【正文】 g , and troubleshooting is reduced , so productivity is improved , reducing labor requirements( particularly for skilled labor ) and minimizing production costs ． ? They are highly automated and relatively pact , so that one operator can attend two or more machines at the same time ． ? The machines are equipped with toolcondition monitoring devices for the detection of tool breakgage and wear , as well as probes for toolwear pensation and for tool positioning ． ? Inprocess and postprocess gaging and inspection of machined workpieces are now features of machining centers ． Machining centers are available in a wide variety of sizes and features , and their costs range 畢業(yè)設(shè)計(jì)◆英文翻譯原文 第 4 頁 共 6 頁 from about $50,000 to $1 million and higher ． Typical capacities range up to 75kw (100 hp) and maximum spindle speeds are usually in the range of 4,0008,000 rpm 。畢業(yè)設(shè)計(jì)◆英文翻譯原文 第 1 頁 共 6 頁 Machining and Turning Centers This chapter describes major devolopments in the design and capabilities of putercontrolled machine tools． Known as machining and turing centers, these machines have flexibility and versatility that other machine tools do not have, and they have, consequently, bee the first choice in machinetool selection． Basic Components of CNC CNC machine tool is usually by the control system, servo systems, detection systems, mechanical drive, and other auxiliary system ponents. Control system for CNC machine tool operation, management and control, by entering the media data are available, interpretation of these data and puting as well as machine tools have an effect。 some are as high as 75,000 rpm for special applications using smalldiameter cutters ． Some pallets are capable of supporting workpieces weighing as much as 7,000 kg (15,000 lb) , although higher capacities are available for special applications ． Many machines are now being constructed on a modular basis , so that various peripheral equipment and accessories can be installed and modified as the demand for different types of products changes ． Because of the high productivity of machining centers , large amounts of chips are produced and must be collected and disposed of properly several designs are available for chip collection , one example of which is shown in Fig． 4． 9． Note the two chip conveyors at the bottom of the crosssectional view of a portion of a horizontalspindle machining center ． These particular conveyors are of the spiral (screw) type 。 a wide range of auxiliary systems, such as: a fixed cycle (can be repeated for a variety of processing), Automatic Tool Changer (exchangeable specify tools, mechanical transmission system transmission gap indemnity pensation for the gap generated errors) and so on. Machining and Turning Centers It was noted that each machine, regardless of how highly it is automated, is designed to perform basically one type of operation． It has also shown that, in manufacturing, most parts require a number of different machining operations on their various surfaces． Note, for example, that the parts shown in have a variety of features and that all surfaces on these parts require different types of machining operations, such as milling, facing, boring drilling, reaming , and threading , to obtain certai