JPWO2020217900A1 - Rotating machine for internal combustion engine and its rotor - Google Patents

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) in the basic magnetic pole trajectory (28). The sensor (38d) as the reference position sensor detects the special magnetic pole (27) in the special magnetic pole trajectory (29). The special pole (27) provides poles of the same polarity across two circumferentially adjacent poles. The special magnetic pole (27) does not provide magnetic poles of the same polarity across three circumferentially adjacent magnetic poles. As a result, a high resolution reference position signal is provided.

Description

Cross-reference of related applications

This application is based on Patent Application No. 2019-85384 filed in Japan on April 26, 2019, and the content of the basic application is incorporated by reference in its entirety.

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

Patent Document 1 and Patent Document 2 disclose a starting generator used in combination with an internal combustion engine. The contents of the prior art document are incorporated by reference as an explanation of the technical elements in this specification.

Japanese Patent No. 5097654 Japanese Patent No. 6221676

Patent Document 1 and Patent Document 2 output an output signal for controlling a rotary electric machine and an output signal for controlling an internal combustion engine. Further improvements are required for rotary electric machines for internal combustion engines and their rotors.

One object disclosed is to provide a rotary electric machine for an internal combustion engine having high reference position detection accuracy, and a rotor thereof.

The rotor of the rotary electric machine for an internal combustion engine disclosed herein includes a rotor core as a yoke and a permanent magnet held by the rotor core, and the permanent magnets are formed so that the polarities alternate in a predetermined basic period PT. It has a plurality of basic magnetic poles and a special magnetic pole formed in a part of a permanent magnet so as to have a polarity different from that of the basic magnetic pole, and the circumferential length LG of the same polarity provided by the special magnetic pole and the basic magnetic pole is , More than 1/2 of the basic cycle and less than or equal to the basic cycle (1/2 × PT <LG ≦ PT).

According to the rotor of a rotary electric machine for an internal combustion engine disclosed, the special magnetic pole can indicate a reference position at at least one position in the rotation direction. Moreover, 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 equal to or less than the basic period PT. The circumferential length LG is represented by 1/2 × PT <LG ≦ PT. The reference position can be indicated without requiring a long period exceeding the basic period PT. As a result, a rotor of a rotary electric machine for an internal combustion engine having high reference position detection accuracy is provided.

The rotary electric machine for an internal combustion engine disclosed here is arranged in the rotor, a stator arranged so as to face the rotor, and a basic magnetic pole orbit in which the basic magnetic poles are arranged along the rotation direction of the rotor. A plurality of rotation position sensors and a reference position sensor arranged in a special magnetic pole orbit in which special magnetic poles are arranged along the rotation direction of the rotor are provided.

The disclosed aspects herein employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses described in this section exemplify the correspondence with the parts of the embodiments described later, and are not intended to limit the technical scope. The objectives, features, and effects disclosed herein will be made clearer by reference to the subsequent detailed description and accompanying drawings.

It is a block diagram of a rotary electric machine for an internal combustion engine. It is a developed view which shows the magnetic pole and a sensor which concerns on 1st Embodiment. It is a waveform diagram which shows the output signal of a plurality of sensors. It is a developed view which shows the magnetic pole and a sensor which concerns on 2nd Embodiment. It is a waveform diagram which shows the output signal of a plurality of sensors. It is a developed view which shows the magnetic pole and a sensor which concerns on 3rd Embodiment.

A plurality of embodiments will be described with reference to the drawings. In a plurality of embodiments, functionally and / or structurally corresponding parts and / or related parts may be designated with the same reference code or reference codes having a hundreds or more different digits. For the corresponding and / or associated part, the description of other embodiments can be referred to.

1st Embodiment In FIG. 1, a rotary electric machine for an internal combustion engine (hereinafter, simply referred to as a rotary electric machine) 10 is also referred to as a generator motor, a start generator, or an AC generator starter. An example of the use of the rotary electric machine 10 is a generator motor of an internal combustion engine 12 for a vehicle. Vehicles are vehicles, ships, aircraft, amusement equipment, or simulation equipment. A typical example of a vehicle is a saddle-riding vehicle. The rotary electric machine 10 may be used for a stationary internal combustion engine such as a generator or an air conditioner.

The rotary electric machine 10 is electrically connected to an electric circuit 11 including an inverter circuit (INV) and a control device (ECU). The electric circuit 11 provides a three-phase power conversion circuit. The electric circuit 11 provides a rectifying circuit that rectifies the output AC power when the rotary electric machine 10 functions as a generator and supplies power to an electric load including a battery. The electric circuit 11 provides a signal processing circuit that receives a reference position signal for ignition control and / or fuel injection control supplied from the rotary electric machine 10. The electrical circuit 11 provides an ignition controller that performs ignition control and / or fuel injection control, and / or fuel injection control. Ignition control executes ignition at a predetermined crank angle. The predetermined crank angle is specified based on the reference signal. The fuel injection control executes fuel injection at a predetermined crank angle. The predetermined crank angle is specified based on the reference signal.

The electric circuit 11 provides a drive circuit that causes the rotary electric machine 10 to function as an electric motor. The electric circuit 11 receives a rotation position signal from the rotary electric machine 10 for causing the rotary electric machine 10 to function as an electric machine. The electric circuit 11 causes the rotary electric machine 10 to function as an electric motor by controlling the energization of the rotary electric machine 10 according to the detected rotation position.

The control device in this specification may also be referred to as an electronic control unit (ECU). The control device or control system is provided by (a) an algorithm as a plurality of logics called if-then-else form, or (b) a trained model tuned by machine learning, for example, an algorithm as a neural network. ..

The control device is provided by a control system that includes at least one computer. The control system may include multiple computers linked by data communication equipment. A computer includes at least one processor (hardware processor) which is hardware. The hardware processor can be provided by (i), (ii), or (iii) below.

(I) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is called a CPU: Central Processing Unit, a GPU: Graphics Processing Unit, RISC-CPU, or the like. Memory is also called a storage medium. A memory is a non-transitional and substantive storage medium that non-temporarily stores "programs and / or data" that can be read by a processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. The program may be distributed by itself or as a storage medium in which the program is stored.

(Ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit that includes a large number of programmed logic units (gate circuits). The digital circuit is a logic circuit array, for example, ASIC: Application-Special Integrated Circuit, FPGA: Field Programmable Gate Array, SoC: System on a Chip, PGA: Programmable Cable. Digital circuits may include memory for storing programs and / or data. Computers may be provided by analog circuits. Computers may be provided by a combination of digital and analog circuits.

(Iii) The hardware processor may be a combination of the above (i) and the above (ii). (I) and (ii) are arranged on different chips or on a common chip. In these cases, the part (ii) is also called an accelerator.

Control devices, signal sources, and controlled objects provide various elements. At least some of those elements can be called blocks, modules, or sections. Moreover, the elements contained in the control system are called functional means only when intentionally.

The controls and methods thereof described in this disclosure are realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. May be done. Alternatively, the controls and methods thereof described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the controls and techniques described in this disclosure include a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured by a combination. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer.

The rotary electric machine 10 is assembled to the internal combustion engine 12. The internal combustion engine 12 has a body 13 and a rotating shaft 14 that is rotatably supported by the body 13 and rotates in conjunction with the internal combustion engine 12. The rotary electric machine 10 is assembled to the body 13 and the rotary shaft 14 to be attached. The body 13 is a structure such as a crankcase and a mission case of the internal combustion engine 12. The rotary shaft 14 is a crank shaft of the internal combustion engine 12, or a rotary shaft that is interlocked with the crank shaft. The rotating shaft 14 rotates when the internal combustion engine 12 is operated.

The rotary shaft 14 rotates the rotary electric machine 10 so that the rotary electric machine 10 functions as a generator. The rotating shaft 14 is a rotating shaft capable of starting the internal combustion engine 12 by the rotation of the rotating electric machine 10 when the rotating electric machine 10 functions as an electric machine. Further, the rotary shaft 14 is a rotary shaft capable of assisting 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 an electric motor. The rotary shaft 14 is also a rotary shaft that provides rotational power in place of the internal combustion engine 12 when the rotary electric machine 10 functions as an electric motor.

The rotary electric machine 10 has a rotor 21, a stator 31, and a sensor unit 37. In the following description, the term axial AD means the direction of the central axis when the stator 31 is regarded as a cylinder. The term RD in the radial direction means the radial direction when the stator 31 is regarded as a cylinder. The term CD in the circumferential direction means the circumferential direction when the stator 31 is regarded as a cylinder.

The rotor 21 is a field magnet. The stator 31 is an armature. The rotor 21 has a cup shape as a whole. The rotor 21 is positioned with its open end facing the body 13. The rotor 21 is fixed to the end of the rotating shaft 14. The rotor 21 and the rotation shaft 14 are connected via a positioning mechanism in the rotation direction such as key fitting. The rotor 21 is fixed by being tightened to the rotating shaft 14 by a fixing bolt 25. The rotor 21 rotates together with the rotating shaft 14. The rotor 21 provides a field, that is, a rotating field, by means of a permanent magnet.

The rotor 21 has a cup-shaped rotor core 22. The rotor core 22 is connected to the rotating shaft 14 of the internal combustion engine 12. The rotor core 22 has an inner cylinder fixed to the rotating shaft 14, an outer cylinder located radially outside 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, which will be described later. The rotor core 22 is also called an iron bowl. The rotor core 22 is made of magnetic metal.

The rotor 21 has a permanent magnet 23 arranged 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 with respect to the axial AD and the radial RD by the holding cup 24 arranged radially inside. The holding cup 24 is made of a thin non-magnetic metal. The holding cup 24 is fixed to the rotor core 22.

The permanent magnet 23 has a plurality of magnet pieces. The segment is also called a magnet piece. Each magnet piece is partially cylindrical. The permanent magnet 23 provides a field of 6 pairs of N poles and S poles, that is, 12 poles by 12 magnet pieces. The number of magnetic poles may be another number. The permanent magnet 23 provides a plurality of N poles and a plurality of S poles inside the permanent magnet 23.

The permanent magnet 23 provides a plurality of basic magnetic poles. The plurality of basic magnetic poles are formed so that the polarities alternate in a predetermined basic period (PT). The plurality of basic magnetic poles provide a rotating magnetic field for a rotating electric machine to function as a generator or a motor. The permanent magnet 23 provides at least a field magnet. The rotor 21 provides a rotating magnetic field to the stator 31. The basic magnetic poles provide a rotational position signal for at least the rotary electric machine 10 to function as an electric machine. The basic magnetic pole is also called a magnetic pole for a rotation signal.

The permanent magnet 23 provides a partial special magnetic pole. The special magnetic pole is formed in a part of the permanent magnet so as to have a polarity different from that of the basic magnetic pole in one magnetic pole piece. Special poles provide a reference position signal for ignition control and / or fuel injection control. The special poles are provided by partial poles that are different from the pole arrangement for the field. The special magnetic pole is also called a magnetic pole for a reference position signal.

The stator 31 and the body 13 are connected via a fixing bolt 34. The stator 31 is fixed by being fastened to the body 13 by a plurality of fixing bolts 34. The stator 31 is arranged between the rotor 21 and the body 13. The stator 31 has a virtual outer peripheral surface that faces the inner surface of the rotor 21 via a gap. The virtual outer peripheral surface 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 surface SD1, a second end surface SD2 on the opposite side of the first end surface SD1, and an outer peripheral surface. The stator core 32 is arranged inside the rotor 21 by being fixed to the body 13 of the internal combustion engine 12. The stator core 32 has a plurality of tooth portions. One teeth 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, 18 magnetic poles 35.

The stator 31 has a stator coil 33 mounted on the stator core 32. The stator coil 33 provides an armature winding. An insulator 36 is arranged between the stator core 32 and the 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 the rotor 21 and the stator 31 as a generator or a motor.

The sensor unit 37 provides a rotation position detecting device for an internal combustion engine. The sensor unit 37 is provided in the rotary electric machine 10 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 fixing bolts 39. The fixing bolt 39 penetrates from the second end surface SD2 toward the first end surface SD1.

The sensor unit 37 includes a plurality of sensors 38. The sensor unit 37 positions the sensor 38 between two adjacent magnetic poles 35. One sensor 38 is positioned to output a reference position signal. One sensor 38 is also called 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 this embodiment, one of the plurality of sensors 38, the sensor 38, provides the reference position sensor. In this embodiment, three of the plurality of sensors 38 provide a rotational position sensor. When the plurality of sensors 38 include four sensors, one sensor can provide a reference position sensor and the remaining three sensors can provide a rotational position sensor. When the plurality of sensors 38 include three sensors, one sensor can provide a reference position sensor and the entire three sensors can provide a rotational position sensor.

The sensor unit 37 has wiring 15 for external connection 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 rotary electric machine 10 has a plurality of power lines 16 that connect the stator coil 33 and the electric circuit 11. The power line 16 is provided by a flexible cable. The power line 16 supplies the electric power induced in the stator coil 33 to the electric circuit 11 when the rotary electric machine 10 functions as a generator. The power line 16 supplies electric power for exciting the stator coil 33 from the electric circuit 11 to the stator coil 33 when the rotary electric machine 10 functions as an electric motor.

In FIG. 2, a developed view of a rotor 21 and a stator 31 arranged so as to face each other is shown. The rotor 21 has the arrow RT in the forward rotation direction. The S pole 26a and the N pole 26b on the basic magnetic pole 26 are interchangeable. The S pole 27a and the N pole 27b of the special magnetic pole 27 are interchangeable.

The permanent magnet 23 has a plurality of magnet pieces 23a, 23b, 23c, 23d. The plurality of magnet pieces 23a, 23b, 23c, 23d are magnetized for each basic magnetic pole 26 to provide the basic magnetic pole 26. In this embodiment, four types of magnet pieces magnetized in four types of magnetizing patterns are used. The plurality of magnet pieces 23a, 23b, 23c, 23d include two types of plurality of magnet pieces 23a, 23b having only the basic magnetic pole 26. The plurality of magnet pieces include two types of two magnet pieces 23c and 23d having both a basic magnetic pole 26 and a 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 an N pole 26b as a basic magnetic pole 26. The basic period PT in which the polarities of the plurality of basic magnetic poles 26 alternate depends on the circumferential width of the plurality of magnet pieces 23a, 23b, 23c, and 23d.

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 the area of the special magnetic pole 27. The special magnetic pole 27 is a part of the basic magnetic pole 26. The special magnetic pole 27 is arranged so as to be sandwiched between the basic magnetic poles 26 in the permanent magnet 23. The special magnetic pole 27 is arranged so as to be sandwiched between the basic magnetic poles 26 in the middle of the permanent magnet 23 in the axial direction. The special magnetic pole 27 is sandwiched between the basic magnetic poles 26 in the axial direction, but may be sandwiched between 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 the area of the special magnetic pole 27. The special magnetic pole 27 is a part of the basic magnetic pole 26. The special magnetic pole 27 is located between the basic magnetic poles 26.

The magnet pieces 23a, 23b, 23c, and 23d are arranged so that the basic magnetic poles 26 alternate along the circumferential direction CD. The two magnet pieces 23c and 23d are arranged so that the basic magnetic pole 26 and the special magnetic pole 27 show continuous polarities along the circumferential direction CD. The two magnet pieces 23c and 23d are arranged so that the special magnetic poles 27 show the polarity of reversing along the circumferential direction CD. The magnet piece 23c is arranged so that, for example, the S pole 26a, which is the basic magnetic pole 26 provided by the magnet piece 23a, and the S pole 27a, which is the special magnetic pole 27 provided by the magnet piece 23c, exhibit continuous polarities. .. The magnet piece 23c and the magnet piece 23d provide two special magnetic poles 27 whose magnetic characteristics are detectable different. The magnet piece 23c and the magnet piece 23d are arranged so that the two special magnetic poles 27 show the polarity of reversing along the circumferential direction CD. The magnet piece 23d is arranged so that, for example, the N pole 26b, which is the basic magnetic pole 26 provided by the magnet piece 23b, and the N pole 27b, which is the special magnetic pole 27 provided by the magnet piece 23d, exhibit continuous polarities. .. The special magnetic pole 27 is magnetized on two magnet pieces 23c and 23d adjacent to the circumferential CD, and has an S pole 27a and an N pole 27b having different polarities.

The basic magnetic poles 26 are arranged so as to appear in the basic magnetic pole orbits 28 extending along the circumferential direction CD. Only a plurality of basic magnetic poles 26 appear in the basic magnetic pole orbits 28. The special magnetic pole 27 is arranged so as to appear in the special magnetic pole orbit 29 extending along the circumferential direction CD. The special magnetic pole orbit 29 is set substantially at the center of the permanent magnet 23 in the axial direction. A plurality of basic magnetic poles 26 and all special magnetic poles 27 appear in the special magnetic pole orbit 29.

The sensor unit 37 has a plurality of sensors 38a, 38b, 38c arranged in the basic magnetic pole orbit 28. The basic magnetic pole orbit 28 is an orbit in which the basic magnetic pole 26 is arranged along the rotation direction of the rotor 21. The sensors 38a, 38b, 38c output a rotation signal. The sensor unit 37 has one sensor 38d arranged in the special magnetic pole track 29. The special magnetic pole orbit 29 is an orbit in which the special magnetic pole 27 is arranged along 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 can be provided by a variety of sensor elements that respond to magnetic flux. The plurality of sensors 38a, 38b, 38c, 38d can be provided by, for example, a sensor utilizing the Hall effect.

According to this embodiment, the special magnetic pole 27 provides magnetic poles of the same polarity across two pieces of magnets adjacent in the circumferential direction. The special pole 27 does not provide poles of the same polarity across three circumferentially adjacent poles. The special magnetic pole 27 provides, for example, magnetic poles having the same polarity over two magnet pieces 23a and 23c adjacent to each other in the circumferential direction, that is, the S pole 26a and the S pole 27a. The special magnetic pole 27 provides, for example, magnetic poles having the same polarity over two magnet pieces 23d, 23b adjacent in the circumferential direction, that is, N pole 26b and N pole 27b.

The special magnetic pole 27 is arranged so as to provide magnetic poles having different polarities to the two magnet pieces 23c and 23d adjacent to the circumferential CD in the section indicating the reference position. In the illustrated embodiment, the S pole 27a and the N pole 27b are arranged on two magnet pieces 23c and 23d adjacent to the circumferential CD, and are given different polarities. The S pole 27a and the N pole 27b are interchangeable. Different polarities include the relationship between the south pole and the north pole, the relationship between the south pole and the unmagnetized pole, or the relationship between the unmagnetized pole and the north pole.

FIG. 3 shows the output signal waveforms of the plurality of sensors 38a, 38b, 38c, 38d. Each of the waveforms A, B, C, and D corresponds to each of the plurality of sensors 38a, 38b, 38c, and 38d. The three sensors 38a, 38b, and 38c as the rotation position sensors output a plurality of output waveforms A, B, and C. The output waveforms A, B, and C are output as a rectangular wave having a basic period PT defined by the basic magnetic pole 26. The phases of the output waveforms A, B, and C are shifted every 1/3 of the period × PT. As a result, the rotation position signal can realize a resolution of a period of 1/3 × PT.

The sensor 38d as the reference position sensor outputs the output waveform D. The output waveform D is a reference position signal. The output waveform D has a basic cycle period of the basic cycle PT and a tooth loss period of the cycle 2 × PT. The period of tooth loss indicates the reference position. The output waveform D alternates in the basic period PT even during the tooth loss period. The output waveform D provides a missing tooth portion between time t101 and time t103. The output waveform D also alternates at time t102. The output waveform D can substantially show the reference position twice even during the tooth loss period. In other words, the output waveform D can realize the resolution of the basic period PT even during the tooth loss period. As a result, the output waveform D provides higher resolution than the period 3/2 × PT (1.5 × PT) during the tooth loss period.

The circumferential length LG of the same polarity provided by the special magnetic pole 27 and the basic magnetic pole 26 exceeds 1/2 of the basic period PT and is equal to or less than the basic period PT. The length LG is 1/2 × PT <LG ≦ PT. The reference position can be indicated without requiring a long period exceeding the basic period PT. As a result, a rotor of a rotary electric machine for an internal combustion engine having high reference position detection accuracy is provided.

The arrival of the reference position can be determined based on the signal period 1/3 × PT given from the rotation position signal. Even in the process in which the rotation speed gradually increases when the internal combustion engine 12 is started, the difference between the signal cycle 1/3 × PT and the basic cycle PT makes it possible to determine the arrival of the tooth-deficient engine. Further, the period 2 × PT tooth loss period provided by the reference position signal provides an opportunity for two tooth loss determinations.

The electric circuit 11 detects a reference position based on a plurality of signals from the sensor unit 37. The electrical circuit 11 executes ignition control and / or fuel injection control based on the reference position. The electrical circuit 11 identifies the ignition position and / or the fuel injection position using, for example, two of the three sensors 38a, 38b, 38c as phase sensors in addition to the signal from the sensor 38d. do. According to this embodiment, the occurrence of so-called misfire in the internal combustion engine 12 can be suppressed. Therefore, ignition and / or fuel injection can be reliably executed even when the internal combustion engine 12 is started. As a result, the start of the internal combustion engine 12 is completed quickly.

According to the above-described embodiment, a rotary electric machine for an internal combustion engine having high reference position detection accuracy is provided. From one viewpoint, it is possible to indicate the arrival of the missing tooth portion (the arrival of the reference position) with high accuracy even at the time of starting when the rotation speed of the internal combustion engine 12 is slow. The reference position can be indicated at an early stage when the internal combustion engine is started. As a result, a rotary electric machine for an internal combustion engine is provided, in which the internal combustion engine 12 starts quickly.

Second Embodiment This embodiment is a modification based on the preceding embodiment. In the above embodiment, the output waveform D, which is the reference position signal, provides the resolution of the basic period PT. Instead, in this embodiment, the reference position signal provides a resolution with a period of 3/4 × PT.

In FIG. 4, the permanent magnet 23 includes a plurality of magnet pieces 223a, 223b, and 223c magnetized for each of the basic magnetic poles 26. The special magnetic poles 227a, 227b, and 227c are magnetized on all of the plurality of magnet pieces. The special magnetic pole 27 is formed so that the polarities alternate at 1/2 of the basic period PT. In this embodiment, three types of magnet pieces magnetized in three types of magnetizing patterns are used. The plurality of magnet pieces 223a, 223b, and 223c include two types of magnet pieces 223a and 223b having a basic magnetic pole 26 and two special magnetic poles 227a and 227b. The plurality of magnet pieces 223a, 223b, and 223c include one magnet piece 223c having a basic magnetic pole 26 and one special magnetic pole 227c. Also in this embodiment, the S pole 26a and the N pole 26b at the basic magnetic pole 26 are interchangeable. The S pole 227a and the N pole 227b of the special magnetic pole 27 are also interchangeable.

The rotor 21 has a plurality of magnet pieces 223a, 223b, and 223c. The plurality of magnet pieces 223a have an S pole 26a as a basic magnetic pole 26, an S pole 227a as a special magnetic pole 27, and an N pole 227b. The plurality of magnet pieces 223b have an N pole 26b as a basic magnetic pole 26, an S pole 227a as a special magnetic pole 27, and an N pole 227b. The S pole 227a and the N pole 227b as the special magnetic pole 227 are magnetized by dividing one magnet piece 223a and 223b into a circumferential CD.

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

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

In FIG. 5, the sensor 38d as the reference position sensor outputs the output waveform D. The output waveform D is a reference position signal. The output waveform D has a period of period 1/2 × PT and a period of tooth loss of period 3/4 × PT. The period of tooth loss indicates the reference position. The output waveform D provides a missing tooth portion between time t201 and time t203. The output waveform D provides higher resolution than the period 3/2 × PT (1.5 × PT) during the tooth loss period.

The arrival of the reference position can be determined based on the signal cycle 1/2 × PT given in the period of the basic cycle. Even in the process in which the rotation speed gradually increases when the internal combustion engine 12 is started, the difference between the signal period 1/2 × PT and the period 3/4 × PT makes it possible to determine the arrival of the tooth loss period.

According to the above-described embodiment, a rotary electric machine for an internal combustion engine having high reference position detection accuracy is provided. From one viewpoint, it is possible to indicate the arrival of the missing tooth portion (the arrival of the reference position) with high accuracy even at the time of starting when the rotation speed of the internal combustion engine 12 is slow. The reference position can be indicated at an early stage when the internal combustion engine is started. As a result, a rotary electric machine for an internal combustion engine is provided, in which the internal combustion engine 12 starts quickly.

Third Embodiment This embodiment is a modification based on the preceding embodiment. In the above embodiment, the special magnetic pole 27 is formed substantially in the center of the permanent magnet 23. Instead, the special magnetic poles 27 may be formed unevenly distributed in either one of the axial directions of the permanent magnets 23.

In FIG. 6, the magnet piece 23c has an S pole 327a as a special magnetic pole 27 arranged at one end in the axial direction of the permanent magnet 23. The magnet piece 23d has an N pole 327b as a special magnetic pole 27 arranged at one end in the axial direction of the permanent magnet 23. As a result, the basic magnetic poles 26 are arranged so as to appear in the basic magnetic pole orbits 28. The special magnetic pole 27 is arranged so as to appear in the special magnetic pole orbit 29. The sensor unit 37 has sensors 38a, 38b, and 38c as rotational position sensors arranged on the basic magnetic pole orbit 28. The sensor unit 37 has a sensor 38d as a reference position sensor arranged in the special magnetic pole track 29. As a result, the sensors 38a, 38b, and 38c output a plurality of rotation position signals indicating the rotation positions. The sensor 38d outputs a reference position signal indicating the reference position. Also in this embodiment, a signal waveform similar to that of the preceding first embodiment can be obtained.

Other Embodiments The disclosure in this specification, drawings and the like is not limited to the exemplified embodiments. The disclosure includes exemplary embodiments and modifications by those skilled in the art based on them. For example, disclosure is not limited to the parts and / or element combinations shown in the embodiments. Disclosure can be carried out in various combinations. The disclosure can have additional parts that can be added to the embodiment. Disclosures include those in which the parts and / or elements of the embodiment are omitted. Disclosures include the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some technical scopes disclosed are indicated by the claims description and should be understood to include all modifications within the meaning and scope equivalent to the claims statement.

Disclosure in the description, drawings, etc. is not limited by the description of the scope of claims. The disclosure in the description, drawings, etc. includes the technical ideas described in the claims, and further covers a wider variety of technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the description, drawings, etc. without being bound 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, 23d. Alternatively, one piece of magnet may provide a plurality of basic magnetic poles 26. The terms of different polarities mean that the magnetic properties are detectable different. Further, terms of different polarities are terms including the relationship between the S pole and the N pole, the relationship between the S pole and the non-magnetized pole, or the relationship between the non-magnetized pole and the N pole.

In the above embodiment, one reference position is set in one cycle T. Instead of this, two or more reference positions may be set in one cycle T. For example, in addition to the plurality of magnet pieces 23a and 23b, a plurality of sets of magnet pieces 23c and 23d can be arranged at a plurality of positions of the rotor 21. In addition to the plurality of magnet pieces 223a and 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 and 23b, a plurality of sets of magnet pieces 323c and 323d may be arranged at a plurality of positions of the rotor 21.

In the above embodiment, the sensor unit 37 includes four sensors 38. Instead, the sensor unit 37 may include three sensors 38. In this case, the sensor unit 37 can include two sensors 38 arranged on the basic magnetic pole orbit 28 and one sensor 38 arranged on the special magnetic pole orbit 29. One sensor 38 arranged in the special magnetic pole orbit 29 is used as both a reference position sensor and a rotation position sensor.

The rotor of the rotary electric machine for an internal combustion engine disclosed herein includes a rotor core as a yoke and a permanent magnet held by the rotor core, and the permanent magnets alternate in polarity at a predetermined basic period PT. It has a plurality of basic magnetic poles formed in the above manner and a special magnetic pole formed in a part of a permanent magnet so as to have a polarity different from that of the basic magnetic poles, and the special magnetic poles are adjacent to each other in the circumferential direction and have different polarities. Having two special magnetic poles (27a, 27b), 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 equal to or less than the basic period (1/2 × PT). <LG ≦ PT).

According to the rotor of the rotary electric machine for an internal combustion engine of the first invention disclosed, the special magnetic pole can indicate a reference position at at least one position in the rotation direction. Moreover, 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 equal to or less than the basic period PT. The circumferential length LG is represented by 1/2 × PT <LG ≦ PT. The reference position can be indicated without requiring a long period exceeding the basic period PT. As a result, a rotor of a rotary electric machine for an internal combustion engine having high reference position detection accuracy is provided.
The rotor of the rotary electric machine for an internal combustion engine of the second invention disclosed herein includes a rotor core (22) as a yoke and a permanent magnet (23) held by the rotor core, and the permanent magnet has a predetermined basic period. A plurality of basic magnetic poles (26) formed so as to alternate polarities in (PT), and a special magnetic pole (27) formed in a part of a 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 is more than 1/2 of the basic period and less than or equal to the basic period (1/2 × PT <LG ≦ PT). The permanent magnet includes a plurality of magnet pieces magnetized for each basic magnetic pole, and special magnetic poles (227a, 227b, 227c) are magnetized on all of the plurality of magnet pieces.

Claims (10)

Rotor core (22) as a yoke and
A permanent magnet (23) held by the rotor core is provided.
The permanent magnet includes a plurality of basic magnetic poles (26) formed so as to alternate polarities in a predetermined basic period (PT), and one of the permanent magnets so as to have a polarity different from that of the basic magnetic poles (26). It has a special magnetic pole (27) formed in the portion and has a special magnetic pole (27).
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 equal to or less than the basic period (1/2 × PT <LG ≦ PT). Rotor of rotating electric machine for internal combustion engine. The rotor of a rotating electric machine for an internal combustion engine according to claim 1, wherein the basic magnetic pole is a rotating magnetic field for the rotating electric machine. The permanent magnet includes a plurality of magnet pieces magnetized for each of the basic magnetic poles.
The rotation for an internal combustion engine according to claim 1 or 2, wherein the special magnetic pole is magnetized on two magnet pieces adjacent to each other in the circumferential direction and has two special magnetic poles (27a, 27b) having different polarities. Electric rotor. The plurality of magnet pieces
Two types of the magnet pieces (23a, 23b) having only the basic magnetic poles, and
The rotor of a rotary electric machine for an internal combustion engine according to claim 3, further comprising two types of the two magnet pieces (23c, 23d) having the basic magnetic pole and the special magnetic pole. The permanent magnet includes a plurality of magnet pieces magnetized for each of the basic magnetic poles.
The rotor of a rotary electric machine for an internal combustion engine according to claim 1 or 2, wherein the special magnetic poles (227a, 227b, 227c) are magnetized on all of the plurality of magnet pieces. The rotor of a rotary electric machine for an internal combustion engine according to claim 5, wherein the special magnetic pole is formed so that the polarities alternate at 1/2 of the basic cycle. The plurality of magnet pieces
Two types of the magnet pieces (223a, 223b) having the basic magnetic pole and the two special magnetic poles (227a, 227b), and
The rotor of a rotary electric machine for an internal combustion engine according to claim 5 or 6, further comprising one magnet piece (223c) having the basic magnetic pole and one special magnetic pole. The rotor of a rotary electric machine for an internal combustion engine according to any one of claims 1 to 7, wherein the special magnetic pole is arranged between the basic magnetic poles in the permanent magnet. The rotor of a rotary electric machine for an internal combustion engine according to any one of claims 1 to 7, wherein the special magnetic pole is arranged at one end in the axial direction of the permanent magnet. The rotor (21) of the rotary electric machine for an internal combustion engine according to any one of claims 1 to 9.
A stator (31) arranged to face the rotor and
A plurality of rotation position sensors (38a, 38b, 38c) arranged in the basic magnetic pole orbit (28) in which the basic magnetic poles are arranged along the rotation direction of the rotor, and
A rotating electric machine for an internal combustion engine including a reference position sensor (38d) arranged in a special magnetic pole orbit (29) in which the special magnetic pole is arranged along the rotation direction of the rotor.

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