JPH09250435A - Engine control method and control device - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: In a wide operating range, the operating range, for example, the engine speed, the best torque under load, the maximum output, the good fuel consumption, the clean exhaust gas characteristics, the good transient response, etc. It is controllable so that it can be obtained. An engine control method obtains a combustion state in which a high torque is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, a combustion ratio value at a predetermined crank angle is set to a load or While holding in the memory as map data of the target combustion ratio value corresponding to at least one of the engine speeds, the actual combustion ratio up to a predetermined crank angle is detected, and the detected value of this combustion ratio and the target combustion ratio value are Based on the comparison, the ignition timing is controlled so that the ignition timing when the detected value is smaller is advanced and the ignition timing when the detected value is larger is delayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a 2-cycle or 4-cycle spark ignition engine, a 2-cycle or 4-cycle diesel engine, and a control system therefor.

[0002]

2. Description of the Related Art A two-cycle spark ignition engine or four
In a cycle spark ignition engine, the ignition timing is controlled so as to obtain a high output in a high negative region, for example, but when controlling this ignition timing, a knocking detection means is provided and knocking is not detected. If so, the ignition timing is advanced, and if knocking is detected, the ignition timing is retarded, and feedback control of the ignition timing is performed based on the knocking presence / absence information so that the ignition timing is advanced to the limit. Such feedback control of the ignition timing is based on the idea that the maximum output when the ignition timing is advanced to the knocking occurrence limit or the maximum torque in the rotation speed range can be generated.

Some diesel engines also advance the fuel injection start timing when knocking is detected so that knocking does not occur even if ignition is delayed even if ignition is detected.

[0004]

By the way, depending on the operating condition such as the engine speed, even if the ignition timing is advanced to the limit of knocking occurrence, the best torque is not generated in the operating range, and the same torque can be generated. Even if the ignition is performed at various ignition timings, the knocking limit may not be reached. In this case, the same best torque cannot be obtained even if the feedback control of the ignition timing is performed based on the knocking presence / absence information.

The same applies to the fuel injection start timing in the diesel engine. Further, not only the best torque, but also a simple and reliable method is required to obtain a good cold start, a good acceleration / deceleration, a clean exhaust gas, a good fuel consumption, or a good maximum output.

The present invention has been made in view of the above points, and has a wide range of operating ranges, such as the best torque in the operating range, for example, the engine speed and the load, or a good startability and a good starting property. It is an object of the present invention to provide an engine control method and a control device therefor capable of controlling so as to obtain excellent transient response, clean exhaust gas, good fuel consumption or good maximum output.

[0007]

In order to solve the above-mentioned problems and to achieve the object, the engine control method of the present invention according to claim 1 corresponds to at least one of the load and the engine speed and is desired. After obtaining a combustion state that provides an operating state, in this combustion state, the combustion rate value at a predetermined crank angle is retained in the memory as map data of the target combustion rate value corresponding to at least one of the load and the engine speed. On the other hand, the actual combustion ratio up to the predetermined crank angle is detected, and based on the comparison between the detection value of this combustion ratio and the target combustion ratio value, the ignition timing is advanced when the detection value is smaller, and the detection value Is characterized in that the ignition timing is controlled so that the larger ignition timing is delayed.

In this way, the actual combustion ratio up to the predetermined crank angle is detected, and based on the comparison between the detected value of this combustion ratio and the target combustion ratio value, the ignition timing at which the detected value is smaller is advanced, The ignition timing is controlled so that the ignition timing is delayed when the detected value is larger, and the ignition timing is controlled in a wide operating range, for example, the engine speed and the minimum advance angle at which the desired operating condition in the load is obtained. It is possible to grasp the ignition timing and perform feedback control so that ignition is performed at the ignition timing.

In the engine control method according to the second aspect of the present invention, the actual combustion ratio up to the predetermined crank angle is the crank angle from the end of the exhaust stroke to the beginning of the compression stroke, and the ignition stroke from the start of the compression stroke. The combustion pressure is detected at at least four crank angles consisting of the crank angle up to the start and two crank angles within the period from the ignition start to the exhaust stroke start, and is calculated based on these combustion pressure data. It is characterized by that.

As described above, the actual combustion ratio up to the predetermined crank angle can be appropriately calculated based on the combustion pressure data.

According to another aspect of the engine control method of the present invention, a combustion state is obtained in which a desired operating state is obtained corresponding to at least one of the load and the engine speed, and in this combustion state, a predetermined combustion ratio is obtained. The crank angle value reaching the above value is stored in the memory as map data of the crank angle value corresponding to at least one of the load and the engine speed, while the actual crank angle reaching the predetermined combustion ratio value is detected, and this crank angle value is detected. Based on the comparison between the detected angle value and the target crank angle value, the ignition timing is advanced when the detected value is a delayed crank angle, and the ignition timing is delayed when the detected value is an advanced crank angle. It is characterized by controlling the ignition timing as described above.

In this way, when the actual crank angle reaching the predetermined combustion ratio value is detected, and the detected value is the delayed crank angle based on the comparison between the detected crank angle value and the target crank angle value. The ignition timing is controlled so that the ignition timing is advanced, and the ignition timing is delayed when the detected value has a more advanced crank angle, and the ignition timing is controlled in a wide operating range, for example, at a desired engine speed and load. It is possible to grasp the ignition timing with the minimum advance angle at which the operating state is obtained and perform feedback control so that ignition is performed at the ignition timing.

According to a fourth aspect of the engine control method of the present invention, the actual crank angle at which the predetermined combustion ratio value reaches the predetermined combustion rate value is
The crank angle from the end of the exhaust stroke to the beginning of the compression stroke, and the crank angle from the start of the compression stroke to the start of ignition,
It is characterized in that the combustion pressure at at least four crank angles consisting of two crank angles within the period from the ignition start to the exhaust stroke start is detected and calculated based on these combustion pressure data. in this way,
The actual crank angle that reaches the predetermined combustion ratio value can be appropriately calculated based on the combustion pressure data.

According to a fifth aspect of the present invention, there is provided an engine control device, which includes an operating state detecting means including an engine speed detecting means, a crank angle detecting means and a combustion pressure detecting means, and a data storage device for holding a target state value. A state value calculation program for calculating an actual state value from the information from each of the detection means, and a control value for the ignition timing based on the comparison between the calculated state value and the target state value held in the data storage device. It has a program storage device that holds a control value calculation program for controlling the ignition timing, and an ignition device that ignites based on the control value of the ignition timing, and controls the ignition timing of A or B described below.

A. The actual combustion ratio up to a predetermined crank angle is calculated by determining the crank angle from the end of the exhaust stroke to the beginning of the compression stroke, the crank angle from the start of the compression stroke to the start of ignition, and the period from the start of ignition to the start of the exhaust stroke. The combustion pressures in at least four crank angles consisting of the two crank angles are detected and calculated based on these combustion pressure data, and based on the comparison of the detected value of the combustion ratio and the target combustion ratio value, The ignition timing is controlled so that the ignition timing when the detected value is smaller is advanced and the ignition timing when the detected value is larger is delayed.

B. The actual crank angle that reaches the specified combustion ratio value is the crank angle from the end of the exhaust stroke to the beginning of the compression stroke, the crank angle from the start of the compression stroke to the start of ignition, and the period from the start of ignition to the start of the exhaust stroke. 2 of
The combustion pressure at at least four crank angles consisting of one crank angle is detected, and the combustion pressure is calculated based on these combustion pressure data. Based on the comparison between the detected value of the crank angle and the target crank angle value, The ignition timing is controlled so that the ignition timing is advanced when the crank angle is delayed, and the ignition timing is delayed when the detected value is advanced.

As described above, the actual combustion ratio up to the predetermined crank angle is appropriately calculated based on the combustion pressure data, and the detected value is smaller based on the comparison between the detected combustion ratio value and the target combustion ratio value. The ignition timing is controlled so as to delay the ignition timing when the detected value is larger, and the actual crank angle that reaches the predetermined combustion ratio value is appropriately calculated based on the combustion pressure data. Based on the comparison between the detected crank angle value and the target crank angle value, advance the ignition timing if the detected value is the delayed crank angle, and advance the ignition timing if the detected value is the advanced crank angle. The ignition timing can be controlled to be delayed.

According to a sixth aspect of the present invention, there is provided a method for controlling an engine in a diesel engine, which obtains a combustion state in which a desired operating state is obtained corresponding to at least one of load and engine speed. The combustion ratio value at a predetermined crank angle is stored in the memory as map data of the target combustion ratio value corresponding to at least one of the load and the engine speed, while the actual combustion ratio up to the predetermined crank angle is detected. Based on the comparison between the detected value of the combustion ratio and the target combustion ratio value, the fuel injection start timing is advanced when the detected value is smaller, and the fuel injection start timing is delayed when the detected value is larger, The feature is that the fuel injection start timing is controlled.

In this way, in the diesel engine, the actual combustion ratio up to the predetermined crank angle is detected, and when the detected value is smaller than the detected value of the combustion ratio and the target combustion ratio value, the fuel is detected. The fuel injection start timing is controlled so as to advance the injection start timing and delay the fuel injection start timing when the detected value becomes larger, and in a wide operating range, desired in that operating range, for example, its engine speed and load. It is possible to grasp the fuel injection start timing at which the above operating state is obtained and perform feedback control so that fuel injection is performed at the fuel injection start timing.

According to a seventh aspect of the present invention, there is provided a method for controlling an engine in a diesel engine, wherein a combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed is obtained. The crank angle value reaching the predetermined combustion ratio is stored in the memory as map data of the target crank angle value corresponding to at least one of the load and the engine speed, while the actual crank angle reaching the predetermined combustion ratio value is detected. If the detected value is a delayed crank angle based on the comparison between the detected crank angle value and the target crank angle value,
The fuel injection start timing is controlled so that the fuel injection start timing is advanced and the fuel injection start timing is delayed when the detected value has a more advanced crank angle.

As described above, in the diesel engine, the actual crank angle that reaches the predetermined combustion ratio value is detected, and based on the comparison between the detected crank angle value and the target crank angle value, the crank with the detected value being delayed is detected. When the angle is a corner, the fuel injection start timing is advanced, and when the detected value is the advanced crank angle, the fuel injection start timing is delayed.
By controlling the fuel injection start timing, in a wide operating range,
Understand the operating range, such as engine speed, high torque or best torque at load, good cold start, acceleration / deceleration, fuel consumption, and fuel injection start timing to obtain clean exhaust gas, and start fuel injection It is possible to perform feedback control so that fuel is injected at certain times.

According to an eighth aspect of the present invention, there is provided a method for controlling an engine in which a desired operating state is obtained in accordance with at least one of a load and an engine speed. Each combustion ratio value at a predetermined crank angle is retained in a memory as map data of a plurality of target combustion ratio values up to the plurality of predetermined crank angles in correspondence with at least one of a load and an engine speed. Of the predetermined crank angle, the actual combustion rate up to the early predetermined crank angle is detected, and based on the comparison between the detected value of this combustion rate and the target combustion rate value up to the early predetermined crank angle, the detected value It is characterized in that the ignition timing is controlled so that the ignition timing is advanced for the smaller value and the ignition timing for the greater detected value is delayed.

In this way, of the plurality of predetermined crank angles,
Detects the actual combustion rate up to a predetermined crank angle in the early stage,
Based on the comparison between the detected value of the combustion ratio and the target combustion ratio value up to a predetermined crank angle in the early stage, advance the ignition timing when the detected value is smaller and delay the ignition timing when the detected value is larger. By performing feedback control of the ignition timing, the combustion can be controlled more finely and good engine characteristics can be obtained.

According to a ninth aspect of the engine control method of the present invention, a combustion state in which a desired operating state is obtained corresponding to at least one of the load and the engine speed is obtained. Each combustion ratio value at a predetermined crank angle is retained in a memory as map data of a plurality of target combustion ratio values up to the plurality of predetermined crank angles in correspondence with at least one of a load and an engine speed. Of at least two actual combustion ratios up to at least two of the predetermined crank angles, the ratio of change of the at least two actual combustion ratios to the crank angle is calculated, and the plurality of predetermined target combustions are calculated. Based on the comparison with the target rate, which is the rate of change of the rate with respect to the crank angle, the rate of change due to the detection value is the target rate. When it is small, it detects that the combustion speed is slow and increases the fuel supply amount to the engine, or it is mixed with fresh air before combustion in the combustion chamber of the engine. Either decrease the amount of recirculated exhaust gas, increase the in-cylinder flow amount of fresh air before combustion in the combustion chamber of the engine, increase the compression ratio, or increase the boost pressure. It is characterized by controlling so as to realize one.

In this way, at least two actual combustion ratios up to at least two predetermined crank angles among the plurality of predetermined crank angles are detected, and a target which is a ratio of change of the plurality of predetermined target combustion ratios with respect to the crank angle. Based on the comparison with the ratio, if the rate of change due to the detected value is smaller than the target rate, it is detected that the combustion speed is slow and the fuel supply amount to the engine is increased, or a new combustion rate before combustion in the engine combustion chamber is detected. Decrease the amount of recirculated exhaust gas that is part of the burnt gas that is formed in the pre-combustion cycle and is mixed with the gas, or increase the in-cylinder flow rate of fresh air before combustion in the engine combustion chamber By increasing the compression ratio or increasing the boost pressure, it is possible to finely control the combustion and obtain good engine characteristics.

According to a tenth aspect of the engine control method of the present invention, a combustion state is obtained in which a desired operating state is obtained corresponding to at least one of the load and the engine speed,
In this combustion state, each crank angle value that becomes a plurality of predetermined combustion ratios corresponds to at least one of the load and the engine speed as map data of a plurality of target crank angle values up to the plurality of predetermined crank angles. The actual crank angle that reaches a small predetermined combustion ratio among the crank angles that reach the plurality of predetermined combustion ratios is detected, and the detected value of this crank angle and the small predetermined combustion ratio are stored. Based on the comparison with the target crank angle value set correspondingly, if the detected value is delayed, the ignition timing is advanced, and if the detected value is advanced, the ignition timing is delayed. It is characterized by controlling the ignition timing.

As described above, the actual crank angle that reaches a small predetermined combustion ratio among the crank angles that reach a plurality of predetermined combustion ratios is detected, and the detected value of this crank angle is associated with the small predetermined combustion ratio. Based on the comparison with the set target crank angle value, the ignition timing is set so that the ignition timing is advanced if the detected value is behind and the ignition timing is delayed if the detected value is ahead. By performing feedback control, combustion can be controlled more finely and good engine characteristics can be obtained.

The engine control method according to the invention of claim 11 obtains a combustion state in which a desired operating state is obtained corresponding to at least one of load and engine speed,
In this combustion state, each crank angle value that becomes a plurality of predetermined combustion ratios corresponds to at least one of the load and the engine speed as map data of a plurality of target crank angle values up to the plurality of predetermined crank angles. And at least two actual crank angles that reach at least two predetermined combustion ratios of the plurality of predetermined combustion ratios are detected in the memory, and the rate of change of the at least two actual crank angles with respect to the combustion ratio. Based on a comparison with a target rate that is a rate of change of the combustion rate of the plurality of predetermined target crank angles, if the rate of change due to the detection value is greater than the target rate, it is detected that the combustion speed is slow. In the pre-combustion cycle, the amount of fuel supplied to the engine is increased or mixed with fresh air before combustion in the combustion chamber of the engine. Decrease the amount of recirculated exhaust gas that is a part of the burnt gas that is generated, increase the in-cylinder flow rate of fresh air in the combustion chamber of the engine before combustion, increase the compression ratio, It is characterized by controlling so as to realize at least one of increasing the supply pressure.

In this way, at least two actual crank angles that reach at least two predetermined combustion ratios out of the plurality of predetermined combustion ratios are detected, and are the ratios of changes of the plurality of predetermined target crank angles with respect to the combustion ratio. Based on comparison with the target rate, if the rate of change due to the detected value is higher than the target rate, it is detected that the combustion speed is slow and the fuel supply amount to the engine is increased or Either reduce the amount of recirculated exhaust gas that is part of the burnt gas that is formed in the pre-combustion cycle and that is mixed with fresh air, or increase the in-cylinder flow rate of fresh air before combustion in the engine combustion chamber Control, increase the compression ratio, or increase the supercharging pressure to achieve any one of them, so that combustion can be controlled more finely and good engine characteristics can be obtained.

According to a twelfth aspect of the present invention, the engine control method is characterized in that the target combustion ratio and the target crank angle have a predetermined width. In this way, by setting the target combustion ratio and the target crank angle to have a predetermined width, it is possible to create a play area in which feedback control is not performed, and it is possible to prevent hunting associated with feedback control and to improve drivability. improves.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an engine control method and a control apparatus therefor according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing the construction of a multi-cylinder spark ignition type 4-cycle engine to which the present invention is applied. The engine 1 includes a crankcase 2, a cylinder body 3 and a cylinder head 4 above the crankcase 2. A piston 7 is slidably mounted in the cylinder body 3 via a connecting rod 8, and the connecting rod 8 is connected to a crankshaft 9. A ring gear 10 having a predetermined number of teeth is mounted on the crankshaft 9, and a crank angle sensor 11 that also functions as an engine speed sensor for detecting a rotational position of the ring gear 10 and measuring a crank angle and an engine speed is provided. Has been. A combustion chamber 13 is formed between the cylinder head 4 and the piston 7. A combustion chamber pressure sensor 5 for detecting the combustion pressure in the combustion chamber 13 is provided on the cylinder head 4 side. A cooling water jacket 6 is formed at appropriate positions on the cylinder head 4 and the cylinder body 3. An exhaust passage 15 and an intake passage 16 are communicated with the combustion chamber 13, and an exhaust valve 17 and an intake valve 18 are provided at their openings. A catalyst 23 such as an exhaust gas purifying three-way catalyst is provided in the middle of an exhaust pipe 22 connected to the exhaust passage 15, and a muffler 24 is provided at an end thereof. The exhaust pipe 22 includes an oxygen concentration sensor (O ₂ sensor) 25 and an exhaust pipe temperature sensor 12
0 are provided and are each connected to the controller 12.

A temperature sensor 26 is attached to the cylinder head 4, and temperature information of the combustion chamber 13 is sent to the control device 12. Further, the catalyst 23 is provided with a catalyst temperature sensor 150 connected to the control device 12. The kill switch 43 of the engine 1 is further connected to the controller 12 to obtain stop information for engine drive control.

On the other hand, an intake pipe 20 is connected to the intake passage 16, and the intake pipe 20 is connected to each cylinder via an intake distribution pipe 28. An intake pipe pressure sensor 32 is attached to the intake distribution pipe 28, and intake pipe pressure information is sent to the control device 12.
The EGR pipe 15 is formed by connecting the intake distribution pipe 28 and the exhaust pipe 22.
2 are provided. The EGR pipe 152 is provided with an EGR adjustment valve 151 connected to the control device 12. An air cleaner 35 is connected to the intake distribution pipe 28 via an intake pipe 33. The air cleaner 35 is provided with an intake air temperature sensor 36, and the intake air temperature information is sent to the control device 12. An intake air amount adjuster 30 is provided in the middle of the intake pipe 33, and a throttle valve 29 is attached to the intake air amount adjuster 30.

The throttle valve 29 is provided with a throttle opening sensor 31, which is connected to the control device 12. A throttle valve bypass passage 37 is provided in the intake pipe 33 of the intake amount adjuster 30, and a bypass passage opening adjustment valve 38 is provided in the bypass passage 37. The bypass passage opening adjustment valve 38 is connected to the control device 12. In the intake pipe 33, a hot-wire intake air amount sensor 34
Is provided, and the intake air amount information is sent to the control device 12.

On the upstream side of the intake valve 18 in the intake passage 16,
An injector 105 is provided for each intake port of each cylinder. The injector 105 is connected to the control device 12, and sends a control signal of the optimum injection amount calculated according to the operating state. Fuel is sent to each injector 105 through a fuel pipe 101a connected to each cylinder. The fuel pipe 101 a is branched from the fuel distribution pipe 104, and the fuel is supplied from the fuel tank 100 to the fuel distribution pipe 104 through the fuel supply pipe 101 and further through the filter 102 by the fuel pump 103. The fuel not injected from the injector 105 is collected in the fuel tank 100 through the fuel return pipe 107. A regulator 106 is provided on the fuel return pipe 107.
Is provided to keep the fuel injection pressure constant.

FIG. 2 is a flow chart of a main routine for controlling various operating states of the engine. Each step will be described below.

Step S11: Initialization is performed, and initial values are set in each flag value and each variable value.

Step S12: Intake air temperature sensor 36
Intake air temperature information from the heat ray intake air amount sensor 34
Intake air amount information from the throttle opening sensor 31, throttle opening information from the throttle opening sensor 31, intake pipe pressure information from the intake pipe pressure sensor 32, catalyst temperature information from the catalyst temperature sensor 150, crank angle information from the crank angle sensor 11. , Temperature information from the temperature sensor 26, exhaust pipe temperature information from the exhaust pipe temperature sensor 120, combustion chamber pressure signal from the combustion chamber pressure sensor 5, oxygen concentration information from the oxygen concentration sensor 25, and an oil sensor (not shown). The remaining oil amount information is fetched and the data is stored in the memory A (i). The engine load can be grasped as an accelerator position or a throttle opening. If this throttle opening and engine speed are determined,
In steady operation, the intake air amount is determined, so the intake air amount can be directly detected and regarded as the engine load. Also,
If the engine speed is determined, the intake pipe negative pressure has a constant relationship with the throttle opening, so that the intake pipe negative pressure can be detected and regarded as the engine load.

Step S13: O of the kill switch 43
Switch information such as N, OFF, ON / OFF of a main switch (not shown) and ON / OFF of a starter switch (not shown) is fetched and stored in the memory B (i). The kill switch 43 is an emergency stop switch and is not provided in the vehicle engine, but is provided in, for example, a small boat engine.

Step S14: The operating state is judged based on the sensor information fetched in the step 12 and the switch information fetched in the step 13, and the variable C in the memory is stored in correspondence with the operating state ,. Enter the corresponding value. Operating state: Throttle opening is above a certain value, engine speed is above a certain value and the rate of change of throttle opening is below a certain value. MBT (Minimum Advance Ign) when the accelerator is in operation
It is determined to be a control state, and 1 is stored in the variable C.

Operating state: When the rate of change of the throttle opening is equal to or more than a predetermined value, it is determined to be a transient operating state, and 2 is stored in the variable C.

Operating state: The throttle opening is below a predetermined value and the engine speed is within a predetermined range, for example, 2000 rp
In the case of m to 5000 rpm, it is determined to be the lean combustion control state, and 3 is stored in the variable C.

Operating state: When the engine is in an abnormal state such as an over-revolution where the engine speed is equal to or higher than a predetermined limit value or an engine temperature is overheat when the temperature is equal to or higher than a predetermined value, it is determined to be an abnormal operation state, and 4 is stored in a variable C.

Operating state: When the engine temperature is lower than a predetermined value and the starter switch is ON, it is determined to be a cold start state, and 5 is stored in the variable C.

Operating state ... When the main switch is OFF or the kill switch is OFF, it is determined that the engine is in a stop state, and 6 is stored in the variable C.

Further, with the same variable C value, the number of times the step S14 in the main routine is checked with the flag P = 1 kept, and if it exceeds R a predetermined number of times, P = 0 is set.

[0048]

When C = 1, the value of R is Rc = 1. When C = 2, the value of R is Rc = 2. When the value of C is 3, the value of R is changed to Rc = 3. Rc _{= 1} <Rc _{= 2} <Rc _{= 3} .

When the C value in the previous main routine is different from the C value this time, P = 0 is set.

Step S15: It is judged whether or not the mode operation is executed. If the variable C is 1 to 3, the process proceeds to step S16, and if the variable C is 4 to 6, the process proceeds to step S20. To do.

Step S16: Based on the value of the flag P ,
When P = 0, the target combustion ratio according to the engine speed and the load is obtained from the map data (corresponding to FIG. 5) in the memory, and the result is stored in the memory D. Also,
The basic ignition timing, the basic fuel injection start timing, and the basic fuel injection amount are also obtained from the map data similar to those shown in FIG. 5 in the memory (the values given as a function of the engine speed and the load are illustrated), and the respective memory E '(1), E'
(2) Put in E '(3). After that, P = 1 is set.
If P = 1, nothing is done and the process proceeds to step S17.

The combustion ratio means the ratio of the fuel burned up to a certain crank angle to the fuel burned in one combustion cycle. Regarding the method of calculating the combustion ratio, one method is to obtain the combustion chamber pressure data at a plurality of predetermined points in one combustion cycle by a linear approximation formula, and the other is to calculate the heat generation amount from the sampled pressure value. Is calculated by a thermodynamic formula to obtain the combustion ratio up to a predetermined crank angle (for example, top dead center). Both methods gave calculation results very close to the true value.

In this case, the data of the combustion chamber pressure is obtained by detecting the combustion chamber pressure at the crank angle in the first period from the end of the exhaust stroke to the beginning of the compression stroke. In this case, the crank angle from the end of the exhaust stroke to the beginning of the compression stroke is the crank angle within the range where the pressure in the combustion chamber is the lowest and approaches the atmospheric pressure. A point or its vicinity. That is, in the 4-cycle engine, as shown in FIG. 6, the combustion gas in the combustion chamber is discharged by the exhaust stroke from the bottom dead center after the explosion, and the pressure in the combustion chamber decreases and approaches the atmospheric pressure as it approaches the top dead center. In the intake stroke after the top dead center, the state close to the atmospheric pressure is maintained due to the introduction of fresh air, and the pressure is gradually increased from the compression stroke after the bottom dead center which is started after the exhaust valve 17 is closed after the intake stroke. The pressure inside the combustion chamber is detected at one point within the range where the pressure inside the combustion chamber decreases and approaches the atmospheric pressure. Although the crank angle a0 is set to BDC in FIG. 6, it may be set to BDC after the compression stroke at the beginning of the compression stroke. Of course, the crank angle during the intake stroke before BDC may be used. On the other hand, in the two-cycle engine, as shown in FIG. 12, when the piston is lowered and the pressure is lowered after the explosion and the exhaust port is opened, the pressure in the combustion chamber is further reduced accordingly, and when the scavenging port is opened, fresh air is released from the crank chamber. As it is introduced, it approaches atmospheric pressure. When the piston rises from the bottom dead center with the exhaust port open, the scavenging port closes and the exhaust port opens, the compression starts and the pressure gradually increases. That is, from the end of the exhaust stroke to the beginning of the compression stroke, after the exhaust port is opened and the exhaust port is open after the start of exhaust, the scavenging port is opened and intake is started, and then the exhaust port is closed. This is the period until the compression starts. In FIG. 12, the crank angle a0 is taken as BDC.

Spark ignition is performed before or after top dead center after compression. (Spark ignition is started at the crank angles shown by arrows and S in FIGS. 6 and 12, respectively.) Spark ignition is started, and ignition is started with a slight delay and combustion is started. The ignition start referred to in each claim is the moment when this ignition combustion is started. That is, the crank angle (FIG. 6, FIG. 1) in the second period, which is the period from the start of the compression stroke to the start of ignition and combustion.
In both cases, the pressure in the smelting chamber is detected at the crank angle a1). After this, the third period, which is the period from the start of ignition (start of ignition and combustion) to the start of the exhaust stroke during the explosive combustion stroke
Of two crank angles (for example, crank angle a2a3 or crank angle a in FIGS. 6 and 12).
2, a4, or crank angles a3, a4, crank angles 2, a5, crank angles a3a5, or crank angles a4, a5), the pressure in the combustion chamber is detected. It is desirable that one of the two crank angles within this period be before the crank angle at which the maximum combustion pressure is reached. Further, when the pressure in the combustion chamber is detected at four or more crank angles, for example, at five or more crank angles referred to in each claim, the number of pressure measurement crank angle points in the first or second period is increased. May be. Also,
Desirably, the pressure may be detected at three or more crank angles within the third period, as in the embodiment of FIGS. 6 and 12. In a diesel engine, fuel injection into the combustion chamber before or after top dead center after compression is started, and after a short delay, combustion starts due to spontaneous ignition. That is, in the diesel engine, the ignition start described in each claim means the moment when the spontaneous ignition is started. Note that the ignition delay from the start of fuel injection to the start of spontaneous ignition is obtained in advance as data based on the engine speed or the load, and this is factored in to calculate the pressure measurement crank angle within the second period and the pressure crank within the third period. The pressure of the combustion chamber is measured by storing the corner points in the memory as data based on the engine speed or the load.

One point in the first period and one in the second period
Point, the combustion chamber pressure at a crank angle of at least 4 points in total of 2 points in the third period is detected, and the combustion ratio is calculated from this by a linear approximation. This approximation formula is combustion rate qx = a + b1 * (P1-P0) + b2 * (P
2-P0) + ... + bn * (Pn-P0).

As can be seen from the above equation, qx is obtained by subtracting the reference pressure P0 from the pressure data P1 to Pn, respectively.
Multiplying the constants b1 to bn by a preset constant a
It is expressed by adding.

Similarly, Pmi is expressed by subtracting the reference pressure P0 from the pressure data P1 to Pn, multiplying the preset constants C1 to Cn, and adding the preset constant.

Here, P0 is the combustion chamber pressure at the point of the atmospheric pressure level (for example, the crank angle near BDC as described above), and each pressure value of P1 to Pn is used to correct the offset voltage due to the drift of the sensor. Drawn from. Further, P1 is the combustion pressure at the crank angle a1 in the first period, and P2 is the combustion chamber pressure at the crank angle a2 in the second period. P3 to Pn are crank angles a3 to an (n = 5 in this embodiment) in the third period.

By such a simple first-order approximation calculation, the combustion ratio up to a predetermined crank angle after ignition can be calculated to be exactly the same as the actual value in a short time. Therefore,
By controlling the ignition timing and the air-fuel ratio of the engine by using such a combustion ratio, it is possible to efficiently take out the energy due to combustion and improve the responsiveness, for example, when performing lean burn control or EGR control. The output fluctuation can be suppressed by accurately following the operating state. Further, it is possible to prevent the generation of NOx due to the rapid progress of combustion. In the second qx calculation method, the amount of heat generated between two pressure measurement points (crank angle) is ΔP for the differential pressure at both pressure measurement points, ΔV for the combustion chamber volume difference, and The front pressure value and the combustion chamber volume value are P, V, and A.
Is heat equivalent, K is specific heat ratio, R is average gas constant, P0 is BD
Assuming the pressure value at C, the heat generation amount Qx = A / (K-1) * ((K + 1) / 2 * ΔP * ΔV
+ K * (P−P0) * ΔV + V * ΔP) can be obtained.

The combustion ratio up to the predetermined pressure measurement point is
The crank angle at which combustion is almost completed is selected as the pressure measurement point, and the crank angle near ignition is similarly selected as the pressure measurement point, and the heat generation amount Qx is measured at each pressure measurement point measured during that time. Is the sum of the calculated values of the above, and is the sum of the calculated values of Qx from the first pressure measurement point to the predetermined pressure measurement point (predetermined crank angle). .

That is, the combustion ratio qx = heat quantity burned up to an arbitrary crank angle / total heat quantity × 100 (%) = (Q1
+ Q2 + ... + Qx) / (Q1 + Q2 + ... + Q
n) × 100.

With the above calculation method, the combustion chamber pressures at a plurality of predetermined crank angles can be measured, and the combustion ratio up to the predetermined crank angle can be accurately calculated based on the data. By controlling the engine using this combustion ratio, stable output and engine rotation can be obtained.

Step S17: An injection amount correction calculation for fuel injection is performed based on the intake air temperature information and the intake pipe negative pressure information. That is, when the intake air temperature is high, the air density is low, and the air flow rate is substantially reduced. Therefore, the air-fuel ratio in the combustion chamber becomes low. Therefore, a correction amount for reducing the fuel injection amount is calculated.

Step S18: The basic fuel injection start, the basic fuel injection amount, and the basic ignition timing according to the engine load and the engine speed are obtained in step S16 and are included in E '(i). Based on this, the fuel injection correction amount and the ignition timing correction amount are calculated according to the correction amount calculated in step S17 and the information stored in the memory A (i), and the control amount is calculated in addition to the reference values. The control amount is set to the memory E (1) for the ignition start timing, the memory E (2) for the ignition period, and the injection start timing and the injection end timing are set to F when P = 1.
When (3), F (4) and P = 0, the injection start timing and the injection end timing are put into E (3) and E (4).

This is input to the memory E (i). Similarly, the control amounts of the servo motor group and the solenoid valve group are calculated according to the information stored in the memory A (i) and are stored in the memory G (i).

Step S19: The actuators such as the servo motor group and the solenoid valve group are driven and controlled according to the control amount of the memory G (i).

Step S20: The engine stop request is judged, and if it is a stop request, the process proceeds to step S21. If it is not the stop request, the process proceeds to step S22.

Step S21: Memory E (i) i = 1 to
Stop data is set so that 4 is set to 0.

Step S22: It is judged whether the engine has started. If the engine has started, the step S23 is performed.
If the engine is not started, go to step S
It moves to 25.

Step S23: The memory F (i) is set with the data previously stored in the memory for starting.

Step S24: The starting motor is driven.

Step S25: Data corresponding to the abnormality content is set in the memory F (i).

Next, the interrupt routine of FIG. 3 will be described. This interrupt routine is executed by interrupting the main routine when a crank signal of a predetermined angle is input.

Step S111: The timer is set so that the interrupt routine is executed at every predetermined crank angle, that is, the interrupt is generated at the next crank angle.

Step S112: The pressure data of the crank angle at which the interruption has occurred is fetched and stored in the memory.

Step S113: When the pressure data of all crank angles are taken into the memory, the process proceeds to step S114.

Step S114: In order to perform control according to the operating state, the identification data is judged, and if the variable C is 1, control of the MBT control routine of step S115 is performed, and if the variable C is 2, step S116. Control of the transient response routine in step S3 is performed, and if the variable C is 3, step S
The lean burn control routine 117 is executed.

Next, the interrupt routine of FIG. 4 will be described. This interrupt routine is executed by interrupting the main routine when the reference crank signal is input.

Step S121: Since this interrupt routine is executed once at the engine rotation and the predetermined crank angle, the cycle is measured.

Step S122: The engine speed is calculated.

Step S123: Memory F (i), i =
Based on the control data of 1 to 4, the ignition start timing, the ignition end timing, the injection start timing, and the injection end timing are set in the timer. The timer activates the ignition device and the injection device at the set timing.

Next, the calculation of the target combustion ratio described with reference to FIGS. 2 and 3 will be described in detail.

FIG. 5 is a map diagram for obtaining the target combustion ratio according to the engine speed and the load. Predetermined crank angle, for example, top dead center TDC, top dead center TDC-10 degrees,
The combustion ratio up to ... is determined by operating conditions,
It shows a three-dimensional configuration in which the target combustion ratio is determined by the load (Lx) and the engine speed (Rx). The target combustion ratio is FMB under predetermined operating conditions (Lx, Rx)
_{It is} calculated as ₀ (Lx, Rx).

FIG. 6 is a graph of combustion chamber pressure for one cycle of combustion in a four-cycle engine. The horizontal axis is the crank angle,
The vertical axis represents the combustion pressure. The crank angle is a0
The combustion pressures P0 to P5 at the six points a5 are detected, and the combustion ratio is calculated based on these pressure values. a0 is the bottom dead center position (BDC) where the suction shifts to the compression shift, which is a state close to the atmospheric pressure. a1 is after compression start but before spark ignition,
a2 is a crank angle after reaching the top dead center (TDC) after spark ignition at S. The four points a3 to a5 are crank angles in the explosion stroke after top dead center. The combustion ratio is calculated based on the pressure data at these points. In the case of a diesel engine that does not perform spark ignition, F
Like I, the fuel is injected near the top dead center. Spontaneous ignition occurs after a delay corresponding to the crank angle d after the start of injection. The crank angle for spontaneous ignition is S. Instead of controlling the ignition timing in the ignition spark engine, in the present diesel engine, the control of the fuel injection timing is performed based on the measured combustion ratio or the measured crank angle based on the difference between the target combustion ratio and the target crank angle, respectively. The injection start timing is advanced / retarded, and the injection end timing is controlled so as to secure a predetermined injection amount.

Next, the control of the combustion ratio based on the calculation of the combustion ratio described in FIGS. 2 and 3 will be described in detail.

FIG. 7 is a diagram showing feedback control of the combustion ratio based on the calculation of the combustion ratio. Predetermined operating conditions (L
x, Rx), when the ignition is performed at the ignition timing IgT, the combustion ratio FMB is actually measured. That is, using the combustion chamber pressure data, a predetermined crank angle, for example, -5 degrees (5
Of combustion rate FMB
Find (Lx, Rx).

Then, the target combustion ratio FMB ₀ (Lx, R
x) and the measured combustion ratio FMB (Lx, Rx) are corrected so that the ignition timing IgT is close to zero. what if,
The target combustion ratio FMB ₀ (Lx, Rx) is the measured combustion ratio F
If smaller than MB (Lx, Rx), ignition timing Ig
Ignition proceeds from T by ΔIgT. Further, if the target combustion rate FMB ₀ (Lx, Rx) is the measured combustion rate FMB (L
x, Rx) is larger than the ignition timing IgT, Δ
IgT is delayed and ignited.

Next, M in the interrupt routine of FIG.
The BT control will be described. FIG. 8 shows an MBT control routine.

Step S115a: The target combustion ratio of the MBT control is stored as a three-dimensional map having the engine load and the engine speed as variables, and is calculated from the target combustion ratio map in step S16 in the main routine.

In a two-stroke engine (FIGS. 11 and 12) described later, the exhaust passage valve is also stored in the memory as a three-dimensional map with two variables, the engine load and the engine speed, as variables. It is calculated from the map based on the rotation speed information. The exhaust timing (compression ratio) variable valve opening is stored as a two-dimensional map in the memory with the engine speed as a variable, and is calculated from the map based on the engine speed information.

Step S115a: The combustion pressure P0 at the six points a0 to a5 shown in the crank angle shown in FIG.
~ P5 are stored in the memory, and the measured combustion ratio is calculated based on these pressure values. Step S115b: The combustion ratio is controlled based on the calculation of the actually measured combustion ratio. The target combustion ratio value in the memory D is compared with the measured combustion ratio value obtained in step S115a. Step S115c: The ignition start timing of the memory E (1) is corrected based on the comparison result in step S115b in accordance with FIG. 7, and is input to the memory F (1). Also, the memory E
The ignition end timing is calculated based on the ignition period of (2) and is input to the memory F (2).

Then, the following control is performed instead of the MBT control routine in FIG. That is, instead of the calculation of the combustion ratio, the crank angle at which the predetermined combustion ratio is obtained is calculated, and the target crank angle is compared with the measured crank angle value calculated from the pressure. Next, ignition timing control is performed based on the comparison result. Advance the ignition timing when the measured crank angle is behind the target crank angle. In addition, the ignition timing is delayed when the calculated crank angle is ahead of the target crank angle.

The target crank angle is obtained from the map data shown in FIG. That is, in FIG. 9, the horizontal axis represents the load (L), and the vertical axis represents the target crank angle CRA that should reach the predetermined combustion ratio, and the target crank angle CRA that should reach the predetermined combustion ratio, such as 60%, 70%, 80%. When CRA ₀ (Rx, Lx) is the actual engine speed rpm (Rx) and the actual engine load (Lx), it is obtained from the map.

That is, FIG. 10 is a diagram showing feedback control of the combustion ratio. Under a predetermined operating condition (Lx, Rx), a target crank angle CRA ₀ (Lx, Rx) that should reach a predetermined combustion ratio, for example, a combustion ratio FMB of 75%, is calculated, and the measured crank angle CRA (IgT) is calculated from the pressure data. Ask for.

Then, the target crank angle CRA ₀ (Lx,
The ignition timing IgT is corrected so that the difference between Rx) and the actually measured crank angle CRA (IgT) approaches zero. what if,
When the measured crank angle CRA (IgT) is ahead of the target crank angle CRA ₀ (Lx, Rx), the ignition timing I
Ignite with a delay of ΔIgT after gT. Further, if the measured crank angle CRA (IgT) lags behind the target crank angle CRA ₀ (Lx, Rx), the ignition is advanced by ΔIgT from the ignition timing IgT.

FIG. 11 is a block diagram of a two-cycle engine to which the present invention is applied. Similar to the four-stroke engine of FIG. 1, the connecting rod 246 is connected to the crankshaft 241.
A combustion chamber 2 is provided between the piston at the tip of the cylinder and the cylinder head.
48 are formed. The crankcase 300 is provided with an engine speed sensor 267 and a crank angle detection sensor 268 for detecting a mark of a ring gear mounted on the crankshaft 241 to detect a reference signal and a crank angle. Further, the crankcase 300 is provided with a crank chamber pressure sensor 210. Crank chamber 301
Is sent from the intake manifold via a reed valve 228. Air is sent from the air cleaner 231 to the intake manifold via the throttle valve 204. An intake total pressure sensor 211 is attached to an intake passage downstream of the throttle valve that communicates with the intake manifold. The throttle valve 204 is operated by a grip 206 connected by a wire 205 via a throttle pulley 203. Grip 206
Is attached to an end portion of a steering handle 207, and an accelerator position sensor 202 is provided at the base portion thereof. 21
Reference numeral 2 is a throttle opening sensor.

A scavenging port 229 opens in the cylinder,
Combustion chamber 2 through a scavenging passage 252 at a predetermined position of the piston
48 and the crank chamber 301 are connected. Further, an exhaust port 254 is opened in the cylinder, and an exhaust passage 253 communicates with it. An exhaust timing variable valve 264 is mounted on the exhaust passage wall near the exhaust port. The variable valve 264 is driven by an actuator 265 composed of a servo motor or the like, and the opening position of the exhaust port is changed to adjust the exhaust timing. An exhaust pipe pressure sensor 213 and an exhaust pipe temperature sensor 223 are provided in the exhaust pipe forming the exhaust passage 253. An exhaust passage valve 281 is provided in the exhaust passage and is driven by an actuator 282 including a servomotor or the like. The exhaust passage valve 281 is throttled in the low speed range to prevent blow-through and to stabilize the rotation.

A knock sensor 201 is mounted on the cylinder head, and a spark plug and a combustion chamber pressure sensor 200 are mounted facing the combustion chamber. The spark plug is connected to the ignition control device 256. An injector 208 is attached to the side wall of the cylinder. Fuel is sent to the injector 208 via a fuel delivery pipe 209.

Further, a combustion gas chamber 279 is formed in the cylinder block so as to communicate with a portion closer to the cylinder head than the exhaust boat opening of the cylinder bore and an intermediate portion of the exhaust port through a communication hole 278. This communication hole is set so that the combustion gas containing almost no blow-through gas is introduced into the combustion gas chamber in the explosion stroke.
An O ₂ sensor 277 for detecting the oxygen concentration in the combustion gas is installed in the combustion gas chamber. A check valve (not shown) is arranged at the inlet of the combustion gas chamber and the outlet of the exhaust port to prevent the flow in the opposite direction.

The drive of such an engine is controlled by a control device 257 having a CPU 271. On the input side of the control device 257, the above-mentioned combustion chamber pressure sensor 200,
Knock sensor 201, accelerator position sensor 202, crank chamber pressure sensor 210, intake pipe pressure sensor 211, throttle opening sensor 212, exhaust pipe pressure sensor 213, crank angle detection sensor 258, engine speed sensor 267 and O ₂ sensor 277 are provided. Connected. In addition, the control device 25
An injector 208, an exhaust timing adjusting valve actuator 265, and an exhaust valve actuator 282 are connected to the output side of 7.

FIG. 12 is a graph of combustion chamber pressure similar to that of the above-described four-cycle engine and FIG. 6 for showing combustion pressure data detection points for measuring the combustion ratio of the two-cycle engine. As mentioned above, combustion chamber pressure data is sampled at 6 crank angles. In the drawing, the range of A is the crank angle region where the exhaust port is open, and the range of B is the crank angle region where the scavenging port is open. The method of calculating and calculating each crank angle (a0 to a5) is substantially the same as that of the above-described 4-cycle engine, and in step S113 of the interrupt routine of FIG.
The combustion pressures P0 to P5 at the six points a0 to a5 where the crank angle is shown are detected, and the combustion ratio is calculated based on these pressure values. Each of the embodiments of the present invention can also be adopted in which combustion is supplied by a vaporizer.

Next, embodiments (1) to (7) will be described in which the combustion timing is finely controlled by feedback-controlling the ignition timing to obtain good engine characteristics.

Embodiment (1) FIG. 13 shows an MBT control routine of another embodiment.
In this embodiment, the configuration is the same as that of the control of FIG. 8, but high output or best torque, good startability, good acceleration, good fuel economy are provided corresponding to at least one of the load and the engine speed. Alternatively, a combustion state in which even cleaner exhaust gas is obtained is obtained, and in this combustion state, respective combustion ratio values at a plurality of predetermined crank angles are obtained (step S215a). Then, each of these combustion ratio values is stored in the memory as map data of a plurality of target combustion ratio values up to a plurality of predetermined crank angles in correspondence with at least one of the load and the engine speed, while the plurality of predetermined crank ratios are held. Of the angles, the actual combustion rate up to a predetermined crank angle in the early stage is detected, and the detected value of this combustion rate is compared with the target combustion rate value up to the early predetermined crank angle (step S).
215b). Based on this comparison, the ignition timing is controlled so as to advance the ignition timing when the detected value is smaller and to delay the ignition timing when the detected value is larger (step S215).
c).

That is, as the combustion ratio data according to the operating condition, as shown in FIGS. 14 to 16, target combustion ratio data at a plurality of crank angles is provided. For example, a target combustion ratio FMB ₀ 1 of a predetermined crank angle (TDC ... CRAl) at the beginning of combustion and a predetermined crank angle (C
RA2) of to have a target combustion ratio FMB ₀ 2. If the measured combustion ratio FMB1 predetermined crank angle CRAl is greater than the target combustion ratio FMB ₀ 1, and that the earlier the ignition timing,
The spark ignition engine delays the ignition timing, and the diesel engine delays the injection start timing.

[0106] If the measured combustion ratio FMB1 conversely is smaller than the target combustion ratio FMB ₀ 1, advance the early or injection start timing of the ignition timing.

Embodiment (2) FIG. 17 shows an MBT control routine of another embodiment.
In this embodiment, high output or best torque corresponding to at least one of load and engine speed,
A combustion state is obtained in which good startability, good acceleration, good fuel economy or even cleaner exhaust gas is obtained, and in this combustion state, each crank angle value that provides a plurality of predetermined combustion ratios is obtained (step S315a). ). This crank angle value,
Map data of a plurality of target crank angle values up to a plurality of predetermined crank angles is stored in a memory corresponding to at least one of a load and an engine speed, while a plurality of crank angles reaching a plurality of predetermined combustion ratios are stored. , An actual crank angle reaching a small predetermined combustion ratio is detected, and the detected value of the crank angle is compared with a target crank angle value set corresponding to the small predetermined combustion ratio (step S).
315b). Based on this comparison, the ignition timing is controlled so that the ignition timing is advanced when the detected value is behind and the ignition timing is delayed when the detected value is ahead (step S315c).

That is, as shown in FIGS. 18 to 20, target crank angle data for a plurality of predetermined combustion ratios is provided as the target crank angle data that provides a predetermined combustion ratio according to the operating condition. For example, a target crank angle CRA that provides a predetermined combustion ratio (for example, 20%) FMB1 at the beginning of combustion.
₀₁ and a predetermined combustion ratio (for example, 75%) FM at the beginning of combustion
To have a target crank angle CRA ₀ 2 as a B2. If the measured crank angle CRAl of the predetermined combustion ratio FMB1 is earlier than the target crank angle CRA ₀ 1, it is determined that the ignition timing is early, so that the spark ignition engine delays the ignition timing and the diesel engine delays the injection start timing. On the contrary, if the measured combustion ratio CRAl is later than the target crank angle CRA ₀ 1, the ignition timing is advanced or the injection start timing is advanced.

Further, according to the operating condition, for example, the target combustion ratio FMB ₀ 1 of the predetermined crank angle (TDC · CRAl) at the early stage of combustion and the predetermined crank angle (CR at the latter stage of combustion)
In those that have a target combustion ratio FMB ₀ 2 of A2), the measured combustion ratio FM in a predetermined crank angle CRAl
Bl and the measured combustion ratio F at a predetermined crank angle CRA2
Calculated combustion rate by comparison with MB2, by comparison with (FMB2-FMBl) / (CRA2 -CRAl) target combustion rate determined from the target combustion rate _{(FMB 0 2-FMB 0 1} ) / (CR2-CRAl), When it is determined that the combustion speed is slower than the target, the fuel supply amount is increased, the EGR amount is decreased,
Any one of intensification of in-cylinder flow, increase of compression ratio, increase of supercharging pressure, or a combination thereof is performed.

This is carried out by increasing the fuel supply amount, for example, by increasing the injection time in a fuel injection type engine and by increasing the throttle area of the main jet in an engine equipped with a carburetor with a variable main jet.

To reduce the EGR, for example, a bypass passage connecting the exhaust passage and the intake passage is provided, and an opening / closing valve (EGR control valve) is arranged in the middle to reduce the opening degree to reduce the EGR amount. Also, in a 4-cycle engine, a mechanism for changing the closing timing of the exhaust valve (for changing the phase of the drive cam with respect to the cam shaft, for arranging a spacer for variable length control between the cam and tappet, etc.) Yes) is installed to accelerate the timing of closing the exhaust valve and reduce the backflow of burnt gas from the exhaust passage.

In the two-cycle engine, the increase of the in-cylinder flow may be such that the crank chamber volume is made variable and the primary compression ratio is made variable. When the volume of the crank chamber is decreased and the primary compression ratio is increased, the scavenging air velocity is increased and the in-cylinder flow is strengthened. In addition, by providing an exhaust control valve in the exhaust passage and controlling the exhaust resistance, there are things that affect the speed of the scavenging air flow.When the opening of the exhaust control valve is increased, the scavenging air flow speed increases and Will be strengthened.

In the four-cycle engine, the increase of the in-cylinder flow is achieved by providing a throttle valve in the intake passage near the intake valve and decreasing the throttle valve opening degree to increase the intake flow velocity and strengthen the in-cylinder flow. . Also, by controlling the overlap period during which the exhaust valve is open and the intake valve is open, and making the overlap period longer than the standard, negative pressure generated near the exhaust valve due to exhaust inertia is passed through the intake valve. To act on the intake passage to increase the intake flow velocity and strengthen the in-cylinder flow.

The increase of the compression ratio is carried out by forming a part of the cylinder head wall forming the combustion chamber with a movable piston and moving the movable piston into the combustion chamber.
Further, a pressure relief hole is provided in the cylinder wall, and an opening / closing control valve is provided in a downstream passage of the pressure relief hole to reduce the opening degree.
The compression ratio decreases when the opening of this valve is opened.

The supercharging pressure is increased by increasing the rotational speed of the supercharger provided at the inlet of the intake passage.

On the other hand, when it is determined that the combustion speed is faster than the target one, any one of the fuel supply amount decrease, the EGR amount increase, the in-cylinder flow reduction, the compression ratio reduction, and the supercharging pressure reduction is performed. , Or a combination thereof.

Embodiment (3) Furthermore, according to the operating state, for example, a target combustion ratio F of a predetermined crank angle (TDC ·· CRA1) at the beginning of combustion is set.
And MB ₀ 1, the target combustion ratio FMB ₀ at 2 intended to have, measured combustion ratio FMBl at a predetermined crank angle CRA1 and the target combustion ratio FMB ₀ 1 comparison result · · NO predetermined crank angle of the combustion late (CRA2). 1, the measured combustion ratio at a predetermined crank angle CRA2 FMB2 and the target combustion ratio FMB ₀ 2 comparison result · · NO. Based on 2, the control is performed as shown in Table 1 in accordance with the combustion patterns 9 of 1 to 9 shown in FIGS.

[0118]

[Table 1]

La: Combustion ratio is larger than target value Eg: Combustion ratio is equal to target value Sm: Combustion ratio is smaller than target value +: Increase in fuel supply amount, decrease in EGR amount, enhancement of in-cylinder flow, compression Increase in ratio, increase in supercharging pressure 0: Maintain current status-: Decrease in fuel supply amount, increase in EGR amount, reduction in in-cylinder flow, reduction in compression ratio, reduction in supercharging pressure That is, the engine is desirable under operating conditions. There is a combustion rate curve. The combustion rate curve, which is related to the crank angle, can be represented by a plurality of points having two magnitudes, that is, a crank angle and a combustion rate, which are digital values. In this embodiment, points for at least two periods are stored in relation to engine load or even engine speed. In order to cover all engine loads and engine speeds, there must be a large number of sets containing points for at least two periods.

The engine is stored in the control unit for comparison with the ideal curve of the combustion ratio obtained in advance corresponding to the load and engine speed of one engine and the operating conditions such as starting and transition. Calculate the actual combustion rate at the same crank angle as the crank angle and target combustion rate data based on the sampled pressure value,
The crank angle is calculated based on the sampled pressure value in the same combustion combustion as the stored combustion ratio and target crank angle data.

If the actual combustion rate of combustion up to the most preceding crank angle of the plurality of crank angles given in advance is smaller than the target combustion rate stored corresponding to the same crank angle, ignition is performed. In the engine, the ignition timing is advanced, and in the diesel engine, the fuel injection start timing of the injector is advanced. This is because in the initial crank angle, the combustion ratio is affected by the combustion start timing rather than the combustion speed. If the actual combustion rate at the same crank angle is greater than the target value, each timing is delayed.

Further, if the respective target crank angles that reach a plurality of combustion ratios are stored in advance, for the target crank angle corresponding to the minimum combustion ratio,
If the actual crank angle is delayed, the ignition timing will be advanced,
Further, in the diesel engine, the fuel injection start timing of the injector is advanced. If the actual combustion rate at the same crank angle is greater than the target value, each timing is delayed.

The change rate of the combustion rate with respect to the crank angle is calculated by dividing the change of the combustion rate corresponding to the two crank angles by the difference between the two cranks. If the rate of change in actual combustion is smaller than the target rate of change obtained from the target data, it is determined that the actual combustion speed is smaller than the ideal combustion speed.

In order to increase the combustion speed in Table 1, the fuel supply amount is increased, the EGR amount is reduced, the in-cylinder flow is strengthened, and the compression ratio is increased, as specifically described in the above embodiment (2). The boost pressure is increased, or a combination thereof is performed.

Further, in order to delay the combustion speed in Table 1, the fuel supply amount is reduced, the EGR amount is increased, the in-cylinder flow is reduced, and the compression ratio is reduced as described in the above embodiment (2). Or a combination thereof.

That is, if the computer has one set of two periods as shown in Table 1, the computer starts the combustion start timing (ignition timing of gasoline engine or injection start timing of diesel engine) or In order to control the combustion speed, the actual combustion ratios of two times are compared, or the combustion ratios of the advanced crank angle and the delayed crank angle are compared.

The result of this control and the actual combustion is close to the ideal or target combustion. In its ideal combustion, the engine can perform high performance under each engine operating condition, stable idling, easy engine starting, rapid acceleration, stable deceleration, and stable combustion without knocking even in an emergency.

The combustion patterns in Table 1 are shown in FIGS. 14 to 16. The combustion patterns 1 to 3 are started at an early timing. The burning pattern of 1 has a high burning velocity, and the burning pattern of 3 has the lowest burning velocity of the three burning patterns.

The combustion pattern of 5 is ideal. The combustion pattern of No. 4 has an appropriate combustion start timing, but the combustion speed is higher than the target. The combustion pattern of No. 6 also has an appropriate combustion start timing, but the combustion speed is slower than the target. The combustion patterns of 7 to 9 are started at a late timing. The combustion patterns of 7 and 8 have a higher burning rate than the target.

The combustion pattern of 9 can be known accurately in the next step. First, the crank angle CRA at the beginning
The actual burn rate at 181 is controlled to match the target. After controlling the combustion start timing, the combustion pattern becomes any of 4 to 6 combustion patterns. Therefore, the computer can know its burning rate to control the above device.

Regarding the combustion pattern of 7, the combustion speed is obviously high, and therefore the combustion speed control is first performed. Thus, the actual burn rate can be varied to bring the value closer to the lower limit of the target, either within or outside the target range.
After the control of the combustion speed, the control for promoting the combustion start timing is performed.

Regarding the combustion pattern of 3, the computer
In addition, the control starts the combustion speed increasing control first, and then delays the combustion start timing.

Controlling the combustion start timing is more effective than changing the other devices by changing the crank angle related to the combustion ratio. Therefore, in all combustion patterns, the computer first controls the ignition timing by controlling the ignition timing of the gasoline engine and the injection start timing of the diesel engine, and then controls other devices. Since these controls are alternated, the actual burn rate curve approaches the target curve immediately.

As noted above, the goal is given as a range, and a computer with a range must have at least one extra datum than if it had a point target, but because of this unresponsive play. Since the computer does not need to constantly change the combustion start timing and the combustion speed control device, it is possible to prevent an unstable operating state that makes the driver uncomfortable.

Embodiment (4) Furthermore, depending on the operating state, for example, a target crank angle CRA _{0 that} provides a predetermined combustion ratio (FMB1) at the beginning of combustion.
1 and a target crank angle CRA ₀ 2 having a predetermined combustion ratio (FMB2) in the latter period of combustion, a comparison result between the actually measured crank angle CRA1 having the predetermined combustion ratio (FMB1) and the target crank angle CRA ₀ 1.・ NO. 3 and
Actual crank angle CRA with a predetermined combustion ratio (FMB2)
2 and comparison · · NO of the target crank angle CRA ₀ 2.
Based on No. 4, according to the combustion patterns 9 of 11 to 19 shown in FIGS.

[0136]

[Table 2]

Ad: Crank angle is larger than the target value Eg: Crank angle is equal to the target value De: Crank angle is smaller than the target value +: Fuel supply amount increase, EGR amount decrease, in-cylinder flow enhancement, compression Increase in ratio, increase in supercharging pressure 0: Maintain current status-: Decrease fuel supply amount, increase EGR amount, reduce in-cylinder flow, reduce compression ratio, reduce supercharging pressure Table 1 accelerates combustion speed The fuel supply amount is increased as specifically described in the above embodiment (2).
Either the EGR amount is reduced, the in-cylinder flow is strengthened, the compression ratio is increased, or the boost pressure is increased, or a combination thereof is performed.

Further, in order to delay the combustion speed in Table 1, the fuel supply amount is reduced, the EGR amount is increased, the in-cylinder flow is reduced, and the compression ratio is reduced as described in the above embodiment (2). Or a combination thereof.

Embodiment (5) Further, depending on the operating condition, it is the initial value of the fuel supply amount according to at least the load disclosed in Japanese Patent Application No. 7-292255, and when the fuel is supplied to the engine, it is lean. A map of the target combustion ratio corresponding to at least one of the load and the engine speed, and the combustion ratio at a predetermined crank angle, with the data of the initial value of the fuel supply amount set so that the air-fuel mixture is formed in the combustion chamber. Either the data is stored in the memory as the data, or the crank angle that reaches the predetermined combustion rate is stored in the memory as the map data of the target crank angle corresponding to at least one of the load and the engine speed. The actual combustion rate of the fuel is detected, and based on the comparison between this detected combustion rate and the target combustion rate, when the detected combustion rate becomes smaller, the fuel supply amount Increase
If the detected combustion ratio is higher, decrease the fuel supply amount,
Alternatively, the actual crank angle that reaches this predetermined combustion rate is detected, and based on the comparison between this detected crank angle and the target crank angle, the fuel supply amount is increased when the target crank angle is ahead and the detected value crank angle is increased. In the case where the lean burn control is performed to perform the fuel supply amount control of either reducing the fuel supply amount when the corner is advancing, that is, when operating in the super lean mode, the embodiment ( Although any one of l) to (3) is executed, as a method for increasing the combustion speed by this control, the EGR amount control is not executed, and it is specifically described in the embodiment (2). As described above, the fuel supply amount is increased, the in-cylinder flow is enhanced, the compression ratio is increased, or the supercharging pressure is increased, or a combination thereof is performed.

For example, when the engine is operated in super lean, the fuel supply amount and the in-cylinder flow enhancement valve are selected. On the other hand, when operating under a strong ERG, the EGR valve or intake / exhaust valve (overlap) is selected.

Embodiment (6) Further, in the control methods of the embodiments (3) and (4),
Which of the ignition timing control and the burning speed control is prioritized is as follows.

That is, since the ignition timing (gasoline ignition timing, diesel injection start timing) has a more immediate effect on the relationship between the crank angle and the combustion ratio, feedback control of the ignition timing is performed first. Then, the control relating to the burning speed is performed. Further, it is possible to obtain a good combustion by optimizing the feedback speed and frequency depending on the difference in response due to the operation.

Alternatively, for example, in the case of a transient response (during acceleration), a change in the combustion speed due to a shift in the air-fuel ratio (A / F) causes a deterioration in response. Therefore, immediately after the transitional state (asynchronously), the increasing fuel amount is added. However, if the volume up to the cylinder is large, such as in an intake pipe injection engine, the effect of fuel control will be delayed, so priority is given to the ignition timing dry operation by the ignition timing, and after that, when the effect of fuel increase begins to appear, the fuel supply amount Give priority to the control of the combustion speed by operation. In this way, the priority of operation is set according to the driving state. Further, feedback control of ignition timing and control relating to combustion speed may be alternately performed.

Embodiment (7) Further, in the control methods of the embodiments (3) and (4),
The target combustion ratio and the target crank angle have a predetermined width so that the feedback control does not operate at a point. In this case, since the target combustion ratio and the target crank angle have a predetermined width, the memory needs to have a double storage capacity. However, it is possible to create a play area where the feedback control is not executed, and the hunting accompanying the feedback control is performed. Can be prevented and the drivability is improved.

As described above, one or more target combustion ratio data corresponding to one or more crank angles,
Alternatively, one or more target crank angle data corresponding to one or more combustion ratios is set for each operating state (maximum output operation, maximum torque operation, start operation, acceleration operation, deceleration operation, low fuel consumption operation or emission operation, etc.). Is stored in the memory according to the load or engine speed,
The engine performance can be improved by performing feedback control for each operating state.

[0146]

As described above, according to the first aspect of the invention, the actual combustion ratio up to the predetermined crank angle is detected, and the detected value is calculated based on the comparison between the detected combustion ratio and the target combustion ratio. The ignition timing is controlled so as to advance the ignition timing when the value is smaller and delay the ignition timing when the detected value is greater, so in a wide operating range, the operating range, for example, the engine speed, load It is possible to grasp the ignition timing with the minimum advance angle that obtains the best torque, maximum output, good fuel economy, clean exhaust gas characteristics, good transient response, etc., and perform feedback control so that ignition is performed at that ignition timing. .

According to the second aspect of the present invention, the actual combustion ratio up to the predetermined crank angle can be appropriately calculated based on the combustion pressure data.

According to the third aspect of the present invention, the actual crank angle that reaches the predetermined combustion ratio value is detected, and based on the comparison between the detected value of this crank angle and the target crank angle value, the detected crank angle is delayed. The ignition timing is controlled so that the ignition timing is advanced in the case of the angle, and the ignition timing is delayed in the case where the detected value is the advanced crank angle, so that the ignition timing is controlled in a wide operating range, for example, the engine speed. The best ignition timing, maximum output, good fuel economy, clean exhaust gas characteristics, good transient response, etc. must be grasped for the ignition timing with the minimum advance angle, and feedback control should be performed to ignite at that ignition timing. You can

According to the fourth aspect of the present invention, the actual crank angle that reaches the predetermined combustion ratio value can be appropriately calculated based on the combustion pressure data.

According to the fifth aspect of the present invention, the actual combustion ratio up to the predetermined crank angle is appropriately calculated based on the combustion pressure data, and the detected value is calculated based on the comparison between the detected combustion ratio value and the target combustion ratio value. The ignition timing is controlled so that the ignition timing that is smaller is advanced and the ignition timing that the detected value is greater is delayed, and the actual crank angle that reaches the predetermined combustion ratio value is calculated based on the combustion pressure data. If the calculated value is calculated appropriately and the detected crank angle is delayed based on the comparison between the detected crank angle value and the target crank angle value, the ignition timing is advanced and the detected value becomes the advanced crank angle. In this case, the ignition timing can be controlled so as to delay the ignition timing.

In the sixth aspect of the invention, in the diesel engine, the actual combustion ratio up to a predetermined crank angle is detected, and the detected value is based on the comparison between the detected combustion ratio and the target combustion ratio. The fuel injection start timing is controlled so that the fuel injection start timing is advanced when it becomes smaller and the fuel injection start timing is delayed when the detected value becomes larger. Number, high torque at load, maximum output, good fuel economy, clean exhaust gas characteristics, good transient response, etc. are grasped and feedback control is performed to inject fuel at the fuel injection start timing. can do.

According to the seventh aspect of the present invention, in the diesel engine, the actual crank angle reaching the predetermined combustion ratio value is detected, and the detected value is determined based on the comparison between the detected crank angle value and the target crank angle value. When the crank angle is delayed, the fuel injection timing is advanced, and when the detected value is the advanced crank angle, the fuel injection timing is delayed.
Since the fuel injection timing is controlled, it is possible to obtain a wide range of operating ranges, for example, engine speed, maximum torque output under load, good fuel economy, clean exhaust gas characteristics, and good transient response. It is possible to grasp the fuel injection timing and perform feedback control so that fuel is injected at the fuel injection timing.

According to the eighth aspect of the present invention, the actual combustion ratio up to a predetermined crank angle in the early stage among a plurality of predetermined crank angles is detected, and the detected value of this combustion ratio and the target combustion up to the early crank angle in the early stage. Based on the comparison with the ratio value, the ignition timing is feedback controlled so that the ignition timing is advanced when the detection value is smaller and the ignition timing is delayed when the detection value is larger. Excellent engine characteristics can be obtained.

According to the ninth aspect of the present invention, at least two actual combustion ratios up to at least two predetermined crank angles among the plurality of predetermined crank angles are detected, and the plurality of predetermined target combustion ratios are changed with respect to the crank angle. Based on comparison with the target ratio, which is a ratio, if the rate of change due to the detected value is smaller than the target ratio, it is detected that the combustion speed is slow and the fuel supply amount to the engine is increased or Reduce the amount of recirculated exhaust gas, which is part of the burnt gas formed in the pre-combustion cycle, mixed with fresh air before combustion, or in-cylinder flow of fresh air before combustion in the engine combustion chamber By increasing the amount, increasing the compression ratio, or increasing the boost pressure, it is possible to control combustion more finely and to achieve good engine characteristics. Obtained.

In the tenth aspect of the present invention, of the crank angles that reach a plurality of predetermined combustion rates, the actual crank angle that reaches a small predetermined combustion rate is detected, and the detected value of this crank angle and the small predetermined combustion rate are detected. Based on the comparison with the target crank angle value set corresponding to the ratio, advance the ignition timing if the detected value is behind, and delay the ignition timing if the detected value is ahead. By performing feedback control of the ignition timing, the combustion can be controlled more finely and good engine characteristics can be obtained.

According to the eleventh aspect of the present invention, at least two actual crank angles that reach at least two predetermined combustion ratios out of the plurality of predetermined combustion ratios are detected, and a plurality of predetermined target crank angles are changed with respect to the combustion ratio. If the rate of change due to the detected value is higher than the target rate based on comparison with the target rate, which is the rate of, the combustion speed is detected as slow and the fuel supply amount to the engine is increased or the combustion chamber of the engine is increased. The amount of recirculated exhaust gas, which is a part of the burnt gas formed in the pre-combustion cycle, mixed with fresh air before combustion in, or the cylinder of fresh air before combustion in the combustion chamber of the engine Combustion can be controlled more finely by controlling at least one of increasing the flow rate, increasing the compression ratio, and increasing the supercharging pressure. Characteristics can be obtained.

According to the twelfth aspect of the present invention, by providing the target combustion ratio and the target crank angle with a predetermined width, it is possible to create a play area in which the feedback control is not executed, and it is possible to prevent hunting due to the feedback control. It is possible to improve the drivability.

[Brief description of drawings]

1 is a multiple cylinder spark ignition type 4 to which the present invention is applied;
It is a block diagram of a cycle engine.

FIG. 2 is a flowchart of a main routine for controlling various operating states of the engine.

FIG. 3 is a diagram showing an interrupt routine.

FIG. 4 is a diagram showing an interrupt routine.

FIG. 5 is a map diagram for obtaining a target combustion ratio according to an engine speed and a load.

FIG. 6 is a graph of combustion chamber pressure for one cycle of combustion in a four-cycle engine.

FIG. 7 is a diagram showing feedback control of a combustion ratio based on calculation of a combustion ratio.

FIG. 8 is an MBT control routine.

FIG. 9 is a diagram of a map for obtaining a target combustion ratio according to an engine speed and a load.

FIG. 10 is a diagram showing feedback control of the combustion ratio based on the calculation of the combustion ratio.

FIG. 11 is a configuration diagram of a two-cycle engine to which the present invention is applied.

FIG. 12 is a graph of combustion chamber pressure, similar to FIG. 6 of the aforementioned 4-cycle engine, for showing combustion pressure data detection points for measuring axial torque of the 2-cycle engine.

FIG. 13 is an MBT control routine of another embodiment.

FIG. 14 is a diagram illustrating an embodiment in which target combustion ratio data for a plurality of crank angles is provided.

FIG. 15 is a diagram illustrating an embodiment in which target combustion ratio data for a plurality of crank angles is provided.

FIG. 16 is a diagram illustrating an embodiment in which target combustion ratio data at a plurality of crank angles is provided.

FIG. 17 is an MBT control routine of another embodiment.

FIG. 18 is a diagram illustrating an embodiment in which target crank angle data for a plurality of predetermined combustion ratios are provided.

FIG. 19 is a diagram illustrating an embodiment in which target crank angle data for a plurality of predetermined combustion ratios are provided.

FIG. 20 is a diagram illustrating an embodiment in which target crank angle data for a plurality of predetermined combustion ratios are provided.

[Explanation of symbols]

1 Engine 9 Crankshaft 10 Ring Gear 11 Crank Angle Sensor 12 Control Device 13 Combustion Chamber 25 Oxygen Concentration Sensor (O ₂ Sensor) 26 Temperature Sensor 31 Throttle Opening Sensor 32 Intake Pipe Pressure Sensor 34 Hot Wire Intake Air Volume Sensor 36 Intake Air Temperature Sensor 105 Injector 106 Regulator 120 Exhaust pipe temperature sensor 150 Catalyst temperature sensor

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F02D 45/00 368 F02M 25/07 550F F02M 25/07 550

Claims (12)

[Claims] 1. A combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, a combustion ratio value at a predetermined crank angle is calculated as a load or an engine speed. Of the target combustion ratio value corresponding to at least one of the two, the actual combustion ratio up to the predetermined crank angle is detected, and the detected value of the combustion ratio is compared with the target combustion ratio value. Based on the above, the ignition timing is controlled so that the ignition timing at which the detection value is smaller is advanced and the ignition timing at which the detection value is larger is delayed. 2. The actual combustion ratio up to the predetermined crank angle is the crank angle between the end of the exhaust stroke and the beginning of the compression stroke, the crank angle from the start of the compression stroke to the start of ignition, and the start of ignition to the exhaust. 2. The engine according to claim 1, wherein combustion pressures at at least four crank angles consisting of two crank angles within the period until the start of the stroke are detected and calculated based on these combustion pressure data. Control method. 3. A combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, a crank angle value that reaches a predetermined combustion ratio value is set as a load or an engine. While holding in the memory as crank angle map data corresponding to at least one of the rotation speeds, the actual crank angle reaching the predetermined combustion ratio value is detected, and the detected crank angle value and the target crank angle value are Based on the comparison, when the detected value has a delayed crank angle, the ignition timing is advanced, and when the detected value has a advanced crank angle, the ignition timing is controlled to be delayed. How to control the engine. 4. The actual crank angle that reaches the predetermined combustion ratio value is the crank angle from the end of the exhaust stroke to the beginning of the compression stroke, the crank angle from the start of the compression stroke to the start of ignition, and the start of ignition. 2 of the period before the start of the exhaust stroke
4. The engine control method according to claim 3, wherein combustion pressures at at least four crank angles including one crank angle are detected and calculated based on the combustion pressure data. 5. An operating state detecting means including an engine speed detecting means, a crank angle detecting means and a combustion pressure detecting means, a data storage device for holding a target state value, and an actual state based on information from the detecting means. A program storage that stores a state value calculation program that calculates a value and a control value calculation program that calculates a control value for ignition timing based on a comparison between the calculated state value and the target state value held in the data storage device. An engine control device comprising a device and an ignition device that ignites based on a control value of the ignition timing, and controls the ignition timing of the following A or B. A. The actual combustion ratio up to a predetermined crank angle is calculated by determining the crank angle from the end of the exhaust stroke to the beginning of the compression stroke, the crank angle from the start of the compression stroke to the start of ignition, and the period from the start of ignition to the start of the exhaust stroke. The combustion pressures in at least four crank angles consisting of the two crank angles are detected and calculated based on these combustion pressure data, and based on the comparison of the detected value of the combustion ratio and the target combustion ratio value, To advance the ignition timing when the detection value is smaller, to delay the ignition timing when the detection value is greater,
Control ignition timing. B. The actual crank angle that reaches the specified combustion ratio value is the crank angle from the end of the exhaust stroke to the beginning of the compression stroke, the crank angle from the start of the compression stroke to the start of ignition, and the period from the start of ignition to the start of the exhaust stroke. The combustion pressures in at least four crank angles consisting of two crank angles are calculated and calculated based on these combustion pressure data. Based on the comparison between the detected crank angle value and the target crank angle value, When the detected value has a delayed crank angle, the ignition timing is advanced, and when the detected value has a advanced crank angle, the ignition timing is controlled to be delayed. 6. A combustion state is obtained in which a desired operating state is obtained corresponding to at least one of load and engine speed, and in this combustion state, a combustion ratio value at a predetermined crank angle is calculated as load or engine speed. Of the target combustion ratio value corresponding to at least one of the two, the actual combustion ratio up to the predetermined crank angle is detected, and the detected value of the combustion ratio is compared with the target combustion ratio value. Based on the above, the fuel injection start timing is controlled so that the fuel injection start timing is advanced when the detected value is smaller and the fuel injection start timing is delayed when the detected value is larger. Engine control method in. 7. A combustion condition is obtained in which a desired operating condition is obtained corresponding to at least one of the load and the engine speed, and in this combustion condition, the crank angle value that reaches a predetermined combustion ratio is set to the load or the engine speed. While holding in the memory as map data of the target crank angle value corresponding to at least one of the number, the actual crank angle reaching the predetermined combustion ratio value is detected, and the detected value of this crank angle and the target crank angle value are detected. Based on the comparison, if the detected value has a later crank angle, the fuel injection start timing is advanced, and if the detected value has a more advanced crank angle, the fuel injection start timing is delayed. A method for controlling an engine in a diesel engine, characterized by controlling the time. 8. A combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, respective combustion ratio values at a plurality of predetermined crank angles are calculated as described above. The map data of a plurality of target combustion ratio values up to a plurality of predetermined crank angles is stored in a memory corresponding to at least one of a load and an engine speed, while an early predetermined crank of the plurality of predetermined crank angles is stored. The actual combustion ratio up to the corner is detected, and based on the comparison between the detected value of this combustion ratio and the target combustion ratio value up to the predetermined crank angle at the early stage, the ignition timing is advanced when the detection value is smaller and detected. A method for controlling an engine, characterized in that ignition timing is controlled so as to delay the ignition timing when the value becomes larger. 9. A combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, respective combustion ratio values at a plurality of predetermined crank angles are calculated as described above. Map data of a plurality of target combustion ratio values up to a plurality of predetermined crank angles is stored in a memory corresponding to at least one of a load and an engine speed, and at least two predetermined cranks of the plurality of predetermined crank angles are stored. At least two actual combustion ratios up to the angle are detected, a ratio of change of the at least two actual combustion ratios to the crank angle is obtained, and a target is a ratio of change of the plurality of predetermined target combustion ratios to the crank angle. Based on the comparison with the ratio, if the rate of change due to the detected value is smaller than the target rate, it is detected that the combustion speed is slow and Whether to increase the fuel supply to the engine or reduce the amount of recirculated exhaust gas that is a part of the burnt gas formed in the pre-combustion cycle that is mixed with fresh air before combustion in the combustion chamber of the engine , Controlling to achieve either one of increasing the in-cylinder flow rate of fresh air before combustion in the combustion chamber of the engine, increasing the compression ratio, and increasing the boost pressure. How to control the engine. 10. A combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, respective crank angle values having a plurality of predetermined combustion ratios, The map data of a plurality of target crank angle values up to the plurality of predetermined crank angles is stored in a memory corresponding to at least one of a load and an engine speed, while each crank angle reaching the plurality of predetermined combustion ratios. Among these, the actual crank angle that reaches a small predetermined combustion rate is detected, and the detected value is based on the comparison between the detected value of this crank angle and the target crank angle value set corresponding to the small predetermined combustion rate. Is advanced, the ignition timing is controlled so as to advance the ignition timing, and when the detected value is advanced, the ignition timing is controlled so as to be delayed. Control method of. 11. A combustion state in which a desired operating state is obtained corresponding to at least one of a load and an engine speed, and in this combustion state, each crank angle value which becomes a plurality of predetermined combustion ratios, The map data of a plurality of target crank angle values up to the plurality of predetermined crank angles is stored in a memory corresponding to at least one of a load and an engine speed, and at least two predetermined combustion ratios among the plurality of predetermined combustion ratios are stored. At least two actual crank angles that reach the combustion rate are detected, the rate of change of the at least two actual crank angles with respect to the combustion rate is determined, and the rate of change of the plurality of predetermined target crank angles with respect to the combustion rate is calculated. Based on a comparison with a certain target rate, if the rate of change due to the detection value is greater than the target rate, it is detected that the combustion speed is slow, Whether to increase the amount of fuel supplied to the engine or reduce the amount of recirculated exhaust gas that is a part of the burnt gas formed in the pre-combustion cycle that is mixed with fresh air before combustion in the combustion chamber of the engine , Controlling to achieve at least one of increasing the in-cylinder flow rate of fresh air in the combustion chamber of the engine, increasing the compression ratio, and increasing the boost pressure. How to control the engine. 12. The target combustion ratio and the target crank angle have a predetermined width.
1. The engine control method described in 1.