JP4412000B2 - Control device for internal combustion engine and control method for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine control device and an internal combustion engine control method, and more particularly to an internal combustion engine control device and an internal combustion engine control capable of improving exhaust performance and engine startability when the engine is started. Regarding the method.

  In JP-A-8-232745 (Patent Document 1), during a period until a predetermined time elapses from the start, the catalyst activity is achieved by retard control of the ignition timing, while the subsequent cooling water temperature rises to a predetermined temperature. In the period up to this point, a technique for suppressing the amount of HC and CO by making the air-fuel ratio lean is disclosed. In this technology, when the air-fuel ratio leaning control and the ignition timing retard control are performed in parallel during the warm-up operation, the engine is in a condition that the ignition timing can be retarded relatively large. The retard amount is suppressed by the leaning of the fuel ratio, and similarly, the leaning is suppressed by the retard of the ignition timing under the condition that the air-fuel ratio is greatly leaned to suppress the HC and CO amounts. As a result, there is an attempt to solve the problem that the cost for improving the exhaust performance during warm-up is greatly reduced.

  Japanese Patent Laid-Open No. 2001-304084 (Patent Document 2) discloses that, during the warm start of the engine, the ignition timing is set for a predetermined period from the start in order to suppress an excessive increase in the engine speed at the start of the engine. A technique for retarding control and then gradually advancing the ignition timing is disclosed.

  Japanese Patent Laid-Open No. 2002-168168 (Patent Document 3) discloses an internal combustion engine in order to prevent a sudden decrease in the engine speed due to the retard of the ignition timing when the internal combustion engine is cold-started, and to avoid a stall. When the engine is controlled so that the ignition timing becomes the target ignition timing that is retarded from the normal timing during idling after the engine is started, the engine speed detected by the engine speed detecting means is the engine cooling speed of the internal combustion engine. When the engine speed falls from a target engine speed determined by the water temperature to a speed range exceeding a second set speed greater than the first set speed for maintaining the target engine speed, normal target ignition is performed. A technique is disclosed in which control is performed to advance at a first advance angle change rate larger than a normal advance angle change rate toward the time.

JP-A-8-232745 JP 2001-304084 A JP 2002-168168 A

It is desired that both improvement in exhaust performance and suppression of reduction in output torque can be achieved at a high level.
An object of the present invention is to provide an internal combustion engine control apparatus and an internal combustion engine control method capable of improving exhaust performance when starting the engine and improving startability of the engine.

The control apparatus for an internal combustion engine according to the present invention is a control apparatus for an internal combustion engine that controls engine parameters when starting the internal combustion engine, and the integrated value of the in-cylinder intake air amount from the initial explosion of the internal combustion engine is a throttle value. between the first predetermined period is a period until the amount of air present in the space from the valve to the intake valve, with the ignition timing is set to the retard side, the air-fuel ratio in the cylinder is set to a lean, the After the first predetermined period, the operation state is switched to a torque-oriented operation state as compared with the operation state up to the first predetermined period.

  According to the present invention, it is possible to prevent deterioration of startability (including stall) of the internal combustion engine while preventing deterioration of exhaust characteristics between the initial explosion and several cycles.

  In the control apparatus for an internal combustion engine of the present invention, the ignition timing set on the retard side is approximately ATDC 15 °.

  In the control apparatus for an internal combustion engine according to the present invention, the first predetermined period corresponds to a time when the integrated value of the in-cylinder intake air amount from the time of the first explosion becomes a predetermined value.

  In the control device for an internal combustion engine according to the present invention, the predetermined value is a value corresponding to an air amount existing in a space from a throttle valve to an intake valve before the start of the internal combustion engine.

  According to the present invention, the amount of intake air decreases with the consumption of air remaining in the intake system, but deterioration of the startability (including stall) of the internal combustion engine is prevented by switching to a torque-oriented operating state. be able to.

The control device for an internal combustion engine of the present invention, the first predetermined time period is characterized in that before Symbol is a period corresponding to a preset time for each start condition of the internal combustion engine.

The control device for an internal combustion engine of the present invention, the first predetermined time period is characterized in that exhaust gas temperature before SL internal combustion engine corresponds to the amount of time until the preset temperature.

The control device for an internal combustion engine of the present invention, the first predetermined time period is characterized in that the rotational speed of the front Symbol internal combustion engine corresponds to the amount of time until the preset value.

  In the control apparatus for an internal combustion engine of the present invention, the combustion cycle of the internal combustion engine corresponds to approximately 10 cycles during the first predetermined period.

  In the control apparatus for an internal combustion engine according to the present invention, the torque-oriented operating state is that the ignition timing is advanced.

  In the control device for an internal combustion engine according to the present invention, the torque-oriented operating state is to increase the in-cylinder intake air amount.

  In the control apparatus for an internal combustion engine of the present invention, the torque-oriented operating state is that the air-fuel ratio is made rich.

  In the control apparatus for an internal combustion engine according to the present invention, after the second predetermined period longer than the first predetermined period, the HC emission amount is suppressed as compared with the operating state from the first predetermined period to the second predetermined period. It is characterized by being able to switch to an important driving state.

  In the control device for an internal combustion engine according to the present invention, the operating state in which the suppression of the HC emission amount is emphasized is to retard the ignition timing.

  In the control apparatus for an internal combustion engine according to the present invention, the operation state in which the suppression of the HC emission amount is emphasized is to reduce the in-cylinder intake air amount.

  In the control apparatus for an internal combustion engine according to the present invention, the operating state in which importance is placed on the suppression of the HC emission amount is that the air-fuel ratio is on the lean side.

The control method for an internal combustion engine of the present invention is (a) a period until the integrated value of the in-cylinder intake air amount from the first explosion of the internal combustion engine becomes the air amount existing in the space from the throttle valve to the intake valve. between the first predetermined period, wherein as the engine start HC oxidation reaction at the cylinder and the exhaust port immediately after is promoted, and sets retarding the ignition timing, the air-fuel ratio in the cylinder to lean A setting step; and (b) after the first predetermined period, a step in which an operation state emphasizing torque is performed as compared with the operation state up to the first predetermined period.

Conventionally, at the time of cold start, the ignition timing is retarded or the air-fuel ratio is changed to the rich side to promote the temperature rise of the exhaust gas purification catalyst, and the torque fluctuation (roughness) is stabilized by roughness control Is known (for example, JP-A-11-280518).
At the time of cold start, since the catalyst is not warmed, HC and CO are discharged in large quantities as tail pipe emissions. Therefore, the warm-up of the catalyst due to a large retardation of the ignition timing is promoted.
In the present invention, the engine exhaust gas from the second cycle is reduced not only by catalyst warm-up but also by HC / CO afterburning in the cylinder / exhaust pipe by making the A / F lean with a large ignition delay from the initial explosion. It makes it possible to reduce it extremely. As a result, the output torque can be prevented by a simple method against the decrease in the output torque due to the retard of the ignition timing during the cold start.

  According to the control apparatus for an internal combustion engine of the present invention, it is possible to realize improvement in exhaust performance when the engine is started and improvement in startability of the engine.

  Hereinafter, an embodiment of a control device for an internal combustion engine of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a piston 13 is provided in a cylinder block 12 of a gasoline engine (hereinafter referred to as an engine) 11 provided in an automobile so as to be capable of reciprocating. The piston 13 is connected to a crankshaft 15 that is an output shaft of the engine 11 via a connecting rod 14. The reciprocating movement of the piston 13 is converted into rotation of the crankshaft 15 by the connecting rod 14. The cylinder block 12 is provided with a water temperature sensor 16 for detecting the cooling water temperature of the engine 11.

  A cylinder head 17 is provided at the upper end of the cylinder block 12. A combustion chamber 18 is provided between the cylinder head 17 and the piston 13. A spark plug 19 is provided on the cylinder head 17 so as to face the combustion chamber 18. The combustion chamber 18 is connected to the intake passage 21 via the intake port 20 and is connected to the exhaust passage 23 via the exhaust port 22. In the intake passage 21, an air cleaner 24 is provided in the upstream portion thereof, and a throttle valve 25 for adjusting the intake air amount is provided in the downstream portion thereof. A surge tank 26 for suppressing pulsation of the intake air amount is provided downstream of the throttle valve 25 in the intake passage 21, and an intake manifold 27 extending from the surge tank 26 is connected to the intake port 20 of each combustion chamber 18. Has been. A fuel injection valve 37 that injects fuel toward the intake port 20 is provided at the downstream end of the intake manifold 27.

  An intake valve 28 and an exhaust valve 29 are slidably supported through the cylinder head 17. The intake port 20 and the combustion chamber 18 are connected and cut off by an intake valve 28, and the exhaust port 22 and the combustion chamber 18 are connected and cut off by an exhaust valve 29.

  A rotation speed sensor 30 for detecting the rotation speed of the crankshaft 15 is provided below the cylinder block 12.

  Further, a starter motor 34 is provided in the vicinity of the engine 11, and the starter motor 34 rotates based on the ON operation of the start switch 35 based on the operation of the ignition key to perform cranking when the engine 11 is started. ing.

  When the engine 11 configured as described above is operated, when the accelerator pedal provided in the interior of the automobile is depressed, the opening of the throttle valve 25 is adjusted according to the depression amount, and the intake air of the engine 11 is adjusted. The amount will be adjusted. In addition, fuel injection by the fuel injection valve 37 is performed during the intake stroke of the engine 11, and a fuel mixture of fuel and air is introduced into the combustion chamber 18, and ignition is performed on the fuel mixture by the spark plug 19. Done. When the fuel mixture in the combustion chamber 18 is ignited and combusted, the piston 13 is reciprocated by the combustion energy at this time, and the engine 11 is driven. Further, the gas after burning in the combustion chamber 18 is sent out of the engine 11 through the exhaust port 22 and the exhaust passage 23 as exhaust when the exhaust valve 29 is opened in the exhaust stroke.

  Next, the configuration of the control system of the vehicle that controls the engine 11 in such a vehicle will be described with reference to FIG.

  The vehicle according to the present embodiment includes an electronic control unit (ECU) 40 that plays a role as the control system. The ECU 40 is configured as an arithmetic and logic circuit including a CPU, a ROM, a RAM, a backup RAM, a timer, and the like, and executes various control processes based on the ON operation of the ignition switch 36 based on the operation of the ignition key. It has become. Here, the ROM is a memory in which various control programs and maps that are referred to when executing these various control programs are stored, and the CPU performs arithmetic processing based on the various control programs and maps stored in the ROM. Execute. The RAM is a memory for temporarily storing calculation results in the CPU, data input from each sensor, and the backup RAM is a nonvolatile memory for storing the stored data when the engine 11 is stopped. is there.

  The ECU 40 configured as described above receives detection signals from various sensors that detect the operation state of the vehicle and the engine 11 including the water temperature sensor 16 and the rotation speed sensor 30. The ECU 40 performs operation control of the engine 11 such as fuel injection and ignition based on the detection signals of the various sensors.

  The ECU 40 obtains the intake air amount based on a detection signal of an air flow meter (not shown) provided in the intake passage 21, obtains the engine rotation speed based on the detection signal of the rotation speed sensor 30, and further uses the detection signal of the water temperature sensor 16 as a detection signal. Based on this, the cooling water temperature is obtained. The ECU 40 calculates the fuel injection amount based on the intake air amount, the engine rotation speed, and the coolant temperature, and calculates the fuel injection timing. The ECU 40 drives and controls the fuel injection valve 37 based on the fuel injection amount. With this drive control of the fuel injection valve 37, an amount of fuel corresponding to the fuel injection amount is injected from the fuel injection valve 37 into each intake port 20. Further, the ECU 40 calculates the ignition timing based on the intake air amount, the engine rotation speed, and the coolant temperature. Then, the ECU 40 drives and controls each spark plug 19 based on the ignition timing. The fuel mixture is ignited in each cylinder by the drive control of each spark plug 19.

  As a result of this experiment by the present inventor, new knowledge has been obtained that the influence of the combustion state from the first explosion to several cycles is large in improving the exhaust performance. That is, by raising the exhaust gas temperature from the first ignition (1st cycle) immediately after the start by a large delay of the ignition timing, and making the air-fuel ratio (A / F) in the cylinder lean (oxygen-rich atmosphere), The engine exhaust gas HC and CO can be extremely reduced.

  FIG. 3 is a diagram showing a temporal change of HC contained in the engine exhaust gas discharged from the engine. In FIG. 3, the horizontal axis indicates the elapsed time from the first explosion. In FIG. 3, “currently relevant value” indicates an experimental result according to the prior art, and “HC oxidation reaction promoting condition” indicates an experimental result according to the present embodiment. Here, the HC oxidation reaction promoting condition in the present embodiment is that the in-cylinder A / F (A / F related to combustion) is lean, and the ignition timing is as shown in FIG. That is, the ignition timing from 1 to 10 cycles immediately after starting the engine is ATDC 15 °, from 11 to 40 cycles is ATDC 7 °, and after 41 cycles, it is ATDC 15 °. As described above, the current value is an experimental result in a state where the ignition timing is not significantly retarded as in the present embodiment and the A / F in the cylinder is not set to lean.

  As shown in FIG. 3, with the current value, the amount of HC discharged in several cycles immediately after startup (within 1 second after startup) is very large. Therefore, in the present embodiment, in several cycles immediately after the start with a very large amount of HC, the ignition timing is greatly retarded (ATDC 15 ° in the above example) in order to suppress the discharge of HC, and the A / F in the cylinder Is lean. As a result, as shown in FIG. 3, the amount of HC in a few cycles immediately after the start was greatly reduced.

  However, there is a problem that if the ignition timing is greatly retarded from the beginning of the first explosion and the combustion of the in-cylinder A / F is continued in a lean manner, sufficient output torque cannot be obtained. Hereinafter, this problem will be described with reference to FIG.

  FIG. 5 shows the temporal change of the engine speed. In FIG. 3, the horizontal axis indicates the elapsed time from the first explosion. As for the current value, the engine speed increases to about 2500 [rpm] immediately after the engine is started. On the other hand, under the HC oxidation reaction acceleration condition in which the ignition timing is largely retarded, the increase in the engine speed is less than the current value. This is because the retarded angle control is significant, so the energy generated by the combustion in the cylinder is used as heat energy (exhaust temperature rise) at a relatively large rate, and as kinetic energy (torque, power) Is used only in a relatively small proportion.

  In FIG. 5, the broken line indicates the engine rotation as a result of not being able to obtain sufficient output torque if the ignition timing is greatly retarded from the initial explosion and combustion in a lean state is continued. Shows a drop in numbers.

  For this reason, in this embodiment, the ignition timing is significantly retarded and the in-cylinder A / F is made lean in several cycles immediately after the start with a very large amount of HC (refer to the peak of the current value in FIG. 3). Thus, the HC emission is effectively suppressed, and thereafter, the combustion state is switched to the torque main body so as to suppress the decrease in the output torque as shown by the broken line in FIG. In this example, the torque-based combustion state is to advance the ignition timing (ATDC 7 ° in the above example). After a few cycles immediately after the start, the engine ambient temperature rises and the exhaust gas temperature rises, so the unburned HC burns sufficiently. For this reason, after several cycles immediately after the start, the amount of HC emission is small even if the combustion state is switched to the torque main body (even if the ignition timing is advanced).

  Here, the transition from the combustion state for suppressing the exhaust of HC in several cycles immediately after the start to the torque-based combustion needs to be performed at an optimal timing. In the above example (FIGS. 4 and 5), the ignition timing is greatly retarded at the 10th cycle, and the ignition timing is advanced from the 11th cycle to the significant retardation. In the present embodiment, detection of the timing (the boundary between the 10th cycle and the 11th cycle) at which this ignition timing is advanced from a large retardation is performed by the following method.

  In FIG. 1, torque-based combustion is shifted to the cycle following the cycle in which the entire air amount from the throttle body (throttle valve 25) to the intake valve 28 is consumed. In a state where the throttle valve 25 is closed before the engine 11 is started, the space (including the surge tank 26) from the throttle valve 25 to the intake valve 28 is filled with air. When the engine 11 is started, the air that has been filled in the space from the throttle valve 25 to the intake valve 28 before the start of the engine 11 first enters the cylinder of the engine 11. Thereafter, when the consumption of the air filled in the space from the throttle valve 25 to the intake valve 28 is completed, the air flows into the cylinder of the engine 11 through the throttle valve 25 having a predetermined opening degree.

  That is, when the air that has been filled in the space from the throttle valve 25 to the intake valve 28 before starting the engine 11 first enters the cylinder of the engine 11, it does not flow through the throttle valve 25. Virtually, the air flows into the cylinder with the throttle valve 25 fully open. At this time, the amount of air flowing into the cylinder is such that the throttle valve 25 having a predetermined opening degree after the consumption of the air filled in the space from the throttle valve 25 to the intake valve 28 is completed before the engine 11 is started. It is larger than the amount of air flowing into the cylinder through the throttle corresponding to. Therefore, in the cycle in which the air filled in the space from the throttle valve 25 to the intake valve 28 is consumed before the engine 11 is started, the air that has flowed in through the throttle valve 25 is subsequently consumed. High output is obtained compared to the cycle.

  From the above, in the present embodiment, in the cycle in which the air that has been filled in the space from the throttle valve 25 to the intake valve 28 from the start of the engine 11 is consumed, in which a relatively high output is obtained. Then, the ignition timing is largely retarded, and then the transition from the cycle in which the air flowing in through the throttle valve 25 is consumed, which has a relatively low output, to the combustion based on the torque, is performed. In the cycle in which the air that has flowed in through the throttle valve 25 is consumed, if the engine is not shifted to torque-based combustion, the engine speed decreases as shown by the broken line in FIG. From this, it is possible to shift to the combustion mainly by torque and to suppress the decrease in the engine speed as shown by the solid line HC oxidation reaction promotion condition.

  In this case, the amount of air that has been filled in the space from the throttle valve 25 to the intake valve 28 before the start of the engine 11 becomes the volume of the space from the closed throttle valve 25 to the intake valve 28 including the surge tank 26. Based on this, it can be obtained in advance. Further, the amount of air consumed in the cylinder can be calculated as the product of the displacement of the engine 11 and the number of cycles. As described above, when the amount of air consumed in the cylinder exceeds the amount of air previously filled in the space from the throttle valve 25 to the intake valve 28 before the engine 11 is started, torque is increased. Transition to the operating state of the subject.

  In the above, as one of means for realizing torque-based combustion, as shown in FIG. 4 and FIG. In the present embodiment, the means for realizing the torque-based combustion is not limited to the method of advancing the ignition timing, but a method of increasing the throttle opening (increasing the air amount) with a constant A / F, A method of making the A / F rich can be used. In addition, since it is well known to perform intake air amount control, fuel injection amount control, or ignition timing control in order to adjust the output torque, a detailed description of the control content is omitted.

  Next, as described above, after the torque-based operation is performed, the operation is shifted from the torque-based operation to the operation for suppressing the HC emission amount at an optimal timing. In the examples of FIGS. 4 and 5, torque-based operation (advancement of ignition timing as an example) is performed from 11 to 40 cycles, but from the 41st cycle, operation for suppressing HC emissions is performed. (The ignition timing is retarded as an example). The timing of the transition can be obtained by the warm-up determination. That is, when the engine temperature Teng of the engine 11 is equal to or higher than the preset temperature T1, the operation is shifted from the torque-based operation to the operation for suppressing the HC emission amount. As the engine temperature rises and the friction of the engine 11 decreases, torque is easily generated, so that the operation can be switched again from the torque-based operation to the operation for suppressing the HC emission amount.

  In the above, as one of means for realizing the combustion for suppressing the HC emission amount, as shown in FIG. 4 and FIG. 5, the ignition timing is retarded. In the present embodiment, the means for realizing the combustion for suppressing the HC emission amount is not limited to the method of retarding the ignition timing, and the throttle opening is reduced with a constant A / F (the air amount is reduced). ) And a method of setting the A / F to the lean side can be used. In addition, since it is well known to perform intake air amount control, fuel injection amount control, or ignition timing control in order to suppress the HC emission amount, a detailed description of the control content is omitted.

  Next, the operation of this embodiment will be described with reference to FIGS. The operation procedure shown in FIG. 2 is stored in advance in the ROM of the ECU 40.

  In the following description, the ignition timing retardation is used as an example of means for realizing torque-based combustion, and the ignition timing advance is used as an example of combustion for suppressing HC emissions. However, the present invention is not limited to this example as described above.

[Step S1]
First, in step S1, the ECU 40 performs a large delay control of the ignition timing from the initial explosion of the engine 11, and sets the in-cylinder A / F to lean. In FIG. 6, the cranking of the engine 11 is performed from the time point T0, and the initial explosion of the engine 11 is performed at the time point T1. In the ECU 40, the ignition timing is set to a significantly retarded angle (ATDC 15 ° in the above example) from the time T0 when cranking is started, and the A / F is set to lean so In addition, the ignition timing is controlled so that the ignition timing is largely retarded and combustion is performed with A / F lean. As the rotational speed of the engine 11 rises from the time T1 of the first explosion, the exhaust temperature rises relatively abruptly. Following step S1, step S2 is performed.

[Step S2]
In step S <b> 2, the air amount Ga <b> 1 existing in the space from the throttle valve 25 to the intake valve 28 before the start of the engine 11 obtained by the ECU 40 and the air amount consumed by combustion in the cylinder of the engine 11 are obtained in advance. Is compared with the integrated value Ga. As a result of the comparison, if Ga is Ga1 or more, the process proceeds to step S3. If Ga is not Ga1 or more, this control flow is returned.

  In FIG. 6, until T2, air existing in the space from the throttle valve 25 to the intake valve 28 before starting the engine 11 flows into the cylinder, so that the charging efficiency (ratio of the air amount to the volume in the cylinder) is increased. Although it is high, since the air whose flow rate is throttled by the throttle valve 25 flows into the cylinder from the time point T2, the charging efficiency is drastically decreased. At time T2, step S6 determines that Ga is greater than or equal to Ga1.

[Step S3]
In step S3, the ECU 40 controls the ignition timing to advance. In the above example from the time T2, the ignition timing is set to ATDC 7 °. As a result, the operation is switched to the operation mainly based on the output torque, and the decrease in the engine speed is suppressed even though the intake air amount has decreased (decrease in charging efficiency) (step S2-Y). By switching to the torque-based operation from the time point T2, the exhaust temperature rises more slowly than in the period before T2. After step S3, step S4 is performed.

[Step S4]
In step S4, the ECU 40 performs warm-up determination. That is, it is determined whether or not the engine temperature Teng of the engine 11 is equal to or higher than a preset temperature T1. As a result of the determination, if Teng is equal to or greater than T1, the process proceeds to step S5. Otherwise, the control flow is returned. At time T3, Teng is equal to or greater than T1.

[Step S5]
In step S5, the ECU 40 controls the ignition timing to be retarded. That is, the ignition timing is largely retarded from the time T3 when Teng is equal to or higher than T1 (ATDC 15 ° in the above example). After step S5, this control flow is returned.

  From the above, the ignition timing is greatly retarded and A / F lean combustion is performed in the period (1) in FIG. 6, and the ignition timing is advanced in the period (2). The ignition timing is again largely retarded during the period.

  As described above, the features of the present embodiment are summarized as follows.

(1) Immediately after starting, the ignition timing / A / F is set so that the HC oxidation reaction is promoted (afterburning) at the in-cylinder / exhaust port. For example, the engine exhaust gas HC and CO can be drastically reduced by raising the exhaust gas temperature by the ignition timing greatly retarded from the first ignition at the start and setting the A / F lean (oxygen-rich atmosphere).

(2) The output torque is increased from the time when the output torque starts to decrease, for example, from the cycle following the cycle in which the entire air amount from the throttle body to the intake valve before starting is consumed. For example, any of the following methods i) to iii) for improving the output torque when the accumulated value Ga of consumed air becomes larger than the air amount Ga1 from the throttle body before starting to the intake valve: Is done.
i) Advance the ignition timing.
ii) Increasing the throttle opening (increasing the intake air amount) at a constant A / F.
iii) Set A / F to the rich side.
When all the air amount from the throttle body to the intake valve before the start is consumed, the intake air amount is reduced due to throttle restriction, and the output torque is also reduced. Therefore, the output torque is increased by performing any one of the above methods i) to iii).

(3) When the engine friction becomes small, the output torque is reduced. For example, when the engine temperature Teng (cooling water temperature) is equal to or higher than a predetermined temperature T1, any one of the following methods i) to iii) for suppressing the HC emission amount is performed.
i) Delay the ignition timing.
ii) Decreasing the throttle opening (decreasing the amount of intake air) at a constant A / F.
iii) Set A / F to the lean side.
By retarding the ignition timing, the temperature of the exhaust gas is raised and combustion of unburned HC is promoted. By reducing the amount of intake air, the mass of the exhaust gas itself is reduced. By making A / F lean, more oxygen is supplied and combustion of unburned HC is promoted.

In the above description, the transition timing from the large retardation control (1) to the torque-based operation (2) is described based on the charging efficiency. Without being limited to this example, any one of the following methods i) to iii) is performed for the transition timing from the large retardation control of (1) to the torque-based operation of (2). be able to.
i) A map in which a predetermined time is set for each start condition (engine temperature) of the engine 11, and a point in time when the predetermined time corresponding to the start condition has elapsed after the engine 11 is started is the transition timing. And
ii) The time point at which the exhaust temperature reaches a preset temperature is set as the transition timing.
iii) The time point when the engine speed reaches a preset value is set as the transition timing.

It is a figure which shows schematic structure of one Embodiment of the control apparatus of the internal combustion engine of this invention. It is a flowchart which shows operation | movement of one Embodiment of the control apparatus of the internal combustion engine of this invention. It is a graph for demonstrating the effect of one Embodiment of the control apparatus of the internal combustion engine of this invention. It is a figure which shows the relationship between the ignition timing and cycle number in one Embodiment of the control apparatus of the internal combustion engine of this invention. It is a graph for demonstrating the other effect of one Embodiment of the control apparatus of the internal combustion engine of this invention. It is a time chart which shows operation | movement of one Embodiment of the control apparatus of the internal combustion engine of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Engine 12 Cylinder block 13 Piston 14 Connecting rod 15 Crankshaft 16 Water temperature sensor 17 Cylinder head 18 Combustion chamber 19 Spark plug 20 Intake port 21 Intake passage 22 Exhaust port 23 Exhaust passage 24 Air cleaner 25 Throttle valve 26 Surge tank 27 Intake manifold 28 Intake valve 29 Exhaust valve 30 Rotational speed sensor 34 Starter motor 35 Start switch 36 Ignition switch 37 Fuel injection valve 40 ECU

Claims (11)

A control device for an internal combustion engine that controls engine parameters when starting the internal combustion engine,
The first predetermined period, which is a period until the integrated value of the in-cylinder intake air amount from the first explosion of the internal combustion engine reaches the air amount existing in the space from the throttle valve to the intake valve, is the ignition timing retarded side And the air-fuel ratio in the cylinder is set to be lean, and after the first predetermined period, the operation state is emphasized in comparison with the operation state up to the first predetermined period. A control device for an internal combustion engine. The control apparatus for an internal combustion engine according to claim 1,
The ignition timing set on the retard side is approximately ATDC 15 °. The control apparatus for an internal combustion engine according to claim 1 or 2 ,
The control apparatus for an internal combustion engine, wherein the combustion cycle of the internal combustion engine corresponds to approximately 10 cycles during the first predetermined period. The control device for an internal combustion engine according to any one of claims 1 to 3 ,
The control state of the internal combustion engine, wherein the torque-oriented operating state is to advance the ignition timing. The control device for an internal combustion engine according to any one of claims 1 to 3 ,
The internal combustion engine control apparatus according to claim 1, wherein the torque-oriented operating state is an increase in a cylinder intake air amount. The control device for an internal combustion engine according to any one of claims 1 to 3 ,
The control state of the internal combustion engine, characterized in that the torque-oriented operating state is that the air-fuel ratio is made rich. The control device for an internal combustion engine according to any one of claims 1 to 6 ,
After the second predetermined period that is longer than the first predetermined period, the operation state is switched to an operation state that emphasizes the suppression of the HC emission amount compared to the operation state from the first predetermined period to the second predetermined period. A control device for an internal combustion engine. The control apparatus for an internal combustion engine according to claim 7 ,
The control state of the internal combustion engine, wherein the operation state in which the suppression of the HC emission amount is emphasized is to retard the ignition timing. The control apparatus for an internal combustion engine according to claim 7 ,
The control state of the internal combustion engine, wherein the operation state in which the suppression of the HC emission amount is emphasized is to reduce a cylinder intake air amount. The control apparatus for an internal combustion engine according to claim 7 ,
The control state of the internal combustion engine, wherein the operation state in which the suppression of the HC emission amount is emphasized is that the air-fuel ratio is set to a lean side. (A) The first predetermined period, which is a period until the integrated value of the in-cylinder intake air amount from the first explosion of the internal combustion engine reaches the air amount existing in the space from the throttle valve to the intake valve, Setting the ignition timing to the retard side so that the HC oxidation reaction is promoted in the cylinder and at the exhaust port immediately after starting, and setting the air-fuel ratio in the cylinder to lean;
(B) After the first predetermined period, there is a step of performing an operation state in which torque is emphasized as compared to the operation state up to the first predetermined period.

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