GB461757A - Improvements in or relating to exhaust systems of two-stroke internal combustion engines - Google Patents

Abstract

461,757. Exhaust systems. SCHNURLE, A. Sept. 2, 1935, No. 24514. Convention date, Aug. 31, 1934. [Class 7 (ii)] In a two-stroke engine cylinder, scavenging is improved, and exhaust ejected, by leading the exhaust gas tangentially into a drum 7 by a pipe 5, the cross-sectional area of which is half that of the cylinder ports 4 to which it is connected by a tapering passage. A high velocity whirl being thus produced in the drum which may be cylindrical or conical. The gas leaves the drum by a pipe 8, which may be tangential, and diverging, and is preferably arranged farther from the axis than the inlet, the drum being stepped for this purpose if necessary. Fig. 6 shows a conical drum having an annular outlet slit 14 which communicates with a passage 15 having continuously increasing cross-section ; the slit may be replaced by a guide ring containing nozzles. The cylinder charge may, or may not, be supplied by a pump. The Specification as open to inspection under Sect. 91 comprises also a multi-cylinder engine, the cylinders of which are connected to the drum by separate pipes which may be arranged to exert an ejector effect on one another. In a radial-cylinder engine the drum may be coaxial with the engine, the crank-shaft extending through the drum. Two exhaust ports may be provided in each cylinder wall, the first to be opened by the piston being connected tangentially to the drum by a pipe 5, the gas whirling in the drum exerting a suction on the other port which is connected axially thereto by a largebore pipe. The pipe 5 may be flattened at its entrance to the drum to produce a nozzle effect. In a multi-cylinder engine separate pipes 5 lead tangentially to the drum and are arranged to produce an ejector action on one another, whereas the subsequently-opened ports are connected to the drum by a common manifold. This subject-matter does not appear in the Specification as accepted.