JP2005233109A - Starter for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a starting failure when starting an internal combustion engine.
An internal combustion engine is started by a motor generator. Motor generator 104 includes a stator 208 that forms a magnetic field for generating a rotational force upon receiving power supply, and a rotor 210 that is supplied with control power for controlling the rotational force. The starter includes a battery 120 for supplying power to the stator 208 and a BBC 112 for supplying control power to the rotor 210.
[Selection] Figure 2

Description

  The present invention relates to an internal combustion engine starter, and more particularly to a technique for supplying electric power for starting an internal combustion engine to an electric motor.

  From the viewpoint of global warming prevention and resource saving, when the vehicle stops at a red light at an intersection, etc., the engine is automatically stopped and the driver operates to start again (for example, by depressing the accelerator pedal) In addition, an idling stop system (also called an economy running system or an engine automatic stop-and-start system) that restarts the engine has been put into practical use.

  In a vehicle equipped with such an idling stop system, a battery that supplies electric power to an electric motor that performs cranking when the engine is started may be provided separately.

  For example, Japanese Patent Laying-Open No. 2003-254208 (Patent Document 1) discloses a vehicle power supply control device that reliably performs both engine start associated with vehicle start-up and engine start associated with idling stop control without promoting battery deterioration. Is disclosed. This vehicle power supply control device is a vehicle power supply control device that executes idling stop control that automatically stops and starts the engine in accordance with the driving state. A power supply control device for a vehicle includes a first battery and a second battery having a higher energy density and a lower output density than the first battery. The vehicle power supply control device supplies power to the starter from the first battery when starting the engine as the vehicle starts. On the other hand, the vehicle power supply control device supplies power to the starter from the second battery when starting the engine in accordance with the idling stop control.

According to Patent Document 1, power is supplied from the first battery to the starter during normal startup, and power is supplied from the second battery having higher energy density and lower output density than the first battery during restart. Is supplied to the starter. For this reason, the reliability of engine start is ensured both during normal start and during restart. Further, at the time of a normal start with a relatively large load, the second battery having a relatively low output density does not supply power to the starter, so that the startability of the engine at that time is reliably ensured. Furthermore, at the time of restart that is performed relatively frequently, the first battery having a relatively low energy density does not supply power to the starting device, so that the deterioration of the battery is prevented from being promoted.
JP 2003-254208 A

  However, in Patent Document 1, the power supply source to the electric motor is either one of the first battery and the second battery at the time of starting and starting the vehicle.

  For example, it is assumed that a field winding type synchronous motor that generates a rotational force by generating a magnetic field by supplying electric power to a rotor and a stator as an electric motor for starting an engine is assumed. Since electric power is supplied to the rotor and the stator from the same supply source, the battery voltage may drop when a large current flows through the stator. When the voltage of the battery drops, the exciting current based on the control power supplied to the rotor may be momentarily interrupted or lowered. When the excitation current is momentarily interrupted or reduced, a sufficient excitation current cannot be flowed, so that the operation of the motor cannot be reliably controlled. If the electric motor is not reliably controlled, there is a problem that the engine starts poorly.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a starting device for an internal combustion engine that can avoid a starting failure when starting the internal combustion engine.

  An internal combustion engine starter according to a first aspect of the invention includes an electric motor that starts the internal combustion engine. The electric motor includes a first winding that forms a magnetic field for generating a rotational force when supplied with electric power, and a second winding that is supplied with control power for controlling the rotational force. The starter further includes power storage means for supplying power to the first winding and power supply means for supplying control power to the second winding.

  According to the first aspect of the invention, the electric motor includes a first winding (for example, a stator winding) that forms a magnetic field for receiving a supply of electric power to generate a rotational force, and a control power for controlling the rotational force. And a second winding (e.g., a rotor winding). The starting device further includes power storage means for supplying power to the stator windings and power supply means for supplying control power to the rotor windings. The power supply means (for example, BBC (backup boost converter)), for example, when electric power is supplied from the power storage means, converts the voltage value of the supplied electric power into a predetermined voltage value and turns the rotor winding Is supplied with an excitation current based on the control power. Thus, even when a voltage drop occurs in the power storage means due to a large current flowing to the stator when the engine is started, the rotor windings are supplied with electric power converted to a predetermined voltage value from the power supply means. Based on the excitation current is supplied. For this reason, the exciting current can be stably supplied to the winding of the rotor without instantaneous interruption or reduction. As a result, a sufficient excitation current can flow, so that the operation of the electric motor can be reliably controlled. Therefore, it is possible to provide a starting device for an internal combustion engine that can avoid a starting failure when starting the internal combustion engine.

  In the internal combustion engine starter according to the second invention, in addition to the configuration of the first invention, the power supply means is supplied with power from the power storage means, and the voltage value of the supplied power is a predetermined voltage. Means for converting to a value and supplying control power.

  According to the second invention, the power supply means is supplied with power from the power storage means, converts the voltage value of the supplied power to a predetermined voltage value, and supplies control power. Thus, even when a voltage drop occurs in the power storage means due to a large current flowing through the stator when the engine is started, a predetermined voltage is supplied from the power supply means (for example, BBC) as control power to the rotor windings. An exciting current based on the power of the value can be stably supplied to the winding of the rotor. Therefore, the operation of the electric motor can be reliably controlled.

  In the internal combustion engine starter according to the third aspect of the invention, in addition to the configuration of the first aspect of the invention, the vehicle is equipped with the first power storage mechanism and the second power storage mechanism. The power storage means is a first power storage mechanism. The power supply means is a second power storage mechanism.

  According to the third invention, the vehicle is equipped with a first power storage mechanism (for example, a starter battery) and a second power storage mechanism (for example, an auxiliary battery). The power storage means is a starting battery. The power supply means is an auxiliary battery. As a result, even if a voltage drop occurs in the starter battery due to a large current flowing through the stator when the engine is started, power of a predetermined voltage value is supplied from the auxiliary battery as control power to the rotor windings. Can be stably supplied to the rotor windings. Therefore, the operation of the electric motor can be reliably controlled.

  In the internal combustion engine starter according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the electric motor is a field winding type synchronous motor.

  According to the fourth invention, a field winding type synchronous motor is used as the electric motor. In the field winding type synchronous motor, as a motor for starting an engine, electric power is supplied to the winding of the rotor and the winding of the stator to form a magnetic field and generate a rotational force. Accordingly, power is supplied to the stator windings by the power storage means, and control power is supplied to the rotor windings by the power supply means (for example, BBC). Therefore, even if a voltage drop occurs in the power storage means due to a large current flowing through the stator when the engine is started, excitation based on power of a predetermined voltage value from the power supply means as control power to the rotor windings. A current can be supplied stably. Therefore, the operation of the electric motor can be reliably controlled.

  In the internal combustion engine starter according to the fifth aspect of the invention, in addition to the configuration of any one of the first to fourth aspects of the invention, the power supply means supplies power to an auxiliary machine mounted on the vehicle.

  According to the fifth invention, the power supply means (for example, BBC) supplies power to the auxiliary machine mounted on the vehicle. For example, when power is supplied from the power storage means, the power supply means converts the voltage value of the supplied power into a predetermined voltage value and supplies the power. Even if a voltage drop occurs in the power storage means due to a large current flowing through the stator when the engine is started by supplying power from the power supply means to the auxiliary equipment (for example, ECU, etc.), Thus, power having a predetermined voltage value is stably supplied. Therefore, it is possible to avoid an unstable operation due to a momentary interruption or reduction in the current supplied to the auxiliary machine.

  In the internal combustion engine starter according to the sixth aspect of the invention, in addition to the configuration of any one of the first to fifth aspects, the first winding is a winding of the stator of the motor. The second winding is a winding of the rotor of the electric motor.

  According to the sixth invention, the first winding is a winding of the stator of the electric motor. The second winding is a winding of the rotor of the electric motor. Electric power is supplied from the power storage means to the stator winding, and an excitation current based on control power is stably supplied from the power supply means (for example, BBC) to the rotor winding. Thereby, operation | movement of an electric motor can be controlled reliably.

  Hereinafter, an internal combustion engine starter according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
With reference to FIG. 1, a vehicle 100 having an internal combustion engine starter according to an embodiment of the present invention will be described.

  Vehicle 100 includes an ECU (Electronic Control Unit) 102, an engine 106, a transmission 116, and a motor generator 104. The engine 106 includes a crankshaft 118 that is an output shaft. One end of the crankshaft 118 is connected to the transmission 116. The other end of the crankshaft 118 is connected to the motor generator 104 via a pulley and a belt 110.

  The motor generator 104 functions as an electric motor that cranks the crankshaft 118 when the engine 106 is started, and functions as a generator during braking. Motor generator 104 according to the present embodiment is a wound field type synchronous motor including a rotor (not shown) and a stator (not shown).

  In the wound field type synchronous motor according to the present embodiment, three-phase AC power is supplied to the stator winding, and excitation current based on the control power is supplied to the rotor winding. There is no particular limitation. For example, an exciting current based on the control power may be supplied to the stator winding, and three-phase AC power may be supplied to the rotor winding.

  When an exciting current is supplied to the rotor winding, a magnetic pole is formed. On the other hand, when three-phase AC power is supplied to the winding of the stator, a rotating magnetic field is formed. The magnetic poles formed on the rotor generate a rotational force by the rotating magnetic field. At this time, the rotational force of the motor generator 104 can be controlled by controlling the excitation current and the AC power to the stator. In the present embodiment, motor generator 104 has a function as an electric motor and a generator. However, in the present invention, at least a function as an electric motor is sufficient.

  The engine 106 is provided with a starter 108. When an ignition key (not shown) is turned on, that is, when the engine 106 is started, power is supplied from the battery 120 to the starter 108. Then, the starter 108 rotates the crankshaft 118, whereby the engine 106 is started.

  When engine 106 is started, it is not particularly limited to starting engine 106 by starter 108. For example, even when engine 106 is started by operating motor generator 104 when the ignition key is turned on. Good.

  The transmission 116 is not particularly limited as long as it is an automatic transmission. For example, it may be a stepped automatic transmission or a continuously variable automatic transmission. The output side of the transmission 116 is connected to the tire 134 via a propeller shaft, a differential mechanism, and a drive shaft. That is, the tire 134 is driven by rotational driving on the output side of the transmission 116.

  The ECU 102 includes a memory (not shown) that stores various data and programs, and a CPU (Central Processing Unit) that executes the programs stored in the memory.

  The vehicle 100 having the control device according to the present embodiment is equipped with an automatic start / stop system for the engine 106, a so-called idling stop system.

  When vehicle state satisfies a predetermined stop condition in vehicle 100, ECU 102 executes an idling stop system. The idling stop system is a system that controls the engine 106 to stop when a condition input to the ECU 102 satisfies a predetermined stop condition. When the stop condition of engine 106 is no longer satisfied, ECU 102 controls motor generator 104 to supply power from battery 120. Then, the motor generator 104 is driven to rotate the crankshaft 118 of the engine 106. Thereby, the engine 106 is restarted (cranking).

  The battery 120 mounted on the vehicle 100 is not particularly limited, but in the present embodiment, for example, a lead storage battery having an output voltage of 12 volts. The battery 120 is connected to the power module 114. Power module 114 is connected to the stator of motor generator 104. Then, power is supplied from the battery 120 to the power module 114. The power supplied from the battery 120 is converted into desired AC power in the power module 114 and supplied to the stator.

  Further, the battery 120 is connected to the BBC 112. The BBC 112 is supplied with power from the battery 120. The BBC 112 converts the voltage value of the supplied power into a predetermined voltage value. The BBC 112 supplies the converted power to the excitation drive circuit 116. Excitation drive circuit 116 is connected to the rotor winding of motor generator 104. The excitation drive circuit 116 supplies excitation current to the rotor windings based on the power supplied as control power from the BBC 112 and the control signal from the ECU 102. The present invention is characterized in that control power is supplied from the BBC 112 to the windings of the rotor.

  As shown in FIG. 2, in the internal combustion engine starter according to the present embodiment, ECU 102 includes an idle stop computer 200 and an MG controller 202. Motor generator 104 includes a stator 208 and a rotor 210.

  The idle stop computer 200 controls the idle stop system, and controls the engine 106 to stop when input from various sensors provided in the vehicle 100 satisfies a predetermined stop condition of the engine 106. If the stop condition of engine 106 is not satisfied, idle stop computer 200 transmits a start control signal for motor generator 104 to MG controller 202.

  When receiving the start control signal, the MG controller 202 controls the motor generator 104 to operate. Specifically, the MG controller 202 transmits a stator drive control signal to the power module drive circuit 204. Then, the MG controller 202 transmits a rotor drive control signal to the excitation drive circuit 116.

  In response to the stator drive control signal, the power module drive circuit 204 converts the DC power supplied from the battery 120 into desired AC power in the power module 114 and supplies the stator 208 with power.

  In the present embodiment, the power module 114 is configured by, for example, a three-phase bridge circuit including six power transistors, but is not particularly limited. Since the configuration and operation of the power module 114 are well-known techniques, detailed description thereof will not be repeated here.

  The excitation drive circuit 116 supplies an excitation current to the rotor 210 based on the rotor drive control signal and the control power supplied from the BBC 112.

  The motor generator 104 is provided with a magnetic pole sensor 206. The magnetic pole sensor 206 detects the rotation angle and rotation speed of the rotor 210. A current sensor 212 is provided between the power module 114 and the motor generator 104. The current sensor 212 detects a current supplied from the power module 114 to the motor generator 104. The magnetic pole sensor 206 and the current sensor 212 transmit respective detection signals to the MG controller 202.

  The MG controller 202 grasps the rotation state of the motor generator 104 and the power supply state based on the received detection signal, and performs desired control.

  The BBC 112 converts the voltage value of the power supplied from the battery 120 into a predetermined voltage value and supplies the excitation drive circuit 116 with power. At this time, the output characteristics of the BBC 112 are not particularly limited. For example, as shown in FIG. 3, the BBC 112 outputs an output voltage with respect to an input voltage in a range from V (1) to V (2). The voltage is converted so as to be V (OUT). The BBC 112 is composed of, for example, a boost converter.

  The operation of the starting device for the internal combustion engine according to the present embodiment based on the above structure will be described.

  When a start control signal for the engine 106 is transmitted from the idle stop computer 200 to the MG controller 202, the MG controller 202 controls the motor generator 104 to operate.

  That is, the MG controller 202 transmits a stator drive control signal to the power module drive circuit 204. Based on the stator drive control signal and the power supplied from the battery 120, the power module drive circuit 204 converts the power module 114 into desired AC power and supplies it to the stator 208.

  Then, the MG controller 202 transmits a rotor drive control signal to the excitation drive circuit 116. The excitation drive circuit 116 supplies an excitation current to the rotor 210 based on the rotor drive control signal and the control power supplied from the BBC 112.

  Thereby, in motor generator 104, when an excitation current is supplied from excitation drive circuit 116 to rotor 210, a magnetic field is formed in rotor 210. A magnetic pole is formed in the rotor 210.

  When three-phase AC power is supplied from the power module 114 to the stator 208, a rotating magnetic field is generated in the stator 208. At this time, the magnetic pole formed on the rotor 210 generates a rotational force by the generated rotating magnetic field. MG controller 202 can perform desired control of motor generator 104 by controlling AC power and excitation current.

  At this time, a large current flows through the stator 208 when the engine 106 is started. When a large current flows, the battery 120 may drop in voltage. At this time, the BBC 112 that supplies the control power to the excitation drive circuit 116 supplies a predetermined voltage value V (OUT) to the excitation drive circuit 116 regardless of the voltage drop of the battery 120.

  As described above, according to the starter for an internal combustion engine according to the present embodiment, the motor generator receives the rotation of the stator windings that form a magnetic field for receiving the supply of electric power and generating a rotational force. And a rotor winding to which control power to be controlled is supplied. The starter further includes a battery for supplying power to the stator windings and a BBC for supplying control power to the rotor windings. When electric power is supplied from the battery, the BBC converts the voltage value of the supplied electric power into a predetermined voltage value, and supplies an excitation current based on the electric power for control to the winding of the rotor. As a result, even if a voltage drop occurs in the battery due to a large current flowing to the stator when the engine is started, the rotor winding has an exciting current based on power converted from the BBC to a predetermined voltage value. Is supplied. For this reason, the exciting current can be stably supplied to the winding of the rotor without instantaneous interruption or reduction. As a result, a sufficient excitation current can flow, so that the operation of the electric motor can be reliably controlled. Therefore, it is possible to provide a starting device for an internal combustion engine that can avoid a starting failure when starting the internal combustion engine.

  Moreover, BBC112 may be connected to auxiliary machines, such as ECU. That is, electric power may be supplied from the BBC 112 to an auxiliary machine such as an ECU. Thus, even if a voltage drop occurs in battery 120 due to a large current flowing through stator 208 when engine 106 is started, a predetermined voltage value V (OUT) is supplied from BBC 112 to the auxiliary machine. Thereby, since stable electric power can be supplied to the auxiliary machine, it is possible to avoid an unstable operation due to a momentary interruption or reduction in the current supplied to the auxiliary machine.

<Second Embodiment>
Hereinafter, a starter for an internal combustion engine according to a second embodiment of the present invention will be described with reference to FIG.

  Compared to the configuration of the starter for the internal combustion engine according to the first embodiment, the starter for the internal combustion engine according to the present embodiment is different from the battery 120 and the BBC 112 in the starter battery. 304, an auxiliary battery 300, and a DC / DC converter 302. Other configurations are the same as the configuration of the starter for the internal combustion engine according to the first embodiment described above. The same reference numerals are assigned to the same components. Their functions are the same. Therefore, detailed description thereof will not be repeated here.

  The starting battery 304 is not particularly limited, but is a lithium ion battery, for example, in the present embodiment. In addition, the auxiliary battery 300 is not particularly limited, but is, for example, a 12-volt lead acid battery in the present embodiment. The auxiliary battery 300 is connected to an auxiliary machine such as an ECU (not shown).

  A DC / DC converter 302 is provided between the starting battery 304 and the auxiliary battery 300. The DC / DC converter 302 functions as a bidirectional buck-boost converter when charging between the starting battery 304 and the auxiliary battery 300.

  The operation of the starting device for the internal combustion engine according to the present embodiment based on the above structure will be described.

  When a start control signal for the engine 106 is transmitted from the idle stop computer 200 to the MG controller 202, the MG controller 202 controls the motor generator 104 to operate.

  That is, the MG controller 202 transmits a stator drive control signal to the power module drive circuit 204. Based on the stator drive control signal and the power supplied from the starter battery 304, the power module drive circuit 204 converts the power module 114 into desired AC power and supplies it to the stator 208.

  Then, the MG controller 202 transmits a rotor drive control signal to the excitation drive circuit 116. The excitation drive circuit 116 supplies an excitation current to the rotor 210 based on the rotor drive control signal and the control power supplied from the auxiliary battery.

  Thereby, in motor generator 104, when an excitation current is supplied from excitation drive circuit 116 to rotor 210, a magnetic field is formed in rotor 210. A magnetic pole is formed in the rotor 210.

  When three-phase AC power is supplied from the power module 114 to the stator 208, a rotating magnetic field is generated in the stator 208. At this time, the magnetic pole formed on the rotor 210 is attracted to the generated rotating magnetic field to generate a rotational force. MG controller 202 can perform desired control of motor generator 104 by controlling AC power and excitation current.

  At this time, a large current flows through the stator 208 when the engine 106 is started. When the large current flows, the starter battery 304 may drop in voltage. At this time, the auxiliary battery 300 that supplies control power to the excitation drive circuit 116 supplies a predetermined voltage value to the excitation drive circuit 116 regardless of the voltage drop of the starter battery 304.

  As described above, according to the internal combustion engine starter according to the present embodiment, the starter battery and the auxiliary battery are mounted on the vehicle. As a result, even if a large current flows through the electric motor when the engine is started and a voltage drop occurs in the starting battery, the control power supplied to the rotor is supplied from the auxiliary battery. A voltage value can be supplied stably. As a result, since an exciting current can be sufficiently passed through the rotor, the operation of the electric motor can be reliably controlled. Therefore, it is possible to provide a starter for an internal combustion engine that can avoid a start failure when starting the internal combustion engine.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure showing composition of vehicles which have a starting device of an internal-combustion engine concerning a 1st embodiment. It is a figure which shows the structure of the starting device of the internal combustion engine which concerns on 1st Embodiment. It is a figure which shows the output characteristic of BBC which concerns on 1st Embodiment. It is a figure which shows the structure of the starting device of the internal combustion engine which concerns on 2nd Embodiment.

Explanation of symbols

  100 vehicle, 102 ECU, 104 motor generator, 106 engine, 108 starter, 110 belt, 112 BBC, 114 power module, 116 excitation drive circuit, 118 crankshaft, 120 battery, 134 tires, 200 idle stop computer, 202 MG controller, 204 Power module drive circuit, 206 Magnetic pole sensor, 208 Stator, 210 Rotor, 212 Current sensor, 300 Auxiliary battery, 302 DC / DC converter, 304 Start-up battery

Claims (6)

A starter for an internal combustion engine,
Including an electric motor for starting the internal combustion engine,
The electric motor includes a first winding that forms a magnetic field for generating a rotational force when supplied with electric power, and a second winding that is supplied with a control electric power for controlling the rotational force,
The starter is
Power storage means for supplying power to the first winding;
A starting device for an internal combustion engine, further comprising power supply means for supplying control power to the second winding.   The power supply means includes means for supplying electric power from the power storage means, converting a voltage value of the supplied electric power to a predetermined voltage value, and supplying the control electric power. 2. A starter for an internal combustion engine according to 1. The vehicle is equipped with a first power storage mechanism and a second power storage mechanism,
The power storage means is a first power storage mechanism,
The starter for an internal combustion engine according to claim 1, wherein the power supply means is a second power storage mechanism.   The starter for an internal combustion engine according to any one of claims 1 to 3, wherein the electric motor is a field winding type synchronous motor.   The starter for an internal combustion engine according to any one of claims 1 to 4, wherein the power supply means supplies power to an auxiliary machine mounted on a vehicle. The first winding is a winding of a stator of the electric motor,
The starter for an internal combustion engine according to any one of claims 1 to 5, wherein the second winding is a winding of a rotor of the electric motor.

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