JP6457840B2 - Control device for internal combustion engine and control method using the same - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine and a control method using the same, and more particularly to a control device for an internal combustion engine suitable for an internal combustion engine for a batteryless system and a control method using the same.

  In order to reduce weight and ease of maintenance, a so-called battery-less internal combustion engine not equipped with a battery is widely used in kick start type two-wheeled vehicles, recoil start type lawn mowers, and the like. An internal combustion engine equipped with a recoil start type starter is used for an outboard motor or the like in preparation for a case where the battery cannot be used due to loss of function even if the battery is mounted. In the present invention, a control device for a machine that can be operated even when the battery function is absent or lost is hereinafter referred to as a batteryless control device.

  An example of an engine start system including a batteryless control device is described in Patent Document 1. In the engine start system described in this publication, the engine is started by a kick starter. When the voltage generated by the generator exceeds a predetermined value, the ECM is activated and outputs a signal to the general load relay to cut off the power supply to the general load. When the engine speed reaches the first set value, the injector and the ignition coil are operated. When the engine speed reaches the second set value and reaches the first set value, when the predetermined time has elapsed, the interruption of the power supply to the general load is released.

  Another example of a control device for a batteryless internal combustion engine is described in Patent Document 2. In the power supply device described in this publication, power generated by an AC generator is supplied to a power supply line via a regulator in order to simultaneously ensure the starting performance and the stability of the power supply voltage during load operation. At that time, the first and second capacitors are connected in parallel, and a switch is interposed in the second capacitor. After the switch is turned on and off to charge the first capacitor, the second capacitor is charged.

JP 2007-192170 A JP 2005-344651 A

  For example, a battery-less internal combustion engine used for motorcycles employs a kick start system, so that the crankshaft of the internal combustion engine (engine) is rotated by a passenger's kick and is directly or connected to the crankshaft. A generator attached to a flywheel or the like provided through the means generates power. The electric power generated by the generator is supplied to a capacitor connected via a regulator, and is used as a power source for the fuel injection system in the subsequent engine rotation.

  By the way, in a batteryless engine, in order to achieve a reliable start of the engine, the capacity of the capacitor is reduced so that the engine can be started even if the electric power generated by the first kick is small. By reducing the capacity of the capacitor, it is possible to store the power necessary for the operation power source of the microcomputer included in the control device in the capacitor by one kick operation.

  Since the capacitor capacity is reduced to ensure startability, the power source of the engine control unit (ECU) is immediately lost when the engine is stopped. For this reason, the microcomputer of the ECU stops, and there is a possibility that the engine stop pre-processing necessary when the engine is stopped cannot be performed. In general-purpose engines used in recent years, even when the engine is suddenly stopped, the microcomputer performs processing such as recording the operation time until the stop and the stop position of the motor in the EEPROM which is a nonvolatile memory. If lost, these processes become impossible.

  In the engine start system described in Patent Document 1, the startability of the engine is improved by switching the supply of electric power generated by the generator to the general load in accordance with the engine speed. However, no consideration is given to ensuring the operation of the microcomputer included in the ECM when the engine is stopped, particularly when the engine is stopped suddenly.

  In Patent Document 2, the power generated by the generator is supplied to two capacitors connected in parallel, and the power stored in these capacitors is also supplied to the load. Here, the microcomputer included in the power supply device generally performs a stop process when the engine is stopped. However, when the engine is suddenly stopped (engine stalled), the power is rapidly lost. At this time, since power is also supplied to the DC load or the like, the microcomputer is not necessarily supplied with power for continuing the stop processing operation.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a battery-less control device for an internal combustion engine that improves the engine startability and also performs a stop processing operation by a microcomputer even when the engine stops abnormally. Is to be able to execute it reliably.

A feature of the present invention that achieves the above object is for a batteryless internal combustion engine that controls an internal combustion engine by electric power generated by an AC generator attached directly to the end of a crankshaft of the internal combustion engine or via a power transmission device. The control device includes a microcomputer for controlling the operation of the internal combustion engine, a voltage regulator for power supply of the microcomputer that supplies power to the microcomputer , and a built-in regulator that rectifies and smoothes the power generated by the AC generator. A first capacitor having a small capacity and a plurality of second capacitors each having a larger capacity than the first capacitor are connected in parallel between the regulator and the voltage regulator for the microcomputer power supply. There is in being.

In this feature, the switching means for switching the second capacitor is a MOSFET, and it is preferable that the microcomputer controls the driving of the MOSFET, and the timing at which the microcomputer commands the plurality of switching means is set for each switching means. It is desirable that the switching is performed sequentially as the rotational speed of the internal combustion engine increases, and when the switching interval of the switching means is equal to or shorter than a predetermined time, it is preferable not to switch until the predetermined time is reached. The plurality of second capacitors may be arranged between the microcomputer power supply voltage regulator and the microcomputer instead of being arranged between the built-in regulator and the microcomputer power supply voltage regulator.

Further, instead of disposing a plurality of second capacitors between the built-in regulator and the microcomputer power supply voltage regulator, a single second capacitor having a larger capacity than the first capacitor is connected to the built-in regulator and the voltage regulator. Connected between the microcomputer power supply voltage regulator or between the microcomputer power supply voltage regulator and the microcomputer, the FET is connected in series to the second capacitor, and the microcomputer has a rotation speed range in which the rotation speed of the internal combustion engine is predetermined. Then, the FET may be PWM-driven to charge the second capacitor by switching from the electrically disconnected state to the connected state.

Furthermore, instead of arranging one second capacitor between the built-in regulator and the microcomputer power supply voltage regulator, the second capacitor is arranged between the microcomputer power supply voltage regulator and the microcomputer, and the microcomputer PWM-drives the FET. Then, the second capacitor may be charged by switching from the electrically disconnected state to the connected state.

Another feature of the present invention that achieves the above object is to provide a control method for a batteryless internal combustion engine in which the control device for the internal combustion engine controls the internal combustion engine by the electric power generated by the AC generator attached to the internal combustion engine. The control device includes a first capacitor between a microcomputer power supply voltage regulator that supplies power to the microcomputer and a built-in regulator to which the output of the AC generator is input, and the built-in regulator and the microcomputer power supply. provided between use voltage regulators or said voltage regulator microcomputer power between the microcomputer, connected in parallel to the power supply line, the first second capacitor capacity is more mass than the capacitor, the rotation speed of the internal combustion engine When a plurality of predetermined rotational speeds are reached, an electrical disconnection state is established using the switching means. There is sequentially switched it to La connection state.

  In this feature, the plurality of second capacitors may not be switched until the predetermined time is reached when the electrical connection state is not switched at the same time and the switching interval of the switching means is equal to or shorter than the predetermined time. Preferably, the plurality of second capacitors are electrically disconnected when the internal combustion engine is started, and once connected, it is desirable to maintain the electrical connection state until the control device of the internal combustion engine is reset.

Further, in this feature, instead of the plurality of second capacitors, one second capacitor having a larger capacity than the first capacitor is connected between the built-in regulator and the microcomputer power supply voltage regulator or the microcomputer power supply. Connected between the voltage regulator and the microcomputer, and when the number of PWM charging times or PWM charging time of the second capacitor reaches a predetermined value, it is considered that the charging is completed, and thereafter the control device of the internal combustion engine is reset It is desirable to maintain an electrical connection.

  According to the present invention, the electric power generated by the generator attached to the engine is disconnected from the first capacitor having a small capacity that is always connected via the regulator, and is charged at a predetermined rotational speed or more, and is separated at the time of starting. Since the second capacitor that maintains the connection state until the control device is reset is used as the microcomputer drive power source, in the battery-less internal combustion engine control device, the microcomputer is improved even when the engine is abnormally stopped while improving the engine startability. It is possible to reliably execute the stop processing operation.

It is a schematic diagram of one Example of the control apparatus for internal combustion engines which concerns on this invention. It is a control flowchart of the control apparatus shown in FIG. It is a figure explaining the voltage which generate | occur | produces when starting an engine using the control apparatus shown in FIG. It is a figure which shows the detail of FIG. It is a figure explaining the voltage generate | occur | produced when an engine is normally stopped using the control apparatus shown in FIG. It is a figure explaining the voltage which generate | occur | produces when carrying out an abnormal stop of an engine using the control apparatus shown in FIG. It is a figure which shows the detail of FIG. 5A, 5B. It is a schematic diagram of the other Example of the control apparatus for internal combustion engines which concerns on this invention. It is a figure explaining the voltage which generate | occur | produces when starting an engine using the control apparatus shown in FIG. It is a figure explaining the voltage generate | occur | produced when an engine is stopped normally using the control apparatus shown in FIG. It is a figure explaining the voltage which generate | occur | produces when carrying out an abnormal stop of an engine using the control apparatus shown in FIG. FIG. 6 is a schematic view of still another embodiment of the control device for an internal combustion engine according to the present invention. FIG. 6 is a schematic view of still another embodiment of the control device for an internal combustion engine according to the present invention. It is a figure explaining the charge timing of the capacitor | condenser in the Example shown to FIG. 10A and B. FIG.

  Several embodiments of a control device for an internal combustion engine according to the present invention will be described below with reference to the drawings. In the following description, a case where a batteryless internal combustion engine included in a 125 cc motorcycle is kick-started and stopped will be described as an example. However, the present invention is limited to an internal combustion engine for a motorcycle. Instead, it can also be applied to lawn mowers and outboard motor internal combustion engines. Further, in the case of an outboard motor, it is common to have a battery, but even if the battery function is lost for some reason, it will be in the same state as a batteryless internal combustion engine. It is called a less internal combustion engine.

  FIG. 1 is a schematic diagram of an embodiment of a control device (ECU) included in a batteryless internal combustion engine. In the internal combustion engine 200, fuel is injected from a fuel injection device (not shown) between the cylinder and a piston that reciprocates in the cylinder, and the spark plug 210 ignites this injected fuel so that it is connected to the cylinder. The crankshaft connected to the connecting rod rotates 220 times. A flywheel magneto 230 is attached to one end side of the crankshaft 220 to reduce rotational pulsation. 4-12 poles, N poles and S poles are alternately arranged on the inner peripheral surface of the flywheel. The permanent magnet and the stator coil arranged on the inner peripheral side of the flywheel magneto A generator is configured. In this embodiment, the AC generator 240 has four poles.

  A plurality of stator coils are arranged in the circumferential direction, and some of them supply power to the microcomputer 170, the injector 271, and the ignition capacitor booster circuit 272. The remaining stator coils are connected via a regulator 250 to a general load 260 such as a fuel pump, an oil pump, or a headlight. The microcomputer 130 is used for initialization processing at the time of engine start and end processing at the time of engine stop, which will be described in detail later.

The drive unit of the microcomputer 130 of the ECU 100 includes a built-in regulator 110 that rectifies and smoothes the power generated by the AC generator 240, a capacitor (C ₀ ) 140 that temporarily stores the output of the built-in regulator 110, and a capacitor (C ₀ And a 5V regulator 120 that converts the voltage of the electric power supplied from 140 into a specified voltage of the microcomputer 130. Between the capacitor (C ₀ ) 140 and the 5V regulator 120, a fuel injection device 271 that is directly driven by the ECU 100, an ignition capacitor boosting circuit 272, and the like are connected. An ignition coil 273 is connected to the ignition capacitor booster circuit via a capacitor or the like. The ignition coil 273 generates a voltage applied to the spark plug 274.

  The ECU 100 receives signals from pulse signal detection means 241 provided in the flywheel magneto 230 for detecting the rotational speed, and these signals are processed by the microcomputer 130. The microcomputer 130 also receives signals 275 from various sensors provided in the engine 200 and various parts of the vehicle body for driving the engine.

Here, as a feature of the present invention, a plurality of second capacitors (C _{1 to} C ₃ ) 161 to 163 are connected in parallel via the MOSFETs 151 to 153 between the capacitor (C ₀ ) 140 and the 5V regulator 120. doing. The MOSFETs 151 to 153 are connected to the microcomputer 130, and their operation threshold values are individually defined in the microcomputer 130, and are operated by the microcomputer 130 in accordance with the definition.

By the way, it is desirable to always record the operation record of the engine 200 for maintenance and management of the engine 200. However, since the EEPROM used for this recording has a limited number of times of writing, the engine is practically stopped. The engine operation history and failure history information are written into the EEPROM as an end process only when the transition is confirmed. Due to the characteristic that the process is performed starting from the time when the engine stop state transition determination is determined, in the conventional battery-less internal combustion engine, the capacitor capacity is small, so the microcomputer stops before completing the end process. Therefore, in this embodiment, the power charged in the second capacitors (C _{1 to} C ₃ ) 161 to 163 can be used for these processes.

When the engine is started, initialization of the microcomputer 130 is started as soon as power is turned on after cranking is started. As soon as initialization is completed, engine control such as ignition and injection becomes possible. In order to improve the startability of the engine, it is important to start up the power supply voltage early, start the microcomputer earlier, and execute ignition / injection from an earlier time point. Therefore, the capacity of the first capacitor (C ₀ ) is reduced, the power supply voltage of the microcomputer 130 is secured early with a small amount of power generated by the AC generator 240 when the engine 200 is started, and the initialization process can be completed. .

  Further, the built-in regulator 110 serving as a power source for the direct drive loads 271 and 272 of the ECU 100 is concerned about heat generation. Therefore, in order to suppress heat generation of built-in regulator 110 as much as possible, the number of windings of AC generator 240 is increased so that the output becomes substantially flat until the engine 200 reaches a high rotational speed from a low rotational speed range. The characteristics of the AC generator 240 are set so that the characteristics can be obtained. On the other hand, there is no power margin for the following reason between the low rotation speed range and the high rotation speed range from the start of the engine 200.

  In the low rotational speed range from the start of the engine 200, the amount of power generated by the AC generator 240 is small, and at the start, the injection time of the injector is long and the power consumption is large. There is also a need to charge a smoothing capacitor. On the other hand, in the high rotation speed range, the load of the DC-DC converter and the injector that operate to charge the ignition capacitor increases, so that the power consumption itself is large.

In the middle rotation speed region of engine 200, the amount of power required by the fuel injection device is less than the amount of power generated by the AC generator, so that a surplus of power is generated. Therefore, the plurality of second capacitors (C _{1 to} C ₃ ) 161 to 163 are charged with this surplus power. At that time, since a plurality of capacitors (C _{1 to} C ₃ ) 161 to 163 are charged step by step, the amount of power required for charging each capacitor (C _{1 to} C ₃ ) 161 to 163 is small, A temporary voltage drop during charging of the capacitors (C _{1 to} C ₃ ) 161 to 163 can be reduced, and a stable voltage can be supplied to the microcomputer 130.

Next, the operation of the ECU 100 according to the present invention shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a flowchart showing an outline of the operation of the ECU when starting the engine. When the crankshaft 220 is rotated by kick start, the AC generator formed on the flywheel attached to the shaft end of the crankshaft 220 generates power, and the first capacitor (C ₀ ) 140 starts to be stored via the built-in regulator 110. Is done. When ignition of fuel by the spark plug proceeds successfully, the engine 200 increases the rotational speed.

It reaches the first set value _{N 1} to the rotational speed of the crank shaft 220 is determined in advance (step S210), and carrying out the connection between the single capacitor _{(C 1)} 161 in the plurality of second capacitors (MOSFET 151 Is turned on) (step S220). Here, the setting rotational speed _{N 1} is, AC generator 240 to the ECU directly drive the load 271 and 272 to the rotational speed of the excess power be supplied power starts to occur, is desirable.

Increase in the rotational speed of the engine 200 is continued, When the second set value N ₂ to reach a predetermined (step S230), carrying out the connection with the second other one of the capacitors in the capacitor (C ₂₎ 162 (Turn on the MOSFET 152). Charging of the capacitor (C ₂ ) 162 is started (step S240). After further rotation speed reaches the third predetermined value N ₃ a predetermined elevated (step S240), carried out the connection permission with the second remaining one capacitor in the capacitor (C ₃₎ 163, a capacitor Charging of (C ₃ ) 163 is started (step S260).

Here, the setting rotational speed N ₃ is good to the rotational speed of the high rotational speed region to reach the surplus electric power is not generated rotational speed sufficiently lower rotational speed than the engine. The set rotational speed N ₂ is an appropriate value between the set rotational speeds N ₁ and N ₃ , and the capacitor (C ₁ ) 161 and the capacitor (C ₂ ) 162 or the capacitor (C ₂ ) 162 and the capacitor (C ₃ ) 163 It is desirable to provide sufficient spacing so that the two capacitors are not switched substantially simultaneously.

In the above procedure, when switching the plurality of second capacitors (C _{1 to} C ₃ ) 161 to 163, switching is not performed unless a predetermined time has elapsed so as not to shorten the switching interval. This is to prevent the occurrence of a situation where the charging of the second capacitors (C _{1 to} C ₃ ) 161 to 163 becomes insufficient if the switching time is too short.

The above is a description of the principle of charging by providing a plurality of second capacitors (C _{1 to} C ₃ ) 161 to 163. Next, a specific example of starting the engine 200 is shown in FIGS. A stop example of the engine 200 will be described using simulation results shown in FIGS. 5 and 6, respectively. At that time, shown in Comparative Example only capacitor corresponding to the first capacitor C ₀ of the present invention when included in the microcomputer power supply unit, as an example of a conventional ECU.

FIG. 3 shows changes over time in the power supply voltage of ECU 100 output from built-in regulator 110 and the power supply voltage of microcomputer 130 output from 5V regulator 120 when engine 200 is started. FIG. 3A is according to the present example, and FIG. 3B is a time change according to the comparative example. When kicking is started by kicking the pedal at time t ₀ , the power supply voltage of the ECU 100 indicated by the alternate long and short dash line 301 starts to increase, and finally increases to about 14V. On the other hand, the microcomputer power supply voltage indicated by the solid line 302 starts to increase around 1 crank start time t ₁ when the cylinder 1 reciprocates. Then, the threshold voltage _Vth at which the microcomputer 130 can be operated is exceeded before reaching the _second cranking start time t2. Since the microcomputer 130 is ready for operation, start the initial process in time t _is, finish the initial processing to the second than the cranking start time t ₂ before the time t _ie. Therefore, it is possible to advance the ignition operation of the engine (first explosion) to around 2 cranking start t _2.

On the other hand, in the comparative example in which a capacitor having a larger capacity than that of the first capacitor C0 is connected, the voltage V _{th that} can drive the microcomputer 130 by the _first and _second cranking start times t ₁ and t _2. Not reached. Then, finally between the second cranking start time t ₂ of the third cranking start time t ₃ reaches the threshold voltage V _th, it starts the initialization process. It takes a processing time P _in for initialization processing, the end time of the initialization process is at a later time than the third cranking start time t _3. That is, in this comparative example, the initialization can be completed only after three crankings are performed, and the first explosion of the engine 200 is the fourth cranking or later at the shortest. In the motorcycle as normal starting device kick starter battery-less, when the initial combustion does not occur until about the third cranking start time t _3, the start of the engine 200 is difficult.

  Details of the ECU when the engine 200 is started will be described with reference to FIG. FIG. 4A shows the time variation of the voltage of each part of the ECU 100 of the present embodiment as in FIG. 3A, and FIG. 4B shows the ECU 100 in the comparative example having the same capacitor arrangement as that in FIG. It is a time change of the voltage of each part. A curve 400 is a voltage waveform after full-wave rectification of the voltage generated by the AC generator 240 by the built-in regulator, and is a voltage waveform at a point indicated by an arrow A in FIG. A voltage waveform indicated by a one-dot chain line 401 is a voltage waveform at a point indicated by an arrow B in FIG. A voltage waveform indicated by a solid line 402 is a voltage waveform on the output side of the 5V regulator 120 indicated by an arrow C in FIG. Since the AC generator 240 of this embodiment has four poles, four peaks of the full-wave rectified value correspond to one cranking.

In this embodiment, since as much as possible reduce the charging time of the first capacitor (C ₀₎ 140 to reduce the capacity of the first capacitor (C ₀₎ 140 as compared with the comparative example described below, first the cranking start when _{t 1} microcomputer supply voltage 402 back and forth is reached microcomputer drivable voltage threshold _{V th.} At this time, since the capacity (C ₀ ) 140 of the first capacitor is small, the smoothing action is small, and the voltage ripple is large in both the microcomputer voltage curve 402 and the ECU power supply voltage 401.

On the other hand, in the comparative example in which only the first capacitor having a large capacity is provided, both the power supply voltage curve of the ECU 100 indicated by the alternate long and short dash line 411 and the driving voltage of the microcomputer 130 indicated by the solid line 412 are smooth with almost no ripple. It is a voltage rise curve. This is because the smoothing action is increased because the capacity of the first capacitor is large. On the other hand, the storage time of the first capacitor becomes long, the time for the drive voltage curve 412 of the microcomputer 130 to reach the drivable voltage threshold V _th of the microcomputer 130 and the time for the power supply voltage curve 411 of the ECU to reach 14 V are the second time. which is later than the crank at the start of t _2. Therefore, according to the present embodiment, the first explosion of the engine 100 can be accelerated compared to the comparative example, and the engine start probability can be increased.

  In the comparative example, when the capacity of the first capacitor is reduced as in the present embodiment, the same effect as in the present embodiment can be obtained when the engine is started, but the second capacitor is not provided, so that the stop is stopped. Insufficient power supply during processing. This will be described later.

  Next, the case where the engine 200 having the ECU 100 of the above embodiment is stopped will be described with reference to FIGS. 5A, 5B and 6. FIG. 5A shows a case of normal stop processing, and FIG. 5B shows a case of abnormal stop processing such as engine stall.

  In FIG. 5A (a), a solid line 500 indicates a change in the rotational speed of the engine 200. FIG. 5A (b) shows a change in the ECU power supply voltage when the ECU 100 of this embodiment is used by a one-dot chain line 501 and a change in the drive voltage of the microcomputer 130 by a solid line 502. FIG. 5A (c) shows a case where the ECU of the comparative example is used, and a change in the ECU power supply voltage is indicated by a one-dot chain line 511, and a change in the microcomputer drive voltage is indicated by a solid line 512.

When the operation is stopped, the engine stop means is turned on at time t _k0 in order to stop the engine 200. When the engine stop means is turned on, ECU 200 stops engine 200. Due to the stop control of the engine 200 by the ECU 100, the ECU 100 starts execution of the normal operation stop process (t _s1 ) at t _k1 when the rotation speed of the engine 200 decreases and reaches the engine stop state transition fixed rotation speed. Engine 200 stops at time _tk2 .

That is, in the case of a normal operation stop, the ECU 100 starts a stop process for storing the current operation information in the nonvolatile memory (EEPROM) at the engine stop state transition determination determination t _k1 (t _k1 = t _s1 ). The stop process requires a stop process time _Pk and ends at the stop process end time _ts2 . At this time, the time t _d during which the power supply voltage of the microcomputer 130 decreases to the threshold voltage V _th is later than the stop processing end time t _s2 , so that the power supply of the microcomputer 130 is secured until the writing to the EEPROM is completed. The writing is completed normally.

  Even if the rotational speed of the engine 200 decreases, the rotational speed of the engine 200 is recovered in the case where the rotational speed does not stop until the engine stop state transition finalized rotational speed is reached. In this case, the stop process is not executed, and writing to the EEPROM is not performed. This avoids unnecessary writing to the storage area of the EEPROM.

On the other hand, also in the comparative example having no second capacitor, when the engine stop means is turned on, the stop process is started at the same timing as in the present embodiment. However, since the second capacitor is not provided, the power supply voltage of the microcomputer becomes equal to or lower than the threshold voltage _Vth before the time _Pk necessary for continuing the stop process elapses. In other words, the time t _d when the threshold voltage _Vth or less is before the time t _s2 at which the stop process will be completed, the microcomputer power is lost before the writing to the EEPROM is completed, resulting in abnormal writing. .

  A solid line 500 in FIG. 5B (a) represents a change in the rotational speed of the engine 200 during an abnormal stop. In FIG. 5B (b), the change in the ECU power supply voltage when the ECU 100 of this embodiment is used is indicated by a one-dot chain line 501 and the change in the drive voltage of the microcomputer 130 is indicated by a solid line 502. FIG. 5B (c) shows a case where the ECU of the comparative example is used, and a change in the ECU power supply voltage is indicated by a one-dot chain line 511, and a change in the microcomputer drive voltage is indicated by a solid line 512.

In the case of an abnormal stop where the engine 200 suddenly stops due to a trouble such as engine stall, the engine 200 stops suddenly as shown by the solid line in FIG. 5B (a). On the other hand, the microcomputer 130 of the ECU 100 detects the stop of the engine 200 with a time delay of t _{ed as} indicated by the one-dot chain line in FIG. This is because the pulsar signal is suddenly interrupted due to a sudden engine stall or the like, the microcomputer 130 cannot update the rotation speed, and maintains the rotation speed before the engine stop for the engine stop determination time t _ed .

When ECU 100 determines the engine stall, engine 200 sets the rotational speed to zero. Since this rotation speed is lower than the rotation speed at which the engine stop state transition determination is normally performed, the ECU 100 records the engine operation information, the cause of the stop, and the like when the rotation speed of the engine 200 is set to 0. The process is started (t _e1 ).

The abnormal stopping process is time consuming _{P e,} the engine 200 is fed from the second capacitor (C1 to C3) 161 to 163 also stops the microcomputer 130 to the time _{t d} to the microcomputer 130 is the threshold Power that is equal to or higher than the voltage _Vth is supplied. Since the time t _d is later than the abnormality stop processing end time elapses abnormal stopping process time P _e t _e2, even when abnormal stop of the engine 200, the power supply of the microcomputer 130 is secured to the completion of the write operation to the EEPROM And writing is completed normally.

On the other hand, in the comparative example that does not have the second capacitor, the power supply to the microcomputer is lost rapidly after the engine 100 stops abnormally. Therefore, even if the abnormal stop process is started at the delay time t _ed after the engine stop as in this embodiment, the time t _d when the microcomputer power supply voltage becomes the threshold voltage V _th is the time required to complete the abnormal stop process. Since the power is lost before the writing to the EEPROM is completed earlier than the time t _{e2 when Pe e} elapses, normal writing cannot be performed.

As described above with reference to FIGS. 5A (b) and 5B (b), in this embodiment, since the plurality of second capacitors (C1 to C3) 161 to 163 are charged, the speed reduction of the engine 100 and Even after the stop, the supply voltage 502 to the ECU direct drive load 170 and the microcomputer 130 exceeds the microcomputer _driveable threshold voltage _Vth for a long time, and normal stop processing and abnormal stop processing after the engine 200 is stopped _tk2. processing time P _k in _either, can be secured P _e, it has become possible stopping process by the microcomputer 130. In other words, the capacities of the plurality of second capacitors (C1 to C3) 161 to 163 are set so as to be a power supply capacity capable of performing the stop process regardless of the abnormal stop process and the normal stop process.

On the other hand, in the ECU of the comparative example having only the first capacitor shown in FIGS. 5A (c) and 5B (c), the capacity of the first capacitor is the same as that of the present embodiment in order to improve the startability of the engine. The capacity is set to about. In this case, the stop process is started at the engine stop state transition determination time _tk1, and the operation information of the current operation is started to be recorded in the EEPROM. However, the supply of power from only the first capacitor is insufficient amount of power, until the processing time P _k or P _e lapse that can complete the stopping process, both the drive power supply voltage 512 and the ECU power supply voltage of the microcomputer 130 early To drop. The drive power supply voltage 512 of the microcomputer 130 _{reaches the driveable} threshold voltage _Vth or less before the stop process is completed. As a result, the stop process ends in failure, and in the worst case, a situation of data corruption occurs.

  In order to solve this problem, unlike the case of the present embodiment, the capacity of the first capacitor is increased to charge the first capacitor during normal operation of the engine so that the first capacitor is abnormally stopped. The power may be supplied from. However, in that case, the engine starting characteristics deteriorate as described above. As another solution method, if the stop process is performed at an engine speed higher than the engine speed at the time of determining the engine stop state transition fixed rotation speed, the normal stop process can be executed before the engine stops. However, if the stop process is started at a higher speed than when the engine stop state transition determination rotational speed is determined, even if the engine is not stopped, data is written to the EEPROM even if it is not stopped, and unnecessary writing is performed due to overwriting. Moreover, it cannot respond to an abnormal stop such as an engine stall.

  FIG. 6 shows in detail the voltage waveform of each part of the ECU 100 when the engine is stopped and after the engine stop state transition fixed rotational speed is determined. FIG. 6A is a voltage waveform when the ECU 100 of the present embodiment is used, and the curve indicated by the solid line 600 is a voltage waveform after full-wave rectification in the built-in regulator 110 at the position of arrow A in FIG. is there. An alternate long and short dash line 601 is a waveform of the ECU power supply voltage at the position of arrow B in FIG. 1, and a solid line 602 is a waveform of the microcomputer power supply voltage at the position of arrow C in FIG.

Since the AC generator has four poles, four peaks correspond to one rotation of the crankshaft 220 in the full-wave rectified waveform 600. Prior to the time ts2 when the ECU 100 completes the stop process, the voltage generated by the AC generator 240 is lower than the microcomputer _driveable threshold voltage _Vth . However, the microcomputer power supply voltage 602 ensures the microcomputer _driveable threshold voltage Vth until the time _ts3 after the stop processing end _ts2 due to the palace from the first capacitor and the second capacitor.

  FIG. 6B is a voltage waveform of each part of the ECU in the comparative example. In this comparative example, as in the case of FIG. 5, the ECU has only the first capacitor, and the capacity of the first capacitor is approximately the same as that of the first capacitor of this embodiment. A solid line 600 is a voltage waveform after full-wave rectification of the built-in regulator 110, an alternate long and short dash line 611 indicates an ECU power supply voltage, and a solid line 612 indicates a microcomputer power supply voltage.

Since the capacity of the first capacitor is small, the ripple is large in both the ECU power supply voltage and the microcomputer power supply voltage. Further, when the rotational speed of engine 200 decreases, the power generation amount of the AC generator cannot be covered only by the power supply from the first capacitor, and the microcomputer power supply voltage decreases to the microcomputer driveable threshold voltage at time t _ms . As is apparent from the figure, the time t _ms is before the time t _s2 at which the ECU 100 completes the normal stop process, and the stop process by the ECU ends in failure, resulting in data corruption in the worst case.

  As described above, according to this embodiment, the ECU has a relatively small first capacitor, and the charging start voltage (engine speed) connected in parallel to the first capacitor is greater than that of the first capacitor. Since it has a plurality of high second capacitors, it is only necessary to charge the first capacitor when starting the engine, and the startability can be improved. In addition, since the power can be supplied from the second capacitor when the engine is stopped after the charging of the second capacitor is completed, the stop process by the microcomputer can be surely executed even after the power supply from the AC generator is stopped.

  Further, in contrast to the conventional method in which whether or not to execute the stop process based on the engine stop state transition determined rotational speed determination, according to the present embodiment, the stop process based on the engine stop state transition determined rotational speed determination is performed. In addition, the stop process can be performed even after the stop. Therefore, it is possible to perform stop processing based on engine stop.

  The amount of rotation that the engine can maintain after being killed is determined by the force to maintain the rotation determined by the inertia of the crankshaft system and the braking force determined by the friction of each part of the engine, the compression loss in the cylinder, etc. . Therefore, for a configuration that can reliably and most easily perform the stop process, since the braking force is low in the high altitude specification, if a method of performing the stop process based on the engine stop state transition fixed rotational speed determination is adopted, It is also possible to reduce the capacity and number of the plurality of second capacitors.

Next, another embodiment of the ECU according to the present invention will be described with reference to FIGS. FIG. 7 is a schematic diagram of another embodiment, FIG. 8 is a graph showing characteristics when the engine is started, and FIG. 9 is a graph showing characteristics when the engine is stopped. This embodiment is different from the embodiment shown in FIG. 1 in the position of the 5V regulator for driving the microcomputer 130. That is, the plurality of second capacitors (C _{1 to} C ₃ ) 161 to 163 are provided on the output side of the 5V regulator 130.

  FIG. 8 is a diagram corresponding to FIG. 3, and FIG. 8A is a graph showing the power supply voltage change 801 and the microcomputer power supply voltage change 802 of the ECU 110 a when the engine is started in this embodiment. FIG. 8B shows a comparative example in which a capacitor having a total capacity equivalent to that of this embodiment is directly connected to the second capacitor connection position of this embodiment.

As shown in FIG. 8A, the microcomputer power supply voltage indicated by the solid line 802 reaches the microcomputer _driveable threshold voltage _Vth between the first cranking and the second cranking, and starts the initialization process. And before the second reaching the cranking start time t _2, to complete the initialization process. That is, since the second cranking start t ₂ allows the initial explosion of the engine 200, the engine can be started 200 in one kicking. Incidentally, a dashed line 801 is a power supply voltage variation of ECU _{100a, P in} is the time required for the initialization process.

On the other hand, in the comparative example shown in FIG. 8B, the power supply voltage of the ECU shows almost the same change as in the present embodiment as shown by a one-dot chain line 811, but the microcomputer power supply voltage shown by the solid line 812 has a large capacity. In order to charge the directly connected capacitor, the time for reaching the microcomputer _driveable threshold voltage _Vth is delayed. As a result, the initialization process start time of the _ECU t is a delay, the initialization processing end time t _ie may exceed the second cranking start time t _2, the initial explosion can not be expected until the fourth start of cranking at the time t _4, There is a risk of starting failure.

  9A and 9B are diagrams corresponding to FIGS. 5A and 5B, FIG. 9A is a diagram at the normal end, and FIG. 9B is a diagram at the abnormal end. FIGS. 9A (a) and 9B (a) are diagrams showing changes in the rotational speed of the engine 200 (solid line 900). FIGS. 9A (b) and 9B (b) show the power supply voltage of the ECU 100a according to this embodiment. It is a figure which shows the change (one-dot chain line 901) and the change of microcomputer power supply voltage (solid line 902). FIG. 9A (c) and FIG. 9B (c) are cases of the comparative example, which has only the first capacitor and has the same capacity as that of the present embodiment in order to improve the engine startability. The conventional type.

As shown in FIGS. 9A (b) and 9B (b), the change in power supply voltage of the ECU 100a is different from the embodiment shown in FIGS. 5A and 5B. That is, the ECU 100a loses its power at an early stage as compared with the embodiment of FIG. 5A and FIG. 5B, but the microcomputer power supply voltage 902 is supplied with power from the second capacitor in a normal stop state or an abnormal stop state. The microcomputer drive threshold voltage _Vth or higher is _maintained until the stop process is completed. In particular, in the abnormal stopping process to determine the like engine stall determines engine stalling the engine stop time t _k2 later time t _e1, then abnormal stopping process time P _e only microcomputer 130 must be able to operate. In this embodiment, since the microcomputer operation stop time (time when the microcomputer power supply voltage becomes _Vth ) t _ms is later than the stop process end time t _e2 , the stop process can be surely executed even in the case of an abnormal stop. .

In the comparative example, the power supply voltage of the ECU indicated by the one-dot chain line 911 shows almost the same change as the power supply voltage 901 of the present embodiment, and the power supply voltage of the ECU is lost early. On the other hand, the microcomputer power supply voltage indicated by the solid line 912 is ensured until after the engine is stopped, but is not ensured until the time t _s2 at which the stop process is finished, so the writing of the stop process to the EEPROM becomes incomplete. , End in failure.

  Also in the present embodiment, as in the first embodiment shown in FIG. 1, it is possible to achieve both improvement of engine startability and securing of stop processing time when the engine is stopped. Further, in this embodiment, since the second capacitor is directly connected to the microcomputer power supply, it is not necessary to supply power to the ECU direct drive load or the sensor system 5V regulator system (not shown), and the microcomputer power supply is ensured in any operating condition. it can. However, when power supply to the capacitor is switched, there is a possibility that the power supply line to the microcomputer may temporarily drop in voltage, so that countermeasures may be required.

  Still another embodiment of the present invention will be described with reference to FIGS. 10A, 10B, and 11. FIG. 10A corresponds to FIG. 1, and FIG. 10B corresponds to FIG. That is, FIG. 10A and FIG. 10B are the same except for the connection positions of the second capacitor 165 and the MOSFET 155. FIG. 11 is a diagram for explaining the charging timing of the capacitor in each embodiment.

In each of the embodiments so far, a plurality of second capacitors are provided, and the charge start rotation speed of the MOSFET connected to each second capacitor is changed. 10A and 10B, there is only one second capacitor 165, and the capacitance of the second capacitor 165 is sufficiently larger than the capacitance of the first capacitor 140. At the same time, when the predetermined engine speed range is reached, the MOSFET 155 is PWM driven to charge the second capacitor 165. Thereby, the same effect as the case of having a plurality of second capacitors is obtained. If the capacity of the second capacitor 165 is about the total capacity of the plurality of second capacitors (C ₁ to C ₃ ) 161 to 163, the same operation as the embodiment shown in FIGS. I can expect.

  In the embodiment shown in FIG. 1, as shown in FIG. 11 (a), the case classification is set according to the rotational speed N of the engine. As described above, during low-speed operation such as when the engine is started, the amount of electric power generated by the AC generator 240 is small. Therefore, the ignition operation of the engine and the initial process are prioritized and electric power is used for them. In this case, there is no margin in the electric power generated by the AC generator 240, and it is fully charged to charge the first capacitor 140.

  During high speed operation, the ignition operation of the engine becomes frequent, and in this case as well, there is no margin in the power generated by the AC generator 140, so the second capacitor is not charged. On the other hand, since the power generated by the AC generator has a margin in the medium speed range, the second capacitor is charged to be used as a power source during ripple suppression and stop processing.

For example, when the engine speed N is N ₁ or less, the second capacitor is not charged as a low speed region. Further, the second capacitor is not charged even if the engine speed N is N ₄ or higher. The medium speed region excluding the low speed region (N ₁ or less) and the high speed region (N ₄ or more) is divided into a plurality of stages (N ₂ , N ₃ ), and the second time only when the divided timing is indicated by the line L ₁ . Charge the capacitor.

In the embodiment shown the contrary in FIGS. 10A and 10B, as shown in FIG. 11 (b), to the transition point N ₄ and the low speed range to a high speed range of the engine speed 200 of the transition point N ₁ In the meantime, one MOSFET 155 is PWM driven at a predetermined duty ratio to charge the second capacitor 165 little by little. When the number of times of PWM charging reaches a predetermined number of times, it is considered that charging is completed, and thereafter, the ON state of MOSFET 155 is continued regardless of the rotational speed of the engine. Thereby, even if it has only one capacitor, the same operation and effect as the case of having a plurality of second capacitors can be obtained. For the determination of the completion of charging, in addition to the number of times of PWM charging, an accumulated time during which the engine rotation speed is in the middle speed range may be used.

  As described above, according to the embodiments of the present invention, the ECU of the batteryless internal combustion engine starts charging in accordance with a plurality of rotational speeds of the engine in addition to the conventional first capacitor directly connected to the built-in regulator. Since the second capacitor is provided in parallel with the first capacitor, it is possible to cope with an abnormal stop of the engine while improving the startability of the engine. Therefore, the use conditions of the batteryless engine can be expanded.

  In the above embodiment, when there are a plurality of second capacitors, the number of second capacitors is three, but the number of second capacitors is not limited to three. However, if the number of the second capacitors is increased, the cost increases and the control becomes complicated. Therefore, it is desirable that the number of capacitors be increased within an economically allowable range.

  In the above embodiment, the flywheel is provided at the end of the crankshaft and the AC generator is provided on the flywheel. However, the AC generator may obtain power from the crankshaft via a power transmission device.

DESCRIPTION OF SYMBOLS 100, 100a ... ECU (control apparatus for internal combustion engines), 110 ... Built-in regulator, 120 ... 5V regulator, 130 ... Microcomputer, 140 ... Capacitor C0, 151-153 ... MOSFET, 161-163 ... Capacitor, 200 ... Internal combustion engine (engine) , 210 ... Spark plug, 220 ... Crankshaft, 230 ... Flywheel magneto, 240 ... AC generator, 241 ... Pulse signal (rotation signal), 250 ... Built-in regulator, 260 ... General load, 271 ... Injector (ECU direct drive load) , 272, ignition capacitor booster circuit (ECU direct drive load), 273, ignition coil, 274, ignition plug, 275, sensor input, 301, 401, 501, 601, 801, 901, ECU power supply voltage according to the present invention , 302, 402, 502, 6 2, 802, 902 ... microcomputer power supply voltage according to the present invention, 311, 411, 511, 611, 811, 911 ... ECU power supply voltage according to comparative example, 312, 412, 512, 612, 812, 912 ... according to comparative example Microcomputer power supply voltage, 400 ... full wave rectified voltage, 500 ... rotational speed, 600 ... full wave rectified voltage, 900 ... rotational speed, N _{1 to} N ₃ ... rotational speed, t ₀ ... at startup, t ₁ , t ₂ , ... t _i ..., t _n ... (i) cranking start time, t _is ... initialization start time, t _ie ... initialization end time, P _in ... initialization period, V _th ... microcomputer operating threshold voltage, t _k0 ... kill switch input time, t _{k1 ...} engine stopped state transition determined rotational speed determination time, t _{k2 ...} engine stop time, t _{s1 ...} normal end processing start time, _{t s} ... successful process completion time, t _{s3 ...} microcomputer downtime according to the present invention, t _{ms ...} microcomputer downtime according to the comparative example, P k _... successful treatment period, t _{e1 ...} abnormal end processing start time, t _{e2 ...} abnormal End process end time, P _e ... Abnormal end process period, τ _{1 to} τ ₃ ... MOSFET ON time, τ ₄ ... MOSFET switching upper limit time.

Claims (11)

In a batteryless control apparatus for an internal combustion engine that controls an internal combustion engine by electric power generated by an AC generator attached directly to the end of the crankshaft of the internal combustion engine or via a power transmission device,
A microcomputer for controlling operation of an internal combustion engine, a microcomputer power supply voltage regulator for supplying power to the microcomputer , and a built-in regulator for rectifying and smoothing power generated by the AC generator, the built-in regulator and the microcomputer A first capacitor having a small capacity and a plurality of second capacitors each having a capacity larger than that of the first capacitor are connected in parallel between the power supply voltage regulators. A control device for an internal combustion engine.   2. The control apparatus for an internal combustion engine according to claim 1, wherein the switching means for switching the second capacitor is a MOSFET, and the microcomputer controls the driving of the MOSFET.   The timing at which the microcomputer instructs the plurality of switching means is different for each switching means, and is sequentially switched as the rotational speed of the internal combustion engine increases, and when the switching interval of the switching means is a predetermined time or less. 3. The control device for an internal combustion engine according to claim 2, wherein switching is not performed until a predetermined time is reached. In a control method for a batteryless internal combustion engine in which a control device for the internal combustion engine controls the internal combustion engine by electric power generated by an AC generator attached to the internal combustion engine,
The control device for an internal combustion engine has a first capacitor between a microcomputer power supply voltage regulator that supplies power to the microcomputer and a built-in regulator to which the output of the AC generator is input,
The control device for the internal combustion engine is connected in parallel to the first capacitor via switching means,
The plurality of second capacitors having a capacity larger than that of the first capacitor are connected from the electrically disconnected state to the connected state using the switching means when the rotational speed of the internal combustion engine reaches a plurality of predetermined rotational speeds. A method for controlling an internal combustion engine characterized by sequentially switching to   The plurality of second capacitors are not switched until the predetermined time is reached when the electrical connection state is not switched at the same time and the switching interval of the switching means is not more than a predetermined time. 5. A method for controlling an internal combustion engine according to 4.   The plurality of second capacitors are electrically disconnected when the internal combustion engine is started, and once connected, the electrical connection state is maintained until the control device of the internal combustion engine is reset. Item 6. A control method for an internal combustion engine according to Item 5. In a batteryless control apparatus for an internal combustion engine that controls an internal combustion engine by electric power generated by an AC generator attached directly to the end of the crankshaft of the internal combustion engine or via a power transmission device,
A microcomputer for controlling operation of an internal combustion engine, a microcomputer power supply voltage regulator for supplying power to the microcomputer , and a built-in regulator for rectifying and smoothing power generated by the AC generator, the built-in regulator and the microcomputer A first capacitor having a small capacity between power supply voltage regulators, and one second capacitor having a larger capacity than the first capacitor between the built-in regulator and the microcomputer power supply voltage regulator, FET is connected in series to the second capacitor,
The microcomputer controls the FET by PWM driving the internal combustion engine control device. In a control method for a batteryless internal combustion engine for controlling the internal combustion engine with electric power generated by an AC generator attached to the internal combustion engine,
The control device for the internal combustion engine includes a microcomputer power supply voltage regulator for supplying power to the microcomputer , a built-in regulator to which the output of the AC generator is input, and the microcomputer power supply voltage regulator and the AC generator. A first capacitor, a second capacitor having a larger capacity than that of the first capacitor, and a FET connected in series to the second capacitor. When the rotational speed of the internal combustion engine reaches a predetermined rotational speed range, the FET is PWM-driven, and the second capacitor is switched from the electrically disconnected state to the connected state and charged. Control method. 2. The internal combustion engine according to claim 1, wherein a plurality of second capacitors are disposed between the microcomputer power supply voltage regulator and the microcomputer instead of being disposed between the built-in regulator and the microcomputer power supply voltage regulator. Control device. Instead of arranging one second capacitor between the built-in regulator and the microcomputer power supply voltage regulator, one second capacitor is arranged between the microcomputer power supply voltage regulator and the microcomputer. 8. The control device for an internal combustion engine according to claim 7, wherein the control device is an internal combustion engine. The second capacitor is connected between the built-in regulator and the microcomputer power supply voltage regulator or between the microcomputer power supply voltage regulator and the microcomputer, and the PWM charge frequency or PWM charge time of the second capacitor is predetermined. 9. The method of controlling an internal combustion engine according to claim 8, wherein the electric connection state is maintained until the control device for the internal combustion engine is reset after it is regarded that the charging has been completed.

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