JP2013174169A - Automatic stop/restart device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an automatic stop/restart device for an engine that improves starting performance at next engine start without leaving combusted gas in a cylinder while preventing ignition in a compression cycle for accelerating reverse rotation when engine restart is discontinued while the reverse rotation or stop is being detected during power distribution to an ignition device for a cylinder into which fuel has been injected.SOLUTION: When a restart is interrupted while power is distributed to an ignition device 12 for a specific cylinder into which fuel has been injected, a starting device 20 is continued to be driven until ignition in the specific cylinder is performed.

Description

  The present invention relates to an engine automatic stop / restart device that automatically stops an engine when an automatic stop condition is satisfied and then restarts the engine when a restart condition is satisfied.

  In recent years, for the purpose of improving the fuel consumption of vehicles such as automobiles and reducing the environmental load, a predetermined condition for stopping the engine by a driver's operation (for example, when the vehicle is below a predetermined vehicle speed and the brake pedal is depressed) Is satisfied), the fuel is automatically cut and the engine is automatically stopped, and then a predetermined condition (for example, release operation of a brake pedal, In addition, an engine automatic stop / restart device has been developed in which fuel injection is restarted and the engine is automatically restarted when an accelerator pedal depression operation is satisfied.

  Conventionally, as such an engine automatic stop / restart device, a crank angle sensor that can detect whether or not the crankshaft of the engine has rotated in reverse after the engine has been automatically stopped has been provided. There has been proposed a device that prevents the crankshaft of the engine from rotating backward by suppressing ignition (for example, see Patent Document 1).

  In addition, when the starter switch is turned off after fuel injection, the ignition command is prohibited and the starter motor is rotated forward until the fuel-injected specific cylinder reaches at least one exhaust stroke. There has also been proposed a device that discharges the air-fuel mixture in a specific cylinder and prevents the next engine from starting difficult by driving in the direction (for example, Patent Document 2).

JP 2006-105143 A Japanese Patent No. 4682966

  In the conventional device disclosed in Patent Document 1, when detecting that the crankshaft is reversely rotated by a sensor capable of detecting reverse rotation of the crankshaft of the engine, fuel injection and ignition during reverse rotation are suppressed. However, if the starter drive is interrupted while detecting the reverse rotation after the ignition device is energized and the ignition is suppressed, the crankshaft returns from the reverse rotation to the normal rotation, or the crankshaft When the rotational speed decreases and stops, the cylinder in the compression stroke is ignited, and the explosion energy may act in the reverse rotation direction of the crankshaft, promoting reverse rotation. There has been a problem that starting gas becomes difficult because the burned gas remains in the cylinder at the time of starting.

  Further, in the conventional device disclosed in Patent Document 2, if the starter switch is turned off during the start-up, the starter motor continues to be driven while the ignition command is prohibited until the injected fuel is discharged. As a result, unburned air-fuel mixture is discharged, and there is a problem that abnormal combustion in the exhaust pipe and an environmental load increase.

  The present invention has been made to solve the above-described problems, and prevents the occurrence of ignition that promotes reverse rotation of the crankshaft of the engine and ensures good startability without increasing the environmental load. It is an object to obtain an engine automatic stop / restart device.

  An engine automatic stop / restart device according to the present invention is an engine automatic stop / restart device that automatically stops an engine when an automatic stop condition is satisfied while the vehicle is running, and then restarts the engine when the restart condition is satisfied. A fuel injection device that injects fuel into the engine, an ignition device that accumulates energy when energized to ignite the engine by energization interruption, a starter that rotates the engine when energized, and an engine A crank angle sensor that detects a crank angle and a rotation direction, various sensors that detect an operating state of the engine, a fuel injection control unit that controls the fuel injection device, a starter control unit that controls the starter, and an ignition device Ignition control means to control, automatic engine stop condition and restart condition based on detection information from various sensors An engine stop / restart determination means for automatically stopping the engine when the automatic stop condition is satisfied and restarting the engine by operating the fuel injection control means, the starter control means and the ignition control means when the restart condition is satisfied The engine stop / restart determination means restarts in a state in which reverse rotation or stop of the crankshaft of the engine is detected while the ignition device is energized with respect to the specific fuel-injected cylinder by the fuel injection device When the condition is not satisfied, the starter is energized until the specific cylinder is ignited.

  According to the engine automatic stop / restart device according to the present invention, even when the engine start is interrupted while the ignition device is energized with respect to the specific cylinder that has been injected with fuel, the start device drives to the combustion stroke to ignite. By doing so, ignition that promotes reverse rotation of the engine is prevented and unburned air-fuel mixture is not discharged, so that abnormal combustion or the like in the exhaust pipe can be prevented. Further, since the burned gas is not left in the engine, it is possible to prevent the next start from being difficult.

It is a block diagram which shows the structure of the engine automatic stop / restart apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the control function structure of the engine automatic stop / restart apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the engine automatic stop process routine by Embodiment 1 of this invention. It is a flowchart which shows the engine stop restart determination processing routine by Embodiment 1 of this invention. It is a flowchart which shows the engine restart control processing routine by Embodiment 1 of this invention. It is a flowchart which shows the fuel-injection control processing routine by Embodiment 1 of this invention. It is explanatory drawing which shows the fuel-injection sequence at the time of the engine restart by Embodiment 1 of this invention. It is a flowchart which shows the ignition control processing routine by Embodiment 1 of this invention. It is a flowchart which shows the ignition energy accumulation | storage determination processing routine by Embodiment 1 of this invention. It is a flowchart which shows the starting device control processing routine by Embodiment 1 of this invention. It is a timing chart which shows the operation | movement at the time of the engine restart by Embodiment 1 of this invention. It is a timing chart which shows the other operation | movement at the time of the engine restart by Embodiment 1 of this invention. 6 is a timing chart showing the operation of a conventional engine automatic stop / restart device described in Patent Document 1; 6 is a timing chart showing the operation of a conventional engine automatic stop / restart device described in Patent Document 2.

Embodiment 1 FIG.
The first embodiment of the present invention will be described below with reference to FIGS. In addition, in each figure, the same code | symbol shows the same or equivalent part.
1 is a block diagram showing an overall schematic configuration of an automatic engine stop / restart device according to Embodiment 1 of the present invention.

  In FIG. 1, the engine automatic stop / restart device includes an engine 10, a starter 20, an engine control device 50 (ECU: Electric Control Unit), and various sensors (vehicle speed sensor 2, accelerator) that detect the operating state of the engine 10. An opening sensor 3, a brake pedal 4, an ignition switch 5), and a power source (vehicle battery not shown) that supplies power to the engine 10, the starter 20, and the engine controller 50.

The engine 10 includes a fuel injection device 11 (injector), an ignition device 12 (ignition coil and spark plug), a ring gear 13 provided on the crankshaft of the engine 10, and a crankshaft facing the ring gear 13. A crank angle sensor 1 for detecting the crank angle is provided.
The fuel injection device 11 supplies fuel to the engine 10, and the ignition device 12 ignites the fuel injected into the engine 10.

  The starter 20 is rotated by being energized from a power source, and rotates a starter motor 23 that rotates the engine 10, a pinion gear 24 provided on the rotation shaft of the starter motor 23, and the pinion gear 24 is pushed in the direction of the rotation axis. A plunger 22 for meshing with the ring gear 13 and a solenoid 21 for moving the plunger 22 in the direction of the rotation axis when energized from a power source are provided.

  The engine control device 50 includes a crank angle sensor 1 that outputs a crank angle signal, a vehicle speed sensor 2 that detects a vehicle speed and outputs a vehicle speed signal, and detects an accelerator opening and outputs an accelerator opening signal. An accelerator opening sensor 3, a brake pedal 4 that outputs a brake signal indicating the operating state of the pedal, and an ignition switch 5 that indicates a key operation state of a user of the vehicle are connected.

  The engine control device 50 drives and controls the engine 10 and the starter 20 based on detection information from the crank angle sensor 1 and various sensors (vehicle speed sensor 2, accelerator opening sensor 3, brake pedal 4, ignition switch 5). The automatic stop is performed when the automatic stop condition is satisfied, and the power source and the starter 20 are connected when the restart condition is satisfied.

  When energization is instructed from the engine control device 50 to the starter device 20, first, energization of the solenoid 21 is performed, and after the plunger 22 is pushed out, energization of the starter motor 23 is started after a predetermined time. It is configured as follows.

Although not specifically illustrated, the engine control device 50 is configured by various I / F circuits and a microcomputer.
Further, a microcomputer (hereinafter simply referred to as “engine control device 50”) in the engine control device 50 is an A / B that converts analog signals (detection signals of various sensors, etc.) into digital signals, although not specifically shown. D converter, CPU for executing various control programs (such as engine automatic stop / restart control program), ROM for storing engine automatic stop / restart control program and various data tables (such as control constants), and various control programs It is comprised with RAM which memorize | stores the variable etc. at the time of execution.

FIG. 2 is a block diagram showing a control function configuration (various processing routines) of the engine automatic stop / restart apparatus according to Embodiment 1 of the present invention.
In FIG. 2, the engine control device 50 includes an engine automatic stop unit 101.
The engine automatic stop means 101 determines whether the automatic stop condition is satisfied / not satisfied and the restart condition is satisfied / not satisfied based on detection information of the crank angle sensor 1 and various sensors, and the fuel injection device 11, the ignition device 12 and the start device. 20 is controlled to automatically stop and restart the engine 10.

The engine automatic stop unit 101 includes an engine stop / restart determination unit 102, an engine restart control unit 103, a fuel injection control unit 104, an ignition control unit 105, an ignition energy accumulation determination unit 106, and a starter control unit 107. And.
The engine stop / restart determination unit 102 determines automatic stop and restart of the engine 10 using detection signals from various sensors as input information.

The engine restart control means 103 performs restart control of the engine 10 using the determination result of the engine stop / restart determination means 102 and the crank angle signal from the crank angle sensor 1 as input information.
The fuel injection control unit 104 drives and controls the fuel injection device 11 using the determination result of the engine stop / restart determination unit 102, the determination result of the engine restart control unit 103, and the crank angle signal as input information.

The ignition control means 105 drives and controls the ignition device 12 using the control state of the starter control means 107, the determination result of the ignition energy accumulation determination means 106 and the crank angle signal as input information.
The ignition energy accumulation determination means 106 determines the ignition energy accumulation state using the control state of the ignition control means 105 as input information.
The starter control unit 107 controls driving of the starter 20 using the determination result of the engine restart control unit 103 as input information.

Next, a schematic operation of the engine automatic stop unit 101 in the engine control device 50 will be described with reference to FIGS. 1 and 2.
First, the engine stop / restart determination means 102 uses the input information from various sensors (vehicle speed sensor 2, accelerator opening sensor 3, brake pedal 4, ignition switch 5, etc.) to determine whether the automatic stop condition of the engine 10 is successful. judge.

The fuel injection control unit 104 receives the determination result indicating that the automatic stop condition is satisfied by the engine stop / restart determination unit 102 and stops the driving of the fuel injection device 11 to stop the engine 10.
Subsequently, the engine stop / restart determination unit 102 determines the success or failure of the restart condition of the engine 10 using input information from various sensors.

  The engine restart control unit 103 receives a determination result indicating that the restart condition is satisfied by the engine stop / restart determination unit 102, generates a starter drive request to the starter control unit 107, and the fuel injection control unit 104. A fuel injection permission command is generated.

The starter control means 107 performs energization and control to the starter 20 in response to the starter drive request from the engine restart control means 103.
Further, the starter control means 107 changes the drive timing of the ignition device 12 by the ignition control means 105 (crank angle corresponding to the ignition coil energization cutoff timing) according to the control state of the starter 20.

When the starter 20 is energized, in the starter 20 (see FIG. 1), first, the solenoid 21 is energized. The solenoid 21 drives the plunger 22 in the direction of the rotation axis, and the pinion gear 24. And the ring gear 13 are engaged with each other.
Thereafter, after a certain time has elapsed, the starter motor 23 is energized, and the starter motor 23 rotates the pinion gear 24 to rotate the ring gear 13 meshed with the pinion gear 24.

  On the other hand, the fuel injection control means 104 drives the fuel injection device 11 at a predetermined fuel injection timing (crank angle corresponding to the fuel injection timing) in accordance with the fuel injection permission command from the engine restart control means 103 to perform fuel injection. Injection is performed and the engine 10 is restarted.

  The ignition control means 105 controls energization and energization interruption (ignition) to the ignition device 12 according to the ignition energy accumulation determination result (to be described later with reference to FIG. 9) by the ignition energy accumulation determination means 106 and the crank angle signal.

  Note that energization to the ignition device 12 is not specifically shown, but a transistor (not shown) disposed on the downstream side of the primary coil (not shown) of the ignition coil in the ignition device 12. This means that the current is supplied from the power source that is turned on and connected to the upstream side of the primary coil in the ignition device 12. At this time, ON drive of the transistor is controlled by a drive signal from the engine control device 50.

When a current is passed through the primary coil in the ignition device 12 and then the transistor is turned off to cut off the current, a high voltage is induced in the secondary coil of the ignition coil. A high voltage spark is triggered and ignition occurs.
In the following description, the state in which the transistor of the ignition device 12 is turned on by the drive signal from the engine control device 50 is assumed to be energizing the ignition device 12.

  The ignition energy accumulation determination unit 106 monitors the energization state and power supply voltage (battery voltage) to the ignition device 12 by the ignition control unit 105, and determines the accumulation state of energy necessary for ignition to the ignition device 12.

Next, the operation of the automatic engine stop / restart device according to Embodiment 1 of the present invention will be described more specifically with reference to FIGS. 3 to 10 together with FIGS.
FIG. 3 is a flowchart showing an engine automatic stop processing routine by the engine automatic stop means 101, and FIG. 4 is a flowchart showing an engine stop / restart determination processing routine by the engine stop / restart determination means 102.

  FIG. 5 is a flowchart showing an engine restart control processing routine by the engine restart control means 103, and FIG. 6 is a flowchart showing a fuel injection control processing routine by the fuel injection control means 104.

  FIG. 7 is an explanatory diagram showing a fuel injection sequence when the engine is restarted by the fuel injection control means 104. The fuel injection timing (hatched block) when the engine 10 has four cylinders (# 1 to # 4 cylinders) is shown in FIG. Each stroke is shown corresponding to each stroke (intake, compression, combustion, exhaust).

FIG. 8 is a flowchart showing an ignition control processing routine by the ignition control means 105, and FIG. 9 is a flowchart showing an ignition energy accumulation determination processing routine by the ignition energy accumulation determination means 106.
FIG. 10 is a flowchart showing a starter control process routine by the starter control means 107.

3 to 10, the processing routines of FIGS. 3 to 5 and 10 are executed at regular intervals (for example, 5 [msec]), and the processing routines of FIGS. This is executed for each input of an angle signal (for example, 10 [deg]).
The processing routines of FIGS. 3 to 10 are executed by an engine automatic stop / restart control program stored in the ROM of the engine control device 50.

  When the ignition switch 5 of the vehicle is turned on, the engine control device 50 starts operation by being supplied with power from the power source (vehicle battery), and a CPU (engine automatic stop means 101) provided in the engine control device 50 The engine automatic stop / restart control program stored in the ROM is executed as shown in FIGS.

  In FIG. 3, the engine automatic stop means 101 in the engine control device 50 first executes an engine stop / restart determination process routine (step S101), and sets an automatic stop request flag F1 and a restart request flag F2. Details of step S101 will be described later with reference to FIG.

  Subsequently, the engine automatic stop unit 101 determines whether or not the automatic stop request flag F1 is “1” (step S012). If it is determined that F1 = 0 (that is, NO), the determination process described later is performed. The process proceeds to (Step S107).

  On the other hand, if it is determined in step S102 that F1 = 1 (that is, YES), the fuel injection permission flag F4 is reset to “0” in order to execute automatic engine stop and stop fuel injection (step S103). ) The automatic stop flag F3 is set to “1” (step S104).

  Subsequently, it is determined whether or not the restart request flag F2 is “1” (step S105). If it is determined that F2 = 0 (that is, NO), no restart request is generated. 3 processing routine is completed.

  On the other hand, if it is determined in step S105 that F2 = 1 (that is, YES), an engine restart control processing routine is executed to restart the engine 10 (step S106), and the processing routine of FIG. To do. Details of step S106 will be described later with reference to FIG.

In step S107, it is determined whether or not the automatic stop flag F3 is “1”. If it is determined that F3 = 0 (that is, NO), it is considered that the engine 10 is not in automatic stop. Therefore, the processing routine of FIG.
On the other hand, if it is determined in step S107 that F3 = 1 (that is, YES), since the engine 10 is automatically stopped, the process proceeds to the determination process of the restart request flag F2 (step S105).

Next, the engine stop / restart determination process (step S101 in FIG. 3) by the engine stop / restart determination means 102 in the engine automatic stop means 101 will be described in detail.
In FIG. 4, the engine stop / restart determination means 102 first determines whether or not the ignition switch 5 is ON (step S201), and if it is determined that the ignition switch 5 is OFF (that is, NO). Then, the process proceeds to a determination process (step S210) described later.

  On the other hand, if it is determined in step S201 that the ignition switch 5 is ON (that is, YES), then it is determined whether the brake pedal 4 is depressed or released (step S202). If it is determined that the pedal 4 is in the released state (that is, NO), the process proceeds to a determination process (step S207) described later.

  On the other hand, if it is determined in step S202 that the brake pedal 4 is in the depressed state (that is, YES), then the accelerator opening signal from the accelerator opening sensor 3 indicates “accelerator opening = 0”. (Step S203), and if it is determined that the accelerator opening> 0 (that is, NO), the process proceeds to step S207.

  On the other hand, if it is determined in step S203 that the accelerator opening = 0 (that is, YES), then the vehicle speed signal from the vehicle speed sensor 2 is “vehicle speed ≦ predetermined vehicle speed (for example, 10 [km / h])”. If the vehicle speed is greater than the predetermined vehicle speed (ie, NO), the vehicle is considered to be traveling normally, and the processing routine of FIG. 4 is terminated.

  On the other hand, if it is determined in step S204 that the vehicle speed ≦ the predetermined vehicle speed (that is, YES), the automatic stop request flag F1 is set to “1” in order to execute the automatic stop process (step S205), and a restart request is made. The flag F2 is reset to “0” (step S206), and the processing routine of FIG.

  In step S207 executed when the determination results in steps S202 and S203 are “NO”, it is determined whether or not the automatic stop request flag F1 is “1”, and F1 = 0 (ie, NO). If it is determined that it is determined that the automatic stop has not occurred, the processing routine of FIG. 4 is terminated.

  On the other hand, if it is determined in step S207 that F1 = 1 (that is, YES), the automatic stop request flag F1 is reset to “0” to execute restart (step S208), and the restart request flag F2 Is set to “1” (step S209), and the processing routine of FIG. 4 is terminated.

  Further, in step S210 executed when the determination result in step S201 is “NO”, the starter drive request flag F5 is reset to “0” as a process when the ignition switch 5 is OFF (step S210). The automatic stop flag F3 is reset to “0” (step S211), the automatic stop request flag F1 is reset to “0” (step S212), and the restart request flag F2 is reset to “0” (step S213). ), The processing routine of FIG.

Next, the engine restart control process (step S106 in FIG. 3) by the engine restart control means 103 in the engine automatic stop means 101 will be described in detail.
In FIG. 5, the engine restart control means 103 first sets the fuel injection permission flag F4 to “1” in order to execute the engine restart (step S301), and the engine speed Ne based on the crank angle signal is set. Whether or not the engine 10 has been started is determined based on whether or not it is less than a predetermined rotational speed (for example, 600 [rpm]) (step S302).

  If it is determined in step S302 that Ne <predetermined rotational speed (that is, YES), the engine 10 has not been started, so the starter drive request flag F5 is set to “1” in order to drive the starter 20. After setting (step S303), the processing routine of FIG. 5 is terminated.

  On the other hand, if it is determined in step S302 that Ne ≧ predetermined rotational speed (that is, NO), it is considered that the engine 10 has been started due to combustion. Therefore, in order to stop the starter 20, the starter drive request flag F5 5 is reset to “0” (step S304), the restart request flag F2 is reset to “0” (step S305), the automatic stop flag F3 is reset to “0” (step S306), and FIG. The processing routine ends.

Next, the fuel injection control process by the fuel injection control means 104 in the engine automatic stop means 101 will be described in detail.
In FIG. 6, the fuel injection control means 104 first determines whether or not the fuel injection permission flag F4 is “1” (step S401), and if it is determined that F4 = 0 (that is, NO), the fuel Since the injection permission command has not been generated, the processing routine of FIG. 6 ends.

  On the other hand, if it is determined in step S401 that F4 = 1 (that is, YES), whether or not the crank angle signal indicates the fuel injection start crank angle in order to determine whether or not it is the predetermined fuel injection start timing. It is determined whether or not (step S402).

If it is determined in step S402 that the crank angle signal is not the fuel injection start crank angle (that is, NO), the processing routine of FIG. 6 is terminated without executing fuel injection.
On the other hand, if it is determined in step S402 that the crank angle signal is the fuel injection start crank angle (that is, YES), the fuel injection control means 104 drives the fuel injection device 11 to cause the engine 10 to start fuel. Is injected (step S403).

  Finally, the fuel injection control means 104 sets the fuel injection completed flag F6 to “1” (step S404), and fuel has been injected into the engine 10 (that unburned fuel remains in the engine 10). ) Is specified, and the processing routine of FIG. 6 is terminated.

FIG. 7 shows a fuel injection sequence when the engine is restarted by the fuel injection control means 104, and the hatching block corresponds to the fuel injection timing.
In FIG. 7, the fuel injection is interrupted during the automatic stop before the restart request (broken line timing) is generated.
Thereafter, after restarting according to the generation of the restart request, fuel injection is resumed in a predetermined plurality of cylinders almost simultaneously with the start of restarting (dashed line timing).

Specifically, immediately after the restart request (broken line timing) in FIG. 7 is generated, fuel injection (see the hatching block) is resumed in the # 1 cylinder in the intake stroke and the # 3 cylinder in the exhaust stroke. The
Thereafter, fuel is injected into each cylinder at a predetermined timing, that is, every 5 [deg] before combustion bottom dead center (BBDC).

Next, the ignition control process by the ignition control means 105 in the engine automatic stop means 101 will be described in detail.
In FIG. 8, the ignition control means 105 first determines whether or not the crankshaft of the engine 10 is rotating (Ne> 0) based on the crank angle signal (Step S501), and the crankshaft is stopped (Ne). = 0) (that is, NO), the process proceeds to a determination process (step S508) described later.

  On the other hand, if it is determined in step S501 that the crankshaft is rotating (Ne> 0) (that is, YES), then whether or not the crankshaft is rotating forward based on the crank angle signal (reversely rotating). ) Is determined (step S502).

Note that the rotation direction of the crankshaft can be determined, for example, based on the voltage level of the crank angle signal.
For example, when the voltage level of the crank angle signal is 0V and 5V, it is determined that the rotation direction of the crankshaft is normal rotation, and when the voltage level of the crank angle signal is 2.5V and 5V, the rotation of the crankshaft is determined. It is determined that the direction is reverse rotation.

If it is determined in step S502 that the rotation direction of the crankshaft is reverse (ie, NO), the process proceeds to step S508.
On the other hand, if it is determined in step S502 that the rotation direction of the crankshaft is normal rotation (that is, YES), it is subsequently determined whether it is time to execute the energization control for the ignition device 12. Therefore, it is determined whether or not the crank angle signal indicates an energization start crank angle to the ignition device 12 (for example, 75 [deg] before compression top dead center (BTDC)) (step S503).

  If it is determined in step S503 that the crank angle signal indicates the energization start crank angle (that is, YES), energization to the ignition device 12 is started (step S504), and then the crank angle signal is determined by the ignition timing. It is determined whether or not an energization cutoff crank angle corresponding to (for example, 5 [deg] before compression top dead center (BTDC)) is indicated (step S505).

On the other hand, if it is determined in step S503 that the crank angle signal is not the energization start crank angle (that is, NO), the process proceeds to the determination process in step S505 without executing step S504.
If it is determined in step S505 that the crank angle signal is not the energization cutoff crank angle (ie, NO), the processing routine of FIG. 8 is terminated.

  On the other hand, if it is determined in step S505 that the crank angle signal is the energization cutoff crank angle (that is, YES), the ignition control means 105 resets the fuel injected flag F6 to “0” (step S506). Then, it is clearly shown that the fuel injected into the engine 10 has been burned, the power supply to the ignition device 12 is cut off, the engine 10 is ignited (step S507), and the processing routine of FIG.

  In step S508, which is executed when the determination results of steps S501 and S502 are “NO”, it is determined whether or not the ignition device 12 is energized, and the ignition device 12 is not energized (ie, , NO), the processing routine of FIG. 8 is terminated.

  On the other hand, if it is determined in step S508 that the ignition device 12 is energized (that is, YES), it is subsequently determined whether or not the restart request flag F2 is “0” (step S509). If F2 = 0 (that is, YES), then whether or not the fuel injection completed flag F6 is “1” in order to determine whether or not unburned fuel exists in the engine 10. It is determined whether or not (step S510).

  On the other hand, if it is determined in step S509 that F2 = 1 (that is, NO), then the starter 20 is driven, and the rotation direction of the crankshaft is forward rotation from the signal from the crank angle sensor 1, and the crank angle sensor 1 8 is terminated while the energization of the ignition device 12 is maintained, assuming that the crank angle by reaches the energization cutoff crank angle.

  If it is determined in step S510 that F6 = 0 (that is, NO), it is assumed that combustion does not occur even when ignited, and the process proceeds to step S507 for cutting off (igniting) the energization to the ignition device 12.

  On the other hand, if it is determined in step S510 that F6 = 1 (that is, YES), it is determined whether or not energy necessary for igniting the fuel is accumulated when the ignition device 12 is de-energized. Therefore, the ignition control means 105 determines whether or not the ignition energy accumulation flag F7 (described later with reference to FIG. 9) from the ignition energy accumulation determination means 106 is “1” (step S511).

  If it is determined in step S511 that F7 = 0 (that is, NO), it is considered that the fuel in the engine 10 will not be ignited even if the energization to the ignition device 12 is interrupted (ignition), and the process proceeds to the ignition device 12. The process proceeds to step S507 for cutting off the energization.

  On the other hand, if it is determined in step S511 that F7 = 1 (that is, YES), if energization to the ignition device 12 is interrupted, it is assumed that the fuel in the engine 10 is ignited and combustion occurs, and the ignition device 12 is returned to. The processing routine of FIG. 8 is terminated while maintaining the energization.

Next, the ignition energy accumulation determination process by the ignition energy accumulation determination unit 106 in the engine automatic stop unit 101 will be described in detail.
In FIG. 9, the ignition energy accumulation determination means 106 first determines whether or not the ignition device 12 is energized (step S601), and determines that the ignition device 12 is not energized (ie, NO). If so, the process proceeds to step S604 described below.

  On the other hand, if it is determined in step S601 that the ignition device 12 is energized (that is, YES), then the energization time to the ignition device 12 is a predetermined time in order to determine the accumulation state of ignition energy. It is determined whether or not (corresponding to ignition energy capable of igniting the fuel) or more (step S602).

Note that the predetermined time, which is a criterion for determining that the ignition energy capable of igniting the fuel has been accumulated in the ignition device 12, is set by map calculation of the power supply voltage and the energization time. For example, the power supply voltage 14 [V] Is about 800 [microseconds].
Here, the energization time to the ignition device 12 can be measured by counting the duration of energization after setting the ignition device 12 from the non-energized state to the energized state in the engine control device 50.

  If it is determined in step S602 that the energization time for ignition ≧ predetermined time (that is, YES), ignition energy that can ignite the fuel is stored in the ignition device 12, and therefore the ignition energy storage flag F7 is set to “ 1 ”(step S603), and the processing routine of FIG. 9 ends.

  On the other hand, if it is determined in step S602 that the energization time for ignition <predetermined time (that is, NO), the ignition energy that can ignite the fuel is not accumulated in the ignition device 12, and therefore the ignition energy accumulation flag F7. Is reset to “0” (step S604), and the processing routine of FIG.

Next, the starting device control process by the starting device control means 107 in the engine automatic stop means 101 will be described in detail.
In FIG. 10, the starter control means 107 first determines whether or not the starter drive request flag F5 is “1” (step S701), and if it is determined that F5 = 0 (that is, NO), The process proceeds to a determination process (step S705) described later.

  On the other hand, if it is determined in step S701 that F5 = 1 (that is, YES), the combustion drive flag F8 is reset to “0” (step S702), and the engine speed Ne is set to the reverse rotation threshold value NeM (for example, It is determined whether it is greater than −40 [rpm]) and less than the normal rotation threshold NeP (for example, 50 [rpm]) (step S703).

  If it is determined in step S703 that NeM <Ne <NeP (that is, YES), energization of the starting device 20 is turned on (step S704), and the processing routine of FIG.

When energization of the starter 20 is started, energization of the solenoid 21 is performed and the pinion gear 24 is pressed against the ring gear 13. After that, since the meshing occurs after a certain period of time, energization to the starter motor 23 is started and the ring gear 13 is driven.
Here, the fixed time is a time (for example, 50 [msec]) required for the pinion gear 24 to contact the ring gear 13 after energization of the solenoid 21 is started.

  On the other hand, if it is determined in step S703 that Ne ≦ NeM or Ne ≧ NeP (that is, NO), step S704 is not executed, and the processing routine of FIG.

  In step S705, which is executed when the determination result in step S701 is “NO”, it is determined whether or not the combustion drive flag F8 is “1”, and F8 = 1 (that is, YES) is determined. Then, the process proceeds to a determination process (step S707) described later.

  On the other hand, if it is determined in step S705 that F8 = 0 (that is, NO), it is subsequently determined whether the rotation direction of the crankshaft is normal rotation (reverse rotation) based on the crank angle signal ( If it is determined in step S706 that the rotation is reverse (that is, NO), the process proceeds to step S707.

  On the other hand, if it is determined in step S706 that the rotation direction of the crankshaft is normal rotation (ie, YES), the combustion drive flag F8 is reset to “0” (step S711), and the starter 20 is energized. Is turned off (step S712), and the processing routine of FIG. 10 is terminated.

  In step S707 executed when the determination result of step S705 is “YES” or the determination result of step S706 is “NO”, it is determined whether or not the ignition device 12 is being energized. If not (NO), the process proceeds to step S711 in order to turn off the energization of the starting device 20.

  On the other hand, if it is determined in step S707 that the ignition device 12 is energized (that is, YES), then fuel injection has been completed to determine whether unburned fuel is present in the engine 10 or not. It is determined whether or not the flag F6 is “1” (step S708), and if it is determined that F6 = 0 (that is, NO), the process proceeds to step S711 in order to turn off the power supply to the starting device 20.

On the other hand, if it is determined in step S708 that F6 = 1 (that is, YES), the energization cutoff crank angle of the ignition device 12 is set to the retard side in order to turn on the energization to the starter 20 (step S709). ).
Here, the delay angle setting value of the crank angle is, for example, 105 [deg] after compression top dead center (ATDC).

  Further, following step S709, the combustion drive flag F8 is set to “1” (step S710), and it is clearly indicated that the starter 20 is driven until the fuel injected into the engine 10 is burned. The process proceeds to step S704 for turning on the apparatus 20.

Next, the operation according to the first embodiment of the present invention will be described with reference to FIG.
FIG. 11 is a timing chart showing the operation of the engine 10 at the time of restart according to Embodiment 1 of the present invention, and shows the operation when the engine automatic stop process is executed in the vehicle running state (Ne ≧ NeP). .

  In FIG. 11, when the restart condition is established based on the driver operation during inertial rotation of the engine 10, the fuel injection is resumed, and the engine rotation speed Ne is set to a predetermined rotation speed (for example, 600 [rpm]) during the engine rotation. When the engine 10 is below, the pinion gear 24 and the ring gear 13 are meshed by starting energization of the starter 20, and then, when the engine 10 starts restarting due to cranking of the starter motor 23, to the ignition device 12. The operation when the ignition switch 5 is turned off after the energizing time of the current time is continued for a predetermined time (for example, 800 [microseconds]) required for ignition is shown.

In FIG. 11, (a) is the engine rotational speed Ne [rpm], and (b) is the crank angle [deg] of the engine 10 measured by the crank angle sensor 1 with respect to the four-cylinder engine 10.
In the crank angle of (b), the temporal transition of the crank angle repeated every 180 [deg] is shown with top dead center = 0 [deg].

(C) shows the state of the ignition switch 5, and (d) shows the state of the automatic stop request flag F1.
The automatic stop request flag F1 in (d) is set to “1” when the automatic stop condition is satisfied, and is reset to “0” when the restart condition is satisfied or when the ignition switch 5 is OFF. Is done.

(E) shows the state of the restart request flag F2. The restart request flag F2 is set to “1” when the restart condition is satisfied, and when the engine 10 is completely started, or the ignition switch When 5 is OFF, it is reset to “0”.
(F) shows the state of the automatic stop flag F3. The automatic stop flag F3 is set to “1” when the engine 10 is automatically stopped, and when the engine 10 has been started, or When the ignition switch 5 is OFF, it is reset to “0”.

(G) shows the state of the fuel injection permission flag F4. The fuel injection permission flag F4 is set to “1” when the restart process is being executed, and the automatic stop process is being executed. Is reset to "0".
(H) shows the state of the starter drive request flag F5. The starter drive request flag F5 is set to “1” when the restart process is being executed, and the engine 10 has been started. Or, when the ignition switch 5 is OFF, it is reset to “0”.

(I) shows the state of the fuel injected flag F6. The fuel injected flag F6 is set to “1” when the fuel injector 11 injects fuel into the engine 10, and the ignition device 12 is When the fuel in the engine 10 is ignited, it is reset to “0”.
(J) shows the state of the ignition energy accumulation flag F7. The ignition energy accumulation flag F7 is determined when the ignition device 12 is energized and it is determined that the energy necessary for ignition is accumulated in the ignition device 12. Is set to “1”, and is reset to “0” when it is determined that the energy required for ignition is not accumulated in the ignition device 12.

  (K) shows the state of the combustion drive flag F8. The combustion drive flag F8 indicates that there is no drive request to the starter 20 and unburned fuel is supplied to the cylinder that is energized to the ignition device 12. If it exists, it is set to “1”, and when there is a drive request to the starter 20, or when the ignition device 12 is not energized, or when there is no unburned fuel in the engine 10 Is reset to "0".

(L) shows the temporal transition of the energized state of the starting device 20 and the energized state of the solenoid 21 (drive state of the pinion gear 24).
(M) shows the temporal transition of the energization state to the starter motor 23. In addition, the energization state to the starter motor 23 is experimentally obtained using a current sensor.

(N) indicates the drive state (injection state) of the fuel injection device 11, and “1” is set when the fuel injection device 11 is injecting fuel into the engine 10. When the fuel is not injected into the fuel tank 10, it is reset to “0”.
(O) indicates the energization state of the ignition device 12, “1” is set when the ignition device 12 is energized, and reset to “0” when the ignition device 12 is not energized. Is done.

  In FIG. 11, when the automatic stop condition is satisfied at time t11 while the vehicle is running, “1” is set to the automatic stop request flag F1 in (d) (step S205 in FIG. 4), and automatic stop is in (f). At the same time that “1” is set in the flag F3, the fuel injection permission flag F4 in (g) is reset to “0” (steps S103 to S104 in FIG. 3), and “F4 = 0” is received. (n) The injection driving of the fuel injection device 11 is stopped (step S401 in FIG. 6).

  Next, when the restart condition is satisfied at time t12 by a driver operation, the automatic stop request flag F1 in (d) is reset to “0” and at the same time, the restart request flag F2 in (e) is set to “1”. Is set (steps S208 to S209 in FIG. 4), and at the same time “1” is set to the fuel injection permission flag F4 in (g), “1” is set to the starter drive request flag F5 in (h). (Steps S301 to S303 in FIG. 5).

  The fuel injection permission flag F4 shown in (g) receives “1”, the injection of the fuel injection device 11 shown in (n) is restarted, and “1” is set in the fuel injected flag F6 shown in (i). . (S401 to 404 in FIG. 6)

Next, at time t13 when the engine rotation speed Ne in (a) decreases below the normal rotation threshold value NeP, “F5 = 1” in (h) is received, and “Ne <NeP (50 [rpm]) in (a). The power to the starting device (l) is turned on (steps S701 to S704 in FIG. 10).
Subsequently, at time t14, energization of the ignition device 12 of (o) is started in preparation for ignition of the cylinder into which the fuel injected at time t12 is sucked (step S504 in FIG. 8).

  Subsequently, when reverse rotation of the crankshaft is detected by the crank angle signal from the crank angle sensor 1 at time t15, “currently energizing the ignition device 12” in (o) and “F2 =” in (e). 1 ”, the energization of the ignition device 12 of (o) is continued (steps S508 to S509 in FIG. 8).

  Subsequently, at time t16, the ignition switch 5 in (c) is turned off, the restart request flag F2 in (e) is reset to “0”, and the automatic stop flag F3 in (f) is reset to “0”. Then, the starter drive request flag F5 of (h) is reset to “0” (steps S210 to S213 in FIG. 4).

  At this time, “reverse rotation” in (a), “while the ignition device 12 is energized” in (o), “F6 = 1” in (i), “F2 = 0” in (e), and (j When “F7 = 1” of () is cut off (ignited), the combustion that promotes reverse rotation is considered to occur, so that “energization of the ignition device 12” in (o) is continued. (Steps S508 to S511 in FIG. 8).

  In addition, from (a) “reverse rotation”, (o) “energization to ignition device 12”, and (i) “F6 = 1”, the energization cutoff crank angle is set to be retarded, “1” is set to the combustion drive flag F8 in (k), and “energization ON to the starter 20” in (l) is continued (steps S705 to S710 in FIG. 10).

  Next, at time t17, when the crank angle in (b) reaches the energization cutoff crank angle (ATDC-105 [deg] set to retard), the energization to the ignition device 12 in (o) is interrupted (ignition). Then, the fuel injection completed flag F6 of (i) is reset to “0” (S505 to S507 in FIG. 8).

  At this time, in the state of “F8 = 1” in (k), the power supply to the ignition device 12 is cut off, so that the combustion drive flag F8 in (k) is reset to “0”, and (l) The energization to the starting device 20 is turned off, and the energization to the starter motor 23 in (m) is turned off (steps S705, S707, S711 to S712 in FIG. 10).

FIG. 12 is a timing chart showing another operation of engine 10 during restart according to Embodiment 1 of the present invention.
In FIG. 12, the engine is automatically stopped from the vehicle running state, and when the restart condition is established based on the driver operation during the engine inertia rotation, the fuel injection is resumed, and the engine rotation speed Ne reaches the predetermined rotation speed during the engine rotation. If it falls below, the energization of the starter 20 is started to mesh the pinion gear 24 and the ring gear 13, and then when the engine 10 starts restarting due to cranking of the starter motor 23, The operation when the ignition switch 5 is turned off before the energization is continued for a predetermined time required for ignition is shown.

In FIG. 12, the operation from time t21 to t25 is the same as the operation from time t11 to time t15 in FIG.
At time t26 following time t25 (time t15), the ignition switch 5 in (c) is turned off, the restart request flag F2 in (e) is reset to “0”, and the automatic stop flag F3 in (f) is set. The starter drive request flag F5 in (h) is reset to “0” (steps S210 to S213 in FIG. 4).

  At this time, “reverse rotation” in (a), “while the ignition device 12 is energized” in (o), “F6 = 1” in (i), “F2 = 0” in (e), and (j ) Of “F7 = 0”, it is considered that the fuel in the engine 10 is not ignited even if the energization to the ignition device 12 is interrupted (ignition), and therefore the energization to the ignition device 12 is interrupted (ignited). (Steps S508 to S511, S507 in FIG. 8).

  Subsequently, the energization to the starting device 20 in (l) is turned off by “reverse rotation” in (a) and “energization OFF in the ignition device 12” in (o) (step S706 in FIG. 10). ~ S707, S712).

Next, in order to emphasize the effect of the first embodiment (FIG. 11) of the present invention, the operation of the conventional apparatus will be described.
FIG. 13 is a timing chart showing the operation of a conventional engine automatic stop / restart device (the above-mentioned Patent Document 1), and shows a case where the operation is compared with the operation of the first embodiment (FIG. 11) of the present invention.

In FIG. 13, the operation from time t31 to t35 is the same as the operation from time t11 to t15 described above (FIG. 11), and a description thereof will be omitted.
In the case of FIG. 13, when a reverse rotation of the engine is detected at time t35 by a crank angle sensor capable of detecting whether or not the crankshaft of the engine is reversely rotated, fuel injection and ignition are suppressed during reverse rotation, but the engine When the engine returns to normal rotation, the suppression of ignition is released.

  As a result, when the restart condition is not satisfied in the state where the engine rotates in reverse (time t36), the normal rotation is detected in the compression stroke at the time of transition from reverse rotation to normal rotation (time t37). When the ignition suppression is released and ignition is performed immediately, the reverse rotation is promoted as shown by the engine rotational speed Ne in FIG. 13A, and the burned gas remains in the engine. Becomes difficult.

  On the other hand, according to the first embodiment (FIG. 11) of the present invention, since ignition is not performed in the above case, reverse rotation is performed as indicated by the engine speed Ne in FIG. 11 (a). The above problem is solved without being promoted.

Similarly, in order to emphasize the effects of the first embodiment (FIG. 11) of the present invention, the operation of another conventional apparatus will be described.
FIG. 14 is a timing chart showing the operation of a conventional engine automatic stop / restart device (the above-mentioned Patent Document 2), and shows a case where the operation is compared with the operation of the first embodiment (FIG. 11) of the present invention.

In FIG. 14, the operation from time t41 to t45 is the same as the operation from time t11 to time t15 described above (FIG. 11), and thus the description thereof is omitted.
In the case of FIG. 14, when the drive request for the starter is lost after the first fuel injection is performed (time t46), the specific cylinder to which fuel is supplied while suppressing the ignition performs at least one exhaust stroke. Since the starter is continuously driven until it reaches the end, the injected fuel is exhausted without being burned, which causes a problem of damage to the three-way catalyst and environmental pollution.

  On the other hand, according to the first embodiment (FIG. 11) of the present invention, the starter 20 is energized until the ignition control is performed on the specific cylinder to which the fuel is supplied. Is not exhausted without being burned, and the above problem is solved.

  As described above, the engine automatic stop / restart apparatus according to Embodiment 1 (FIGS. 1 to 12) of the first invention automatically stops the engine 10 when the automatic stop condition is satisfied while the vehicle is running, An engine automatic stop / restart device that restarts the engine 10 when a restart condition is satisfied, and a fuel injection device 11 that injects fuel into the engine 10, energy is accumulated by being energized, and the engine 10 is shut off by energization. An ignition device 12 that performs ignition, a starter device 20 that rotates the engine 10 when energized, a crank angle sensor 1 that detects a crank angle and a rotation direction of the engine 10, and an operating state of the engine 10 Various sensors (vehicle speed sensor 2, accelerator opening sensor 3, brake pedal 4, ignition switch 5), and fuel injection device 1 A fuel injection control means 104 that controls the starter 20, a starter control means 107 that controls the starter 20, an ignition control means 105 that controls the ignition device 12, and an automatic stop condition of the engine 10 based on detection information from various sensors. The restart condition is determined, and the engine 10 is automatically stopped when the automatic stop condition is satisfied. When the restart condition is satisfied, the fuel injection control means 104, the starter control means 107, and the ignition control means 105 are operated to operate the engine 10. Engine stop / restart determination means 102 for restarting the engine.

The engine stop / restart determination means 102 is a restart condition in a state in which reverse rotation or stop of the crankshaft of the engine 10 is detected while the ignition device 12 is energized to a specific cylinder that has been injected by the fuel injection device 11. If is not established, the starter is energized until the specific cylinder is ignited.
Further, when the engine stop / restart determination unit 102 determines that the restart condition is not satisfied, the ignition control unit 105 delays the energization cutoff crank angle and delays the ignition timing of the ignition device 12.

  As described above, when the reverse rotation of the crankshaft of the engine 10 is detected, even if the restart is interrupted in the energized state in which the energization to the ignition device 12 is started with respect to the specific cylinder that has been injected with fuel, the compression is performed. In the stroke, the ignition device 12 is turned off without being ignited, or the engine 10 is rotated by the starter 20 (starter motor 23), and the drive of the starter 20 is continued until the combustion stroke. Ignition is performed.

As a result, even if the engine 10 is interrupted while the ignition device 12 is energized with respect to the specific fuel-injected cylinder, ignition that promotes reverse rotation of the crankshaft of the engine 10 is prevented, and at the same time, It is possible to prevent combustion fuel discharge and abnormal combustion in the exhaust pipe.
In addition, since the burned gas does not stay in the engine 10, it is possible to prevent the next start from becoming difficult.

  Furthermore, after determining that the restart condition is not satisfied, when the ignition is performed by the starter 20 until the combustion stroke is performed, the ignition timing is retarded, thereby suppressing unnecessary forward rotation of the crankshaft. The engine 10 can be stopped.

  Further, the engine automatic stop / restart apparatus according to Embodiment 1 of the present invention includes ignition energy accumulation determination means 106 for determining the amount of ignition energy accumulated in the ignition apparatus 12, and the ignition control means 105 is an engine When the reverse rotation of the crankshaft 10 is detected, it is determined that the restart condition is not satisfied by the engine stop / restart determination unit 102 and the ignition energy accumulation determination unit 106 determines that the ignition energy amount is small. If this is the case, power to the ignition device 12 is immediately shut off. Specifically, the ignition energy accumulation determination means 106 monitors the power supply voltage and the energization time to the ignition device 12, and sets the predetermined time of the determination reference by map calculation of the power supply voltage and the energization time, thereby igniting energy. Determine the amount.

  In this way, the ignition energy accumulation determination means 106 is provided, and the accumulated energy of the ignition device 12 can be stored even when restart is interrupted in a state where the ignition device 12 is energized with respect to the specific cylinder that has been injected with fuel when reverse rotation is detected. Is small, the engine 10 is stopped without igniting the injected fuel by immediately shutting off the ignition device 12, and ignition in the compression stroke that promotes reverse rotation of the crankshaft of the engine 10 is performed. Can be prevented.

  1 crank angle sensor, 2 vehicle speed sensor, 3 accelerator opening sensor, 4 brake pedal, 5 ignition switch, 10 engine, 11 fuel injection device, 12 ignition device, 13 ring gear, 20 start device, 21 solenoid, 22 plunger, 23 Starter motor, 24 pinion gear, 50 engine control device, 101 engine automatic stop means, 102 engine stop restart determination means, 103 engine restart control means, 104 fuel injection control means, 105 ignition control means, 106 ignition energy accumulation determination means 107 Starter control means, F1 automatic stop request flag, F2 restart request flag, F3 automatic stop flag, F4 fuel injection permission flag, F5 starter drive request flag, F6 fuel injection completed flag, F7 ignition energy storage Product flag, F8 combustion drive flag, Ne engine speed.

Claims (4)

An engine automatic stop / restart device that automatically stops the engine when an automatic stop condition is satisfied while the vehicle is running, and then restarts the engine when the restart condition is satisfied,
A fuel injection device for injecting fuel into the engine;
An ignition device that accumulates energy when energized and ignites the engine by energization interruption;
A starting device for rotating the engine by being energized;
A crank angle sensor for detecting a crank angle and a rotation direction of the engine;
Various sensors for detecting the operating state of the engine;
Fuel injection control means for controlling the fuel injection device;
Starter control means for controlling the starter;
Ignition control means for controlling the ignition device;
An automatic stop condition and a restart condition of the engine are determined based on detection information from the various sensors, the engine is automatically stopped when the automatic stop condition is satisfied, and the fuel injection control means is detected when the restart condition is satisfied. Engine stop / restart determination means for operating the starter control means and the ignition control means to restart the engine,
The engine stop / restart determination means includes
When the restart condition is not satisfied in a state in which reverse rotation or stop of the crankshaft of the engine is detected while the ignition device is energized with respect to the specific cylinder that has been injected with fuel by the fuel injection device, An engine automatic stop / restart device characterized by energizing the starter until ignition of a specific cylinder is performed.   The engine automatic stop reactivation according to claim 1, wherein the ignition control means delays the ignition timing of the ignition device when the engine stop / restart determination means determines that the restart condition is not satisfied. Starter. Ignition energy accumulation determination means for determining the amount of ignition energy accumulated in the ignition device,
The ignition control means is in a state in which it is determined that the restart condition is not satisfied by the engine stop / restart determination means when reverse rotation of the crankshaft of the engine is detected, and the ignition energy accumulation determination means The engine automatic stop / restart device according to claim 1 or 2, wherein when it is determined that the ignition energy amount is small, the energization to the ignition device is immediately interrupted.   4. The engine automatic stop / restart device according to claim 3, wherein the ignition energy accumulation determining means determines the amount of ignition energy by monitoring a power supply voltage and an energization time to the ignition device.

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