精密铣削技术在加工中心的应用探讨.doc

/ /精密铣削技术在加工中心的应用探讨论文关键词：刀具 种类选择 切削用量Paper keywords: type selection tool cutting parameter论文摘要：机械制造业在整个国民经济中占有十分重要的地位,而其中金属切削加工是基本而又可靠的精密加工手段。在进行数控编程的过程中，刀具的选择和切削用量的确定是十分重要，它不仅对被加工零件的质量影响巨大，甚至可以决定着机床功效的发挥和安全生产的顺利进行。所以，在编制加工程序时，选择合理的刀具和切削用量，是编制高质量加工程序的前提。Abstract: machinery manufacturing occupies an important position in the whole national economy, and the metal cutting processing is the basic and reliable means of precision machining. In CNC programming process, cutting tool selection and cutting amount determination is very important, it not only had a huge impact on the quality of processed parts, it can even determine the machine tool of efficacy and safety in production smoothly. So, when processing program, choose reasonable tool and cutting parameter, is the premise of high quality processing program. 一、引言First, the introduction 机械制造业在整个国民经济中占有十分重要的地位,而其中金属切削加工是基本而又可靠的精密加工手段,在机械、电机、电子等各种现代产业部门中都起着重要的作用。工具的设计、制造和使用自古以来就很受重视,这里我们所说的工具,不仅仅指进行机械加工的机床,我们更关心的是直接进行切削加工的刀具。刀具是推动金属切削加工技术发展的一个极为活跃而又十分关键的因素,可以说切削加工技术发展、革新的历史就是刀具发展的历史。Machinery manufacturing occupies an important position in the whole national economy, and the metal cutting processing is the basic and reliable precision machining method, the mechanical, electrical, electronic, etc. Various kinds of modern industry department plays an important role. Tool in the design, manufacture and use is very important, since the ancient times here what we call the tool, not only refers to the mechanical processing machine tool, we are more interested in machining tool directly. Cutting tool is to promote the development of metal cutting processing technology a very active and very key factors, machining technology, so to speak, the history of development of the history of development, innovation is the tool. 我单位在2008年引进了小巨人公司制作的两台车铣加工中心。但一直未能在零件上真正实现和普及数控车铣加工中心的铣削功能。刀具选择、加工路径规划 、切削用量设定等，编程人员只要设置了有关的参数，就可以自动生成NC程序并传输至数控机床完成加工。因此，数控加工中的刀具选择和切削用量确定是在人机交互状态下完成的，这与普通机床加工形成鲜明的对比，同时也要求编程人员必须掌握刀具选择和切削用量确定的基本原则，在编程时充分考虑数控加工的特点。研究掌握数控车铣加工中心的铣削功能，对于形状复杂以及精度要求很高的回转体零件的精密加工，提升我单位数控精密加工能力，具有很重要的现实意义。My unit in 2008 introduced the little giant company made two cars milling machining center. On parts but have not been able to realize and popularize milling function of nc milling machining center. Tool selection, cutting path planning, cutting parameter setting, etc., programmers as long as you set the related parameters, you can automatically generate NC program and transfer to the CNC machine to complete processing. Therefore, nc machining of cutting tool selection and cutting amount is determined in the condition of human-computer interaction, in sharp contrast with the ordinary machine tool processing, also requires programming staff must master basic principles defined by the cutting tool selection and cutting amount, according to the characteristics of nc machining in the programming. Research master nc milling processing center milling function, for complex shape and high accuracy requirement of the precision machining of axially symmetrical parts, increases my units CNC precision machining ability, has the very important practical significance. 二、数控铣加工常用刀具的种类Second, nc milling processing kinds of commonly used tools 数控铣加工刀具种类很多，为了适应数控机床高速、高效和自动化程度高的特点，所用刀具正朝着标准化、通用化和模块化的方向发展，主要包括铣削刀具和孔加工刀具两大类。为了满足高效和特殊的铣削要求，又发展了各种特殊用途的专用刀具。数控铣刀具的分类有多种方法，根据刀具结构可分为：整体式；镶嵌式，采用焊接或机夹式连接，机夹式又可分为不转位和可转位两种；特殊型式，如复合式刀具，减震式刀具等。根据制造刀具所用的材料可分为：高速钢刀具；硬质合金刀具；金刚石刀具；其他材料刀具，如立方氮化硼刀具，陶瓷刀具等。从切削工艺上可分为：平端立铣刀、圆角立铣刀、球头刀和锥度铣刀等。Nc milling tool is a lot of more phyletic, the numerically-controlled machine tool in order to adapt to high speed, high efficiency and high degree of automation, the tool is moving in the direction of standardization, generalization and modularization, including milling cutting tool and machining cutter two kinds big. In order to meet the requirements of high efficiency and special milling, and development of various special-purpose dedicated tool. CNC milling cutter with there are many ways of classification, according to the cutting tool structure can be divided into: (1) integral; (2) the Mosaic, machine clamp type or welding connection, the machine clamp type: dont transposition and indexable two; (3) special types, such as composite cutting tools, suspension type knives, etc. According to the materials used in the manufacture cutting tools can be divided into: (1) high speed steel cutting tools; (2) carbide cutting tools; (3) diamond tool; (4) other material cutting tools, such as cubic boron nitride cutting tools, ceramic knives, etc. From the cutting process can be divided into: flat end mill, rounded end mill, ball head dao and taper milling cutters, etc. 三、加工中心刀具类型的选择Three, the choices of machining center tool 刀具的选择是在数控编程的人机交互状态下进行的。应根据机床的加工能力、工件材料的性能、加工工序、切削用量以及其它相关因素正确选用刀具及刀柄。刀具选择总的原则是：安装调整方便，刚性好，耐用度和精度高。在满足加工要求的前提下，尽量选择较短的刀柄，以提高刀具加工的刚性。生产中，被加工零件的几何形状是选择刀具类型的主要依据。Cutting tool choice is in the numerical control programming of human-computer interaction condition. Should be based on the processing capacity of the machine tool, workpiece material performance, processing process, selection of cutting parameter, and other factors associated with the correct tools and the handle. Tool to choose the general rule is: easy to install, good rigidity, durability and high precision. On the premise of meet the processing requirements, to choose a shorter handle as far as possible, in order to improve the rigidity of machining tool. Production, the geometry of the parts processed is to choose the cutting tool types of main basis. 1）铣削刀具的选用。加工曲面类零件时，为了保证刀具切削刃与加工轮廓在切削点相切，而避免刀刃与工件轮廓发生干涉，一般采用球头刀，粗加工用两刃铣刀，半精加工和精加工用四刃铣刀；铣较大平面时，为了提高生产效率和提高加工表面粗糙度，一般采用刀片镶嵌式盘形铣刀；铣小平面或台阶面时一般采用通用铣刀；铣键槽时，为了保证槽的尺寸精度、一般用两刃键槽铣刀1) the selection of milling cutter. Surface parts processing, in order to guarantee the contour tool cutting edge and the cutting point of tangency, and avoid the blade and workpiece contour happened interference, generally adopts the ball head dao, stocking two milling cutter, semi-finishing and finish machining with milling cutter; Milling large plane, in order to improve the production efficiency and improve the processing surface roughness, generally USES the blade inlaid type disc cutter; Commonly used while small flat or level surface milling universal milling cutter; Milling keyways, in order to ensure the accuracy of the slot size, general with two keyway milling cutter blade2）孔加工刀具的选用。数控机床孔加工一般无钻模，由于钻头的刚性和切削条件差，选用钻头直径D应满足L/D5（L为钻孔深度）的条件；钻孔前先用中心钻定位，保证孔加工的定位精度；精绞前可选用浮动绞刀，绞孔前孔口要倒角；镗孔时应尽量选用对称的多刃镗刀头进行切削，以平衡镗削振动；尽量选择较粗和较短的刀杆，以减少切削振动。在经济型数控加工中，由于刀具的刃磨、测量和更换多为人工手动进行，占用辅助时间较长，因此，必须合理安排刀具的排列顺序。一般应遵循以下原则：尽量减少刀具数量；一把刀具装夹后，应完成其所能进行的所有加工部位；粗精加工的刀具应分开使用，即使是相同尺寸规格的刀具；先铣后钻；先进行曲面精加工，后进行二维轮廓精加工；在可能的情况下，应尽可能利用数控机床的自动换刀功能，以提高生产效率等。另外，刀具的耐用度和精度与刀具价格关系极大，必须引起注意的是，在大多数情况下，选择好的刀具虽然增加了刀具成本，但由此带来的加工质量和加工效率的提高，则可以使整个加工成本大大降低。总之，根据被加工工件材料的热处理状态、切削性能及加工余量，选择刚性好，耐用度高的铣刀，是充分发挥数控铣床的生产效率和获得满意的加工质量的前提。2) the selection of machining tools. CNC machining, generally no jig, due to the rigidity of drill bit and cutting condition is poor, select bit diameter D L/D to meet 5 or less drilling depth is (L) conditions; Before drilling with a center drill positioning, assure the precision of hole processing; Fine ground before floating reamer, optional hole orifice chamfering before; When boring, should try to choose more symmetrical blade boring cutter for cutting, boring to balance vibration; As far as possible choose thicker and shorter cutter bar, in order to reduce the cutting vibration. In economical nc machining, the tool grinding, measurement and replace for the manual, take up support for a long time, therefore, have to arrange the order of the knives. In general should follow the following principles: (1) try to reduce the amount of cutting tools; (2) a tool clamping, shall complete it to all of the machining parts; (3) rough finish machining of cutting tools should be used separately, even if is the same size specifications of the cutting tool; (4) milling after the first drill; (5) for surface finishing first, two-dimensional contour after finishing; 6. Where possible, should as far as possible use of nc machine tools in the automatic tool change function, in order to improve the production efficiency, etc. Precision and cutting tool and cutting tool durability and price relationship is great, must pay attention that in most cases, choose good although increased the cost of tools, but as a result of the processing quality and processing efficiency, can make whole processing cost is reduced greatly. Anyhow, depending on the materials of the processed workpiece heat treatment state, the cutting performance and machining allowance, choose good rigidity, high durability of cutter, is to give full play to the production of CNC milling machine efficiency and satisfactory machining quality of the premise. 3）切削速度的确定。进给速度是数控机床切削用量中的重要参数，主要根据零件的加工精度和表面粗糙度要求以及刀具、工件的材料性质选取。最大进给速度受机床刚度和进给系统的性能限制。在轮廓加工中，在接近拐角处应适当降低进给量，以克服由于惯性或工艺系统变形在轮廓拐角处造成“超程”或“欠程”现象。确定进给速度的原则：1）当工件的质量要求能够得到保证时，为提高生产效率，可选择较高的进给速度。一般在100200mm/min范围内选取。2）在切断、加工深孔或用高速钢刀具加工时，宜选择较低的进给速度，一般在2050mm/min范围内选取。3）当加工精度，表面粗糙度要求高时，进给速度应选小些，一般在2050mm/min范围内选取。4）刀具空行程时，特别是远距离“回零”时，可以选择该机床数控系统给定的最高进给速度。3) the determination of cutting speed. Feeding speed is an important parameter in CNC machine tool cutting dosages, mainly according to the requirements of the parts machining accuracy and surface roughness and cutting tool, workpiece material properties of the selection. Largest feed speed limited by the stiffness of machine tool and the feed system performance constraints. In contour machining, on the corner close to should be appropriate to reduce feeding, to overcome due to inertia or process system deformation on the corner profile distance or owe phenomenon. Determine the feeding speed of principles: 1) when the workpiece quality requirements can be guaranteed, in order to improve the production efficiency, can choose high feed speed. Is in commonly 100 200 mm/min range selection. 2) in deep hole or cutting, processing with high speed steel cutting tool processing, should choose low feed rate, generally within the scope of 20 50 mm/min. 3) when the machining accuracy, surface roughness requirement is high, the feed rate should fall, generally within the scope of 20 50 mm/min. 4) tooling empty trip, especially when back to zero at a distance, you can choose the machine tool numerical cont