CN113692691A

CN113692691A - Rotating electric machine for internal combustion engine and rotor thereof

Info

Publication number: CN113692691A
Application number: CN202080029630.5A
Authority: CN
Inventors: 山下辉
Original assignee: Denso Duolimu Co ltd
Current assignee: Denso Duolimu Co ltd
Priority date: 2019-04-26
Filing date: 2020-04-01
Publication date: 2021-11-23
Anticipated expiration: 2040-04-01
Also published as: CN113692691B; JP7129560B2; JPWO2020217900A1; WO2020217900A1

Abstract

The rotor (21) has a plurality of permanent magnets (23). The stator (31) includes a sensor unit (37). The sensor unit (37) includes a plurality of sensors (38). Sensors (38a, 38b, 38c) as rotational position sensors detect the basic magnetic pole (26) on the basic magnetic pole track (28). A sensor (38d) as a reference position sensor detects the special magnetic pole (27) on the special magnetic pole track (29). The special magnetic pole (27) provides a magnetic pole of the same polarity on two circumferentially adjacent magnetic poles. The special magnetic pole (27) does not provide a magnetic pole of the same polarity on three magnetic poles adjacent in the circumferential direction. As a result, a high-resolution reference position signal is provided.

Description

Rotating electric machine for internal combustion engine and rotor thereof

Cross Reference to Related Applications

The application is based on japanese patent application No. 2019-85384 filed from 26.4.2019 to the sun, the disclosure of which is incorporated by reference in its entirety.

Technical Field

The disclosure in this specification relates to a rotating electrical machine for an internal combustion engine and a rotor thereof.

Background

Patent documents 1 and 2 disclose a starter generator used in combination with an internal combustion engine. The disclosures in the prior art documents are incorporated by reference into the present application as descriptions of technical elements in the present specification.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5097654

Patent document 2: japanese patent No. 6221676

Disclosure of Invention

In patent document 1 and patent document 2, an output signal for controlling the rotating electric machine and an output signal for controlling the internal combustion engine are output. Further improvements in rotating electrical machines for internal combustion engines and rotors therefor are demanded.

An object of the present disclosure is to provide a rotating electric machine for an internal combustion engine and a rotor thereof, which have high detection accuracy of a reference position.

A rotor of a rotating electrical machine for an internal combustion engine disclosed herein includes a rotor core as a yoke, and a permanent magnet held by the rotor core, the permanent magnet having a plurality of basic magnetic poles formed with polarities alternating with a prescribed basic period PT, and a special magnetic pole formed on a part of the permanent magnet so as to have a polarity different from that of the basic magnetic poles, the circumferential length LG of the same polarity provided by the special magnetic pole and the basic magnetic poles exceeding 1/2 of the basic period and being equal to or less than the basic period (1/2 x PT < LG < PT ≦ PT).

According to the rotor of the rotary electric machine for an internal combustion engine disclosed, the special magnetic pole can show the reference position at least one point in the rotational direction. The circumferential length of the same polarity provided by the special magnetic pole and the basic magnetic pole exceeds 1/2 of the basic period PT and is less than or equal to the basic period PT. The circumferential length LG is represented by 1/2 XPT < LG ≦ PT. The reference position can be shown without a long period exceeding the basic period PT. As a result, the rotor of the rotating electric machine for an internal combustion engine having high detection accuracy of the reference position is provided.

The rotary electric machine for an internal combustion engine disclosed herein includes: the above rotor; a stator disposed opposite to the rotor; a plurality of rotational position sensors disposed on a basic magnetic pole orbit in which basic magnetic poles are disposed along a rotational direction of the rotor; and a reference position sensor disposed on a special magnetic pole track in which a special magnetic pole is disposed along a rotation direction of the rotor.

The various embodiments disclosed in the present specification adopt different technical means to achieve respective purposes. The reference signs in parentheses in the claims and the items thereof are merely examples of correspondence with the parts of the embodiments described below, and are not intended to limit the technical scope. The objects, features and effects disclosed in the present specification will become more apparent by referring to the following detailed description and accompanying drawings.

Drawings

Fig. 1 is a block diagram of a rotating electric machine for an internal combustion engine.

Fig. 2 is a development view showing a magnetic pole and a sensor according to the first embodiment.

Fig. 3 is a waveform diagram showing output signals of a plurality of sensors.

Fig. 4 is a development view showing a magnetic pole and a sensor according to a second embodiment.

Fig. 5 is a waveform diagram showing output signals of a plurality of sensors.

Fig. 6 is a development view showing a magnetic pole and a sensor according to a third embodiment.

Detailed Description

Various embodiments are described with reference to the drawings. In each embodiment, corresponding parts and/or associated parts in function and/or structure are sometimes denoted by the same reference numerals or by reference numerals differing only in digits of hundreds or more. For the corresponding parts and/or the associated parts, reference may be made to the relevant explanations in the other embodiments.

First embodiment

In fig. 1, a rotating electrical machine for an internal combustion engine (hereinafter simply referred to as a rotating electrical machine) 10 is also referred to as a Generator motor, a Starter engine, or an alternator Starter. One example of the use of the rotating electrical machine 10 is a generator motor of an internal combustion engine 12 for a vehicle. The vehicle is a vehicle, a ship, an airplane, an entertainment device or a simulation device. A typical example of the vehicle is a saddle-ride type vehicle. The rotary electric machine 10 may also be used for a stationary internal combustion engine such as a generator or an air conditioner.

The rotating electric machine 10 is electrically connected to a circuit 11 including an inverter circuit (INV) and a control unit (ECU). Circuit 11 provides a three-phase power conversion circuit. When the rotating electrical machine 10 operates as a generator, the circuit 11 provides a rectifier circuit that rectifies the output ac power and supplies power to an electrical load including a battery. The circuit 11 provides a signal processing circuit that receives a reference position signal for ignition control and/or fuel injection control provided by the rotating electrical machine 10. The circuit 11 provides an ignition controller, and/or a fuel injection controller, that performs ignition control and/or fuel injection control. The ignition control performs ignition at a prescribed crank angle. The prescribed crank angle is determined based on the reference signal. The fuel injection control performs fuel injection at a prescribed crank angle. The prescribed crank angle is determined based on the reference signal.

The circuit 11 provides a drive circuit that causes the rotating electrical machine 10 to function as a motor. (ii) a The circuit 11 receives a rotational position signal for causing the rotating electrical machine 10 to function as a motor from the rotating electrical machine 10. The electric circuit 11 controls the energization of the rotating electrical machine 10 based on the detected rotational position, thereby causing the rotating electrical machine 10 to function as a motor.

The Control device in this specification is sometimes referred to as an Electronic Control Unit (ECU). The control apparatus or the control system is provided with (a) an algorithm as a plurality of logics of a form called if-then-else or (b) a learning completion model adjusted by machine learning, for example, an algorithm as a neural network.

The control means is provided by a control system comprising at least one computer. The control system may comprise a plurality of computers linked by data communication means. The computer includes at least one processor as hardware (hardware processor). The hardware processor may be provided by (i), (ii) or (iii) below.

(i) The hardware processor may be at least one processor core that executes programs stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. Processor cores are called Central Processing Units (CPUs), Graphics Processing Units (GPUs), RISC (Reduced Instruction Set Computing) -CPUs, and the like. The memory is also referred to as a storage medium. The memory is a non-transitory and tangible storage medium that non-transitory holds "programs and/or data" that can be read by the processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. The program may be used in its own right or as a storage medium storing the program.

(ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit comprising a plurality of logic cells (gates) programmed. Digital circuits are also called Logic Circuit arrays, such as Application-Specific Integrated circuits (ASICs), Field Programmable Gate Arrays (FPGAs), System on a Chip (SoC), Programmable Gate Arrays (PGAs), Complex Programmable Logic Devices (CPLDs), and so on. The digital circuitry may include memory that holds programs and/or data. The computer may be provided by an analog circuit. The computer may also be provided by a combination of digital and analog circuitry.

(iii) The hardware processor may be a combination of (i) above and (ii) above. (i) And (ii) on different chips or on a common chip. In these cases, the section (ii) is also referred to as an accelerator.

The control device, the signal source, and the controlled object provide various elements. At least some of these elements may be referred to as blocks, modules, or segments. Furthermore, the elements included in the control system are referred to as functional units only in the intentional case.

The control section and the method thereof described in the present disclosure may be realized by a dedicated computer provided by constituting a processor programmed to execute one or more functions embodied by a computer program and a memory. Alternatively, the control unit and the method thereof described in the present disclosure may be implemented by a dedicated computer provided by making a processor be constituted by one or more dedicated hardware logic circuits. Alternatively, the control unit and the method thereof described in the present disclosure may be implemented by one or more special purpose computers including a processor programmed to execute one or more functions, and a combination of a memory and a processor configured by one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

The rotary electric machine 10 is assembled to the internal combustion engine 12. The internal combustion engine 12 includes: a body 13 and a rotary shaft 14, and the rotary shaft 14 is rotatably supported by the body 13 and rotates in conjunction with the internal combustion engine 12. The rotating electrical machine 10 is assembled to a body 13 and a rotating shaft 14 to be mounted. The body 13 is a structure such as a crankcase or a transmission of the internal combustion engine 12. The rotary shaft 14 is a crankshaft of the internal combustion engine 12 or a rotary shaft linked with the crankshaft. The rotary shaft 14 is rotated by the operation of the internal combustion engine 12.

The rotating shaft 14 rotates the rotating electrical machine 10 so that the rotating electrical machine 10 functions as a generator. The rotating shaft 14 is a rotating shaft that can start the internal combustion engine 12 by rotation of the rotating electrical machine 10 when the rotating electrical machine 10 functions as a motor. The rotary shaft 14 is a rotary shaft that can support (assist) the rotation of the internal combustion engine 12 by the rotation of the rotary electric machine 10 when the rotary electric machine 10 functions as a motor. The rotary shaft 14 is also a rotary shaft that supplies rotary power instead of the internal combustion engine 12 when the rotary electric machine 10 functions as a motor.

The rotating electric machine 10 includes: a rotor 21, a stator 31, and a sensor unit 37. In the following description, the term "axial direction AD" means a direction of a central axis when the stator 31 is regarded as a cylindrical body. The term radial direction RD means a diameter direction in the case where the stator 31 is regarded as a cylindrical body. The term circumferential direction CD means a circumferential direction in the case where the stator 31 is regarded as a cylindrical body.

The rotor 21 is an excitation element. The stator 31 is an armature. The rotor 21 is cup-shaped as a whole. The rotor 21 is positioned with its open end facing the body 13. The rotor 21 is fixed to an end of the rotary shaft 14. The rotor 21 is connected to the rotary shaft 14 via a positioning mechanism such as a key fitting in the rotational direction. The rotor 21 is fixed by being fastened to the rotary shaft 14 by a fixing bolt 25. The rotor 21 rotates together with the rotary shaft 14. The rotor 21 is excited, i.e., rotationally excited, by permanent magnets.

The rotor 21 has a cup-shaped rotor core 22. The rotor core 22 is connected to the rotary shaft 14 of the internal combustion engine 12. The rotor core 22 includes an inner cylinder fixed to the rotating shaft 14, an outer cylinder located radially outward of the inner cylinder, and an annular bottom plate extending between the inner cylinder and the outer cylinder. The rotor core 22 provides a yoke for a permanent magnet described later. The rotor core 22 is also referred to as an iron bowl. The rotor core 22 is made of a magnetic metal.

The rotor 21 has a permanent magnet 23 disposed on the inner surface of the rotor core 22. The permanent magnet 23 is fixed to the inside of the outer cylinder. The permanent magnet 23 is fixed in the axial direction AD and the radial direction RD by a holding cup 24 disposed on the radially inner side. The retaining cup 24 is made of a thin non-magnetic metal. The retaining cup 24 is fixed to the rotor core 22.

The permanent magnet 23 has a plurality of magnet pieces. The segments are also referred to as magnet pieces. Each magnet piece is partially cylindrical. The permanent magnet 23 provides six pairs of N-pole and S-pole, i.e., 12-pole excitation, by means of 12 magnet pieces. The number of poles may be other numbers. The permanent magnet 23 has a plurality of N poles and a plurality of S poles provided on the inner side thereof.

The permanent magnet 23 provides a plurality of basic magnetic poles. The plurality of basic magnetic poles are formed so that polarities alternate with a predetermined basic Period (PT). The plurality of basic magnetic poles provide a rotating magnetic field for the rotating electric machine so that the rotating electrode functions as a generator or a motor. The permanent magnet 23 at least provides excitation. The rotor 21 supplies a rotating magnetic field to the stator 31. The basic magnetic poles provide rotational position signals for causing the rotating electrical machine 10 to function at least as a motor. The basic magnetic pole is also called a magnetic pole for a rotation signal.

The permanent magnet 23 provides part of a special magnetic pole. The special magnetic pole is formed on a portion of the permanent magnet in such a manner as to have a different polarity from the basic magnetic pole in one pole piece. The special pole provides a reference position signal for ignition control, and/or fuel injection control. The special magnetic pole is provided by a portion of the magnetic pole different from the magnetic pole arrangement used for excitation. The special magnetic pole is also called a magnetic pole for reference position signal.

The stator 31 and the body 13 are connected via fixing bolts 34. The stator 31 is fastened and fixed to the body 13 by a plurality of fixing bolts 34. The stator 31 is disposed between the rotor 21 and the body 13. The stator 31 has a virtual outer peripheral surface facing the inner surface of the rotor 21 with a gap therebetween. The imaginary outer circumference is provided by a plurality of magnetic poles 35. The stator 31 is fixed to the body 13.

The stator 31 has a stator core 32. The stator core 32 has a first end face SD1, a second end face SD2 on the opposite side of the first end face SD1, and an outer peripheral surface. The stator core 32 is disposed inside the rotor 21 through the body 13 fixed to the internal combustion engine 12. The stator core 32 has a plurality of tooth portions. One tooth portion provides one magnetic pole 35. The stator core 32 provides a plurality of magnetic poles 35. The stator core 32 provides an outer salient pole type iron core. The stator 31 has, for example, eighteen magnetic poles 35.

The stator 31 has a stator coil 33 attached to the stator core 32. The stator coil 33 provides an armature winding. An insulator 36 is disposed between stator core 32 and stator coil 33. The insulator 36 is an electrically insulating member. The insulator 36 is made of an electrically insulating resin. The stator coil 33 is a three-phase winding. The stator coil 33 can selectively function as a generator or a motor with respect to the rotor 21 and the stator 31.

The sensor unit 37 provides a rotational position detection device for the internal combustion engine. The sensor unit 37 is provided in the rotating electric machine 10 that is interlocked with the internal combustion engine 12. The sensor unit 37 is provided on the stator 31. The sensor unit 37 is provided on the stator core 32 of the rotary electric machine 10. The sensor unit 37 is fixed to the first end surface SD1 of the stator core 32 by a fixing bolt 39. The fixing bolt 39 penetrates from the second end surface SD2 toward the first end surface SD 1.

The sensor unit 37 includes a plurality of sensors 38. The sensor unit 37 positions the sensor 38 between the adjacent two magnetic poles 35. A sensor 38 is positioned to output a reference position signal. One sensor 38 is also referred to as a reference position sensor. The other at least one sensor 38 is positioned to output a rotation signal. The other at least one sensor 38 is also referred to as a rotational position sensor. In the present embodiment, one sensor 38 of the plurality of sensors 38 provides a reference position sensor. In this embodiment, three sensors 38 of the plurality of sensors 38 provide rotational position sensors. In the case where the plurality of sensors 38 includes four sensors, one sensor may provide a reference position sensor, while the remaining three sensors may provide rotational position sensors. Where the plurality of sensors 38 includes three sensors, one sensor may provide a reference position sensor and all three sensors may provide rotational position sensors.

The sensor unit 37 has an external connection wire 15 for taking out signals output from the plurality of sensors 38 to the outside. The wiring 15 can transmit a reference position signal and a rotation signal. The rotating electric machine 10 includes a plurality of power lines 16 connecting the stator coil 33 and the circuit 11. The power line 16 is provided by a flexible cable. When the rotating electrical machine 10 functions as a generator, the power line 16 supplies electric power induced by the stator coil 33 to the electric circuit 11. On the other hand, when the rotating electric machine 10 functions as a motor, the power line 16 is used to supply power for exciting the stator coil 33 from the circuit 11 to the stator coil 33.

In fig. 2, a developed view of the rotor 21 and the stator 31 arranged oppositely is illustrated. The rotor 21 rotates in the normal direction indicated by an arrow RT. In addition, the S pole 26a and the N pole 26b of the basic magnetic pole 26 can be exchanged. The S pole 27a and the N pole 27b of the special magnetic pole 27 can be exchanged.

The permanent magnet 23 includes a plurality of

magnet pieces

23a, 23b, 23c, and 23 d. The plurality of

magnet pieces

23a, 23b, 23c, and 23d are magnetized for each basic magnetic pole 26 to provide the basic magnetic pole 26. In the present embodiment, 4 kinds of magnet pieces magnetized in 4 kinds of magnetization patterns are used. The plurality of

magnet pieces

23a, 23b, 23c, 23d include two kinds of

magnet pieces

23a, 23b having only the basic magnetic poles 26. The plurality of magnet pieces include two

magnet pieces

23c, 23d of two kinds having both the basic magnetic pole 26 and the special magnetic pole 27. The plurality of magnet pieces 23a have an S pole 26a as a basic magnetic pole 26. The plurality of magnet pieces 23b have N poles 26b as basic magnetic poles 26. The basic period PT in which the polarities of the plurality of basic magnetic poles 26 alternate depends on the circumferential widths of the plurality of

magnet pieces

23a, 23b, 23c, and 23 d.

One magnet piece 23c has an N pole 26b as a basic magnetic pole 26 and an S pole 27a as a special magnetic pole 27. In the magnet piece 23c, the area of the basic magnetic pole 26 is larger than that of the special magnetic pole 27. The special pole 27 is a part of the basic pole 26. The special magnetic pole 27 is disposed so as to be sandwiched by the basic magnetic poles 26 in the permanent magnet 23. The special magnetic pole 27 is disposed so as to be sandwiched by the basic magnetic poles 26 in the middle of the permanent magnet 23 in the axial direction. The special magnetic pole 27 is sandwiched by the basic magnetic poles 26 in the axial direction, but may be sandwiched by the basic magnetic poles 26 in the circumferential direction.

One magnet piece 23d has an S pole 26a as a basic magnetic pole 26 and an N pole 27b as a special magnetic pole 27. In the magnet piece 23d, the area of the basic magnetic pole 26 is larger than that of the special magnetic pole 27. The special pole 27 is a part of the basic pole 26. The special magnetic pole 27 is located at a position sandwiched by the basic magnetic poles 26.

The

magnet pieces

23a, 23b, 23c, 23d are arranged such that the basic magnetic poles 26 alternate along the circumferential direction CD. The two

magnet pieces

23c, 23d are configured such that the basic magnetic pole 26 and the special magnetic pole 27 show polarities that are continuous along the circumferential direction CD. The two

magnet pieces

23c, 23d are arranged such that the special magnetic pole 27 shows a polarity reversed in the circumferential direction CD. The magnet piece 23c is arranged, for example, such that the S-pole 26a provided as the basic magnetic pole 26 by the magnet piece 23a and the S-pole 27a provided as the special magnetic pole 27 by the magnet piece 23c show continuous polarities. The magnet piece 23c and the magnet piece 23d provide two special magnetic poles 27 whose magnetic characteristics are detectably different. The magnet piece 23c and the magnet piece 23d are arranged such that the two special magnetic poles 27 show polarities that are reversed in the circumferential direction CD. The magnet piece 23d is, for example, arranged such that the N-pole 26b provided as the basic magnetic pole 26 by the magnet piece 23b and the N-pole 27b provided as the special magnetic pole 27 by the magnet piece 23d show continuous polarities. The special magnetic pole 27 has an S pole 27a and an N pole 27b magnetized by two

magnet pieces

23c and 23d adjacent to each other in the circumferential direction CD and having different polarities.

The primary pole 26 is configured to appear on a primary pole track 28 extending in the circumferential direction CD. On the basic pole track 28, only a plurality of basic poles 26 are present. The special pole 27 is configured to appear on a special pole track 29 extending in the circumferential direction CD. The special pole track 29 is set at substantially the center in the axial direction of the permanent magnet 23. On the special pole track 29, a plurality of basic poles 26 and all special poles 27 are present.

The sensor unit 37 has a plurality of

sensors

38a, 38b, 38c arranged on the primary pole track 28. The basic magnetic pole track 28 is a track in which the basic magnetic poles 26 are arranged in the rotational direction of the rotor 21. The

sensors

38a, 38b, 38c output rotation signals. The sensor unit 37 has one sensor 38d arranged on the special pole track 29. The special magnetic pole orbit 29 is an orbit in which the special magnetic poles 27 are arranged in the rotation direction of the rotor 21. The sensor 38d outputs a reference position signal. The plurality of

sensors

38a, 38b, 38c, 38d detect the magnetic flux provided by the permanent magnet 23. The plurality of

sensors

38a, 38b, 38c, 38d may be provided by various sensor elements responsive to magnetic flux. The plurality of

sensors

38a, 38b, 38c, 38d may be provided by sensors utilizing the hall effect, for example.

According to the present embodiment, the special magnetic poles 27 provide magnetic poles of the same polarity on two circumferentially adjacent magnet pieces. The special magnetic pole 27 does not provide a magnetic pole of the same polarity on three magnetic poles adjacent in the circumferential direction. The special magnetic pole 27 is provided with magnetic poles of the same polarity, i.e., an S pole 26a and an S pole 27a, for example, on two

magnet pieces

23a, 23c adjacent in the circumferential direction. The special magnetic pole 27 is provided with magnetic poles of the same polarity, i.e., an N pole 26b and an N pole 27b, on two

magnet pieces

23d, 23b adjacent in the circumferential direction, for example.

The special magnetic poles 27 are arranged so as to provide magnetic poles of different polarities on the two

magnet pieces

23c, 23d adjacent in the circumferential direction CD in a section showing the reference position. In the illustrated embodiment, the S pole 27a and the N pole 27b are arranged on the two

magnet pieces

23c and 23d adjacent to each other in the circumferential direction CD and have different polarities. The S pole 27a and the N pole 27b can be interchanged. The different polarities include a relationship of S-pole to N-pole, S-pole to no magnetization, or no magnetization to N-pole.

Fig. 3 shows output signal waveforms of the plurality of

sensors

38a, 38b, 38c, 38 d. The waveform A, B, C, D corresponds to each of the plurality of

sensors

38a, 38b, 38c, 38d, respectively. The three

sensors

38a, 38b, 38c as rotational position sensors output a plurality of output waveforms A, B, C. The output waveform A, B, C is output as a rectangular wave of a predetermined basic period PT of the basic magnetic pole 26. The phase of the output waveform A, B, C is shifted 1/3 x PT per cycle. As a result, the rotational position signal can achieve a resolution of 1/3 × PT.

The sensor 38D as the reference position sensor outputs an output waveform D. The output waveform D is a reference position signal. The output waveform D has a fundamental period of the fundamental period PT and a missing tooth period of the period 2 × PT. The reference position is shown during missing teeth. The output waveform D also alternates with the basic period PT during missing teeth. The output waveform D provides a missing tooth portion between time t101 and time t 103. The output waveform D also alternates at time t 102. The output waveform D can basically show the reference position twice during missing teeth. In other words, the output waveform D can achieve the resolution of the basic period PT also during missing teeth. As a result, the output waveform D provides a higher resolution than the period 3/2 × PT (1.5 × PT) during the missing tooth period.

The circumferential length LG of the same polarity provided by the special pole 27 and the basic pole 26 exceeds 1/2 of the basic period PT and is below the basic period PT. The length LG is 1/2 multiplied by PT which is less than LG and less than PT. The reference position can be shown without a long period exceeding the basic period PT. As a result, the rotor of the rotating electric machine for an internal combustion engine having high detection accuracy of the reference position is provided.

The arrival of the reference position can be judged based on the signal period 1/3 × PT given from the rotational position signal. The difference between the signal period 1/3 × PT and the basic period PT can also determine the arrival of the missing gear mechanism during the gradual increase in the rotation speed at the start of the internal combustion engine 12. In addition, the missing tooth period of the period 2 × PT provided by the reference position signal provides an opportunity of two missing tooth determinations.

The circuit 11 detects a reference position based on a plurality of signals from the sensor unit 37. The circuit 11 executes ignition control, and/or fuel injection control based on the reference position. In addition to the signal from the sensor 38d, the circuit 11 determines the ignition position, and/or the fuel injection position, for example, using two of the three

sensors

38a, 38b, 38c as phase sensors. According to the present embodiment, the occurrence of so-called misfire in the internal combustion engine 12 can be suppressed. Therefore, even at the time of starting the internal combustion engine 12, ignition and/or fuel injection can be reliably performed. As a result, the start of the internal combustion engine 12 is completed quickly.

According to the above-described embodiments, a rotating electrical machine for an internal combustion engine is provided that has high detection accuracy of a reference position. From one point of view, even at the time of start of the internal combustion engine 12 at a slow rotation speed, the arrival of the missing tooth portion (the arrival of the reference position) can be displayed with high accuracy. The reference position can be shown at an early stage at the time of startup of the internal combustion engine. As a result, the internal combustion engine rotating electric machine is provided in which the internal combustion engine 12 is started quickly.

Second embodiment

This embodiment is a modification of the previous embodiment. In the above embodiment, the output waveform D as the reference position signal provides the resolution of the basic period PT. Instead, in the present embodiment, the reference position signal provides a resolution of 3/4 × PT periodically.

In fig. 4, the permanent magnet 23 includes a plurality of

magnet pieces

223a, 223b, 223c magnetized for each of the basic magnetic poles 26. The special

magnetic poles

227a, 227b, 227c are magnetized by all of the plurality of magnet pieces. The special magnetic poles 27 are formed with polarities alternating at 1/2 of the basic period PT. In the present embodiment, 3 kinds of magnet pieces magnetized in 3 kinds of magnetization patterns are used. The plurality of

magnet pieces

223a, 223b, 223c include two types of

magnet pieces

223a, 223b having the basic magnetic pole 26 and two special

magnetic poles

227a, 227 b. The plurality of

magnet pieces

223a, 223b, 223c includes one magnet piece 223c having the basic magnetic pole 26 and one special magnetic pole 227 c. In the present embodiment, the S pole 26a and the N pole 26b of the basic magnetic pole 26 can be exchanged. The S pole 227a and the N pole 227b of the special magnetic pole 27 can also be exchanged.

The rotor 21 has a plurality of

magnet pieces

223a, 223b, 223 c. The plurality of magnet pieces 223a have an S pole 26a as the basic magnetic pole 26, and S pole 227a and N pole 227b as the special magnetic pole 27. The plurality of magnet pieces 223b have an N pole 26b as the basic magnetic pole 26, and S pole 227a and N pole 227b as the special magnetic poles 27. The S pole 227a and the N pole 227b as the special magnetic poles 227 are magnetized by dividing one

magnet piece

223a, 223b into two in the circumferential direction CD.

One magnet piece 223c has an S pole 26a as the basic magnetic pole 26 and an N pole 227c as the special magnetic pole 27. The N pole 227c extends over the entire circumferential direction CD of the one magnet piece 223 c.

The plurality of

magnet pieces

223a, 223b, 223c are arranged so that the S poles 26a and the N poles 26b as the basic magnetic poles 26 alternate. The magnet piece 223c is arranged to provide a polarity continuous with any one of the special magnetic poles (the S pole 227a or the N pole 227b) in the circumferential direction CD.

In fig. 5, the sensor 38D as the reference position sensor outputs an output waveform D. The output waveform D is a reference position signal. The output waveform D has a period of 1/2 × PT and a tooth-missing period of 3/4 × PT. The reference position is shown during missing teeth. The output waveform D provides a missing tooth portion between time t201 and time t 203. The output waveform D provides a higher resolution during tooth loss than the period 3/2 × PT (1.5 × PT).

The arrival of the reference position can be judged based on the signal period 1/2 × PT given during the basic period. The difference between the signal period 1/2 × PT and the period 3/4 × PT can also determine the arrival of the missing tooth period during the gradual increase in the rotation speed at the start of the internal combustion engine 12.

Third embodiment

This embodiment is a modification of the previous embodiment. In the above embodiment, the special magnetic pole 27 is formed substantially at the center of the permanent magnet 23. Alternatively, the special magnetic pole 27 may be formed to be offset to either one of the axial directions of the permanent magnet 23.

In fig. 6, the magnet piece 23c has an S-pole 327a as the special magnetic pole 27 disposed at one end in the axial direction of the permanent magnet 23. The magnet piece 23d has an N pole 327b as the special magnetic pole 27 disposed at one end in the axial direction of the permanent magnet 23. As a result, the primary pole 26 is configured to appear on the primary pole track 28. The special pole 27 is configured to appear on a special pole track 29. The sensor unit 37 has

sensors

38a, 38b, and 38c as rotational position sensors disposed on the basic pole track 28. The sensor unit 37 has a sensor 38d as a reference position sensor disposed on the special pole rail 29. As a result, the

sensors

38a, 38b, 38c output a plurality of rotational position signals indicating the rotational positions. The sensor 38d outputs a reference position signal showing the reference position. The present embodiment can also obtain the same signal waveform as in the first embodiment.

Other embodiments

The disclosures in the specification and drawings are not limited to the illustrated embodiments. The present disclosure includes the embodiments already listed and modifications thereof that can be made by those skilled in the art. For example, the present disclosure is not limited to the combinations of components and/or elements disclosed in the embodiments. The present disclosure may be implemented in various combinations. The present disclosure may also include additional parts that may be added to the embodiments. The present disclosure includes embodiments in which components and/or elements of the embodiments are omitted. The present disclosure encompasses permutations and combinations of parts and/or elements between one embodiment and other embodiments. The technical scope of the present disclosure is not limited to the scope described in the embodiments. The technical scope of the present disclosure is defined by the claims, and all changes that come within the meaning and range of equivalency of the claims are to be embraced therein.

The disclosure in the specification, drawings, and the like is not limited to the description of the claims. The disclosure in the specification, the drawings of the specification, and the like includes the technical ideas described in the claims, and further relates to a more diverse and broader technical idea than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure contents of the specification, the drawings of the specification, and the like without being limited by the description of the claims.

In the above embodiment, the plurality of basic magnetic poles 26 are provided by the plurality of

magnet pieces

23a, 23b, 23c, 23 d. Alternatively, the plurality of basic magnetic poles 26 may be provided by one magnet piece. The term different polarity means that the magnetic properties are detectably different. Further, the term different polarity is a term encompassing the relationship of S pole to N pole, S pole to no magnetization, or no magnetization to N pole.

In the above embodiment, one reference position is set in one period T. Alternatively, two or more reference positions may be set in one cycle T. For example, in addition to the plurality of

magnet pieces

23a, 23b, a plurality of sets of

magnet pieces

23c, 23d may be arranged at a plurality of positions of the rotor 21. In addition to the plurality of

magnet pieces

223a, 223b, a plurality of magnet pieces 223c may be arranged at a plurality of positions of the rotor 21. Similarly, in addition to the plurality of

magnet pieces

23a, 23b, a plurality of sets of

magnet pieces

323c, 323d may be arranged at a plurality of positions of the rotor 21.

In the above embodiment, the sensor unit 37 includes 4 sensors 38. Alternatively, the sensor unit 37 may also comprise 3 sensors 38. In this case, the sensor unit 37 may also comprise two sensors 38 arranged on the basic pole track 28 and one sensor 38 arranged on the special pole track 29. One sensor 38 arranged on the specific pole rail 29 is used as both the reference position sensor and the rotational position sensor.

Claims

1. A rotor of a rotating electric machine for an internal combustion engine, comprising:

a rotor core (22) as a yoke, and

a permanent magnet (23) held by the rotor core;

the permanent magnet has a plurality of basic magnetic poles (26) formed with polarities alternating in a predetermined basic period PT, and a special magnetic pole (27) formed on a part of the permanent magnet so as to have a polarity different from that of the basic magnetic poles (26);

the circumferential length LG of the same polarity provided by the special magnetic pole and the basic magnetic pole exceeds 1/2 of the basic period and is less than the basic period, and 1/2 multiplied by PT < LG ≦ PT.

2. The rotor of a rotating electrical machine for an internal combustion engine according to claim 1, wherein the basic magnetic pole provides a rotating magnetic field for the rotating electrical machine.

3. The rotor of a rotating electrical machine for an internal combustion engine according to claim 1 or 2,

the permanent magnet includes a plurality of magnet pieces magnetized for each of the basic magnetic poles;

the special magnetic pole has two special magnetic poles (27a, 27b) magnetized by two circumferentially adjacent magnet pieces and having different polarities.

4. The rotor of a rotating electrical machine for an internal combustion engine according to claim 3,

the plurality of magnet pieces include:

a plurality of magnet pieces (23a, 23b) of two kinds having only the basic magnetic poles; and

two of the magnet pieces (23c, 23d) having two kinds of the basic magnetic pole and the special magnetic pole.

5. The rotor of a rotating electrical machine for an internal combustion engine according to claim 1 or 2,

the special magnetic poles (227a, 227b, 227c) are magnetized by all of the plurality of magnet pieces.

6. The rotor of a rotating electrical machine for an internal combustion engine according to claim 5, wherein the special magnetic poles are formed so that polarities alternate at 1/2 of the basic cycle.

7. The rotor of a rotating electrical machine for an internal combustion engine according to claim 5 or 6,

the plurality of magnet pieces include:

a plurality of magnet pieces (223a, 223b) having two kinds of the basic magnetic pole and the two special magnetic poles (227a, 227 b); and

one of the magnet pieces (223c) having the basic magnetic pole and one of the special magnetic poles.

8. The rotor of a rotating electrical machine for an internal combustion engine according to any one of claims 1 to 7, wherein the special magnetic pole is arranged to be sandwiched by the basic magnetic poles in the permanent magnet.

9. The rotor of a rotating electrical machine for an internal combustion engine according to any one of claims 1 to 7, wherein the special magnetic pole is arranged on one end in an axial direction of the permanent magnet.

10. A rotating electrical machine for an internal combustion engine, comprising:

a rotor (21) of a rotating electrical machine for an internal combustion engine according to any one of claims 1 to 9;

a stator (31) disposed opposite to the rotor;

a plurality of rotational position sensors (38a, 38b, 38c) disposed on a basic magnetic pole track (28) in which the basic magnetic poles are disposed along a rotational direction of the rotor; and

and a reference position sensor (38d) disposed on a special magnetic pole track (29) in which the special magnetic pole is disposed along the rotational direction of the rotor.