JP2002303163A - Control device for internal combustion engine with variable valve system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control the amount of air sucked into a combustion chamber even when the cause of the operation delay of a variable valve system is changed. SOLUTION: A valve lift amount changer 9 is controlled to be in a predetermined operation delayed condition defined by the cause of the operation delay of the valve lift amount changer 9, and the valve lift amount changer 9 is controlled to be in a targeted valve open condition in accordance with a targeted suction air amount corresponding to a required load and a predetermined operation delayed condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a control device for an internal combustion engine having a variable valve mechanism.

[0002]

2. Description of the Related Art Conventionally, a variable valve mechanism for changing a valve opening characteristic of an intake valve or an exhaust valve is provided, and the amount of intake air sucked into a combustion chamber is controlled by controlling the variable valve mechanism. A control device for an internal combustion engine with a variable valve mechanism is known. An example of this type of control device for an internal combustion engine with a variable valve mechanism is disclosed in Japanese Patent No. 2785505, for example. In the control device for an internal combustion engine with a variable valve mechanism described in Japanese Patent No. 2785505, the variable valve mechanism has an operation delay because it is controlled by hydraulic pressure. The operation delay of this variable valve mechanism is
For example, it occurs due to various operation delay causes such as a low oil temperature and a low engine speed. When the cause of the operation delay changes, for example, when the oil temperature changes or the engine speed changes, the operation delay of the variable valve mechanism changes.

[0003]

However, Patent No. 27
In the control device for an internal combustion engine with a variable valve mechanism described in Japanese Patent No. 85505, although the amount of intake air drawn into the combustion chamber is controlled by controlling the variable valve mechanism, the operation of the variable valve mechanism is controlled. No consideration is given to the fact that the operation delay of the variable valve mechanism changes as the cause of the delay changes. Therefore, in the control device for an internal combustion engine with a variable valve mechanism described in Japanese Patent No. 2785505, when the operation delay of the variable valve mechanism changes with the change in the cause of the operation delay of the variable valve mechanism, However, the actual operation delay of the variable valve mechanism deviates from the planned operation delay, and as a result, there is a possibility that the amount of intake air drawn into the combustion chamber cannot be appropriately controlled.

In view of the above problems, the present invention is provided with a variable valve mechanism capable of appropriately controlling the amount of intake air drawn into the combustion chamber even when the cause of the operation delay of the variable valve mechanism changes. It is an object to provide a control device for an internal combustion engine.

[0005]

According to the first aspect of the present invention, a variable valve mechanism for changing a valve opening characteristic of an intake valve or an exhaust valve is provided, and the variable valve mechanism is controlled. In a control device for an internal combustion engine with a variable valve mechanism that controls the amount of intake air drawn into the combustion chamber, the variable valve mechanism is controlled so as to be in a predetermined operation delay state determined by the cause of the operation delay of the variable valve mechanism. And controlling the variable valve mechanism based on the target intake air amount corresponding to the required load and the predetermined operation delay state so that the variable valve mechanism is in the target valve opening state. A control device for an internal combustion engine with a mechanism is provided.

In the control device for an internal combustion engine with a variable valve mechanism according to the first aspect, the variable valve mechanism is controlled so as to be in a predetermined operation delay state determined by the cause of the operation delay of the variable valve mechanism. Therefore, when the cause of the operation delay of the variable valve mechanism changes, the actual operation delay of the variable valve mechanism deviates from the scheduled operation delay with the change of the operation delay of the variable valve mechanism. Can be suppressed.
Specifically, in the control device for an internal combustion engine with a variable valve mechanism according to the first aspect, even if the operation delay of the variable valve mechanism changes as the cause of the operation delay of the variable valve mechanism changes. The variable valve mechanism is controlled so that the scheduled intake air amount and the actual intake air amount do not differ so much. Therefore, when the cause of the operation delay of the variable valve mechanism changes, the amount of intake air sucked into the combustion chamber more appropriately than the control device of the internal combustion engine with the variable valve mechanism described in Japanese Patent No. 2785505 is increased. Can be controlled.

According to the second aspect of the present invention, the intake air is changed so that the actual intake pipe pressure changes with a predetermined delay determined by the engine operating condition with respect to the change of the first target intake pipe pressure determined by the engine operating condition. While controlling the throttle valve, a second target intake pipe pressure is calculated by subtracting the operation delay of the variable valve mechanism from the actual intake pipe pressure, and the target of the variable valve mechanism is calculated based on the second target intake pipe pressure. The control apparatus for an internal combustion engine with a variable valve mechanism according to claim 1, wherein the control unit determines an open state.

In the control device for an internal combustion engine with a variable valve mechanism according to the present invention, for example, when the intake pipe pressure is controlled by a throttle valve, the intake pipe pressure changes immediately even if the throttle valve opening is changed. In view of the above, the intake throttle valve is controlled such that the actual intake pipe pressure changes with a predetermined delay determined from the engine operating conditions with respect to the change in the first target intake pipe pressure determined from the engine operating conditions. Therefore, when the engine operating condition changes, it is possible to prevent the intake throttle valve from being controlled so as to immediately change the actual intake pipe pressure even though the actual intake pipe pressure cannot be changed immediately. . Furthermore, in the control device for an internal combustion engine with a variable valve mechanism according to the second aspect, the intake pipe pressure can be controlled by the variable valve mechanism, and in view of the fact that the variable valve mechanism has an operation delay, the actual intake pressure is reduced. A second target intake pipe pressure is calculated by subtracting the operation delay of the variable valve mechanism from the pipe pressure. Therefore, a more appropriate target intake pipe pressure can be set than when the operation delay of the variable valve mechanism is not considered.

According to the third aspect of the invention, the actual valve opening state of the variable valve mechanism changes with a predetermined delay determined from the engine operating conditions with respect to the target valve opening state of the variable valve mechanism. In addition to controlling the variable valve mechanism actuator, a first target intake air amount is calculated based on a predetermined delay determined from the required load and the engine operating conditions and a gain determined from the engine operating conditions. Calculating a second target intake air amount obtained by subtracting an operation delay of the variable valve operating mechanism from the second target air amount, and determining a target valve opening state of the variable valve operating mechanism based on the second target intake air amount. A control device for an internal combustion engine with a variable valve mechanism according to 1 or 2 is provided.

In the control device for an internal combustion engine with a variable valve mechanism according to the third aspect, the variable valve mechanism has an operation delay, and the operation delay changes in accordance with a change in the cause of the operation delay. In view of the above, the variable valve mechanism actuator is controlled such that the actual valve opening state of the variable valve mechanism changes with a predetermined delay determined from the engine operating conditions with respect to the target valve opening state of the variable valve mechanism. Specifically, even if the operation delay of the variable valve mechanism changes as the cause of the operation delay of the variable valve mechanism changes, the scheduled open state of the variable valve mechanism and the The actuator for the variable valve mechanism is controlled so that the actual valve opening state does not differ so much. Therefore, when the operation delay of the variable valve mechanism is not taken into consideration, or when the operation delay of the variable valve mechanism is taken into account, the operation delay may change as the cause of the operation delay changes. It is possible to more appropriately control the actuator for the variable valve mechanism than in the case where it is not performed.

Further, in the control device for an internal combustion engine with a variable valve mechanism according to the third aspect, the valve opening state of the variable valve mechanism is changed more than when the intake air amount is changed by changing the throttle valve opening. The point that the intake air amount is changed more quickly when the intake air amount is changed by changing,
And that many drivers are more accustomed to the control responsiveness of the intake air amount by changing the throttle valve opening than the control responsiveness of the intake air amount by changing the valve opening state of the variable valve mechanism. In addition, in the case of delaying the change of the intake air amount, in consideration of the fact that the total intake air amount becomes excessive or insufficient unless the gain is set, a predetermined delay and the engine operating condition determined from the required load and the engine operating condition are considered. The first target intake air amount is calculated based on the gain determined from the following equation. Specifically, when the intake air amount is changed mainly by changing the opening state of the variable valve mechanism, or when the intake air amount is changed by changing the throttle valve opening, the intake air amount is changed. A predetermined delay is provided so that the control responsiveness is substantially the same as the control responsiveness. Further, the gain is set so that the actual intake air amount does not become excessive or insufficient as the control response of the intake air amount is delayed. Therefore, it is possible to prevent the control responsiveness of the intake air amount from becoming too fast, and to suppress the actual intake air amount from becoming excessive or insufficient relative to the target intake air amount.

Further, in the control device for an internal combustion engine with a variable valve mechanism according to the third aspect, in consideration of the fact that the variable valve mechanism has an operation delay, the operation delay of the variable valve mechanism is determined from the first target intake air amount. The discounted second target intake air amount is calculated.
Therefore, a more appropriate target intake air amount can be set than when the operation delay of the variable valve mechanism is not considered.

According to the fourth aspect of the present invention, the predetermined operation delay state is a state having an almost constant operation delay. A control device for an internal combustion engine with a variable valve mechanism is provided.

In the control apparatus for an internal combustion engine with a variable valve mechanism according to a fourth aspect, the predetermined operation delay state is a state having a substantially constant operation delay. Specifically, the predetermined operation delay state is such that the scheduled intake air amount and the actual intake air amount change even if the operation delay of the variable valve mechanism changes with the cause of the operation delay of the variable valve mechanism. The state is such that the intake air amount does not differ so much. Therefore, even when the cause of the operation delay of the variable valve mechanism changes, the intake air amount can be controlled as in the case where the cause of the operation delay does not change.

According to the fifth aspect of the present invention, in an internal combustion engine having a non-linear torque characteristic, control for linearizing near an operating point is performed. A control device for an internal combustion engine with a variable valve mechanism as described above is provided.

In the control device for an internal combustion engine with a variable valve mechanism according to the fifth aspect, the control for linearizing near the operating point is performed, so that the calculation can be simplified.

According to the invention described in claim 6, the predetermined delay is determined from the engine speed and the required load, and the gain is determined from the engine speed and the required load. A control device for an internal combustion engine with a variable valve mechanism as described above is provided.

In the control device for an internal combustion engine with a variable valve mechanism according to claim 6, the predetermined delay is determined from the engine speed and the required load, and the gain is determined from the engine speed and the required load. A more appropriate target intake air amount can be calculated than when a predetermined delay and a gain are determined from only one of the engine speed and the required load.

According to the seventh aspect of the present invention, the actual intake pipe pressure falls within the range of the intake pipe pressure which can be controlled to the target intake air amount by the variable valve operating mechanism. A control device for an internal combustion engine with a variable valve mechanism according to claim 2, wherein the control device controls the intake pipe pressure of the internal combustion engine.

In the control device for an internal combustion engine with a variable valve mechanism according to the present invention, the actual intake pipe pressure falls within the range of the intake pipe pressure which can be controlled to the target intake air amount by the variable valve mechanism. Thus, the actual intake pipe pressure is controlled by the intake throttle valve. Therefore, as the actual intake pipe pressure becomes a value outside the range of the intake pipe pressure that can be controlled to the target intake air amount by the variable valve operating mechanism, the actual intake pipe pressure and the target intake pipe pressure are reduced. Can be suppressed from being different.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a first embodiment of a control device for an internal combustion engine with a variable valve mechanism according to the present invention, and FIG.
FIG. 2 is a detailed view of an intake system and the like of the control device for an internal combustion engine with a variable valve mechanism shown in FIG. 1 and 2, 1 is an internal combustion engine, 2 is an intake valve, 3 is an exhaust valve, 4 is a cam for opening and closing the intake valve, 5 is a cam for opening and closing the exhaust valve, and 6 is a cam for the intake valve. Reference numeral 4 denotes a camshaft which carries the exhaust valve cam 7. FIG. 3 is a detailed view of the intake valve cam and camshaft shown in FIG. As shown in FIG. 3, the cam profile of the cam 4 of the present embodiment changes in the direction of the camshaft center axis. That is, in the cam 4 of the present embodiment, the nose height at the left end in FIG. 3 is larger than the nose height at the right end. That is, the valve lift of the intake valve 2 of the present embodiment is smaller when the valve lifter is in contact with the right end of the cam 4 than when the valve lifter is in contact with the left end of the cam 4.

Referring back to FIGS. 1 and 2, reference numeral 8 denotes a combustion chamber formed in the cylinder, and 9 denotes a cam 4 with respect to the intake valve 2 in the direction of the camshaft center axis to change the valve lift. This is a valve lift changing device for moving.
That is, by operating the valve lift changing device 9, the cam 4 and the valve lifter are brought into contact at the left end (FIG. 3) of the cam 4, or the cam 4 and the valve lifter are brought into contact at the right end (FIG. 3) of the cam 4. Or you can. When the valve lift of the intake valve 2 is changed by the valve lift changing device 9, the opening area of the intake valve 2 is changed accordingly. In the intake valve 2 of the present embodiment, as the valve lift increases, the intake valve 2
Are designed to increase the opening area. Reference numeral 10 denotes a driver for driving the valve lift changing device 9, and reference numeral 11 denotes an opening / closing timing shift device for shifting the opening / closing timing of the intake valve without changing the opening period of the intake valve 2. That is, by operating the opening / closing timing shift device 11, the opening / closing timing of the intake valve 2 can be shifted to the advance side or the retard side. Reference numeral 12 denotes an oil control valve that controls a hydraulic pressure for operating the opening / closing timing shift device 11.

Reference numeral 13 denotes a crankshaft, 14 denotes an oil pan, 15 denotes a fuel injection valve, 16 denotes a sensor for detecting a valve lift amount and an opening / closing timing shift amount of the intake valve 2, and 17 denotes an engine speed. It is a sensor.
Reference numeral 18 denotes an intake pipe pressure sensor for detecting a pressure in an intake pipe for supplying intake air into the cylinder, 19 an air flow meter, 20 a cooling water temperature sensor for detecting the temperature of internal combustion engine cooling water, and 21 an in-cylinder. Intake air temperature sensor for detecting the temperature of the intake air supplied to the intake pipe,
Reference numeral 22 denotes an electronic control unit (ECU). 50 is a cylinder, 51 and 52 are intake pipes, 53 is a surge tank, 54 is an exhaust pipe, 55 is a spark plug, and 56 is a throttle valve whose opening can be changed irrespective of the accelerator pedal opening.
In the present embodiment, the amount of intake air sucked into the combustion chamber 8 is controlled by the valve opening characteristics of the intake valve 2 and the throttle valve opening. In other embodiments, however, they and the idle speed control valve (FIG. (Not shown), it is also possible to control the amount of intake air.

FIG. 4 is a detailed view of the valve lift changing device shown in FIG. 4, reference numeral 30 denotes a magnetic body connected to the intake valve camshaft 6, 31 denotes a coil for urging the magnetic body 30 to the left, and 32 denotes a compression spring for urging the magnetic body 30 to the right. is there. As the amount of energization to the coil 31 increases, the amount by which the cam 4 and the camshaft 6 move to the left increases, and the valve lift of the intake valve 2 decreases.

FIG. 5 shows how the valve lift of the intake valve changes as the valve lift changing device is operated. As shown in FIG. 5, the valve lift of the intake valve 2 is increased as the amount of current supplied to the coil 31 is reduced (solid line → dashed line → dashed line). Further, in the present embodiment, the opening period of the intake valve 2 is also changed as the valve lift changing device 9 is operated. That is, the operating angle of the intake valve 2 is also changed. Specifically, as the valve lift of the intake valve 2 is increased, the operating angle of the intake valve 2 is increased (solid line → dashed line → dashed line). Further, in the present embodiment, the timing at which the valve lift amount of the intake valve 2 reaches a peak is changed as the valve lift amount changing device 9 is operated. More specifically, as the valve lift of the intake valve 2 is increased, the timing at which the valve lift of the intake valve 2 reaches its peak is delayed (solid line → dashed line → dashed line).

FIG. 6 is a detailed view of the opening / closing timing shift device shown in FIG. In FIG. 6, reference numeral 40 denotes the intake valve 2
Is an advance-side oil passage for shifting the opening / closing timing of the intake valve to the advance side, 41 is a retard-side oil passage for shifting the opening / closing timing of the intake valve 2 to the retard side, and 42 is an oil pump. As the oil pressure in the advance side oil passage 40 increases, the opening / closing timing of the intake valve 2 is shifted to the advance side.
That is, the camshaft 6 with respect to the crankshaft 13
Is advanced. On the other hand, the retard side oil passage 41
As the hydraulic pressure increases, the opening / closing timing of the intake valve 2 is shifted to the retard side. That is, the rotation phase of the camshaft 6 with respect to the crankshaft 13 is retarded.

FIG. 7 is a diagram showing how the opening / closing timing of the intake valve shifts as the opening / closing timing shift device is operated. As shown in FIG.
As the oil pressure within 0 increases, the opening / closing timing of the intake valve 2 is shifted to the advance side (solid line → dashed line → dashed line). At this time, the opening period of the intake valve 2 is not changed.
That is, the length of the period during which the intake valve 2 is open is not changed.

In this embodiment, the intake valve 2 is controlled by the valve lift changing device 9 and the opening / closing timing shift device 11.
The valve opening characteristics of the exhaust valve 3 are not changed, and the valve opening characteristics of the exhaust valve 3 are not changed. However, in other embodiments, the valve lift changing device and the opening / closing timing shift device for the exhaust valve are provided. It is also possible to make it possible to change the opening characteristics. In that case, it is possible to reduce the intake air amount by increasing the valve overlap amount of the intake valve and the exhaust valve. Further, in the present embodiment, the intake valve 2 and the exhaust valve 3 are mechanically driven by the cams 4 and 5, but in other embodiments, the intake valve and / or the exhaust valve can be electromagnetically driven. It is.

FIG. 8 is a block diagram showing a configuration of a control device for an internal combustion engine with a variable valve mechanism according to the first embodiment.
In FIG. 8, reference numeral 100 denotes an intake pipe pressure control block for controlling the intake pipe pressure, 200 denotes a valve lift control block for controlling the valve lift of the intake valve 2, and 3.
Reference numeral 00 denotes a target intake air amount calculation block for calculating a target intake air amount which is a target value of the intake air amount taken into the combustion chamber 8. Reference numeral 400 denotes a target valve lift calculation block for calculating a target valve lift which is a target value of the valve lift of the intake valve 2, and 500 denotes an accelerator pedal. As shown in FIG. 8, in a target intake air amount calculation block 300, an accelerator pedal opening θ which is an output value of an accelerator pedal opening sensor (not shown) attached to the accelerator pedal 500 is input, and the intake air amount is calculated. The calculated value mL, dm / dt, m for the quantity is output.

The target valve lift amount calculation block 400 receives the calculated values mL and dm / dt relating to the intake air amount calculated in the target intake air amount calculation block 300, and receives the intake pipe pressure sensor 18 of the internal combustion engine 1. Of the intake pipe pressure and the valve lift VL which is the output value of the sensor 16 of the internal combustion engine 1 are input, and further, the calculated value PL regarding the intake pipe pressure calculated in the intake pipe pressure control block 100 is input. Is done. On the other hand, from the target valve lift amount calculation block 400, the calculated value pm. limit, pm. dot. The calculated value Lr regarding the limit and the valve lift is output.

The intake pipe pressure control block 100 includes a value Pr relating to the intake pipe pressure determined from the intake pipe pressure required for the known purge control and the intake pipe pressure required for generating the known brake booster pressure. Is input, and the calculated value m regarding the intake air amount calculated in the target intake air amount calculation block 300 and the calculated value pm. Regarding the intake pipe pressure calculated in the target valve lift amount calculation block 400 are input. limit, pm. dot. li
mit and an intake pipe pressure P which is an output value of the intake pipe pressure sensor 18 of the internal combustion engine 1 are input. On the other hand, the intake pipe pressure control block 100 outputs a throttle valve opening TA indicating the opening of the throttle valve 56 to the internal combustion engine 1 and outputs a calculated value PL relating to the intake pipe pressure.

The valve lift control block 200 includes:
The calculated value Lr relating to the valve lift calculated in the target valve lift calculation block 400 and the internal combustion engine 1
And the valve lift amount VL, which is the output value of the sensor 16 of FIG. On the other hand, the valve lift amount control block 200 outputs a control duty Dvl for driving the valve lift amount changing device 9.

FIG. 9 is a detailed view of the intake pipe pressure control block 100 shown in FIG. In FIG. 9, reference numeral 101 denotes a block for setting a limit value regarding the intake pipe pressure. Specifically, the actual intake pipe pressure is controlled by the throttle valve 56 such that the actual intake pipe pressure falls within the range of the intake pipe pressure that can be controlled to the target intake air amount by the valve lift amount changing device 9. It is a block for. 1
02 is a block for calculating the throttle valve opening TA. 103 is a target intake pipe pressure PL obtained by subtracting the operation delay TL of the valve lift changing device 9 from the intake pipe pressure P.
Is a block for calculating. The relationship between the intake pipe pressure P and the target intake pipe pressure PL is, for example, PL = (1 + s × TL) P
(S is a predetermined constant). For example, in block 104, a limit value pm. The output with the limit imposed is output. In block 105, the difference between the two input values is output. In block 106, the gain is set by multiplying the input value by 1 / Tp. In block 107, the integrated value of the input value is output.

That is, in the intake pipe pressure control block 100, the actual intake pipe pressure is changed with a predetermined delay Tp determined from the engine speed or the like with respect to a change in the first target intake pipe pressure Pr determined from a purge request or a brake booster pressure. Pressure P
The throttle valve opening TA for controlling the throttle valve 56 is changed so as to change. Actual intake pipe pressure P
The relationship between the first target intake pipe pressure Pr and the predetermined delay Tp is, for example, P = Pr / (1 + s × Tp) (s is a predetermined constant). In the intake pipe pressure control block 100, a second target intake pipe pressure P obtained by subtracting the operation delay TL of the valve lift changer 9 from the actual intake pipe pressure P is calculated.
L is calculated and output.

FIG. 10 is a diagram showing the relationship between the actual intake pipe pressure P, the first target intake pipe pressure Pr, and the second target intake pipe pressure PL. As shown in FIG. 10, when, for example, the purge request changes at time t1 and the first target intake pipe pressure Pr changes, the intake pipe pressure does not change immediately even if the throttle valve opening TA is changed. Lift amount changing device 9
Has an operation delay TL, the second target intake pipe pressure PL is set as shown by a one-dot chain line. as a result,
The actual intake pipe pressure P is shown by a broken line.

FIG. 11 is a detailed view of the valve lift control block 200 shown in FIG. In FIG. 11, in block 201, a gain is set by multiplying the input target valve lift amount Lr by a value 1 / TL. Further, in block 202, the gain is set by multiplying by the value 1 / a. That is, even if a request to change the target valve lift amount Lr by the predetermined amount ΔLr is issued, the control duty Dvl of the valve lift amount changing device 9 at that time is set to, for example, ΔLr / (TL × a), which is smaller than ΔLr. Is done. That is, the valve lift is gradually changed over time. In other words, the actual valve opening state L of the valve lift amount changing device 9 differs from the target valve opening state (Lr) of the valve lift amount changing device 9 with respect to the engine speed, the cooling water temperature, and the like. Is controlled so as to change with a predetermined delay TL determined from. The relationship between the actual valve opening state L of the valve lift changing device 9, the target valve lift Lr, and the predetermined delay TL is, for example, L =
Lr / (1 + s × TL) (s is a predetermined constant).
Generally speaking, the valve lift changing device 9 is controlled so as to have a predetermined operation delay TL determined by the cause of the operation delay of the valve lift changing device such as the engine speed and the cooling water temperature. The operation delay TL is set so as not to change much even if the cause of the operation delay of the valve lift changing device changes. That is, this operation delay TL
Is set to be substantially constant even if the cause of the operation delay of the valve lift changing device changes. Therefore, even if the operation delay of the valve lift changing device 9 changes as the cause of the operation delay of the valve lift changing device 9 changes, the influence is reduced. That is, the change in the operation delay of the valve lift changer 9 becomes less noticeable. This effect is achieved by the valve lift changing device 9 as in the present embodiment.
Is more remarkable when the valve lift changing device is hydraulically driven than when electromagnetically driven.

FIG. 12 is a diagram showing the relationship between the target valve lift change amount Lr and the control duty Dvl of the valve lift change device 9. As shown in FIG.
When a request to change the target valve lift amount by the predetermined amount ΔLr is issued, for example, the control duty Dvl of the valve lift amount changing device 9 is set to ΔLr / (TL × a), and the valve lift amount gradually increases over time. Will be changed to

FIG. 13 is a detailed diagram of the target intake air amount calculation block 300 shown in FIG. In FIG. 13, in block 301, a predetermined delay Tm to be considered when calculating the first target intake air amount m from the input accelerator pedal opening (required load) θ is set. The predetermined delay Tm is set, for example, based on the engine speed, but instead, the engine speed and the accelerator pedal opening (required load)
It is also possible to set this predetermined delay Tm based on both of θ. Further, the predetermined delay Tm may be a predetermined constant. In block 302, a gain Km that is considered when calculating the first target intake air amount m from the input accelerator pedal opening (required load) θ is set. The gain Km is set, for example, based on the engine speed. Instead, the gain Km is set based on both the engine speed and the accelerator pedal opening (required load) θ.
It is also possible to set m. Also, this gain Km
May be a predetermined constant. As described above, the first target intake air amount m is calculated based on the accelerator pedal opening (required load) θ, the predetermined delay Tm, and the gain Km. The relationship between the first target intake air amount m, the accelerator pedal opening (required load) θ, the predetermined delay Tm, and the gain Km is, for example, m = (Km × θ) / (1 + s × Tm) (where s is Predetermined constant).

In block 303, the operation delay TL of the valve lift changing device 9 which is considered when calculating the second target intake air amount mL from the first target intake air amount m is set. The value of this actuation delay TL is the same as that used in blocks 100 and 200, but alternatively the value of this actuation delay TL may be different from that used in blocks 100 and / or 200. It is possible. As described above, the second target intake air amount mL is calculated by subtracting the operation delay TL of the valve lift changing device 9 from the first target intake air amount m. The relationship between the second target intake air amount mL, the first target intake air amount m, and the operation delay TL of the valve lift amount changing device is, for example, mL = (1 + s ×
TL) m (s is a predetermined constant).

FIG. 14 is a diagram showing the relationship between the accelerator pedal opening θ and the second target intake air amount mL. As shown in FIG. 14, when the accelerator pedal opening θ increases at time t3, the second target intake air amount mL becomes equal to the delays Tm and Tm described above.
It increases by the amount of L later than the accelerator pedal opening θ. Further, the second target intake air amount mL is equal to the gain K described above.
The value is temporarily increased by m. Next, when the accelerator pedal opening θ decreases at time t4, the second target intake air amount mL decreases after the accelerator pedal opening θ by the delays Tm and TL. Further, the second target intake air amount mL temporarily becomes smaller by the amount of the gain Km described above.

FIG. 15 is a detailed diagram of the target valve lift amount calculation block 400 shown in FIG. In FIG.
In block 401, based on the second target intake pipe pressure PL calculated in the intake pipe pressure control block 100, the second target intake air amount mL calculated in the target intake air amount calculation block 300, and a predetermined map or calculation formula. Thus, the target valve lift amount Lr is calculated. In a predetermined map or calculation formula, the target valve lift amount Lr increases as the second target intake pipe pressure PL increases, and
It increases as the second target intake air amount mL increases. In block 402, the actual intake pipe pressure is changed by the throttle valve 56 so that the actual intake pipe pressure change rate falls within the range of the intake pipe pressure change rate that can be controlled to the target intake air amount by the valve lift changer 9. Upper and lower limits of the change speed of the intake pipe pressure are set to control the change rate of the pipe pressure. In blocks 403 and 404, the actual intake pipe pressure is controlled by the throttle valve 56 such that the actual intake pipe pressure falls within the range of the intake pipe pressure that can be controlled to the target intake air amount by the valve lift amount changing device 9. Therefore, an upper limit and a lower limit of the intake pipe pressure are set.

That is, the target valve lift amount calculation block 400 changes the valve lift amount based on the target intake air amount m, mL corresponding to the accelerator pedal opening (required load) and the operation delay TL of the valve lift changing device. A target valve lift amount Lr for controlling the valve lift amount changing device 9 so that the device 9 is brought into the target valve opening state is calculated.
Specifically, based on the second target intake pipe pressure PL, a target valve lift amount Lr for controlling the valve lift amount changing device 9 so that the valve lift amount changing device 9 is in the target valve opening state is calculated. . Further, based on the second target intake air amount mL, a target valve lift amount Lr for controlling the valve lift amount changing device 9 such that the valve lift amount changing device 9 is brought into the target valve opening state is calculated.

In a modification of the present embodiment, in an internal combustion engine having a non-linear torque characteristic, control for linearizing near an operating point is performed. More specifically, when the intake air amount is desired to be m when the intake pipe pressure is pm, the valve lift amount VV
L is m = B × pm + C × VVL + A × pm × VVL + D (1) That is, VVL = (m−B × pm−D) / (C + A × pm) (2) , B, C, and D are predetermined constants). In the present invention, P is set in consideration of the operation delay of the valve lift changing device 9.
Since L and mL are used, the valve lift amount VVL is as follows: VVL = (mL−B × PL−D) / (C + A × PL) (3) This calculation formula (3) is executed in block 402 in the above-described embodiment. However, in this calculation method, a calculation error increases in an internal combustion engine having a non-linear torque characteristic. Therefore, in this modified example, the above-described equation (1) is changed to the operating point (pm = pm0,
Control for linearizing near (VVL = VVL0) is performed.
Specifically, the following linearization is performed. m = (dm.dpm) .times.pm + (dm.dVVL) .times.VVL-A.times.pm0.times.VVL0 + D (1 ') dm / dpm = B + A.times.VVL0 dm / dVVL = C + A.times.pm0

This equation (1 ') completely coincides with equation (1) at the operating point. Using this formula (1 ′), formula (3) is as follows. VVL = (mL-B * PL-DA * VVL0 * (PL-pm0)) / (C + A * pm0) (3 ') In this modification, the calculation formula (3') is used as the block 402. Used in corresponding blocks. This method is effective not only for the non-linear case represented by the mathematical formula as shown in the calculation formula (1) but also for the non-linear case represented by the map.

In another modification of this embodiment, the amount of intake air to be changed by changing the valve lift is
The intake pipe pressure is controlled so as to fall within the range of the intake air amount that changes by changing the valve lift amount. Further, in still another modification of the present embodiment, the actual intake air amount is estimated from the air-fuel ratio control based on the output value of the sensor, and the deviation between the estimated actual intake air amount and the target intake air amount is calculated. Feedback control is executed so as to disappear.

According to the above-described embodiment, the valve lift changing device 9 is controlled so as to be in a predetermined operation delay state determined by the operation delay cause of the valve lift changing device 9. Specifically, as shown in FIG. 12, even if the operation delay of the valve lift change device 9 changes with the change of the cause of the operation delay of the valve lift change device 9, the intake air scheduled to be changed. The valve lift changing device 9 is controlled so that the amount does not differ so much from the actual intake air amount. Therefore, when the cause of the operation delay of the valve lift amount changing device 9 changes, the actual operation delay of the valve lift amount changing device 9 is scheduled with the change of the operation delay of the valve lift amount changing device 9. The deviation from the operation delay can be suppressed. Therefore, when the cause of the operation delay of the valve lift changing device 9 changes, the patent No. 27
It is possible to control the amount of intake air drawn into the combustion chamber more appropriately than the control device for an internal combustion engine with a variable valve mechanism disclosed in Japanese Patent No. 85505.

Further, according to the above-described embodiment, when the intake pipe pressure is controlled by the throttle valve 56 or the idle speed control valve, the intake pipe pressure does not change immediately even if the throttle valve opening is changed. ,
For example, with respect to a change in the first target intake pipe pressure Pr determined from the engine operating conditions such as a purge request and a brake booster pressure request, the actual intake pipe pressure has a predetermined delay Tp determined from the engine operating conditions such as the engine speed. The throttle valve 56 and / or the idle throttle control valve are controlled so that P changes. Therefore, when the engine operating conditions such as a purge request and a brake booster pressure request change, the throttle valve 56 and the throttle valve 56 are configured to change the actual intake pipe pressure immediately even though the actual intake pipe pressure cannot be changed immediately. It is possible to prevent the idle throttle control valve from being controlled.

Further, according to the above-described embodiment, the intake pipe pressure can also be controlled by the valve lift changer 9, and in view of the fact that the valve lift changer 9 has an operation delay, the actual intake pipe pressure P Target intake pipe pressure PL obtained by subtracting the operation delay TL of the valve lift changing device 9 from
(= (1 + s × TL) P) is calculated. Therefore, a more appropriate target intake pipe pressure PL can be set than when the operation delay TL of the valve lift changer 9 is not considered.

According to the above-described embodiment, the valve lift changing device 9 has an operation delay, and the operation delay changes in accordance with a change in the cause of the operation delay. The actual valve opening state (L) of the valve lift changing device 9 changes with a predetermined delay TL determined from engine operating conditions such as the engine speed and cooling water temperature with respect to the target valve opening state (Lr) of No. 9. Thus, the valve lift changing device 9 is controlled. Specifically, as shown in FIG. 12, even if the operation delay of the valve lift amount changing device 9 changes as the cause of the operation delay of the valve lift amount changing device 9 changes, the valve lift amount changing device 9 does not operate. The valve lift changing device 9 is controlled so that the planned valve opening state and the actual valve opening state of the valve lift changing device 9 do not differ so much. Therefore, when the operation delay of the valve lift change device 9 is not taken into account, or the operation delay of the valve lift change device 9 is taken into account, the operation delay changes with the change of the cause of the operation delay. It is possible to control the valve lift changing device 9 more appropriately than in a case where possible points are not considered.

Further, according to the above-described embodiment, the valve opening state (Lr, Dvl) of the valve lift changer 9 is changed more than when the intake air amount is changed by changing the throttle valve opening TA. Therefore, when the intake air amount is changed, the intake air amount is changed more quickly, and many drivers change the valve opening state (Lr, Dvl) of the valve lift amount changing device 9 to perform suction. The point of getting used to the control responsiveness of the intake air amount by changing the throttle valve opening TA rather than the control responsiveness of the air amount, and if the change of the intake air amount is delayed, the gain must be set. In consideration of the fact that the total intake air amount becomes excessive or insufficient, the accelerator pedal opening (required load) θ
And a predetermined delay Tm determined from engine operating conditions such as the engine speed and the accelerator pedal opening θ and a gain Km determined from the engine operating conditions such as the engine speed and the accelerator pedal opening θ. The target intake air amount m is calculated. Specifically, the valve lift changing device 9 is mainly used.
When the intake air amount is changed by changing the valve opening state (Lr, Dvl), the control responsiveness of the intake air amount when the intake air amount is changed by changing the throttle valve opening TA and A predetermined delay Tm is provided so that control response is substantially the same. Further, the gain Km is set so that the actual intake air amount does not become excessive or deficient as the control response of the intake air amount is delayed. Therefore, it is possible to prevent the control responsiveness of the intake air amount from becoming too fast, and to suppress the actual intake air amount from becoming excessive or insufficient relative to the target intake air amount.

According to the above-described embodiment, in consideration of the fact that the valve lift changing device 9 has an operation delay TL, the second target in which the operation delay TL of the valve lift changing device 9 is subtracted from the first target intake air amount m. Second target intake air volume mL (=
(1 + s × TL)) is calculated. Therefore, a more appropriate target intake air amount mL can be set than when the operation delay TL of the valve lift amount changing device 9 is not considered.

Further, according to the above-described embodiment, the predetermined operation delay state is a state having an almost constant operation delay. Specifically, the predetermined operation delay state is such that even if the operation delay of the valve lift amount changing device 9 changes as the cause of the operation delay of the valve lift amount changing device 9 changes, the scheduled intake air The amount is not so different from the actual amount of intake air. More specifically, even if the cause of the operation delay of the valve lift changer 9 changes, the time required from the start of the change of the valve lift to the end of the change of the valve lift is substantially constant. The valve lift changing device 9 is controlled (see FIG. 12). Therefore, even when the cause of the operation delay of the valve lift changing device 9 changes, the intake air amount can be controlled in the same manner as when the cause of the operation delay does not change.

Further, according to the above-described embodiment, since the control for linearizing near the operating point is performed based on the calculation formula (3 ′), the calculation can be simplified. According to the above-described embodiment, the delay Tm is determined from the engine speed and the accelerator pedal opening (required load) θ, and the gain Km is determined from the engine speed and the accelerator pedal opening (required load) θ. Therefore, the target intake air amount can be calculated more appropriately than when the delay Tm and the gain Km are determined from only one of the engine speed and the accelerator pedal opening (required load) θ.

Further, according to the above-described embodiment, the throttle valve 56 and / or the throttle valve 56 are controlled so that the actual intake pipe pressure falls within the range of the intake pipe pressure which can be controlled to the target intake air amount by the valve lift amount changing device 9. Alternatively, the actual intake pipe pressure is controlled by an idle speed control valve. Therefore, as the actual intake pipe pressure becomes a value outside the range of the intake pipe pressure that can be controlled to the target intake air amount by the valve lift amount changing device 9, the actual intake pipe pressure and the target intake pipe The difference from the pressure can be suppressed.

In the above-described embodiment, the valve lift changing device 9 for the intake valve 2 is controlled with a delay TL. In other embodiments, the valve lift for the exhaust valve 3 is controlled. The control can be executed with a delay for the quantity changing device. That is, the present invention is applicable not only to the intake valve but also to the exhaust valve.

[0057]

According to the first aspect of the invention, when the cause of the operation delay of the variable valve mechanism changes, the actual operation of the variable valve mechanism changes as the operation delay of the variable valve mechanism changes. It can be suppressed that the operation delay of the device deviates from the scheduled operation delay. Therefore, when the cause of the operation delay of the variable valve mechanism changes, the amount of intake air sucked into the combustion chamber more appropriately than the control device of the internal combustion engine with the variable valve mechanism described in Japanese Patent No. 2785505 is increased. Can be controlled.

According to the second aspect of the present invention, when the engine operating conditions change, the intake throttle valve changes the actual intake pipe pressure immediately even though the actual intake pipe pressure cannot be changed immediately. Can be prevented from being controlled. Further, a more appropriate target intake pipe pressure can be set than when the operation delay of the variable valve mechanism is not considered.

According to the third aspect of the present invention, when the operation delay of the variable valve mechanism is not taken into consideration, or when the operation delay of the variable valve mechanism is taken into account, the cause of the operation delay varies. Accordingly, the variable valve mechanism actuator can be more appropriately controlled than when the operation delay is not considered. Further, it is possible to prevent the control response of the intake air amount from becoming too fast, and to suppress the actual intake air amount from becoming excessive or insufficient relative to the target intake air amount. Further, a more appropriate target intake air amount can be set than when the operation delay of the variable valve mechanism is not considered.

According to the fourth aspect of the present invention, even when the cause of the operation delay of the variable valve mechanism changes, the intake air amount can be controlled in the same manner as when the cause of the operation delay does not change. .

According to the fifth aspect of the invention, the calculation can be simplified.

According to the sixth aspect of the present invention, it is possible to calculate a target intake air amount more appropriate than when a predetermined delay and a predetermined gain are determined from only one of the engine speed and the required load.

According to the seventh aspect of the invention, the actual intake pipe pressure falls outside the range of the intake pipe pressure which can be controlled to the target intake air amount by the variable valve operating mechanism. Thus, it is possible to suppress the difference between the actual intake pipe pressure and the target intake pipe pressure.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a control device for an internal combustion engine with a variable valve mechanism according to the present invention.

FIG. 2 is a detailed view of an intake system and the like of the control device for the internal combustion engine with the variable valve mechanism shown in FIG. 1;

FIG. 3 is a detailed view of the intake valve cam and camshaft shown in FIG. 1;

FIG. 4 is a detailed view of a valve lift changing device and the like shown in FIG. 1;

FIG. 5 is a view showing a state in which the valve lift of the intake valve changes as the valve lift changing device is operated.

FIG. 6 is a detailed view of the opening / closing timing shift device shown in FIG. 1;

FIG. 7 is a diagram showing a state in which the opening / closing timing of the intake valve shifts as the opening / closing timing shift device is operated.

FIG. 8 is a block diagram showing a configuration of a control device for an internal combustion engine with a variable valve mechanism according to the first embodiment.

FIG. 9 is a detailed view of the intake pipe pressure control block 100 shown in FIG.

FIG. 10 shows an actual intake pipe pressure P and a first target intake pipe pressure P
FIG. 7 is a diagram showing a relationship between r and a second target intake pipe pressure PL.

11 is a valve lift amount control block 2 shown in FIG.
FIG.

FIG. 12 is a diagram showing a relationship between a target valve lift amount change amount Lr and a control duty Dvl of the valve lift amount change device 9.

13 is a target intake air amount calculation block 3 shown in FIG.
FIG.

FIG. 14 is a diagram showing a relationship between an accelerator pedal opening θ and a second target intake air amount mL.

FIG. 15 is a detailed diagram of a target valve lift amount calculation block 400 shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Intake valve 3 ... Exhaust valve 4, 5 ... Cam 6, 7 ... Camshaft 8 ... Combustion chamber in a cylinder 9 ... Valve lift change device 11 ... Opening / closing timing shift device 16 ... Sensor 18 ... Intake pipe Pressure sensor 19 ... Air flow meter 56 ... Throttle valve

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F02D 41/04 310 F02D 41/04 310C 320 320 41/18 41/18 D 43/00 301 43/00 301K 301Z F term (Reference) 3G018 AB07 AB17 BA04 BA31 CA12 EA11 EA16 EA26 FA01 FA06 FA07 FA08 FA09 GA06 3G084 BA05 BA23 DA05 FA02 FA07 FA10 FA11 FA20 FA33 FA38 FA39 3G092 AA11 BA02 DA01 DA02 DA04 DA10 DG05 DG09 EC02 EC08 FA09 HA01Z13 HF08Z 3G301 HA01 HA19 JA03 LA01 LA07 PA01Z PA07Z PA10Z PA11Z PE01Z PE04Z PE08Z PF03Z

Claims (7)

[Claims] A variable valve mechanism for changing a valve opening characteristic of an intake valve or an exhaust valve, wherein the variable valve mechanism controls the variable valve mechanism to control an amount of intake air drawn into a combustion chamber. In a control device for an internal combustion engine with a valve mechanism,
The variable valve mechanism is controlled to be in a predetermined operation delay state determined from the cause of the operation delay of the variable valve mechanism, and the variable valve mechanism is controlled based on the target intake air amount corresponding to the required load and the predetermined operation delay state. A control device for an internal combustion engine with a variable valve mechanism, wherein the variable valve mechanism is controlled so that the mechanism is in a target valve opening state. 2. The intake throttle valve is controlled such that the actual intake pipe pressure changes with a predetermined delay determined by the engine operating conditions with respect to the change of the first target intake pipe pressure determined by the engine operating conditions. The second target intake pipe pressure is calculated by subtracting the operation delay of the variable valve mechanism from the intake pipe pressure of the above, and the target valve opening state of the variable valve mechanism is determined based on the second target intake pipe pressure. The control device for an internal combustion engine with a variable valve mechanism according to claim 1. 3. The variable valve mechanism actuator is controlled such that an actual valve opening state of the variable valve mechanism changes with a predetermined delay determined from engine operating conditions with respect to a target valve opening state of the variable valve mechanism. At the same time, a first target intake air amount is calculated based on a predetermined delay determined from the required load and the engine operating condition and a gain determined from the engine operating condition, and the operation delay of the variable valve mechanism is calculated from the first target intake air amount. The variable valve actuation device according to claim 1 or 2, wherein a discounted second target intake air amount is calculated, and a target valve opening state of the variable valve actuation mechanism is determined based on the second target intake air amount. Control device for internal combustion engine with mechanism. 4. The system according to claim 1, wherein said predetermined operation delay state is a state having a substantially constant operation delay.
4. The control device for an internal combustion engine with a variable valve mechanism according to claim 3. 5. The internal combustion engine with a variable valve mechanism according to claim 1, wherein in the internal combustion engine having a non-linear torque characteristic, control for linearizing near an operating point is performed. Control device. 6. The internal combustion engine with a variable valve mechanism according to claim 3, wherein the predetermined delay is determined from an engine speed and a required load, and the gain is determined from the engine speed and a required load. Control device. 7. Controlling an actual intake pipe pressure by an intake throttle valve so that the actual intake pipe pressure falls within a range of an intake pipe pressure that can be controlled to a target intake air amount by a variable valve mechanism. The control device for an internal combustion engine with a variable valve mechanism according to claim 2.