| 摘要 |
523,694. Casting engine cylinder blocks. RANSOMES, SIMS & JEFFERIES, Ltd., and MILLER, N. B. Jan. 12, 1939, No. 1089. [Classes 83 (i) and 83 (ii)] Moulding processes; patterns.-The cylinder block of an air-cooled internal - combustion engine, including the cylinder 1, crank case 7, and pockets 3, 4 for the inlet and exhaust valves with an air gap 6 between the cylinder and said pockets is cast in a two-part mould with its parting plane P-P containing the centre lines c<SP>1</SP>, c<SP>2</SP> of the cylinder and the crank-shaft and passing between the pockets 3, 4, which mould is made made from a pattern having substantially all its projections extending at right angles to the plane P-P. Small projections or deviations from the right angle can be provided by making such parts of the pattern as loose pieces which can be removed after the main pattern is drawn. An air gap 14 may be formed between the pockets 3, 4 by a core. The space 6 may be produced by parts of the mould or by a core and cores are used for forming the cylinder crank-case, ports, and other hollow parts in the usual way. The casting has a pocket 8 for the valve gear and bosses 12 for securing separately made covers. A selfcontained, N, two-cylinder block can be cast similarly, the two cylinders having a common crank-case 7, Fig. 9, and valve-gear pocket 8, but each its own valve pocket 3, 4, Fig. 11. In this case the parting plane P-P is at right angles to the crank-shaft. |
