GB773583A - Improvements relating to four-stroke internal combustion engines and a method of operation therefor - Google Patents

Abstract

773,583. Combustion chambers; supplying liquid fuel or rich mixture. STUMPFIG, F., and BELLWINKEL, C. Nov. 12, 1953 [Nov. 15, 1952], No. 31395/53. Class 7 (3). In a method of operating a four-stroke engine wherein at least the major part of the combustion air is introduced into the cylinder space and pure fuel or very rich mixture is introduced into a combustion chamber d in communication with the cylinder space, the contents of the combustion chamber are so guided during the suction or compression stroke as to hinder escape of fuel from the combustion chamber until the moment of ignition and to cause the fuel droplets to be thrown against the combustion chamber wall and evaporated thereon, the rest of the combustion air, which may comprise a weak mixture, is compressed in a space o, and the contents of the chamber d are completely burnt after ignition in the air outside the chamber. In the cylinder head c are the inlet and exhaust valves e, g, respectively, the inlet valve e having a passage member f attached thereto, and the combustion chamber d. When the inlet valve e is closed the combustion chamber d communicates through a tangential passage h with the air compression space o beneath the inlet valve and through an opening i leading into the cylinder space. When the inlet valve is open the member f is situated in front of the passage h and so connects a fuel or rich mixture supply pipe k with the combustion chamber d; the latter has a sparking plug l secured therein. The opening i lies substantially opposite the exhaust valve g. The engine may also embody the following features:-(1) Operate on heavy oil which may be supplied for normal running either after the engine has been started on a petrol-air mixture or when the fuel pipe, fuel or combustion chamber have been electrically pre-heated. (2) The very rich mixture may be produced in a carburetter, not shown. (3) Air only is drawn in through the fuel pipe and fuel is injected by a pump either into the pipe or directly into the combustion chamber. (4) A fuel vapour with or without air may be produced instead of a rich mixture and supplied through the fuel pipe, the fuel droplets being evaporated in the combustion chamber. (5) The very rich mixture may be drawn into the combustion chamber through a special admission valve, not shown. (6) The exhaust valve may be disposed between the combustion chamber and the exhaust pipe, not shown. (7) The combustion chamber may be spherical or heart-shaped in cross-section and together with the air compressor chamber may be disposed outside the cylinder head. (8) The valves may be arranged overhead or on the side or a combination of both. (9) A member m may be provided in the piston to close the opening i at T.D.C. of the piston and the sparking plug may be arranged slightly eccentrically of the opening i. (10) The fuel pipe is thermally insulated from the combustion chamber. (11) The mixture may be ignited by the heat of compression. During the suction stroke air passes into the cylinder space in the direction of the arrow I and a very rich mixture is drawn out of the pipe k and tangentially enters the combustion chamber d to whirl therein the fuel droplets being thereby thrown against the chamber walls where they are evaporated or gasefied and cracked ; the shape of the combustion chamber largely prevents the passage of fuel droplets into the cylinder space. During the compression stroke the air is forced into the chamber d directly through opening i and indirectly from space o via passage h so that not only is the whirling of the gas therein maintained but a transverse whirl is also imparted thereto. An ignitable mixture is thus formed in the vicinity of plug l and is ignited thereby and since at T.D.C. the opening i is closed by the piston the remainder of the rich mixture in the combustion chamber passes through the passage h into the space o where it mixes with the air therein and burns without knocking during the following working stroke.