JP3589131B2 - Intake air amount control device for variable valve type internal combustion engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an intake air amount control device for a variable valve internal combustion engine that controls an intake air amount by a variable valve mechanism, and particularly to a technique for improving stability during idling operation.
[0002]
[Prior art]
Conventionally, for the purpose of improving fuel efficiency by reducing pump loss, for example, as disclosed in Japanese Patent Application Laid-Open No. 10-37727, there has been known a variable valve mechanism capable of arbitrarily controlling the opening and closing timing of intake and exhaust valves. I have. In an internal combustion engine equipped with a variable valve operating mechanism, the intake air amount is controlled by changing the closing timing of the intake valve, so that substantially non-throttle operation can be performed.
[0003]
[Problems to be solved by the invention]
By the way, in an internal combustion engine equipped with a variable valve operating mechanism, the intake air amount is controlled by the closing timing of the intake valve. There is a characteristic that the response of the amount is quick. For this reason, there is a possibility that the driving performance may be reduced due to a feeling of rattling or the like, and from the viewpoint of solving such a problem, it is necessary to perform a process such as smoothing the response to the control signal of the variable valve mechanism. Must. However, the amount of intake air controlled by the variable valve mechanism includes the amount of auxiliary air for maintaining a predetermined idle rotation speed. And the stability during idling may be reduced.
[0004]
Accordingly, the present invention has been made in view of the above-described conventional problems and, in view of the above-mentioned conventional problems, prevents a decrease in responsiveness of an auxiliary air amount, thereby improving the stability during idle operation of a variable valve type internal combustion engine. The purpose is to provide.
[0005]
[Means for Solving the Problems]
For this reason, according to the first aspect of the present invention, as shown in FIG. 1, the variable valve means B capable of arbitrarily controlling the opening / closing timing of the intake valve A and the main air for calculating the main air amount based on a driver request. the amount computing means C, a supplementary air quantity calculating means D for calculating the auxiliary air amount based on the engine requirements, and response lag processing unit E for performing the response delay processing to the main air amount, the response delay Target air amount calculating means F for calculating a target air amount obtained by adding the auxiliary air amount to the processed main air amount; and opening / closing timing of the intake valve A by the variable valve means B based on the target air amount. And an intake air amount control device G for controlling the intake air amount by controlling the intake air amount control device of the variable valve type internal combustion engine.
[0006]
According to such a configuration, the response delay processing means E performs the response delay processing only on the main air amount. Then, the target air amount calculating means F calculates a target air amount obtained by adding the main air amount and the auxiliary air amount subjected to the response delay processing, and the intake air amount controlling means G calculates the target air amount based on the target air amount. Control of the intake air amount is performed. That is, since the response delay processing is not performed on the auxiliary air amount for which the response is not desired to be reduced, even if the auxiliary air amount increases stepwise due to the application of the auxiliary equipment load, for example, it is possible to quickly respond. It becomes.
[0007]
The invention according to claim 2 is characterized in that the response delay processing means performs a smoothing process corresponding to a first-order intake manifold delay of the internal combustion engine on the main air amount .
[0008]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the response delay processing is not performed on the auxiliary air amount, for example, the auxiliary air amount increases stepwise by application of the auxiliary load. However, it is possible to quickly respond to the increased amount and improve the stability of the idling operation.
[0009]
According to the second aspect of the present invention, the smoothing process corresponding to the intake manifold first-order lag is performed on the main air amount requested by the driver, so that the intake air is sensitively changed according to the change in the accelerator opening. The amount is prevented from increasing or decreasing, and smooth operating characteristics can be obtained over the entire operating region.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 2 is a system diagram showing one embodiment of the present invention.
[0011]
The ignition plug 4 and the electromagnetically driven valves 5 and 6 (variable valve operating means) are arranged in the cylinder head 2 of the internal combustion engine 1 so as to view the combustion chamber 3. Each intake port 7 is provided with a fuel injection valve 8 that injects fuel according to the engine operating state. An intake passage 9 connected to the intake port 7 is provided with an air flow meter 10 for detecting an intake air amount Q taken into the combustion chamber 3 and an electronically controlled throttle valve 11.
[0012]
The electronically controlled throttle valve 11 is provided with a throttle sensor 12 for detecting the throttle opening TVO. The crank pulley 13 is provided with a crank angle sensor 14 that outputs a reference angle signal Ref at a reference crank angle and outputs a unit angle signal Pos for each unit crank angle. In addition, an accelerator pedal sensor 15 for detecting an accelerator opening (accelerator pedal depression amount) APO, a water temperature sensor 16 for detecting a cooling water temperature Tw representing the engine body temperature, and a state where various auxiliary machines are operating. Various accessory switches 17 that are turned on are provided. Here, examples of the various accessory switches 17 include a power steering switch, an air conditioner switch, an electric load switch, a radiator fan switch, and a blower fan switch.
[0013]
Output signals of the air flow meter 10, the throttle sensor 12, the crank angle sensor 14, the accelerator pedal sensor 15, the water temperature sensor 16, and the various auxiliary switches 17 are respectively input to a control unit 18 having a built-in microcomputer. The control unit 18 calculates the engine speed Ne and determines the cylinder (determines which cylinder is at the top dead center) based on the signal from the crank angle sensor 14, and converts the signal from each sensor into a signal. Based on this, control of the ignition plug 4, the electromagnetically driven valves 5, 6, the fuel injection valve 8, and the electronically controlled throttle valve 11 is performed.
[0014]
The control unit 18 realizes main air amount calculation means, auxiliary air amount calculation means, response delay processing means, target air amount calculation means, and intake air amount control means by software.
[0015]
Next, the configuration of the electromagnetically driven valves 5 and 6 will be described with reference to FIG.
A plate-shaped movable element 22 is attached to a shaft portion 21 of a valve body 20 serving as an intake / exhaust valve. Springs 23 and 24 are disposed above and below the mover 22 such that the valve body 20 is elastically supported at the neutral position when not in operation. A valve closing electromagnet 25 and a valve opening electromagnet 26 are provided above and below the mover 22, respectively.
[0016]
Then, in order to open the valve body 20, after the energization of the valve-closing electromagnet 25 is stopped, the valve-opening electromagnet 26 is energized, and the lower surface of the movable element 22 is pressed against the urging force of the spring 24. The valve body 20 is attracted to the valve opening electromagnet 26 to separate the valve body 20 from the seat portion. On the other hand, in order to close the valve element 20, after the energization of the valve-opening electromagnet 26 is stopped, the valve closing electromagnet 25 is energized, and the upper surface of the movable element 22 is pressed against the urging force of the spring 23. The valve body 20 is seated on the seat portion by being attracted to the valve closing electromagnet 25. By repeating such operations periodically, a function as a valve train of the internal combustion engine is exhibited.
[0017]
Further, in this internal combustion engine, the opening and closing timing of the intake and exhaust valves, particularly the closing timing (IVC) of the intake valve, is controlled (early closing control) by the electromagnetically driven valves 5 and 6 for the purpose of improving fuel efficiency by reducing pump loss. Thus, the intake air amount is controlled to perform the substantially non-throttle operation. In this case, the electronically controlled throttle valve 11 is used for obtaining a target negative pressure in the intake passage under predetermined operating conditions.
[0018]
Specifically, the opening timing (IVO) of the intake valve is set to a substantially constant timing near the top dead center (TDC) of the exhaust gas, and the closing timing (IVC) of the intake valve is set to the target torque including the driver required torque and the engine required torque. Control is performed in consideration of the throttle opening TVO in accordance with the target air amount corresponding to the torque. On the other hand, the opening timing (EVO) and closing timing (EVC) of the exhaust valve are controlled so as to be the timing having the highest thermal efficiency.
[0019]
Next, control of the intake air amount of the variable valve type internal combustion engine will be described.
As shown in FIG. 4, the configuration of the control block includes a main air amount calculation unit 30, an auxiliary air amount calculation unit 31, a response delay processing unit 32, a target air amount calculation unit 33, and an IVC calculation unit 34. .
[0020]
The main air amount calculation unit 30 functions as main air amount calculation means, and calculates a main air amount corresponding to a torque required by the driver based on the accelerator opening APO and the engine rotation speed Ne.
[0021]
The auxiliary air amount calculation unit 31 functions as an auxiliary air amount calculation unit, and is equivalent to an idle required torque including a friction component based on the cooling water temperature Tw, an auxiliary load component based on the auxiliary load application state, an idle rotation speed control component, and the like. Is calculated. Here, the idle rotation speed control amount is an air amount that is increased or decreased by feedback control so that the actual engine rotation speed Ne becomes the target idle rotation speed under the idle operation condition.
[0022]
The response delay processing unit 32 functions as a response delay processing unit, and performs a response delay process on the main air amount calculated by the main air amount calculation unit 30 to prevent deterioration in engine operability. That is, in the electromagnetically driven valve 5, since the intake air amount increases / decreases with good responsiveness by controlling the opening / closing timing of the intake valve, it is the same as the conventional control of the intake air amount by the throttle valve from the viewpoint of preventing the rattle or the like. As described above, for example, a so-called smoothing process corresponding to the first-order intake manifold delay is performed by the following equation.
[0023]
Main air amount after correction = Qt ′ × (1−F) + Qt × F
Here, Qt is the main air amount calculated latest by the main air amount calculation unit 30, Qt 'is the current corrected main air amount, and F is a weighted average weighting constant (0 <F <1).
[0024]
By performing such a correction, the intake air amount is prevented from being excessively increased or decreased in response to a change in the accelerator opening APO, and, similarly to the conventional intake air amount control using a throttle valve, over the entire operation range. Smooth operation characteristics can be obtained.
[0025]
The target air amount calculation unit 33 calculates the target air amount by adding the auxiliary air amount calculated by the auxiliary air amount calculation unit 31 to the main air amount subjected to the response delay processing by the response delay processing unit 32. I do.
[0026]
The IVC calculator 34 calculates the closing timing of the intake valve based on the target air amount calculated by the target air amount calculator 33. Then, the electromagnetically driven valve 5 is controlled based on the calculation result. These series of processes correspond to intake air amount control means.
[0027]
FIG. 5 is a flowchart showing the control of the intake air amount. Since the detailed control contents are the same as those of the control block shown in FIG. 4, only the outline will be described here.
[0028]
The auxiliary air amount calculator 31 calculates the auxiliary air amount (S1), and the main air amount calculator 30 calculates the main air amount (S2). Then, the response delay processing unit 32 performs a response delay process on the main air amount (S3), and the auxiliary air amount is added to the main air amount subjected to the response delay process by the target air amount calculation unit 33. A target air amount is calculated (S4). Thereafter, the closing timing of the intake valve is calculated by the IVC calculation unit 34 (S5), and the electromagnetically driven valve 5 is controlled based on the calculation result (S6).
[0029]
With this configuration, the response delay processing is not performed on the auxiliary air amount whose response is not desired to be reduced, and the auxiliary air amount and the main air amount on which the response delay processing has been performed are based on the target air amount. Thus, the electromagnetically driven valve 5 is controlled. This effect will be described with reference to FIG. 6 as an example when a load of an auxiliary device such as an air conditioner is applied during the idling operation. When the response delay processing is performed on the entire target air amount, the intake air amount increases as indicated by the characteristic A, and the auxiliary air amount corresponding to the load of the auxiliary equipment cannot be rapidly increased. However, according to the present embodiment, since the intake air amount increases as indicated by the characteristic B, the auxiliary air amount corresponding to the auxiliary equipment load increases quickly, and the stability of the idling operation is maintained.
[0030]
The electronically controlled throttle valve 11 controls the opening degree based on the target air amount (main air amount + auxiliary air amount) and the target negative pressure so as to realize the target negative pressure. In this case, the target air amount is , The main air amount and the auxiliary air amount before the response delay processing are added. This is because control of the air amount by the throttle valve causes a response delay.
[0031]
The opening / closing timing of the intake valve is not limited to the electromagnetically driven valve 5 as in this embodiment, but may be any configuration that can be controlled by some means.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing a configuration of the present invention. FIG. 2 is a system diagram showing an embodiment of the present invention. FIG. 3 is a basic structural diagram of an electromagnetically driven valve. FIG. FIG. 6 is a flowchart showing a change in the amount of intake air when an auxiliary load is applied.
REFERENCE SIGNS LIST 1 internal combustion engine 5 electromagnetically driven valve 11 electrically controlled throttle valve 14 crank angle sensor 15 accelerator pedal sensor 16 water temperature sensor 17 various auxiliary switches 18 control unit 30 main air amount calculation unit 31 auxiliary air amount calculation unit 32 response delay processing unit 33 Target air amount calculation unit 34 IVC calculation unit

Claims (2)

Variable valve operating means capable of arbitrarily controlling the opening and closing timing of the intake valve;
Main air amount calculating means for calculating a main air amount based on a driver request;
Auxiliary air amount calculating means for calculating an auxiliary air amount based on an engine request;
Responsiveness delay processing means for performing responsiveness delay processing on the main air amount ,
Target air amount calculating means for calculating a target air amount obtained by adding the auxiliary air amount to the main air amount subjected to the response delay processing ,
Intake air amount control means for controlling the opening and closing timing of the intake valve by the variable valve means based on the target air amount to control the intake air amount;
An intake air amount control device for a variable valve type internal combustion engine, comprising: The response delay processing means, the intake air amount of the variable valve type internal combustion engine according to claim 1, wherein the performing the smoothing process of the intake manifold 1-order lag corresponds an internal combustion engine with respect to the main air amount Control device.

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