OVERLOAD PREVENTING APPARATUS OF MATERIAL TESTER

摘要

PURPOSE:To accurately test a test piece, by integrating load deviation when the load acting on the test piece exceeds a tolerant value and correcting the operation quantity of a load control mechanism on the basis of the integrated value. CONSTITUTION:When disturbance load epsilon4 is applied, the load r1 acting on a test piece 3 increases. As a result, when load deviation epsilon1 exceeds tolerant loads S3, S4, the outputs of comparators 23, 24 are reversed to an H-level and an error integrator 27 becomes an operative state. Whereupon, the load deviation epsilon1 is given to an error integrator 27 through a switch circuit SW2. The error integrator 27 integrates the load deviation epsilon1 to output the integrated value epsilon5. This integrated value epsilon5 is added so that the operation quantity epsilon2 outputted from an error amplifier 9 is reduced. Therefore, the load r1 reaching a tolerant range is controlled so as to gradually become zero by the action of the error integrator 27.