| 摘要 |
PROBLEM TO BE SOLVED: To provide a material testing machine having an expanded moving speed range on a cross head, and with its movement avoided from becoming intermittent at low-speed movement. SOLUTION: An upper gripping tool 17 and a lower gripping tool 18 for holding a test piece TP are mounted facing each other on the lower surface of the cross head 5 and on the upper surface of a fixed table 1, respectively. The cross head 5 is threadedly engaged with vertically extending screw rods 2 and 3. The cross head 5 goes up and down, when the screw rods 2 and 3 are rotatively driven by a motor 7. The torque of the motor 7 is transmitted to the screw rods 2 and 3, by a continuously variable transmission 12 and a transmission device 13. When the moving speed of the cross head 5 is changed, not only is the rotational speed of the motor 7 changed, but also the speed change ratio of the variable transmission 12 is changed. As a result, the speed range of moving speed is expanded, while the movement of the cross head 5 can be prevented from becoming intermittent in low-speed movement. COPYRIGHT: (C)2005,JPO&NCIPI
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