A control device prevents damage due to backward rotation of a rotary engine and prevents misjudgment of backward rotation of the rotary engine. The control device for a rotary engine includes a motor mechanically connected to the shaft of the rotary engine, a controller (a motor ECU) that performs energization control of the motor to start the rotary engine by driving the motor, and a sensor (such as a motor rotation sensor). When starting the rotary engine, the controller stops energization to the motor based on an electric signal from the sensor when the shaft of the rotary engine rotates backward a predetermined angle or more, and then the shaft of the rotary engine continues to rotate backward for a predetermined time.

A system for starting an engine of a vehicle has a fuel injector injecting fuel into a closed intake port to form an air fuel mixture. The system also includes an actuator rotating a crankshaft in a first direction to open the intake port by moving a piston within a cylinder coupled to the crankshaft. A combustion chamber defines between the cylinder and the port receiving the air fuel mixture through the intake port. The actuator rotates the crankshaft in a second direction to close the intake port. A spark plug ignites the air fuel mixture to start the engine. The engine also includes many other disclosed features.

A method for starting an internal combustion engine has the steps of: oscillating a crankshaft of the engine using the electrical actuator; then injecting fuel in a combustion chamber and igniting the fuel in this combustion chamber to cause the crankshaft to turn in a reverse direction; then injecting fuel in another combustion chamber and igniting the fuel in the other combustion chamber to cause the crankshaft to turn in a forward direction; and then injecting fuel in the other combustion chamber and igniting fuel in the other combustion chamber to cause the crankshaft to turn in the forward direction.

In a system for controlling rotation of torque applied to a rotating shaft of an engine of a vehicle that uses the engine as a drive source thereof, a motor is provided. A main controller controls the engine and the motor. The main controller selectably activates the motor that applies first torque to the rotating shaft of the engine, and deactivates the motor. A rotary electric machine includes a rotor connected to the rotating shaft of the engine. A rotation parameter detector measures a rotation parameter associated with rotation of the rotor of the rotary electric machine. A sequence controller performs, in response to an occurrence of a trigger situation, a control sequence that controls, independently of the main controller, the rotary electric machine based on the rotation parameter measured by the rotation parameter detector, thus applying second torque to the rotating shaft of the engine.

In order to provide an engine automatic stop and restart apparatus capable of realizing excellent startability, and preventing an excessive load from being imposed on a starter (30) and a power transmission system, a starter drive inhibition determination section (12) inhibits, in a case where an engine restart condition is satisfied, when a backward rotation of an engine (20) is detected based on a crank angle of a crankshaft of the engine (20) detected by a crank angle sensor (1) for detecting the crank angle, a drive of the starter (30) configured to crank the crankshaft so as to restart the engine (20), and releases, when a stop of the engine (20) is detected, the drive inhibition of the starter (30).

A device for automatically stopping and restarting an internal combustion engine is provided with a crank angle sensor (1) that detects a crank angle of an engine (10), a fuel injection unit (11) that injects fuel into the engine, and the device is also provided with a starter activation prohibition determination means that prohibits activation of a starter (20) by determining that the engine is in reverse rotation during inertial rotation of the engine, and removes the starter activation prohibition depending on the crank angle when the engine starts reverse rotation.

A control device according to the present invention performs an automatic stop control in which an injection of fuel from a fuel injection valve is stopped and a rotation of an engine is stopped when an automatic stop condition is satisfied. Furthermore, the control device controls an injection operation of fuel and an ignition operation to the fuel in consideration of compression when the fuel is actually ignited in an expansion stroke cylinder, when a re-start demand occurs after an initiation of the automatic stop control and the engine is to be re-started by an ignition start-up. Specifically, the control device predicts a crank angle at an actual ignition time point in a case where processing for performing the ignition start-up at the present time whenever a predetermined time period has passed. Then, the control device initiates the ignition start-up when the crank angle falls within a predetermined range in which a sufficient compression can be attained. Thereby, the engine is more certainly re-started by the ignition start-up.

A control device sets reverse rotation period as a cranking prohibition period, and when a start request of an engine is generated during reverse rotation period, cranking is started by driving either or both of the first starter and the second starter when it is detected that a crankshaft is shifted from reverse rotation to forward rotation based on an information of a rotation angle sensor. As a result, the delay from generation of the start request of the engine until cranking is started can be reduced, so that the starting time of the engine can be shortened.

If an internal combustion engine that has been automatically stopped is to be restarted under a decreased engine speed, a control unit of the internal combustion engine starts cranking when a crank angle of a cylinder in compression stroke of the internal combustion engine is closer to bottom dead center than a threshold value set in advance. More specifically, if an engine speed of the internal combustion engine is in forward rotation, the cranking is begun when the crank angle of the cylinder in compression stroke is closer to the bottom dead center than a threshold value set in advance. If the engine speed of the internal combustion engine is in backward rotation, the cranking is begun when the crank angle of the cylinder in compression stroke is closer to the bottom dead center than another threshold value set in advance.

A method for starting an internal combustion engine of a snowmobile is disclosed. The method comprises actuating a start switch of the snowmobile; in response to the start switch being actuated, sensing a temperature; in response to the sensed temperature being above a predetermined temperature, starting the engine using a motor-generator; and in response to the sensed temperature being below the predetermined temperature, starting the engine using a recoil starter.