JPH08189405A - Cylinder injection type spark ignition engine - Google Patents

Abstract

PURPOSE: To control injection timing and ignition timing by being matched to the change delay of an intake air condition control value when the fuel injection pattern of an cylinder injection-type spark ignition engine is switched so as to optimize combustion during a switching period. CONSTITUTION: Injection timing and ignition timing out of a swirl ratio, an EGR rate, the injection timing and the ignition timing which are changed when a fuel injection pattern is switched among compression stroke ignition, two-time ignition and intake stroke ignition according to a load change, are delayed to be moved to values after changed by being matched to the delay of changes in the swirl ratio and the EGR rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder injection type spark ignition engine.

[0002]

2. Description of the Related Art A cylinder injection type spark ignition engine is known in which an injection pattern indicating where fuel is to be injected is switched according to an operating load of the engine and a swirl ratio is switched according to the injection pattern. (Japanese Patent Laid-Open No. 5-79)
337). Also, depending on the operating load of the engine,
Switching the injection pattern, EGR according to the injection pattern
A cylinder injection type spark ignition engine that switches the rate is known (see Japanese Patent Laid-Open No. 63-248962).

[0003]

However, the injection pattern is changed according to the operating load of the engine, the swirl ratio and the EGR rate are changed according to the injection pattern, and at the same time, the fuel injection timing and the ignition timing are changed according to the load. However, since changes in swirl ratio and EGR rate are delayed compared to changes in fuel injection timing and ignition timing, optimum combustion cannot be obtained immediately after switching the injection pattern, and knocking or misfire occurs. , Drivability, and exhaust emission deteriorate.

In view of the above problems, the present invention controls a fuel injection timing and an ignition timing in accordance with a delay of changes in EGR rate, swirl ratio, etc. at the time of switching injection patterns, and optimizes combustion at the time of switching injection patterns. An object is to provide an internal injection type spark ignition engine.

[0005]

According to claim 1 of the present invention, an operating condition detecting means for detecting an engine operating condition and an engine operating stroke corresponding to the engine operating condition detected by the operating condition detecting means. Injection pattern switching means for switching a fuel injection pattern indicating where to perform fuel injection, fuel injection timing control value storage means for storing in advance fuel injection timing control values corresponding to the fuel injection patterns, and An ignition timing control value storage means for storing in advance an ignition timing control value corresponding to the fuel injection pattern, and a swirl ratio control value storage means for storing in advance a swirl ratio control value corresponding to each of the fuel injection patterns, A fuel injection timing control value corresponding to each fuel injection pattern stored in advance in the fuel injection timing control value storage means corresponding to the switching of the fuel injection pattern. Fuel injection timing control value switching means for switching to the fuel injection timing control value, and each fuel injection pattern in which the ignition timing control value is stored in advance in the ignition timing control value storage means in correspondence with the switching of the fuel injection pattern. Ignition timing control value switching means for switching to the ignition timing control value, and each fuel injection pattern in which swirl ratio control value is stored in advance in the swirl ratio control value storage means in correspondence with the switching of the fuel injection pattern. The swirl ratio control value switching means for switching to the swirl ratio control value, the fuel injection timing control value switched by the fuel injection timing switching means in response to the switching of the fuel injection pattern, and the ignition timing switching means. At least one of the ignition timing control values that can be switched after switching Later, cylinder injection type spark ignition engine comprising a correction means for correcting the direction of the difference between the value before switching is smaller is provided.

According to the second aspect of the present invention, the fuel injection is performed in the engine operating stroke corresponding to the operating condition detecting means for detecting the engine operating condition and the engine operating condition detected by the operating condition detecting means. Which corresponds to each of the fuel injection patterns, a fuel injection timing control value storing means for storing in advance a fuel injection timing control value corresponding to each of the fuel injection patterns, and an injection pattern switching means for corresponding to each of the fuel injection patterns. Ignition timing control value storage means for storing an ignition timing control value in advance, EGR amount control value storage means for storing an EGR amount control value corresponding to each fuel injection pattern in advance, and switching of the fuel injection pattern The fuel injection timing control value corresponding to each of the fuel injection patterns stored in advance in the fuel injection timing control value storage means. A fuel injection timing control value switching means for switching to a value, and an ignition timing corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in correspondence with the switching of the fuel injection pattern. Ignition timing control value switching means for switching to the control value,
EGR amount control value switching means for switching the EGR amount control value to the EGR amount control value corresponding to each fuel injection pattern stored in advance in the EGR amount control value storage means in response to the switching of the fuel injection pattern, Corresponding to the switching of the fuel injection pattern, at least one of the fuel injection timing control value switched by the fuel injection timing switching unit and the ignition timing control value switched by the ignition timing switching unit is set to a value after switching. An in-cylinder injection spark ignition engine is provided which is provided with a correction unit that corrects a value immediately after switching so as to reduce the difference from the value before switching.

According to the third aspect of the present invention, the fuel injection is performed in the engine operating stroke corresponding to the operating condition detecting means for detecting the engine operating condition and the engine operating condition detected by the operating condition detecting means. Which corresponds to each of the fuel injection patterns, a fuel injection timing control value storing means for storing in advance a fuel injection timing control value corresponding to each of the fuel injection patterns, and an injection pattern switching means for corresponding to each of the fuel injection patterns. Ignition timing control value storage means for storing an ignition timing control value in advance, swirl ratio control value storage means for storing a swirl ratio control value corresponding to each of the fuel injection patterns in advance, and switching of the fuel injection pattern At the time of fuel injection corresponding to each fuel injection pattern stored in advance in the fuel injection timing control value storage means corresponding to Fuel injection timing control value switching means for switching to a control value, and ignition corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in correspondence with switching of the fuel injection pattern. Ignition timing control value switching means for switching to the timing control value, and swirl corresponding to each fuel injection pattern previously stored in the swirl ratio control value storage means in correspondence with switching of the fuel injection pattern A swirl ratio control value switching means for switching to a ratio control value, and switching of the fuel injection timing control value by the fuel injection timing control value switching means and ignition timing control value by the ignition timing control value switching means when switching the fuel injection pattern. In-cylinder provided with control value switching delay means for delaying at least one of switching Ishiki spark ignition engine is provided.

According to claim 4 of the present invention, the fuel injection is performed in the engine operation stroke in correspondence with the operating condition detecting means for detecting the engine operating condition and the engine operating condition detected by the operating condition detecting means. Which corresponds to each of the fuel injection patterns, a fuel injection timing control value storing means for storing in advance a fuel injection timing control value corresponding to each of the fuel injection patterns, and an injection pattern switching means for corresponding to each of the fuel injection patterns. Ignition timing control value storage means for storing an ignition timing control value in advance, EGR amount control value storage means for storing an EGR amount control value corresponding to each fuel injection pattern in advance, and switching of the fuel injection pattern The fuel injection timing control value corresponding to each of the fuel injection patterns stored in advance in the fuel injection timing control value storage means. A fuel injection timing control value switching means for switching to a value, and an ignition timing corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in correspondence with the switching of the fuel injection pattern. Ignition timing control value switching means for switching to the control value,
EGR amount control value switching means for switching the EGR amount control value to the EGR amount control value corresponding to each fuel injection pattern stored in advance in the EGR amount control value storage means in response to the switching of the fuel injection pattern, Control value switching delay means for delaying at least one of switching of the fuel injection timing control value by the fuel injection timing control value switching means and switching of the ignition timing control value by the ignition timing control value switching means when switching the fuel injection pattern. An in-cylinder injection spark ignition engine is provided.

[0009]

According to the first aspect of the present invention, at least one of the fuel injection timing and the ignition timing after switching has a predetermined value for a predetermined period before switching in accordance with the delay of the change of the swirl ratio when switching the fuel injection pattern. Is corrected so as to approach the value of, and combustion immediately after switching the fuel injection pattern is optimized.

According to the second aspect of the present invention, the value after switching of at least one of the fuel injection timing and the ignition timing is set for a predetermined period before switching in accordance with the delay of the change in the EGR amount when switching the fuel injection pattern. Is corrected so as to approach the value of, and combustion immediately after switching the fuel injection pattern is optimized.

According to the third aspect of the present invention, the switching of at least one of the fuel injection timing and the ignition timing is delayed according to the delay of the change of the swirl ratio at the time of switching the fuel injection pattern, and the combustion immediately after the switching of the fuel injection pattern is performed. Optimized.

According to the fourth aspect of the present invention, the switching of at least one of the fuel injection timing and the ignition timing is delayed in accordance with the delay of the change in the EGR amount when the fuel injection pattern is switched, and the combustion immediately after the switching of the fuel injection pattern is performed. Optimized.

[0013]

1 is a diagram showing the configuration of a first embodiment of the present invention. In FIG. 1, 1 is an engine body, 2 is a cylinder block, 3 is a piston that reciprocates in the cylinder block, Reference numeral 4 denotes a cylinder head fixed on the cylinder block 2, 5 is a combustion chamber formed between the piston 3 and the cylinder head 4, 6a is a first intake valve, 6b is a second intake valve, and 7a is a first intake valve. Port, 7b is the second intake port, 8
Indicates a pair of exhaust valves, and 9 indicates a pair of exhaust ports. FIG. 2 is a plan sectional view of the cylinder head.
As shown in FIG. 3, the first intake port 7a is a helical intake port, and the second intake port 7b is a straight port that extends substantially straight. Also, the cylinder head 4
An ignition plug 10 is arranged at the center of the inner wall surface of the fuel injection valve 11, and a fuel injection valve 11 is arranged near the inner wall surface of the cylinder head 4 near the first intake valve 6a and the second intake valve 6b.

FIG. 3 is a side sectional view of the combustion chamber portion.
As shown in FIG. 3, on the top surface of the piston 3, a shallow dish portion 12 having a substantially circular contour shape extending from below the fuel injection valve 11 to below the spark plug 10 is formed. A deep bowl portion 13 having a substantially hemispherical shape is formed in the portion, and a concave portion 14 having a substantially spherical shape is formed in a connecting portion between the shallow dish portion 12 and the deep dish portion 13 below the spark plug.

As shown in FIG. 1, the first intake port 7a and the second intake port 7b of each cylinder are provided with a first intake passage 15a and a second intake passage 15b formed in each intake manifold 15, respectively. The SCV1 is connected to the surge tank 16 and is connected to the second intake passage 15b.
7 is placed. These SCVs 17 are connected via a common shaft 18 to an actuator 19 composed of, for example, a step motor. The step motor 19 is controlled based on an output signal of an electronic control unit (hereinafter referred to as ECU) 30.

The surge tank 16 is connected to an air cleaner 21 via an intake duct 20, and a throttle valve 23 driven by an actuator 22 composed of a step motor is arranged in the intake duct 20. The throttle valve 23 is closed to some extent only when the engine load is extremely low, and is kept fully open when the engine load is slightly increased.
On the other hand, each exhaust port 9 is connected to an exhaust manifold 24, and the exhaust manifold 24 is communicated with the surge tank 16 via an EGR pipe 25.
An EGR control valve 26 is arranged midway. This EGR
The control valve 26 is the actuator 2 including a step motor.
7 is connected. This actuator 27 is an ECU 30
It is controlled based on the output signal of.

The ECU 30 is composed of a digital computer and is connected to each other via a bidirectional bus 31.
It comprises an M32, a ROM 33, a CPU 34, an input port 35, an output port 36 and the like. An accelerator pedal position sensor 41 that generates an output voltage proportional to the amount of depression is connected to the accelerator pedal 40, and the output voltage of the accelerator pedal position sensor 41 is input to the input port 35 via the AD converter 37. The top dead center sensor 42 generates an output pulse when, for example, the first cylinder reaches the intake top dead center, and this output pulse is input to the input port 35. The CPU 34 calculates the current crank angle from the output pulse of the top dead center sensor 42 and the output pulse of the crank angle sensor 43, and calculates the engine speed from the output pulse of the crank angle sensor 43. on the other hand,
The output port 36 is connected to the spark plug 10 via an ignition circuit (not shown) and to each fuel injection valve 11 and each actuator 19, 22, 27 via a drive circuit (not shown).

Since the ECU 30 detects the operating state based on the signals from the accelerator opening sensor 41 and the crank angle sensor 43, it serves as an operating state detecting means in the present invention and switches the fuel injection pattern according to the operating state. Therefore, the role of the injection pattern switching means and the fuel injection timing control value, the ignition timing control value, the swirl ratio control value, and the EGR amount control value corresponding to each fuel injection pattern are stored in advance. , Ignition timing control value storage means, swirl ratio control value storage means, EGR amount control value storage means, and fuel injection timing control value, ignition timing control value, swirl ratio control value corresponding to switching of fuel injection pattern,
Since the EGR amount control value is switched, the role of the fuel injection timing control value switching unit, the ignition timing control value switching unit, the swirl ratio control value, the EGR amount control value switching unit, and the fuel injection timing corresponding to the switching of the fuel injection pattern The value after the switching of the control value and the ignition timing control value is corrected in such a direction that the difference between the value before the switching and the value before the switching becomes smaller, and therefore, it serves as a correcting means.

In this embodiment, as shown in FIG. 4, when the amount of fuel injection is small, such as during engine low load operation, compression stroke injection is performed only at the end of the compression stroke,
When the fuel injection amount is medium, such as during medium load operation, the first injection is performed during the intake stroke, and then the second injection is performed at the end of the compression stroke. When the fuel injection amount is large as in the case of time, the intake stroke injection is performed only during the intake stroke. Hereinafter, the injection of fuel for each of the compression stroke injection, the two-time injection, and the intake stroke injection, and how the fuel burns thereafter will be described.

The compression stroke injection is carried out at the timing and amount shown by A in FIG. The fuel injected is the deep dish 1
3, the intake control valve 17 is slightly opened at this time, as shown by 6A in FIG. 6, and a small amount of air flows into the combustion chamber 5 from the second intake port 17b and is weak. Since the swirling flow is generated, it is diffused while being vaporized by this weak swirling flow, and inside the combustion chamber 5,
A ignitable rich air-fuel mixture is formed in the basin 13 and the recess 14. The other areas are air or E
Filled with GR gas. Therefore, there is a ignitable rich air-fuel mixture in the central part, around which a so-called strong stratified state in which there is no combustible air-fuel mixture is formed, and the ignitable rich air-fuel mixture in the central part is ignited by the spark plug 10 Only the mixture burns. In addition, at the time of this compression stroke injection, EG
The R valve is controlled as shown in 7A of FIG. 7 so as to obtain the above combustion while considering the output, the exhaust emission and the like.

The double injection is performed at the timing and quantity as shown by B1 and B2 in FIG. The first injection B1 is performed toward the back surface of the head portion of each intake valve 6a, 6b during the intake stroke, and the injected fuel is reflected by the back surface of the head portion of each intake valve 6a, 6b to be reflected in each intake port 7a, 7b. And then these fuels flow into the combustion chamber 5 with the intake air. The amount of fuel injected at the first time is small, and the air-fuel mixture occupying the entire combustion chamber 5 is considerably lean, but at this time,
The intake control valve 17 is fully closed as shown by 6B in FIG. 6, and the intake air flows into the combustion chamber 5 only from the first intake port 17a having a helical shape to generate a strong swirling flow. The fuel injected the second time is swirled by this strong swirling flow, so that it is a mixture that allows rapid flame propagation.

Next, at the end of the compression stroke, the second injection B2 is performed, but this injection fuel causes the deep plate portion 13 to be injected.
And a rich air-fuel mixture that can be ignited is formed in the recess 14. Therefore, a so-called weakly stratified air-fuel mixture is formed in which there is a rich air-fuel mixture that can be ignited in the central portion and there is a lean air-fuel mixture that is capable of rapid flame propagation around the air-fuel mixture. The rich mixture in the center is ignited by the fire, and the spark produced by the combustion of the rich mixture in the center triggers the surrounding lean mixture to burn. Good combustion is obtained because propagation is possible. It should be noted that, at the time of this two-time injection, EGR
The valve is controlled as shown in 7B of FIG. 7 so as to obtain the above combustion while considering the output, the exhaust emission and the like.

The intake stroke injection is carried out at the timing and amount shown by C in FIG. The fuel is injected toward the rear surface of the umbrella portion of each intake valve 6a, 6b during the intake stroke, and this injected fuel is reflected by the rear surface of the umbrella portion of each intake valve 6a, 6b and flows into each intake port 7a, 7b. Each intake port 7a, 7
In b, it mixes with the intake air, and then these fuels flow into the combustion chamber 5 together with the intake air. At this time, the intake control valve 17 is fully opened as shown by 6C in FIG.
Almost no swirling flow occurs inside. Therefore, since the premixed air-fuel mixture is the same as being supplied into the combustion chamber 5 via the intake valves 6a and 6b, the injected fuel is uniformly dispersed in the combustion chamber 5. Since the amount of injected fuel at this time is large, the uniform air-fuel mixture formed as described above has a concentration capable of being ignited, and therefore is satisfactorily combusted when ignited by the spark plug 10. The EGR valve outputs at the time of this intake stroke injection,
Control is performed as shown in 7C of FIG. 7 in consideration of exhaust emission and the like.

The above is the operation in the steady state of each fuel injection pattern in this embodiment. Then, the opening degrees of the SCV 17 and the EGR control valve 26 in each fuel injection pattern are greatly different as shown in FIGS. Therefore, when changing the fuel injection pattern, SCV17
And the opening degree of the EGR control valve 26 is greatly changed.
However, changes in the swirl ratio and the EGR rate inside the combustion chamber 5 are delayed because the SCV 17 and the EGR control valve 26 are far from the combustion chamber 5.

For example, regarding the swirl ratio, D in FIG.
In the switching from the compression stroke injection to the double injection as in the above, since the increase of the swirl ratio is slow as indicated by D1, the injection timing and the ignition timing are immediately switched as indicated by the broken lines in D2 and D3. If the timing for the latter two injections is adjusted, the first fuel injection is performed before the swirl ratio becomes strong, and the fuel is ignited in a state where the fuel is not swirled sufficiently, flame propagation is delayed, and combustion is deteriorated. On the contrary, when switching from the double injection to the compression stroke injection as shown in E of FIG.
Since the swirl ratio decreases slowly as shown in E1, E
As indicated by the broken line in E2 and E3, if the injection timing and the ignition timing are immediately adjusted to the timing for compression stroke injection after the switching, the fuel is injected before the swirl ratio becomes weak, and the fuel is appropriately concentrated near the spark plug. It is ignited before the air-fuel mixture is formed and the combustion deteriorates.

Regarding the EGR rate, as shown in D of FIG. 9, when the compression stroke injection is switched to the double injection, the increase of the EGR rate is slow as shown in D4.
As indicated by the broken lines in D5 and D6, if the injection timing and the ignition timing are immediately switched to the timing for two-time injection after the switching, the EGR transiently becomes too small, combustion becomes faster, and NOx increases. Or knocking occurs. On the contrary, in the switching from the double injection to the compression stroke injection as shown by E in FIG. 9, the EGR rate decreases slowly as shown by E4, so that the injection timing is shown by E5 and E6 with broken lines. If the ignition timing is immediately adjusted to the timing for compression stroke injection after switching, the EGR transiently increases and combustion slows, resulting in misfire due to poor flame propagation.

Therefore, in this embodiment, when the fuel injection pattern is switched, the fuel injection timing and the ignition timing are controlled in accordance with the delay of the change of the intake air state control value such as the swirl ratio and the EGR rate when the fuel injection pattern is switched. Optimize the combustion of. For example, regarding the swirl ratio, in switching from compression stroke injection to double injection as in D of FIG. 8, the injection timing is transiently advanced as shown by the solid line in D2 and D3 of FIG. By delaying the ignition timing, or by increasing the interval between the injection timing and the ignition timing by both, ignition is performed when an ignitable mixture is formed,
When switching from the double injection to the compression stroke injection as shown by E in FIG. 8, as shown by the solid lines E2 and E3 in FIG.
Ignition is performed when a mixture that can be ignited is formed by transiently delaying the injection timing or advancing the ignition timing, or by shortening the interval between the injection timing and the ignition timing.

Regarding the EGR rate, when the compression stroke injection is switched to the double injection as in D of FIG. 9, only the ignition timing is transiently changed as shown by the solid lines in D5 and D6 of FIG. 9 or by delaying the injection timing and the ignition timing to suppress the increase in combustion pressure due to the excessive combustion speed, and to suppress the increase of NOx and the occurrence of knocking.
In the switching from the double injection to the compression stroke injection such as E, the ignition timing is transiently advanced or the injection timing and the ignition timing are advanced, as indicated by the solid lines in E5 and E6 of FIG. Prevents misfire by compensating for the decrease in burning rate.

10 and 11 are flowcharts of the operation of the ECU in the first embodiment of the present invention for controlling the ignition timing and the injection timing when switching the fuel injection pattern as described above. The value after switching is corrected so that the difference from the value before switching becomes small. FIG. 10 is a calculation of a base loop that is always executed when the ECU is not executing interrupt processing, and steps 1-2 are steps of detecting an operating state and selecting a corresponding fuel injection pattern. step 1
Then, the fuel injection amount is obtained from the map stored in the ROM on the basis of the signal of the accelerator opening sensor and the signal of the engine rotation sensor, and in FIG. 4 stored in the ROM on the basis of the fuel injection amount and the engine speed in step 2. The fuel injection pattern for this time is selected from the map as shown. It is to be noted that hysteresis is shown by a broken line in FIG.

In step 3, it is determined whether or not the fuel injection pattern has changed from the previous time. If it has changed, in step 4, an EGR valve opening change command and an SCV opening change command are issued, and in steps 5 and 6. The initial value X is added to the correction value Xi for the basic injection timing in this fuel injection pattern.
i ₀ is substituted for the initial value Xs ₀ for the correction value Xs for the basic ignition timing in the current fuel injection pattern, and step 7
Then, the basic injection amount and the basic ignition timing are calculated from the map stored in the ROM according to the fuel injection pattern, the injection amount, and the engine speed, and the correction values Xi and Xs in which the initial values are substituted in step 8 to add. If the current fuel injection pattern has not changed from the previous one in step 3, the process jumps to step 7. In this way, in steps 4 to 8, if the current fuel injection pattern has changed from the previous time, the first injection timing and ignition timing corresponding to the switching of the fuel injection pattern are obtained. After that, another process is executed and the process returns to the beginning of the base loop.

FIG. 11 shows that the correction amount of the injection timing and the ignition timing is gradually changed from the initial value to the correction amount 0 (zero).
The 80 ° CA interrupt processing is shown in step 101.
1 to 107 relate to the injection timing, and steps 108 to 114 relate to the injection timing. First, in step 101, the injection timing correction amount Xi ≠
If it is NO, that is, if Xi = 0, then
If it is held as it is, and if YES, the routine proceeds to step 102, where it is judged whether the correction amount is positive or negative.
When it becomes negative by subtracting Δi by 03 (Step 10
4) The process proceeds to step 107. If the result of the determination in step 102 is negative, Δi is added in step 105, and if it becomes positive (step 106), step 107
Then, in step 107, Xi = 0 is set. As described above, the fuel injection timing is gradually changed from the value before the switching of the fuel injection pattern to the value after the switching, and the initial value and the step value Δi are appropriately adjusted according to the change of the swirl ratio and / or the EGR rate. By selecting, optimal combustion can be obtained when switching the fuel injection pattern.

Similarly, in step 108, it is judged whether or not the ignition timing correction amount Xs ≠ 0, and NO, that is, Xs = 0.
If so, it is held as it is, and if YES, the process proceeds to step 109 to determine whether the correction amount is positive or negative, and if it is positive, Δs is subtracted by Δs in step 110, and if negative (step 111), the process proceeds to step 114. Go ahead, step 1
If the determination result of 09 is negative, Δs is added in step 112, and if it is positive (step 113), the process proceeds to step 114, and Xs = 0 is set in step 114. As described above, the ignition timing is gradually changed from the value before the fuel injection pattern is switched to the value after the fuel injection pattern is switched, and the initial value and the step value Δs are appropriately selected according to the change of the swirl ratio and / or the EGR rate. As a result, optimum combustion can be obtained when switching the fuel injection pattern.

As described above, in the first embodiment of the present invention, as described above, after the fuel injection timing and the ignition timing are switched according to the delay in the change of the swirl ratio and the EGR rate when the fuel injection pattern is switched. Since the difference between the value of and the value before change is corrected to be small and optimum combustion is obtained, knocking, misfire, etc. are prevented, and drivability and exhaust emission are improved.

Next, FIG. 12 is a flowchart of the operation of the ECU in the second embodiment of the present invention.
The switching of the ignition timing and the injection timing is corrected so as to be delayed by a predetermined time from the switching of the fuel injection pattern.
Steps 11 to 13 are the same as steps 1 to 3 in FIG. 11, and the fuel injection pattern of this time is selected from the injection amount of this time, and it is determined whether or not it is different from the previous time.
When the current fuel injection pattern has changed from the previous time, the routine proceeds to step 14, and a flag is set to indicate that the processing accompanying the fuel injection pattern switching is being executed, and step 1
5, the EGR valve opening change command is issued in step 15,
An SCV opening change command is issued, the timer is started in step 16, and the process returns.

On the other hand, when the fuel injection pattern does not change from the previous time, the routine proceeds from step 13 to step 17 and whether or not the flag is set in step 17, that is, whether or not the processing associated with the fuel injection pattern switching is being executed. If it is being executed, proceed to step 18,
If it is judged whether the elapsed time T of the timer has reached a predetermined delay time Ta or not, the routine proceeds to step 19, where the injection timing and the ignition timing are switched, the timer is cleared at step 20, and the flag is set at step 21. Clear and return. If the flag is not set in step 17, the routine returns because it is in a steady state, and if it is determined in step 18 that the elapsed time of the timer has not reached the delay time, the routine returns as it is. The ignition timing is not switched.

As described above, in the second embodiment of the present invention, a predetermined delay time elapses after the command for switching the fuel injection pattern is issued and the opening degree change of the EGR valve and the SCV is started. The fuel injection timing and ignition timing are changed.

[0037]

According to the first aspect of the present invention, the fuel injection timing and the ignition timing are corrected according to the delay of the change of the swirl ratio and the EGR rate when the fuel injection pattern is switched,
According to claim 2, the switching of the fuel injection timing and the ignition timing is delayed according to the delay of the change of the swirl ratio and the EGR rate when the fuel injection pattern is switched, and the optimum combustion is obtained. Accordingly, the swirl ratio and the EGR rate can be set for each injection pattern, and the degree of freedom in design increases.

[Brief description of drawings]

FIG. 1 is an overall view of a cylinder injection type spark ignition engine according to the present invention.

FIG. 2 is a plan sectional view of a cylinder head of the engine of FIG.

FIG. 3 is a side sectional view of a combustion chamber portion.

FIG. 4 is a diagram showing a change in a fuel injection pattern with respect to an operating state.

FIG. 5 is a diagram showing a fuel injection amount and a fuel injection timing.

FIG. 6 is a diagram showing an SCV opening for each fuel injection pattern.

FIG. 7 is a diagram showing an opening degree of an EGR valve for each fuel injection pattern.

FIG. 8 is a diagram for explaining the correction of the injection timing and the ignition timing, which is executed in response to the delay of the change of the swirl ratio when the fuel injection pattern is switched.

FIG. 9 is a diagram for explaining the correction of the injection timing and the ignition timing, which is executed in response to the delay in the change of the EGR rate when the fuel injection pattern is switched.

FIG. 10 is a flowchart of a base routine for correcting the injection timing and the ignition timing according to the first embodiment.

11 is a flowchart of an interrupt routine for the base routine of FIG.

FIG. 12 is a flowchart for executing correction of injection timing and ignition timing according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine main body 2 ... Cylinder block 3 ... Piston 4 ... Cylinder head 5 ... Combustion chamber 6a ... 1st intake valve 6b ... 2nd intake valve 7a ... 1st intake port (helical type) 7b ... 2nd intake port (straight type) ) 8 ... Exhaust valve, 9 ... Exhaust port 10 ... Spark plug 11 ... Fuel injection valve 15 ... Intake manifold 15a ... First intake passage 15b ... Second intake passage 16 ... Surge tank 17 ... Swirl control valve (SCV) 19 ... Actuator 20 ... Intake duct 21 ... Air cleaner 22 ... Actuator 23 ... Throttle valve 24 ... Exhaust manifold 25 ... EGR pipe 26 ... EGR control valve 27 ... Actuator 30 ... Electronic control unit (ECU) 40 ... Accelerator pedal 41 ... Accelerator opening sensor 42 ... Top dead center sensor 43 ... Crank angle sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F02D 43/00 JN F02M 25/07 550 R F02P 5/15

Claims (4)

[Claims] 1. An operating state detecting means for detecting an engine operating state, and a fuel injection pattern indicating where in the engine operating stroke fuel injection is to be performed, corresponding to the engine operating state detected by the operating state detecting means. Injection pattern switching means, fuel injection timing control value storage means for storing in advance fuel injection timing control values corresponding to each of the fuel injection patterns, and ignition timing control values corresponding to each of the fuel injection patterns in advance. Ignition timing control value storage means, swirl ratio control value storage means for storing in advance swirl ratio control values corresponding to the respective fuel injection patterns, and fuel injection timing control corresponding to switching of the fuel injection patterns. A fuel whose value is switched to a fuel injection timing control value corresponding to each fuel injection pattern stored in advance in the fuel injection timing control value storage means. Injection timing control value switching means, and switches the ignition timing control value to an ignition timing control value corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in response to the switching of the fuel injection pattern. Ignition timing control value switching means, and switches the swirl ratio control value to a swirl ratio control value corresponding to each fuel injection pattern stored in advance in the swirl ratio control value storage means in response to the switching of the fuel injection pattern. At least a swirl ratio control value switching means, a fuel injection timing control value switched by the fuel injection timing switching means and an ignition timing control value switched by the ignition timing switching means, corresponding to the switching of the fuel injection pattern. On the other hand, the difference between the value after switching and the value before switching immediately after switching is small. Cylinder injection type spark ignition engine comprising a correction means for correcting the that direction. 2. An operating state detecting means for detecting an engine operating state, and a fuel injection pattern indicating where in the engine operation stroke fuel injection should be performed, corresponding to the engine operating state detected by the operating state detecting means. Injection pattern switching means, fuel injection timing control value storage means for storing in advance fuel injection timing control values corresponding to each of the fuel injection patterns, and ignition timing control values corresponding to each of the fuel injection patterns in advance. Ignition timing control value storage means, EGR amount control value storage means for storing in advance EGR amount control values corresponding to the respective fuel injection patterns, and fuel injection timing control corresponding to switching of the fuel injection patterns. Fuel injection for switching the value to the fuel injection timing control value corresponding to each fuel injection pattern stored in advance in the fuel injection timing control value storage means Timing control value switching means, and ignition for switching the ignition timing control value to the ignition timing control value corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in response to the switching of the fuel injection pattern. Timing control value switching means, and EGR for switching the EGR amount control value to the EGR amount control value corresponding to each fuel injection pattern stored in advance in the EGR amount control value storage means corresponding to the switching of the fuel injection pattern. At least one of a fuel injection timing control value switched by the fuel injection timing switching means and an ignition timing control value switched by the ignition timing switching means in response to the switching of the fuel injection pattern. The value after switching is corrected so that the difference from the value before switching becomes smaller immediately after switching. Cylinder injection type spark ignition engine comprising a correction means for. 3. An operating state detecting means for detecting an engine operating state, and a fuel injection pattern indicating where in the engine operation stroke fuel injection should be performed, corresponding to the engine operating state detected by the operating state detecting means. Injection pattern switching means, fuel injection timing control value storage means for storing in advance fuel injection timing control values corresponding to each of the fuel injection patterns, and ignition timing control values corresponding to each of the fuel injection patterns in advance. Ignition timing control value storage means, swirl ratio control value storage means for storing in advance swirl ratio control values corresponding to the respective fuel injection patterns, and fuel injection timing control corresponding to switching of the fuel injection patterns. A fuel whose value is switched to a fuel injection timing control value corresponding to each fuel injection pattern stored in advance in the fuel injection timing control value storage means. Injection timing control value switching means, and switches the ignition timing control value to an ignition timing control value corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in response to the switching of the fuel injection pattern. Ignition timing control value switching means, and switches the swirl ratio control value to a swirl ratio control value corresponding to each fuel injection pattern stored in advance in the swirl ratio control value storage means in response to the switching of the fuel injection pattern. Swirl ratio control value switching means, and at least one of switching of the fuel injection timing control value by the fuel injection timing control value switching means and switching of the ignition timing control value by the ignition timing control value switching means when switching the fuel injection pattern. -Cylinder injection spark ignition engine equipped with control value switching delay means for delaying 4. An operating state detecting means for detecting an engine operating state, and a fuel injection pattern indicating where in the engine operation stroke fuel injection is to be performed, corresponding to the engine operating state detected by the operating state detecting means. Injection pattern switching means, fuel injection timing control value storage means for storing in advance fuel injection timing control values corresponding to each of the fuel injection patterns, and ignition timing control values corresponding to each of the fuel injection patterns in advance. Ignition timing control value storage means, EGR amount control value storage means for storing in advance EGR amount control values corresponding to the respective fuel injection patterns, and fuel injection timing control corresponding to switching of the fuel injection patterns. Fuel injection for switching the value to the fuel injection timing control value corresponding to each fuel injection pattern stored in advance in the fuel injection timing control value storage means Timing control value switching means, and ignition for switching the ignition timing control value to the ignition timing control value corresponding to each fuel injection pattern stored in advance in the ignition timing control value storage means in response to the switching of the fuel injection pattern. Timing control value switching means, and EGR for switching the EGR amount control value to the EGR amount control value corresponding to each fuel injection pattern stored in advance in the EGR amount control value storage means corresponding to the switching of the fuel injection pattern. Quantity control value switching means, and at least one of switching of the fuel injection timing control value by the fuel injection timing control value switching means and switching of the ignition timing control value by the ignition timing control value switching means when switching the fuel injection pattern. An in-cylinder injection spark ignition engine comprising a control value switching delay means for delaying.