金属切削加工基础知识节选--机械毕业设计外文翻译

金属切削加工基础知识节选--机械毕业设计外文翻译 金属切削加工基础知识1 机械加工工艺系统 从机械制造的整个过程来看机器的最基本组成单元为零件也就是首先要制造出合格的零件然后组装成部件再由零部件装配成机器因此制造出符合 要求 对教师党员的评价套管和固井爆破片与爆破装置仓库管理基本要求三甲医院都需要复审吗 的各种零件是机械加工的主要目的而机械加工中绝大部分材料是金属材料故机械加工主要是对各种金属进行切削加工 零件的表面通常是几种简单表面如平面圆柱面圆锥面球面成形表面等的组合而零件的表面是通过各种切削加工 方法 快递客服问题件处理详细方法山木方法pdf计算方法pdf华与华方法下载八字理论方法下载 得到的其中在金属切削机床上利用工件和刀具彼此间协调的相对运动切除被加工零件多余的材料获得在形状尺寸和表面质量都符合要求的这种加工方法称为金属切削加工 金属切削加工常作为零件的最终加工方法它需要用金属切削刀具直接对零件进行加工它们之间要有确定的相对运动和承受很大的切削力通常需在金属切削机床上进行加工零件和刀具需通过机床夹具和刀架与机床进行可靠的联接带动它们做相对的运动实现切削加工这种由金属切削机床刀具夹具和工件构成的机械加工封闭系统称为机械加工工艺系统其中金属切削机床是加工机械零件的工作机械起支承和提供动力作用刀具起直接对零件进行切削加工作用机床夹具用来对零件定位和夹紧使之有正确的加工位置本章就围绕机械加工工艺系统四个组成部分进行 分析 定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析 阐述机械零件加工的整个过程切削运动与切削用量 1 切削运动 金属切削加工时工件是机械加工过程中被加工对象的总称任何一个工件都 是经过由毛坯加工到成品的过程在这个过程中要使刀具对工件进行切削加工形成各种表面必须使刀具与工件间产生相对运动这种在金属切削加工中必须的相对运动称为切削运动以车床加工外圆柱面为例图表示出了车削运动切削层及工件上形成的表面 图 车削运动切削层及工件上形成的表面 切削运动可分为主运动和进给运动两种 1主运动 主运动是切除工件上多余金属层形成工件新表面所必需的运动它是切削加工中最基本最主要的运动通常它的速度最高消耗的机床功率最多如车削加工镗削加工时是工件的回转运动铣削加工和钻削加工是刀具的回转运动刨削加工是刨刀的直线运动 2进给运动 进给运动是把被切削金属层间断或连续投入切削的一种运动与主运动相配合即可不断地切除金属层 获得所需的表面进给运动的特点是速度小消耗功率少可由一个或多个运动组成图-1所示外圆车削中沿工件轴向的纵向进给运动是连续的沿工件径向的横向进给运动它是间断的 3 切削层 切削层是指切削时刀具切削工件一个单行程所切除的工件材料层图-1所示工件旋转一周回到原来的平面时由于刀具纵向进给运动是连续的刀具从位置?移动到了位置?在两个位置间形成的工件材料层图中ABCD区域就是切削层 4 切削过程中工件上形成的表面 工件在切削过程中形成了三个表面其中待加工表面是指工件上即将被切削掉的表面即图中外圆表面1过渡表面是工件上切削刃正在切削的表面如图中表面2已加工表面是指工件上经切削加工后形成的表面如图中外圆表面3 切削用量 刀具与工件之间有了相对运动才可以进行切削加工用来衡量切削运动大小的参数称为切削用量切削速度进给量和背吃刀量切削深度称为切削用量的三要素只有合理地确定切削用量才能顺利地进行切削 1 切削速度 刀具切削刃上选定点相对于工件主运动的速度单位为 或 由于切削刃上各点的切削速度是不同的计算时常用最大切削速度代表刀具的切削速度外圆车刀车削外圆时的切削速度计算式为 式中 工件待加工表面的直径mm 工件的转速 2 进给量 刀具在进给运动方向上相对于工件的位移量称进给量不同的加工方法由于所用刀具和切削运动形式不同进给量的表述和度量方法也不同进给量的单位是 用于车削镗削等或 行程用于刨削磨削等进给量表示进给运动的速度进给运动速度还可以用进给速度 单位是 或每齿进给量 用于铣刀铰刀等多刃刀具单位是 齿表示一般 式中 主运动的转速 刀具齿数 3 背吃刀量切削深度 在垂直于主运动方向和进给运动方向的工作平面内测量的刀具切削刃与工件切削表面的接触长度对于外圆车削背吃刀量为工件上已加工表面和待加工表面间的垂直距离单位 即 式中 工件待加工表面的直径 工件已加工表面的直径 切削加工刀具的基本知识 金属切削过程中直接完成切削工作的是刀具而刀具能否胜任切削工作主要由刀具切削部分的合理几何形状与刀具材料的物理机械性能决定 1 刀具切削部分的结构要素 切削刀具的种类很多结构也多种多样车刀刨刀均属单刃刀具而钻头铣刀等为多刃刀具虽然它们形状不同但它们切削部分的结构要素及其几何形状都具有许多共同的特征因此正确认识与理解单刃刀具是认识与理解多刃刀具的基础 如图3-1所示车刀由刀体夹持部分与刀头切削部分组成刀体用来将车刀夹持在车床刀架上起支承和传力作用刀头担负切削工作车刀切削部分又称刀头由前刀面主后刀面副后刀面主切削刃副切削刃和刀尖所组成 图3-1车刀的组成 其定义分别为 1前刀面前面刀具上与切屑接触并相互作用的表面 2主后刀面主后面 刀具上与工件过渡表面相对并相互作用的表面 3副后刀面副后面 刀具上与工件已加工表面相对并相互作用的表面 4主切削刃 前刀面与主后刀面的交线它完成主要的切削工作 5副切削刃 前刀面与副后刀面的交线它配合主切削刃完成切削工作并最终 形成已加工表面 图3-2刨刀钻头铣刀切削部分的形状 6刀尖 主切削刃和副切削刃连接处的一段刀刃它可以是小的直线段或圆弧 由此可见车刀主要由三个刀面两条切削刃和一个刀尖组成其它各类刀具如刨刀钻头铣刀等都可看作是车刀的演变和组合如图3-2所示刨刀切削部分的形状与车刀相同图3-2a钻头可看作是两把一正一反并在一起同时车削孔壁的车刀因而有两个主切削刃两个副切削刃还增加了一个横刃图3-2b铣刀可看作由多把车刀组合而成的复合刀具其每一个刀齿相当于一把车刀图3-2c 2 刀具的几何角度 1刀具角度参考坐标系 刀具角度是确定刀具切削部分几何形状的重要参数要确定刀具的角度必须先确定用于定义和 规定 关于下班后关闭电源的规定党章中关于入党时间的规定公务员考核规定下载规定办法文件下载宁波关于闷顶的规定 刀具角度的各种基准坐标平面组成各种参考坐标系以外圆车刀为例在生产实践中最常用的坐标系是正交平面参考坐标系如图3-3所示主要三个平面组成 基面 过切削刃选定点垂直于该点假定主运动方向的平面用Pr表示 切削平面 过切削刃选定点与切削刃相切并垂直于刀具基面的平面主切削平面用Ps表示副切削平面用Ps表示 正交平面 过切削刃选定点同时垂直于刀具基面和切削平面的平面用Po表示 这三个平面两两相互垂直称为正交故此坐标系叫做正交平面参考坐标系在图中过主切削刃选定点和过副切削刃选定点都可以建立正交平面参考坐标系它 们的基面同为平行刀具底面的平面 图3-3正交平面参考坐标系 2刀具角度 建立了正交平面参考坐标系刀具的各个刀面与坐标系平面之间就产生了交角这样可以用它们来表示各个刀面的倾斜程度从而改变刀具的锋利与强弱设计刃磨和测量刀具的几何形状对外圆车刀来说刀面主要有三个每个刀面按一面两角分析法需要两个角度来确定其空间位置因此总共需要六个角度来确定外圆车刀的几何形状这六个角度称为外圆车刀的独立角度如图3-4所示 图3-4 正交平面参考坐标系的刀具角度 刀具角度是制造和刃磨刀具所需要的并在刀具设计图上予以标注的角度以外圆车刀为例角度定义为 前角 在正交平面内测量的前刀面与基面之间的夹角前角表示前刀面的倾斜程度前角越大刀具越锋利根据前刀面与基面相对位置的不同又分别规定为正前角零度前角和副前角 主后角 在正交平面内测量的主后刀面与切削平面之间的夹角主后角表示主后刀面的倾斜程度一般为正值 副后角 在副切削刃的正交平面内测量的副后刀面与切削平面之间的夹角副后角表示副后刀面的倾斜程度一般为正值 主偏角 在基面内测量的主切削刃在基面上的投影与进给运动方向的夹角主偏角一般为正值 副偏角 在基面内测量的副切削刃在基面上的投影与进给运动反方向的夹角副偏角一般为正值 刃倾角 在切削平面内测量的主切削刃与基面之间的夹角当刃倾角为正时刀尖的强度较低铁屑向刀架方向流出适用于精加工类型刀具 3 常用刀具材料 1刀具材料应具有的性能 金属切削过程中刀具切削部分在高温下承受着很大切削力与剧烈摩擦切削工作时还伴随着冲击与振动引起切削温度的波动因此刀具切削部分材料应具有良好的机械和物理化学性能主要是 高硬度 刀具材料的硬度必须高于被加工材料的硬度一般刀具材料在室温下都应具有60HRC以上的硬度 高耐磨性 刀具与工件之间有很大的相对运动速度产生的摩擦很大需要很高的耐磨性一般来说材料硬度越高耐磨性越好 足够的强度与韧性 切削时刀具和工件间产生很大的切削力同时又有较大的冲击力故要求刀具材料要有足够的强度与韧性来保证刀具不产生破坏 高的耐热性 高耐热性是指在高温下仍能维持刀具切削性能的一种特性通常用高温硬度值来衡量也可用刀具切削时允许的耐热温度值来衡量它是影响刀具材料切削性能的重要指标耐热性越好的材料允许的切削速度越高 刀具材料还需有较好的工艺性与经济性工具钢应有较好的热处理工艺性淬火变形小淬透层深脱碳层浅高硬度材料需有可磨削加工性需焊接的材料宜有较好的导热性与焊接工艺性此外在满足以上性能要求时宜尽可能满足资源丰富价格低廉的要求 选择刀具材料时很难找到各方面的性能都是最佳的因为材料性能之间有的是相互制约的只能根据工艺需要保证主要需求的性能如粗加工锻件毛坯需保持 有较高的强度与韧性而加工硬材料需有较高的硬度等Metal machining knowledge 1 Mechanical processing system From the whole process of mechanical manufacturing the most basic components of machine part also is the first to produce qualified parts and then assembled into components again from zero parts assembly into machine therefore manufactured to meet the requirements of the various parts of processing machinery is main purpose and in the vast majority of material machining is a metal material so the machining is mainly to a variety of metal cutting Parts of the surface is usually several simple surface such as plane cylindrical surface conical surface forming surface and spherical combination and the surface of the part is through a variety of machining method in which the metal cutting machine tool with the workpiece and tool coordination relative movement of resection of part machining surplus materials access to in shape size and surface quality are compatible with the requirements of this process is called the metal cutting processing Metal cutting processing often as part of the final processing method it needs to use metal cutting tools to process parts between them to determine the relative motion and bear great cutting force usually in the metal cutting machine tool for processing parts and tools required by machine tool fixture and tool and machine tool for reliable connection they do the relative motion drive realize the cutting process the metal cutting machine tool cutting tool fixture and workpiece machining closed system called mechanical processing system the metal cutting machine tool processing machinery parts mechanical work supporting and providing dynamic action cutting tool direct action of parts machining machine tool fixture used on parts positioning and clamping the correct position of processing The chapter on machining process system four part is analyzed the mechanical parts of the processing of the whole process 2 Cutting motion and parameters 21 Cutting movement Metal cutting processing workpiece machining process is processed object in general any one of the workpiece are composed of rough processing to finished product process in this process to make the tool on the workpiece machining to form various surfaces must make the tool and workpiece relative motion is generated this in metal cutting processing must be relative motion is known as the cutting movement To lathe processing outer cylindrical surface as an example Figure 2-1 shows a turning movement cutting layer and formed on the workpiece surface Figure 2-1 turning movement cutting layer and formed on the workpiece surface Cutting motion can be divided into the main movement and feed movement of the two kind 1Main movement Main movement is the removal of the unnecessary metal layer forming the new surface necessary for the movement it is the most basic cutting the main motion it is usually the highest speed consumption of machine tool power most such as turning boring machining workpiece turning milling and drilling processing cutter rotary motion planing is planing linear motion 2Feed motion Feed movement is to be cutting metal layer intermittent or continuous input of cutting a movement with the main movement coordination can becontinuously removed metal layerto obtain the desired surface Feed motion is characterized by low speed low power consumption can be composed of one or more exercise Figure 2-1 in excircle turning along the axial direction of the longitudinal feed motion is continuous radially along the workpiece transverse feeding motion it is intermittent 3Layer cutting Cutting layer refers to cutting cutting workpiece to a single stroke the resection of the workpiece material layer Shown in Figure 2-1 the workpiece rotates a circle back to the original level because the tool longitudinal feed motion is continuous the cutting tool from the position I had moved to position II in the two position of the formed workpiece material layer Figure ABCD region is cutting layer 4The cutting process is formed on the workpiece surface The workpiece in the cutting process in the formation of the three surfaces one of the surfaces to be processed is refers to the workpiece to be cut away the surface figure external circular surface 1 the transition surface is the workpiece cutting edges are cutting surface as shown in the figure 2 surface surface refers to the workpiece by the cutting process after the formation of the the surface of external circular surface as shown in figure 3 22 Cutting Between the tool and the workpiece with relative movement can be cutting used to measure the movement of cutting size parameter called the cutting parameters cutting speed feed rate and depth depth called the cutting elements of the three It is only reasonable to determine the amount of cutting can be carried out smoothly cutting 1Cutting speed The cutting edge of selected points on the workpiece relative to the main movement speed unit or Because each point on the cutting edge of the cutting speed is different when calculating the imum cutting speed cutting tool used on behalf of the cutting speed The outer circle lathe turning cutting speed calculation formula 2-2 In the workpiece surface diameter mm INCLUDEPICTURE "httpcomFilesUpLoadfiles20081203liucuttingfilesimage009gif" \ MERGEFORMATINET 梬orkpiece speed 2 Feed Cutting tool in the direction of feed on the workpiece relative to the displacement of said feed different processing methods the cutting tool and the cutting movement in different forms the feed formulation and measurement methods are also different Feed unit used for turning boring or Stroke used for planing grinding etc The feed that feed movement speed Feed velocity can also be used to feed speed company Or feed per tooth used for milling cutter reamer cutter unit is Tooth Express In general 2-3 Type ofmain motor speed the cutter teeth 3 Back cutting depth depth of cut In the direction perpendicular to the direction of main movement and feed movement in the direction of the working plane measurement of workpiece and the cutting tool edge cutting surface contact length For cylindrical turning back cutting depth for the workpiece on the machined surface and the vertical distance between the surface to be machined the unit That is 2-4 In the workpiece surface diameter machined surface diameter 3 Cutting tool basic knowledge In the process of metal cutting cutting work is done directly tool and the cutting tool is fit for cutting work mainly by cutting part of the tool geometry and cutting tool materials reasonable physical mechanical properties 31 Cutting part of the tool structural elements Cutting tool type are many varied structure Lathe tool planer is a single-point cutting tool and the drill bit cutter cutter although they differ in shape but they are cutting part of the structural elements and geometry have many features in common so a correct understanding and understanding a single-point cutting tool is the recognition and understanding of knife with foundation As shown in Figure 3-1 tool comprises a knife body clamping part and the cutter head cutting The knife body is used to the tool clamp on lathe tool holder supporting and force transmission effect the cutter head to cutting work Tool cutting part also known as the cutter head by the rake face the flank minor flank the main cutting edge a secondary cutting edge and tip Figure 3-1tool Their definitions respectively 1 front front tool and chip contact and the interaction of surface 2 the flank main behind the cutter and workpiece transition surface relative to and interacts with the surface of 3 the minor flank side behind tool and machined surface relative to and interacts with the surface of 4 the main cutting edge rake face and flank of the intersection of main It completes the main cutting work 5 a secondary cutting edge rake face and flank of the line side It is matched with the main cutting edge finish cutting and finally forming the machined surface Figure 3-2 cutter drill bit milling cutter cutting section shape 6 the main cutting edge and the side cutting edges at the connection of a blade It can be small line segment or arc Thus turning tool is mainly composed of three blades two cutting edges and a nose and other types of tools such as knives drill bits milling cutter can be seen as the evolution and combination tool As shown in Figure 3-2 planing cutting part of the tool shape and same Figure 3-2a the drill bit can be regarded as two positive and reverse turning hole wall and at the same time the tool which has two main cutting edge two side cutting edge also adds a transverse blade FIG 3-2b milling cutter a plurality of cutter can be regarded as the combination of composite tools each of which corresponds to a lathe tool cutter tooth Figure 3-2c 32 Tool geometric angle 1 Tool angle reference coordinate system The angle of cutting tool is to determine the cutting part of the tool geometry parameters to determine the angle of cutting tool must determine for definitions and regulations angle of various reference plane consisting of various reference coordinate system outside round tool as an example in the production practice of the most commonly used coordinates are orthogonal plane reference coordinate system as in Figure 3-3 in three main planar composition ? surface cutting edge of selected points perpendicular to the point of main movement direction of plane assumption To express with Pr ? the cutting plane cutting edge of selected points and cutting edge tangential and perpendicular to the cutting tool the flat base surface The main cutting plane is indicated by Ps side cutting plane with P s ? orthogonal plane cutting edge selected point and perpendicular to the base surface and the cutting plane of the plane cutter To express with Po The three planar two two mutually perpendicular called orthogonal coordinate system so called orthogonal plane reference frame in the picture the main cutting edge and the side cutting edges of selected points selected point can be established in the orthogonal plane reference coordinate system their base with the bottom surface of the flat surface parallel tool 分享到 翻译结果重试 抱歉系统响应超时请稍后再试 支持中英中日在线互译 支持网页翻译在输入框输入网页地址即可 提供一键清空复制功能支持双语对照查看使您体验更加流畅 Figure3-3 orthogonal plane reference coordinate system 2 Angles of cutter Establishment of plane coordinate system cutter knife surface and each coordinate plane arose between angle so that they can be used to express the degree of tilt of each knife thereby changing the sharp edges of the cutter and the strength design grinding and measuring tool geometry the cylindrical turning tool knife surface are three main one each blade according to the side two analysis requires two angles to determine the spatial position therefore requires a total of six angles to determine the outer circle lathe tool geometry the six angle is called the outer circle lathe tool independent point of view as shown in figure 3-4 Figure3-4The orthogonal plane of the reference coordinate system of cutting tool angle The angle of cutting tool manufacturing and grinding tool is needed and the cutter design drawing shall be stated angle outside round tool as an example the angle is defined ? anterior horn in the orthogonal plane measurement of the rake face and the angle between the front surface angle of rake face inclined degree Higher the rake angle cutter sharper rake face and the base surface according to the relative positions of the different respectively defined as positive rake angle zero rake angle and side rake angle ? the angle in the orthogonal plane measurement of the flank and the angle between the cutting plane After the main main flank angle of tilt degree generally positive ? side angle in the side cutting edges orthogonal plane measuring side flank face and the angle between the cutting plane Back clearance angle said side flank inclination degree generally positive ? the main angle in the inner base surface measurement of the main cutting edge on the base with the direction of feed angle projection The main general positive angle ? on the surface side angle measurement in the secondary cutting edge on the surface projection and the feed motion in the opposite direction angle General positive side angle ? in a cutting plane cutting edge inclination measurement in the main cutting edge and base of the angle between the When the blade is positive the strength of the tool tip is low iron filings to knife direction outflow applicable to finish type cutter 33 Commonly used tool materials 1 Tool material should have the properties of In the process of metal cutting cutting part of the tool at a high temperature under a lot of cutting force and cutting of intense friction when working also accompanied by shock and vibration caused by cutting temperature fluctuations therefore cutting part of the tool materials should have good mechanical and physical and chemical properties mainly ? high hardness hardness must be higher than the material hardness general cutting tool materials at room temperature shall be above 60HRC hardness ? high wear resistance between the tool and the workpiece has a lot of relative motion velocity friction require high wear resistance material generally the higher hardness wear resistance ? sufficient strength and toughness of cutting tool and workpiece to produce great cutting force simultaneously also has the big impact force the cutting tool material should have enough strength and toughness to ensure that the tool does not generate damage ? high heat resistance and high heat resistance is at a high temperature can still maintain the cutting performance of a character usually with high temperature hardness values measured can also be used while the tool is cutting allows the heat resisting temperature values measured It is the important index of cutting tool material Heat resistance and better material allows the cutting speed is higher Tool material should also have better technological and economic Tool steel should have good heat treatment quenching deformation hardening layer depth decarburized layer shallow high hardness materials need grinding processing welding material should have better thermal conductivity and welding technology In addition in satisfies the performance requirement should as far as possible to meet the requirements of rich resources low price Selection of cutting tool materials it is difficult to find all aspects of performance are the best because the material properties between some restrict each other can according to the needs of technology to ensure that the main performance requirements such as rough rough forging required to maintain a higher strength and toughness and machining of hard materials with high hardness