| 摘要 |
PROBLEM TO BE SOLVED: To provide a material testing machine which allows a gripper for gripping a specimen to have sufficient gripping force, with an inexpensive structure without power consumption.SOLUTION: A material testing machine has a hydraulic circuit including a manual hydraulic pump device 8, a hydraulic cylinder 50, a closing accumulator 9a which stores hydraulic pressure for closing a pair of gripping teeth through movement of a pair of gripping tooth holders 12 of an upper chuck part 1 and a lower chuck part 2, an opening accumulator 9b which stores hydraulic pressure for opening a pair of gripping teeth through movement of the pair of gripping tooth holders 12 of the upper chuck part 1 and the lower chuck part 2, and switching valves 61 and 62 for switching flow channels of hydraulic oil. |
