REVERSIBLY ROTATING ENGINE

摘要

This invention is characterized in that, in order to use an engine like a nut runner by shifting between a forward rotational mode and a reverse rotational mode, rotation positions taken by a crankshaft when a primary current has a maximum voltage during forward and reverse rotations of the engine are set symmetric with respect to and ahead of a rotation position of the crankshaft corresponding to the upper dead point of a piston. When the voltage of the primary current in an electromotive coil (97) becomes maximal in a predetermined rotation position, which is ahead of the upper dead point of the piston (7) with respect to the rotational direction of the crankshaft, while the engine is rotated forwardly or the engine is rotated reversely, this voltage is detected by an ignition unit (177) in a position, in which the voltage reaches a predetermined level in the vicinity of the maximum level, or in a position, in which the voltage drops from the maximum level by a predetermined voltage, so that the primary current is short-circuited to generate a high voltage current in a secondary circuit and perform electric discharge at an ignition plug (45). Since the time of this ignition is set in the same position, which is ahead of the upper dead point, whether the engine is rotated forwardly or the engine is rotated reversely, it is unnecessary to regulate an ignition time according to the directions of the rotation.