JP2016035257A - Internal combustion engine automatic stop/restart control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine automatic stop/restart control system capable of starter-less starting of an internal combustion engine while preventing the reverse rotation of the internal combustion engine.SOLUTION: It is detected whether a rotation direction of an internal combustion engine is a direction of normal rotation or reverse rotation on the basis of a signal from a crank angle sensor, and fuel injection and spark ignition are implemented if the rotation is determined to be the normal rotation. With the configuration, the fuel injection and the spark ignition are implemented after it is determined that the rotation of the internal combustion engine is the normal rotation, so that the starter-less starting of the internal combustion engine can be realized while preventing the reverse rotation of the internal combustion engine.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an automatic stop / restart control system for an internal combustion engine having a function of restarting the internal combustion engine in a process in which the rotation speed of the internal combustion engine is decreased by automatic stop control.

  In recent years, vehicles equipped with an automatic stop / restart control system for an internal combustion engine (so-called idle stop control system) are increasing for the purpose of improving fuel consumption and reducing exhaust emissions. Conventional general idle stop control systems stop fuel injection and spark ignition when the driver stops the vehicle to automatically stop the internal combustion engine, and then the driver tries to start the vehicle. When an operation is performed (brake release operation, accelerator depression operation, etc.), the starter or the starter motor is automatically energized to crank the internal combustion engine and restart it.

  In such an idle stop control system, a restart request may occur while the rotational speed of the internal combustion engine decreases due to the stop of fuel injection and spark ignition. For example, if the brake pedal is depressed while the intersection signal is “red”, the automatic stop control is executed and the rotational speed of the internal combustion engine decreases, but the intersection signal changes from “red” to “blue” along the way. This is a case where the brake pedal is switched to the accelerator pedal when the state is shifted to the state.

  The occurrence of a restart request while the rotational speed is decreasing is generally referred to as “Change of Mind”. When this “change of mind” occurs, if the starter is energized and the internal combustion engine is cranked and restarted after the rotation of the internal combustion engine is completely stopped, it takes time from the occurrence of the automatic stop request to the completion of the restart. Will cause the driver to feel a delay in restarting.

  Therefore, when a restart request is generated in the middle of a decrease in the rotational speed of the internal combustion engine due to idle stop control, the rotational speed of the internal combustion engine can be started without using a starter (restartable only by fuel injection). In the speed range, there has been proposed a so-called starterless start in which the internal combustion engine is restarted only by fuel injection without using a starter.

  This starterless start is also referred to as a combustion start. For example, in Japanese Patent Application Laid-Open No. 2010-242621 (Patent Document 1), when a restart request is generated during rotation descent after stopping fuel injection in idle stop control. An automatic stop / restart system has been proposed that can increase the starter-less start-up time and reduce the starter-use frequency to improve the starter durability.

JP 2010-242621 A

  By the way, in such idle stop control, when the fuel injection is stopped to stop the internal combustion engine, the rotation speed of the crankshaft gradually decreases. In this state, the cylinder in the compression stroke The resistance when the volume of the sealed combustion chamber is reduced and the resistance when the volume of the combustion chamber sealed by the cylinder in the expansion stroke is expanded are resistance components of the rotation of the crankshaft. In the cylinder during the compression stroke, the air in the combustion chamber acts as a compression spring, and in the cylinder during the expansion stroke, the air in the combustion chamber acts as a tension spring.

  Therefore, in an internal combustion engine that is in a stopping process, after the rotational speed of the crankshaft reaches an extremely low speed, the crankshaft starts to rotate in the reverse direction by the action of air in the combustion chamber. Furthermore, after the crankshaft rotates in the reverse direction, the crankshaft again rotates forward due to the action of air in the combustion chamber. Such a state is generally called a swing back state. It is known that the rotation direction of the crankshaft is normally reversed once or a plurality of times in the swing-back state.

  Therefore, if a “change of mind” occurs during the reverse rotation of the crankshaft and fuel injection and spark ignition occur, fuel combustion occurs, resulting in combustion torque and reverse rotation of the internal combustion engine. Will continue to promote. It is well known that when the internal combustion engine rotates in reverse, the normal engine operating state cannot be maintained, causing various problems.

  A first object of the present invention is to provide an automatic stop / restart control system for an internal combustion engine that can perform a starterless start without causing the internal combustion engine to reversely rotate.

  A second object of the present invention is to provide an automatic stop / restart control system for an internal combustion engine that can start a starter without causing the internal combustion engine to reversely rotate.

  The first feature of the present invention is to detect whether the rotation direction of the internal combustion engine is the normal rotation direction or the reverse rotation direction based on the signal from the crank angle sensor, and only when the fuel rotation direction is determined to be the normal rotation direction. There is a place where combustion is done.

  The second feature of the present invention is that fuel injection and spark ignition are performed after a predetermined time has elapsed from the starter on signal.

  According to the present invention, when the internal combustion engine is determined to be in the normal rotation direction, combustion is performed by spark ignition, so that it is possible to perform starterless start without reverse rotation of the internal combustion engine. .

  Further, since it is assumed that the fuel injection and the spark ignition are performed after the internal combustion engine is considered to have been rotated forward by the rotation of the starter, the starter can be started without reversely rotating the internal combustion engine. .

It is a block diagram which shows the structure of the automatic stop / restart control system of the internal combustion engine to which this invention is applied. It is a control flowchart figure of the automatic stop / restart control system of the internal combustion engine which becomes the 1st Embodiment of this invention. It is a time chart figure explaining the control result by the control flowchart shown in FIG. It is a control flowchart figure of the automatic stop / restart control system of the internal combustion engine which becomes the 2nd Embodiment of this invention. It is a time chart explaining the control result by the control flowchart shown in FIG. It is a control flowchart figure of the automatic stop / restart control system of the internal combustion engine which becomes the 1st Embodiment of this invention. It is a time chart figure explaining the control result by the control flowchart shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention. Is also included in the range.

  As can be seen from FIG. 1, an automatic stop / restart control system for an internal combustion engine according to an embodiment of the present invention includes an input system, an output system, and a control device that calculates an output of an output system from an input signal from the input system; It is composed of

  As specific input examples of the input system, a starter signal 10 for cranking the internal combustion engine, a crank angle sensor signal 11 for outputting a reverse rotation detection signal for detecting reverse rotation of the internal combustion engine, and an accelerator pedal operation amount are detected. An accelerator sensor signal 12 to be detected, a brake sensor signal 13 to detect the operation amount of the brake pedal, a vehicle speed sensor signal 14 to detect the vehicle speed of the vehicle, and the like are input.

  The starter signal 10 is a signal obtained by detecting that the starter motor is energized. The crank angle sensor signal 11 is a signal obtained by detecting the rotation of the gear teeth formed on the crankshaft, and outputs a forward / reverse rotation detection pulse signal and a normal angle pulse signal. The accelerator sensor signal 12 is an analog signal obtained by detecting the operation state of the accelerator pedal, and is used after being A / D converted. The brake sensor signal 13 is an analog signal obtained by detecting the operation state of the brake pedal, and is also used after being A / D converted. The vehicle speed sensor signal 14 is a signal obtained by detecting the current traveling vehicle speed by detecting the rotational speed of the output driven gear of the transmission.

  The control device 15 is composed of a computer system mainly including a microcomputer, and performs a predetermined calculation based on the input signal from the input system described above and sends a drive control signal to the output system. The control unit 15 can be realized by one or more microcomputers that operate according to a set program, and the set program is a starterless of an automatic stop / restart control system according to an embodiment of the present invention to be described later. A series of instructions for performing a start or starter start can be included.

  Functions related to the present embodiment executed by the control device 15 include a starter ON continuation detection unit 15A, an internal combustion engine rotation direction detection unit 15B, an ignition control unit 15C, and a fuel injection control unit 15D. These functional units can be realized by a software program set in the microcomputer.

  Further, the control device 15 is provided with an input / output circuit, an input system is connected to the input circuit, and an A / D converter or the like for converting an analog signal into a digital signal is provided. In addition, the output circuit uses a start timing used for spark ignition, a register that sets the energization angle, the ignition timing, a comparator that compares the register value and the angle elapsed signal value, and outputs a comparison result, and is used for fuel injection. A fuel injection timing, a register for setting the fuel injection amount, a comparator for comparing the value of the register with the value of the angle elapsed signal and the value of the time elapsed signal, and outputting a comparison result. The output of the comparator is used for driving control of an igniter 16 and an injector 17 which will be described later.

  The output system includes an igniter 16 that controls a primary current that flows through a primary coil of an ignition coil that applies a high voltage to an ignition plug in the combustion chamber, an injector that is attached to each combustion chamber or intake port of an internal combustion engine and injects fuel There are seventeen. The control device 15 calculates the cylinder to be ignited, the energization start timing at which the primary current starts to flow through the ignition coil, the energization angle, the spark ignition timing (ignition timing) at which the primary current is stopped, and the like, and supplies a signal to the igniter 16 To do. The control device 15 calculates a cylinder for injecting fuel, a fuel injection amount, a fuel injection timing, and the like, and supplies a signal to the injector 17.

  In the automatic stop / restart control system for an internal combustion engine as described above, several embodiments of the present invention will be described in detail below.

  In the automatic stop / restart control system for an internal combustion engine as described above, when the vehicle is in a running state and an engine stop request (execution of idle stop control) is generated, fuel injection and spark ignition are almost synchronized with this. Is stopped and the rotational speed decreases. This engine stop request is mainly in response to the driver's request (driving operation). When the driver depresses the accelerator, the engine speed decreases with a relatively slow engine speed when the fuel injection stops. When stepped to -key, it shows a deceleration characteristic of a relatively steep rotational speed.

  Next, in the process in which the rotational speed decreases due to the stop of fuel injection, a situation occurs in which “change of mind”, which is a request for restarting the internal combustion engine, is output. For example, if the brake pedal is depressed while the intersection signal is “red”, the fuel injection is stopped and the rotational speed of the internal combustion engine decreases, but the intersection signal changes from “red” to “ This corresponds to the case where the brake pedal is switched to the accelerator pedal when shifting to the “blue” state. As described above, when the “change of mind” is output in the process of reducing the engine speed, the starterless start sequence is started. If it is determined that the restart cannot be performed unless the starter is used, a restart sequence by the starter is executed. In this case, the rotation speed of the crankshaft of the internal combustion engine is almost stopped or completely stopped.

  In such an automatic stop / restart control system for an internal combustion engine, when the rotation speed of the crankshaft reaches an extremely low speed, a swing-back state may occur. Therefore, when a "change of mind" occurs in the swing-back state in which the crankshaft is rotating in reverse, fuel injection occurs and fuel ignition occurs, resulting in combustion torque that is generated by the internal combustion engine. The reverse rotation is encouraged to continue. Therefore, the present embodiment is characterized in that starterless start is started in a state where the crankshaft is rotating forward in a region where the swingback state occurs.

  There are various methods for detecting the reverse rotation of the internal combustion engine by the rotation direction detector 15B that detects the rotation direction of the internal combustion engine. In this embodiment, a crank angle sensor that outputs a reverse rotation detection pulse is used.

  A method of detecting reverse rotation of the crankshaft using a crank angle sensor that outputs a reverse rotation detection pulse is described in, for example, Japanese Patent Application Laid-Open Nos. 2005-233622 and 2005-256842. This method discriminates the difference in the rotation direction of the crankshaft by using the output of a signal in which the pulse lengths of the reverse rotation pulse and the forward rotation pulse differ depending on the rotation direction of the crankshaft. For example, the first value of the free-run counter is obtained by detecting the falling edge of the crank angle pulse, and then the second value of the free-run counter is obtained by detecting the rising edge of the crank angle pulse. Is greater than or less than a predetermined threshold value, it is determined whether the rotation is forward rotation or reverse rotation.

  In addition, various methods for detecting reverse rotation of the crankshaft have been proposed, and the present embodiment is not limited to using a crank angle sensor that outputs a pulse for detecting reverse rotation. The point is that in this embodiment, it is only necessary to be able to discriminate between reverse rotation and normal rotation of the crankshaft, and a detailed description for discriminating this normal / reverse rotation will be omitted.

  Next, the specific control of the present embodiment will be described in detail with reference to FIGS. 2 and 3. The reverse rotation phenomenon of the crankshaft occurs in a region where the rotation speed is considerably low. There is no need to monitor reverse rotation if is equal to or greater than the set reference rotational speed. Therefore, the rotational speed that may cause reverse rotation has a considerably low value equal to or lower than the idle rotational speed, and is an experimental value determined through an actual vehicle test. For this reason, the control flowchart shown in FIG. 2 is executed when the number of revolutions has decreased below the number of revolutions that may cause reverse rotation.

  Here, in the control flowchart shown in FIG. 2, the rising point of the crank angle sensor that outputs the reverse rotation detection pulse is the forward / reverse rotation determination reference position, and the rising point of the crank angle sensor is the angle reference position. . Therefore, when the forward rotation / reverse rotation determination reference position is before the angle reference position, the forward rotation / reverse rotation is determined from the crank angle sensor. In this case, the fuel injection timing and spark ignition timing can be set using the result of determining whether the crankshaft is rotating forward or reverse before executing fuel injection and spark ignition.

  First, in step S20, it is determined whether there is a restart request. In this case, it is determined whether or not the accelerator pedal is depressed. When the accelerator pedal is not depressed, the idle stop control is continued. On the other hand, when the accelerator pedal is depressed, it is determined that there is a restart request due to “change of mind”, and the process proceeds to step S21.

  In step S21, the rotational direction of the crankshaft is detected in order to determine whether reverse rotation of the crankshaft has occurred. In this case, the difference in the rotation direction of the crankshaft is discriminated using the fact that the crank angle sensor outputs a signal in which the pulse lengths of the reverse rotation pulse and the forward rotation pulse are different.

  Next, the process proceeds to step S22, and it is determined whether the current rotation direction of the crankshaft is the normal rotation direction or the reverse rotation direction. If it is determined in this step 22 that the direction of reverse rotation is reached, the process goes to the end and waits for the next activation timing. Therefore, in this state, fuel injection and spark ignition are not executed, so that combustion torque that promotes reverse rotation of the crankshaft does not occur. For this reason, the crankshaft is in a swing-back state along the operation stroke of the internal combustion engine itself.

  On the other hand, if it is determined in step S22 that the current rotation direction of the crankshaft is the normal rotation direction, fuel injection and spark ignition are executed to prepare for starterless start. In this case, the process proceeds to step S23 and the spark ignition timing is calculated. Since the rotation speed is extremely low, a predetermined fixed spark ignition timing is used. In step S24, the fuel injection timing is calculated. Similarly, since the rotation speed is extremely low, a predetermined fixed fuel injection timing is used.

  Here, in addition to the spark ignition timing obtained in step S23, the energization start timing and the energization angle are also obtained. These values are also fixed values determined in advance. Similarly, the fuel injection amount (= time) is also obtained separately from the fuel injection timing obtained in step S24, and these values are also fixed fixed values. Of course, these predetermined fixed values reflect values of fluctuation parameters such as the temperature of the internal combustion engine and the battery voltage. In addition, it is also possible to use the value adjusted according to the operating state of the internal combustion engine without using a fixed value as described above.

  Next, the process proceeds to step S25, and the spark ignition timing is set in the register of the input / output circuit of the control device 15. Similarly, in step 26, the fuel injection timing is set in the register of the input / output circuit of the control device 15. Energization is started at the energization start timing based on the angle signal coming from the crank angle sensor by the spark ignition timing set in the register of the input / output circuit, energized only for a predetermined energization angle, and then energized. Thus, spark ignition is performed.

  Also, fuel injection is started based on the angle signal coming from the crank angle sensor at the fuel injection timing set in the register of the input / output circuit, and when fuel injection is executed for a predetermined time by the time signal from the timer, the fuel is injected. The injection is stopped.

  In this way, even if the engine is in a swing-back state when a restart request due to “Change of Mind” occurs, the injected fuel is burned by spark ignition only when the crankshaft is in the forward rotation direction. Therefore, the starterless start can be executed without causing reverse rotation of the crankshaft.

  FIG. 3 is a time chart showing control results according to the control flowchart shown in FIG. 2, but FIG. 3 shows only one cylinder as a representative. In this example, when starterless start is performed in the swing-back state, the fuel injection start timing is set to BTDC 70 °, the energization start timing is set to BTDC 30 °, and the spark ignition timing is set to BTDC 10 °. Further, as described above, the rise of the crank angle sensor that outputs the reverse rotation detection pulse is the forward / reverse rotation determination reference position, and the rise of the crank angle sensor is the angle reference position. And the case where the restart request | requirement (at the time of generation | occurrence | production of a change of mind) is shown in the state in which the swingback has generate | occur | produced just before BTDC10 degrees is shown. In addition, the time difference between the engine rotation direction and the forward / reverse rotation determination is due to the time delay of the calculation shown in FIG. 2, so the actual rotation / reverse rotation determination result is actually used. Is.

  In FIG. 3, when a restart request is generated at time A, the crankshaft is rotating forward at this time, so that fuel injection is started at time B of BTDC 70 °, and fuel injection is executed. Furthermore, energization is started at time C of BTDC 30 ° thereafter, and energization of the ignition coil is started. When reverse rotation occurs in this state, the signal of the crank angle sensor continuously appears as a normal rotation signal before reverse rotation and a reverse rotation signal when reverse rotation occurs. Since reverse rotation can be detected based on the pulse lengths of these signals, it is assumed that reverse rotation has occurred from time D to time E, and the spark ignition is not executed because the process ends in step S22 shown in FIG. However, energization is continued to the ignition coil during this period. Next, when reverse rotation is reversed to forward rotation, the spark ignition timing is reached at time F of BTDC 10 °, and spark ignition is executed. As a result, combustion torque is generated with the crankshaft rotating in the forward direction, so that starterless start is promptly executed.

  Thus, in this embodiment, it is detected whether the rotation direction of the internal combustion engine is the normal rotation direction or the reverse rotation direction based on the signal from the crank angle sensor, and the fuel is burned when it is determined as the normal rotation direction. I did it. This makes it possible to perform starterless start without reversely rotating the internal combustion engine.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. In this embodiment, the first fuel injection and spark ignition in the restart request and the subsequent fuel are described. The difference between the injection and the spark ignition is that the timing to be set is changed by the rising and falling of the crank pulse.

  Here, in the control flowchart shown in FIG. 4, unlike the control flowchart shown in FIG. 2, the falling edge of the crank angle sensor is the reference position of the angle. Therefore, when the forward / reverse rotation determination reference position is after the angular reference position, the forward / reverse rotation is determined from the reverse rotation detection crank angle sensor. In this case, in order to prevent the fuel injection and spark ignition from being executed at the time of reversing from the normal rotation to the reverse rotation, the normal rotation is determined at the timing of the normal rotation / reverse rotation determination reference position only for the first time after the restart. Later, fuel injection timing and spark ignition timing are set.

  In FIG. 4, steps S20 to S24 are the same as those in the first embodiment, and a description thereof will be omitted. And it progresses to step S40 and it is judged whether it is the first fuel injection after restart. If it is determined that this is the first fuel injection, the process proceeds to step S41, and the process proceeds to step S42 where it is determined that the fuel is injected after the first time. In the case of the first fuel injection, in step S41, the fuel injection timing is set in the register of the input / output circuit of the controller 15 at the pulse rising point of the crank angle sensor. On the other hand, in the case of fuel injection after the first time, in step S42, the fuel injection timing is set in the register of the input / output circuit of the controller 15 at the pulse falling point of the crank angle sensor.

  When the fuel injection timing has been set, the routine proceeds to step S43, where it is determined whether or not it is the first spark ignition after restart. If it is determined that this is the first spark ignition, the process proceeds to step S44, and the process proceeds to step S445 where it is determined that the first and subsequent sparks are ignited. If it is the first spark ignition, in step S44, the spark ignition timing is set in the register of the input / output circuit of the controller 15 at the pulse rising point of the crank angle sensor. On the other hand, in the case of spark ignition after the first time, in step S45, the spark ignition timing is set in the register of the input / output circuit of the control device 15 at the pulse falling point of the crank angle sensor.

  FIG. 5 is a time chart showing the control results according to the control flowchart shown in FIG. 4, but only one cylinder is shown as a representative in FIG. In this example, when starterless start is performed in the swing-back state, the fuel injection start timing is set to BTDC 70 °, the energization start timing is set to BTDC 30 °, and the spark ignition timing is set to BTDC 10 °. And the case where the restart request | requirement was made in the state which the shakeback generate | occur | produced just before BTDC10 degrees is shown. Further, as described above, the rising edge of the crank angle sensor that outputs the reverse rotation detection pulse is the forward / reverse rotation determination reference position, and the falling edge of the crank angle sensor is the angle reference position.

  In FIG. 5, when a restart request is generated at time A, the fuel injection is the first fuel injection at this time and the crankshaft is rotating forward. Therefore, at time H of BTDC 70 °, the fuel injection start timing is reached at the pulse rising point of the crank angle sensor. Fuel injection is performed. After the next time, at time G, the fuel injection start timing is reached at the pulse falling point of the crank angle sensor.

  Furthermore, energization is started at time C of BTDC 30 ° thereafter, and energization of the ignition coil is started. When reverse rotation occurs in this state, the signal of the crank angle sensor appears continuously from the signal before reverse rotation and the signal when reverse rotation occurs. Since reverse rotation can be detected based on the pulse lengths of these signals, the spark ignition is not executed because the process goes to the end in step S22 shown in FIG. However, energization is continued to the ignition coil during this period. Here, if the control is performed with the falling edge of the angle reference pulse when reversing from the normal rotation to the reverse rotation, BTDC 10 ° is recognized at time I in the early reverse rotation and erroneous spark ignition occurs. On the other hand, if the spark ignition is performed only at the first time at the time J which is the rising point, the spark ignition is not executed at this time because it is already determined to be in the reverse rotation state. Next, when reverse rotation is reversed to forward rotation, the spark ignition timing is reached at time F of BTDC 10 °, and spark ignition is executed. As a result, combustion torque is generated with the crankshaft rotating in the forward direction, so that starterless start is promptly executed.

  Next, a third embodiment of the present invention will be described with reference to FIGS. 6 and 7. In this embodiment, the restart is performed using a starter instead of the starterless start. Is different. This is an example of starting by the starter when the rotation of the internal combustion engine has not stopped but starterless starting is not possible. It is assumed that the starter signal is turned on when reverse rotation occurs in the swing back state, and the starter pinion is not engaged with the ring gear.

  This control flowchart is executed in the rotation speed range in which the first and second embodiments can perform the starterless start, whereas this embodiment is executed in the extremely low speed rotation speed range in which the starterless start cannot be performed. . In this case, the control flow shown in FIG. 6 is executed on the premise that the rotation speed is in an extremely low speed rotation speed range where the starterless start cannot be performed by detecting the rotation speed.

  In FIG. 6, it is determined whether there is a restart request in step S20. In this case, it is determined whether or not the accelerator pedal is depressed. When the accelerator pedal is not depressed, the idle stop control is continued. On the other hand, if the accelerator pedal is depressed, it is determined that there is a restart request due to “change of mind”, and the process proceeds to step S60.

  In step S60, it is determined whether a predetermined time T has elapsed since the starter signal was sent to the starter. In this case, the starter pinion is engaged with the ring gear. The predetermined time T is set to a time required for the ring gear to be rotated by the starter and the crankshaft of the internal combustion engine to reverse from reverse rotation to normal rotation. Therefore, even if the crankshaft rotates in the reverse direction, the crankshaft is in the normal rotation state after the predetermined time T has elapsed. For this reason, in step S60, if the predetermined time T has not elapsed, it is assumed that the engine is in the reverse rotation state, and the process proceeds to step S61, where the execution of fuel injection and spark ignition is stopped.

  On the other hand, if it is determined in step S61 that the crankshaft is rotating forward after the lapse of the predetermined time T, the process proceeds to step S62, and execution of fuel injection and spark ignition is permitted. Then, the control steps from step S63 to step S66 are executed. Since these control steps are the same as the control steps from step 23 to step S26 of the first embodiment, description thereof will be omitted.

  FIG. 7 is a time chart showing a control result according to the control flowchart shown in FIG. 6, but only one cylinder is shown as a representative in FIG. In this example, when the starter is started in the swing-back state, the fuel injection start timing is set to BTDC 70 °, the energization start timing is set to BTDC 30 °, and the spark ignition timing is set to BTDC 10 °. And the case where the restart request | requirement was made in the state which the shakeback generate | occur | produced just before BTDC10 degrees is shown.

  In FIG. 7, when a restart request is generated at time A, the fuel injection and spark ignition permission signals are turned off. Even if the starter signal is turned ON at time K when the swingback occurs in this state and the crankshaft rotates in the reverse direction, the fuel injection and spark ignition are not executed because the permission signal is turned OFF.

  Then, at time K, the starter signal is turned ON and the starter rotates to rotate the ring gear, but the fuel injection is performed while the starter is rotating for a predetermined time T but the crankshaft is not reversed to the normal rotation. Spark ignition is not performed. Thereafter, when a predetermined time T has elapsed, it is assumed that the crankshaft is sufficiently forward rotating, and fuel injection and spark ignition are executed.

  According to this embodiment, since the rotation of the crankshaft is determined from the rotation time of the ring gear by the starter without detecting the rotation direction of the crankshaft, the normal rotation state without using the crank angle sensor for detecting reverse rotation. Can be determined.

  In the present embodiment, the starterless start is not performed separately from the first and second embodiments described above, and the present invention can also be used for an automatic stop / restart control system for an internal combustion engine that performs only the starter start. Since reverse rotation may occur even when the internal combustion engine is started by the starter, it is effective to apply this embodiment.

  Here, although three examples are illustrated in the present specification, it is possible to implement these examples in combination. For example, the embodiment 1 or the embodiment 2 and the embodiment 3 are combined, the embodiment 1 or the embodiment 2 is executed when the rotational speed is higher than the predetermined speed, and the embodiment 3 is executed when the rotational speed is lower than the predetermined speed. It is also possible to do. By adopting such a configuration, it is possible to restart with a “change of mind” and restart when the internal combustion engine is completely stopped, and the automatic stop / restart of the internal combustion engine is also effective from a practical viewpoint. It can be a start control system.

  As described above, the present invention detects the forward or reverse rotation direction of the internal combustion engine based on the signal from the crank angle sensor, and performs fuel injection and spark ignition after it is determined to be forward rotation. According to this, since the fuel injection and the spark ignition are performed after it is determined that the internal combustion engine is normally rotated, the starterless start can be performed without rotating the internal combustion engine in the reverse direction.

  When starting the starter, fuel injection and spark ignition are performed after a predetermined time has elapsed from the starter on signal. According to this, since the fuel injection and the spark ignition are performed after the internal combustion engine is regarded as the normal rotation, it is possible to perform the starter start without the reverse rotation of the internal combustion engine.

  DESCRIPTION OF SYMBOLS 10 ... Starter signal, 11 ... Crank angle sensor signal for reverse rotation detection, 12 ... Accelerator sensor signal, 13 ... Brake sensor signal, 14 ... Vehicle speed sensor signal, 15 ... Control device, 15A ... Starter ON continuation detection part, 15B ... Rotation Direction detection unit, 15C ... ignition control unit, 15D ... fuel injection control unit 15D, 16 ... igniter, 17 ... injector.

Claims (5)

Engine stop means for stopping fuel injection by the fuel injection means and spark ignition by the ignition means when an engine stop request is generated during operation of the internal combustion engine, and the internal combustion engine during stoppage of fuel injection and spark ignition by the engine stop means An internal combustion engine comprising: restarting means that restarts fuel injection by the fuel injection means and spark ignition by the ignition means when a restart request is generated by the driver while the rotational speed of the engine is decreasing In the automatic stop / restart control system of
The restarting means has a rotation direction detecting means for detecting whether the rotation direction of the internal combustion engine is forward rotation or reverse rotation based on a signal from a crank angle sensor, and the rotation direction of the internal combustion engine is detected by the rotation direction detection means. When the reverse rotation direction is determined, fuel injection by the fuel injection unit and spark ignition by the ignition unit are not executed, and when the rotation direction of the internal combustion engine is determined to be normal rotation by the rotation direction detection unit, An automatic stop / restart control system for an internal combustion engine, wherein the fuel injected by the fuel injection means is burned by the ignition means. The automatic stop / restart control system for an internal combustion engine according to claim 1,
The restarting means sets the initial fuel injection timing and the initial spark ignition timing in the register of the input / output circuit at the rising point of the crank angle sensor, and sets the fuel injection timing and spark ignition timing after the initial time to the crank angle sensor. An automatic stop / restart control system for an internal combustion engine, wherein the register is set at the falling point of the internal combustion engine. Automatic stop of an internal combustion engine provided with an engine stop means for stopping fuel injection by the fuel injection means and spark ignition by the ignition means when an engine stop request is generated during operation of the internal combustion engine, and a starter start means for restarting by the starter / In the restart control system,
The starter starting means has rotation direction determination means for determining whether or not the internal combustion engine has entered a normal rotation state after a predetermined time has elapsed from the starter on signal, and the starter on / off state is determined by the rotation direction determination means. If it is determined that a predetermined time has not elapsed from the signal, fuel injection by the fuel injection means and spark ignition by the ignition means are not executed, and a predetermined time has elapsed from the starter ON signal by the rotation direction determination means. If it is determined that the fuel is burned, the fuel is burned by the fuel injection means and the ignition means. Engine stop means for stopping fuel injection by the fuel injection means and spark ignition by the ignition means when an engine stop request is generated during operation of the internal combustion engine, and the internal combustion engine during stoppage of fuel injection and spark ignition by the engine stop means Starterless starting means for restarting by restarting fuel injection by the fuel injection means and spark ignition by the ignition means when a restart request is generated by the driver in the process of decreasing the rotational speed of the engine, and the starterless In an automatic stop / restart control system for an internal combustion engine provided with a starter starting means for restarting by a starter separately from the starting means,
The restarting means has a rotation direction detecting means for detecting whether the rotation direction of the internal combustion engine is forward rotation or reverse rotation based on a signal from a crank angle sensor, and the rotation direction of the internal combustion engine is detected by the rotation direction detection means. When the reverse rotation direction is determined, fuel injection by the fuel injection unit and spark ignition by the ignition unit are not executed, and when the rotation direction of the internal combustion engine is determined to be normal rotation by the rotation direction detection unit, The fuel injected by the fuel injection means is burned by the ignition means,
The starter starting means has rotation direction determination means for determining whether or not the internal combustion engine has entered a normal rotation state after a predetermined time has elapsed from the starter on signal, and the starter on / off state is determined by the rotation direction determination means. If it is determined that a predetermined time has not elapsed from the signal, fuel injection by the fuel injection means and spark ignition by the ignition means are not executed, and a predetermined time has elapsed from the starter ON signal by the rotation direction determination means. If it is determined that the fuel is burned, the fuel is burned by the fuel injection means and the ignition means. The automatic stop / restart control system for an internal combustion engine according to claim 4,
When the rotational speed of the internal combustion engine is higher than a predetermined rotational speed, restarting by the starterless starting means is executed, and when the rotational speed of the internal combustion engine is lower than a predetermined rotational speed, restarting by the starter starting means is executed. An automatic stop / restart control system for an internal combustion engine.

Images