| 摘要 |
PURPOSE:To permit molding of a powder molding having a uniform density distribution by feeding the output signals in the upper and lower directions of the molding detected by density distribution detectors back to respective upper and lower pressure control valves and controlling the control pressures for upper and lower punches respectively separately. CONSTITUTION:After the molding is discharged from a powder molding machine, the density distributions at some ten points in the axial direction of the molding are detected by gamma ray density detectors. The detected output signals are fed back to the upper punch pressure control valve 13 and the lower pressure control valve 15. The set pressure of the upper control valve 13 is increased and the pressurizing force of the upper punch 1 is increased up to the set pressure when the output signals are fed back to the upper and lower punch pressure control valves 13, 15 if the density in the upper part in; for example, the axial direction, is lower than the density in the lower part. The pressurizing force of the lower punch 2 is also decreased down to the set pressure as the set pressure of the lower control valve 5 is lowered. The densities in the upper and lower parts of the molding are, therefore, uniformized. |
