(A) ;4(3H)-OXO-5,6,7,8-TETRAHYDROPYRIDO(2,3-D)PYRIMIDINE DERIVATIVE

摘要

PURPOSE:To specify the axial direction of a rotational shaft so that the insertion of the shaft and the removal of a rotor from a mold are not disturbed by oppositely opening a pin point gate and through holes for inserting the shaft of the rotor at the center of an openable nonmagnetic mold provided at the hole of a cylindrical cavity. CONSTITUTION:A cavity 18 is formed via a bottom 26 and a cylindrical inner peripheral wall via a stationary side mold 25 made of a nonmagnetic material. Magnetized yokes 28 made of a ferromagnetic material having a plurality of poles at equal central angles are arranged on the raidal outer periphery of the cavity 18. A through hole 32, to which a rotational shaft 30 of a rotor is inserted, is opened at a stationary mold 24 formed with a bottom 26 in coincidence with the central axis of the cavity 18. A movable mold 40 made of a nonmagnetic material is arranged above the caivity 18, a pin point gate 44 for injecting molten mixture is opened at the center of the raised part 42 of the conical trapezoid formed in the mold 40 in coincidence to the central axis to the hole 32. Thus, the shaft 30 is forcibly axially pressed by hydraulic pressure of the mixture 54 at the time of injecting from the gate 44, and specified at the position as prescribed.