Engine and engine-operated working machine
AssigneeHitachi Koki Co., Ltd.
InventorsAkira Mezaki, Shigetoshi Ishida
Life of this patent
Estimating the term…
Abstract
An engine is configured such that, during the starting of the engine, when it is being detected that throttle opening has been set at a starting position, if it is detected that the engine speed has exceeded a predetermined speed slightly lower than a speed when a centrifugal clutch becomes an engaged state, a control unit retards the ignition timing from a general angle to a first angle BTDC, and then advances the ignition timing to a second angle at predetermined intervals, and holds the ignition timing at the second angle for a predetermined time period, thereby preventing the engine from stopping due to fouling on the spark plug while suppressing the engine speed at the speed when the centrifugal clutch becomes the engaged state, or less.
Claims8
An engine comprising:
- a cylinder;
- a carburetor configured to supply an air-fuel mixture into the cylinder and includes a throttle valve;
- and
- an ignition device configured to ignite the air-fuel mixture in the cylinder, wherein:
- the engine comprises:
- an engine-speed detecting unit configured to detect the speed of the engine;
- a throttle-opening detecting unit configured to detect a state that an opening of the throttle valve is held at a predetermined position for starting of the engine;
- and
- a control unit configured to control the ignition timing of the ignition device;
- and
- if the engine has exceeded a predetermined speed during a time while the throttle-opening detecting unit is detecting the state that the opening of the throttle valve is held at the predetermined position at a time of starting of the engine the control unit performs control such that:
- the ignition timing is retarded from a general angle to a first angle;
- the retarded ignition timing is intermittently advanced from the first angle to a second angle;
- and
- the retarding to the first angle and the advancing to the second angle are repeated alternatively.
Dependencies are inferred from the claim text.