tailieunhanh - Ebook CAD/CAM/CIM (3rd edition): Part 2
(BQ) Part 2 book "CAD/CAM/CIM" has contents: Manufacturing automation, CNC machine tools, robots in computer integrated manufacturing, computer aided quality control, collaborative engineering, graphic standards, shop floor data collection systems,. and other contenrs. | CHAPTER MANUFACTURING AUTOMATION One of the major developments that led to CIM was the introduction of computer control of manufacturing equipment and operations. Till the advent of microprocessors and personal computers, manufacturing automation was mainly through the so-called hard automation through hydraulic, pneumatic or electric methods. Programmable logic controllers (PLC) have now become a very convenient tool for flexible automation. PLC’s are widely used in pneumatic, hydraulic, electric, and electronic automation. CNC machine tools, robots, transfer machines, industrial drives etc. use PLC’s. This chapter introduces the readers to the concepts of low cost automation as well as automation using PLC’s through simple application circuits. INTRODUCTION Apart from the soft data processing aspects of automation like what was discussed in chapter 10, manufacturing involve machinery and equipment to shape raw materials to parts of desired geometry. Manufacturing processes like casting, welding, forming of sheet metals and tubes, extrusion, injection molding, spinning, drawing, forging, rolling, cutting, machining, lithography, assembly etc involve different kinds of machinery and equipment. Automation involves not only carrying out the manufacturing process without human intervention but also many connected operations like stock feeding, proper sequencing of various steps involved in manufacturing, removal of the processed part from the machine or equipment, measurement of the completed part and the removal of swarf and lubricants. For example, in a pressure die casting operation, the molding machine may be hydraulically operated while the molten metal may be automatically transferred from the melting furnace to the injection chamber. The cast part is automatically picked up after the separation of the dies and the parts are cooled and trimmed. Automation is employed to lubricate the dies, cool the dies after part removal etc. Sensors are employed to
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