Complex curved surface creation method

Claim 1

A complex curved machining surface creation method for generating a curved machining surface with a rounded section curve having a radius R provided at an intersection where a first curve approximated by straight lines on a first three-dimensional curved machining surface intersects a second curve approximated by straight lines on a second three-dimensional curved machining surface, wherein a point of intersection of the first an second curves being denoted by P 0 , straight line approximation points located one after another from the point of intersection P 0 to a starting point of the first curve being denoted by P j (j=0, 1, 2, . . . ), and staight line approximation points located one after another from the point of intersection P 0 to an end point of the second curve being denoted by P j (j=0, 1, 2, . . . ), said method comprising the steps of: performing operations of setting P -s =P -E =P i-1 , P s =P j and P E =P j+1 (where i, j each have an initial value of 0), and obtaining points of tangency P -T , P T at which two straight lines P -S P -E and P S P E are tangent to a circle of radius R, where P -S , P -E , P S and P E are end points of the straight lines; determining whether the points of tangency P -T , P T lie between P -E ˜P 0 an P 0 ˜P E , respectively; designating a circular arc P -T ,P T the rounded section curve of the curved surface creating the complex curved machining surface joining the first and second three-dimensional curved machining surface a and inserted at the intersection if the points of tangency P -T , P T lie between P -E ˜P 0 and P 0 ˜P E , respectively; executing said steps of performing, determining an designating, with the operation of setting i=i-1 being performed if P -T , does not lie between P -E ˜P 0 and the operation of setting j=j+1 being performed if P T does not lie between P 0 ˜P E ; and machining the complex curved machining surface.