CN111997772A

CN111997772A - Hybrid vehicle and abnormality diagnosis method thereof

Info

Publication number: CN111997772A
Application number: CN202010400787.6A
Authority: CN
Inventors: 板垣宪治
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2019-05-27
Filing date: 2020-05-13
Publication date: 2020-11-27
Anticipated expiration: 2040-05-13
Also published as: CN111997772B; JP7172855B2; JP2020192841A

Abstract

The invention provides a hybrid vehicle and an abnormality diagnosis method thereof. A vehicle (1) is provided with: the vehicle control system includes an engine (10) with a supercharger (15), a battery (70), a second motor generator (22) configured to be capable of receiving and supplying electric power to and from the battery, and an ECU (100) configured to control the engine and the second motor generator. The engine includes: an exhaust passage (14) from the engine body (11); a bypass passage (161) configured to allow exhaust gas to flow while bypassing the supercharger (15); and a waste gate valve (162) for adjusting the flow rate of the exhaust gas guided from the engine body (11) to the bypass passage. An ECU (100) controls an engine so that an operating point of the engine is moved from a natural intake region to a supercharging region regardless of an accelerator opening degree of a vehicle during operation of the engine, and diagnoses whether or not a wastegate valve is stuck in a closed state.

Description

Hybrid vehicle and abnormality diagnosis method thereof

Technical Field

The present disclosure relates to a hybrid vehicle and an abnormality diagnostic method thereof, and more particularly, to a hybrid vehicle provided with an engine with a supercharger and an abnormality diagnostic method thereof.

Background

Engines with superchargers are known. By the supercharger increasing the torque in the low rotation region, the exhaust gas amount can be reduced while maintaining the same power, thereby improving the fuel consumption of the hybrid vehicle. For example, a hybrid vehicle disclosed in japanese patent application laid-open No. 2015-58924 includes an engine with a turbocharger and a motor generator.

Disclosure of Invention

In a hybrid vehicle including an engine with a supercharger, there is a possibility that an abnormality may occur in a supercharging system. More specifically, the hybrid vehicle is provided with a Waste Gate Valve (WGV). The wastegate valve is a valve mechanism that adjusts the flow rate of exhaust gas that is guided from the engine body to a bypass passage (a passage configured to flow exhaust gas bypassing the supercharger). There is a possibility that the wastegate valve is stuck in a closed state, or conversely, the wastegate valve is stuck in an open state. When the wastegate valve is stuck and the supercharging system is not normally operated, it is difficult to obtain a desired output or running driving force from the engine. Therefore, it is preferable to more reliably detect the sticking of the wastegate valve.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to more reliably detect a jam of a wastegate valve in a hybrid vehicle including an engine with a supercharger.

(1) A hybrid vehicle according to one aspect of the present disclosure includes: the electric vehicle includes an engine with a supercharger, an electric storage device, a rotating electric machine configured to be capable of receiving and supplying electric power to and from the electric storage device, and a control device configured to control the engine and the rotating electric machine. The engine includes: an exhaust passage from the engine main body; a bypass passage connected to the exhaust passage and configured to allow exhaust gas to flow while bypassing the supercharger; and a wastegate valve provided in the bypass passage and adjusting the flow rate of exhaust gas guided from the engine body to the bypass passage. The control device controls the engine such that an operating point of the engine is moved from a natural intake region to a supercharging region regardless of an accelerator opening degree of the hybrid vehicle during operation of the engine, and diagnoses whether or not the wastegate valve is stuck in a closed state.

(2) The hybrid vehicle further includes at least one of a boost pressure sensor that is provided in an intake path leading to the engine main body and detects boost pressure at which the supercharger boosts the intake path, and an intake air amount sensor that is provided in the intake path and detects an amount of intake air entering the intake path. The control device diagnoses whether the wastegate valve is stuck in the closed state based on the boost pressure of the intake path or the intake air amount.

Depending on the driving mode of the vehicle, the supercharging operation of the supercharger may not be performed once during the operation of the engine (for example, during the stroke of the vehicle). In this case, there is no opportunity to diagnose the wastegate valve as having an irrelevant stuck. Therefore, in the configurations of (1) and (2), the engine operating point is forcibly moved into the supercharging region regardless of the accelerator opening degree. Therefore, the stuck-closed state of the wastegate valve is diagnosed at least once during the operation of the engine, so the frequency of diagnosing the stuck-closed state increases. Therefore, according to the configurations (1) and (2), the closed sticking of the wastegate valve can be detected more reliably.

(3) The control device controls the engine so that the operating point moves from the natural intake region to the supercharging region along the equal power line, and when the power of the engine is excessive or insufficient with respect to the required power of the hybrid vehicle, the excessive or insufficient power is compensated for by receiving and supplying electric power between the power storage device and the rotating electric machine.

In the configuration of the above (3), the engine operating point is moved along the equal power line. Thus, when the required power of the hybrid vehicle varies while the engine power is constant, the output variation of the hybrid vehicle can be suppressed by supplying the necessary electric power from the power storage device to the rotating electric machine or by regenerating the excessive electric power from the rotating electric machine to the power storage device.

(4) A hybrid vehicle according to another aspect of the present disclosure includes: the electric vehicle includes an engine with a supercharger, an electric storage device, a rotating electric machine configured to be capable of receiving and supplying electric power to and from the electric storage device, and a control device configured to control the engine and the rotating electric machine. The engine includes: an exhaust passage from the engine main body; a bypass passage connected to the exhaust passage and configured to allow exhaust gas to flow while bypassing the supercharger; and a wastegate valve provided in the bypass passage and adjusting the flow rate of exhaust gas guided from the engine body to the bypass passage. The control device controls the engine such that an operating point of the engine is moved from the supercharging region to the natural intake region regardless of an accelerator opening degree of the hybrid vehicle during operation of the engine, and diagnoses whether or not the wastegate valve is stuck open.

According to the configuration of the above (4), contrary to the configuration of the above (1), the open sticking of the wastegate valve can be detected more reliably.

(5) In a method for diagnosing an abnormality of a hybrid vehicle according to still another aspect of the present disclosure, the hybrid vehicle includes: an engine with a supercharger and a rotating electrical machine configured to be capable of receiving and supplying electric power to and from an electric storage device. The engine includes: an exhaust passage from the engine main body; a bypass passage connected to the exhaust passage and configured to allow exhaust gas to flow while bypassing the supercharger; and a wastegate valve provided in the bypass passage and adjusting the flow rate of exhaust gas guided from the engine body to the bypass passage. The abnormality diagnosis method of a hybrid vehicle includes the steps of: controlling the engine such that an operating point of the engine is moved from a natural intake region to a supercharging region regardless of an accelerator opening degree of the hybrid vehicle during operation of the engine; and diagnosing whether the wastegate valve is stuck in a closed state while maintaining the operating point of the engine in the supercharging region.

According to the method of the above (5), as in the configuration of the above (1), the sticking of the wastegate valve can be detected more reliably.

The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description, which is to be read in connection with the accompanying drawings.

Drawings

Fig. 1 is an overall configuration diagram of a hybrid vehicle according to embodiment 1 of the present disclosure.

Fig. 2 is a diagram showing an example of the structure of the engine.

Fig. 3 is a diagram showing a configuration example of a vehicle control system according to the present embodiment.

Fig. 4 is a diagram for explaining the supercharging control.

Fig. 5 is a flowchart showing the processing procedure of the supercharging control.

Fig. 6 is a diagram for explaining the closing lock diagnostic control in embodiment 1.

Fig. 7 is a flowchart showing the processing procedure of the close sticking diagnosis control in embodiment 1.

Fig. 8 is a diagram for explaining the open jam diagnostic control in embodiment 2.

Fig. 9 is a flowchart showing the processing procedure of the open jam diagnostic control in embodiment 2.

Detailed Description

Hereinafter, the present embodiment will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated.

[ embodiment 1]

< Structure of hybrid vehicle >

Fig. 1 is an overall configuration diagram of a hybrid vehicle according to embodiment 1 of the present disclosure. Referring to fig. 1, vehicle 1 is a hybrid vehicle, and includes engine 10, first motor generator (MG1)21, second motor generator (MG2)22, planetary gear mechanism 30, drive device 40, drive wheel 50, Power Control Unit (PCU) 60, Battery (BAT)70, and Electronic Control Unit (ECU) 100.

The engine 10 is an internal combustion engine such as a gasoline engine. The engine 10 generates power for running the vehicle 1 in accordance with a control signal from the ECU 100. The engine 10 includes a supercharger 15. The detailed structure of engine 10 will be described with reference to fig. 2.

Each of the first motor generator 21 and the second motor generator 22 is a permanent magnet synchronous motor or an induction motor. The first motor generator 21 and the second motor generator 22 have

rotor shafts

211 and 221, respectively.

The first motor generator 21 rotates a crankshaft (not shown) of the engine 10 using electric power of the battery 70 when the engine 10 is started. The first motor generator 21 may generate electric power using the power of the engine 10. The ac power generated by the first motor generator 21 is converted into dc power by the PCU60, and the battery 70 is charged with the dc power. The ac power generated by the first motor generator 21 may be supplied to the second motor generator 22.

The second motor generator 22 rotates drive shafts 46 and 47 (to be described later) using at least one of electric power from the battery 70 and electric power generated by the first motor generator 21. The second motor generator 22 may generate electric power by regenerative braking. The ac power generated by the second motor generator 22 is converted into dc power by the PCU60, and the battery 70 is charged with the dc power. The second motor generator 22 corresponds to a "rotating electric machine" according to the present disclosure.

The planetary gear mechanism 30 is a single pinion planetary gear mechanism, and is disposed on an axis Cnt coaxial with the output shaft 101 of the engine 10. The planetary gear mechanism 30 transmits the torque output from the engine 10 and distributes the torque to the first motor generator 21 and the output gear 31. The planetary gear mechanism 30 includes a sun gear S, a ring gear R, pinion gears P, and a carrier C.

The ring gear R is disposed coaxially with the sun gear S. The pinion P meshes with the sun gear S and the ring gear R. The carrier C holds the pinion gears P so as to be rotatable and revolvable. Each of the engine 10 and the first motor generator 21 is mechanically linked to the drive wheels 50 through the planetary gear mechanism 30. The output shaft 101 of the engine 10 is coupled to the carrier C. The rotor shaft 211 of the first motor generator 21 is coupled to the sun gear S. The ring gear R is linked to the output gear 31.

In the planetary gear mechanism 30, the carrier C serves as an input element, the ring gear R serves as an output element, and the sun gear S serves as a reaction force element. The carrier C receives the torque output from the engine 10. The planetary gear mechanism 30 is configured to transmit torque output from the engine 10 to the output shaft 101 and distribute the torque to the sun gear S (and the first motor generator 21) and the ring gear R (and the output gear 31). The reaction torque generated by the first motor generator 21 acts on the sun gear S. The ring gear R outputs torque to the output gear 31.

The drive device 40 includes a driven gear 41, an intermediate shaft 42, a drive gear 43, and a differential gear 44. The differential gear 44 corresponds to a final reduction gear and has a ring gear 45. The drive device 40 further includes

drive shafts

46 and 47, an oil pump (MOP)48, and an Electric Oil Pump (EOP) 49.

The driven gear 41 meshes with the output gear 31 coupled to the ring gear R of the planetary gear mechanism 30. In addition, the driven gear 41 also meshes with a drive gear 222 attached to the rotor shaft 221 of the second motor generator 22. The intermediate shaft 42 is mounted to the driven gear 41 and is arranged in parallel with the axis Cnt. A drive gear 43 is mounted to the countershaft 42 and meshes with a ring gear 45 of the differential gear 44. In the drive device 40 having the above-described configuration, the driven gear 41 functions to combine the torque output from the second motor generator 22 to the rotor shaft 221 and the torque output from the ring gear R included in the planetary gear mechanism 30 to the output gear 31. The resultant driving torque is transmitted to the driving wheel 50 through the driving

shafts

46 and 47 extending leftward and rightward from the differential gear 44.

The oil pump 48 is, for example, a mechanical oil pump. The oil pump 48 is disposed coaxially with the output shaft 101 of the engine 10, and is driven by the engine 10. The oil pump 48 supplies lubricant to the planetary gear mechanism 30, the first motor generator 21, the second motor generator 22, and the differential gear 44 when the engine 10 is operated.

The electric oil pump 49 is driven by electric power supplied from the battery 70 or another vehicle-mounted battery (e.g., an auxiliary battery), not shown. When the engine 10 is stationary, the electric oil pump 49 supplies lubricant to the planetary gear mechanism 30, the first motor generator 21, the second motor generator 22, and the differential gear 44.

The PCU60 converts the dc power stored in the battery 70 into ac power in accordance with a control signal from the ECU100, and supplies the ac power to the first motor generator 21 and the second motor generator 22. The PCU60 also converts ac power generated by the first motor generator 21 and the second motor generator 22 into dc power and supplies the dc power to the battery 70. The PCU60 includes a first inverter (INV1)61, a second inverter (INV2)62, and a Converter (CONV) 63.

The first inverter 61 converts a direct-current voltage into an alternating-current voltage in accordance with a control signal from the ECU100, and drives the first motor generator 21. The second inverter 62 converts the dc voltage into the ac voltage in accordance with a control signal from the ECU100, and drives the second motor generator 22. The converter 63 boosts the voltage supplied from the battery 70 and supplies the boosted voltage to the first inverter 61 and the second inverter 62 in accordance with a control signal from the ECU 100. The converter 63 also steps down the dc voltage supplied from one or both of the first inverter 61 and the second inverter 62 and charges the battery 70 in accordance with a control signal from the ECU 100.

The battery 70 is configured to include a secondary battery such as a lithium ion secondary battery or a nickel metal hydride battery. Alternatively, a capacitor such as an electric double layer capacitor may be used instead of the battery. Battery 70 corresponds to "power storage device" according to the present disclosure.

The ECU100 is configured to include a Central Processing Unit (CPU), a memory, an input/output port, a counter, and the like, all of which are not shown. The CPU executes the control program. The memory stores various control programs, maps, and the like. The input/output port controls transmission and reception of various signals. The counter measures time. The ECU100 outputs control signals based on signals input from each sensor (described below) and control programs and maps stored in a memory, and controls the respective devices so that the vehicle 1 becomes a desired state.

As main processes executed by the ECU100, "supercharging control" for controlling the supercharging of the supercharger 15 and "closing stuck diagnostic control" for diagnosing whether or not there is a closing stuck in a wastegate valve (WGV) (see fig. 2) included in the supercharger 15 are executed. Details of these controls will be described later.

< Engine Structure >

Fig. 2 is a diagram showing an example of the structure of engine 10. Referring to fig. 2, engine 10 is, for example, an in-line four-cylinder spark-ignition internal combustion engine. The engine 10 includes an engine main body 11. The engine main body 11 includes four cylinders 111 to 114. The four cylinders 111 to 114 are arranged side by side in one direction. Since the structures of the respective cylinders 111 to 114 are the same, the structure of the cylinder 111 will be representatively described below.

The cylinder 111 is provided with two intake valves 121, two exhaust valves 122, an injector 123, and an ignition plug 124. Further, an intake passage 13 and an exhaust passage 14 are connected to the cylinder 111. The intake passage 13 is opened and closed by an intake valve 121. The exhaust passage 14 is opened and closed by an exhaust valve 122. A mixture of air and fuel is generated by adding fuel (e.g., gasoline) to air supplied to the engine main body 11 through the intake passage 13. Fuel is injected into the cylinder 111 through the injector 123, thereby generating an air-fuel mixture in the cylinder 111. Then, the ignition plug 124 ignites the mixture in the cylinder 111. In this manner, the air-fuel mixture is combusted in the cylinder 111. Combustion energy generated when the air-fuel mixture is burned in the cylinder 111 is converted into kinetic energy by a piston (not shown) inside the cylinder 111, and is output to the output shaft 101 (refer to fig. 1).

The engine 10 also includes a turbo supercharger 15. The supercharger 15 is a turbocharger that supercharges intake air using exhaust energy. The supercharger 15 includes a compressor 151, a turbine 152, and a shaft 153.

The supercharger 15 is configured to supercharge intake air (i.e., increase the density of air taken into the engine body 11) by rotating the turbine 152 and the compressor 151 using exhaust energy. More specifically, the compressor 151 is disposed in the intake passage 13, and the turbine 152 is disposed in the exhaust passage 14. The compressor 151 and the turbine 152 are coupled to each other by a shaft 153 and integrally rotate. The turbine 152 is rotated by the exhaust flow discharged from the engine main body 11. The rotational force of the turbine 152 is transmitted to the compressor 151 through the shaft 153 to rotate the compressor 151. The compressor 151 is rotated, so that intake air flowing to the engine body 11 is compressed, and the compressed air is supplied to the engine body 11.

An air flow meter 131 is provided in the intake passage 13 upstream of the compressor 151. An intercooler 132 is provided in the intake passage 13 downstream of the compressor 151. A throttle valve (intake throttle valve) 133 is provided in the intake passage 13 on the downstream side of the intercooler 132. Therefore, the air flowing into the intake passage 13 is supplied to each of the cylinders 111 to 114 of the engine body 11 sequentially through the air flow meter 131, the compressor 151, the intercooler 132, and the throttle valve 133.

An Air Flow Meter (AFM) 131 outputs a signal corresponding to the Flow rate of Air flowing in the intake passage 13. The intercooler 132 cools the intake air compressed by the compressor 151. The throttle valve 133 is configured to be able to adjust the flow rate of intake air flowing in the intake passage 13.

A startup catalytic converter 141 and an aftertreatment device 142 are provided on the downstream side of the turbine 152 in the exhaust passage 14. Further, a WGV device 16 is provided in the exhaust passage 14. The WGV apparatus 16 is configured to allow exhaust gas discharged from the engine main body 11 to flow while bypassing the turbine 152, and to be able to adjust the amount of exhaust gas to be bypassed. The WGV apparatus 16 includes a bypass passage 161, a WGV162, and a WGV actuator 163.

The bypass passage 161 is connected to the exhaust passage 14, and causes exhaust gas to flow bypassing the turbine 152. Specifically, the bypass passage 161 branches from a portion of the exhaust passage 14 on the upstream side of the turbine 152 (for example, between the engine body 11 and the turbine 152), and merges into a portion of the exhaust passage 14 on the downstream side of the turbine 152 (for example, between the turbine 152 and the start-up catalytic converter 141).

The WGV162 is disposed in the bypass passage 161. The WGV162 is configured to be able to adjust the flow rate of the exhaust gas guided from the engine body 11 to the bypass passage 161 according to the opening degree of the WGV 162. The greater the degree to which the WGV162 is closed, the smaller the flow rate of the exhaust gas guided from the engine body 11 to the bypass passage 161, and the greater the flow rate of the exhaust gas flowing into the turbine 152, the higher the pressure of the intake air (i.e., the boost pressure).

The WGV actuator 163 adjusts the opening degree of the WGV162 in accordance with the control of the ECU 100. The WGV actuator 163 may be a negative pressure type actuator that applies a negative pressure to one side of a diaphragm (not shown), or may be an electric actuator that electrically drives the WGV 162.

The exhaust gas discharged from the engine main body 11 passes through any one of the turbine 152 and the WGV 162. Each of the start-up catalytic converter 141 and the aftertreatment device 142 includes, for example, a three-way catalyst, and removes harmful substances in exhaust gas. In more detail, since the start-up catalytic converter 141 is disposed on the upstream side (portion near the combustion chamber) of the exhaust passage 14, the start-up catalytic converter 141 is raised to the activation temperature in a short time after the engine 10 is started. In addition, the aftertreatment device 142 located on the downstream side purifies HC, CO, and NOx that cannot be purified by the startup catalytic converter 141.

< control System Structure >

Fig. 3 is a diagram showing a configuration example of a control system of the vehicle 1 in the present embodiment. Referring to fig. 3, vehicle 1 further includes an accelerator opening degree sensor 801, a turbine rotation speed sensor 802, a boost pressure sensor 803, and a crank angle sensor 804.

The accelerator opening degree sensor 801 detects a depression amount (accelerator opening degree Acc) of an accelerator pedal (not shown) by a user. The turbine speed sensor 802 detects the speed of the turbine 152 of the supercharger 15. The boost pressure sensor 803 is provided on the upstream side of the intercooler 132, and detects the boost pressure of the supercharger 15. The crank angle sensor 804 detects the rotation speed of the crankshaft (i.e., the engine rotation speed Ne) and the rotation angle of the crankshaft (crank angle). Each sensor outputs a signal indicating its detection result to the ECU 110.

The ECU110 cooperatively controls (cooperatively controls) the engine 10, the first motor generator 21, and the second motor generator 22. First, the ECU110 determines a required driving force from the accelerator opening degree and the vehicle speed, and calculates a required power of the engine 10 from the required driving force. The ECU110 determines, for example, an engine operating point (a combination of the engine rotational speed Ne and the engine torque Te) at which the fuel consumption of the engine 10 becomes minimum, so that the system efficiency with respect to the required power of the engine 10 becomes optimal, based on the required power of the engine 10. ECU100 generates signals for driving first motor generator 21 and second motor generator 22, controls PCU60 so that engine 10 operates at an engine operating point, and controls the respective portions of engine 10 (injector 123, spark plug 124, throttle valve 133, WGV actuator 163, supercharger 15, and the like).

The ECU100 may be divided into two or three ECUs (an ECU that controls the engine, an ECU that controls the PCU60, and the like), for example, for each function.

< supercharging control >

Fig. 4 is a diagram for explaining the supercharging control. In fig. 4 and fig. 6 and 8 described later, the horizontal axis represents the engine rotation speed Ne and the vertical axis represents the engine torque Te.

Referring to fig. 4, the engine 10 is normally controlled to move on a recommended action line L in which an engine operation point is set in advance. In the example shown in fig. 4, the recommended operation line L is an optimum fuel consumption line that links the operation points at which the fuel consumption of the vehicle 1 becomes minimum. The recommended operation line L is located below a maximum torque line MAX indicating a maximum torque that can be output by the engine 10.

Further, the engine 10 is controlled to move on the equal power line PL where the engine power Pe is equal to the required engine power. The ECU100 sets the intersection of the recommended operation line L and the equal power line PL as a target operation point (an engine operation point E is shown in fig. 4).

Further, the engine 10 is controlled according to the "supercharge line TL" at which supercharge by the supercharger 15 is started. The region above the pressure increase line TL is a pressure increase region, and the region below the pressure increase line TL is a Natural intake (NA) region.

Fig. 5 is a flowchart showing the processing procedure of the supercharging control. The processing shown in this flowchart is called from a main routine (not shown) and repeatedly executed when the engine 10 is operating and it is not diagnosed that the WGV162 is stuck. The steps (hereinafter, simply referred to as "S") in the flowcharts shown in fig. 5 and fig. 7 and 9 described later are basically realized by software processing performed by the ECU100, but may be realized by hardware processing performed by an electronic circuit built in the ECU 100.

Referring to fig. 4, in S1, ECU100 determines whether the engine operating point is within the supercharging region.

When the engine operating point is within the supercharging region (yes in S1), that is, when the accelerator pedal is depressed or the like so that the engine torque Te exceeds a predetermined level (supercharging line TL shown in fig. 4), the ECU100 advances the process to S2 to request supercharging of the supercharger 15. More specifically, the ECU100 outputs a "WGV close command" to the WGV actuator 163 so that the WGV162 is closed to the first opening degree D1. Thus, if the WGV162 is in a normal operating state, the WGV162 is closed and supercharging is performed.

On the other hand, when the engine operating point is outside the supercharging region (no in S1), that is, when the engine operating point is within the NA region, the ECU100 proceeds to S3 and requests the stop of the supercharging by the supercharger 15. More specifically, the ECU100 outputs a "WGV open command" to the WGV actuator 163 so that the WGV162 is opened to a second opening degree D2 (for example, fully opened) that is larger than the first opening degree D1. Thus, if the WGV162 is in a normal operating state, the WGV162 is opened and the supercharging is stopped. When any of the above-described steps S2 and S3 is executed, the process returns to the main routine.

The first opening degree D1 and the second opening degree D2 are appropriately set in a range where the second opening degree D2 is larger than the first opening degree D1, respectively. The first opening degree D1 and the second opening degree D2 may be fixed values or variable values according to the situation.

< closure sticking diagnostic control >

There is a possibility that the WGV162 may be stuck in a closed state (close stuck). If the closing sticking of the WGV162 occurs, it becomes difficult to obtain a desired output or running driving force from the engine 10. More specifically, the controllability of the engine torque Te is deteriorated due to the continuous supercharging. As a result, each device connected to the engine 10 may be damaged. Therefore, it is preferable to more reliably detect the close sticking of the WGV 162.

Therefore, in the present embodiment, the "close sticking diagnostic control" that is a control of performing the close sticking diagnosis of the WGV162 regardless of the accelerator operation by the user is executed for each trip of the vehicle 1. Here, the "trip" is a period from when the ignition switch of the vehicle 1 is turned ON (IG-ON) to when the ignition switch is turned OFF (IG-OFF). In other words, the stroke is a period from the start to the stop of the electric system of the vehicle 1. Wherein the execution timing of the close sticking diagnostic control does not have to be every trip of the vehicle 1. For example, the execution may be performed once per a predetermined number of (a plurality of) trips, or may be performed once per a predetermined period.

Fig. 6 is a diagram for explaining the closing lock diagnostic control in embodiment 1. Referring to fig. 6, in this example, it is first assumed that the engine operating point E1 of the vehicle 1 is within the NA range. At this time, the WGV162 is controlled to be opened at the second opening degree D2, and the supercharging by the supercharger 15 is stopped.

In the stuck-closed diagnosis control of embodiment 1, the ECU100 controls the engine 10 such that the engine operating point is moved from E1 to E2 along the equal power line PL regardless of the accelerator opening Acc. The engine operating point E2 is in the supercharging region. Therefore, the ECU100 outputs the WGV close command in accordance with the supercharging control described in fig. 4 and 5.

At this time, by monitoring whether or not the supercharging pressure is normally executed in response to the WGV close command, it is possible to diagnose an abnormality of the supercharger WGV 162. To describe in more detail, when the WGV162 is normal, the WGV actuator 163 changes the opening degree of the WGV162 to the first opening degree D1 in response to the WGV close command, thereby normally performing supercharging. On the other hand, when the closing lock of the WGV162 occurs, the opening degree of the WGV162 is not changed (the opening degree is fixed to D2), and therefore the supercharging by the supercharger 15 cannot be normally performed. Therefore, by determining whether or not supercharging is normally performed when the engine operating point is moved into the supercharging region based on the pressure (intake pressure) or volume (intake air amount) of the air drawn into the intake passage 13, it is possible to diagnose whether or not there is a stuck in the WGV 162.

Depending on the traveling mode of the vehicle 1, the supercharging operation of the supercharger 15 may not be performed once during the trip, and for example, the vehicle 1 may not travel at high speed once during the trip of the vehicle 1. In such a case, there is no opportunity to diagnose whether or not there is an unclock in the WGV162 as described above. Therefore, in the present embodiment, the engine operating point is forcibly moved into the supercharging region regardless of the accelerator opening Acc for each stroke of the vehicle 1. Thus, the closing sticking of the WGV162 is diagnosed at least once per stroke of the vehicle 1, so the frequency of diagnosing the closing sticking (the number of diagnoses) can be increased. Therefore, according to the present embodiment, the close sticking of the WGV162 can be detected more reliably.

< control flow >

Fig. 7 is a flowchart showing the processing procedure of the close sticking diagnosis control in embodiment 1. A series of processes shown in this flowchart are repeatedly executed by ECU100 at predetermined control cycles during operation of engine 10.

Referring to fig. 7, in S11, the ECU100 determines whether the closing stuck of the WGV162 is diagnosed in the present trip. Thus, it is confirmed whether the stuck-closed state of the WGV162 has been diagnosed every time the control cycle elapses after the engine 10 is started.

When the close sticking of the WGV162 has been diagnosed (yes in S11), the process returns to the main routine. If the stuck-closed WGV162 is not diagnosed (no in S11), the process proceeds to S12.

In S12, ECU100 determines whether the engine operating point is within the NA region. If the engine operating point is within the NA range (yes in S12), the ECU100 proceeds to S13.

At S13, ECU100 controls engine 10 so that the engine operating point is moved to the high torque side until the engine operating point enters the supercharging region, regardless of accelerator opening Acc detected by accelerator opening sensor 801. Here, as described in fig. 6, it is preferable to move the engine operating point along the equal power line PL. After the engine operating point moves into the supercharging region, this state is maintained for at least the time (for example, several seconds) required for the WGV diagnosis in step S14 described below.

If the engine operating point is not within the NA range (no in S12), that is, if the engine operating point is already within the supercharging region, the process of S13 is skipped and the process proceeds to S14. In this case, it can be diagnosed that the WGV162 is stuck with an irrelevant lock as usual.

In S14, the ECU100 determines whether or not the WGV162 is stuck in a closed state based on whether or not the WGV162 is operating in accordance with the WGV close command output to the WGV actuator 163 (WGV diagnosis). In this embodiment, the ECU100 determines whether or not the WGV162 has operated in accordance with the WGV close command based on a change in the boost pressure (the detection value of the boost pressure sensor 803). More specifically, a range (normal range) of values in which the boost pressure can be obtained when the WGV162 is normal is obtained in advance for each first opening degree D1, and is stored in the memory of the ECU100 as a map, for example. The ECU100 reads the normal range corresponding to the first opening degree D1 indicated by the WGV close command by referring to this map. Then, it is determined whether the supercharge pressure detected by the supercharge pressure sensor 803 is within a normal range.

The ECU100 may also determine whether or not the WGV162 has operated in accordance with the WGV close command by comparing the boost pressure with the atmospheric pressure (a detection value of an atmospheric pressure sensor (not shown)). Instead of or in addition to the boost pressure, the ECU100 may determine whether or not the WGV162 has operated in accordance with the WGV close command based on a change in the intake air amount (detected value of the airflow meter 131).

In the case where the boost pressure is outside the normal range (yes in S15), although the ECU100 requests the execution of the boost, the boost pressure does not rise into the normal range. In this case, the ECU100 advances the process to step S16. Then, the ECU100 determines that the WGV162 is not operating as instructed, and diagnoses that the closing jam of the WGV162 has occurred. Then, the ECU100 can notify the user (driver) of the vehicle 1 that the abnormality of the WGV162 has occurred and record the fact that the closing of the WGV162 has been stuck in the diagnosis (S17).

On the other hand, when the boost pressure is within the normal range (yes in S15), the ECU100 proceeds the process to S16, and diagnoses that the close sticking of the WGV162 has not occurred. When the processing of S17 or S18 ends, the processing returns to the main routine.

As described above, in the present embodiment, the ECU100 actively moves the engine operating point into the supercharging region before a long time elapses after the engine 10 is started. Thereby, at least one time per trip of the vehicle 1, a condition is created that enables diagnosing the stuck-closed state of the WGV 162. As a result, the frequency of diagnosing the close sticking of the WGV162 increases, and therefore, the possibility that diagnosis is missed because there is no diagnosis opportunity even though the close sticking of the WGV162 actually occurs can be reduced. Therefore, according to the present embodiment, the close sticking of the WGV162 can be detected more reliably.

In the present embodiment, the engine operating point is moved from the NA region to the supercharging region along the equal power line PL, but the diagnosis of the stuck-closed state is not necessarily performed along the equal power line PL. However, by following the equal power line PL, the output fluctuation of the vehicle 1 accompanying the diagnosis can be suppressed. When the required power of the vehicle 1 varies while the engine power Pe is constant, the excess or deficiency of the engine power Pe is compensated by the above-described cooperative control. That is, the required electric power is supplied from the battery 70 to the second motor generator 22, or the excessive electric power is regenerated from the second motor generator 22 to the battery 70, whereby the output variation of the vehicle 1 can be suppressed.

[ embodiment 2]

In embodiment 2, a configuration for diagnosing whether or not the WGV162 has caused "open jam" in a stuck open state will be described. The configuration of the hybrid vehicle according to embodiment 2 is basically the same as the configuration of the vehicle 1 according to embodiment 1 (see fig. 1 to 3), and therefore, description thereof will not be repeated.

Fig. 8 is a diagram for explaining the open jam diagnostic control in embodiment 2. In the example shown in fig. 8, first, the engine operating point E1 of the vehicle 1 is in the supercharging region. At this time, the supercharger 15 is supercharging.

In embodiment 2, the ECU100 moves the engine operating point from E1 to E2 along the equal power line PL regardless of the accelerator opening Acc. The engine operating point E2 is in the NA region. The ECU100 outputs a WGV open command in accordance with the supercharging control.

In a case where the WGV162 is normal, the WGV actuator 163 changes the opening degree of the WGV162 to the second opening degree D2 in response to the WGV opening instruction, whereby the supercharging is stopped. On the other hand, when the WGV162 is stuck open, the opening degree of the WGV162 is not changed, and the supercharging pressure of the supercharger 15 is not normally stopped. Therefore, the presence or absence of the open sticking in the WGV162 is diagnosed by determining whether the supercharging is stopped when the engine operating point is moved into the NA region based on the intake pressure or the intake air amount in the intake passage 13.

Fig. 9 is a flowchart showing the processing procedure of the open jam diagnostic control in embodiment 2. Referring to fig. 9, in S21, the ECU100 determines whether or not the open sticking of the WGV162 has been diagnosed in the present stroke.

When the open sticking of the WGV162 has been diagnosed (yes in S21), the process returns to the main routine. In the case where the open sticking of the WGV162 is not diagnosed (no in S21), the process proceeds to S22.

In S22, the ECU100 determines whether the engine operating point is within the supercharging region. If the engine operating point is within the supercharging region (yes at S22), the ECU100 proceeds to S23.

At S23, ECU100 controls engine 10 so that the engine operating point is shifted to the low torque side until the engine operating point enters the natural intake air region, regardless of accelerator opening Acc. In this case, it is also preferable to move the engine operating point along the equal power line PL.

In S24, the ECU100 determines whether or not the WGV162 is stuck open based on whether or not the WGV162 is operating in accordance with the WGV open command output to the WGV actuator 163 (WGV diagnosis). In the case where the supercharging pressure detected by the supercharging pressure sensor 803 is outside the normal range (which may be different from that in embodiment 1) (yes in S25), although the ECU100 requests the supercharging to be stopped, the supercharging pressure does not fall within the normal range. In this case, the ECU100 advances the process to step S26. Then, the ECU100 determines that the WGV162 is not operating as instructed, and diagnoses that the opening jam of the WGV162 has occurred. Then, the ECU100 notifies the user of the vehicle 1 that an abnormality of the WGV162 has occurred, and records the fact that the opening jam of the WGV162 has occurred in the diagnosis (S27).

On the other hand, when the boost pressure is within the normal range (yes in S25), the ECU100 proceeds the process to S26, and diagnoses that open sticking of the WGV162 has not occurred. When the processing of S27 or S28 ends, the processing returns to the main routine.

As described above, in embodiment 2, the ECU100 moves the engine operating point into the supercharging region at least once for each stroke of the vehicle 1, thereby creating a situation in which the open sticking of the WGV162 can be diagnosed. This increases the frequency of diagnosing the open jam of the WGV162, and therefore, the possibility of missed diagnosis that causes the open jam of the WGV162 can be reduced, and the open jam of the WGV162 can be detected more reliably.

In embodiments 1 and 2, an example in which the supercharger 15 is a turbo supercharger that supercharges using exhaust energy is described. However, the supercharger 15 may be a type that drives a compressor by using the rotation of the engine 10.

While the embodiments of the present invention have been described, the embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. A hybrid vehicle is provided with:

an engine with a supercharger;

an electrical storage device;

a rotating electric machine configured to be capable of receiving and supplying electric power to and from the power storage device; and

a control device configured to control the engine and the rotating electric machine,

the engine includes:

an exhaust passage from the engine main body;

a bypass passage connected to the exhaust passage and configured to allow exhaust gas to flow while bypassing the supercharger; and

a wastegate valve provided in the bypass passage and configured to adjust a flow rate of exhaust gas guided from the engine body to the bypass passage,

the control device controls the engine such that an operating point of the engine is moved from a natural intake region to a supercharging region regardless of an accelerator opening degree of the hybrid vehicle during operation of the engine, and diagnoses whether or not the wastegate valve is stuck in a closed state.

2. The hybrid vehicle according to claim 1, wherein,

the hybrid vehicle further includes at least one of a supercharging pressure sensor that is provided in an intake path leading to the engine main body and detects supercharging pressure at which the supercharger supercharges the intake path, and an intake air amount sensor that is provided in the intake path and detects an intake air amount entering the intake path,

the control device diagnoses whether the wastegate valve is stuck in the closed state based on a boost pressure of the intake path or an intake air amount.

3. The hybrid vehicle according to claim 1 or 2, wherein,

the control device controls the engine so that the operating point moves from the natural intake region to the supercharging region along an equal-power line, and when the power of the engine is excessive or insufficient with respect to the required power of the hybrid vehicle, the control device compensates for the excess or deficiency by receiving and supplying electric power between the power storage device and the rotating electric machine.

4. A hybrid vehicle is provided with:

an engine with a supercharger;

an electrical storage device;

the engine further includes:

an exhaust passage from the engine main body;

the control device controls the engine such that an operating point of the engine is moved from a supercharging region to a natural intake region regardless of an accelerator opening degree of the hybrid vehicle during operation of the engine, and diagnoses whether or not the wastegate valve is stuck open.

5. An abnormality diagnosis method for a hybrid vehicle, the hybrid vehicle including: an engine with a supercharger, and a rotating electrical machine configured to be capable of receiving and supplying electric power to and from an electric storage device,

the engine includes:

an exhaust passage from the engine main body;

the abnormality diagnostic method of a hybrid vehicle includes the steps of:

controlling the engine in such a manner that an operating point of the engine is moved from a natural intake region to a supercharging region regardless of an accelerator opening degree of the hybrid vehicle during operation of the engine; and

diagnosing whether the wastegate valve is stuck in a closed state while maintaining an operating point of the engine in the supercharging region.