| 摘要 |
PURPOSE:To aim at improvements in engine performance and reduction in a rate of fuel consumption under each running condition of an engine, by controlling each operation timing of both suction and exhaust valves in a manner conformable to engine requirements, while making the valve lift adjustable so as not to produce any interference between a piston head part and a valve lower end. CONSTITUTION:Each operation timing of both suction and exhaust valves is preset so as to accord with the case where an engine is driven at high speed. In time of low engine speed, valve timing is controlled at the timing advance side by a signal out of an engine speed sensor 11 and simultaneously, valve lift of either valve for suction or exhaust at the side approximating to a piston to be situated in and around a top dead point is lowered down whereby interference between a piston head part and a valve lower end is prevented from occurring. In times of high speed and high load of the engine, the said timing is restored to the original setting one. According to this method, a dead space in a combustion chamber is brought to nothing, and the valve timing is controlled to a proper valve so that engine performance is improved and, what is more, a rate of fuel consumption is well improved. |
