Engine starting system and starter

An engine starting system comprising:

• a first starter that is connected to a crankshaft of an engine and rotatably drives the crankshaft,
• a second starter that cranks the engine by rotatably driving a ring gear connected to the crankshaft, and
• a controller that controls operation of the first starter and the second starter, wherein
• the first starter is a motor generator having a function of an electric generator and a function of an electric motor,
• the second starter is a pinion enmeshing starter including
• a motor that receives electric power to cause it to rotate,
• a pinion that moves axially to mesh with the ring gear,
• a one-way clutch that transmits torque in only one direction from the motor to the pinion and blocks torque transmission from the pinion to the motor, and
• a solenoid device having a function of moving the pinion axially and a function of starting/stopping power supply to the motor,
• a magnitude relationship such that required passage torque is greater than engine starting torque is defined as a passage conditional expression, where
• the required passage torque is obtained by adding rotational torque obtained with kinetic energy stored in the engine from the start of cranking and driving torque which can be outputted with motor operation of the first starter, and
• the engine starting torque is obtained by adding compression torque and friction torque of the engine,
• the controller includes
• a start control section that, after activating the second starter to start cranking in response to a request for starting the engine, starts operation of the first starter and stops motor operation of the second starter at a predetermined timing, and
• a passage determination unit that determines whether the passage conditional expression holds after cranking is started by the second starter,
• the start control unit stops operation of the second starter and increases an output due to motor operation of the first starter if the passage conditional expression holds before the engine passes a first compression top dead center, regardless of whether the engine has passed the first compression top dead center.

A first starter comprising a motor generator connected to a crank shaft of an engine and having a function of an electric motor that rotatably drives the crankshaft and a function of an electric generator, and

• operation of the first starter being controlled by a controller together with a second starter which is a pinion enmeshing starter that cranks the engine by rotatably driving a ring gear connected to the crankshaft, wherein
• a magnitude relationship such that required passage torque is greater than engine starting torque is defined as a passage conditional expression, where
• the required passage torque is obtained by adding rotational torque obtained with kinetic energy stored in the engine from the start of cranking and driving torque which can be outputted with motor operation of the electric motor, and
• the engine starting torque is obtained by adding compression torque and friction torque of the engine,
• the controller includes
• a start control section that, after activating the second starter to start cranking in response to a request for starting the engine, stops operation of the second starter and starts motor operation of the first starter at a predetermined timing, and
• a passage determination section that determines whether the passage conditional expression is satisfied after cranking is started by the second starter,
• the start control section stops operation of the second starter and transmits a start signal for a starting motor operation of the first starter if the passage conditional expression holds before the engine passes a first compression top dead center, regardless of whether the engine has passed the first compression top dead center, and
• the first starter has a start signal receiver that receives the start signal.

A second starter, operation of the second starter being controlled by a controller together with a first starter that is connected to a crank shaft of an engine and the second starter comprising a motor generator having a function of an electric motor that rotatably drives the crank shaft and a function of an electric generator, and

• the second starter being a pinion enmeshing starter that cranks the engine by rotatably driving a ring gear connected to the crankshaft, wherein
• a magnitude relationship such that required passage torque is greater than engine starting torque is defined as a passage conditional expression, where the required passage torque is obtained by adding rotational torque obtained with kinetic energy stored in the engine from the start of cranking and driving torque which can be outputted with motor operation of the first starter, and the engine starting torque is obtained by adding compression torque and friction torque of the engine,
• the controller includes
• a start control section that, after activating the second starter to start cranking in response to a request for starting the engine, stops operation of the second starter and starts motor operation of the first starter at a predetermined timing, and
• a passage determination section that determines whether the passage conditional expression holds after cranking is started by the second starter,
• the start control section stops motor operation of the first starter and transmits a stop signal for stopping operation of the second starter if the passage conditional expression holds before the engine passes a first compression top dead center, regardless of whether the engine has passed the first compression top dead center, and
• the second starter has a stop signal receive that receives the stop signal.

A first starter comprising a motor generator connected to a crank shaft of an engine and having a function of an electric motor that rotatably drives the crankshaft and a function of an electric generator, and

• operation of the first starter being controlled by a controller together with a second starter which is a pinion enmeshing starter that cranks the engine by rotatably driving a ring gear connected to the crankshaft, wherein
• a magnitude relationship such that required passage torque is greater than engine starting torque is defined as a passage conditional expression, where
• the required passage torque is obtained by adding rotational torque obtained with kinetic energy stored in the engine from the start of cranking and driving torque which can be outputted with motor operation of the electric motor, and
• the engine starting torque is obtained by adding compression torque and friction torque of the engine,
• the controller includes
• a start control section that, after activating the second starter to start cranking in response to a request for starting the engine, starts motor operation of the first starter and stops operation of the second starter at a predetermined timing, and
• a passage determination section that determines whether the passage conditional expression holds after cranking is started by the second starter,
• the start control section stops operation of the second starter and transmits a start signal for increasing an output due to motor operation of the first starter if the passage conditional expression holds before the engine passes a first compression top dead center, regardless of whether the engine has passed the first compression top dead center, and
• the first starter has a start signal receiver that receives the start signal.

A second starter, operation of the second starter being controlled by a controller together with a first starter that is connected to a crank shaft of an engine and the second starter comprising a motor generator having a function of an electric motor that rotatably drives the crank shaft and a function of an electric generator, and

• the second starter being a pinion enmeshing starter that cranks the engine by rotatably driving a ring gear connected to the crankshaft, wherein
• a magnitude relationship such that required passage torque is greater than engine starting torque is defined as a passage conditional expression, where the required passage torque is obtained by adding rotational torque obtained with kinetic energy stored in the engine from the start of cranking and driving torque which can be outputted with motor operation of the first starter, and the engine starting torque is obtained by adding compression torque and friction torque of the engine,
• the controller includes
• a start control section that, after activating the second starter to start cranking in response to a request for starting the engine, starts motor operation of the first starter and stops operation of the second starter at a predetermined timing, and
• a passage determination unit that determines whether the passage conditional expression holds after cranking is started by the second starter,
• the start control section increases an output due to motor operation of the first starter and transmits a stop signal for stopping operation of the second starter if the passage conditional expression holds before the engine passes a first compression top dead center, regardless of whether the engine has passed the first compression top dead center, and
• the second starter has a stop signal receive that receives the stop signal.