| 摘要 |
PROBLEM TO BE SOLVED: To rationalize acceleration of a striker.SOLUTION: A machine tool includes a tool holder which loads a chisel tool 7 movably along an axis 3 of operation. The machine tool includes a primary drive 22 which is arranged around the axis 3 of operation, and the primary drive 22 includes a first magnetic coil 46, an annular magnet 42 which is permanently and radially magnetized, and a second magnetic coil 47 in order in a striking direction. A striking mechanism has a striker 4 and an anvil 13 on the axis 3 of operation in the magnetic coils in order along the striking direction 5. Further, the striking mechanism includes an air spring 23 which acts on the striker 4 along the striking direction 5. While the striker 4 advances in the opposite direction from the striking direction 5, an induced voltage of the first magnetic coil 46 is measured. A control part 12 starts an acceleration period according to change in plus/minus sign of the induced voltage. The primary drive 22 accelerates the striker 4 in the striking direction during the acceleration period. |
