Abstract: A control device for a hybrid vehicle causes the hybrid vehicle to travel in limp-home mode with motive power from an engine when either a motor or a battery for travel cannot be used. The engine incorporated in the hybrid vehicle includes an EGR device for recirculating part of exhaust gas to an intake system of the engine again. Even if an operation state of the engine satisfies a prescribed EGR permission condition for operating the EGR device, during the travel in limp-home mode with an abnormality detection flag being set to 1, the control device prohibits operation of the EGR device.

Abstract: After completion of warm-up of an engine, upon satisfaction of an exhaust gas recirculation condition by setting the drive mode of a hybrid vehicle to a normal mode according to the driver's accelerator operation, when a power difference ?Pe representing a decrease rate of a power demand Pe* required for the engine is less than a preset reference value ?, the engine and motors MG1 and MG2 are controlled to ensure output of a power equivalent to the power demand Pe* from the engine with prohibition for exhaust gas recirculation via an EGR valve and to ensure output of a torque equivalent to a torque demand Tr* to a ring gear shaft or an axle (steps S300 to S330 and step S390).

Abstract: When the engine being in an idling operation and it is in a running state (S410, S420), a value 1 is set to a learning-determination flag F1 (step S460) and the learning of the idling control value is performed when the transmission is in the state of Lo gear and it is not immediately after a Hi-Lo shifting has been performed (S430 to S450).

Abstract: A control device for a hybrid vehicle causes the hybrid vehicle to travel in limp-home mode with motive power from an engine when either a motor or a battery for travel cannot be used. The engine incorporated in the hybrid vehicle includes an EGR device for recirculating part of exhaust gas to an intake system of the engine again. Even if an operation state of the engine satisfies a prescribed EGR permission condition for operating the EGR device, during the travel in limp-home mode with an abnormality detection flag being set to 1, the control device prohibits operation of the EGR device.

Abstract: In a hybrid vehicle 20, when a deceleration demand based on accelerator-off is made in selecting an S position that allows arbitrary selection of shift positions SP1 to SP6, and fuel cut cannot be prohibited from a state of a battery 50, an engine 22 and motors MG1 and MG2 are controlled so that a driving force based on a torque demand Tr* is outputted with the fuel cut (Steps S410, S420, S360 to S400). When the deceleration demand based on the accelerator-off is made in selecting the S position, and the fuel cut can be prohibited from the state of the battery 50, the engine 22 and the motors MG1 and MG2 are controlled so that the engine 22 substantially performs self-sustaining operation at a target rotation speed Ne0 and a driving force based on the torque demand Tr* is outputted (Steps S340 to S400).

Abstract: In an engine 5 including an in-cylinder injector, the valve timing of an intake valve is retarded by VVT (Variable Valve Timing) controlled by an engine ECU to decompress in a combustion chamber at engine startup. In accordance with a configuration in which the valve timing of intake valve is advanced in a stepped manner from an initial set value, fuel injection from in-cylinder injector is inhibited during the time when the advance is equal to or below a predetermined standard value, and fuel injection from in-cylinder injector is allowed when exceeding the predetermined standard value, whereby degradation in the exhaust emission level in accordance with start time decompression control can be suppressed.

Abstract: After completion of warm-up of an engine, upon satisfaction of an exhaust gas recirculation condition by setting the drive mode of a hybrid vehicle to a normal mode according to the driver's accelerator operation, when a power difference ?Pe representing a decrease rate of a power demand Pe* required for the engine is less than a preset reference value ?, the engine and motors MG1 and MG2 are controlled to ensure output of a power equivalent to the power demand Pe* from the engine with prohibition for exhaust gas recirculation via an EGR valve and to ensure output of a torque equivalent to a torque demand Tr* to a ring gear shaft or an axle (steps S300 to S330 and step S390).

Abstract: The technique of the invention determines whether input data for driving and controlling a cooling fan have any abnormality (steps S100 and S110), sets an actual drive level F* of the cooling fan to a high level (Hi) in the event of detection of any abnormality (step S130), and controls a fan motor to drive the cooling fan at the set drive level F* (step S140). This arrangement effectively prevents a temperature rise to an abnormally high level in any of an engine and motors even in the event of any abnormality arising in the input data.

Abstract: In a hybrid vehicle 20, when a deceleration demand based on accelerator-off is made in selecting an S position that allows arbitrary selection of shift positions SP1 to SP6, and fuel cut cannot be prohibited from a state of a battery 50, an engine 22 and motors MG1 and MG2 are controlled so that a driving force based on a torque demand Tr* is outputted with the fuel cut (Steps S410, S420, S360 to S400). When the deceleration demand based on the accelerator-off is made in selecting the S position, and the fuel cut can be prohibited from the state of the battery 50, the engine 22 and the motors MG1 and MG2 are controlled so that the engine 22 substantially performs self-sustaining operation at a target rotation speed Ne0 and a driving force based on the torque demand Tr* is outputted (Steps S340 to S400).

Abstract: A control method of a vehicle includes a step of running the vehicle in an EV running mode in accordance with an operation of a driver, a step of performing a warming-up running, when it is determined that warming up is required, and a step of prohibiting the EV running mode such that the warming up running can be performed.

Abstract: A delay time for delaying starting of an internal combustion engine in a hybrid vehicle is set to a predetermined time based on an engine coolant temperature and a state of an air conditioner switch. Starting of the engine is delayed for the predetermined time if it is determined that a vehicle can run using only a motor based on a required torque, a required power and an SOC of the battery. The predetermined time is determined based on a time necessary for completing preheating of an engine by a preheating device, preparations of sensors such as an air-furl ratio sensor, and warming-up of an exhaust gas purifying device. As a result, it is possible to efficiently perform start of the engine and operation immediately after the engine start, and to make control at the engine start time simple.

Abstract: When the engine being in an idling operation and it is in a running state (S410, S420), a value 1 is set to a learning-determination flag F1 (step S460) and the learning of the idling control value is performed when the transmission is in the state of Lo gear and it is not immediately after a Hi-Lo shifting has been performed (S430 to S450).

Abstract: When an engine power demand Pe* is not greater than a maximum power Pemax, the drive control sets a target rotation speed Ne* and a target torque Te* of an engine according to a reference operation curve obtained in air-fuel ratio control with a stoichiometric air-fuel ratio (step S125). When the engine power demand Pe* exceeds the maximum power Pemax, on the other hand, upon failure of a preset fuel increase prohibition condition, the drive control sets the target rotation speed Ne* to a maximum rotation speed Nemax (step S140) and sets a target air-fuel ratio used for the air-fuel ratio control of the engine to a rich air-fuel ratio based on the engine power demand Pe* (step S150).

Abstract: An engine ECU carries out control of an intermittent operation of an engine mounted on a hybrid vehicle. The engine is provided with an EGR apparatus controlling a flow rate of an EGR gas by means of an EGR valve from downstream of a three-way catalytic converter through an EGR pipe. When an engine stop request is issued, the engine ECU allows the engine to operate at idle and stops actuation of EGR by outputting a control signal (valve-closing signal) to the EGR valve. Then, the engine ECU estimates a remaining amount of the EGR gas within an intake pipe based on an amount of intake air detected by an airflow meter or the like, and when the estimated remaining amount of the EGR gas is equal to or smaller than a prescribed value, the engine ECU performs engine stop processing.

Abstract: In a vehicle incorporating an internal combustion engine having in-cylinder injectors and intake manifold injectors and performing engine intermittent operation control, at the end of vehicle operation, the fuel pressure is decreased in both a high-pressure delivery pipe and a low-pressure delivery pipe by actuation (opening) of an electromagnetic relief valve and by stop of operation of a low-pressure fuel pump. This prevents deterioration in emission performance at the next engine start attributable to fuel leakage due to degradation in oil tightness of the injectors during the operation stop period. When the engine is temporarily stopped by engine intermittent operation control, while the low-pressure fuel pump is stopped, actuation (opening) of the electromagnetic relief valve is prohibited. At the engine restart after temporary stop, the fuel in the high-pressure delivery pipe having its pressure secured at a certain level is injected to quickly start the engine.

Abstract: A low-pressure delivery pipe provided with intake manifold injectors, a fuel pressure regulator, a high-pressure fuel pump, a high-pressure delivery pipe provided with in-cylinder injectors, and an electromagnetic relief valve are connected in series at the downstream of a low-pressure fuel pump that discharges a fuel within a fuel tank at a prescribed pressure. Since the low-pressure delivery pipe is arranged downstream of the low-pressure fuel pump, the fuel pressure within the low-pressure delivery pipe is lowered upon stop of vehicle operation, in response to stop of the low-pressure fuel pump. The fuel pressure within the high-pressure delivery pipe is also lowered in response to stop of the low-pressure fuel pump, by opening the electromagnetic relief valve upon stop of vehicle operation. Thus, oil tightness of the injectors during the stop of vehicle operation is ensured.

Abstract: The engine ECU executes a program including the step of determining whether there is a possibility of occurrence of air bubbles within the high-pressure delivery pipe when there is an engine start request, the step of transmitting an open-instruction signal to the electromagnetic relief valve when there is a possibility of occurrence of air bubbles, the step of transmitting a drive-instruction signal to the feed pump, the step of transmitting a close-instruction signal to the electromagnetic relief valve after the feed pump is driven for a predetermined period of time, the step of transmitting a drive-instruction signal to the starter, and the step of transmitting an injection-instruction signal to the EDU.

Abstract: In a vehicle incorporating an internal combustion engine having in-cylinder injectors and intake manifold injectors and performing engine intermittent operation control, at the end of vehicle operation, the fuel pressure is decreased in both a high-pressure delivery pipe and a low-pressure delivery pipe by actuation (opening) of an electromagnetic relief valve and by stop of operation of a low-pressure fuel pump. This prevents deterioration in emission performance at the next engine start attributable to fuel leakage due to degradation in oil tightness of the injectors during the operation stop period. When the engine is temporarily stopped by engine intermittent operation control, while the low-pressure fuel pump is stopped, actuation (opening) of the electromagnetic relief valve is prohibited. At the engine restart after temporary stop, the fuel in the high-pressure delivery pipe having its pressure secured at a certain level is injected to quickly start the engine.

Abstract: In a vehicle incorporating an internal combustion engine having in-cylinder injectors and intake manifold injectors and performing engine intermittent operation control, at the end of vehicle operation, the fuel pressure is decreased in both a high-pressure delivery pipe and a low-pressure delivery pipe by actuation (opening) of an electromagnetic relief valve and by stop of operation of a low-pressure fuel pump. This prevents deterioration in emission performance at the next engine start attributable to fuel leakage due to degradation in oil tightness of the injectors during the operation stop period. When the engine is temporarily stopped by engine intermittent operation control, while the low-pressure fuel pump is stopped, actuation (opening) of the electromagnetic relief valve is prohibited. At the engine restart after temporary stop, the fuel in the high-pressure delivery pipe having its pressure secured at a certain level is injected to quickly start the engine.

Abstract: The start control procedure of the invention lags an open-close timing VVT of an intake valve, restricts a throttle opening TH of a throttle valve, and starts cranking an engine with a lower torque Tlow. When a pressure Pf of a fuel supplied to in-cylinder fuel injection valves reaches or exceeds a preset reference value, which is greater than a sum of an in-cylinder compression pressure Pin and a closed valve position-retaining pressure Pcv of the in-cylinder fuel injection valves, the start control procedure cranks the engine with a standard cranking torque Tset. The start control procedure then starts advance of the open-close timing VVT of the intake valve, cancels the restriction of the throttle opening TH, and starts fuel injection from the in-cylinder fuel injection valves.