Theory and Design of CNC Systems docx

[...]... 10.2 Design of Software Architecture 10.2.1 CNC System Modeling 10.3 Design of Soft-NC System 10.3.1 Design of Task Module 10.3.2 Design of the System Kernel 10.3.3 PLC Program Scanning and Scheduling 10.3.4... Part I Principles and NCK Design of CNC Systems Chapter 1 Introduction to NC Systems NC machines, being typical mechatronics products, comprise machine tools that have a mechanical component and a numerical control system that is an electrical component In this chapter, the history, the constituent units, the functions, and future directions of NC systems, being the intelligence of NC machines, will... structure of the incremental-type encoder with three kinds of slit - A, B, and Z; Slits A and B generate an output waveform, the Z slit generates the zero phase The light emitted from an LED is detected by a photo-detector after passing one slit of the rotation disk and one of the slits A, B, or Z on a fixed slit panel Slits A and B are arranged for a phase difference of 90 degrees and the electric signal of. .. of servo motor 1.3.1.1 DC Servo Motor The DC Servo Motor is built as shown in Fig 1.4a The stator consists of a cylindrical frame, which plays the role of the passage for magnetic flux and mechanical supporter, and the magnet, which is attached to the inside of the frame The rotor consists of a shaft and brush A commutator and a rotor metal supporting frame (rotor core) are attached to the outside of. .. computer with tens of thousands of vacuum tubes and the machine tool was controlled by activating an oil-pressure motor and controlling a relay according to the result of logical processing However, as semiconductors appeared and were applied to NC during the 1960s, electrical motors and power elements during the 1970s and PC components during the 1980s, so Hardwired NC evolved into a Softwired NC machine... Fig 1.5 The components and structure of an encoder 2 Absolute-type encoder The structure and the signal generation method of an absolute-type encoder are identical with those of an incremental-type encoder However, the disk slit of an absolute-type encoder and the arrangement of photo-detectors are different from those of an absolute-type encoder as shown in Fig 1.7 In this type of encoder, the slit... tool post or table and plays the role of changing the rotation of a servo motor into linear movement A Linear Movement (LM) guide is used to increase the accuracy and smoothness of the linear movement An LM guide consists of an M-shaped guide rail and a transferring part, Fig 1.8 The bearing exists between the guide rail and the transferring part and lubricant is supplied to the surface of the LM guide... screw Encoder Driver CNC board Final product Encoder Part P/G NC Code Post-line Workpiece Machine table Full-closed loop CMM Semi-closed loop On-line =? Finishing Fig 1.2 The architecture of NC machine tools and machining operation flow driven by the advance in capacity and availability of microprocessors and memory Such CNC is called “Softwired NC” Through observing the advancement of NC, the fact that... amount of current The factor that limits the output of the power is the heat from the inside of the motor due to current Therefore, efficient removal of the heat is essential to generate high torque The velocity range of DC servo motors is very broad and the price is very low However, friction with the brushes results in mechanical loss and noise and it is necessary to maintain the brushes 1.3 CNC Driving... AC Servo Motor The stator consists of a cylindrical frame and a stator core The stator core is located in the frame and an armature coil is wound around the stator core The end of the coil is connected with a lead wire and current is provided from the lead wire The rotor consists of a shaft and a permanent magnet and the permanent magnet is attached to the outside of the shaft In a synchronous-type . Open CNC 353 10.1 Introduction . . 353 10.2 DesignofSoftwareArchitecture 356 10.2.1 CNCSystemModeling 356 10.3 DesignofSoft-NCSystem 359 10.3.1 Design of Task Module . 359 10.3.2 DesignoftheSystemKernel. Principles and NCK Design of CNC Systems 1 Introduction to NC Systems 3 1.1 Introduction . . 3 1.2 TheHistoryofNCandNCMachineTools 6 1.3 CNC Driving System Components . . . 8 1.3.1 DrivingMotorandSensor. of two parts with a total of 11 chapters: Part I is composed of Chapters 1–6 on the principle and design of CNC, and Part II is composed of an open-architectural soft CNC system. Specifically,