JP5012766B2 - Intake control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake-air control device for an internal combustion engine capable of achieving fuel consumption improvement of the internal combustion engine in such a manner that actual open/close characteristics of air intake valve changes on an optimal fuel consumption performance line, when the internal combustion engine becomes in transient operating condition due to rapid change in accelerator operation amount. <P>SOLUTION: When an accelerator operation amount changes rapidly, a target in-cylinder air amount KL is set based on the accelerator operation amount in the process of changing. The target in-cylinder air amount KL makes a transition similarly to a transition of the in-cylinder air amount at maximum filling efficiency when the adjustment of the in-cylinder air amount is made by only the open/close operation of a throttle valve 13 based on an accelerator operation amount. The target working angle t&theta; and the target valve timing tVVTin of an air intake valve 9 which are set based on the target in-cylinder air amount KL, when a working angle and a valve timing of the air intake valve 9 are varied based on these, at a speed at which the working angle and the valve timing can be transition on an optimal fuel consumption performance line, makes a transition on the optimal fuel consumption performance line. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an intake control device for an internal combustion engine.

  In an internal combustion engine mounted on a vehicle such as an automobile, an amount of fuel corresponding to the amount of air in the cylinder when the intake valve is closed is supplied into the cylinder, and an air-fuel mixture consisting of air and fuel is supplied in the cylinder. It is driven by burning. Therefore, the output adjustment of the internal combustion engine is performed by adjusting the in-cylinder air amount when the intake valve is closed based on the accelerator operation by the driver of the vehicle, and adjusting the amount of air-fuel mixture in the cylinder according to the in-cylinder air amount. This is done by increasing or decreasing. The in-cylinder air amount at this time is set to a value corresponding to the output request to the internal combustion engine by the driver's accelerator operation so that the engine output corresponding to the output request can be obtained by burning the air-fuel mixture in the cylinder. Become.

  The adjustment of the in-cylinder air amount in an internal combustion engine is usually realized by adjusting the air flow area of the passage through an opening / closing operation of a throttle valve provided in the intake passage. More specifically, the larger the accelerator operation amount corresponding to the driver's output request to the internal combustion engine, the more the throttle valve is operated to the open side to increase the air flow area of the intake passage, and the intake valve is closed. The amount of in-cylinder air is increased. However, when adjusting the cylinder air amount when the intake valve is closed by adjusting the throttle valve opening based on the accelerator operation amount as described above, when adjusting the cylinder air amount to a small value, Since the throttle valve in the intake passage is operated to the region on the closing side, the pump loss of the internal combustion engine increases and adversely affects the fuel consumption of the engine.

  Therefore, as shown in Patent Document 1, an internal combustion engine is provided with a variable valve mechanism capable of continuously changing the opening / closing characteristics of the intake valve, and by varying the opening / closing characteristics of the intake valve by driving the mechanism. It has been proposed to adjust the in-cylinder air amount. In this case, compared with the case where the cylinder air amount is adjusted only by adjusting the throttle valve opening, the opening of the valve can be adjusted to the open side value. It becomes possible to reduce the pump loss of the internal combustion engine and to improve the fuel consumption of the engine.

  When adjusting the in-cylinder air amount through variable opening / closing characteristics of the intake valve, the adjustment is performed, for example, as follows based on the accelerator operation amount. That is, a target opening / closing characteristic that is a target of the opening / closing characteristic of the intake valve is set based on the accelerator operation amount, etc., and the variable valve mechanism is driven based on the target opening / closing characteristic so that the opening / closing characteristic of the intake valve becomes the target opening / closing characteristic. Done.

  Regarding the target opening / closing characteristics set based on the accelerator operation amount, etc., the in-cylinder air amount at which the engine output becomes a value corresponding to the accelerator operation amount is obtained under the condition that the internal combustion engine is in a steady operation. In addition, the intake valve opening / closing characteristics are optimized so that the fuel consumption of the internal combustion engine is optimized by reducing pump loss or the like. Here, if the accelerator operation amount is changed while maintaining the steady state of the internal combustion engine, for example, the accelerator operation amount is gradually changed, the target opening / closing characteristic also changes accordingly. The curve representing the transition of the target opening / closing characteristic that changes in this way is an optimal fuel consumption operation line that represents the transition of the opening / closing characteristics of the intake valve that can optimize the fuel consumption of the internal combustion engine by reducing pump loss or the like.

Therefore, when adjusting the cylinder air amount based on the accelerator operation amount to adjust the engine output to a value corresponding to the output request of the driver for the internal combustion engine, the actual opening / closing characteristic of the intake valve is set to the target opening / closing characteristic. In addition, the fuel consumption of the internal combustion engine can be brought into an optimum state by shifting the fuel consumption on the fuel consumption optimum operation line.
JP 2006-112231 A (paragraphs [0001], [0003], [0032], FIG. 13 to FIG. 16, FIG. 23)

  By the way, when the driver suddenly changes the accelerator operation amount and the internal combustion engine enters a transient operation state, the target opening / closing characteristic also changes suddenly in accordance with the sudden change of the accelerator operation amount. For example, when the accelerator operation amount is suddenly changed from small to large, the target opening / closing characteristic is suddenly changed from a characteristic corresponding to a small accelerator operation amount on the fuel efficiency optimum operation line to a characteristic corresponding to a large accelerator operation amount.

  In this way, when the target opening / closing characteristic suddenly changes, the actual opening / closing characteristic of the intake valve can follow the sudden change of the target opening / closing characteristic with good responsiveness. It is difficult because of a response delay in the change. In other words, the speed of change of the target opening / closing characteristic when changing with the sudden change in the accelerator operation amount becomes a value faster than the speed that can be realized when changing the actual opening / closing characteristic of the intake valve. In this case, when the accelerator operation amount is suddenly changed, the target opening / closing characteristic changes suddenly on the fuel efficiency optimum operating line, whereas the actual opening / closing characteristic cannot follow the suddenly changing target opening / closing characteristic as described above. .

  Thus, when the actual opening / closing characteristics cannot follow the target opening / closing characteristics, the variable valve mechanism is driven so that the actual opening / closing characteristics reach the target opening / closing characteristics at the fastest speed. For this reason, the actual opening / closing characteristics are changed so as to be linearly closer to the target opening / closing characteristics that change on the fuel efficiency optimal operation line, and thereby change significantly away from the fuel efficiency optimal operation line. Therefore, in the transient operation state of the internal combustion engine due to a sudden change in the accelerator operation amount, the actual opening / closing characteristics cannot be changed on the fuel consumption optimum operating line, and therefore the deterioration of the fuel consumption of the engine is unavoidable. .

  The present invention has been made in view of such circumstances, and its purpose is that when the internal combustion engine is in a transient operation state due to a sudden change in the accelerator operation amount, the actual opening / closing characteristics of the intake valve are on the fuel efficiency optimum operating line. An object of the present invention is to provide an intake control device for an internal combustion engine that can improve the fuel consumption of the internal combustion engine by changing.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, according to the first aspect of the present invention, the intake valve is closed by opening and closing the throttle valve provided in the intake passage based on the accelerator operation amount to adjust the air flow area of the passage. Applied to an internal combustion engine capable of adjusting the in-cylinder air amount to a value corresponding to the accelerator operation amount, and capable of continuously varying the opening / closing characteristics of the intake valve And adjusting the value of the in-cylinder air amount to a value corresponding to the accelerator operation amount by varying the opening / closing characteristics of the intake valve by driving the variable valve mechanism, thereby adjusting the opening of the throttle valve. In the intake control device for an internal combustion engine that can be adjusted to a value on the open side compared to when adjusting the in-cylinder air amount only by opening and closing the valve,
A first setting means for setting a target in-cylinder air amount, which is a target value of the in-cylinder air amount when the intake valve is closed, based on the accelerator operation amount; and a target value for the opening / closing characteristics of the intake valve. Second setting means for setting a target opening / closing characteristic used when driving and controlling the variable valve mechanism based on the target in-cylinder air amount, and the opening / closing characteristic of the intake valve becomes the target opening / closing characteristic. An opening / closing characteristic control means for driving the variable valve mechanism based on the target opening / closing characteristic, and the first setting means, when the accelerator operation amount suddenly changes, the throttle setting based on the accelerator operation amount in the changing process. The change in the in-cylinder air amount at the maximum charging efficiency when the in-cylinder air amount is adjusted only by opening and closing the valve is determined, and the value that changes is set as the target in-cylinder air amount.

  According to the above configuration, the target in-cylinder air amount in the changing process when the accelerator operation amount changes suddenly is adjusted when the in-cylinder air amount is adjusted only by opening / closing the throttle valve based on the change in the accelerator operation amount. It becomes a value almost equal to the actual in-cylinder air amount at the maximum filling efficiency. In other words, the target in-cylinder air amount in the process of changing the accelerator operation amount is determined by taking into account the occurrence of delay in response of the actual opening / closing characteristics of the intake valve due to the drive of the variable operation valve mechanism, and the fuel consumption of the opening / closing characteristics. The value is substantially equal to the in-cylinder air amount that can be realized by changing the opening and closing characteristics while changing on the optimum operating line. The fuel efficiency optimum operating line is for obtaining an engine output corresponding to the accelerator operation amount when the accelerator operation amount is changed while maintaining the steady state of the internal combustion engine, such as gradually changing the accelerator operation amount. It is a curve representing the transition of the opening / closing characteristics of the intake valve that can secure the in-cylinder air amount and can optimize the fuel consumption of the engine by reducing pump loss.

  Then, a target opening / closing characteristic is set based on the target in-cylinder air amount in the process of changing the accelerator operation amount that changes suddenly. The target opening / closing characteristic set in this way causes the actual opening / closing characteristic of the intake valve to change on the fuel consumption optimum operating line when the variable valve mechanism is driven to vary the opening / closing characteristic of the intake valve based on the target opening / closing characteristic. It will change on the fuel efficiency optimum operating line at a possible speed. Therefore, when the internal combustion engine is in a transient operation state due to a sudden change in the accelerator operation amount, the actual opening / closing characteristics of the intake valve are set so that the in-cylinder air amount when the intake valve is closed corresponds to the accelerator operation amount. When the engine speed is changed, the open / close characteristic can be changed on the fuel efficiency optimum operation line, thereby improving the fuel efficiency of the internal combustion engine.

  According to a second aspect of the present invention, in the intake control device for an internal combustion engine according to the first aspect, a target intake pressure that is a target value of the pressure on the downstream side of the throttle valve in the intake passage is set by the first setting means. Third setting means for setting based on the set target in-cylinder air amount and the target opening / closing characteristics of the intake valve set by the second setting means, and a target which is a target value of the opening degree of the throttle valve Fourth setting means for setting the throttle opening as a value at which the pressure on the downstream side of the throttle valve in the intake passage becomes the target intake pressure, and the opening of the throttle valve Opening control means for opening and closing the throttle valve based on the target throttle opening so as to achieve the target throttle opening, and the third setting means includes: Based on the target in-cylinder air amount and the target opening / closing characteristics, the pressure downstream of the throttle valve in the intake passage capable of realizing the maximum charging efficiency in that state is obtained, and the obtained value is set as the target intake pressure. It was.

  According to the above configuration, in the changing process when the accelerator operation amount suddenly changes, based on the target in-cylinder intake pressure and the target opening / closing characteristics of the intake valve, the throttle valve in the intake passage that can achieve the maximum charging efficiency in that state. The downstream pressure is set as the target intake pressure. Then, the throttle valve opening at which the pressure downstream of the throttle valve in the intake passage can be set as the target intake pressure is set as the target throttle opening, and the target valve is set so that the throttle valve opening becomes the target throttle opening. Opening and closing is performed based on the throttle opening. By opening and closing the throttle valve in this way, the opening amount of the throttle valve is set to the open side value as much as possible while the cylinder air amount when the intake valve is closed is set to the target cylinder air amount, in other words, the internal combustion engine. It can be set to an optimum value for reducing the pump loss.

Hereinafter, an embodiment in which the present invention is embodied in an intake control device for an automobile engine will be described with reference to FIGS.
In the engine 1 shown in FIG. 1, a throttle valve 13 is provided in an intake passage 3 connected to the combustion chamber 2 so as to be openable and closable. Air is sucked into the combustion chamber 2 through the intake passage 3 and fuel injection is performed. The fuel injected from the valve 4 is supplied to the combustion chamber 2. When the air / fuel mixture is ignited by the spark plug 5, the air / fuel mixture burns, the piston 6 reciprocates, and the crankshaft 7 that is the output shaft of the engine 1 rotates. On the other hand, the air-fuel mixture after burning in the combustion chamber 2 is sent out from each combustion chamber 2 to the exhaust passage 8 as exhaust gas.

  In the engine 1, the combustion chamber 2 and the intake passage 3 are connected and cut off by the opening / closing operation of the intake valve 9, and the combustion chamber 2 and the exhaust passage 8 are connected and cut off by the opening / closing operation of the exhaust valve 10. . The intake valve 9 and the exhaust valve 10 are opened and closed with the rotation of the intake camshaft 11 and the exhaust camshaft 12 to which the rotation of the crankshaft 7 is transmitted.

  The engine 1 is provided between the intake valve timing variable mechanism 16 provided on the intake camshaft 11 and the intake valve 9 of the intake camshaft 11 as a variable valve mechanism that varies the opening / closing characteristics of the intake valve 9. The variable valve lift mechanism 14 is provided. The variable valve lift mechanism 14 changes the maximum lift amount and the operating angle of the intake valve 9 in synchronization with each other as shown in FIG. 2 through rotational driving of the electric motor 15 within a predetermined rotation angle range. . The intake side valve timing variable mechanism 16 (FIG. 1) is driven by controlling the hydraulic pressure acting on the mechanism 16 through a hydraulic circuit, and the relative rotation phase (valve timing) of the intake camshaft 11 with respect to the crankshaft 7 is controlled. To change. Through the driving of the intake side valve timing varying mechanism 16, both the valve opening timing and the valve closing timing of the valve 9 are maintained while the valve opening period (operating angle) of the intake valve 9 is kept constant as shown in FIG. It is advanced or retarded.

  Further, the engine 1 shown in FIG. 1 is provided on the exhaust camshaft 12 as a variable valve mechanism that makes the opening / closing characteristics of the exhaust valve 10 variable, and the relative rotational phase of the exhaust camshaft 12 with respect to the crankshaft 7 (valve An exhaust-side valve timing variable mechanism 17 that can change the timing is also provided. The exhaust side valve timing varying mechanism 17 is driven by controlling the hydraulic pressure acting on the mechanism 17 through a hydraulic circuit. Through the driving of the exhaust side valve timing variable mechanism 17, both the valve opening timing and the valve closing timing of the valve 10 are maintained while the valve opening period (operating angle) of the exhaust valve 10 is kept constant as shown in FIG. It is advanced or retarded.

Next, the electrical configuration of the intake air control apparatus in the present embodiment will be described with reference to FIG.
The intake control device includes an electronic control device 21 that executes various controls related to the engine 1. The electronic control unit 21 is a CPU that executes various arithmetic processes related to the above control, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores the arithmetic results of the CPU, etc. The input / output port for inputting / outputting is provided.

Various sensors shown below are connected to the input port of the electronic control unit 21.
An accelerator position sensor 28 that detects an operation amount (accelerator operation amount) of an accelerator pedal 27 that is depressed by an automobile driver.

A throttle position sensor 30 that detects the opening (throttle opening) of the throttle valve 13 provided in the intake passage 3.
An air flow meter 32 for detecting the amount of air taken into the combustion chamber 2 through the intake passage 3;

A crank position sensor 34 that outputs a signal corresponding to the rotation of the crankshaft 7 and is used for calculating the engine rotation speed, calculating the crank angle, and the like.
A position sensor 35 that is used to detect the rotation angle of the electric motor 15 within the predetermined rotation angle range and to determine the operating angle and the maximum lift amount of the intake valve 9.

  Intake used to output a signal corresponding to the rotation position of the intake shaft 11 based on the rotation of the intake camshaft 11 to obtain the relative rotation phase of the intake camshaft 11 with respect to the crankshaft 7 (valve timing of the intake valve 9). Cam position sensor 36;

  Exhaust gas used to output a signal corresponding to the rotational position of the shaft 12 based on the rotation of the exhaust camshaft 12 and to determine the relative rotation phase of the exhaust camshaft 12 with respect to the crankshaft 7 (valve timing of the exhaust valve 10). Cam position sensor 37;

  The output port of the electronic control unit 21 includes drive circuits for the fuel injection valve 4, the throttle valve 13, the variable valve lift mechanism 14 (electric motor 15), the intake side valve timing variable mechanism 16, the exhaust side valve timing variable mechanism 17, and the like. Etc. are connected.

  Then, the electronic control unit 21 grasps the engine operating state based on the detection signals input from the various sensors, and outputs command signals to various driving circuits connected to the output port according to the grasped engine operating state. . In this way, various operation controls of the engine 1 such as intake control and fuel injection amount control in the engine 1 are performed through the electronic control unit 21.

  In the engine 1, an amount of fuel corresponding to the amount of in-cylinder air (the amount of air in the combustion chamber 2) when the intake valve 9 is closed through the fuel injection amount control is injected and supplied from the fuel injection valve 4. An air-fuel mixture composed of fuel and air is combusted inside (in the combustion chamber 2). For this reason, the output adjustment of the engine 1 is performed by adjusting the in-cylinder air amount when the intake valve 9 is closed based on the depression operation of the accelerator pedal 27 by the driver, and the amount of the air-fuel mixture in the cylinder is adjusted to the in-cylinder air amount. This is done by increasing or decreasing the amount. The in-cylinder air amount at this time is a value corresponding to the output request to the engine 1 by the driver's accelerator operation, and the engine output corresponding to the output request is obtained by burning the air-fuel mixture in the cylinder. Become.

Next, adjustment of the in-cylinder air amount when the intake valve 9 of the engine 1 is closed will be described in detail.
Regarding the adjustment of the in-cylinder air amount in the engine 1, as the accelerator operation amount increases, the throttle valve 13 is operated to the open side to increase the air flow area of the passage 3, and the cylinder when the intake valve 9 is closed. It is conceivable to employ an adjustment method in which the amount of internal air is increased. However, in this case, when adjusting the in-cylinder air amount to a small value, the throttle valve 13 in the intake passage 3 is operated to the closed side region, so that the pump loss of the engine 1 increases and the fuel consumption of the engine 1 increases. Will be adversely affected.

  In view of this, in this embodiment, the opening / closing characteristics of the intake valve 9 by driving the variable valve mechanisms such as the variable valve lift mechanism 14 and the variable intake valve timing mechanism 16, that is, the maximum lift amount and the operating angle, and the valve The in-cylinder air amount is adjusted by changing the timing. In this case, the opening degree of the valve 13 can be adjusted to a value on the open side as compared with the case where the in-cylinder air amount is adjusted only by adjusting the opening degree of the throttle valve 13. By adjusting the degree, it is possible to reduce the pump loss of the engine 1 and to improve the fuel consumption of the engine 1.

  When adjusting the in-cylinder air amount through variable of the maximum lift amount and the operating angle of the intake valve 9 and the valve timing, the adjustment is performed, for example, as follows based on the accelerator operation amount. That is, the target operating angle is set as a target value of the maximum lift amount and operating angle of the intake valve 9 based on the accelerator operation amount and the engine speed, and the target operating operation is performed so that the operating angle of the intake valve 9 becomes the target operating angle. Based on the angle, the variable valve lift mechanism 14 is driven. Since the maximum lift amount and the operating angle of the intake valve 9 are made variable in synchronization as described above by driving the valve lift variable mechanism 14, the valve is set so that the operating angle becomes a target value (target operating angle). Driving the variable lift mechanism 14 also drives the mechanism 14 so that the maximum lift amount becomes a target value. A target valve timing, which is a target value of the valve timing of the intake valve 9, is also set based on the accelerator operation amount and the engine rotation speed, and the target valve for setting the valve timing of the intake valve 9 as the target valve timing is also set. The intake side valve timing variable mechanism 16 is also driven based on the timing.

  The target operating angle and the target valve timing set based on the accelerator operation amount and the engine speed are the target opening / closing characteristics that are target values of the opening / closing characteristics of the intake valve 9. Regarding the target opening / closing characteristics such as the target operating angle and the target valve timing, an in-cylinder air amount where the engine output becomes a value corresponding to the accelerator operation amount is obtained under the condition that the engine 1 is in a steady operation, and The open / close characteristics of the intake valve 9 (maximum lift amount and operating angle, and valve timing) at which the fuel efficiency of the intake air is optimized by reducing pump loss or the like. Here, if the accelerator operation amount is changed while maintaining the steady state of the engine 1 such as gradually changing the accelerator operation amount, the target opening / closing characteristics (target operating angle and target valve timing) also change accordingly. become. The curve representing the transition of the target operating angle and the target valve timing that changes in this way indicates the transition of the operating angle (maximum lift amount) and valve timing of the intake valve 9 that can optimize the fuel consumption of the engine 1 by reducing pump loss or the like. This represents the fuel consumption optimal operation line.

  Incidentally, this optimum fuel consumption operation line is, for example, as shown by a solid line in FIG. Then, when adjusting the in-cylinder air amount based on the accelerator operation amount to adjust the engine output to a value corresponding to the output request for the engine 1 of the driver, the actual operating angle and valve timing of the intake valve 9 are set as described above. The fuel consumption of the engine 1 can be brought into an optimal state by making the transition on the fuel consumption optimal operation line in accordance with the target operating angle and the target valve timing.

  By the way, when the driver suddenly changes the accelerator operation amount and the engine 1 enters a transient operation state, the target opening / closing characteristics such as the target operating angle and target valve timing of the intake valve 9 also change suddenly in accordance with the sudden change of the accelerator operation amount. Will do. For example, when the accelerator operation amount is suddenly changed from small to large, the target operating angle and the target valve timing are changed from the state corresponding to the small accelerator operation amount on the fuel efficiency optimum operation line (solid line in FIG. 5). It suddenly changes to a state corresponding to a large quantity.

  On the optimum operation line in FIG. 5, the state corresponding to the small amount of accelerator operation at the target operating angle and the target valve timing is, for example, the state indicated by the point P1, and the accelerator operation at the target operating angle and the target valve timing is shown. An example of the state corresponding to the large amount is a state indicated by a point P2. Therefore, when the accelerator operation amount is suddenly changed from small to large, the target operating angle and the target valve timing are suddenly changed from the state of the point P1 on the same line to the state of the point P2, for example, along the fuel efficiency optimum operation line. To do.

  When the target operating angle and target valve timing of the intake valve 9 change suddenly in this way, the actual operating angle (maximum lift amount) and valve timing of the intake valve 9 are changed with respect to the target operating angle and the target valve timing, respectively. It is difficult to follow with good responsiveness. This is because a response delay occurs in changes in the actual operating angle (maximum lift amount) and valve timing of the intake valve 9 by driving variable valve mechanisms such as the variable valve lift mechanism 14 and the intake side valve timing variable mechanism 16. . In other words, when the target operating angle and the speed of the target valve timing when the accelerator operation amount changes with a sudden change, the actual operating angle (maximum lift amount) of the intake valve 9 and the valve timing change. It will be faster than possible. In this case, when the accelerator operation amount is suddenly changed, the target operating angle and target valve timing of the intake valve 9 change on the fuel consumption optimum operating line and change suddenly, whereas the actual operating angle (maximum lift) of the intake valve 9 changes. Quantity) and valve timing cannot follow the target operating angle and target valve timing which change suddenly as described above.

  Thus, when the actual operating angle and valve timing of the intake valve cannot follow the target operating angle and target valve timing, the actual operating angle and valve timing reach the target operating angle and target valve timing at the fastest speed. The variable valve lift mechanism 14 and the intake side valve timing variable mechanism 16 are driven. Therefore, the actual operating angle and valve timing are linear as shown by the arrows in the figure with respect to the target operating angle and target valve timing that change from the point P1 to the point P2, for example, on the fuel efficiency optimum operating line. As a result, the fuel consumption is changed so as to approach the fuel consumption optimum operation line. Therefore, in the transient operation state of the engine 1 due to a sudden change in the accelerator operation amount, the actual operating angle (maximum lift amount) and valve timing of the intake valve 9 cannot be changed on the fuel efficiency optimum operation line. It becomes inevitable that the fuel consumption of the engine 1 deteriorates.

  In order to deal with such a problem, in the present embodiment, when the engine 1 enters a transient operation state due to a sudden change in the accelerator operation amount, the in-cylinder air amount when the intake valve 9 is closed corresponds to the accelerator operation amount. Therefore, when the actual operating angle and valve timing of the intake valve 9 are changed, they can be changed on the fuel efficiency optimum operation line.

  Specifically, the target operating angle and the target valve timing of the intake valve 9 in the process of changing the accelerator operation amount that changes suddenly are changed on the fuel efficiency optimal operation line as follows based on the accelerator operation amount and the engine speed. That is, when the valve lift variable mechanism 14 and the intake valve timing variable mechanism 16 are driven based on the target operating angle and target valve timing to vary the operating angle and valve timing of the intake valve 9, the operating angle and valve timing are changed. The target operating angle and the target valve timing are changed at such a speed that the timing can change on the fuel efficiency optimum operation line.

  As a result, when the engine 1 is in a transient operation state due to a sudden change in the accelerator operation amount, the occurrence of the above-described problem that the actual operating angle and valve timing of the intake valve 9 cannot be changed on the fuel efficiency optimal operation line is suppressed. As a result, the fuel consumption of the engine 1 can be improved.

  Next, an outline of processing for changing the target operating angle and target valve timing of the intake valve 9 as described above in the transient operation state of the engine 1 due to a sudden change in the accelerator operation amount will be described with reference to FIG. FIG. 3 is a flowchart showing a target opening / closing characteristic setting routine for setting target opening / closing characteristics such as a target operating angle and target valve timing of the intake valve 9. The target opening / closing characteristic setting routine is periodically executed through the electronic control unit 21 by, for example, a time interruption every predetermined time.

  In the routine, first, based on the accelerator operation amount and the engine speed, a target in-cylinder air amount KL that is a target value of the in-cylinder air amount when the intake valve 9 is closed is calculated (S101). Specifically, the maximum amount when the in-cylinder air amount is adjusted when the intake valve 9 is closed based only on the opening / closing operation of the throttle valve 13 based on the conditions of the accelerator operation amount and the engine rotation speed. The in-cylinder air amount at the charging efficiency is obtained, and the obtained value is set as the target in-cylinder air amount KL.

  Thereafter, the target operating angle tθ and the target valve timing tVVTin of the intake valve 9 are set based on the target in-cylinder air amount KL so as to obtain the in-cylinder air amount corresponding to the set target in-cylinder air amount KL. The target valve timing tVVTex of the exhaust valve 10 based on the target in-cylinder air amount KL is also set (S102).

  The variable valve lift mechanism 14 and the variable intake valve timing are set based on the target operating angle tθ and the target valve timing tVVTin so that the operating angle and the valve timing of the intake valve 9 become the target operating angle tθ and the target valve timing tVVTin, respectively. The mechanism 16 is driven. Further, the exhaust side valve timing variable mechanism 17 is driven based on the target valve timing tVVTex so that the valve timing of the exhaust valve 10 becomes the target valve timing tVVTex.

  Here, a case where the accelerator operation amount changes suddenly and the engine 1 enters a transient operation state will be described. In this case, the maximum charging efficiency when the in-cylinder air amount is adjusted only by the opening / closing operation of the throttle valve 13 based on the accelerator operation amount and the engine speed in the changing process in the excessive operation state through the process of step S101. The transition of the in-cylinder air amount at is obtained, and the transition value is set to the target in-cylinder air amount KL.

  As a result, the target in-cylinder air amount KL in the changing process when the accelerator operation amount suddenly changes is the value obtained when the in-cylinder air amount is adjusted only by opening / closing the throttle valve 13 based on the change in the accelerator operation amount. The value is almost equal to the actual in-cylinder air amount at the maximum charging efficiency. In other words, the target in-cylinder air amount KL is determined based on the operating angle of the intake valve 9 and the response delay of the valve timing due to the drive of the variable valve lift mechanism 14 and the variable intake valve timing mechanism 16, While the valve timing is changed on the fuel efficiency optimum operation line (solid line in FIG. 5), the value becomes substantially equal to the in-cylinder air amount that can be realized by the change.

  The target operating angle tθ and the target valve timing tVVTin set based on the target in-cylinder air amount KL are the same when the operating angle and valve timing of the intake valve 9 are varied based on them. The timing shifts on the optimum fuel consumption operation line at a speed at which the timing can be shifted on the optimum fuel consumption operation line. Therefore, when the engine 1 enters a transient operation state due to a sudden change in the accelerator operation amount, the operating angle of the intake valve 9 is set so that the in-cylinder air amount when the intake valve 9 is closed is a value corresponding to the accelerator operation amount. When the valve timing is changed, they can be changed on the fuel efficiency optimum operation line, and thereby the fuel efficiency of the engine 1 can be improved.

  Next, a procedure for setting a target throttle opening used as a target value when the throttle valve 13 is opened and closed will be described with reference to a flowchart of FIG. 7 showing a target throttle opening setting routine.

  In this routine, first, a target intake pressure tPm that is a target value of the pressure on the downstream side of the throttle valve 13 in the intake passage 3 is set (S201). Specifically, based on the target in-cylinder air amount KL set in the target opening / closing characteristic setting routine (FIG. 6), the target operating angle tθ of the intake valve 9 and the target valve timing tVVTin, the maximum charging efficiency is realized in that state. The pressure on the downstream side of the throttle valve 13 in the intake passage 3 to be obtained is obtained, and the obtained value is set as the target intake pressure tPm.

  Thereafter, a target throttle opening tTA that is a target value of the opening of the throttle valve 13 is set based on the set target intake pressure tPm (S202). Specifically, the target throttle opening degree tTA is set based on the target intake pressure tPm as a value for setting the pressure on the downstream side of the throttle valve 13 in the intake passage 3 as the target intake pressure tPm. When the target throttle opening degree tTA is thus set, the throttle valve 13 is opened and closed based on the target throttle opening degree tTA so that the opening degree of the throttle valve 13 becomes the target throttle opening degree tTA.

  Here, a case where the accelerator operation amount changes suddenly and the engine 1 enters a transient operation state will be described. Also in this case, the throttle in the intake passage 3 that can achieve the maximum charging efficiency in the state based on the target in-cylinder air amount KL, the target operating angle tθ of the intake valve 9 and the target valve timing tVVTin through the process of step S202. The pressure on the downstream side of the valve 13 is set to the target intake pressure tPm. Thereby, even when the accelerator operation amount changes suddenly, the opening degree of the throttle valve 13 that can set the pressure on the downstream side of the throttle valve 13 in the intake passage 3 as the target intake pressure tPm is set to the target throttle opening degree tTA. The valve 13 is opened and closed so that the opening becomes the target throttle opening tTA.

  By the opening / closing operation of the throttle valve 13 and the driving of the variable valve lift mechanism 14 and the intake side valve timing variable mechanism 16 based on the target operating angle tθ and the target valve timing tVVTin described above, the intake valve 9 When the valve is closed, the cylinder air amount becomes the target cylinder air amount KL. In other words, the in-cylinder air amount is a value corresponding to an output request to the engine 1 by the driver's accelerator operation. Therefore, the engine output corresponding to the output request can be obtained through the combustion of the air-fuel mixture consisting of air and fuel in the cylinder. Further, the opening / closing operation of the throttle valve 13 based on the target throttle opening degree tTA described above enables the opening degree of the throttle valve 13 while setting the in-cylinder air amount when the intake valve 9 is closed to the target in-cylinder air amount KL. As long as the value is on the open side, in other words, the value is optimal for reducing the pump loss of the engine 1.

  Next, an engine that adjusts the in-cylinder air amount when the intake valve 9 is closed by varying the opening / closing characteristics such as the operating angle (maximum lift amount) and valve timing of the intake valve 9 and the opening / closing operation of the throttle valve 13. The intake control 1 will be described with reference to FIG. FIG. 2 is a control block diagram showing an outline of processing executed by the electronic control unit 21 in performing the intake control.

  The process B1 for setting the target in-cylinder air amount KL corresponds to step S101 (FIG. 6) of the target opening / closing characteristic setting routine. In the process B1, the following in-cylinder air amount KL is calculated based on the throttle passage intake air temperature Ta, the intake pipe intake air temperature Tm, the inclination a, the estimated intake pressure Pm, and the residual burned gas amount b. (Ta / Tm) · (a · Pm−b) (1) ”.

  The throttle passage intake air temperature Ta is the temperature of air passing around the throttle valve 13 in the intake passage 3, and the intake pipe intake air temperature Tm is the temperature of air flowing downstream of the throttle valve 13 in the intake passage. Incidentally, in the above equation (1) used in the processing B1, the term “Ta / Tm” based on the throttle passage intake air temperature Ta and the intake pipe intake air temperature Tm is assumed to be “1.0”.

  The estimated intake pressure Pm is the throttle in the intake passage 3 when it is assumed that the in-cylinder air amount when the intake valve 9 is closed is adjusted only by opening / closing the throttle valve 13 based on the accelerator operation amount and the engine speed. This is an estimated value of the pressure on the downstream side of the valve 13. This estimated intake pressure Pm is based on an estimated throttle passage air flow rate that is a value obtained by estimating the flow rate of air downstream of the valve 13 in the intake passage 3 when the throttle valve 13 is opened and closed as described above. It is calculated using a model formula determined by experiments or the like.

  The estimated throttle passage air flow used for calculating the estimated intake pressure Pm is based on the assumption that the in-cylinder air amount is adjusted only by opening / closing the throttle valve 13 based on the accelerator operation amount and the engine speed. Based on an estimated throttle opening, etc., which is an estimated value of the opening of the valve 13, it is calculated using a model formula determined by experiments or the like. Further, the estimated throttle opening used for calculating the estimated throttle passage air flow rate is calculated using a model formula determined by an experiment or the like based on the accelerator operation amount and the engine speed.

  The slope a is a value that determines the magnitude of the change in the target in-cylinder air amount KL with respect to the change in the estimated in-cylinder pressure Pm in the relationship between the estimated intake pressure Pm and the target in-cylinder air amount KL expressed by Equation (1). The residual burned gas amount b is a value corresponding to the amount of exhaust gas remaining in the cylinder when the intake valve 9 is closed. In FIG. 9, the solid line shows the change with respect to the change in the estimated intake pressure Pm with respect to the target in-cylinder air amount KL set by the equation (1). The solid line, the inclination a, the residual burned gas amount b, Has the relationship shown in FIG. The inclination a and the amount of residual burned gas b are determined by referring to a map determined in advance through experiments or the like based on the operating angle and valve timing of the intake valve 9 that provides the maximum charging efficiency at the engine speed at that time. Calculated.

  As for the operating angle and the valve timing used for calculating the inclination a and the residual burned gas amount b, for example, the operating angle and valve timing of the intake valve 9 at which the maximum charging efficiency is obtained at each engine speed. Is calculated based on the engine speed.

  In FIG. 8, the process B2 for setting the target operating angle tθ and the target valve timings tVVTin and tVVTex corresponds to step S102 (FIG. 6) of the target opening / closing characteristic setting routine. In the process B2, according to the target in-cylinder air amount KL, the target operating angle tθ and the target valve timing tVVTin of the intake valve 9 that can maximize the fuel efficiency improvement by reducing the pump loss of the engine 1, and the exhaust valve 10 are set. The target valve timing tVVTex is set. Then, the variable valve lift mechanism 14 and the intake side valve timing variable mechanism 16 are driven based on the target operating angle tθ and the target valve timing tVVTin set as described above, whereby the operating angle and valve timing of the intake valve 9 are respectively set. The target operating angle tθ and the target valve timing tVVTin are set. Further, the exhaust side valve timing variable mechanism 17 is driven based on the target valve timing tVVTex set as described above, so that the valve timing of the exhaust valve becomes the target valve timing tVVTex.

  The process B3 for setting the target intake pressure tPm in FIG. 8 corresponds to step S201 (FIG. 7) of the target throttle opening setting routine. In the process B3, the pressure on the downstream side of the throttle valve 13 in the intake passage 3 that can realize the maximum charging efficiency based on the target cylinder air amount KL, the target operating angle tθ, and the target valve timing tVVTin. The target intake pressure tPm is set. Specifically, based on the target in-cylinder air amount KL and the target valve timing tVVTin, the maximum charging efficiency in that state is obtained by referring to a map determined in advance through experiments or the like, and the maximum charging efficiency and the target operating angle tθ are determined. Using this, the target intake pressure tPm is set. FIG. 11 shows the relationship between the maximum charging efficiency and the target intake pressure tPm with a solid line for each target operating angle tθ. Then, the target intake pressure tPm set as described above is set as a value corresponding to the obtained maximum charging efficiency based on the solid line corresponding to the target operating angle tθ.

The process B4 for setting the target throttle opening tTA in FIG. 8 corresponds to step S202 (FIG. 7) of the target throttle opening setting routine.
In the process B4, first, the throttle passage air amount mt for setting the in-cylinder air amount when the intake valve 9 is closed to the target in-cylinder air amount KL is the intake passage volume V, the air gas constant R, the intake air amount. Based on the pipe intake temperature Tm, the target intake pressure tPm, and the target in-cylinder air amount KL, it is calculated using the following equation: “mt = V / (R · Tm) · (dtPm / dt) + KL (2)” The The throttle passage air amount mt in equation (2) is the amount of air that passes around the throttle valve 13 in the intake passage 3 from when the intake valve 9 is opened to when the intake valve 9 is closed. In addition, as the intake pipe intake air temperature Tm in the expression (2), a standard constant value is used as the temperature of the air downstream of the throttle valve 13 in the intake passage 3. In addition, the term “dtPm / dt” in Equation (1) represents a value obtained by differentiating the target intake pressure tPm with respect to time.

  Thereafter, the throttle opening area μAt as the opening area of the throttle valve 13 for obtaining the throttle passing air amount mt is based on the air gas constant R, the throttle passing intake air temperature Ta, the target intake pressure tPm, and the atmospheric pressure Pac. It is calculated using the following formula: “μAt = [{square root (R · Ta)} · mt] / φ (tPm / Pac) (3)”. In addition, the term “square root (R · Ta)” in the expression (3) represents the square root of “R · Ta”. In addition, as the throttle passage intake air temperature Ta and the atmospheric pressure Pac in the expression (3), for example, constant values in a standard state such as a standard atmospheric pressure and a standard atmospheric temperature are used. Further, the term “φ (tPm / Pac)” in the equation (2) is calculated with reference to the map of FIG. 12 that is determined in advance by experiments or the like based on the term “tPm / Pac”.

  Then, the target throttle opening tTA is calculated based on the throttle opening area μAt calculated using the equation (2) as described above. The calculation of the target throttle opening degree tTA is performed, for example, with reference to a map determined in advance by experiments or the like based on the throttle opening area μAt. The calculated target throttle opening tTA is set as a target value for the opening of the throttle valve 13. FIG. 13 is a graph showing the relationship between the target throttle opening tTA and the throttle opening area μAt set in this way. When the target throttle opening degree tTA is set as described above, the valve 13 is opened and closed so that the opening degree of the throttle valve 13 becomes the target throttle opening degree tTA.

  Finally, with respect to the intake control of the engine 1 in this embodiment, the control is executed during the transient operation of the engine 1, taking as an example the case where the accelerator operation amount suddenly changes from small to large and the engine 1 enters a transient operation state. This will be summarized with reference to FIG. 14A to 14F show the accelerator operation amount, the target cylinder air amount KL, the target operating angle tθ of the intake valve 9, and the target valve timing of the intake valve 9 when the engine is in a transient operation state. Changes in tVVTin, target intake pressure tPm, and target throttle opening tTA are shown.

  When the driver rapidly increases the accelerator operation amount from small to large as shown in FIG. 14 (a), the target in-cylinder air amount KL set based on the accelerator operation amount in the increasing process is the same. As in the transition of the in-cylinder air amount at the maximum charging efficiency when the in-cylinder air amount is adjusted only by the opening operation of the throttle valve 13 based on the accelerator operation amount, the transition proceeds to the increasing side. The transition of the target in-cylinder air amount KL to the increasing side at this time is shown in FIG. The target in-cylinder air amount KL that changes in this way is based on the operating angle of the intake valve 9 and the response delay of the valve timing due to the drive of the variable valve lift mechanism 14 and the intake side valve timing variable mechanism 16, and the operating angle thereof. In addition, while changing the valve timing on the fuel efficiency optimum operating line (solid line in FIG. 5), the value becomes substantially equal to the in-cylinder air amount that can be realized by the change.

  Further, the target operating angle tθ and the target valve timing tVVTin change as shown by the solid line (c) and the solid line (d) in FIG. 14 according to the target in-cylinder air amount KL changing as described above. Will be. Regarding the transition of the target operating angle tθ and the target valve timing tVVTin, when the operating angle and valve timing of the intake valve 9 are varied based on them, the operating angle and the valve timing (both shown by broken lines) are used as fuel consumption. It is performed on the fuel efficiency optimum operation line with a speed that can be shifted on the optimum operation line. Therefore, when the engine 1 enters a transient operation state due to a sudden increase in the accelerator operation amount, the in-cylinder air amount when the intake valve 9 is closed is set to a value corresponding to the accelerator operation amount. When the operating angle and the valve timing are changed, they can be changed on the fuel efficiency optimum operation line, and thereby the fuel efficiency of the engine 1 can be improved.

  Further, the target intake pressure tPm is set based on the target in-cylinder air amount KL when the accelerator operation amount suddenly changes from small to large, the target operating angle tθ of the intake valve 9 and the target valve timing tVVTin. The target intake pressure tPm set in this way is the downstream side of the throttle valve 13 in the intake passage 3 that can achieve the maximum charging efficiency in the state of the target in-cylinder air amount KL, the target operating angle tθ, and the target valve timing tVVTin. The value corresponds to the pressure, and changes as indicated by the solid line in FIG. In order to obtain the target intake pressure tPm that changes in this way, in other words, the target throttle opening tTA so that the pressure (actual intake pressure) on the downstream side of the throttle valve 13 in the intake passage 3 becomes the target intake pressure tPm. Is set. As a result, the target throttle opening degree tTA changes as shown in FIG. Then, by opening / closing the throttle valve 13 based on the target throttle opening degree tTA, the opening degree of the throttle valve 13 can be achieved while setting the in-cylinder air amount when the intake valve 9 is closed to the target in-cylinder air amount KL. As much as possible, the value on the open side, in other words, the optimum value for reducing the pump loss of the engine 1 is set. By adjusting the opening of the throttle valve 13 at this time, the transition of the actual intake pressure (broken line in FIG. 14E) substantially matches the transition of the target intake pressure tPm indicated by the solid line in FIG.

  Here, the case where the accelerator operation amount suddenly changes from small to large and the engine 1 enters a transient operation state has been described as an example. However, in the transient operation state of the engine 1 where the accelerator operation amount changes suddenly from large to small. However, the advantage by executing the intake control described above can be obtained similarly.

According to the embodiment described in detail above, the following effects can be obtained.
(1) When the accelerator operation amount changes abruptly, the target in-cylinder air amount KL set based on the accelerator operation amount in the changing process can be obtained only by opening / closing the throttle valve 13 based on the accelerator operation amount. It changes in the same way as the change in the amount of air in the cylinder at the maximum charging efficiency when the adjustment is made. The target in-cylinder air amount KL that changes in this way is based on the operating angle of the intake valve 9 and the response delay of the valve timing due to the drive of the variable valve lift mechanism 14 and the intake side valve timing variable mechanism 16, and the operating angle thereof. In addition, while changing the valve timing on the fuel efficiency optimum operating line, the value becomes substantially equal to the in-cylinder air amount that can be realized by the change. Therefore, the target operating angle tθ and the target valve timing tVVTin set based on the target in-cylinder air amount KL are the same when the operating angle and valve timing of the intake valve 9 are varied based on them. The valve timing shifts on the fuel consumption optimal operation line at a speed at which the valve timing can be shifted on the fuel consumption optimal operation line. Therefore, when the engine 1 enters a transient operation state due to a sudden change in the accelerator operation amount, the operating angle of the intake valve 9 is set so that the in-cylinder air amount when the intake valve 9 is closed is a value corresponding to the accelerator operation amount. When the valve timing is changed, they can be changed on the fuel efficiency optimum operation line, and thereby the fuel efficiency of the engine 1 can be improved.

  (2) Based on the target in-cylinder air amount KL when the accelerator operation amount suddenly changes, the target operating angle tθ of the intake valve 9 and the target valve timing tVVTin, the intake passage 3 capable of realizing the maximum charging efficiency in those states The target intake pressure tPm is set as the pressure downstream of the throttle valve 13. Then, the target throttle opening tTA is set so as to obtain the target intake pressure tPm set in this way, and the throttle valve 13 is opened and closed based on the target throttle opening tTA. Accordingly, the cylinder air amount when the intake valve 9 is closed is set to the target cylinder air amount KL, and the opening degree of the throttle valve 13 is set to the open side as much as possible, in other words, the pump loss of the engine 1 is reduced. Can be set to an optimum value.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows the whole engine with which the intake control device of this embodiment is applied. The timing chart which shows the transition (valve opening / closing characteristic) of the lift amount of an intake valve and an exhaust valve with respect to the change of a crank angle. The timing chart which shows transition (valve opening / closing characteristic) of the lift amount of the intake valve and the exhaust valve with respect to the change of a crank angle. The timing chart which shows the transition (valve opening / closing characteristic) of the lift amount of an intake valve and an exhaust valve with respect to the change of a crank angle. The graph which shows the fuel consumption optimal operation line of opening-and-closing characteristics, such as the operating angle of an intake valve, and valve timing. The flowchart which shows the procedure which sets the target valve timing of an intake valve and an exhaust valve, and the target valve timing of an intake valve. The flowchart which shows the setting procedure of target throttle opening. The control block diagram which shows the outline | summary of the process performed in an electronic controller in performing intake control of an engine. The graph which shows transition of the target cylinder air quantity with respect to the change of target intake pressure. A map that defines the target operating angle and target valve timing of the intake valve that provides the maximum charging efficiency for each engine speed. The graph which shows the relationship between the maximum filling efficiency for every target operating angle, and target intake pressure. The map for calculating | requiring the term "(phi) (tPm / Pac)" of Formula (3) based on a term "tPm / Pac". The graph which shows the relationship between throttle opening area and target throttle opening. (A) to (f) are time charts showing changes in the accelerator operation amount, the target in-cylinder air amount, the target operating angle, the target valve timing, the target intake pressure, and the target throttle opening when the engine is in a transient operation state. .

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Combustion chamber, 3 ... Intake passage, 4 ... Fuel injection valve, 5 ... Spark plug, 6 ... Piston, 7 ... Crankshaft, 8 ... Exhaust passage, 9 ... Intake valve, 10 ... Exhaust valve, 11 DESCRIPTION OF SYMBOLS ... Intake camshaft, 12 ... Exhaust camshaft, 13 ... Throttle valve, 14 ... Valve lift variable mechanism, 15 ... Electric motor, 16 ... Intake side valve timing variable mechanism, 17 ... Exhaust side valve timing variable mechanism, 21 ... Electronic control Devices (first setting means, second setting means, third setting means, fourth setting means, opening / closing characteristic control means, opening degree control means), 27 ... accelerator pedal, 28 ... accelerator position sensor, 30 ... Throttle position sensor 32 ... Air flow meter 34 ... Crank position sensor 35 ... Position sensor 36 ... Intake cam position sensor 37 Exhaust cam position sensor.

Claims (2)

The in-cylinder air amount when the intake valve is closed corresponds to the accelerator operation amount by opening and closing the throttle valve provided in the intake passage based on the accelerator operation amount to adjust the air flow area of the passage. Applied to an internal combustion engine that can be adjusted to a value, and equipped with a variable valve mechanism that can continuously change the opening and closing characteristics of the intake valve, corresponding to the accelerator operation amount of the in-cylinder air amount By adjusting the opening / closing characteristics of the intake valve by driving the variable valve mechanism, the opening of the throttle valve is adjusted only by the opening / closing operation of the valve. In the intake control device for an internal combustion engine that can be adjusted to a value on the open side compared to the case,
First setting means for setting a target in-cylinder air amount that is a target value of the in-cylinder air amount when the intake valve is closed based on the accelerator operation amount;
Second setting means for setting a target opening / closing characteristic, which is a target value of the opening / closing characteristic of the intake valve and is used when driving and controlling the variable valve mechanism, based on the target in-cylinder air amount;
An opening / closing characteristic control means for driving the variable valve mechanism based on the target opening / closing characteristic so that the opening / closing characteristic of the intake valve becomes the target opening / closing characteristic;
When the accelerator operation amount changes suddenly, the first setting means has a maximum when the in-cylinder air amount is adjusted only by opening / closing the throttle valve based on the accelerator operation amount in the changing process. An intake control device for an internal combustion engine, wherein a transition of the in-cylinder air amount at a charging efficiency is obtained, and a value of the transition is set as a target in-cylinder air amount. The intake control apparatus for an internal combustion engine according to claim 1,
A target intake pressure that is a target value of the pressure downstream of the throttle valve in the intake passage is set to a target in-cylinder air amount set by the first setting means and an intake air set by the second setting means. Third setting means for setting based on a target opening / closing characteristic of the valve;
A target throttle opening, which is a target value of the throttle valve opening, is set based on the target intake pressure as a value at which the pressure on the downstream side of the throttle valve in the intake passage becomes the target intake pressure. Setting means;
An opening control means for opening and closing the throttle valve based on the target throttle opening so that the opening of the throttle valve becomes the target throttle opening;
Further comprising
The third setting means obtains a pressure downstream of the throttle valve in the intake passage capable of realizing the maximum charging efficiency in the state based on the target cylinder air amount and the target opening / closing characteristic, and the obtained value Is set to the target intake pressure. An intake control device for an internal combustion engine, wherein

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