| 摘要 |
PURPOSE:To reduce cost by insert-casting a pipe while changing the number of turns of iron wires according to a pouring temp., pouring weight and the wall thickness of the pipe. CONSTITUTION:The pipe 1 is formed to a required shape and the size, material quality and number of turns of the iron wires 3 are adjusted according to the wall thickness of the pipe 1. the number of turns, size and material quality of the iron wires 3 are determined by considering so as not to allow the pipe 1 to be welded or eroded during pouring. More specifically, the number of turns of the iron wires is increased when the pouring temp. is high and the heat capacity of a casting 2 is large. The number of turns of the iron wires 3 is conversely decreased when the heat capacity is small and the thorough welding is not executed. The size of the iron wires 3 is made larger or the number of turns thereof is increased in the position before a gate where much molten metal flows or the like. The size of the iron wires 3 is made smaller or the number of turns is decreased at the point where the molten metal is liable to solidify. The cost of an operation for boring a three-dimensionally curved hole is reduced by the above-mentioned method. |
