JPS57175051A - Gate for cast pipe joint - Google Patents

Abstract

PURPOSE: To prevent generation of casting defects in the stage of casting a pipe joint by providing excess metal between the gate for casting and the inside surface of the pipe joint and forming the rupture initiation point of the gate at the point where the end face of the gate and the slope of the excess metal intersect, thereby widening the rupture plane of the gate and retarding the solidification of charged molten metal.

CONSTITUTION: In the stage of casting a pipe joint, an excess metal part 4 is provided between a gate 3 after a riser and the working surface 1a in the end part 1 of the joint. The excess metal 4 has a slope 4a on the inner side, and a set rupture plane P-P of the gate is provided flush to this slope. The size of the juncture of the gate 3 and the metal 4 at the plane P-P is made smallest within the section of the gate 3 to make the gate easier to break after solidification. In this case, a rupture initiation point 5a is formed at the point where the end face 3a of the gate 3 and the slope 4a of the metal 4 intersect. The angle α of this intersecting part is set at 30W120°, and the length l of the plane P-P is increased to improve the flow of molten metal flowing in this part, whereby the solidification in this part is retarded and the generation of casting defects such as internal defects is prevented.

COPYRIGHT: (C)1982,JPO&Japio