Abstract: The spindle position orientation apparatus of a boring machine includes a main spindle attached to a casing and around which a cylindrical cam is fixed, a slider disposed on a guide rod to be movable right and left thereby rotating the cylindrical cam, and a limit switch which is opened and closed by a dog attached to a piston. The piston is disposed in a hydraulic cylinder fixed to the casing, one end of the piston is fixed to the slider and the dog is formed on the other end.

Abstract: Disclosed is a hydraulic control system of a transfer system for a machine tool, including a hydraulic pump for generating hydraulic pressure, a first directional control valve for controlling the flow direction of fluid from the hydraulic pump, a first flow speed control part located between the first direction control valve and a rotary cylinder to control the flow speed of fluid flowing therebetween, a second direction control valve controlling a flow direction of fluid fed from the first directional control valve and returned to a fluid tank, and a second flow speed control part for controlling flow speed of the returning fluid in accordance with a port variation of the second directional control valve.