 is a turbine pump having pump cases 20 and 22 and an impeller 24. The pump case 22 is press-fitted into the housing 16 and abuts against the housing 18 in the axial direction. The pump cases 20 and 22 are pump cases that rotatably accommodate an impeller 24 as a rotating member. C-shaped pump passages 202 are formed between the pump cases 20 and 22 and the impeller 24, respectively. The fuel sucked from the suction port 200 provided in the pump case 20 is pressurized in the pump passage 202 by the rotation of the impeller 24 and is pumped to the motor 14 side. The fuel pumped to the motor 14 side passes through the fuel passage 204 between the stator core 30 and the rotor 60 and is supplied from the discharge port 206 to the engine side.

  The motor 14 is an inner rotor type so-called brushless motor. The motor 14 has a stator core 30, an insulator 40, and a coil 48. As shown in FIG. 1, the stator core 30 is composed of six coil cores 32 that are installed separately at equal intervals in the circumferential direction. The coil core 32 is formed by caulking magnetic steel plates laminated in the axial direction. The coil core 32 includes a tooth 34 extending in the radial direction and an outer core 36 extending on both sides in the circumferential direction on the radially outer side of the tooth 34. The outer peripheral core 36 is formed in an arc shape with substantially the same thickness. The teeth 34 side of the inner peripheral surface 37 of the outer peripheral core 36 is located radially outside the virtual straight line 100 that connects both ends of the inner peripheral surface 37 in the circumferential direction.

  The pair of insulators 40 are formed in substantially the same shape, and are fitted to the coil cores 32 by being fitted to the coil cores 32 from both ends in the axial direction. The insulator 40 has an inner flange 42 on the radially inner side and an outer flange 44 on the radially outer side, and forms a winding space between the inner flange 42 and the outer flange 44. The coil 48 is formed by winding a winding in this winding space. The outer casing 44 is provided on the outer core 36 side of the insulator 40, and both end sides in the circumferential direction of the coil winding surface 46, which is the radially inner side surface of the outer casing 44, are formed in an arc shape along the outer core 36. In addition, the tooth winding side of the coil winding surface 46 is a plane along the virtual straight line 100. The coil 48 is formed by concentrically winding the windings around the insulator 40 for each coil core 32.

  As shown in FIG. 2, the insulating resin material 50 covers the stator core 30, the insulator 40, and the coil 48 except for the radially inner circumferential surface and the radially outer circumferential surface of the stator core 30. The end cover 52 is integrally molded with the insulating resin material 50 and forms a discharge port 206. The terminal 56 exposed from the end cover 52 and insert-molded is electrically connected to the coil 48.

  The rotor 60 includes a shaft 62 and a permanent magnet 64, and is rotatably installed on the inner periphery of the stator core 30. Both ends of the shaft 62 are rotatably supported by the bearing 26. The permanent magnet 64 is a plastic magnet formed into a cylindrical shape by kneading magnetic powder into a thermoplastic resin material such as PPS (polyphenylene sulfide) or POM (polyacetal). The permanent magnet 64 forms eight magnetic pole portions 65 in the rotation direction. The eight magnetic pole portions 65 are magnetized so as to form different magnetic poles alternately in the rotational direction on the outer peripheral surface facing the coil core 32.

Next, the winding process for forming the coil 48 will be described.
(1) First, the coil core 32 is formed by caulking magnetic steel plates laminated in the axial direction.
(2) The insulators 40 are fitted and attached to the coil cores 32 from both axial ends of the coil cores 32, respectively.
(3) The coil core 32 to which the insulator 40 is attached is placed on the base 122 of the winding device 120 shown in FIG. The mounting surface 124 of the base 122 on which the coil core 32 is mounted is a concave arc surface that matches the convex arc surface of the outer peripheral surface of the outer core 36. Guides 130 and 134 are respectively fixed with bolts or the like on both sides of the base 122 along the axial direction of the coil core 32 and on both ends in the axial direction. The guide surface 132 at the upper end of the guide 130 extends linearly in the axial direction of the coil core 32 and is formed in a smooth convex curved shape with respect to the winding 142 in order to guide the winding 142. The guide surface 136 at the upper end of the guide 134 has a shape substantially along the coil winding surface 46 of the insulator 40. That is, both circumferential sides of the guide surface 136 are along arcs on both circumferential sides of the coil winding surface 46 of the insulator 40, and the center of the guide surface 136 is substantially along the teeth 34 side of the coil winding surface 46 of the insulator 40. . Further, the guide surface 136 is formed in a smooth convex curved shape with respect to the winding 142 in order to guide the winding 142.

(4) After the coil core 32 to which the insulator 40 is attached is placed on the base 122, the nozzle 140 that supplies the winding 142 is brought closer to the coil core 32.
(5) Then, as shown in FIG. 3A, the nozzle 140 is moved in the axial direction of the coil core 32 while applying tension to the winding 142 to contact the guide surface 132 at the upper end of the guide 130. When the nozzle 140 reaches the axial end of the coil core 32, the winding 142 moves from the guide surface 132 of the guide 130 to the guide surface 136 of the guide 134.
(6) At this time, the nozzle 140 moves from one end side in the circumferential direction of the guide surface 136 toward the teeth 34 while applying tension to the winding 142 downward, and stops or slows down near the teeth 34. . As a result, the winding 142 is arranged on the tooth 34 side of the coil winding surface 46 of the insulator 40 that is located radially outside the both ends in the circumferential direction of the coil winding surface 46 on the outer peripheral core 36 side with respect to the virtual straight line 100. Can be pushed in.

Further, when winding the winding in the winding space of the insulator 40 positioned radially inward from both circumferential ends of the coil winding surface 46 on the outer peripheral core 36 side with respect to the virtual straight line 100, the guide surface Normal aligned winding is performed without pressing the winding 142 on the 136 side.
In this way, the winding 142 is concentrated and wound around the insulator 40 attached to each coil core 32.

  In the first embodiment described above, the thickness of the outer peripheral core 36 of the coil core 32 is made substantially equal, and the teeth 34 side of the inner peripheral surface 37 is closer to the imaginary straight line 100 connecting the circumferential ends of the inner peripheral surface 37 of the outer core 36. Since the coil core 32 is not formed in a portion unnecessary as a magnetic circuit, a part of the insulator 40 is installed instead. Thereby, winding space which the insulator 40 forms increases, reducing the coil core 32 in size. Therefore, if the number of turns of the winding 142 is the same, both end positions in the circumferential direction around which the coil 48 is wound can be recessed toward the teeth 34 side. As a result, as shown in FIG. 1B, the gap 110 formed by the coils 48 adjacent to each other in the circumferential direction is increased, so that insulation between the coils 48 is ensured.

In addition, since the winding space of the insulator 40 is increased, the number of turns of the winding 142 can be increased without the coils 48 adjacent in the circumferential direction being too close to each other. Thereby, motor efficiency can be improved.
In addition, since the teeth side of the coil winding surface 46 of the outer casing 44 of the insulator 40 is a plane along the virtual straight line 100, the coil 40 is wound on the far side of the winding space of the insulator 40 along the plane of the coil winding surface 46. The winding can be easily wound while preventing collapse.

(Second and third embodiments)
A second embodiment of the present invention is shown in FIG. 4, and a third embodiment is shown in FIG. In addition, the same code | symbol is attached | subjected to the substantially same component as 1st Embodiment.
In the second embodiment shown in FIG. 4, the outer flange 72 on the outer peripheral core 36 side of the insulator 70 is formed in an arc shape along the outer peripheral core 36 from both ends in the circumferential direction toward the teeth 34. The teeth 34 side of the coil winding surface 74 that is the radially inner side surface of the outer collar 72 is located on the radially outer side of the virtual straight line 100. Further, the coil winding surface 74 of the outer collar 72 is not a flat surface on the teeth 34 side as in the first embodiment, but is a concave arc surface facing from the both ends in the circumferential direction toward the teeth 34. Also in the insulator 70 having such a shape, the guide surface 136 of the guide 134 of the winding device 120 shown in FIG. 3 of the first embodiment is used as the coil winding surface 74 of the outer casing 72 of the insulator 70 in the second embodiment. Accordingly, the winding 142 can be concentrated and wound in the winding space of the insulator 70 formed radially outside the virtual straight line 100.
In the third embodiment shown in FIG. 5, the shapes of the coil core 32 and the insulator 40 are the same as those of the first embodiment. However, the winding method of the coil 142 forming the coil 80 is not an aligned winding but a random winding.

(Other embodiments)
In the above embodiments, the motor of the present invention is applied to the fuel pump. However, the motor of the present invention is not limited to the fuel pump and may be used as a drive source for other devices.
As described above, the present invention is not limited to the above-described plurality of embodiments, and can be applied to various embodiments without departing from the gist thereof.

(A) is sectional drawing which shows the coil core and insulator by 1st Embodiment, (B) is the figure which looked at the motor except a rotor from one axial end side. Sectional drawing which shows the fuel pump by 1st Embodiment. (A) is explanatory drawing which shows the winding process of a coil, (B) is the fragmentary sectional view which looked at (A) from the B direction. Sectional drawing which shows the coil core and insulator by 2nd Embodiment. Sectional drawing which shows the coil core and insulator by 3rd Embodiment. Sectional drawing which shows the conventional coil core and insulator.

Explanation of symbols

10: Fuel pump, 12: Pump, 14: Motor, 30: Stator core, 32: Coil core, 34: Teeth, 36: Outer core, 37: Inner circumferential surface, 40, 70: Insulator, 48, 80: Coil, 60: Rotor, 64: Permanent magnet, 100: Virtual straight line

Claims (4)

A stator core having a plurality of coil cores installed in the circumferential direction, the teeth extending in the radial direction, and an outer circumferential core extending in the circumferential direction on the radially outer side of the teeth;
An insulator that covers the coil core and that is at least partially disposed radially outward from a virtual straight line connecting the circumferential ends of the inner peripheral surface of the outer peripheral core;
A coil that is formed by winding a winding around the outer periphery of the insulator and switches a magnetic pole formed in the circumferential direction radially inward of the coil core by controlling energization;
A rotor that is rotatably installed on the inner peripheral side of the stator core and has magnetic poles that are alternately different in the rotation direction formed on the outer peripheral surface facing the stator core, and a method of manufacturing a motor,
A first step of placing the coil core fitted with the insulator on a base of a winding device with the outer peripheral core down;
After the first step, the winding is brought into contact with the guide surfaces at the upper ends of the guides positioned at both ends in the circumferential direction of the coil core and the guide surfaces at the upper ends of the guides positioned at both ends in the axial direction of the coil core. A second step of winding the winding around the insulator by moving a nozzle for supplying a wire in an axial direction and a circumferential direction of the coil core,
The guide surfaces at the upper ends of the guides positioned at both ends in the circumferential direction of the coil core extend linearly in the axial direction of the coil core, and the guide surfaces at the upper ends of the guides positioned at both ends in the axial direction of the coil core are The shape is almost along the inner coil winding surface,
In the second step, the nozzle applies tension to the winding toward the outer side in the radial direction of the coil core, guide surfaces at the upper ends of guides positioned at both ends in the circumferential direction of the coil core, and both ends in the axial direction of the coil core. When the winding is brought into contact with the guide surface at the upper end of the guide located at the end of the guide and moved from one end side in the circumferential direction of the coil core toward the tooth side, the virtual straight line is stopped or slowed down near the teeth. A method of manufacturing a motor, wherein the winding is pushed into a coil winding surface of the insulator positioned radially outward with respect to the insulator. The teeth side of the inner peripheral surface of the outer peripheral core is located radially outside of the virtual straight line,
The teeth side of the coil winding surface on the outer peripheral core side of the insulator is located radially outside the virtual straight line,
The method for manufacturing a motor according to claim 1. The method for manufacturing a motor according to claim 2, wherein the teeth side of the coil winding surface on the outer peripheral core side is a plane along the virtual straight line. A motor manufactured by the manufacturing method according to any one of claims 1 to 3,
A pump driven by the motor for sucking and boosting fuel;
With fuel pump.

Images