Spark plug ignition system for use in rotary piston engine

Claim 2

A spark plug ignition system for use in a rotary piston internal combustion engine comprising a housing structure having a peripheral wall formed with a multilobed inner peRipheral surface, a multilobed rotary piston mounted for rotation within said housing structure, said housing structure being formed with an intake port connected with an air source through a choke valve and a throttle valve, an exhaust port and at least two spark plugs arranged one behind the other in the direction of rotation of said rotary piston, said ignition system comprising means for detecting the engine temperature, means for detecting the engine speed, means for detecting the positioning of the choke valve and means for controlling the ignition timing of each of said two spark plugs whereby, when the engine temperature detected by said engine temperature detecting means is lower than a predetermined value and said engine speed is also smaller than a predetermined value during the substantial closure of said choke valve, the ignition timing of one of said two spark plugs which is positioned at the leading side with respect to the piston rotational direction is retarded while the other spark plug positioned at the trailing side with respect to the piston rotational direction is switched off.

Claim 3

The ignition system as claimed in claim 1, further comprising means for detecting the low load drive of the engine by which, when the engine temperature detected by said engine temperature detecting means is lower than the predetermined value and said engine speed is also smaller than the predetermined value during the substantial closure of said choke valve and concurrently when the engine is operated under low load drive, the ignition timing of siad leading spark plug can be retarded while the other trailing spark plug is switched off.

Claim 4

An ignition system as claimed in claim 1, wherein said engine temperature detecting means includes a first detector means operable only when the engine temperature exceeds over a first predetermined value and a second detector means operable only when the engine temperature exceeds over a second predetermined value whereby, when the engine temperature detected is lower than said first predetermined value and the engine speed is also smaller than the predetermined value during the substantial closure of the choke valve, the ignition timing of the leading spark plug is retarded while the other spark plug is switched off; when said engine temperature detected is existing between said first and second predetermined values and the engine speed is also smaller than the predetermined value during the substantial closure of said choke valve, the ignition timing of the leading spark plug is fixed at the normal timing while the other trailing spark plug is switched off; and when said engine temperature is higher than the second predetermined value and the engine speed is also smaller than the predetermined value during the substantial closure of said choke valve, both the leading and trailing spark plugs are normally switched on.

Claim 5

A spark plug ignition system for use in a rotary piston internal combustion engine comprising a housing structure having a peripheral wall formed with a multilobed inner peripheral surface, a multilobed rotary piston mounted for rotation within said housing structure, said housing structure being formed with an intake port connected with an air source through a choke valve and a throttle valve, an exhaust port and at least two spark plugs arranged one behind the other in the direction of rotation of said rotary piston, siad ignition system comprising a first means for detecting the engine temperature and operable only when said engine temperature exceeds over a first predetermined value, a second means for detecting the engine temperature and operable only when said engine temperature exceeds over a second predetermined value, means for detecting the engine speed and operable only when said engine speed exceeds over a predetermined value, means for detecting the positioning of the choke valve, means for detecting the low load drive of the engine and means for controlling the ignition timing of each of said two spark pluGs whereby, when the engine temperature detected is lower than said first predetermined value and the engine speed is smaller than the predetermined value during the substantial closure of the choke valve under low load drive, the ignition timing of one of said two plugs positioned at the leading side with respect to the piston rotational direction is retarded while the other spark plug positioned at the trailing side with respect to the piston rotational direction is switched off; when the engine temperature detected is existing between said first and second predetermined values and the engine speed is smaller than the predetermined value during the substantial closure of the choke valve under the low load drive, the leading spark plug is normally switched on while the other trailing spark plug is switched off; and when the engine temperature detected is higher than the second predetermined value and the engine speed is smaller than the predetermined value during the substantial closure of the choke valve under the low load drive, both the leading and trailing spark plugs is normally switched on.

Claim 6

A spark plug ignition system for use in a rotary piston internal combustion engine comprising a housing structure having a peripheral wall formed with a multilobed inner peripheral surface, a multilobed rotary piston mounted for rotation within said housing structure, said housing structure being formed with an intake port connected with an air source through a choke valve and a throttle valve, an exhaust port and at least two spark plugs arranged one behind the other in the direction of rotation of said rotary piston, siad ignition system comprising a first means for detecting the engine temperature and operable only when said engine temperature exceeds over a first predetermined value, a second means for detecting the engine temperature and operable only when said engine temperature exceeds over a second predetermined value, means for detecting the engine speed and operable only when said engine speed exceeds over a predetermined value, means for detecting the positioning of the choke valve, means for detecting the low load drive of the engine and means for controlling the ignition timing of each of said two spark pluGs whereby, when the engine temperature detected is lower than said first predetermined value and the engine speed is smaller than the predetermined value during the substantial closure of the choke valve under low load drive, the ignition timing of one of said two plugs positioned at the leading side with respect to the piston rotational direction is retarded while the other spark plug positioned at the trailing side with respect to the piston rotational direction is switched off; when the engine temperature detected is existing between said first and second predetermined values and the engine speed is smaller than the predetermined value during the substantial closure of the choke valve under the low load drive, the leading spark plug is normally switched on while the other trailing spark plug is switched off; and when the engine temperature detected is higher than the second predetermined value and the engine speed is smaller than the predetermined value during the substantial closure of the choke valve under the low load drive, both the leading and trailing spark plugs is normally switched on.