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: 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: 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 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 hybrid vehicle, when the shift position SP is set to the S position at which a driver is allowed to select any one of the shift positions SP1 to SP6, and it is determined that warm-up of a purifying device has not been completed, the target air-fuel ratio AF* is set based on the S position/low coolant temperature-time target air-fuel ratio setting map. The air-fuel ratio AF* set based on the S position/low coolant temperature-time target air-fuel ratio setting map tends to be richer than the target air-fuel ratio AF* set based on any one of the normal-time target air-fuel ratio setting map and the D position/low coolant temperature-time target air-fuel ratio setting map that are used when the D position is selected.

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: In a hybrid vehicle, when the shift position SP is set to the S position at which a driver is allowed to select any one of the shift positions SP1 to SP6, and it is determined that warm-up of a purifying device has not been completed, the target air-fuel ratio AF* is set based on the S position/low coolant temperature-time target air-fuel ratio setting map. The air-fuel ratio AF* set based on the S position/low coolant temperature-time target air-fuel ratio setting map tends to be richer than the target air-fuel ratio AF* set based on any one of the normal-time target air-fuel ratio setting map and the D position/low coolant temperature-time target air-fuel ratio setting map that are used when the D position is selected.

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: The auto engine start control of the invention regulates a throttle valve to a restricted opening to reduce an air intake flow at an ordinary start of an engine (step S140). When the driver stamps on an accelerator pedal to raise an engine power demand Pe* to or above a preset threshold value Pref, the auto engine start control regulates the throttle valve to a standard opening to ensure the air intake flow corresponding to the engine power demand Pe* (step S150) and thereby cranks the engine. This arrangement desirably dampens potential vibration induced by ignition at the ordinary start of the engine, while ensuring prompt output of the required driving force from the engine under the condition of the higher engine power demand Pe*.

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 hybrid vehicle of the invention, in the event of specification that an exhaust treatment catalyst is in a preset adequate state at step S112, combustion control of an engine starts after a decrease of an intake pipe pressure P to a preset reference negative pressure Pref and reduction of an intake air flow into a cylinder of the engine by engine motoring. In the event of specification that the exhaust treatment catalyst is not in the preset adequate state but in an inadequate state at step S112, on the other hand, the combustion control of the engine immediately starts, prior to the decrease of the intake pipe pressure P to the preset reference negative pressure Pref.

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 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: 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: When a starter switch is switched from OFF to ON, a hybrid ECU determines that a driver intends to start driving a vehicle, reads a temperature of each of items (engine coolant, injectors, lubricating oil, and the like), and makes a determination on the necessity of preheating depending on whether each of the items has reached a corresponding one of suitable temperatures. If preheating is required, the hybrid ECU sets an engine start permission flag so as to prohibit the engine from being started, and instructs an engine ECU to preheat the item requiring preheating. On the other hand, if every one of the items has reached the suitable temperature range of its own, the hybrid ECU determines that preheating is not required, and sets the engine start permission flag so as to permit the starting of 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.

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 control technique of the invention sets smaller values to an engine stop reference value and an engine start reference value in the state of use of a regular fuel, compared with values in the ordinal state. When a calculated engine power demand Pe* is less than the engine stop reference value, the control stops the operation of the engine. When the calculated engine power demand Pe* exceeds the engine start reference value, on the other hand, the control starts the operation of the engine. This arrangement facilitates the start of the engine in the state of use of the regular fuel, compared with the start in the ordinary state. A corrective revolution speed ?N is added to a target revolution speed Ne* of the engine, in order to respond to a decrease in output power from the internal combustion engine.

Abstract: The auto engine start control of the invention regulates a throttle valve to a restricted opening to reduce an air intake flow at an ordinary start of an engine (step S140). When the driver stamps on an accelerator pedal to raise an engine power demand Pe* to or above a preset threshold value Pref, the auto engine start control regulates the throttle valve to a standard opening to ensure the air intake flow corresponding to the engine power demand Pe* (step S150) and thereby cranks the engine. This arrangement desirably dampens potential vibration induced by ignition at the ordinary start of the engine, while ensuring prompt output of the required driving force from the engine under the condition of the higher engine power demand Pe*.

Abstract: The temperature of a component provided in or associated with an internal combustion engine is estimated with no regard to the automatic stop and the automatic start of the internal combustion engine, and at least one of the estimated temperature of the component and a parameter used to estimate the same temperature is initialized in response to the internal combustion engine being started non-automatically.