JP6692269B2 - Internal combustion engine controller - Google Patents

Description

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

  In recent years, in general-purpose machines such as power generators and vehicles such as small motorcycles, it has become difficult for carburetor systems to comply with exhaust gas regulations that will become stricter in the future, so adoption of a fuel injection system for the purpose of reducing exhaust gas Is being promoted. However, the selling price of general-purpose machines such as generators and vehicles such as small motorcycles is lower than the selling price of vehicles such as large motorcycles and four-wheeled vehicles. In this case, it is difficult to directly adopt a fuel injection system, which is more expensive than a carburetor system, to 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 for sensors.

  Here, for example, an intake air temperature sensor in a fuel injection system is generally used to calculate the density of air taken into the internal combustion engine. Specifically, the fuel injection system calculates the intake air temperature of the internal combustion engine based on the output of the intake air temperature sensor, detects the air density taken into the internal combustion engine based on the calculated intake air temperature of the internal combustion engine, The ignition timing and fuel injection are controlled. Therefore, when the fuel injection system is adopted, it is necessary to mount the intake air temperature sensor on the internal combustion engine. Further, when installing the intake air temperature sensor in the internal combustion engine, it is necessary to install wiring wires and couplers, and it is also necessary to machine the part of the internal combustion engine in which the intake air temperature sensor is installed. As a result, the cost ratio of the fuel injection system to the selling price is higher than that of the carburetor system. Therefore, particularly in an internal combustion engine control device that controls a fuel injection system in a general-purpose machine such as a generator or a vehicle such as a small motorcycle, it is required to omit the intake air temperature sensor from the fuel injection system for the purpose of cost reduction. ing.

  Under such circumstances, Patent Document 1 relates to an intake air temperature estimation device for an internal combustion engine that estimates the intake air temperature of the internal combustion engine 1 in order to set the fuel injection amount, and relates to the outside air temperature and the heat from the engine room to the intake system of the engine. A configuration is disclosed in which the amount of transfer and the amount of heat transfer from the engine room to the intake system of the engine are estimated, and the intake temperature of the internal combustion engine 1 is estimated based on these estimation results. The outside air temperature is estimated using the ON or OFF time of the cooling fan, the heat generation amount of the engine, and the vehicle speed. Further, the amount of heat transfer from the engine room to the intake system of the engine is estimated by using the heat generation amount of the engine and the heat radiation amount of the engine room. Furthermore, the amount of heat conduction from the engine room to the intake system of the engine is estimated using the amount of heat generated by the engine and the temperature of the engine.

JP, 9-189256, A

  However, according to the study by the present inventor, when estimating the intake air temperature of the internal combustion engine with the configuration of Patent Document 1, it is difficult to actually mount it on a vehicle due to the complicated method, and the control is performed. Since the capacity of the storage means such as the ROM of the device is increased, the cost is increased. Further, when estimating the heat transfer amount from the engine room to the intake system of the engine and the heat transfer amount from the engine room to the intake system of the engine as in the configuration of Patent Document 1, a motorcycle without the concept of an engine room is used. Is not applicable. Further, when the outside air temperature is estimated by using the vehicle speed or the time when the cooling fan is turned on or off as in the configuration of Patent Document 1, an inexpensive two-wheeled vehicle or the like is not equipped with the vehicle speed detection means and the cooling fan. Since it also exists, it cannot be applied. Further, the outside air temperature used for estimating the intake air temperature in the configuration of Patent Document 1, the heat transfer amount from the engine room to the intake system of the engine, and the heat transfer amount from the engine room to the intake system of the engine are Since it is an estimated value, the intake air temperature may not be estimated accurately.

  The present invention has been made through the above studies, and can be mounted on an actual vehicle including a two-wheeled vehicle, has a simple configuration, and can reduce the capacity of the storage means such as the ROM of the control device. An object of the present invention is to provide an internal combustion engine control device that can suppress the overall cost and can calculate the intake air temperature of the internal combustion engine with practically sufficient accuracy.

In order to achieve the above object, in the first aspect of the present invention, in an internal combustion engine control device including a control unit for controlling an operating state of an internal combustion engine mounted on a vehicle, the control unit is the internal combustion engine. Gets the ambient temperature, the obtains the injector temperature is the temperature of the injector from the resistance value of the injector of an internal combustion engine, calculates the intake air temperature increase of the internal combustion engine from the ambient temperature and the injector temperature, the internal combustion calculating an injection amount correction value from the fuel injection amount per unit time of the engine, the by subtracting the injection amount correction value from the intake temperature increase to calculate the corrected intake air temperature increase, the corrected to the ambient temperature The internal combustion engine control device calculates the intake temperature of the internal combustion engine by adding the intake air temperature increase amount.

  In the present invention, in addition to the first aspect, the control unit uses the correlation characteristic that defines a relationship between a temperature difference between the injector temperature and the ambient temperature and an intake air temperature increase amount, and the intake air temperature is The second aspect is to calculate the amount of increase.

The present invention, in addition to the first or second aspect, wherein the control unit sets the filtering processing calculated the intake temperature and the third aspect.

The present invention, in addition to any one of the first to third aspects, includes a first temperature sensor arranged in a casing of the internal combustion engine controller, and a position separated from the first temperature sensor in the casing. A second temperature sensor disposed in the first temperature sensor and the second temperature sensor. A fourth aspect is to calculate the ambient temperature by correcting with the other detected temperature.

In an internal combustion engine control device according to a first aspect of the present invention, in an internal combustion engine control device including a control unit that controls an operating state of an internal combustion engine mounted on a vehicle, the control unit is an atmosphere of the internal combustion engine. The temperature is obtained, the injector temperature that is the temperature of the injector is obtained from the resistance value of the injector of the internal combustion engine, the intake air temperature rise amount of the internal combustion engine is calculated from the ambient temperature and the injector temperature, and the internal combustion engine calculating an injection amount correction value from the fuel injection amount per unit time, the by subtracting the injection amount correction value from the intake temperature increase to calculate the corrected intake air temperature increase, the corrected intake air temperature to the ambient temperature Since the intake air temperature of the internal combustion engine is calculated by adding the amount of increase, it can be mounted on an actual vehicle including a two-wheeled vehicle and has a simple configuration. Controller can be suppressed overall cost capacity storage means such as a ROM in order to be reducing, with a practically sufficient accuracy can be calculated intake air temperature of the internal combustion engine. Further, the intake air temperature can be calculated accurately by calculating the intake air temperature in consideration of the decrease in the intake air temperature due to the running wind according to the vehicle speed of the vehicle.

  Further, according to the internal combustion engine control device of the second aspect of the present invention, the control unit uses the correlation characteristic that defines the relationship between the difference temperature between the injector temperature and the ambient temperature and the intake air temperature increase amount. Since the intake air temperature rise amount is calculated, the intake air temperature rise amount that correlates with the difference temperature between the injector temperature and the ambient temperature of the engine is used, and the correlation characteristic that defines the relationship between the difference temperature and the intake air temperature rise amount is used. Can be calculated by

Further, according to the internal combustion engine control device of the third aspect of the present invention, since the control unit filters the calculated intake air temperature, the injector temperature rising characteristic and the intake air temperature rising characteristic coincide with each other. By doing so, the intake air temperature can be calculated accurately.

Further, according to the internal combustion engine control device of the fourth aspect of the present invention, the first temperature sensor arranged in the housing of the internal combustion engine control device and the first temperature sensor arranged in a position separated from the first temperature sensor in the housing. A second temperature sensor provided, and the control unit corrects the temperature detected by one of the first temperature sensor and the second temperature sensor by the temperature detected by the other of the first temperature sensor and the second temperature sensor. Since the ambient temperature is calculated in this way, the ambient temperature can be calculated accurately.

FIG. 1A is a schematic diagram showing a configuration of an internal combustion engine controller according to a first embodiment of the present invention, and FIG. 1B is a schematic diagram showing a configuration of an injector in FIG. 1A. Is. FIG. 2 is a flow chart showing a flow of intake air temperature calculation processing of the internal combustion engine control apparatus in the first embodiment. FIG. 3A is a diagram showing an intake air temperature increase amount table referred to by the internal combustion engine controller in the first embodiment, and FIG. 3B is presented by the internal combustion engine controller in the first embodiment. It is a figure which shows transition of intake air temperature. FIG. 4 is a schematic diagram showing the configuration of the internal combustion engine controller in the second embodiment.

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

(First embodiment)
<Configuration of internal combustion engine control device>
First, the configuration of the internal combustion engine controller according to the first embodiment will be described with reference to FIG. The internal combustion engine control device according to the present embodiment is typically 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, but for convenience of description, it will be described below. The internal combustion engine controller 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 controller according to a first embodiment of the present invention, and FIG. 1B is a schematic diagram showing a configuration of an injector in FIG. 1A. Is.

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

  The ECU 10 operates using electric power from a battery B mounted on the vehicle, and has a waveform shaping circuit 11, a thermistor element 12, an A / D converter 13, an ignition circuit 14, a drive circuit 15, and a resistance value detection. A circuit 16, an EEPROM (Electrically Erasable Programmable Read-Only Memory) 17, a ROM (Read-Only Memory) 18, a RAM (Random Access Memory) 19, a timer 20, and a central processing unit (Cent). There is. Each component of the ECU 10 is housed in a housing 10a of the ECU 10. Further, typically, the ECU 10 and the engine have their surroundings exposed to the outside air, and the ECU 10 is arranged apart from it so as not to be affected by the radiant heat of the engine and the heat transfer from the engine. It is something.

  The waveform shaping circuit 11 shapes the 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 ignition circuit 14 that is typically a heating element in the housing 10a of the ECU 10, and is located on the atmosphere side of the ECU 10 (for example, a housing whose distance to the housing 10a is about several millimeters). The chip thermistor is arranged at a position (close to the body 10a) and detects an ambient temperature (outside air temperature) that is an ambient temperature outside the casing 10a of the ECU 10. Specifically, the thermistor element 12 exhibits an electric resistance value corresponding to the ambient temperature and outputs an electric signal indicating a voltage corresponding to the electric 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 electric signal. The temperature detected by the thermistor element 12 is equal to the ambient temperature (outside air temperature) which is the ambient temperature around the engine. Further, since the thermistor element 12 is arranged on a circuit board (not shown) like other constituent elements of the ECU 10, it is not necessary to separately provide wiring and electrically connect the thermistor element 12 via the wiring.

  The A / D converter 13 outputs an electric signal indicating the opening degree of the throttle valve of the engine output from the throttle opening 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 electric 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 electric signals thus converted into digital form to the CPU 21.

  The ignition circuit 14 includes a switching element such as a transistor which is on / off controlled according to a control signal from the CPU 21, and the on / off operation of the switching element causes the fuel in the engine to be supplied through an ignition plug (not shown). And the operation of the ignition coil 6 which generates 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 has the largest heat generation amount in the housing 10a.

  The drive circuit 15 includes a switching element such as a transistor that is on / off controlled 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. In addition, 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 fuel is ejected from the injector 7 by operating the solenoid 7c while the coil 7a is energized.

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

  The EEPROM 17 stores data regarding 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 various learning values.

  The ROM 18 is composed of a non-volatile storage device, and has a control program for intake air temperature calculation processing described later, data on an intake air temperature increase amount table used in the intake air temperature calculation processing, data on an injector injection amount subtraction value calculation table and injector temperature. Stores various control data such as data related to tables.

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

  The timer 20 executes a timekeeping process according to a control signal from the CPU 21.

  CPU21 as a control part controls operation | movement of ECU10 whole. In the present embodiment, the CPU 21 executes the control program for the intake air temperature calculation processing stored in the ROM 18 to execute the intake air temperature increase amount table and the injector injection amount subtraction value calculation table stored in the ROM 18. The intake air temperature is calculated with reference. The CPU 21 controls the operating state of the engine by controlling the ignition circuit 14 and the drive circuit 15 based on the thus calculated intake air temperature and the separately detected engine temperature.

  The internal combustion engine control device 1 having such a configuration calculates the intake air temperature by executing the intake air temperature calculation process described below. Hereinafter, the intake air temperature calculation process in this embodiment will be described more specifically.

<Intake air temperature calculation processing>
A specific flow of the intake air temperature calculation processing according to the present embodiment will be described in detail with reference to FIGS. 2 and 3.

  FIG. 2 is a flow chart showing a flow of intake air temperature calculation processing of the internal combustion engine control apparatus in the first embodiment. FIG. 3A is a diagram showing an intake air temperature increase amount table referred to by the internal combustion engine controller in the first embodiment, and FIG. 3B is presented by the internal combustion engine controller in the first embodiment. It is a figure which shows transition of intake air temperature.

  The temperature of the intake air to the internal combustion engine is approximately the same as the outside air temperature at the outside air intake port, but it is increased by receiving heat from the intake passage. At this time, there is a correlation between the intake air temperature increase amount and the difference between the temperature of the intake passage and the outside air temperature. Therefore, the intake air temperature increase amount can be calculated by using the temperature of the intake passage and the ambient temperature. Further, since the temperature of the suction path can be represented by the injector temperature Tinj, it can be regarded as the same as the injector temperature Tinj.

  The flowchart shown in FIG. 2 starts at the timing when the ignition switch of the vehicle is switched from the off state to the on state and the CPU 21 operates, and the intake air temperature calculation process proceeds to the process of step S1. The intake air temperature calculation process is repeatedly executed every predetermined control period while the CPU 21 is operating with the vehicle ignition switch on.

  In the process of step S1, the CPU 21 detects the ambient temperature of the engine (thermistor temperature Tthr) via the thermistor element 12 and the A / D converter 13. As a result, the process of step S1 is completed, and the intake air temperature calculation process proceeds to step S2.

  In the process of step S2, the CPU 21 detects the resistance value (INJ resistance value) of the injector 7 via the resistance value detection circuit 16. Here, since the resistance value of the injector 7 has a characteristic of increasing in proportion to the temperature, the injector temperature Tinj can be obtained by utilizing this characteristic. The CPU 21 calculates the value of the injector temperature Tinj corresponding to the detected resistance value of the injector 7 from the injector temperature table which shows the relationship between the resistance value of the injector 7 and the value of the injector temperature Tinj stored in the ROM 18 in advance. .. As a result, the process of step S2 is completed, and the intake air temperature calculation process proceeds to step S3.

  In the process of step S3, the CPU 21 searches the intake air temperature increase amount table shown in FIG. 3A stored in advance in the ROM 18 to find the difference temperature between the injector temperature Tinj and the ambient temperature of the engine (injector temperature Tinj− The value of the intake air temperature increase amount ΔTA corresponding to the engine ambient temperature Tthr) is obtained. Here, according to the study by the present inventor, the intake air temperature and the above-mentioned difference temperature increase with the increase of the injector temperature Tinj, and there is a strong correlation between the above-mentioned difference temperature and the intake air temperature increase amount ΔTA. Therefore, the data of the intake air temperature increase amount table shown in FIG. 3A becomes a correlation characteristic curve that defines the relationship between the above-mentioned difference temperature and the intake air temperature increase amount ΔTA, and the intake air temperature increase amount ΔTA is calculated using the above-mentioned difference temperature. Can be asked. As a result, the process of step S3 is completed, and the intake air temperature calculation process proceeds to step S4.

  In the process of step S4, the CPU 21 searches the injector injection amount subtraction value calculation table that defines the relationship between the fuel injection amount per unit time and the injector injection amount subtraction value, which is stored in advance in the ROM 18, and determines the predetermined value. The injector injection amount subtraction value (injection amount correction value) corresponding to the fuel injection amount per unit time is calculated. Here, the fuel injection amount is calculated by converting the fuel injection time of the injector 7, or the fuel injection time of the injector 7 is used as it is. Then, the CPU 21 subtracts the injector injection amount subtraction value from the intake air temperature increase amount ΔTA calculated in the process of step S3 to calculate the corrected intake air temperature increase amount ΔTB. When the fuel injection amount (fuel injection time) increases during high load of the internal combustion engine, the vehicle speed increases and the traveling wind that the vehicle receives increases, so the intake path through which intake air passes is cooled, The actual amount of increase in intake air temperature from the ambient temperature is lower than the intake air temperature increase amount ΔTA calculated from the injector temperature Tinj. Therefore, the CPU 21 subtracts the injector injection amount subtraction value, which is the intake air temperature cooled by the running wind and decreased, from the intake air temperature increase amount ΔTA, thereby correcting the actual intake air temperature corresponding to the increase amount from the ambient temperature. The amount ΔTB of rise in the intake air temperature is calculated. As a result, the process of step S4 is completed, and the intake air temperature calculation process proceeds to step S5.

  In the process of step S5, the CPU 21 calculates, as the intake air temperature TA, a value obtained by adding the corrected intake air temperature increase amount ΔTB calculated in the process of step S4 to the ambient temperature of the engine detected in the process of step S1. As a result, the process of step S5 is completed, and the intake air temperature calculation process proceeds to step S6.

  In the process of step S6, the CPU 21 delays the change of the intake air temperature by filtering the intake air temperature TA calculated in the process of step S5. The filtering process is typically a process of obtaining a weighted average or moving average. As a result, the process of step S6 is completed, and the current series of intake air temperature calculation processes is completed.

  The CPU 21 controls the ignition circuit 14 on the basis of the intake air temperature estimated by executing the above intake air temperature calculation process, and ignites a mixture of fuel and air in the engine via an ignition plug (not shown). Further, the CPU 21 controls the drive circuit 15 on the basis of the intake air temperature estimated by executing the above intake air temperature calculation processing, and causes the injector 7 to supply fuel to the engine.

  As described above, the intake air temperature sensor can be eliminated from the internal combustion engine control device 1, so that the ignition timing and the fuel injection can be controlled with a low-cost system.

  Further, by controlling the ignition timing and the fuel injection using the fuel injection system, exhaust gas can be reduced as compared with the carburetor system.

  Further, in the development stage, when the carburetor system is shifted to the fuel injection system, the design of the mounting position of the throttle body, the injector, the fuel pump, etc. with respect to the vehicle, and the development items such as the change of the crank sensor, the reluctor and the ignition coil are required. Although there is a wide variety, it is easy to replace the carburetor system with the fuel injection system because there is no need to develop the installation of the intake air temperature sensor.

  FIG. 3B is a diagram showing a transition of the intake air temperature exhibited by the internal combustion engine controller according to the present embodiment. FIG. 3B shows the transition of the intake air temperature when the throttle valve is fully opened.

  Since the engine load becomes large when the throttle opening is fully opened, self-heating of the injector 7 becomes larger than that in the emission traveling mode. From this, the transition P1 of the added value obtained by adding the intake air temperature increase amount ΔTA calculated in the process of step S3 of the intake air temperature calculation process shown in FIG. 2 to the ambient temperature of the engine is shown by the solid line in FIG. 3 (b). It deviates from the transition P0 of the measured temperature value. In the present embodiment, in the process of step S4, the corrected intake air temperature increase amount ΔTB is calculated by subtracting the injector injection amount subtraction value from the intake air temperature increase amount ΔTA, and in the process of step S5, the corrected intake air temperature is corrected to the ambient temperature. The intake air temperature TA is calculated by adding the increase amount ΔTB. As a result, the transition P2 of the intake air temperature TA obtained by adding the corrected intake air temperature increase amount ΔTB to the ambient temperature is substantially the same as the transition P0 of the measured value of the intake air temperature, as shown in FIG. 3B.

  However, since the rising characteristic of the intake temperature is slower than the rising characteristic of the injector temperature, the intake temperature TA deviates from the measured value P0 of the intake temperature at the rising. In the present embodiment, in the process of step S6, the intake air temperature TA is filtered in order to match the injector temperature increase characteristic and the intake air temperature increase characteristic, and a correction for delaying the intake air temperature TA increase characteristic is performed. As a result, the corrected transition P3 of the intake air temperature TA matches the measured value P0 of the intake air temperature at the rising edge, as shown in FIG.

  In the internal combustion engine control apparatus according to the present embodiment described above, the ambient temperature of the internal combustion engine is acquired, the injector temperature that is the temperature of the injector 7 is acquired from the resistance value of the coil 7a of the injector 7, and the ambient temperature and the injector temperature of the internal combustion engine are acquired. Since the intake air temperature rise of the internal combustion engine is calculated from this, and the intake air temperature rise of the internal combustion engine is calculated by adding the intake air temperature rise amount to the ambient temperature, it can be installed in an actual vehicle including a two-wheeled vehicle. Since it has such a structure and the capacity of the storage means such as the ROM of the control device can be reduced, the overall cost can be suppressed, and the intake air temperature of the internal combustion engine can be calculated with sufficient accuracy in practical use.

  Further, the internal combustion engine control device according to the present embodiment calculates the intake air temperature increase amount by using the correlation characteristic that defines the relationship between the difference temperature between the injector temperature and the ambient temperature and the intake air temperature increase amount. The intake air temperature increase amount that is correlated with the difference temperature between the injector temperature and the engine ambient temperature can be calculated using the correlation characteristic that defines the relationship between the difference temperature and the intake air temperature increase amount.

  Further, in the internal combustion engine control apparatus according to the present embodiment, the injection amount correction value of the injector 7 is calculated from the fuel injection amount per unit time of the internal combustion engine, and the injection amount correction value is subtracted from the intake air temperature increase amount to obtain the corrected intake air amount. Since the intake air temperature is calculated by calculating the temperature rise amount and adding the corrected intake air temperature rise amount to the ambient temperature, the intake air temperature is considered in consideration of the decrease in intake air temperature due to the running wind according to the vehicle speed of the vehicle. The intake air temperature can be accurately calculated by calculating

  Further, since the internal combustion engine control device in the present embodiment filters the calculated intake air temperature, the intake air temperature is accurately calculated by matching the injector temperature increase characteristic with the intake temperature increase characteristic. be able to.

  Further, in the internal combustion engine control device in the present embodiment, by calculating the ambient temperature of the engine by the temperature sensor in the internal combustion engine control device, it is possible to eliminate the need to separately provide an outside air temperature sensor outside the device, simple The cost can be further reduced by the configuration.

(Second embodiment)
<Configuration of internal combustion engine control device>
The configuration of the internal combustion engine controller according to the present embodiment will be described with reference to FIG. The internal combustion engine control device according to the present embodiment is typically 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, but for convenience of description, it will be described below. The internal combustion engine controller will be described as being mounted on a vehicle such as a motorcycle.

  In addition, in FIG. 4, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

  The thermistor element 12a as the first temperature sensor is a region in which the temperature is the highest in the housing 10a of the ECU 10 (typically a region close to a heating element which is a distance of about several millimeters to the heating element which is the ignition circuit 14). ) Of the chip thermistor, which has an electric resistance value corresponding to the temperature thereof and outputs an electric signal indicating a voltage corresponding to the electric resistance value to the A / D converter 13. The thermistor element 12a may be replaced with another temperature sensor such as a thermocouple as long as it can output such an electric signal.

  The thermistor element 12b serving as the second temperature sensor has an ambient temperature (outside air temperature) that is the ambient temperature outside the chassis 10a of the ECU 10 in the chassis 10a of the ECU 10, that is, the ambient temperature around the engine. A chip thermistor arranged in a region close to (outside air temperature) (typically, a region close to the casing 10a whose distance to the casing 10a is about several millimeters), and an electric resistance value corresponding to the temperature. And an electric signal indicating a voltage corresponding to the electric resistance value is output to the A / D converter 13. The thermistor element 12b may be replaced with another temperature sensor such as a thermocouple as long as it can output such an electric signal.

  The A / D converter 13 outputs an electric signal indicating the opening degree of the throttle valve of the engine output from the throttle opening 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 electric signals output from the thermistor elements 12a and 12b are respectively converted from an analog form to a digital form. The A / D converter 13 outputs these electric signals thus converted into digital form to the CPU 21.

<Arrangement position of the thermistor element>
Next, the arrangement positions of the thermistor elements 12a and 12b will be described more specifically.

  The thermistor elements 12a and 12b and the ignition circuit 14 are arranged in a housing 10a that houses each component of the ECU 10. The ignition circuit 14 is typically a driver IC and is a component that generates the largest amount of heat within the housing 10a. The thermistor element 12a is arranged closer to the ignition circuit 14 having the largest heat generation amount in the housing 10a, and the thermistor element 12b is arranged farther from the ignition circuit 14 than the thermistor element 12a. ing. That is, the thermistor element 12a is disposed at a position where the temperature of the ignition circuit 14 is most directly affected by the heat generated by the ignition circuit 14, and the thermistor element 12b is most affected by the heat generated by the ignition circuit 14. It is arranged at a position most affected by the atmospheric temperature outside the casing 10a (which is the ambient temperature of the ECU 10 and corresponds to the ambient temperature of the engine) close to the casing 10a.

  The internal combustion engine controller 1 having such a configuration calculates the ambient temperature of the engine by executing the ambient temperature calculation process described below. Hereinafter, the operation of the internal combustion engine controller 1 when executing the atmospheric temperature calculation process in the present embodiment will be described more specifically.

<Ambient temperature calculation process>
First, in the atmosphere temperature calculation process in the present embodiment, as a premise, the atmosphere is calculated from the first difference temperature ΔT12 obtained by subtracting the detection temperature T2 of the thermistor element 12b from the detection temperature T1 of the thermistor element 12a and the detection temperature T2 of the thermistor element 12b. Table data showing a correlation characteristic line that predefines a relationship with the second difference temperature ΔT2a obtained by subtracting the temperature Ta is stored in the ROM 18 in advance and prepared.

  The first difference temperature ΔT12 basically corresponds to the heat generation amount of the ignition circuit 14, that is, the heat generation amount of the ECU 10. The second difference temperature ΔT2a is the temperature detected by the thermistor element 12b in consideration of the fact that the temperature T2 detected by the thermistor element 12b may differ from the ambient temperature Ta of the engine due to the influence of the amount of heat generated by the ignition circuit 14 or the like. It corresponds to the difference temperature between T2 and the ambient temperature Ta of the engine.

  In the atmosphere temperature calculation process according to the present embodiment, the first difference temperature ΔT12 is calculated, and the second difference temperature ΔT2a corresponding to the value of the first difference temperature ΔT12 is calculated by searching the table data indicating the correlation characteristic line. Find the value of. Then, a value obtained by subtracting the second difference temperature ΔT2a from the detected temperature T2 of the thermistor element 12b is calculated as the ambient temperature Ta of the engine. As a result, the ambient temperature Ta is calculated by correcting the temperature detected by the thermistor element 12b with the temperature detected by the thermistor element 12a. Ta can be calculated.

  In the internal combustion engine control device according to the present embodiment described above, one of the thermistor element 12a arranged in the housing of the internal combustion engine control device 1 and the thermistor element 12b arranged in a position separated from the thermistor element 12a in the housing. Since the ambient temperature is calculated by correcting the detected temperature of 1 with the other detected temperature, in addition to the effect of the first embodiment, the ambient temperature can be calculated with high accuracy.

  In the present embodiment, the detected temperature of the thermistor element 12b is corrected by the detected temperature of the thermistor element 12a. However, by resetting the table data and searching the reset table data, the detection of the thermistor element 12a is detected. The temperature may be corrected by the temperature detected by the thermistor element 12b.

  The present invention is not limited in the kind, shape, arrangement, number, etc. of the members to the above-mentioned embodiment, and appropriately replaces the constituent elements with those having the same operational effect, and does not depart from the gist of the invention. It goes without saying that the range can be changed as appropriate.

  Specifically, in the first and second embodiments described above, the ambient temperature is calculated using the thermistor element 12 in the ECU 10, but the ambient temperature is calculated using the resistance value of the relay or the like in the ECU 10. Alternatively, an outside air temperature sensor may be separately provided to measure the outside air temperature.

  In addition, in the first and second embodiments, the intake air temperature increase amount ΔTA is calculated using a table that defines the relationship between the temperature difference between the injector temperature and the engine ambient temperature and the intake air temperature increase amount ΔTA. However, the intake air temperature increase amount ΔTA may be calculated using a predetermined arithmetic expression that defines the relationship between the temperature difference between the injector temperature and the ambient temperature of the engine and the intake air temperature increase amount ΔTA.

  In the first and second embodiments, the intake air temperature is calculated by adding the corrected intake air temperature increase amount ΔTB to the ambient temperature. However, the intake air temperature is calculated according to the required calculation accuracy of the intake air temperature. The intake air temperature may be calculated by adding the intake air temperature increase amount ΔTA corresponding to the difference temperature between the injector temperature and the ambient temperature of the engine to the temperature.

  Further, although the intake air temperature TA is filtered in the first embodiment and the second embodiment, when performing the control in which it is not necessary to match the injector temperature rising characteristic and the intake temperature rising characteristic, The air temperature TA may not be filtered.

  As described above, the present invention can be mounted on an actual vehicle including a two-wheeled vehicle, has a simple structure, and can reduce the capacity of the storage means such as the ROM of the control device, thereby suppressing the overall cost. It is possible to provide an internal combustion engine control device capable of calculating the intake air temperature of the internal combustion engine with sufficient accuracy in practical use, and is widely applied to the internal combustion engine control device of a motorcycle or the like due to its general and universal character. Expected to be possible.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine control device 2 ... Crank angle sensor 3 ... Crank shaft 4 ... Throttle opening sensor 5 ... Oxygen sensor 6 ... Ignition coil 7 ... Injector 7a ... Coil 7b ... Coil equivalent circuit 7c ... Solenoid 10 ... ECU
10a ... Casing 11 ... Waveform shaping circuit 12 ... Thermistor element 12a ... Thermistor element 12b ... Thermistor element 13 ... A / D converter 14 ... Ignition circuit 15 ... Drive circuit 16 ... Resistance value detection circuit 17 ... EEPROM
18 ... ROM
19 ... RAM
20 ... Timer 21 ... CPU
B ... Battery

Claims (4)

In an internal combustion engine control device including a control unit for controlling the operating state of an internal combustion engine mounted on a vehicle ,
The control unit is
Obtaining the ambient temperature of the internal combustion engine,
Obtaining the injector temperature, which is the temperature of the injector, from the resistance value of the injector of the internal combustion engine,
Calculate the intake air temperature rise amount of the internal combustion engine from the ambient temperature and the injector temperature,
An injection amount correction value is calculated from the fuel injection amount per unit time of the internal combustion engine,
A corrected intake air temperature increase amount is calculated by subtracting the injection amount correction value from the intake air temperature increase amount,
Calculating the intake air temperature of the internal combustion engine by adding the corrected intake air temperature increase amount to the ambient temperature,
An internal combustion engine control device characterized by the above. The control unit is
The intake air temperature increase amount is calculated using a correlation characteristic that defines the relationship between the temperature difference between the injector temperature and the ambient temperature and the intake air temperature increase amount.
The internal combustion engine controller according to claim 1, wherein The control unit is
Filtering the calculated intake air temperature,
The internal combustion engine controller according to claim 1 or 2 , characterized in that. A first temperature sensor disposed in the housing of the internal combustion engine controller;
A second temperature sensor arranged at a position separated from the first temperature sensor in the housing;
Further equipped with,
The control unit is
Calculating the ambient temperature by correcting one of the detected temperatures of the first temperature sensor and the second temperature sensor with the other detected temperature of the first temperature sensor and the second temperature sensor,
The internal combustion engine control device according to any one of claims 1 to 3 , wherein: