Measuring working force of a mechanical press with oil pressures compared to a corresponding relationship

摘要

Pressurized oil is charged into a hydraulic chamber (12) formed within a slide (3) of a mechanical press (1). A relationship between a working force (F) during a press working and a pressure (P) of the pressurized oil is preliminarily measured for every predetermined initial pressure of the pressurized oil. A computer (33) stores the measured results as a plurality of pressurizing characteristics (A1), (A2) and (A3). The computer (33) stores through a pressure sensor (27), a pressure of the pressurized oil while a press working is not performed, as a preload pressure (Pa1). And it stores a maximum pressure of the pressurized oil during the press working as a peak pressure (Pb1). It further selects a pressurizing characteristic (A1) corresponding to the preload pressure (Pa1) from among the plurality of pressurizing characteristics and thereafter calculates a working force (F1) based on the selected pressurizing characteristic (A1) and the peak pressure (Pb1). <IMAGE> <IMAGE>