REPETITION LOAD CONTROL DEVICE OF MATERIAL TESTING MACHINE

摘要

PURPOSE:To eliminate a change of load to a body to be tested and enhance a reliability of the test by subtracting a mean desired value of a repetition load from a detecting signal in a previous stage of an amplifying means in a feed back loop. CONSTITUTION:A hydraulic load mechanism 11 has a servo valve and loads a body to be tested by a signal from a servo amplifier 12. A load operating by this loading is detected in a load cell 13 and a load amplifier 14 and fed back to a comparison section 17 through an adding point 15 and a multiplier 16. To this adding point 15, a reverse signal of a mean value of a repetition load to be added to the body to be tested is added and to the multiplier 16, an amplification setting signal is inputted. These signals are calculated in a computer system 18 and outputted. The amplification can be automatically set as highly as possible, so that a high control accuracy can be maintained and an accuracy in a minute amplitude control of a highly average level can be enhanced.