DETECTION OF FLUCTUATION IN BOTTOM DEAD POINT OF PRESS WORKING

摘要

PURPOSE:To detect easily the fluctuation in the bottom dead point of press working without being affected by a change in external temp., etc. by comparing said fluctuation between the previous time and the present time and stopping the press machine when the deviation value thereof exceeds a permissible value. CONSTITUTION:The system executes initialization to reset an I/O 5 upon closing of a power source and thereafter the system reads the permissible deviation value set to a digital switch 10 and stores the set data in an RAM4. The distance between a proximity body 11 which faces a bottom dead point position A by moving vertically cooperatively with the ram of the press machine and a proximity switch 12 is outputted from the switch 12 and is inputted via an amplifier 13 and an A/D converter 14 to a digital peak hold 15 which outputs the data on the bottom dead point position to the I/O 5. When the data on the deviation value of the fluctuation in the bottom dead point between the previous time and the present time exceeds a set value, an LED18 for displaying overflow is lighted and the stop signal for the press machine is outputted through a driver 21 for outputting the stop signal, by which the press machine is stopped.