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however, its implementation costs are higher. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Types of NC ServoDrive System ClosedLoop ServoDrive Position pare circuit Speed control circuit Worktable Instruction Speed feedback signal Position feedback signal Leadscrew Servomotor . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Application of CNC The applications of CNC are divided into two categories: (1)Machine tool applications。 (2)The type of servodrive system。 (3)the servodrive unit。NUMERICAL CONTROL TECHNOLOGY Chapter 1 Introduction to Numerical Control Teacher Xu Cijun 13872082953 62956 . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 、 Fundamental of NC Technology 、 Classifications of NC Machines 、 Features of Numerical Control and Its Application Areas Course Description: ? NC is one of the most important achievements in mechanical engineering field in 20 century. ? It is a crossing and integrating technology prising of puter technology, automatic control technology, information technology, sense technology, and machining technology. ? Numerical Control Technology has became one of the important technical basic classes of mechanical engineering specialty. Toshiba events . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL 、 Development History of NC 1946the first puter appeared in the world, which lift the curtain on the mankind into information time. 1948Parsons Corporation brought forward using puter to control machine when they machined the surface contours of airfoil shape. Parsons Corporation was a minihelicopter manufacturer. The machining accuracy of the airfoil shape was 177。 (4)the feedback transducer。 (3)Application of NC . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Types of NC Motion Control System Motion control systems for NC can be divided into two types: (1) Pointtopoint control system (點位控制系統(tǒng) )。 (2) nonmachine tool applications. It should be noted that the applications are not always identified by the name “ numerical control” , this term is used principally in the machine tool industry. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Application of CNC Machine Tool Application The most mon applications of NC are in machine tool control, machining was the first application of NC . Machining is a manufacturing process in which the geometry of work is produced by removing excess material. By controlling the relative motion between a cutting tool and the workpiece, the desired geometry is created. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Application of CNC Machine Tool Application The mon NC machine tools are listed in the following along with their typical features: NC lathe (數控車床 ) Turning requires twoaxis continuous path control, either to produce a straight cylindrical geometry or to create a profile. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Application of CNC Machine Tool Application NC boring mill (數控鏜銑床 ) horizontal or vertical spindle. Boring is similar to turning, except that an internal cylinder is created instead of an external cylinder. The operation requires continuous path, twoaxis control.. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Application of CNC Machine Tool Application NC drill press (數控鉆床 ) These machines use pointtopoint control of workhead and two axis control of the worktable. Some NC drill presses have turrets containing six or eight drill bits. . Chapter 1 INTRODUCTION TO NUMERICAL CONTROL Application of CNC Machine Tool Application NC milling machine (數控銑床 ) It requires continuous