JP6967880B2 - Electronic control device - Google Patents

Description

The present invention relates to an electronic control device, and more particularly to an electronic control device for a vehicle in which a secondary battery such as a lead battery is charged by a three-phase AC generator and an internal combustion engine is started by using the three-phase AC generator.

In recent years, in vehicles such as automobiles, a rotor having a field magnetic flux generating magnet connected to a crankshaft (crankshaft) of an engine which is an internal combustion engine and driven by the rotation thereof, and a stator winding for generating a power generation output. Using a three-phase alternator equipped with a stator wound around, it is controlled to charge a secondary battery such as a lead battery, and to start the engine by rotating the crankshaft of the engine. An electronic control device has been proposed.

Under such circumstances, Patent Document 1 relates to a starting device and a starting control device for an internal combustion engine. Disclosed is a configuration in which the engine is started from a state in which the piston is in the exhaust stroke by rotating in the normal direction.

Japanese Patent No. 4230116

However, according to the study of the present inventor, in the configuration of Patent Document 1, specifically, the crankshaft from the power supply voltage, the engine temperature, etc. to the compression top dead center based on the data such as the map held in advance. The time required to reverse the speed is determined, the reverse rotation operation is performed, the rotation speed during the reverse rotation operation (time between crank pulses), etc. is monitored, and the compression top dead center is determined from the reduction ratio of the rotation speed, and the reverse rotation is performed. It is necessary to have a configuration in which it is detected from the crank pulse that the rotation has turned forward due to the compression reaction force of the compression top dead center during operation, and the compression top dead center is determined. Therefore, according to the configuration of Patent Document 1, it is necessary to hold a plurality of types of data according to the power supply voltage and temperature conditions to switch the data, and to store the data in a memory such as ROM (Read-Only Memory) in advance. Must be retained. In addition, the rotation speed ratio must be calculated for each crank pulse, which is a processing load. Further, the accuracy of determining the compression top dead center changes depending on the accuracy of detecting the crank position, and in order to accurately determine the compression top dead center, it is necessary to increase the number of teeth of the retractor and detect the crank position in detail.

Further, according to the study of the present inventor, in the configuration of Patent Document 1, the minimum voltage of the power supply voltage at the start of reverse rotation operation is held, and compression is performed when a power supply voltage equal to or lower than the held minimum voltage is detected. It is possible to adopt a configuration in which it is determined to be the top dead point, but in such a case, the minimum voltage of the power supply voltage at the start of reverse operation is lower than the power supply voltage at the compression top dead point depending on the engine temperature and power supply voltage. Therefore, it is possible that the compression top dead point cannot be determined.

The present invention has been made through the above studies, and an object of the present invention is to provide an electronic control device capable of determining the compression stroke of an engine with a simple configuration.

In order to achieve the above object, the present invention relates to an electronic control device including a voltage detector for detecting the voltage of a battery that supplies power to an electric motor that drives an engine that is an internal combustion engine to rotate a crank shaft. When the voltage of the battery detected by the voltage detection unit becomes less than a predetermined threshold value after the electric motor starts driving the crank shaft, it is determined that the stroke of the engine is in the compression stroke. A determination unit for determining the compression stroke and a control unit for controlling the duty for driving the electric motor are provided, and the determination unit is detected by the voltage detection unit after the electric motor starts driving. when the voltage of the battery is not become less than the predetermined threshold, when the elapsed time from when the electric motor starts the driving Ru der predetermined time or more, the stroke the compression stroke of the engine The first aspect is to determine that there is.

Further, in the second aspect of the present invention, in addition to the first aspect, the control unit gradually increases the duty to a predetermined value.

Further, in the present invention, in addition to the first or second aspect, the determination unit determines whether or not the elapsed time is equal to or longer than the predetermined time after the electric motor has started the driving. The third aspect is to determine that the stroke of the engine is in the compression stroke when the voltage of the battery becomes less than the predetermined threshold value before the determination.

Further, in the present invention, in addition to any one of the first to third aspects, the drive of the electric motor rotates the crank shaft in a direction opposite to that during operation of the engine. This is the fourth aspect.

Further, in the present invention, in addition to any one of the first to fourth aspects, the fifth aspect is that the engine is a single-cylinder internal combustion engine.

According to the electronic control device according to the first aspect of the present invention, when the battery voltage detected by the voltage detector after the electric motor starts driving the crank shaft becomes less than a predetermined threshold value, A determination unit for determining whether the engine stroke is in the compression stroke and a control unit for controlling the duty for driving the electric motor are provided, and the determination unit starts driving the electric motor. later when the voltage of the battery voltage detection unit detects is not become less than the predetermined threshold, when the elapsed time from when the electric motor starts driving the Ru der predetermined time or more, the stroke of the engine compression stroke Since it is determined that there is, it is possible to determine the compression stroke of the engine with a simple configuration. In addition, it is not necessary to hold data such as a map depending on the power supply voltage and temperature conditions, and the memory capacity can be reduced. Further, since the compression stroke of the engine can be determined even in the processing cycle having a low processing priority, it is not necessary to increase the load of the task having a high processing priority such as synchronizing with the crank pulse. Further, since the crank position detection signal is not used, the compression stroke of the engine can be determined regardless of the accuracy of detecting the crank position. Further, it is possible to suppress erroneous determination of the compression top dead center due to a drop in the power supply voltage at the start of the reverse rotation operation.

Further, according to the electronic control device according to the second aspect of the present invention, the control unit gradually increases the duty to a predetermined value, so that the compression stroke of the engine can be determined more reliably with a simple configuration. can do.

Further, according to the electronic control device according to the third aspect of the present invention.
The voltage of the battery is a predetermined threshold value after the determination unit determines whether or not the elapsed time from the start of driving of the electric motor is equal to or longer than the predetermined time. When it becomes less than, it is determined that the engine stroke is in the compression stroke. Therefore, the compression stroke of the engine can be determined more reliably and practically with a simple configuration.

Further, according to the electronic control device according to the fourth aspect of the present invention, the drive of the electric motor rotates the crank shaft in the direction opposite to that during the operation of the engine. It is possible to accurately determine the compression stroke of the engine and to contribute to a more reliable start of the engine.

Further, according to the electronic control device according to the fifth aspect of the present invention, since the engine is a single-cylinder internal combustion engine, it is possible to more reliably determine the compression stroke of the engine with a simple configuration. ..

FIG. 1 is a circuit diagram showing a configuration of an electronic control device according to an embodiment of the present invention. FIG. 2 is a flowchart showing an example of the flow of the compression stroke determination process executed by the electronic control device in the present embodiment. FIG. 3 shows an example of the relationship between the reverse operation start time and duty drive end time in the compression stroke determination process executed by the electronic control device in the present embodiment and the duty of the three-phase AC generator, and the elapsed time from the reverse operation start time. It is a figure which shows the schematic example of time, and the example of the detection time of the crank position in step S11 of FIG.

Hereinafter, the electronic control device according to the embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

〔composition〕
First, the configuration of the electronic control device according to the embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a circuit diagram showing a configuration of an electronic control device according to the present embodiment.

As shown in FIG. 1, the electronic control device 100 in the present embodiment is typically mounted on a vehicle such as a motorcycle, and a lead battery 101, which is a secondary battery, is charged by a three-phase AC generator 110. The engine is provided with an ECU (Electronic Control Unit) 130 that starts the engine by rotating the crank shaft of the engine, which is a single-cylinder internal combustion engine, using the three-phase AC generator 110.

Reference numeral 102 in the figure indicates a voltage sensor that detects the voltage difference between the positive electrode and the negative electrode of the lead battery 101 as the voltage of the lead battery 101, and reference numeral 103 indicates a crank angle that detects the rotation angle of the crank shaft of the engine. Shows the sensor. In addition to lead batteries, nickel-metal hydride batteries and lithium-ion batteries can also be used as secondary batteries. Further, the voltage of the lead battery 101 is not limited to the one that directly detects the voltage difference between the positive and negative sides of the lead battery 101, but the voltage drop amount when the three-phase AC generator 110 is energized can be detected. If this is the case, the voltage difference between the positive side and the negative side in the electric circuit including the lead battery 101 and the three-phase alternator 110 may be detected.

Although the detailed configuration of the three-phase AC generator 110 is omitted, a coil for generating a three-phase power output (rotor winding) composed of a U-phase coil 110a, a V-phase coil 110b, and a W-phase coil 110c. ) Is wound around the stator and permanent magnets for generating field magnetic flux corresponding to the coils 110a, 110b and 110c of each phase are mounted and arranged so as to orbit the outer peripheral side of the stator. A rotor is provided, and the rotor is connected to the crank shaft of the engine.

The U-phase coil 110a is electrically connected to the other terminal of one U-phase switching element 131a of the AC / DC converter 131 and one terminal of the other U-phase switching element 131b of the AC / DC converter 131. It has a connection terminal 111a to be connected to. The V-phase coil 110b is electrically connected to the other terminal of one V-phase switching element 131c of the AC / DC converter 131 and one terminal of the other V-phase switching element 131d of the AC / DC converter 131. It has a connection terminal 111b to be connected to. Further, the W-phase coil 110c is connected to the other terminal of one W-phase switching element 131e of the AC / DC converter 131 and one terminal of the other W-phase switching element 131f of the AC / DC converter 131. It has a connection terminal 111c for electrically connecting.

Here, the change over time in the output voltage output from the three-phase alternator 110 is synchronized with the rotation of the rotor of the three-phase alternator 110 driven by the crank shaft of the engine. Specifically, assuming that one cycle of the phase in the rotation direction of the rotor (rotation phase: rotation angle) is 360 ° (one rotation of the rotor), the U-phase coil 110a is relative to one cycle of the rotation phase of the rotor. And the phase of the corresponding permanent magnet is about 120 ° earlier than the phase of the V-phase coil 110b and the corresponding permanent magnet, and the phase of the V-phase coil 110b and the corresponding permanent magnet is the phase of the W-phase coil 110c. And it is set to be about 120 ° earlier than the phase of the corresponding permanent magnet. Correspondingly, the output voltage output from the U-phase coil 110a is about 120 ° ahead of the output voltage output from the V-phase coil 110b, and the output voltage is output from the V-phase coil 110b. Is set so that the phase advances by about 120 ° from the output voltage output from the W-phase coil 110c.

The ECU 130 is an arithmetic processing unit including a microcomputer and includes an AC (Alternate Current) / DC (Direct Current) converter 131, a control unit 132, a memory 133, and a timer 134, which are power converters. The AC / DC converter 131 may be provided outside the ECU 130 as a power module or the like.

The AC / DC converter 131 typically has switching elements 131a, 131b, 131c, 131d, 131e and 131f connected in a three-phase bridge, and according to a control signal from the control unit 132, the switching elements 131a, 131b, Each of 131c, 131d, 131e and 131f is turned on or off to convert the three-phase alternating current supplied from the three-phase alternating current generator 110 into a direct current, and to supply the direct current to the lead battery 101. Further, the AC / DC converter 131 turns each of the switching elements 131a, 131b, 131c, 131d, 131e and 131f into an ON state or an OFF state according to a control signal from the control unit 132, and the DC current supplied from the lead battery 101. Is converted into a three-phase alternating current and a three-phase alternating current is supplied to the three-phase alternating current generator 110. In such a case, the AC / DC converter 131 functions as a DC / AC converter. The switching elements 131a, 131b, 131c, 131d, 131e and 131f are typically transistors, respectively, and in FIG. 1, as an example, as an N-type MOSFET (Metal-Oxide-Semiconductor Field-Effective Transistor). Each is shown.

Specifically, the AC / DC converter 131 corresponds to a pair of switching elements 131a, 131b, 131c, 131d, 131e and 131f for each of the three phases of U phase, V phase and W phase. Have.

That is, in the AC / DC converter 131, when the pair of U-phase switching elements 131a and the switching element 131b are electrically connected, the switching element 131a is in the on state, and the switching element 131b is in the off state. The U-phase output voltage is set to a high level, and the U-phase output voltage is set to a low level when the switching element 131a is in the off state and the switching element 131b is in the on state.

Further, in the AC / DC converter 131, when the pair of V-phase switching elements 131c and the switching element 131d are electrically connected, the switching element 131c is in the on state, and the switching element 131d is in the off state. The output voltage of the V phase is set to a high level, and the output voltage of the V phase is set to a low level when the switching element 131c is in the off state and the switching element 131d is in the on state.

Further, in the AC / DC converter 131, when the pair of W-phase switching elements 131e and the switching element 131f are electrically connected, the switching element 131e is in the on state and the switching element 131f is in the off state, W The output voltage of the phase is set to a high level, and the output voltage of the W phase is set to a low level when the switching element 131e is in the off state and the switching element 131f is in the on state.

Here, the switching element 131a includes a control terminal electrically connected to the control unit 132, one input terminal electrically connected to the high potential side of the lead battery 101, the switching element 131b, and three-phase AC power generation. It has the other input terminal electrically connected to the connection terminal 111a of the machine 110. The switching element 131a operates on / off according to a predetermined control signal applied from the control unit 132 to the control terminal, and when it is in the on state, a current is applied from one input terminal to the other input terminal. Flows.

Further, the switching element 131b includes a control terminal electrically connected to the control unit 132, one input terminal electrically connected to the switching element 131a and the connection terminal 111a of the three-phase AC generator 110, and a lead battery. It has the other input terminal electrically connected to the low potential side of 101. The switching element 131b operates on / off according to a predetermined control signal applied from the control unit 132 to the control terminal, and when it is in the on state, a current flows from one input terminal to the other input terminal. It flows.

Further, the switching element 131c includes a control terminal electrically connected to the control unit 132, one input terminal electrically connected to the high potential side of the lead battery 101, a switching element 131d, and a three-phase alternator. It has the other input terminal electrically connected to the connection terminal 111b of 110. The switching element 131c operates on / off according to a predetermined control signal applied from the control unit 132 to the control terminal, and when it is in the on state, a current flows from one input terminal to the other input terminal. It flows.

Further, the switching element 131d includes a control terminal electrically connected to the control unit 132, one input terminal electrically connected to the switching element 131c and the connection terminal 111b of the three-phase AC generator 110, and a lead battery. It has the other input terminal electrically connected to the low potential side of 101. The switching element 131d operates on / off according to a predetermined control signal applied from the control unit 132 to the control terminal, and when it is in the on state, a current flows from one input terminal to the other input terminal. It flows.

Further, the switching element 131e includes a control terminal electrically connected to the control unit 132, one input terminal electrically connected to the high potential side of the lead battery 101, a switching element 131f, and a three-phase alternator. It has the other input terminal electrically connected to the connection terminal 111c of 110. The switching element 131e operates on / off according to a predetermined control signal applied from the control unit 132 to the control terminal, and when it is in the on state, a current flows from one input terminal to the other input terminal. It flows.

Further, the switching element 131f includes a control terminal electrically connected to the control unit 132, one input terminal electrically connected to the switching element 131e and the connection terminal 110c of the three-phase AC generator 110, and a lead battery. It has the other input terminal electrically connected to the low potential side of 101. The switching element 131f operates on / off according to a predetermined control signal applied from the control unit 132 to the control terminal, and when it is in the on state, a current flows from one input terminal to the other input terminal. It flows.

The control unit 132 controls the operation of the entire ECU 130 by reading the necessary control program and control data from the memory 133 and executing the control program. The control unit 132 is connected to the voltage sensor 102 and the crank angle sensor 103, and has an electric signal indicating the voltage of the lead battery 101 detected by the voltage sensor 102 and electricity indicating the rotation angle of the crank shaft detected by the crank angle sensor 103. It is configured so that a signal is input. Further, the control unit 132 includes a voltage detection unit 132a and a determination unit 132b as functional blocks.

Further, the control unit 132 executes a compression stroke determination process described in detail later, and in the compression stroke determination process, the voltage detection unit 132a detects the voltage of the lead battery 101 via the voltage sensor 102. When the voltage of the battery 101 at the time when the three-phase AC generator 110 starts driving the crank shaft of the engine and thereafter becomes less than a predetermined threshold value, the determination unit 132b is in the compression stroke of the engine. It is to judge that. At this time, the voltage of the battery 101 becomes equal to or higher than a predetermined threshold in the period from the start of driving of the crank shaft of the engine by the three-phase AC generator 110 to the determination of the compression stroke by the determination unit 132b. The duty for driving the three-phase alternator 110 is controlled so as to be continuously maintained.

Necessary control programs and control data are stored in the memory 133. The timer 134 executes various timekeeping processes according to the control signal from the control unit 132.

In the electronic control device 100 having such a configuration, when the engine is started by rotating the crank shaft of the engine using the three-phase alternator 110, the control unit 132 executes the compression stroke determination process shown below. Thereby, with a simple configuration, the compression stroke determination, which is a determination indicating that the engine stroke is in the compression stroke, and more specifically, the position of the piston of the engine is at the compression top dead center, is performed. Hereinafter, the operation of the control unit 132 when executing the compression stroke determination process will be described with reference to FIGS. 2 and 3.

[Compression stroke judgment process]
FIG. 2 is a flowchart showing an example of the flow of the compression stroke determination process executed by the electronic control device 100 in the present embodiment. Further, FIG. 3 shows an example of the relationship between the reverse rotation operation start time and duty drive end time in the compression stroke determination process executed by the electronic control device 100 in the present embodiment and the duty of the three-phase AC generator, reverse rotation. It is a figure which shows the schematic example of the elapsed time from the operation start time, and the example of the detection time of the crank position in step S11 of FIG.

The compression stroke determination process shown in FIG. 2 starts at the timing when the ignition switch of the vehicle is switched from the off state to the on state and the ECU 130 of the electronic control device 100 operates, and the compression stroke determination process proceeds to the process of step S1. In the compression stroke determination process, when the crank shaft is rotated (normal rotation) in the same positive direction as during engine operation, the engine piston is compressed so as to move from before the compression top dead point to after the compression top dead point. From the viewpoint of making it possible to reliably overcome the top dead point, the engine is started by rotating (reversing) the crank shaft in the direction opposite to that during engine operation, but in principle, It is also possible to execute the compression stroke determination process applied when starting the engine by rotating the crank shaft in the same direction as during operation of the engine.

In the process of step S1, the control unit 132 rotates the crank shaft in the direction opposite to that during the engine operation by starting the drive of the three-phase AC generator 110 (electric motor) using the power of the lead battery 101. To output a control signal instructing the AC / DC converter 131 to start the engine by rotating the crank shaft of the engine in the direction opposite to that during the operation of the engine by using the three-phase AC generator 110. Prior to that, the timing operation of the timer 134 is started, and the time when the three-phase AC generator 110 starts the reverse operation (reverse start time) is acquired and stored in the memory 133 based on the initial count value at the start. Equally hold. As a result, the process of step S1 is completed, and the compression stroke determination process proceeds to the process of step S2. The reversal start time is shown at time t = T0 in FIGS. 3 (a) and 3 (b), respectively.

In the process of step S2, the voltage detection unit 132a detects as the initial value of the current voltage (motor drive voltage) V of the lead battery 101 via the voltage sensor 102, and the control unit 132 detects such an initial value as a predetermined threshold value. It is possible to confirm that it is Vth or higher. As a result, the process of step S2 is completed, and the compression stroke determination process proceeds to the process of step S3. If the initial value of the voltage V of the lead battery 101 is less than the predetermined threshold value Vth, the compression stroke determination process this time can be terminated as it is.

In the process of step S3, the control unit 132 acquires the current time t based on the current count value of the timer 134. As a result, the process of step S3 is completed, and the compression stroke determination process proceeds to the process of step S4.

In the process of step S4, the control unit 132 shows the relationship between the elapsed time (t−T0) from the reverse operation start time T0 to the current time t and the duty value for driving the three-phase AC generator 110. From the duty table, the duty value corresponding to the elapsed time from the reverse operation start time T0 to the current time t acquired in the process of step S3 is searched. The duty table is preset and stored in the memory 133, and as shown in FIG. 3A, the duty value is from the reverse rotation operation start time T0 to the duty drive end time TE. May be set to be held at a constant value, or as shown in FIG. 3 (b), the duty value becomes a predetermined value (100 in the illustrated example) as the elapsed time from the reverse rotation drive start time T0 increases. Although it is indicated by%, it may be set to gradually increase to 80%, 90%, etc.). Further, at this time, the duty value may be corrected by multiplying the duty value by a correction coefficient calculated from the vehicle-related states such as the engine temperature, the atmospheric temperature, the throttle temperature, and the voltage of the lead battery 101. .. As a result, the process of step S4 is completed, and the compression stroke determination process proceeds to the process of step S5.

In the process of step S5, the control unit 132 outputs a control signal capable of driving the three-phase AC generator 110 with the duty value searched for in the process of step S4 to the AC / DC converter 131, thereby leading the lead. The electric power of the battery 101 is used to start driving the three-phase alternator 110 to rotate the crank shaft in the direction opposite to that during the operation of the engine. At this time, the drive current of the three-phase AC generator 110 from the start of the reverse operation is limited so that the voltage of the lead battery 101 can be maintained at a predetermined threshold value Vth or higher. As a result, the process of step S5 is completed, and the compression stroke determination process proceeds to the process of step S6.

In the process of step S6, the voltage detection unit 132a detects the current voltage (motor drive voltage) V of the lead battery 101 while the three-phase AC generator 110 is being driven via the voltage sensor 102. As a result, the process of step S6 is completed, and the compression stroke determination process proceeds to the process of step S7.

In the process of step S7, the determination unit 132b determines whether or not the value of the motor drive voltage V detected in the process of step S6 is less than a predetermined threshold value Vth. As a result of the determination, when the motor drive voltage V is less than the predetermined threshold value Vth (step S7: Yes), the determination unit 132b advances the compression stroke determination process to the process of step S11. On the other hand, when the motor drive voltage V is equal to or higher than the predetermined threshold value Vth (step S7: No), the determination unit 132b advances the compression stroke determination process to the process of step S8. The predetermined threshold voltage Vth is, for example, a value (V3 × K) obtained by multiplying the minimum battery voltage V3 at the starting compression top dead point obtained by the experiment by the correction coefficient K according to the water temperature and the battery voltage. Alternatively, a value (V3-K') obtained by subtracting the correction coefficient K'from the minimum battery voltage V3 can be used.

In the process of step S8, the control unit 132 acquires the current time t based on the count value of the timer 134. As a result, the process of step S8 is completed, and the compression stroke determination process proceeds to the process of step S9.

In the process of step S9, the control unit 132 calculates the elapsed time T1 (= t−T0) from the reverse operation start time T0 to the current time t acquired in the process of step S8. As a result, the process of step S9 is completed, and the compression stroke determination process proceeds to the process of step S10.

In the process of step S10, the determination unit 132b determines whether or not the elapsed time T1 calculated in the process of step S9 is less than the predetermined time. As a result of the determination, when the elapsed time T1 is less than the predetermined time (step S10: Yes), the determination unit 132b returns the compression stroke determination process to the process of step S3. On the other hand, when the elapsed time T1 is equal to or longer than the predetermined time (step S10: No), the determination unit 132b advances the compression stroke determination process to the process of step S11.

In step S11, the determination unit 132b is, respectively illustrated via a crank angle sensor 103 detects the rotation angle of the current crankshaft (current crank position) (FIGS. 3 (a) and 3 (b) At time t = T ), the detected current crank position is determined to be the compression top dead center. If the motor drive voltage V lower than the predetermined threshold voltage Vth cannot be detected within the predetermined time, the determination unit 132b may determine that the reverse rotation operation is started from the compression top dead center. As a result, the process of step S11 is completed, and the compression stroke determination process proceeds to the process of step S12.

In the process of step S12, the control unit 132 ends the reverse operation of the crank shaft of the engine by stopping the driving of the three-phase AC generator 110. As a result, the process of step S12 is completed, and the series of compression stroke determination processes this time is completed.

In this embodiment, compression is performed by combining the rotation angle (crank position) of the crank shaft based on a signal such as the crank pulse of the crank angle sensor 103 and the voltage fluctuation of the lead battery 101 based on the output signal of the voltage sensor 102. The dead point may be determined separately from the exhaust top dead point. Specifically, attention may be paid to the voltage near the exhaust top dead center and the voltage near the compression top dead center, and the lower of these voltages may be determined as the compression top dead center.

As is clear from the above description, in the electronic control device 100 in the present embodiment, the determination unit 132b is the lead battery 101 detected by the voltage detection unit 132a after the three-phase alternator 110 starts driving the crank shaft. When the voltage becomes less than the predetermined threshold Vth, the compression stroke determination for determining that the engine stroke is in the compression stroke is performed, the control unit 132 starts driving the crank shaft of the three-phase AC generator 110. Since the duty for driving the three-phase AC generator 110 is controlled so that the voltage of the lead battery 101 is maintained at a predetermined threshold value Vth or more during the period from the time when the determination unit 132b determines the compression stroke, the duty is controlled. With a simple configuration, it is possible to determine the compression stroke of the engine. In addition, it is not necessary to hold data such as a map depending on the power supply voltage and temperature conditions, and the memory capacity can be reduced. Further, since the compression stroke of the engine can be determined even in the processing cycle having a low processing priority, it is not necessary to increase the load of the task having a high processing priority such as synchronizing with the crank pulse. Further, since the crank position detection signal is not used, the compression stroke of the engine can be determined regardless of the accuracy of detecting the crank position. Further, it is possible to eliminate the erroneous determination of the compression top dead center due to the drop in the power supply voltage at the start of the reverse rotation operation.

Further, in the electronic control device 100 of the present embodiment, since the control unit 132 gradually increases the duty to a predetermined value, it is possible to more reliably determine the compression stroke of the engine with a simple configuration.

Further, in the electronic control device 100 of the present embodiment, the voltage of the lead battery 101 becomes less than a predetermined threshold Vth within a predetermined time from the time when the determination unit 132b starts driving the three-phase AC generator 110. At that time, since it is determined that the engine stroke is in the compression stroke, it is possible to more reliably and practically determine the compression stroke of the engine with a simple configuration.

Further, in the electronic control device 100 in the present embodiment, since the three-phase AC generator 110 is controlled to rotate the crank shaft in the direction opposite to that during the operation of the engine, it has a simple configuration and is more accurate. Well, it is possible to determine the compression stroke of the engine and to contribute to a more reliable start of the engine.

Further, since the electronic control device 100 in the present embodiment targets an engine which is a single-cylinder internal combustion engine, it is possible to more reliably determine the compression stroke of the engine with a simple configuration. ..

The present invention is not limited to the above-described embodiment in terms of the type, arrangement, number, etc. of the constituent elements, and deviates from the gist of the invention, such as appropriately substituting such constituent elements with those having the same effect. Of course, it can be changed as appropriate as long as it is not.

As described above, the present invention can provide an electronic control device capable of determining the compression stroke of an engine with a simple configuration, and due to its general-purpose universal nature, it is electronic for vehicles such as motorcycles. It is expected that it can be widely applied to control devices.

100 ... Electronic control device 101 ... Lead battery 102 ... Voltage sensor 103 ... Crank angle sensor 110 ... Three-phase alternator 130 ... ECU
131 ... AC / DC converter 132 ... Control unit 132a ... Voltage detection unit 132b ... Judgment unit 133 ... Memory 134 ... Timer

Claims (5)

In an electronic control device provided with a voltage detector that detects the voltage of a battery that supplies electric power to an electric motor that drives the crank shaft of an engine that is an internal combustion engine to rotate.
When the voltage of the battery detected by the voltage detection unit after the electric motor starts driving the crank shaft becomes less than a predetermined threshold value, compression for determining that the stroke of the engine is in the compression stroke. Judgment unit that judges the process and
A control unit that controls the duty for driving the electric motor,
Equipped with
When the voltage of the battery detected by the voltage detection unit after the electric motor starts driving is not less than the predetermined threshold value, the determination unit starts from the time when the electric motor starts driving. an electronic control unit elapsed time is when Ru der predetermined time or more, stroke of the engine and judging that it is in the compression stroke. The electronic control device according to claim 1, wherein the control unit gradually increases the duty to a predetermined value. The determination unit determines that the voltage of the battery is less than the predetermined threshold value after the electric motor starts driving and before determining whether or not the elapsed time is equal to or longer than the predetermined time. The electronic control device according to claim 1 or 2, wherein when the engine stroke is determined to be in the compression stroke. The electronic control device according to any one of claims 1 to 3, wherein the drive of the electric motor rotates the crank shaft in a direction opposite to that during operation of the engine. The electronic control device according to any one of claims 1 to 4, wherein the engine is a single-cylinder internal combustion engine.

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