JP2004353485A - Intake air control method for premixed compression ignition combustion internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of setting the ignition timing of a premixed air-fuel mixture in a transient operation to a more suitable timing in a premixed compression ignition combustion internal combustion engine. <P>SOLUTION: In a stationary operation, the EGR rate of intake air in one intake air port (intake air port in which a first intake air valve is installed) is set higher than the EGR rate of intake air in the other intake air port (intake air port in which a second intake air valve is installed). When an operation comes into the transient operation in which an EGR gas amount in a cylinder is increased, the lift amount of the other intake valve (second intake valve) is reduced for a specified time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a premixed compression ignition combustion internal combustion engine in which a premixed gas used for combustion is formed in a cylinder, and more particularly to intake control in a premixed compression ignition combustion engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an internal combustion engine, by injecting fuel into a cylinder during an intake stroke and / or a compression stroke, a premixed air of the fuel and intake air (air) is formed, and the premixed air is used for combustion. Accordingly, the development of a homogeneous charge compression ignition combustion internal combustion engine in which emission of NOx and smoke is suppressed is being promoted.
[0003]
In such a premixed compression ignition combustion internal combustion engine, there is a possibility that a so-called premature ignition may occur, in which the formed premixed gas is ignited and burned before reaching the top dead center of the compression stroke due to a rise in pressure or temperature in the cylinder. There is. Therefore, there is known a technique for preventing the occurrence of premature ignition by adjusting the amount of recirculated exhaust gas (hereinafter, referred to as EGR gas) introduced into a cylinder based on the NOx concentration in the exhaust gas (for example, see, for example, Japanese Patent Application Laid-Open No. H11-157556). And Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-152853 A
[Patent Document 2]
JP-A-2000-120457
[Patent Document 3]
JP-A-10-274104
[0005]
[Problems to be solved by the invention]
In the premixed compression ignition combustion internal combustion engine, the ignition timing is controlled by controlling the recirculation exhaust rate of the premixed gas in the cylinder (the ratio of the amount of EGR gas in the gas, hereinafter referred to as the EGR rate). I have. When the EGR rate increases, the oxygen concentration decreases, so that the ignitability of the premixed gas decreases and the ignition timing is delayed. On the other hand, when the EGR rate decreases, the oxygen concentration of the premixed gas increases, so that the ignitability increases and the ignition timing is advanced.
[0006]
Conventionally, the amount of fresh air (air) flowing into a cylinder is controlled by changing the opening degree of a throttle valve provided in an intake passage, or the EGR valve provided in an EGR passage provided in an EGR passage for guiding EGR gas to an intake system. The EGR rate of the premixed air is controlled by controlling the amount of EGR gas flowing into the cylinder by changing the opening. In the transient operation in which the change in the engine load is large, such as during acceleration or deceleration, in order to set the ignition timing of the premixed gas to an appropriate time, the change in the EGR gas amount in the cylinder is also larger than that in the steady operation. There is a need to. However, since the response of the new air amount control by changing the opening of the throttle valve and the control of the EGR amount by changing the opening of the EGR valve have a large response delay, the response of the control of the EGR rate of the premixed gas also occurs, and the ignition timing is reduced. There is a possibility that premature ignition, ignition delay, or misfire may occur at an inappropriate time.
[0007]
Accordingly, an object of the present invention is to provide a technique capable of setting the ignition timing of the premixed gas during transient operation to a more suitable timing in a premixed compression ignition combustion internal combustion engine.
[0008]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
That is, in a premixed compression ignition combustion internal combustion engine having a plurality of intake ports, during normal operation, the EGR rate of intake air at one intake port is set higher than the EGR rate of intake air at the other intake port in advance. When the operation state of the engine becomes a transient operation, the amount of EGR gas in the cylinder is changed by temporarily changing the lift amount and / or closing timing of the intake valve of each intake port.
[0009]
More specifically, the intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to the present invention has a plurality of intake ports per cylinder,
An exhaust gas recirculation device that introduces EGR gas into each of the one intake port and the other intake port;
An exhaust gas recirculation exhaust rate control device that controls the EGR rate of intake air at each intake port by changing the amount of EGR gas introduced into one intake port and the other intake port by the exhaust gas recirculation device; ,
A variable valve that changes a lift amount and a valve closing timing of an intake valve of one intake port (hereinafter, referred to as one intake valve) and an intake valve of the other intake port (hereinafter, referred to as another intake valve). And a mechanism,
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. At
When the operating state of the internal combustion engine is a steady operation, the EGR rate of the intake air at one intake port is set to be higher than the EGR rate of the intake air at the other intake port in advance by the intake recirculation exhaust rate control device. When the operating state of the internal combustion engine is changed to a transient operation in which the change in the amount of EGR gas in the cylinder is larger than that in the steady operation, the variable valve mechanism is used to set one of the intake valves and / or the other of the intake valves for a predetermined period. The EGR gas amount in the cylinder is changed by changing the lift amount and / or the valve closing timing of the cylinder.
[0010]
Control of the amount of intake air introduced into the cylinder by changing the lift amount of the intake valve or closing timing is more responsive than control of the new air amount by changing the opening of the throttle valve or EGR gas amount by changing the opening of the EGR valve. The delay is small. Therefore, according to the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, when the operation state of the internal combustion engine is in the transient operation, the EGR gas amount in the cylinder changes more quickly. Therefore, the response delay of the EGR rate of the premixed gas in the cylinder is suppressed, and the EGR rate of the premixed gas is more quickly changed to an EGR rate (hereinafter, required EGR) at which the ignition timing of the premixed gas becomes a desired timing. Rate). That is, even during the transient operation, the ignition timing of the premixture can be set to a more suitable timing.
[0011]
Here, the predetermined period is defined as a period of time when the operation state of the internal combustion engine is changed to a transient operation, and then changing the lift amount and / or closing timing of one intake valve and / or the other intake valve to change the premixed air-fuel mixture. This is a period until the actual EGR rate becomes the required EGR rate. After changing the lift amount and / or closing timing of one of the intake valves and / or the other intake valve, when this predetermined period has elapsed, the control of these intake valves is returned to the same control as in the normal operation. .
[0012]
Further, in the intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to the present invention, the homogeneous charge compression ignition combustion internal combustion engine has a plurality of intake ports per cylinder, and supplies EGR gas only to one intake port. If the engine includes an exhaust recirculation device to be introduced, and a variable valve mechanism that changes a lift amount and a valve closing timing of one intake valve and the other intake valve, respectively, the operation state of the internal combustion engine However, when the operation becomes a transient operation in which the change in the amount of EGR gas in the cylinder becomes larger than that during the steady operation, the lift amount and / or the lift amount of one intake valve and / or the other intake valve are controlled by the variable valve mechanism for a predetermined period. Alternatively, the EGR gas amount in the cylinder may be changed by changing the valve closing timing.
[0013]
According to such an intake control method of the homogeneous charge compression ignition combustion internal combustion engine, similarly to the above, when the operation state of the internal combustion engine becomes a transient operation, the EGR gas amount in the cylinder changes more quickly. Therefore, the response delay of the EGR rate of the premixed gas in the cylinder is suppressed, and the actual EGR rate of the premixed gas can be more quickly set to the required EGR rate. That is, even during the transient operation, the ignition timing of the premixture can be set to a more suitable timing.
[0014]
In the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, when the operation state of the internal combustion engine is a transient operation in which the amount of EGR gas in the cylinder is increased, the lift amount of the other intake valve is maintained for a predetermined period. May be reduced.
[0015]
By reducing the lift amount of the other intake valve, the introduction amount of intake air having a low EGR rate into the cylinder decreases, and the introduction amount of intake air having a high EGR rate into the cylinder increases. Therefore, the amount of EGR gas in the cylinder increases more quickly. Therefore, even when the operation state of the internal combustion engine is a transient operation in which the amount of EGR gas in the cylinder is increased, the actual EGR rate of the premixed gas is prevented from being lower than the required EGR rate due to a response delay. As a result, it is possible to suppress the occurrence of premature ignition.
[0016]
Here, when the operation state of the internal combustion engine is the transient operation in which the amount of EGR gas in the cylinder is increased, the time of acceleration of the vehicle at which the engine load becomes higher can be exemplified.
[0017]
On the other hand, in the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, when the operation state of the internal combustion engine is a transient operation in which the amount of EGR gas in the cylinder is reduced, the operation of one of the intake valves is performed for a predetermined period. The lift amount may be reduced.
[0018]
By reducing the lift amount of one intake valve, the amount of intake of intake air with a high EGR rate into the cylinder decreases, and the amount of intake of intake air with a low EGR rate into the cylinder increases. Therefore, the amount of EGR gas in the cylinder decreases more quickly. Therefore, even when the operation state of the internal combustion engine is a transient operation in which the amount of EGR gas in the cylinder is reduced, the actual EGR rate of the premixed gas is prevented from becoming higher than the required EGR rate due to a response delay. Therefore, it is possible to suppress ignition delay and occurrence of misfire.
[0019]
Here, when the operation state of the internal combustion engine is a transient operation in which the amount of EGR gas in the cylinder is reduced, a time of deceleration of the vehicle at which the engine load becomes lower can be exemplified.
[0020]
In the method of the present invention, when the homogeneous charge compression ignition combustion internal combustion engine is an engine in which the closing timing of the other intake valve is later than the intake stroke bottom dead center during steady operation, the operating state of the internal combustion engine is changed to When the engine is in the low rotation region and the transient operation is performed to increase the amount of EGR gas in the cylinder, the lift amount of the other intake valve is reduced for a predetermined period, and the closing timing of the other intake valve is reduced. May be advanced toward the bottom dead center of the intake stroke.
[0021]
When the operation state of the internal combustion engine is in the low rotation region, the flow rate of the intake air flowing into the cylinder from the intake port is slow, so if the closing timing of the intake valve is later than the bottom dead center of the intake stroke, the intake air in the cylinder will be reduced. Outflow to intake port. Therefore, the intake efficiency of the intake air is deteriorated.
[0022]
According to the control as described above, the occurrence of premature ignition can be suppressed by reducing the lift amount of the other intake valve, and at the same time, the closing timing of the other intake valve is set at the bottom dead center of the intake stroke. By advancing in the direction, the amount of outflow of intake air flowing out of the cylinder to the other intake port is reduced, so that the intake efficiency of intake air can be improved.
[0023]
Further, in the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, when the homogeneous charge compression ignition combustion internal combustion engine is in a steady operation, the closing timing of one intake valve is more than the intake stroke bottom dead center. In the case of a slow engine, when the operation state of the internal combustion engine is in the low rotation region and becomes a transient operation in which the amount of EGR gas in the cylinder is reduced, the lift amount of one intake valve is reduced for a predetermined period. In addition, the closing timing of the one intake valve may be advanced toward the bottom dead center of the intake stroke.
[0024]
According to such control, the occurrence of misfire can be suppressed by reducing the lift amount of one intake valve, and at the same time, the closing timing of one intake valve is advanced toward the bottom dead center of the intake stroke. By squaring, the amount of outflow of intake air flowing out of the cylinder to one intake port is reduced, so that the intake efficiency of intake air can be improved as described above.
[0025]
In the above control, if the intake valve closing timing is earlier than the intake stroke bottom dead center, the amount of intake air in the cylinder decreases. It may be up to the bottom dead center of the travel.
[0026]
In the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, the engine for which the close timing of the other intake valve is at or after the bottom dead center of the intake stroke during steady operation is performed. In this case, when the operating state of the internal combustion engine is in the high rotation region and becomes a transient operation in which the amount of EGR gas in the cylinder is increased, the lift amount of the other intake valve is reduced for a predetermined period. In addition, the closing timing of the other intake valve may be retarded.
[0027]
When the operation state of the internal combustion engine is in the high rotation region, the flow rate of the intake air flowing into the cylinder from the intake port is high, so even if the closing timing of the intake valve is somewhat later than the intake stroke bottom dead center, Even after the dead center, the intake air flows into the cylinder due to the inertial effect. However, even when the operation state of the internal combustion engine is in the high rotation region, if the closing timing of the intake valve becomes too late from the bottom dead center of the intake stroke, the intake air in the cylinder flows out to the intake port. Therefore, when the operating state of the internal combustion engine is in the high rotation region, the amount of intake air in the cylinder changes depending on the timing at which the closing timing of the intake valve is retarded from the bottom dead center of the intake stroke. When the amount of intake air in the cylinder changes, the actual compression ratio, which is the actual compression ratio of the premixed gas in the compression stroke, changes. If the actual compression ratio of the premix changes, the ignition time of the premix also changes.
[0028]
Therefore, according to the above control, the amount of EGR gas in the cylinder is increased more quickly by reducing the lift amount of the other intake valve, and the closing timing of the other intake valve is retarded. By controlling the actual compression ratio of the premixed gas by adjusting the retard angle of the premixed gas, the ignition timing of the premixed gas during the transient operation can be made more suitable.
[0029]
Further, in the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, when the homogeneous charge compression ignition combustion internal combustion engine is in a steady operation, the closing timing of one intake valve is at or after the bottom dead center of the intake stroke. In the case of a certain engine, when the operation state of the internal combustion engine is in the high rotation region and becomes a transient operation in which the amount of EGR gas in the cylinder is reduced, the lift amount of one of the intake valves is reduced for a predetermined period. In addition, the closing timing of the one intake valve may be retarded.
[0030]
According to such control, the amount of EGR gas in the cylinder is reduced more quickly by reducing the lift amount of one intake valve, and the retard angle at the time of retarding the closing timing of one intake valve is reduced. By controlling the actual compression ratio of the premixed gas by adjusting the matching, the ignition timing of the premixed gas during the transient operation can be set to a more suitable timing as described above.
[0031]
It should be noted that in the premixed compression ignition combustion internal combustion engine according to the present invention as described above, at least one intake port and at least one other intake port are required. Further, the number of one intake port and the number of the other intake port may be the same or different. Further, when there is a plurality of one intake port or the other intake port, the above-described control may be applied to all the intake ports, or may be applied to some of the intake ports.
[0032]
Further, the present invention may employ the following means in order to solve the above problems.
That is, in the premixed compression ignition internal combustion engine, when the operating state of the internal combustion engine is in a transient operation, the closing timing of the intake valve is temporarily changed to thereby reduce the EGR rate of the premixed air in the cylinder. The actual compression ratio of the premixed gas is controlled in consideration of the response delay.
[0033]
More specifically, an intake control method for a premixed compression ignition internal combustion engine according to the present invention comprises:
An exhaust gas recirculation device for introducing EGR gas into the intake port;
A variable valve mechanism for changing the closing timing of the intake valve of the intake port,
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. And
During steady-state operation, in a homogeneous charge compression ignition combustion internal combustion engine in which the intake valve closing timing is after the intake stroke bottom dead center,
When the operation state of the internal combustion engine becomes a transient operation in which the amount of EGR gas in the cylinder is increased, the closing timing of the intake valve is retarded by a predetermined angle or more by a variable valve mechanism for a predetermined period. .
[0034]
In the premixed compression ignition combustion internal combustion engine, the number of intake ports may be one or more. When there are a plurality of intake ports, the above control may be applied to all the intake ports or may be applied to some of the intake ports.
[0035]
Here, the predetermined period is defined as a period from when the operation state of the internal combustion engine becomes the transient operation to when the actual EGR rate of the premixed air becomes the required EGR rate by changing the closing timing of the intake valve. Period. When the predetermined period has elapsed since the operation state of the internal combustion engine became the transient operation, the closing timing of the intake valve is returned to the same timing as in the normal operation.
[0036]
Further, the predetermined angle means that even if the closing timing of the intake valve is retarded within a range of the predetermined angle from the bottom dead center of the intake stroke, even after the bottom dead center of the intake stroke, the intake air flows from the intake port into the cylinder due to the inertia effect. Is the angle that flows into That is, when the closing timing of the intake valve is retarded by more than the predetermined angle from the bottom dead center of the intake stroke, the intake air in the cylinder flows out to the intake port.
[0037]
According to the above-described control, the closing timing of the intake valve is retarded by a predetermined angle or more from the bottom dead center of the intake stroke, so that the intake air in the cylinder flows out to the intake port. As a result, the ignition timing of the premixed gas is delayed. Therefore, when the operation state of the internal combustion engine becomes a transient operation in which the amount of EGR gas in the cylinder increases, a response delay occurs in the EGR rate in the cylinder, and the actual EGR rate in the cylinder becomes lower than the required EGR rate. Even if there is, the occurrence of premature ignition can be suppressed.
[0038]
Further, in the intake control method for a homogeneous charge compression ignition internal combustion engine according to the present invention,
An exhaust gas recirculation device for introducing EGR gas into the intake port;
A variable valve mechanism for changing the closing timing of the intake valve of the intake port,
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. And
During steady-state operation, in a premixed compression ignition combustion internal combustion engine in which the closing timing of the intake valve is slower than the intake stroke bottom dead center,
When the operation state of the internal combustion engine is in the low rotation region and the operation is a transient operation in which the amount of EGR gas in the cylinder is reduced, the closing timing of the intake valve is reduced by the variable valve operating mechanism during the intake stroke for a predetermined period. You may advance to the dead point.
[0039]
When the operation state of the internal combustion engine is in the low rotation region, if the closing timing of the intake valve is later than the bottom dead center of the intake stroke, the intake air in the cylinder flows out to the intake port. According to the above-described control, the amount of intake air flowing out of the cylinder is reduced by advancing the closing timing of the intake valve toward the bottom dead center of the intake stroke. And the ignition timing of the premixed gas is advanced. Therefore, when the operation state of the internal combustion engine is a transient operation in which the amount of EGR gas in the cylinder is reduced, a response delay occurs in the EGR rate in the cylinder, and the actual EGR rate in the cylinder becomes higher than the required EGR rate. Even if there is, ignition delay and occurrence of misfire can be suppressed.
[0040]
BEST MODE FOR CARRYING OUT THE INVENTION
<First embodiment>
Hereinafter, a specific embodiment of an intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to the present invention will be described with reference to the drawings.
[0041]
1 and 2 are diagrams showing a schematic configuration of an internal combustion engine according to the present embodiment. The internal combustion engine 1 shown in FIG. 1 is a multi-cylinder diesel engine having four cylinders 2 (only one cylinder is shown). A fuel injection valve 10 for directly injecting fuel into the combustion chamber is provided at a substantially central portion of the cylinder 2. The cylinder 2 has a first intake port 3, a second intake port 4, and two exhaust ports 5.
[0042]
The first intake port 3 and the second intake port 4 communicate with an intake manifold 12, and the intake manifold 12 is connected to an intake passage 11. The intake passage 11 is provided with a throttle valve 15 for adjusting a flow rate of fresh air (air) flowing through the intake passage 11. On the other hand, the two exhaust ports 5 are communicated with an exhaust manifold 13, and the exhaust manifold 13 is connected to an exhaust passage 14.
[0043]
As shown in FIG. 2, the first intake port 3 and the second intake port 4 are provided with a first intake valve 6 and a second intake valve 7, respectively. Exhaust valves not shown are provided. The first intake valve 6 and the second intake valve 7 are respectively provided with a first variable valve mechanism 8 and a second variable valve mechanism 9 for controlling the lift amount and opening / closing timing of each intake valve 6, 7. ing. An example of the variable valve mechanism is an electromagnetically driven valve.
[0044]
Further, the internal combustion engine 1 according to the present embodiment is provided with an exhaust gas recirculation device 20 that recirculates part of the exhaust gas discharged from the internal combustion engine 1 to the intake system. The exhaust gas recirculation device 20 includes a main EGR passage 21 that communicates with the exhaust manifold 13, a first EGR passage 22 that communicates the main EGR passage 21 with the first intake port 3, and a main EGR passage 21 that communicates with the second intake air. A second EGR passage 23 communicating with the port 4. The main EGR passage 21, the first EGR passage 22, and the second EGR passage 23 are formed of an electromagnetic valve or the like, and the inside of the main EGR passage 21, the first EGR passage 22, or the second EGR passage 23 depends on the magnitude of the applied voltage. A main EGR valve 26, a first EGR valve 24, and a second EGR valve 25 for adjusting a flow rate of flowing exhaust gas (EGR gas) are provided, respectively.
[0045]
In the exhaust gas recirculation device 20 configured as described above, when the main EGR valve 26, the first EGR valve 24, and the second EGR valve 25 are opened, a part of the exhaust gas (EGR gas) discharged from the internal combustion engine 1 is opened. Flows into the main EGR passage 21 via the exhaust manifold 13, and EGR gas flowing through the main EGR passage 21 passes through the first EGR passage 22 or the second EGR passage 23 and passes through the first intake port 3 or the second intake port. 4 is introduced. The EGR gas introduced into each of the intake ports 3 and 4 mixes with fresh air (air) to form intake air, and the intake air is introduced into the cylinder 2. In addition, the first EGR valve 24 and the second EGR valve 25 change the amount of EGR gas introduced into each of the intake ports 3 and 4, thereby changing the intake at the first intake port 3 (hereinafter, referred to as first intake) and the second intake port. The EGR rate with respect to intake air (hereinafter, referred to as second intake) at intake port 4 is controlled.
[0046]
The internal combustion engine 1 configured as described above is provided with an electronic control unit (ECU: Electronic Control Unit) 30 for controlling the internal combustion engine 1. The ECU 30 is a unit that controls the operating state of the internal combustion engine 1 according to the operating conditions of the internal combustion engine 1 and the driver's requirements.
[0047]
The ECU 30 is electrically connected to various sensors such as a crank position sensor 31 that outputs a signal corresponding to the rotation angle of the output shaft of the internal combustion engine 1 and an accelerator opening sensor 32 that outputs a signal corresponding to the accelerator opening. The output signals of these sensors are input to the ECU 30.
[0048]
On the other hand, the ECU 30 is electrically connected to the fuel injection valve 10, the throttle valve 15, the first variable valve mechanism 8, the second variable valve mechanism 9, the main EGR valve 26, the first EGR valve 24, the second EGR valve 25, and the like. The above components are controlled by the ECU 30.
[0049]
The ECU 30 includes a CPU, a ROM, a RAM, and the like. For example, the ECU 30 calculates an engine speed based on a time interval or the like at which the crank position sensor 31 outputs a pulse signal, and outputs the engine speed to an output signal of the accelerator opening sensor 32 and the like. The engine load is calculated based on the engine load.
[0050]
Further, the internal combustion engine 1 according to the present embodiment injects fuel from the fuel injection valve 10 into the cylinder 2 during an intake stroke or a compression stroke in accordance with a command from the ECU 30, so that fuel and intake air are This is an internal combustion engine that performs so-called premixed compression ignition combustion in which a premixed gas is formed and the premixed gas is used for combustion.
[0051]
In the internal combustion engine 1 according to the present embodiment, the ECU 30 determines the lift amount and the opening / closing valve timing of the first intake valve 6 and the second intake valve 7 and the main EGR valve in accordance with the operating state of the internal combustion engine 1. The amount of intake air introduced into the cylinder 2 and the EGR rate are controlled by adjusting the degrees of opening of the 26, the throttle valve 15, the first EGR valve 24, and the second EGR valve 25. The EGR rate of the premixed gas in the cylinder 2 is controlled by controlling the amount of intake air introduced into the cylinder 2 and the EGR rate.
[0052]
Next, an intake control method for an internal combustion engine according to the present embodiment will be described with reference to the drawings. FIG. 3 shows the relationship between the operating state of the internal combustion engine 1 according to the present embodiment, the control of the first and second intake valves 6 and 7, the amount of EGR gas in the cylinder 2, and the ignition timing of the premixed gas. It is a time chart which shows. FIGS. 4 and 5 are valve profiles showing control of the first and second intake valves 6 and 7 when the operation state of the internal combustion engine 1 according to the present embodiment is a transient operation in which the engine load increases. . 6 to 8 are valve profiles showing control of the first and second intake valves 6, 7 when the operation state of the internal combustion engine 1 according to the present embodiment is in a transient operation in which the engine load is reduced. .
[0053]
In the intake control method for an internal combustion engine according to the present embodiment, the opening of the second EGR valve 25 is adjusted to be larger than the opening of the first EGR valve 24 when the operating state of the internal combustion engine 1 is steady operation. The control is performed such that the amount of EGR gas introduced into the second intake port 4 becomes larger than the amount of EGR gas introduced into the first intake port 3. For this reason, the EGR rate of the second intake becomes higher than the EGR rate of the first intake.
[0054]
Then, when the vehicle provided with the internal combustion engine 1 is accelerated, and the operating state of the internal combustion engine 1 becomes a transient operation in which the engine load increases, that is, a transient operation in which the amount of EGR gas in the cylinder 2 increases. In this case, the opening degree of the main EGR valve 26 is made larger than in the normal operation, and further, as shown in FIG. 3, the lift amount of the first intake valve 6 is controlled to be smaller than that in the normal operation for a predetermined period. You.
[0055]
When a predetermined period has elapsed after the operation state of the internal combustion engine 1 has changed to the transient operation, the lift amount of the first intake valve 6 is returned to the same lift amount as in the normal operation.
[0056]
In FIG. 3, the solid line of the line indicating the EGR amount in the cylinder 2 and the line indicating the ignition timing of the premixed air indicates the case where the lift amount of the first EGR valve 6 is controlled as described above. The dotted line shows a case where the lift amount of the first EGR valve 6 is not controlled as described above, and only the opening degree of the main EGR valve 26 is controlled.
[0057]
According to the intake valve control method for the internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is a transient operation in which the amount of EGR gas in the cylinder 2 is increased, the lift of the first intake valve 6 By temporarily reducing the amount, the amount of first intake air having a low EGR rate introduced into the cylinder 2 decreases, and the amount of second intake air having a high EGR rate introduced into the cylinder 2 increases. Therefore, as shown in FIG. 3, since the EGR amount in the cylinder 2 increases more quickly, it is possible to suppress the actual EGR rate of the premixed air from becoming lower than the required EGR rate due to a response delay. Therefore, as shown in FIG. 3, even when the operating state of the internal combustion engine 1 is in the transient operation as described above, it is possible to suppress the occurrence of premature ignition of the premixture.
[0058]
Here, the predetermined period refers to controlling the main EGR valve 26 and the first intake valve 6 after the operation state of the internal combustion engine 1 becomes the transient operation, so that the actual EGR rate of the premixed gas becomes the required EGR rate. This is the period until the rate is reached.
[0059]
Further, in the intake control method for the internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is a steady operation, the closing timing of the first intake valve 6 is set later than the bottom dead center of the intake stroke. In this case, when the operation state of the internal combustion engine 1 is in the low rotation region and the operation is a transient operation in which the amount of EGR gas in the cylinder 2 is increased, the lift amount of the first intake valve 6 is reduced as shown in FIG. The control may be performed for a predetermined period of time while the valve timing is made smaller and the valve closing timing of the first intake valve 6 is advanced toward the bottom dead center of the intake stroke. The dashed line in FIG. 4 indicates a period corresponding to the bottom dead center of the intake stroke.
[0060]
According to such control, the occurrence of premature ignition can be suppressed by reducing the lift amount of the first intake valve 6, and at the same time, the closing timing of the first intake valve 6 is set at the bottom dead center of the intake stroke. In this case, the amount of intake air flowing out of the cylinder 2 to the first intake port 3 is reduced, so that the efficiency of intake of intake air into the cylinder 2 can be improved.
[0061]
In the intake control method for an internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is a steady operation, the closing timing of the first intake valve 6 is set to be after the bottom dead center of the intake stroke. When the operation state of the internal combustion engine 1 is in the high rotation region and the operation is a transient operation in which the amount of EGR gas in the cylinder 2 is increased, the lift amount of the first intake valve 6 is temporarily reduced as shown in FIG. The control for delaying the valve closing timing of the first intake valve 6 may be performed for a predetermined period of time, in addition to the control for a predetermined period. The dashed line in FIG. 5 indicates a period corresponding to the bottom dead center of the intake stroke.
[0062]
According to such control, the amount of EGR gas in the cylinder 2 is increased more quickly by reducing the lift amount of the first intake valve 6, and the valve closing timing of the first intake valve 6 is retarded. By controlling the actual compression ratio of the premixed gas in the compression stroke by adjusting the retard angle of the premixed gas, the ignition timing of the premixed gas during the transient operation as described above can be made more suitable.
[0063]
In the intake control method for the internal combustion engine according to the present embodiment, as described above, when the operation state of the internal combustion engine 1 is a steady operation, the EGR rate of the second intake is set to be higher than the EGR rate of the first intake. In addition, when the operation state of the internal combustion engine 1 is a transient operation in which the engine load is increased, that is, a transient operation in which the amount of EGR gas in the cylinder 2 is increased, the opening degree of the main EGR valve 26 is changed. Control for increasing the value and decreasing the lift amount of the first intake valve 6 is performed for a predetermined period. On the other hand, when the operating state of the internal combustion engine 1 is a transient operation in which the engine load is reduced, that is, a transient operation in which the amount of EGR gas in the cylinder 2 is reduced, the opening degree of the main EGR valve 26 is reduced. At the same time, as shown in FIG. 6, control for reducing the lift amount of the second intake valve 7 is performed for a predetermined period.
[0064]
According to the intake valve control method for the internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is in a transient operation in which the amount of EGR gas in the cylinder 2 is reduced, the lift of the second intake valve 7 By temporarily reducing the amount, the amount of the second intake having a high EGR rate introduced into the cylinder 2 decreases, and the amount of the first intake having a low EGR rate introduced into the cylinder 2 increases. Therefore, since the EGR amount in the cylinder 2 decreases more quickly, it is possible to suppress the actual EGR rate of the premixed air from becoming higher than the required EGR rate due to a response delay. Therefore, even when the operation state of the internal combustion engine 1 is in the transient operation as described above, it is possible to suppress the ignition delay of the premixed gas and the occurrence of misfire.
[0065]
Here, the predetermined period is a period in which the operation state of the internal combustion engine 1 becomes a transient operation, and then the main EGR valve 26 and the second intake valve 7 are controlled so that the actual EGR rate of the premixed gas becomes the required EGR rate. This is the period until the rate is reached.
[0066]
Further, in the intake control method for the internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is a steady operation, the closing timing of the second intake valve 7 is set later than the bottom dead center of the intake stroke. In this case, when the operation state of the internal combustion engine 1 is in the low rotation region and the operation is a transient operation in which the EGR gas amount in the cylinder 2 is reduced, the lift amount of the second intake valve 7 is reduced as shown in FIG. At the same time, control for advancing the closing timing of the second intake valve 7 toward the bottom dead center of the intake stroke may be performed for a predetermined period. The dashed line in FIG. 7 indicates a time corresponding to the bottom dead center of the intake stroke.
[0067]
According to such control, the ignition delay and the occurrence of misfire can be suppressed by reducing the lift amount of the second intake valve 7, and at the same time, the closing timing of the second intake valve 7 is reduced to the intake stroke bottom dead center. By advancing to the point, the outflow amount of the intake air flowing from the cylinder 2 to the second intake port 4 is reduced, so that the efficiency of intake of the intake air into the cylinder 2 can be improved.
[0068]
In the intake control method for an internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is a steady operation, the closing timing of the second intake valve 7 is set to be after the bottom dead center of the intake stroke. When the operating state of the internal combustion engine 1 is in the high rotation region and is in the transient operation in which the amount of EGR gas in the cylinder 2 is reduced, the lift amount of the second intake valve 7 is reduced as shown in FIG. At the same time, control for delaying the closing timing of the second intake valve 7 may be performed for a predetermined period. The dashed line in FIG. 8 indicates a period corresponding to the bottom dead center of the intake stroke.
[0069]
According to such control, the EGR gas amount in the cylinder 2 is reduced more quickly by reducing the lift amount of the second intake valve 7, and the valve closing timing of the second intake valve 7 is retarded. By controlling the actual compression ratio of the premixed gas in the compression stroke by adjusting the retard angle of the premixed gas, the ignition timing of the premixed gas during the transient operation as described above can be made more suitable.
[0070]
Next, a control routine for the first and second intake valves 6, 7 according to the present embodiment will be described with reference to a flowchart shown in FIG.
[0071]
The flowchart shown in FIG. 9 is a flowchart showing a control routine of the intake valve according to the present embodiment. This intake valve control routine is a routine that is repeatedly executed by the ECU 30 at predetermined time intervals, and is stored in advance in a ROM provided in the ECU 30.
[0072]
In this routine, first, in S101, the ECU 30 determines whether or not the operating state of the internal combustion engine 1 is a transient operation based on the engine speed, the engine load, and the like.
[0073]
In S101, when it is determined that the operation state of the internal combustion engine 1 is not the transient operation, that is, the operation state of the internal combustion engine 1 is the steady operation, the ECU 30 proceeds to S109, and the first and second intake valves 6, 7 Then, the intake valve control at the time of steady operation is executed, and the execution of this routine is temporarily ended.
[0074]
On the other hand, when it is determined in S101 that the operation state of the internal combustion engine 1 is a transient operation, the ECU 30 proceeds to S102, and based on the engine speed, the engine load, and the like, the operation state of the internal combustion engine 1 is in the acceleration state. Or whether the vehicle is in a deceleration state.
[0075]
Next, the ECU 30 proceeds to S103, and based on the engine speed, the engine load, and the like, the operating state of the internal combustion engine 1 is in which operating region (for example, in the high rotation region or in the low rotation region). Is determined.
[0076]
Next, the ECU 30 proceeds to S104, and calculates an excess or deficiency amount of the EGR gas in the cylinder 2 necessary for setting the EGR rate of the premixed gas to the required EGR rate. At this time, the excess or deficiency of the EGR gas in the cylinder is calculated based on the MAP of the engine speed and the engine load. The MAP is predetermined experimentally or empirically, and is stored in the ROM of the ECU 30.
[0077]
Next, the ECU 30 proceeds to S105, where the determination result of the acceleration / deceleration state of the internal combustion engine 1 in S102, the operating region of the internal combustion engine 1 determined in S103, and the excess amount of EGR gas in the cylinder 2 calculated in S104. The amount of change between the lift amount of the first intake valve 6 or the second intake valve 7 and the valve closing timing is calculated based on the shortage amount.
[0078]
Next, the ECU 30 proceeds to S106 and calculates a response delay time of the EGR rate of the premixed gas based on the MAP between the engine speed and the engine load. The response delay time at this time is a response delay time that occurs when the control of the first and second intake valves 6 and 7 is not the intake valve control during the transient operation, and the MAP is experimental or empirical. And is stored in the ROM of the ECU 30.
[0079]
Next, the ECU 30 proceeds to S107, and based on the response delay time of the EGR rate calculated in S106, controls the intake valve (hereinafter, referred to as the first control) reflecting the change amount between the lift amount and the valve closing timing calculated in S105. (Periodical operation intake valve control) is calculated.
[0080]
Next, the ECU 30 proceeds to S108, executes the first transient operation intake valve control on the first and second intake valves 6, 7, and ends the execution of this routine once.
[0081]
According to such an intake valve control routine, even when the operation state of the internal combustion engine 1 is in a transient operation, the lift of the first intake valve 6 or the second intake valve 7 is determined according to the operation state of the internal combustion engine 1. Since the amount and the valve closing timing are adjusted, the amount of EGR gas in the cylinder 2 changes more quickly, and the response delay of the EGR rate of the premixed gas is suppressed. Therefore, the ignition timing of the premixed gas can be made more suitable.
[0082]
Further, in the above-described intake valve control routine, when the operating state of the internal combustion engine 1 is in the transient operation, the first state is determined based on the operating region of the internal combustion engine 1 and the EGR gas excess / deficiency in the cylinder 2. The amount of change between the lift amount and the closing timing of the intake valve 6 or the second intake valve 7 is calculated. In the control of the intake valve according to the present embodiment, the operating state of the internal combustion engine 1 is changed to the transient operation. At this time, the lift amount and the valve closing timing of the first intake valve 6 or the second intake valve 7 may be changed to a predetermined predetermined lift amount and a predetermined valve closing timing.
[0083]
In the internal combustion engine 1 according to the present embodiment, a first EGR passage 22 is communicated with the first intake port 3 and a second EGR passage 23 is communicated with the second intake port 4. When the operation state is steady operation, the control is performed such that the amount of EGR gas introduced into the second intake port 4 becomes larger than the amount of EGR gas introduced into the first intake port 3. Only the EGR passage into which the EGR gas is introduced may be provided, and the EGR gas may not be introduced into the first intake port 3.
[0084]
Even with such a configuration, when the operation state of the internal combustion engine 1 is in a transient operation, the first and second intake valves 6 and 7 are controlled as described above to thereby control the inside of the cylinder 2. The EGR gas amount changes more quickly, and the response delay of the EGR rate of the premixed gas is suppressed. Therefore, the ignition timing of the premixed gas can be made more suitable.
[0085]
<Second embodiment>
Next, a second embodiment of the intake control method for a premixed internal combustion engine according to the present invention will be described with reference to the drawings.
[0086]
10 and 11 are diagrams showing a schematic configuration of the internal combustion engine according to the present embodiment.
[0087]
The cylinder 2 of the internal combustion engine 1 according to the present embodiment is provided with one intake port 16 communicating with the intake manifold 12 and one exhaust port 17 communicating with the exhaust manifold 13. As shown in FIG. 11, the intake port 16 is provided with an intake valve 18, and the exhaust port 17 is provided with an exhaust valve (not shown). The intake valve 18 is provided with a variable valve mechanism 19 that controls the lift amount and the valve closing timing of the intake valve 18.
[0088]
Further, the internal combustion engine 1 according to the present embodiment includes an exhaust gas recirculation device 27 that recirculates a part of the exhaust gas discharged from the internal combustion engine 1 to the intake system. The exhaust gas recirculation device 20 includes an EGR passage 28 that communicates with the exhaust manifold 13 and the intake port 16. The EGR passage 28 includes an electromagnetic valve or the like, and is provided with an EGR passage according to the magnitude of an applied voltage. An EGR valve 29 for adjusting the flow rate of the exhaust gas (EGR gas) flowing through the inside 28 is provided. By changing the amount of EGR gas introduced into the intake port 16 by the EGR valve 29, the EGR rate of intake air at the intake port 16 is controlled.
[0089]
Further, the movable valve mechanism 19 and the EGR valve 29 are electrically connected to the ECU 30, and each unit is controlled by the ECU 30.
[0090]
Configurations other than these are the same as in the above-described first embodiment, and a description thereof will not be repeated. The internal combustion engine 1 according to the present embodiment is an internal combustion engine that performs homogeneous charge compression ignition combustion, similarly to the internal combustion engine 1 according to the above-described first embodiment.
[0091]
Next, an intake control method for an internal combustion engine according to the present embodiment will be described with reference to the drawings. FIG. 12 is a valve profile showing control of the intake valve 18 when the operation state of the internal combustion engine 1 according to the present embodiment is in a transient operation in which the engine load increases. FIG. 13 is a valve profile showing control of the intake valve 18 when the operation state of the internal combustion engine 1 according to the present embodiment is in a transient operation in which the engine load is reduced. 12 and 13 indicate a period corresponding to the bottom dead center of the intake stroke.
[0092]
In the intake control method for the internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is in a steady operation, the closing timing of the intake valve 18 is made later than the bottom dead center of the intake stroke. Then, when the vehicle provided with the internal combustion engine 1 is accelerated, and the operating state of the internal combustion engine 1 becomes a transient operation in which the engine load increases, that is, a transient operation in which the amount of EGR gas in the cylinder 2 increases. In this case, the opening degree of the EGR valve 29 is made larger than that during the normal operation, and control for delaying the closing timing of the intake valve 18 by a predetermined angle or more is performed for a predetermined period as shown in FIG.
[0093]
Here, the predetermined angle means that even if the closing timing of the intake valve 18 is retarded within the predetermined angle from the bottom dead center of the intake stroke, the inertia effect is applied to the intake port 18 from the intake port 16 and thereafter. This is the angle at which the intake air flows into the cylinder 2. That is, when the closing timing of the intake valve 18 is delayed from the bottom dead center of the intake stroke by a predetermined angle or more, the intake air in the cylinder 2 flows out to the intake port 16.
[0094]
On the other hand, in the intake control method for the internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is in the low rotation range, the vehicle provided with the internal combustion engine 1 is accelerated, and the operation state of the internal combustion engine 1 is increased. However, when the engine is in the transient operation in which the engine load is low, that is, in the transient operation in which the EGR gas amount in the cylinder 2 is reduced, the opening degree of the EGR valve 29 is made smaller than that in the normal operation. As shown in FIG. 13, a control for reducing the lift amount of the intake valve 18 and advancing the valve closing timing toward the bottom dead center of the intake stroke is performed for a predetermined period.
[0095]
When a predetermined period has elapsed since the operation state of the internal combustion engine 1 has changed to the transient operation, the closing timing of the intake valve 16 is returned to the same timing as during the steady operation.
[0096]
Here, the predetermined period refers to the actual EGR rate of the premixed air by controlling the EGR valve 29 and controlling the closing timing of the intake valve 18 after the operation state of the internal combustion engine 1 becomes the transient operation. Is a period until the required EGR rate is reached.
[0097]
According to the intake valve control method for an internal combustion engine according to the present embodiment, when the operation state of the internal combustion engine 1 is a transient operation in which the amount of EGR gas in the cylinder 2 is increased, the closing timing of the intake valve 18 Is retarded by a predetermined angle or more, so that the intake air in the cylinder 2 flows out to the intake port 16. Therefore, the actual compression ratio, which is the actual compression ratio of the premixed gas in the compression stroke, decreases, and the ignition timing of the premixed gas is delayed. Therefore, even if a response delay occurs in the EGR rate in the cylinder 2 and the actual EGR rate in the cylinder becomes lower than the required EGR rate, occurrence of premature ignition can be suppressed.
[0098]
Further, when the operating state of the internal combustion engine 1 according to the present embodiment is in the low rotation region, the closing timing of the intake valve 18 is later than the bottom dead center of the intake stroke, so that the intake air in the cylinder 2 flows to the intake port 16. leak. According to the intake valve control method for the internal combustion engine according to the present embodiment, when the operating state of the internal combustion engine 1 is in the low rotation region and the operation becomes the transient operation in which the EGR gas amount in the cylinder 2 is reduced, Since the closing timing of the intake valve 18 is advanced toward the bottom dead center of the intake stroke, the outflow of intake air from the cylinder 2 decreases. Therefore, the actual compression ratio of the premixed gas increases, and the ignition timing of the premixed gas is advanced. Therefore, even if a response delay occurs in the EGR rate in the cylinder 2 and the actual EGR rate in the cylinder becomes higher than the required EGR rate, it is possible to suppress the occurrence of ignition delay and misfire.
[0099]
Next, a control routine of the intake valve 18 according to the present embodiment will be described with reference to a flowchart shown in FIG.
[0100]
The flowchart shown in FIG. 14 is a flowchart showing a control routine of the intake valve according to the present embodiment. This intake valve control routine is a routine that is repeatedly executed by the ECU 30 at predetermined time intervals, and is stored in advance in a ROM provided in the ECU 30.
Note that S101 to S104, S106, and S109 in the flowchart shown in FIG. 14 are the same as those in the flowchart shown in FIG. 9 described in the first embodiment, and thus description thereof will be omitted.
[0101]
In this routine, the ECU 30 proceeds to S205 after S104. In S205, the ECU 30 determines the target actual compression ratio, which is the actual compression ratio of the premixed gas at which the ignition timing of the premixed gas becomes more suitable, based on the excess or deficiency of the EGR gas in the cylinder 2 calculated in S104. Is calculated.
[0102]
Next, the ECU 30 proceeds to S206, and based on the determination result of the acceleration / deceleration state of the internal combustion engine 1 in S102, the operating region of the internal combustion engine 1 determined in S103, and the target actual compression ratio calculated in S205, The change amount of the closing timing of the intake valve 18 is calculated.
[0103]
Further, following S106, the ECU 30 proceeds to S207, and controls the intake valve (hereinafter, referred to as the “first”) in which the change amount of the valve closing timing calculated in S206 is reflected based on the response delay time of the EGR rate calculated in S106. 2 Transient operation during intake valve control) is calculated.
[0104]
Next, the ECU 30 proceeds to S208, executes the second transient operation intake valve control for the intake valve 18, and ends the execution of this routine once.
[0105]
According to such an intake valve control routine, even if the operating state of the internal combustion engine 1 becomes a transient operation and a response delay of the EGR rate of the premixed air occurs, the operation state of the internal combustion engine 1 is changed according to the operating state. Since the closing timing of the intake valve 18 is adjusted and the actual compression ratio of the premixed gas is controlled, the ignition timing of the premixed gas can be made more suitable.
[0106]
In the above-described intake valve control routine, when the operating state of the internal combustion engine 1 is in the transient operation, the target actual compression ratio is calculated based on the EGR gas excess / deficiency in the cylinder, and the target actual compression ratio is calculated. The change amount of the closing timing of the intake valve 18 is calculated based on the ratio and the operating range of the internal combustion engine 1. In the control of the intake valve according to the present embodiment, the operating state of the internal combustion engine 1 is a transient operation. In this case, the closing timing of the intake valve 18 may be changed to a predetermined closing timing.
[0107]
【The invention's effect】
According to the intake control method for the homogeneous charge compression ignition combustion internal combustion engine according to the present invention, in the homogeneous charge compression ignition combustion internal combustion engine, even when the operating state of the internal combustion engine is in the transient operation, the ignition timing of the premixed air is more improved. It can be a suitable time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine according to a first embodiment.
FIG. 2 is a diagram showing a schematic configuration of a main part of the internal combustion engine according to the first embodiment.
FIG. 3 is a time chart showing a relationship among an operating state of the internal combustion engine, control of an intake valve, an amount of EGR gas in a cylinder, and an ignition timing of premixed gas according to the first embodiment.
FIG. 4 is a first valve profile showing control of an intake valve when the operation state of the internal combustion engine according to the first embodiment is a transient operation in which the amount of EGR gas in a cylinder is increased.
FIG. 5 is a second valve profile showing control of the intake valve when the operation state of the internal combustion engine according to the first embodiment is a transient operation in which the amount of EGR gas in the cylinder is increased.
FIG. 6 is a first valve profile showing control of the intake valve when the operation state of the internal combustion engine according to the first embodiment is a transient operation in which the amount of EGR gas in the cylinder is reduced.
FIG. 7 is a second valve profile showing control of the intake valve when the operation state of the internal combustion engine according to the first embodiment is a transient operation for reducing the amount of EGR gas in the cylinder.
FIG. 8 is a third valve profile showing control of the intake valve when the operation state of the internal combustion engine according to the first embodiment is a transient operation for reducing the amount of EGR gas in the cylinder.
FIG. 9 is a flowchart showing a control routine of the intake valve according to the first embodiment;
FIG. 10 is a diagram showing a schematic configuration of an internal combustion engine according to a second embodiment.
FIG. 11 is a diagram showing a schematic configuration of a main part of an internal combustion engine according to a second embodiment.
FIG. 12 is a valve profile showing control of an intake valve when the operation state of the internal combustion engine according to the second embodiment is a transient operation in which the amount of EGR gas in a cylinder is increased.
FIG. 13 is a valve profile showing control of an intake valve when the operation state of the internal combustion engine according to the second embodiment is a transient operation for reducing the amount of EGR gas in a cylinder.
FIG. 14 is a flowchart illustrating a control routine of an intake valve according to the second embodiment.
[Explanation of symbols]
1 ... internal combustion engine
2 ... cylinder
3 ... First intake port
4 Second intake port
5 ... Exhaust port
6 First intake valve
7 Second intake valve
8 First variable valve mechanism
9 Second variable valve mechanism
10. Fuel injection valve
11 ... Intake passage
12. Intake manifold
13. Exhaust manifold
14. Exhaust passage
15. Throttle valve
16. Intake port
17. Exhaust port
18. Intake valve
19. Variable valve mechanism
20..Exhaust gas recirculation device
21..Main EGR passage
22..First EGR passage
23 .. Second EGR passage
24..First EGR valve
25 .. Second EGR valve
26..Main EGR valve
27..Exhaust gas recirculation device
28 EGR passage
29 EGR valve
30 ECU
31 Crank position sensor
32. Accelerator opening sensor

Claims (10)

It has multiple intake ports per cylinder,
An exhaust gas recirculation device that introduces a part of the exhaust gas as recirculated exhaust gas into each of the one intake port and the other intake port;
Intake recirculation for controlling a recirculation exhaust rate of intake air in each intake port by changing a recirculation exhaust amount introduced into the one intake port and the other intake port by the exhaust recirculation device, respectively. An exhaust rate control device,
A variable valve mechanism that changes a lift amount and a valve closing timing of the intake valve of the one intake port and the intake valve of the other intake port, respectively.
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. At
When the operating state of the internal combustion engine is a steady operation, the intake air recirculation / exhaust rate control device determines in advance the intake air recirculation / exhaust rate at the one intake port and the intake air recirculation / exhaust rate at the other intake port. Rate, and when the operating state of the internal combustion engine is in a transient operation in which the change in the amount of recirculated exhaust gas in the cylinder is larger than that in a steady operation, the variable valve mechanism causes a predetermined period of time. The amount of recirculated exhaust gas in the cylinder is changed by changing the lift amount and / or closing timing of the intake valve of the one intake port and / or the intake valve of the other intake port. An intake control method for a mixed compression ignition combustion internal combustion engine. It has multiple intake ports per cylinder,
An exhaust gas recirculation device that introduces a part of exhaust gas to only one intake port as recirculated exhaust gas;
A variable valve mechanism that changes a lift amount and a valve closing timing of the intake valve of the one intake port and the intake valve of the other intake port, respectively,
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. At
When the operating state of the internal combustion engine is a transient operation in which the change in the amount of recirculated exhaust gas in the cylinder is larger than that in the steady operation, the variable valve mechanism controls the intake valve of the one intake port for a predetermined period. And / or changing the lift amount and / or closing timing of the intake valve of the other intake port to change the amount of recirculated exhaust gas in the cylinder. Control method. The lift amount of the intake valve of the other intake port is reduced during the predetermined period when the operating state of the internal combustion engine is a transient operation that increases the amount of recirculated exhaust gas in the cylinder. 3. The intake control method for a premixed compression ignition combustion internal combustion engine according to claim 1. The lift amount of the intake valve of the one intake port is reduced during the predetermined period when the operating state of the internal combustion engine is a transient operation that reduces the amount of recirculated exhaust gas in the cylinder. An intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to any one of claims 1 to 3. The internal combustion engine is a premixed compression ignition combustion internal combustion engine in which during normal operation, the closing timing of the intake valve of the other intake port is slower than the intake stroke bottom dead center,
When the operation state of the internal combustion engine is in the low rotation region and becomes a transient operation in which the amount of recirculated exhaust gas in the cylinder is increased, the lift amount of the intake valve of the other intake port is reduced during the predetermined period. 4. The intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to claim 3, wherein the closing timing of the intake valve of the other intake port is advanced toward the bottom dead center of the intake stroke. . The internal combustion engine is a premixed compression ignition combustion internal combustion engine in which, during steady-state operation, the closing timing of the intake valve of the one intake port is slower than the intake stroke bottom dead center,
When the operating state of the internal combustion engine is in the low rotation region and becomes a transient operation in which the amount of recirculated exhaust gas in the cylinder is reduced, the lift amount of the intake valve of the one intake port is reduced during the predetermined period. 5. The intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to claim 4, wherein the closing timing of the intake valve of the one intake port is advanced toward the bottom dead center of the intake stroke. . The internal combustion engine is a premixed compression ignition combustion internal combustion engine in which during normal operation, the closing timing of the intake valve of the other intake port is after the bottom dead center of the intake stroke,
When the operation state of the internal combustion engine is in the high rotation region and becomes a transient operation in which the amount of recirculated exhaust gas in the cylinder is increased, the lift amount of the intake valve of the other intake port is reduced during the predetermined period. 4. The intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to claim 3, wherein the closing timing of the intake valve of the other intake port is retarded. The internal combustion engine is a premixed compression ignition combustion internal combustion engine in which during normal operation, the closing timing of the intake valve of the one intake port is after the bottom dead center of the intake stroke,
When the operation state of the internal combustion engine is in the high rotation region and becomes a transient operation in which the amount of recirculated exhaust gas in the cylinder is reduced, the lift amount of the intake valve of the one intake port is reduced during the predetermined period. 5. The intake control method for a homogeneous charge compression ignition combustion internal combustion engine according to claim 4, wherein the closing timing of the intake valve of the one intake port is retarded. An exhaust gas recirculation device that introduces a part of the exhaust gas to the intake port as recirculated exhaust gas;
A variable valve mechanism for changing the closing timing of the intake valve of the intake port,
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. And
At the time of steady operation, in the premixed compression ignition combustion internal combustion engine in which the closing timing of the intake valve of the intake port is after the bottom dead center of the intake stroke,
When the operating state of the internal combustion engine is in a transient operation in which the amount of recirculated exhaust gas in the cylinder is increased, the closing timing of the intake valve is retarded by a predetermined angle or more by the variable valve mechanism for a predetermined period. An intake control method for a homogeneous charge compression ignition combustion internal combustion engine. An exhaust gas recirculation device that introduces a part of the exhaust gas to the intake port as recirculated exhaust gas;
A variable valve mechanism for changing the closing timing of the intake valve of the intake port,
A premixed compression ignition combustion internal combustion engine that performs premixed compression ignition combustion in which a premixed mixture of fuel and intake air is formed in a cylinder during an intake stroke and / or a compression stroke, and the premixed gas is used for combustion. And
During steady-state operation, in a premixed compression ignition combustion internal combustion engine in which the closing timing of the intake valve of the intake port is later than the intake stroke bottom dead center,
When the operating state of the internal combustion engine is in the low rotation region and is in a transient operation in which the amount of recirculated exhaust gas in the cylinder is reduced, the closing timing of the intake valve by the variable valve mechanism for a predetermined period. The intake control method for a premixed compression ignition combustion internal combustion engine, wherein the intake stroke is advanced toward the bottom dead center of the intake stroke.

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