| 摘要 |
<p>639,756. Starting ; two-stroke engines. RICARDO, H. R., and HOLT, G. A. March 15,1948, No. 7753. Classes 7 (ii) and 7 (v)] In a two-stroke compression ignition engine having scavenging ports B<SP>2</SP> fed by a pump E the piston E<SP>1</SP> of which is 90 degrees in advance of the working piston D<SP>1</SP>, the exhaust valve G<SP>1</SP> is arranged to close earlier at starting to increase the compression ratio. The valve G<SP>1</SP> is actuated by a rocker arm H, Fig. 3, with an eccentric pivot H<SP>4</SP> which is rotatable by a lever J, a stop J<SP>1</SP> defining the normal running position and a stop J<SP>2</SP> the starting position in which the clearance between the rocker H and valve stem G<SP>2</SP> is increased to produce later opening and earlier closing of the valve. The transfer passage F contains a rotary valve F<SP>1</SP>, and the scavenging ports B2 are tangential to the cylinder to cause swirling of the air charge. The pump connecting rod E2 may be pivoted to the main connecting rod D or connected to a separate crank. In a modification the timing of the exhaust valve is varied by interposing an adjustable member between the rocker arm and valve stem. Specification 522,001 is referred to.</p> |
