JP2002188548A - Engine start control device - Google Patents

Abstract

(57) [Problem] To provide an engine start control device which cranks and starts an engine by a starter motor, and automatically stops energization of the starter motor when the engine start is completed. The engine can be started reliably and quickly while preventing cranking. SOLUTION: An engine speed is set to a first reference speed (N).
_ref3 ), the energization of the starter motor is continued, and when the engine speed reaches the first reference speed, the energization of the starter motor is stopped, and the engine speed is lower than the first reference speed. When the number of revolutions decreases to two reference revolutions ( _Nref2 ), the power supply to the starter motor is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine start control device for starting an engine by cranking the engine with a starter motor, and more particularly to a system suitable for a system in which the crankshaft of the engine is directly connected to the rotation shaft of the starter motor. The present invention relates to an engine start control device.

[0002]

2. Description of the Related Art In a conventional engine starting device having a starter motor, the starter motor is energized only while a user turns on a starter switch to crank the engine. The user intuitively determines that the engine has been started based on the pointer value of the engine tachometer, the starting sound, and the like, and cancels the ON operation by himself. If the engine has not been started when the on-operation is released, the starter switch is turned on again to try to restart the engine.

On the other hand, from the viewpoint of the environment and energy saving, in order to suppress the exhaust gas and fuel consumption particularly during idling, when the vehicle is stopped, the engine automatically stops, and the throttle grip is operated from the automatic stop state. For example, Japanese Patent Application Laid-Open No. 11-160167 discloses an automatic engine stop / start system that automatically starts a starter motor and restarts the engine when the start operation of the engine is detected.

[0004]

In a system in which the engine is automatically restarted, such as a vehicle employing the above-described automatic engine stop / start system, the starter detects that the engine has been completely started. It is necessary to automatically stop energizing the motor.

Here, in a general starting mechanism in which the rotational force of a starter motor is input to a crankshaft of an engine via a reduction gear, the rotation speed between the cranking speed of the engine by the starter motor and the idling speed of the engine is determined. Since there is a relatively large rotation difference and the engine speed increases after the engine starts, the completion of the engine start can be relatively easily detected based on the engine speed.

However, in a starting mechanism in which the crankshaft of the engine and the rotation shaft of the starter motor are directly connected, the cranking rotation speed of the starter motor increases and the difference from the idling rotation speed decreases. Therefore, the completion of the engine start is determined based on the engine speed,
If the starter motor is automatically stopped, cranking will be terminated even though the engine has not been completely started, and conversely, cranking will continue even though the engine has been started. It can happen.

[0007] Such a phenomenon can also occur when the user cranks the engine by turning on the starter switch, and the starter switch is turned on even when the engine is not completely started. In some cases, the engine is turned off, and conversely, the engine is turned on even after the engine has been started.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an engine start control device capable of accurately recognizing a stop timing of a starter motor and automatically stopping the starter motor.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an engine which is started by cranking an engine by a starter motor, and automatically stops energizing the starter motor when the engine has been started. In the engine start control device, the power supply to the starter motor is continued until the engine speed reaches the first reference speed, and the power supply to the starter motor is stopped when the engine speed reaches the first reference speed, When the engine speed drops to a second reference speed lower than the first reference speed, the power supply to the starter motor is restarted.

According to the above-described feature, the starter motor is automatically stopped when the engine speed that is highly likely to have reached the complete explosion state is automatically stopped. Is prevented. In addition, if the engine speed subsequently decreases, the starter motor is immediately re-driven, so even if the engine has not reached the complete explosion state, the automatic restart before the engine stops will promptly return to the complete explosion state. Migration is possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall side view of a scooter type motorcycle to which an engine start control device of the present invention is applied,
The vehicle further stops the engine automatically when the vehicle stops, and then the throttle grip is opened or
Alternatively, when a start operation such as an operation of turning on a starter switch is performed, an automatic engine stop / start function for automatically driving a starter motor and restarting the engine is provided.

The front part of the vehicle body and the rear part of the vehicle body are connected via a low floor part 4, and the body frame constituting the skeleton of the vehicle body is generally composed of a down tube 6 and a main pipe 7. A fuel tank and a storage box (both not shown) are supported by a main pipe 7, and a seat 8 is disposed above the main tank 7.

At the front of the vehicle body, a handle 11 is provided above and supported by the steering head 5, a front fork 12 extends below, and a front wheel FW is supported at its lower end. The upper part of the handle 11 is covered with a handle cover 13 also serving as an instrument panel. A bracket 15 projects from the lower end of the rising portion of the main pipe 7, and a hanger bracket 18 of the swing unit 2 is swingably connected to and supported by the bracket 15 via a link member 16.

The swing unit 2 is provided with a single-cylinder four-cycle engine E at the front thereof. A belt-type continuously variable transmission 10 is configured from the engine E to the rear, and a rear wheel RW is supported by a reduction mechanism 9 provided at a rear portion thereof via a centrifugal clutch. The rear cushion 3 is interposed between the upper end of the speed reduction mechanism 9 and the upper bent portion of the main pipe 7. A carburetor 17 connected to an intake pipe 19 extending from the engine E and an air cleaner 14 connected to the carburetor 17 are provided at the front of the swing unit 2.

FIG. 2 is a cross-sectional view of the swing unit 2 taken along the crankshaft 201, and FIG. 3 is a partially enlarged view of the swing unit 2. The same reference numerals as those described above denote the same or equivalent parts.

The swing unit 2 is covered by a crankcase 202 formed by combining left and right crankcases 202L and 202R, and the crankshaft 201 is rotatably supported by bearings 208 and 209 fixed to the crankcase 202R. Have been. On the crankshaft 201,
A connecting rod (not shown) is connected via a crank pin 213.

The left crankcase 202L also serves as a belt-type continuously variable transmission chamber case.
Belt drive pulley 2
10 is provided rotatably. Belt drive pulley 2
10 includes a fixed pulley half 210L and a movable pulley half 210R, and the fixed pulley half 210L is fixed to the left end of the crankshaft 201 via a boss 211,
On the right side, the movable pulley half 210R is connected to the crankshaft 20.
1 and can approach / separate from the fixed-side pulley half 210L. Both pulley halves 210L,
A V-belt 212 is wound around 210R.

A cam plate 215 is fixed to the crankshaft 201 on the right side of the movable pulley half 210R.
A slide piece 215a provided on the outer peripheral end is slidably engaged with a cam plate sliding boss 210Ra formed in the axial direction at the outer peripheral end of the movable pulley half 210R. Cam plate 215 of movable pulley half 210R
Has a tapered surface inclined toward the cam plate 215 toward the outer periphery, and the tapered surface and the movable pulley half 210R
A dry weight pole 216 is accommodated in a space between the two.

When the rotation speed of the crankshaft 201 increases, the dry weight ball 2 which is located between the movable pulley half 210R and the cam plate 215 and rotates together is provided.
16 moves in the centrifugal direction due to the centrifugal force, and the movable pulley half 210R is pressed by the dry weight ball 216 and moves leftward to approach the fixed pulley half 210L. As a result, the V-belt 212 sandwiched between the two pulley halves 210L and 210R moves in the centrifugal direction, and its winding diameter increases.

At the rear of the vehicle, the belt drive pulley 21
A driven pulley (not shown) corresponding to 0 is provided, and the V-belt 212 is wound around the driven pulley. The power of the engine E is automatically adjusted by this belt transmission mechanism, transmitted to the centrifugal clutch, and drives the rear wheel RW via the speed reduction mechanism 9 and the like.

A starter / generator (ACG starter) 1 in which a starter motor and an AC generator are combined is disposed in the right crankcase 202R. In the ACG starter 1, the outer rotor 60 is fixed to the tapered end of the crankshaft 201 by a screw 253.

The stator 50 disposed on the inner peripheral side of the outer rotor 60 is
Fixed to 2. A fan 280 fixed to the outer rotor 60 by bolts 246 is provided. Fan 2
A radiator 282 is provided adjacent to 80, and the radiator 282 is covered by a fan cover 281.

As shown in an enlarged manner in FIG.
The sensor case 28 is fitted in the inner periphery of the zero.
In this sensor case 28, a rotor angle sensor (magnetic pole sensor) 29 and a pulser sensor (ignition pulser) 30 are provided at equal intervals along the outer periphery of the boss 60a of the outer rotor 60. The rotor angle sensor 29 is for controlling the energization of the stator coil of the ACG starter 1, and is provided for each of the U, V, and W phases of the ACG starter 1. Ignition pulsar 30
Is for engine ignition control, and only one is provided. Rotor angle sensor 29 and ignition pulser 30
Can be constituted by a Hall IC or a magnetoresistive (MR) element.

Rotor angle sensor 29 and ignition pulser 3
The lead wire of No. 0 is connected to the substrate 31, and a wire harness 32 is connected to the substrate 31. Outer rotor 60
A boss 60a is fitted with a magnet ring 33 magnetized in two stages so as to exert a magnetic action on each of the rotor angle sensor 29 and the ignition pulser 30.

In one of the magnetized bands of the magnet ring 33 corresponding to the rotor angle sensor 29, N poles and S poles are alternately arranged at intervals of 30 ° in the circumferential direction corresponding to the magnetic poles of the stator 50. Is formed, and the other magnetized band of the magnet ring 33 corresponding to the ignition pulser 30 is provided with one in the circumferential direction.
Magnetized portions are formed at 15 ° to 40 ° in some places.

The ACG starter 1 functions as a starter motor (synchronous motor) when the engine is started, is driven by a current supplied from a battery, and
To start the engine. After the engine starts, it functions as a synchronous generator, charges the battery with the generated current, and supplies current to each of the electrical components.

Returning to FIG. 2, a sprocket 231 is fixed on the crankshaft 201 between the ACG starter 1 and the bearing 209. The sprocket 231 is connected to the camshaft (not shown) from the crankshaft 201. The chain for driving is wound around. The sprocket 231 is formed integrally with a gear 232 for transmitting power to a pump for circulating lubricating oil.

FIG. 4 is a block diagram of an electrical system including the ACG starter 1. The ECU 3 includes a three-phase full-wave rectification bridge circuit 300 that performs full-wave rectification of three-phase alternating current generated by the power generation function of the ACG starter 1, and a full-wave rectification bridge circuit 300.
Regulator 10 that limits the output of the regulator to a predetermined regulated voltage (regulator operating voltage: for example, 14.5 V)
0 is included.

Further, the ECU 3 according to the present embodiment includes a start control unit 500 that enables reliable engine start while preventing excessive cranking at the time of engine start, and a power generator when the engine speed is in a predetermined low engine speed range. A power generation control unit 400 for increasing the amount and a swingback control unit 700 for reversing the crankshaft to a predetermined position immediately after the engine is stopped to improve the next engine startability.

An ignition coil 21 is connected to the ECU 3, and an ignition plug 22 is connected to a secondary side of the ignition coil 21. The ECU 3 is connected to a throttle sensor 23, a fuel sensor 24, a seat switch 25, an idle switch 26, a cooling water temperature sensor 27, the rotor angle sensor 29, and an ignition pulser 30, and a detection signal is input to the ECU 3 from each unit.

Further, the ECU 3 includes a starter relay 3
4. Starter switch 35, stop switch 36,3
7, standby indicator 38, fuel indicator 39, speed sensor 40, motorcycle star 41,
And a headlight 42 are connected. Headlight 4
2 is provided with a dimmer switch 43.

A current is supplied from the battery 2 to the above components via the main fuse 44 and the main switch 45. The battery 2 is directly connected to the ECU 3 by a starter relay 34, while the main switch 4
5 and not through the main fuse 44 but the ECU 3
Having a circuit connected to it.

Next, the start control unit 5 of the ECU 3
00, power generation control unit 400 and swingback control unit 7
The operation of 00 will be described with reference to the functional block diagram of FIG.

The three-phase full-wave rectifier bridge circuit 300 is configured by connecting three sets of two FETs connected in series in parallel, and is controlled based on the output of the driver 80.

In the start control unit 500, the engine speed discriminating unit 52 discriminates the engine speed based on the detection signal of the ignition pulser 30 and the frequency signal of the generated voltage. The engine start determination unit 51 controls the function of the ACG starter 1 as a starter motor based on the state of the starter switch 35, the throttle opening, the engine speed, and the like.

The flowchart of FIG. 6 and the flowchart of FIG.
Referring to the timing chart, the start control unit 500
Will be described. It is used in the flowchart
The definitions of each reference value, timer and flag are as follows:
is there. (1) Start failure speed N_ref1 When the ACG starter 1 is energized, the ACG starter 1
The engine speed naturally reaches if there is no abnormality in the engine
The number of rotations to be performed. (2) Restart speed N_ref2  An engine that restarts the ACG starter 1 that has been paused
The number of rotations. (3) Start / stop rotation speed N_ref3 The number of times of the engine to temporarily stop energizing the ACG starter 1
Is the number of turns. (4) Revolution N_ref4 The engine speed reached when the engine completely explodes.
You. (5) Start completion flag F_run  The complete explosion of the engine continues for a predetermined time, and
When cranking by tarta 1 is no longer needed,
Set when engine start is completed. (6) Start stop flag F_stop Engine speed is poor starting speed N_ref1Does not reach
Set when the state has continued for a predetermined time. (7) During suspension flag F_off The engine speed is the start / stop speed N_ref3Reached
Period during which power to the starter motor is temporarily stopped
Only set. (8) First timer T_m1 Engine speed is poor starting speed N_ref1Does not reach
Time the duration. (9) Second timer T_m2 Engine speed is complete explosion speed N_ref4Is beyond
Time duration. (10) Start stop reference value T_stop Timer T_m1Engine start failure based on the count value of
Is a reference value for determining_m1Council
The start value is the start stop reference value T_stopStop when it reaches
Flag F_stopIs set. (11) Start completion reference value T_run Timer T_m2The engine is completely based on the count value
This is a reference value for judging that
T_m2Is the start completion reference value T_runReach
And start completion flag F_runIs set.

The engine start control process of this embodiment is repeatedly executed at predetermined intervals by the engine start determination section 51 in an interrupted manner.

When the start operation of the starter switch 35 or the predetermined start operation is detected in step S10 of FIG.
Also, it is determined whether or not the ON state of the starter switch 35 has been detected. If it has not been detected last time, the initial process is executed in step S12.

[0039] In step S12, force the engine start to the paused flag F _off which is set when the temporarily stopping the energization of the ACG starter 1, ACG starter 1 can not be sufficiently crank the engine Stop flag F that is set when stopping
_stop and a first timer T for counting the duration during which the ACG starter 1 cannot sufficiently crank the engine.
_m1 and a second timer T _m2 that counts the continuation time during which the engine speed Ne exceeds the complete explosion speed N _ref4.
And are reset.

In step S13, the temporary stop flag _Foff is referred to. Since the reset state is initially set, the process proceeds to step S14. In step S14, a start completion flag F that is set when the engine start is completed
_Run is referred to, and the process proceeds to step S15 since it is initially in a reset state. In step S15, the ACG starter 1
And the engine is cranked by the ACG starter 1 (time t0 in FIG. 7).

In step S16, the engine speed Ne
Is compared with the poor start rotation speed N _ref1 . As shown at the time t1 in FIG.
When below the _{re f1,} in step S17, the first timer _{T m1} is incremented. At step S18, the count value of the first timer _{T m1} is compared with the start stop reference value _{T stop,} initially the count value falls below the reference value _{T sto p,} the current cycle is immediately terminated.

After the next cycle, step S1
Steps S12 to S13 are skipped,
The process proceeds to S14, S15, and S16, and in step S16, the engine speed Ne is changed to the poor starting speed _Nref1.
Until it is determined that the time exceeds the threshold value, the process proceeds to step S17 in the same manner as described above, and the first timer _Tm1 continues to be incremented.

Thereafter, as in case 1 of FIG.
Until the engine speed Ne is 6 and the poor starting speed N_ref1
In step S18, the first tie
Ma T _m1Is the start stop reference value T_stop To
If it is determined that it has exceeded, in step S19,
Start suspension flag F_stop Is set. Therefore,
From the next cycle onward, the process starts from step S13.
Proceeding to step S20, the ACG starter 1 is turned off.
Therefore, the starter switch 35 is turned on again.
Or until the specified starting operation is performed.
Is stopped.

On the other hand, in step S18, the first
Ima T_m1Is the start stop reference value T_stop 
At time t2 before it is determined that
The rotation speed Ne is the starting failure rotation speed N_ref1 Exceeds
If this is detected in step S16, the process proceeds to step S16.
Proceed to step S21. In step S21, the timer T
_m1Is reset, and the start suspension flag F
_stopIs reset.

In step S22, the engine speed Ne
Is compared with the restart rotation speed N _ref2, and the engine rotation speed Ne is changed to the restart rotation speed N, for example, at time t3.
When below the _{ref 2,} paused flag _{F off} is referred to in step S23. here,
Since the suspension flag _Foff is in the reset state, the process returns to step S16 via steps S25 and S27 described later.

Thereafter, the engine speed Ne reaches the restarting rotation speed _{N ref2} at time t4, which is compared when it is detected in step S22, in step S25, the engine speed Ne and the start and stop rotational speed _{N ref3} . As long as the engine rotation speed Ne is lower than the start / stop rotation speed _Nref3 , the _{process proceeds} to step S27 through step S27.
Return to 16.

Thereafter, at time t7, the engine speed Ne reaches the start / stop speed _Nref3, and when this is detected in step S25, in step S26, the ACG starter 1 is turned off and the suspension flag F _off is set. In step S27,
The engine speed Ne is compared with the complete explosion speed _{Nref4.
Since it is less} than _ref4 , the process returns to step S16.

Thereafter, after step S16 described above,
The process repeats, but the engine is fully started
If not, the ACG starter 1 is stopped at time t7.
Immediately after the engine speed Ne gradually decreases (case
2). Then, at time t8, the engine speed Ne
Is the restart rotation speed N_ref2And this is the step
If detected in step S22, the operation proceeds to step S23.
And the suspension flag F _off Is referred to. This time
In step S26, the suspension flag F_off
 Has already been set, the process proceeds to step S24.
No. In step S24, the ACG starter 1 is restarted.
And the suspension flag F_off Is reset. Subordinate
Therefore, the engine speed Ne increases again from the time t8.
Turn around.

On the other hand, the engine is completely exploded (Case 3), and the engine speed Ne changes from time t9 to time t1.
In 0 reached complete explosion rotational speed _{N ref4,} which when it is detected in step S27, in step S28, the second timer _{T m2} is incremented. In step S29, the count value of the second timer _{T m2} is compared with the completion of the starting reference value _{T the run,} when the count value reaches the start completion reference value _{T the run,} start completion flag _{F the run} is set in step S30, the engine The start control ends. According to the present embodiment, when the engine speed rises to a predetermined speed ( _Nref3 ) during cranking by the ACG starter as a starter motor, the cranking is interrupted and the engine speed is monitored. The number is a predetermined number of revolutions (N
_ref2 ), the ACG starter is restarted and cranked again, so that the engine can be reliably started while preventing excessive cranking.

Returning to FIG. 5, in addition to the function of normally controlling the amount of power generation (voltage), the power generation control unit 400 controls the phase of the stator coil of the ACG starter 1 from the battery 2 by applying a retarded electric current from the battery 2. It has a function of increasing the amount (hereinafter referred to as “ACG energization control”).

Here, the retard angle energizing means energizing the stator coil with a delay corresponding to a predetermined electrical angle from a detection signal at the time of the change of the magnetic pole of the magnetization zone 33 detected by the rotor angle sensor 29. That means. However, the output voltage (battery voltage) of the full-wave rectifier bridge circuit 300 is regulated in order to prevent the engine rotation from becoming unstable due to the sudden change in the engine load caused by the operation of the regulator 100 in the low rotation range. The voltage is controlled to fall within a predetermined voltage range equal to or lower than the voltage.

In the power generation control unit 400, the engine speed determination unit 48 detects the engine speed based on, for example, a detection signal of the ignition pulsar 30, and if the engine speed is in a predetermined power generation control region, the retard angle is determined. Command 80
To supply. Upon receiving the retard command, the driver 80 reads a preset energization delay amount from the retard amount setting unit 49 and performs the retard energization. The energization duty ratio is supplied from the duty ratio setting unit 47 to the driver 80.

The driver 80 detects a magnetic pole detection signal from the rotor angle sensor 29, that is, a signal that is turned on each time the sensor 29 detects the magnetized band of the magnet ring 33 formed corresponding to the magnetic pole of the outer rotor 60. I do. Then, the PWM control signal is output to each FET of the full-wave rectification bridge circuit 300 by delaying the amount corresponding to the energization delay amount from the rise of the signal.

The battery voltage discriminating section 46 determines the battery voltage Vb as a control voltage maximum value VMax defining a voltage control range.
And the control voltage minimum value VMin, and based on the comparison result, the energization duty set in the duty ratio setting unit 47 is increased or decreased to keep the battery voltage Vb within the control range. That is, when the battery voltage Vb reaches the control voltage maximum value VMax, the energization duty is reduced by a predetermined minute value (for example, 1%), and when the battery voltage Vb falls to the control voltage minimum value VMin, the energization duty is increased by the same minute value. Let it.

FIG. 8 is a flowchart showing the operation of the power generation control unit 400 described above.
Is started after the end of the engine start control.

In step S41, it is determined whether or not the engine speed is in the power generation control region. The power generation control region is set to, for example, 1000 rpm or more and 3500 rpm or less. If the engine speed is in the power generation control region, the process proceeds to step S42, and a flag F _AC indicating that the engine speed is in the power generation control region is set.
_It is determined whether _G is set (= 1).
If the flag F _ACG has not been set, the process proceeds to step S43, where the flag F _ACG is set. In step S44, the scheduled value ACGAGL is set to the energization delay amount acgagl. The predetermined value ACGAGL can be appropriately set in advance, but in the present embodiment, for example, the electrical angle 60
°.

In the following step S45, the energization duty
The initial value ACDUTY is set in acduty. The initial value ACDU
The TY can also be set appropriately in advance, but in the present embodiment, it is, for example, 40%. Steps S43 to S45
Is completed, the process proceeds to step S47. If step S42 is affirmative, steps S43 to S45 are skipped and the process proceeds to step S47. If the engine speed does not exist in the power generation control region, the flag _FACG is reset (= 0) in step S46, and then the process proceeds to step S47.

In the step S47, it is determined whether or not the flag F _ACG is set. Flag F _ACG
Is set, it is determined in step S48 whether or not the battery voltage Vb is equal to or higher than the control voltage maximum value VMax. The control voltage maximum value VMax is set to a value lower than the regulation voltage, for example, 13.5 volts. If the battery voltage Vb is not equal to or higher than the control voltage maximum value VMax, the process proceeds to step S49, and it is determined whether the battery voltage Vb is equal to or lower than the control voltage minimum value VMin. Control voltage minimum value VMin
Is set to 13.0 volts, for example.

If it is determined in step S49 that the battery voltage Vb is not lower than the control voltage minimum value VMin, it is determined that the battery voltage Vb is within the ACG energizing voltage range set to a value lower than the regulated voltage of the regulator, and the process proceeds to step S50. ACG energization control is performed according to the energization delay amount acgagl and the energization duty acduty.

If it is determined in step S48 that the battery voltage Vb is equal to or higher than the control voltage maximum value VMax, the flow advances to step S51 to reduce the energization duty acduty to a small value DDUT.
Reduce by Y. The minute value DDUTY is, for example, 1%. If it is determined in step S49 that the battery voltage Vb is equal to or lower than the control voltage minimum value VMin, the process proceeds to step S52, in which the energization duty acduty is increased by the minute value DDUTY.
After the processing in steps S51 and S52, the process proceeds to step S50.

The minute value DDUTY when increasing and decreasing the energization duty acduty does not necessarily have to be the same, and is proportional to the difference between the control voltage maximum value VMax or the control voltage minimum value VMin and the current value. Small value DDUTY
May be changed.

On the other hand, in step S47, the flag F _ACG
If is not set, since it is not in the power generation control region, the process proceeds to step S53, and the ACG energization control is stopped.

FIG. 9 is a diagram showing the timing of the current (phase current) flowing in each phase of the stator coil and the output of the rotor angle sensor 29 during the ACG energization control. The retarding energization control is not performed.
Current is supplied to each of the U, V, and W phases of the stator coil in response to a change in the positive / negative (NS) of the detection output. On the other hand, when the retarding energization control is performed, the expected retarding amount d (=
The current is supplied to each of the U, V, and W phases of the stator coil with a delay of 60 °).

In FIG. 9, the energization angle T due to duty chopping is 180 °, but can be determined within 180 ° by the energization duty supplied from the duty ratio setting section 47 to the driver 80.

FIG. 10 shows the engine speed Ne, that is, ACG.
4 is a table of an energization duty in which the rotation speed of the starter 1 is set as a parameter. Detects engine speed,
With reference to FIG. 8, the energization duty according to the engine speed is determined.

As described above, according to the power generation control of this embodiment, it is possible to stably increase the amount of power generation in a low rotation speed range without operating a normal voltage regulator. Therefore, it is possible to minimize fluctuations in engine load during idling operation or the like, minimize fluctuations in engine rotation, and stabilize idling operation.

Returning to FIG. 5, swingback control section 700
In order to improve the startability of the engine by reducing the cranking torque at the time of starting the engine, the crankshaft is reversely rotated immediately after the engine is stopped and returned to a predetermined position.

The stage determination section 73 divides one rotation of the crankshaft 201 into 36 stages of stages # 0 to # 35 based on the output signal of the rotor angle sensor 29, and detects the timing of the pulse signal generated by the ignition pulser 30. Is determined as the reference stage (stage # 0), and the current stage is determined.

The stage transit time detecting section 74 detects the transit time Δtn of the stage based on the time from when the stage judging section 73 judges a new stage to when the next stage is judged. The reverse rotation control unit 75 generates a reverse rotation drive command based on the determination result by the stage determination unit 73 and the passage time Δtn detected by the stage passage time detection unit 74.

The duty ratio setting unit 72 dynamically controls the duty ratio of the gate voltage supplied to each power FET of the full-wave rectification bridge circuit 300 based on the result of the determination by the stage determination unit 73. The driver 80
The drive pulse having the set duty ratio is supplied to each power FET of the full-wave rectification bridge circuit 300.

Next, the swingback control unit 7
The operation of 00 will be described with reference to the flowchart of FIG. 11 and the operation explanatory diagram of FIG. FIG. 12A shows the relationship between the cranking torque (reverse load) required to reverse the crankshaft 201 and the crank angle. The cranking torque is obtained immediately before reaching the compression top dead center (at the time of reverse rotation). It rises sharply. FIG. 2B shows the relationship between the crank angle and the stage, and FIG. 2C shows the change in the angular speed of the crankshaft during the reverse rotation.

When the engine stoppage is detected in step S61, in steps S62 and S63, the stage determination section 7
The current stage already determined in 3 is referenced. Here, if the current stage is any of stages # 0 to # 11, the process proceeds to step S64, and stage # 1
If it is one of 2 to # 32, the process proceeds to step S65,
Otherwise (ie, any of stages # 33 to # 35), the process proceeds to step S66. Step S64,
In S66, the duty ratio setting unit 72 sets the duty ratio of the drive pulse to 70%, and in step S65, sets it to 80%.

The dynamic control of the duty ratio is as follows.
As will be described later in detail, the angular velocity of the crankshaft 201 during the reverse rotation is sufficiently reduced before the angle corresponding to the compression top dead center at which the cranking torque increases (at the time of reverse rotation), and the quick reverse drive is performed at other angles. Done to make it possible.

In step S67, the driver 80 operates the full-wave rectifier bridge circuit 30 at the set duty ratio.
By controlling each power FET of 0, reverse rotation energization is started. In step S68, the energization time Δ of the passed stage #n
tn is measured by the stage passage time detector 74.

In step S69, the reverse rotation control unit 75 determines whether or not the crankshaft 201 has passed the stage # 0, that is, near the top dead center. If it has not passed through the stage # 0, in step S71, the ratio of the passing time Δtn of the stage #n that passed immediately before and the passing time Δtn−1 of the stage # (n−1) that passed immediately before [ Δtn / Δtn-1] is compared with a reference value Rref (4/3 in the present embodiment). The transit time ratio [Δtn /
If Δtn-1] does not exceed the reference value Rref, the process returns to step S62 to engage in reverse rotation driving, and in parallel with this, the above-described processing is repeated.

Here, the engine stop position, that is, the reverse rotation start position, is closer to the next compression top dead center than the intermediate position between the previous and next compression top dead centers as shown by the curve A in FIG. Side, in other words, passing through the top dead center of the exhaust (at normal rotation)
After that, when the process reaches the compression top dead center, the crankshaft can pass through the stage # 0 (exhaust top dead center) even though the ACG starter 1 is driven in reverse at a duty ratio of 70%. Therefore, this corresponds to step S69.
In step S70, it is determined whether the crankshaft 201 has reached the stage # 32. If it is determined that the crankshaft 201 has reached the stage # 32, the reverse rotation energization is stopped in step S72, and then the crankshaft is further reversely rotated by inertia and then stopped.

On the other hand, as shown by the curve B in FIG. 12C, the reverse rotation start position is closer to the previous compression top dead center than the intermediate position between the previous and next compression top dead centers, in other words, Since the ACG starter 1 is driven in reverse at a duty ratio of 70% during the process of passing through the compression top dead center (at the time of forward rotation) and then reaching the exhaust top dead center, the reverse rotation load is reduced as shown in FIG. a)
As shown in (2), when rising before reaching stage # 0 (during reverse rotation), the angular velocity of the crankshaft 201 sharply decreases. If it is determined in step S71 that the passing time ratio [Δtn / Δtn−1] is equal to or more than 4/3 of the reference value, the reverse rotation energization is stopped in step S72, and the reverse rotation of the crankshaft is stopped when the energization is stopped. And stop at almost the same time.

As described above, in the swingback control of the present embodiment, whether the crankshaft has passed the angle corresponding to the top dead center and whether the angular velocity of the crankshaft has decreased during the reverse rotation driving after the engine is stopped is determined. When the crankshaft passes through the top dead center at the time of reverse rotation, the reverse rotation energization is terminated immediately after that,
The reverse rotation energization is also terminated when the angular speed of the crankshaft decreases due to the increase in the reverse rotation load. Therefore, regardless of the reverse rotation start position, the crankshaft can be returned to a position just before the previous compression top dead center (at the time of reverse rotation) and to a position where the compression reaction force is low.

Further, in the swingback control of the present embodiment, the angular velocity of the crankshaft 201 is detected based on the output of the rotor angle sensor 29 for detecting the rotor angle (that is, the stage) of the ACG starter. There is no need to separately provide a sensor for detecting the angle of the crankshaft 201.

[0080]

According to the present invention, the starter motor is automatically stopped when an engine speed that is highly likely to have reached the complete explosion state is automatically stopped. Ranking is prevented. In addition, if the engine speed subsequently decreases due to an error in the complete explosion determination based on the engine speed, the starter motor is immediately restarted. Therefore, even when it is difficult to determine the complete explosion based on the engine rotation speed because the cranking rotation speed of the engine by the starter motor is almost equal to the idling rotation speed of the engine, the engine can be reliably started.

[Brief description of the drawings]

FIG. 1 is an overall side view of a scooter type motorcycle to which the present invention is applied.

FIG. 2 is a sectional view taken along a crankshaft of the swing unit of FIG. 1;

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a block diagram of a control system of a starter / generator.

FIG. 5 is a block diagram showing a configuration of a main part of the ECU of FIG. 4;

FIG. 6 is a flowchart of engine start control.

FIG. 7 is a timing chart of engine start control.

FIG. 8 is a flowchart illustrating a process of the output control device.

FIG. 9 is a diagram showing timings of a phase current of a stator coil and an output of a rotor angle sensor during ACG energization control.

FIG. 10 is a table of an energization duty using an engine speed as a parameter.

FIG. 11 is a flowchart of swingback control.

FIG. 12 is an explanatory diagram of an operation of swingback control.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Starter and generator (ACG starter), 2 ... Battery, 3 ... ECU, 4 ... Full-wave rectifier, 5 ... Regulator,
29: rotor angle sensor, 30: ignition pulser, 50: stator, 60: outer rotor, 62: magnet, 20
1 ... Crankshaft

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 28, 2000 (200.12.
28)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

On the other hand, from the viewpoint of the environment and energy saving, in order to suppress the exhaust gas and fuel consumption particularly during idling, when the vehicle is stopped, the engine automatically stops, and the throttle grip is operated from the automatic stop state. For example, Japanese Patent Application Laid- Open No. 5-149221 discloses an automatic engine stop / start system that automatically starts a starter motor and restarts the engine when the start operation of the engine is detected.

Claims (4)

[Claims] An engine start control device for starting an engine by cranking with a starter motor and automatically stopping energization of the starter motor when the engine start is completed, wherein the engine speed is reduced to a first reference speed. Means for continuing to energize the starter motor until the engine speed reaches, means for stopping energization of the starter motor when the engine speed reaches the first reference speed, and an engine speed lower than the first reference speed. Means for restarting energization of the starter motor when the rotation speed decreases to a second reference rotation speed. 2. The engine start control device according to claim 1, wherein an idling rotational speed of the engine is substantially equal to a cranking rotational speed of the engine by the starter motor. 3. The engine according to claim 1, wherein the engine start is completed when the engine speed continuously exceeds a third reference speed higher than the first reference speed for a predetermined time or more. An engine start control device according to any one of the preceding claims. 4. The engine start control device according to claim 3, wherein after the completion of the engine start, a retard control for delaying the ignition timing from a reference timing in a low rotation range of the engine is executed.