Control system for reversible internal combustion engine

A control system for an internal combustion engine comprising a rotational direction change-over switch. to be operated when a rotational direction of the two-cycle internal combustion engine should be reversed;

• an AC magneto generator constructed to generate an AC output voltage of 2n cycles (“n” is an integral number of more than 1) per revolution of said internal combustion engine with a phase of said AC output voltage being set so that either of zero cross points of said AC output voltage corresponds to said low speed ignition position on the reverse rotation of said internal combustion engine;
• a signal generator constructed to generate a pulse signal of one polarity and a pulse signal of other polarity in synchronization with said rotation of said internal combustion engine with generation positions of said pulse signals being set so that said pulse signals of one polarity and of other polarity are generated at said low speed ignition position on the forward rotation of said internal combustion engine and at the position advanced relative to said low speed ignition position of said forward rotation of said engine, respectively and so that the polarity of half wave of said AC output voltage of said magneto generator when said pulse signal of one polarity is generated is identical to the polarity of half wave of said AC output voltage of said magneto generator when said pulse signal of other polarity is generated;
• rotational direction judgment means to judge said rotational direction of said internal combustion engine from the polarity of said half wave of said AC output voltage when said signal generator, generates the pulse signal of either polarity;
• ignition position arithmetical operation means to arithmetically operate the ignition positions of said internal combustion engine when it rotates forwardly and reversely at a set value or more than of said rotational speed, respectively;
• steady-state operation ignition control means to ignite said internal combustion engine when said ignition position arithmetically operated by said ignition position arithmetical operation means is detected in the condition where said internal combustion engine rotates forwardly and reversely at said set value or more than of said rotational speed, to ignite said internal combustion engine when said pulse signal of one polarity generated by said signal generator is detected in the condition where said internal combustion engine forwardly rotates at less than said set value of said rotational speed and to ignite said internal combustion engine when said zero cross point of said AC output voltage corresponding to said low speed ignition position of the reverse rotation is detected in the condition where said internal combustion engine reversely rotates at less than said set value of said rotational speed;
• rotational direction change-over means including speed reduction means to reduce said rotational speed of said internal combustion engine when said rotational direction change-over switch is operated, ignition position over-advance means to ignite said internal combustion engine at an advance angle position necessary for reversing said rotational direction of said internal combustion engine when said rotational speed is reduced to less than a set value and reversion initial ignition control means to ignite said internal combustion engine at a reversion initial ignition position suitable for a first ignition position after said rotational direction is reversed when the reversion of said rotational direction of said internal combustion engine is judged by said rotational direction judgment means;
• said rotational direction change-over control means adapted to decide said reversion initial ignition position when the rotational direction of said internal combustion engine is changed from the forward direction to the reverse direction on a rotation angle position information obtained from zero cross points of said AC output voltage of said magneto generator and set said reversion initial ignition position when said rotational direction of said internal combustion engine is changed from the reverse direction to the forward direction, at a position where said signal generator generates the pulse signal of one-polarity.