US Patent No. 9,254,541

MACHINE TOOL HAVING ROTARY TABLE


Patent No. 9,254,541
Issue Date February 09, 2016 
Title Machine Tool Having Rotary Table
Inventorship Zheng Tong, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,254,541

1. A machine tool that is configured to be controlled by a numerical controller, the machine tool comprising:
a rotary table on which a workpiece is to be mounted;
a clamping mechanism configured to clamp the rotary table against rotation;
a sensor configured to
detect completion of a clamping operation or unclamping operation of the clamping mechanism, and
output a completion signal;
a clamping mechanism operation time measuring unit, wherein when a machining program is executed and a clamp command or an
unclamp command is output by the numerical controller, the clamping mechanism operation time measuring unit is configured
to measure a clamping mechanism operation time

from a time when the clamp or unclamp command is output
to a time (i) when completion of the clamping or unclamping operation is detected by the sensor and (ii) the machine tool
starts a next operation;

a clamping mechanism operation time storage unit configured to store the measured clamping mechanism operation time; and
an actual clamping mechanism operation time calculating unit configured to determine an actual clamping mechanism operation
time by subtracting, from the stored clamping mechanism operation time, a preset amount of time required from completion of
clamping mechanism operation to start of the next operation by the machine tool,

wherein another clamp command or another unclamp command is output by the numerical controller at a cycle time corresponding
to the actual clamping mechanism operation time determined by the clamping mechanism operation time calculating unit for the
machine tool to start the next operation.