JP2008121587A - Engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent engine failure even in a manual operation type engine. <P>SOLUTION: The device comprises clutch state detection means SW1, SW2 and SW3 for detecting an operating state of a clutch pedal 40, and a control means 100 for determining establishment of a restart condition for the pushing of the clutch pedal 40 detected by the means SW1, SW2 and SW3, and restarting the engine. The control means 100 prohibits combustion restart when the clutch pedal 40 is pushed quickly such that a predetermined quick operation requirement is satisfied. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an engine control device, and more particularly to an engine control device that automatically stops an engine during idling and restarts the engine by combustion.

  As a device for automatically stopping and restarting the engine, for example, as in an engine control device disclosed in Patent Document 1, fuel is injected into a cylinder in an expansion stroke in a stopped state to burn the engine. The one that can be started immediately has been developed.

In addition, as in the engine control device disclosed in Patent Document 2, a so-called manual operation type vehicle in which the clutch is engaged or disengaged by manual operation has been developed that can automatically stop the engine. .
JP 2004-124753 A JP 2005-320978 A

  By the way, in the manual operation type engine, the clutch operation speed varies depending on the driver. For this reason, it has become clear that when the clutch operation is fast (for example, about 0.4 seconds), the combustion restart operation by the control device is not in time, causing engine stall.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide an engine control device that can reliably prevent engine stall even in a manually operated engine.

  In order to solve the above problem, the present invention executes automatic stop control for automatically stopping the engine when a predetermined engine stop condition is satisfied, and after the stop, when a predetermined restart condition is satisfied, An engine control device that automatically restarts the engine by injecting fuel into the engine and igniting the electric drive means, capable of starting the engine, and clutch state detecting means for detecting the operation state of the clutch pedal, And a control means for restarting the engine with at least the clutch pedal depression operation detected by the clutch state detection means as a requirement for satisfying the restart condition, wherein the control means has a predetermined quick operation requirement for the clutch pedal. When the engine is depressed so fast that it is satisfied, combustion restart is prohibited and the engine is driven by the electric drive means. A control device for an engine, characterized in that is to restart. In this aspect, when the engine is restarted, the depression operation of the clutch pedal is verified, and when the quick operation is performed, the combustion restart is prohibited. Even when it is performed, engine stall due to combustion restart can be reliably prevented, and restart by the electric drive means can be executed. In the present invention, “quick operation” means rapid clutch pedal operation. Specifically, based on the time when the clutch pedal is depressed from the free state to the maximum value of the clutch stroke, the depression speed, etc. It is identified by whether or not the level is faster than a set threshold value.

  In a preferred aspect, the control means performs engine restart by the electric drive means when the stop position of the piston at the time of automatic stop is out of a predetermined appropriate range, and the clutch pedal When the quick operation is performed, combustion restart is prohibited even when the piston at the time of automatic stop is stopped within the appropriate range, and the electric drive means is driven. In this aspect, when restarting the engine due to combustion, it is determined whether combustion restart is appropriate according to the stop position of the piston, and only when the engine is stopped at a stop position suitable for combustion restart. Since the combustion restart is executed, the success rate of the combustion restart can be maintained high, and even if the engine is stopped at a suitable stop position, the quick operation is being performed. Therefore, even if the clutch pedal is disengaged too quickly, engine stall can be reliably prevented and the engine can be restarted by electric drive means. It can be certain.

  In a preferred aspect, the control means executes stop control so that each piston is stopped within the appropriate range when the engine is automatically stopped. In this aspect, it is possible to increase the probability of stopping the engine in a state where the engine can be restarted by combustion, and accordingly, the restart operation by the combustion restart can be ensured at a higher frequency.

  In a preferred aspect, the control means has a function of counting the number of quick operations when the engine restart condition is satisfied, and prohibits automatic stop control when the number of quick operations exceeds a predetermined number of times. It is. In this aspect, it is possible to suppress unnecessary automatic stop control according to the driver and prevent a start delay at the time of restart. In other words, a driver with a large number of quick operations is considered to be less demanded to stop the engine automatically. Therefore, when the number of quick operations is large, the engine automatic stop control is prohibited to ensure the start delay at the time of restart. It can be suppressed.

  In a preferred aspect, when the restart condition is satisfied, the control means burns the air-fuel mixture in the cylinder in the compression stroke when the engine is stopped, reverses the engine, and then the air-fuel mixture in the cylinder in the expansion stroke when the engine is stopped. To restart the engine. In this aspect, even with an engine that requires time for restart by the amount of reverse rotation, engine stall due to restart delay can be reliably prevented.

  As described above, the present invention can reliably prevent engine restart due to combustion restart even when the clutch pedal is disengaged excessively rapidly. This has the remarkable effect that it can be surely prevented.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 show a schematic configuration of a four-cycle spark ignition engine having an engine control apparatus according to the present invention.

  Referring to the drawings, the engine includes an engine 1 having a cylinder head 10 and a cylinder block 11 and an engine control unit 100 that controls the engine.

  The engine 1 is provided with four cylinders 12A to 12D (see FIG. 2). Further, in each of the cylinders 12A to 12D, a piston 13 connected to the crankshaft 3 by a connecting rod (not shown) is fitted, so that a combustion chamber 14 is formed above the piston 13. The pistons 13 provided in the cylinders 12A to 12D are configured to move up and down as the crankshaft 3 rotates with a predetermined phase difference. Here, in the engine 1 that is a four-cylinder four-cycle engine, each of the cylinders 12A to 12D performs a cycle composed of intake, compression, expansion, and exhaust strokes with a predetermined phase difference. Crank angle in order of No. cylinder (cylinder 12A in the example shown), No. 3 cylinder (cylinder 12C in the example shown), No. 4 cylinder (cylinder 12D in the example shown), and No. 2 cylinder (cylinder 12B in the example shown) The phase difference is 180 ° (180 ° CA).

  A spark plug 15 is installed at the top of the combustion chamber 14 of each cylinder 12A to 12D so that the plug tip faces the combustion chamber 14. A fuel injection valve 16 that directly injects fuel into the combustion chamber 14 is provided on the side of the combustion chamber 14. This fuel injection valve 16 incorporates a needle valve and a solenoid (not shown), and is driven and opened for a time corresponding to the pulse width of the pulse signal input from the engine control unit 100, and according to the valve opening time. An amount of fuel is injected toward the vicinity of the electrode of the spark plug 15.

  In addition, an intake port 17 and an exhaust port 18 that open toward the combustion chamber 14 are provided in the upper portions of the cylinders 12A to 12D. In addition, an intake valve 19 and an exhaust valve 20 are respectively provided at a connection portion between the ports 17 and 18 and the combustion chamber 14. An intake passage 21 and an exhaust passage 22 are connected to the intake port 17 and the exhaust port 18. As shown in FIG. 2, the downstream side of the intake passage 21 close to the intake port 17 branches into an independent branch intake passage 21a corresponding to each cylinder 12A to 12D, and the upstream end of each branch intake passage 21a. Are respectively communicated with the surge tank 21b. A common intake passage 21c is provided upstream of the surge tank 21b. A throttle body 24 is provided in the common intake passage 21c. The throttle body 24 includes a throttle valve 24a capable of adjusting the amount of air flowing into each of the cylinders 12A to 12D, an actuator 24b that drives the throttle valve 24a, an idling speed control device (ISC) 24c, Is provided. In the illustrated embodiment, the ISC 24 c is of an electromagnetic drive type in which the valve opening amount can be changed by the engine control unit 100. An air flow sensor 25 for detecting the intake flow rate and an intake pressure sensor 26 for detecting the intake pressure are provided on the upstream side and the downstream side of the throttle valve 24a, respectively.

  Further, as shown in FIG. 1, the engine 1 is provided with an alternator 28 connected to the crankshaft 3 by a timing belt or the like. The alternator 28 includes a regulator circuit 28a that adjusts the amount of power generation by controlling the current of a field coil (not shown) and adjusting the output voltage, and is supplied from the engine control unit 100 that is input to the regulator circuit 28a. Based on the control signal, control of the power generation amount corresponding to the electric load of the vehicle, the voltage of the vehicle-mounted battery, and the like is executed.

  The engine 1 is provided with a starter motor (an example of electric drive means) 36 for starting the engine. The starter motor 36 has a motor 36a and a pinion gear 36d. The pinion gear 36d reciprocates on the output shaft of the motor 36a in a state where relative rotation is impossible. The crankshaft 3 is provided with a flywheel (not shown) and a ring gear 35 fixed to the flywheel concentrically with the center of rotation. When the starter motor 36 is used to restart the engine, the pinion gear 36d moves to a predetermined meshing position and meshes with the ring gear 35 fixed to the flywheel. 3 is driven to rotate.

  Further, the engine 1 is provided with two crank angle sensors 30 and 31 for detecting the rotation angle of the crankshaft 3, and the engine rotation based on a detection signal (pulse signal) output from one crank angle sensor 30. The speed Ne is detected, and the rotation angle of the crankshaft 3 is detected based on the detection signals out of phase output from the crank angle sensors 30 and 31. Further, the engine 1 includes a cam angle sensor 32 that detects the rotational position of the intake camshaft, a water temperature sensor 33 that detects the coolant temperature, and an accelerator that detects the accelerator opening corresponding to the accelerator operation amount of the driver. Sensors 34 are provided, and detection signals output from these sensors are input to the engine control unit 100.

  As shown in FIG. 1, the engine control unit 100 includes a CPU 101, a memory 102, a counter timer group 103, an interface 104, and a microprocessor having a bus 105 that connects these units 101 to 104. , 30, 31 and 34, based on detection signals from input elements, various calculations are performed, and control signals for each actuator such as the fuel injection valve 16, ignition device 27, or starter motor 36 are output. It is. For example, the fuel injection amount, injection timing, and ignition timing corresponding to the operating conditions are calculated, and a control signal is output to the fuel injection valve 16 and the ignition device 27. Further, the target opening of the throttle valve 24a is calculated according to the operating conditions, and a control signal is output to the actuator 24b so that the opening of the throttle valve 24a becomes the target opening.

  In the present embodiment, a clutch stroke sensor SW1, a clutch upper switch SW2, and a clutch lower switch SW3 that indicate the operation state of the clutch pedal 40 are connected to the engine control unit 100 as input elements.

  FIG. 3 is a schematic configuration diagram showing the configuration of the clutch pedal according to the present embodiment.

  Referring to FIG. 3, the clutch pedal 40 includes a pedal bracket 41 fixed to the dash lower panel 2, a lever 43 whose upper end is pivotally supported by the pedal bracket 41 via a support shaft 42, And a master cylinder 44 driven by a lever 43.

  A pedal pad 45 is integrally formed on the free end (lower end) of the lever 43. A spring mechanism 46 interposed between the lever 43 and the pedal bracket 41 is provided at the center of the lever 43, and the lever 43 is urged counterclockwise in the drawing by the spring mechanism 46. Further, the rod 43 of the master cylinder 44 is connected to the lever 43 via a pin 47. Thus, the rotation of the lever 43 input from the pedal pad 45 by the driver is converted into a reciprocating motion and transmitted to the master cylinder 44, and the clutch is connected / disconnected by the hydraulic pressure corresponding to the depression amount. ing.

  In order to detect the depression state of the lever 43, the master cylinder 44 is provided with a clutch stroke sensor SW1. In the illustrated example, the clutch stroke sensor SW <b> 1 is configured to detect the amount of depression of the lever 43 by detecting the amount of displacement of the rod 48 of the master cylinder 44 and output it to the engine control unit 100. The pedal bracket 41 is provided with stoppers 49 and 50 that restrict the clutch stroke CS of the lever 43. The stopper 49 is attached with a clutch upper switch SW2 constituted by a b contact, and the stopper 50 is fitted with a clutch lower switch SW3 constituted by an a contact. Each of the switches SW2 and SW3 is provided at a position corresponding to the start and end of the clutch stroke CS where the lever 43 rotates.

  The clutch upper switch SW2 is provided at a position corresponding to the start end of the clutch stroke CS. When the lever 43 is in a free state, that is, the lever 43 moves the rod 48 of the master cylinder 44 to the most When it is pulled to the side, it contacts the lever 43 to block the contact, and when the pedal pad 45 of the lever 43 is depressed, the contact is connected and the detection signal is output to the engine control unit 100. Has been.

  The clutch lower switch SW3 is provided at a position corresponding to the end of the clutch stroke CS. When the lever 43 is depressed most, the clutch lower switch SW3 contacts the lever 43, connects the contact, and sends a detection signal to the engine control unit 100. It is configured to output.

  Referring to FIG. 1, the memory 102 of the engine control unit 100 stores a basic program, various programs including an engine automatic stop process and a restart process, and processing conditions thereof.

  The program stored in the memory 102 includes an engine stop control module. The engine stop control module automatically stops fuel injection by stopping fuel injection into each cylinder 12A to 12D at a predetermined timing when a preset automatic engine stop condition is satisfied (fuel cut). This is a program for executing various controls so that the stop position of the piston 13 at the time of automatic stop is stopped within an appropriate range A described later. The engine automatic stop condition in this embodiment is set when the clutch pedal 40 is released, the transmission is shifted to neutral, the vehicle speed is equal to or lower than a predetermined value, and the water temperature is equal to or higher than a predetermined temperature (for example, 80 ° C.).

  Next, the program stored in the memory 102 includes a restart control module. The restart control module is a program for restarting the engine when a restart condition is established based on a clutch pedal operation or the like by the driver after the engine is automatically stopped by the engine stop control module. The restart control module includes a combustion restart control module that automatically restarts the engine by combustion in a stop expansion stroke cylinder that was in an expansion stroke when the engine was automatically stopped when a restart condition was satisfied. A starter start control module that forcibly restarts the engine by the starter motor 36 is logically included, and these are alternatively selected.

  The starter start control module meshes the pinion gear 36d of the starter motor 36 with the ring gear 35 fixed to the flywheel, and transmits the rotation of the motor 35a to the flywheel via the pinion gear 36d and the ring gear 35. This is a program for forcibly starting the engine.

  The combustion restart control module firstly injects and ignites fuel in the compression stroke cylinder at the time of stoppage that was in the compression stroke at the time of automatic engine stop, and then performs the first combustion, and then in the expansion stroke at the time of automatic engine stop. This is a program for restarting the engine by injecting and igniting fuel into the stop-time expansion stroke cylinder to cause the second combustion. In this combustion restart, the engine is slightly rotated reversely by the first combustion, the piston 13 of the stop-time compression stroke cylinder is pushed down, and the piston 13 of the stop-time expansion stroke cylinder is raised. As a result, the air in the stop expansion cylinder is compressed. Therefore, by injecting fuel into the compressed air and igniting it, the second combustion is realized, and the engine is automatically restarted as a result of applying a positive rotation driving torque to the crankshaft 3. Thus, if the engine is automatically restarted by combustion, it is not necessary to use the starter motor 36, and the use frequency of the starter motor 36 can be reduced.

  In order to properly restart the engine by simply igniting the fuel injected into the stop expansion stroke cylinder without using the starter motor 36 or the like by the combustion restart control module, By sufficiently securing the obtained combustion energy, the cylinder that reaches the compression top dead center must overcome the compression reaction force and exceed the compression top dead center. Therefore, it is necessary to secure a predetermined amount of air in the stop-time compression stroke cylinder and to secure a sufficient amount of air in the stop-time expansion stroke cylinder. Further, the distance between the stop position of the piston in the expansion stroke cylinder and the bottom dead center must not be too long so that the piston of this cylinder can rotate beyond the bottom dead center by the combustion energy. Therefore, in the present embodiment, the automatic stop range shown in FIG. 4 is stored in the memory 102 of the engine control unit 100 in order to satisfy the above-described conditions.

  FIG. 4 is an explanatory diagram showing the relationship between the amount of air in the cylinder that becomes the compression stroke and the expansion stroke when the engine shown in FIG. 1 is stopped, and the crank angle.

  Referring to FIG. 4, the appropriate range A is a predetermined range slightly lower than the position at which the piston 13 of the expansion stroke cylinder at the time of stop has a crank angle of 90 ° CA after compression top dead center, for example, The crank angle after compression top dead center is stored in the memory 102 as a range in which the crank angle is 100 ° to 120 ° CA.

  The program stored in the engine control unit 100 includes an engine stop control module that stops the piston 13 in the appropriate range A during automatic stop. The engine stop control module logically includes a throttle valve control module, an alternator control module, a piston stop position identification module, and a piston stop position determination module.

  The throttle valve control module is a program that controls the throttle valve 24a to adjust the amount of intake air flowing into each of the cylinders 12A to 12D. Specifically, first, the opening degree of the throttle valve 24a is set to a large value when fuel injection is stopped, and a predetermined amount of air is sucked into the stop expansion stroke cylinder and the stop compression stroke cylinder. When the time has elapsed, the opening of the throttle valve 24a is reduced.

  The alternator control module is a program for adjusting the stop position of the piston 13 by controlling the power generation amount of the alternator 28 to adjust the degree of decrease in the engine rotational speed Ne after the stop of fuel injection. The alternator control module first controls the engine rotational speed Ne to a predetermined pre-stop rotational speed N1 before stopping fuel injection. Then, the fuel injection is stopped in a state where the engine rotation speed Ne becomes the rotation speed N1 before the stop. Thereafter, in the process of decreasing the engine rotation speed Ne, the engine rotation speed Ne for each 180 ° CA (when each cylinder 12A to 12D passes through the compression top dead center) is detected, and the detection result and a predetermined predetermined value are detected. The power generation amount of the alternator 28 is controlled so that the degree of depression of the engine rotational speed Ne becomes the predetermined degree of depression by comparing with the degree of depression. The pre-stop rotational speed N1 is a value set in advance so that the degree of depression of the engine rotational speed Ne becomes the predetermined degree of depression more.

  If the throttle valve control module and the alternator control module are used, the stop position of the piston 13 can be kept close to the appropriate range A to some extent. However, there are many cases where it is difficult to keep the stop position of the piston 13 within the appropriate range A depending on individual differences of engines and atmospheric conditions. Therefore, in the present embodiment, the piston stop position identification module and the piston stop position determination module are executed, so that the stop position of the piston 13 is more reliably set within the appropriate range A. If the vehicle stops at a position outside the proper range A, the starter start control module is switched.

  The piston stop position identification module is a program for identifying the stop position of the piston 13 when the engine is automatically stopped, and calculates the stop position of the piston 13 based on the signals of the crank angle sensors 30 and 31. Specifically, based on the phase difference between the detection signals output from the crank angle sensors 30 and 31 that output a pulse signal as a detection signal, whether forward rotation or reverse rotation is determined, The position of the piston 13 in each of the cylinders 12A to 12D is identified by counting the rise of the pulse related to the detection signal as a CA counter value.

  The piston stop position determination module is a program for determining whether or not the calculated stop position of the piston 13 is within the preset appropriate range A. Based on the calculation result of this process, the engine control unit 100 executes the combustion restart control module as long as it is within the proper range A and the starter start control module as long as it is outside the proper range A. It is configured as follows.

  Next, even if the piston 13 is stopped in the appropriate range A, if the driver's clutch pedal operation is too fast (for example, 0.3 seconds / clutch stroke CS), The accelerator may be depressed before the torque desired by the driver is sufficiently output, which may cause engine stall. Therefore, in the present embodiment, a module that executes clutch operation state detection control is provided in the memory 102, and the combustion restart is prohibited under a predetermined condition. In addition, a module that performs quick operation count control because it is considered that the engine automatic stop itself is unnecessary in a driving situation in which a rapid clutch pedal operation (hereinafter referred to as “quick operation”) is frequently performed by the driver. The automatic engine stop is prohibited under a predetermined condition.

  Based on the outputs of the clutch stroke sensor SW1, the clutch upper switch SW2, and the clutch lower switch SW3, the clutch operation state detection control module detects the operation speed of the clutch pedal 40 (that is, the driver moves the pedal pad from the position of the solid line to the virtual line). This is a program for calculating the speed of depressing to the position indicated by. Various methods are possible to embody such an operation.

  FIG. 5 is a timing chart for explaining a method of calculating the clutch operation speed, in which (A) is during normal operation and (B) is during quick operation.

  Referring to FIGS. 5A and 5B, as a method of determining the clutch operating speed, the clutch stroke sensor SW1 detects the maximum value after the clutch upper switch SW2 is turned on (in FIG. 3, the clutch pedal). The value is determined based on the time M1 until the 40 lever 43 is moved to the position of the imaginary line). After the clutch upper switch SW2 is turned on, the clutch lower switch SW3 is once turned on. Thereafter, a method of determining based on the time M2 until turning OFF, and a method of selecting the gradient M3 when the clutch stroke sensor SW1 is displaced from 0 to the maximum value are exemplified. As is clear from FIGS. 5A and 5B, regarding the times M1 and M2, the quick operation time is shorter than the normal operation time. Therefore, an appropriate determination value is set by an experiment or the like. It is possible to determine whether or not a quick operation has been performed depending on whether or not. In addition, when the gradient M3 is selected, the gradient (absolute value thereof) is larger during the quick operation than during normal operation. It is possible to determine whether or not a quick operation has been performed depending on whether or not.

  The modules described above are coupled to each other with various strengths, and are configured so as to realize the following control procedure as a whole.

  Next, an example of engine control according to the present embodiment will be described.

  6 and 7 are flowcharts showing an example of engine control according to the embodiment of FIG.

  First, referring to FIG. 6, in the same flow, engine control unit 100 waits for an engine stop condition to be satisfied (step S10). In this stop condition, at least the clutch pedal depression operation detected by the clutch stroke sensor SW1, the clutch upper switch SW2, and the clutch lower switch SW3 as the clutch state detecting means is a determination requirement.

  If YES in step S10, the engine control unit 100 further determines whether or not the quick operation count Cn is less than the preset count Cst set in the memory 102 (step S11). By this determination, the engine automatic stop is stopped in the driving situation where the quick operation of the clutch pedal 40 is frequently performed.

  If the determination in step S11 is YES, the engine control unit 100 performs a series of controls for automatic engine stop.

  First, the engine control unit 100 controls the engine rotation speed Ne to the rotation speed N1 before stop while reading the CA counter value that is being counted by the alternator control module (steps S12 and S13). Then, after the engine speed Ne reaches N1, the fuel supply from the fuel injection valve 16 is stopped (step S14). Subsequently, the engine control unit 100 opens the throttle valve 24a to reduce the intake negative pressure (step S15). Next, the engine control unit 100 determines whether or not the engine rotational speed Ne is lower than a predetermined rotational speed N2 (for example, about 500 rpm) (step S16). If the condition is not satisfied, the process returns to step S15 to return to the piston. The control of the stop position adjustment of 13 is continued, and when the condition is satisfied, the throttle valve 24a is closed (step S17). After that, the engine control unit 100 continues to execute the stop position adjustment of the piston 13 by controlling the power generation amount of the alternator 28 even after the throttle valve 24a is stopped, and the engine 1 is completely stopped from the degree of change of the CA counter value. It waits to do (step S18). Until the engine 1 is completed, the engine control unit 100 continues to control the adjustment of the stop position of the piston 13, and when the engine 1 is completed, the control of the alternator 28 is terminated (step S19). The determined stop position of the piston 13 is stored in the storage area of the memory 102 (step S20).

  Next, engine restart will be described.

  Referring to FIG. 7, engine control unit 100 waits for a restart condition to be established after automatic stop of engine 1 (step S30). In this determination, as the restart condition, it is determined whether or not the clutch pedal 40 is depressed, that is, whether or not the time M1 has elapsed in FIG. If the determination is YES, a quick operation determination is further executed (step S31). This quick operation determination is performed based on at least one of the times M1, M2 and the gradient M3 described in FIG. If YES in step S31, that is, if a quick operation is performed by the driver, the engine control unit 100 increments the number of quick operations Cn (step S32) and indicates that the quick operation has been executed. The flag F is updated to (1 in this embodiment) (step S33). On the other hand, if NO in step S31, that is, if it is determined that the operation speed of the clutch pedal is within the range of the normal operation, the value indicates that the quick operation has not been executed (0 in the present embodiment). The flag F is updated (step S34). Note that the values of the flags F and the number of quick operations Cn are retained from when the ignition switch is turned on until it is turned off, and are initialized to a null value when the ignition switch is turned off.

  After updating the value of the flag F, the engine control unit 100 executes control for automatically restarting the engine 1.

  First, the engine control unit 100 determines whether or not the piston stop position stored in step S29 in FIG. 6 is within the appropriate range A shown in FIG. 4 (step S35). If YES in step S35, the engine control unit 100 further refers to the value of the flag F and determines whether or not a quick operation has been performed (step S36). When the flag F is 0 in this determination, that is, only when the quick operation is not performed, the engine control unit 100 performs the combustion restart (step S37) while the flag F is 1. In this case, that is, when the quick operation is performed, the starter restart is executed regardless of whether or not the piston stop position is within the appropriate range A (step S38). By executing this control, even when the driver requests an extremely quick restart, there is no risk of engine stall due to insufficient output. Further, if NO in step S36, that is, if the piston stop position is outside the appropriate range A, the starter restart in step S38 is also executed. In the present embodiment, any known technique can be used as it is for the combustion restart and the starter restart, and therefore, detailed description thereof is omitted.

  After executing the restart control, the engine control unit 100 shifts to normal operation (step S39), and then shifts to step S10.

  As described above, in the present embodiment, when the engine 1 is restarted, the depression operation of the clutch pedal 40 is verified, and the combustion restart is prohibited when the quick operation is performed. Even when the shut-off operation 40 is performed too rapidly, it is possible to realize reliable restart by the starter motor 36 as the electric drive means while reliably preventing the engine stall due to combustion restart.

  Further, in the present embodiment, when the stop position of the piston 13 at the time of automatic stop is out of the predetermined appropriate range A, the starter motor 36 restarts the engine 1 and the clutch pedal is When the quick operation is performed, the restart of combustion is prohibited and the starter motor 36 is driven even when the piston 13 at the time of automatic stop is stopped within the appropriate range A. For this reason, in this embodiment, when restarting the engine 1 by combustion, the suitability is determined according to the stop position of the piston 13, and the engine 1 is stopped at a stop position suitable for combustion restart. Only when the combustion restart is executed, the success rate of the combustion restart can be maintained high, and the quick operation is performed even if the engine 1 is stopped at a suitable stop position. In this case, the combustion restart is prohibited. Therefore, even when the clutch pedal 40 is cut off excessively rapidly, the engine stall due to the combustion restart can be reliably prevented. The restart of the engine 1 can be ensured.

  In the present embodiment, stop control is performed so that each piston 13 is stopped within a predetermined appropriate range A when the engine is automatically stopped by a method such as controlling the power generation amount of the alternator 28. For this reason, in this embodiment, the probability of stopping the engine 1 in a state where it can be restarted by combustion can be increased, and the restarting operation by the combustion restart can be ensured more frequently. .

  In addition, the present embodiment has a function of counting the number of quick operations Cn when the restart condition of the engine 1 is satisfied. When the number of quick operations Cn exceeds a predetermined set number Cst, automatic stop control is prohibited. To do. For this reason, in this embodiment, it becomes possible to suppress unnecessary automatic stop control according to the driver, and to prevent a start delay at the time of restart. That is, a driver with a large number of quick operations is considered to be less demanded to automatically stop the engine 1. Therefore, when the number of quick operations Cn is large, by prohibiting the engine automatic stop control, the start delay at the time of restart is reduced. It can be reliably suppressed.

  Further, according to the present embodiment, when the restart condition is satisfied, the air-fuel mixture in the cylinder in the compression stroke is combusted when the engine is stopped to reverse the engine 1, and then the air-fuel mixture in the cylinder in the expansion stroke is stopped when the engine is stopped. The engine 1 is restarted by burning. For this reason, in this embodiment, even in the engine 1 that requires time for restart by the amount corresponding to the reverse rotation operation, engine stall due to restart delay can be reliably prevented.

  As described above, in the present embodiment, even when the shut-off operation of the clutch pedal 40 is performed excessively rapidly, engine stall due to combustion restart can be reliably prevented. Therefore, even in the manually operated engine 1, There is a remarkable effect that the engine stall can be surely prevented.

1 shows a schematic configuration of a four-cycle spark ignition engine having an engine control device according to the present invention. 1 shows a schematic configuration of a four-cycle spark ignition engine having an engine control device according to the present invention. It is a schematic block diagram which shows the structure of the clutch pedal which concerns on this embodiment. FIG. 2 is an explanatory diagram showing a relationship between an air amount of a cylinder that becomes a compression stroke and an expansion stroke and a crank angle when the engine shown in FIG. 1 is stopped. It is a timing chart for demonstrating the calculation method of a clutch operation speed, (A) is at the time of normal driving | operation, (B) is at the time of quick operation. It is a flowchart which shows the example of control of the engine which concerns on embodiment of FIG. It is a flowchart which shows the example of control of the engine which concerns on embodiment of FIG.

Explanation of symbols

1 Engine 12A-12D Cylinder 13 Piston 15 Spark Plug 16 Fuel Injection Valve 36 Starter Motor 40 Clutch Pedal 100 Engine Control Unit A Appropriate Range Cn Quick Operation Count Cst Set Count SW1 Clutch Stroke Sensor SW2 Clutch Upper Switch SW3 Clutch Lower Switch

Claims (5)

Automatic stop control is performed to automatically stop the engine when a predetermined engine stop condition is satisfied. After the stop, when a predetermined restart condition is satisfied, fuel is injected into a predetermined cylinder and automatically ignited. An engine control device for restarting the engine automatically,
Electric drive means capable of starting the engine;
Clutch state detecting means for detecting the operation state of the clutch pedal;
Control means for restarting the engine with at least the clutch pedal depression operation detected by the clutch state detection means as a requirement for satisfying the restart condition;
The control means prohibits combustion restart when the clutch pedal is depressed quickly enough to satisfy a predetermined quick operation requirement, and restarts the engine by the electric drive means. Engine control device. The engine control device according to claim 1,
The control means performs engine restart by the electric drive means when the piston stop position at the time of automatic stop is out of a predetermined appropriate range, and the clutch pedal is quickly operated. In this case, even if the piston at the time of automatic stop is stopped within the appropriate range, combustion restart is prohibited and the electric drive means is driven. apparatus. The engine control device according to claim 2,
The control unit is configured to execute stop control so as to stop each piston within the appropriate range when the engine is automatically stopped. In the engine control device according to any one of claims 1 to 3,
The control means has a function of counting the number of quick operations when the engine restart condition is satisfied, and prohibits automatic stop control when the number of quick operations exceeds a predetermined number of times. An engine control device. The engine control device according to any one of claims 1 to 4,
When the restart condition is satisfied, the control means burns the air-fuel mixture in the cylinder in the compression stroke when the engine is stopped, reverses the engine, and then burns the air-fuel mixture in the cylinder in the expansion stroke when the engine is stopped. An engine control device for restarting the engine.

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