Coolant feeder

摘要

A spindle protective structure capable of reliably detecting coolant leakage from a jointing device and protecting a spindle. A flow sensor is provided in the line of a drain pipe for discharging coolant leaking from the rotary joint, so that an alarm is made when the flow of coolant in the drain pipe exceeds a predetermined value. Since the coolant leaking from the jointing device is detected directly and an alarm is outputted, coolant leakage can be found out more quickly than by observing visually whether the flow of coolant jetting from a tip of a tool is normal or not.