Diagnostic device and diagnostic method for a hybrid vehicle

Abstract

A diagnosis device and a diagnosis method for a hybrid vehicle. The diagnosis device is configured to diagnose the hybrid vehicle. The diagnosis device performs load operation during diagnosis processing, that is, diagnosis of an engine is performed when a predetermined execution condition is satisfied during load operation of the engine. The diagnosis device performs early implementation processing of load operation during diagnosis, that is, a first clutch is engaged and a second clutch is released, travel is performed using driving force generated by a second motor, and load operation of the engine is performed in a state where load is applied by the first motor in a manner that satisfies the execution condition of the load operation during diagnosis processing.

Description

Technical Field

[0001] This disclosure relates to diagnostic devices and methods for hybrid vehicles. Background Technology

[0002] As a vehicle diagnostic device, there exists a diagnostic device for engine diagnostics. Among the engine diagnostic items, there are those that are desired to be performed under stable idling conditions. On the other hand, there are vehicles that automatically stop the engine when parked, in situations where idling would normally occur, with the aim of improving emissions and reducing fuel consumption. In such vehicles that automatically stop the engine, the opportunity to perform diagnostics during idling is limited because idling is performed infrequently.

[0003] In contrast, the vehicle diagnostic device described in Japanese Patent Application Publication No. 2008-151041 prohibits the automatic shutdown of the engine if incomplete diagnostics exist when the automatic shutdown condition is met. Furthermore, this diagnostic device ensures the opportunity for diagnostics to be performed during idling by performing idling operation instead of automatic shutdown.

[0004] In engine diagnostics, there are diagnostics that are ideally performed under specific operating conditions under load. However, since the engine's operating state changes progressively depending on the vehicle's driving conditions, the opportunity to obtain the desired operating state for diagnostic purposes is limited. In particular, in hybrid vehicles that utilize an electric motor for propulsion, the engine may sometimes stop while the vehicle is in motion, further limiting the opportunities for performing engine diagnostics under load. Summary of the Invention

[0005] The present disclosure discloses a diagnostic device for a hybrid vehicle, applicable to a hybrid vehicle comprising: an engine that generates driving force through fuel combustion; a first motor that receives power from an external source to generate electricity; a second motor that generates driving force in response to the power supply; a battery capable of charging and discharging; and a first clutch and a second clutch that connect / disconnect the power transmission. The first clutch, the first motor, and the second clutch are sequentially arranged from the engine side along the path of driving force transmission from the engine to the wheels. The diagnostic device performs: a diagnostic process during load operation, diagnosing the engine when predetermined execution conditions are met during load operation; and an advance execution process for the load operation diagnostic process, engaging the first clutch and disengaging the second clutch, driving using the driving force generated by the second motor, and performing load operation of the engine in a manner that satisfies the execution conditions of the load operation diagnostic process while a load is applied via the first motor.

[0006] When the aforementioned diagnostic device performs advance implementation processing for load operation diagnostics, the engine and the first motor are connected to each other and disconnected from the wheels. The hybrid vehicle then travels using 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. Furthermore, the engine and the first motor are disconnected from the wheels. Therefore, regardless of the hybrid vehicle's driving conditions, the engine can operate in any configuration. In the aforementioned diagnostic device, the engine is subjected to load operation in a manner that satisfies the execution conditions of the load operation diagnostic processing through advance implementation processing for load operation diagnostics. Therefore, after performing advance implementation processing for load operation diagnostics, load operation diagnostics can be performed regardless of the hybrid vehicle's driving conditions. Thus, the aforementioned diagnostic device for hybrid vehicles makes advance implementation of engine diagnostics during load operation possible.

[0007] In the aforementioned pre-implementation processing for load operation, a load is applied to the engine through the regenerative operation of the first motor. At this time, if the battery is fully charged or nearly fully charged, it becomes impossible to recover the electricity generated by the first motor through regenerative operation back into the battery. Therefore, the pre-implementation processing for load operation diagnosis in the aforementioned diagnostic device is preferably performed under the condition that there is a certain or greater charge reserve in the battery.

[0008] In situations where the battery charge is low, it is sometimes necessary to regenerate the battery by using the engine to power the first motor. On the other hand, during the early implementation of diagnostics under load, although the first motor generates electricity, the second motor consumes power, which may cause the battery charge to decrease. Therefore, the early implementation of diagnostics under load in the aforementioned diagnostic device is preferably performed under the condition that the engine does not require power for battery charging.

[0009] There is a limit to the driving force that the second motor can generate. Therefore, the driving force generated by the second motor alone is sometimes insufficient to meet the driving force required by the driver. Therefore, the advance implementation of load operation diagnosis in the above-mentioned diagnostic device is preferably performed 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.

[0010] The diagnostic device for the aforementioned hybrid vehicle can also be configured to perform: idling operation diagnostic processing, performing engine diagnostics while the engine is idling; and early implementation processing of idling operation diagnostics, disengaging the first clutch and engaging the second clutch, using the driving force generated by one or both of the first and second motors for driving, and idling the engine. When early implementation processing of idling operation diagnostics 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 be driven using the driving force generated by one or both of the first and second motors. On the other hand, since the engine is disconnected from the wheels, idling can be performed regardless of the driving conditions. Therefore, by performing early implementation processing of idling operation diagnostics, idling operation diagnostics can be performed regardless of the driving conditions of the hybrid vehicle. Furthermore, such early implementation processing of idling operation diagnostics is preferably performed under the condition that the engine does not require driving for battery charging. In addition, the early implementation of diagnostics during idling is preferably performed when the maximum driving force that the first and second motors can generate is greater than the driving force required by the driver.

[0011] Another aspect of this disclosure provides a diagnostic method for a hybrid vehicle. The hybrid vehicle includes: an engine that generates driving force through fuel combustion; a first motor that generates electricity by receiving external power; a second motor that generates power in response to the power supply; a battery capable of charging and discharging; and a first clutch and a second clutch for connecting / disconnecting power transmission. In the path of driving force transmission from the engine to the wheels, the first clutch, the first motor, and the second clutch are sequentially arranged from the engine side. The method includes: performing a diagnostic process during load operation, i.e., diagnosing the engine when predetermined execution conditions are met during load operation; and performing an advance implementation process for the load operation diagnostic process, i.e., engaging the first clutch and disengaging the second clutch, driving using the driving force generated by the second motor, and, while a load is applied by the first motor, performing load operation of the engine in a manner that satisfies the execution conditions of the load operation diagnostic process. Attached Figure Description

[0012] Figure 1 This is a diagram schematically illustrating the configuration of a drive system for a hybrid vehicle to which one embodiment of the diagnostic device is applicable.

[0013] Figure 2 This is a diagram schematically illustrating the configuration of one embodiment of the diagnostic device.

[0014] Figure 3 It is shown Figure 1 A diagram showing the state of the hybrid vehicle's drive system in hybrid driving mode.

[0015] Figure 4 It is shown Figure 1 A diagram showing the state of the drive system of a hybrid vehicle in electric driving mode.

[0016] Figure 5 yes Figure 2 The flowchart illustrates the mandatory implementation process of diagnostics performed by the diagnostic device during load operation.

[0017] Figure 6 yes Figure 2 The flowchart shows the mandatory implementation procedure for diagnostics performed by the diagnostic device during idling.

[0018] Figure 7 It is shown Figure 1 A diagram illustrating the mandatory implementation of load operation diagnostics in the drive system of a hybrid vehicle.

[0019] Figure 8 It is shown Figure 1 A diagram illustrating the state of mandatory implementation of diagnostics during idling in the drive system of a hybrid vehicle. Detailed Implementation

[0020] The following is for reference Figures 1 to 8 An embodiment of a diagnostic device for hybrid vehicles will be described in detail.

[0021] <Composition of the drive system in a hybrid vehicle>

[0022] First, refer to Figure 1 The configuration of the drive system of the hybrid vehicle to which the diagnostic device of this embodiment is applicable will be described. The hybrid vehicle has four wheels: left and right front wheels 10 and left and right rear wheels 11. Furthermore, the hybrid vehicle has 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. Additionally, the hybrid vehicle is equipped with a battery 12 capable of being charged and discharged.

[0023] The first power unit 20 is connected to the left and right front wheels 10 via the transmission 25. The first power unit 20 has two drive sources: an engine 21 that generates driving force through fuel combustion, and a first motor 22 that generates driving 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 converter 13. The first power unit 20 is also equipped with two clutches for connecting / disconnecting power transmission: 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, in the path of driving force transmission from the engine 21 to the front wheels 10, the first clutch 23, the first motor 22, and the second clutch 24 are sequentially arranged from the engine 21 side.

[0024] On the other hand, the second power unit 30 has a second motor 31 as a drive source, which generates driving force in response to the power supply from the battery 12 and generates electricity by receiving power from an external source. The second motor 31 is directly connected to the left and right rear wheels 11. In addition, the second motor 31 is electrically connected to the battery 12 via the second converter 14.

[0025] <Composition of Diagnostic Devices>

[0026] Next, refer to Figure 2 Explain the composition of the diagnostic device for hybrid vehicles.

[0027] The hybrid vehicle is equipped with an electronic control unit 40 for vehicle control. The electronic control unit 40 includes a processing unit 41 and a storage unit 42. The storage unit 42 stores programs and data for vehicle control. Furthermore, the electronic control unit 40 reads and executes the programs from the storage unit 42 via the processing unit 41 to perform vehicle control. Additionally, as part of vehicle control, the electronic control unit 40 performs diagnostics on the hybrid vehicle. In this embodiment, such an electronic control unit 40 constitutes a diagnostic device for the hybrid vehicle.

[0028] Various sensor signals are input to the electronic control unit 40. These sensors include an accelerator pedal sensor 43, a vehicle speed sensor 44, an air flow meter 45, a crankshaft angle sensor 46, an exhaust sensor 47, and a fuel pressure sensor 48. The accelerator pedal sensor 43 detects the amount of operation of the accelerator pedal by the driver. The vehicle speed sensor 44 detects the vehicle speed, i.e., the speed of the hybrid vehicle. The air flow meter 45 detects the amount of air intake into the engine 21. The crankshaft angle sensor 46 detects the rotational phase of the output shaft, i.e., the crankshaft, of the engine 21. The exhaust sensor 47 detects the exhaust characteristics (nature, state) of the engine 21, including air-fuel ratio, oxygen, and NOx sensors. The fuel pressure sensor 48 detects the fuel supply pressure of the engine 21. Additionally, a signal indicating the charge level of the battery 12 is input to the electronic control unit 40.

[0029] Based on the detection results of these sensors, the electronic control unit 40 controls the engine 21, the first motor 22, the second motor 31, the transmission 25, the first clutch 23, and the second clutch 24, thereby controlling the hybrid vehicle. Furthermore, the engine 21 is equipped with a throttle valve 26 for adjusting the intake air volume, a fuel 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 of fuel injected by the injector 27, the timing of fuel injection, and the timing of ignition by the ignition device 28. Additionally, the electronic control unit 40 controls the power supplied to the battery 12 via the first converter 13 and the second converter 14, thereby controlling the power operation / regenerative torque of the first motor 22 and the second motor 31. Furthermore, the electronic control unit 40 controls the gear shifts of the transmission 25 and the opening and closing states of the first clutch 23 and the second clutch 24.

[0030] <Switching Driving Modes>

[0031] The electronic control unit 40 switches the driving mode of the hybrid vehicle according to driving conditions and the charging status of the battery 12. During normal driving, the electronic control unit 40 uses two driving modes: hybrid driving mode and electric driving mode.

[0032] Figure 3 The diagram shows the state of the hybrid vehicle's drive system in hybrid driving mode. During 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 running.

[0033] Figure 4 The diagram illustrates the state of the hybrid vehicle's drive system in electric driving mode. During hybrid driving mode, the electronic control unit 40 disengages the first clutch 23 and engages the second clutch 24. Consequently, the electronic control unit 40 sets the state where the first motor 22 is connected to the front wheels 10, but the engine 21 is disconnected from the front wheels 10. Then, the electronic control unit 40 generates driving force by powering at least one of the first motor 22 and the second motor 31.

[0034] Diagnostic procedures for Engine 21

[0035] The electronic control unit 40 performs diagnostics on the sensors and systems of the engine 21. Individual execution conditions are set for each diagnostic item of the engine 21. In the following description, diagnostics with execution conditions set for performing diagnostics under load on the engine 21 will be recorded as "load operation diagnostics." Diagnostic records with execution conditions set for performing diagnostics under idle speed on the engine 21 will be recorded as "idle speed diagnostics." Furthermore, the processing of the electronic control unit 40 for performing load operation diagnostics will be recorded as "load operation diagnostic processing," and the processing of the electronic control unit 40 for performing idle speed diagnostics will be recorded as "idle speed diagnostic processing." Load operation diagnostics include diagnosing the exhaust sensor 47, fuel pressure sensor 48, exhaust gas purification catalyst, catalyst preheating system, fuel vapor treatment system, exhaust gas recirculation system, fuel supply system, and variable valve timing system. On the other hand, idle speed diagnostics include diagnosing the idle speed control (ISC) system.

[0036] Such diagnosis is performed when the engine 21 reaches an operating state that meets the execution conditions. Under normal vehicle control conditions, the operating state of the engine 21 is determined by the situation at every moment. Therefore, depending on the situation, the execution conditions may not be met for an extended period after the hybrid vehicle has started driving. In response, the electronic control unit 40 performs an advance execution process for load operation diagnosis, enabling advance execution of load operation diagnosis. Furthermore, the electronic control unit 40 performs an advance execution process for idling operation diagnosis, enabling advance execution of idling operation diagnosis.

[0037] <Proactive Implementation of Diagnostics During Load Operation>

[0038] Figure 5 The diagram shows a flowchart of the processes executed by the electronic control unit 40 for advance diagnostics during load operation. The electronic control unit 40 repeatedly executes these processes according to predetermined control cycles during the operation of the hybrid vehicle. Figure 5 The processing of flowcharts.

[0039] When it begins Figure 5 During processing, the electronic control unit 40 first determines in step S100 whether the load operation diagnostics have been completed after the start of the current driving of the hybrid vehicle. If the load operation diagnostics have been completed (yes), the electronic control unit 40 directly ends the current processing; if not completed (no), the processing proceeds to step S110.

[0040] When the process proceeds to step S110, the electronic control unit 40 determines whether a charging drive for the engine 21 is requested. If a charging drive is requested (yes), the electronic control unit 40 terminates the current process directly; otherwise, if no charging drive is requested (no), the process proceeds to step S120. The charging drive for the engine 21 is the drive that enables the first motor 22 to operate regeneratively. This charging drive for the engine 21 is requested when the charge level of the battery 12 drops below a certain amount.

[0041] When the process proceeds to step S120, the electronic control unit 40 determines whether there is a driver drive request for the engine 21. If there is a driver drive request (yes), the electronic control unit 40 directly terminates the current process; otherwise, if there is no driver drive request (no), the process proceeds to step S130. "Whether there is a driver drive request" refers to "whether the engine 21 is needed to provide the driving force required by the driver through pressing the accelerator pedal." Here, if the maximum value of the driving force that the second motor 31 can generate is greater than the driving force requested by the driver, it is considered that there is a driver drive request.

[0042] When the process proceeds to step S130, the electronic control unit 40 determines whether there is a certain amount of remaining charging capacity in the battery 12. If the electronic control unit 40 determines that there is no sufficient remaining charging capacity (No), it directly terminates the current process; if it determines that there is sufficient remaining charging capacity (Yes), it proceeds to step S140. Furthermore, the difference between the current charge level of the battery 12 and its full charge level is defined as the remaining charging capacity of the battery 12. The electronic control unit 40 determines that there is sufficient remaining charging capacity in the battery 12 if this difference is a certain value or higher.

[0043] When the process progresses to step S140, the electronic control unit 40 engages the first clutch 23 in step S140. Furthermore, in the subsequent step S150, the electronic control unit 40 disengages the second clutch 24. Thus, the engine 21 and the first motor 22 are interconnected and disconnected from the front wheels 10. Then, in the next step S160, the electronic control unit 40 begins electric driving of the hybrid vehicle using the driving force generated by the second motor 31. Furthermore, in the subsequent step S170, the electronic control unit 40 begins load operation of the engine 21. That is, at this time, the electronic control unit 40 operates the engine 21 under load by regenerating the first motor 22. Then, in step S180, the electronic control unit 40 controls the engine 21 and the first motor 22 in a manner that satisfies the diagnostic execution conditions, performs diagnostic processing during load operation, and then concludes the process. Figure 5 The processing.

[0044] <Pre-emptive measures for diagnosis during idling>

[0045] Figure 6 The diagram illustrates the pre-implementation processing steps for diagnostics during idling. The electronic control unit 40 repeatedly implements these steps according to predetermined control cycles during the operation of the hybrid vehicle. Figure 6 The processing.

[0046] When it begins Figure 6 During the processing, the electronic control unit 40 first determines in step S200 whether the idling diagnosis has been completed after the start of the current driving of the hybrid vehicle. If the idling diagnosis has been completed (yes), the electronic control unit 40 directly ends the current processing; if it has not been completed (no), the processing proceeds to step S210.

[0047] When the process proceeds to step S210, the electronic control unit 40 determines whether a charging drive for the engine 21 is requested. If a charging drive is requested (yes), the electronic control unit 40 terminates the current process directly; otherwise, it proceeds to step S220. It then determines whether there is a driver's request for the engine 21. If there is a driver's request (yes), the electronic control unit 40 terminates the current process directly; otherwise, it proceeds to step S230. In step S230, if the maximum driving force that the first motor 22 and the second motor 31 can generate is greater than the driving force requested by the driver, it is considered that there is a driver's request for driving.

[0048] When the process proceeds to step S230, the electronic control unit 40 disengages the first clutch 23. Furthermore, in the subsequent step S240, the electronic control unit 40 engages the second clutch 24. Thus, the first power unit 20 is in a state where the engine 21 is disconnected from the front wheel 10 and the first motor 22 is connected to the front wheel 10. Then, in the next step S250, the electronic control unit 40 begins electric driving using the first motor 22 and the second motor 31. Furthermore, in step S260, the electronic control unit 40 begins idling operation of the engine 21. Then, in step S270, the electronic control unit 40 performs diagnostic processing during idling operation, and then the process ends. Figure 6 The processing.

[0049] Furthermore, in this embodiment... Figure 5 Steps S140 to S170 correspond to the advance implementation of diagnostics during load operation. Furthermore, in this embodiment, Figure 6 Steps S230 to S260 correspond to the early implementation of diagnostics during idling.

[0050] <Effects of the Implementation Method>

[0051] The function and effects of this embodiment, configured as described above, will be explained.

[0052] If the diagnostics during load operation are not completed, the electronic control unit 40 performs advance implementation of the diagnostics during load operation in the following manner. Specifically, in this case, the electronic control unit 40 engages the first clutch 23 and disengages the first motor 22 from the front wheels 10 by engaging the first clutch 23 and disengaging the second clutch 24. Then, the electronic control unit 40 drives the rear wheels 11 via the second motor 31 for electric propulsion of the hybrid vehicle, and applies a load to the engine 21 via the first motor 22.

[0053] Figure 7 The diagram shows the current state of the hybrid vehicle's drive system. As shown, the engine 21 and the first motor 22 are disconnected from the front wheels 10. However, the engine 21 and the first motor 22 are still interconnected, so the load on the engine 21 changes due to the regenerative torque of the first motor 22. Therefore, by controlling the output of the engine 21 and the regenerative torque of the first motor 22, the operating state of the engine 21 can be arbitrarily changed. The electronic control unit 40 then controls the engine 21 to operate in a manner that meets the execution conditions and performs diagnostic processing during load operation.

[0054] Furthermore, if the battery 12 is fully charged or nearly fully charged at this time, it becomes impossible to charge the battery 12 with the electricity generated by the regenerative operation of the first motor 22. Therefore, the electronic control unit 40 only performs the pre-implementation processing of the load operation diagnosis in the above scheme when the battery 12 has sufficient charging capacity.

[0055] On the other hand, if the idling diagnostics are not completed, the electronic control unit 40 performs advance idling diagnostics processing in the following manner. Specifically, in this case, the electronic control unit 40 disconnects the engine 21 from the front wheels 10 while the first motor 22 is connected to the front wheels 10 by disengaging the first clutch 23 and engaging the second clutch 24. Then, the electronic control unit 40 performs electric driving of the hybrid vehicle using at least one of the first motor 22 and the second motor 31, and performs idling diagnostics processing while the engine 21 is idling.

[0056] Figure 8 The figure shows the current state of the hybrid vehicle's drive system. As shown, the engine 21 is in an unloaded state, without connection to any external load. The electronic control unit 40 performs idle operation diagnostics on the engine 21 in this state. Furthermore, the first motor 22 is connected to the front wheel 10, and the second motor 31 is connected to the rear wheel 11. Therefore, the hybrid vehicle can be electrically driven by the first motor 22 driving the front wheel 10, the second motor 31 driving the rear wheel 11, or both.

[0057] The diagnostic device for hybrid vehicles according to the above-described embodiment can achieve the following effects.

[0058] (1) If the diagnostic process during load operation is not completed, the electronic control unit 40 performs the following advance execution process for the diagnostic process during load operation. That is, during the advance execution process for the diagnostic process during load operation, the electronic control unit 40 engages the first clutch 23 and releases the second clutch 24, using the driving force generated by the second motor 31 to drive the hybrid vehicle. Furthermore, while a load is applied by the first motor 22, the electronic control unit 40 performs load operation of the engine 21 in a manner that satisfies the execution conditions of the diagnostic process during load operation. Thus, the diagnostic process during load operation can be performed regardless of the driving conditions of the hybrid vehicle. Therefore, the diagnostic device for the hybrid vehicle in this embodiment makes it possible to perform the diagnostic process during load operation in advance.

[0059] (2) In the advance implementation process during load operation, the engine 21 is subjected to a load through the regenerative operation of the first motor 22. Therefore, if the advance implementation process during load operation is performed when the battery 12 is fully charged or nearly fully charged, the battery 12 may become overcharged. In this embodiment, the advance implementation process for load operation diagnosis is performed on the condition that there is a certain or more charge reserve in the battery 12. Therefore, it is difficult for the battery 12 to become overcharged.

[0060] (3) During the advance implementation of load operation diagnostics, although the first motor 22 generates electricity, the second motor 31 consumes power, so the charge level of the battery 12 may decrease. Regarding this, the electronic control unit 40 executes the advance implementation of load operation diagnostics on the condition that the motor 21, which is required for charging the battery 12, is not being driven. Therefore, it is unlikely that insufficient charging of the battery 12 will occur during the execution of the advance implementation of load operation diagnostics.

[0061] (4) The electronic control unit 40 performs the advance implementation processing of 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, the situation where the driving performance of the hybrid vehicle is deteriorated due to insufficient driving force caused by the execution of the advance implementation processing of load operation diagnosis is avoided.

[0062] (5) If the diagnostic processing during idling is not completed, the electronic control unit 40 performs the following advance implementation processing for idling diagnostics. That is, during the advance implementation processing for idling diagnostics, the electronic control unit 40 releases the first clutch 23 and engages the second clutch 24. Then, the electronic control unit 40 uses the driving force generated by one or both of the first motor 22 and the second motor 31 to drive and performs idling operation of the engine 21. Thus, idling diagnostic processing can be performed regardless of the driving conditions of the hybrid vehicle. Therefore, the diagnostic device for the hybrid vehicle of this embodiment makes advance implementation of idling diagnostics possible.

[0063] (6) The electronic control unit 40 performs the advance implementation process of the idling operation diagnosis under the condition that the engine 21 does not require the drive for charging the battery 12. Therefore, it is difficult to cause insufficient charging of the battery 12 during the execution of the advance implementation process of the idling operation diagnosis.

[0064] (7) The electronic control unit 40 performs early implementation processing of idling operation 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, the situation where the driving performance of the hybrid vehicle is deteriorated due to insufficient driving force caused by the early implementation processing of idling operation diagnosis is avoided.

[0065] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other within the scope of technical inconsistency.

[0066] • The execution conditions for the advance implementation of diagnostics during load operation and diagnostics during idling can also be appropriately changed.

[0067] • The diagnostic device can also be configured to perform advance processing of diagnostics during idling only, without performing advance processing of diagnostics during load operation.

[0068] • During load operation diagnostic processing, multiple load operation diagnostics can be executed simultaneously or sequentially. Similarly, during idle operation diagnostic processing, multiple idle operation diagnostics can be executed simultaneously or sequentially.

[0069] The first motor 22 and the second motor 31 in the above embodiments function as both electric motors that generate driving force in response to power supply and generators that receive power from external sources to generate electricity. If electric travel using the driving force of the first motor 22 is not required, a rotary motor specifically designed for regenerative drive that does not function as an electric motor can be used as the first motor 22. Similarly, if regenerative power generation using the second motor 31 is not required, a rotary motor specifically designed for power operation drive that does not function as a generator can be used as the second motor 31.

[0070] • The diagnostic device of this embodiment is also applicable to hybrid vehicles in which the first power unit 20 and the second power unit 30 drive the same wheel.

Claims

1. A diagnostic device for a hybrid vehicle, The hybrid vehicle includes: an engine that generates driving force through fuel combustion; a first motor that generates electricity by receiving external power; a second motor that generates power in response to the power supply; a battery capable of charging and discharging; and a first clutch and a second clutch for connecting / disconnecting the power transmission. Furthermore, in the path of driving force transmission from the engine to the wheels, starting from the engine side, the first clutch, the first motor, and the second clutch are arranged sequentially. The diagnostic device is configured to perform: Diagnostic processing during load operation involves performing diagnostics on the engine when predetermined execution conditions are met during load operation; and The pre-implementation processing for load operation diagnostics involves engaging the first clutch and disengaging the second clutch, utilizing the driving force generated by the second motor for driving, and, while a load is applied via the first motor, performing load operation of the engine in a manner that satisfies the execution conditions of the load operation diagnostic processing. The diagnostic device is configured to perform advance implementation processing of the diagnostics during load operation under the condition that the engine is not required to charge the battery.

2. The diagnostic device for hybrid vehicles according to claim 1, The diagnostic device is configured to perform advance implementation processing of the load operation diagnosis under the condition that there is a certain or more charge reserve in the battery.

3. The diagnostic device for hybrid vehicles according to claim 1 or 2, The diagnostic device is configured to perform advance processing of the load operation diagnosis under 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.

4. A diagnostic device for a hybrid vehicle, The hybrid vehicle has: an engine that generates driving force through the combustion of fuel; a first motor that generates electricity by receiving external power; a second motor that generates power in response to the power supply; and a battery that can be charged and discharged. The system includes a first clutch and a second clutch to connect / disconnect power transmission, and, in the path of power transmission from the engine to the wheels, starting from the engine side, the first clutch, the first motor, and the second clutch are sequentially arranged. The diagnostic device is configured to perform: Diagnostic processing during load operation involves performing diagnostics on the engine when predetermined execution conditions are met during load operation; and The pre-implementation processing for load operation diagnostics involves engaging the first clutch and disengaging the second clutch, utilizing the driving force generated by the second motor for driving, and, while a load is applied via the first motor, performing load operation of the engine in a manner that satisfies the execution conditions of the load operation diagnostic processing. The first motor generates driving force in response to the power supply, and The diagnostic device is configured to perform: Diagnostic processing during idling: The engine is diagnosed under the condition that it is idling. and The early implementation of diagnostics during idling involves disengaging the first clutch and engaging the second clutch, utilizing the driving force generated by one or both of the first and second motors for propulsion, and simultaneously idling the engine. The diagnostic device is configured to perform advance implementation processing of the diagnostics during idling, provided that the engine is not required to charge the battery.

5. The diagnostic device for hybrid vehicles according to claim 4, The early implementation of the idling operation diagnosis is 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 required by the driver.

6. A diagnostic method for hybrid vehicles, The hybrid vehicle has: an engine that generates driving force through the combustion of fuel; a first motor that generates electricity by receiving external power; a second motor that generates power in response to the power supply; and a battery that can be charged and discharged. The system includes a first clutch and a second clutch to connect / disconnect power transmission, and, in the path of power transmission from the engine to the wheels, starting from the engine side, the first clutch, the first motor, and the second clutch are sequentially arranged. The diagnostic method includes: Perform diagnostic processing during load operation, that is, perform engine diagnosis when the predetermined execution conditions are met during the load operation of the engine. and The pre-implementation processing for load operation diagnostics involves engaging the first clutch and disengaging the second clutch, using the driving force generated by the second motor for driving, and, while a load is applied by the first motor, performing load operation of the engine in a manner that satisfies the execution conditions of the load operation diagnostic processing. The diagnostic method is configured to perform advance implementation processing of the load operation diagnostics under the condition that the engine is not required to charge the battery.

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