GB751743A - Improvements in or relating to an air intake for an internal combustion engine - Google Patents

Abstract

751,743. Inlet ports; arrangement for fuel injectors and igniters. TEXACO DEVELOPMENT CORPORATION. Oct. 9, 1953 [Oct. 27, 1952], No. 27806/53. Classes 7(2) and 7(3) INLET PORTS In an arrangement of air intake ports in an engine of the uniflow-scavenged type in which the air whirls around the cylinder axis and is introduced into the cylinder 12, Fig. 1, through ports 20, Fig. 2, uniformly distributed in the cylinder wall, and wherein combustion of the air-fuel mixture is effected by a single flame-front, each of the ports having a flow axis perpendicular to the cylinder axis, the opposed walls of each port being parallel, and the downstream side wall of each port being disposed tangentially to the main wall of the cylinder, the width of each port is approximately one-half the cylinder radius so that the total number of ports is small, preferably six. The angle between the adjacent walls of adjacent, ports is 60 degrees and the height of each port is three-quarters of its width; each port has an associated vane 40, the length of which is one-third of the port length, the spacing between the vanes and port walls being such that the arc of each port, where it enters the cylinder, is bisected by the vane centre-line. The downstream wall of each port is disposed tangentially relative to the inner wall of the cylinder or to a circle having a diameter of 95 per cent of that of the cylinder. The trailing vane edges may either be rounded or as shown in Fig. 2. GENERAL CONSTRUCTION AND OPERATION The cylinder 12, Fig. 1, of a two-stroke engine has two exhaust passages 19 leading to a common manifold (not shown), each passage being provided with a poppet valve 18 whilst an intake manifold 21 opens into the piston-controlled ports 20 located above the B.D.C. position so that air drawn therethrough swirls around the cylinder at 4-9 times the engine speed. A fuel nozzle 26 is arranged to direct a coneshaped spray into one side of a diameter of the disc-shaped combustion-chamber 25 in the direction of air swirl to impregnate a localized segment of the air at a fuel-air weight ratio of 0.05-0.09; fuel injection is initiated 50-20 crank-angle degrees before T.D.C. and continues for 80-90 per cent of the time required for the air to complete one swirl. For reduced load conditions the injection period is reduced. Ignition is effected by glow-plug, compression, or, as shown, by a sparking plug 30 located 20 degrees-75 degrees downstream of the fuel nozzle with its electrodes 31 positioned close to the periphery of the combustion space; the spark occurs at 4-10 degrees crank angle after the fuel injection commences to ignite the impregnated segment and form the flame front. Specifications 596,846 and 666,507 are referred to.