| 摘要 |
PROBLEM TO BE SOLVED: To minimize a load applied to a thread mechanism in starting the movement of an object by simultaneously applying a driving force by a thread mechanism and a force by a booster to an expansion rod in starting to move the object by installing the booster to the expansion rod. SOLUTION: A motor 9 is started to move an object and, at the same time, a shut-off valve 19 and a check valve 17 are opened, then a rotating force of the output shaft of a motor 9 is transmitted to a thread shaft 4 of a ball thread mechanism 3 through a transmission mechanism 10, and the thread shaft 4 begins to rotate. Accordingly, a nut 5 of a ball thread mechanism 3 begins to move to the right and left while its rotation is prevented by a slider 12 and a rail member 11 and, at the same time with this, an output rod of a booster 14 is pushed out to the right and left by pressure oil of an accumulator 20, a projected member 13 is pushed out to the right and left by a booster 14, an expansion rod 6 is moved to the left by receiving an auxiliary force by the booster 14 and is expanded. By doing this, a load acting to the thread mechanism in starting can be minimized. |
