GB1221470A - Apparatus for saving fuel and cleansing exhaust gas in a multi-cylinder engine - Google Patents

Abstract

1,221,470. I.C. engines. NISSAN JIDOSHA K.K. Nov.21, 1968 [Jan. 25, 1968], No. 55220/68. Heading F1B. In a multicylinder automobile engine, valves mounted in selected branches of the inlet manifold are operable to isolate selected cylinders from the manifold, the valves being operated by connecting means accommodated at one end in cylinder means, means responsive to coasting condition of the automobile causing actuating means to open a pipe means to communicate negative pressure from the manifold to the cylinder means so as to close the valves, whereby the selected cylinders are isolated from the manifold and the remaining cylinders receive increased mixture supply to improve combustion during coasting with a transmission gear engaged. During coasting with a transmission gear engaged, the suction in the inlet manifold 4, Figs. 1 and 2, communicated via a pipe 13 to a cylinder 15 is high enough to draw a piston valve 14 leftwards against the action of a spring 19 to close a vent 17 and to communicate the suction via holes 14b and a port 16 to the space A above a piston 21. Consequently, the piston 21 moves upwards to close valves 10 in the inlet manifold branches 6, 7 leading to the two inner cylinders of the four-cylinder engine. In addition, a projection 30 lifts a flap valve 28 against the action of a spring 32 to vent the branches 6, 7 downstream of the valves 10 to atmosphere via an inter-communicating pipe 26 and a vent pipe 27. Mixture is now supplied only to the two outer cylinders connected to the branches 5, 8, and the engine runs on these two cylinders only. Since the mixture is being supplied to two cylinders instead of four, each cylinder receives twice as much mixture as if all four cylinders were operative, so that the combustion is improved and less carbon monoxide and unburnt hydrocarbons are exhausted to atmosphere. In addition, the air drawn in through the vent pipe 27 by the two inoperative cylinders oxidizes hydrocarbons in the exhaust. In a modification, Fig.3 (not shown), the suction-operated piston valve 14 is replaced by a solenoid valve (34) energized by a vacuum switch (33) operated by the manifold suction. In another modification, Figs. 4 and 5 (not shown), the solenoid valve (34) is energized by switches (46, 47, 48) in series, these switches being closed when the clutch and accelerator pedals are not depressed and the gear lever is not in neutral position.