摘要:
An automotive reciprocating engine design is disclosed preferably including an extruded cylinder bore block with cylinder bores and a surrounding coolant passage extending from a top flat surface to a bottom flat surface; a cast, closed bottom, open top crankcase with vertical walls having flat upper surfaces; and a stamped metal mid-plate interposed in sealing relationship between the bottom surface of the cylinder block and the flat top surfaces of the crankcase. The crankcase contains bearing supports for a crankshaft and the mid-plate contains holes for connecting rods attached to pistons in the cylinder bores. The design facilitates low cost manufacture of strong, light weight components and easier assembly of the engine, and permits flexible manufacture of a family of engines with different displacements by substitution of a cylinder block of different length or of different bore diameter.
摘要:
An aluminum casting of composition that is hardenable due to the presence of suitable amounts of silicon, magnesium and, optionally, other hardening constituents such as copper, nickel and the like is heat treated for improved tensile strength at 300.degree. C. The casting, which as formed has a microstructure of aluminum rich dendrites, silicon particles and hardening particles, is reheated above 500.degree. C. to redissolve the hardening particles and redistribute hardening constituents through the aluminum dendrites, cooling the casting to 350.degree. C. to 450.degree. C. and holding there to reform an abundance of large stable hardening precipitates in the aluminum dendrites and then air cooling the casting. The thus treated casting may then be artificially age hardened such as by a T5 temper practice.