JP6232793B2 - 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). However, if the waste gate valve fails and its opening cannot be controlled accurately, the supercharging pressure cannot be controlled, and the required output may not be obtained. On the other hand, a technique has been proposed in which a failure of the waste gate valve is determined and fail safe control is performed when it is determined as a failure.

  For example, Patent Document 1 discloses a turbocharged engine having a function of diagnosing a failure related to an exhaust bypass valve (waste gate valve) including an actuator and a fail-safe function when a failure is detected. . In this technique, an open failure or a close failure of the exhaust bypass valve is determined based on at least the throttle opening and the boost pressure in the operation region where the exhaust bypass valve is closed or opened. When a failure is detected, ignition timing control, air-fuel ratio control, or throttle opening is controlled according to the determination result.

JP 2003-328766 A

  However, in Patent Document 1 described above, failure diagnosis is not performed unless the operation region is capable of performing failure diagnosis, and there may be a case where an opportunity for failure diagnosis cannot be secured. In addition, this technology compares the preset set boost pressure with the actual boost pressure to determine whether the exhaust bypass valve is open or closed. Is affected. That is, since the failure of the exhaust bypass valve is determined by an indirect method of checking the boost pressure, for example, when the actual boost pressure fluctuates due to a factor other than the failure of the exhaust bypass valve. It lacks the accuracy of failure determination.

  The present invention has been devised in view of such a problem, and an object thereof is to provide an engine control device capable of improving the accuracy of waste gate valve failure determination. 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. Based on the position detected by the detecting means and the position detected by the detecting means, the failure determination of the waste gate valve is performed in two stages before starting the engine and after starting the engine. Failure determination means.

Furthermore, the failure determination means opens the waste gate valve fully open and the waste gate valve detected by the detection means when the waste gate valve is fully closed before the engine is started. when the fully open position of the waste gate valve in which the detected by the detection means when the is within the predetermined range, and determining means determines that the waste gate valve is faulty.

( 2 ) Further, setting means for setting a target position of the waste gate valve in accordance with an operating state of the engine, and the electric motor so that the position of the waste gate valve becomes the target position set by the setting means. And a control means for controlling the actuator. In this case, the failure determination means, when the absolute value of the difference between the target position set by the setting means and the position detected by the detection means is greater than or equal to a predetermined value after the engine is started, More preferably, it is determined that the waste gate valve may be broken.

( 3 ) It is preferable to include a cleaning unit that performs cleaning by opening and closing the waste gate valve when the failure determination unit determines that the waste gate valve may be broken. In this case, the failure determination unit has an absolute value of a difference between the target position set by the setting unit and the position detected by the detection unit equal to or greater than the predetermined value even after cleaning by the cleaning unit. In this case, it is more preferable to determine that the waste gate valve has failed.

( 4 ) It is preferable to include a failure notification unit that notifies the failure and stores a failure code corresponding to the failure when the failure determination unit determines that the waste gate valve has failed.

( 5 ) Moreover, it is preferable to provide a throttle opening setting means for setting the opening of a throttle valve interposed in the intake passage based on the operating state of the engine. In this case, it is more preferable that the throttle opening setting means restricts the upper limit value of the throttle valve opening when the failure determination means determines that the waste gate valve has failed.

According to the disclosed engine control device, the failure determination of the waste gate valve is performed using the actual position of the waste gate valve detected by the hall sensor, so that the accuracy of the failure determination can be improved. Moreover , since the failure determination is performed in two stages before the engine is started and after the engine is started, the failure determination accuracy can be further improved. Furthermore, whether or not the waste gate valve operates correctly is checked using the value detected by the detection means, and if it does not operate, it is determined that there is a failure. Therefore, a failure of the waste gate valve can be detected early. .

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 relation of the valve position to the opening of a waste gate valve. It is a flowchart which illustrates the procedure of the learning control in the engine control apparatus which concerns on one Embodiment. It is a flowchart which illustrates the procedure of the opening control of a waste gate valve in the engine control apparatus which concerns on one Embodiment. It is a flowchart which illustrates the procedure of the failure control in the engine control apparatus which concerns on one Embodiment. It is a figure which illustrates the determination method which distinguishes an open failure and a closed failure in the failure determination of the engine control apparatus which concerns on a modification. It is a flowchart which illustrates the procedure of the failure control in the engine control apparatus which concerns on a modification.

  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 of the throttle valve 26 (throttle opening TH). The throttle opening TH 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, and the like 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 TH, 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, learning control, failure control and cleaning control related to the waste gate valve 17 and opening control (throttle control) related to the throttle valve 26 will be described.

[2. Overview of control]
[2-1. Wastegate valve 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 is performed before the engine 10 is started, and is performed only once during one drive cycle. Here, it is performed before cranking after the ignition key is turned on (hereinafter referred to as key-on). Note that the drive cycle here means a period from key-on to key-on again. That is, the learning control is performed only once between the key-on and the key-off.

In the learning control, 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 fully closed position _SCL . Subsequently, the waste gate valve 17 is controlled to fully open, then the valve position S is detected by the Hall sensor 47, it is stored as the fully open position S _OP, and a fully closed position S _CL fully open position S _OP, the valve The operating range R of the body 17a is calculated. Then, the initial fully closed position _ISCL and the initial operation range IR are learned from these detection results and calculation results. That is, the initial fully closed position _ISCL and the initial operation range IR are values learned by learning control.

For example, the fully closed position S _CL detected by the hall sensor 47 may be set (learned) as the initial fully closed position IS _CL as it is, or the detected fully closed position S _CL and the previous time stored in the memory. based upon the initial fully closed position iS _CL 'control may learn the initial fully closed position iS _CL. 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 Based on the above, the initial operation range IR may be learned. The initial operation range IR learned here is stored in the memory and set as the reference operation range _RBA .

[2-3. Failure control]
The failure control is based on the result of learning control or the detection result of the hall sensor 47 to determine whether or not the waste gate valve 17 operates normally. Is control for notifying the user of the failure. The failure control includes a first failure control that is performed before the engine 10 is started and a second failure control that is performed after the engine 10 is started. The first failure control is performed only once during one drive cycle (for example, before cranking after key-on). On the other hand, the second failure control is performed many times during one drive cycle, and once it is determined that “failed”, failure determination is not performed until the next key-on.

In the first failure control, the initial operating range IR learned by the learning control in the case of less than the predetermined range R _P, it is determined that the wastegate valve 17 is faulty. 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 determined not to operate normally.

Instead of the initial operating range IR, to the failure determination by the reference operating range R _BA may be implemented, the position at which the wastegate valve 17 is controlled to the fully closed to fully open and (full closed position S _CL) If the control position at which the (fully open position S _OP) is within a predetermined range R _P, it may be determined that the wastegate valve 17 is faulty. 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.

In the second failure control, the valve position (target position S _TGT described later) corresponding to the target opening D _TGT set in the opening control and the actual valve position of the waste gate valve 17 detected by the Hall sensor 47 ( Hereinafter, the failure of the waste gate valve 17 is determined from the actual position S _A. Here, first, the absolute value | S _TGT -S _A | of the difference between the target position S _TGT and the actual position S _A is compared with the predetermined value S _T, and the absolute value | S _TGT -S _A | If it is less than _T is the waste gate valve 17 is determined to be normal, the absolute value | S _TGT -S _a | a is equal to or greater than the predetermined value S _T is likely to waste gate valve 17 is faulty It is determined.

If the waste gate valve 17 is determined to be possibly faulty, the type of the failure from the relationship between the target position S _TGT and the actual position S _A (open failure whether closure failure) is determined. For example, when the distance between the actual position S _A and the reference position S _BA is longer than the distance between the target position _STGT and the reference position S _BA (that is, the target position between the reference position S _BA and the actual position S _A If the _STGT exists), the waste gate valve 17 is not moved to the closed side, so the type of failure is determined to be an open failure.

In this case, the same determination is performed again after the cleaning control described later is performed. In other words, even after cleaning, the absolute value of the difference between the target position S _TGT and the actual position S _A | S _TGT -S _A | is equal to or higher than a predetermined value S _T, and the actual position S _A and the reference position S _BA the length of is longer than the length of the target position S _TGT and the reference position S _BA, it is determined that the wastegate valve 17 is open failure. If this is the open failure, since there may be cases in crowded mere chewing once by carrying out the cleaning, to eliminate the deviation between the target position by biting S _TGT and the actual position S _A, the failure determination accuracy This is to increase it.

On the other hand, when the length between the actual position S _A and the reference position S _BA is shorter than the length between the target position S _TGT and the reference position S _BA (that is, the actual position S _{BA is} between the reference position S _BA and the target position S _TGT). In the case where the position S _A exists), the waste gate valve 17 is not moved to the open side, so that the type of failure is determined as a closed failure. In this case, it is determined that the waste gate valve 17 has a closed failure without performing the cleaning control.

  In the first failure control and the second failure control, when it is determined that the waste gate valve 17 has failed, the failure is notified to the user by lighting of 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]
The cleaning control is a control executed when there is a possibility that the waste gate valve 17 has failed in the second failure control described above, and the failure type is determined to be an open failure. In the cleaning control, the waste gate valve 17 is forcibly opened and closed to perform cleaning. “Forced” here means that the waste gate valve 17 is opened and closed regardless of the above-described opening degree control.

  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, if it is determined in the second failure control that there is a possibility of an open failure, it is determined that there is a possibility that carbon has adhered or deposit has occurred, and the waste gate valve 17 is cleaned. Is done.

  Specifically, the waste gate valve 17 is controlled to be fully opened and then repeatedly opened. Thereby, the carbon adhering to the valve body 17a and the rod 17b is wiped off, the carbon is removed from the waste gate valve 17, and the generation of deposits 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.

[2-5. Throttle control]
The throttle control is control that optimizes the opening of the throttle valve 26 (throttle opening TH) based on the operating state of the engine 10. In the throttle control, for example, the throttle opening based on the engine speed Ne, engine load P, air amount, charging efficiency Ec (target charging efficiency, actual charging efficiency, etc.), supercharging pressure, accelerator opening APS, cooling water temperature WT, etc. TH target value (target throttle opening) TH _TGT is set. Then, the throttle valve 26 is controlled so as to achieve the set target throttle opening TH _TGT .

In the throttle control, when it is determined that the waste gate valve 17 has failed in the first failure control described above, and when it is determined in the second failure control that the waste gate valve 17 has failed. Further, the upper limit value TH _MAX of the throttle opening TH is limited. In other words, the preset upper limit value TH _MAX of the throttle opening TH is changed to a small value. As a result, when the set target throttle opening TH _TGT is larger than the changed upper limit value TH _MAX ′, the throttle valve 26 is opened only to the changed upper limit value TH _MAX ′. This is because when the waste gate valve 17 was closed failures or if not move more than a predetermined range R _P is to suppress the excessive increase of the supercharging pressure by throttling the throttle opening TH.

[3. Control configuration]
As shown in FIG. 1, the engine control device 1 is provided with an engine load calculation unit 2, a waste gate calculation unit 3 and a throttle calculation unit 4 as elements for performing the above control. As shown in FIGS. 1 and 2, the waste gate calculation unit 3 includes a learning unit 3a, a valve opening setting unit 3b, an opening control unit 3c, a failure determination unit 3d, a failure notification unit 3e, and a cleaning unit 3f. The throttle calculation unit 4 is provided with a throttle opening setting unit 4a and a throttle control unit 4b. 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, the exhaust pressure, the vehicle speed V, the rotational speed Ne, the accelerator opening 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 and the throttle calculation unit 4.

[3-2. Wastegate operation unit]
The learning unit 3a performs the above-described learning control before 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 operation range IR are learned using the fully closed position S _CL and the fully open position S _OP detected by the hall sensor 47. 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 . Here set reference position S _BA and the reference operation range R _BA is transmitted to the valve degree of opening setting unit 3b. Further, the initial operation range IR is transmitted to the failure determination unit 3d.

The valve opening setting unit (setting unit) 3b and the opening control unit (control unit) 3c perform the above-described opening control. The valve opening setting unit 3b sets the target opening D _TGT of the waste gate valve 17 based on the operating state of the engine 10, and sets the valve position (target position S _TGT ) corresponding to the target opening D _TGT. It is. 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. Valve opening 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.

Valve opening setting unit 3b, to the preset map (solid line in the figure), to reflect the transmitted reference position S _BA and the reference operation range R _BA from the learning unit 3a. Specifically, the valve opening 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 (one-dot chain line in the figure) is set (updated) as an operation range from the fully closed to the fully opened waste gate valve 17. That is, the valve opening setting unit 3b adjusts the target position S _TGT corresponding to the target opening D _TGT using the learning result in the learning unit 3a. The target position _STGT set by the valve opening setting unit 3b is transmitted to the opening control unit 3c and the failure determination unit 3d.

The opening degree control unit 3c outputs a control signal for the electric actuator 18 in accordance with the target position _STGT corresponding to the target opening degree D _TGT set by the valve opening degree 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 determination unit (failure determination unit) 3d and the failure notification unit (failure notification unit) 3e perform the above-described failure control. The failure determination unit 3d first performs first failure control before the engine 10 is started. That is, it is determined learning unit 3a initial operation range IR transmitted from the comparison with the predetermined range R _P, the waste gate valve 17 when the initial operating range IR is less than the predetermined range R _P has failed.

Moreover, the failure determination unit 3d performs the second failure control after the engine 10 is started. That is, the absolute value | S _TGT -S _A | of the difference between the target position S _TGT set by the valve opening setting unit 3b and the actual position S _A of the waste gate valve 17 at this time is calculated, and the absolute value | S _TGT -S _A | is compared with a predetermined value S _T. Failure determination unit 3d, the absolute value | S _TGT -S _A | is determined that in the case of more than the predetermined value S _T might have failed, the absolute value | S _TGT -S _A | a predetermined value S _T If it is less, it is determined to be normal.

Failure determination section 3d, if it is determined that there is possibility of a failure, determining the type of fault from the relationship between the target position S _TGT and the actual position S _A. If it is determined that an open failure has occurred, a command is sent to the cleaning unit 3f to perform cleaning. Failure determination section 3d is the absolute value after cleaning | determines within not less than the predetermined value S _T, the waste gate valve 17 is open failure | S _TGT -S _A.

Further, the malfunction determining unit 3d, the absolute value | S _TGT -S _A | a is equal to or greater than the predetermined value S _T, if the type of fault is determined to be disabled閉故, without performing a cleaning Waste It is determined that the gate valve 17 has a closed failure. In this case, the failure determination unit 3d sends a command to the throttle opening setting unit 4a so as to limit the upper limit value TH _MAX of the throttle opening TH. The determination result in the failure determination unit 3d is transmitted to the failure notification unit 3e.

  The failure notification unit 3e turns on the warning lamp 51 and notifies the user of the failure when the determination result that the waste gate valve 17 has failed is transmitted from the failure determination unit 3d. Furthermore, a failure code corresponding to the failure of the waste gate valve 17 is stored. For example, when a failure is determined in the first failure control, a failure code corresponding to the failure is stored, and when it is determined as an open failure or a closed failure in the second failure control, these failures are supported. The failure code to be stored is stored. The failure notification unit 3e 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 cleaning unit (cleaning unit) 3f performs the above-described cleaning control. That is, the cleaning unit 3f performs cleaning by opening and closing the waste gate valve 17 when a command for performing cleaning is transmitted from the failure determination unit 3d.

[3-3. Throttle calculator]
The throttle opening setting unit (throttle opening setting means) 4a and the throttle control unit 4b perform the above-described throttle control. The throttle opening setting unit 4 a sets a target throttle opening TH _TGT that is a target opening of the throttle valve 26 based on the operating state of the engine 10. The target throttle opening TH _TGT is based on, for example, the engine speed Ne, engine load, air amount, charging efficiency Ec (target charging efficiency, actual charging efficiency, etc.), supercharging pressure, accelerator opening APS, cooling water temperature WT, etc. Is set. In the present embodiment, the target throttle opening TH _TGT 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 _TGT increases as the engine rotational speed Ne increases or the charging efficiency Ec increases. In addition, description is abbreviate | omitted about a specific opening degree characteristic.

The throttle opening setting unit 4a, when a command for limiting the upper limit TH _MAX of the throttle opening TH is transmitted from the failure determination unit 3d, the preset upper limit TH of the throttle opening TH. Change _MAX to a smaller value. Thereby, the throttle opening degree setting unit 4a determines that the target throttle opening degree TH is set when the target throttle opening degree TH _TGT to be set based on the operating state of the engine 10 is larger than the changed upper limit value TH _MAX '. Set _TGT to the changed upper limit value TH _MAX ′. Information on the target throttle opening TH _TGT set here is transmitted to the throttle control unit 4b.

The throttle control unit 4b outputs a control signal for the throttle valve 26 in accordance with the target throttle opening TH _TGT set by the throttle opening setting unit 4a. Here, the control signal is output to the throttle valve 26 so that the actual throttle opening TH becomes the target throttle opening TH _TGT .

[4. flowchart]
4 to 6 are flowcharts for explaining the respective procedures of learning control, opening control of the waste gate valve 17 and failure 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, the valve when in step W10, the waste gate valve 17 is the valve position when it is fully closed (fully closed position) S _CL is detected, the waste gate valve 17 is fully opened The position (fully opened position) S _OP is detected, and the operating range R is calculated. In the subsequent step W20, the initial fully closed position _ISCL and the initial operation range IR are learned. Then, in step W30, 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 subsequent step W40, the reference position _SBA and the reference operation range _RBA are transmitted to the valve opening setting unit 3b, and the initial operation range IR is transmitted to the failure determination unit 3d. Then, this flow ends. That is, this flowchart is executed only once immediately after key-on (that is, before the engine 10 is started).

Next, opening control performed in the valve opening setting unit 3b and the opening control unit 3c will be described. 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 information on the load P is transmitted to the valve opening setting unit 3b. In step X20, the target opening degree D _TGT of the waste gate valve 17 is set in the valve opening degree 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 determination unit 3d and the failure notification unit 3e will be described. As shown in FIG. 6, in step Y10, it is determined whether or not the flag A is A = 0. Here, the flag A is a variable for checking whether or not the engine 10 has been started. A = 0 corresponds to before the engine 10 starts, and A = 1 corresponds to after the engine 10 starts. When the flag A is A = 0, the process proceeds to step Y20, and when A = 1, the process proceeds to step Y110.

  In step Y20, it is determined whether or not the flag B is B = 0. Here, the flag B is a variable for checking whether or not the determination relating to the first failure control has been performed. B = 0 corresponds to before the determination of the first failure control, and B = 1 corresponds to the first failure control. Respond after determination of failure control. When the flag B is B = 0, the process proceeds to step Y30, and when B = 1, the process proceeds to step Y80.

In step Y30, it is determined whether or not the initial operation range IR has been transmitted from the learning unit 3a (that is, whether or not step W40 in the flowchart of FIG. 5 has been performed). If the initial operating range IR has not been transmitted, this flow is returned, and the processes in steps Y10 to Y30 are repeated until the initial operating range IR is transmitted. When the initial operating range IR is transmitted, the process proceeds to step Y40, the initial operating range IR is equal to or less than the predetermined range R _P is determined.

If initial operation range IR is less than the predetermined range R _P, is determined that the wastegate valve 17 is faulty, the process proceeds to step Y50. In step Y50, a command is sent to the throttle opening setting unit 4a so as to limit the upper limit value TH _MAX of the throttle opening TH. In subsequent step Y60, the failure code corresponding to the first failure control is stored. In the flowchart, the term “failure code (initial)” is used to distinguish it from other failure codes. In step Y50, the warning lamp 51 is turned on to notify the user of the failure, and this flow ends.

On the other hand, in step Y40, the initial operating range IR is equal to or larger than the predetermined range R _P, the process proceeds to step Y80, the flag B is set to B = 1. In step Y90, it is determined whether or not the engine 10 has been started. If the engine 10 has not yet been started, this flow is returned. In this case, in the next calculation cycle, the process proceeds from step Y20 to step Y80, and the same determination is performed in step Y90.

When engine 10 is started, flag A is set to A = 1 in step Y100. In the subsequent step Y110, it is determined whether or not the key has been turned off. If the key-on state is continuing, the process proceeds to step Y120, and if the key-off state is keyed, the process proceeds to step Y260. In step Y120, it is determined whether or not the target position _STGT is set in the valve opening setting unit 3b (that is, whether or not step X40 in the flowchart of FIG. 6 is performed). If the target position S _TGT is not set, the process returns. If the target position S _TGT is set, the process proceeds to step Y130.

When the target position S _TGT is set, the waste gate valve 17 is controlled by the opening degree control unit 3c so that the valve position S becomes the target position S _TGT . In step y130 as, the actual position S _A of the waste gate valve 17 at this time is detected by the Hall sensor 47. In step Y140, the absolute value of the difference between the target position S _TGT and the actual position S _A | S _TGT -S _A | is equal to or more than a predetermined value S _T is determined. When the absolute value | S _TGT -S _A | is equal to or greater than the predetermined value S _T , the process proceeds to step Y145, and when the absolute value | S _TGT -S _A | is less than the predetermined value S _T , the process proceeds to step Y270.

In step Y145, it is determined whether the type of failure is an open failure. In this determination, for example, as described above, long whether Kaya than the distance between the actual position S _A and the reference position S distance between the _BA is the target position S _TGT and the reference position S _BA, the reference position S _BA and the actual position whether or not the target position S _TGT is present is determined between the S _a. If it is determined that the type of failure is an open failure, it is determined in step Y150 whether or not the flag K is K = 1.

  Here, the flag K is a variable for checking whether or not cleaning has been performed. K = 0 corresponds to the case where cleaning is not performed, and K = 1 corresponds to the completion of cleaning. When the flag K is K = 0, the process proceeds to step Y160, and when K = 1, the process proceeds to step Y180. In step Y160, a command to perform cleaning is sent to the cleaning unit 3f. In step Y170, the flag K is set to K = 1, and this flow is returned.

In the above predetermined value S _T | even in the next calculation cycle, and the target position S _TGT that has been set in step Y120, the absolute value of the difference between the actual position S _A detected in step Y130 | S _TGT -S _A If the failure type is an open failure, the process proceeds to step Y150 again. Since the flag K is set to K = 1 this time, the process proceeds to step Y180, where it is determined that the waste gate valve 17 has an open failure. In other words, if there is a possibility of failure and the failure type is an open failure, the absolute value of the difference between the target position S _TGT and the actual position S _A | S _TGT -S _A | If the above value S _T, is determined to formally failure.

  In step Y180, a failure code corresponding to the open failure of the second failure control is stored. In the flowchart, the term “failure code (open)” is used to distinguish it from other failure codes. In step Y190, the warning lamp 51 is turned on to notify the user of the failure. In step Y200, the flags A, B, and K are all reset to 0, and this flow ends.

On the other hand, as a result of the cleaning, in the next calculation cycle, the absolute value of the difference between the target position S _TGT set at step Y120 and the actual position S _A detected at step Y130 | S _TGT -S _A | If is became less than the predetermined value S _T, the process proceeds to step Y270. In step Y270, the flag K is reset to K = 0, and this flow is returned. That is, in this case, considered the target position S _TGT and the actual position S _A is deviated by deposition of carbon or the like, malfunction can not be determined.

If it is determined in step Y145 that there is no open failure (that is, a closed failure), it is immediately determined that the waste gate valve 17 has a closed failure, and the process proceeds to step Y220. In step Y220, a command is sent to the throttle opening setting unit 4a so as to limit the upper limit value TH _MAX of the throttle opening TH. In step Y230, a failure code corresponding to the closed failure in the second failure control is stored. In the flowchart, “failure code (closed)” is expressed to distinguish from other failure codes. In step Y240, the warning lamp 51 is turned on to notify the user of the failure. In step Y200, the flags A, B, and K are all reset to 0, and this flow ends.

  This flowchart is executed again when it is determined that there is a failure once and the calculation is completed and then the key is turned on. On the other hand, if it is not determined that there is a failure, the process is repeated until the key is turned off. If the key is turned off, the process proceeds from step Y110 to step Y260, and flags A, K, and B are all reset to 0. End the flow.

[5. effect]
(1) In the engine control apparatus 1 described above, the failure determination of the waste gate valve 17 is performed using the actual position of the waste gate valve 17 detected by the hall sensor 47, so that the accuracy of the failure determination can be improved. . Furthermore, since the failure determination is performed in two stages before the engine 10 is started and after the engine 10 is started, the failure determination accuracy can be further improved.

(2) In the above-described engine control device 1, before the start of the engine 10, and the fully closed position S _CL fully open position S _OP of the waste gate valve 17 is detected by the Hall sensor 47, the operating range R of the valve body 17a initial operating range IR sought is within a predetermined range R _P, it is determined that the wastegate valve 17 is faulty. That is, the failure is not determined by comparing the command value for the waste gate valve 17 and the sensor value, but is determined from the fully closed position _SCL and the fully open position S _{OP of} the detected waste gate valve 17. The

  In other words, the engine control device 1 described above does not determine whether or not the waste gate valve 17 moves according to the command value before starting the engine 10, but the waste gate valve 17 is closed or opened. Whether or not it operates correctly is checked using the sensor value, and if it does not operate, it is determined as a failure. Thereby, the failure of the waste gate valve 17 can be detected at an early stage.

(3) In the above-described engine control device 1, after the start of the engine 10, the absolute value of the difference between the actual position S _A detected by the target position set by the valve opening setting unit 3b S _TGT and Hall sensor 47 If | S _TGT -S _A | is equal to or greater than the predetermined value S _T , it is determined that there is a possibility that the waste gate valve 17 has failed. That is, after starting of the engine 10, determines possibility of failure of the waste gate valve 17 is compared with the actual position S _A which is detected between the target position S _TGT that has been set. Thereby, the failure determination accuracy of the waste gate valve 17 can be increased.

(4) In the engine control apparatus 1 described above, cleaning is performed when it is determined that the waste gate valve 17 may be broken. 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. Then, even after cleaning, if the absolute value | S _TGT -S _A | of the difference between the target position S _TGT and the actual position S _A is equal to or greater than the predetermined value S _T, it is determined that the waste gate valve 17 has failed. Therefore, it is possible to eliminate the deviation between the target position S _TGT and the actual position S _a according crowded mere chewing, can increase the failure determination accuracy.
In addition, 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.

  (5) In the engine control apparatus 1 described above, when it is determined that the waste gate valve 17 has failed, the failure of the waste gate valve 17 is notified and the corresponding failure code is stored. Thereby, it is possible to notify the user of the failure of the waste gate valve 17. In addition, by storing the failure code, the repair person can easily understand the content of the failure.

(6) In the engine control apparatus 1 described above, when the failure determination unit 3d determines that the waste gate valve 17 has failed, the upper limit value TH _MAX of the throttle opening TH is limited. Therefore, even if the waste gate valve 17 is out of order, an excessive increase in the supercharging pressure can be suppressed. Thereby, even if the waste gate valve 17 breaks down, it becomes possible to travel and the user can bring the vehicle to a sales company, a repair shop, or the like.

[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, in the first failure control, if the initial operating range IR learned by the learning control is less than the predetermined range R _P, but to determine the failure of the wastegate valve 17, the failure of the first fault control The determination is not limited to the above. For example, when the waste gate valve 17 is fully closed before the engine 10 is started, the valve position S (fully closed position S _CL ) is detected by the hall sensor 47, and then the waste gate valve 17 is fully opened. The valve position S (fully opened position S _OP ) is detected by the hall sensor 47. When the fully closed position S _CL and the fully open position S _OP is within a predetermined range R _P, it may be determined that the wastegate valve 17 is faulty. In this case, the learning unit 3a can be omitted.

Further, in the above-described second failure control, whether or not there is a possibility of failure is first determined, and then the type of failure is determined, but the second failure control is not limited to this. For example, the difference between the target position S _TGT and the actual position S _A is calculated, and a threshold value S _FO for determining an open failure (hereinafter referred to as an open failure threshold value S _FO ) and a threshold value S _FC for determining a closed failure (hereinafter referred to as a closed failure) compared threshold of S _FC) respectively, may be determined whether directly open failure or closing failure. A determination method in this case will be described with reference to FIGS.

FIG. 7 is a diagram in which the left end is the reference position S _BA (valve position S = 0) and the horizontal axis is the valve position S (stroke amount), and the valve body 17a can move within the reference operation range R _BA . The alternate long and _short dash line is the target position S _TGT , and the thin broken line is the actual position S _A. Are denoted with letter 1,2 subscript subscripts to the actual position S _A in the figure. As shown in FIG. 7, if the value obtained by subtracting the target position S _TGT from the actual position S _A1 (S _A1 -S _TGT ) is equal to or greater than the open failure threshold _SFO , there is a possibility that the waste gate valve 17 has an open failure. It is determined that there is. In other words, when the following expression (1) is satisfied, it is determined that there is a possibility that the waste gate valve 17 has an open failure.

S _A1 -S _TGT ≧ S _FO (1)
When it is determined for the first time that the expression (1) is satisfied, cleaning control described later is performed, and the waste gate valve 17 is cleaned. Then, after the cleaning, when the above equation (1) is satisfied again, it is determined that the waste gate valve 17 has an open failure.

On the other hand, the target position S minus the actual position S _A2 from _TGT (S _TGT -S _A2) is equal to or larger than closing failure threshold S _FC, the waste gate valve 17 is determined to be closing failure. In other words, when the following expression (2) is satisfied, it is determined that the waste gate valve 17 has a closed failure.
S _TGT -S _A2 ≧ S _FC (2)
When such implementing the failure determination of the waste gate valve 17, it is possible to set the open failure threshold S _FO and closing failure threshold S _FC to different values, thereby failure determination in an open faults and closing failure It is possible to provide a difference in accuracy.

  A flowchart relating to the failure control in this case is shown in FIG. This flowchart is a modification of the flowchart of FIG. 6, and steps (for example, step Y10 and step Z10) with the same numerals are processed in the same manner as described above. Only processing different from the flowchart will be described. As shown in FIG. 8, in step Z142, it is determined whether or not the above equation (1) is satisfied. If this relationship is satisfied, there is a possibility of an open failure, so the processing after step Z150 is performed. . On the other hand, if the expression (1) is not satisfied, it is determined in step Z210 whether the above expression (2) is satisfied.

When this relationship is satisfied, it is determined that a closed failure has occurred, and the processing after step Z220 is performed. On the other hand, if the expression (2) is not satisfied, the flag K is set to K = 0 in step Z250, and this flow is returned. In this way, in the second failure control, a control configuration may be adopted in which an open failure and a closed failure are determined.
In the second failure control, the open failure may be determined immediately without performing the cleaning control. In this case, the cleaning unit 3f can be omitted. On the contrary, the cleaning control may be performed before determining the closed failure.

  Moreover, the failure determination part 3d should just implement 1st failure control before the start of the engine 10, for example, may be implemented during cranking. Further, the failure determination unit 3d does not perform the second failure control a predetermined number of times after the engine 10 is started, but does not execute the second failure control until the next key-on is performed after the predetermined number of times. May be.

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 embodiment, although the learning initial fully closed position IS _CL and the initial operating range IR at the learning control 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.

  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 3b Valve opening degree setting part (setting means)
3c Opening control unit (control means)
3d Failure determination unit (failure determination means)
3e Failure notification unit (failure notification means)
3f Cleaning section (cleaning means)
4 Throttle calculation unit 4a Throttle opening setting unit 4b Throttle control unit (throttle control 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)

Claims (5)

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;
Failure determination means for performing failure determination of the waste gate valve in two stages before starting the engine and after starting the engine based on the position detected by the detection means ;
The failure determination means, when starting the engine, when the waste gate valve is fully closed, when the waste gate valve is fully closed, and when the waste gate valve is fully opened. Engine control , wherein the waste gate valve is determined to be faulty when the waste gate valve detected by the detecting means is within a predetermined range. Equipment . Setting means for setting a target position of the wastegate valve according to the operating state of the engine;
Control means for controlling the electric actuator so that the position of the waste gate valve becomes the target position set by the setting means,
The failure determination means, after the engine is started, when the absolute value of the difference between the target position set by the setting means and the position detected by the detection means is a predetermined value or more, and judging that there is a possibility that the valve has failed, the control device according to claim 1, wherein the engine. When it is determined by the failure determination means that there is a possibility that the waste gate valve is in failure, the cleaning means for opening and closing the waste gate valve to perform cleaning,
The failure determination means, when the absolute value of the difference between the target position set by the setting means and the position detected by the detection means is not less than the predetermined value even after cleaning by the cleaning means, 3. The engine control device according to claim 2 , wherein the waste gate valve is determined to be malfunctioning. The failure notifying means for notifying the failure and storing a failure code corresponding to the failure when the waste determining valve determines that the waste gate valve has failed is provided. The engine control device according to any one of 1 to 3 . Based on the operating state of the engine, comprising throttle opening setting means for setting the opening of the throttle valve interposed in the intake passage,
The throttle opening setting means, when the waste gate valve is determined to be faulty by the failure determining means, and limits the upper limit value of the degree of opening of the throttle valve, according to claim 1 The engine control apparatus according to any one of to 4 .

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