JP5817540B2 - Control device for internal combustion engine with variable valve gear - Google Patents

Description

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

  2. Description of the Related Art Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-228481, there is known an internal combustion engine including a variable valve operating device that can vary valve opening / closing characteristics of an intake valve and an exhaust valve. In this type of variable valve apparatus, the target valve opening / closing characteristics of each of these valves are set during transient operation. In the above publication, the optimum intake valve phase angle and exhaust valve phase angle are calculated from the viewpoint of fuel consumption and output in accordance with the engine speed and engine load.

JP 2009-228481 A

  In the variable valve operating apparatus, it is preferable that the amount of change in the valve opening / closing characteristics of the intake valve and the exhaust valve is determined and controlled based on this so that the required target intake air amount can be quickly realized. However, in the variable valve operating apparatus that separately controls the intake valve and the exhaust valve as described above, it is likely to be a problem how to determine the valve opening / closing characteristics of each.

  When a target intake air amount or a target load is given, the combination of the valve opening / closing characteristics of the intake valve and the valve opening / closing characteristics of the exhaust valve is not necessarily unique. That is, there may be a plurality of pairs of valve opening / closing characteristics of the intake valve and the exhaust valve for reaching a certain target state. When there are a plurality of candidates as described above, how to select and determine a pair of valve opening / closing characteristics of the intake valve and the exhaust valve becomes a problem.

  In addition, the target valve opening / closing characteristic of the exhaust valve and the target control amount for realizing it can be determined without considering the drive of the intake valve, and conversely, the target valve opening / closing characteristic of the intake valve and The case where the process which determines the target control amount which implement | achieves it is performed is assumed. In this case, the intake air amount, load factor, etc. may not be consistent with the target value and the actual value, causing hunting of control, and even if hunting does not occur, the control stability may be reduced. Can occur.

  The present invention has been made to solve the above-described problems. In an internal combustion engine including a variable valve gear that can individually change the valve opening / closing characteristics of an intake valve and an exhaust valve, the control stability is considered. It is another object of the present invention to provide a control device for an internal combustion engine with a variable valve operating device that can set a target value for changing valve characteristics.

A control device for an internal combustion engine with a variable valve operating device according to a first invention is
Control means for controlling a variable valve gear capable of individually changing the phase of the intake valve and the phase of the exhaust valve;
A map in which a phase of the intake valve is associated with a first axis and a phase of the exhaust valve is associated with a second axis orthogonal to the first axis, the phase of the intake valve on the first axis A plurality of points determined from the value and the phase value of the exhaust valve on the second axis are provided on the map, and a load value of the internal combustion engine is associated with each of the plurality of points, A map in which equal load values are associated with a plurality of points having different coordinates on a plane composed of the first axis and the second axis;
Calculating means for calculating a target load of the internal combustion engine;
Means for identifying a plurality of equal load points, which are points where a load equal to the target load is set on the map by comparing the target load value with the load value on the map;
A first intake phase that is a phase of the intake valve and a first exhaust phase that is a phase of the exhaust valve set by the control means in the variable valve device during driving of the variable valve device; Means for identifying a current point on the map corresponding to the first intake phase and the first exhaust phase;
Means for calculating a distance between two points on the map between each of the plurality of equal load points and the current point;
A selection means for selecting, as a target point, an equal load point that is the smallest point-to-point distance among the plurality of two-point distances obtained by calculation;
The exhaust valve determined from the second intake phase that is the phase of the intake valve determined from the first axis component of the target point and the second axis component of the target point by comparing the target point with the map Means for reading out from the map a second exhaust phase that is a phase of
With
The control means changes the phase of the intake valve toward the second intake phase by a first difference that is a difference between the first intake phase and the second intake phase, and the first exhaust phase and the first exhaust phase. The variable valve apparatus is controlled so as to change the phase of the exhaust valve toward the second exhaust phase by a second difference that is a difference from two exhaust phases .

According to a second invention, in the first invention,
The intake valve phase change limit width that is the limit of the phase change amount of the intake valve that can be changed by the variable valve device within a predetermined time on the map and the variable valve device that can be changed within a predetermined time A means for storing in advance an exhaust phase change limit width that is a limit of an exhaust valve phase change amount;
The control means includes
When the first difference is less than or equal to half of the intake phase change limit width, the variable valve apparatus is controlled to change the phase of the intake valve by the first difference;
Controlling the variable valve operating system so as to change the phase of the intake valve by half of the intake phase change limit width when the first difference exceeds half of the intake phase change limit width;
When the second difference is less than or equal to half of the exhaust phase change limit width, the variable valve apparatus is controlled to change the phase of the exhaust valve by the second difference;
When the second difference exceeds half of the exhaust phase change limit width, the variable valve apparatus is controlled so as to change the phase of the exhaust valve by half of the exhaust phase change limit width .

According to the control device of the variable valve device equipped with an internal combustion engine according to the first invention, it can be determined according to the setting guidance of reducing valves opening and closing characteristics and exhaust valve opening profiles combined way even change time be a plurality of valves Therefore, it is possible to set a target value for changing the valve characteristics while taking control stability into consideration.

According to the second invention, it is possible to reach the target load at an early stage within a feasible range while ensuring control stability .

It is a whole block diagram for demonstrating the structure of the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 1 of this invention with the internal combustion engine system structure with a variable valve apparatus to which this is applied. It is a figure for demonstrating the subject which should be solved by the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 1 of this invention. It is a figure for demonstrating the subject which should be solved by the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 1 of this invention. It is a figure which shows the equal KL map group with which the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 1 of this invention is provided. It is a top view of the equal KL map with which the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 1 of this invention is provided. 4 is a flowchart of a routine that is executed by the ECU 50 in the control device for an internal combustion engine with a variable valve device according to the first embodiment of the present invention; It is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention. It is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention. It is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention. It is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention. It is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention. It is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 2 of this invention. It is a figure for demonstrating operation | movement of the control apparatus of the internal combustion engine with a variable valve apparatus concerning Embodiment 2 of this invention.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is an overall configuration diagram for explaining the configuration of a control device for an internal combustion engine with a variable valve device according to a first embodiment of the present invention, together with the configuration of an internal combustion engine system with a variable valve device to which this is applied. is there. The internal combustion engine system of the present embodiment includes a gasoline engine 10. Each cylinder of the engine 10 is provided with a piston 12, and a combustion chamber 14 is formed by the piston 12. The piston 12 is connected to a crankshaft 16 that is an output shaft of the engine 10. Although only one cylinder is shown in FIG. 1 for convenience, the engine 10 is actually an in-line four-cylinder gasoline engine. In many cases, an engine mounted on a vehicle includes a plurality of cylinders, and the engine 10 includes a plurality of cylinders in the same manner.

  The engine 10 includes an intake passage 18 that sucks intake air into each cylinder and an exhaust passage 20 that discharges exhaust gas from each cylinder. The intake passage 18 is provided with an air flow sensor 22 for detecting the intake air amount and an electronically controlled throttle valve 24. The throttle valve 24 is driven based on the accelerator opening and the like, and adjusts the intake air amount. Each cylinder has a fuel injection valve 26 for injecting fuel into the intake port, a spark plug 27 provided in the combustion chamber 14, an intake valve 28 for opening and closing the intake passage 18 with respect to the cylinder, An exhaust valve 30 that opens and closes the exhaust passage 20 with respect to the inside of the cylinder is provided. The engine 10 also includes a supercharger 32 that supercharges intake air using exhaust pressure. The supercharger 32 has a turbine 34 provided in the exhaust passage 20 and a compressor 36 provided in the intake passage 18. When the supercharger 32 is operated, the turbine 34 receives the exhaust pressure and rotates to drive the compressor 36, whereby the compressor 36 supercharges the intake air.

  The engine 10 includes a phase variable mechanism 38 and a working angle variable mechanism 40. The phase variable mechanism 38 and the operating angle variable mechanism 40 are variable valve operating apparatuses of the engine 10. The phase variable mechanism 38 is an intake valve phase variable mechanism that variably sets the phase (opening / closing timing) of the intake valve 28, and an exhaust valve phase variable that variably sets the phase (opening / closing timing) of the exhaust valve 30. And the mechanism. The working angle variable mechanism 40 is different from the intake valve working angle variable mechanism that variably sets the working angle (opening period) and the lift amount of the intake valve 28, and the working angle (opening period) of the exhaust valve 30. And an exhaust valve working angle variable mechanism that variably sets the lift amount.

  In the present embodiment, the phase of the intake valve 28 and the exhaust valve 30 is individually advanced or retarded by the phase variable mechanism 38, and the operating angle of the intake valve 28 and the exhaust valve 30 is determined by the operating angle variable mechanism 40. The lift amount can be increased or decreased individually.

  Furthermore, the system of the present embodiment includes a sensor system including a crank angle sensor 42 and an intake pressure sensor 44, and an ECU (Electronic Control Unit) 50 that controls the operating state of the engine 10. First, the sensor system will be described. The crank angle sensor 42 outputs a signal synchronized with the rotation of the crankshaft 16, and the ECU 50 detects the engine speed (engine speed) and the crank angle based on this output. can do. The intake pressure sensor 44 detects intake air pressure (supercharging pressure).

  In addition to the sensors 24, 42, and 44, the sensor system includes various sensors (for example, a water temperature sensor that detects the temperature of engine cooling water, an air-fuel ratio that detects the exhaust air-fuel ratio). Sensors, an accelerator opening sensor that detects the accelerator opening, a cam angle sensor that detects the rotation angle of the camshaft, and the like. These sensors are connected to the input side of the ECU 50. Various actuators including the throttle valve 24, the fuel injection valve 26, the spark plug 27, the phase variable mechanism 38, the operating angle variable mechanism 40, and the like are connected to the output side of the ECU 50.

  And ECU50 detects driving | operation information of an engine by a sensor system, and performs driving | operation control by driving each actuator based on the detection result. Specifically, the engine speed and the crank angle are detected based on the output of the crank angle sensor 42, and the intake air amount is calculated by the air flow sensor 22. Further, the engine load (load factor) is calculated based on the intake air amount, the engine speed, and the like. Then, the fuel injection timing and ignition timing are determined based on the crank angle, and when these timings arrive, the fuel injection valve 26 and the spark plug 27 are driven. Thereby, the air-fuel mixture is combusted in the cylinder, and the engine can be operated. Further, the ECU 50 controls the phase, the operating angle, and the lift amount of the intake valve 28 by driving the phase variable mechanism 38 and the operating angle variable mechanism 40.

[Operation of Embodiment 1]
(Problem of the first embodiment)
2 and 3 are diagrams for explaining problems to be solved by the control device for an internal combustion engine with a variable valve operating apparatus according to the first embodiment of the present invention. 2 is a diagram showing the relationship between the target air amount (hereinafter referred to as target KL) and the phase of the intake valve 28, and FIG. 2 is a diagram showing the relationship between the target KL and the phase of the exhaust valve 30. 2 (b).

  The problem is how to determine the valve opening and closing characteristics of the intake valve 28 and the exhaust valve 30 during the transition of the engine 10. That is, when correcting the valve opening / closing characteristics of the intake valve 28 and the valve opening / closing characteristics of the exhaust valve 30 during transition, there is a degree of freedom in how to combine these characteristics. Even if one or both of the valve opening / closing characteristics of the intake valve 28 and the valve opening / closing characteristics of the exhaust valve 30 are different, a combination of valve opening characteristics that realizes an equal load KL is assumed. FIG. 3 is a diagram showing the equal KL lines 62, 64, 66. FIG. 3 shows contour KL lines (only 62, 64 and 66 are shown in FIG. 3) in the manner of contour lines. It is a problem how to determine the valve opening / closing characteristics (phase) of the intake valve 28 and the exhaust valve 30 so as to determine which point on the equal KL line is determined.

  As an example, it is assumed that the target valve opening / closing characteristics of the exhaust valve 30 and the target control amount that realizes the target valve opening / closing characteristics are determined without considering the driving of the intake valve 28. On the other hand, on the other hand, it is also assumed that the target valve opening / closing characteristics of the intake valve 28 and the target control amount for realizing the target are determined without considering the driving of the exhaust valve 30. For example, it is assumed that the current valve opening / closing characteristic (phase) is at a point 68 on the equal KL map (in a steady state, an appropriate value). Thereafter, it is assumed that the valve opening / closing characteristics are changed (that is, the phase is changed) with the point on the equal KL line 64 as a target in accordance with the change of the target KL. For example, it is conceivable to aim at point 70 or point 72. In this case, if the influence of the target valve opening / closing characteristics of the intake valve 28 and the exhaust valve 30 is not mutually considered, the advance angle amount and the retard angle amount reach the point 80 after passing through the target equal KL line 64. May be set as a target point. Then, this time, with the point 80 as a reference, the retard amount and the advance amount are determined again with a certain point on the equal KL line 64 as a target. However, as in the previous case, however, there is a risk that the advance amount and the retard amount that pass the target equal KL line 64 may be determined, and such a situation is repeated to cause hunting. .

(Control according to the first embodiment)
In the first embodiment, when the intake valve 28 and the exhaust valve 30 are to be operated simultaneously in order to achieve the target KL during the transition, the control target values of the intake valve 28 and the exhaust valve 30 are determined by the following method. This method is a control method for determining the VVT control target value corresponding to the target KL, that is, the amount of change in the valve opening / closing characteristics, using the target KL as input information. The change amount of the valve opening / closing characteristics includes the phase, the lift amount, and the opening / closing valve amount. The change of the “open / close valve amount” is to adjust the closing timing of the valve in a mechanism that controls the closing timing of the valve while fixing the valve opening timing. In this embodiment, a case where the phase is changed will be described as an example.

  FIG. 4 is a diagram showing an equal KL map group 58 provided in the control device for an internal combustion engine with a variable valve operating apparatus according to the first embodiment of the present invention. In the first embodiment, it is assumed that the equal KL map group 58 is created in advance for the engine 10 and the ECU 50 stores the equal KL map group 58. The equal KL map group 58 includes a plurality of the above-described equal KL maps according to the intake pressure. In FIG. 4, for convenience of explanation, the equal KL map 60 at a specific intake pressure is shown through.

  Each equal KL map has a relationship between the opening / closing characteristic (phase) of the intake valve 28 and the load KL realized by each valve opening / closing characteristic information with the opening / closing characteristic (phase) of the exhaust valve 30 as the vertical axis. Are divided by equal KL lines for each region having the same load KL. The contour KL line is defined in the manner of the contour line.

  FIG. 5 is a plan view of an equal KL map 60 provided in the control device for an internal combustion engine with a variable valve operating apparatus according to the first embodiment of the present invention. In FIG. 6, for the sake of convenience, only the equal KL lines 62, 64, and 66 are shown, but actually, a larger number of equal KL lines are included. Each phase of the intake valve 28 and the exhaust valve 30 is determined according to one point on the equal KL map 60. As described above, the equal KL map is a map that defines the value of the load KL of the engine 10 and the set of the phase of the intake valve 28 and the phase of the exhaust valve 30. The distance between two points on the equal KL map represents a change period required for changing the phases of the intake valve 28 and the exhaust valve 30 from one point to the other point. Each equal KL map is created assuming that the intake manifold pressure is constant. In the first embodiment, the ECU 50 selects the equal KL map 60 corresponding to the current intake pressure from the equal KL map group 58 based on the output of the intake pressure sensor 44.

Next, the ECU 50 calculates a target KL based on the output of the accelerator opening sensor, and executes a process of specifying an equal KL line corresponding to the target KL on the equal KL map 60. In the first embodiment, as an example, the equal KL line 64 is specified.
In the first embodiment, it is assumed that the current valve opening / closing characteristics (valve timing, phase) are at point 68. In the first embodiment, the point 74 closest to the point 68 on the target equal KL line 64 is set as the target. The closest point 74 may be selected by comparing the distance between the point 68 on the equal KL map 60 and each point on the equal KL line 64.

  When a point on the equal KL map 60 is determined, the respective phases of the intake valve 28 and the exhaust valve 30 are determined accordingly. Therefore, if the current point (for example, point 68) on the equal KL map 60 and the equal KL line (for example, point 64) corresponding to the target KL are specified, each of the intake valve 28 and the exhaust valve 30 is uniquely defined. In addition, the phase angle change amount (“A” and “B” in FIG. 5) that is the shortest change time can be specified.

  As described above, according to the control apparatus for an internal combustion engine with a variable valve device according to the first embodiment, the map that defines the relationship between the target KL, the phases of the intake valve 28 and the exhaust valve 30, and the change time is provided. By using this, it is possible to set a target value for changing the valve characteristics while ensuring control stability.

  In addition, among various combinations of the phases of the intake valve 28 and the exhaust valve 30, a set of phases to be targeted can be uniquely determined. That is, among the phases included in the same section (the same equal KL line) on the equal KL map 60, a plurality of selection candidates corresponding to the target KL are assumed, and the phase having the minimum change period is set as the target value. It can be determined uniquely. Therefore, the change time is minimized and control stability is also ensured.

  Furthermore, by controlling the phase variable mechanism 38 according to the set target value, hunting can be suppressed and control stability can be improved. The phases of the intake valve 28 and the exhaust valve 30 can be changed so as to achieve the target KL in a shorter change period. Since the valve opening / closing characteristics can be quickly changed to the valve opening / closing characteristics realizing the target KL, the transient response is improved.

[Specific Processing in First Embodiment]
FIG. 6 is a flowchart of a routine executed by the ECU 50 in the control device for an internal combustion engine with a variable valve operating apparatus according to the first embodiment of the present invention. 7-12 is a figure for demonstrating the content of the specific process concerning Embodiment 1 of this invention.

  In the routine of FIG. 6, first, the ECU 50 executes a process of calculating the target torque from the throttle opening degree or the like (step S100).

  Next, the ECU 50 executes a process for calculating the target KL from the target torque, the engine speed NE, and the like (step S102).

  Next, the ECU 50 executes a process of selecting an equal KL map corresponding to the current intake manifold pressure (intake pressure) (step S104). Specifically, based on the output value of the intake pressure sensor 44, a process of reading an equal KL map corresponding to the current intake pressure from the equal KL map group 58 stored in the ROM of the ECU 50 is executed. In the present embodiment, the equal KL map 60 is read.

  Next, the ECU 50 executes processing for setting the closest point on the target KL line as the target valve timing (target valve opening / closing characteristics) (step S106). Referring to FIG. 7, first, an equal KL line corresponding to the target KL is selected on the equal KL map 60. Here, the equal KL line 66 is selected as an example. Next, a point (point 68 in FIG. 7) on the equal KL map 60 corresponding to the current phase is specified. Next, a point 76 is calculated as a point on the equal KL line 66 that is the shortest distance from the point 68. This point 76 is “the closest point on the target KL line”, and the phase on the IN-VVT axis and the phase on the EX-VVT axis corresponding to this point 76 are set as the target valve timing.

Next, the ECU 50 executes a process for determining whether or not the target valve timing can be reached from the current valve timing to the next update time (step S108). In the first embodiment, the update time is 8 ms. The ECU 50 determines whether or not the phase can be changed from the point 68 to the target valve timing (point 76) within 8 ms.
Here, it demonstrates with reference to FIG. A broken line 80 in FIG. 8 represents the maximum phase range that the phase variable mechanism 38 can change within 8 ms, centering on the point 68. A region surrounded by the broken line 80 is referred to as a changeable range 82. The changeable range 82 is determined by the hardware performance or the like (movable speed) of the phase variable mechanism 38. In the present embodiment, the description will be made assuming that the moving speed toward the advance side is the same as the moving speed toward the retard side. The changeable range 82 is determined by two widths of “IN phase change limit width” and “Ex phase change limit width”. The “IN phase change limit width” is a phase width that can be changed within 8 ms by the intake valve phase change mechanism of the phase variable mechanism 38. The “Ex phase change limit width” is a phase width that the exhaust valve phase change mechanism of the phase variable mechanism 38 can change within 8 ms. In the present embodiment, it is assumed that the ECU 50 stores information on the changeable range 80 in advance in a storage device (RAM, ROM, etc.) as a numerical value for determination.
If the next target valve timing point on the equal KL map 60 from the current point 68 is not within the changeable range 82, the phase variable mechanism 38 cannot realize the target valve timing by the next update time. . Step S108 is a determination process executed from such a viewpoint.
In this routine, as described above, the phase is changed from the point 68 to the target valve timing (point 76). In this case, the point 76 does not exist within the changeable range 82. Therefore, the determination result of step S108 is not established (No).

  When the condition of step S108 is not satisfied (No), the ECU 50 executes a process of determining whether or not the intake valve phase variable mechanism (Ex-VVT) can reach the target valve timing (step S112). . In this step, the ECU 50 executes a process of determining whether or not the value in the IN-VVT axis direction between the point 68 and the point 76 is equal to or less than “a half value of the IN phase limit width”. In this routine, the “value in the IN-VVT axis direction between the point 68 and the point 76” is larger than the “half value of the IN phase limit width”. That is, when the IN-VVT axial direction component is viewed, the point 76 exceeds the changeable range 82 of the point 68. In this case, the determination result in step S112 is not established (No).

  When the condition of step S112 is not satisfied (No), the ECU 50 executes a process of determining whether or not the exhaust valve phase variable mechanism (Ex-VVT) can reach the target valve timing (step S114). . In this step, the ECU 50 executes a process of determining whether or not the value in the Ex-VVT axis direction between the point 68 and the point 76 is equal to or less than “a half value of the Ex phase limit width”. In this routine, “the value in the Ex-VVT axis direction between the point 68 and the point 76” is smaller than “a half value of the Ex phase limit width”. That is, when viewing the Ex-VVT axial direction component, the point 76 is inside the changeable range 82 of the point 68. In this case, the determination result in step S114 is established (Yes).

When the condition of step S114 is satisfied (Yes), the ECU 50 moves the exhaust valve phase variable mechanism (Ex-VVT) toward the target, and the intake valve phase variable mechanism (IN-VVT) is the maximum distance. A process for moving is executed (step S118).
If it demonstrates using FIG. 9, in the range of the changeable range 82, the phase change about the exhaust valve 30 will be performed to such an extent that it matches the position of the point 76 in the EX-VVT direction. On the other hand, the phase of the intake valve 28 is changed by the maximum distance of the changeable range 82 (that is, the limit of the line 80). As a result, the valve timing moves to point 77 after the phase change. Thereafter, the current routine ends and the process returns. In the routine after the next time, the same processing is executed with the point 77 as a starting point, so that the target valve timing (point 76) can be finally reached.

When the condition of step S108 is satisfied (Yes), the ECU 50 executes a process of controlling the phase variable mechanism 38 of the intake valve 28 and the exhaust valve 30 toward the target point (step S110). The case where this process is performed will be described with reference to FIG.
In FIG. 10, the point 78 is set as the target valve timing. This point 78 falls within the changeable range 82, and in this case, the condition of step S108 is satisfied (Yes). Therefore, the ECU 50 advances the intake valve 28 and retards the exhaust valve 30 so as to move to the point 78. Thereafter, the current routine ends and the process returns.

When the condition of step S112 is satisfied (Yes), the ECU 50 moves the intake valve phase variable mechanism (IN-VVT) toward the target, and the exhaust valve phase variable mechanism (EX-VVT) Processing for moving the maximum distance is executed (step S116).
Here, for convenience, an example of a scene in which the control in step S116 is executed will be described with reference to FIG. Since the equal KL map shown in FIG. 11 is a schematic diagram for explaining the relationship between the target valve timing point and the changeable range 82, the equal KL line is omitted. In FIG. 11, a point 86 is a point on the current equal KL map, and a point 88 is a target valve timing point. In this case, as the point 88 corresponding to the target valve timing protrudes from the changeable range 82 in the EX-VVT axis direction, the EX-VVT retarded side from the current point (in FIG. It is located on the upper side. On the other hand, the phase of the intake valve 28 is changed to the extent that it matches the position of the point 88 in the EX-VVT direction within the changeable range 82. As a result, the point on the equal KL map moves from the point 88 to the point 90.
Thereafter, the current routine ends and the process returns. In the routine after the next time, the same processing is executed again with the point after movement as the start point, so that the target valve timing (point 88) can be finally reached.

If the condition in step S114 is not satisfied (No), the ECU 50 performs processing for moving the exhaust valve phase variable mechanism (Ex-VVT) and the intake valve phase variable mechanism (IN-VVT) by the maximum distance. Execute (Step S120).
Here, for convenience, an example of a scene in which the control in step S120 is executed will be described with reference to FIG. The equal KL map shown in FIG. 12 is a schematic diagram for explaining the relationship between the target valve timing (phase) point and the changeable range 82, and therefore the equal KL line is omitted. In FIG. 12, a point 86 is a point on the current equal KL map, and a point 92 is a target valve timing point. The point 92 corresponding to the target valve timing is located in the upper right direction on the paper surface of the KL map so as to protrude from the changeable range 82 in both the EX-VVT axis direction and the IN-VVT axis direction so as to protrude from the current point 86. ing. In this case, the phase of the intake valve 28 and the exhaust valve 30 is changed to the maximum distance of the changeable range 82 (that is, the vertex of the rectangular broken line 80). As a result, the valve timing moves to the vertex 94 of the rectangular broken line 80 after the phase change. Thereafter, the current routine ends and the process returns. In the routine after the next time, the same processing is executed again with the point after the movement as the start point, so that the target valve timing can finally be reached.

Among the specific processes described above, in particular, according to the processes of steps S100 to S106, the control stability is determined using a map that defines the relationship between the target KL, the phases of the intake valve 28 and the exhaust valve 30, and the change time. It is possible to set a target value for changing the valve characteristics while ensuring the above.
By controlling the phase variable mechanism 38 according to the set target value, the phases of the intake valve 28 and the exhaust valve 30 can be changed so as to achieve the target KL in a short change period.

  Of the specific processes described above, according to the processes in steps S108 to S120, the valve is related to the update time (changeable range 82) while the phase variable mechanism 38 basically follows the set target value. Even when the timing cannot be reached, it can be appropriately dealt with. That is, the phase change amount of the intake valve 28 and the phase change amount of the exhaust valve 30 are divided into the IN-VVT axis component and the EX-VVT axis component according to the position of the target point on the equal KL map. Can be uniquely determined within the range of the changeable range 82. Therefore, it is possible to reach the target KL at an early stage within a feasible range while ensuring control stability.

  Although Embodiment 1 uses the equal KL map 60 as a function, the valve opening / closing characteristic storage form for realizing the present invention is not limited to the map. The same content as the equal KL map may be expressed by an equation (equation), and the shortest distance between the current valve timing point and the equal KL line may be calculated.

  In the first embodiment, one point (point 76 in FIG. 7) at which the change period between the current valve opening / closing characteristic and the realization of the target valve opening / closing characteristic is minimized is set as the target valve timing. doing. However, the present invention is not necessarily limited to a mode in which the point at which the change period is minimized is set, and a “point at which the change period is near the minimum” may be set. For example, on the equal KL line, “a point where the change period becomes longer by a predetermined period ΔT than the minimum change period” may be selected as a point of the target valve timing. Even in this case, candidates for valve opening / closing characteristics to be targeted can be narrowed down from among innumerable combinations on the equal KL line in accordance with the guideline for shortening the change period.

  The engine 10 according to the first embodiment is also a supercharged engine including the supercharger 32. In the supercharging region of the supercharged engine, the intake manifold pressure changes very slowly compared to the speed at which the valve moves. In such a case, the control device for the variable valve gear-equipped internal combustion engine according to the first embodiment exhibits a higher effect. That is, in the supercharging region, the state where the torque is controlled by the throttle fully opened and the wastegate valve (WGV) has the smallest pumping loss and the best fuel efficiency. If the valve opening / closing characteristic control by the variable valve apparatus is performed more quickly according to the first embodiment, the intake air amount can be increased at an early stage, so that the boost pressure rises earlier.

Embodiment 2. FIG.
FIGS. 13 and 14 are diagrams for explaining the operation of the control device for the internal combustion engine with the variable valve operating apparatus according to the second embodiment of the present invention, and shows an equal KL map 100 used in the second embodiment. FIG.
The control apparatus for an internal combustion engine with a variable valve operating apparatus according to the second embodiment is applied to the internal combustion engine system shown in FIG. However, in the second embodiment, in the internal combustion engine system of FIG. 1, the configuration of the phase variable mechanism 38 is different from that of the first embodiment. In the second embodiment, the phase variable mechanism 38 is assumed that the intake valve phase variable mechanism is an electric type and the exhaust valve phase variable mechanism is a hydraulic type, and the operation speeds of both are different.

  FIG. 14A is a schematic diagram showing a phase changeable range when the moving speed is the same between the intake valve phase varying mechanism and the exhaust valve phase varying mechanism (the same as in the first embodiment). On the other hand, FIG. 14B is a schematic diagram for explaining the difference in the changeable range of the phase of the intake valve and the exhaust valve when the movable speed of the intake valve phase variable mechanism is larger than that in the case of FIG. FIG. In FIG. 14A and FIG. 14B, a point corresponding to the current valve timing is defined as a point 202. For point 202, dashed lines 204, 206 represent the maximum phase range that phase variable mechanism 38 can change within 8 ms in each case.

  Comparing FIG. 14A and FIG. 14B, FIG. 14B has a larger width in the IN-VVT axis direction. This is because the movable speed of the intake valve phase varying mechanism is higher in FIG. 14B than in the case of FIG. In the second embodiment, the following correction is performed in order to use a common equal KL map while coping with such a difference in movable speed.

In the second embodiment, the value of the IN-VVT axis in the equal KL map 60 is corrected by the following equation.
L = (Target IN-VVT-Current IN-VVT) x EX-VVT movable speed / IN-VVT movable speed

  The corrected distance L is calculated by correcting the distance on the equal KL map between the current valve timing and the target valve timing by the ratio of the operating speeds of the intake valve phase variable mechanism and the exhaust valve phase variable mechanism. ing. By applying the above formula to the equal KL map 60, the equal KL map 100 is obtained. As shown in FIG. 13, the equal KL map 100 includes “corrected IN-VVT”. An equal KL map 100 shown in FIG. 13 is a map obtained by correcting the equal KL map 60 according to the above correction formula. The equal KL lines 112, 114, 116 are obtained by correcting the equal KL lines 62, 64, 66 of the equal KL map 60. In the equal KL map 60, it is assumed that the broken line arrow “before axis correction” in FIG. 13 is the minimum distance from the point 118 to the equal KL line 114. On the other hand, after correction, the solid line arrow “after axis correction” represents the minimum distance to the equal KL line 114.

  As described above, according to the second embodiment, the basic value of the change period represented in the equal KL map 60 in the embodiment can be corrected based on the phase change speeds of the intake valve 28 and the exhaust valve 30. , Etc. KL map 100 can be obtained. Thereby, the equal KL map can be corrected so as to match the phase change speed.

  In the above formula, an example in which the IN-VVT axis is corrected is described, but the EX-VVT axis may be corrected. Further, as described in the first embodiment, the change amount of the valve opening / closing characteristics includes the phase, the lift amount, the operating angle, the opening / closing valve amount, and the like. Correction may be performed based on the speed ratio.

10 Engine 12 Piston 14 Combustion chamber 16 Crankshaft 18 Intake passage 20 Exhaust passage 22 Air flow sensor 24 Throttle valve 26 Fuel injection valve 27 Spark plug 28 Intake valve 30 Exhaust valve 32 Supercharger 34 Turbine 36 Compressor 38 Phase variable mechanism 40 Working angle Variable mechanism 42 Crank angle sensor 44 Intake pressure sensor 58, etc. KL map group 60, etc. KL map

Claims (2)

Control means for controlling a variable valve gear capable of individually changing the phase of the intake valve and the phase of the exhaust valve;
A map in which a phase of the intake valve is associated with a first axis and a phase of the exhaust valve is associated with a second axis orthogonal to the first axis, the phase of the intake valve on the first axis A plurality of points determined from the value and the phase value of the exhaust valve on the second axis are provided on the map, and a load value of the internal combustion engine is associated with each of the plurality of points, A map in which equal load values are associated with a plurality of points having different coordinates on a plane composed of the first axis and the second axis;
Calculating means for calculating a target load of the internal combustion engine;
Means for identifying a plurality of equal load points, which are points where a load equal to the target load is set on the map by comparing the target load value with the load value on the map;
A first intake phase that is a phase of the intake valve and a first exhaust phase that is a phase of the exhaust valve set by the control means in the variable valve device during driving of the variable valve device; Means for identifying a current point on the map corresponding to the first intake phase and the first exhaust phase;
Means for calculating a distance between two points on the map between each of the plurality of equal load points and the current point;
A selection means for selecting, as a target point, an equal load point that is the smallest point-to-point distance among the plurality of two-point distances obtained by calculation;
The exhaust valve determined from the second intake phase that is the phase of the intake valve determined from the first axis component of the target point and the second axis component of the target point by comparing the target point with the map Means for reading out from the map a second exhaust phase that is a phase of
With
The control means changes the phase of the intake valve toward the second intake phase by a first difference that is a difference between the first intake phase and the second intake phase, and the first exhaust phase and the first exhaust phase. 2. A control device for an internal combustion engine with a variable valve device that controls the variable valve device so as to change the phase of the exhaust valve toward the second exhaust phase by a second difference that is a difference from two exhaust phases . The intake valve phase change limit width that is the limit of the phase change amount of the intake valve that can be changed by the variable valve device within a predetermined time on the map and the variable valve device that can be changed within a predetermined time A means for storing in advance an exhaust phase change limit width that is a limit of an exhaust valve phase change amount;
The control means includes
When the first difference is less than or equal to half of the intake phase change limit width, the variable valve apparatus is controlled to change the phase of the intake valve by the first difference;
Controlling the variable valve operating system so as to change the phase of the intake valve by half of the intake phase change limit width when the first difference exceeds half of the intake phase change limit width;
When the second difference is less than or equal to half of the exhaust phase change limit width, the variable valve apparatus is controlled to change the phase of the exhaust valve by the second difference;
The variable valve device is controlled to change the phase of the exhaust valve by half of the exhaust phase change limit width when the second difference exceeds half of the exhaust phase change limit width. The control apparatus for an internal combustion engine with a variable valve operating apparatus according to claim 1.

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