JP2010209759A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine improving restartability by prohibiting ignition if the crankshaft reversely rotates, and releasing ignition prohibition at an appropriate timing. <P>SOLUTION: When a crank angle signal is output from a crank angle sensor of the internal combustion engine, polarity of alternating voltage of an alternating current generator driven by rotation of the crankshaft is determined (S102). Regular rotation of the crankshaft is determined when a cycle of the determined polarity coincides with a polarity cycle in regular rotation to be output from the alternating current generator when the crankshaft is rotated in a regular direction, and reverse rotation is determined when the same does not coincide (S110-S114). Ignition of the internal combustion engine is prohibited when reverse rotation of the crankshaft is determined (S116), and prohibition of ignition of the internal combustion engine is released when the cycle of the determined polarity coincides with the polarity cycle in regular rotation after determination of reverse rotation of the crankshaft (S106, S120-S134). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine that prohibits ignition when a crankshaft is reversely rotated.

  If the rotation speed of the crankshaft is insufficient, such as during cranking of an internal combustion engine, the crankshaft may reverse from rotation in the normal rotation direction to rotation in the reverse rotation direction. If ignition is performed in such a state, a reverse load may act on the crankshaft or the like to cause damage to the engine body. Thus, conventionally, a technique has been proposed in which ignition of the internal combustion engine is prohibited when reverse rotation of the crankshaft is detected (see, for example, Patent Document 1).

  By the way, in order to restart the internal combustion engine after prohibiting the ignition, it is necessary to cancel the ignition prohibition, and when the internal combustion engine stops (more precisely, the rotation of the crankshaft stops) It is common to do. Further, the technology described in Patent Document 2 below is configured to cancel the ignition prohibition when a predetermined time has elapsed since the ignition was prohibited.

Japanese Patent No. 2780257 Japanese Patent Laying-Open No. 2005-220866

  However, if the ignition prohibition is canceled when the internal combustion engine stops, the restart operation (specifically, before the internal combustion engine stops (before the rotation of the crankshaft completely stops), for example) In the case of a starter motor or a motorcycle, when the start lever (continuous operation of the kick starter pedal) is performed, the prohibition of ignition has not been released, so that there has been a problem that the start cannot be started.

  Further, when the ignition prohibition is canceled after a lapse of a predetermined time as in the technique described in Patent Document 2, it is considered that the crankshaft is still reverse when the predetermined time has elapsed. If ignition prohibition is canceled and ignition is performed, the engine body may be damaged as described above.

  Accordingly, the object of the present invention is to solve the above-mentioned problems, prohibit ignition when the crankshaft is reversely rotated, and cancel the ignition prohibition at an appropriate timing to improve restartability. It is to provide a control device.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided crank angle signal output means for outputting a crank angle signal for each predetermined crank angle of the crankshaft of the internal combustion engine, driven by rotation of the crankshaft. An AC generator that outputs an AC voltage; a polarity determining means that determines a polarity of an AC voltage output from the AC generator when the crank angle signal is output; and a cycle of the determined polarity is determined by the crank. When the shaft is rotated in the forward rotation direction, the crank cycle is compared with the forward polarity polarity cycle to be output from the AC generator, and the determined polarity cycle matches the forward rotation polarity cycle. A crankshaft rotation direction determining means that determines that the shaft is forward rotation while the crankshaft is reverse when the shaft does not match, and the internal combustion engine when the crankshaft is determined to be reverse rotation Ignition prohibiting means for prohibiting ignition, and the ignition prohibiting means, after the crankshaft is determined to be reverse rotation, when the determined polarity cycle coincides with the forward rotation polarity cycle, the internal combustion engine It was configured to lift the prohibition of engine ignition.

  In the control apparatus for an internal combustion engine according to claim 2, the crankshaft rotation direction determination means has the determined polarity cycle coincides with the forward rotation polarity cycle every time the crank angle signal is output. And determining that the crankshaft has returned from the reverse rotation to the normal rotation when the predetermined number of times has been reached after the crankshaft has been determined to be reverse rotation. Configured.

  In the control device for an internal combustion engine according to claim 3, the fuel injection prohibiting unit includes a fuel injection prohibiting unit that prohibits fuel injection of the internal combustion engine when the crankshaft is determined to be reverse. After the crankshaft is determined to be reverse, the prohibition of fuel injection of the internal combustion engine is canceled when the determined polarity cycle coincides with the forward rotation polarity cycle.

  In the control apparatus for an internal combustion engine according to claim 1, when the crank angle signal is output, the polarity of the AC voltage output from the AC generator is determined, and the cycle of the determined polarity is the polarity during forward rotation. The crankshaft is determined to be forward rotation when it matches the cycle, while the crankshaft is determined to be reverse rotation when it does not match, and the ignition of the internal combustion engine is prohibited when the crankshaft is determined to be reverse rotation. Therefore, the reverse rotation of the crankshaft can be accurately detected and ignition can be prohibited, so that the reverse load does not act on the crankshaft and the like, and damage to the internal combustion engine body can be prevented.

  In addition, after the crankshaft is determined to be reverse rotation, when the determined polarity cycle coincides with the forward polarity polarity cycle, the configuration prohibits the ignition inhibition of the internal combustion engine, in other words, the crankshaft reverse rotation Since it is configured to cancel the ignition prohibition when it is detected that the motor has returned to normal rotation, the ignition prohibition will not be canceled when the crankshaft is rotating in reverse. For example, even when a restart operation is performed by the driver before the internal combustion engine stops, the ignition prohibition is canceled if the crankshaft is rotating forward, so that the engine cannot be started. It does not fall and restartability can be improved.

  In the control apparatus for an internal combustion engine according to claim 2, it is determined whether or not the polarity cycle determined every time the crank angle signal is output matches the polarity cycle during forward rotation, and the crankshaft is reversely rotated. Since the crankshaft is determined to have returned to normal rotation from reverse rotation when the number of times determined to be coincident has reached a predetermined number of times, the crankshaft is reversely rotated. Therefore, it is possible to accurately detect the return from normal rotation to the normal rotation, and to cancel the ignition prohibition at a more appropriate timing.

  In the control device for an internal combustion engine according to claim 3, since the fuel injection of the internal combustion engine is prohibited when the crankshaft is determined to be reverse rotation, in addition to the above-described effects, the load due to reverse rotation is It does not act on the shaft or the like, and damage to the internal combustion engine body can be more reliably prevented.

  Further, after the crankshaft is determined to be reverse rotation, when the determined polarity cycle coincides with the forward rotation polarity cycle, the configuration is configured to release the prohibition of fuel injection of the internal combustion engine, in other words, the crankshaft is Since it is configured to cancel the prohibition of fuel injection when it is detected that the reverse rotation has returned to the normal rotation, the prohibition of fuel injection will not be canceled when the crankshaft is rotating in reverse. The prohibition can be canceled at an appropriate timing, and even if the restart operation is performed by the driver before the internal combustion engine stops, the fuel injection prohibition is canceled if the crankshaft is rotating forward. Therefore, fuel can be injected, and restartability can be further improved.

1 is a schematic diagram showing an overall control apparatus for an internal combustion engine according to an embodiment of the present invention. It is explanatory drawing of the rotor etc. which comprise the generator shown in FIG. FIG. 2 is a block diagram showing the overall configuration of an ECU shown in FIG. 1. 2 is a flowchart showing the operation of the control device for the internal combustion engine shown in FIG. 1. 5 is a sub-routine flow chart of the reverse rotation detection process of FIG. 2 is a time chart showing the operation of the control device for the internal combustion engine shown in FIG. 1. 5 is a sub-routine flowchart of the ignition output process of FIG. FIG. 5 is a sub-routine flowchart of the fuel injection process of FIG. 4. 5 is a flowchart showing the operation of the control device for the internal combustion engine executed in parallel with the flowchart of FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment for carrying out an internal combustion engine control apparatus according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing an overall control apparatus for an internal combustion engine according to an embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes an internal combustion engine (hereinafter referred to as “engine”) mounted on a vehicle (not shown) (for example, a motorcycle). The engine 10 is a four-cycle single-cylinder water-cooled type and is composed of a gasoline engine having a displacement of about 250 cc. Reference numeral 10a denotes a crankcase of the engine 10.

  A throttle valve 14 is disposed in the intake pipe 12 of the engine 10. The throttle valve 14 is mechanically connected via a throttle wire (both not shown) to an accelerator (throttle grip) provided on the vehicle handlebar so as to be manually operated by the driver, depending on the operation amount of the accelerator. The amount of air that is opened and closed and drawn into the engine 10 from the air cleaner 16 through the intake pipe 12 is adjusted.

  In the intake pipe 12, an injector 20 is disposed near the intake port on the downstream side of the throttle valve 14, and gasoline fuel is injected into the intake air adjusted by the throttle valve 14. The injected fuel is mixed with intake air to form an air-fuel mixture, and the air-fuel mixture flows into the combustion chamber 24 when the intake valve 22 is opened.

  The air-fuel mixture flowing into the combustion chamber 24 is ignited and burned when the spark plug 30 is spark-discharged by the high voltage supplied from the ignition coil 26, and the piston 32 is driven downward in FIG. Rotate. The exhaust gas generated by the combustion flows through the exhaust pipe 40 when the exhaust valve 36 is opened. A catalyst device 42 is disposed in the exhaust pipe 40 to remove harmful components in the exhaust gas. The exhaust gas purified by the catalyst device 42 flows further downstream and is discharged to the outside of the engine 10.

  A throttle opening sensor 44 composed of a potentiometer is provided in the vicinity of the throttle valve 14 to generate an output indicating the opening θTH of the throttle valve 14. An intake air temperature sensor 46 is provided on the upstream side of the throttle valve 14 of the intake pipe 12 to generate an output indicating the temperature TA of the intake air, and an absolute pressure sensor 50 is provided on the downstream side to provide the absolute pressure in the intake pipe (engine Load) produces an output indicating PBA.

  A water temperature sensor 52 is attached to the cooling water passage 10b of the cylinder block of the engine 10, and generates an output corresponding to the temperature (engine cooling water temperature) TW of the engine 10. A crank angle sensor (crank angle signal output means) 54 comprising an electromagnetic pickup is disposed near the crankshaft 34 of the engine 10 and on the wall surface (static position) of the crankcase 10a. The crank angle sensor 54 will be described in detail later.

  An AC generator (hereinafter simply referred to as “generator”) 60 is connected to the crankshaft 34 of the engine 10. The generator 60 includes a rotor (timing rotor) 60a connected to the crankshaft 34, a permanent magnet 60b attached to the rotor 60a, and three-phase stator coils 60c, 60d disposed at positions facing the permanent magnet 60b. 60e and reverse detection coil 60f.

  FIG. 2 is an explanatory diagram of the rotor 60a and the like constituting the generator 60 shown in FIG.

  As shown in FIG. 2, the rotor 60 a has a cylindrical shape and rotates in conjunction with (synchronizes with) the crankshaft 34. The rotor 60a also serves as the flywheel of the engine 10. On the outer peripheral side of the rotor 60a, a plurality (18 pieces) of projections 60g made of a magnetic material are arranged at equal angular intervals with a predetermined distance. Specifically, the 18 protrusions 60g are arranged such that the rear end positions of the protrusions 60g in the rotational direction of the rotor 60a are equally spaced at predetermined crank angles (more specifically, 20 °) of the crankshaft 34. Placed in.

  One of the plurality of protrusions 60g is a protrusion (indicated by reference numeral 60g1 in FIG. 2) for detecting the crank angle reference position, and the length from the front end position to the rear end position is longer than that of the other protrusions 60g2. The rear end position is set to be 10 ° before top dead center (BTDC 10 ° (crank angle reference position)). Hereinafter, the protrusion 60g1 is referred to as a “reference protrusion 60g1”.

  The crank angle sensor 54 described above is disposed at a stationary position facing the protrusion 60g of the rotor 60a. Therefore, the crank angle sensor 54 outputs a pulse signal each time the protrusion 60g passes in the vicinity as the rotor 60a rotates. Specifically, the crank angle sensor 54 outputs a pulse signal having a negative amplitude when the front end position of each projection 60g passes in the rotation direction, and has a positive amplitude when the rear end position passes. Is output. That is, the crank angle sensor 54 outputs a pulse signal (crank angle signal) having a negative polarity or a positive polarity at every predetermined crank angle (20 °) of the crankshaft 34.

  The permanent magnet 60b is attached to the inner peripheral side of the rotor 60a, and the S pole and the N pole are alternately arranged at equal angles (specifically, every 30 °), in other words, the S pole and the N pole. Are arranged every 60 ° as one set (one pair). Further, the reverse rotation detection coil 60f is arranged to be at the crank angle reference position (BTDC 10 °).

  Thus, when the rotor 60a (specifically, the permanent magnet 60b attached to the rotor 60a) is rotated with the rotation of the crankshaft 34, the generator 60 rotates the stator coils 60c, 60d, 60e and reversely by electromagnetic induction. An AC voltage is output from the detection coil 60f. Specifically, the stator coils 60c, 60d, and 60e output a three-phase AC voltage composed of U, V, and W phases, and the reverse rotation detection coil 60f outputs a one-phase AC voltage.

  Thus, the generator 60 is composed of a permanent magnet type AC generator and is driven by the rotation of the crankshaft 34 to output an AC voltage. The AC voltage output from the above-described reverse rotation detection coil 60f is an AC voltage that takes one period of time required for the rotor 60a (crankshaft 34) to rotate 60 °.

  Returning to the description of FIG. 1, the three-phase AC voltage output from the stator coils 60 c, 60 d and 60 e of the generator 60 is input to the battery 64 via the regulating rectifier 62.

  The regulate rectifier 62 includes a rectifier circuit 62a and an output voltage adjustment circuit 62b. The rectifier circuit 62a rectifies the three-phase AC voltage input from the stator coils 60c, 60d, and 60e into a DC voltage by a bridge circuit (not shown) and outputs the DC voltage to the output voltage adjustment circuit 62b. The output voltage adjusting circuit 62b adjusts the input DC voltage to generate a power supply voltage, supplies the power supply voltage to the battery 64 and charges it, and at the same time, an electronic control unit (hereinafter referred to as “ECU”). ) 70 is also supplied as an operating power source. The battery 64 supplies operating power to the ECU 70 when no AC voltage is output from the generator 60, for example, when the engine is started.

  The output of each sensor such as the crank angle sensor 54 described above and the AC voltage output from the reverse rotation detection coil 60 f of the generator 60 are input to the ECU 70.

  FIG. 3 is a block diagram showing the overall configuration of the ECU 70.

  The ECU 70 comprises a microcomputer, and as shown in FIG. 3, a waveform shaping circuit 70a, a rotation speed counter 70b, a reference voltage source 70c, a comparator circuit 70d, an A / D conversion circuit 70e, a CPU 70f, and an ignition circuit 70g, a drive circuit 70h, a ROM 70i, a RAM 70j, and a timer 70k.

  The waveform shaping circuit 70a shapes the output (pulse signal, signal waveform) of the crank angle sensor 54 into a rectangular pulse signal (specifically, the negative pulse signal is set to the high level, while the positive polarity signal is set). The pulse signal is shaped so as to be at a low level) and output to the rotation speed counter 70b. The rotational speed counter 70b counts the input pulse signal to detect (calculate) the engine rotational speed NE, and outputs a signal indicating the engine rotational speed NE to the CPU 70f. The reference voltage source 70c outputs the negative DC voltage as a reference voltage to the non-inverting input terminal of the comparator circuit 70d.

  The comparator circuit 70d is composed of an operational amplifier, and the AC voltage of the reverse rotation detection coil 60f is input to the inverting input terminal. The comparator circuit 70d compares the AC voltage with the reference voltage. When the AC voltage is larger than the reference voltage (in other words, when the polarity of the AC voltage is positive), the comparator circuit 70d outputs a high-level comparison result signal. When it is smaller (when the polarity of the AC voltage is negative), a low level comparison result signal is output to the CPU 70f. The A / D conversion circuit 70e receives the output of each sensor such as the throttle opening sensor 44 and the intake air temperature sensor 46, converts the analog signal value into a digital signal value, and outputs it to the CPU 70f.

  The CPU 70f performs an operation according to a program stored in the ROM 70i based on the converted digital signal, the comparison result signal from the comparator circuit 70d, and the like, and the ignition control signal of the ignition coil 26 when the crank angle is the ignition output timing. Is output to the ignition circuit 70g (that is, ignition timing control is performed). Further, the CPU 70f similarly performs a calculation according to a program stored in the ROM 70i based on each signal, and sends a fuel injection control signal to the drive circuit 70h at the fuel injection timing (performs fuel injection control).

  The ignition circuit 70g performs ignition by energizing the ignition coil 26 in accordance with an ignition control signal from the CPU 70f. The drive circuit 70h drives the injector 20 to inject fuel in response to a fuel injection control signal from the CPU 70f. In the RAM 70j, for example, data such as the ignition timing and the fuel injection amount calculated in the ignition timing control and the fuel injection control are written. The timer 70k is used for time measurement processing performed in a program described later.

  FIG. 4 is a flowchart showing the operation of the control apparatus for an internal combustion engine according to this embodiment. The illustrated program is executed (looped) every time a crank angle signal is input in the ECU 70.

  First, in S10, processing for detecting (detecting) reverse rotation of the crankshaft 34 is performed. FIG. 5 is a sub-routine flowchart of the reverse rotation detection process of S10 of FIG.

  Prior to the description of the figure, detection of reverse rotation of the crankshaft 34 will be described with reference to the time chart of FIG.

  In FIG. 6, the actual rotation direction of the crankshaft 34, the output signal of the waveform shaping circuit 70a and the crank angle sensor 54, the AC voltage output from the reverse rotation detection coil 60f of the generator 60, and the AC voltage in order from the top. The polarity detection state, a forward rotation cycle counter CTFORWARD and a reverse rotation detection flag F_REVERSE, which will be described later, are shown.

  For example, from the time t1 to t6 when the crankshaft 34 rotates in the forward rotation direction, the crank angle sensor 54 moves in the rotation direction when the rotor 60a rotates as the crankshaft 34 rotates as described above. On the other hand, a negative pulse signal is output when the front end position of each projection 60g passes, and a positive pulse signal is output when the rear end position passes.

  The waveform shaping circuit 70a shapes the waveform so that the negative pulse signal of the crank angle sensor 54 is at a high level and the positive pulse signal is at a low level, and outputs the signal. Therefore, the interval between the falling edges of each pulse signal output from the waveform shaping circuit 70a corresponds to the time required for the crankshaft 34 to rotate 20 ° (20 CA) as shown in the figure.

  Further, the reverse rotation detection coil 60f of the generator 60 outputs an alternating voltage having a period of one period required for the rotor 60a (crankshaft 34) to rotate 60 °. When the crank angle signal is output from the crank angle sensor 54, the AC voltage polarity is compared with the comparison result of the comparator circuit 70d when each pulse signal of the waveform shaping circuit 70a falls (falling edge). When detected (determined) based on the signal, as shown in the figure, it can be seen that the positive electrode is obtained at time t1, the positive electrode at time t2, and the negative electrode at time t3.

  In FIG. 6, when the crankshaft 34 reverses at time t6 but does not reverse at time t6 (when the rotation in the normal rotation direction is continued), the polarity of the generator 60 is indicated by an imaginary line. Similarly, during the following time points t4 to t6, the positive electrode is obtained at time t4, the positive electrode is obtained at time t5, and the negative electrode is obtained at time t6 (specifically, the ignition output timing).

  That is, at the time when the crank angle signal is output, the polarity cycle of the AC voltage to be output from the AC generator 60 when the crankshaft 34 is rotated in the forward rotation direction is “positive electrode”, “positive electrode”, “negative electrode”. It becomes the order of. Hereinafter, this cycle is also referred to as “forward rotation polarity cycle”.

  Therefore, in the control apparatus for an internal combustion engine according to this embodiment, when the crank angle signal is output, the polarity of the alternating voltage output from the generator 60 is determined, and the cycle of the determined polarity is corrected. The crankshaft 34 is determined to be forward rotation (detects forward rotation of the crankshaft 34) when the determined polarity cycle matches the forward rotation polarity cycle compared with the rotation polarity cycle. When not, the crankshaft 34 is determined to be in reverse (detection of reverse rotation of the crankshaft 34).

  When the description of FIG. 5 starts with reference to FIG. 6 based on the above, first, in S100, the current voltage polarity REVACG0 (described later) set at the previous program execution is set to the previous voltage polarity REVACG1, and the previous voltage polarity REVACG1 is set. The previous voltage polarity REVACG1 set at the time of program execution is set to the previous voltage polarity REVACG2, and the previous voltage polarity REVACG1 and the previous voltage polarity REVACG2 are updated.

  Next, in S102, the polarity of the AC voltage output from the generator 60 is determined (detected) at the present time (more precisely, when the crank angle signal is output). Specifically, the polarity is determined based on the comparison result signal of the comparator circuit 70d. More specifically, as shown in FIG. 6, when the AC voltage of the generator 60 is larger than the reference voltage, the polarity is positive, and when it is smaller, the polarity is negative. Is determined.

  Next, in S104, the polarity of the determined AC voltage is set (updated) to the current voltage polarity REVACG0. That is, the current voltage polarity REVACG0 means the polarity of the current AC voltage, and the previous voltage polarity REVACG1 is when the previous crank angle signal is output (for example, the time t2 when the current time is the time t3 in FIG. 6). The voltage polarity REVACG2 represents the polarity of the AC voltage when the crank angle signal of the previous time is output (for example, the time point t1 when the current time is the time point t3).

  Next, in S106, it is determined whether or not the bit of the reverse rotation detection flag F_REVERSE (described later) is 1. Since the initial value of the flag F_REVERSE is set to 0, when the process of S106 is executed for the first time, it is negated and the process proceeds to S108, where the crank angle is the ignition output timing at which the ignition control signal should be output (for example, BTDC 10 ° (crank angle reference Position)).

  The determination in S108 is made based on the output of the waveform shaping circuit 70a. Specifically, since the reference protrusion 60g1 is arranged at the crank angle reference position that is the ignition output timing as described above, when the reference protrusion 60g1 passes near the crank angle sensor 54, as shown in FIG. In addition, a pulse signal having a long high level period is output from the waveform shaping circuit 70a. Therefore, when such a falling edge of the long pulse signal is detected, it can be determined that the crank angle is the ignition output timing.

  When the result in S108 is negative, the subsequent processing is skipped. When the result is affirmative, the process proceeds to S110 to determine whether or not the voltage polarity REVACG2 is positive. When the result in S110 is affirmative, the routine proceeds to S112, where it is determined whether or not the previous voltage polarity REVACG1 is positive. When the result is affirmative, the routine proceeds to S114, where it is determined whether or not the current voltage polarity REVACG0 is negative.

  That is, S110 to S114 compare the polarity cycle of the AC voltage obtained by the processing of S100 to S104 with the polarity cycle during forward rotation (specifically, the polarity cycle comprising the positive electrode, the positive electrode, and the negative electrode). This is a process for determining whether or not the polarity cycle of this is coincident with the polarity cycle during forward rotation.

  In S114, in other words, in other words, when the polarity cycle of the AC voltage matches the polarity cycle during forward rotation, the crankshaft 34 is determined to be forward rotation, and the subsequent processing is skipped. On the other hand, if any of the processes from S110 to S114 is negative, that is, for example, as shown at time t6 in FIG. 6, the cycle of the polarity of the AC voltage does not match (does not match) the polarity cycle during forward rotation. The shaft 34 is determined to be reverse rotation, and the process proceeds to S116, where the bit of the reverse rotation detection flag F_REVERSE is set to 1. Accordingly, the flag F_REVERSE being set to 1 means that the crankshaft 34 has been determined to be reverse rotation, and being set to 0 means that the crankshaft 34 has been determined to be normal rotation.

  Next, in S118, the values of the positive voltage count counter CTACGP and the normal rotation cycle count counter CTFORWARD used in the processing described later are reset to zero. Other processes in FIG. 5 will be described later.

  Returning to the description of FIG. 4, the process then proceeds to S <b> 12 to perform an ignition output process.

  FIG. 7 is a sub-routine flowchart showing the ignition output process.

  As shown in FIG. 7, the engine rotation NE is calculated (detected) based on the output of the crank angle sensor 54 in S200, and the routine proceeds to S202 where the opening θTH of the throttle valve 14 is calculated based on the output of the throttle opening sensor 44. (To detect. Next, in S204, based on the calculated engine speed NE and the throttle opening degree θTH, a preset map value is searched to calculate the ignition timing.

  Next, the routine proceeds to S206, where it is determined whether or not the crank angle is the ignition output timing. When the determination is negative, the subsequent processing is skipped, while when the determination is affirmative, the processing proceeds to S208, and whether the bit of the reverse rotation detection flag F_REVERSE is 1 or not. to decide.

  If NO in S208, that is, if it is determined that the crankshaft 34 is rotating forward, the process proceeds to S210, and an ignition control signal is output so that ignition is performed at the calculated ignition timing. On the other hand, if the determination in S208 is affirmative, that is, if it is determined that the crankshaft 34 is reverse, the process proceeds to S212, and the output of the ignition control signal is prohibited, in other words, the ignition of the engine 10 is prohibited.

  Returning to the description of FIG. 4, the process then proceeds to S <b> 14 to perform fuel injection processing.

  FIG. 8 is a sub-routine flowchart showing the fuel injection process.

  As shown in FIG. 8, in S300, a map value set in advance is searched from the engine speed NE and the throttle opening degree θTH, and the fuel injection amount and the fuel injection timing are calculated. Next, in S302, it is determined whether or not the fuel injection timing at which the crank angle is calculated. When the result in S302 is negative, the subsequent processing is skipped. When the result is affirmative, the process proceeds to S304 to determine whether or not the bit of the reverse rotation detection flag F_REVERSE is 1.

  When the result in S304 is negative, the program proceeds to S306, and a fuel injection control signal for injecting fuel from the injector 20 is output. On the other hand, when the result in S304 is affirmative, that is, when it is determined that the crankshaft 34 is reversely rotated, the process proceeds to S306, and the output of the fuel injection control signal is prohibited, in other words, the fuel injection of the engine 10 is prohibited.

  As described above, when it is determined that the crankshaft 34 is reversely rotated and the bit of the reverse rotation detection flag F_REVERSE is set to 1, ignition and fuel injection of the engine 10 are prohibited, and in the program loop after the next time, FIG. In S106 of the chart, the determination is affirmed and the process proceeds to S120. The processes after S120 are processes for determining the timing for canceling the prohibition of the ignition and the fuel injection described above.

  To explain below, in S120, it is determined whether or not the current voltage polarity REVACG0 is negative. When the result in S120 is negative, the program proceeds to S122, in which the value of the positive voltage counter CTACGP is incremented by one. Since the process of S122 is repeatedly executed until it is affirmed in S120, the value of the counter CTACGP is determined to be positive in the program loop before the current AC voltage is determined to be negative in S120 (specifically, Means the number of times denied in S120.

  When the result in S120 is affirmative, the program proceeds to S124, in which it is determined whether or not the value of the positive voltage count counter CTACGP is 2. That is, in S120 and S124, whether or not the polarity of the AC voltage is currently determined to be negative and whether or not it has been determined to be positive in the previous two program loops, in other words, the polarity cycle of the AC voltage is positive. This is a process for determining whether or not it coincides with the rotating polarity cycle (specifically, a polarity cycle comprising a positive electrode, a positive electrode, and a negative electrode).

  If the result in S124 is negative, that is, if they do not match (for example, at the time t7 or t8 in FIG. 6), the process proceeds to S126, and the value of the normal rotation cycle counter CTFORWARD is reset to 0. In FIG. 6, assuming that the actual crankshaft 34 returns to normal rotation at time t9 (at time t10), the process proceeds to S128, and the value of the counter CTFORWARD is incremented by one. Therefore, the counter CTFORWARD indicates the number of times that the crankshaft 34 is determined to be the same after the crankshaft 34 is determined to be reverse.

  Next, the process proceeds to S130, the value of the positive voltage count counter CTACGP is reset to 0, and the process proceeds to S132, in which it is determined whether or not the value of the forward rotation period counter CTFORD is greater than or equal to a predetermined number (specifically, twice). For example, it is determined whether or not the number of times determined to match has reached a predetermined number. When the result in S132 is negative, the subsequent processing is skipped, while when the result is affirmative (at time t11 in FIG. 6), it is determined that the crankshaft 34 has surely returned from reverse rotation to normal rotation, and the flow proceeds to S134. The bit of the reverse rotation detection flag F_REVERSE is set to 0.

  When the bit of this flag F_REVERSE is set to 0, as described above, it is negated in S208 to be executed later and proceeds to S210, so that the ignition control signal is output and ignition is resumed. The prohibition of ignition of the engine 10 is released. Similarly, the result in S304 is negative and the process proceeds to S306, so that the fuel injection control signal is output and fuel injection is resumed, that is, the prohibition of fuel injection of the engine 10 is released.

  FIG. 9 is a flow chart showing the operation of the control device for the internal combustion engine executed by the ECU 70 every predetermined time, for example, every 5 msec, in parallel with the flow chart of FIG.

  In the following, in S400, it is determined whether or not a crank angle signal has been input from the crank angle sensor 54 from the previous program execution to the current program execution. When the result in S400 is affirmative, the subsequent processing is skipped. When the result is negative, the program proceeds to S402, in which it is determined whether or not the engine 10 is stopped. More precisely, whether or not the crankshaft 34 is completely stopped. to decide. In S402, when the crank angle signal is not input from the crank angle sensor 54 for a predetermined time (for example, 200 msec), it is determined that the engine 10 is stopped.

  When the result in S402 is negative, the program is terminated as it is. When the result is affirmative, the program proceeds to S404, and the reverse rotation detection flag F_REVERSE is set to 0. Thus, when the engine 10 is stopped, the bit of the flag F_REVERSE is set to 0 to cancel the ignition prohibition / fuel injection prohibition and prepare for the next program execution.

  As described above, according to the embodiment of the present invention, the crank angle signal output means for outputting the crank angle signal for each predetermined crank angle of the crankshaft 34 of the internal combustion engine (engine) 10 (crank angle sensor 54), An AC generator 60 that is driven by the rotation of the crankshaft 34 to output an AC voltage; and a polarity determination unit that determines the polarity of the AC voltage output from the AC generator 60 when the crank angle signal is output. (ECU 70, S10, S102), comparing the cycle of the determined polarity with the polarity cycle at the time of forward rotation to be output from the AC generator 60 when the crankshaft 34 is rotated in the forward rotation direction, When the determined polarity cycle coincides with the forward rotation polarity cycle, the crankshaft 34 is determined to be normal rotation, and when the determined polarity cycle does not coincide, the crankshaft 34 Crankshaft rotation direction determining means for determining reverse rotation (ECU70. S10, S110 to S116), and ignition prohibiting means for prohibiting ignition of the internal combustion engine when the crankshaft 34 is determined to be reverse rotation (ECU70. S10, S12, S116, S208, S212), and after the crankshaft 34 is determined to be reverse rotation, the ignition prohibiting means, when the determined polarity cycle coincides with the forward rotation polarity cycle, The prohibition of ignition of the internal combustion engine 10 is canceled (S10, S12, S106, S120 to S134, S208, S210).

  Thus, when the crank angle signal is output, the polarity of the AC voltage output from the AC generator 60 is determined, and when the determined polarity cycle matches the polarity cycle during forward rotation, the crankshaft 34 While it is determined that the rotation is normal, the crankshaft 34 is determined to be reverse when it does not match, and when the crankshaft 34 is determined to be reverse, the ignition of the engine 10 is prohibited. Can be accurately detected and ignition can be prohibited, so that a reverse load does not act on the crankshaft 34 or the like, and damage to the engine body can be prevented.

  Further, after the crankshaft 34 is determined to be reversely rotated, when the determined polarity cycle coincides with the forward polarity polarity cycle, the engine 10 is configured to release the prohibition of ignition, in other words, the crankshaft 34. Since the ignition prohibition is canceled when it is detected that the motor has returned from the reverse rotation to the normal rotation, the ignition prohibition is not canceled when the crankshaft 34 is reversely rotated, that is, the ignition prohibition is not performed. The release can be performed at an appropriate timing, and even if the restart operation is performed by the driver before the engine 10 stops, for example, the ignition prohibition is canceled if the crankshaft 34 is rotating forward. Therefore, it is possible to improve the restartability without falling into the inability to start.

  The crankshaft rotation direction determining means determines whether the determined polarity cycle matches the forward rotation polarity cycle each time the crank angle signal is output, and the crankshaft 34 When the number of times determined to be coincident reaches a predetermined number (twice) after the reverse rotation is determined, it is determined that the crankshaft 34 has returned from the reverse rotation to the normal rotation (S10, S120 to S134). Since it comprised, it can detect correctly that the crankshaft 34 returned to reverse rotation from reverse rotation, and cancellation | release of ignition prohibition can be performed at a further appropriate timing.

  In addition, when it is determined that the crankshaft 34 is reverse, fuel injection prohibiting means for prohibiting fuel injection of the internal combustion engine (engine) 10 is provided (ECU 70. S10, S14, S116, S304, S308) and the fuel. The injection prohibiting means cancels the prohibition of fuel injection of the internal combustion engine 10 when the determined polarity cycle coincides with the forward polarity polarity cycle after the crankshaft 34 is determined to be reverse. (S10, S14, S106, S120 to S134, S304, S306).

  As described above, when the crankshaft 34 is determined to be reverse, the fuel injection of the engine 10 is prohibited. Therefore, the load due to the reverse rotation does not act on the crankshaft 34 and the like, and the engine body is damaged. It can prevent more reliably.

  Further, after the crankshaft 34 is determined to be reverse, when the determined polarity cycle coincides with the forward polarity polarity cycle, the prohibition of fuel injection of the engine 10 is canceled, in other words, the crankshaft Since it is configured to cancel the prohibition of fuel injection when it is detected that 34 has returned from the reverse rotation to the normal rotation, the prohibition of fuel injection is not canceled when the crankshaft 34 is reverse, that is, The fuel injection prohibition can be canceled at an appropriate timing, and even if the restart operation is performed by the driver before the engine 10 stops, for example, the fuel injection can be performed if the crankshaft 34 is rotating forward. Since the prohibition is lifted, it becomes possible to inject fuel and further improve the restartability.

  In the above description, the forward polarity polarity cycle is a polarity cycle composed of a positive electrode, a positive electrode, and a negative electrode. However, these are merely examples, and needless to say, the polarity cycle is appropriately changed according to the specifications of the generator 60.

  Moreover, although the predetermined number of times compared with the normal rotation period counter CTFORWARD and the exhaust amount of the engine 10 are shown by specific numerical values, these are examples and are not limited.

  In addition, although a motorcycle has been described as an example of the vehicle, the present invention is not limited thereto. For example, a so-called saddle type vehicle in which a driver rides over a seat (saddle) such as a scooter or an ATV (All Terrain Vehicle). Any other vehicle (for example, a four-wheeled vehicle) may be used.

  10 engine (internal combustion engine), 34 crankshaft, 54 crank angle sensor, 60 AC generator, 70 ECU (electronic control unit)

Claims (3)

  Crank angle signal output means for outputting a crank angle signal for each predetermined crank angle of the crankshaft of the internal combustion engine, an AC generator driven by rotation of the crankshaft to output an AC voltage, and the crank angle signal is output. Polarity determining means for determining the polarity of the AC voltage output from the AC generator, and the period of the determined polarity output from the AC generator when the crankshaft is rotated in the forward rotation direction. The crankshaft is determined to be forward rotation when the determined polarity cycle coincides with the forward polarity polarity cycle, while the crankshaft is A crankshaft rotation direction determining means for determining reverse rotation; and an ignition prohibiting means for prohibiting ignition of the internal combustion engine when the crankshaft is determined to be reverse rotation. The ignition prohibiting means cancels the prohibition of ignition of the internal combustion engine when the determined polarity cycle coincides with the forward polarity polarity cycle after the crankshaft is determined to be reverse. Control device for internal combustion engine.   The crankshaft rotation direction determination means determines whether the determined polarity cycle matches the forward rotation polarity cycle each time the crank angle signal is output, and determines that the crankshaft is reverse rotation. 2. The control device for an internal combustion engine according to claim 1, wherein when the number of times determined to be coincident reaches a predetermined number after the determination, the crankshaft is determined to have returned from reverse rotation to normal rotation.   When it is determined that the crankshaft is reverse rotation, the fuel injection prohibiting means for prohibiting fuel injection of the internal combustion engine is provided, and the fuel injection prohibiting means is determined after the crankshaft is determined to be reverse rotation. 3. The control apparatus for an internal combustion engine according to claim 1, wherein when the polarity cycle coincides with the forward polarity polarity cycle, prohibition of fuel injection of the internal combustion engine is canceled.

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