数控技术中英文教学概述.ppt

. Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 1.2.1 Types of NC Motion Control System 1.2.1.1 Point-to-point control system Point –to point (positioning) control in NC It is also called Positioning control system, Which moves the worktable to a programmed location without regard to the path taken to get to the location. That is to say ,the path between points is of little concern and is not particularly controlled. The program consists of a series of point locations at which operations are performed. Such as drilling or punching a hole. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 1.2.1 Types of NC Motion Control System 1.2.1.1 point-to-point control system Many NC point –to-point systems contain a more complex MCU. IN these servos, positioning commands are evaluated simultaneously so that vector motion in two axes is possible. The movements between points can be done along straight or 450 vectors paths determined by the machine ways or slides. Such systems are some times called straight-cut control system.（点位/直线） . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 1.2.1 Types of NC Motion Control System 1.2.1.2 Contouring Control System It is also called continuous path control system, which manages the simultaneous motion (resultant motion)of the cutting tool in two, three, four, of five axes by interpolating(插补)the proper path between prescribed points. It enables the cutting tool to generate angular surfaces, two-dimensional curves, or three-dimensional contours in the workpiece, such as milling and turning operations. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 1.2.1 Types of NC Motion Control System 1.2.1.3 Interpolation To cut along a circular path,the circle must be divided into a series of straight-line segments that approximate the circular path.The tool is commanded to machine each line segment in succession so that the machined surface closely matches the desired shape. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 1.2.2 Typ