JP6191311B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device including a fuel injection system that uses both port injection and in-cylinder injection and a supercharging system that uses exhaust pressure.

  Conventionally, in an engine equipped with a supercharging system that uses the exhaust pressure of the engine, a waste gate valve (open / close valve) is provided in a bypass for bypassing the turbocharging turbine that is interposed in the exhaust passage, and supercharging is performed. A technique for controlling the open / close state according to the state is known. That is, the rotational speed of the supercharging turbine is controlled by opening and closing the wastegate valve according to the presence or absence of supercharging.

  For example, if the wastegate valve is closed during supercharging, the rotational speed of the supercharging turbine increases. As a result, the amount of intake air that is supercharged increases, and the supercharging efficiency improves. Also, if the wastegate valve is opened at the start of the engine that does not require supercharging, the hot exhaust gas flows downstream through the bypass without passing through the supercharging turbine. Therefore, the temperature raising efficiency of the exhaust gas purification device disposed on the downstream side of the turbocharging turbine and the warm-up performance of the catalyst are improved (see, for example, Patent Document 1).

JP 2009-228486 A

  By the way, in general intake control at the time of supercharging, the opening change of the wastegate valve is performed prior to the change of the opening degree of the throttle valve. That is, the opening of the wastegate valve is first controlled to raise the boost pressure, and then the throttle valve is controlled so that the amount of air introduced into the cylinder becomes the amount of air corresponding to the desired engine output. The opening is adjusted. Such a method is advantageous in increasing the response of the engine output.

  On the other hand, intake control having a different concept from the above method has also been proposed. That is, the opening degree of the throttle valve is changed prior to changing the opening degree of the wastegate valve. In this method, after the opening degree of the throttle valve is set, the supercharging pressure is adjusted by the opening degree control of the wastegate valve, and the amount of air introduced into the cylinder is controlled. This method is advantageous in reducing the pumping loss of the engine by increasing the throttle opening early so as to reduce the flow velocity and intake pressure of the intake air passing through the throttle valve.

  However, the combustion state in the cylinder may change due to the difference in the opening control methods of the throttle valve and the wastegate valve during supercharging. For example, if the opening degree of the wastegate valve is controlled first, the fluctuation of the intake pressure is delayed with respect to the fluctuation of the exhaust pressure. Similarly, when the opening degree of the throttle valve is controlled first, the fluctuation of the exhaust pressure is delayed with respect to the fluctuation of the intake pressure. Therefore, when these opening degree control methods are switched and used in accordance with the operation state, the combustion state may deteriorate or knock may occur depending on the operation state.

  One of the purposes of this case was devised in view of the above-mentioned problems, and control for changing the throttle opening in advance of the wastegate opening, and the wastegate opening in advance of the throttle opening. In an engine control apparatus that uses a change control together, it is to improve the combustion stability of the engine. The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

(1) An engine control device disclosed herein is an engine control device including a supercharging system having a turbine with a wastegate valve, and a throttle valve interposed in an intake passage. This control device has a throttle advance mode in which the throttle opening is changed in advance of the wastegate opening in supercharging, and the wastegate opening is changed in advance of the throttle opening in supercharging. Mode selection means for selecting any of the supercharging advance mode is provided. And an ignition timing control means for controlling an ignition timing in accordance with the mode type selected by the mode selection means , wherein the ignition timing control means has the ignition timing in accordance with the mode type and the engine load. that controls the time.

Here, the engine load means a force that exerts a resistance against the engine, a work rate (engine output, horsepower), and a work (energy). Typically, an engine output required for the engine and a parameter correlated therewith are handled as the load. Specific examples of the load include charging efficiency Ec, volumetric efficiency Ev, engine target torque, intake and exhaust pressure, supercharging pressure, vehicle speed V, accelerator opening APS, operating condition of external load device, vehicle driving environment Information about
Preferably, the ignition timing control means calculates the load based on an intake air amount of the engine. The intake air amount here preferably includes the volume, mass, filling efficiency Ec, volume efficiency Ev, and the like of the intake air.

( 2 ) When the load is less than a predetermined load, the ignition timing control means preferably sets the ignition timing in the throttle advance mode to be retarded rather than the ignition timing in the supercharge advance mode.
In other words, when the load is less than a predetermined load, the ignition timing control means preferably sets the ignition timing in the supercharging advance mode to the advance setting rather than the ignition timing in the throttle advance mode.
The retard amount of the ignition timing in the throttle advance mode based on the ignition timing in the supercharge advance mode is smaller as the load is smaller except for an extremely low load region (load region less than a predetermined load). It is preferable to set large.

( 3 ) It is preferable that the ignition timing control means sets the ignition timing in the supercharging advance mode to a retard setting rather than the ignition timing in the throttle advance mode when the load is equal to or greater than a predetermined load.
In other words, the ignition timing control means preferably sets the ignition timing in the throttle preceding mode to an advance angle setting rather than the ignition timing in the supercharging preceding mode when the load is equal to or greater than a predetermined load.
In addition, it is preferable that the retard amount of the ignition timing in the supercharging advance mode based on the ignition timing in the throttle advance mode is set to be larger as the load is larger.

( 4 ) It is preferable to provide a calculation means for calculating a deviation amount between the target opening and the actual opening of the wastegate valve. In this case, it is preferable that the ignition timing control means controls the ignition timing according to the type of the mode when the deviation amount calculated by the calculation means is a predetermined value or more.
The ignition timing control means preferably calculates the predetermined value based on the intake air amount of the engine and the engine speed.

  According to the disclosed engine control device, it is possible to improve the combustion state of the engine by providing ignition timing characteristics corresponding to each of two types of modes having different characteristics (that is, the throttle preceding mode and the supercharging preceding mode). Can do.

It is a figure which illustrates the structure of the engine which concerns on one Embodiment. It is a figure which illustrates the block configuration of an engine control apparatus. It is a graph for demonstrating the opening degree change of a waste gate valve and a throttle valve, (a) respond | corresponds at the time of a throttle advance mode, (b) respond | corresponds at the time of a supercharging advance mode. It is an example map for determining a load area | region. A map example for setting the ignition timing I _G, X of (a) the engine rotational speed Ne, the map showing the relationship between the charging efficiency Ec and the ignition timing _{I G, (b), (} c) is (a) filling with -X sectional efficiency Ec and the ignition timing is a graph showing the relationship between I _G. It is a flowchart which illustrates the control procedure in an engine control apparatus.

  An engine control apparatus as an embodiment will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit of the present embodiment, and can be selected or combined as necessary.

[1. Device configuration]
[1-1. engine]
The engine control device of the present embodiment is applied to the on-vehicle gasoline engine 10 (hereinafter simply referred to as the engine 10) shown in FIG. The engine 10 includes a supercharging system using an exhaust pressure and an EGR system (exhaust gas recirculation system). FIG. 1 shows one of a plurality of cylinders (cylinders) provided in a multi-cylinder engine 10. A piston is slidably mounted in the cylinder, and the reciprocating motion of the piston is converted into rotational motion of the crankshaft via a connecting rod (connecting rod).

An intake port and an exhaust port are provided on the top surface of each cylinder, and an intake valve and an exhaust valve are provided in each port opening. In addition, a spark plug 15 is provided between the intake port and the exhaust port in a state where the tip thereof protrudes toward the combustion chamber. The timing of ignition at the spark plug 15 (ignition timing I _G ) is controlled by the engine control device 1.

[1-2. Fuel injection system]
An in-cylinder injection valve 11 (direct injection injector) that directly injects fuel into the cylinder is provided as an injector for supplying fuel to each cylinder. The fuel injection amount from the in-cylinder injection valve 11 and the injection timing thereof are controlled by the engine control device 1. For example, a control pulse signal is transmitted from the engine control device 1 to the in-cylinder injection valve 11, and the injection hole of the in-cylinder injection valve 11 is opened only during a period corresponding to the magnitude of the control pulse signal. Accordingly, the fuel injection amount becomes an amount corresponding to the magnitude (drive pulse width) of the control pulse signal, and the injection timing corresponds to the time when the control pulse signal is transmitted.

  The in-cylinder injection valve 11 is connected to a variable flow rate fuel pump 14 through a fuel supply path 13 including a common rail 13A. The fuel pump 14 operates by receiving a driving force from the engine 10 or an electric motor, and discharges the fuel in the fuel tank to the fuel supply path 13. As a result, the fuel pressurized by the fuel pump 14 is supplied from the fuel supply passage 13 to the common rail 13A and supplied into the cylinders through the in-cylinder injection valves 11 attached to the respective cylinders. The amount of fuel discharged from the fuel pump 14 and the fuel pressure are controlled by the engine control device 1.

[1-3. Intake and exhaust system]
The upper part of the intake valve is connected to an intake variable valve mechanism 28 for changing the valve lift amount and valve timing, and the upper part of the exhaust valve is connected to an exhaust variable valve mechanism 29. The operations of the intake valve and the exhaust valve are controlled by the engine control device 1 described later via these variable valve mechanisms 28 and 29. Each of the variable valve mechanisms 28 and 29 includes, for example, a variable valve lift mechanism and a variable valve timing mechanism as a mechanism for changing the rocking amount and rocking timing of the rocker arm.

  The variable valve lift mechanism is a mechanism that continuously changes the valve lift amount of each of the intake valve and the exhaust valve. This variable valve lift mechanism has a function of changing the magnitude of swing (valve lift amount) transmitted from the cam fixed to the camshaft to the rocker arm or tappet. The variable valve timing mechanism is a mechanism for changing the opening / closing timing (valve timing) of each of the intake valve and the exhaust valve. This variable valve timing mechanism has a function of changing the rotational phase of the cam or camshaft that causes the rocker arm to swing.

  The intake system 20 and the exhaust system 30 of the engine 10 are provided with a turbocharger 16 (supercharger) that performs supercharging with exhaust pressure. The turbocharger 16 is interposed across both the intake passage 21 connected to the upstream side of the intake port and the exhaust passage 31 connected to the downstream side of the exhaust port. The turbine 16A (supercharging turbine) of the turbocharger 16 is rotated by the exhaust pressure in the exhaust passage 31 and transmits the rotational force to the compressor 16B on the intake passage 21 side. In response to this, the compressor 16B feeds the air in the intake passage 21 while compressing it to the downstream side, and supercharges each cylinder. The supercharging operation of the turbocharger 16 is controlled by the engine control device 1.

  An intercooler 25 is provided on the intake passage 21 downstream of the compressor 16B to cool the compressed air. Further, an air filter 22 is provided on the upstream side of the compressor 16B, and air taken in from the outside is filtered. Further, a bypass passage 23 is provided so as to connect the upstream and downstream intake passages 21 of the compressor 16 </ b> B, and a bypass valve 24 is interposed on the bypass passage 23. The amount of air flowing through the bypass passage 23 is adjusted according to the opening degree of the bypass valve 24. The bypass valve 24 is controlled, for example, in the opening direction when the vehicle is suddenly decelerated, and functions to release the supercharging pressure supplied from the compressor 16B to the upstream side again. The opening degree of the bypass valve 24 is controlled by the engine control device 1.

  An exhaust gas recirculation (EGR) passage 34 is provided between the downstream side of the compressor 16 </ b> B in the intake system 20 and the upstream side of the turbine 16 </ b> A in the exhaust system 30. The EGR passage 34 is a passage that guides exhaust gas that has just been exhausted from the cylinder to the upstream side of the cylinder again. The EGR passage 34 is provided with an EGR cooler 35 for cooling the reflux gas. Cooling the reflux gas lowers the combustion temperature in the cylinder and reduces the generation rate of nitrogen oxides. Further, an EGR valve 36 for adjusting the recirculation amount of the exhaust gas is interposed at the junction between the EGR passage 34 and the intake system 20. The valve opening degree of the EGR valve 36 is variable and is controlled by the engine control device 1.

  A throttle body is connected to the downstream side of the intercooler 25, and an intake manifold (intake manifold) is connected to the downstream side thereof. The throttle body is disposed on the upstream side of the junction between the EGR passage 34 and the intake system 20 described above. An electronically controlled throttle valve 26 is provided inside the throttle body. The amount of air flowing toward the intake manifold is adjusted according to the opening of the throttle valve 26 (throttle opening TH). The throttle opening TH is controlled by the engine control device 1.

  The intake manifold (intake manifold) is provided with a surge tank 27 for temporarily storing air flowing to each cylinder. The junction between the aforementioned EGR passage 34 and the intake system 20 is located upstream of the surge tank 27. Therefore, outside air and exhaust gas can be mixed in the surge tank 27. The intake manifold downstream of the surge tank 27 is formed so as to branch toward the intake port of each cylinder, and the surge tank 27 is located at the branch point. The surge tank 27 functions to alleviate intake pulsation and intake interference that can occur in each cylinder.

  A catalyst device 33 is interposed on the exhaust passage 31 downstream of the turbine 16A. This catalyst device 33 purifies, decomposes, and removes components such as PM (Particulate Matter), nitrogen oxide (NOx), carbon monoxide (CO), and hydrocarbon (HC) contained in the exhaust gas, for example. It has a function to do. Further, an exhaust manifold (exhaust manifold) branched toward the exhaust port of each cylinder is connected to the upstream side of the turbine 16A.

  A bypass 32 is provided so as to connect the upstream and downstream exhaust passages 31 of the turbine 16 </ b> A, and an electronically controlled wastegate valve 17 is interposed on the bypass 32. The wastegate valve 17 is a supercharging pressure adjustment valve that changes the supercharging pressure by controlling the exhaust flow rate flowing into the turbine 16A side. The wastegate valve 17 is provided with a wastegate actuator 18 to electrically control the position (that is, the opening degree) of the valve body. The opening degree of the wastegate valve 17 (the wastegate opening degree D) is controlled by the engine control device 1.

[1-4. Sensor system]
An accelerator opening sensor 41 that detects the amount of depression of the accelerator pedal (accelerator opening A _PS ) is provided at an arbitrary position of the vehicle. The accelerator opening A _PS is a parameter corresponding to the driver's acceleration request and intention to start, in other words, a parameter correlated to the load of the engine 10 (output request to the engine 10).

  An air flow sensor 42 that detects an intake air flow rate Q is provided in the intake passage 21. The intake air flow rate Q is a parameter corresponding to the flow rate of air that has passed through the air filter 22. An intake manifold pressure sensor 43 and an intake air temperature sensor 44 are provided in the surge tank 27. The intake manifold pressure sensor 43 detects the pressure in the surge tank 27 as intake manifold pressure, and the intake air temperature sensor 44 detects the intake air temperature in the surge tank 27.

In the vicinity of the crankshaft, an engine rotation speed sensor 45 that detects the engine rotation speed Ne (the number of rotations per unit time) is provided. A cooling water temperature sensor 46 that detects the temperature of the engine cooling water (water temperature W _T ) is provided at an arbitrary position on the cooling water circulation path of the engine 10. Further, the fuel pump 14 is provided with a fuel pressure sensor 50 that detects the pressure (fuel pressure) of the fuel injected from the in-cylinder injection valve 11.

  The wastegate actuator 18 is provided with a hall sensor 47 that detects the stroke of the valve body drive member corresponding to the wastegate opening degree D. The stroke detected by the hall sensor 47 corresponds to the amount of movement of the valve body driving member from the reference position. In addition, a linear air-fuel ratio sensor 48 and an oxygen concentration sensor 49 are disposed inside the catalyst device 33. The linear air-fuel ratio sensor 48 detects the air-fuel ratio of the exhaust gas flowing into the catalyst device 33, and the oxygen concentration sensor 49 detects the oxygen concentration of the exhaust gas flowing out from the catalyst device 33. Various information detected by the various sensors 41 to 50 is transmitted to the engine control device 1.

  A selection switch 51 for selecting and setting a plurality of travel modes having different power performances is provided at an arbitrary position in the passenger compartment. Here, either the sport mode or the eco mode is selected and set according to the driver's switch operation. The sport mode is a travel mode in which control is performed with more emphasis on acceleration than fuel efficiency and power consumption, and the eco mode is a travel mode in which control is performed with greater emphasis on fuel efficiency and power consumption than acceleration. The travel mode information selected and set here is transmitted to the engine control device 1. The selection switch 51 can be regarded as a type of sensor that detects the state of the driver's switch operation.

[1-5. Control system]
A vehicle equipped with the engine 10 is provided with an engine control device 1 (Engine Electronic Control Unit). The engine control device 1 is configured as, for example, an LSI device or a built-in electronic device in which a microprocessor, ROM, RAM, and the like are integrated, and is connected to a communication line of an in-vehicle network provided in the vehicle. Note that various known electronic control devices such as a brake control device, a transmission control device, a vehicle stability control device, an air conditioning control device, and an electrical component control device are communicably connected to each other on the in-vehicle network. An electronic control device other than the engine control device 1 is called an external control system, and a device controlled by the external control system is called an external load device.

The engine control device 1 is an electronic control device that comprehensively controls a wide range of systems such as an ignition system, a fuel system, an intake / exhaust system, and a valve system related to the engine 10, and air supplied to each cylinder of the engine 10. The amount, fuel injection amount, ignition timing I _{G of} each cylinder, supercharging pressure, etc. are controlled. The aforementioned various sensors 41 to 51 are connected to the input port of the engine control device 1. Input information includes accelerator opening A _PS , intake air flow rate Q, intake manifold pressure, intake air temperature, engine speed Ne, cooling water temperature W _T , stroke of waste gate actuator 18, exhaust air / fuel ratio, oxygen concentration, fuel pressure, travel mode information, etc. It is.

Specific control objects of the engine control device 1 include the fuel injection amount injected from the in-cylinder injection valve 11 and its injection timing, the ignition timing I _G by the ignition plug 15, the valve lift amounts of the intake and exhaust valves, and the valve The timing, the operating state of the turbocharger 16, the throttle opening TH, the opening of the bypass valve 24, the wastegate opening D and the like can be mentioned. In the present embodiment, the relationship between the advance control for changing the opening degree of either the waste gate valve 17 or the throttle valve 26 ahead of the other opening degree and the ignition timing control at the spark plug 15 will be described in detail. .

[2. Overview of control]
[2-1. Advance control]
The advance control is a control that is performed by selecting either the throttle advance mode or the supercharge advance mode in accordance with the operating state, load, travel mode, etc. of the engine 10, and is mainly performed during supercharging (acceleration). Any preceding mode is selectively implemented.

  The throttle advance mode is a predetermined opening that is close to or fully open when the throttle opening TH and the wastegate opening D are both changed to secure the amount of intake air introduced into the cylinder. In this mode, the intake air amount is controlled by increasing / decreasing the throttle opening TH while keeping the state fixed at. In other words, the throttle advance mode is a mode in which the throttle opening TH is changed in advance of the wastegate opening D.

  In the throttle advance mode, for example, as shown in FIG. 3A, the throttle opening TH is controlled according to the target air amount in a state where the wastegate opening D is controlled to be fully open (or a predetermined opening close to full opening). Is controlled. After that, when the amount of air introduced into the cylinder is insufficient only by controlling the throttle opening TH, the throttle opening TH is controlled to be fully open (or a predetermined opening close to full opening), and the waist The gate opening D is controlled in the closing direction.

That is, in the throttle advance mode, the throttle opening TH can be made relatively large before the boost pressure rises, and the pumping loss of the engine 10 is reduced. Throttle preceding mode is suitable for use at relatively low slow acceleration is the time rate of change .DELTA.A _PS accelerator opening A _PS.
However, combustion is improved by reducing the internal EGR amount as compared with the supercharging advance mode, and the optimal ignition timing is retarded, so that knocking is likely to occur. Such a tendency becomes conspicuous particularly in a low load region or a low rotation region where the intake air amount is small. However, the extremely low load range is excluded.

  On the other hand, the supercharging advance mode is a predetermined value close to full open or close to full open when both the throttle opening TH and the wastegate opening D are changed in order to secure the amount of intake air introduced into the cylinder. In this mode, the amount of intake air is controlled by increasing / decreasing the wastegate opening D while maintaining a fixed state at the opening. In other words, the supercharging advance mode is a mode in which the wastegate opening degree D is changed in advance of the throttle opening degree TH.

In the supercharging advance mode, for example, as shown in FIG. 3B, the wastegate opening D is adjusted to be fully closed (or a predetermined opening close to full closing) according to the supercharging pressure during supercharging. After that, the throttle opening TH is adjusted in the opening direction. That is, in the supercharging advance mode, the supercharging pressure can be raised prior to the opening of the throttle opening TH, and the acceleration response is improved. Supercharged preceding mode is suitable for use at relatively large rapid acceleration time change rate .DELTA.A _PS accelerator opening A _PS.

  However, closing the wastegate valve 17 increases the amount of exhaust gas flowing to the turbine 16A as compared with the throttle preceding mode, so that the boost pressure rises faster. For this reason, mismatching between the charging efficiency Ec and the ignition timing control is likely to occur, and knocking is likely to occur. Such a tendency becomes remarkable particularly in a high load region or a high rotation region.

  The throttle advance mode and the supercharge advance mode may be set in association with the travel mode (sport mode, eco mode, etc.) of the vehicle on which the engine 10 is mounted, and may be set according to the operating state, load, acceleration request, etc. of the engine 10. It may be set accordingly. In the present embodiment, the contents of ignition timing control to be described subsequently are changed according to these preceding modes.

[2-2. Ignition timing control]
In the ignition timing control, basically, the ignition timing _IG is set based on the engine speed Ne and the charging efficiency Ec corresponding to the load. However, the relationship between the ignition timing _IG , the engine rotational speed Ne, and the charging efficiency Ec is not fixed (unique relationship) but is changed according to the travel mode selected in the preceding control. This is because the influence of the type of the preceding mode on the combustion state in the cylinder is different.

For example, in the supercharging advance mode, since the wastegate opening D is closed before the throttle opening TH is opened, the exhaust amount (internal EGR amount) that flows backward from the exhaust port to the cylinder is likely to increase. The combustion state in the inside changes. The ignition timing _IG is controlled in consideration of such a change in the combustion state. Further, the combustion state in the cylinder varies depending not only on the traveling mode but also on the load of the engine 10. Therefore, the ignition timing I _G in the present embodiment shall be changed in consideration of the operating conditions of the engine 10.

[3. Configuration of control device]
As shown in FIG. 2, the engine control apparatus 1 includes an engine load determination unit 2, a mode selection unit 3, a waste gate calculation unit 4, a throttle calculation unit 5, an ignition calculation unit as elements for performing the above control. 6 (ignition timing control means) is provided. The wastegate calculation unit 4 includes a wastegate opening setting unit 4a, a wastegate control unit 4b, and a deviation amount calculation unit 4c. Further, the throttle calculation unit 5 is provided with a throttle opening setting unit 5a and a throttle control unit 5b, and the ignition calculation unit 6 is provided with an ignition timing setting unit 6a and an ignition timing control unit 6b. Each of these elements may be realized by an electronic circuit (hardware), may be programmed as software, or some of these functions are provided as hardware, and the other part is software. It may be a thing.

[3-1. Engine load determination unit]
The engine load determination unit 2 calculates the charging efficiency Ec corresponding to the load of the engine 10. The charging efficiency Ec is calculated based on the intake flow rate Q and the engine speed Ne. Other parameters corresponding to the load of the engine 10 include a target torque of the engine 10 and a volumetric efficiency Ev. In addition, parameters corresponding to the load of the engine 10 are calculated using information such as intake pressure, exhaust pressure, supercharging pressure, vehicle speed V, accelerator opening A _PS , operating state of the external load device, traveling environment of the vehicle, and the like. Also good.

  The engine load determination unit 2 determines whether the operating state of the engine 10 is in a high load region or a low load region based on the engine rotation speed Ne and the charging efficiency Ec. This determination is performed based on, for example, a map as shown in FIG. The value (boundary line) of the charging efficiency Ec that gives the upper limit of the low load region is set so as to decrease as the engine speed Ne increases. In the map in FIG. 4, the boundary line between the low load region and the high load region is set in a curved shape that falls to the right. Information regarding the charging efficiency Ec and the load region calculated here is transmitted to the waste gate calculation unit 4, the throttle calculation unit 5, and the ignition calculation unit 6. Note that the load region information determined here is used in ignition timing control described later.

[3-2. Mode selection section]
The mode selection unit 3 (mode selection means) selects and sets the preceding mode in the preceding control. Here, for example, the traveling mode is selected according to the operation state of the selection switch 51. In this case, the mode selection unit 3 selects the supercharging advance mode when the sports mode is selected with the selection switch 51. On the other hand, when the eco mode is selected by the selection switch 51, the throttle advance mode is selected. The information of the preceding mode selected here is transmitted to the waste gate calculation unit 4, the throttle calculation unit 5, and the ignition calculation unit 6.

Instead of the operation state of the selection switch 51, a control configuration may be employed in which the travel mode is selected according to the operating state of the engine 10, the magnitude of the driver's acceleration request, or the like. For example, select the supercharge preceding mode when the accelerator opening change rate .DELTA.A _PS is a predetermined value or more, it is also possible to select a throttle preceding mode when the accelerator opening change rate .DELTA.A _PS is less than a predetermined value .

[3-3. Westgate operation unit]
The wastegate opening degree setting unit 4 a sets a reference opening degree D ₀ that is a target opening degree of the wastegate valve 17 based on the operating state of the engine 10. Criteria opening D _0, for example the engine rotational speed Ne and the engine load, air quantity, charging efficiency Ec (target charging efficiency, such as the actual charging efficiency), the supercharging pressure, the accelerator opening degree A _PS, based on the cooling water temperature W _T, etc. Is set. In the present embodiment, the reference opening degree D ₀ is calculated based on a three-dimensional map that uses the engine speed Ne and the charging efficiency Ec as arguments.

  The charging efficiency Ec is obtained by normalizing the volume of air filled in the cylinder per unit combustion cycle (unit time) to the gas volume in the standard state and then dividing by the cylinder volume. In other words, the charging efficiency Ec represents the ratio of the mass of air filled in the cylinder to the mass of air occupying the cylinder under standard atmospheric conditions, and the air introduced into the cylinder per unit combustion cycle (unit time). It is a parameter corresponding to the quantity. Therefore, parameters correlating to the intake air amount such as the volume efficiency Ev, the intake flow rate Q, the target torque, and the target engine output can be used instead of the charging efficiency Ec.

  On this three-dimensional map, an “open mode region” that gives the normal open characteristic to the wastegate valve 17 and a “closed mode region” that gives the normal close characteristic opposite to this are set. The open mode area is an area mainly corresponding to the low load and low rotation operating conditions, and the closed mode area corresponds to the operation states (medium load to high load, medium rotation to high rotation) excluding the open mode area. It is an area to do.

  The normal open characteristic is “a characteristic in which the open (open) state is the standard state”, and the wastegate opening D is equal to or greater than the predetermined opening (eg, close to full open or close to full open unless a predetermined exceptional condition is satisfied). Opening degree). In the open mode region, the wastegate opening degree D is basically controlled to be fully open. However, it is assumed that the wastegate opening degree D decreases as the load of the engine 10 or the engine speed Ne increases in the open mode region.

  The normal close characteristic is a characteristic that sets the closed state to the standard state, and the wastegate opening degree D is set as long as a predetermined exception condition (a condition different from the above-mentioned exception condition) is not satisfied. This is a characteristic that is less than the opening (the opening is smaller than the above-mentioned predetermined opening, for example, an opening that is close to or close to full closing). In the closed mode region, the wastegate opening degree D is basically controlled to be nearly fully closed. However, when the engine 10 has a high load and a high speed, the wastegate opening degree D increases as the load or the engine speed Ne increases in order to suppress an excessive increase in the supercharging pressure. To give unique characteristics.

Wastegate control unit 4b includes a reference degree of opening D ₀ set by the wastegate opening setting unit 4a, depending on the type of the preceding mode selected by the mode selection unit 3, a control signal of the wastegate actuator 18 Output. If supercharging preceding mode is selected, wastegate control unit 4b, prior to the operation of the throttle valve 26, so that the actual wastegate opening D is reference opening D _0, the wastegate actuator 18 And output a control signal. That is, when the supercharging advance mode is selected, the operation of the wastegate actuator 18 is controlled so that the wastegate opening degree D is changed prior to the throttle opening degree TH. Control of the throttle opening TH, after the waste gate opening D is controlled to criteria opening D _0, will be initiated.

On the other hand, when the throttle preceding mode is selected, wastegate control unit 4b, irrespective of the reference opening degree D _0, as waste gate opening D becomes a predetermined opening degree near the fully open or fully open, West A control signal is output to the gate actuator 18. This state is maintained while the throttle opening TH is being changed. Further, after the throttle opening TH is controlled to be fully open or a predetermined opening close to full open, the wastegate opening D becomes the standard opening D ₀ when the amount of air introduced into the cylinder is insufficient. Then, a control signal is output to the wastegate actuator 18.

Note that “when the amount of air introduced into the cylinder is not insufficient” means a state where supercharging is not required. Therefore, focusing only on the control at the time of supercharging, in the throttle advance mode, the wastegate opening degree D is fully opened or opened to a predetermined opening degree close to full opening, and then is throttled in the closing direction.
Upon receiving the control signal, the wastegate actuator 18 drives the valve body driving member with a stroke corresponding to the control signal. Thus, if the operating properly waist gate valve 17 is wastegate opening D becomes reference opening D _0.

Shift amount calculating section 4c (calculating means), a reference degree of opening D ₀ set by the wastegate opening setting unit 4a, the actual wastegate opening D (actual calculated from the detected stroke hall sensor 47 The amount of deviation Z from the waste gate opening) is calculated. Here, the absolute value of the difference between the actual wastegate opening D and the reference opening D ₀ is calculated as the deviation amount Z (Z = | D−D ₀ |). Information on the deviation amount Z calculated here is transmitted to the ignition calculation unit 6.

[3-4. Throttle calculator]
The throttle opening setting unit 5 a sets a target throttle opening TH ₀ that is the target opening of the throttle valve 26 based on the operating state of the engine 10. Target throttle opening degree TH _0, for example the engine rotational speed Ne and the engine load, air quantity, charging efficiency Ec (target charging efficiency, such as the actual charging efficiency), the supercharging pressure, the accelerator opening degree A _PS, etc. to the cooling water temperature W _T Set based on. In the present embodiment, the target throttle opening TH ₀ is calculated based on a three-dimensional map with the engine speed Ne and the charging efficiency Ec as arguments. On this map, an opening characteristic is set such that the target throttle opening TH ₀ increases as the engine speed Ne increases or as the charging efficiency Ec increases. In addition, description is abbreviate | omitted about a specific opening degree characteristic. Information on the target throttle opening TH ₀ set here is transmitted to the throttle control unit 5b.

Throttle control unit 5b, according to the target throttle opening degree TH ₀ set by the throttle opening degree setting unit 5a, and outputs the control signal of the throttle valve 26. Here, a control signal is output to the throttle valve 26 so that the actual throttle opening TH becomes the target throttle opening TH ₀ . At this time, the throttle control unit 5b controls the operation timing and the operation speed of the throttle valve 26 according to the type of the preceding mode selected by the mode selection unit 3, similarly to the wastegate control unit 4b.

If supercharging preceding mode is selected, the throttle control unit 5b, after the waste gate opening D is controlled to criteria opening D _0, to start the operation of the throttle valve 26. Further, the operation speed is controlled so that the change of the throttle opening TH becomes rapid (as shown in FIG. 3B, the change gradient of the broken line is equal to or greater than a predetermined gradient).

On the other hand, when the throttle advance mode is selected, the throttle valve 26 is controlled so that the throttle opening TH is changed while the wastegate opening D is controlled to be fully open or a predetermined opening close to full open. Start operation. Further, the operating speed is controlled so that the throttle opening TH changes slowly (as shown in FIG. 3A, the change gradient of the broken line is less than the predetermined gradient). The throttle valve 26 is driven according to the control signal transmitted from the throttle control unit 5b. Thereby, the throttle opening TH becomes the target throttle opening TH ₀ .

[3-5. Ignition calculation unit]
Ignition timing setting unit 6a is configured to set the ignition timing I _G at the spark plug 15 based on the operating state of the engine 10. Here, based on the engine speed Ne and the charging efficiency Ec, a standard ignition timing _IG is set, the load region determined by the engine load determination unit 2, and the travel mode selected by the mode selection unit 3 Based on this, the ignition timing _IG is corrected. However, the correction of the ignition timing I _G is carried out, and when the deviation amount Z calculated in the shift amount calculating part 4c is the predetermined value Z ₀ or higher.

The three-dimensional map for setting a standard ignition timing I _G (three-dimensional map of the default), illustrated in Figure 5 (a). In this map, the lower the engine rotational speed Ne, or the higher the charging efficiency Ec, ignition timing characteristics as the ignition timing I _G is moved in the retard direction is set. The hatched area in FIG. 5 (a) is an area corresponding to the high load area determined by the engine load determination unit 2, and the area without hatching is an area corresponding to the low load area.

Ignition timing setting unit 6a, when the operating state of the engine 10 is in a low load range is corrected to the retard direction the ignition timing I _G in the throttle prior mode than the ignition timing I _G in supercharged preceding mode . This correction in the retarding direction corresponds to an operation of pushing down a non-hatched area in the three-dimensional map shown in FIG. Here, graphs when the three-dimensional map of FIG. 5A is cut at a predetermined rotational speed position (XX line in the figure) are shown in FIGS. 5B and 5C.

In the low load region, as shown in FIG. 5 (b), the ignition timing I _G in supercharged prior mode is set to the standard ignition timing I _G. On the other hand, the ignition timing I _G in the throttle prior mode, which is corrected to the retard direction than. Therefore, in the operating state of the same engine rotational speed Ne and the charging efficiency Ec, ignition timing I _G throttle prior mode is set to the timing delayed from the ignition timing I _G of supercharging prior mode.

Incidentally, when based on the standard ignition timing I _G, the amount of retardation of the ignition timing I _G in the throttle prior mode (retard amount) is set larger charging efficiency Ec is small. However, in the extremely low load region, the difference in exhaust pressure due to the opening and closing of the wastegate becomes small, so the difference in the amount of internal EGR also becomes small. That is, as the filling efficiency Ec decreases in the extremely low load region, the difference in the internal EGR amount also decreases. Therefore, the ignition timing I _G shown in FIG. 5 (b), as the load decreases in the extremely low load region, is set so as to gradually approach the standard ignition timing I _G.

Further, the ignition timing setting section 6a, when the operating state of the engine 10 is in the high load region, the retarding direction the ignition timing I _G in supercharged preceding mode than the ignition timing I _G in the throttle prior mode to correct. This correction in the retard direction corresponds to an operation of pushing down the hatched area in the three-dimensional map shown in FIG. That is, in the high load region, as shown in FIG. 5 (c), the ignition timing I _G in the throttle prior mode is set to the standard ignition timing I _G.

On the other hand, the ignition timing I _G in supercharged preceding mode, which is corrected to the retard direction than. Therefore, in the operating state of the same engine rotational speed Ne and the charging efficiency Ec, ignition timing I _G of supercharging prior mode it is set to the timing delayed from the ignition timing I _G throttle prior mode. Incidentally, when based on the standard ignition timing I _G, the amount of retardation of the ignition timing I _G in supercharged preceding mode (retard amount) is set larger the larger charging efficiency Ec is.

As shown in FIG. 5 (a) ~ (c) , the engine rotational speed Ne, in the three-dimensional map with the coordinate axes charging efficiency Ec and the ignition timing I _G, over a curved surface representing the ignition timing I _G throttle preceding mode line of intersection of a curved surface which represents the ignition timing I _G of the sheet prior mode, corresponding to a boundary line between the high-load region and the low load region shown in the map of FIG. As a boundary of this intersection line, as the magnitude relationship between the ignition timing I _G of the ignition timing I _G and supercharged preceding mode throttle preceding mode is inverted, it is set ignition timing I _G in each preceding mode Will be.

Ignition timing control unit 6b, as ignition is executed at the set ignition timing I _G in the ignition timing setting unit 6a, and outputs an ignition signal to the ignition plug 15. If used as a reference standard ignition timing I _G as shown in FIG. 5, the ignition timing I _G throttle prior mode in the low load region is retarded set compared to supercharge the prior mode. Conversely, the ignition timing I _G of supercharging prior mode in the low load region is set advance angle as compared with the throttle prior mode.
On the other hand, the ignition timing I _G of supercharging prior mode in the high load region is retarded set as compared to throttle the prior mode. Conversely, the ignition timing I _G throttle prior mode in the high load region is advance angle setting compared to supercharge the prior mode.

[4. flowchart]
FIG. 6 is a flowchart for explaining the procedure of ignition timing control. This flow is repeatedly performed in the engine control apparatus 1 at a predetermined calculation cycle. In step A <b> 10, various information detected by the various sensors 41 to 51 is input to the engine control device 1. Here, information relating to the engine speed Ne, the intake air flow rate Q, the stroke corresponding to the wastegate opening degree D, the accelerator opening degree A _PS , the operation state of the selection switch 51 and the like are input. In step A20, the engine load determination unit 2 calculates the charging efficiency Ec of the engine 10 based on the intake flow rate Q, the engine rotational speed Ne, and the like. Further, in step A30, the engine load determination unit 2 determines whether the operating state of the engine 10 belongs to a low load region or a high load region based on a map as shown in FIG.

In step A40, the mode selection unit 3 selects the preceding mode in the preceding control according to the operation state of the selection switch 51. Alternatively, based on the time rate of change .DELTA.A _PS accelerator opening A _PS, prior mode is selected. In this case, when the time change rate .DELTA.A _PS accelerator opening A _PS is a predetermined value or more, is selected supercharged preceding mode, when the time rate of change .DELTA.A _PS is less than the predetermined value, the throttle preceding mode is selected Is done. In step A50, the waste gate degree of opening setting unit 4a, reference opening degree D ₀ wastegate valve 17 is set. Criteria opening D ₀ is set based on the engine rotational speed Ne and the charging efficiency Ec.

In step A60, the shift amount calculating section 4c, is calculated as an absolute value is a deviation Z of the difference between the actual wastegate opening D and Criteria opening D ₀ calculated from the detected stroke hall sensor 47 . In step A70, calculated in the previous step shift amount Z is equal to or a predetermined value Z ₀ or higher is determined. Here, if Z ≧ Z _0, it is determined that the opening degree deviation of the waste gate valve 17 is large, and the process proceeds to Step A70. On the other hand, if Z <Z _0, it is determined that the wastegate valve 17 is controlled with high accuracy substantially according to the reference opening D ₀ , and the process proceeds to step A120.

In step A 120, the spark plug 15 is controlled by the ignition timing I _G of the normal setting. In this case, for example, as shown in FIG. 5A, a standard ignition timing _IG is set based on the engine speed Ne and the charging efficiency Ec. Further, to ignite the spark plug 15 to the ignition timing I _G, control signals from the ignition timing control unit 6b is output, the control in the calculation cycle is completed.

In step A80, it is determined whether or not the operating state of the engine 10 determined in step A30 is in a low load region. If the operating state belongs to the low load region, the process proceeds to step A90. On the other hand, when the operation state belongs to the high load region, the process proceeds to step A100.
In step A90, it is determined whether or not the preceding mode selected in step A40 is the throttle preceding mode. Here, the preceding mode proceeds to step A110 if a throttle preceding mode, as indicated by the broken line in FIG. 5 (b), the ignition timing I _G is corrected to the retard direction. At this time, the intake air quantity introduced into the cylinder is varied by changing in advance the throttle opening TH to the wastegate opening D, even if the combustion state becomes unstable, the ignition timing of the I _G The combustion state is stabilized by setting the retard angle.

If the preceding mode is the supercharging preceding mode in step A90, the process proceeds to step A120. At this time, since the operating state of the engine 10 belongs to the low load region, even if the wastegate opening degree D is changed prior to the throttle opening degree TH, the combustion state of the engine 10 is hardly affected. Accordingly, the ignition timing _IG is set to an advance angle than in the case of the throttle advance mode, and the engine output is ensured.

Step A100 is a step determined when the operating state of the engine 10 belongs to the high load region. Here, it is determined whether or not the preceding mode selected in step A40 is the supercharging preceding mode. Here, the flow advances to step A110, if the preceding mode is the supercharge preceding mode, as indicated by the broken line in FIG. 5 (c), the ignition timing I _G is corrected to the retard direction. In the high load region, changing the wastegate opening degree D prior to the throttle opening degree TH increases the exhaust pressure, increases the internal EGR amount, and tends to make the combustion state unstable. Meanwhile, since the present ignition timing control I _G is corrected to the retard direction, the occurrence of abnormal combustion in the cylinder is suppressed, the combustion state is stabilized.

If the preceding mode is the throttle preceding mode in step A110, the process proceeds to step A120. At this time, since the operating state of the engine 10 belongs to the high load region, the wastegate opening degree D is relatively narrowed. That is, even if the throttle opening TH is changed prior to the wastegate opening D, the combustion state of the engine 10 is not significantly affected. Therefore, the ignition timing I _G than in the supercharged preceding mode is the advance setting, the engine output is ensured.

Table 1 below shows the relationship between the operating state of the engine 10 in the above control, the type of the preceding mode, and the ignition timing setting. In the low load region, towards the ignition timing I _G throttle preceding mode than the ignition timing I _G of supercharged preceding mode is retarded setting. Conversely, in the high load region, towards the ignition timing I _G of supercharged preceding mode than the ignition timing I _G throttle preceding mode is retarded setting. In other words, in the low load region, the direction of ignition timing I _G of supercharged preceding mode than the ignition timing I _G throttle preceding mode is the advance setting, in the high load region, the ignition of the supercharged preceding mode towards the ignition timing I _G throttle preceding mode is the advance setting than timing I _G. Thus, in the above control, depending on operating conditions of the engine 10 that is determined by the engine load determining unit 2, the preceding mode is switched to the ignition timing I _G are targeted to be corrected in the retarding direction.

[5. Action, effect]
(1) In the engine control device 1 described above, the ignition calculation unit 6 is given ignition timing characteristics corresponding to the throttle advance mode and the supercharge advance mode, and the operation of the spark plug 15 is controlled. For example, as shown in FIG. 5B, the ignition timing characteristic indicated by the solid line in the figure is given in the supercharging advance mode, and the ignition timing characteristic indicated by the broken line in the figure is given in the throttle advance mode. By imparting such ignition timing characteristics, it is possible to set the ignition timing I _G in response to each preceding mode, it is possible to improve the combustion state of the engine 10 regardless of the type of the preceding mode.

(2) Further, in the engine control device 1, when setting the ignition timing I _G, the operating state corresponding to the load of the engine 10 as well as the type of the preceding modes are considered. For example, as shown in FIG. 4, it is determined whether the operating state of the engine 10 is a low load state or a high load state, and an ignition timing characteristic according to the load state is given. By way of giving such ignition timing characteristics vary depending on the load, the ignition timing of each mode in consideration of the influence on the I _G to be able to control the ignition timing I _G, combustion of the engine 10 regardless of the load The condition can be improved.

(3) For example, as shown in FIG. 5 (b), when the operating state of the engine 10 belongs to the low load range, the ignition of the throttle preceding mode than the ignition timing I _G of supercharged preceding mode Timing _IG is set to be retarded. Thereby, the unstable combustion accompanying the change of the intake air amount introduced into the cylinder can be suppressed, and the combustion state of the engine 10 can be stabilized.

Further, in the throttle preceding mode, the internal EGR amount in the cylinder is reduced compared to the supercharging preceding mode, combustion is improved, and knocking is likely to occur in a low load region. On the other hand, in the engine control device 1, since the ignition timing I _G under throttle prior mode in the low load region is corrected to the retard direction, it is possible to suppress the occurrence of such knocking.

Further, the retard amount of the ignition timing I _G under throttle prior mode in the low load region is set larger charging efficiency Ec is small. With such a setting, it is possible to effectively suppress the occurrence of knock resulting from a decrease in intake fluidity in the cylinder, and the combustion state of the engine 10 can be further stabilized.

(4) Alternatively, as shown in FIG. 5 (c), when the operating state of the engine 10 belongs to the high load range, ignition supercharged preceding mode than the ignition timing I _G throttle preceding mode Timing _IG is set to be retarded. Thereby, the unstable combustion accompanying the increase in the amount of internal EGR can be suppressed, and the combustion state of the engine 10 can be stabilized.

Further, in the supercharging advance mode, the exhaust resistance is likely to increase as compared with the throttle advance mode, and knocking is particularly likely to occur in a high load region. On the other hand, in the engine control device 1, since the ignition timing I _G under supercharged prior mode in the high load region is corrected to the retard direction, it is possible to suppress the occurrence of such knocking.

Further, the retard amount of the ignition timing I _G under supercharged prior mode in the high load region is set larger the larger charging efficiency Ec is. With such a setting, it is possible to effectively suppress the occurrence of knock resulting from a decrease in scavenging performance, and the combustion state of the engine 10 can be further stabilized.

(5) Further, in the engine control device 1, when the deviation amount Z of the actual wastegate opening D and Criteria opening D ₀ is the predetermined value Z ₀ or higher, the ignition timing I _G is corrected . Thereby, it can suppress that a combustion state becomes unstable by the opening degree shift of the wastegate valve 17, and a combustion state can be stabilized.

(6) Since the reference opening D ₀ is calculated based on the charging efficiency Ec and the engine speed Ne, for example, the reference opening D ₀ is calculated according to the supercharging pressure of the turbocharger 16. Compared with simple control, an appropriate wastegate opening degree D corresponding to the exhaust amount and exhaust pressure reaching the wastegate valve 17 can be obtained. Thereby, the internal EGR amount that can be generated by the change in the wastegate opening degree D can be accurately predicted, and the supercharging amount and the supercharging pressure can be accurately controlled. Therefore, the combustion state of the engine 10 can be stabilized.

[6. Modified example]
Regardless of the embodiment described above, various modifications can be made without departing from the spirit of the invention. Each structure of this embodiment can be selected as needed, or may be combined appropriately.

  In the above-described embodiment, as illustrated in FIG. 4, an example of determining whether the operation state of the engine 10 is the low load region or the high load region based on the engine rotation speed Ne and the charging efficiency Ec is illustrated. However, the determination method of the driving state is not limited to this. For example, instead of the charging efficiency Ec, a parameter corresponding to the load of the engine 10 may be used.

In this case, the engine 10 is used by using target torque, volumetric efficiency Ev, intake pressure or exhaust pressure, supercharging pressure, vehicle speed V, accelerator opening A _PS , operating state of the external load device, information on the traveling environment of the vehicle, and the like. It is conceivable to calculate a parameter corresponding to 10 loads. Even in such a case, the same effects as those of the above-described embodiment can be obtained. Similarly, wastegate opening D and the throttle opening degree TH, with regard map according to the setting of the ignition timing I _G, may not necessarily have the same parameters as in the above-described embodiment as an argument.

In the above-described embodiment, the reference opening degree D ₀ of the waste gate valve 17 and the target throttle opening degree TH ₀ are independent of each other in the waste gate opening degree setting unit 4a and the throttle opening degree setting unit 5a. Although what is set is illustrated, the method of setting the reference opening D ₀ and the target throttle opening TH ₀ is not limited to this. That is, one of the preceding modes may be set first and the other may be set thereafter.

For example, a three-dimensional map that gives the reference throttle opening TH _BASE using the engine speed Ne and the charging efficiency Ec as arguments is stored in the throttle opening setting unit 5a. Similarly, a three-dimensional map that gives the reference wastegate opening degree D _BASE using the engine speed Ne and the charging efficiency Ec as arguments is stored in the wastegate opening degree setting unit 4a.

The throttle opening setting unit 5a calculates the reference throttle opening TH _BASE in the throttle advance mode, and corrects the target throttle opening TH ₀ to the opening side with respect to the reference throttle opening TH _BASE . On the other hand, the waist gate opening setting unit 4a, and calculates the reference opening degree D _0, to lower the only boost pressure amount that the throttle opening TH is corrected to the open side, the reference degree of opening D ₀ to the open side to correct. Even in such a control configuration, the same effects as those of the above-described embodiment can be obtained. It should be noted that maps, formulas, functions, and the like that give the correction amount of the target throttle opening TH _{0 and} the correction amount of the reference opening D ₀ are stored in the waste gate opening setting unit 4a and the throttle opening setting unit 5a, respectively. You may keep it.

In the above-described embodiment, the reference opening degree D ₀ of the wastegate valve 17 is set using a three-dimensional map in which the open mode region and the closed mode region are set. The opening degree characteristic of the degree D ₀ is arbitrary. Therefore, the normal open characteristic and the normal close characteristic of the wastegate valve 17 are not essential elements in this case. The same applies to the opening characteristics of the throttle valve 26.

DESCRIPTION OF SYMBOLS 1 Engine control apparatus 2 Engine load determination part 3 Mode selection part (mode selection means)
4 Westgate operation unit 4a Westgate opening setting unit 4b Westgate control unit 4c Deviation amount calculation unit (calculation means)
5 Throttle calculation section 5a Throttle opening setting section 5b Throttle control section 6 Ignition calculation section (ignition timing control means)
6a Ignition timing setting unit 6b Ignition timing control unit 15 Spark plug 17 Wastegate valve 26 Throttle valve
Ne rotation speed
Ec filling efficiency
D Westgate opening
TH throttle opening

Claims (4)

In an engine control device comprising a supercharging system having a turbine with a wastegate valve and a throttle valve interposed in an intake passage,
A throttle advance mode that changes the throttle opening prior to the wastegate opening during supercharging, and a turbo advance mode that changes the wastegate opening prior to the throttle opening during supercharging. Mode selection means for selecting any one of
Ignition timing control means for controlling the ignition timing according to the type of mode selected by the mode selection means ,
The engine control device, wherein the ignition timing control means controls the ignition timing in accordance with a type of the mode and a load of the engine. The ignition timing control means sets the ignition timing in the throttle preceding mode to be retarded from the ignition timing in the supercharging advance mode when the load is less than a predetermined load. Item 4. The engine control device according to Item 1 . The ignition timing control means sets the ignition timing in the supercharging advance mode to be retarded rather than the ignition timing in the throttle advance mode when the load is a predetermined load or more. Item 3. The engine control device according to Item 1 or 2 . A calculating means for calculating a deviation amount between the target opening and the actual opening of the wastegate valve;
Said ignition timing control means, when the deviation amount calculated by the calculating means is equal to or greater than a predetermined value, and controlling the ignition timing in accordance with the type of the mode, according to claim 1 to 3 The engine control device according to any one of the above.

Images