WO2018180468A1

WO2018180468A1 - Internal combustion engine control device

Info

Publication number: WO2018180468A1
Application number: PCT/JP2018/009742
Authority: WO
Inventors: 佐々木　亮; 隆広加島
Original assignee: 本田技研工業株式会社
Priority date: 2017-03-27
Filing date: 2018-03-13
Publication date: 2018-10-04
Also published as: JP2018162748A

Abstract

An internal combustion engine control device (1) that comprises an injector temperature calculation unit (21a), an engine temperature calculation unit (21b), an operating state control unit (21c), a fuel injection amount calculation unit (21d), and a sampling counter (21e). Every time the counter value of the sampling counter (21e) becomes a prescribed counter value, the fuel injection amount calculation unit (21d) reduces a startup fuel increase correction coefficient. The prescribed counter value is set so as to increase as engine rotational speed increases.

Description

Internal combustion engine control device

The present invention relates to an internal combustion engine control device, and more particularly to an internal combustion engine control device applied to a general-purpose machine such as a generator or a vehicle such as a motorcycle.

In recent years, in general-purpose machines such as generators and vehicles such as small motorcycles, it has become difficult to meet exhaust gas regulations that will become stricter in the future with carburetor systems, so a fuel injection system has been adopted to reduce exhaust gas. Is promoted. However, since the selling price of vehicles such as general-purpose machines such as generators and small motorcycles is lower than that of vehicles such as large motorcycles and four-wheeled vehicles, such selling prices are considered. It is difficult to adopt a fuel injection system that is more expensive than a carburetor system as it is for a general-purpose machine such as a generator or a vehicle such as a small motorcycle. For this reason, in general-purpose machines such as generators and vehicles such as small motorcycles, cost reduction is required for parts related to the fuel injection system, particularly sensors.

Here, for example, a temperature sensor in a fuel injection system is generally used for detecting a warm-up state of an internal combustion engine. More specifically, the fuel injection system calculates the temperature of the internal combustion engine based on the output of the temperature sensor, detects the warm-up state of the internal combustion engine based on the calculated temperature of the internal combustion engine, and determines the ignition timing. And control of fuel injection. For this reason, when adopting a fuel injection system, it is necessary to attach a temperature sensor to the internal combustion engine. Furthermore, when installing a temperature sensor in the internal combustion engine, it is necessary to install wires and couplers for wiring, and it is necessary to process the part of the internal combustion engine where the temperature sensor is installed. As a result, the ratio of the cost of the fuel injection system to the sales price is higher than that of the carburetor system. For this reason, in an internal combustion engine control device that controls a fuel injection system in a vehicle such as a general-purpose machine such as a generator or a small motorcycle, a temperature sensor is required to be omitted from the fuel injection system for the purpose of cost reduction. Yes.

Under such circumstances, Patent Document 1 relates to the electronic control unit 20 of the engine 10 by paying attention to the correlation between the temperature of the injector 15 and the temperature of the engine 10 and calculating the temperature of the engine 10 from the temperature of the injector 15. A configuration for controlling the engine 10 at the temperature of the engine 10 is disclosed.

Further, Patent Document 2 relates to a post-startup injection amount control device 54 for the internal combustion engine 2, and a post-startup fuel increase correction for performing an increase correction of the fuel injection amount during a predetermined period from the start of the internal combustion engine 2, and the internal combustion engine. 2 discloses a configuration for executing warm-up fuel increase correction for correcting increase in fuel injection amount in accordance with the temperature 2.

JP 2016-98665 A JP-A-5-214981

According to the study by the present inventor, in the fuel injection amount increase correction by the fuel increase correction after starting the internal combustion engine, generally, the increase due to the correction is decreased with the passage of time from the start of the internal combustion engine. However, as a technique for reducing the increase in this way, there is a method in which the increase correction is decreased by a predetermined value in synchronization with the rotational speed of the internal combustion engine. When such a method is used, since the increase correction is decreased in synchronization with the rotational speed of the internal combustion engine, there is an advantage that there is no need to divide timer resources for time measurement. When the number increases, the increase in the fuel injection amount by the fuel increase correction after the start becomes zero at an early stage, and the substantial increase correction execution time is shortened.

Here, when the temperature of the internal combustion engine is detected using the water temperature sensor as in the configuration disclosed in Patent Document 2, since the reaction of the water temperature increase immediately after the start of the internal combustion engine is slow, the warm-up fuel increase correction is performed. Although the increase in the fuel injection amount does not become zero at an early stage, when the temperature of the internal combustion engine (internal combustion engine temperature) is calculated from the temperature of the injector (injector temperature) as in the configuration disclosed in Patent Document 1. Since the reaction of the internal combustion engine temperature at the time of starting the internal combustion engine is quicker than that by the water temperature detection, the increase in the fuel injection amount due to the warm-up fuel increase correction tends to become zero at an early stage. In particular, it becomes more prominent if the injector temperature is correlated with a temperature sensitive part such as a plug seat in the combustion chamber. Further, in a situation where the rotational speed of the internal combustion engine becomes high, the increase in the fuel injection amount by the post-startup fuel increase correction becomes zero earlier, so the actual fuel injection amount becomes the required fuel injection amount. It is considered that there is a possibility that it will lead to a decrease in drivability and an engine stall.

The present invention has been made after the above study, and provides an internal combustion engine control device that can appropriately perform fuel increase correction at the start of the internal combustion engine to suppress a decrease in drivability and occurrence of engine stall. For the purpose.

In order to achieve the above object, the present invention is applied to an internal combustion engine, and calculates an injector temperature based on the coil resistance value of the injector and an internal combustion engine temperature based on the injector temperature. In the internal combustion engine control device having an internal combustion engine temperature calculation unit that controls an operation state of the internal combustion engine based on the internal combustion engine temperature, the injector temperature using a start-up fuel increase correction coefficient A fuel injection amount calculation unit that calculates a fuel injection amount that is obtained by correcting the reference injection amount calculated from the above, and a thinning counter that counts every predetermined period after the start of the internal combustion engine, the fuel injection amount calculation unit Each time the count value of the decimation counter reaches a predetermined count value, the start-up fuel increase correction coefficient is decreased, Count value is that rotational speed of the internal combustion engine is set to be higher as large as the first aspect.

According to the present invention, in addition to the first aspect, the fuel injection amount calculation unit obtains a constant value from the previous value of the starting fuel increase correction coefficient every time the count value of the decimation counter reaches the predetermined count value. It is a second aspect to execute a calculation process for calculating the current value of the starting fuel increase correction coefficient by subtraction.

According to the present invention, in addition to the first aspect, the fuel injection amount calculation unit sets the previous value of the start-up fuel increase correction coefficient at a constant rate each time the count value of the thinning counter reaches the predetermined count value. It is a third aspect to execute a calculation process for calculating the current value of the start-time fuel increase correction coefficient by reducing the starting fuel increase correction coefficient.

In addition to the first aspect, the present invention provides that the fuel injection amount calculation unit starts the engine every time the count value reaches the predetermined count value until the count value of the thinning counter reaches a predetermined threshold value. A first calculation process for calculating the current value of the start time fuel increase correction coefficient by decreasing the previous value of the hour fuel increase correction coefficient at a constant rate is executed, and the count value of the decimation counter is set to a predetermined threshold value. After that, every time the count value reaches the predetermined count value, the current value of the starting fuel increase correction coefficient is calculated by subtracting a constant value from the previous value of the starting fuel increase correction coefficient. Executing the calculation process 2 is a fourth aspect.

According to the internal combustion engine control apparatus of the first aspect of the present invention, the fuel injection amount calculation unit decreases the start-up fuel increase correction coefficient every time the count value of the thinning counter reaches a predetermined count value, and the predetermined count value Is set so as to increase as the rotational speed of the internal combustion engine increases. Therefore, the period from the start of the internal combustion engine until the start-time fuel increase correction coefficient becomes zero is determined as the rotational speed of the internal combustion engine. It can be made substantially constant without being affected, and the fuel increase correction at the start of the internal combustion engine can be appropriately executed to suppress drivability deterioration and engine stall.

Further, according to the internal combustion engine control apparatus according to the second aspect of the present invention, the fuel injection amount calculation unit starts from the previous value of the starting fuel increase correction coefficient every time the count value of the thinning counter reaches a predetermined count value. Since the calculation process for calculating the current value of the starting fuel increase correction coefficient is performed by subtracting a certain value, the degree of decrease in the fuel increase correction amount at the start is adjusted according to the characteristics at the start of the internal combustion engine. Can be linearly changed, and drivability deterioration and engine stall can be more appropriately suppressed.

Further, according to the internal combustion engine control apparatus according to the third aspect of the present invention, the fuel injection amount calculation unit calculates the previous value of the start-time fuel increase correction coefficient every time the count value of the thinning counter reaches a predetermined count value. Since the calculation process for calculating the current value of the fuel increase correction coefficient at start-up is performed by decreasing it at a constant rate, the fuel increase correction amount at start-up is reduced in accordance with the characteristics at the start of the internal combustion engine. The degree can be changed non-linearly, and drivability deterioration and engine stall can be more appropriately suppressed.

Further, according to the internal combustion engine control apparatus according to the fourth aspect of the present invention, the fuel injection amount calculation unit determines that the count value reaches the predetermined count value until the count value of the thinning counter reaches the predetermined threshold value. The first calculation process for calculating the current value of the start-time fuel increase correction coefficient by decreasing the previous value of the start-time fuel increase correction coefficient at a constant rate is executed, and the count value of the thinning counter reaches a predetermined threshold value After that, every time the count value reaches the predetermined count value, a second calculation process is performed to calculate the current value of the start time fuel increase correction coefficient by subtracting a certain value from the previous value of the start time fuel increase correction coefficient. Therefore, the degree of decrease in the fuel increase correction amount at the start can be switched from non-linear to linear according to the characteristics at the start of the internal combustion engine. It is possible to more appropriately suppress the raw.

FIG. 1A is a schematic diagram showing a configuration of an internal combustion engine control apparatus according to an embodiment of the present invention. FIG. 1B is a schematic diagram showing the configuration of the injector in FIG. 1A. FIG. 2 shows the change in the count value of the thinning counter and the change in the start-up fuel increase correction coefficient in accordance with the change in the engine speed when the start-up fuel increase correction coefficient calculation process of the internal combustion engine control apparatus in the present embodiment is executed. It is a figure shown with the execution timing of a fuel injection amount calculation process. FIG. 3A is a diagram illustrating an example of table data representing a relationship between an engine speed and a predetermined count value used in the start-up fuel increase correction coefficient calculation process of the internal combustion engine control apparatus according to the present embodiment. FIG. 3B is a diagram showing an example of a change in the start-up fuel increase correction coefficient accompanying a change in the number of thinning-outs in the start-up fuel increase correction coefficient calculation process. FIG. 4 is a flowchart illustrating an example of the flow of the start-up fuel increase correction coefficient calculation process of the internal combustion engine control device according to the present embodiment.

Hereinafter, an internal combustion engine control apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[Configuration of internal combustion engine controller]
First, with reference to FIG. 1A and FIG. 1B, the structure of the internal combustion engine control apparatus in this embodiment is demonstrated. The internal combustion engine control device in the present embodiment is typically suitably mounted on an internal combustion engine mounting body such as a general-purpose machine such as a generator or a vehicle such as a motorcycle. The internal combustion engine control device will be described as being mounted on a vehicle such as a motorcycle.

FIG. 1A is a schematic diagram showing a configuration of an internal combustion engine control apparatus according to the present embodiment, and FIG. 1B is a schematic diagram showing a configuration of an injector in FIG. 1A.

As shown in FIGS. 1A and 1B, the internal combustion engine control device 1 according to the present embodiment is based on the temperature of functional parts of an engine that is an internal combustion engine such as a gasoline engine mounted on a vehicle not shown. The electronic control unit (Electronic Control Unit: ECU) 10 is provided.

The ECU 10 operates by using electric power from the battery B mounted on the vehicle, and includes a waveform shaping circuit 11, a thermistor element 12 (temperature detection element), an A / D converter 13, an ignition circuit 14, and a drive circuit. 15, resistance value detection circuit 16, EEPROM (Electrically Erasable Programmable Read-Only Memory) 17, ROM (Read-Only Memory) 18, RAM (Random Access Memory) 19, timer 20 and central processing unit ce ) 21. Each component of the ECU 10 is accommodated in a casing 10a of the ECU 10. Also, typically, the ECU 10 and the engine are in contact with the outside air, and the ECU 10 is arranged away from the engine 10 so as not to be affected by the radiant heat of the engine and the heat transfer from the engine. Is.

The waveform shaping circuit 11 shapes a crank pulse signal corresponding to the rotation angle of the crankshaft 3 of the engine output from the crank angle sensor 2 to generate a digital pulse signal. The waveform shaping circuit 11 outputs the digital pulse signal thus generated to the CPU 21.

The thermistor element 12 is separated from the heat generating element that is typically the ignition circuit 14 in the casing 10a of the ECU 10, and is located on the atmosphere side of the ECU 10 (for example, a casing whose distance to the casing 10a is about several millimeters). A chip thermistor disposed at a position close to the body 10a, and detects an ambient temperature (outside temperature), which is an ambient temperature outside the casing 10a of the ECU 10. Specifically, the thermistor element 12 exhibits an electrical resistance value corresponding to the ambient temperature, and outputs an electrical signal indicating a voltage corresponding to the electrical resistance value to the A / D converter 13. The thermistor element 12 may be replaced with another temperature sensor such as a thermocouple as long as it can output such an electrical signal. The temperature detected by the thermistor element 12 is equal to the ambient temperature (outside temperature) that is the ambient temperature around the engine.

The A / D converter 13 is an electric signal indicating the opening degree of the throttle valve of the engine output from the throttle opening degree sensor 4 and an electric signal indicating the oxygen concentration in the atmosphere sucked into the engine output from the oxygen sensor 5. , And the electrical signal indicating the ambient temperature output from the thermistor element 12 is converted from an analog form to a digital form. The A / D converter 13 outputs these electrical signals thus converted into digital form to the CPU 21.

The ignition circuit 14 includes a switching element such as a transistor that is controlled to be turned on / off in accordance with a control signal from the CPU 21. When the switching element is turned on / off, the fuel in the engine is passed through a spark plug (not shown). And the operation of the ignition coil 6 for generating a secondary voltage for igniting the air-fuel mixture. The ignition circuit 14 is typically a driver IC (Integrated Circuit) that is a semiconductor element, and is a component that generates the largest amount of heat in the housing 10a.

The drive circuit 15 includes a switching element such as a transistor that is controlled to be turned on / off according to a control signal from the CPU 21, and the switching element is turned on / off to energize the coil 7a of the injector 7 that supplies fuel to the engine. / Switch the de-energized state. Here, the injector 7 is attached to an intake pipe or a cylinder head (not shown) of the engine, and heat generated from the engine is transferred. Further, as shown in FIG. 1B in particular, the equivalent circuit 7b of the coil 7a of the injector 7 is represented by a series circuit including an inductance component L and an electric resistance component R. The coil 7a is a component for electrically driving the solenoid 7c of the injector 7, and the fuel is ejected from the injector 7 when the solenoid 7c operates in the energized state of the coil 7a.

The resistance value detection circuit 16 measures an electrical resistance value (resistance value) that is a physical quantity that varies depending on the electrical resistance component of the coil 7a of the injector 7, and sends an electrical signal indicating the measured resistance value to the CPU 21. Output.

The EEPROM 17 stores data relating to various learning values such as a fuel injection amount learning value and a throttle reference position learning value. Note that the EEPROM 17 may be replaced with another storage medium such as a data flash as long as it can store data relating to such various learning values.

The ROM 18 is configured by a non-volatile storage device, and stores various control data such as a control program for starting fuel increase correction coefficient calculation processing, which will be described later, and table data used in starting fuel increase correction coefficient calculation processing. is doing.

The RAM 19 is composed of a volatile storage device and functions as a working area for the CPU 21.

The timer 20 performs a time measurement process according to a control signal from the CPU 21.

CPU21 controls the operation of the entire ECU10. In the present embodiment, the CPU 21 executes a control program stored in the ROM 18, thereby causing an injector temperature calculation unit 21a, an engine temperature calculation unit 21b, an operation state control unit 21c, a fuel injection amount calculation unit 21d, and a thinning-out. It functions as a counter 21e. Here, the injector temperature calculation unit 21 a calculates the temperature of the injector 7 (injector temperature) corresponding to the resistance value of the coil 7 a of the injector 7. The engine temperature calculation unit 21b calculates the temperature of the engine (engine temperature) based on the injector temperature calculated by the injector temperature calculation unit 21a. The operation state control unit 21c controls the operation state of the engine by controlling the ignition circuit 14 and the drive circuit 15 based on the engine temperature calculated by the engine temperature calculation unit 21b. The fuel injection amount calculation unit 21d calculates the fuel injection amount. In particular, the fuel injection amount is obtained by correcting the reference injection amount calculated from the injector temperature using the starting fuel increase correction coefficient KAST when the engine is started. Is calculated. The thinning counter 21e counts every fixed period after the engine is started. The starting fuel increase correction coefficient KAST is typically a correction coefficient that is multiplied by the basic fuel injection amount at the time of starting the engine to increase the fuel injection amount.

In addition, as a temperature of the functional component of the engine, an injector temperature can be cited as a suitable example from the viewpoint of simplicity of measurement, etc., but as a functional component of the engine, a resistance value corresponding to the engine temperature can be measured. If there is any other functional equipment, the temperature of the functional equipment may be used as the temperature of the functional parts of the engine. Also, when acquiring the engine temperature having a correlation with the injector temperature, taking into account that the temperature of the engine spark plug seat is close to the actual temperature inside the engine, actually measuring the temperature of the engine spark plug seat, It is easy to obtain this as the engine temperature.

The internal combustion engine control device 1 having such a configuration appropriately executes fuel increase correction at engine startup by executing the following startup fuel increase correction coefficient calculation processing, thereby reducing drivability and Suppresses the occurrence of engine stalls. Hereinafter, the operation of the internal combustion engine control device 1 when executing the start time fuel increase correction coefficient calculation processing in the present embodiment will be specifically described with reference to FIGS. 2 and 3 as well.

[Start-up fuel increase correction coefficient calculation processing]
FIG. 2 shows the count value CTKAST of the decimation counter and the start-up fuel increase correction coefficient KAST according to the change in the engine speed NE when the start-up fuel increase correction coefficient calculation process of the internal combustion engine control apparatus 1 in this embodiment is executed. It is a figure which shows this change with the execution timing of fuel injection amount calculation processing. FIG. 3A is a diagram showing an example of table data representing the relationship between the engine speed NE and a predetermined count value used in the start-up fuel increase correction coefficient calculation process of the internal combustion engine control apparatus 1 in the present embodiment. FIG. 3B is a diagram showing an example of a change in the start-up fuel increase correction coefficient accompanying a change in the number of thinning-outs in the start-up fuel increase correction coefficient calculation process.

As shown in FIG. 2 (a) to FIG. 2 (d), in the start-up fuel increase correction coefficient calculation processing in this embodiment, a predetermined start-up fuel increase correction end condition is typically set from when the engine is started. During the period until the fuel consumption is satisfied, the thinning counter 21e counts down the count value CTKAST from the predetermined count value at every execution timing of the fuel injection amount calculation process (fuel injection amount calculation timing). Each time the count value CTKAST of the thinning counter 21e becomes zero (time t = t1, t2, t3, t4, t5, and t6), the fuel injection amount calculation unit 21d typically has a numerical value of 1 or more. The value of a certain start-up fuel increase correction coefficient KAST is decreased, and the count value CTKAST of the thinning counter 21e is set to a predetermined count value again. Note that the thinning counter 21e may be an addition counter.

Here, as indicated by a curve L1 in FIG. 3A, the predetermined count value, which is the initial value by which the thinning counter 21e counts down the count value CTKAST, is set to increase as the engine speed NE increases. Specifically, even if the engine speed NE is increased, the engine speed is set such that the time interval during which the start time fuel increase correction coefficient KAST is decreased is substantially constant without depending on the engine speed NE. The predetermined count value is set to increase as NE increases.

Further, as shown by a curve L2 in FIG. 3B, the fuel injection amount calculation unit 21d subtracts a constant value from the previous value of the start time fuel increase correction coefficient KAST, thereby reducing the start time fuel increase. The current value of the correction coefficient KAST may be calculated, or, as indicated by the curve L3 in FIG. 3B, the previous value of the start-time fuel increase correction coefficient KAST is decreased at a constant rate so that the previous value is obtained as shown in FIG. 3B. Alternatively, the current value of the start-time fuel increase correction coefficient KAST may be calculated which is decreased with a non-linear characteristic different from the mode indicated by the curve L2.

Further, as shown by a curve L4 in FIG. 3B, the fuel injection amount calculation unit 21d starts the fuel at start-up every time the count value CTKAST reaches a predetermined count value until the count value CTKAST of the thinning counter 21e reaches a predetermined threshold value. A process of calculating the current value of the starting fuel increase correction coefficient KAST by decreasing the previous value of the increase correction coefficient KAST at a constant rate is executed, and after the count value CTKAST of the decimation counter reaches a predetermined threshold value, the thinning is performed. Every time the count value of the counter 21e becomes a predetermined count value, a process of calculating the current value of the start time fuel increase correction coefficient KAST by subtracting a constant value from the previous value of the start time fuel increase correction coefficient KAST is executed. (Until the count value CTKAST reaches a predetermined threshold value, it exhibits the same characteristics as the curve L2 shown in FIG. After pointer count value CTKAST reaches a predetermined threshold, it exhibits the same characteristics as the curve L3 shown in FIG. 3B).

In the following, referring to FIG. 4, the calculation of the current value for decreasing the previous value of the starting fuel increase correction coefficient KAST at a constant rate, and the subtraction of the constant value from the previous value of the starting fuel increase correction coefficient KAST The operation of the fuel injection amount calculation unit 21d in the starting fuel increase correction coefficient calculation process that combines the calculation of the current value will be described in detail.

FIG. 4 is a flowchart showing an example of the flow of the startup fuel increase correction coefficient calculation process of the internal combustion engine control apparatus 1 in the present embodiment.

The flowchart shown in FIG. 4 starts when the ignition switch of the vehicle is switched from the off state to the on state and the CPU 21 operates, and the start time fuel increase correction coefficient calculation processing proceeds to step S1. The start-up fuel increase correction coefficient calculation process is repeatedly executed at predetermined control intervals while the CPU 21 is operating with the ignition switch of the vehicle turned on.

In the process of step S1, the fuel injection amount calculation unit 21d determines whether or not the post-startup fuel increase correction end flag is on, thereby determining whether or not post-startup fuel increase correction is being performed. Is determined. As a result of the determination, when the post-startup fuel increase correction end flag is in the off state (step S1: Yes), the fuel injection amount calculation unit 21d determines that post-startup fuel increase correction is being performed, and starts The fuel increase correction coefficient calculation process proceeds to the process of step S2. On the other hand, if the post-startup fuel increase correction end flag is in the on state (step S1: No), the fuel injection amount calculation unit 21d determines that post-startup fuel increase correction is not being performed, and this time series. The start-time fuel increase correction coefficient calculation process ends. Note that the initial state of the post-startup fuel increase correction end flag is the off state.

In the process of step S2, the thinning counter 21e subtracts 1 from the count value CTKAST. Thereby, the process of step S2 is completed, and the start time fuel increase correction coefficient calculation process proceeds to the process of step S3.

In step S3, the fuel injection amount calculation unit 21d determines whether the count value CTKAST of the thinning counter 21e is equal to or less than zero. As a result of the determination, if the count value CTKAST of the thinning counter 21e is equal to or less than zero (step S3: Yes), the fuel injection amount calculation unit 21d advances the start time fuel increase correction coefficient calculation processing to the processing of step S4. On the other hand, when the count value CTKAST of the thinning-out counter 21e is not less than or equal to zero (step S3: No), the fuel injection amount calculation unit 21d ends the current series of start time fuel increase correction coefficient calculation processing.

In the process of step S4, the fuel injection amount calculation unit 21d retrieves a predetermined count value corresponding to the current engine speed NE from the table data shown in FIG. 3A, and the predetermined count obtained by retrieving the count value CTKAST of the thinning counter 21e. Set to value. Thereby, the process of step S4 is completed, and the start time fuel increase correction coefficient calculation process proceeds to the process of step S5.

In step S5, the fuel injection amount calculation unit 21d determines whether or not the value of the start time fuel increase correction coefficient KAST is equal to or less than a predetermined threshold value. As a result of the determination, if the value of the start time fuel increase correction coefficient KAST is equal to or less than the predetermined threshold value (step S5: Yes), the fuel injection amount calculation unit 21d advances the start time fuel increase correction coefficient calculation process to the process of step S7. . On the other hand, when the value of the start time fuel increase correction coefficient KAST is not less than or equal to the predetermined threshold value (step S5: No), the fuel injection amount calculation unit 21d advances the start time fuel increase correction coefficient calculation process to the process of step S6. Note that the predetermined threshold value may be set as a single value or a plurality as required. Further, a process for calculating the current value of the starting fuel increase correction coefficient KAST by decreasing the previous value of the starting fuel increase correction coefficient KAST at a constant rate, and a constant value from the previous value of the starting fuel increase correction coefficient KAST. When it is not necessary to combine the process of calculating the current value of the start-time fuel increase correction coefficient KAST by subtracting, it is not necessary to set the predetermined threshold value, and either one of the processes may be executed. .

In the process of step S6, the fuel injection amount calculation unit 21d sets a value obtained by multiplying the previous start time fuel increase correction coefficient KAST by a predetermined coefficient α (0 <α <1) as the current start time fuel increase correction coefficient KAST. To do. Thereby, the process of step S6 is completed, and the start time fuel increase correction coefficient calculation process proceeds to the process of step S8. Note that the predetermined coefficient α may be not only a constant value but also a variable value, or a combination thereof, as necessary.

In step S7, the fuel injection amount calculation unit 21d sets a value obtained by subtracting the positive predetermined value β from the previous start time fuel increase correction coefficient KAST as the current start time fuel increase correction coefficient KAST. Thereby, the process of step S7 is completed, and the start time fuel increase correction coefficient calculation process proceeds to the process of step S8. Note that the predetermined value β may be not only a constant value but also a variable value, or a combination thereof, as necessary.

In step S8, the fuel injection amount calculation unit 21d determines whether or not the starting fuel increase correction coefficient KAST is 1 or less. As a result of the determination, if the starting fuel increase correction coefficient KAST is 1 or less (step S8: Yes), the fuel injection amount calculating unit 21d advances the starting fuel increase correction coefficient calculating process to the process of step S9. On the other hand, if the start time fuel increase correction coefficient KAST is not 1 or less (step S8: No), the fuel injection amount calculation unit 21d ends the current start time fuel increase correction coefficient calculation process.

In step S9, the fuel injection amount calculation unit 21d sets the post-startup fuel increase correction end flag to the on state. Thereby, the process of step S9 is completed, and this series of start time fuel increase correction coefficient calculation process ends.

As is apparent from the above description, in the internal combustion engine control apparatus 1 according to the present embodiment, the fuel injection amount calculation unit 21d starts the fuel increase correction coefficient KAST at the start every time the count value CTKAST of the decimation counter 21e becomes a predetermined count value. Since the predetermined count value is set so as to increase as the engine speed NE increases, the period from the start of the engine to the start-time fuel increase correction coefficient KAST becomes zero. It can be made substantially constant without being influenced by NE, and the fuel increase correction at the time of starting the engine can be appropriately executed to suppress the decrease in drivability and the occurrence of engine stall.

Further, in the internal combustion engine control apparatus 1 in the present embodiment, the fuel injection amount calculation unit 21d has a constant value from the previous value of the starting fuel increase correction coefficient KAST every time the count value CTKAST of the thinning counter 21e becomes a predetermined count value. Since the current value of the starting fuel increase correction coefficient KAST is calculated by subtracting, the degree of decrease in the fuel increasing correction amount at the start can be linearly changed in accordance with the characteristics at the start of the engine. It is possible to more appropriately suppress the degradation of engine performance and engine stall.

In the internal combustion engine control apparatus 1 according to the present embodiment, the fuel injection amount calculation unit 21d keeps the previous value of the starting fuel increase correction coefficient KAST constant every time the count value CTKAST of the thinning counter 21e becomes a predetermined count value. Since the current value of the starting fuel increase correction coefficient KAST is calculated by decreasing the ratio, the degree of decrease in the fuel increasing correction amount at the start can be changed nonlinearly in accordance with the characteristics at the start of the engine. It is possible to more appropriately suppress a decrease in drivability and an engine stall.

Further, in the internal combustion engine control apparatus 1 in the present embodiment, every time the fuel injection amount calculation unit 21d reaches the count value CTKAST of the decimation counter 21e until the count value CTKAST of the decimation counter 21e reaches a predetermined threshold value. In addition, the current value of the starting fuel increase correction coefficient KAST is calculated by decreasing the previous value of the starting fuel increase correction coefficient KAST at a constant rate, and after the count value CTKAST of the thinning counter 21e reaches the predetermined threshold value, Every time the count value CTKAST of the decimation counter 21e becomes a predetermined count value, the current value of the start time fuel increase correction coefficient KAST is calculated by subtracting a constant value from the previous value of the start time fuel increase correction coefficient KAST. The degree of decrease in the fuel increase correction amount at the start according to the engine start characteristics Can be switched from the non-linear to linear, it is possible to more appropriately suppress the occurrence of reduction and engine stall in drivability.

In the present invention, the type, shape, arrangement, number, and the like of the members are not limited to the above-described embodiment, and the gist of the invention is appropriately replaced such that the constituent elements are appropriately replaced with those having the same operational effects. Of course, it can be changed as appropriate without departing from the scope.

For example, in this embodiment, the temperature of the spark plug seat of the engine is used as the engine temperature corresponding to the injector temperature. However, the present invention is not limited to this. For example, the engine cooling water temperature or the cylinder wall temperature is used. Also good.

Further, the configuration of the present embodiment may be used not only for a single cylinder engine but also for a multi-cylinder engine. In that case, the temperature of the cylinder can be estimated from the coil resistance value of the injector of each cylinder of the multi-cylinder engine, and the fuel injection amount of the cylinder can be controlled in accordance with the temperature of each cylinder.

As described above, the present invention can provide an internal combustion engine control device that can appropriately perform fuel increase correction at the time of starting the internal combustion engine and suppress the decrease in drivability and the occurrence of engine stall. Because of its universal character, it is expected to be widely applicable to general-purpose machines such as generators and internal combustion engine control devices for vehicles such as motorcycles.

Claims

An injector temperature calculation unit that is applied to an internal combustion engine and calculates an injector temperature based on a coil resistance value of the injector, an internal combustion engine temperature calculation unit that calculates an internal combustion engine temperature based on the injector temperature, and the internal combustion engine temperature An internal combustion engine control device having an operation state control unit for controlling an operation state of the internal combustion engine based on
A fuel injection amount calculation unit that calculates a fuel injection amount obtained by correcting a reference injection amount calculated from the injector temperature using a starting fuel increase correction coefficient;
A decimation counter that counts at regular intervals from the start of the internal combustion engine,
The fuel injection amount calculation unit decreases the starting fuel increase correction coefficient every time the count value of the thinning counter reaches a predetermined count value,
The internal combustion engine controller according to claim 1, wherein the predetermined count value is set so as to increase as the rotational speed of the internal combustion engine increases.
The fuel injection amount calculation unit subtracts a constant value from the previous value of the start time fuel increase correction coefficient every time the count value of the decimation counter reaches the predetermined count value, thereby determining the start time fuel increase correction coefficient. The internal combustion engine control device according to claim 1, wherein a calculation process for calculating a current value is executed.
The fuel injection amount calculation unit decreases the previous value of the start time fuel increase correction coefficient at a constant rate each time the count value of the decimation counter reaches the predetermined count value, thereby increasing the start time fuel increase correction coefficient. The internal combustion engine control device according to claim 1, wherein calculation processing for calculating a current value of the engine is executed.
The fuel injection amount calculation unit
Until the count value of the decimation counter reaches a predetermined threshold value, the previous value of the start-up fuel increase correction coefficient is decreased at a constant rate each time the count value reaches the predetermined count value. Execute the first calculation process for calculating the current value of the fuel increase correction coefficient,
After the count value of the decimation counter reaches a predetermined threshold value, every time the count value reaches the predetermined count value, a predetermined value is subtracted from the previous value of the start time fuel increase correction coefficient, thereby The internal combustion engine control device according to claim 1, wherein a second calculation process for calculating a current value of the fuel increase correction coefficient is executed.