JP6454539B2 - Internal combustion engine control device - Google Patents

Description

  The present invention relates to an internal combustion engine control device, and more particularly to an internal combustion engine control device applied to an internal combustion engine of a vehicle such as a two-wheeled vehicle.

  In recent years, for an internal combustion engine of a vehicle such as a two-wheeled motor vehicle, the operation of the internal combustion engine is performed using a controller in cooperation with the fuel supply to the internal combustion engine, the supply of air, and the ignition of the mixture comprising fuel and air An electronically controlled internal combustion engine controller that electronically controls the state is employed.

  Specifically, such an internal combustion engine control device includes an intake air amount and a crank angle sensor for an internal combustion engine obtained by using respective detection signals from sensors such as an air flow sensor, a throttle opening sensor, and an intake manifold negative pressure sensor. The fuel injection amount for realizing an appropriate air-fuel ratio in the internal combustion engine is calculated based on the rotational speed of the internal combustion engine obtained using this detection signal, and the fuel injection amount is injected into the internal combustion engine with this fuel injection amount. And the ignition is performed on the mixture of intake air and injected fuel at a predetermined ignition timing. Further, at this time, in the internal combustion engine control apparatus, the limit values for the fuel injection amount and the ignition timing are set in consideration of characteristics relating to MBT (Minimum Advance for the Best Torque) and knocking in the internal combustion engine. There is also. Further, in such an internal combustion engine control device, the fuel to the air-fuel mixture corresponding to the combustion state in the combustion chamber is detected by using detection signals from sensors such as an in-cylinder pressure sensor, a knock sensor, and an ion current sensor. Some have a configuration in which the injection amount and the ignition timing are each adjusted.

  Under such circumstances, Patent Document 1 relates to an engine control method, and relates to a crank angle sensor, an oxygen concentration sensor, a temperature sensor, a throttle opening sensor, an intake pipe pressure sensor, a hot-wire intake air amount sensor, an intake air temperature sensor, an exhaust gas. Using a tube temperature sensor and a catalyst temperature sensor, preignition that occurs before ignition due to an increase in the in-cylinder temperature is prevented, and even if ignition occurs before ignition, proper processing is performed to prevent engine damage. It has a structure to prevent.

JP-A-9-273436

  However, according to the study of the present inventor, in the configuration of Patent Document 1, various sensors such as an oxygen concentration sensor, an intake pipe pressure sensor, a hot-wire intake air amount sensor, an exhaust pipe temperature sensor, and a catalyst temperature sensor are used. It is necessary to provide it, and it is considered that the configuration is complicated and the cost of the entire vehicle tends to increase.

  Further, according to the study of the present inventor, in order to more accurately capture the combustion vibration at the time of abnormal combustion such as knock that is evaluated to have a frequency of 5 to 10 kHz, data sampling with a period of at least 100 μs or less is necessary. Therefore, high responsiveness of the sensor, high speed of the reading circuit, and the like are required, and the configuration is more complicated and the cost of the entire vehicle tends to increase.

  In other words, at present, the combustion state in the combustion chamber is detected with a simple configuration that can be suitably applied to a motorcycle such as a motorcycle that is particularly required to be lightweight and small, and according to the combustion state. Therefore, it can be said that there is a long-awaited situation for realizing an internal combustion engine control device capable of controlling the operating state of the internal combustion engine.

  The present invention has been made after the above studies, and provides an internal combustion engine control device capable of detecting the combustion state in the combustion chamber and controlling the operation state of the internal combustion engine according to the combustion state with a simple configuration. For the purpose.

In order to achieve the above object, the present invention is provided with a control unit that controls the operating state of the internal combustion engine while cooperating the supply of fuel, the supply of air, and the ignition of an air-fuel mixture comprising the fuel and the air. In the internal combustion engine control apparatus, the control unit is configured to inject a first temperature corresponding to a first assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from an instantaneous torque of the internal combustion engine and the fuel injection of the internal combustion engine. The first temperature and the second temperature coincide with each other according to a difference from a second temperature corresponding to a second assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from a quantity. When the first temperature is higher than the second temperature, the fuel injection amount is increased. On the other hand, when the first temperature is lower than the second temperature, the fuel injection is performed. before the fuel in a manner which reduced the amount By controlling the injection quantity, the first aspect that controls the operating state of the internal combustion engine.
Further, according to the present invention, in addition to the first aspect, the control unit calculates the instantaneous torque according to a calculated value obtained by subtracting a minimum value of the rotational speed from a maximum value of the rotational speed of the crankshaft of the internal combustion engine. The calculation is a second aspect.

In the present invention, in addition to the first or second aspect, the control unit calculates the second temperature in consideration of a predetermined time delay reflecting a heat transfer characteristic of a combustion chamber constituting unit of the internal combustion engine. This is the third aspect.

In addition to any one of the first to third aspects, the present invention provides the control unit, wherein the difference between the first temperature and the second temperature and a predetermined threshold value of the operating state of the internal combustion engine. The fourth aspect is to limit the value of the difference in accordance with the magnitude relationship between and.

According to the present invention, in addition to any one of the first to fourth aspects, the control unit includes a difference between a third temperature corresponding to a wall surface temperature of the combustion chamber of the internal combustion engine and the first temperature. Accordingly, a fifth aspect is to control the timing of the ignition of the air-fuel mixture so that the third temperature and the first temperature coincide with each other.

According to the present invention, in addition to the fifth aspect, the third temperature is mounted on the mounting portion of the internal combustion engine on the intake valve side as the wall surface temperature of the combustion chamber on the intake valve side of the internal combustion engine. The sixth aspect is that the temperature sensor is detected.

According to the internal combustion engine control apparatus according to the first aspect of the present invention described above, the control unit corresponds to the first assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from the instantaneous torque of the internal combustion engine. According to the difference between the temperature and the second temperature corresponding to the second assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from the fuel injection amount of the internal combustion engine, the first temperature and the second temperature are In order to agree , the fuel injection amount is increased when the first temperature is higher than the second temperature, while the fuel injection amount is decreased when the first temperature is lower than the second temperature. Since the operation state of the internal combustion engine is controlled by controlling the fuel injection amount in the aspect, the combustion state in the combustion chamber is detected with a simple configuration, and the operation state of the internal combustion engine is determined according to the combustion state. Can be controlled. In particular, a first assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from the instantaneous torque of the internal combustion engine, a second assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from the fuel injection amount of the internal combustion engine, This difference can be used as an appropriate indicator to indicate whether the combustion state in the combustion chamber is good or bad, so that the internal combustion engine is operated at a relatively low load, such as during a warm-up of the internal combustion engine. Even in a low temperature state caused by the above, it is possible to accurately grasp the combustion state in the combustion chamber and control the operation state of the internal combustion engine. Further, the fuel consumption rate of the internal combustion engine can be improved by appropriately controlling the operating state of the internal combustion engine in this way.

Further, according to the internal combustion engine control apparatus according to the third aspect of the present invention, the control unit takes into account the predetermined time delay reflecting the heat transfer characteristics of the combustion chamber constituting portion of the internal combustion engine, and the second temperature. Therefore, the second temperature can be appropriately calculated from the fuel injection amount of the internal combustion engine, and the internal combustion engine can be controlled while appropriately controlling the continuous injection amount using the first temperature. The operating state can be appropriately controlled.

Further, according to the internal combustion engine control apparatus according to the fourth aspect of the present invention, the control unit has a magnitude relationship between the difference between the first temperature and the second temperature and the predetermined threshold value of the operating state of the internal combustion engine. Accordingly, since the difference value is limited, the operation state of the internal combustion engine can be accurately controlled so as to suppress the occurrence of an abnormal combustion state such as knock while accurately controlling the fuel injection amount.

Moreover, according to the internal combustion engine control apparatus according to the fifth aspect of the present invention, the control unit responds to the difference between the third temperature corresponding to the wall surface temperature of the combustion chamber of the internal combustion engine and the first temperature. Since the timing of ignition of the air-fuel mixture is controlled so that the third temperature and the first temperature coincide with each other, the operating state of the internal combustion engine is appropriately controlled while appropriately controlling the ignition timing. Can do. In particular, the difference between the wall surface temperature of the combustion chamber in which the flame generated in the air-fuel mixture in the combustion chamber is difficult to propagate and the assumed wall surface temperature of the combustion chamber of the internal combustion engine calculated from the instantaneous torque of the internal combustion engine is the combustion Low temperature due to transient temperature conditions such as when the internal combustion engine is warming up or when the internal combustion engine is operated at a relatively low load because it can be used as an appropriate indicator that indicates whether the indoor combustion state is good or bad Even in the state, the operation state of the internal combustion engine can be controlled by accurately grasping the combustion state in the combustion chamber. Further, the fuel consumption rate of the internal combustion engine can be improved by appropriately controlling the operating state of the internal combustion engine in this way.

Further, according to the internal combustion engine control apparatus according to the sixth aspect of the present invention, the third temperature is the wall surface temperature of the combustion chamber on the intake valve side of the internal combustion engine, at the mounting site of the internal combustion engine on the intake valve side. Since the temperature is detected by the attached temperature sensor, the third temperature of the combustion chamber on the intake valve side of the internal combustion engine in which the flame generated by the ignition in the air-fuel mixture in the combustion chamber is not likely to propagate is noticeable. The wall surface temperature can be used, and by using the third temperature, the combustion state in the combustion chamber can be reliably detected, and the operation state of the internal combustion engine can be controlled in accordance with the combustion state.

FIG. 1 is a schematic diagram showing a configuration of an internal combustion engine and an internal combustion engine control device applied thereto in an embodiment of the present invention. FIG. 2 is a flowchart showing the flow of the sensor correction process when the cold machine power is turned on in the internal combustion engine control apparatus of the present embodiment. FIG. 3 is a flowchart showing the flow of the internal combustion engine operation state control process during the operation of the internal combustion engine in the internal combustion engine control apparatus of the present embodiment. FIG. 4A is a schematic diagram of table data showing the relationship between the instantaneous torque of the internal combustion engine used in the internal combustion engine operation state control process in the internal combustion engine control apparatus of the present embodiment and the assumed wall surface temperature of the combustion chamber. FIG. 4B is a schematic diagram of table data showing the relationship between the engine speed and throttle opening and the knock generation threshold used in the internal combustion engine operating state control process in the internal combustion engine control apparatus of the present embodiment. 4 (c) is a schematic diagram of table data showing the relationship between the fuel injection amount of the internal combustion engine used in the internal combustion engine operation state control process and the assumed wall surface temperature of the combustion chamber in the internal combustion engine control apparatus of the present embodiment; FIG. 4D is a graph showing the relationship between the rotational speed and throttle opening of the internal combustion engine used in the internal combustion engine operating state control process in the internal combustion engine control apparatus of this embodiment, and the knock occurrence threshold. It is a schematic view of the cable data.

  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]
First, the configuration of an internal combustion engine to which the internal combustion engine control apparatus according to the present embodiment is applied will be described with reference to FIG.

  FIG. 1 is a schematic diagram showing a configuration of an internal combustion engine and an internal combustion engine control device applied thereto in the present embodiment.

  As shown in FIG. 1, the internal combustion engine 1 includes a cylinder block 2 that is mounted on a vehicle such as a two-wheeled vehicle (not shown) and has one or more cylinders 2a. A coolant passage 3 through which coolant for cooling the cylinder block 2 flows is formed in a side wall of a portion corresponding to the cylinder 2 a of the cylinder block 2. 1 shows an example in which the number of cylinders 2a is only one for convenience.

  A piston 4 is disposed inside the cylinder 2a. The piston 4 is connected to the crankshaft 6 via a connecting rod 5. The crankshaft 6 is provided with a reluctator 7 that rotates coaxially therewith. On the outer peripheral surface of the reluctator 7, a plurality of teeth 7 a are juxtaposed in a predetermined pattern in the circumferential direction.

  A cylinder head 8 is assembled to the upper part of the cylinder block 2. The inner wall surface of the cylinder block 2, the upper surface of the piston 4, and the inner wall surface of the cylinder head 8 cooperate to define the combustion chamber 9 of the cylinder 2a.

  The cylinder head 8 is provided with a spark plug 10 that ignites a mixture of fuel and air in the combustion chamber 9. There may be a plurality of spark plugs 10 for each combustion chamber 9.

  The cylinder head 8 is assembled with an intake pipe 11 that communicates with the combustion chamber 9. In the cylinder head 8, an intake passage 11 a that communicates the combustion chamber 9 and the intake pipe 11 is formed. An intake valve 12 is provided at a corresponding connection portion between the combustion chamber 9 and the intake passage 11a. The intake pipe 11 may be a manifold according to the number of cylinders 2a, and the number of intake passages 11a is equal to the number of cylinders 2a. There may be a plurality of intake valves 12 for each combustion chamber 9.

  The intake pipe 11 is provided with an injector 13 for injecting fuel therein. The intake pipe 11 is provided with a throttle valve 14 on the upstream side of the injector 13. The throttle valve 14 is a component of a throttle device (not shown), and the main body of the throttle device is assembled to the intake pipe 11. The injector 13 may inject fuel directly into the corresponding combustion chamber 9. The number of injectors 13 and throttle valves 14 may be plural.

  The cylinder head 8 is assembled with an exhaust pipe 15 that communicates with the combustion chamber 9. An exhaust passage 15 a that communicates the combustion chamber 9 and the exhaust pipe 15 correspondingly is formed in the cylinder head 8. An exhaust valve 16 is provided at a corresponding connection portion between the combustion chamber 9 and the exhaust passage 15a. The exhaust pipe 15 may be a manifold according to the number of cylinders 2a, and the number of exhaust passages 15a is equal to the number of cylinders 2a and exhaust pipes 15. The number of exhaust valves 16 for each combustion chamber 9 may be plural.

[Configuration of internal combustion engine controller]
Next, the configuration of the internal combustion engine control device in the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the internal combustion engine control apparatus 100 according to this embodiment includes an ECU (Electronic) electrically connected to a crank angle sensor 101, an intake air temperature sensor 102, a throttle opening sensor 103, and an intake air temperature sensor 104. Control Unit) 105 is provided.

  The crank angle sensor 101 is mounted on a lower case or the like (not shown) assembled to the lower part of the cylinder block 2 in a manner facing the tooth portion 7 a formed on the outer peripheral surface of the reluctator 7, and as the crankshaft 6 rotates. By detecting the rotating tooth portion 7a, the rotational speed of the crankshaft 6 is detected as the rotational speed of the internal combustion engine 1 (internal combustion engine rotational speed NE). The crank angle sensor 101 inputs an electric signal indicating the detected internal combustion engine speed NE to the ECU 105.

  The intake air temperature sensor 102 is attached to the intake pipe 11 in a state of entering the intake pipe 11, detects the temperature of the air flowing into the intake pipe 11 as the intake air temperature TA, and indicates the detected intake air temperature TA. An electric signal is input to the ECU 105.

  The throttle opening sensor 103 is attached to the main body of the throttle device, detects the opening of the throttle valve 14 as the throttle opening TH, and inputs an electric signal indicating the detected throttle opening TH to the ECU 105.

  The intake-side temperature sensor 104 is a wall surface temperature (cylinder) on the intake valve 12 side, which is a portion where a flame generated when the air-fuel mixture in the combustion chamber 9 is ignited by the spark plug 10 and is ignited is difficult to propagate. The block 2 or the cylinder head 8 is mounted on the cylinder block 2 or the cylinder head 8 so as to detect the inner wall surface temperature (TCC) on the intake valve 12 side and on the combustion chamber 9 side. An electric signal indicating wall surface temperature TCC is input to ECU 105. Here, the wall surface temperature TCC on the intake valve 12 side is a temperature at a portion where the flame generated by the ignition of the air-fuel mixture in the combustion chamber 9 is difficult to propagate. It is a temperature that reacts sensitively to the state of combustion. On the other hand, as will be described in detail later, the assumed wall surface temperature TCCTQ of the combustion chamber 9 calculated from the instantaneous torque of the internal combustion engine 1 is the combustion of the air-fuel mixture in the combustion chamber 9 that generates the best torque of the internal combustion engine 1. The assumed wall surface temperature TCCTI of the combustion chamber 9 calculated from the fuel injection amount of the internal combustion engine 1 is a temperature that reflects this state, and the air-fuel mixture in the combustion chamber 9 generated corresponding to the fuel injection amount of the internal combustion engine 1 It is a temperature that reflects the state of combustion. If the temperature is sensitive to the combustion state of the air-fuel mixture in the combustion chamber 9, the wall surface temperature of the cylinder block 2 or the like detected by a temperature sensor other than the intake side temperature sensor 104 is used as the wall surface. A combustion chamber that can be employed as the temperature TCC and is calculated from other than the instantaneous torque as long as it reflects the combustion state of the air-fuel mixture in the combustion chamber 9 that generates the best torque of the internal combustion engine 1. It is also possible to employ the assumed wall surface temperature of 9 as the assumed wall surface temperature TCCTQ.

  The ECU 105 operates using electric power from a battery provided in the vehicle. The ECU 105 includes a microcomputer 106, and the microcomputer 106 includes a memory 106a and a CPU (Central Processing Unit) 106b. The CPU 106b functions as a control unit that executes various control processes of the vehicle such as a sensor correction process and an internal combustion engine operating state control process.

  The memory 106a is configured by a non-volatile storage device, and stores a control program and control data for sensor correction processing and internal combustion engine operation state control processing.

  The CPU 106 b controls the overall operation of the ECU 105 using electrical signals from the crank angle sensor 101, the intake air temperature sensor 102, the throttle opening sensor 103, and the intake air temperature sensor 104.

  The internal combustion engine control apparatus 100 having the above-described configuration has a simple configuration and a combustion chamber by executing the following sensor correction process when the cold machine power is turned on and the internal combustion engine operation state control process during the operation of the internal combustion engine. The combustion state in 9 is detected and the operation state of the internal combustion engine 1 is controlled. Hereinafter, with reference also to FIGS. 2 to 4, the operation of the internal combustion engine control device 100 when executing the sensor correction process when the cold machine is turned on and the internal combustion engine operation state control process during the internal combustion engine operation will be described in detail. explain.

[Sensor correction processing when the cold machine is turned on]
First, with reference to FIG. 2, the operation of the internal combustion engine control device 100 when executing sensor correction processing when the cold machine is turned on will be described. It is preferable that the sensor correction process when the cold machine power is turned on is executed in order to execute the internal combustion engine operation state control process during the operation of the internal combustion engine more accurately. That is, when the sensor correction process at the time of turning on the cold machine power is executed, the internal combustion engine operation state control process during the operation of the internal combustion engine is executed after the completion of the sensor correction process.

  FIG. 2 is a flowchart showing a flow of sensor correction processing when the cold machine power is turned on in the internal combustion engine control apparatus 100 of the present embodiment.

  The flowchart shown in FIG. 2 starts at the timing when the ignition switch (not shown) is turned on and the internal combustion engine control device 100 is operated, and the sensor correction process when the cold machine power is turned on proceeds to the process of step S1.

  In the process of step S1, the CPU 106b determines whether or not the ignition switch of the vehicle is turned on for the first time, that is, whether or not the cold machine power is turned on for the first time after the vehicle is manufactured. Whether or not the cold machine power is turned on for the first time after the vehicle is manufactured refers to, for example, on / off information of a flag in the memory 106a that is turned on when the cold machine power is turned on for the first time after the vehicle is manufactured. This can be determined. As a result of the determination, if the cold machine power supply has already been turned on, the CPU 106b ends the current series of sensor correction processes. On the other hand, when the cold machine power is turned on for the first time, the CPU 106b advances the sensor correction process to the process of step S2.

  In step S2, the CPU 106b detects the internal combustion engine rotational speed NE based on the electric signal input from the crank angle sensor 101, and determines whether the internal combustion engine 1 is not started based on the internal combustion engine rotational speed NE. Is determined. As a result of the determination, if the internal combustion engine 1 has already been started, the CPU 106b ends the current series of sensor correction processes. On the other hand, when the internal combustion engine 1 has not been started, the CPU 106b advances the sensor correction process to the process of step S3.

  In step S3, the CPU 106b determines that the intake air temperature TA and the wall surface temperature TCC on the intake valve 12 side are within a predetermined error range based on the electric signals input from the intake air temperature sensor 102 and the intake air temperature sensor 104. It is discriminated whether or not there is. As a result of the determination, if these temperatures are not within the respective predetermined error ranges, the CPU 106b ends the current series of sensor correction processes. On the other hand, when these temperatures are within the respective predetermined error ranges, the CPU 106b advances the sensor correction process to the process of step S4.

  In the process of step S4, the CPU 106b compares the intake air temperature TA with the wall surface temperature TCC on the intake valve 12 side while referring to the master data stored in the memory 106a, so that the intake valve 12 side Each of the wall surface temperature TCC errors is corrected. For example, when the wall surface temperature TCC is 2 ° C. higher than the standard temperature in the master data to be obtained using the intake air temperature TA, the CPU 106b corrects the wall surface temperature TCC to be 2 ° C. lower. Here, as the master data, a correspondence relationship between the intake air temperature TA and the wall surface temperature TCC on the intake valve 12 side in the internal combustion engine 1 that exhibits the output characteristics of the mass production median value is set in advance based on these actually detected temperatures. What was stored in the memory 106a is used. Such correction may be made using another reference temperature as necessary. As a result, the correction of the intake side temperature sensor 104 is accurately performed so that the performance of the mass production central specification of the internal combustion engine 1 can be exhibited, and the internal combustion engine operating state control process during the internal combustion engine operation is accurately performed. Will lead to results. Thereby, the process of step S4 is completed and a series of this sensor correction process is complete | finished.

[Internal combustion engine operating state control process during internal combustion engine operation]
Next, the operation of the internal combustion engine control apparatus 100 when executing the internal combustion engine operation state control process during the operation of the internal combustion engine will be described with further reference to FIGS.

  FIG. 3 is a flowchart showing the flow of the internal combustion engine operation state control process during the internal combustion engine operation in the internal combustion engine control apparatus 100 of the present embodiment. FIG. 4A is a schematic diagram of table data showing the relationship between the instantaneous torque of the internal combustion engine 1 used in the internal combustion engine operation state control process in the internal combustion engine control apparatus 100 of the present embodiment and the assumed wall surface temperature of the combustion chamber 9. FIG. 4B is a schematic diagram of table data showing the relationship between the engine speed and throttle opening and the knock occurrence threshold used in the internal combustion engine operating state control process in the internal combustion engine control apparatus 100 of the present embodiment. FIG. 4C is table data showing the relationship between the fuel injection amount of the internal combustion engine 1 used in the internal combustion engine operation state control process in the internal combustion engine control apparatus 100 of the present embodiment and the assumed wall surface temperature of the combustion chamber. FIG. 4D shows the internal combustion engine speed and the throttle opening used in the internal combustion engine operating state control process in the internal combustion engine control apparatus 100 of the present embodiment. Tsu is a schematic diagram of a table data showing the relationship between the click generation threshold.

  The flowchart shown in FIG. 3 starts at the timing when the ignition switch (not shown) is turned on and the internal combustion engine control device 100 is operated, and the internal combustion engine operating state control process during the operation of the internal combustion engine is the process of step S11. move on. The internal combustion engine operating state control process during the operation of the internal combustion engine is repeatedly executed at predetermined control cycles while the internal combustion engine control apparatus 100 is operating.

  In the process of step S11, the CPU 106b detects the internal combustion engine rotational speed NE based on the electric signal input from the crank angle sensor 101, and whether the internal combustion engine 1 is in operation based on the internal combustion engine rotational speed NE. Is determined. As a result of the determination, if the internal combustion engine 1 is not in operation, the CPU 106b ends the current series of internal combustion engine operation state control processing. On the other hand, when the internal combustion engine 1 is in operation, the CPU 106b advances the internal combustion engine operation state control process to the process of step S12.

  In the process of step S12, the CPU 106b acquires information on the wall surface temperature TCC on the intake valve 12 side via the intake side temperature sensor (combustion chamber temperature sensor) 104. Thereby, the process of step S12 is completed and the combustion chamber temperature control process proceeds to the process of step S13.

  In the process of step S13, the CPU 106b subtracts the minimum value of the rotational speed from the maximum value of the rotational speed of the crankshaft 6 in a predetermined cycle of the operation stroke of the internal combustion engine 1 based on the electric signal input from the crank angle sensor 101. The calculated value (rotational speed fluctuation value) is calculated, and the torque that should be actually generated by the internal combustion engine 1 is calculated as the instantaneous torque of the internal combustion engine 1 according to the calculated value. Thereby, the process of step S13 is completed, and the fuel chamber temperature control process proceeds to the process of step S14.

  In the process of step S14, the CPU 106b calculates the assumed wall surface temperature TCCTQ of the combustion chamber 9 from the instantaneous torque of the internal combustion engine 1 calculated in the process of step S13. Specifically, in the present embodiment, the instantaneous torque and the assumed wall surface temperature set in advance based on the temperature characteristic of the internal combustion engine 1 that exhibits the output characteristic of the mass production median value as shown in FIG. Table data defining a characteristic curve L1 indicating the relationship with TCCTQ is stored. The CPU 106b calculates the assumed wall surface temperature TCCTQ by reading the assumed wall surface temperature TCCTQ corresponding to the instantaneous torque of the internal combustion engine 1 calculated in the process of step S13 from the table data shown in FIG. By calculating the assumed wall surface temperature TCCTQ with reference to such master table data, the performance variation existing in the internal combustion engine 1, specifically, the mechanical tolerance and electrical crossing associated with the internal combustion engine 1 are ignited. The tolerance of the time can be absorbed. Here, the assumed wall surface temperature TCCTQ can be calculated while reproducing the delay time and the amount of attenuation until the amount of heat corresponding to the instantaneous torque of the internal combustion engine 1 is transmitted to the sensor and detected by a weighted average or a delay timer. More preferred. Thereby, the process of step S14 is completed, and the combustion chamber temperature control process proceeds to the process of step S15.

  In the process of step S15, the CPU 106b calculates a difference TCCDIGD between the wall surface temperature TCC on the intake valve 12 side acquired in the process of step S12 and the assumed wall surface temperature TCCTQ calculated in the process of step S14. Here, the wall surface temperature TCC on the intake valve 12 side is a temperature at a portion where a flame generated by the mixture in the combustion chamber 9 being ignited hardly propagates, and the combustion of the mixture in the combustion chamber 9 is performed. Since the assumed wall surface temperature TCCTQ is a temperature that reflects the combustion state of the air-fuel mixture in the combustion chamber 9 that generates the best torque of the internal combustion engine 1, the difference TCCDIGD Is preferably within a predetermined range. Therefore, the value of the difference TCCIGD between the wall surface temperature TCC on the intake valve 12 side and the assumed wall surface temperature TCCTQ is an index indicating whether the combustion state in the combustion chamber 9 is good or bad. Thereby, the process of step S15 is completed and the combustion chamber temperature control process proceeds to the process of step S16.

  In the process of step S16, the CPU 106b determines whether or not the value of the difference TCCDIGD calculated in the process of step S15 is greater than or equal to a predetermined threshold value of the internal combustion engine 1. Specifically, as the predetermined threshold, in this embodiment, the internal combustion engine 1 is operated at the best torque by controlling the wall surface temperature TCC on the intake valve 12 side so as to coincide with the assumed wall surface temperature TCCTQ. Since the state is intended to be realized, a threshold (MBT (Minimum Advance for the Best Torque) threshold) corresponding to the ignition timing at which the torque of the internal combustion engine 1 becomes maximum or a predetermined (for example, 50%) of the internal combustion engine 1 are set. It is preferable to employ a threshold value (knock occurrence threshold value) corresponding to a knocking level of the internal combustion engine 1 that is larger than a threshold value corresponding to the mass combustion crank angle (mass combustion point threshold value). Specifically, table data defining a characteristic curve L2 corresponding to the value of the knock generation threshold value with respect to the internal combustion engine speed NE and the throttle opening TH as shown in FIG. 4B is stored in the memory 106a. Based on the electrical signals input from the crank angle sensor 101 and the throttle opening sensor 103, the CPU 106b sets a knock occurrence threshold value that is a value on the characteristic curve L2 corresponding to the internal combustion engine speed NE and the throttle opening TH. Read from the table data shown in (b). Then, the CPU 106b determines whether or not the difference TCCIGD value is equal to or greater than the read knock occurrence threshold. As a result of the determination, if the value of the difference TCCIGD is equal to or greater than the knock occurrence threshold, the CPU 106b advances the internal combustion engine operating state control process to the process of step S17. On the other hand, when the value of the difference TCCIGD is less than the knock occurrence threshold, the CPU 106b advances the internal combustion engine operating state control process to the process of step S18. In addition, as a predetermined threshold value, you may employ | adopt combining a MBT threshold value and a mass combustion point threshold value as needed.

  In the process of step S17, the CPU 106b sets the value of the difference TCCIDIGD to a predetermined threshold that is preferably a knock occurrence threshold obtained in the process of step S16. Thereby, the process of step S17 is completed and the combustion chamber temperature control process proceeds to the process of step S19.

  In the process of step S18, the CPU 106b maintains the value of the difference TCCIDIGD calculated in the process of step S15 as it is. Thereby, the process of step S18 is completed, and the combustion chamber temperature control process proceeds to the process of step S19.

  In the process of step S19, the CPU 106b responds to the value of the difference TCCIGD calculated in the process of step S15 or the value of the difference TCCIGD set to a predetermined threshold that is preferably a knock occurrence threshold in the process of step S17. The operating state of the internal combustion engine 1 is controlled by feedback controlling the ignition timing of the air-fuel mixture in the combustion chamber 9 so that the wall surface temperature TCC on the intake valve 12 side and the assumed wall surface temperature TCCTQ coincide. Specifically, when the wall surface temperature TCC on the intake valve 12 side is higher than the assumed wall surface temperature TCCTQ, the CPU 106b determines that the ignition timing has a tendency to advance, and retards the ignition timing. On the other hand, when the wall surface temperature TCC on the intake valve 12 side is smaller than the assumed wall surface temperature TCCTQ, the CPU 106b determines that the ignition timing tends to be retarded and advances the ignition timing. Here, generally, in the internal combustion engine 1, the peak in-cylinder pressure corresponding to the average effective pressure (IMEP) as the best torque is uniquely determined, and the assumed wall surface temperature TCCTQ obtained from the peak in-cylinder pressure and the instantaneous torque is positive. It has a correlation. For this reason, controlling the wall surface temperature TCC on the intake valve 12 side so as to coincide with the assumed wall surface temperature TCCTQ is synonymous with realizing the operating state of the internal combustion engine 1 at the best torque. Thereby, the process of step S19 is completed, and the combustion chamber temperature control process proceeds to the process of step S20.

  In the process of step S20, the CPU 106b acquires the fuel injection amount of the internal combustion engine 1 discharged from the injector 13, and calculates the assumed wall surface temperature TCCTI of the combustion chamber 9 according to the fuel injection amount. Specifically, in the present embodiment, the fuel injection amount set in advance based on the temperature characteristic of the internal combustion engine 1 that exhibits the output characteristic of the mass production median value as shown in FIG. Table data defining a characteristic curve L3 indicating the relationship with the temperature TCCTI is stored. The CPU 106b calculates the assumed wall surface temperature TCCTI by reading the assumed wall surface temperature TCCTI corresponding to the acquired fuel injection amount from the table shown in FIG. By calculating the assumed wall surface temperature TCCTI with reference to such master table data, the performance variation existing in the internal combustion engine 1, specifically, the mechanical tolerance and electrical crossing associated with the internal combustion engine 1 are ignited. The tolerance of the time can be absorbed. Here, it is preferable to calculate the assumed wall surface temperature TCCTI while reproducing a delay time and an attenuation amount until a heat amount corresponding to the fuel injection amount is transmitted to the sensor and detected by a weighted average or a delay timer. Thereby, the process of step S20 is completed and the combustion chamber temperature control process proceeds to the process of step S21.

  In the process of step S21, the CPU 106b calculates the difference TCCDTID between the assumed wall surface temperature TCCTI calculated in the process of step S14 and the assumed wall surface temperature TCCTI calculated in the process of step S20. Here, the assumed wall surface temperature TCCTI is a temperature reflecting the combustion state of the air-fuel mixture in the combustion chamber 9 that generates the best torque of the internal combustion engine 1, and the assumed wall surface temperature TCCTI is the fuel injection of the internal combustion engine 1. Since the temperature reflects the state of combustion of the air-fuel mixture in the combustion chamber 9 that corresponds to the amount, it is preferable that these differences TCCDID are within a predetermined range. Therefore, the value of the difference TCCDID between the assumed wall surface temperature TCCTQ and the assumed wall surface temperature TCCTI serves as an index indicating whether the combustion state in the combustion chamber 9 is good or bad. Thereby, the process of step S21 is completed and the combustion chamber temperature control process proceeds to the process of step S22.

  In the process of step S22, the CPU 106b determines whether or not the value of the difference TCCDID calculated in the process of step S21 is greater than or equal to a predetermined threshold value of the internal combustion engine 1. Specifically, as the predetermined threshold value, in the present embodiment, a torque corresponding to the fuel injection amount is generated in the internal combustion engine 1 by controlling the assumed wall surface temperature TCCTQ and the assumed wall surface temperature TCCTI to coincide with each other. Therefore, it is preferable to employ a knock generation threshold value that is larger than the MBT threshold quality or the quantity combustion point threshold value. Specifically, table data defining a characteristic curve L4 corresponding to the value of the knock generation threshold value for the internal combustion engine speed NE and the throttle opening TH as shown in FIG. 4D is stored in the memory 106a. Based on the electrical signals input from the crank angle sensor 101 and the throttle opening sensor 103, the CPU 106b sets a knock occurrence threshold value that is a value on the characteristic curve L4 corresponding to the internal combustion engine speed NE and the throttle opening TH. Read from the table data shown in (d). Then, the CPU 106b determines whether or not the difference TCCIGD value is equal to or greater than the read knock occurrence threshold. As a result of the determination, if the value of the difference TCCDID is equal to or greater than the knock occurrence threshold, the CPU 106b advances the internal combustion engine operating state control process to the process of step S23. On the other hand, when the value of the difference TCCDID is less than the knock occurrence threshold, the CPU 106b advances the internal combustion engine operating state control process to the process of step S24.

  In the process of step S23, the CPU 106b sets and limits the value of the difference TCCDID to a predetermined threshold that is preferably a knock occurrence threshold obtained in the process of step S22. Thereby, the process of step S23 is completed, and the combustion chamber temperature control process proceeds to the process of step S25.

  In the process of step S24, the CPU 106b maintains the value of the difference TCCDID calculated in the process of step S21 as it is. Thereby, the process of step S24 is completed and the combustion chamber temperature control process proceeds to the process of step S25.

  In the process of step S25, the CPU 106b responds to the value of the difference TCCDID calculated in the process of step S21 or the value of the difference TCCDID set to a predetermined threshold that is preferably a knock occurrence threshold in the process of step S23. The operating state of the internal combustion engine 1 is controlled by feedback-controlling the combustion injection amount so that the assumed wall surface temperature TCCTQ matches the assumed wall surface temperature TCCTI. Specifically, when the assumed wall surface temperature TCCTQ is higher than the assumed wall surface temperature TCCTI, the CPU 106b determines that the air-fuel mixture in the combustion chamber 9 has a lean tendency and increases the fuel injection amount. On the other hand, when the assumed wall surface temperature TCCTQ is lower than the assumed wall surface temperature TCCTI, the CPU 106b determines that the air-fuel mixture in the combustion chamber 9 tends to be rich, and reduces the fuel injection amount. That is, the feedback control that matches the assumed wall surface temperature TCCCT and the assumed wall surface temperature TCCTI in this way means that the internal combustion engine 1 generates a torque corresponding to the fuel injection amount, which corresponds to the actual torque. By controlling the fuel injection amount with the target temperature set as a target, a good combustion state in the combustion chamber 9 exhibiting an air-fuel ratio corresponding to the operating state of the master internal combustion engine 1 is also realized in the individual internal combustion engines 1 in mass production. Means that you can. Thereby, the process in step S25 is completed, and the current series of combustion chamber temperature control process ends.

  In order to simplify the internal combustion engine operation state control process during the operation of the internal combustion engine, it is also possible to control the ignition timing based directly on the value of the difference TCCIGD calculated in the process of step S15. In such a case, each processing from step S16 to step S18 can be omitted. Further, it is possible to control the fuel injection amount directly based on the value of the difference TCCDID calculated in the process of step S21. In such a case, the processes of steps S22 to S24 are omitted. It is also possible. In addition to the ignition timing and the fuel injection amount, the parameter for controlling the operating state of the internal combustion engine 1 includes the air supply amount. Therefore, in addition to the adjustment of the ignition timing and the fuel injection amount, the air supply amount is adjusted. The operation state of the internal combustion engine 1 may be controlled, or the operation state of the internal combustion engine 1 may be controlled by appropriately combining these.

  As is clear from the above description, in the internal combustion engine control apparatus 100 according to the present embodiment, the control unit 106b has the first assumed wall surface temperature of the combustion chamber 9 of the internal combustion engine 1 calculated from the instantaneous torque of the internal combustion engine 1. According to the difference between the corresponding first temperature TCCTI and the second temperature TCCTI corresponding to the second assumed wall surface temperature of the combustion chamber 9 of the internal combustion engine 1 calculated from the fuel injection amount of the internal combustion engine 1, Since the fuel injection amount is controlled so that the first temperature TCCCT and the second temperature TCCTI coincide with each other, the combustion state in the combustion chamber 9 is detected with a simple configuration, and the internal combustion is performed according to the combustion state. The operating state of the engine 1 can be controlled. In particular, the first assumed wall surface temperature TCCTQ of the combustion chamber 9 of the internal combustion engine 1 calculated from the instantaneous torque of the internal combustion engine 1 and the second of the combustion chamber 9 of the internal combustion engine 1 calculated from the fuel injection amount of the internal combustion engine 1. The difference between the estimated wall surface temperature TCCTI and the internal combustion engine 1 can be used as an appropriate index indicating whether the combustion state in the combustion chamber 9 is good or bad. Even in a low temperature state resulting from the operation of the engine 1 with a relatively low load, it is possible to accurately grasp the combustion state in the combustion chamber 9 and control the operation state of the internal combustion engine 1. Moreover, the fuel consumption rate of the internal combustion engine 1 can be improved by appropriately controlling the operating state of the internal combustion engine 1 in this way.

  Further, in the internal combustion engine control apparatus 100 in the present embodiment, the control unit 106b sets the second temperature TCCTI in consideration of a predetermined time delay reflecting the heat transfer characteristics of the components of the combustion chamber 9 of the internal combustion engine 1. Therefore, the second temperature TCCTI can be appropriately calculated from the fuel injection amount of the internal combustion engine 1, and the internal combustion engine can be controlled while appropriately controlling the continuous injection amount using the first temperature TCCTI. The operating state of the engine 1 can be appropriately controlled.

  In the internal combustion engine control apparatus 100 according to the present embodiment, the control unit 106b responds to the magnitude relationship between the difference TCCDID between the first temperature TCCTQ and the second temperature TCCTI and a predetermined threshold value of the operating state of the internal combustion engine 1. Thus, since the difference value TCCDID is limited, the operating state of the internal combustion engine 1 can be accurately controlled so as to suppress the occurrence of an abnormal combustion state such as knock while accurately controlling the fuel injection amount. .

  Further, in the internal combustion engine control apparatus 100 according to the present embodiment, the control unit 106b corresponds to the difference TCCDIGD between the third temperature TCC corresponding to the wall surface temperature of the combustion chamber 9 of the internal combustion engine 1 and the first temperature TCCTQ. Since the timing of ignition of the air-fuel mixture is controlled so that the third temperature TCC and the first temperature TCCTQ coincide with each other, the operating state of the internal combustion engine 1 is appropriately controlled while appropriately controlling the ignition timing. Can be controlled. In particular, the wall surface temperature TCC of the combustion chamber 9 in which the flame generated by ignition in the air-fuel mixture in the combustion chamber 9 is difficult to propagate, and the assumed wall surface temperature TCCTQ of the combustion chamber of the internal combustion engine 1 calculated from the instantaneous torque of the internal combustion engine 1. Can be used as an appropriate index indicating whether the combustion state in the combustion chamber 9 is good or bad, so that a transient temperature state such as during warm-up of the internal combustion engine 1 or the internal combustion engine 1 is relatively low. Even in a low temperature state caused by driving with a load, the combustion state in the combustion chamber 9 can be accurately grasped and the operation state of the internal combustion engine 1 can be controlled. Moreover, the fuel consumption rate of the internal combustion engine 1 can be improved by appropriately controlling the operating state of the internal combustion engine 1 in this way.

  Further, in the internal combustion engine control apparatus 100 according to the present embodiment, the third temperature TCC is mounted on the mounting portion of the internal combustion engine on the intake valve 12 side as the wall surface temperature of the combustion chamber on the intake valve 12 side of the internal combustion engine 1. Therefore, as the third temperature TCC, the intake valve 12 side of the internal combustion engine 1 in which the flame generated by ignition in the air-fuel mixture in the combustion chamber 9 does not easily propagate is noticeable. The wall surface temperature of the combustion chamber 9 can be used, and the combustion state in the combustion chamber 9 is reliably detected using the third temperature TCC, and the operation state of the internal combustion engine 1 is controlled according to the combustion state. can do.

  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.

  As described above, the present invention can provide an internal combustion engine control apparatus that can detect the combustion state in the combustion chamber and control the operation state of the internal combustion engine according to the combustion state with a simple configuration. Therefore, it is expected that it can be widely applied to an internal combustion engine control device such as a vehicle because of its general purpose universal character.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder block 2a ... Cylinder 3 ... Coolant passage 4 ... Piston 5 ... Connecting rod 6 ... Crankshaft 7 ... Retractor 7a ... Tooth part 8 ... Cylinder head 9 ... Combustion chamber 10 ... Spark plug 11 ... Intake pipe 11a ... Intake passage 12 ... Intake valve 13 ... Injector 14 ... Throttle valve 15 ... Exhaust pipe 15a ... Exhaust passage 16 ... Exhaust valve 100 ... Internal combustion engine control device 101 ... Crank angle sensor 102 ... Intake temperature sensor 103 ... Throttle opening sensor 104 ... Intake Side temperature sensor 105 ... ECU
106 ... Microcomputer 106a ... Memory 106b ... CPU

Claims (6)

In an internal combustion engine control device comprising a control unit for controlling the operating state of an internal combustion engine while cooperating the supply of fuel, the supply of air, and the ignition of an air-fuel mixture comprising the fuel and the air,
The control unit calculates the internal combustion engine from a first temperature corresponding to a first assumed wall surface temperature of a combustion chamber of the internal combustion engine calculated from an instantaneous torque of the internal combustion engine and an injection amount of the fuel of the internal combustion engine. according to a difference between the second temperature corresponding to the second assumed wall surface temperature of the combustion chamber of the engine, such that the first temperature and the second temperature are identical, the first temperature When the fuel temperature is higher than the second temperature, the fuel injection amount is increased. On the other hand, when the first temperature is lower than the second temperature, the fuel injection amount is decreased. An internal combustion engine control apparatus that controls the operating state of the internal combustion engine by controlling the injection amount of the fuel. 2. The internal combustion engine according to claim 1, wherein the control unit calculates the instantaneous torque according to a calculated value obtained by subtracting a minimum value of the rotational speed from a maximum value of a rotational speed of a crankshaft of the internal combustion engine. Engine control device. Wherein the control unit is configured by adding a predetermined time delay that reflects the heat transfer characteristics of the combustion chamber structure of an internal combustion engine, according to claim 1 or 2, characterized in that to calculate the second temperature Internal combustion engine control device. The control unit limits the value of the difference according to a magnitude relationship between the difference between the first temperature and the second temperature and a predetermined threshold value of the operating state of the internal combustion engine. An internal combustion engine control device according to any one of claims 1 to 3 . The control unit matches the first temperature with the third temperature according to a difference between a third temperature corresponding to a wall surface temperature of the combustion chamber of the internal combustion engine and the first temperature. The internal combustion engine control device according to any one of claims 1 to 4 , wherein the timing of the ignition of the air-fuel mixture is controlled to do so. The third temperature is detected as a temperature of the wall surface of the combustion chamber on the intake valve side of the internal combustion engine by a temperature sensor mounted on a mounting site of the internal combustion engine on the intake valve side. The internal combustion engine controller according to claim 5 .

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