A coolant supply device and supply method that can appropriately control the spraying of coolant using a single parameter. A pump (101) supplies coolant to a tool (D), and a measurement device (22) measures the discharge pressure of the pump (101). A control device (50) has a function for determining, from the rotation rate of the pump (101), the coolant flow path diameter for the tool (D) and the target value for the pump discharge pressure (target pressure) when the tool (D) is drilling.

In a machine tool spindle device, a draw bar is arranged inside a center hole of a spindle, and a disc spring is arranged inside a spring member arrangement space between the draw bar and the center hole. A draw bar inner pipe is inserted inside a through hole of the draw bar, and the interior of the draw bar inner pipe is used as a coolant passage. A gap between the draw bar inner pipe and the through hole is used as an air passage for supplying the purge air, and the interior of the spring member arrangement space is used as a coolant supply passage for supplying coolant to cooling jackets of the spindle.

Cooling medium from a main shaft (20) of a machine tool (10) is pressurized by a pump (300) and led to a nozzle (242) via a second case passage (222). A relief valve (500) is also connected to the second case passage and discharges cooling medium from an outlet port (511b) when the cooling medium pressure within the second case passage exceeds a pressure set value (Ts). At a prescribed rotational speed (Ns), the pump discharges cooling medium, at a prescribed pressure (Tr) that is higher than the pressure set value (Ts), from an outlet port (302) of the pump. The cross-sectional area (S2) of an outlet port (511b) of the relief valve is smaller than the cross-sectional area (S1) of an inlet port (511a) thereof. Therefore, at the prescribed rotational speed, a change of the discharge state of the cooling medium from the outlet port (511b) is visually observable.

Utilities supplied through a first utility path of a turning tool holder via a docking device is supplied to a second utility path of an adjacent rotating tool holder through a communication arrangement, there is no need to provide a complex hydraulic line, a pneumatic line and a coupler for receiving the utilities from the docking device at a rearward side of the rotating tool holder. A rearward size of the rotating tool holder may be minimized, so that even when the rotating tool holder is mounted on the turret, no interference occurs with the docking device in the rearward direction when the turret rotates. As a result, it is possible to use the rotating tool holder, to which utilities supply is necessary, even in the turret which is provide with the docking device.

Provided is a cutting fluid tank for a machine tool, with which the operator's time and effort for cleaning are reduced and the maintainability is enhanced, without entailing an increase in size. In a tank body, a cutting fluid flow channel having a spiral shape and extending from a tank center region to a tank outer peripheral region is formed by a flow channel forming plate. An inflow port into which a cutting fluid from inside a machining chamber flows is provided at an outer peripheral region of the lid, whereas an outflow port to take out the cutting fluid in the tank body to an outside is provided at a center region of the lid. A pump to pump up and supply the cutting fluid to the machining chamber is provided at the outflow port.

A machine tool, includes: a frame; a hollow ram disposed on the frame in a reciprocable manner; a hollow spindle rotatably supported by the ram, the spindle including a spindle hole located at a distal end, and a spline hole located at a basal end; a guide block disposed in the spindle and having a guide hole extending along a center axis of the spindle; and a spindle drive shaft rotatably supported by the frame, the spindle drive shaft including a spline shaft that engages with the spline hole, and a support shaft disposed at a distal end of the spline shaft to be guided in sliding contact with the guide hole.

A machine tool including a cutting fluid supply unit configured to supply a cutting fluid to be discharged from a leading end of a tool mounted on a spindle, a detection unit configured to detect information for determining arrival of the cutting fluid to the leading end of the tool, and a control unit configured to determine the arrival of the cutting fluid based on the information detected by the detection unit and control the cutting fluid supply unit, wherein the control unit is configured to set a supply speed of the cutting fluid after the cutting fluid supply unit starts to supply the cutting fluid until determination of the arrival of the cutting fluid to be higher than a supply speed after the determination.