Cooling medium spray device

A cooling medium spray device that increases a pressure of a cooling medium supplied from a main shaft of a machine tool and sprays the cooling medium, comprising:

• a body part, a support part, a pump, a cap, a nozzle and a pressure control device,
• wherein:
• the body part is removably attachable to the main shaft, and has a body part passage through which the cooling medium supplied from the main shaft passes in a state in which the body part has been attached to the main shaft,
• the support part has a support part interior space, in which the body part is rotatably disposed, a first passage and a second passage, the first passage communicating with the body part passage,
• the pump includes a rotary part, an inlet part and an outlet part, the rotary part being connected to the body part and rotatably disposed within the support part interior space of the support part, the inlet part communicates with the first passage of the support part, the outlet part communicates with the second passage of the support part, and the pump being configured such that, by rotating the rotary part, the pressure of the cooling medium that is being suctioned from the inlet part is increased to a pressure corresponding to the rotational speed of the rotary part such that pressurized cooling medium is discharged from the outlet part,
• the cap is disposed at a location of the support part that is on a first side of the pump in an axial direction so as to close the support part interior space of the support part, the cap having a cap passage that communicates with the second passage of the support part and a nozzle mounting hole that communicates with the cap passage,
• the nozzle is mounted in the nozzle mounting hole of the cap, and has a spray hole that discharges the cooling medium and a nozzle passage that communicates with the nozzle mounting hole,
• the pressure control device has a discharge passage, an inlet part, an outlet part, a valve seat and a valve element, the inlet part of the pressure control device being provided on an inflow side of the discharge passage so as to communicate with the second passage, the outlet part of the pressure control device being provided on an outflow side of the discharge passage, the valve seat being provided in the inlet part of the pressure control device, the valve element being configured to open and close the valve seat, and the pressure control device being configured such that, owing to the valve element opening and closing the valve seat based on the pressure of the cooling medium within the second passage and a pressure set value, the pressure of the cooling medium within the second passage is prevented from exceeding the pressure set value,
• the pump is configured such that when the rotational speed of the rotary part is a prescribed rotational speed, the pressure of the cooling medium that is being discharged from the outlet part of the pressure control device is a predetermined value that is higher than the pressure set value, and
• the outlet part of the pressure control device has a first sectional area and the inlet part of the pressure control device has a second sectional area that is larger than the first sectional area, so that, in a state in which the rotary part of the pump is rotating at the prescribed rotational speed, a change of a discharge state of the cooling medium from the outlet part is visually determinable.