JP5247554B2 - Engine start control device - Google Patents

Description

  The present invention relates to an engine start control device, and more particularly to an engine start control device that reversely drives a crankshaft to a predetermined position immediately after engine stop and at the time of engine start.

  Conventionally, in order to reduce cranking torque at the time of engine start and improve startability, the crankshaft is reversely driven by an ACG starter motor that rotates in synchronization with the crankshaft and returned to a predetermined position. There is known an engine start control device in which the engine is normally driven.

  Patent Document 1 discloses an engine start control device that executes rewinding control for reversely driving a crankshaft to a predetermined position after compression top dead center immediately after the engine is stopped. This engine start control device is configured to change the duty ratio of the ACG starter motor in accordance with the crankshaft angle at the start of reverse rotation.

Japanese Patent No. 3824132

  By the way, idle stop (idling stop) control is known in which the engine is temporarily stopped when a predetermined condition is satisfied during a temporary stop such as waiting for a signal, and the engine is restarted in response to a throttle operation. When the engine is stopped by this idle stop control, as described above, rewinding control for reversely driving the crankshaft may be executed immediately after the engine is stopped.

  In addition, when the engine is started by operating the starter switch from the complete stop state rather than temporarily stopping by the idle stop control, the crankshaft is reversely driven by the ACG starter motor to return to a predetermined position. Swing back control is known that improves startability by forward rotation.

  The engine start control device described in Patent Document 1 is configured to change the duty ratio in accordance with the crankshaft angle when the reverse rotation is performed immediately after the engine is stopped. The relationship with the duty ratio was not studied. As a result, for example, if the reverse rotation duty ratio during rewinding control and swingback control is set in common, if the set value is large, the reverse rotation time during swingback control is reduced and inertial force is applied during forward rotation. While the startability is improved, at the time of rewinding control, the crankshaft is returned before the compression top dead center, and there is a possibility that the inertial force may return too much in the forward rotation direction. When the set value is small, the reaction of the compression reaction force during the rewinding control is reduced, and the crankshaft can be stopped at a predetermined position in a short time, while the reverse rotation time becomes long during the swingback control. There is a problem that startability is lowered and generation of inertia force in the forward rotation direction is weakened.

  An object of the present invention is to solve the above-described problems of the prior art and provide an engine start control device that can reversely drive a crankshaft at an optimum rotational speed for each of rewind control and swingback control. .

  In order to achieve the above object, the present invention executes an idle stop control for automatically stopping the engine (E) when a predetermined condition is satisfied, and a motor (70) for driving the crankshaft (51) in the normal rotation direction or the reverse rotation direction. Thus, in the engine start control device (80) that reversely drives the crankshaft (51) to a predetermined position after the engine (E) is stopped, the crankshaft (51) is moved when the engine is started by operating the starter switch (35). A swingback control unit (90) that performs a swingback control for reversely driving to a predetermined position, and a rewinding control for reversely driving the crankshaft (51) to a predetermined position immediately after the engine is stopped by idle stop control. An idle stop start rewinding control unit (100), and the swing back The first feature is that the motor current value at the time of reverse rotation driving by the idle stop start rewinding control unit (100) is set smaller than the motor current value at the time of reverse rotation driving by the control unit (90). is there.

  A second feature is that the magnitude of the current value is determined by a motor duty ratio for driving the motor.

  Further, when it is detected that the idle stop start rewinding control unit (100) has reached the predetermined position after the compression top dead center, the energization to the motor (70) is stopped and the timer (102) ) Is started, and when the measured time reaches a predetermined time, there is a third feature in that it shifts to an idle stop state.

  The predetermined position after the compression top dead center is determined by the motor angle sensor (29) that detects the rotation angle of the motor (70) during the reverse rotation of the motor (70). There is a fourth feature in that the point in time is detected.

  The predetermined position after the compression top dead center is a point in time when the deceleration of the motor (70) exceeds a predetermined value during the reverse rotation of the motor (70), and the deceleration of the motor (70). Has a fifth feature in that it is calculated based on a change in the passing speed of a 720 degree motor stage obtained by equally dividing two rotations of the crankshaft (51) by 72 motor stages.

  Further, the motor (70) has a fifth feature in that the motor (70) is an ACG starter motor that serves both as a starter motor and an AC generator.

  According to the first feature, the swingback control unit that performs swingback control that reversely drives the crankshaft to a predetermined position when the engine is started by operating the starter switch, and the crankshaft is predetermined immediately after the engine is stopped by the idle stop control. An idle stop start rewinding control unit that performs a rewinding control to reversely drive to a position, and based on the motor current value at the time of reverse rotation driving by the swingback control unit, at the time of reverse rotation driving by the rewinding control unit at the start of idle stop Since the motor current value is set to be smaller, the reverse speed of the motor is increased during swingback control to shorten the reverse rotation time and the engine startability is improved, while the reverse speed is decreased during rewind control. It prevents the compression top dead center from being overcome and is caused by the compression reaction force. Ri to reduce the recoil return, it is possible to stop immediately the optimum position of the crank shaft to restart.

  According to the second feature, since the magnitude of the current value is determined by the motor duty ratio for driving the motor, the magnitude of the current value can be easily set.

  According to the third feature, when it is detected that the idling stop start rewinding control unit has reached a predetermined position after the compression top dead center, the motor stop energization and the timer measures the time. When the measurement time reaches a predetermined time, the state shifts to the idle stop state, so that it is possible to shift to the idle stop state in a state where the swing back due to the compression reaction force has stopped.

  According to the fourth feature, the predetermined position after the compression top dead center is the time when the forward rotation of the motor is detected by the motor angle sensor that detects the rotation angle of the motor during the reverse rotation of the motor. At the time of reverse rotation driving, it is possible to determine that the predetermined position after the compression top dead center is detected by detecting that the piston is pushed back due to an increase in the compression reaction force.

  According to a fifth feature, the predetermined position after the compression top dead center is a point in time when the motor deceleration exceeds a predetermined value during reverse rotation driving of the motor, and the motor deceleration is performed by two rotations of the crankshaft. Is calculated based on a change in the passing speed of the 720 degree motor stage equally divided by 72 motor stages, so that a predetermined position after the compression top dead center can be set at intervals of 10 degrees.

  According to the sixth feature, since the motor is an ACG starter motor that serves both as a starter motor and an AC generator, in addition to starting the engine and generating electric power after starting, one motor provided on the crankshaft It is also possible to execute swingback control and rewind control.

1 is a side view of a scooter type motorcycle to which an engine start control device according to an embodiment of the present invention is applied. It is the sectional view on the AA line of FIG. It is a block diagram of the control system of an ACG starter motor. It is the block diagram which showed the structure of the principal part in ECU which concerns on the drive control of an ACG starter motor. It is a time chart which shows the flow of the swing back control at the time of engine starting. It is a flowchart which shows the procedure of the engine back swing back control. It is a time chart which shows the flow of the rewinding control at the time of idle stop start. It is a flowchart which shows the procedure of the idling stop start rewinding control. It is a graph which shows the drive state of a fuel-injection apparatus and an ignition device at the time of an idle stop start. It is a flowchart which shows the procedure of the fuel injection at the time of an idle stop start, and ignition control. It is a timing chart which shows the relationship between the rotation angle of a crankshaft, a 720 degree motor stage, etc. It is a flowchart which shows the procedure of injection / ignition stage conversion control. 7 is a correspondence table between a 720 degree motor stage and an injection / ignition stage.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of a scooter type motorcycle 1 to which an engine start control device according to an embodiment of the present invention is applied. The front part of the vehicle body and the rear part of the vehicle body are connected via the low floor part 4. The body frame is generally composed of a down tube 6 and a main pipe 7. A seat 8 is disposed above the main pipe 7.

  The handle 11 is axially supported by the head pipe 5 and extends upward, and a front fork 12 that rotatably supports the front wheel WF is attached to one lower side. A handle cover 13 that also serves as an instrument panel is attached to the upper portion of the handle 11. Further, an ECU 80 as an engine start control device is disposed in front of the head pipe 5.

  At the rear end of the down tube 6, a bracket 15 projects from the rising portion of the main pipe 7. A hanger bracket 18 of the swing unit 2 is supported on the bracket 15 via a link member 16 so as to be swingable.

  A four-cycle single-cylinder engine E is disposed at the front of the swing unit 2. A continuously variable transmission 10 is disposed behind the engine E, and a rear wheel WR is supported on the output shaft of the speed reduction mechanism 9. A rear shock unit 3 is interposed between the upper end of the speed reduction mechanism 9 and the bent portion of the main pipe 7. Above the swing unit 2, a throttle body 20 and an air cleaner 14 of a fuel injection device connected to an intake pipe 19 extending from the engine E are disposed.

  2 is a cross-sectional view taken along line AA in FIG. The swing unit 2 has a crankcase 74 that is a right case 75 on the right side in the vehicle width direction and a left case 76 on the left side in the vehicle width direction. The crankshaft 51 is rotatably supported by bearings 53 and 54 fixed to the crankcase 70. A connecting rod 73 is connected to the crankshaft 51 via a crankpin 52.

  The left case 76 also serves as a speed change chamber case, and a belt drive pulley including a movable pulley half 60 and a fixed pulley half 61 is attached to the left end of the crankshaft 51. The stationary pulley half 61 is fastened to the left end of the crankshaft 51 by a nut 77. In addition, the movable pulley half 60 is splined to the crankshaft 51 so as to be slidable in the axial direction. A V-belt 62 is wound between the pulley halves 60 and 61.

  On the right side of the movable pulley half 60, the ramp plate 57 is fixed to the crankshaft 51. A slide piece 58 attached to the outer peripheral end portion of the lamp plate 57 is engaged with a lamp plate sliding boss portion 59 formed in the axial direction at the outer peripheral end of the movable pulley half 60. Further, a tapered surface that is inclined toward the movable pulley half 60 as it goes radially outward is formed on the outer peripheral portion of the ramp plate 57. A plurality of tapered surfaces are formed between the tapered surface and the movable pulley half 60. The weight roller 63 is accommodated.

  When the rotational speed of the crankshaft 51 increases, the weight roller 63 moves radially outward by centrifugal force. As a result, the movable pulley half 60 moves to the left in the drawing and approaches the fixed pulley half 61, and as a result, the V-belt 62 sandwiched between the pulley halves 60, 61 moves outward in the radial direction. It moves to increase its winding diameter. On the rear side of the swing unit 2, a driven pulley (not shown) in which the winding diameter of the V-belt 62 is variable corresponding to both pulley halves 60 and 61 is provided. The driving force of the engine E is automatically adjusted by the belt transmission mechanism, and is transmitted to the rear wheel WR via a not-shown centrifugal clutch and speed reduction mechanism 9 (see FIG. 1).

  Inside the right case 75, an ACG starter motor 70 in which a starter motor and an AC generator are combined is disposed. The ACG starter motor 70 includes an outer rotor 71 fixed to the tapered end portion of the crankshaft 51 with a mounting bolt 120, and a stator 72 disposed inside the outer rotor 71 and fixed to the right case 75 with a mounting bolt 121. It is configured. A radiator 68 and a cover member 69 in which a plurality of slits are formed are attached to the right side of the blower fan 65 fixed to the outer rotor 71 with mounting bolts 67.

  A sprocket 55 around which a cam chain for driving a camshaft (not shown) is wound is fixed to the crankshaft 51 between the ACG starter motor 70 and the bearing 54. The sprocket 55 is integrally formed with a gear 56 that transmits power to an oil pump (not shown) that circulates engine oil.

  FIG. 3 is a block diagram of a control system of the ACG starter motor 70. The same reference numerals as those described above denote the same or equivalent parts. The ECU 80 includes a full-wave rectification bridge circuit 81 for full-wave rectification of the three-phase AC of the ACG starter motor 70, and an output of the full-wave rectification bridge circuit 81 with a predetermined regulated voltage (regulator operating voltage: 14.5 V, for example). A regulator 82 that restricts the crankshaft 51 to a predetermined position when the engine is started, and a rewinding control unit 100 at the start of idle stop that reverses the crankshaft 51 to a predetermined position when the idle stop is started. And a motor stage conversion means 110 for restarting that sets an injection / ignition stage when the engine is restarted from an idle stop state, and a 720 degree motor stage as a crankshaft position at the start of idle stop control. 720 degree motor stage storage means 111, And a injection and ignition stage correspondence table 112 that is used to set the fire stage. Details of each control described above will be described later.

  The ECU 80 includes a fuel injection device 28, a motor angle sensor 29, an ignition coil 21, a throttle opening sensor 23, a fuel sensor 24, a seat switch 25 that detects the seating state of an occupant, an idle stop control permission switch 26, and a cooling water temperature sensor 27. And the ignition pulser 30 is connected, and the detection signal from each part is input into ECU80. A spark plug 22 is connected to the secondary side of the ignition coil 21.

  Furthermore, a starter relay 34, a starter switch 35, stop switches 36 and 37, a standby indicator 38, a fuel indicator 39, a vehicle speed sensor 40, and a headlight 42 are connected to the ECU 80. The headlight 42 is provided with a dimmer switch 43. Electric power is supplied to each of the above components from the battery 46 via the main fuse 44 and the main switch 45.

  FIG. 4 is a block diagram showing a configuration of a main part in the ECU 80 related to drive control of the ACG starter motor 70. The full-wave rectification bridge circuit 81 is configured by connecting three sets of two power FETs connected in series in parallel. A smoothing capacitor 86 is disposed between the battery 46 and the full-wave rectification bridge circuit 81.

  The stage determination unit 83 divides the two rotations of the crankshaft 51 into 72 stages (720 degree motor stage) of stages # 0 to 71 based on the output signals of the motor angle sensor 29 and the ignition pulser 30, and the current stage. Determine. Note that the stage is determined by rotating the crankshaft 51 once for stage # 0 until the stroke determination (front / back determination of two rotations of the crankshaft) is completed based on the output value of the PB sensor after the engine is started. It is performed by a 360 degree motor stage divided into 36 stages of ~ 35. The ignition pulser 30 is provided integrally with the motor angle sensor 29 of the ACG starter motor 70 and detects the rotation angle of the ACG starter motor 70 attached to the crankshaft 51.

  The ECU (engine start control device) 80 according to this embodiment reverses to a predetermined position once when the engine E is started by operating the starter switch 35 (see FIG. 3) from a state where the engine E is stopped. In other words, by starting normal rotation after swinging back to a predetermined position, the running speed to the compression top dead center is lengthened, and the rotational speed of the crankshaft 51 when first overcoming the compression top dead center It is possible to execute “swing-back control at engine start” to increase the engine speed. According to this engine start swingback control, it is possible to improve the startability when the engine is started by the starter switch 35.

  Further, the ECU 80 can execute idle stop control for temporarily stopping the engine when a predetermined condition is satisfied when the vehicle stops, such as waiting for a signal. The predetermined condition for starting the idle stop is, for example, that the idle stop control permission switch 26 is on, the seat switch 35 detects the seating of the occupant, and the vehicle speed detected by the vehicle speed sensor 40 is a predetermined value (for example, 5 km / h) The engine speed detected by the ignition pulser 30 is not more than a predetermined value (for example, 2000 rpm) and the throttle opening detected by the throttle opening sensor 23 is not more than a predetermined value (for example, 5 degrees). It is assumed that a predetermined time has elapsed in this state. Then, the engine E is restarted when the throttle opening becomes a predetermined value or more during idle stop.

  Furthermore, the ECU 80 according to the present embodiment reverses the crankshaft 51 from the stop position to a predetermined position when the engine E is temporarily stopped when the above-described idle stop condition is satisfied. By returning, the run-up period up to the compression top dead center is lengthened, and “idling stop start rewinding control” that improves the startability at the time of restart can be executed. The rewinding control is not executed when the main switch 35 is turned off and the engine E is stopped.

  The engine start situation determination unit 84 starts the engine E by operating the starter switch 35, that is, is a situation in which the engine E is started from the complete stop state, or restarted by the throttle operation from the idle stop state. Determine if it is a situation. When it is determined that the engine is in a state of starting from a complete stop state, the duty for reversely rotating the ACG starter motor 70 by swingback control by the swingback reverse rotation duty ratio setting unit 92 included in the swingback control unit 90 is determined. A ratio is set.

  On the other hand, when it is determined by the engine start state determination unit 84 that the engine is restarted from the idle stop state, the reverse rotation reverse duty ratio setting unit 101 included in the idle stop start rewind control unit 100 A duty ratio for reversing the ACG starter motor 70 for rewinding control is set. The idle stop start rewinding control unit 100 includes a timer 102 that detects various predetermined times.

  The drive control unit 85 supplies the drive pulse having the duty ratio set by the swing back control unit 90 to each power FET of the full-wave rectification bridge circuit 81 during the swing back control, while the idle control during the rewind control. A drive pulse having a duty ratio set by the stop start rewinding control unit 100 is supplied to each power FET of the full-wave rectification bridge circuit 81. The engine start control device (ECU) 80 according to the present embodiment is characterized in that the duty ratio at the time of swingback control is different from the duty ratio at the time of rewinding control. Specifically, the reverse rotation duty ratio during the rewinding control is set to be smaller than the reverse rotation duty ratio during the swingback control (for example, 100% during the swingback control, 45% during the rewinding control). . Hereinafter, the swing back control and the rewind control will be described in detail with reference to FIGS.

  FIG. 5 is a time chart showing the flow of swingback control when starting the engine. In this figure, the motor rotation speed, the motor rotation state, and the starter switch operating state are shown from above. When the starter switch 35 is turned on at time t10 from a state where the engine E is completely stopped (not restarted from the idle stop state), the swingback control unit 90 causes the ACG starter with a duty ratio of 100%. The reverse rotation driving of the motor 70 is started.

  Next, at time t11, normal rotation driving with a duty ratio of 100% is started. At time t13, the engine E is started and the rotational speed of the ACG starter motor 70 becomes higher than the driving speed by energization control, and energization is stopped accordingly. At time t14, the starter switch 35 is turned off by the occupant confirming the start of the engine E. The motor stage is detected at 360 degrees from time t12, and then the motor stage is fixed at 720 degrees when the stroke determination is completed at time t15.

  FIG. 6 is a flowchart showing a procedure of engine start swingback control. In step S100, it is determined whether or not the engine E is stopped. If an affirmative determination is made in step S100, the process proceeds to step S101 to determine whether or not an idle stop is being performed. If an affirmative determination is made in step S101, the process proceeds to step S102 to determine the reverse motor duty ratio (100%) for swingback control. If a negative determination is made in steps S100 and S101, the process returns to each determination. In a succeeding step S103, it is determined whether or not the starter switch 35 is turned on. If an affirmative determination is made, the process proceeds to step S104. If a negative determination is made, the process returns to the determination in step S103.

  In step S104, reverse rotation driving of the ACG starter motor is started with a duty ratio of 100%. In a succeeding step S105, it is determined whether or not a predetermined position after the compression top dead center is detected. This predetermined position can be set, for example, at a position 30 degrees after compression top dead center. If an affirmative determination is made in step S105, the process proceeds to step S106, and the forward rotation driving of the ACG starter motor 70 is started at a duty ratio of 100%. If a negative determination is made in step S105, the process returns to step S104.

  Next, in step S107, simultaneous injection in which fuel is injected every two revolutions of the crank at a preset stage of the 360 degree motor stage and ignition is performed at every revolution of the crank at the preset stage of the 360 degree motor stage. 360 degree ignition is started. In step S108, whether or not the stroke determination of the engine E (determination of each stroke of the intake, exhaust, compression, and combustion of the engine corresponding to the crank 720 degrees) has been completed by using the output value of the PB sensor in the second rotation of the crank. If a positive determination is made, the 720 degree motor stage is determined in step S109, and the injection / ignition stage is determined in step S110. In step S111, ignition control and injection control are started once every 720 degrees (once every two rotations of the crank), and the series of controls is terminated. If a negative determination is made in step S108, the process returns to step S107.

  As described above, in the engine start control device according to the present embodiment, by setting the reverse drive duty ratio to 100% during the swing back control, the reverse drive as preparation for the forward drive can be performed in as short a time as possible. Configured to complete. On the other hand, in the rewinding at the start of the idle stop, there is no problem even if the reverse rotation is performed at a slow speed such as a duty ratio of 45% because the normal rotation drive is not continuously performed after the reverse rotation drive. Then, according to the rewinding control at the start of idle stop described below, the reverse rotation speed at the time of rewinding is reduced so that it does not return too much in the forward rotation direction from the compression top dead center and is received at the time of reverse rotation. The influence of the compression reaction force can be reduced, and the crankshaft 51 can be quickly stopped at the optimum position for restart. In addition, you may comprise so that each preset duty ratio may be corrected according to engine water temperature etc.

  FIG. 7 is a time chart showing the flow of rewinding control at the start of idle stop. In this figure, the motor rotation speed, throttle opening, and motor rotation state are shown from the top. At time t20, the idle stop condition as described above is satisfied, and the idle stop control is started. Thereafter, when it is detected that the crankshaft 51 is stopped at time t21, rewinding control with a duty ratio of 45% is started.

  At time t22, the crankshaft 51 approaches the compression top dead center in the reverse rotation direction, and the piston's compression reaction force increases, so that the reverse rotation energization with the duty ratio of 45% is continued and the piston is pushed back. 51 turns into normal rotation, in other words, swinging back of the crankshaft 51 is started. When the idling stop start rewinding control unit 100 detects that the ACG starter motor 70 has started normal rotation based on the output signal of the motor angle sensor 29, the crankshaft reaches a predetermined position after the compression top dead center. It is determined that the ACG starter motor 70 is deenergized, and the timer 102 (see FIG. 4) starts measuring a predetermined time for waiting for the swing back.

  Next, during time t23 to t24, the rotation is slightly reversed by the driving resistance of the exhaust valve and stops at time t24. At time t25, when the time measured by the timer 102 reaches a predetermined time waiting for swingback, the state shifts to the idle stop state.

  Thereafter, at time t26, it is detected that the throttle opening is equal to or greater than a predetermined value by the occupant's throttle operation, and normal rotation driving with a duty ratio of 100% is started to restart the engine. At time t <b> 27, the engine starts, so that the rotation speed exceeds the drive rotation speed of the ACG starter motor 70, and the restart is completed.

  The predetermined position after the compression top dead center may be detected based on a change (deceleration) in the passing speed of a 720 degree motor stage obtained by equally dividing two rotations of the crankshaft 51 by 72 motor stages. it can. The passage speed of the stage is made possible by measuring the passage time of each stage. Although details of the 720 degree motor stage will be described later, in the swing back control described above, detection of a predetermined position after compression top dead center during reverse rotation is also performed when the 720 degree motor stage reaches the predetermined stage, It can be performed based on a change in the passing speed of the 720 degree motor stage.

  FIG. 8 is a flowchart showing the procedure of idle stop start rewinding control. In step S200, it is determined whether or not an idle stop condition is satisfied. If an affirmative determination is made, the process proceeds to step S201, and a stop process of the engine E is executed. If a negative determination is made in step S200, the process returns to the determination in step S200.

  Next, in step S202, it is determined based on the output signal of the motor angle sensor 29 whether or not the rotation of the crankshaft 51 has stopped. If a negative determination is made in step S202, the process returns to the determination in step S202. On the other hand, if a positive determination is made, the process proceeds to step S203, and the motor duty ratio for rewinding control (45%) is determined. In subsequent step S204, reverse rotation driving at a duty ratio of 45% is started. In step S205, it is determined whether forward rotation is detected by the motor angle sensor 29. If an affirmative determination is made, the process proceeds to step S206. If a negative determination is made in step S205, the process returns to step S204. In step S206, which is shifted when the normal rotation of the crankshaft 51 is detected, the motor duty ratio is set to zero, that is, energization of the ACG starter motor 70 is stopped, and in step S207, the timer 102 waits for the swing back. Measurement for a predetermined time (for example, 2 seconds) is started. Then, in step S208, it is determined whether or not a predetermined time for waiting for swingback has elapsed. If a negative determination is made, the process returns to the determination in step S208. If an affirmative determination is made, the process proceeds to step S209 to enter the idle stop state. Transition to end a series of control.

  FIG. 9 is a graph showing driving states of the fuel injection device 28 and the ignition device (ignition plug 22) at the start of idle stop. In this figure, the measured value of the intake negative pressure by the PB sensor and the drive pulses of the ignition device and the fuel injection device are shown from the top. FIG. 10 is a flowchart showing a procedure of engine stop control at the start of idle stop.

  The engine start control device according to the present embodiment is configured to stop only fuel injection and continue the ignition operation as it is at the start of idle stop. Referring to FIG. 10, in step S300, it is determined whether or not an idle stop condition is satisfied. If an affirmative determination is made, the process proceeds to step S301. If a negative determination is made in step S300, the control is terminated as it is. In step S301, fuel injection by the fuel injection device 28 is stopped, and ignition by the spark plug 22 is continued as it is. When the engine is stopped (crankshaft rotation is stopped) in step S302, a series of control is finished. According to the configuration described above, even if unburned gas remains in the combustion chamber of the engine E at the start of idle stop, it is completely burned until the crankshaft 51 stops. Is possible.

  By the way, when the engine is started, the fuel injection device and the ignition device are driven once when the engine speed reaches a predetermined value or more until the engine stroke determination is completed and the 720 degree motor stage is determined. After performing simultaneous injection, it is usual to perform injection at a timing for each predetermined crank angle and to perform one fixed ignition for one rotation of the crank (360 degrees). Therefore, even when the engine is restarted from the engine stop state due to idle stop, simultaneous injection, injection at a predetermined crank angle timing, and 360 degree ignition are performed until the stroke determination is completed. It was.

  On the other hand, in the engine start control device according to the present embodiment, the 720 degree motor stage determined before starting the idle stop is stored and held even during the idle stop, and the stroke determination is performed when the engine is restarted. Without being performed, the fuel injection and ignition control based on the 720 degree motor stage can be executed from the beginning. Hereinafter, this will be described in detail with reference to FIGS.

  FIG. 11 is a timing chart showing the relationship between the rotation angle of the crankshaft 51 and the 720 degree motor stage. In this figure, from the top, four strokes of a four-cycle engine (compression, combustion, exhaust, intake), crankshaft rotation angle, crank pulse, output signal of motor angle sensor 29 (W phase, U phase, V phase), fuel An injection (FI) stage that is a reference for the drive timing of the injection device, an ignition stage (IG) stage that is a reference for the drive timing of the ignition device, and a 720 degree motor stage are shown.

  The 720 degree motor stage is a stage in which one stage is set to 10 degrees, and a period of two rotations of the crankshaft (720 degrees) is assigned to 72 stages # 0 to 71 in total. Further, the motor angle sensor 29 is configured so that the W phase, the U phase, and the V phase each output a pulse signal having a width of 30 degrees at intervals of 30 degrees, and each phase is shifted by 10 degrees. Thus, the rotation angle of the crankshaft 51 can be detected every 10 degrees, and the reference position is determined by the crank pulse signal. The pulsar rotor attached to the crankshaft 51 for detecting the crank pulse signal is composed of four short relaxers having a detection width of 22.5 degrees in the circumferential direction and one having a detection width of 82.5 degrees in the circumferential direction. Are arranged in a shape arranged at intervals of 37.5 degrees. The output of the W phase configured to output a signal at the center position of the long reluctator is a reference for deriving the crank rotation angle.

  The 360-degree motor stage is determined by the crank pulse signal and the rotor sensor signal, and the PB value (output value of the PB sensor) is reduced by the intake negative pressure in the intake stroke on the front side, and in the combustion stroke on the back side after rotating 360 degrees. A front / back determination based on the fact that the intake air is not performed and the PB value becomes high is performed. As a result, when the front / back determination for two rotations of the crankshaft is determined, the 720 degree motor stage is determined. For example, the position 30 degrees before the compression top dead center can be detected when the 720 degree motor stage is # 69. The ignition is performed between the IG stages 9 to 11, and the fuel injection is performed between the FI stages 12 to 17.

  FIG. 12 is a flowchart showing a procedure of injection / ignition stage conversion control. In step S400, it is determined whether or not an idle stop is being performed. If an affirmative determination is made, the process proceeds to step S401. In step S401, it is determined whether or not the throttle is opened by a predetermined opening or more. If an affirmative determination is made, the process proceeds to step S402. If a negative determination is made in steps S400 and 401, the process returns to each determination.

  In step S402, the ACG starter motor 70 is driven forward in order to restart the engine. In step S403, based on the 720 degree motor stage at the start of idling stop stored in the 720 degree motor stage storage means 111, the injection stage and ignition stage correspondence table 112 shown in FIG. The IG stage is derived. For example, if the 720 degree motor stage is # 2-4, the FI stage is converted to # 4 and the IG stage is converted to # 12. In addition, since power supply to the ECU 30 is continued during the idle stop, the 720-degree motor stage storage unit 111 can be configured by a RAM whose stored contents are reset when the power is turned off.

  In step S404, driving of the fuel injection device and the ignition device is started in accordance with the FI stage and IG stage found in step S403 and the predetermined fuel injection map and ignition map. The fuel injection map can be configured as a map for determining the fuel injection time based on the engine speed Ne, the throttle opening θ, the intake pressure value by the PB sensor, and the like. In step S405, it is determined whether or not the engine speed (motor speed) Ne has reached a start completion speed (for example, 1000 rpm) or more. If a negative determination is made, the process returns to the determination in step S405. If an affirmative determination is made, the process proceeds to step S406, the drive of the ACG starter motor 70 is stopped, and a series of control is terminated.

  According to the injection / ignition stage conversion control described above, it is not necessary to determine the stroke of the engine when restarting from the idle stop, and optimal fuel injection and ignition control based on the 720 degree motor stage can be executed from the beginning. The startability at the time of restart can be improved. In addition, since simultaneous injection is not performed, fuel consumption can be improved.

  In addition, the shape and structure of the ACG starter motor, pulsar rotor, motor angle sensor, internal configuration of the ECU (engine start control device), respective reverse duty ratios in swingback control and idle stop start rewinding control, 720 degree motor stage, The correspondence relationship with the injection / ignition stage is not limited to the above embodiment, and various changes can be made. For example, as described in the above embodiment, swing back control at engine start, rewind control at start of idle stop, fuel injection stop and ignition continuation control at start of idle stop, injection at restart from idle stop state The ignition stage conversion control can be applied in combination. The engine start control device according to the present invention is not limited to a motorcycle, and can be applied to a tricycle, a four-wheel vehicle, or the like.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 21 ... Ignition coil (ignition device), 22 ... Ignition plug (ignition device), 28 ... Fuel injection device, 29 ... Motor angle sensor, 30 ... Ignition pulser, 51 ... Crankshaft, 70 ... ACG starter motor (Motor), 80 ... ECU (engine start control device), 81 ... full-wave rectification bridge circuit, 90 ... swingback control unit, 91 ... reverse rotation duty ratio setting unit for swingback, 100 ... rewinding control unit at start of idle stop , 101 ... Reverse rotation duty ratio setting unit for rewinding, 102 ... Timer, 110 ... Motor stage conversion means at restart 110, 111 ... 720 degree motor stage storage means, 112 ... Injection / ignition stage correspondence table

Claims (6)

Idle stop control is performed to automatically stop the engine (E) when a predetermined condition is satisfied, and the crankshaft (51) is driven forwardly or reversely by a motor (70) to stop the crankshaft after the engine (E) is stopped In the engine start control device (80) that reversely drives (51) to a predetermined position,
A swingback control section (90) for performing swingback control for reversely driving the crankshaft (51) to a predetermined position when the engine is started by operating a starter switch (35);
Immediately after engine stop by idle stop control, an idle stop start rewinding control unit (100) for performing rewinding control for reversely driving the crankshaft (51) to a predetermined position,
The motor current value at the time of reverse rotation by the idle stop start rewinding control unit (100) is set smaller than the motor current value at the time of reverse rotation driving by the swingback control unit (90). An engine start control device.   The engine start control device according to claim 1, wherein the magnitude of the current value is determined by a motor duty ratio for driving the motor.   When it is detected that the idle stop start rewinding control unit (100) has reached a predetermined position after compression top dead center, the motor (70) is deenergized and the timer (102) The engine start control device according to claim 1 or 2, wherein time measurement is started, and when the measurement time reaches a predetermined time, the engine shifts to an idle stop state.   The predetermined position after the compression top dead center is detected by the motor angle sensor (29) detecting the rotation angle of the motor (70) during the reverse rotation of the motor (70). The engine start control device according to claim 3, wherein the engine start control device is at a point in time. The predetermined position after the compression top dead center is a time point when the deceleration of the motor (70) exceeds a predetermined value during the reverse drive of the motor (70),
The deceleration of the motor (70) is calculated based on a change in the passing speed of a 720 degree motor stage obtained by equally dividing two rotations of the crankshaft (51) by 72 motor stages. Item 4. The engine start control device according to Item 3.   The engine start control device according to any one of claims 1 to 5, wherein the motor (70) is an ACG starter motor that serves as both a starter motor and an AC generator.

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