A method for operating a drive device for a motor vehicle, which has an internal combustion engine and an electric motor. A drive shaft of the internal combustion engine can be coupled to a motor shaft of the electric motor by a shift clutch. The shift clutch is adjusted to a desired clutch torque over a dragging period for startup of the internal combustion engine. Prior to the startup, a quantity of heat that is expected to accrue in the shift clutch during the startup is predicted and, when the predicted quantity of heat exceeds a limit value, at least one operating parameter of the drive device that influences the startup is chosen in such a way that the quantity of heat expected to accrue is reduced.

A restart control device is applied to a vehicle which is provided with an internal combustion engine, an electric motor, a driving wheel, and a clutch. The restart control device has a restart-condition determining portion which determines whether a restart condition for restarting the internal combustion engine is established while the vehicle is coasting; a push-start portion which starts the internal combustion engine by a push-start; a start-up portion which starts the internal combustion engine by use of an electric motor; and a doubly start-up portion which tries to start the internal combustion engine by one of the push-start portion and the start-up portion when the restart-condition determining portion determines that the restart condition is established. The doubly start-up portion tries to start the internal combustion engine by another one of the push-up portion and the start-up portion when the internal combustion engine has not been started.

A restart control device is applied to a vehicle which is provided with an internal combustion engine, an electric motor, a driving wheel, and a clutch. The restart control device has a restart-condition determining portion which determines whether a restart condition for restarting the internal combustion engine is established while the vehicle is coasting; a push-start portion which starts the internal combustion engine by a push-start; a start-up portion which starts the internal combustion engine by use of an electric motor; and a doubly start-up portion which tries to start the internal combustion engine by one of the push-start portion and the start-up portion when the restart-condition determining portion determines that the restart condition is established. The doubly start-up portion tries to start the internal combustion engine by another one of the push-up portion and the start-up portion when the internal combustion engine has not been started.

Systems and methods for starting an engine of a hybrid vehicle are described. In one example, the method selects one or more electric machines to start an engine. The method may reference a data structure, such as a matrix or table, and the matrix or table outputs which of the one or more electric machines is applied to start the engine.

Systems and methods for starting an engine of a hybrid vehicle are described. In one example, the method selects one or more electric machines to start an engine. The method may reference a data structure, such as a matrix or table, and the matrix or table outputs which of the one or more electric machines is applied to start the engine.

A control device for a hybrid electric vehicle includes an electronic control unit. The electronic control unit is configured to perform a start-up control of shifting the connection and disconnection clutch to a coupled state at the time of starting the internal combustion engine to rotate the internal combustion engine by the driving torque of the electric motor, and starting the first fuel injection mode using the direct injection injector. The electronic control unit is configured to switch from the first fuel injection mode to a second fuel injection mode for using the port injector prior to an end of the start-up control when the number of times of combustion cycles of the internal combustion engine with the first fuel injection mode reaches a predetermined first target number of times.

Method and system for starting an internal combustion engine of a hybrid vehicle, adapted to rotate a drive shaft providing torque via a transmission unit comprising a first clutch connecting the engine to an input shaft of a gearbox connected to a torque converter connected to a second clutch connecting the torque converter to the at least one driving wheel, where the input shaft is connected to an electric machine; the method comprising: disengaging the second clutch to a predetermined torque level such that there is a slip in the second clutch; engaging the lock-up clutch; engaging the first clutch to bring the engine to a first rotational speed; disengaging the first clutch when the engine has reached the first rotational speed; starting the engine, and engaging the first clutch when the engine has started and rotates with a second rotational speed.

A start control device for a hybrid vehicle includes a battery, first and second rotary electric machines, an engine, a first determination unit configured to determine whether the battery is in a low output state, a cranking control unit configured to perform a cracking of the engine, and a second determination unit configured to perform a cranking completion determination. In a case where a maximum output of the battery is in the low output state, the cranking control unit causes the first rotary electric machine to run at a low output target rotation speed, and the second determination unit determines that the cranking is completed when a condition that an actual rotation speed of the first rotary electric machine continues to be within a target range for a predetermined time is satisfied.

A kinetic energy recovery system (KERS) is provided. The KERS (1) comprises a first speed-up gear arrangement (12) having an input (10) connectable to a vehicle powertrain. The KERS further comprises a hydraulic variator made up of first and second bent axis motors (20,22) fluidly connected to one another, wherein at least the first motor (20) is a variable displacement motor, and the first motor (20) is connected to an output of the first speed-up gear arrangement (12). A second speed-up gear arrangement (34) has an input connected to the second motor (22). At least one flywheel (52) is connected to an output of the second speed-up gear arrangement (34), where the at least one flywheel is located in a vacuum within at least one flywheel chamber (58).

A kinetic energy recovery system (KERS) is provided. The KERS (1) comprises a first speed-up gear arrangement (12) having an input (10) connectable to a vehicle powertrain. The KERS further comprises a hydraulic variator made up of first and second bent axis motors (20,22) fluidly connected to one another, wherein at least the first motor (20) is a variable displacement motor, and the first motor (20) is connected to an output of the first speed-up gear arrangement (12). A second speed-up gear arrangement (34) has an input connected to the second motor (22). At least one flywheel (52) is connected to an output of the second speed-up gear arrangement (34), where the at least one flywheel is located in a vacuum within at least one flywheel chamber (58).