1 附 錄 A 數控車床作為普通車床的替代品，已經開始普及，但是對于數控車加工的工藝裝備和參數設定往往還有依靠經驗給出的情況，這對于發揮數控高效率工作并無益處。 數控車床加工的工藝與普通車床的加工工藝類似，但由于數控車床是一次裝夾，連續自動加工完成所有車削工序，因而應注意以下幾個方面。 1、合理選擇切削用量 對于高效率的金屬切削加工來說，被加工材料、切削工具、切削條件是三大要素。這些決定著加工時間、刀具壽命和加工質量。經濟有效的加工方式必然 是合理的選擇了切削條件。切削條件的三要素：切削速度、進給量和切深直接引起刀具的損傷。伴隨著切削速度的提高，刀尖溫度會上升，會產生機械的、化學的、熱的磨損。切削速度提高 20%，刀具壽命會減少 1/2。進給條件與刀具后面磨損關系在極小的范圍內產生。但進給量大，切削溫度上升，后面磨損大。它比切削速度對刀具的影響小。切深對刀具的影響雖然沒有切削速度和進給量大，但在微小切深切削時，被切削材料產生硬化層，同樣會影響刀具的壽命。 用戶要根據被加工的材料、硬度、切削狀態、材料種類、進給量、切深等選擇使用的切削速度。最適合的加 工條件的選定是在這些因素的基礎上選定的。有規則的、穩定的磨損達到壽命才是理想的條件。 然而，在實際作業中，刀具壽命的選擇與刀具磨損、被加工尺寸變化、表面質量、切削噪聲、加工熱量等有關。在確定加工條件時，需要根據實際情況進行研究。對于不銹鋼和耐熱合金等難加工材料來說，可以采用冷卻劑或選用剛性好的刀刃。 2、合理選擇刀具 (1)粗車時，要選強度高、耐用度好的刀具，以便滿足粗車時大背吃刀量、大進給量的要求。 (2)精車時，要選精度高、耐用度好的刀具，以保證加工精度的要求。 (3) 為減少換刀時 間和方便對刀，應盡量采用機夾刀和機夾刀片。 3、合理選擇夾具 (1) 盡量選用通用夾具裝夾工件，避免采用專用夾具； (2) 零件定位基準重合，以減少定位誤差。 4、確定加工路線 加工路線是指 數控機床加工過程中，刀具相對零件的運動軌跡和方向。 (1) 應能保證加工精度和表面粗糙要求； 2 (2) 應盡量縮短加工路線，減少刀具空行程時間。 5、加工路線與加工余量的聯系 目前，在數控車床還未達到普及使用的條件下，一般應把毛坯上過多的余量，特別是含有鍛、鑄硬皮層的余量安排在普通車床上加工。如必 須用數控車床加工時，則需注意程序的靈活安排。 3 附 錄 B CNC lathe as a substitute for ordinary lathe, has begun to spread, but for NC machining technology and equipment and parameter settings often have to rely on the experience given the circumstances, which for the efficient work of NC did not play good. CNC lathe process -sing technology and processing technology is similar but is a fixture as CNC lathes, turning continuous automatic processing to complete all the processes, and therefore should pay attention to the following areas. 1 A reasonable choice of cutting For high efficiency metal cutting, it is processed materials, cutting tools, cutting conditions are the three elements. These determine the processing time, tool life and machining quality. Cost-effective processing methods must be a reasonable choice of the cutting conditions. Three elements of cutting conditions: cutting speed, feed rate and cutting depth of the damage directly caused by the tool. With the increased cutting speed, tool tip temperature will rise, will have mechanical, chemical, thermal wear and tear. 20% increase in cutting speed, tool life will be reduced by 1 / 2. Feeding conditions and tool wear ties in the back of a very small range of produce. However, feeding a large amount of cutting temperature rise, followed by abrasion. Tool than the cutting speed on the impact of small. Depth of cut of the tool cutting speed and feed although not large, but in the small cutting depth of cut, hardened layer produced by the cutting material, it will also affect the tools life. The user is processed according to the material, hardness, cutting conditions, material type, feed rate, depth of cut and so choose to use the cutting speed. The most suitable processing conditions are selected on the basis of these factors the selected. A regular and stable life of the wear to the ideal conditions. However, in actual operation, the choice of tool life and tool wear, dimensional change is processed, surface quality, cutting noise, processing, heat and so on. In determining the processing conditions, the need to study the actual situation. Stainless steel and heat-resistant alloys for difficult to machine materials, it can be rigid with a good selection of coolant or blade. 2 A reasonable selection tool (1) Rough car, to choose the strength, durability good tool to meet the rough car back to eat a large quantity of knives, large feed requirements. 4 (2) Fine car, to choose the high precision, durability good tool to ensure the processing precision. (3) To reduce tool change time and convenience on the knife, should be adopted in machines and machine clip folder knife blade. 3. Reasonable choice of fixture (1) Try to use common workpiece clamping fixture to avoid the use of special fixtures； (2) Parts locating datum overlap, to reduce the positioning error. 4. Determine the processing route Processing line is the index of control of machining process, the tool relative to the trajectory and orientation of parts. (1) Should be able to ensure the machining accuracy and surface roughness requirements； (2) Processing line should be as short as possible, to reduce air travel time of the tool. 5. Processing, and the allowance of the contact line At present, the increasing use of CNC lathe has not yet reached the conditio