JP2004286038A - Internal combustion engine control device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve fuel consumption by eliminating a pump loss by stratified combustion under partial loading, and to increase output by premixed combustion at the time of the maximum output. <P>SOLUTION: An ignition source 14 is provided near a fuel injection valve 13 at the time of partial loading. Mixture is ignited after injecting fuel, and a generated flame is diffused in a cylinder by spraying the fuel, thereby carrying out stratified combustion. On the other hand, when a load is increased and soot and the like is generated by the stratified combustion, fuel injection is carried out several times, and premixture is generated by the injection in the first half, and the premixture is burned in a short time by injecting a flame generated by the injection in the last half into the cylinder. Combustion time is shortened, and knocking can be prevented. Furthermore, a compression rate of an engine is increased to raise thermal efficiency, and fuel consumption is improved. The generation of unburned hydrocarbon can be prevented by stratified suction. By cylinder injection of the fuel, reponsiveness of the fuel is enhanced to improve operability. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control apparatus and a control method for a spark ignition internal combustion engine, in particular, for directly injecting fuel into a cylinder.

  In order to improve the fuel consumption rate of the internal combustion engine, it is necessary to increase the compression ratio to increase the thermal efficiency and to burn a lean mixture having a low fuel concentration instantaneously. In addition, in order to generate the maximum output in a predetermined cylinder volume, it is necessary to make maximum use of the air flowing into the cylinder and burn more fuel efficiently. The former is a diesel engine and the latter is a gasoline engine combustion method. The present invention relates to a gasoline engine that is a spark ignition internal combustion engine.

  FIG. 2 shows the combustion state of the engine. FIG. 2A shows the case of a gasoline engine. A uniform air-fuel mixture is formed in the cylinder, ignited by the spark plug 14, and the flame spreads around (premix combustion). When the air-fuel ratio is large, the propagation of the flame is delayed, and the combustion tends to be unstable. Therefore, the amount of intake air is reduced by the throttle valve to prevent the air-fuel ratio from increasing when the torque is small. On the other hand, even when the air-fuel ratio becomes small, a large air-fuel ratio can be used because the entire inside of the cylinder has a uniform air-fuel ratio, and soot and the like are less generated. FIG. 2B shows the case of a diesel engine. Hot compressed air is produced in the cylinder, and fuel is injected into the cylinder by the fuel injection valve 13. As the fuel flies in the high-temperature air, each fuel droplet evaporates and burns in a part of the cylinder (stratified combustion). For this reason, since the fuel is burned from around the fuel droplet, the fuel can be burned even if the fuel amount is small (even if the air-fuel ratio is large). However, when the fuel amount becomes large (the air-fuel ratio becomes small), the air around the liquid droplets is consumed by combustion, so that air shortage and soot are likely to occur, and the air utilization rate at high output becomes a problem. .

  FIG. 3 shows the relationship between the air-fuel ratio of the engine and the torque generated by the engine. Although the characteristics of the gasoline engine shown by the solid line in FIG. 3 depend on the emission measures, most of the torque (operating range) is operated at an air-fuel ratio (A / F) of 14.7 (theoretical air-fuel ratio). That is, when controlling the torque, the fuel amount is controlled in accordance with the air amount, and the air-fuel ratio is kept constant. If more torque is required, the air-fuel ratio is reduced to increase the torque. Under normal operating conditions, the minimum air-fuel ratio is A / F13. On the other hand, in the case of the diesel engine shown by the broken line, when the fuel amount is small (the torque is small), the air-fuel ratio is large, and the air-fuel ratio decreases as the torque increases. When the air-fuel ratio decreases and approaches A / F of 14.7, as shown in FIG. 2B, the air tends to be insufficient due to the stratified combustion, and soot and the like are generated. Therefore, the gasoline engine has a larger torque.

  FIG. 4 shows the relationship between the fuel amount and the air amount. In the case of the gasoline engine indicated by the solid line, the amount of fuel and air both increase, and the increase in air decreases at the point that the air-fuel ratio in FIG. 3 decreases. The amount of air is determined by the reciprocating motion of the cylinder. Therefore, in a gasoline engine, the intake pipe pressure is increased or decreased by a throttle valve, and the amount of mass air entering the cylinder is changed. For this reason, at a partial load with a small throttle valve opening (small intake pipe pressure), pumping loss (throttle loss) occurs and fuel consumption is reduced. On the other hand, in the diesel engine, the air amount is almost constant (there is no throttle loss), and only the fuel increases. Therefore, the fuel efficiency of the partial load increases.

  As described above, since the diesel engine performs stratified combustion, the fuel efficiency of the partial load increases, but the maximum output is small. On the other hand, a gasoline engine has a large maximum output due to premixed combustion, but at partial load, fuel efficiency decreases due to pump loss.

  An object of the present invention is to provide an apparatus and a method capable of improving fuel efficiency by eliminating pump loss by stratified combustion at a partial load, and increasing output by premixed combustion at maximum output.

  In order to solve the above-mentioned problems of the prior art, in the present invention, at the time of partial load, an ignition source is provided near the fuel injection valve, and after fuel is injected, the mixture is ignited, and the generated flame is sprayed with fuel. It diffuses into the cylinder and causes stratified combustion. On the other hand, if the load increases and stratified combustion causes soot, etc., the fuel injection is performed multiple times, the premixed air is created in the cylinder in the first half of injection, and the premixed air is created in the second half of the flame. Is injected into the cylinder to burn the premixed gas in a short time.

  When the fuel injection amount is small as in the case of a partial load, the start of the injection and the ignition timing can be relatively close, so that the fuel is not dispersed very much in the cylinder and burns in a relatively narrow range (stratified combustion). By increasing the start of the injection in accordance with the increase in the load, the range in which the air-fuel mixture is formed (the pre-air-fuel mixture) can be increased, so that the pre-mixed combustion occurs and the generated torque can be increased.

  According to the present invention, the combustion time can be reduced, knocking can be prevented, the compression ratio of the engine can be increased, the thermal efficiency can be increased, and the fuel consumption can be increased. The generation of unburned hydrocarbons can be prevented by the stratified intake. The direct fuel injection in the cylinder improves the responsiveness of the fuel and improves the operability.

  FIG. 1 shows a configuration of a control system according to a first embodiment of the present invention. Fuel is sent from the fuel tank 1 to the fuel pump 2 and pressurized. The pressurized fuel detects the fuel pressure by the pressure sensor 3 and sends a pressure signal to the control circuit 5. The control circuit 5 compares the fuel pressure with a predetermined target, and if it is equal to or more than the set value, opens the spill valve 4 of the fuel pump 2 and controls the fuel pressure to the target pressure. The pressurized fuel is sent to the fuel injection valve 13. A signal (torque signal) intended by the driver is sent from the accelerator pedal 19 to the control circuit 5. In response to this, the control circuit 5 calculates the injection amount per injection taking into account the signal of the engine speed sensor 10 and sends it to the injection valve drive unit 20 of the fuel injection valve 13. As a result, the fuel injection valve 13 opens, and fuel is injected into the combustion chamber 7. At this time, the fuel injection timing and the injection amount (injection time) are selected by the control circuit 5 to optimal values. For the fuel injected into the combustion chamber 7, a signal is sent from the control circuit 5 to the ignition circuit 22 at an optimal ignition timing, and a high voltage is generated in the ignition circuit 22 and sent to the spark plug 14 to be spark-ignited. Ignite. The pressure in the combustion chamber 7 rises, acts on the piston 9, applies a rotational force to the crankshaft 16, and drives the tires 18 a and 18 b from the transmission 15 via the differential gear 17 to travel. The generated torque of the engine 6 detects the combustion pressure of the combustion chamber 7 by the pressure sensor 8 and sends it to the control circuit 5 where it is compared with the signal of the accelerator pedal 19 which is intended by the driver. This comparison result is reflected in the fuel injection of the next cylinder. The air amount of the engine 6 is measured by an air amount detector, and the flow rate is controlled by a throttle valve. The air is controlled by a swirl control valve 28 arranged in the intake pipe 27 so that an appropriate turbulence can be generated in the cylinder. The valve lift of the intake valve 12 is controlled by the valve lift control device 11. The combustion gas is exhausted from the exhaust valve 21.

A first embodiment of the present invention will be described with reference to a longitudinal sectional view of a combustion chamber in FIG. The fuel injection valve 13 and the ignition plug 14 are installed in the sub-combustion chamber 23 formed in the engine head 25. At this time, the positional relationship between the fuel injection valve 13 and the ignition plug 14 is preferably such that the ignition plug 14 is provided on the downstream side of the spray of the fuel injection valve 13. This is because the flame nuclei formed by the spark plugs 14 are easily dispersed by spraying into the cavities 24 provided in the combustion chamber 7 and the piston 9. However, if the spark plug 14 is too close to the spray, the spark plug 14 may be wet with the spray and cause poor ignition, so the positional relationship is important. Also, by squeezing the outlet portion 26 of the sub-combustion chamber 23, the ejection speed of the flame nucleus can be adjusted. Even in this case, if the throttling is excessive, a pressure loss occurs and the thermal efficiency is reduced.

FIG. 6 shows the relationship between the air-fuel ratio A / F and the exhaust gas (HC, NOx). When the fuel injection timing is a crank angle of 90 °, the peak value of NOx is near A / F16. Such a change in the NOx emission amount tends to be observed in the case of a uniform air-fuel mixture. This is because the injected spray is dispersed throughout the cylinder by the movement of the piston and the flow of air in the cylinder due to the movement of the piston until the injection timing reaches the crank angle of 90 ° and the middle stage of the intake stroke. As the injection timing increases, the generated air-fuel ratio at the peak value of NOx increases. At the same time, the generation of NOx becomes gentle. Also,
HC emissions also change. Comparing the injection timing 90 ° and the injection timing 180 °, HC near the A / F 15 has an injection timing 90 ° of 3800 ppmC and an injection timing 180 ° of 6500 ppmC. The reason why the HC is different at the same air-fuel ratio is that the air-fuel ratio at the combustion is different. In other words, the reason is that the air-fuel ratio at the point where the fuel is actually combusted is smaller at the injection timing of 180 °. For this reason, when the air-fuel ratio becomes large, when the injection timing is 90 °, poor combustion (misfire) occurs at a small air-fuel ratio. The reason why the air-fuel ratio that stably burns (the HC does not increase) when the injection timing is increased is increased because the ignition timing becomes closer to the ignition timing when the injection timing is increased because the fuel becomes difficult to be dispersed and becomes a stratified mixture. It is. By selecting the injection timing in this way, a uniform mixture and a stratified mixture can be freely formed. Therefore, when the engine torque is small, the injection timing is increased to approach the ignition timing. As the torque increases, the injection timing is reduced to approach a uniform mixture.

  FIG. 7 shows a second embodiment in a longitudinal sectional view of a combustion chamber. In this embodiment, the fuel injection valve 13 is protruded into the combustion chamber 7, and the injection port is perforated so that the fuel is widely dispersed in the cylinder. In such a case, when fuel is injected near the bottom dead center where the piston is lowered, the fuel directly hits the cylinder wall surface, and a wall flow is created. In such a state, good combustion cannot be expected. Therefore, in the case of such an injection valve having a wide spray, the cavity 24 is located near the top dead center, and it is necessary to blow the fuel at a timing such that the fuel can be blown into the cavity 24. As an example, the fuel can be injected in a plurality of times as shown in FIG. Pre-injection is performed near the crank angle of 0 degree to create a uniform mixture. A spark is created by post-injection near the ignition timing, and the homogeneous mixture formed by pre-injection is rapidly burned. Since the injection amount can be adjusted by either post-injection or pre-injection, injection can be performed in an optimal state. As described above, when the injection valve is divided into two before and after, it is effective even if the injection valve shown in FIG. 5 has a small injection angle.

  FIG. 9 shows a flowchart of calculation of the fuel injection time when performing the pre-injection and the post-injection. In step 101, the accelerator opening α and the engine speed Ne are read. At this time, if the air amount is measured, the air amount Qa may be added. In step 102, the fuel amount Qf is calculated. In step 103, it is determined that Qf> Qf1. In the case of NO, the routine proceeds to step 109, where the injection time Tp2 is calculated by adding the invalid injection amount Qx. In step 110, Tp2 is injected at the time of post-injection to complete. If step 103 is Yes, the process proceeds to step 104, where the minimum injection amount Qf0 is subtracted to calculate Qf2. In step 105, the injection time Tp1 is calculated by adding the invalid injection amount Qx to Qf2. Tp1 is injected at the time of pre-injection. In step 107, Tx2 is calculated by adding Qx to Qf0, and Tp2 is injected at the time of post-injection. As described above, it is necessary to add the invalid injection amount Qx for each of the front and rear injections.

  FIG. 10 shows a fuel pressure control device. Fuel is supplied from a fuel tank 1 to a fuel pump 2. The fuel pump 2 is driven by a motor 30 and sends pressurized fuel to a high-pressure pipe 34. The high-pressure pipe 34 is provided with injection valves 13 a to 13 d, an accumulator 33, a fuel pressure sensor 3, and a relief valve 32. The gas is sealed in the relief valve 33 as a damper, and when the fuel pressure increases, the fuel flows into the accumulator. When the pressure decreases, the fuel is sent to the high-pressure pipe 34. When the fuel becomes too high, the relief valve 32 causes the fuel to flow off, thereby preventing the pressure from rising. The fuel pressure sensor 3 sends a signal proportional to the pressure to the control circuit 5 and sends it to the electromagnetic spill device 4 of the fuel pump 2 to control the discharge amount of the fuel pump 2 to control the fuel pressure. Also, a signal is sent to the controller 31 of the motor 30 to control the number of revolutions of the fuel pump 30 to control the fuel pressure. In this embodiment, both the electromagnetic spill device 4 and the controller 31 are installed, but the fuel pressure can be controlled with either one. However, when the fuel pump 2 is driven by the engine, there is no motor 30, so that only the electromagnetic spill device 4 is used.

FIG. 11 shows a control system diagram of the EGR. The air enters the engine 6 through the air flow meter 35, the throttle valve 37, and the intake pipe 27, is exhausted, and is discharged to the exhaust pipe 41. The exhaust pipe 41 has a catalyst 39. Here, when EGR becomes necessary, a signal is sent from the control device 5 to the EGR valve 38 to open the EGR valve. Further, a signal is sent to the throttle valve actuator 36, the throttle valve 37 is closed, and the pressure in the intake pipe 27 is made lower than the atmospheric pressure. Then, exhaust gas flows from the exhaust pipe 41 to the intake pipe 27 via the EGR valve 38 in proportion to the intake pipe pressure. Since the flow rate of the exhaust gas at this time is proportional to the intake pipe pressure, the intake pipe pressure is detected by the intake pipe pressure sensor 40, sent to the control circuit 5, and the opening of the throttle valve 37 is adjusted by the throttle valve actuator 36. . By controlling the opening of the throttle valve 37, the pressure of the intake pipe 27 can be controlled, and the EGR amount can be accurately controlled by feedback control.

FIG. 12 shows a third embodiment of the present invention. The air is adjusted by the throttle valve 213 and is sucked into the engine via the intake pipe 214. The lift of the intake valve 208 can be changed by switching cams 203 having different shapes. The switching of the cam is performed by switching the rocker arm 210 by the hydraulic control valve 202. The hydraulic control valve 202 is, for example, an electromagnetic solenoid. The opening of the throttle valve is controlled by a motor 212. A sensor 220 for detecting the in-cylinder pressure is attached to the engine. Further, an injection valve 204 for directly injecting fuel into the cylinder is mounted. A sensor 205 for detecting an air-fuel ratio of exhaust gas is attached to the exhaust pipe. A catalyst is attached to the exhaust pipe. It is desirable that the catalyst be capable of removing NOx even under conditions of excess oxygen. Further, under the stoichiometric air-fuel ratio condition, a function is required for a three-way catalyst capable of simultaneously removing HC, CO, and NOx. Further, a part of the exhaust gas is controlled by valves 215 and 218 for controlling the exhaust pipe flow rate. This lowers the combustion temperature and reduces NOx. These control valves are controlled by the control device 201. In order to reduce fuel consumption, it is desirable to reduce the pumping loss by bringing the pressure in the intake pipe close to the atmospheric pressure. Therefore, the throttle valve 212 is set in a fully open state as much as possible. However, when the exhaust gas is recirculated from the pipe 216, the pressure in the intake pipe needs to be smaller than the pressure in the exhaust pipe, so the throttle valve is closed.

  FIG. 13 shows the operation of the third embodiment of the present invention. The lift of the intake valve cam is changed as shown in FIG. 13 according to the operating conditions. When a large amount of air is needed, the lift of the intake valve is set to A. When the air amount is small, the lift of the intake valve is changed like lift B and lift C. Changing the lift also changes the overlap with the exhaust valve. During high-power operation, the overlap period between the exhaust valve and the intake valve is increased. In this way, the air amount can be changed by the lift of the intake valve.

  FIG. 14 shows an example of the configuration of the rocker arms 221, 223, 224 and the cams 225, 226, 227. Driven by the rocker arm 223 and the cam 225, the intake valve is reciprocated. The rocker arm 226 and the cam 224 are not fixed and are free. When switching the cam, the cam is driven by the rocker arm 224 and the cam 226 to reciprocate the intake valve. The rocker arm 223 and the cam 225 are not fixed and are in a free state. By doing so, the cam can be switched. In this example, the lift of the cam is changed. However, the shape of the cam may be changed to simultaneously control the timing of opening and closing the valve.

  FIG. 15 shows a map for selecting a cam with respect to the accelerator opening and the engine speed. In this example, cam switching was selected in three stages. When the engine speed is low and the accelerator opening is small, a cam A with a small lift is selected. As the engine speed and the accelerator opening increase, the cam is switched to a cam with a larger lift.

  FIG. 16 shows a map for selecting a cam with respect to the engine torque and the engine speed. In this example, cam switching was selected in three stages. The engine torque is a target torque predetermined for the accelerator opening. When the engine speed is low and the engine is small, a cam A with a small lift is selected. As the engine speed and the engine torque increase, the cam is switched to a cam with a larger lift.

FIG. 17 shows a method of controlling the amount of intake air when the air-fuel ratio A / F is switched. If a throttle valve is fully opened or a cam with a large lift is selected, reducing the air-fuel ratio increases the fuel amount and increases the shaft torque. When the air-fuel ratio is around 16, the emission amount of NOx tends to increase, so the air-fuel ratio is skipped from 18 to 15. At this time, if the air-fuel ratio is switched to 15 while keeping the air amount unchanged, the fuel amount increases, the shaft torque increases as indicated by C, and a sense of discomfort is felt. Therefore, when switching the air-fuel ratio, the amount of air is reduced to prevent an increase in the amount of fuel, and the shaft torque is changed from A to B to reduce shock. Adjustment of the air amount is performed by switching the throttle valve or the cam. If the operation is performed by the throttle valve, the pressure in the intake pipe becomes small, and the pumping loss increases. In addition, even when the shaft torque is reduced and the target shaft torque does not reach the target even if the air-fuel ratio is set to, for example, 70 or more, the air amount is adjusted by the cam or the throttle valve.

  FIG. 18 shows the relationship between the fuel amount and the shaft torque. Since the shaft torque can be increased by increasing the fuel amount, the shaft torque can be controlled by the fuel amount.

FIG. 19 shows a fourth embodiment of the present invention. The fuel injection amount Qf is obtained by an engine state detection unit 301 that detects an engine state such as the accelerator opening α and the engine speed N, and a fuel injection amount calculation unit 302 that calculates the fuel injection amount Qf. The air amount of the engine is calculated in 304 based on the charging efficiency map 303, and the air amount of each cam is obtained to calculate the air-fuel ratio. At 305, it is determined whether the air-fuel ratio is within the flammable range. At 306, a cam is selected, and at 307, the throttle valve opening is determined. If the amount of air is too large, the air-fuel mixture becomes lean, so switch to a cam with less lift. In-cylinder injection directly controls the air-fuel mixture in the cylinder, so that the limit of the lean air-fuel mixture can be made larger than that of the conventional intake port injection system, so that the range of the shaft torque that can be controlled by the fuel amount is wide. Therefore, the shaft torque can be controlled by the fuel amount without finely controlling the air amount as in the related art.

  FIG. 20 shows a fifth embodiment of the present invention. At 311 the accelerator opening is detected, and at 312 the target torque is determined. The fuel amount is determined by the fuel amount calculating means 313 from the target torque. If the air-fuel ratio is determined in advance for the shaft torque, the air amount Qa can be obtained. The air-fuel ratio is determined at 316, and if the air-fuel ratio is 18 or more, the throttle valve is fully opened at 318, the torque of the engine is detected by the torque detecting means 319, and the fuel injection amount is controlled to reach the target torque. I do. On the other hand, when the air-fuel ratio is 18 or less, the air amount is controlled at 321 so as to reach the target air-fuel ratio. The air amount is determined by, for example, the throttle valve opening or the lift of the cam. Here, the air amount may be detected by the air amount sensor 322 and the air amount may be controlled so as to be a target air amount.

  FIG. 21 shows a map of the target air-fuel ratio. Although the air-fuel ratio is reduced with an increase in the shaft torque, the air-fuel ratio is switched to the point C so that the air-fuel ratio 16 is skipped at the point B. When the torque is further increased, the air-fuel ratio is decreased so as to approach point D. If the air-fuel ratio is further reduced, the mixture becomes too rich. Therefore, in this region, it is desirable to detect the air amount and perform the air-fuel ratio control.

  FIG. 22 shows the relationship between the throttle valve opening degree θth and the engine speed N and the intake air amount Qa. When the air amount is controlled by the throttle valve, the throttle valve opening is obtained from a map for the intake air amount. When performing more precise control, the air amount is detected and feedback is applied.

  23 and 24 show a sixth embodiment of the present invention. If the air-fuel ratio is 18 or more, the air-fuel mixture may be too lean and the operability and exhaust purification performance may be reduced. Therefore, the combustion fluctuation is detected and the throttle valve opening or the cam lift is set so as to reduce the amount of air. I do.

  FIG. 25 shows a seventh embodiment of the present invention. The electrode 234 is embedded in the cylinder gasket 231 of the engine, and a high voltage is applied from the electrode 232. The gasket has a hole 233 for screwing.

  FIG. 26 shows a longitudinal sectional view of FIG. A high voltage is applied between the electrodes 238 and 239 from the ignition coil, causing a spark discharge. As a result, the air-fuel mixture is ignited from near the cylinder wall surface and from multiple points, so that the combustion speed is increased. In addition, since combustion is performed near the wall surface, the so-called quench region near the wall surface is reduced, unburned hydrocarbons are reduced, and knocking is less likely to occur. The insulating layers 235 and 237 are provided on the upper and lower surfaces of the gasket. When the electrode 239 is ground, the insulating layer 237 may not be provided.

FIG. 1 is a conceptual diagram showing a first embodiment of the present invention and showing a configuration of the present control system. FIG. 2 is a conceptual diagram showing a combustion state in a combustion chamber of the engine. FIG. 4 is a correlation diagram between an air-fuel ratio and generated torque. FIG. 4 is a correlation diagram between a fuel amount and an air amount. FIG. 3 is a vertical sectional view of a combustion chamber. FIG. 4 is a correlation diagram between an air-fuel ratio A / F and HC and NOx in exhaust gas. FIG. 6 shows a second embodiment of the present invention, and is a longitudinal sectional view of a combustion chamber similar to FIG. 5. FIG. 3 is a chart showing a fuel injection timing. The flowchart figure of calculation of a fuel injection time. FIG. 2 is a block diagram of a fuel pressure control device. The conceptual diagram showing the control system of EGR. The conceptual diagram which shows the 3rd Example of this invention and shows the structure of this control system. FIG. 4 is a time chart showing the operation of the intake valve. FIG. 3 is a perspective view showing a configuration of a rocker arm. The map figure of selection of an engine speed, an accelerator opening, and a cam. The map figure of selection of an engine speed, engine torque, and a cam. FIG. 4 is a correlation diagram between an air-fuel ratio A / F and a shaft torque. FIG. 4 is a correlation diagram between a fuel amount and a shaft torque. FIG. 9 is a block diagram of the control system, showing a fourth embodiment of the present invention. FIG. 13 is a block diagram of the control system, showing a fifth embodiment of the present invention. The map figure with respect to engine torque of a target air-fuel ratio. FIG. 4 is a correlation diagram of a throttle valve opening degree with respect to an engine speed and an intake air amount. FIG. 13 is a block diagram of the present control system, showing a sixth embodiment of the present invention. FIG. 24 is a block diagram of the present control system as in FIG. 23. FIG. 13 is a top view illustrating the configuration of the cylinder gasket of the engine according to the seventh embodiment of the present invention. FIG. 26 is a longitudinal sectional view of FIG. 25.

Explanation of reference numerals

  DESCRIPTION OF SYMBOLS 1 ... Fuel tank, 2 ... Fuel pump, 3 ... Fuel pressure sensor, 4 ... Electromagnetic spill device, 5 ... Control circuit, 6 ... Engine, 7 ... Combustion chamber, 8 ... Combustion pressure sensor, 9 ... Piston, 12 ... Intake valve , 13 ... fuel injection valve, 14 ... spark plug, 19 ... accelerator pedal, 21 ... exhaust valve, 24 ... cavity, 28 ... swirl control valve.

Claims (8)

Fuel injection means for directly injecting fuel into a combustion chamber of a spark ignition engine;
Ignition means for igniting the air-fuel mixture in the combustion chamber;
Torque detection means for detecting the output torque of the spark ignition engine,
Valve means for introducing intake air into the combustion chamber;
Fuel control means for controlling the fuel amount and the injection timing of the fuel injected from the fuel injection means,
Ignition timing control means for controlling the ignition timing of the ignition means,
In a control device for a spark ignition internal combustion engine, comprising: an intake air amount control means for controlling an intake air amount to the combustion chamber;
The fuel control means changes the amount of fuel, and the intake air amount control means changes the amount of intake air so that the value of the output torque detected by the torque detection means approaches a predetermined value. While changing
Providing the ignition means in the vicinity of the fuel injection means,
At the time of partial load, after fuel is injected, the air-fuel mixture is ignited, and the resulting flame is diffused into the cylinder with fuel spray and burned.
If the load increases and soot occurs due to stratified combustion, the fuel injection is divided into multiple injections, a premixed air mixture is created in the cylinder in the first half of injection, and the flame created in the second half of this premixed air is used as a cylinder. A control device for a spark-ignition internal combustion engine, characterized in that a premixed gas is burned by injecting the premixed air into the engine.   2. The control device for a spark ignition internal combustion engine according to claim 1, wherein said intake air amount control means keeps the intake air amount constant, and said fuel control means changes the fuel amount and changes the air-fuel ratio.   2. The spark ignition internal combustion engine according to claim 1, wherein said intake air amount control means changes the intake air amount in a stepwise manner, and said fuel control means changes the fuel amount and changes the air-fuel ratio. Control device.   2. A spark ignition according to claim 1, wherein said intake air amount control means changes the intake air amount according to a predetermined function, and said fuel control means changes the fuel amount and changes the air-fuel ratio. Control device for internal combustion engine. The fuel injection means injects fuel directly into the combustion chamber of the spark ignition engine,
The ignition means ignites the air-fuel mixture in the combustion chamber,
The torque detecting means detects an output torque of the spark ignition engine,
Valve means for introducing intake air into the combustion chamber;
Fuel control means controls the fuel amount and injection timing of the fuel injected from the fuel injection means,
The ignition timing control means controls the ignition timing of the ignition means,
In the method for controlling a spark ignition internal combustion engine, wherein the intake air amount control means controls an intake air amount to the combustion chamber,
The fuel control unit changes the fuel amount, the intake air amount control unit changes the intake air amount, and adjusts the air-fuel ratio so that the value of the output torque detected by the torque detection unit approaches a predetermined value. Change it,
Providing the ignition means in the vicinity of the fuel injection means,
At the time of partial load, after fuel is injected, the air-fuel mixture is ignited, and the resulting flame is diffused into the cylinder with fuel spray and burned,
If the load increases and soot occurs due to stratified combustion, the fuel injection is divided into multiple injections, a premixed mixture is created in the cylinder by the first half of injection, and the flame created by this second half of injection is used as the cylinder A method for controlling a spark ignition internal combustion engine, characterized in that a premixed gas is burned by injecting the mixture into a gas.   6. A control method for a spark ignition internal combustion engine according to claim 5, wherein said intake air amount control means keeps the intake air amount constant, and said fuel control means changes the fuel amount and changes the air-fuel ratio.   6. The spark ignition internal combustion engine according to claim 5, wherein said intake air amount control means changes the intake air amount in a stepwise manner, and said fuel control means changes the fuel amount and changes the air-fuel ratio. Control method. 6. The spark ignition according to claim 5, wherein the intake air amount control means changes the intake air amount according to a predetermined function, and the fuel control means changes the fuel amount and changes the air-fuel ratio. A control method for an internal combustion engine.

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