【正文】 of knife: (1) Appropriation knife from lather produce manufacturer oneself 寧夏大學機械工程學院 2020 屆畢業(yè)設計 68 development, haft for use is also appropriation of. This kind of the advantage be that the manufacturing cost is low, but lack in general use. (2)in general use knife according to certain in general use standard(like VDI, Germany engineer39。寧夏大學機械工程學院 2020 屆畢業(yè)設計 65 NUMERICAL CONTROL Numerical control is a form of programmable automation in which the processing equipment is controlled by means of numbers， letters， and other symbols． The numbers， letters， and symbols are coded in an appropriate format to define a program of instructions for a particular work part or job． When the job changes， the program of instructions is changed． The capability to change the program is what makes N／ C suitable for lowand mediumvolume production． It is much easier to write programs than to make major alterations of the processing equipment． Number control lather main use to carry on a car to pare towards revolving body spare parts, the Tang pare, drill to pare, the Jiao pare, offend silk etc. process of work preface. General ability auto inside pletion outside cylinder noodles, conic surface, surface of sphere, cylinder thread, slot and carry noodles etc. the slice of work preface pare to process. The host is the topic that the number control lather and include a tool machine body, sign pillar, principal axis and enter etc. is to the organization machine parts. Number control equip, is number control tool machine of core, include hardware and correspond of software, used for an importation numeral turn of spare parts procedure, and pletion importation information of saving, the transformation of data, put to repair operation and realization various control function. Drive to equip, he is number control the drive of organization of the tool machine performance parts, include a principal axis to drive unit and enter to the unit, principal axis electrical engineering and enter etc. to electrical engineering. He under the control that number control to equip pass electricity or electricity liquid servo system realization principal axis with enters give drive. When several enter to give allied move, can 寧夏大學機械工程學院 2020 屆畢業(yè)設計 66 pletion fixed position, straight line, process of flat surface curve and space curve. Assistance equips the index number control tool machine of some necessity of kit parts, in order to assurance number control tool machine of circulate, such as cool off, row scraps, lubricate, illuminate, monitor etc. It include a liquid to press friendly move equip, row scraps equip, exchange work set, number control to turn Taiwan and number control cent degree head. Plait distance and other subsidiary equipments, can use to carry on the procedure of spare parts to draw up outside machine, saving. Modern number control lather to all have X, Z two stalk of allied move function, knife position and point of a knife arc radius of pensate function, and process fix circulation function. The number control the structure of lather 1. The number control a lather brief introduction The number control constitute of lather: Number control system, bed body, principal axis and enter to the system, turn round a knife, operation frontpanel and assistance system etc.. (1) The economy number control lather: Adoption step enter electric motor and list slice machine to mon the car of the lather pare into to the system carry on reformation behind formation of the simple number control lather. The cost is lower, automation degree and function be all more bad, the car pare to process accuracy also not high, be applicable to request not high of turn round type spare parts of the car pare to process. The economy number control lather (2) Common number control lather: Pare to proc