Hybrid vehicle diagnostic equipment

Abstract

To enable early execution of engine diagnosis.SOLUTION: In the state that an engine 21 is connected to a first motor 22 and is disconnected from a front wheel 10, the engine 21 is load-operated in such a manner that a load is added thereto by the first motor 22 while traveling with a driving force generated by a second motor 31, whereby diagnosis of the engine 21, that is executed during load operation, is performed.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a diagnostic device for a hybrid vehicle. [Background technology]

[0002] There are vehicle diagnostic devices that perform engine diagnosis. Some engine diagnostic items are desirably performed during stable operation during idling. On the other hand, there are vehicles that automatically stop the engine in situations where the engine would normally be idling, such as when the vehicle is stopped, in order to improve emissions and reduce fuel consumption. In such vehicles that automatically stop the engine, idling is not performed frequently, so there are limited opportunities to perform diagnosis during idling.

[0003] In contrast, the vehicle diagnostic device described in Patent Document 1 prohibits the automatic engine shutdown if there is an incomplete diagnosis when the automatic shutdown condition is met. The diagnostic device then performs idling instead of automatic shutdown, thereby ensuring an opportunity to perform a diagnosis during idling. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-151041 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, some engine diagnostic items are desired to be performed under specific operating conditions during load operation. However, since the operating state of the engine changes successively depending on the vehicle's running conditions, opportunities to obtain an operating state suitable for diagnosis are limited. In particular, in a hybrid vehicle capable of electric running using a motor, the engine may be stopped even while the vehicle is running, so opportunities to perform engine diagnosis during load operation are further limited. [Means for solving the problem]

[0006] A diagnostic device for a hybrid vehicle that solves the above problems is applied to a hybrid vehicle having an engine that generates driving force by burning fuel, a first motor that receives external power and generates electricity, a second motor that generates driving force in response to power supply, a chargeable and dischargeable battery, a first clutch and a second clutch that connect and disconnect power transmission, and in which the first clutch, the first motor, and the second clutch are arranged in this order from the engine side in a transmission path of driving force from the engine to the wheels. The diagnostic device performs a load operation diagnostic process that diagnoses the engine when a predetermined execution condition is satisfied during load operation of the engine, and an early execution process of load operation diagnosis that performs load operation of the engine so as to satisfy the execution condition of the load operation diagnostic process while running with the first clutch engaged and the second clutch released by running with the driving force generated by the second motor and applying a load by the first motor.

[0007] When the diagnostic device performs the early execution process of the load operation diagnosis, the engine and the first motor are connected to each other and are separated from the wheels. Then, the hybrid vehicle runs by the driving force generated by the second motor. In this state, the load applied to the engine can be adjusted by changing the regenerative torque of the first motor. Then, the engine and the first motor are separated from the wheels. Therefore, at this time, the engine can be in any operating state regardless of the running condition of the hybrid vehicle. In the diagnostic device, the engine is operated under load by the early execution process of the load operation diagnosis so as to satisfy the execution condition of the load operation diagnosis process. Therefore, when the early execution process of the load operation diagnosis process is executed, the load operation diagnosis process can be executed regardless of the running condition of the hybrid vehicle. Therefore, the diagnostic device for the hybrid vehicle enables early execution of the engine diagnosis during the load operation.

[0008] In the above-mentioned early execution process during load operation, a load is applied to the engine by the regenerative operation of the first motor. At this time, if the battery is fully charged or close to being fully charged, the power generated by the first motor through the regenerative operation cannot be recovered by the battery. Therefore, it is desirable to execute the early execution process of the load operation diagnosis in the above-mentioned diagnostic device on the condition that the battery has a certain amount of charge remaining.

[0009] When the battery charge level is low, it may be necessary to operate the first motor in a regenerative manner using the engine to charge the battery. On the other hand, in the early implementation process of the on-load diagnosis, the first motor generates power, but the second motor consumes power, which may result in a decrease in the battery charge level. Therefore, it is desirable to execute the early implementation process of the on-load diagnosis in the above-mentioned diagnostic device on the condition that the engine is not required to be driven to charge the battery.

[0010] There is a limit to the driving force that the second motor can generate. Therefore, the driving force generated by the second motor alone may not be enough to satisfy the driving force required by the driver. Therefore, it is desirable to execute the early execution process of the load operation diagnosis in the above-mentioned diagnostic device on the condition that the maximum value of the driving force that the second motor can generate is greater than the driving force required by the driver.

[0011] The above-mentioned diagnostic device for a hybrid vehicle may be further configured to perform an idle operation diagnostic process for diagnosing the engine on condition that the engine is idling, and an early idle operation diagnostic process for idling the engine while running with the driving force generated by one or both of the first and second motors by releasing the first clutch and engaging the second clutch. When the early idle operation diagnostic process is performed, the first motor is connected to the wheels, but the engine is disconnected from the wheels. At this time, the hybrid vehicle can run with the driving force generated by one or both of the first and second motors. Meanwhile, since the engine at this time is disconnected from the wheels, the hybrid vehicle can run in idle regardless of the running condition. Therefore, by performing the early idle operation diagnostic process, the idle operation diagnostic process can be performed regardless of the running condition of the hybrid vehicle. It is preferable that such early idle operation diagnostic process is performed on the condition that the engine is not required to be driven for charging the battery. In addition, it is desirable that the early implementation process of the idle operation diagnosis be performed on the condition that the maximum value of the driving force that the first motor and the second motor can generate is greater than the driving force requested by the driver. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a schematic configuration of a drive system of a hybrid vehicle to which an embodiment of a diagnosis device is applied; [Diagram 2] FIG. 1 is a diagram illustrating a schematic configuration of an embodiment of a diagnostic device. [Diagram 3] 2 is a diagram showing a state of the drive system of the hybrid vehicle in FIG. 1 in a hybrid driving mode. [Figure 4] 2 is a diagram showing a state in an electric driving mode in a drive system of the hybrid vehicle in FIG. 1. [Diagram 5] 3 is a flowchart of a forced execution routine for a load operation diagnosis executed by the diagnostic device of FIG. 2. [Figure 6]3 is a flowchart of a forced execution routine of an idle operation diagnosis executed by the diagnosis device of FIG. 2. [Figure 7] 4 is a diagram showing a state during forced execution of a load operation diagnosis in the drive system of the hybrid vehicle of FIG. 1. FIG. [Figure 8] 2 is a diagram showing a state during forced execution of an idle driving diagnosis in the drive system of the hybrid vehicle of FIG. 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of a diagnostic device for a hybrid vehicle will be described in detail with reference to FIGS. <Configuration of hybrid vehicle drive system> First, the configuration of a drive system of a hybrid vehicle to which the diagnosis device of this embodiment is applied will be described with reference to Fig. 1. The hybrid vehicle has four wheels: left and right front wheels 10 and left and right rear wheels 11. The hybrid vehicle is equipped with two power units: a first power unit 20 that drives the left and right front wheels 10, and a second power unit 30 that drives the left and right rear wheels 11. The hybrid vehicle is also equipped with a chargeable and dischargeable battery 12.

[0014] The first power unit 20 is connected to the left and right front wheels 10 via a transmission 25. The first power unit 20 has two drive sources: an engine 21 that generates drive force by burning fuel, and a first motor 22 that generates drive force in response to power supplied from the battery 12 and generates electricity by receiving power from an external source. The first motor 22 is electrically connected to the battery 12 via a first inverter 13. The first power unit 20 is provided with two clutches that connect and disconnect power transmission, that is, a first clutch 23 and a second clutch 24. The engine 21 is connected to the first motor 22 via the first clutch 23. The first motor 22 is connected to the transmission 25 via the second clutch 24. That is, the first clutch 23, the first motor 22, and the second clutch 24 are arranged in this order from the engine 21 side in the transmission path of the drive force from the engine 21 to the front wheels 10.

[0015] On the other hand, the second power unit 30 includes a second motor 31 as a drive source that generates drive force in response to power supply from the battery 12 and generates power by receiving power from an external source. The second motor 31 is directly connected to the left and right rear wheels 11. The second motor 31 is also electrically connected to the battery 12 via a second inverter 14.

[0016] <Diagnostic device configuration> Next, the configuration of the diagnostic device for a hybrid vehicle will be described with reference to FIG. The hybrid vehicle is equipped with an electronic control unit 40 for vehicle control. The electronic control unit 40 includes an arithmetic processing device 41 and a storage device 42. The storage device 42 stores programs and data for vehicle control. The electronic control unit 40 controls the vehicle by having the arithmetic processing device 41 read and execute the programs from the storage device 42. The electronic control unit 40 also diagnoses the hybrid vehicle as part of the vehicle control. In this embodiment, the electronic control unit 40 constitutes a diagnostic device for the hybrid vehicle.

[0017] The electronic control unit 40 receives detection signals from various sensors. These sensors include an accelerator pedal sensor 43, a vehicle speed sensor 44, an air flow meter 45, a crank angle sensor 46, an exhaust sensor 47, and a fuel pressure sensor 48. The accelerator pedal sensor 43 detects the amount of accelerator pedal operation by the driver. The vehicle speed sensor 44 detects the vehicle speed, which is the traveling speed of the hybrid vehicle. The air flow meter 45 detects the amount of intake air of the engine 21. The crank angle sensor 46 detects the rotation phase of the crankshaft, which is the output shaft of the engine 21. The exhaust sensor 47 is a sensor such as an air-fuel ratio sensor, an oxygen sensor, and a NOx sensor that detects the exhaust properties of the engine 21. The fuel pressure sensor 48 detects the fuel supply pressure of the engine 21. In addition, a signal indicating the charge amount of the battery 12 is input to the electronic control unit 40.

[0018] The electronic control unit 40 controls the hybrid vehicle by controlling the engine 21, the first motor 22, the second motor 31, the transmission 25, the first clutch 23, and the second clutch 24 based on the detection results of these sensors. The engine 21 is provided with a throttle valve 26 for adjusting the amount of intake air, an injector 27 for injecting fuel, and an ignition device 28 for igniting the fuel. The electronic control unit 40 controls the operating state of the engine 21 by controlling the opening of the throttle valve 26, the amount and timing of fuel injection by the injector 27, and the ignition timing of the ignition device 28. The electronic control unit 40 also controls the power transmission / reception between the battery 12 through the first inverter 13 and the second inverter 14, thereby controlling the power running / regenerative torque of the first motor 22 and the second motor 31. The electronic control unit 40 also controls the gear stage of the transmission 25, and the open / closed states of the first clutch 23 and the second clutch 24.

[0019] <Switching driving modes> The electronic control unit 40 switches the driving mode of the hybrid vehicle according to the driving conditions and the state of charge of the battery 12. During normal driving, the electronic control unit 40 uses two driving modes: a hybrid driving mode and an electric driving mode.

[0020] 3 shows the state of the drive system of the hybrid vehicle in the hybrid driving mode. When driving in the hybrid driving mode, the electronic control unit 40 engages both the first clutch 23 and the second clutch 24 to connect the engine 21 to the front wheels 10. Then, the electronic control unit 40 drives the hybrid vehicle with the engine 21 operating.

[0021] 4 shows the state of the drive system of the hybrid vehicle in the electric driving mode. When driving in the hybrid driving mode, the electronic control unit 40 disengages the first clutch 23 and engages the second clutch 24. As a result, the electronic control unit 40 keeps the first motor 22 connected to the front wheels 10, but keeps the engine 21 disconnected from the front wheels 10. The electronic control unit 40 generates driving force by powering at least one of the first motor 22 and the second motor 31.

[0022] <Engine 21 diagnostic process> The electronic control unit 40 diagnoses the sensors and systems of the engine 21. An individual execution condition is set for each diagnostic item of the engine 21. In the following description, a diagnosis in which an execution condition is set so that a diagnosis is performed during load operation of the engine 21 is referred to as a load operation diagnosis. Also, a diagnosis in which an execution condition is set so that a diagnosis is performed during idling operation of the engine 21 is referred to as an idle operation diagnosis. Furthermore, a process of the electronic control unit 40 for performing a load operation diagnosis is referred to as a load operation diagnosis process, and a process of the electronic control unit 40 for performing an idle operation diagnosis is referred to as an idle operation diagnosis process. The load operation diagnosis includes diagnosis of the exhaust sensor 47, the fuel pressure sensor 48, the exhaust purification catalyst, the catalyst warm-up system, the fuel vapor processing system, the exhaust gas recirculation system, the fuel supply system, and the variable valve system. On the other hand, the idle operation diagnosis includes diagnosis of an idle speed control (ISC) system.

[0023] Such a diagnosis is executed when the engine 21 is in an operating state that satisfies the execution conditions. On the other hand, when the vehicle is normally controlled, the operating state of the engine 21 is determined by the course of events. Therefore, depending on the situation, the execution conditions may not be satisfied for a long time after the hybrid vehicle starts running. In response to this, the electronic control unit 40 executes early execution processing of the load operation diagnosis to enable early execution of the load operation diagnosis. Furthermore, the electronic control unit 40 executes early execution processing of the idle operation diagnosis to enable early execution of the idle operation diagnosis.

[0024] <Early diagnosis during load operation> 5 shows a flowchart of the process executed by the electronic control unit 40 for early implementation of the load operation diagnosis. The electronic control unit 40 repeatedly executes the process of the flowchart in FIG. 5 at every predetermined control period while the hybrid vehicle is running.

[0025] 5, the electronic control unit 40 first determines in step S100 whether or not the load operation diagnosis has been completed after the hybrid vehicle started traveling this time. If the load operation diagnosis has already been completed (YES), the electronic control unit 40 ends the current process, and if it has not been completed (NO), the electronic control unit 40 proceeds to step S110.

[0026] When the process proceeds to step S110, the electronic control unit 40 determines in step S110 whether or not charging drive of the engine 21 is requested. If charging drive is requested (YES), the electronic control unit 40 ends the current process, and if charging drive is not requested (NO), the electronic control unit 40 proceeds to step S120. The charging drive of the engine 21 is the drive of the engine 21 for regenerative operation of the first motor 22. Such charging drive of the engine 21 is requested when the charge amount of the battery 12 falls below a certain amount.

[0027] When the process proceeds to step S120, the electronic control unit 40 determines whether or not there is a driver drive request for the engine 21. If there is a driver drive request (YES), the electronic control unit 40 ends the current process, and if there is no driver drive request (NO), the electronic control unit 40 proceeds to step S130. The presence or absence of a driver drive request indicates whether or not the engine 21 needs to be driven to ensure the driving force requested by the driver through depression of the accelerator pedal. Here, it is determined that there is a driver drive request when the maximum value of the driving force that the second motor 31 can generate is greater than the driving force requested by the driver.

[0028] When the process proceeds to step S130, the electronic control unit 40 determines in step S130 whether the battery 12 has a certain amount of charge remaining capacity or more. If the electronic control unit 40 determines that the battery 12 does not have a certain amount of charge remaining capacity (NO), it ends the current process as is, and if the electronic control unit 40 determines that the battery 12 does not have a certain amount of charge remaining capacity (YES), it proceeds to step S140. Note that here, the difference between the current charge amount and the full charge amount of the battery 12 is set as the charge remaining capacity of the battery 12. If the difference is equal to or greater than a certain value, the electronic control unit 40 determines that the battery 12 has a certain amount of charge remaining capacity or more.

[0029] When the process proceeds to step S140, the electronic control unit 40 engages the first clutch 23 in step S140. The electronic control unit 40 also releases the second clutch 24 in the following step S150. As a result, the engine 21 and the first motor 22 are connected to each other and are disconnected from the front wheels 10. Then, in the next step S160, the electronic control unit 40 starts electric running of the hybrid vehicle using the driving force generated by the second motor 31. Furthermore, in the following step S170, the electronic control unit 40 starts a loaded operation of the engine 21. That is, at this time, the electronic control unit 40 operates the engine 21 under a loaded state by performing a regenerative operation of the first motor 22. Then, in step S180, the electronic control unit 40 controls the engine 21 and the first motor 22 so as to satisfy the execution condition of the diagnosis, and then executes the loaded operation diagnosis process, and ends the process of FIG. 5.

[0030] <Early implementation of diagnosis during idling> A processing procedure for early implementation processing of the idle driving diagnosis is shown in Fig. 6. The electronic control unit 40 repeatedly executes the processing of Fig. 6 at every predetermined control period while the hybrid vehicle is running.

[0031] 6, the electronic control unit 40 first determines in step S200 whether or not the idle driving diagnosis has been completed after the hybrid vehicle started traveling this time. If the idle driving diagnosis has already been completed (YES), the electronic control unit 40 ends the current process, and if it has not been completed (NO), the electronic control unit 40 proceeds to step S210.

[0032] When the process proceeds to step S210, the electronic control unit 40 determines in step S210 whether or not charging drive of the engine 21 is requested. If charging drive is requested (YES), the electronic control unit 40 ends the current process, and if not (NO), the process proceeds to step S220. The electronic control unit 40 determines whether or not there is a driver drive request for the engine 21. If there is a driver drive request (YES), the electronic control unit 40 ends the current process, and if there is no driver drive request (NO), the process proceeds to step S230. In step S230, if the maximum value of the drive force that the first motor 22 and the second motor 31 can generate is greater than the drive force requested by the driver, it is determined that there is a driver drive request.

[0033] When the process proceeds to step S230, the electronic control unit 40 disengages the first clutch 23 in step S230. Furthermore, the electronic control unit 40 engages the second clutch 24 in the following step S240. As a result, the first power unit 20 is in a state in which the engine 21 is disconnected from the front wheels 10 and the first motor 22 is connected to the front wheels 10. Then, in the next step S250, the electronic control unit 40 starts electric traveling by the first motor 22 and the second motor 31. Furthermore, in step S260, the electronic control unit 40 starts idling operation of the engine 21. Then, in step S270, the electronic control unit 40 executes idling operation diagnosis processing, and then ends the processing of FIG. 6.

[0034] In this embodiment, steps S140 to S170 in Fig. 5 correspond to the early implementation processing of the load operation diagnosis. Also, in this embodiment, steps S230 to S260 in Fig. 6 correspond to the early implementation processing of the idle operation diagnosis.

[0035] <Effects of the embodiment> The operation and effects of the present embodiment configured as above will be described. When the load driving diagnosis is incomplete, the electronic control unit 40 executes early execution processing of the load driving diagnosis in the following manner. That is, in this case, the electronic control unit 40 engages the first clutch 23 and releases the second clutch 24, thereby connecting the engine 21 and the first motor 22 to each other and disconnecting them from the front wheels 10. Then, the electronic control unit 40 applies a load to the engine 21 by the first motor 22 while driving the rear wheels 11 by the second motor 31 to perform electric running of the hybrid vehicle.

[0036] 7 shows the state of the drive system of the hybrid vehicle at this time. As shown in the figure, the engine 21 and the first motor 22 are disconnected from the front wheels 10 at this time. In addition, since the engine 21 and the first motor 22 are connected to each other at this time, the load of the engine 21 changes due to the regenerative torque of the first motor 22. Therefore, at this time, the operating state of the engine 21 can be arbitrarily changed by controlling the output of the engine 21 and the regenerative torque of the first motor 22. Therefore, the electronic control unit 40 controls the engine 21 to an operating state that satisfies the execution condition and executes the load operation diagnostic process.

[0037] If the battery 12 is fully charged or nearly fully charged at this time, the power generated by the regenerative operation of the first motor 22 cannot be charged into the battery 12. Therefore, the electronic control unit 40 executes the early implementation process of the load operation diagnosis in the above-mentioned manner only when the battery 12 has a sufficient charge capacity.

[0038] On the other hand, if the idle driving diagnosis is incomplete, the electronic control unit 40 executes early implementation processing of the idle driving diagnosis in the following manner. That is, in this case, the electronic control unit 40 releases the first clutch 23 and engages the second clutch 24 to disconnect the engine 21 from the front wheels 10 while keeping the first motor 22 connected to the front wheels 10. Then, the electronic control unit 40 executes the idle driving diagnosis processing with the engine 21 idling while driving the hybrid vehicle electrically using at least one of the first motor 22 and the second motor 31.

[0039] FIG. 8 shows the state of the drive system of the hybrid vehicle at this time. As shown in the figure, the engine 21 at this time is in an unloaded state, that is, not connected to an external load. The electronic control unit 40 idles the engine 21 in this state and executes the idle operation diagnostic process. Note that the first motor 22 at this time is connected to the front wheels 10, and the second motor 31 is connected to the rear wheels 11. Therefore, the hybrid vehicle can be driven electrically by driving the front wheels 10 by the first motor 22, driving the rear wheels 11 by the second motor 31, or both of them.

[0040] According to the hybrid vehicle diagnosis device of the present embodiment described above, the following effects can be achieved. (1) When the load driving diagnostic process is incomplete, the electronic control unit 40 executes the following early execution process of the load driving diagnosis. That is, in the early execution process of the load driving diagnosis, the electronic control unit 40 engages the first clutch 23 and releases the second clutch 24 to run the hybrid vehicle with the driving force generated by the second motor 31. Then, with a load applied by the first motor 22, the electronic control unit 40 performs the load operation of the engine 21 so as to satisfy the execution condition of the load driving diagnostic process. This makes it possible to execute the load driving diagnostic process regardless of the driving condition of the hybrid vehicle. Therefore, the diagnostic device for a hybrid vehicle of this embodiment enables the early execution of the load driving diagnosis.

[0041] (2) In the early implementation process during load operation, a load is applied to the engine 21 by the regenerative operation of the first motor 22. Therefore, if the early implementation process during load operation is executed when the battery 12 is fully charged or close to being fully charged, there is a risk that the battery 12 will be overcharged. In this regard, in this embodiment, the early implementation process of the diagnosis during load operation is executed on the condition that the battery 12 has a certain amount of charge remaining. Therefore, overcharging of the battery 12 is less likely to occur.

[0042] (3) In the early implementation process of the load operation diagnosis, the first motor 22 generates power, but the second motor 31 consumes power, which may reduce the charge level of the battery 12. In this regard, the electronic control unit 40 executes the early implementation process of the load operation diagnosis on the condition that the engine 21 is not required to be driven in order to charge the battery 12. Therefore, the battery 12 is less likely to become insufficiently charged due to the execution of the early implementation process of the load operation diagnosis.

[0043] (4) The electronic control unit 40 executes the early execution process of the load operation diagnosis on the condition that the maximum value of the driving force that the second motor 31 can generate is greater than the driving force required by the driver. Therefore, by executing the early execution process of the load operation diagnosis, it is possible to prevent the hybrid vehicle from having insufficient driving force and thus preventing the drivability from deteriorating.

[0044] (5) When the idle driving diagnosis process is incomplete, the electronic control unit 40 executes the following early idle driving diagnosis process. That is, in the early idle driving diagnosis process, the electronic control unit 40 releases the first clutch 23 and engages the second clutch 24. Then, the electronic control unit 40 performs the idle operation of the engine 21 while running with the driving force generated by one or both of the first motor 22 and the second motor 31. This makes it possible to execute the idle driving diagnosis process regardless of the running condition of the hybrid vehicle. Therefore, the hybrid vehicle diagnosis device of this embodiment enables early execution of the idle driving diagnosis.

[0045] (6) The electronic control unit 40 executes the early implementation process of the idle operation diagnosis on the condition that the operation of the engine 21 is not required to charge the battery 12. Therefore, the battery 12 is less likely to be insufficiently charged due to the execution of the early implementation process of the idle operation diagnosis.

[0046] (7) The electronic control unit 40 executes the early implementation process of the idle driving diagnosis on the condition that the maximum value of the driving force that the first motor 22 and the second motor 31 can generate is greater than the driving force required by the driver. Therefore, by executing the early implementation process of the idle driving diagnosis, it is possible to prevent the hybrid vehicle from having insufficient driving force and thus preventing the drivability from deteriorating.

[0047] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction. The execution conditions for the early execution process of the load operation diagnosis / idle operation diagnosis may be changed as appropriate.

[0048] The diagnostic device may be configured to execute only the early execution process of the load operation diagnosis without executing the early execution process of the idle operation diagnosis. In the load operation diagnostic process, a plurality of load operation diagnoses may be executed simultaneously or sequentially. Similarly, in the idle operation diagnostic process, a plurality of idle operation diagnoses may be executed simultaneously or sequentially.

[0049] The first motor 22 and the second motor 31 in the above embodiment function as an electric motor that generates driving force in response to power supply, and function as a generator that generates electricity by receiving external power. If electric running using the driving force of the first motor 22 is not performed, a rotating electric machine dedicated to regenerative driving that does not function as an electric motor may be used as the first motor 22. Also, if regenerative power generation is not performed by the second motor 31, a rotating electric machine dedicated to power running that does not function as a generator may be used as the second motor 31.

[0050] The diagnostic device of this embodiment can also be applied to a hybrid vehicle in which the first power unit 20 and the second power unit 30 are configured to drive the same wheels. [Explanation of symbols]

[0051] 10…Front wheel 11…Rear wheel 12…Battery 13…First inverter 14…Second inverter 20...Front wheel power unit 21…Engine 22…First motor 23…First clutch 24…Second clutch 25…Gearbox 26…Throttle valve 27…Injector 28…Ignition device 30…Rear wheel power unit 31…Second motor 40...Electronic control unit 41... Processing unit 42...Storage device 43...Accelerator pedal sensor 44...Vehicle speed sensor 45…Air flow meter 46...Crank angle sensor 47...Exhaust sensor 48...Fuel pressure sensor

Claims

1. A diagnostic device for a hybrid vehicle having an engine that generates driving force by burning fuel, a first motor that receives power from an external source to generate power, a second motor that generates power in response to power supply, a chargeable and dischargeable battery, and a first clutch and a second clutch that connect and disconnect power transmission, the first clutch, the first motor, and the second clutch being arranged in this order from the engine side in a driving force transmission path from the engine to wheels, a load operation diagnostic process for diagnosing the engine when a predetermined execution condition is satisfied during a load operation of the engine; an early implementation process of a load operation diagnosis in which the first clutch is engaged, the second clutch is released, and the vehicle travels with a driving force generated by the second motor while a load is applied by the first motor, and the engine is operated under load so as to satisfy an execution condition of the load operation diagnosis process; Do the following: A diagnostic device for a hybrid vehicle that executes the early implementation process of the load operation diagnosis on condition that the engine is not required to be driven in order to charge the battery.

2. A diagnostic device for a hybrid vehicle having an engine that generates driving force by burning fuel, a first motor that receives power from an external source to generate power, a second motor that generates power in response to power supply, a chargeable and dischargeable battery, and a first clutch and a second clutch that connect and disconnect power transmission, the first clutch, the first motor, and the second clutch being arranged in this order from the engine side in a driving force transmission path from the engine to wheels, a load operation diagnostic process for diagnosing the engine when a predetermined execution condition is satisfied during a load operation of the engine; an early implementation process of a load operation diagnosis in which the first clutch is engaged, the second clutch is released, and the vehicle travels with a driving force generated by the second motor while a load is applied by the first motor, and the engine is operated under load so as to satisfy an execution condition of the load operation diagnosis process; Do the following: A diagnostic device for a hybrid vehicle that executes the early implementation process of the load operation diagnosis on condition that a maximum value of the driving force that the second motor can generate is greater than a driving force requested by a driver.

3. 3. The hybrid vehicle diagnostic device according to claim 1, wherein the early implementation process of the load operation diagnosis is performed on the condition that the battery has a certain amount of charge remaining.

4. A diagnostic device for a hybrid vehicle having an engine that generates driving force by burning fuel, a first motor that receives power from an external source to generate power, a second motor that generates power in response to power supply, a chargeable and dischargeable battery, and a first clutch and a second clutch that connect and disconnect power transmission, the first clutch, the first motor, and the second clutch being arranged in this order from the engine side in a driving force transmission path from the engine to wheels, a load operation diagnostic process for diagnosing the engine when a predetermined execution condition is satisfied during a load operation of the engine; an early implementation process of a load operation diagnosis in which the first clutch is engaged, the second clutch is released, and the vehicle travels with a driving force generated by the second motor while a load is applied by the first motor, and the engine is operated under load so as to satisfy an execution condition of the load operation diagnosis process; Do the following: The first motor generates a driving force in response to power supply, And the diagnostic device an idle operation diagnostic process for diagnosing the engine on condition that the engine is idling; an early implementation process of an idle operation diagnosis in which the first clutch is released and the second clutch is engaged to run the vehicle using driving force generated by one or both of the first motor and the second motor while the engine is idled; A diagnostic device for hybrid vehicles.

5. 5. The diagnostic device for a hybrid vehicle according to claim 4, wherein the early implementation process of the idling diagnosis is performed on the condition that the engine is not required to be driven in order to charge the battery.

6. 6. The diagnostic device for a hybrid vehicle according to claim 4, wherein the early implementation process of the idle driving diagnosis is executed on the condition that a maximum value of the driving force that can be generated by the first motor and the second motor is greater than a driving force requested by a driver.

Images