JP3998119B2 - Engine start control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine start control device that starts an engine by cranking it with a starter motor, and more particularly to an engine start control device suitable for a system in which an engine crankshaft and a rotation shaft of a starter motor are directly connected.
[0002]
[Prior art]
In a conventional engine starter equipped with a starter motor, the starter motor is energized and cranks the engine only while the user turns on the starter switch. 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 releases the ON operation by himself. If the engine cannot be started when the on operation is released, the engine is tried to be restarted by turning on the starter switch again.
[0003]
On the other hand, from the viewpoint of environment and energy saving, in order to reduce exhaust gas and fuel consumption especially when idling, the engine automatically stops when the vehicle is stopped, and the start operation such as the throttle grip is operated from the automatic stop state. When an engine is detected, an automatic engine stop / start system that automatically starts the starter motor and restarts the engine is disclosed in, for example,5-149221It is disclosed in the gazette.
[0004]
[Problems to be solved by the invention]
In a system in which the engine is automatically restarted, such as a vehicle that employs the above-described engine automatic stop / start system, the system senses that the engine has been started and automatically stops energizing the starter motor. It is necessary to let
[0005]
Here, in a general starting mechanism that inputs the rotational force of the starter motor to the crankshaft of the engine via a reduction gear, the engine cranking speed by the starter motor and the engine idling speed are relatively small. Since there is a large rotational difference and the engine speed increases after the engine is started, the completion of the engine start can be detected relatively easily based on the engine speed.
[0006]
However, in the starting mechanism in which the crankshaft of the engine and the rotation shaft of the starter motor are directly connected, the cranking rotation speed by the starter motor increases and the difference from the idling rotation speed decreases. For this reason, if the start of the engine is determined based on the engine speed and the starter motor is automatically stopped, the cranking is ended even if the engine is not completely started, and vice versa. There may be a case where cranking is continued even though the engine has been started.
[0007]
Note that this phenomenon can also occur when the user cranks the engine by turning on the starter switch. When the engine is not completely started, the starter switch is turned off. On the contrary, the on-operation may continue even though the engine start has been completed.
[0008]
An object of the present invention is to solve the above-described problems of the prior art and to provide an engine start control device that recognizes the stop timing of a starter motor accurately and automatically stops it.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an engine start control device that starts an engine by cranking the engine with a starter motor, and automatically stops energization of the starter motor when the engine start is completed. The energization of the starter motor is continued until the number reaches the first reference speed, and when the engine speed reaches the first reference speed, the energization to the starter motor is stopped and the engine speed becomes the first reference speed. The energization to the starter motor is resumed when the speed decreases to a second reference rotational speed lower than the number.
[0010]
According to the above-described features, the starter motor is automatically stopped when the engine speed at which it is highly likely that the engine has reached a complete explosion state, so unnecessary cranking after the engine complete explosion is prevented. The In addition, if the engine speed decreases thereafter, the starter motor is restarted immediately, so even if the complete explosion state has not been reached, the automatic restart from before the engine stops can quickly Migration is possible.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall side view of a scooter type motorcycle to which the engine start control device of the present invention is applied. The vehicle further stops the engine automatically when the vehicle is stopped, and then the throttle grip is opened. Alternatively, when a start operation such as turning on the starter switch is performed, an automatic engine stop / start function for automatically driving the starter motor and restarting the engine is provided.
[0012]
The front part of the vehicle body and the rear part of the vehicle body are connected via a lower floor part 4, and the vehicle body frame forming the skeleton of the vehicle body is generally composed of a down tube 6 and a main pipe 7. The fuel tank and the storage box (both not shown) are supported by the main pipe 7, and the seat 8 is disposed above the fuel tank and the storage box.
[0013]
At the front of the vehicle body, a handle 11 is provided on the upper side of the steering head 5 so as to be pivoted, a front fork 12 extends downward, and a front wheel FW is pivotally supported on the lower end thereof. The upper part of the handle 11 is covered with a handle cover 13 that also serves as an instrument panel. A bracket 15 protrudes from the lower end of the rising portion of the main pipe 7, and a hanger bracket 18 of the swing unit 2 is connected to the bracket 15 through a link member 16 so as to be swingable.
[0014]
The swing unit 2 is equipped 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 pivotally supported by a speed reduction mechanism 9 provided at a rear portion thereof via a centrifugal clutch. A 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. In front of the swing unit 2, a carburetor 17 connected to an intake pipe 19 extending from the engine E and an air cleaner 14 coupled to the carburetor 17 are disposed.
[0015]
FIG. 2 is a cross-sectional view of the swing unit 2 cut along the crankshaft 201, and FIG. 3 is a partially enlarged view thereof. The same reference numerals as those described above represent the same or equivalent parts.
[0016]
The swing unit 2 is covered with a crankcase 202 configured 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. . A connecting rod (not shown) is connected to the crankshaft 201 via a crankpin 213.
[0017]
The left crankcase 202L also serves as a belt type continuously variable transmission chamber case, and a belt drive pulley 210 is rotatably provided on the crankshaft 201 extending to the left crankcase 202L. The belt driving pulley 210 includes a fixed pulley half 210L and a movable pulley half 210R. The fixed pulley half 210L is fixed to the left end portion of the crankshaft 201 via a boss 211, and a movable side on the right side thereof. The pulley half body 210R is spline-fitted to the crankshaft 201 and can approach and separate from the stationary pulley half body 210L. A V-belt 212 is wound between the pulley halves 210L and 210R.
[0018]
A cam plate 215 is fixed to the crankshaft 201 on the right side of the movable pulley half 210R, and a slide plate 215a provided on the outer peripheral end of the movable pulley half 210R is formed in the axial direction at the outer peripheral end of the movable pulley half 210R. The sliding boss portion 210Ra is slidably engaged. The cam plate 215 of the movable pulley half 210R has a tapered surface whose outer periphery is inclined toward the cam plate 215, and a dry weight pole 216 is formed in a space between the tapered surface and the movable pulley half 210R. Is housed.
[0019]
When the rotational speed of the crankshaft 201 increases, the dry weight ball 216 that rotates between the movable pulley half 210R and the cam plate 215 and moves together is moved in the centrifugal direction by centrifugal force, and the movable pulley half 210R It is pressed by the dry weight ball 216 and moves to the left to approach the fixed pulley half 210L. As a result, the V-belt 212 sandwiched between the pulley halves 210L and 210R moves in the centrifugal direction, and its winding diameter increases.
[0020]
A driven pulley (not shown) corresponding to the belt driving pulley 210 is provided at the rear of the vehicle, and the V-belt 212 is wound around this driven pulley. By this belt transmission mechanism, the power of the engine E is automatically adjusted and transmitted to the centrifugal clutch, and the rear wheel RW is driven via the speed reduction mechanism 9 and the like.
[0021]
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 tip tapered portion of the crankshaft 201 with a screw 253.
[0022]
The stator 50 disposed on the inner peripheral side of the outer rotor 60 is fixed to the crankcase 202 by bolts 279. The outer rotor 60 is provided with a fan 280 fixed by bolts 246. A radiator 282 is provided adjacent to the fan 280, and the radiator 282 is covered with a fan cover 281.
[0023]
As shown in an enlarged view in FIG. 3, the sensor case 28 is fitted in the inner periphery of the stator 50. In the 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 performing energization control on the stator coil of the ACG starter 1, and one rotor angle sensor 29 is provided corresponding to each of the U phase, V phase, and W phase of the ACG starter 1. Only one ignition pulser 30 is provided for engine ignition control. Both the rotor angle sensor 29 and the ignition pulser 30 can be configured by a Hall IC or a magnetoresistive (MR) element.
[0024]
The lead wires of the rotor angle sensor 29 and the ignition pulser 30 are connected to a substrate 31, and a wire harness 32 is coupled to the substrate 31. On the outer periphery of the boss 60a of the outer rotor 60, 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 is fitted.
[0025]
In one magnetized band of the magnet ring 33 corresponding to the rotor angle sensor 29, N poles and S poles alternately arranged at intervals of 30 ° in the circumferential direction are formed corresponding to the magnetic poles of the stator 50. In the other magnetized band of the magnet ring 33 corresponding to the ignition pulser 30, a magnetized portion is formed at one place in the circumferential direction in a range of 15 ° to 40 °.
[0026]
The ACG starter 1 functions as a starter motor (synchronous motor) when the engine is started, and is driven by a current supplied from a battery to rotate the crankshaft 201 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 electrical component.
[0027]
Returning to FIG. 2, a sprocket 231 is fixed on the crankshaft 201 between the ACG starter 1 and the bearing 209, and a camshaft (not shown) is driven from the crankshaft 201 to the sprocket 231. A chain is wrapped around. The sprocket 231 is formed integrally with a gear 232 for transmitting power to a pump for circulating lubricating oil.
[0028]
FIG. 4 is a block diagram of an electrical system including the ACG starter 1. The ECU 3 has a three-phase full-wave rectification bridge circuit 300 for full-wave rectification of the three-phase alternating current generated by the power generation function of the ACG starter 1, and an output of the full-wave rectification bridge circuit 300 with a predetermined regulated voltage (regulator operating voltage: for example, 14.5 V).
[0029]
Furthermore, the ECU 3 of the present embodiment increases the power generation amount when the engine speed is in a predetermined low speed range, and a start control unit 500 that enables reliable engine start while preventing excessive cranking at the time of engine start. And a swing back control unit 700 for improving the next engine startability by reversing the crankshaft to a predetermined position immediately after the engine is stopped.
[0030]
An ignition coil 21 is connected to the ECU 3, and a spark plug 22 is connected to the secondary side of the ignition coil 21. Further, the ECU 3 is connected with 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 detection signals are input to the ECU 3 from various parts.
[0031]
Furthermore, a starter relay 34, a starter switch 35, stop switches 36 and 37, a standby indicator 38, a fuel indicator 39, a speed sensor 40, a motorcycle star 41, and a headlight 42 are connected to the ECU 3. The headlight 42 is provided with a dimmer switch 43.
[0032]
A current is supplied from the battery 2 to each of the above parts via the main fuse 44 and the main switch 45. The battery 2 has a circuit that is directly connected to the ECU 3 by the starter relay 34 and connected to the ECU 3 only through the main fuse 44 without passing through the main switch 45.
[0033]
Next, the operations of the start control unit 500, the power generation control unit 400, and the swing back control unit 700 of the ECU 3 will be described with reference to the functional block diagram of FIG.
[0034]
The three-phase full-wave rectification 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.
[0035]
In the start control unit 500, the engine speed determination unit 52 determines the engine speed based on the detection signal of the ignition pulser 30, the frequency signal of the generated voltage, and the like. 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.
[0036]
Hereinafter, the operation of the start control unit 500 will be described with reference to the flowchart of FIG. 6 and the timing chart of FIG. The definitions of the reference values, timers and flags used in the flowchart are as follows.
(1) Start failure speed N_ref1
When the ACG starter 1 is energized, if there is no abnormality in the ACG starter 1 or the engine, the engine speed is the speed that should naturally be reached.
(2) Restart speed N_ref2
 This is the engine speed at which the temporarily stopped ACG starter 1 is restarted.
(3) Start / stop speed N_ref3
This is the engine speed at which energization to the ACG starter 1 is temporarily stopped.
(4) Complete explosion speed N_ref4
This is the engine speed that is reached when the engine is completely exploded.
(5) Start completion flag F_run
It is set when the complete explosion state of the engine continues for a predetermined time and cranking by the ACG starter 1 is no longer necessary, that is, when the engine start is completed.
(6) Start stop flag F_stop
Engine speed is poor starting speed N_ref1It is set when the state that does not reach is continued for a predetermined time.
(7) Pause flag F_off
Engine speed is start / stop speed N_ref3It is set only during the period when the power to the starter motor is temporarily stopped.
(8) First timer T_m1
Engine speed is poor starting speed N_ref1Measure the duration that does not reach.
(9) Second timer T_m2
Engine speed is complete explosion speed N_ref4Measure the duration that exceeds.
(10) Start cancellation reference value T_stop
Timer T_m1Is a reference value for determining engine start failure based on the count value of the timer T_m1The count value is the start cancellation reference value T_stopWhen it reaches, start stop flag F_stopIs set.
(11) Start completion reference value T_run
Timer T_m2Is a reference value for determining that the engine has been completely started based on the count value of the timer T_m2Is the reference value T_runReaches the start completion flag F_runIs set.
[0037]
The engine start control process of the present embodiment is repeatedly executed in an interrupted manner at a predetermined cycle in the engine start determination unit 51.
[0038]
In step S10 in FIG. 6, when the start operation of the starter switch 35 or a predetermined start operation is detected, it is determined in step S11 whether or not the start state of the starter switch 35 has been detected in the previous step S10. Is done. If the previous time has not been detected, initial processing is executed in step S12.
[0039]
In step S12, a temporary stop flag F that is set when power supply to the ACG starter 1 is temporarily stopped._offA start stop flag F that is set when the ACG starter 1 forcibly stops the engine start because the engine cannot be cranked sufficiently._stopAnd a first timer T that counts the duration during which the ACG starter 1 cannot crank the engine sufficiently_m1And engine speed Ne is complete explosion speed N_ref4A second timer T that counts the duration exceeding_m2And are reset.
[0040]
In step S13, the pause flag F_offIs first referred to as being in a reset state, the process proceeds to step S14. In step S14, a start completion flag F set when the engine start is completed._runIs first referred to as being in a reset state, the process proceeds to step S15. In step S15, a drive current is supplied to the ACG starter 1, and the engine is cranked by the ACG starter 1 (time t0 in FIG. 7).
[0041]
In step S16, the engine speed Ne is set to the start failure speed N._ref1Compared with As shown at time t1 in FIG._ref1 Is less than the first timer T in step S17._m1Is incremented. In step S18, the first timer T_m1The count value is the start cancellation reference value T_stop The count value is initially set to the reference value T_stop This cycle ends as it is.
[0042]
In the next cycle and after, steps S11 to S12 are skipped, and the process proceeds to steps S13, S14, S15, and S16. In step S16, the engine speed Ne is set to the engine start speed N._ref1 Until it is determined that the first timer T is exceeded, the process proceeds to step S17 as described above, and the first timer T_m1Keeps incrementing.
[0043]
After that, as in case 1 of FIG. 7, the engine speed Ne remains at the start failure speed N until time t6._ref1In step S18, the first timer T_m1The count value is the start cancellation reference value T_stop If it is determined that the engine has exceeded the start stop flag F in step S19._stop Is set. Accordingly, in the next cycle and thereafter, the process proceeds from step S13 to step S20, and the ACG starter 1 is turned off. Therefore, until the starter switch 35 is turned on again or a predetermined start operation is performed. The ranking operation is canceled.
[0044]
On the other hand, in step S18, the first timer T_m1The count value is the start cancellation reference value T_stop Before it is determined that the engine speed Ne has exceeded_ref1 If this is detected in step S16, the process proceeds to step S21. In step S21, the timer T_m1Is reset and the start stop flag F_stopIs reset.
[0045]
In step S22, the engine speed Ne is set to the restart speed N._ref2 For example, as shown at time t3, the engine speed Ne is_ref2 If it is less than, a pause flag F in step S23_off Is referenced. Here, pause flag F_off Is in a reset state, the process returns to step S16 via steps S25 and S27 described later.
[0046]
After that, at time t4, the engine speed Ne becomes the restart speed N._ref2 When this is detected in step S22, in step S25, the engine speed Ne is changed to the start / stop speed N._ref3 Compared with Engine speed Ne is the start / stop speed N_ref3As long as it is less than, return to step S16 via step S27.
[0047]
After that, at time t7, the engine speed Ne becomes the start / stop speed N_ref3When this is detected in step S25, in step S26, the ACG starter 1 is turned off and the pause flag F_off Is set. In step S27, the engine speed Ne and the complete explosion speed N_ref4 The engine speed Ne is initially the complete explosion speed N_ref4  Return to step S16.
[0048]
Thereafter, the processing from step S16 onward is repeated, but if the engine is not completely started, the engine speed Ne gradually decreases immediately after the ACG starter 1 is stopped at time t7 (case 2). . Then, at time t8, the engine speed Ne becomes the restart speed N._ref2When this is detected in step S22, a pause flag F is detected in step S23._off Is referenced.
This time, in the step S26, the pause flag F_off Has already been set, the process proceeds to step S24. In step S24, the ACG starter 1 is restarted and the suspension flag F_off Is reset. Therefore, the engine speed Ne starts to increase again from time t8.
[0049]
On the other hand, the engine is in a complete explosion state (case 3), and the engine speed Ne is the complete explosion speed N at time t9 or t10._ref4 When this is detected in step S27, in step S28, the second timer T_m2Is incremented. In step S29, the second timer T_m2 The count value of the start complete reference value T_runThe count value is compared with the start completion reference value T_run Is reached, the start completion flag F in step S30_run Is set, and the engine start control ends.
According to this embodiment, the engine speed is set to a predetermined speed (N) during cranking by an ACG starter as a starter motor._ref3), The cranking is interrupted and the engine speed is monitored, and then the engine speed is set to a predetermined speed (N_ref2), The ACG starter is restarted and cranked again, so that the engine can be reliably started while preventing excessive cranking.
[0050]
Returning to FIG. 5, the power generation control unit 400 increases the power generation amount by retarding current from the battery 2 to the stator coil of each phase of the ACG starter 1 in addition to the function of normally controlling the power generation amount (voltage). (Hereinafter referred to as “ACG energization control”).
[0051]
Here, the retarded angle energization means that the stator coil is energized with a delay corresponding to a predetermined electrical angle from the detection signal when the magnetic pole of the magnetized band 33 is detected detected by the rotor angle sensor 29. . 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 a sudden change in engine load caused by the operation of the regulator 100 in a low rotation range. It is controlled to be within a predetermined voltage range below the voltage.
[0052]
In the power generation control unit 400, the engine speed determination unit 48 detects the engine speed based on, for example, a detection signal from the ignition pulser 30, and if the engine speed is within the planned power generation control region, the retard command is sent to the driver. 80. The driver 80 that has received the retard command reads the preset energization retard amount from the retard amount setting unit 49 and conducts the retard energization. The energization duty ratio is supplied from the duty ratio setting unit 47 to the driver 80.
[0053]
The driver 80 detects a magnetic pole detection signal from the rotor angle sensor 29, that is, a signal that rises on each time the sensor 29 detects a magnetized band of the magnet ring 33 formed corresponding to the magnetic pole of the outer rotor 60. 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.
[0054]
The battery voltage determination unit 46 compares the battery voltage Vb with the control voltage maximum value VMax and the control voltage minimum value VMin that define the voltage control range, and based on the comparison result, the energization set in the duty ratio setting unit 47 The duty 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 decreases to the control voltage minimum value VMin, the energization duty is increased by the same minute value. Let
[0055]
FIG. 8 is a flowchart showing the operation of the power generation control unit 400 described above, which is started after the engine start control by the start control unit 500 is completed.
[0056]
In step S41, it is determined whether or not the engine speed exists in the power generation control region. The power generation control area is set to, for example, 1000 rpm or more and 3500 rpm or less. If the engine speed exists in the power generation control area, the process proceeds to step S42, and a flag F indicating that the engine speed exists in the power generation control area._ACG Is set (= 1). Flag F_ACG If is not set, the process proceeds to step S43 and the flag F_ACG Is set. In step S44, the scheduled value ACGAGL is set to the energization delay amount acgagl. The scheduled value ACGAGL can be appropriately set in advance, but in this embodiment, for example, the electrical angle is 60 °.
[0057]
In the subsequent step S45, the initial value ACDUTY is set to the energization duty acduty. The initial value ACDUTY can be appropriately set in advance, but is 40% in the present embodiment, for example. If steps S43 to S45 are completed, the process proceeds to step S47. If step S42 is positive, steps S43 to S45 are skipped and the process proceeds to step S47. On the other hand, when the engine speed does not exist in the power generation control region, the flag F is set in step S46._ACG After resetting (= 0), the process proceeds to step S47.
[0058]
In step S47, flag F_ACG Whether or not is set is determined. Flag F_ACG Is set, it is determined in step S48 whether or not the battery voltage Vb is equal to or greater than the control voltage maximum value VMax. The control voltage maximum value VMax is set to a value lower than the regulated voltage, for example, 13.5 volts. When the battery voltage Vb is not equal to or higher than the maximum control voltage value VMax, the routine proceeds to step S49, where it is determined whether or not the battery voltage Vb is equal to or lower than the minimum control voltage value VMin. The control voltage minimum value VMin is set to 13.0 volts, for example.
[0059]
If the battery voltage Vb is not less than the control voltage minimum value VMin in step S49, it is determined that the battery voltage Vb is within the ACG energization voltage range set to a value lower than the regulator regulated voltage. ACG energization control is performed according to the retard amount acgagl and the energization duty acduty.
[0060]
If it is determined in step S48 that the battery voltage Vb is greater than or equal to the control voltage maximum value VMax, the process proceeds to step S51, and the energization duty duty is reduced by the minute value DDUTY. The minute value DDUTY is, for example, 1%. If it is determined in step S49 that the battery voltage Vb is less than or equal to the control voltage minimum value VMin, the process proceeds to step S52 to increase the energization duty acduty by the minute value DDUTY. After the processing of steps S51 and S52, the process proceeds to step S50.
[0061]
The minute value DDUTY when increasing and decreasing the energization duty is not necessarily the same, and is minute in proportion to the difference between the control voltage maximum value VMax or the control voltage minimum value VMin and the current value. The value DDUTY may be changed.
[0062]
On the other hand, in step S47, the flag F_ACG  If is not set, since it is not the power generation control region, the process proceeds to step S53, and the ACG energization control is stopped.
[0063]
FIG. 9 is a diagram showing timings of currents (phase currents) flowing through the phases of the stator coil and the output of the rotor angle sensor 29 during ACG energization control. In the normal case where the retarded angle energization control is not performed, currents are supplied to the U, V, and W phases of the stator coil in response to changes in the positive and negative (NS) detection output of the rotor angle sensor 29. On the other hand, when the retarded angle energization control is performed, the stator coils U, V, and V are delayed by a predetermined retard amount d (= 60 °) from the change of the positive / negative (NS) detection output of the rotor angle sensor 29. A current is supplied to each W phase.
[0064]
In FIG. 9, the energization angle T by duty chopping is 180 °, but can be determined within 180 ° by the energization duty supplied from the duty ratio setting unit 47 to the driver 80.
[0065]
FIG. 10 is an energization duty table in which the engine speed Ne, that is, the rotation speed of the ACG starter 1 is set as a parameter. The engine speed is detected, and an energization duty according to the engine speed is determined with reference to FIG.
[0066]
Thus, according to the power generation control of the present embodiment, it is possible to stably increase the power generation amount without operating a normal voltage regulator in a low rotation range. Therefore, fluctuations in engine load can be reduced during idle operation, etc., so that fluctuations in engine rotation can be minimized and idling can be stabilized.
[0067]
Returning to FIG. 5, the swingback control unit 700 reversely rotates the crankshaft to a predetermined position immediately after the engine stops in order to reduce the cranking torque when starting the engine and improve the engine startability. return.
[0068]
The stage determination unit 73 divides one rotation of the crankshaft 201 into 36 stages # 0 to # 35 based on the output signal of the rotor angle sensor 29, and detects the detection timing of the pulse signal generated by the ignition pulser 30 as a reference stage. The current stage is determined as (stage # 0).
[0069]
The stage passage time detection unit 74 detects the passage time Δtn of the stage based on the time from when the stage determination unit 73 determines a new stage until the next stage is determined. 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.
[0070]
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 determination result by the stage determination unit 73. The driver 80 supplies the drive pulse having the set duty ratio to each power FET of the full-wave rectification bridge circuit 300.
[0071]
Next, the operation of the swing back control unit 700 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 rotation load) required to reverse the crankshaft 201 and the crank angle. The cranking torque is just before reaching the compression top dead center (during reverse rotation). It rises rapidly. FIG. 4B shows the relationship between the crank angle and the stage, and FIG. 4C shows the change in the angular velocity of the crankshaft during reverse rotation.
[0072]
When engine stop is detected in step S61, the current stage already determined by the stage determination unit 73 is referred to in steps S62 and S63. Here, if the current stage is any one of stages # 0 to # 11, the process proceeds to step S64. If any of the stages # 12 to # 32, the process proceeds to step S65, and otherwise (that is, stages # 33 to ##). 35), the process proceeds to step S66. In steps S64 and S66, the duty ratio setting unit 72 sets the duty ratio of the drive pulse to 70%, and in step S65, the duty ratio is set to 80%.
[0073]
Such dynamic control of the duty ratio sufficiently lowers the angular velocity of the crankshaft 201 at the time of reverse rotation just before the compression top dead center equivalent angle (at the time of reverse rotation) at which cranking torque increases, as will be described in detail later. At the same time, it is performed in order to enable quick reverse drive at other angles.
[0074]
In step S67, the driver 80 controls each power FET of the full-wave rectifier bridge circuit 300 with the set duty ratio to start reverse energization. In step S68, the energization time Δtn of the stage #n that has passed is measured by the stage passage time detector 74.
[0075]
In step S69, the reverse rotation control unit 75 determines whether or not the crankshaft 201 has passed through stage # 0, that is, near the top dead center. If it has not passed stage # 0, in step S71, the ratio of the passing time Δtn of stage #n that passed immediately before and the passing time Δtn-1 of stage # (n−1) that passed immediately before [ [Delta] tn / [Delta] tn-1] is compared with a reference value Rref (4/3 in this embodiment). If the passage time ratio [Δtn / Δtn-1] does not exceed the reference value Rref, the process returns to step S62 to engage reverse rotation, and the above-described processes are repeated in parallel.
[0076]
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. In this case, in the process from passing through the exhaust top dead center (during forward rotation) to compression top dead center, the crankshaft is driven even though the ACG starter 1 is driven in reverse at a duty ratio of 70%. Can pass through stage # 0 (exhaust top dead center). Accordingly, this is detected in step S69, and the process proceeds to step S70 to determine whether or not the crankshaft 201 has reached stage # 32. If it is determined that the crankshaft 201 has reached stage # 32, the reverse energization is stopped in step S72, and then the crankshaft is further rotated in the reverse direction by the inertial force and then stopped.
[0077]
On the other hand, as indicated by curve B in FIG. 12 (c), 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, the compression up In the process from passing through the dead center (during forward rotation) to exhaust top dead center, the ACG starter 1 is driven in reverse at a duty ratio of 70%, so the reverse load is shown in FIG. As shown, when it rises before reaching stage # 0 (at the time of reverse rotation), the angular velocity of the crankshaft 201 decreases rapidly. When it is determined in step S71 that the passing time ratio [Δtn / Δtn-1] is 4/3 or more of the reference value, the reverse energization is stopped in step S72, and the reverse rotation of the crankshaft is stopped. Stops almost simultaneously.
[0078]
Thus, in the swing back control of the present embodiment, during reverse rotation driving after the engine is stopped, it is monitored whether the crankshaft has passed the top dead center equivalent angle and whether the crankshaft angular velocity has decreased. When the crankshaft passes the top dead center at the time of reverse rotation, the reverse rotation energization is terminated immediately thereafter, and the reverse rotation energization is also ended when the angular velocity of the crankshaft decreases due to an increase in the reverse load. Therefore, regardless of the reverse rotation start position, the crankshaft can be returned to a position before the previous compression top dead center (during reverse rotation) and to a low compression reaction force.
[0079]
Furthermore, in the swing back control of the present embodiment, the angular velocity of the crankshaft 201 is detected based on the output of the rotor angle sensor 29 that detects the rotor angle (ie, stage) of the ACG starter. There is no need to separately provide a sensor for detecting the angle.
[0080]
【The invention's effect】
According to the present invention, since the starter motor is automatically stopped when the engine speed that is highly likely to have reached the complete explosion state is detected, unnecessary cranking after the engine complete explosion is prevented. . In addition, if the complete explosion determination based on the engine speed is incorrect and the engine speed subsequently decreases, the starter motor is restarted immediately. Therefore, even if it is difficult to determine complete explosion based on the engine speed because the cranking speed of the engine by the starter motor and the idling speed of the engine are approximately the same, 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 cross-sectional view taken along the crankshaft of the swing unit of FIG.
FIG. 3 is a partially enlarged view of FIG. 2;
FIG. 4 is a block diagram of a control system of a starter / generator.
5 is a block diagram showing a configuration of a main part of the ECU of FIG. 4. FIG.
FIG. 6 is a flowchart of engine start control.
FIG. 7 is a timing chart of engine start control.
FIG. 8 is a flowchart showing processing of the output control device.
FIG. 9 is a diagram showing timings of stator coil phase currents and rotor angle sensor outputs during ACG energization control;
FIG. 10 is a table of energization duty with engine speed as a parameter.
FIG. 11 is a flowchart of swingback control.
FIG. 12 is an operation explanatory diagram 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, 201 ... crankshaft

Claims (4)

In the engine start control device that starts the engine by cranking with the starter motor, and automatically stops energization to the starter motor when the engine start is completed.
Means for energizing the starter motor until the engine speed reaches the first reference speed;
Means for stopping energization of the starter motor when the engine speed reaches the first reference speed;
Look including a resume means energization of the starter motor when the engine speed decreases to lower the second reference rotational speed than the first reference rotation speed,
The engine start control device, 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. The engine start control device according to claim 1 , wherein an idling speed of the engine is substantially equal to an engine cranking speed by the starter motor. 2. The engine start control according to claim 1 , wherein when the engine speed falls below a fourth reference speed lower than the second reference speed for a predetermined time or more, the energization to the starter motor is stopped. apparatus. 4. The engine start control device according to claim 3 , wherein after the completion of the engine start, an energization control is performed to retard the energization timing with respect to a reference timing in a low engine speed range.

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