JP6222210B2 - Control device for internal combustion engine - Google Patents

Description

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

  2. Description of the Related Art Conventionally, a control device for an internal combustion engine including an intake side variable valve timing mechanism and an exhaust side variable valve timing mechanism is known (see, for example, Patent Document 1).

  Such an internal combustion engine changes the rotational phase of the intake camshaft and the exhaust camshaft with respect to the crankshaft by the intake side variable valve timing mechanism and the exhaust side variable valve timing mechanism, thereby adjusting the valve timing of the intake valve and the exhaust valve. It is configured to be variable. Then, by controlling the overlap period of the intake valve and the exhaust valve according to the operating state of the internal combustion engine, it is possible to improve output, improve fuel consumption, reduce exhaust emission, and the like.

  And in the control apparatus of the internal combustion engine of patent document 1, when shifting from the acceleration operation to the steady operation, the valve timing of the exhaust valve is advanced by a predetermined amount from the state where the overlap period is zero, The valve timing of the intake valve is advanced more than a predetermined amount. As a result, the exhaust valve opens while the in-cylinder pressure is high, so that the internal EGR amount can be increased.

JP 2007-32515 A

  Here, in an internal combustion engine having an intake side variable valve timing mechanism and an exhaust side variable valve timing mechanism, the valve timing of the exhaust valve is set to the most advanced position in the initial state (before the start of operation). The valve timing is set to the most retarded position. For this reason, in the initial state, the overlap period has a negative negative value, that is, the minus overlap period has the maximum value. The minus overlap means that there is a period in which both the intake valve and the exhaust valve are closed after the exhaust valve is closed until the intake valve is opened.

  In such an internal combustion engine control device, the target phase angle and target overlap period of the intake valve and the exhaust valve are calculated from the base map according to the operating state, and the deviation between the target phase angle and the actual phase angle is calculated. The intake-side variable valve timing mechanism and the exhaust-side variable valve timing mechanism are controlled so as to eliminate this.

  The target phase angle of the exhaust valve is a target retard amount from the initial position (most advanced position) of the exhaust valve, and the target phase angle of the intake valve is the initial position (maximum position) of the intake valve. This is a target advance amount from the retard position. Further, each target value calculated from the base map (hereinafter also referred to as “base map value”) is a value that is an optimum fuel consumption point according to the driving state.

  When the valve timing is controlled based on the target phase angle that is the optimum point of fuel consumption in this way, for example, when the valve timings of the intake valve and the exhaust valve are advanced, as shown in FIG. There is a possibility that the actual overlap period transiently exceeds the target overlap period due to, for example, a delay in following the exhaust valve on the side that reduces the overlap.

  Therefore, when the valve timing of the intake valve and the exhaust valve is advanced, the target phase angle of the intake valve whose operating direction increases the overlap is set to a value lower than the base map value. It is conceivable to prevent the overlap period of the current period from exceeding the target overlap period. However, if the target phase angle is lower than the base map value, it takes time for the valve timing of the intake valve to converge to the fuel efficiency optimum point.

  A similar problem exists when the valve timings of the intake valve and the exhaust valve are retarded.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to converge the valve timing to the base map value while suppressing the actual overlap period from exceeding the target overlap period. It is an object of the present invention to provide a control device for an internal combustion engine that can be easily made.

  An internal combustion engine control apparatus according to the present invention controls an internal combustion engine including an intake side variable valve timing mechanism that varies a valve timing of an intake valve and an exhaust side variable valve timing mechanism that varies a valve timing of an exhaust valve. A first calculation means, a second calculation means, a first target phase angle setting means, and a second target phase angle setting means. The first calculation means is configured to calculate the target phase angle and the target overlap period of the intake valve and the exhaust valve based on the rotation speed and load factor of the internal combustion engine. The second calculating means is configured to calculate the target phase angle of the intake valve based on the target overlap period and the actual phase angle of the exhaust valve when the valve timings of the intake valve and the exhaust valve are advanced. Yes. The first target phase angle setting means sets the value calculated by the first calculation means as the target phase angle of the exhaust valve when the valve timing of the intake valve and the exhaust valve is advanced, and the target of the intake valve A value calculated by the second calculation means is set as the phase angle. In the second target phase angle setting means, when the valve timings of the intake valve and the exhaust valve are advanced, both the intake valve and the exhaust valve are in a closed state after the exhaust valve is closed until the intake valve is opened. During the minus overlap, the value calculated by the first calculation means is set as the target phase angle of the exhaust valve and the intake valve.

  The target phase angle of the exhaust valve is a target retard amount from the initial position (most advanced position) of the exhaust valve, and the target phase angle of the intake valve is the initial position (maximum position) of the intake valve. This is a target advance amount from the retard position. The actual phase angle of the exhaust valve is the actual phase angle of the exhaust valve (retard amount from the initial position). The overlap period is an angle range (period) in which both the intake valve and the exhaust valve are opened, and the target overlap period is the target value. That is, if the overlap period is a positive value, there is a period when both the intake valve and the exhaust valve are open, and if the overlap period is a negative value, both the intake valve and the exhaust valve are closed. There is a period of time to become a state.

  With this configuration, the first calculation means calculates the target phase angle (base map value) of the intake valve from the base map according to the operating state, and the second calculation means calculates the intake air that is equal to or less than the base map value. The target phase angle of the valve can be calculated. Then, at the time of overlap when the valve timing of the intake valve and the exhaust valve is advanced, the value calculated by the second calculation means is set as the target phase angle of the intake valve, so that the actual overlap period is set as the target. Exceeding the overlap period can be suppressed. Further, when the valve timing of the intake valve and the exhaust valve is advanced, at the time of minus overlap, the valve timing of the intake valve is set by setting the value calculated by the first calculation means as the target phase angle of the intake valve. It is possible to facilitate convergence to the base map value. Therefore, when the valve timing of the intake valve and the exhaust valve is advanced, the valve timing of the intake valve is easily converged to the base map value while suppressing the actual overlap period from exceeding the target overlap period. be able to.

  In the control device for an internal combustion engine, when the valve timings of the intake valve and the exhaust valve are advanced, based on the target phase angle of the intake valve calculated by the first calculation means and the actual phase angle of the exhaust valve. Further, it may be provided with a judging means for judging whether or not the time is minus overlap.

  If comprised in this way, it can be judged easily whether it is a time of minus overlap.

  In the control apparatus for an internal combustion engine, the second calculating means may be configured to detect the target phase angle of the exhaust valve based on the target overlap period and the actual phase angle of the intake valve when the valve timings of the intake valve and the exhaust valve are retarded. The first target phase angle setting means is configured to calculate the value calculated by the second calculation means as the target phase angle of the exhaust valve when the valve timing of the intake valve and the exhaust valve is retarded. And setting the value calculated by the first calculation means as the target phase angle of the intake valve, and the second target phase angle setting means delays the valve timing of the intake valve and the exhaust valve. In the case of the negative overlap, the target phase angle of the exhaust valve and the intake valve is calculated by the first calculating means at the time of minus overlap. It may be configured to set. The actual phase angle of the intake valve is the actual phase angle of the intake valve (advance amount from the initial position).

  With this configuration, when the valve timing of the intake valve and the exhaust valve is retarded, the valve timing of the exhaust valve is set to the base map value while suppressing the actual overlap period from exceeding the target overlap period. To make it easier to converge.

  In this case, when the valve timings of the intake valve and the exhaust valve are retarded, a minus overlap is made based on the target phase angle of the exhaust valve calculated by the first calculation means and the actual phase angle of the intake valve. You may provide the judgment means which judges whether it is time.

  If comprised in this way, it can be judged easily whether it is a time of minus overlap.

  In the control device for an internal combustion engine, the second calculation means may perform intake air based on the target overlap period, the actual phase angle of the exhaust valve, and the valve swing angle when the valve timings of the intake valve and the exhaust valve are advanced. The target phase angle of the valve may be calculated. The valve swing angle is an angle range of the intake valve and the exhaust valve that varies due to a cam reaction force that periodically increases and decreases with the opening / closing operation of the intake valve and the exhaust valve, and is a preset value, for example.

  With this configuration, when the valve timing of the intake valve and the exhaust valve is advanced, even if the intake valve and the exhaust valve fluctuate due to the cam reaction force, the actual overlap period exceeds the target overlap period. Can be suppressed.

  In the control apparatus for an internal combustion engine in which the second calculation means calculates the target phase angle of the intake valve based on the valve swing angle, the calculation is performed by the first calculation means when the valve timing of the intake valve and the exhaust valve is advanced. A determination means may be provided for determining whether or not a negative overlap occurs based on the target phase angle of the intake valve, the actual phase angle of the exhaust valve, and the valve swing angle.

  If comprised in this way, it can be judged whether it is the time of minus overlap in consideration of a valve | bulb swing angle.

  In the control apparatus for an internal combustion engine in which the second calculation means calculates the target phase angle of the intake valve based on the valve swing angle, the second calculation means is configured to delay the valve timing of the intake valve and the exhaust valve. The target phase angle of the exhaust valve is calculated based on the target overlap period, the actual phase angle of the intake valve, and the valve swing angle, and the first target phase angle setting means is configured to calculate the valve timing of the intake valve and the exhaust valve. Is set to the value calculated by the second calculating means as the target phase angle of the exhaust valve, and the value calculated by the first calculating means is set as the target phase angle of the intake valve. The second target phase angle setting means is configured to be minus over when the valve timings of the intake valve and the exhaust valve are retarded. Tsu when up, may be configured to set a value calculated by the first calculating means as a target phase angle of the exhaust valve and intake valve.

  With this configuration, when the valve timing of the intake valve and the exhaust valve is retarded, even if the intake valve and the exhaust valve fluctuate due to the cam reaction force, the actual overlap period exceeds the target overlap period. Can be suppressed.

  In this case, when the valve timings of the intake valve and the exhaust valve are retarded, based on the target phase angle of the exhaust valve calculated by the first calculation means, the actual phase angle of the intake valve, and the valve swing angle. Thus, there may be provided a judging means for judging whether or not the time is minus overlap.

  If comprised in this way, it can be judged whether it is the time of minus overlap in consideration of a valve | bulb swing angle.

  An internal combustion engine control apparatus according to the present invention controls an internal combustion engine including an intake side variable valve timing mechanism that varies a valve timing of an intake valve and an exhaust side variable valve timing mechanism that varies a valve timing of an exhaust valve. A first calculation means, a second calculation means, a first target phase angle setting means, and a second target phase angle setting means. The first calculation means is configured to calculate the target phase angle and the target overlap period of the intake valve and the exhaust valve based on the rotation speed and load factor of the internal combustion engine. The second calculating means is configured to calculate the target phase angle of the exhaust valve based on the target overlap period and the actual phase angle of the intake valve when the valve timings of the intake valve and the exhaust valve are retarded. Yes. The first target phase angle setting means sets the value calculated by the second calculation means as the target phase angle of the exhaust valve when the valve timing of the intake valve and the exhaust valve is retarded, and the target of the intake valve A value calculated by the first calculation means is set as the phase angle. When the valve timing of the intake valve and the exhaust valve is retarded, the second target phase angle setting means sets both the intake valve and the exhaust valve to a closed state after the exhaust valve is closed until the intake valve is opened. During the minus overlap, the value calculated by the first calculation means is set as the target phase angle of the exhaust valve and the intake valve.

  According to the control apparatus for an internal combustion engine of the present invention, the valve timing can be easily converged to the base map value while suppressing the actual overlap period from exceeding the target overlap period.

1 is a schematic configuration diagram illustrating an example of an engine controlled by an ECU according to a first embodiment of the present invention. It is a figure for demonstrating the intake side VVT mechanism of FIG. 1, and the intake side OCV which controls it. It is the block diagram which showed the structure of ECU of FIG. It is a flowchart for demonstrating the target phase angle setting control of the valve timing in 1st Embodiment. In 1st Embodiment, it is the figure which showed an example of the opening / closing timing at the time of overlap in case the valve timing of an intake valve and an exhaust valve is advanced. In 1st Embodiment, it is the figure which showed an example of the opening / closing timing at the time of a minus overlap in case the valve timing of an intake valve and an exhaust valve is advanced. It is a flowchart for demonstrating the target phase angle setting control of the valve timing in 2nd Embodiment of this invention. It is the figure which showed an example of the opening / closing timing in case the valve timing of the intake valve and exhaust valve in a prior art example is advanced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a case where the present invention is applied to ECU 400 that controls engine (internal combustion engine) 1 mounted on a vehicle will be described.

(First embodiment)
-Engine-
As shown in FIG. 1, the engine 1 is, for example, a port injection type four-cylinder gasoline engine, and a piston 1c is provided in a cylinder block 1a. The piston 1 c is connected to the crankshaft 15 via a connecting rod 16. FIG. 1 shows only the configuration of one cylinder of the engine 1.

  A cylinder head 1b is attached to the upper end of the cylinder block 1a, and a combustion chamber 1d is formed between the cylinder head 1b and the piston 1c. A spark plug 3 is disposed in the combustion chamber 1 d of the engine 1. The ignition timing of the spark plug 3 is adjusted by the igniter 4.

  An oil pan 18 is provided below the cylinder block 1 a of the engine 1. The lubricating oil stored in the oil pan 18 is pumped up by an oil pump 19 through an oil strainer 20 (see FIG. 2) during operation of the engine 1 and used for lubricating and cooling each part in the engine 1. The The lubricating oil is also used as hydraulic oil for an intake side VVT mechanism 100in and an exhaust side VVT mechanism 100ex, which will be described later. The oil pump 19 is, for example, a mechanical pump that is driven by the rotation of the crankshaft 15 of the engine 1.

  A signal rotor 17 is attached to the crankshaft 15, and a crank position sensor 37 is disposed in the vicinity of the signal rotor 17. The crank position sensor 37 is provided for detecting the rotational position of the crankshaft 15. A water temperature sensor 31 that detects the temperature of the cooling water is disposed in the cylinder block 1 a of the engine 1.

An intake passage 11 and an exhaust passage 12 are connected to the combustion chamber 1 d of the engine 1. In the intake passage 11, an air cleaner 7, an air flow meter 32 for measuring the intake air amount, an intake temperature sensor 33 for measuring the intake air temperature, an electronically controlled throttle valve 5 for adjusting the intake air amount, and the like are arranged. Has been. The throttle valve 5 is driven by a throttle motor 6. The opening degree of the throttle valve 5 is detected by a throttle opening degree sensor 36. An O ₂ sensor 34 and a catalytic converter (three-way catalyst) 8 for detecting the oxygen concentration in the exhaust gas are disposed in the exhaust passage 12.

  An intake valve 13 is provided between the intake passage 11 and the combustion chamber 1d, and an exhaust valve 14 is provided between the exhaust passage 12 and the combustion chamber 1d. The opening / closing drive of the intake valve 13 and the exhaust valve 14 is performed by each rotation of the intake camshaft 21 and the exhaust camshaft 22 to which the rotation of the crankshaft 15 is transmitted via a timing belt or the like. An intake side VVT mechanism 100 in which the valve timing of the intake valve 13 is made variable is provided at the end of the intake camshaft 21, and an exhaust side VVT in which the valve timing of the exhaust valve 14 is made variable at the end of the exhaust camshaft 22. A mechanism 100ex is provided. Details of the intake side VVT mechanism 100in and the exhaust side VVT mechanism 100ex will be described later.

  An intake side cam position sensor 38 and an exhaust side cam position sensor 39 are disposed in the vicinity of the intake camshaft 21 and the exhaust camshaft 22, respectively. The intake side cam position sensor 38 is provided for detecting the rotational position of the intake camshaft 21, and the exhaust side cam position sensor 39 is provided for detecting the rotational position of the exhaust camshaft 22.

  An injector (fuel injection valve) 2 for fuel injection is disposed in the intake passage 11. The fuel injected from the injector 2 is mixed with the intake air to be mixed into the combustion chamber 1d. The air-fuel mixture introduced into the combustion chamber 1d is ignited by the spark plug 3 and combusted / exploded. Due to the combustion / explosion of the air-fuel mixture, the piston 1c reciprocates and the crankshaft 15 rotates.

-VVT mechanism-
Next, the intake-side VVT mechanism 100in and the intake-side OCV (oil control valve) 200in that controls the intake-side VVT mechanism 100in will be described. Note that the exhaust side VVT mechanism 100ex and the exhaust side OCV 200ex are configured in substantially the same manner as the intake side VVT mechanism 100in and the intake side OCV 200in, respectively, and thus description thereof is omitted.

  As shown in FIG. 2, the intake-side VVT mechanism 100 in includes a vane rotor 101 and a housing 102 that houses the vane rotor 101. The vane rotor 101 is connected to the intake camshaft 21 (see FIG. 1). The housing 102 is provided with a timing pulley 102a, and the timing pulley 102a is connected to the crankshaft 15 (see FIG. 1) via a timing belt (not shown). Inside the housing 102, an advance side hydraulic chamber 111 and a retard side hydraulic chamber 112 that are partitioned by the vane 101a of the vane rotor 101 are formed.

  In the intake-side VVT mechanism 100 in, the vane rotor 101 rotates relative to the housing 102 in accordance with the hydraulic pressure in the advance-side hydraulic chamber 111 and the hydraulic pressure in the retard-side hydraulic chamber 112. That is, when the hydraulic pressure in the advance-side hydraulic chamber 111 is made higher than the hydraulic pressure in the retard-side hydraulic chamber 112, the rotational phase of the intake camshaft 21 is advanced with respect to the rotational phase of the crankshaft 15 (advance angle). On the contrary, if the hydraulic pressure in the retarded hydraulic chamber 112 is made higher than the hydraulic pressure in the advanced hydraulic chamber 111, the rotational phase of the intake camshaft 21 is delayed relative to the rotational phase of the crankshaft 15. (Retard). In this manner, the valve timing of the intake valve 13 is variable by adjusting the rotational phase of the intake camshaft 21 with respect to the crankshaft 15.

  The intake side VVT mechanism 100in is connected to an intake side OCV 200in that controls the hydraulic pressure of hydraulic oil supplied to the advance side hydraulic chamber 111 and the retard side hydraulic chamber 112.

  Lubricating oil (operating oil) pumped up from the oil pan 18 by the oil pump 19 is supplied to the intake side OCV 200in through the oil supply passage 131. The intake-side OCV 200in is connected to the advance side hydraulic chamber 111 via the advance side passage 121 and is connected to the retard side hydraulic chamber 112 via the retard side passage 122. Further, two oil discharge passages 132 and 133 are connected to the intake side OCV 200in. The intake-side OCV 200in is an electromagnetically driven flow control valve, and is controlled by the ECU 400 (see FIG. 3).

  The intake-side OCV 200in includes a spool 202 disposed inside the casing 201 so as to be reciprocally movable, a compression coil spring 203 that urges the spool 202 to one side, and a spool 202 against the urging force of the compression coil spring 203. And an electromagnetic solenoid 204 for moving to the other side.

  In the intake side OCV 200in, when the spool 202 moves, the supply / discharge amount of hydraulic fluid to the advance side passage 121 and the retard side passage 122 changes, so that the advance side hydraulic chamber 111 and the retard side hydraulic pressure are changed. The hydraulic pressure in the chamber 112 can be adjusted.

-ECU-
Next, the ECU 400 that controls the engine 1 will be described.

  As shown in FIG. 3, the ECU 400 includes a CPU 401, a ROM 402, a RAM 403, a backup RAM 404, an input interface 405, an output interface 406, and a bus 407 for connecting them. The ECU 400 is an example of the “first calculation means”, “second calculation means”, “first target phase angle setting means”, “second target phase angle setting means”, and “determination means” according to the present invention. These are realized by the CPU 401 executing the program stored in the ROM 402.

  The CPU 401 executes arithmetic processing based on various control programs and maps stored in the ROM 402. The ROM 402 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The RAM 403 is a memory that temporarily stores calculation results by the CPU 401 and detection results of various sensors. The backup RAM 404 is a non-volatile memory that stores data to be saved when the ignition is turned off.

The input interface 405 includes a water temperature sensor 31, an air flow meter 32, an intake air temperature sensor 33, an O ₂ sensor 34, an accelerator opening sensor 35 for detecting the accelerator opening, a throttle opening sensor 36, a crank position sensor 37, and an intake side cam. A position sensor 38, an exhaust side cam position sensor 39, a vehicle speed sensor 30 for detecting the vehicle speed, and the like are connected.

  The output interface 406 is connected to the injector 2, the igniter 4, the throttle motor 6, the intake side OCV 200in, the exhaust side OCV 200ex, and the like.

  ECU 400 performs various controls of engine 1 including drive control of throttle motor 6 (throttle opening control), fuel injection control of injector 2 and ignition timing control of spark plug 3 based on the output signals of various sensors. Run.

  ECU 400 also controls intake side VVT mechanism 100in and exhaust side VVT mechanism 100ex in accordance with the operating state of engine 1. Specifically, ECU 400 sets target phase angles of intake valve 13 and exhaust valve 14 based on the operating state of engine 1, and there is no deviation between the target phase angle and the actual phase angle (actual phase angle). Thus, the intake side OCV 200in and the exhaust side OCV 200ex are controlled.

  Here, in the engine 1, in the initial state (before the start of operation), the valve timing of the exhaust valve 14 is set to the most advanced position, and the valve timing of the intake valve 13 is set to the most retarded position. For this reason, in the initial state, the overlap period has a negative negative value, that is, the minus overlap period has the maximum value. The minus overlap means that there is a period in which both the intake valve and the exhaust valve are closed after the exhaust valve is closed until the intake valve is opened.

  The target phase angle of the exhaust valve 14 is a target retardation amount from the initial position (most advanced angle position) of the exhaust valve 14, and the target phase angle of the intake valve 13 is the target phase angle of the intake valve 13. This is the target advance angle amount from the initial position (most retarded angle position).

-Valve timing target phase angle setting control-
Next, the target timing angle setting control of the valve timing executed by the ECU 400 will be described with reference to FIG. Note that the following flow is repeatedly executed by the ECU 400 at predetermined time intervals.

  First, in step ST1 of FIG. 4, various information is acquired. For example, the intake air amount is acquired from the air flow meter 32, and the rotation speed (the number of rotations per unit time) of the engine 1 is calculated based on the detection result of the crank position sensor 37. The actual phase angle InFPA of the intake valve 13 is calculated based on the detection results of the crank position sensor 37 and the intake cam position sensor 38, and the exhaust valve is calculated based on the detection results of the crank position sensor 37 and the exhaust cam position sensor 39. 14 actual phase angles ExFPA are calculated.

  Next, in step ST2, the target phase angle and the target overlap period of the intake valve 13 and the exhaust valve 14 are calculated from the base map according to the operating state of the engine 1. Specifically, the target phase angle (base map value) InTPA of the intake valve 13 is calculated from a first base map using the rotational speed and load factor of the engine 1 as parameters, and the rotational speed and load factor of the engine 1 are calculated. The target overlap period TOPA is calculated from the second base map using as parameters. Then, the target phase angle (base map value) ExTPA of the exhaust valve 14 is calculated from the following equation (1). That is, the base map value ExTPA of the exhaust valve 14 is a calculated value calculated using the base map value InTPA of the intake valve 13 and the target overlap period TOPA.

ExTPA = TOPA- (InTPA + IOPA) (1)
In Expression (1), IOPA is an initial overlap period (angle range) and is a negative value. The overlap period IOPA in the initial state and the first and second base maps are stored in the ROM 402, for example. The load factor is the ratio of the intake air amount in the current operating state to the maximum intake air amount to the engine 1, and is calculated based on the intake air amount and the rotational speed of the engine 1, for example.

  Each target value (base map value InTPA of the intake valve 13, base map value ExTPA of the exhaust valve 14 and target overlap period TOPA) calculated in step ST2 is a value that becomes the optimum fuel consumption point according to the driving state. This corresponds to the “value calculated by the first calculation means” of the present invention.

  Next, in step ST3, it is determined whether or not the intake side VVT mechanism 100in is displaced to the advance side. Whether or not the intake side VVT mechanism 100in is displaced toward the advance side is determined based on the target phase angle and the actual phase angle of the intake valve 13. That is, when the actual phase angle InFPA of the intake valve 13 calculated in step ST1 is compared with the target phase angle InTPA of the intake valve 13 calculated in step ST2, the target phase angle InTPA is larger than the actual phase angle InFPA. It is determined that it is displaced to the advance side. When the intake side VVT mechanism 100in is displaced to the advance side, the process proceeds to step ST4. On the other hand, when the intake side VVT mechanism 100in is not displaced to the advance side (displaces to the retard side), the process proceeds to step ST5.

  Next, in step ST4, it is determined whether or not the exhaust side VVT mechanism 100ex is displaced to the advance side. Whether or not the exhaust side VVT mechanism 100ex is displaced to the advance side is determined based on the target phase angle and the actual phase angle of the exhaust valve 14. That is, when the actual phase angle ExFPA of the exhaust valve 14 calculated in step ST1 is compared with the target phase angle ExTPA of the exhaust valve 14 calculated in step ST2, the target phase angle ExTPA is smaller than the actual phase angle ExFPA. It is determined that it is displaced to the advance side. When the exhaust side VVT mechanism 100ex is displaced to the advance side, the process proceeds to step ST6. On the other hand, when the exhaust side VVT mechanism 100ex is not displaced to the advance side (displaces to the retard side), the process proceeds to step ST9.

  Further, in step ST5, it is determined whether or not the exhaust side VVT mechanism 100ex is displaced to the advance side. Whether or not the exhaust side VVT mechanism 100ex is displaced to the advance side is determined by the same method as in step ST4. When the exhaust side VVT mechanism 100ex is displaced to the advance side, the process proceeds to step ST9. On the other hand, if the exhaust side VVT mechanism 100ex is not displaced to the advance side (displaces to the retard side), the process proceeds to step ST10.

[When valve timing of intake valve and exhaust valve is advanced]
When the valve timings of the intake valve 13 and the exhaust valve 14 are advanced (Yes in steps ST3 and ST4), the target phase angle of the intake valve 13 is recalculated in step ST6. This is because when the base map value InTPA is used as the target phase angle of the intake valve 13 on the side of increasing the overlap, the actual overlap period is caused by the follow-up delay of the exhaust valve 14 on the side of reducing the overlap. This is because FOPA may exceed the target overlap period TOPA. That is, as will be described later, in order to prevent the actual overlap period FOPA from exceeding the target overlap period TOPA, the target phase angle of the intake valve 13 on the side where the overlap is increased is recalculated. The target phase angle of the intake valve 13 is calculated by the following equation (2).

InTPA2 = TOPA− (ExFPA + IOPA) (2)
In Expression (2), InTPA2 is the recalculated target phase angle of the intake valve 13. As shown in FIG. 5, the target phase angle InTPA2 is a value equal to or smaller than the base map value InTPA, and corresponds to the “value calculated by the second calculation means” of the present invention.

  In this equation (2), for example, when the actual overlap period FOPA reaches the target overlap period TOPA before the actual phase angle InFPA of the intake valve 13 reaches the target phase angle (base map value) InTPA. Waits for the displacement of the actual phase angle ExFPA of the exhaust valve 14, and the target phase angle InTPA2 approaches the base map value InTPA with the displacement of the actual phase angle ExFPA. When the actual phase angle ExFPA of the exhaust valve 14 becomes the target phase angle (base map value) ExTPA, the target phase angle InTPA2 of the intake valve 13 becomes the base map value InTPA. That is, the recalculated target phase angle InTPA2 is a target value of the intake valve 13 that can be allowed in a range where the actual overlap period FOPA does not exceed the target overlap period TOPA with respect to the actual phase angle ExFPA of the exhaust valve 14. is there.

  Thereafter, in step ST7, it is determined whether or not it is a negative overlap. Specifically, it is determined whether or not the following expression (3) is satisfied, and when expression (3) is not satisfied, it is determined that the time is minus overlap. And when it is a time of minus overlap, it moves to step ST9. On the other hand, if it is not a negative overlap (overlap), the process proceeds to step ST8.

InTPA ≧ −IOPA-ExFPA (3)
In the expression (3), as shown in FIG. 6, the target of the intake valve 13 is within the region remaining after subtracting the actual phase angle ExFPA of the exhaust valve 14 from the range of the negative overlap period IOPA in the initial state. It is determined whether or not the phase angle InTPA is located, and when the target phase angle InTPA is located within the region, the expression (3) is not satisfied and it is determined that a negative overlap occurs.

  Then, as shown in FIG. 5, at the time of overlap (No in Step ST7), in Step ST8, the target phase recalculated in Step ST6 is used as the target phase angle of the intake valve 13 on the side where the overlap is increased. The angle InTPA2 is set, and the base map value ExTPA calculated in step ST2 is set as the target phase angle of the exhaust valve 14 on the side that reduces the overlap. That is, at the time of overlap in a situation where the valve timings of the intake valve 13 and the exhaust valve 14 are advanced, the target phase angle of the intake valve 13 is set so that the actual overlap period FOPA does not exceed the target overlap period TOPA. A recalculated target phase angle InTPA2 that is less than or equal to the base map value InTPA is set.

  At the time of overlap, -IOPA-ExFPA is set as the lower limit guard value of the target phase angle of the intake valve 13, so that the value is not suppressed more than necessary. That is, when the recalculated target phase angle InTPA2 of the intake valve 13 is lower than the lower limit guard value (−IOPA−ExFPA), the lower limit guard value is set as the target phase angle of the intake valve 13. IOPA is the initial overlap period, and ExFPA is the actual phase angle of the exhaust valve 14.

  On the other hand, as shown in FIG. 6, at the time of minus overlap (Yes in Step ST7), the base map value InTPA calculated in Step ST2 is set as the target phase angle of the intake valve 13 in Step ST9. As the target phase angle of the exhaust valve 14, the base map value ExTPA calculated in step ST2 is set. In other words, when the valve timing of the intake valve 13 and the exhaust valve 14 is advanced, it is not necessary to limit the target phase angle of the intake valve 13 at the time of minus overlap. A map value InTPA is set.

[When valve timing of intake valve and exhaust valve is retarded]
When the valve timings of the intake valve 13 and the exhaust valve 14 are retarded (No in steps ST3 and ST5), the target phase angle of the exhaust valve 14 is recalculated in step ST10. This is because when the base map value ExTPA is used as the target phase angle of the exhaust valve 14 on the side of increasing the overlap, the actual overlap period is caused by the follow-up delay of the intake valve 13 on the side of decreasing the overlap. This is because FOPA may exceed the target overlap period TOPA. That is, as will be described later, in order to prevent the actual overlap period FOPA from exceeding the target overlap period TOPA, the target phase angle of the exhaust valve 14 on the side where the overlap is increased is recalculated. The target phase angle of the exhaust valve 14 is calculated by the following equation (4).

ExTPA2 = TOPA- (InFPA + IOPA) (4)
In Expression (4), ExTPA2 is the recalculated target phase angle of the exhaust valve 14. This target phase angle ExTPA2 is a value equal to or smaller than the base map value ExTPA, and corresponds to the “value calculated by the second calculation means” of the present invention.

  In this equation (4), for example, when the actual overlap period FOPA reaches the target overlap period TOPA before the actual phase angle ExFPA of the exhaust valve 14 reaches the target phase angle (base map value) ExTPA. Waits for the displacement of the actual phase angle InFPA of the intake valve 13, and the target phase angle ExTPA2 approaches the base map value ExTPA with the displacement of the actual phase angle InFPA. When the actual phase angle InFPA of the intake valve 13 becomes the target phase angle (base map value) InTPA, the target phase angle ExTPA2 of the exhaust valve 14 becomes the base map value ExTPA. That is, the recalculated target phase angle ExTPA2 is a target value of the exhaust valve 14 that can be allowed in a range where the actual overlap period FOPA does not exceed the target overlap period TOPA with respect to the actual phase angle InFPA of the intake valve 13. is there.

  Thereafter, in step ST11, it is determined whether or not it is a negative overlap. Specifically, it is determined whether or not the following equation (5) is satisfied, and when the equation (5) is not satisfied, it is determined that a negative overlap occurs. And when it is a time of minus overlap, it moves to step ST9. On the other hand, if it is not a negative overlap (overlap), the process proceeds to step ST12.

ExTPA ≧ −IOPA-InFPA (5)
In equation (5), is the target phase angle ExTPA of the exhaust valve 14 located within the region remaining after subtracting the actual phase angle InFPA of the intake valve 13 from the range of the negative overlap period IOPA in the initial state? When the target phase angle ExTPA is located within the region, the expression (5) is not satisfied and it is determined that the time is minus overlap.

  At the time of overlap (No in step ST11), in step ST12, the target phase angle ExTPA2 recalculated in step ST10 is set as the target phase angle of the exhaust valve 14 on the side where the overlap is increased. The base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13 on the lap reduction side. That is, at the time of overlap in a situation where the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, the target phase angle of the exhaust valve 14 is set so that the actual overlap period FOPA does not exceed the target overlap period TOPA. A recalculated target phase angle ExTPA2 that is equal to or smaller than the base map value ExTPA is set.

  At the time of overlap, -IOPA-InFPA is set as the lower limit guard value of the target phase angle of the exhaust valve 14, so that the value is not suppressed more than necessary. That is, when the recalculated target phase angle ExTPA2 of the exhaust valve 14 is lower than the lower limit guard value (-IOPA-InFPA), the lower limit guard value is set as the target phase angle of the exhaust valve 14. IOPA is the initial overlap period, and InFPA is the actual phase angle of the intake valve 13.

  On the other hand, at the time of negative overlap (Yes in step ST11), in step ST9, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13, and the target phase angle of the exhaust valve 14 is set. As described above, the base map value ExTPA calculated in step ST2 is set. That is, when the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, there is no need to limit the target phase angle of the exhaust valve 14 at the time of minus overlap. A map value ExTPA is set.

[When the valve timing of the intake valve is advanced and the valve timing of the exhaust valve is retarded]
When the valve timing of the intake valve 13 is advanced and the valve timing of the exhaust valve 14 is retarded (Yes in step ST3, No in step ST4), the valve timing of the intake valve 13 and the exhaust valve 14 is changed. Since the overlap period is increased, the actual overlap period FOPA does not exceed the target overlap period TOPA. Therefore, in step ST9, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13, and the base map value ExTPA calculated in step ST2 is set as the target phase angle of the exhaust valve 14. Is set.

[When the valve timing of the intake valve is retarded and the valve timing of the exhaust valve is advanced]
When the valve timing of the intake valve 13 is retarded and the valve timing of the exhaust valve 14 is advanced (No in step ST3, Yes in step ST5), the valve timings of the intake valve 13 and the exhaust valve 14 are In order to displace the overlap period to decrease, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13 in step ST9, and the target phase angle of the exhaust valve 14 is set in step ST2. The base map value ExTPA calculated in is set.

  In the first embodiment, the “first calculation means” of the present invention is realized by executing step ST2 by the ECU 400, and the “second calculation” of the present invention is performed by executing step ST6 or ST10 by the ECU 400. Means "are realized. Further, by executing step ST8 or ST12 by ECU 400, the “first target phase angle setting means” of the present invention is realized, and by executing step ST9 by ECU 400, “second target phase angle setting unit” of the present invention is realized. Means "are realized. Further, by executing step ST7 or ST11 by ECU 400, the “determination means” of the present invention is realized.

-Effect-
In the first embodiment, as described above, the target phase angle (base map value) InTPA of the intake valve 13 is calculated from the base map according to the operating state (for example, the rotational speed and load factor of the engine 1), and the intake air When the valve timings of the valve 13 and the exhaust valve 14 are advanced, a target phase angle InTPA2 that is equal to or less than the base map value InTPA is calculated (re-established) as the target phase angle of the intake valve 13 that is displaced toward the side that increases the overlap period. Configured to calculate).

  By configuring in this manner, by setting the recalculated target phase angle InTPA2 as the target phase angle of the intake valve 13 at the time of overlap when the valve timings of the intake valve 13 and the exhaust valve 14 are advanced. The actual overlap period FOPA can be prevented from exceeding the target overlap period TOPA. Further, when the valve timings of the intake valve 13 and the exhaust valve 14 are advanced, at the time of minus overlap, the base map value InTPA is set as the target phase angle of the intake valve 13, thereby making the valve timing of the intake valve 13 a base. It can be made easy to converge to the map value InTPA. That is, unlike the overlap, there is no need to limit the target phase angle of the intake valve 13, so the base map value InTPA is set as the target phase angle. Accordingly, when the valve timings of the intake valve 13 and the exhaust valve 14 are advanced, the valve timing of the intake valve 13 is set to the base map value while suppressing the actual overlap period FOPA from exceeding the target overlap period TOPA. It can be made easy to converge to InTPA. As a result, fuel consumption can be improved.

  In the first embodiment, the target phase angle (base map value) ExTPA of the exhaust valve 14 is calculated from the base map according to the operating state (for example, the rotational speed and load factor of the engine 1), and the intake valve 13 and When the valve timing of the exhaust valve 14 is retarded, the target phase angle ExTPA2 that is equal to or less than the base map value ExTPA is calculated (recalculated) as the target phase angle of the exhaust valve 14 that is displaced toward the side that increases the overlap period. It is configured as follows.

  With this configuration, when the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, the target phase angle ExTPA2 recalculated as the target phase angle of the exhaust valve 14 is set at the time of overlap. The actual overlap period FOPA can be prevented from exceeding the target overlap period TOPA. Further, when the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, a base map value ExTPA is set as a target phase angle of the exhaust valve 14 to set the base timing of the exhaust valve 14 as a base. It is possible to facilitate convergence to the map value ExTPA. That is, unlike the overlap, there is no need to limit the target phase angle of the exhaust valve 14, so the base map value ExTPA is set as the target phase angle. Accordingly, when the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, the valve timing of the exhaust valve 14 is set to the base map value while suppressing the actual overlap period FOPA from exceeding the target overlap period TOPA. It is possible to easily converge to ExTPA. As a result, exhaust emission can be reduced.

  Further, in the first embodiment, it is possible to easily determine whether or not it is a negative overlap by determining whether or not the above formula (3) is satisfied. Similarly, it is possible to easily determine whether or not it is a minus overlap time by determining whether or not the above formula (5) is satisfied.

(Second Embodiment)
Next, target phase angle setting control of valve timing according to the second embodiment of the present invention will be described. Note that the engine 1 and the ECU 400 that controls the engine 1 are configured in substantially the same manner as in the first embodiment, and thus the description of the overlapping parts is omitted.

  Here, when the intake camshaft 21 drives the intake valve 13 to open and close, the cam reaction force (force received from the valve spring) periodically increases and decreases with the opening and closing operation of the intake valve 13, and the cam reaction force that increases and decreases It acts on the intake side VVT mechanism 100in. Similarly, when the exhaust camshaft 22 drives the exhaust valve 14 to open and close, the cam reaction force periodically increases and decreases as the exhaust valve 14 opens and closes, and the increased and decreased cam reaction force acts on the exhaust-side VVT mechanism 100ex. To do.

  When a cam reaction force that increases or decreases acts on the intake-side VVT mechanism 100in, the intake valve 13 may fluctuate within a predetermined angle range (a fluctuation in the actual phase angle with respect to the target phase angle occurs), and the exhaust-side VVT mechanism. When a cam reaction force that increases or decreases to 100ex is applied, the exhaust valve 14 may fluctuate within a predetermined angle range. As described above, when the fluctuation of the actual phase angle with respect to the target phase angle occurs at the valve timing of the intake valve 13 and the exhaust valve 14, the actual overlap period exceeds the target overlap period, and the internal EGR amount is excessive. There is a risk.

  Therefore, in the second embodiment, by setting the target phase angle in consideration of the valve swing angle caused by the cam reaction force, even if the intake valve 13 and the exhaust valve 14 fluctuate due to the cam reaction force, the actual overshoot The lap period is prevented from exceeding the target overlap period.

  Next, valve timing target phase angle setting control according to the second embodiment will be described with reference to FIG. Note that the flow of FIG. 7 is repeatedly executed by the ECU 400 at predetermined time intervals. Steps ST1 to ST5 are the same as those in the first embodiment, and a description thereof will be omitted.

[When valve timing of intake valve and exhaust valve is advanced]
When the valve timings of the intake valve 13 and the exhaust valve 14 are advanced (Yes in steps ST3 and ST4), the target phase angle of the intake valve 13 is recalculated in step ST6a. In the second embodiment, the target phase angle of the intake valve 13 is calculated in consideration of the valve swing angle caused by the cam reaction force. The target phase angle of the intake valve 13 is calculated by the following equation (6).

InTPA3 = TOPA− (ExFPA + (IOPA + OSPA)) (6)
In Expression (6), InTPA3 is the recalculated target phase angle of the intake valve 13. This target phase angle InTPA3 is a value equal to or smaller than the base map value InTPA, and corresponds to the “value calculated by the second calculation means” of the present invention. TOPA is the target overlap period calculated in step ST2, and IOPA is the initial overlap period. ExFPA is the actual phase angle of the exhaust valve 14 calculated in step ST1.

  OSPA is a valve swing angle, and is, for example, a value obtained by summing the swing angle of the intake valve 13 (variable angle range) caused by the cam reaction force and the swing angle of the exhaust valve 14 caused by the cam reaction force. . The valve swing angle OSPA may be obtained by adding a predetermined margin (margin) to the total value of the swing angle of the intake valve 13 and the swing angle of the exhaust valve 14. Further, the valve swing angle OSPA is a value set in advance according to the specifications of the engine 1, for example, and is stored in the ROM 402.

  The target phase angle InTPA3 calculated by the equation (6) is smaller by the valve swing angle OSPA than the target phase angle InTPA2 of the first embodiment calculated by the above equation (2). In other words, even if the recalculated target phase angle InTPA3 is shaken (varied) in the intake valve 13 and the exhaust valve 14 due to the cam reaction force, the actual overlap period FOPA is equal to the target overlap period TOPA. It is a value set not to exceed.

  Then, in step ST7a, it is determined whether or not it is a negative overlap. Specifically, it is determined whether or not the following formula (7) is satisfied, and when the formula (7) is not satisfied, it is determined that a negative overlap occurs. And when it is a time of minus overlap, it moves to step ST9a. On the other hand, if it is not a negative overlap (overlap), the process proceeds to step ST8a.

InTPA ≧ − (IOPA + OSPA) −ExFPA (7)
In Expression (7), InTPA is the target phase angle (base map value) of the intake valve 13 calculated in step ST2. In this step ST7a, when there is a possibility of overlap due to the shake (fluctuation) of the intake valve 13 and the exhaust valve 14 caused by the cam reaction force, it is determined that it is an overlap time.

  At the time of overlap (No in step ST7a), in step ST8a, the target phase angle InTPA3 recalculated in step ST6a is set as the target phase angle of the intake valve 13 on the side where the overlap is increased. The base map value ExTPA calculated in step ST2 is set as the target phase angle of the exhaust valve 14 on the lap reduction side.

  At the time of overlap, -IOPA-ExFPA is set as the lower limit guard value of the target phase angle of the intake valve 13, so that the value is not suppressed more than necessary. That is, when the recalculated target phase angle InTPA3 of the intake valve 13 is lower than the lower limit guard value (−IOPA−ExFPA), the lower limit guard value is set as the target phase angle of the intake valve 13.

  On the other hand, at the time of negative overlap (Yes in step ST7a), in step ST9a, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13, and the target phase angle of the exhaust valve 14 is set. As described above, the base map value ExTPA calculated in step ST2 is set.

[When valve timing of intake valve and exhaust valve is retarded]
When the valve timings of the intake valve 13 and the exhaust valve 14 are retarded (No in steps ST3 and ST5), the target phase angle of the exhaust valve 14 is recalculated in step ST10a. In the second embodiment, the target phase angle of the exhaust valve 14 is calculated in consideration of the valve swing angle caused by the cam reaction force. The target phase angle of the exhaust valve 14 is calculated by the following equation (8).

ExTPA3 = TOPA- (InFPA + (IOPA + OSPA)) (8)
In Expression (8), ExTPA3 is the recalculated target phase angle of the exhaust valve 14. This target phase angle ExTPA3 is a value equal to or smaller than the base map value ExTPA, and corresponds to the “value calculated by the second calculation means” of the present invention. InFPA is the actual phase angle of the intake valve 13 calculated in step ST1.

  The target phase angle ExTPA3 calculated by the equation (8) is smaller by the valve swing angle OSPA than the target phase angle ExTPA2 of the first embodiment calculated by the above equation (4). In other words, even if the recalculated target phase angle ExTPA3 is shaken (varied) in the intake valve 13 and the exhaust valve 14 due to the cam reaction force, the actual overlap period FOPA is equal to the target overlap period TOPA. It is a value set not to exceed.

  Thereafter, in step ST11a, it is determined whether or not it is a negative overlap. Specifically, it is determined whether or not the following formula (9) is satisfied, and when the formula (9) is not satisfied, it is determined that a negative overlap occurs. And when it is a time of minus overlap, it moves to step ST9a. On the other hand, if it is not a negative overlap (overlap), the process proceeds to step ST12a.

ExTPA ≧ − (IOPA + OSPA) −InFPA (9)
In Expression (9), ExTPA is the target phase angle (base map value) of the exhaust valve 14 calculated in step ST2. In this step ST11a, when there is a possibility of overlap due to the fluctuation (variation) of the intake valve 13 and the exhaust valve 14 caused by the cam reaction force, it is determined that it is an overlap time.

  At the time of overlap (No in step ST11a), in step ST12a, the target phase angle ExTPA3 recalculated in step ST10a is set as the target phase angle of the exhaust valve 14 on the side where the overlap is increased. The base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13 on the lap reduction side.

  At the time of overlap, -IOPA-InFPA is set as the lower limit guard value of the target phase angle of the exhaust valve 14, so that the value is not suppressed more than necessary. That is, when the recalculated target phase angle ExTPA3 of the exhaust valve 14 is lower than the lower limit guard value (-IOPA-InFPA), the lower limit guard value is set as the target phase angle of the exhaust valve 14.

  On the other hand, at the time of minus overlap (Yes in step ST11a), in step ST9a, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13, and the target phase angle of the exhaust valve 14 is set. As described above, the base map value ExTPA calculated in step ST2 is set.

[When the valve timing of the intake valve is advanced and the valve timing of the exhaust valve is retarded]
When the valve timing of the intake valve 13 is advanced and the valve timing of the exhaust valve 14 is retarded (Yes in step ST3, No in step ST4), the valve timing of the intake valve 13 and the exhaust valve 14 is changed. Since the overlap period is increased, the actual overlap period FOPA does not exceed the target overlap period TOPA. Therefore, in step ST9a, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13, and the base map value ExTPA calculated in step ST2 is set as the target phase angle of the exhaust valve 14. Is set.

[When the valve timing of the intake valve is retarded and the valve timing of the exhaust valve is advanced]
When the valve timing of the intake valve 13 is retarded and the valve timing of the exhaust valve 14 is advanced (No in step ST3, Yes in step ST5), the valve timings of the intake valve 13 and the exhaust valve 14 are In order to displace the overlap period to decrease, in step ST9a, the base map value InTPA calculated in step ST2 is set as the target phase angle of the intake valve 13, and the target phase angle of the exhaust valve 14 is set in step ST2. The base map value ExTPA calculated in is set.

  In the second embodiment, step ST6a or ST10a is executed by the ECU 400 to realize the “second calculation means” of the present invention. Further, by executing step ST8a or ST12a by ECU 400, the “first target phase angle setting means” of the present invention is realized, and by executing step ST9a by ECU 400, “second target phase angle setting unit” of the present invention is realized. Means "are realized. Further, by executing step ST7a or ST11a by ECU 400, the “determination means” of the present invention is realized.

-Effect-
In the second embodiment, as described above, when the valve timings of the intake valve 13 and the exhaust valve 14 are advanced, in addition to the target overlap period TOPA and the actual phase angle ExFPA of the exhaust valve 14, the valve swing angle OSPA Is used to calculate (recalculate) the target phase angle InTPA3 of the intake valve 13 that is displaced toward the side of increasing the overlap period. When the valve timings of the intake valve 13 and the exhaust valve 14 are advanced, the target phase angle InTPA3 recalculated as the target phase angle of the intake valve 13 is set when overlapping.

  With this configuration, the intake valve 13 on the side where the overlap is increased is set to a target phase angle InTPA3 that is smaller than the first embodiment by the valve swing angle OSPA, so that the intake valve is driven by the cam reaction force. Even if 13 and the exhaust valve 14 fluctuate, it is possible to suppress the actual overlap period FOPA from exceeding the target overlap period TOPA. Therefore, it is possible to suppress an excessive amount of internal EGR.

  In the second embodiment, when the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, the valve swing angle OSPA is used in addition to the target overlap period TOPA and the actual phase angle InFPA of the intake valve 13. The target phase angle ExTPA3 of the exhaust valve 14 that is displaced toward the side that increases the overlap period is calculated (recalculated). When the valve timings of the intake valve 13 and the exhaust valve 14 are delayed, the target phase angle ExTPA3 recalculated as the target phase angle of the exhaust valve 14 is set.

  With this configuration, the exhaust valve 14 on the side where the overlap is increased is set with a target phase angle ExTPA3 that is smaller than the first embodiment by the valve swing angle OSPA, so that the intake valve is driven by the cam reaction force. Even if 13 and the exhaust valve 14 fluctuate, it is possible to suppress the actual overlap period FOPA from exceeding the target overlap period TOPA. Therefore, it is possible to suppress an excessive amount of internal EGR.

  Further, in the second embodiment, by determining whether or not a negative overlap occurs in consideration of the valve swing angle OSPA, the swing (fluctuation) of the intake valve 13 and the exhaust valve 14 due to the cam reaction force is determined. When there is a possibility of overlap, it can be determined that it is an overlap time.

  The remaining effects of the second embodiment are similar to those of the first embodiment.

(Other embodiments)
In addition, embodiment disclosed this time is an illustration in all the points, Comprising: It does not become a basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Further, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the scope of the claims.

  For example, in the first embodiment, the base map value InTPA is set as the target phase angle of the intake valve 13 at the time of minus overlap when the valve timings of the intake valve 13 and the exhaust valve 14 are advanced, and the intake valve 13 shows an example in which the base map value ExTPA is set as the target phase angle of the exhaust valve 14 at the time of minus overlap when the valve timings of the exhaust valve 14 and the exhaust valve 14 are retarded. If the base map value InTPA is set as the target phase angle of the intake valve 13 at the time of minus overlap when the valve timing of the exhaust valve 14 is advanced, the valve timing of the intake valve 13 and the exhaust valve 14 is retarded. Minus over in case During the lap, it may be set a target phase angle ExTPA2 recalculated as the target phase angle of the exhaust valve 14. Similarly, if the base map value ExTPA is set as the target phase angle of the exhaust valve 14 at the minus overlap when the valve timings of the intake valve 13 and the exhaust valve 14 are retarded, the intake valve 13 and the exhaust valve 14 The target phase angle InTPA2 recalculated as the target phase angle of the intake valve 13 may be set at the time of minus overlap when the valve timing is advanced.

  In the first embodiment, the intake side VVT mechanism 100in is controlled by the intake side OCV 200in. However, the present invention is not limited to this, and the intake side VVT mechanism may be electrically operated. The same applies to the exhaust-side VVT mechanism 100ex.

  In the first embodiment, the working angle of the intake valve 13 and the exhaust valve 14 is constant. However, the present invention is not limited to this, and the working angle of the intake valve and the exhaust valve may be variable.

  In the first embodiment, an example in which the base map value is calculated based on the rotation speed and load factor of the engine 1 has been described. The base map value may be calculated in consideration of the above.

  In the first embodiment, after recalculating the target phase angle of the intake valve 13, an example of determining whether or not minus overlap is shown, but not limited to this, whether or not minus overlap is determined. Judgment may be made and the target phase angle of the intake valve may be recalculated when it is not a negative overlap. That is, the flowchart of FIG. 4 is an example and is not limited to the procedure.

  In the first embodiment, an example in which the engine 1 is a four-cylinder gasoline engine has been described. However, the present invention is not limited to this, and the engine may be a diesel engine or the like, and the number of cylinders and the type of the engine (V type, Any type of horizontally opposed type may be used.

  In the first embodiment, the oil pump 19 is mechanical. However, the present invention is not limited to this, and the oil pump may be electric.

  In the first embodiment, the base map value ExTPA of the exhaust valve 14 is calculated based on the base map value InTPA of the intake valve 13 and the target overlap period TOPA. However, the present invention is not limited to this. The base map value of the valve may be derived from the map. Further, the target phase angle of the exhaust valve and the target overlap period may be derived from the map, and the target phase angle of the intake valve may be calculated using the result.

  Note that a modification of the first embodiment described above may be applied to the second embodiment.

  In the second embodiment, the valve swing angle OSPA is an example of a preset value. However, the present invention is not limited to this, and the valve swing angle is a calculated value calculated according to the operating state of the engine. Also good.

  The present invention is applicable to an internal combustion engine control device that controls an internal combustion engine that includes an intake side variable valve timing mechanism and an exhaust side variable valve timing mechanism.

1 engine (internal combustion engine)
13 Intake valve 14 Exhaust valve 100in Intake side VVT mechanism (Intake side variable valve timing mechanism)
100ex Exhaust side VVT mechanism (Exhaust side variable valve timing mechanism)
400 ECU (control device for internal combustion engine)

Claims (9)

An internal combustion engine control device comprising an intake side variable valve timing mechanism that varies a valve timing of an intake valve and an exhaust side variable valve timing mechanism that varies a valve timing of an exhaust valve,
First calculation means for calculating a target phase angle and a target overlap period of the intake valve and the exhaust valve based on a rotation speed and a load factor of the internal combustion engine;
Second calculating means for calculating a target phase angle of the intake valve based on the target overlap period and an actual phase angle of the exhaust valve when valve timings of the intake valve and the exhaust valve are advanced;
When the valve timings of the intake valve and the exhaust valve are advanced, the value calculated by the first calculation means is set as the target phase angle of the exhaust valve, and the target phase angle of the intake valve is First target phase angle setting means for setting the value calculated by the second calculation means;
When the valve timings of the intake valve and the exhaust valve are advanced, minus over, in which both the intake valve and the exhaust valve are closed after the exhaust valve is closed until the intake valve is opened A control device for an internal combustion engine, comprising: second target phase angle setting means for setting values calculated by the first calculation means as target phase angles of the exhaust valve and the intake valve at the time of lap. The control apparatus for an internal combustion engine according to claim 1,
When the valve timings of the intake valve and the exhaust valve are advanced, a minus overlap is made based on the target phase angle of the intake valve calculated by the first calculation means and the actual phase angle of the exhaust valve. A control device for an internal combustion engine, comprising: determination means for determining whether or not it is time. The control apparatus for an internal combustion engine according to claim 1 or 2,
The second calculating means calculates a target phase angle of the exhaust valve based on the target overlap period and the actual phase angle of the intake valve when valve timings of the intake valve and the exhaust valve are retarded. Configured to
The first target phase angle setting means sets a value calculated by the second calculation means as a target phase angle of the exhaust valve when valve timings of the intake valve and the exhaust valve are retarded. , Configured to set a value calculated by the first calculation means as a target phase angle of the intake valve,
When the valve timing of the intake valve and the exhaust valve is retarded, the second target phase angle setting means is the first calculation means as the target phase angle of the exhaust valve and the intake valve at the time of minus overlap. A control device for an internal combustion engine, wherein the control device is configured to set the value calculated by the above. The control apparatus for an internal combustion engine according to claim 3,
When the valve timings of the intake valve and the exhaust valve are retarded, a minus overlap is made based on the target phase angle of the exhaust valve calculated by the first calculation means and the actual phase angle of the intake valve. A control device for an internal combustion engine, comprising: determination means for determining whether or not it is time. The control apparatus for an internal combustion engine according to claim 1,
When the valve timing of the intake valve and the exhaust valve is advanced, the second calculation means is configured to control the intake valve based on the target overlap period, the actual phase angle of the exhaust valve, and the valve swing angle. An internal combustion engine control apparatus configured to calculate a target phase angle. The control apparatus for an internal combustion engine according to claim 5,
When the valve timings of the intake valve and the exhaust valve are advanced, the target phase angle of the intake valve calculated by the first calculation means, the actual phase angle of the exhaust valve, and the valve swing angle are A control device for an internal combustion engine, comprising: a determination unit that determines whether or not a negative overlap occurs. The control apparatus for an internal combustion engine according to claim 5 or 6,
When the valve timing of the intake valve and the exhaust valve is retarded, the second calculation means is configured to determine the exhaust valve based on the target overlap period, the actual phase angle of the intake valve, and the valve swing angle. Configured to calculate a target phase angle of
The first target phase angle setting means sets a value calculated by the second calculation means as a target phase angle of the exhaust valve when valve timings of the intake valve and the exhaust valve are retarded. , Configured to set a value calculated by the first calculation means as a target phase angle of the intake valve,
When the valve timing of the intake valve and the exhaust valve is retarded, the second target phase angle setting means is the first calculation means as the target phase angle of the exhaust valve and the intake valve at the time of minus overlap. A control device for an internal combustion engine, wherein the control device is configured to set the value calculated by the above. The control apparatus for an internal combustion engine according to claim 7,
When the valve timings of the intake valve and the exhaust valve are retarded, the target phase angle of the exhaust valve calculated by the first calculation means, the actual phase angle of the intake valve, and the valve swing angle A control device for an internal combustion engine, comprising: a determination unit that determines whether or not a negative overlap occurs. An internal combustion engine control device comprising an intake side variable valve timing mechanism that varies a valve timing of an intake valve and an exhaust side variable valve timing mechanism that varies a valve timing of an exhaust valve,
First calculation means for calculating a target phase angle and a target overlap period of the intake valve and the exhaust valve based on a rotation speed and a load factor of the internal combustion engine;
Second calculating means for calculating a target phase angle of the exhaust valve based on the target overlap period and an actual phase angle of the intake valve when valve timings of the intake valve and the exhaust valve are retarded;
When the valve timings of the intake valve and the exhaust valve are retarded, a value calculated by the second calculation means is set as the target phase angle of the exhaust valve, and the target phase angle of the intake valve is First target phase angle setting means for setting the value calculated by the first calculation means;
When the valve timing of the intake valve and the exhaust valve is retarded, minus over which both the intake valve and the exhaust valve are closed after the exhaust valve is closed and before the intake valve is opened A control device for an internal combustion engine, comprising: second target phase angle setting means for setting values calculated by the first calculation means as target phase angles of the exhaust valve and the intake valve at the time of lap.

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