HORIZONTAL PLANE SETTING MACHINE

PROBLEM TO BE SOLVED: To provide a horizontal plane setting machine capable of preventing fluctuation of a detection value of a tilt sensor even if a motor is driven at high speed, and performing automatic leveling at high speed. SOLUTION: In this horizontal plane setting machine for forming horizontal rotating irradiation light by light L1 emitted in the perpendicular direction to a rotating shaft 14d from a rotary head 14, the rotating shaft 14d is rotationally supported by a shaft cylinder part 15 supported tiltably to a body case 12, and the shaft cylinder part 15 is connected to the body case 12 through an extension spring 25, and connected to a Y-axis motor MY and an X-axis motor MX through a pair of tilting adjustment mechanisms 24a, 24b arranged mutually perpendicularly. When performing an automatic leveling operation wherein the motors MX, MY rotate the tilting adjustment mechanisms 24a, 24b based on a detection value of the tilt sensor and tilt the shaft cylinder part 15 in the X-direction and the Y-direction, if the extension spring at the automatic leveling start time has an extended form furthermore than the form on the leveling position, the motors MX, MY are driven, and automatic leveling is performed after tilting once the shaft cylinder part 15 so that the extension spring has a contracted form furthermore than the form on the leveling position. Inherent ricketiness in the periphery of the tilting adjustment mechanisms 24a, 24b does not appear as backlash in an output from the tilt sensor even by high-speed motor driving, to thereby enable high-speed leveling. COPYRIGHT: (C)2005,JPO&NCIPI