Numerical control boring and milling machining method of internal spherical surface

The invention relates to a numerical control boring and milling machining method of an internal spherical surface, and belongs to the field of numerical control machining. The method comprises the following steps: determining the movement track of the radius of circular arc center of a cutter according to the internal spherical surface to be machined, and putting the cutter on the upper surface of a part; determining a cutting point; from the cutting point, causing the cutter to rotate a circle around the center line of the internal spherical surface to be machined in a horizontal plane until the cutter goes back to the cutting point; causing the cutter to do a cutting motion along the track in a vertical plane, wherein the cutting stepping value range is between 1/4 to 1/5 of the radius of circular arc; and taking a position after the cutting motion as a new starting point of horizontal circular motion, continuing to cause the cutter to rotate a circle around the center line of the internal spherical surface to be machined in the horizontal plane, and causing the cutter to go back to the starting point. The method overcomes the defect that the traditional method only bore a cylindrical surface in the part, and the method is suitable for machining various kinds of internal spherical surfaces. The machining time is averagely about five minutes, and the machining efficiency can be increased by over 2 times.