| 摘要 |
<p>PURPOSE:To remove the abrasion or the breakage of the grind stone on the periphery of a blade, while the shock generated when the blade is brought in contact with a table by keeping the supporting force of a rotor shaft lower than cutting time, when the table is brought in contact with the table at the operation of set up. CONSTITUTION:When the command of set up is outputted from PC, spindle- controlling part sends such an indication that the exciting current outputted from a magnet driver 73 to a compensation-treating circuit 72 is dropped lower than cutting time, and the exciting current corresponding to said indication is fed to each electric magnets 62n, 64n, and then the supporting force of the rotor shaft 61 in a spindle 6 is reduced lower than cutting time. When the spindle 6 is lowered, the grind stone 5a on the outer periphery of the blade 5 fitted to the rotor shaft 61 of the spindle 6, is brought in contact with the upper surface of a chuck table 10, but since the supporting force of the rotor shaft 61 is reduced lower than normal cutting time, the shock generated when the blade 5 is brought in contact with the chuck table 10 may be made small, whereby the abrasion or the breakage of the grind stone 5a on the outer periphery of the blade 5 may be removed.</p> |
