高速切削加工的发展及需求论文.doc

0722422 孙康 机制4班高速切削加工的发展及需求Abstract: HSC is to achieve high efficiency of the core technology manufacturers, intensive processes and equipment packaged so that it has a high production efficiency. It can be said that the high-speed machining is an increase in the quantity of equipment significantly improve processing efficiency essential to the technology. High-speed machining is the major advantages : improve production efficiency, improve accuracy and reduce the processing of cutting resistance.Key words：High-speed machining；processing efficiency；spindle speedHigh-speed machining and demand for the developmentHigh-speed machining is contemporary advanced manufacturing technology an important component of the high-efficiency, High-precision and high surface quality, and other features. High-speed machining is oriented to the 21st century a new high-tech, high-efficiency, High-precision and high surface quality as a basic feature, in the automobile industry, aerospace, Die Manufacturing and instrumentation industries gained increasingly widespread application, and has made significant technical and economic benefits. contemporary advanced manufacturing technology an important component part.The high-speed machining of meaning, at present there is no uniform understanding, there are generally several points as follows : high cutting speed. usually faster than that of their normal cutting 5 -10 times; machine tool spindle speed high, generally spindle speed in -20000r/min above 10,000 for high-speed cutting; Feed at high velocity, usually 15 -50m/min up to 90m/min; For different cutting materials and the wiring used the tool material, high-speed cutting the meaning is not necessarily the same; Cutting process, bladed through frequency (Tooth Passing Frequency) closer to the machine-tool - Workpiece system the dominant natural frequency (Dominant Natural Frequency), can be considered to be high-speed cutting. Visibility high-speed machining is a comprehensive concept. At this stage, in order to achieve high-speed machining, general wiring with high flexibility of high-speed CNC machine tools, machining centers, By using a dedicated high-speed milling, drilling. These equipment in common is : We must also have high-speed and high-speed spindle system feeding system, Cutting can be achieved in high-speed process. High-speed cutting with the traditional cutting the biggest difference is that Machine-tool-workpiece the dynamic characteristics of cutting performance is stronger influence. In the system, the machine spindle stiffness, grip or form, a long knife set, spindle Broach, torque tool set, Performance high-speed impact are important factors. In the high-speed cutting, material removal rate (Metal Removal Rate, MRR), unit time that the material was removed volume, usually based on the machine-tool-workpiece whether Processing System chatter. Therefore, in order to satisfy the high-speed machining needs, we must first improve the static and dynamic stiffness of machine spindle is particularly the stiffness characteristics. HSC reason at this stage to be successful, a very crucial factor is the dynamic characteristics of the master and processing capability.In order to better describe the machine spindle stiffness characteristics of the project presented new dimensionless parameter - DN value, used for the evaluation of the machine tool spindle structure on the high-speed machining of adaptability. DN value of the so-called axis diameter per minute speed with the product. The newly developed spindle machining center DN values have been great over one million. To reduce the weight bearing, but also with an array of steel products than to the much more light ceramic ball bearings; Bearing Lubrication most impressive manner mixed with oil lubrication methods. In the field of high-speed machining. have air bearings and the development of magnetic bearings and magnetic bearings and air bearings combined constitute the magnetic gas / air mixing spindle.Feed the machine sector, high-speed machining used in the feed drive is usually larger lead, multiple high-speed ball screw and ball array of small-diameter silicon nitride (Si3N4) ceramic ball, to reduce its centrifugal and gyroscopic torque; By using hollow-cooling technology to reduce operating at high speed ball screw as temperature generated by the friction between the lead screw and thermal deformation.In recent years, the use of linear motor-driven high-speed system of up to Such feed system has removed the motor from workstations to Slide in the middle of all mechanical transmission links, Implementation of Machine Tool Feed System of zero transmission. Because no linear motor rotating components, from the role of centrifugal force, can greatly increase the feed rate. Linear Motor Another major advantage of the trip is unrestricted. The linear motor is a very time for a continuous machine shop in possession of the bed. Resurfacing of the very meeting where a very early stage movement can go, but the whole system of up to the stiffness without any influence. By using high-speed screw, or linear motor can greatly enhance machine system of up to the rapid response. The maximum acceleration linear motors up to 2-10G (G for the acceleration of gravity), the largest feed rate of up to 60 -200m/min or higher. In addition, the campaign machine performance will also directly affect the processing efficiency and accuracy of processing. Mold and the free surface of high-speed machining, the main wiring with small cut deep into methods for processing. Machine requirements in the feed rate conditions, should have high-precision positioning functions and high-precision interpolation function, especially high-precision arc interpolation. Arc processing is to adopt legislation or thread milling cutter mold or machining parts, the essential processing methods.HSC has a lot of advantages such as : a large number of materials required resection of the workpiece with ultrafine, thin structure of the workpiece, Traditionally, the need to spend very long hours for processing mobile workpiece and the design of rapid change, short product life cycle of the workpiece, able to demonstrate high-speed cutting brought advantages.、高速切削加工的发展及需求高速切削加工是当代先进制造技术的重要组成部分，拥有高效率、高精度及高表面质量等特征。高速切削加工是面向21世纪的一项高新技术，它以高效率、高精度和高表面质量为基本特征，在汽车工业、航空航天、模具制造和仪器仪表等行业中获得了愈来愈广泛的应用，并已取得了重大的技术经济效益，是当代先进制造技术的重要组成部分。高速切削是实现高效率制造的核心技术，工序的集约化和设备的通用化使之具有很高的生产效率。可以说，高速切削加工是一种不增加设备数量而大幅度提高加工效率所必不可少的技术。高速切削加工的优点主要在于：提高生产效率、提高加工精度及降低切削阻力。 有关高速切削加工的含义，目前尚无统一的认识，通常有如下几种观点：切削速度很高，通常认为其速度超过普通切削的5-10倍；机床主轴转速很高，一般将主轴转速在10000-20000r/min以上定为高速切削；进给速度很高，通常达15-50m/min，最高可达90m/min；对于不同的切削材料和所釆用的刀具材料，高速切削的含义也不尽相同；切削过程中，刀刃的通过频率(Tooth Passing Frequency)接近于“机床刀具工件”系统的主导自然频率(Dominant Natural Frequency)时，可认为是高速切削。可见高速切削加工是一个综合的概念。现阶段，为了实现高速切削加工，一般釆用高柔性的高速数控机床、加工中心，也有釆用专用的高速铣、钻床。这些设备的共同之处是：必须同时具有高速主轴系统和高速进给系统，才能实现材料切削过程的高速化。高速切削与传统切削最大的区别是，“机床刀具工件”系统的动态特性对切削性能有更强的影响力。在该系统中，机床主轴的刚度、刀柄形式、刀长设定、主轴拉刀力、刀具扭力设定等，都是影响高速切削性能的重要因素。 在高速切削中，材料去除率(Metal Removal Rate，MRR)，即单位时间内材料被切除的体积，通常受限于“机床-刀具-工件”工艺系统是否出现“颤振”。因此，为了满足高速切削加工的需求，首先要提高机床动静刚度尤其是主轴的刚度特性。现阶段高速切削之所以能够成功，一个很关键的因素在于对系统动态特性问题的掌握和处理能力。为了更好地描述机床