JP2001182592A - Exhaust emission control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively raise the temperature of a catalyst converter without damaging operability in a direct-injection-type spark ignition engine for supplying additional fuel after an expansion process for promoting the start of the catalyst converter. SOLUTION: Before the catalyst converter reaches an active state, the additional fuel injection is performed after the expansion process and time of opening an exhaust valve is proceeded. When the exhaust valve opening time is proceeded, the exhaust valve opens while pressure in a combustion chamber is high, gas flow from the combustion chamber to an exhaust gas passage and gas turbulence at the back of the exhaust valve strengthens. Thus, the additional fuel and the gas are mixed suitably, combustion of the additional fuel is kept and continued well in the exhaust gas passage. While, delay of the ignition time is not necessarily required, so that main combustion is not degraded and the operability can be also kept well.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an exhaust gas purification device for an internal combustion engine, and more particularly to an exhaust gas purification device for improving the exhaust emission performance of a direct fuel injection type engine under low-temperature operation conditions.

[0001]

2. Description of the Related Art In a cylinder fuel injection type internal combustion engine, main combustion (combustion for generating engine output) is performed at a lean air-fuel ratio in order to activate a catalytic converter immediately after starting. In some cases, additional fuel is injected into the combustion chamber after the expansion stroke, and this additional fuel is burned with oxygen remaining in the combustion chamber, thereby supplying high-temperature exhaust gas to the catalytic converter. In this case, in the main combustion, the fuel supplied into the combustion chamber is appropriately mixed with the air, and the mixture is ignited with the spark plug after being ignited and the flame is propagated, but when the additional fuel is burned, the main combustion is performed. Since it is not possible to form an air-fuel mixture as in the case of (1), it is necessary to devise a means of satisfactorily burning the additional fuel.

For example, in the technique disclosed in Japanese Patent Application Laid-Open No. H10-153138, the ignition timing of main combustion is made slower than usual to slow down the combustion speed of main combustion, and additional fuel is exposed to the flame of main combustion. To secure a period of time. However, if the ignition timing is delayed, the combustion state of the main combustion deteriorates. Therefore, the ignition timing can be retarded only within a range where the operability of the engine can be ensured.
That is, there is a limit in retarding the ignition timing from the viewpoint of drivability, and this is an obstacle in promoting the activation of the catalytic converter.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is intended to increase the flow or turbulence of the exhaust gas flowing into the catalytic converter by advancing the opening timing of the exhaust valve to increase the additional fuel. It is an object of the present invention to provide an exhaust gas purifying apparatus which promotes combustion of the exhaust gas.

[0004]

According to a first aspect of the present invention, there is provided an in-cylinder fuel injection type internal combustion engine which has a catalytic converter in an exhaust passage and sparks fuel injected before a compression top dead center to start combustion. On the other hand, when the condition before the catalytic converter reaches the active state is established, additional fuel injection is performed after the expansion stroke, and the exhaust valve opening timing is advanced.

According to a second aspect of the present invention, in a cylinder fuel injection type internal combustion engine having a catalytic converter in an exhaust passage, a catalytic converter active state determining device for detecting a catalytic converter active state and variably controlling an exhaust valve opening timing. A variable valve operating device, and a controller that controls exhaust valve opening timing and fuel injection by the variable valve operating device based on the catalytic converter active state, wherein the controller expands the main combustion when the catalytic converter is not in an active state. After the stroke, additional fuel injection is performed and the exhaust valve opening timing is advanced.

According to a third aspect of the present invention, in the first or second aspect, the main combustion is performed at a lean air-fuel ratio.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, the main combustion is performed by stratified combustion by compression stroke injection.

According to a fifth aspect of the present invention, in the first or second aspect of the invention, the advance amount of the exhaust valve opening timing is reduced as the exhaust passage temperature increases.

According to a sixth aspect of the present invention, the controller according to the second aspect of the present invention includes an ignition timing correction device for correcting the ignition timing to a retard side when the exhaust valve opening timing is advanced.

According to a seventh aspect of the present invention, the catalytic converter active state judging device according to the second aspect of the present invention is constituted by a temperature sensor for detecting a temperature of an engine portion representing the catalytic converter temperature.

[0011]

[Function / Effect] When the opening timing of the exhaust valve is advanced, the exhaust valve opens while the pressure in the combustion chamber is high, and the flow of gas flowing from the combustion chamber to the exhaust passage and the turbulence of the gas behind the exhaust valve increase. . As a result, the additional fuel and the gas are mixed well, and the combustion of the additional fuel is favorably maintained in the exhaust passage. On the other hand, it is not necessary to delay the ignition timing, so that the main combustion is not deteriorated, and the operability can be maintained satisfactorily.

When the air-fuel mixture in the cylinder is stratified by the compression stroke injection of the fuel to perform the lean air-fuel ratio operation,
Since the degree of leanness can be increased as compared with the case without stratification, a larger amount of oxygen can be left in the combustion chamber, and the amount of additional fuel can be increased accordingly. However, in the combustion chamber after stratified combustion, there is a tendency that the region where oxygen remains and the region where there is almost no oxygen tend to be separated. Not surviving,
In a region not involved in the combustion, a large amount of oxygen remains but the gas temperature is low. Even if the additional fuel is supplied into the combustion chamber in which the influence of the stratified combustion remains, it is difficult to obtain stable combustion of the additional fuel. On the other hand, by advancing the opening timing of the exhaust valve, even if the combustion of the additional fuel in the combustion chamber is unstable as described above, it is possible to reliably burn the additional fuel in the exhaust passage. It becomes possible.

On the other hand, since the advance angle of the exhaust valve opening timing can be a factor of deteriorating the fuel consumption of the engine, the advance amount should be reduced as the combustion in the exhaust passage becomes more likely to occur, such as when the exhaust passage temperature rises. However, this is preferable from the viewpoint of minimizing deterioration of fuel efficiency.

Further, since the retarding of the ignition timing has the effect of slowing down the combustion and promoting the combustion of additional fuel, it is used together with the retarding of the exhaust valve opening timing as long as the main combustion and operability are not deteriorated. It is desirable to promote the activation of the catalytic converter.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of an internal combustion engine to which the present invention is applied. In the drawing, reference numeral 1 denotes a main body of a direct injection spark ignition engine (hereinafter referred to as "engine"), and reference numerals 2 and 3 denote an intake passage and an exhaust passage, respectively. 4 is a catalytic converter provided in the middle of the exhaust passage 3, 8 is an engine crankshaft,
Reference numeral 9 denotes an ignition plug, and reference numeral 10 denotes a fuel injection nozzle provided to inject and supply fuel directly into the combustion chamber of the engine 1.
Reference numeral 12 denotes an air flow meter for detecting an engine intake air amount, 13 denotes a throttle chamber, 14 denotes a throttle valve, and 15 denotes a throttle actuator for driving the throttle valve. 16 is a throttle opening sensor for detecting the opening of the throttle valve 14, 18 is a temperature sensor for detecting the temperature of the catalytic converter 4, 19 is an air-fuel ratio sensor for detecting the oxygen concentration in the exhaust gas, and 20 is the temperature of the engine coolant. A water temperature sensor 21 for detecting the engine crankshaft 8
Crank angle sensor for detecting the position and rotational speed of the
Reference numeral 2 denotes an accelerator opening sensor that detects the amount of depression of an accelerator pedal.

The controller 23 comprehensively controls a fuel injection amount, a fuel injection timing, an ignition timing, a throttle opening, and the like based on various operation state signals. For example, although the details will be described later, taking the fuel injection amount control as an example, the controller 2
Reference numeral 3 denotes an injection amount obtained by calculating a basic fuel injection amount from an intake air amount signal from the air flow meter 12 and an engine rotation speed signal from the crank angle sensor 21 and correcting the basic fuel injection amount based on a coolant temperature, a throttle opening, and the like. The signal is output to the fuel injection nozzle 10 as an injection pulse. Since the fuel injection amount is basically determined as a function of the valve opening time (injection pulse width) of the fuel injection nozzle 10 and the fuel pressure, calculation or table search is performed based on these parameters so that the target fuel amount is obtained. To set and correct the fuel injection pulse width.

On the other hand, the controller 23 controls a plurality of operation modes or combustion states by changing the fuel injection timing according to the engine operation state. The first is a homogeneous combustion mode, in which fuel is injected and supplied in the intake stroke to sufficiently diffuse the fuel into the combustion chamber and the cylinder until ignition to form a homogeneous mixture. To burn. The second is a stratified combustion mode, in which fuel is injected and supplied after entering the compression stroke, and stratified combustion is performed by concentrating a rich mixture near the spark plug. The suction stroke injection is performed mainly when a large output is required, and the compression stroke injection is mainly performed when improving the fuel consumption and the exhaust emission at a partial load. The third is a mode in which additional fuel is supplied by sub-injection during the expansion stroke, mainly for the purpose of increasing the exhaust gas temperature and promoting the activation of the catalytic converter during stratified combustion operation under low-temperature operation conditions.

Further, the controller 23 variably controls the opening timing of the exhaust valve of the engine 1 by the variable valve operating device 24.
In the figure, 25 and 26 are an intake valve, an exhaust valve, and 27, respectively.
And 28 are an intake cam shaft and an exhaust cam shaft for driving these. In this example, the variable valve train 24 includes an exhaust camshaft 28
The phase of the exhaust camshaft 28 with respect to the crankshaft 8 is changed by changing the relative position between the crankshaft 8 and the sprocket 28a attached to the shaft end by hydraulic pressure, electromagnetic force, or the like, thereby changing the valve opening timing of the exhaust valve 26. The variable valve operating device is not limited to the device that changes the camshaft phase, and various devices such as a device that selectively uses a plurality of cams having different profiles or phases are applicable. is there.

The present invention promotes the activation of such a direct-injection engine by effectively heating the catalytic converter without impairing the operability under low-temperature operating conditions such as at the time of a cold start. The purpose is to improve exhaust purification performance. Hereinafter, an example of the control operation in the controller 23 for that purpose will be described with reference to FIGS. 2 is a control routine that is periodically executed by the controller 23 while the ignition switch is ON, for example, about every 10 ms. FIG. 3 is a time-series diagram showing the relationship between various controls by the control routine and the control values. FIG. 4 shows a timing chart of a control operation when the engine is idling from the start to the completion of warm-up of the engine, and FIG. 4 shows a timing chart according to the present embodiment with reference to these drawings. A control operation example will be described.

In the process shown in FIG. 2, the fuel injection amount Tpm of the main injection, the injection timing ITm, the ignition timing ADV are calculated, and the execution / non-execution of the sub-injection for supplying the additional fuel in the expansion stroke is determined. When performing the sub-injection, the injection amount Tps and the injection timing ITs are calculated, and further, the exhaust valve opening timing EVO for performing the advance correction with the sub-injection is calculated.

First, in S101, the crank angle sensor 21
The engine rotation speed Ne is calculated based on the crank angle signal sent from the engine, the air flow meter 12, the accelerator opening sensor 22, the water temperature sensor 20, the temperature sensor 1
8, the intake air amount Qa, the accelerator opening APS, the water temperature Tw, and the catalytic converter temperature Te are read.

Next, in S102, it is determined from the position of the starter switch whether or not the engine has been started. If the starter switch is ON, since the cranking is currently being performed by the starter motor, the process proceeds to S108 to calculate the fuel injection amount for starting. If the starter switch is OFF, it is determined that the start operation has been completed, and control during engine operation is performed by the processing of S103 to S107 described below.

In step S103, a control map of the target equivalent ratio (FIG. 5) is obtained from the engine speed Ne and the accelerator pedal opening AP.
Search), and set the target equivalent ratio map set value TFBYA
Search for mp. This map shows that the air-fuel ratio is lean in the operating region where TFBYAmp is set to a value smaller than 1, the stoichiometric air-fuel ratio in the region where TFBYAmp is set to 1, and the air-fuel ratio in the region where TFBYAmp is set to a value larger than 1. Are set to be controlled in a rich manner.

Next, at S104, a water temperature correction coefficient TWK of the fuel injection amount is calculated based on the water temperature Tw. TW
K is a value corresponding to the water temperature after the warm-up is completed, and the water temperature Tw is 1.
Has the characteristic that the value increases as the value becomes lower (see FIG. 6). Next, in S105, the map setting value TFBYAmp of the target equivalent ratio is corrected by the water temperature correction coefficient TWK, and the final target equivalent ratio TFBYA is calculated. That is, even when the vehicle is operated under the same operation conditions (Ne, AP), when the water temperature Tw is low, the air-fuel ratio is corrected to the rich side in order to oppose friction. When the warm-up of the engine is completed, TWK becomes 1, so that the final target equivalence ratio TFBYA and TFBYAmp match.

Next, at S106, the engine speed N
e, The basic fuel injection amount Tp is calculated from the intake air amount Qa. The basic fuel injection amount Tp is a fuel injection amount when the air-fuel ratio is set to the stoichiometric air-fuel ratio. Note that K in the equation of S106 is a proportional constant. In the next S107, the fuel injection amount Tpm of the main injection is calculated from the basic fuel injection amount Tp and the target equivalent ratio TFBYA.

Next, in step S109, the target equivalent ratio TFBY
It is determined whether or not A is smaller than 1, that is, whether or not to control the air-fuel ratio lean. If this determination is YES, S
At 110, the fuel injection timing ITm for stratified charge combustion and the ignition timing ADV are calculated. Specifically, the engine speed N
e, ITm and ADV are searched from the stratified combustion control map in which control values are stored in correspondence with the fuel injection amount Tpm. The stratified combustion fuel injection timing control map stores a crank angle position at which fuel injection ends.

On the other hand, if the determination in S109 is NO, the fuel injection timing ITm for homogeneous combustion and the ignition timing AD
V is calculated. Specifically, ITm and ADV are searched from a homogeneous combustion control map in which control values are stored in correspondence with the engine speed Ne and the fuel injection amount Tpm. The homogenous combustion fuel injection timing control map stores a crank angle position at which fuel injection is started.

In S112, the control values for main combustion calculated in the steps up to this point are stored in the memory in the controller 23. The stored control value is read out from the memory and used in a fuel injection control routine and an ignition control routine that are executed at a predetermined time or at a predetermined crank angle separately from the present control routine. The fuel injection control routine generates an injection signal based on the read fuel injection amount Tpm and the fuel injection timing ITm, and outputs the injection signal to the fuel injection nozzle 1.
Output to 0. Further, the ignition control routine outputs an ignition signal to the ignition device so that ignition is performed at the read ignition timing ADV.

Steps S113 to S113 are the sub-injection control processing when additional fuel is supplied in the expansion stroke. First, S11
At 3, it is determined from the position of the starter switch whether or not the engine has been started. Tps during start operation
= 0, so that the sub injection is not performed (S122).
Next, in S114, it is determined whether or not the engine rotation speed Ne is greater than a determination value NESP for determining a complete explosion of the engine. Until the engine completely explodes, sub-injection is not performed because combustion is unstable. The elapsed time after the start and the fluctuation rate of the engine rotation speed Ne may be measured, and it may be determined from these measured values whether the engine is in an unstable state immediately after the start.

If Ne> NESP in the determination at S114, it is determined at S115 whether the target equivalent ratio TFBYA is smaller than 1. Here, the target equivalent ratio TFBYA is 1
If it is larger than the above, since surplus oxygen hardly remains in the combustion chamber after the main combustion, even if the sub-injection is performed, the fuel cannot be sufficiently burned. Therefore, when the target equivalent ratio is larger than 1, the sub injection is not performed.

At the determination of S115, the target equivalent ratio TFBYA
When S ≦ 1, in the next S116, the water temperature Tw becomes equal to the determination value TWSP (for example, 8) for determining the complete warm-up of the engine.
(Equivalent to 0 ° C.). Tw ≧ TWS
P indicates that the engine has been warmed up,
In this case, since the activity of the catalytic converter 4 is considered to be almost sufficient, the sub-injection is not performed.

If Tw <TWSP in the judgment of S116, it is the low-temperature operation condition before the completion of warm-up, and in this case, S11
At 7, it is determined whether the catalytic converter temperature Te is within a predetermined temperature range (TESP1 <Te <TESP2). Part of the fuel supplied into the combustion chamber by the sub-injection is burned in the combustion chamber, and the rest is burned after being discharged to the exhaust passage, but if the temperature of the exhaust passage is too low, the fuel in the exhaust passage may be burned. Since good combustion cannot be performed, the sub-injection is not performed when the catalytic converter temperature Te is lower than the lower limit value TESP1. Here, the catalytic converter temperature Te is used as a temperature representing the temperature of the exhaust passage. The temperature of the exhaust passage may be detected or estimated instead of the catalytic converter temperature, and this temperature may be compared with a determination value.

On the other hand, when the catalytic converter temperature Te is
If it is larger than ESP2, there is no need to actively raise the temperature of the catalytic converter 4, so no sub-injection is performed. In addition,
In the case where the second catalytic converter is arranged downstream of the catalytic converter 4, in the case of an engine that also needs to quickly raise the temperature of the second catalytic converter, the downstream catalytic converter is activated even after the upstream catalytic converter reaches the activation temperature. The sub-injection may be continued until the catalytic converter reaches the activation temperature.

In the determination of S117, TESP1 <Te
If <TESP2 is satisfied, then in S118, an amount of fuel that just reacts with the oxygen remaining in the burned gas after the main combustion is determined from the basic fuel injection amount Tp and the target equivalent ratio TFBYA in the sub-injection. It is calculated as the fuel injection amount Tps.

The fuel injection amount Tps of the sub-injection is set so that the air-fuel ratio of the exhaust gas flowing into the catalytic converter 4 becomes substantially the stoichiometric air-fuel ratio based on the detection signal of the air-fuel ratio sensor 19.
May be feedback controlled.

Next, at S119, the fuel injection timing ITs of the sub-injection is calculated based on the catalytic converter temperature Te. ITs is set to have such a characteristic that when Te is low, the expansion stroke is in the middle, and when Te is large, it is retarded (toward the exhaust stroke) (see FIG. 7). This is because when the catalytic converter 4 is not activated at all, the combustion of the sub-injected fuel is completed when the gas discharged from the combustion chamber reaches the catalytic converter 4, and the catalytic converter 4 is activated to some extent. In this case, the gas in a state in which the unburned fuel and oxygen remain is allowed to flow into the catalytic converter 4 and burn in the catalytic converter 4. ITs is set as a crank angle position at which the sub-injection starts.

In the next step S120, the catalytic converter temperature T
Based on e, an advance correction amount ΔEVO of the exhaust valve opening timing is calculated. ΔEVO is set to a characteristic that increases as Te decreases. The reason for setting such characteristics is as follows. That is, as the opening timing of the exhaust valve 5 is advanced, the exhaust valve 5 is opened while the pressure in the combustion chamber is high, the flow of gas flowing out from the combustion chamber to the exhaust passage becomes stronger, and the oxygen remaining in the combustion chamber is increased. And the fuel supplied by the sub-injection is improved. Therefore, as Te is smaller (= the temperature of the exhaust passage is lower), the exhaust valve opening timing is advanced. On the other hand, when Te is large (= the temperature of the exhaust passage is high), good combustion can be obtained without increasing the flow of the gas flowing into the exhaust passage so much. In this case, deterioration of fuel efficiency is minimized. To suppress this, the amount of advance of the exhaust valve opening timing is reduced. The setting range of ΔEVO is, for example, 0 to 30 degrees as a crank angle.

In S121, the reference timing E for the exhaust valve opening timing is set.
VO1 is corrected by the advance correction amount △ EVO, and the final exhaust valve opening timing EVO is calculated. Here, the exhaust valve opening timing is set to B
This is represented by the advance amount from DC, and the exhaust valve opening timing is corrected to the advance side by adding △ EVO to EVO1. In a normal engine, the opening timing of the exhaust valve is set to about 45 degrees before the bottom dead center in terms of the crank angle, so that the reference timing EVO1 may be set to, for example, 45 degrees. In this case, the corrected exhaust valve opening timing EVO is set between 75 and 45 degrees before BDC.

In the processing from S113 to S117,
If it is determined that the sub-injection is not to be performed, the fuel injection amount Tps of the sub-injection is set to 0 in S122, and then the exhaust valve opening timing EVO is set to the reference timing EVO1 in S123.

Finally, in S124, the control value for sub-injection calculated in each step up to this point and the exhaust valve opening timing EVO
Are stored in the memory in the controller 23. The stored fuel injection amount Tps of the sub-injection and the fuel injection timing ITs of the sub-injection are read from the memory and used in the above-described fuel injection control routine. The fuel injection control routine generates an injection signal based on the fuel injection amount Tps and the fuel injection timing ITs only when the read fuel injection amount Tps is not 0, and outputs this injection signal to the fuel injection nozzle 10.

The stored exhaust valve opening timing EVO is
It is read out and used in a variable valve operating device control routine that is executed at a predetermined time or at a predetermined crank angle separately from this routine. The variable valve control routine controls the hydraulic pressure or the electromagnetic force supplied to the variable valve according to the read exhaust valve opening timing EVO to control the opening timing of the exhaust valve.

As described above, the sub-injection is performed while all the determinations from S113 to S117 are YES (t in FIG. 4).
4 to t5). While the sub-injection is taking place,
The advance correction of the exhaust valve opening timing EVO is executed, and this EVO
Is advanced greatly with the start of the sub-injection, and the advance correction amount decreases as the catalytic converter temperature Te increases.

Since the operation after t1 in FIG. 4 is an idling operation condition and is constant, the map setting value TFBYAmp of the target equivalent ratio retrieved from the control map of FIG.
It becomes a smaller constant value (for example, 0.5). However,
Until the water temperature Tw becomes the warm-up completion temperature, the water temperature correction coefficient TWK is set to a value of 1 or more, and the value decreases as the water temperature Tw increases. Therefore, the final target equivalent ratio TFBYA decreases as the water temperature Tw increases, and the air-fuel ratio of main combustion gradually increases in leanness. As the degree of lean increases, the amount of oxygen remaining after main combustion increases, so that the fuel injection amount Tps of sub-injection can be increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an embodiment of an engine to which the present invention can be applied.

FIG. 2 is a flowchart showing the processing content of an embodiment of the exhaust gas purification control according to the present invention.

FIG. 3 is an explanatory diagram chronologically showing a relationship between various controls and control values according to the embodiment.

FIG. 4 is a timing chart according to the control of the embodiment in a case where an idling operation is performed from the start until the warm-up of the engine is completed.

FIG. 5 is an explanatory diagram showing an example of a map for providing a set value of a target equivalent ratio TFBYAmp for main combustion from an engine rotation speed Ne and an accelerator opening APS.

FIG. 6 shows a correction coefficient TWK of a fuel injection amount according to a water temperature Tw.
FIG. 4 is a characteristic diagram showing an example of a map that gives a value.

FIG. 7 shows a correction amount Δ of an exhaust valve opening timing according to a catalyst temperature Te.
FIG. 4 is a characteristic diagram showing an example of a map for giving EVO.

FIG. 8 is a characteristic diagram showing an example of a map for giving an injection timing ITs of additional fuel according to a water temperature Tw.

[Explanation of symbols]

 1 engine ”. Reference Signs List 2 intake passage 3 exhaust passage 4 catalytic converter 8 crankshaft 9 spark plug 10 fuel injection nozzle 12 air flow meter 13 throttle chamber 14 throttle valve 15 throttle actuator 16 throttle opening sensor 18 temperature sensor 19 air-fuel ratio sensor 20 water temperature sensor 21 crank angle sensor 22 Accelerator opening sensor 23 Controller 24 Variable valve gear 25 Intake valve 26 Exhaust valve 27 Intake camshaft 28 Exhaust camshaft 28a Cam sprocket

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Keiji Okada, Inventor, Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Takashi Fukuda 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa, F Nissan Motor Co., Ltd. Terms (reference) 3G091 AA02 AA12 AA17 AA24 AA28 AB01 BA03 BA07 CB02 CB03 CB05 CB07 DA01 DA02 DC03 EA01 EA05 EA07 EA16 FA02 FA04 FB02 FC07 3G301 HA01 HA04 HA16 HA19 JA21 KA02 KA05 LA01 NE01 PA12 NE01 MA02 PD03A PD03Z PD12A PE03Z PE08Z PF03Z PF16Z

Claims (7)

[Claims] 1. An in-cylinder fuel injection type internal combustion engine having a catalytic converter in an exhaust passage and starting combustion by spark ignition of fuel injected before a compression top dead center, conditions before the catalytic converter reaches an active state. In this case, the exhaust gas purification device for the internal combustion engine is configured to perform additional fuel injection after the expansion stroke and to advance the exhaust valve opening timing. 2. An in-cylinder fuel injection type internal combustion engine having a catalytic converter in an exhaust passage, a catalytic converter active state determining device for detecting a catalytic converter active state, and a variable valve device for variably controlling an exhaust valve opening timing. A controller that controls the exhaust valve opening timing and fuel injection by the variable valve operating device based on the catalytic converter activation state, wherein the controller is configured to add additional fuel after the expansion stroke due to main combustion when the catalytic converter is not active. An exhaust purification device for an internal combustion engine that performs injection and advances the exhaust valve opening timing. 3. The exhaust gas purifying apparatus for an internal combustion engine according to claim 1, wherein the main combustion is performed at a lean air-fuel ratio. 4. The exhaust gas purifying apparatus for an internal combustion engine according to claim 1, wherein the main combustion is performed by stratified combustion by compression stroke injection. 5. The exhaust gas purifying apparatus for an internal combustion engine according to claim 1, wherein the advance amount of the exhaust valve opening timing is reduced as the exhaust passage temperature increases. 6. The exhaust gas purifying apparatus for an internal combustion engine according to claim 2, wherein the controller has an ignition timing correcting device for correcting the ignition timing to a retard side when the exhaust valve opening timing is advanced. 7. The exhaust gas purifying apparatus for an internal combustion engine according to claim 2, wherein said catalytic converter active state determining device comprises a temperature sensor for detecting a temperature of an engine portion representing a catalytic converter temperature.