JP6341319B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device including a supercharging system that uses exhaust pressure.

  Conventionally, in an engine equipped with a supercharging system that uses the exhaust pressure of the engine, an electric waste gate valve (open / close valve) is provided in a bypass for bypassing a turbocharging turbine interposed in the exhaust passage. There is something. The waste gate valve is a supercharging pressure control valve that adjusts the supercharging state (supercharging pressure), and is controlled by the electric actuator so that the flow rate of exhaust gas flowing into the supercharging turbine is controlled. The rotational speed of the turbine is controlled.

  For example, when the output demand for the engine is high, such as during acceleration, the rotational speed of the supercharging turbine increases by reducing or closing (closing) the opening of the waste gate valve. Accordingly, the amount of intake air to be supercharged is increased and the supercharging efficiency is improved, so that a high output can be obtained. On the other hand, when the output demand for the engine is low, such as during deceleration, the rotational speed of the supercharging turbine decreases by increasing or opening (opening) the wastegate valve. As a result, the amount of intake air that is supercharged is reduced, and the amount of intake air commensurate with the output is sent.

  In this way, by controlling the opening degree of the waste gate valve according to the required output, it is possible to control the amount of intake air that is supercharged (that is, the supercharging pressure). In other words, in order to accurately control the supercharging pressure, it is necessary to accurately control the opening degree of the waste gate valve. However, the waste gate valve may change over time due to long-term use or may be deformed due to temperature. Therefore, even if the waste gate valve is driven by the electric actuator so as to achieve the target opening, the actual opening of the waste gate valve may not match the target opening.

  For this reason, a technique for learning the reference position of the waste gate valve has been proposed. For example, Patent Document 1 discloses a control device that learns the reference position of the waste gate valve when a predetermined condition is satisfied after the engine is warmed up. Here, the predetermined condition is that the feedback control of the supercharging pressure is being performed, the amount of change in the opening degree of the waste gate valve is larger than a predetermined value, and the like. According to this technique, the reference position of the waste gate valve can be correctly learned without being affected by temperature.

Japanese Patent No. 4434057

  However, it is unclear whether the control device of Patent Document 1 can constantly ensure a chance to learn the waste gate valve. That is, if the predetermined condition is not satisfied after the engine is warmed up, learning of the reference position of the waste gate valve is not performed. If the learning opportunity is not properly secured, there is a risk that the accuracy of the supercharging pressure control may be reduced due to the aging of the waste gate valve or thermal deformation.

  The present invention has been devised in view of such problems, and it is to provide an engine control device that constantly secures learning opportunities for waste gate valves and can improve the accuracy of supercharging pressure control. With the goal. 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 waste gate valve that is interposed in a bypass route that bypasses a turbocharging turbine on an exhaust passage and is driven by an electric actuator. And detecting means for detecting the position of the waste gate valve. Further, first learning for fully closing the waste gate valve before starting the engine and learning an initial fully closed position of the waste gate valve from the position detected by the detecting means, and after starting the engine, Learning means for performing second learning for learning the zero point of the waste gate valve from the position detected by the detection means with the waste gate valve fully closed; and a learning value obtained by the first learning; Calculating means for calculating a difference from a learning value obtained in the second learning.

  Preferably, the learning means sets the initial fully closed position as a reference position when controlling the opening degree of the waste gate valve, and corrects the reference position at the zero point. Further, before starting the engine, it includes during cranking of the engine start, but it is preferable to perform it before cranking.

(2) It is preferable that the learning means performs the second learning while the vehicle is accelerating.
(3) In the first learning, the learning unit detects the position detected by the detection unit with the waste gate valve fully closed and the position detected by the detection unit with the waste gate valve fully opened. It is preferable to learn the initial operating range of the waste gate valve from the position. In this case, it is preferable that the learning unit sets the initial operation range as a reference operation range at the time of opening control of the waste gate valve.

(4) It is more preferable to provide a failure control means for notifying a failure of the waste gate valve and storing a failure code corresponding to the failure when the initial operation range is less than a predetermined range. In other words, when the width of the initial operation range is less than the predetermined range width, the failure control means preferably notifies the failure of the waste gate valve and stores a failure code corresponding to the failure. .
(5) It is preferable to provide a cleaning unit that opens and closes the waste gate valve to perform cleaning when the difference calculated by the calculation unit is equal to or greater than a predetermined value.

  According to the disclosed engine control device, since the first learning for learning the initial fully closed position of the waste gate valve is performed before the engine is started, the learning opportunity of the waste gate valve can be constantly ensured. Further, since the second learning for learning the zero point of the waste gate valve is performed after the engine is started, the learning process can be performed in two stages. As a result, the fully closed position of the waste gate valve can be accurately learned. If the opening control of the waste gate valve is performed based on the fully closed position, the accuracy of the supercharging pressure control can be improved.

It is a figure which illustrates the block configuration of the control apparatus of the engine which concerns on one Embodiment, and the structure of the engine to which this control apparatus was applied. It is a figure which illustrates the block configuration of the waste gate calculating part of the control apparatus of FIG. It is the example of a map which showed the relationship of the valve position with respect to the opening degree of a waste gate valve. It is a flowchart which illustrates the procedure of the learning control in an engine control apparatus. It is a flowchart which illustrates the procedure of the opening degree control in an engine control apparatus. It is a flowchart which illustrates the procedure of the failure control in an engine control apparatus. It is a flowchart which illustrates the procedure of the cleaning control in an engine control apparatus.

  Hereinafter, embodiments 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 housed in the cylinder, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft via the 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) is controlled by the engine control device 1 described later.

[1-2. Fuel injection system]
As an injector for supplying fuel to each cylinder, an in-cylinder injection valve (direct injection injector) 11 that directly injects fuel into the cylinder is provided. 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 port of the in-cylinder injection valve 11 is opened only during a period corresponding to the magnitude of the control pulse signal. Thereby, the fuel injection amount becomes an amount corresponding to the magnitude (drive pulse width) of the control pulse signal, and the injection start time 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 (supercharger) 16 that supercharges intake air into the cylinder using 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 (supercharging turbine) 16A of the turbocharger 16 rotates with 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 supplies air while compressing the air in the intake passage 21 to the downstream side, and supercharges each cylinder. The supercharging operation by 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. An air filter 22 is provided on the upstream side of the compressor 16B, and air taken in from the outside is filtered. Further, an intake bypass passage 23 is provided so as to connect the intake passage 21 upstream and downstream of the compressor 16B, and a bypass valve 24 is interposed on the intake bypass passage 23. The amount of air flowing through the intake 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 that has just been exhausted from the cylinder to the upstream side of the cylinder again. An EGR cooler 35 for cooling the reflux gas is interposed in the EGR passage 34. Cooling the reflux gas lowers the combustion temperature in the cylinder and reduces the generation rate of nitrogen oxides (NOx). In addition, an EGR valve 36 for adjusting the exhaust gas recirculation amount is interposed at a 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 to the intake manifold is adjusted according to the opening degree of the throttle valve 26 (throttle opening degree). The throttle opening is controlled by the engine control device 1.

  The intake manifold is provided with a surge tank 27 for temporarily storing the 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. 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 upstream of the turbine 16A.

  An exhaust bypass passage (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 waste gate valve 17 is interposed on the exhaust bypass passage 32. The waste gate 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 waste gate valve 17 is provided with an electric actuator 18. The electric actuator 18 uses electric power such as an auxiliary battery or a drive battery mounted on the vehicle as a drive source, and its operation is controlled by the engine control device 1.

The waste gate valve 17 mechanically connects the valve body 17a that opens and closes the exhaust bypass passage 32, the valve body 17a and the electric actuator 18, and a rod (valve body drive member) 17b that is driven to reciprocate by the electric actuator 18. Have The valve body 17a is connected so as to open and close according to the stroke amount of the rod 17b (the movement length of the rod 17b in the axial direction), and the position S of the valve body 17a (hereinafter referred to as the valve position S) is It is controlled by the engine control device 1. In the valve position S, the position S of the valve body 17a when the waste gate valve 17 is fully closed is set as a reference position S _BA (ie, 0). Stroke of the rod 17b from the reference position S _BA corresponds to the valve opening D of the waste gate valve 17. That is, the valve opening degree D is electrically controlled by the engine control device 1.

[1-4. Detection system]
An accelerator position sensor 41 that detects the amount of depression of the accelerator pedal (accelerator opening APS) is provided at an arbitrary position of the vehicle. The accelerator opening APS 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 for detecting the intake 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 an 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 WT) 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 electric actuator 18 is provided with a hall sensor 47 that detects the stroke amount of the rod 17b corresponding to the valve opening degree D. The hall sensor 47 is a position detection sensor using a hall element, and the valve position S is detected by the hall sensor 47. 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.

  Further, a warning lamp 51 is provided on the meter panel of the vehicle to notify the user of the failure when the waste gate valve 17 fails.

[1-5. Control system]
A vehicle equipped with the engine 10 is provided with an engine control device 1. The engine control device 1 is configured, for example, as an LSI device or an embedded electronic device in which a microprocessor, ROM, RAM, etc. are integrated, and is connected to a communication line of an in-vehicle network provided in the vehicle.

  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. Air supplied to each cylinder of the engine 10 This controls the amount, fuel injection amount, ignition timing of each cylinder, supercharging pressure, and the like. The aforementioned various sensors 41 to 50 are connected to the input port of the engine control device 1. Input information includes accelerator opening APS, intake air flow rate Q, intake manifold pressure, intake air temperature, engine speed Ne, cooling water temperature WT, valve position S, exhaust air-fuel ratio, oxygen concentration, fuel pressure, and the like.

  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 by the ignition plug 15, the valve lift amounts and valve timings of the intake and exhaust valves, The operating state of the turbocharger 16, the throttle opening, the opening of the bypass valve 24, the valve opening D of the waste gate valve 17, the lighting of the warning lamp 51, and the like. In the present embodiment, opening control of the waste gate valve 17, learning control performed before the opening control is performed, failure control and cleaning control using the results of learning control will be described.

[2. Overview of control]
[2-1. Opening control]
The opening degree control is control for optimizing the valve opening degree D of the waste gate valve 17 in accordance with the operating state of the engine 10 and the magnitude of the output required for the engine 10. The accuracy of the opening control of the waste gate valve 17 affects the accuracy of the supercharging pressure control. In other words, if the valve opening degree D can be controlled with high accuracy, the accuracy of supercharging pressure control can be increased.

In the opening degree control, for example, the target of the valve opening degree D is determined based on the engine rotational speed Ne, the load P acting on the engine 10, the air amount, the charging efficiency Ec (target charging efficiency, actual charging efficiency, etc.), the accelerator opening APS, and the like. Value (target opening) D _TGT is set. Then, the rod 17b is controlled by the electric actuator 18 so that the set target opening degree D _TGT is obtained. In the opening degree control, the target opening degree D _TGT is set using the reference position _SBA and the reference operation range R _BA set in the learning control described below, and the valve opening degree D is controlled.

[2-2. Learning control]
The learning control is control for determining the reference position S _BA and the reference operation range R _BA of the waste gate valve 17 using the hall sensor 47. The reference position S _BA and the reference operation range R _BA are values serving as a reference when the opening degree of the waste gate valve 17 is controlled. The learning control includes first learning that is performed before the engine 10 is started and second learning that is performed after the engine 10 is started.

  The first learning is learning control that is performed only once during one drive cycle. Here, the first learning is performed before cranking after the ignition key is turned on (hereinafter referred to as key-on). On the other hand, the second learning is learning control that is performed many times during one drive cycle, and is performed during acceleration traveling here. Note that the drive cycle here means a period from key-on to key-on again. That is, the first learning is performed only once between the key-on and the key-off, and the second learning is performed a plurality of times between the key-on and the key-off.

In the first learning, the waste gate valve 17 is first controlled to be fully closed, and the valve position S at that time is detected by the hall sensor 47 and stored as the first fully closed position _SCL1 . Subsequently, the waste gate valve 17 is controlled to be fully open, and the valve position S at that time is detected by the hall sensor 47 and stored as the fully open position S _OP . From the first fully closed position S _CL1 and the fully open position S _OP The operating range R of the valve body 17a is calculated. Then, the initial fully closed position _ISCL and the initial operation range (width of the initial operation range) IR are learned from these detection results and calculation results. The initial fully closed position _ISCL and the initial operation range IR are values learned by the first learning, and are used for determining whether or not there is an abnormality in the system.

For example, the first fully closed position S _CL1 detected by the hall sensor 47 may be set (learned) as the initial fully closed position IS _CL as it is, or stored in the memory with the detected first fully closed position S _CL1. may be learned initial fully closed position iS _CL based on the in initial fully closed position iS _CL of the previous control which 'is. Here learned initial fully closed position IS _CL together with is stored in the memory, it is set as the reference position S _BA.

Further, for example, the calculated operation range R may be set (learned) as it is as the initial operation range IR, or the calculated operation range R and the initial operation range IR ′ at the previous control stored in the memory The initial operating range IR may be learned based on The initial operation range IR learned here is stored in the memory and set as the reference operation range _RBA . The first learning may be performed before the engine 10 is started, and may be performed, for example, during cranking. However, since the startability is better if the waste gate valve 17 is opened during cranking, the first learning is performed here before cranking.

Further, in the second learning, the waste gate valve 17 is controlled to the fully closed valve position S at that time is detected by the Hall sensor 47, it is stored as the second fully closed position S _CL2, the second fully closed position S _A zero point S ₀ is learned from _CL2 . That is, in the second learning, the zero point S ₀ is learned from the fully closed position (second fully closed position S _CL2 ) during actual driving. By learning the zero point S ₀ including the effect of thermal expansion due to heat reception of the exhaust gas, the position control of the waste gate valve 17 can be performed with higher accuracy.

For example, the detected second fully closed position S _CL2 may be set (learned) as the zero point S ₀ as it is, or the detected second fully closed position S _CL2 and the previous control time stored in the memory it may be learned zero point S ₀ on the basis of the zero point S ₀ '. Here the zero point S ₀ learned in is stored in the memory. When the difference between the zero point S ₀ learned by the learning initial fully closed position IS _CL and the second learning at the first learning is a predetermined value or more S _P, the cleaning control described later is performed.

Further, in the second learning, the zero point S ₀ is compared with the initial fully closed position IS _CL learned in the first learning, and the reference position S _BA (that is, the initial fully closed position IS _CL ) set in the first learning is compared. It is corrected by zero point S _0. For example, if the initial fully closed position IS _CL obtained in the first learning and zero point S ₀ obtained in the second learning are different, the reference position S _BA is zero S ₀ and the one set in the first learning The corrected reference position is used as the new reference position _SBA in the opening degree control. The initial if all the closed position IS _CL and zeros S ₀ are the same, the reference position S _BA, which is set in the first learning is used as such in the opening control (correction amount is zero).

[2-3. Failure control]
The failure control is a control for determining whether or not the waste gate valve 17 operates normally using a result of the learning control, and informing the user of the failure when it does not operate normally (fails). It is. In the failure control, when the initial operation range IR learned in the first learning is less than the predetermined range (predetermined range width) R _P , it is determined that the waste gate valve 17 has failed. This determination is performed only once during one drive cycle (for example, before cranking after key-on).

That is, before the start of the engine 10, when the waste gate valve 17 is also controlled to fully open after being controlled fully closed, variations in the valve position S is within the predetermined range R _P is the waste gate valve 17 Is not working properly (the system is abnormal). Note that the failure determination may be performed based on the reference operation range _RBA instead of the initial operation range IR. Here, the predetermined range R _P, a preset fixed value, for example, the waste gate valve 17 is set to a range (moving length) extent move if normal.

  When it is determined that the waste gate valve 17 has failed, the user is notified of the failure by turning on the warning lamp 51 or an alarm. Further, a failure code corresponding to the failure of the waste gate valve 17 is stored in the engine control device 1. Thereby, it is possible to prompt the user to bring the vehicle to a sales company, a repair shop, or the like, and it is possible to make the repair person easily recognize the content of the failure.

[2-4. Cleaning control]
In the cleaning control, the difference ΔS (= | IS _CL −S ₀ |) between the initial fully closed position IS _CL learned in the first learning and the zero point S ₀ learned in the second learning is equal to or _larger than the predetermined value S _P. In this case, the waste gate valve 17 is opened and closed to perform cleaning. The waste gate valve 17 may be attached with carbon contained in the exhaust gas, and if the attached carbon adheres to the deposit, it may cause a malfunction of the waste gate valve 17.

In particular, in the case of the engine 10 in which fuel is injected by the in-cylinder injection valve 11, there is a high possibility that deposits will occur. Therefore, the initial if the difference ΔS between the fully closed position IS _CL and zeros S ₀ is a predetermined value or more S _P is is determined that the carbon deposits or adhered might have occurred, wastegate The valve 17 is cleaned. The predetermined value _SP is a constant value set in advance, and is set to a value larger than the detection error by the hall sensor 47, for example.

  Specifically, the waste gate valve 17 is controlled to be fully opened and then repeatedly opened. Thereby, carbon adhering to the valve body 17a and the rod 17b is removed, carbon is removed from the waste gate valve 17, and generation | occurrence | production of a deposit is prevented. In particular, when cleaning is performed while the engine 10 is in operation, the carbon removed from the waste gate valve 17 is blown away by the exhaust gas, so that the carbon can be removed more effectively.

  In the cleaning control, since the waste gate valve 17 is opened and closed, the supercharging pressure can fluctuate. Therefore, the supercharging pressure is checked before the cleaning control is performed. When the supercharging pressure is relatively low, cleaning is performed, and when the supercharging pressure is high, the cleaning is suspended. When the supercharging pressure is high, it can be said that the engine output required for the engine 10 is high and high output is about to be obtained. Therefore, the cleaning is suspended and is performed when the supercharging pressure is lowered.

[3. Control configuration]
As shown in FIG. 1, the engine control device 1 is provided with an engine load calculation unit 2 and a waste gate calculation unit 3 as elements for performing the above-described control. As shown in FIGS. 1 and 2, the waste gate calculation unit 3 includes a learning unit 3 a, a setting unit 3 b, an opening degree control unit 3 c, a failure control unit 3 d, a calculation unit 3 e, and a cleaning unit 3 f. 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 calculation unit]
The engine load calculation unit 2 calculates the magnitude of the load P of the engine 10. The load P here means a force that exerts resistance on the engine 10, a work rate (engine output, horsepower), a work (energy), and the like. Typically, an engine output required for the engine 10 and a parameter correlated therewith are handled as the load P.

  The load P is calculated based on the amount of air introduced into the cylinder, for example. Alternatively, it is calculated based on the intake flow rate, the exhaust flow rate, and the like. In addition, the load P may be calculated based on the intake pressure and exhaust pressure, the vehicle speed V, the rotational speed Ne, the accelerator operation amount APS, the operating state of the external load device, and the like. In the present embodiment, the charging efficiency Ec or the volumetric efficiency Ev is calculated based on the intake flow rate Q and the rotational speed Ne, and the magnitude of the load P is calculated based on these values. The value of the load P calculated here is transmitted to the waste gate calculation unit 3.

[3-2. Wastegate operation unit]
The learning unit (learning means) 3a performs the above-described learning control. That is, the learning unit 3 a performs the first learning before the engine 10 is started and performs the second learning after the engine 10 is started. Specifically, the learning unit 3a controls the full opening of the waste gate valve 17 after the key-on and before the engine 10 is started (reciprocates once from the fully closed state to the fully opened state).

At this time, the initial fully closed position IS _CL and the initial operating range IR are learned using the first fully closed position S _CL1 and the fully open position S _OP detected by the hall sensor 47 (first learning). Then, the initial fully closed position _ISCL and the initial operation range IR are set as the reference position _SBA and the reference operation range _RBA . The reference position S _BA and the reference operation range R _BA set here are transmitted to the setting unit 3b. Further, the initial closed position IS _CL learned in the first learning is transmitted to the calculation unit 3e, the initial operating range IR is transmitted to the fault control unit 3d.

The learning unit 3a controls the waste gate valve 17 to be fully closed during acceleration traveling after the engine 10 is started. At this time, the zero point S ₀ is learned using the second fully closed position S _CL2 detected by the hall sensor 47 (second learning). Then, compared with the initial fully closed position IS _CL and zeros S _0, to correct the reference position S _BA. The corrected reference position _SBA is transmitted to the setting unit 3b. Further, the zero point S ₀ learned in the second learning is transmitted to the calculation unit 3e.

The learning unit 3a performs the first learning only once during one drive cycle, and the second learning is performed once or more during one drive cycle. Here, the learning unit 3a performs the second learning during acceleration traveling. However, after the second learning is performed once during acceleration, the second learning is performed when acceleration traveling is started again after a predetermined time has elapsed. This prevents the second learning from being repeated many times during one acceleration.
The setting part 3b and the opening degree control part 3c implement the above-mentioned opening degree control. The setting unit 3b sets a target opening degree D _TGT of the waste gate valve 17 based on the operating state of the engine 10, and sets a valve position (target position S _TGT ) corresponding to the target opening degree D _TGT . The target opening _DTGT is based on, for example, the engine speed Ne, the engine load P, the air amount, the charging efficiency Ec (target charging efficiency, actual charging efficiency, etc.), the supercharging pressure, the accelerator opening APS, the cooling water temperature WT, etc. Is set. Setting portion 3b, the target position S _TGT as a target opening degree D _TGT set is set using the map shown in FIG. 3, for example. 3, the horizontal axis valve opening D of the waste gate valve 17, the vertical axis is a map taking the valve position S, thereby the target position S _TGT corresponding to the target opening D _TGT is set.

The setting unit 3b reflects the reference position S _BA and the reference operation range R _BA transmitted from the learning unit 3a on a preset map (solid line in the figure). Specifically, the setting unit 3b sets (updates) the transmitted reference position S _BA (white circle in the figure) as the valve position when the waste gate valve 17 is fully closed, and transmits the transmitted reference operation range R _BA ( A one-dot chain line in the figure) is set (updated) as an operating range from the fully closed to fully opened waste gate valve 17. That is, the setting unit 3b adjusts the target position S _TGT corresponding to the target opening degree D _TGT using the learning result in the learning unit 3a. The target position _STGT set by the setting unit 3b is transmitted to the opening degree control unit 3c.

The opening degree control unit 3c outputs a control signal for the electric actuator 18 according to the target position _STGT corresponding to the target opening degree D _TGT set by the setting unit 3b. Here, a control signal is output to the electric actuator 18 so that the actual valve position S becomes the target position _STGT . Thereby, the valve opening degree D is controlled to the target opening degree D _TGT .

The failure control unit (failure control means) 3d performs the above-described failure control. That is, the fault control unit 3d is the initial operating range IR transmitted from the learning section 3a with a predetermined range R _P, if the initial operating range IR is less than the predetermined range R _P, the waste gate valve 17 is faulty It is determined that Then, the warning lamp 51 is turned on to notify the user of the failure. Furthermore, a failure code corresponding to the failure of the waste gate valve 17 is stored. The failure control unit 3d may sound an alarm instead of the warning light 51 to notify the user of the failure, or may use the warning light 51 and the alarm together.

The calculation unit (calculation unit) 3e and the cleaning unit (cleaning unit) 3f perform the above-described cleaning control. The calculation unit 3e calculates the difference ΔS (= | IS _CL −) between the initial fully closed position IS _CL that is the learning value of the first learning and the zero point S ₀ that is the learning value of the second learning transmitted from the learning unit 3a. S ₀ |) is calculated. Then, the cleaning unit 3f compares the difference ΔS calculated by the calculation unit 3e and the predetermined value S _P, the difference ΔS is equal to or larger than the predetermined value S _P (i.e. initial fully closed position IS _CL and zeros S ₀ there determines that if deviated more than a predetermined value S _P), it is necessary to clean the waste gate valve 17.

  When it is determined that the cleaning is necessary, the cleaning unit 3f determines whether or not the supercharging pressure is equal to or lower than a predetermined pressure. If the supercharging pressure is equal to or lower than the predetermined pressure, the cleaning unit 3f opens and closes the waste gate valve 17. Perform cleaning. On the other hand, when the supercharging pressure is higher than the predetermined pressure, the cleaning is suspended and the cleaning is performed after waiting for the supercharging pressure to decrease.

[4. flowchart]
4 to 7 are flowcharts for explaining the respective procedures of learning control, opening degree control, failure control, and cleaning control. Each of these flowcharts is started with key-on, and is repeatedly executed at a predetermined calculation cycle set in advance in the engine control device 1.

First, the learning control performed in the learning unit 3a will be described. As shown in FIG. 4, in step W10, it is determined whether or not the flag F ₁ is F ₁ = 0. Here, the flag F ₁ is a variable for checking whether or not the first learning has already been performed, and F ₁ = 0 corresponds to the fact that the first learning has not been performed yet, and F ₁ = 1. Corresponds to having already completed the first learning. When the flag F ₁ is F ₁ = 0, the process proceeds to Step W20, and when F ₁ = 1, the process proceeds to Step W70.

First learning is performed in steps W20 to W40. That is, in step W20, the valve position (first fully closed position) _SCL1 when the waste gate valve 17 is fully closed is detected, and the valve position (fully opened) when the waste gate valve 17 is fully opened. Position) S _OP is detected, and the operating range R is calculated. In the subsequent step W30, the initial fully closed position _ISCL and the initial operation range IR are learned. Then, in step W40, with the initial fully closed position IS _CL is set to the reference position S _BA, initial operation range IR is set to the reference operation range R _BA.

In the subsequent step W50, the reference position S _BA and the reference operation range R _BA are transmitted to the setting unit 3b, the initial operation range IR is transmitted to the failure control unit 3d, and the initial fully closed position IS _CL is transmitted to the calculation unit 3e. . In step W60, the flag F ₁ is set to F ₁ = 1. Thus, the processing from step W20 to step W60 is performed only when the flag F ₁ is F ₁ = 0 immediately after key-on (that is, before the engine 10 is started).

In step W70, it is determined whether the vehicle is accelerating. If the vehicle is accelerating, the process proceeds to step W80. If the vehicle is not accelerating, the process proceeds to step W140. In Step W80, it is determined whether or not the flag F ₂ is F ₂ = 0. Here, the flag F ₂ is a variable for checking whether or not the second learning can be performed. F ₂ = 0 corresponds to that the second learning can be performed, and F ₂ = 1 is the first learning. Corresponding to the fact that second learning is not possible. The second learning is performed many times during one drive cycle. However, after the second learning is performed once, it is performed again after a predetermined time has elapsed. This flag F ₂ is for checking whether or not a predetermined time has passed. When the flag F ₂ is F ₂ = 0, the process proceeds to Step W90, and when the flag F ₂ is F ₂ = 1, the process proceeds to Step W140.

In steps W90 to W110, the second learning is performed. That is, in step W90, the valve position when the waste gate valve 17 is fully closed (the second fully closed position) S _CL2 is detected. When the process proceeds to step W90, the acceleration gate is running, so the waste gate valve 17 is normally controlled to be fully closed. That is, by performing the second learning during the acceleration traveling in which the waste gate valve 17 is controlled to be fully closed, the learning control can be performed with little influence on the traveling.

In step W100, zero point S ₀ is learned. In step W110, the reference position S _BA is corrected by zero point S ₀ learned. In step W120, is transmitted is corrected reference position S _BA in setting portion 3b, zero point S ₀ is transmitted to the calculation unit 3e. In step W130, the flag F ₂ is set to F ₂ = 1, and it is determined whether the process proceeds to step W170 and the key is turned off. If the key remains on, this flow is returned.

In the next cycle, the process proceeds from step W10 to step W70, and if acceleration traveling is continued, the process proceeds to step W80. Here, since the flag F ₂ is set to F ₂ = 1 in the previous cycle, the process proceeds to step W140, and 1 is added to the count value C. In step W150, the count value C is equal to or a predetermined value C ₀ or more is determined. If the count value C is less than the predetermined value C ₀ , the process proceeds to step W170. If the key is not keyed off, this flow is returned.

Similarly, in the next cycle, when the process proceeds to step W140, 1 is added to the count value C, and the determination in step W150 is performed. In step W150, the count value C is calculation time is repeated until it is determined that the predetermined value C ₀ or higher, after implementing the second learning once, then corresponds to a predetermined time to implement. When the count value C becomes equal to or greater than the predetermined value C ₀ , the process proceeds to step W160, the flag F ₂ is reset to F ₂ = 0, the count value C is reset to 0, and the process proceeds to step W170. If the acceleration travel is finished while the count value C is being added, the process proceeds from step W70 to step W165, the flag F ₂ is reset to F ₂ = 0, and the count value C is reset to 0. Then, the process proceeds to Step W170.

If it is determined in step W170 that the key has been turned off, the process proceeds to step W180 where both the flags F ₁ and F ₂ are reset to 0 and the count value C is reset to 0, and this flow ends. When the key is turned on again, the processing from step W10 is performed.

Next, the opening degree control implemented in the setting part 3b and the opening degree control part 3c is demonstrated. As shown in FIG. 5, in step X <b> 10, various information detected by the various sensors 41 to 50 is input to the engine control device 1. Further, the engine load calculation unit 2 calculates the load P of the engine 10 and transmits information on the load P to the setting unit 3b. In Step X20, the target opening degree D _TGT of the waste gate valve 17 is set in the setting unit 3b.

In step X30, valve opening D and the reference positional relationship is transmitted from the learning unit 3a to a map set with the valve position S S _BA and a reference operating range R _BA is reflected. At step X40, it sets the target position S _TGT corresponding to the target opening degree D _TGT that has been set. In step X50, the opening control unit 3c outputs a control signal to the electric actuator 18 so that the actual valve position S becomes the set target position _STGT, and the flow returns.

Next, failure control performed in the failure control unit 3d will be described. As shown in FIG. 6, in step Y10, it is determined whether or not the initial operation range IR is transmitted from the learning unit 3a (that is, whether or not step W50 in the flowchart of FIG. 4 is performed). If the initial operating range IR is not transmitted, this flow is returned, and the determination in step Y10 is repeated until the initial operating range IR is transmitted. When the initial operating range IR is transmitted, the process proceeds to step Y20, the initial operating range IR is equal to or less than the predetermined range R _P is determined.

Initial operating range IR is equal to or larger than the predetermined range R _P, and the flow ends. On the other hand, the initial operating range IR If there is less than the predetermined range R _P, is determined that the wastegate valve 17 is faulty, the fault code is stored in step Y 30. Subsequently, in step Y40, the warning lamp 51 is turned on to notify the user of the failure, and this flow ends. That is, the failure determination in step Y20 is performed only once after the key-on, when the initial operating range IR is transmitted.

  Finally, cleaning control performed in the calculation unit 3e and the cleaning unit 3f will be described. As shown in FIG. 7, in step Z10, it is determined whether or not the flag G is G = 0. Here, the flag G is a variable for checking whether or not the cleaning is pending. G = 1 corresponds to the pending state and G = 0 corresponds to the not pending state. When the flag G is G = 0, the process proceeds to step Z20, and when G = 1, the process proceeds to step Z50.

In Step Z20, it is determined whether or not the initial fully closed position _ISCL is transmitted from the learning unit 3a (that is, whether or not Step W50 in the flowchart of FIG. 4 is performed). If the initial fully closed position IS _CL is not transmitted, the flow returns. If the initial fully closed position IS _CL is transmitted, the process proceeds to step Z30. The determination in step Z20 continues until the key is turned off after it is once established.

In step Z30, whether zero point S ₀ is transmitted (i.e., whether the step W120 in the flowchart of FIG. 4 is performed) it is determined. If the zero point S ₀ is not transmitted, the flow returns, and if the zero point S ₀ is transmitted, the process proceeds to step Z40. The determination in step Z30 is satisfied when step W120 is performed in the flowchart of FIG. 4, and is not satisfied when step W120 is not performed (that is, when flag F ₂ = 1).

In step Z40, the difference between the initial fully closed position IS _CL and zeros S ₀ [Delta] S (absolute value of the initial fully closed position minus the zero point S ₀ from IS _CL) is calculated in the calculation unit 3e, cleaning unit 3f the difference ΔS is equal to or greater than a predetermined value S _P is determined at. If the difference ΔS between the initial fully closed position IS _CL and zeros S ₀ is not equal to or greater than the predetermined value S _P, cleaning is determined to be unnecessary, the process returns to the flow. On the other hand, the difference ΔS between the initial fully closed position IS _CL and zeros S ₀ is equal to or larger than the predetermined value S _P, the boost pressure is checked in step Z50. Specifically, it is determined whether or not the supercharging pressure is equal to or lower than a predetermined pressure. If it is equal to or lower than the predetermined pressure, the process proceeds to Step Z60, and if higher than the predetermined pressure, the process proceeds to Step Z80.

  In step Z60, the waste gate valve 17 is opened and closed to perform cleaning. In step Z70, the flag G is set to G = 0, and this flow is returned. On the other hand, in step Z80, the execution of cleaning is suspended. In step Z90, the flag G is set to G = 1, and this flow is returned. In this case, the process proceeds from step Z10 to step Z50 in the next cycle, and the supercharging pressure is checked again. This process is repeated until the supercharging pressure becomes equal to or lower than the predetermined pressure, and cleaning is performed when the supercharging pressure decreases.

[5. effect]
(1) In the above-described engine control device 1, for carrying out the first learning for learning the initial fully closed position IS _CL of the waste gate valve 17 before the start of the engine 10, ensuring the learning opportunities of the waste gate valve 17 constantly can do. Further, since the second learning for learning the zero point S ₀ of the waste gate valve 17 is performed after the engine 10 is started, the learning process can be made in two stages. Further, since the second learning is learning after the valve element 17a and the rod 17b of the waste gate valve 17 receive heat from the exhaust, learning is performed including the influence of thermal expansion and the like by calculating the difference ΔS. be able to. As a result, the fully closed position of the waste gate valve 17 can be accurately learned. If the opening control of the waste gate valve 17 is performed based on this fully closed position, the accuracy of the supercharging pressure control can be improved. it can.

  (2) In the engine control apparatus 1 described above, the second learning is performed while the vehicle is accelerating. Usually, since the required output is large during acceleration traveling, the waste gate valve 17 is fully closed to increase the supercharging pressure. Therefore, by performing the second learning during the acceleration traveling, it is not necessary to fully close the waste gate valve 17 in order to perform the learning control, and then the learning can be performed. Therefore, a learning opportunity can be ensured without affecting driving.

(3) Further, in the engine control device 1, in addition to the initial closed position IS _CL in the first learning, by detecting the fully opened position S _OP learning the initial operating range IR. Thus, in addition to the reference position S _BA can set the range (reference operating range R _BA) of the waste gate valve 17 actually moves, by performing the opening control of the wastegate valve 17 by using the In addition, the accuracy of the supercharging pressure control can be further increased.

(4) In the engine control apparatus 1 described above, when the initial operation range IR learned in the first learning is less than the predetermined range R _P , the failure of the waste gate valve 17 is notified and the corresponding failure code is stored. Is done. Thereby, the failure of the waste gate valve 17 can be determined at an early stage (that is, before the engine 10 is started), and the user can be notified of the failure. In addition, by storing the failure code, the repair person can easily understand the content of the failure.

(5) In the above-described engine control device 1, cleaning when the difference ΔS between the zero point S ₀ learned initialized learned and fully closed position IS _CL in the second learning at the first learning is a predetermined value or more S _P Is implemented. As a result, the carbon adhering to the waste gate valve 17 is removed, and the carbon is removed from the waste gate valve 17, thereby preventing the occurrence of deposits. In particular, by performing the cleaning while the engine 10 is operating, the carbon removed from the waste gate valve 17 can be blown off by the exhaust, and the carbon can be more effectively removed.

[6. Others]
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 embodiment, by reflecting the reference position S _BA set by the learning unit 3a to the map, while setting the target position S _TGT corresponding to the target opening degree D _TGT, using learning result in opening control The method is not limited to this. For example, the fully closed position of the waste gate valve 17 is stored in advance as the initial reference position, and the deviation amount between the reference position _SBA set by the learning unit 3a and the initial reference position is calculated. Then, a target position _STGT corresponding to the target opening degree D _TGT is set using a preset map shown by a solid line in FIG. 3, and the opening degree control is performed by adding and subtracting the deviation amount to the set target position _STGT. You may transmit to the part 3c.

Further, in the above embodiment, has learned the initial fully closed position IS _CL and the initial operating range IR at a first learning may be carried out learning of at least the initial fully closed position IS _CL. By using this initial fully closed position _ISCL as a reference at the time of opening control, the opening control can be performed with high accuracy, and the accuracy of supercharging pressure control can be increased.
In the above-described embodiment, the case where the second learning is performed during acceleration traveling is illustrated, but the second learning can be performed after the engine 10 is started. Further, the second learning may be performed once during one drive cycle. Further, the failure control unit 3d and the cleaning unit 3f can be omitted.

  Further, the configuration of the engine 10 is not limited to the above-described configuration, and any engine including an electric waste gate valve interposed in a bypass route that bypasses the supercharging turbine on the exhaust passage is applicable. The means for detecting the position of the waste gate valve 17 is not limited to the hall sensor 47, and any means capable of detecting the position of the valve body 17a of the waste gate valve 17 and the stroke amount of the rod 17b may be used.

DESCRIPTION OF SYMBOLS 1 Engine control apparatus 2 Engine load calculation part 3 Waste gate calculating part 3a Learning part (learning means)
3b Setting unit 3c Opening control unit 3d Failure control unit (failure control means)
3e Calculation unit (calculation means)
3f Cleaning section (cleaning means)
10 Engine 11 In-cylinder injection valve 16 Turbocharger 16A Turbine (supercharged turbine)
17 Waste gate valve 17a Valve body 17b Rod 18 Electric actuator 31 Exhaust passage 32 Exhaust bypass passage (bypass)
47 Hall sensor (detection means)
IS _CL initial fully closed position
S _CL1 first fully closed position
S _CL2 2nd fully closed position
S _OP fully open position
S ₀ Zero point
IR initial operating range
R Operating range

Claims (3)

An engine control device including a waste gate valve that is interposed in a bypass route that bypasses a supercharged turbine on an exhaust passage and is driven by an electric actuator,
Detecting means for detecting a position of the waste gate valve;
Before the engine is started, the waste gate valve is fully closed and the position detected by the detection means and the position detected by the detection means with the waste gate valve fully open are detected. Learning means for learning the initial operating range;
An engine control device comprising: failure control means for notifying a failure of the waste gate valve and storing a failure code corresponding to the failure when the initial operation range is less than a predetermined range. . The learning means first learns the initial fully closed position of the waste gate valve from the position detected by the detecting means by fully closing the waste gate valve before starting the engine; Performing a second learning to fully close the waste gate valve after startup and learn the zero point of the waste gate valve from the position detected by the detection means;
2. The engine control according to claim 1, wherein the control device includes calculation means for calculating a difference between a learning value obtained by the first learning and a learning value obtained by the second learning. apparatus. The engine control device according to claim 2, wherein the learning unit performs the second learning while the vehicle is accelerating.

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