Building a model of dressing the working surfaces of wheels during the two-side grinding of round end faces at CNC machines

Abstract

This paper reports the spatial mathematical modeling of the process of dressing the working surface of grinding wheels for implementing the double-sided grinding of the ends of cylindrical components. Parts with high-precision end surfaces that are commonly used include bearing rollers, piston fingers, crosspieces of cardan shafts, and others. The geometric accuracy of surfaces is ensured by simultaneously grinding the ends at two-sided end-grinding machines with crossed axes of the part and wheels that operate under a self-blunting mode. Before starting the machining, the wheels are dressed in a working position. Moreover, the total orientation angle of the tools is selected subject to the condition of uniform distribution of allowance along the rough sections of wheels. Dressing involves a single-crystal diamond tool with a variable feed. That ensures different development of the surface of abrasive tools, which prolongs their operating time between dressings and improves overall stability. The constant size of micro irregularities at the calibration site enhances the quality of machining. The calibration site is made in the form of a straight line belonging to the plane that passes through the axis of rotation of the wheel and is perpendicular to the plane of the machined part. Based on the spatial mathematical models of the processes of removal of allowance and shape formation when dressing the wheel, the surface of the grinding wheel was investigated. Mathematical models for shaping the ends of parts when grinding with wheels with conical calibration sites have been proposed; it is shown that when applying the proposed machining scheme, there is no geometric error in the size of the part. In addition, due to the uniform distribution of the allowance along the rough area of the wheel, the quality of the surface layer of the ends of parts increases. The devised method for dressing the working surface of wheels could be used to grind the ends of non-circular components.

Construction of spherical non-circular wheels formed by symmetrical arcs of loxodrome

“…The practical side of the issue of manufacturing non-circular wheels is revealed in [12], which presents a device for the manufacture of non-circular gears. In addition, paper [13] developed a technique for processing the working surface of the wheels, which can be used for grinding the ends of non-circular parts. In [14], it is proposed to improve the procedure for the manufacture of non-circular wheels by generating geometric features of non-circular contours.…”

Building a model of the process of shaping tapered calibrating areas of wheels at the two-sided grinding of round ends

“…However, when considering the dressing of the grinding wheel, the rotational movement of the dressing tool was not taken into consideration. Work [14] proposes a scheme for dressing the tool for double-sided end grinding of round parts. On the end surface of the grinding wheel, it is proposed to execute a calibration area but it is not defined how its dimensions and location should be determined.…”