【机械类毕业论文中英文对照文献翻译】浅论车削加工中的振动与控制
收藏
资源目录
编号：77692104
类型：共享资源
大小：13.47KB
格式：RAR
上传时间：2020-05-07
上传人：柒哥
认证信息
个人认证
杨**（实名认证）
湖南
IP属地：湖南
6
积分
- 关 键 词：
-
机械类毕业论文中英文对照文献翻译
机械类
毕业论文
中英文
对照
文献
翻译
车削
加工
中的
振动
控制
- 资源描述：
-
【机械类毕业论文中英文对照文献翻译】浅论车削加工中的振动与控制,机械类毕业论文中英文对照文献翻译,机械类,毕业论文,中英文,对照,文献,翻译,车削,加工,中的,振动,控制
- 内容简介：
-
Shallow Theory Turning Processing of Vibration and ControlThe author:Lan Wenqing【Abstract】In the machine process creation of vibration all have is forced a vibration and from arouse vibration, and tool machine, tongs, knife and work piece the dynamic state characteristic of craft system for constitute relevant.Detailed analysis the car pare to process medium vibration of main type and creation of reason, vibration of endanger, and from the knife, tongs, sliced to pare crafts etc. to put forward to let up or cancellation vibration of measure. 【Key words】The car pare low frequency vibration;High frequency vibration;Cancellation measure PrefaceIn turning process vibrations, not only interfere with the normal cutting process, serious impact on the products surface quality, still can shorten the machine and tools using life. The resulting noise may even affect the operator to normal work motion, carrying on the negative influence, and bring certain But in order to reduce vibration, often have to reduce the amount of feed processing, which reduces the productivity. I through in the work of this phenomenon continually observing, analysis and practice, the summary, made some effect, this paper discussed some opinions for everybody.1. The classification of vibration, generally in machining the vibrations have forced vibration and the excitedself vibration, and machine tool, cutting tool and workpiece, fixture of the dynamic characteristic of the process system concerned. In eliminating turn components (such as electric machine, workpiece, etc) and transmission system axis (such as pulley, rolling bearing, hydraulic transmission system pressure pulse, etc.), the vibration of the vibration after turning machining is mainly the change in velocity with turning the excitedself vibration, mainly is the turning process workpiece system (the bending vibration frequency close to the natural frequency of the workpiece low frequency vibration) and the deformation of the tool produced the bending vibration (its vibration frequency close to turning the natural frequency of the high frequency vibration).2. Vibration analysis of the causes of low frequency vibration frequency low, usually compare low of noise, vibration in the more violent, the vibration of the machined surface traces left deep and wide. Usually in low frequency vibration system and cutter systems workpiece in vibration, they sometimes hasten far, sometimes approach, produce an equal and opposite effect reaction. In vibration process, when the workpiece and tool is far, far and cutting force F hasten workpiece displacement direction is same, wrought for positive system obtain input energy E (+), when the workpiece is approaching the knives cutting force F with workpiece displacement direction opposite approach, wrought negative, system energy consumption E (-), in turning process, by various factors are likely to cause periodic change, cutting force and make F F is far reaching, E (+) E (-), namely in each vibration cycle, the workpiece (or cutting force of cutter) of reactive power is always greater than it is (or tool) workpiece of reactive power, thereby negative (or tool) obtain workpiece self-excited vibration energy supplement.In turning process, the influence periodically change, cutting force and make F F cut out the situation has the following factors:2.1 Cutting and tool relative motion produces friction. When in processing toughness steel with radial cutting component F began cutting speed increases, a speed since the beginning, with cutting speed decreases. According to the principle that cutting Fv mainly depends on the radial cutting component of cutting and tool relative motion, namely, the friction produced before cutting and tool the friction sword. Friction varies with the increase of friction velocity decreases characteristics, namely negative friction properties. In mechanical system, which has negative friction properties of the system is easy to stimulate cutting vibration.2.2 Regeneration of workpiece before cutting in turn left when a trace of vibration caused by cutting thickness cyclical change, thus affecting the cycle of cutting force change. Say commonly, after turn (after the chatter marks cutting times) relative to turn (previous) before cutting of chatter marks will not synchronous, they always have a poor phase in a vibration value phi, in the period of chatter marks, Ycos omega curve Yn = t, Y n (t) on the phase lag in previous Yn - 1 (t) namely 0 phi F is far reaching, which produced vibration. Therefore, in addition to increasing system in the direction of the Y stiffness and damping, try to reduce the Fy and any stop cutting component of the workpiece and along the direction of tool relative displacement of y. factors, usually can weaken or eliminate vibration. Main can adopt the following measures:(1) Turning time, generally when v = 30 70m/min speed range, easy to produce the vibration, so choose turning speed cutting force should avoid appear with the slower speed area, or low range in high-speed cutting vibration very not easy the creation,.(2) Avoid scraps wide and thin, otherwise susceptible to the cutting vibration. In the permission cases (such as machine tools have enough rigidity, enough motor power, surface roughness of workpiece reference when less demanding, etc), suitable enlargement of feeding and reduce cutting depth also help curb vibration.(3) Suitable enlargement of cutting tools rake Angle gamma can reduce vibration Fy force, thereby deadening. But in cutting speed higher range, the influence of vibration anterior horn, so high speed will weaken the negative rake Angle cutting and not produce strong vibration. Usually adopt double ventral horn vibrating knife, use figure 1 front width f to control tool and cutting contact, can significantly reduce length of cutting force, thus inhibiting vibration. 1 0 speed, high speed gamma gamma 0 when F趋近，E(+)E(-)，即在每一振动周期中，切削力对工件(或刀具)所做之正功总是大于它对工件(或刀具)所做之负功，从而使工件(或刀具)获得能量补充产生自激振动。 在车削过程中，影响切削力周期性地变化，并使F退出F切人的情况有以下几个因素： 2.1切削与刀具相对运动产生的摩擦力。在加工韧性钢材时径向切削分力F开始随切削速度的增加而增大，自某一速度开始，随切削速度的增加而下降。据切削原理可知，径向切削分力Fv主要取决于切削与刀具相对运动产生的摩擦力，即切削与刀具前刀面的摩擦力。摩擦力具有随摩擦速度的增加而下降的特性，即负摩擦特性。在机械系统中，具有负摩擦特性的系统容易激发切削振动。 2.2再生切削时因工件在前一转时振动留下的痕迹引起切削厚度周期性的变化，从而影响切削力的周期变化。一般说，后转(后次)切削的振纹相对于前转(前次)切削的振纹总不同步，它们在相位上总有一个差值，在一个振动周期中，对振纹曲线Yn =Ycost，Y n(t)在相位上滞后于前次的Yn-1(t)即0 F趋近，而产生了振动。因此，除了增加系统沿Y方向的刚度及阻尼外，设法减少切削分力Fy及任何阻止工件与刀具沿Y方向的相对位移的因素，通常都能减弱或消除振动。主要可采取下面几种措施：(1)车削时，一般当v=3070mmin速度范围内，容易产生振动，因此选择车削速度时应避开出现切削力随速度下降的中速区，在高速或低速范围进行切削，自振极不易产生。 (2)应尽量避免宽而薄的切屑的切削，否则极易产生振动。在许可的情况下(如机床有足够的刚度，足够的电机功率，工件表面粗糙度参考值要求较低时等)，适当增大进给量和减小切削深度也有助于抑制振动。 (3)适当增大刀具前角可减小Fy力，从而减弱振动。但在切削速度较高的范围内，前角对振动的影响将减弱，所以高速下采用负前角切削，不致产生强烈的振动。通常采用双前角消振刀，利用图1前面的宽度f来控制刀具和切削的接触长度，可显著减小切削力，从而抑制振动。低速时10，高速时00，1与2之间相差15 (4)当切削深度和进给量不变时，随着主偏角K增大，切削分力Fy减少。因此，适当增大刀具主偏角，可以消除或减小振动。(5)刀具后角太大或刀刃过分锋利，刀具切人工件时，容易产生振动。当后角减小到23时，振动有明显的减弱。在刀具后面磨出一段负倒棱，如图2所示，约01-03mm负倒棱，可以减小径向切削力和抑制振动。 (6)刀架系统如果有负刚度是时，容易“啃人”工件产生振动。因此，尽可能避
- 温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。
川公网安备: 51019002004831号