JPS5479000A - Failure detection system - Google Patents

Abstract

PURPOSE: To detect the failure with good accuracy corresponding to the machine, by taking the failure criteria through the use of the average of shock of a plurality of operation cycles of the machine of lever operation and the dispersion from the average.

CONSTITUTION: In the reciprocating machine, such as press machines, for example, the acceleration sensor 4 detecting the shock at machining is mounted on the metal mold support stand 5, the proximity switch 8 detecting machining cycle is mounted on the press main body, and the signals from them are fed to the failure detector 10. Further, when the worker closes the start switch 28, the signal from the sensor 4 is integrated with the integrator 22, A/D converted, and is inputted to the operation unit 100. On the other hand, the cycle signal from the proximity switch 8 is inputted to the unit 100. The unit 100 takes the average of a plurality of cycles of the integrating value (shock value) of oscillation as comparison reference value, makes the criteria of two stages, for example, by multiplicating a constant with the maximum value of the dispersion from the average, and compares the difference between the shock and compared reference every operation cycle of machine with the criteria, and indication from the latch 26 for alarming and from the latch 26b for emergency stop can be made.

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