轴类零件的加工及工艺分析

目录第一章数控机床的产生与发展·······················································41.1数控车床的发展趋势··························································4第二章零件的工艺分析····································································52.1零件的用途··········································································52.2零件图的工艺分析······························································52.3零件的表面粗糙度·····························································62.4零件的尺寸精度··································································6第三章零件加工过程·········································································63.1正确选择工件坐标原点·······················································73.2确定对刀点、换刀点及刀点位置······································7第四章制定数控车削加工工艺方案················································84.1加工工序的划分····································································84.2.加工顺序的确定·····································································104.3加工路线的确定·····································································10第五章工具的选择···············································································115.1毛坯的选择··············································································115.2机床的选择··············································································115.3刀具的选择··············································································1325.4量具的选择···············································································145.5夹具的选择···············································································15第六章切削参数的确定·········································································156.1确定主轴转速··············································································156.2确定进给速度··············································································166.3切削用量的确定··········································································166.4加工余量的确定··········································································186.5背吃刀量的确定··········································································18第七章切削液的选择··············································································18第八章装夹方式和定位基准的选择··················································198.1装夹方式的选择···········································································198.2定位基准的选择··········································································20第九章程序的编制及工艺文件的制定···············································219.1制定刀具卡··················································································219.2制定工艺卡··················································································249.3制定工序卡··················································································259.4数控加工程序的编制································································26总结参考文献3第一章数控机床的发展1.1数控车床的发展趋势数控技术的应用不但给传统制造业带来了革命性的变化，使制造业成为工业化的象征，而且随着数控技术的不断发展和应用领域的扩大，他对国计民生的一些重要行业（IT、汽车、轻工、医疗等）的发展起着越来越重要的作用，因为这些行业所需装备的数字化已是现代发展的大趋势。从目前世界上数控技术及其装备发展的趋势来看,其主要研究热点大致分为以下4个方面。(1)高速、高精加工技术及装备的新趋势(2)轴联动加工和复合加工机床快速发展(3)智能化、开放式、网络化成为当代数控系统发展的主要趋势(4)重视新技术标准、规范的建立为了满足市场和科学技术发展的需要,为了达到现在制造技术对数控技术提出了更高的要求,数控未来仍然继续想开放式,基于PL的地六代方向、高速化和高精度化、智能化等方向发展。4第二章零件的工艺分析数控加工工艺是采用数控机床加工零件时所运用各种方法和技术手段的总和，应用于整个数控加工工艺过程。数控加工工艺是伴随着数控机床的产生、发展而逐步完善起来的一种应用技术，它是人们大量数控加工实践的经验总结。数控加工工艺过程是利用切削工具在数控机床上直接改变加工对象的形状、尺寸、表面状态等，使其成为成品或半成品的过程。2.1零件的用途图中所设计的零件为一复杂的轴类零件，而轴类零件又是机器中经常遇到的典型零件之一。它主要用来连接和支承传动零部件，传递扭矩和承受载荷，图示的零件也不例外。轴类零件是旋转体零件，其长度大于直径，一般由同心轴的外圆柱面、圆锥面、内孔和螺纹及相应的端面所组成。根据结构形状的不同，轴类零件可分为光轴、阶梯轴、空心轴和曲轴等，图示零件则为阶梯轴。所以，图中所示零件的用途是连接其它配合件，起的作用是支承其它传动零部件，传递扭矩和承受载荷，可用于汽车、机械等行业。2.2零件图的工艺分析5技术要求如下：（1）、不准用砂布及锉刀等修饰表面。（2）、未注倒角1×45o,锐角倒钝0.2×45°。（3）、未注公差尺寸为0.03结构工艺性分析零件的结构工艺性是指零件对加工方法的适应性，即所设计的零件结构应便于加工成型。尺寸标注方法分析零件图上的尺寸标注方法应适应数控车床加工的特点。如图所示，应以同一基准标注尺寸或直接给出坐标尺寸。这种标注方法既便于编程，又利于设计基准，工艺基准，测量基准。2.3零件的表面粗糙度零件的表面工作部位的不同，可有不同的表面粗糙度。例如，普通机床6主轴支承轴颈的表面粗糙度为Ra1.6～6.3μm。随着机器运转速度的增大和精密度的提高，轴类零件表面粗糙度值要求也将越来越小。该零件表面粗糙度均为1.6μm对外圆柱面的粗糙度要求比较低，为Ra=1.6m。对外圆弧的粗糙度要求：为Ra=1.6m。对外螺纹的粗糙度要求：为Ra=1.6m。2.4零件的尺寸精度该零件的总长度为143mm包括一个Φ26mm的镗孔。一个R25.8mm的圆弧。一个R20mm圆弧。的一个长为Φ28mm宽为10mm的槽和一个长为Φ33mm宽为10mm的槽。一个长为Φ20宽为36mm，导程为1.5的螺纹，加工的端面有长Φ40mm宽20mm，长Φ54宽10mm，长Φ50mm宽5mm，长Φ41.4mm宽8.7mm，长Φ46mm，长Φ35mm宽15mm。还有一部分要倒角，其中M36的螺纹需倒角2mm，其余部分倒角为C1.5.行位公差要求包括Φ28的槽上公差和下公差各要求为0.02和Φ33的公差要求为上公差要求为0下公差要求为-0.05Φ26的内孔上公差要求为0.04下公差要求为0.端面Φ54的公差要求为0.03。R25.8长度为31的圆弧上下公差各要求为0.03。零件的总长度上下公差要求各为0.05.第三章零件加工过程通过加工工艺分析以及程序编写，开始对机床工艺参数进行设定，加工出零件，根据毕业设计要求，采用编程方式是手工编程，再将编写正确的程序输入数控系统FANUC中心进行零件加工；首先还要对机床工艺参数进行设定，包括设工件坐标原点、对刀点、换刀点等。3.1正确选择工件坐标原点在数控车床CAK6140上建立工件坐标系（也称编程坐标系），一般将工件坐7标系的Z轴设成与机床主轴中心线重合，X轴设在工件的左端面或右端面。3.2确定对刀点、换刀点及刀点位置对刀就是确定刀尖在工件坐标系中的位置，对刀的好坏将直接影响到车削零件的尺寸精度。常用的对刀方法为试切法。如下图所示：对刀点的选择原则如下：（1）所选的对刀点应使程序编制简单；（2）对刀点应选择在容易找正、便于确定零件加工原点的位置；（3）对刀点应选在加工时检验方便、可靠的位置；（4）对刀点的选择应有利于提高加工精度。（5）引起的加工误差小。在使用对刀点确定加工原点时，每把刀具的半径与长度尺寸都是不同的，刀具装在机床上后，应在控制系统中设置刀具的基本位置。“刀位点”是指刀具的定位基准点。其对工件对刀操作步骤如下：开电源开关和数控车床上的电源开关和开机按钮，做好加工前的准备工作，把机床设置回原点,选用硬质合金毛坯一端为基准把毛坯件装在三爪卡盘上，在控制面板上选择主轴正转，转动手轮按钮，把手轮旋转钮对在Z上，用手轮将刀具移动到需要接近工件时打少移动速度慢慢的用刀去接触毛坯的边沿，直到有少