JP2003184712A - Control device for internal combustion engine starter generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine starter generator capable of surely preventing a piston of an engine from exceeding a top dead center when a starter generator is rotated in a reverse direction at once in start of the engine. <P>SOLUTION: The device is provided with a PWM control means controlling an inverter circuit 3, when the inverter circuit 3 is controlled so as to reversely rotate a crankshaft in starting the internal combustion engine, to make a wave shape of a drive current supplied to armature coils Lu-Lw of a starter generator 1 from a battery through the inverter circuit 3 a PWM wave form that intermits at a set duty ratio. The piston of the engine is prevented from exceeding the top dead center by controlling the duty ratio when the crankshaft is reversely rotated. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting an internal combustion engine.
Charge the starter motor (starting motor) and battery
Star for internal combustion engine that doubles as generator (generator)
Generator (motor for starting the internal combustion engine and charging the battery)
And a rotating electric machine that also serves as an electric generator). 2. Description of the Related Art Generally, when an internal combustion engine is stopped,
Stop the ignition by the fire device, or supply fuel to the engine.
Stop the combustion in the cylinder by stopping the supply.
I try to make it. Combustion no longer occurs in the cylinder
Then, after the engine continues to rotate for a while due to inertia,
As Ston rises toward compression top dead center,
From the ton side until the load on the crankshaft reaches a peak.
Stop during at. Therefore, the stop position of the engine (the engine stops
The crank angle position when the engine is stopped) will be
At the position where the load on the starter motor reaches its peak
It is generally the position in front. FIG. 7 shows the stroke of a single-cylinder four-cycle internal combustion engine.
Shows the relationship between the change and the pressure change in the cylinder
The pressure in the cylinder drops from the peak during the combustion stroke.
And then show the lowest value at the end of the exhaust stroke.
To the compression stroke. Stop the internal combustion engine
Therefore, if combustion in the cylinder is stopped, the engine will shut down.
Example of the process in which the pressure in the Linda rises to its peak
For example, stop at point A. To start the engine in this state
When the starter motor is driven,
Such load torque reaches a peak, and then the load torque
After the peak, the load on the starter motor decreases.
Go on. As described above, when starting the engine, the starter
A large load is applied to the motor immediately after starting the motor
Therefore, in order to start the engine without any trouble,
Use a motor with very high starting torque
It is necessary, and it is inevitable that the motor becomes large. Ma
Also has a large starting torque as a starter motor
Even if you use something, depending on the battery consumption
Can not overcome the load applied at the start,
May fail to start. To prevent such a problem from occurring,
Therefore, when starting the engine, once turn the crankshaft
Rotate in the reverse direction (for example, from point A to point B in FIG. 7)
After reducing the load on the starter motor,
Start the crankshaft by reversing the rotation direction of the tarter motor
Rotation in the normal direction (forward rotation direction)
Utilizes the piston with a relatively small torque
The starter motor when the motor exceeds the first compression top dead center
Control method of starter motor to overcome overload
Has been proposed. Controlling the starter motor in this way
Start-up motor than the conventionally used starter motor
Using a motor with a small torque as the starter motor
Seki can be started. As described above, when the engine is started,
After rotating the crankshaft once in the reverse direction,
When using the method of reversing the direction and rotating in the starting direction
When the crankshaft is reversed, the piston
Limit the rotation angle range when reversing so that it does not exceed
There is a need to. To solve this problem, Japanese Patent Laid-Open No. 2000-2000
No. 283010, the reverse of the crankshaft
Immediately after starting the rotation, a predetermined position (for example, in FIG.
The crank angle reaches the angle corresponding to the top dead center of the exhaust stroke
At the set position before the crankshaft)
A tie that stops the starter motor according to this rotation speed
Internal combustion engine start control device that determines the timing
Was done. [0008] Japanese Patent Application Laid-Open No. 2000-283
As shown in the control device of No.010, the reverse of the crankshaft
Immediately after starting rotation, the crankshaft is
Detects the rotation speed and sets the crankshaft according to the rotation speed.
In order to determine the stop timing of
It is necessary to detect the crank angle immediately after starting operation.
You. In order to reduce air pollution by exhaust gas, internal combustion
As in the case of controlling to stop the engine frequently,
Start the engine with the ignition switch closed.
When the engine is stopped
The control unit (ECU) that controls the engine also
When the engine is started, the
Immediately after starting the reverse rotation of the rank axis, the rotation of the crankshaft
It is possible to accurately recognize the angular position. However, the ignition switch must be
When starting the engine for the first time after closing, the ECU
Cannot accurately detect the position of the crankshaft,
Immediately after starting the reverse rotation of the shaft, the rotation speed is accurately detected.
In many cases, the above method
Is the motor stop timing when reversing the crankshaft
The crankshaft is reversed.
May cause the piston to go over top dead center
Was. An object of the present invention is to provide an ignition switch.
When the engine is started for the first time after closing the
Make sure to starter motor before reaching top dead center during reverse rotation.
Be able to stop the engine to ensure the engine starts
Starter for an internal combustion engine
A control device for a generator is provided. SUMMARY OF THE INVENTION The present invention relates to a compressor for an internal combustion engine.
Magnet rotor attached to rank shaft, and magnet rotor
Armature iron core having a magnetic pole portion facing the magnetic pole of n-phase (n
Is an integer of 2 or more)
And a magnet rotor for each armature coil of the stator.
Internal combustion engine equipped with a position sensor for detecting a rotational angle position of a vehicle
The starter generator for Seki and each arm of the bridge
For feedback connected in parallel with the switch element and the switch element
It consists of a diode and the AC terminal is the n-phase
When connected to the input / output terminals derived from the armature coil
A bridge-type inductor whose DC terminal is connected to the battery
The inverter circuit and the starter generator when starting the internal combustion engine
Operating the motor as a brushless DC motor
Once the crankshaft is rotated in the reverse direction
And then rotate it in the starting direction.
Control the inverter circuit accordingly and after the internal combustion engine starts
Operates the starter generator as a generator
From the child coil by the feedback diode of the inverter circuit
Charging delivered to the battery through a configured rectifier circuit
Inverter that controls the inverter circuit to control the current
Starter generator for internal combustion engine, comprising starter circuit control device
It is intended for the control device of the generator. In the present invention, the inverter circuit control
The control device rotates the crankshaft in the reverse direction when starting the internal combustion engine.
When controlling the inverter circuit to rotate,
Drive current wave supplied to the armature coil through the barter
If the shape is a PWM waveform that is intermittent at the set duty ratio,
PWM control means for controlling the inverter circuit as much as possible
ing. When the internal combustion engine starts, the crankshaft rotates
When the inverter circuit is controlled to drive in the direction
The torque that the rotor gives to the crankshaft
Occasionally, the piston of the engine is closed to reach top dead center.
Limited to less than the torque that needs to be applied to the link shaft
Thus, the duty ratio is set. As described above, once the engine is started,
When reversing the crankshaft, it is applied to the starter generator.
The drive current is changed to a PWM waveform, and the crankshaft is
Torque from the magnet rotor to the crankshaft
To reach the top dead center when the internal combustion engine reverses
Less than the torque that needs to be applied to the crankshaft
Set the duty ratio of the drive current to
If the crankshaft is reversed when starting the engine,
In addition, the engine piston can be moved to TDC without any special control.
Can be reliably prevented from displacing beyond
Engine with the ignition switch closed.
When starting and stopping the engine repeatedly,
Start the engine first after closing the ignition switch
In this case, the engine can be reliably started. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
Control device for starter generator for internal combustion engine according to the invention
An embodiment of the device will be described. FIG. 1 shows a starter generator according to the present invention.
1 shows an example of the configuration of a data controller. In FIG.
Starter generator for internal combustion engine, 2 is battery, 3 is
Provided between the battery 2 and the starter generator 1
Inverter circuit, 4 is an electronic control unit (ECU)
It is. The illustrated starter generator 1 includes a rotor
The yoke and the magnet field attached to the rotor yoke
Directly attached to the internal combustion engine crankshaft (not shown)
Magnet rotor (not shown), and the magnet rotor
Armature core having magnetic pole portion facing pole and armature core
And three-phase armature coils Lu to Lw wound around
A stator in which the three-phase armature coils are star-connected;
For U, V, W three-phase armature coils Lu to Lw
To detect the rotational angle position of each magnet rotor.
Starter for internal combustion engine having sensors hu, hv and hw
It is a generator. This starter generator
Similar structure to Lasiles DC motor and magnet AC generator
The brushless DC motor is used when starting the engine.
Driven as a machine to drive the crankshaft of the engine
Used as a motor. Also, after the engine starts,
When the magnet rotor is driven by the internal combustion engine
Battery generator (magnet generator)
Driven as The position sensors hu, hv and hw are, for example,
Starter generator 1 at 120 degree electrical angle
A Hall IC that detects the polarity of the magnetic poles of the magnet rotor
When the N pole of the magnet rotor is detected and when the S pole
Squares that indicate different levels when detecting
Outputs a wave-shaped position detection signal. Magnet rotor has two poles
When the rotor is running forward (with the crankshaft
Position sensor hu to hw when rotating in the starting direction)
An example of the position detection signals Hu to Hw respectively obtained from
These are shown in FIGS. 2A to 2C, respectively. In FIG.
Θ on the horizontal axis indicates the rotation angle of the crankshaft, and the H level and L
The levels are high and low (or zero level, respectively).
). When the rotor rotates in the reverse direction, the position sensor h
The position detection signals Hu to Hw obtained from u to hw are respectively
3 (A) to 3 (C). The illustrated inverter circuit 3 has a well-known three-phase
Ridge type inverter circuit.
NPN transistors that constitute the switch elements of the two arms respectively
Transistors Tu, Tv and Tw and their transistors
Between the collector and emitter of the
Feedback diodes Du, Dv and
And Dw and the switch element of the lower three arms of the bridge
NPN transistors Tx, Ty and
And Tz between the collector and emitter of these transistors
(At both ends of the switch element)
It consists of feedback diodes Dx, Dy and Dz.
You. In this inverter circuit 3, the bridge
Transistors that constitute the switch element of the upper arm
Collectors Tu to Tw are connected in common and the common connection
A DC terminal 3a having a positive polarity is derived from the connection point, and is connected to the DC terminal.
The child 3 a is connected to the positive terminal of the battery 2. Also
A switch that constitutes the switch element of the lower arm of the bridge
The emitters of the transistors Tx to Tz are connected in common, and
One end of the shunt resistor r for current detection is connected to the common connection point of
Connected to the DC terminal 3 having a negative polarity from the other end of the resistor r.
b has been derived. The DC terminal 3b is connected to the battery 2
Is connected to the negative electrode terminal. Each of the transistors Tu-Tw
The respective collectors of the emitter and the transistors Tx to Tz
Are connected to each other, and U,
V, W three-phase AC side terminals 3u, 3v and 3w are derived.
And these AC terminals 3u, 3v and 3w are respectively
Star-connected three-phase armature of starter generator 1
From the non-neutral side terminals of the coils Lu, Lv and Lw respectively
Connected to the derived input / output terminals 1u, 1v and 1w.
ing. The ECU 4 has a CPU 4a, a ROM 4b, an R
Microcomputer having AM4c, timer 4d, etc.
And an inverter circuit according to a command given from the CPU.
To the transistors Tu to Tw and Tx to Tz, respectively.
Driver circuit for providing dynamic signals Su to Sw and Sx to Sz
4e and the detected value of the voltage across battery 2
A / D converter 4f which converts the signal into a signal and inputs it to CPU 4a
And the state of the cell switch 5 which is closed when starting the engine
Detection of detecting the state and inputting the detection result to the CPU 4a
Circuit 4g and flow rate of air introduced into the intake pipe to the internal combustion engine
Slot to detect throttle valve opening
CPU 4a converts the output of the sensor 6 into a digital signal.
And an A / D converter 4h for inputting the A / D signal to the A / D converter. ECU4
For microcomputers, the ignition switch (not shown) is closed.
Through the power supply circuit (not shown) from the battery 2
When the power supply voltage is applied, the operation state is set. The starter generator 1 is a starter motor
Determine the excitation pattern of the armature coil when driving as
Therefore, the position detection signals output by the position sensors hu to hw
Hu to Hw are input to the CPU 4a. CPU 4a
Is obtained from a combination of the levels of the position detection signals Hu to Hw.
Driving the starter generator in a predetermined rotation direction
To determine the excitation pattern of the armature coil necessary for
Armature coil of a predetermined phase according to the specified excitation pattern
In order to supply the drive current to the
Drive signal (switch element conducting)
Signal for giving or not giving
To the driver circuit 4e. The driver circuit 4e is C
Inverter circuit according to command signal given from PU
A drive signal is given to the third predetermined transistor. The starter generator 1 is a starter motor
And operate the engine crankshaft in the starting direction (forward rotation).
Direction) when rotating the inverter circuit transistor
Given to the bases of Tu-Tw and Tx-Tz, respectively
The drive signals Su to Sw and Sx to Sz shown in FIG.
(F) and (G) to (I), the starter generator
When rotating the motor 1 in the reverse direction opposite to the starting direction.
Of the transistors Tu to Tw and Tx to Tz of the inverter circuit
Drive signals Su to Sw and S respectively applied to the base
x to Sz are shown in (D) to (F) and (G) to (I) in FIG.
Indicated. Transistors Tu to Tw and Tx to Tz
Are the drive signals Su to Sw applied to the respective bases.
And when Sx to Sz are at the H level, respectively.
To the armature coils Lu to Lw in a predetermined phase order.
The commutating drive current is passed and the starter generator rotates.
The child is rotated in a predetermined direction. The shunt resistor provided in the inverter circuit 3
The voltage between both ends of the arrester r is input to the overcurrent detection circuit 7 and
I have. The overcurrent detection circuit 7 detects the voltage across the resistor r
From a circuit that compares with a reference voltage that limits the drive current
And the starter generator through the inverter circuit
When the drive current flowing through the resistor exceeds the limit,
When the terminal voltage exceeds the reference voltage, the ECU driver
An inverter circuit drive stop command signal is given to the circuit 4e.
The driver circuit 4e receives the drive stop command signal.
Supply of the drive signal to the inverter circuit 3 is stopped when
To stop supplying drive current to starter generator 1
It is configured to be. The reference numeral 8 indicates that the crank angle position of the internal combustion engine is the first.
Coincide with the reference position θa and the second reference position θb, respectively.
Pulser that generates pulse signals Vsa and Vsb when
The output of this pulser is passed through the waveform shaping circuit 9 to the ECU.
4 is input to the CPU. The first reference position θa is above
Dead center position (Crank angle when piston reaches top dead center
Angle position) and set to a position advanced enough to
The reference position θb is determined by the ignition timing when the engine is started and at low speed.
It is set at the corresponding position. The CPU uses the pulsar 8
From the output pulse signal, the crankshaft rotation information (crankshaft
Angle information and rotation speed information), and
Obtain throttle valve opening information from the rotary sensor 6
To calculate the ignition timing of the engine, and calculate the calculated ignition timing.
When detected, ignites an internal combustion engine ignition device (not shown).
The ignition operation is performed by giving a signal. CPU is also a pulsar
8 and the rotation information given from the throttle sensor.
Throttle valve opening and sensor not shown
Fuel injection for still other control conditions given by
Calculate the time and when the predetermined fuel injection timing is detected
During the calculated injection time from the injector to the intake pipe or
Inject fuel into the cylinder. Control of these ignition timings
Or by the CPU to control the fuel injection time
The function realizing means to be realized may be the same as the conventional one. In this embodiment, the CPU 4a is connected to the ROM 4b
By executing the program stored in the
The inverter control means for controlling the data circuit 3 is constituted.
This inverter control means starts the engine when the internal combustion engine is started.
Generator 1 is operated as a brushless DC motor.
And reverse the crankshaft of the internal combustion engine once in the opposite direction to the starting direction.
Rotation in the starting direction and then in the starting direction.
Controls the inverter circuit 3 according to the outputs of the sensors hu to hw
After the internal combustion engine starts, the starter generator 1
By operating as a generator, the armature coils Lu to Lw
Feedback diodes Du to Dw and Dx of the inverter circuit 3
To the battery 2 through a rectifier circuit composed of
The inverter circuit 3 controls the supplied charging current.
Is configured to be controlled. In the present invention, the inverter control means
Stage rotates the crankshaft in the reverse direction when the internal combustion engine starts
When controlling the inverter circuit to cause
Of the drive current supplied to the armature coil through the motor circuit
PWM waveform intermittently with a set duty ratio DF
PWM control means for controlling an inverter circuit so that
The configuration is provided with. The PWM control means includes an inverter circuit 3
When a drive signal is supplied to the switch element of
The drive signal given to the lower switch element of the circuit and the upper
At least one of the drive signals given to the switch element is specified
By making the waveform intermittent at the duty ratio DF of
Drive power supplied to the armature coil of the starter generator
The flow is a PWM waveform intermittent with a duty ratio DF. S
When driving the rotor of the tarta generator in the reverse direction
Drive signal given to the lower switch element of the inverter circuit 3
Of drive signal when signals Sx to Sz are intermittent waveforms
FIGS. 4A to 4F show an example of such a case. The PWM control means controls the drive current by PWM control.
The duty ratio DF at the time of control is
Inverter circuit is controlled to drive the rank axis in the reverse direction.
The starter generator magnet rotor
When the internal combustion engine rotates in reverse, the torque applied to the
Seki piston on the crankshaft to reach the top dead center
Limit it to a value less than the torque you need to give
Is set to an appropriate size. In order to configure the inverter control means,
One of the algorithms of the program executed by the CPU 4a
A flowchart showing an example is shown in FIG. This algorithm
In the first case, the cell switch 5
It is determined whether or not is turned on. as a result,
When it is determined that the cell switch 5 is in the ON state
Next, in step 2, the pattern shown in FIG.
Drive signal to the switch element of the inverter circuit
And rotate the rotor of the starter generator (SG) in the reverse direction.
Rotate to. At this time, the lower switch of the inverter circuit 3
Drive signals Sx to Sz to be applied to the
As a waveform intermittent at F,
The torque given to the rank shaft is
Less than the torque required to displace beyond top dead center
Limit to a low value. Thus, the starter generator
PWM control of the drive current given to the starter generator
The torque applied to the crankshaft from the
When the shaft is reversed, the starter generator
The crankshaft to stop before the top dead center
Ensures that the piston does not cross top dead center when rotated
be able to. In step 3, the starter generator
Starter generator until it is determined that 1 has stopped
Control of the inverter circuit to reverse the
In step 3, it is determined that the starter generator has stopped.
To step 4 when the starter generator
Rotate the first rotor in the engine start direction (forward direction)
Therefore, the inverter circuit is switched in the pattern shown in FIG.
Drive signal to the switch element. At this time,
The load on the tartar generator 1 has been reduced
The starter generator accelerates at a stretch and the crankshaft
The engine is rotated in the starting direction,
Displace the ton beyond the compression top dead center. Therefore, the engine can be started without any trouble.
You. In step 5, it is determined that the start of the engine has been completed.
Drive signal to the inverter circuit until
When it is determined that the movement has been completed,
To stop supplying the drive signal to the inverter circuit.
The signals Su to Sw and Sx to Sz are all set to the zero level.
And all switch elements of the inverter circuit are turned off.
And stop driving the motor. In step 3, the starter generator
Data is stopped or not.
For example, the position detection signal H given from the position sensors hu to hw
When the level change of u to Hw is no longer detected,
Performed by a method that determines that the data generator has stopped
be able to. It is determined that the start of the engine has been completed.
For example, position detection signals Hu to H obtained from position sensors
The rotation speed of the engine detected from the cycle of the level change of w starts.
By determining whether or not the
I can. When the start of the engine is completed, the starter generator
The rotor of the generator becomes driven by the engine.
The starter generator 1 is a generator (magnet power generation)
Machine), and the three-phase AC voltage is applied to the armature coil.
Induce. This AC voltage is supplied to the feedback
3 composed of the ions Du to Dw and Dx to Dz
Rectified by the full-wave rectifier circuit
Is applied to the battery 2, so that the charging current is supplied to the battery 2.
Be paid. After the engine has started, the starter generator
When operating 1 as a generator,
In order to prevent overcharging, the detection is performed through the A / D converter 4f.
The output voltage of the battery should be kept below the set value.
To control the inverter circuit 3. For example, the battery 2
When the terminal voltage is below the set value, the inverter circuit 3
Keep all switch elements in the off state and start
The charging current is supplied from the generator 1 to the battery,
When the terminal voltage of the
The transistors Tx to Tz at the lower stage of the path 3 are simultaneously turned on.
To short-circuit the output of starter generator 1
As a result, supply of the charging current to the battery 2 is stopped. The terminal voltage of the battery has exceeded the set value.
Sometimes, the lower transistor Tx of the inverter circuit 3
~ Tz at the same time, instead of an inverter circuit
And turn on the upper transistors at the same time.
May be. After the engine is started, control the charging of the battery
To do so, at predetermined time intervals (eg, at 2 msec intervals)
One of the algorithms of the program executed by the CPU 4a
A flowchart showing an example is shown in FIG. This algo
In the case of rhythm, first, in step 1
Reading the digitally converted value VB of the slave voltage, and
Whether the terminal voltage VB of the battery exceeds the set value
Is determined, and if the set value is not exceeded, step 3
And turn off all switch elements of the inverter circuit
Keep in condition. In step 2, the battery terminal voltage is set
When it is determined that the value exceeds
Simultaneously use lower transistors Tx to Tz of the inverter circuit
To turn on the battery to stop charging the battery. In the above example, the flow chart shown in FIG.
And a series of flowcharts shown in FIG.
During the start of the internal combustion engine
Motor as a brushless DC motor
Rotate the crankshaft once in the reverse direction opposite to the starting direction.
And then respond to the position sensor output to rotate in the starting direction.
After the internal combustion engine starts, the inverter circuit is controlled
Armature by operating starter generator as generator
It is composed of the feedback diode of the inverter circuit from the coil.
Charging power supplied to the battery through the rectifier circuit
Inverter that controls the inverter circuit to control the flow
Data control means. In particular, the file shown in FIG.
According to step 2 of the flowchart, when starting the internal combustion engine,
Turn the inverter so that the crankshaft rotates in the reverse direction.
Armature coil through the inverter circuit when controlling the
The duty of the drive current supplied to the
Inverter circuit is controlled to make PWM waveforms intermittent by the ratio.
A PWM control means for controlling is configured. In the above example, the bridge of the inverter circuit
Transistor as a switch element that composes each arm of
However, each arm of the bridge of the inverter circuit is
Switch elements such as MOSFETs and IGBTs
Uses other semiconductor switch elements that can be controlled on and off
You can also. When MOSFET is used as a switching element
Has a parasitic die formed between its drain and source.
The diode can be used as a feedback diode.
You. In the above example, the three-phase armature core
Use a starter generator with an
An n-phase (n is an integer of 2 or more) armature coil on the stator side
When the present invention is used when a starter generator having
Can be used. In the example shown in FIG.
To determine whether the starter generator has stopped
It is determined that the starter generator has stopped
Sometimes the direction of rotation is reversed to the starting direction
Rotates in the direction opposite to the starter generator start direction
Start after a certain period of time
The rotation direction of the generator is reversed to the starting direction.
May be. That is, the starter generator
Drive only for a set period of time
Is also good. As described above, according to the present invention, the engine
Once the crankshaft is reversed to start,
The drive current given to the data generator is a PWM waveform
When rotating the crankshaft in reverse,
The torque applied to the crankshaft
Must be given to the crankshaft to reach top dead center.
Drive current should be limited to a value less than a certain torque.
Since the duty ratio is set, when starting the engine
No special control is required when reversing the crankshaft
Also ensure that the engine piston displaces beyond top dead center
Can be prevented. Therefore, according to the present invention
Engine with the ignition switch closed.
When starting and stopping the engine repeatedly,
Start the engine first after closing the ignition switch
In this case, the engine can be reliably started.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing a configuration of an embodiment of a control device according to the present invention. FIG. 2 is a signal waveform diagram showing an output signal of a position sensor and a drive signal given to an inverter circuit when the starter generator of the present invention is driven in a normal rotation direction. FIG. 3 is a signal waveform diagram showing an output signal of a position sensor and a drive signal given to an inverter circuit when driving a starter generator in a reverse rotation direction. FIG. 4 is a signal waveform diagram showing a drive signal given to an inverter circuit when driving a starter generator of the present invention in a reverse direction. FIG. 5 is a flowchart showing an example of an algorithm of a program executed by a CPU at the time of starting to realize an inverter control means in the embodiment of the present invention. FIG. 6 is a block diagram showing a configuration of a CPU according to an embodiment of the present invention.
Is a flowchart showing an example of an algorithm of a program to be executed by the program. FIG. 7 is an explanatory diagram showing a relationship between a stroke change and a cylinder internal pressure of a single-cylinder four-cycle internal combustion engine. [Description of Signs] 1 ... Starter generator, 2 ... Battery, 3 ... Inverter circuit, 4 ... ECU.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Shuichi Muramatsu             3744 Ooka, Numazu-shi, Shizuoka Japan Domestic Electric Stock             In the company F term (reference) 3G093 BA00 CA01 DA01 DA06 DA07                       DA12 EA02 EB08 EC02 FA11                 5H560 AA10 BB04 BB07 BB12 DA03                       DC12 EB01 EB07 GG04 JJ02                       TT12 TT15 UA02 XA12

Claims (1)

Claims 1. An n-phase (n is an integer of 2 or more) magnet rotor attached to a crankshaft of an internal combustion engine and an armature iron core having a magnetic pole portion facing a magnetic pole of the magnet rotor. A) a starter generator for an internal combustion engine, comprising: a stator formed by winding an armature coil of the present invention; and a position sensor for detecting a rotation angle position of the magnet rotor with respect to the armature coil of each phase of the stator. , Each arm of the bridge includes a switch element and a feedback diode connected in parallel to the switch element, and an AC terminal is connected to an input / output terminal derived from the n-phase armature coil, and a DC A bridge-type inverter circuit whose side terminals are connected to the battery;
When the internal combustion engine is started, the starter generator is operated as a brushless DC motor to rotate the crankshaft of the internal combustion engine once in the reverse direction opposite to the start direction, and then in the output of the position sensor so as to rotate in the start direction. After the internal combustion engine is started, the starter generator is operated as a generator to supply the battery from the armature coil to the battery through a rectifier circuit configured by a feedback diode of the inverter circuit. A starter generator for an internal combustion engine, comprising: an inverter control means for controlling the inverter circuit so as to control a charging current to be supplied. The inverter control means rotates the crankshaft in a reverse direction when the internal combustion engine is started. Control the inverter circuit to rotate the PWM control means for controlling the inverter circuit so as to make the waveform of the drive current supplied to the armature coil through the inverter circuit into a PWM waveform intermittent at a set duty ratio when the internal combustion engine is started. Sometimes, when controlling the inverter circuit to drive the crankshaft in the reverse direction, the torque given to the crankshaft by the magnet rotor during the reverse rotation of the internal combustion engine to make the piston of the internal combustion engine reach the top dead center. The control device for a starter generator for an internal combustion engine, wherein the duty ratio is set so as to limit the duty ratio to a value smaller than a torque required to be applied to the crankshaft.