JP2016075247A - Engine control device - Google Patents

Abstract

An engine control apparatus capable of suppressing a change in behavior of a vehicle when a battery voltage abnormality is detected.
A signal corresponding to a voltage of a battery charged by electric power generated by engine power is input to a voltage information input terminal. A signal that depends on the engine speed is input to the engine speed information input terminal. The processing device performs engine ignition control and fuel supply control. The processing device determines whether a voltage abnormality has occurred in the battery based on the voltage of the battery. When it is determined that a voltage abnormality has occurred in the battery and the engine stop permission condition is satisfied, the engine is stopped. When it is determined that a voltage abnormality has occurred in the battery and the engine stop permission condition is not satisfied, the engine speed is gradually decreased. When the engine speed is greater than the engine speed determination threshold, it is determined that the engine stop permission condition is not satisfied.
[Selection] Figure 2

Description

  The present invention relates to an engine control device that detects that an output voltage of a battery that accumulates electric power generated by power of an internal combustion engine is an overvoltage and reflects a detection result in engine control.

  An internal combustion engine ignition device disclosed in Patent Document 1 below samples an output voltage of a power supply unit and detects an abnormality of the power supply unit. When an abnormality of the power supply unit is detected, the supply of the ignition signal to the ignition circuit is stopped and the internal combustion engine is stopped. Thereby, various electric circuits can be protected from overvoltage.

JP 2004-324516 A

  If the abnormality of the power supply unit is detected while the vehicle is running and the engine is stopped, the behavior of the vehicle may change abruptly. Further, if the engine is stopped during a jump specific to motocross travel, the gyro effect due to the engine rotation changes, and the attitude of the vehicle may be destroyed.

  The objective of this invention is providing the engine control apparatus which can suppress the change of the behavior of a vehicle, when the battery voltage abnormality is detected.

An engine control apparatus according to a first aspect of the present invention provides:
A voltage information input terminal to which a signal corresponding to the voltage of the battery charged by the electric power generated by the power of the engine is input;
A rotational speed information input terminal to which a signal dependent on the rotational speed of the engine is input;
A processing device for performing ignition control and fuel supply control of the engine,
The processor is
Determining whether a voltage abnormality has occurred in the battery based on the voltage of the battery;
When it is determined that a voltage abnormality has occurred in the battery and the engine stop permission condition is satisfied, a stop process for stopping the engine is executed,
When it is determined that a voltage abnormality has occurred in the battery and the engine stop permission condition is not satisfied, a rotation speed decrease process for gradually decreasing the rotation speed of the engine is executed,
When the engine speed is greater than the engine speed determination threshold, it is determined that the engine stop permission condition is not satisfied.

In addition to the configuration of the engine control apparatus according to the first aspect, the engine control apparatus according to the second aspect of the present invention includes:
The processing device gradually decreases at least one of the fuel cut rotation speed and the ignition cut rotation speed in the rotation speed decrease process.

In addition to the configuration of the engine control apparatus according to the first or second aspect, the engine control apparatus according to the third aspect of the present invention includes:
A throttle opening input terminal to which a signal corresponding to the throttle opening of the engine is input;
The processor is
When the throttle opening of the engine is larger than a throttle opening determination threshold, it is determined that the engine stop permission condition is not satisfied.

In addition to the configurations of the first to third engine control devices, the engine control device according to the fourth aspect of the present invention includes:
The processing device is
When it is detected that the duration of the state in which the voltage of the battery is equal to or higher than the overvoltage determination threshold exceeds the abnormality determination duration, it is determined that a voltage abnormality has occurred in the battery.

  In the engine control apparatus according to the first aspect, when the engine stop permission condition is not satisfied, the engine speed is gradually decreased, so that the change in the behavior of the vehicle due to the engine stop is suppressed.

  In the engine control device according to the second aspect, at least one of the fuel cut speed and the ignition cut speed gradually decreases, so that the engine speed also gradually decreases.

  In the engine control apparatus according to the third aspect, the occupant's throttle operation is reflected in the determination of whether or not the engine stop permission condition is satisfied.

  In the engine control apparatus according to the fourth aspect, it is possible to prevent a decrease in the engine speed based on a temporary voltage abnormality.

FIG. 1 is a block diagram of an engine control device according to an embodiment and other engine-related parts. FIG. 2A is a flowchart of processing executed by the voltage abnormality determination unit, and FIG. 2B is a flowchart of processing executed by the engine stop processing unit. FIG. 3A is a graph showing a region where the engine stop permission condition is satisfied in a two-dimensional space in which the engine speed NE and the throttle opening TH are variables, and FIGS. 3B and 3C respectively show the ignition cut speed. It is a graph which shows an example of the time change of fuel cut rotation speed. 4A and 4B are graphs showing other examples of changes over time in the ignition cut speed and the fuel cut speed, respectively.

  FIG. 1 is a block diagram of an engine control device according to an embodiment and other engine-related parts.

  The crank angle sensor 11 generates a crank pulse, which is a signal that depends on the rotational speed of the engine, according to the rotational angle of the crankshaft of the engine 10. The cycle of the crank pulse depends on the rotational speed of the engine 10. The crank pulse is input to the rotation speed information input terminal 31 of the electronic control unit (ECU) 30.

  The engine 10 is an internal combustion engine such as a gasoline engine. An injector 13 supplies fuel to the engine 10. The high voltage induced in the ignition coil 12 causes a spark discharge in the spark plug of the engine 10 and the engine 10 is ignited.

  The generator 14 is driven by the power of the engine 10. The electric power generated by the generator 14 is supplied to the battery 16 through the rectifier circuit 15, whereby the battery 16 is charged. A voltage signal corresponding to the voltage of the battery 16 is input to the voltage information input terminal 32 of the ECU 30. A throttle opening sensor 18 detects the opening of the throttle valve 17 and outputs a throttle opening signal corresponding to the throttle opening. A throttle opening signal is input to a throttle opening input terminal 33 of the ECU 30.

  Next, the configuration and function of the ECU 30 will be described. The crank pulse input to the rotation speed information input terminal 31 is filtered by the input circuit 34 and then input to the waveform shaping circuit 35. The waveform shaping circuit 35 shapes the waveform of the crank pulse. The shaped crank pulse is input to a central processing unit (CPU) 50. The engine speed calculation unit 51 of the CPU 50 calculates the engine speed NE based on the shaped crank pulse.

  The voltage signal input to the voltage information input terminal 32 is input to the A / D conversion circuit 37 via the input circuit 36. The input circuit 36 divides the voltage of the battery 16 so that the voltage input to the A / D conversion circuit 37 falls within the A / D conversion possible range. Data A / D converted by the A / D conversion circuit 37 is input to the CPU 50. The battery voltage calculation unit 52 of the CPU 50 calculates the battery voltage VB based on the input data.

  The throttle opening signal input to the throttle opening input terminal 33 is filtered by the input circuit 38 and then input to the A / D conversion circuit 39. Data A / D converted by the A / D conversion circuit 39 is input to the CPU 50. The throttle opening calculation unit 53 of the CPU 50 calculates the throttle opening TH based on the input data.

  CPU 50 further includes a voltage abnormality determination unit 54 and an engine stop processing unit 55. The processing of the voltage abnormality determination unit 54 and the engine stop processing unit 55 will be described later with reference to FIGS. 2A and 2B.

  The ignition circuit 41 drives the ignition coil 12. An injector drive circuit 42 drives the injector 13. The ignition circuit 41 and the injector drive circuit 42 are controlled by the CPU 50. That is, the CPU 50 performs ignition control of the engine 10 and fuel supply control.

  The ROM 44 stores computer programs for realizing the functions of the engine speed calculation unit 51, the battery voltage calculation unit 52, the throttle opening calculation unit 53, the voltage abnormality determination unit 54, the engine stop processing unit 55, and the like of the CPU 50. . The RAM 45 stores various data used in processing executed by the CPU 50. In the processing executed by the CPU 50, the timer 46 is used.

  FIG. 2A shows a flowchart of processing executed by the voltage abnormality determination unit 54. The voltage abnormality determination unit 54 is activated at a constant cycle, for example, a cycle of 100 ms.

  In step SA1, the battery voltage VB calculated by the battery voltage calculation unit 52 is read. In step SA2, the battery voltage VB is filtered. In the filtering process, for example, a noise component of voltage fluctuation is removed.

  In step SA3, it is determined whether or not a voltage abnormality has occurred in the battery 16 (FIG. 1). Step SA3 includes step SA31 and step SA32. First, in step SA31, it is determined whether or not the battery voltage VB is equal to or higher than an overvoltage determination threshold. If the battery voltage VB is less than the overvoltage determination threshold, the process ends. If the battery voltage VB is greater than or equal to the overvoltage determination threshold, it is determined in step SA32 whether or not the continuation timer has exceeded the abnormality determination continuation time. The continuation timer is set when the battery voltage VB first detects that the battery voltage VB is equal to or higher than the overvoltage determination threshold, and starts counting time. As the overvoltage determination threshold, for example, a value slightly higher than the rated voltage of the battery 16 is adopted.

  In step SA32, when the continuation timer does not exceed the abnormality determination continuation time, the process ends. When the continuation timer exceeds the abnormality determination continuation time, it is determined that a voltage abnormality has occurred in the battery 16. If it is determined that a voltage abnormality has occurred in the battery 16, “overvoltage abnormality confirmation” is set in the battery state in step SA4. A battery state storage area is secured in the RAM 45 (FIG. 1).

  If “overvoltage abnormality confirmation” is set in the battery state, this setting is not automatically canceled. For example, the “normal state” is set as the battery state by the intervention of a vehicle occupant or a maintenance inspector.

  FIG. 2B shows a flowchart of processing executed by the engine stop processing unit 55 (FIG. 1). The engine stop processing unit 55 is activated, for example, every stroke cycle of the engine 10.

  In step SB1, it is determined whether or not the battery status is “overvoltage abnormality confirmed”. If the battery state is not “overvoltage abnormality confirmed”, the process is terminated. If the battery state is “overvoltage abnormality confirmed”, it is determined in step SB2 whether or not the engine speed NE and the throttle opening TH satisfy the engine stop allowable condition.

  The engine stop permission condition will be described with reference to FIG. 3A. FIG. 3A shows a region 56 in which the engine stop permission condition is satisfied in a two-dimensional space having the engine speed NE and the throttle opening TH as variables. When the engine speed NE is equal to or less than the rotation speed determination threshold value NEt and the throttle opening degree TH is equal to or less than the throttle opening degree determination threshold value THt, the engine stop permission condition is satisfied. When the engine speed NE is greater than the rotation speed determination threshold value NEt, or when the throttle opening degree TH is greater than the throttle opening degree determination threshold value THt, the engine stop permission condition is not satisfied.

  If it is determined in step SB2 (FIG. 2B) that the engine stop permission condition is satisfied, an engine stop process is executed in step SB3. Specifically, in step SB3, the driving of the ignition coil 12 (FIG. 1) and the injector 13 (FIG. 1) is stopped. Thereby, supply of fuel to the engine 10 (FIG. 1) and ignition are stopped, and the rotational speed of the engine 10 is reduced.

  When it is determined in step SB2 that the engine stop permission condition is not satisfied, a rotation speed decrease process is executed in step SB4. Step SB4 includes steps SB41 to SB43. When step SB4 is activated, it is determined in step SB41 whether the withdrawal timer has expired. The withdrawal timer expires when a certain time ts has elapsed after setting. If the withdrawal timer is not set, it is determined that the withdrawal timer has expired.

  If it is determined in step SB41 that the withdrawal timer has not expired, the process ends. If it is determined in step SB41 that the withdrawal timer has expired, the withdrawal timer is set in step SB42. As soon as the withdrawal timer is set, timing starts.

  After step SB42, in step SB43, the ignition cut rotational speed and the fuel cut rotational speed are decreased by the step width ΔNE of the rotational speed removal. The ignition cut speed means an upper limit value of the engine speed NE at which the ignition of the engine 10 (FIG. 1) is not cut. The fuel cut speed means the upper limit value of the engine speed NE at which the fuel supply to the engine 10 (FIG. 1) is not stopped. That is, when the engine speed NE exceeds the ignition cut speed, the ignition cut is performed. When the engine speed NE exceeds the fuel cut speed, the supply of fuel to the engine 10 (FIG. 1) is stopped. As an example, the ignition cut speed and the fuel cut speed are the same. When step SB42 is completed, the processing of the engine stop processing unit 55 (FIG. 1) ends.

  With reference to FIG. 3B and FIG. 3C, the time change of the ignition cut speed and the fuel cut speed will be described. 3B and 3C show examples of changes over time in the ignition cut speed and the fuel cut speed, respectively. 3B and 3C represent the elapsed time, the vertical axis in FIG. 3B represents the ignition cut speed, and the vertical axis in FIG. 3C represents the fuel cut speed. The solid line in FIG. 3B indicates the ignition cut speed, and the solid line in FIG. 3C indicates the fuel cut speed.

  If the battery state is “overvoltage abnormality confirmed” and the engine stop permission condition is not satisfied, step SB4 (FIG. 2B) is executed, so that the ignition cut speed is increased every time a certain time ts elapses. And the fuel cut speed is subtracted by the step size ΔNE. As shown in FIG. 3B and FIG. 3C, the ignition cut speed and the fuel cut speed decrease stepwise with time. When the current engine speed NE is smaller than the ignition cut speed and the fuel cut speed, ignition and fuel are supplied as usual. The fuel supply amount is calculated according to the throttle opening TH.

  At time t1, the ignition cut speed becomes equal to or lower than the current engine speed NE. At this time, the supply of current to the ignition coil 12 is stopped and the ignition is cut off. Similarly, at time t1, the fuel cut speed becomes equal to or less than the current engine speed NE. At this point, the supply of fuel to the engine 10 (FIG. 1) is stopped. When the ignition is cut and the fuel supply is stopped, the engine speed NE decreases.

  When the current engine speed NE falls below the ignition cut speed and the fuel cut speed at time t2, ignition and fuel supply are resumed. When the occupant notices a decrease in the engine speed and operates the throttle grip in the closing direction, the engine speed NE decreases according to the occupant's operation.

  At time t3, the ignition cut speed and the fuel cut speed are further reduced to be lower than the current engine speed NE. At this point, the ignition cut and the fuel supply stop are resumed. As a result, the engine speed NE further decreases. When the occupant further operates the throttle grip in the closing direction, the engine speed NE decreases as indicated by the broken line NE1.

  At time t4, the engine speed NE decreases to the speed determination threshold value NEt. At this time, when the throttle opening TH is closed to the throttle opening determination threshold THt (FIG. 3A) or less, the engine stop permission condition is satisfied. For this reason, step SB3 (FIG. 2B) is executed, and the engine is stopped.

  If the occupant does not operate the throttle grip in the closing direction even after time t3, as indicated by the broken line NE2, the engine speed NE decreases following the decrease in the ignition cut speed and the fuel cut speed. At time t5, even if the engine speed NE decreases to the speed determination threshold value NEt, if the throttle opening degree TH is larger than the throttle opening degree determination threshold value THt, the engine stop process in step SB3 is not executed. For this reason, even after time t5, the engine speed NE decreases as the engine speed NE follows the decrease in the ignition cut speed and the fuel cut speed.

  If the state where the throttle opening TH is larger than the throttle opening determination threshold THt continues, the engine is stopped when the ignition cut speed and the fuel cut speed become 0 at time t6.

  In the above embodiment, both the engine speed NE and the throttle opening TH are used to determine whether or not the engine stop permission condition (step SB2) is satisfied. As another method, it may be determined whether or not the engine stop permission condition (step SB2) is satisfied based only on the engine speed NE. In this case, step SB3 (FIG. 2B) is executed at time t5 when the engine speed NE has decreased to the ignition cut speed and the fuel cut speed. As a result, the engine stops as indicated by a broken line NE3 in FIGS. 3B and 3C.

  In the above embodiment, even if the battery state becomes “overvoltage abnormality confirmed”, the engine does not stop immediately, and the rotation speed reduction process (step SB4) is executed. For this reason, the engine speed NE gradually decreases. Here, “gradually” means that the engine speed is gradually decreased by cutting the ignition and stopping the fuel supply, compared to a decrease in engine speed when the engine is immediately stopped. .

  Since the engine 10 (FIG. 1) does not stop immediately when the battery status becomes “overvoltage abnormality confirmed”, a sudden change in the behavior of the vehicle can be prevented. Further, since engine speed NE gradually decreases, further progress of deterioration due to overvoltage abnormality of battery 16 can be suppressed.

  Further, in the above embodiment, in step SA32 (FIG. 2A), when the period in which the battery voltage is equal to or higher than the overvoltage determination threshold exceeds the abnormality determination duration, the battery state is set to “overvoltage abnormality confirmed”. . For this reason, it is possible to prevent a decrease in the engine speed due to the occurrence of an overvoltage temporarily. In addition, the throttle opening TH is included in the engine stop permission condition (FIG. 3A). For this reason, the operation of the throttle by the occupant is reflected in the process of reducing the engine speed. As an example, when the occupant operates the throttle grip in the closing direction after the voltage abnormality of the battery 16 (FIG. 1) occurs, an early engine stop is realized. Even after the voltage abnormality of the battery 16 occurs, if the occupant does not operate the throttle grip in the closing direction, the engine speed decreases gradually.

  In the above embodiment, both the ignition cut speed and the fuel cut speed were gradually reduced after the battery state became “overvoltage abnormality confirmed”. As another method, either one of the ignition cut speed and the fuel cut speed may be reduced and the other may be maintained at a constant value. In this case, the engine speed NE is gradually reduced by executing either the ignition cut or the fuel supply stop.

  A modification of the embodiment will be described with reference to FIGS. 4A and 4B. In the above embodiment, as shown in FIGS. 3B and 3C, the ignition cut speed and the fuel cut speed were decreased stepwise with time. In the modification shown in FIGS. 4A and 4B, the ignition cut speed and the fuel cut speed are smoothly reduced with the passage of time. The correspondence relationship between the ignition cut speed and the elapsed time and the correspondence relationship between the fuel cut speed and the elapsed time are stored, for example, in the ROM 44 (FIG. 1).

  Also in the modification shown in FIGS. 4A and 4B, the same effect as the embodiment shown in FIGS. 3B and 3C can be obtained. From the viewpoint of reducing the influence of the ignition cut and the fuel cut on the behavior of the vehicle, and from the viewpoint of reducing the degree of deterioration of the battery 16 (FIG. 1) due to overvoltage, the correspondence relationship between the ignition cut speed and the elapsed time, and the fuel It is preferable to optimize the correspondence between the cutting speed and the elapsed time.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Engine 11 Crank angle sensor 12 Ignition coil 13 Injector 14 Generator 15 Rectifier circuit 16 Battery 17 Throttle valve 18 Throttle opening sensor 30 Electronic control unit (ECU)
31 Rotation speed information input terminal 32 Voltage information input terminal 33 Throttle opening input terminal 34 Input circuit 35 Waveform shaping circuit 36 Input circuit 37 A / D conversion circuit 38 Input circuit 39 A / D conversion circuit 41 Ignition circuit 42 Injector drive circuit 44 ROM
45 RAM
46 Timer 50 Central processing unit (CPU)
51 Engine Speed Calculation Unit 52 Battery Voltage Calculation Unit 53 Throttle Opening Calculation Unit 54 Voltage Abnormality Determination Unit 55 Engine Stop Processing Unit 56 Area Where Engine Stop Allowance Condition is Satisfied NE Engine Speed NEt Speed Determination Threshold TH THt Throttle opening determination threshold VB Battery voltage

Claims (4)

A voltage information input terminal to which a signal corresponding to the voltage of the battery charged by the electric power generated by the power of the engine is input;
A rotational speed information input terminal to which a signal dependent on the rotational speed of the engine is input;
A processing device for performing ignition control and fuel supply control of the engine,
The processor is
Determining whether a voltage abnormality has occurred in the battery based on the voltage of the battery;
When it is determined that a voltage abnormality has occurred in the battery and the engine stop permission condition is satisfied, a stop process for stopping the engine is executed.
When it is determined that a voltage abnormality has occurred in the battery and the engine stop permission condition is not satisfied, a rotation speed decrease process for gradually decreasing the rotation speed of the engine is executed,
An engine control device that determines that the engine stop permission condition is not satisfied when the engine speed is greater than a engine speed determination threshold value.   The engine control device according to claim 1, wherein the processing device gradually decreases at least one of a fuel cut rotational speed and an ignition cut rotational speed in the rotational speed lowering process. A throttle opening input terminal to which a signal corresponding to the throttle opening of the engine is input;
The processor is
The engine control device according to claim 1 or 2, wherein when the throttle opening of the engine is larger than a throttle opening determination threshold, it is determined that the engine stop permission condition is not satisfied. The processor is
4. The battery according to claim 1, wherein when detecting that the duration of the state in which the voltage of the battery is equal to or higher than an overvoltage determination threshold exceeds the abnormality determination duration, it is determined that a voltage abnormality has occurred in the battery. The engine control apparatus according to item 1.

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