Inner and outer double-layer nested pouring system of special-shaped double-layer hollow thin-wall casting

The inner and outer double-layer nested gating system comprises an outer-ring sprue and an inner-ring sprue, the outer-ring sprue and the inner-ring sprue share the same cross gate, the cross gate is arranged at the bottom end of the casting, an outer skin and an inner skin are arranged at the inner end of the outer-ring sprue, and the inner skin is arranged at the outer end of the outer-ring sprue. A hollow area is reserved between the outer skin and the inner skin; the inner ring sprue is divided into a first flow gate and a second flow gate which are respectively connected with a machining part of a casting, and an included angle of 45 degrees is formed between the first flow gate and the second flow gate and the horizontal plane. By means of the system, the mold filling efficiency of the complex special-shaped double-layer large hollow thin-wall casting is improved. The cleaning difficulty is small, runner residues are reduced, and the casting machining difficulty and the casting machining time are reduce