US 6,687,566 B2 · Method of machining a female screw and dressing a grinding wheel for female screw machining

Abstract

The present invention provides a method of machining a female screw groove in a workpiece whereby the spindle of an internal grinding wheel for machining the workpiece into a female screw is tilted relative to the screw's axis at an angle (ξ) smaller than the lead angle (α) of the female screw. First, specifications of the female screw, data on the configuration of the thread groove, and the tilt angle are supplied to a program for calculating data on dressing of the grinding wheel wherein the locus of the groove on cross-sections normal to the axis of the grinding wheel and wheel dressing data are calculated. Second, the grinding wheel on the aforementioned spindle is shaped or dressed by simultaneous triaxial control of the rotation of the single point dresser about a b-axis, and the feed of the grinding wheel table along a z-axis and a cross slide along an x-axis based on the foregoing data. Thereupon, the female screw is machined with the dressed grinding wheel.

Claims17

Dependent claims

A method of machining a female screw groove in a hole in a female screw workpiece extending along a z-axis with an internal grinding wheel coupled to a spindle having an axis, the axis of the spindle being tilted relative to the z-axis at an angle smaller than the lead angle of the female screw, whereby relative rotation is caused between the workpiece and the grinding wheel while relative movement is caused between the grinding wheel and the workpiece along the z-axis and along an x-axis normal to the z-axis, the method comprising of:

A. providing data representing specifications of the female screw and the tilt angle of the axis of the wheel spindle relative to the z-axis;
B. obtaining data on dressing the grinding wheel from the data representing the specifications of the female screw and the tilt angle of the wheel spindle axis;
C. dressing the grinding wheel on the basis of the obtained dressing data by simultaneous triaxial control of relative movement between the grinding wheel and a single point dresser along the z-axis of the workpiece and the x-axis, and rotation of a tip of the single point dresser about a b-axis in the plane defined by the x- and z-axes;
and
D. machining the female screw groove with the dressed grinding wheel.

2 more elements

A method of dressing with a single point dresser an internal grinding wheel for machining a female screw, the grinding wheel including a spindle which has an axis tilted during dressing relative to a z-axis of a workpiece at an angle smaller than the lead angle of the female screw to be machined in the workpiece, the method comprising:

I. providing data representing specifications of the female screw and the tilt angle of the spindle axis relative to the z-axis of the workpiece;
II. calculating data representing an outer shape of the grinding wheel from the data representing specifications of the female screw and the tilt angle of the wheel spindle axis;
III. generating, from the data calculated in step II, data representing (i) relative movement between the single point dresser and the grinding wheel along the z-axis and an x-axis normal to the z-axis and (ii) simultaneous rotation of a tip of the single point dresser in the x-z plane about a b-axis normal to the x-z plane;
and
IV. dressing the grinding wheel on the basis of the data generated in step (III).

2 more elements

Dependencies are inferred from the claim text.

Method of machining a female screw and dressing a grinding wheel for female screw machining

Life of this patent

Method of machining a female screw and dressing a grinding wheel for female screw machining

Life of this patent

Abstract

Claims17