GB239427A - Improvements in or relating to internal combustion engines - Google Patents

Abstract

239,427. Renault, L. Oct. 18, 1924, [Convention date]. Cylinders receiving liquid fuel. - An auxiliary charge of carburetted air, compressed in a chamber 2 to a pressure lower than that finally attained on the compression stroke in the cylinder, is ignited immediately before the piston reaches the top dead centre position, and entering the combustion chamber 1 through a valve 3, vaporizes and ignites the main charge of heavy fuel, which is injected directly into the combustion chamber 1 through a nozzle 10, or supplied to a point above the valve 3 and carried into the combustion chamber by the auxiliary charge. The fuel may be supplied by a measuring pump, or drawn into the chamber 2 by the engine. The chamber 2 is charged from a carburettor 17, which in a two-stroke-cycle engine may be supplied with air under pressure by a pipe 18 connected to the scavenging air supply pipe 19. The chamber 2 communicates with the cylinder through a passage 4, which towards the end of the compression stroke is closed by the engine piston 14, so as to arrest compression in the chamber 2 before the final pressure in the combustion chamber has been attained. The valve 3 may be operated either by fluid-pressure or mechanically and opens during the period of ignition only. Starting is facilitated by cutting off the supply of heavy fuel entirely, and by providing means to prevent the compression pressure in the combustion chamber 1 from exceeding that normally attained in the chamber 2. This may be effected in a four-stroke-cycle engine by a release valve in the combustion chamber 1. The engine may be run on the auxiliary charge of fuel alone when idling or at light loads. In some cases, when the engine has warmed up, the auxiliary chamber 2 may be cut out, the fuel being ignited by the heat of compression in the chamber 1; for this purpose a stop valve may be provided in the passage 4.