JPS64318A - Supercharged engine - Google Patents

Abstract

PURPOSE: To secure the desired output performance as checking the occurrence of knocking by controlling the closing timing of a suction valve to the later timing of more than the specified angle than a bottom dead point at time of high engine speed, and hang the closing timing subjected to variable control according to a suction air charging quantity at time of low engine speed, at a high load driving area.

CONSTITUTION: A tappet 23, opening or closing a suction valve 6 by rotation of a cam-shaft 21 is held on the rocking member 25 supported on this cam shaft 21 free of rocking motion. And, this rocking member 25 is rocked by a motor 27 via a worm gear 26 whereby an engaging position between the worm gear 26 and the rocking members 25 is varied to some extent, and also engaging relation between the tappet 23 and a cam on the camshaft 21 is varied, thus the on-off timing of the suction valve is controlled. At this time, at an electronic control unit 28, when an engine is in a high load driving area, closing timing of the suction valve 6 is controlled to the later timing of more than 50 degrees than at least a bottom dead point at time of high engine speed, while at time of low engine speed, the motor 27 is controlled to variably control the closing timing of the suction valve 6 according to a suction air charging quantity.

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