US Patent No. 9,212,887

METHOD FOR MEASURING REFERENCE POINT OF INCLINED ROTATING TABLE IN WIRE ELECTRIC DISCHARGE MACHINE AND MEASURING JIG


Patent No. 9,212,887
Issue Date December 15, 2015
Title Method For Measuring Reference Point Of Inclined Rotating Table In Wire Electric Discharge Machine And Measuring Jig
Inventorship Hikaru Yamane, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,212,887

1. A measuring method for obtaining a reference point on a table center of an inclined rotating table in a wire electric discharge
machine using a measuring jig, wherein
an X-axis is a direction of lateral movement on a horizontal plane of the wire electric discharge machine that machines a
workpiece by moving a wire electrode and the workpiece relative to each other while supporting the wire electrode with upper
and lower wire guides,

a Y-axis is a direction of longitudinal movement on the horizontal plane which is perpendicular to the X-axis,
a Z-axis is a direction of vertically upward movement,
a biaxial rotation unit is placed on a table of the wire electric discharge machine, the biaxial rotation unit including
a first rotating table which rotates a work fixing section that fixes the workpiece, and
a second rotating table which rotates about an axis orthogonal to the rotating table and inclines the workpiece with respect
to an X-Y plane, and

the measuring jig includes
a fixed section for being fixed to the work fixing section,
an arm section which is provided to stand on the fixed section, and
a section to be measured which is provided at a distal end of the arm section and has a conductive spherical surface,
the measuring method comprising:
a step of measuring a height from a bottom surface of the fixed section of the measuring jig to a distal end of the spherical
surface in the section to be measured of the measuring jig;

a step of acquiring an angle of inclination of the second rotating table;
a step of fixing the measuring jig to the work fixing section;
a step of measuring a height from a table surface of the wire electric discharge machine to an upper end of the spherical
surface;

a step of bringing the wire electrode into contact with the spherical surface from opposing directions on a same straight
line and measuring two points on the spherical surface;

a step of bringing the wire electrode into contact with the spherical surface from a direction along a straight line which
passes through a midpoint of the obtained two points and intersects the straight line at right angles and measuring one point
on the spherical surface;

a step of obtaining a center point position on the X-Y plane of the spherical surface on the basis of positions of the measured
three points; and

a step of calculating coordinates of a reference point on a table center of the second rotating table from the height from
the bottom surface of the fixed section to the distal end of the spherical surface, the height from the table surface of the
discharge machine to the upper end of the spherical surface, the angle of inclination of the second rotating table, and the
center point position on the X-Y plane of the spherical surface, which are measured.