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超声
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超声换能器弧形盖片冲裁模设计,超声,换能器,弧形,盖片冲裁模,设计
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摘 要超声换能器是一种基于能量转换的声学检测器件，在工业超声无损检测中占有重要地位。顶盖盖片是超声换能器结构的组成部分，在其工艺成型、维护、保养及声学检测中，具有重要作用。论文对超声换能器弧形盖片冲裁模进行了设计，可为超声换能器制造提供一定参考。为尽可能满足实际超声换能器弧形盖片的技术要求，需要对超声换能器弧形盖片的材料及形状结构进行分析，使得该超声换能器弧形盖片冲裁模设计采用级进模作为冲裁工艺方案。通过对搭边值、送料进距、条料的宽度、材料利用率等相关值的分析计算，确定符合经济利用价值的超声换能器弧形盖片排样形式。基于冲孔落料的工序，确定合理的冲裁间隙，进而对冲裁工艺进行分析计算；在对超声换能器弧形盖片冲裁模零部件结构的设计中，重点对凸凹模的结构、定位装置、卸料装置、导向装置和固定装置进行分析计算。通过分析并选定冲压设备，且对该冲压设备的参数进行校核，以此达到检验模具结构、尺寸及精度要求的目的。超声换能器弧形盖片冲裁模具的设计，已经初步运用于课题组超声换能器的研制，达到了基本技术指标要求。关键词： 超声换能器弧形盖片，冲裁模，冲孔落料，级进模ABSTRACTUltrasonic transducer is an acoustic testing device based on energy conversion, which plays an important role in industrial ultrasonic nondestructive testing. The top cover plate is an integral part of the structure of ultrasonic transducer, which plays an important role in the process of forming, maintenance and acoustic detection. In this paper, the design of the blanking die for the arc cover plate of the ultrasonic transducer can provide an important reference for the manufacture of the ultrasonic transducer. 为尽可能满足实际超声换能器弧形盖片的技术要求，需要对超声换能器弧形盖片的材料及形状结构进行分析，使得该超声换能器弧形盖片冲裁模设计采用级进模的冲裁工艺方案。通过对搭边值、送料进距、条料的宽度、材料利用率等相关值的分析计算，确定符合经济利用价值的超声换能器弧形盖片排样形式。基于冲孔落料的工序，确定合理的冲裁间隙，进而对冲裁工艺进行分析计算；在对超声换能器弧形盖片冲裁模零部件结构的设计中，重点对凸凹模的结构、定位装置、卸料装置、导向装置和固定装置进行分析计算。通过分析并选定冲压设备，且对该冲压设备的参数进行校核，以此达到检验模具结构、尺寸及精度要求的目的。In order to meet the technical requirements of the actual ultrasonic transducer arc-shaped cover sheet as much as possible, it is necessary to analyze the material and shape structure of the ultrasonic transducer arc-shaped cover sheet, so that the design of the ultrasonic transducer arc-shaped cover sheet stamping die adopts the progressive die stamping process. Based on the analysis and calculation of the values of edge value, feeding distance, strip width, material utilization, etc., the layout form of the arc-shaped cover plate of the ultrasonic transducer which accords with the economic utilization value is determined. Based on the punching blanking process, the reasonable blanking clearance is determined, and then the blanking process is analyzed and calculated. In the design of the part structure of the ultrasonic transducer arc cover blanking die, the structure of the convex and concave die, the positioning device, the unloading device, the guiding device and the fixing device are mainly analyzed and calculated. Through the analysis and selection of stamping equipment, and the parameters of the stamping equipment are checked, so as to achieve the purpose of checking the die structure, size and accuracy requirements. 超声换能器弧形盖片冲裁模具的设计，已经初步运用于课题组超声换能器的研制，达到了基本技术指标要求。The design of the die for cutting the arc cover of the ultrasonic transducer has been applied to the development of the ultrasonic transducer of the research group, which has reached the basic technical requirements.Key Words：Ultrasonic transducer arc cover, Blanking die, Punching and blanking, Progressive dieIV目 录摘 要IABSTRACTII第一章绪论11.1课题的选题背景及冲压工艺概述11.2冲压模具的国内外现状及发展趋势11.3超声换能器弧形盖片冲裁模设计主要内容2第二章超声换能器弧形盖片的工艺方案42.1设计任务42.1.1工件的技术要求及零件图42.1.2工件的材料分析52.1.3工件的形状结构分析52.1.4工件的尺寸精度和断面粗糙度52.2冲裁工艺方案62.3本章小结7第三章超声换能器弧形盖片的排样设计83.1排样形式83.2排样的相关计算83.2.1搭边值83.2.2送料进距93.2.3条料的宽度93.3排样图103.4材料利用率103.5本章小结11第四章超声波换能器弧形盖片冲裁工艺计算124.1冲裁间隙的确定124.2凸、凹模刃口尺寸的确定124.2.1凸、凹模刃口尺寸计算原则134.2.2确定凸、凹模刃口尺寸计算方法134.2.3冲孔凸模刃口尺寸计算144.2.4落料刃口尺寸计算144.3冲裁工序力154.3.1冲裁公序力分析154.3.2冲裁力154.3.3卸料力164.3.4推件力174.3.5冲裁工序力的确定184.4冲裁压力中心计算184.5本章小结20第五章超声换能器弧形盖片冲裁模零部件结构设计215.1凹模的结构设计215.1.1确定凹模结构形式215.1.2确定凹模刃口形式215.1.3凹模外形尺寸225.1.4凹模的材料材料和技术要求245.2定位装置的设计245.2.1挡料销245.2.2导正销245.2.3导料板255.3卸料装置的设计255.3.1弹性单元的设计265.3.2卸料板的设计285.4固定板的设计285.5凸模的结构设计295.5.1确定凸模结构形式295.5.2确定凸模固定方法295.5.3凸模长度计算295.5.4凸模的材料和技术要求305.6固定零件的设计305.6.1模柄305.6.2垫板315.6.3紧固件315.6.4模架315.7导向零件335.7.1导柱的选择335.7.2导套的选择335.8本章小结34第六章冲压设备参数的分析356.1压力机的技术参数356.2相关技术参数的校核366.2.1冲裁力的校核366.2.2模具闭合高度的校核366.2.3压力机工作台尺寸的校核376.3本章小结37第七章 结论38参考文献39致谢40附录1 英文文献原文41附录2 英文文献翻译62第一章 绪论1.1课题的选题背景及冲压工艺概述超声换能器是一种基于能量转换的声学检测器件，在工业超声无损检测中占有重要地位。顶盖盖片是超声换能器结构的组成部分，在其工艺成型、维护、保养及声学检测中，具有重要作用。随着模具新兴技术迅速的发展，在工作中提高了制造过程中的生产效率，以及降低了产业和人力成本，奠定了其在工业生产制造中的重要地位。论文对超声换能器弧形盖片冲裁模进行了设计，以此极大可能的去满足实际应用的需求及超声换能器弧形盖片的技术要求。冲压工艺是以组装在冲压设备上的模具为标准，使板料产生分离或塑性变形，从而达到轮廓形状及性能的工件生产目标。在制造工作过程中常以变形性质为基础，将冲压工序分成分离和成型。其中的分离工序复称冲裁，是指板料在一定压力作用下，其承受压力高出材料的抗剪强度而沿特定轮廓断裂成制件的工序；而其中的成型工序是指板料在一定压力作用下，其所受应力在没有达到抗剪强度的情况下高出屈服强度，使板料塑性变形并达到工件生产目标。冲压工艺容易实现自动化生产的目标，使工业制造业的生产效率大大提高且在一定基础上降低材料成本消耗；操作工艺简便，不需要操作者的技艺有较高的水平；成型的零件因不需要接着进行机械加工，使其尺寸精度较高、质量稳定和一致性好;冲压件一般使用表面质量较好的板材作为原始材料，从而极大可能的减少后续表面的处理工序，使其生产更加便利;获得的零件强度高、刚度大和重量轻，所以在加工方法中较为先进。 1.2冲压模具的国内外现状及发展趋势由于国外发达区域的模具工业开始的时间比较早，持有较为先进的经验及生产管理技术。基于模具产业链，充分利用前沿技术，一是通过信息优势，加快了模具产业的完善进度；二是基于新兴技术的普及，极大的提高了模具制造业的行业竞争力；三是在工业制造中将快速制模和成型技术的应用普遍化；四是对该行业的工作人员进行一定的精简，完善工作及生产制度；五是更进一步精确了模具在市场中的定位；六是管理信息系统的成本投入符合制造生产的实际需求；七是模具类产业的多项标准的程度较高。虽然国内在制造模具和利用模具的时间较为早，可是产业化一直未形成，并且在很长的时间被视为生产后方，更加的延缓了模具行业的发展速度，造成了中国模具行业低于国际先进水平，具体体现为以下六大方面，一是模具标准化（现代化、发展化、信息化、智能化）程度低；二是自动化生产制度的不完善，造成工业制造的效率无法全面提高；三是在高速、高精度、大型模具制造方面异常困难；四是仿真工艺欠缺，模具寿命短，制造成本代价较高；五是对新兴材料的研究与开发投入成本降低，使其无法达到先进水平；六是对于模具产品及制品没有更好的检测工艺，有极大的提高空间。 在全球化的新局势下，现代制造业将会重新组合资本、技术和劳动力市场，中国成为制造业基地的趋势已无法逆转。为了推动我国模具产业的进步，必须大力支持模具制造企业应用现代先进制造技术，以此来提升竞争实力去满足成熟模具制造产业的迫切需求。我国必须向模具高级人才培养计划大力投入时间和金钱，以此完成人才储备；加大模具检测设备的研究与更替，以此加快向精密、高效和多功能方向发展；我国模具行业对新工艺、新理念和新模式的认同感必须加快提升，从而更好的去接近世界水平。1.3超声换能器弧形盖片冲裁模设计主要内容超声换能器顶盖是超声换能器外衣的关键构成部分，在实际制造过程中占有极其重要的地位，为了满足其在实际应用情况中的需求，本次设计决定采用冲裁模设计。冲裁模也可以称做冲压工艺，是应用安装在压力机上的模具对板料按规定的轮廓形状及性能要求产生分离或塑性变形的一种措施。在设计过程中，将此次设计大致分为五个部分，第一部分是通过对超声换能器弧形盖片的材料及相关内容进行验证，确定超声换能器弧形盖片的冲裁工艺；第二部分通过对搭边值、送料进距、条料的宽度、材料利用率等相关值的计算，从而确定符合经济利用价值的超声换能器弧形盖片排样形式；第三部分是在超声换能器弧形盖片所需工序的基础上，明确冲裁间隙，同时完成冲裁工艺的一系列相关计算；第四部分是超声换能器弧形盖片冲裁模零部件结构的设计，主要是凸凹模的结构、定位装置、卸料装置、导向装置和固定装置，且在符合产品需要的基础上，选择标准件；第五部分是选定符合相关参数的冲压设备，并对该冲压设备的某些参数进行一定的校核，以此达到检验模具结构及尺寸、精度要求的目的，从而确保冲裁出质量合格的超声换能器弧形盖片。最后通过上述设计绘出超声换能器弧形盖片装配图和零件图。第二章 超声换能器弧形盖片的工艺方案本章节在设计任务的基础上，通过分析超声换能器弧形盖片的技术要求、材料要求、形状结构要求以及精度和断面粗糙度，以此来在更深层上认知本次设计任务的实际需求和基本目的。2.1设计任务通过超声换能器弧形盖片的冲裁模设计且在冲裁模理论知识的基础上，能够更进一步的掌握和应用。此外能够熟练的利用Solidworks三维软件去完成超声换能器弧形盖片的一系列冲裁模设计，最后利用三维软件导出或二维软件独立完成所需工程图纸的绘制。2.1.1工件的技术要求及零件图工件名称为超声换能器弧形盖片，它的整体几何外形较为简单，外部轮廓的长为100mm, 上偏差为+0.140mm、下偏差为-0.140mm；宽为60mm，上偏差为+0.120mm、下偏差为-0.120mm的弧形，中间有四个直径为6mm的圆孔，形状简单，尺寸适中，为一多工序冲裁件。所选材质为08钢，厚度t=2mm，精度等级IT10级，批量生产。超声换能器弧形盖片零件图如图2.1。图2.1超声换能器弧形盖片零件图2.1.2工件的材料分析此次超声换能器弧形盖片采用的材料为08钢。材料特性：08钢为碳素钢且极软，在强度和硬度上的体现较低，而在塑性和韧性的体现上极高，也造成其的冷加工及焊接的良好性能。同时需要注意08钢的时效敏感性，以及其极低的淬硬性及淬透性。据文献1P203表8-1黑色金属材料的力学性能可得表2.1 08钢力学性能表。表2.1 08钢力学性能表抗拉强度b (MPa)屈服强度s (MPa)伸长率5()断面收缩率 ()硬度(HB)试样尺寸(mm)抗剪强度 b(MPa)325(33)195(20)3360未热处理,131252553532.1.3工件的形状结构分析1）冲裁件的几何形状设计应最大可能的简单、对称及排样合理，以此来达到节省材料的需求。2）超声换能器弧形盖片的外形及内孔没有尖角，在一定程度上降低了超声换能器弧形盖片在冲压时开裂的可能性，降低了成本需求。3）超声换能器弧形盖片内孔与边缘的最小距离为7mm，能满足公式a2t（t为料厚），极大的降低了变形的可能性。2.1.4工件的尺寸精度和断面粗糙度1、尺寸精度：该超声换能器弧形盖片的精度可以通过确定尺寸的尺寸公差，从而使其在冲裁工作中得到保证。据文献1p213表8-14标准公差数值，以精度IT10为准来确定该超声换能器弧形盖片的尺寸公差，可得表2.2工件各公差尺寸。 表2.2工件各公差尺寸尺寸（mm）1006076公差（mm）100-0.140+0.14060-0.120+0.1207-0.058060+0.048据上所述可绘出冲裁件的尺寸公差图2.2。图2.2冲裁件的尺寸公差2、断面粗糙度：因超声换能器弧形盖片的厚度为2mm，可知超声换能器弧形盖片的断面粗糙度为Ra12.5。表2.3一般冲裁件断面的近似粗糙度取自文献1p7表2-5表2.3一般冲裁件断面的近似粗糙度材料厚度/mm112233445粗糙度Ra/m6.312.525501002.2冲裁工艺方案因冲裁模的结构样式多样，可选择的工艺方案较多，故需要在工艺分析的条件上，通过概括考虑产品的模具制造、模具结构、生产批量、质量要求、生产效率、和产品生产的经济性等许多因素，从而确定切合具体生产条件的最佳工艺方案。该冲裁件为超声换能器弧形盖片，只需冲孔和落料两个基本工序，据零件图和生产批量，可知连续冲裁模和复合冲裁模较为适合本产品需要。 方案一：先冲孔后落料分别在不同工位上的连续冲裁模。该方案主要是通过条料的传送以及定位装置和导料装置的方向控制下，在不同工位完成冲孔和落料两个工序。因工作零件中的所有凸模安装在上模部分，使得超声换能器弧形盖片和圆形废料均能实现自然脱落，较易实现自动化。不过所需模具结构比较复杂、制造成本代价高以及定位基准较多。方案二：落料和冲孔两道工序同时在一个工位上进行的复合模。该方案主要将凸模和凸凹模的冲孔工序以及凹模和凸凹模的落料工序在一个工位上同时完成。虽然生产效率高且能满足制件的高精度要求，但是对于模具零件的精度要求高，成本代价高且制造周期长。因超声换能器弧形盖片的外形简单、精度要求为IT10级且大批量生产 ，为达到切合具体生产条件的目的，本次超声换能器弧形盖片冲裁模设计采用连续冲裁模。2.3本章小结通过分析了解超声换能器弧形盖片所选材料的特性和力学性能，以及剖析超声换能器弧形盖片的形状结构，且在保证尺寸精度和断面粗糙度的基础上，确定该超声换能器弧形盖片的冲裁工艺方案连续冲裁模。第三章 超声换能器弧形盖片的排样设计排样在冲压生产中有着降低成本、确保制件质量和模具寿命的作用。合理的排样设计决定着原材料的利用率，使其经济价值有着绝对的体现，且可以改善操作流程，使其工作效率有着绝对的提升。3.1排样形式目前普遍使用的排样形式以废料的量为标准，可将排样分为有废料的排样、少废料的排样和无废料的排样。据实际应用情况的了解，本次超声换能器弧形盖片的冲裁模设计选择有余料排样。超声换能器弧形盖片在板料上有直排、斜排和冲裁搭边等排布形式。为了超声换能器弧形盖片的质量和尺寸精度要求，以及连续冲裁模具使用周期的需求，该冲裁模设计据超声换能器弧形盖片的零件图最终选用直排。3.2排样的相关计算该超声换能器弧形盖片冲裁模设计对超声换能器弧形盖片的排样方式有两种表现形式，具体是超声换能器弧形盖片的纵向排列和横向排列。通过对相关值的一系列分析计算，选择带材利用较高的形式。3.2.1搭边值搭边会在连续冲裁模工作过程中补偿定位及剪板下料时所造成的工作误差；在一定基础上提升板料的刚度，以及保证连续冲裁模生产的超声换能器弧形盖片的合格性；使连续冲裁模工作过程中板料的送进可以更加的便利，且连续冲裁模的工作效率得到提升。故本次超声换能器弧形盖片冲裁模设计需确定合乎实际应用的搭边值。由于此次超声换能器弧形盖片采用的材料为08钢，且超声换能器弧形盖片的厚度为2mm，可由表3.1获知搭边值。表3.1搭边a和a1数值取自文献1p20表2-18 表3.1 搭边a和a1数值（低碳钢） （mm）材料厚度t圆件及圆角r2t 矩形件 边长L50矩形边长L50 或 圆角r2t工件间a1沿边a工件间a1沿边a工件间a1沿边a0.25以下1.82.02.22.52.83.00.250.501.21.51.82.02.22.50.50.81.01.21.51.81.82.00.81.20.81.01.21.51.51.81.21.61.01.21.51.81.82.01.62.01.21.51.82.52.02.22.02.51.51.82.02.22.22.5本次超声换能器弧形盖片的材料厚度t=2mm，可由表3.1可知此工件的搭边值得工作间a1=2.2，沿边a=2.5。3.2.2送料进距通过板料上的两个超声换能器弧形盖片中的某一个共同点的直线距离来确定送料进距。可由公式（3-1）取自文献2P32中的式（2-2）来计算送料进距A：A=D+a1 （3-1）式中： A 送料进距，单位mm； D 在送料方向上冲裁件的宽度，单位mm； a1 工件之间的搭边值，单位mm。故：（1）A1=D+a1=60mm2.2mm=62.2mm。 (2) A2=D+a1=100mm2.2mm=102.2mm。3.2.3条料的宽度因为模具在工作时会产生误差，如条料的裁剪误差和送料时出现的误差，故实际情况中的条料宽度就应该略大于理论宽度，以此来防止模具在工作过程中出现误差。因排样形式选择有余料排样，故此次连续冲裁模的模具采用无侧压装置模具。可由公式（3-2）取自文献2P33中的式（2-3）来计算条料的宽度B：B=L+2a+b0-0 (3-2)式中： B条料的宽度，单位mm； L工件与送料方向垂直的最大尺寸，单位mm； a工件与条料侧边之间的搭边数值，单位mm； b0条料与导料板之间的间隙，单位mm； 条料下料的下偏差数值，单位mm； 根据文献2 P33表2-11和2-12,取b0=0.8mm，=1.0mm。故：B1=L+2a+b0-0=100+22.5+1.0+0.8-1.00=107.8-1.00mm B2=L+2a+b0-0=60+22.5+1.0+0.8-1.00=67.8-1.00mm 3.3排样图除沿边值调整为a=3.9以外，其他数据均据上所述故，由此可得到图3.1排样图。图3.1 横向排样图图3.2 纵向排样图3.4材料利用率 材料的利用率主要是很衡量经济利用的指标。可由公式（3-3）取自文献1P18中的式（2-1）来计算一个进距内的材料利用率：=nAbh100% （3-3）式中： n 额进距内的冲裁件数目； A 冲裁件面积 mm2； b 条料宽度，mm； h 进距，mm。可利用Solidworks三维软件测量冲裁件的实际面积，为从而得出图3.2工件实际面积。图3.3 工件实际面积故： 1=nAbh100%=4599.99107.862.2100%=68.6% 2=nAbh100%=4599.9967.8102.2100%=66.4%由此可知，本次超声换能器弧形盖片冲裁模设计选择超声换能器弧形盖片纵向排列的表现形式。3.5本章小结本章主要通过对排样所产生的搭边值、送料进距、条料的宽度、材料利用率等相关值按一定公式进行计算，从而确定符合经济利用价值和实际经验的超声换能器弧形盖片排样形式。第四章 超声波换能器弧形盖片冲裁工艺计算冲裁工艺是以组装在冲压设备上的模具为标准，使板料产生分离或塑性变形，从而实现轮廓形状及性能的工件生产目标。为了极大可能的去满足实际应用的需求及超声换能器弧形盖片的技术要求，需要对冲裁工艺进行分析、确定和计算。4.1冲裁间隙的确定工件的断面质量、尺寸精度、模具的生命周期和冲裁工序等都会被凸、凹模的冲裁间隙（冲裁模具中凹、凸模刃口的尺寸之差）所影响，如在模具工作时，冲裁间隙若过大，必将造成模具的使用周期减少的情况，相反又会造成工作所需冲裁力较大的情况。故为了切合冲裁的实际需求和经济价值体现，需选用适当的冲裁间隙，一般用Z表示，如图4.1所示。图4.1 冲裁间隙示意图本次超声换能器弧形盖片冲裁模设计确定冲裁间隙时采用经验确定法。据文献2p35 表2-13冲裁模初始双边间隙取最小间隙Zmin=0.22mm；最大间隙Zmax=0.26mm。4.2凸、凹模刃口尺寸的确定冲裁模具在工作时需要基于模具的刃口尺寸来保证工件尺寸的精度要求，以及冲裁间隙的合理性。该超声换能器弧形盖片冲裁模设计通过配合加工法来使凸、凹模刃口尺寸得到确定。4.2.1凸、凹模刃口尺寸计算原则首先是刃口尺寸在计算过程中，需要区别冲孔、落料两种情况，并且模具适用后所产生的磨损等情况也要考虑；其次是在遵循一定原则的基础上去确定模具刃口尺寸及制造公差，并且在切合实际要求的基础上去分析模具精度与冲件精度之间的关系。4.2.2确定凸、凹模刃口尺寸计算方法凸、凹模刃口尺寸的计算方法一般有两种，分别是互换法和配合法。圆形和形状规则的工件一般用互换法,因此可以同时进行加工，使得制造周期短、便于成批加工、成本代价低，不过对于凸、凹模制造精度要求高；另一种是配合法，一般将先加工件确立为基准件，并以此为标准去加工未加工件，可以最大可能的保证间隙的最小值以及基准件的制造公差。本次超声换能器弧形盖片冲裁模设计选择配合加工法。凸模和凹模在磨损后所产生的最终结果都为实体缩小，因不同基准件的确定，超声换能器弧形盖片的尺寸会产生增大、减小和不变的三种情况，本设计将磨损后尺寸增大的定为A类、尺寸减小的定为B类、尺寸不变的定为C类。因设计的超声换能器弧形盖片的最终成形只需要两个工序，分别是冲孔和落料，所以在冲孔工作时将冲孔凸模定为基准件，落料工作时将落料凹模定为基准件。据上所述可得到图4.2凸、凹模刃口磨损图。图4.2凸、凹模刃口磨损图4.2.3冲孔凸模刃口尺寸计算计算冲孔刃口尺寸时，先将凸模定为基准件，然后通过凸模的实际尺寸来配合加工对应凹模的相关尺寸，需确保Zmin=0.22mm。因凸模刃口磨损的原因，会使孔的尺寸60+0.048mm逐渐减小，属于B类尺寸。可由公式（4-1）取自文献2P38中的式（2-13）来计算。B=Bmin+x-2/40 （4-1）式中：B超声换能器弧形盖片的基本尺寸，单位mm；x磨损系数；超声换能器弧形盖片公差，单位mm。据文献1P16中的表2-13系数x可知：磨损系数X=0.75取=4。故：B=Bmin+x-2/40=(6+0.750.048)-0.048/40=6.036-0.0120=6+0.024+0.0364.2.4落料刃口尺寸计算计算落料刃口尺寸时，先将凹模定为基准件，然后通过凹模实际尺寸来配合加工对应凸模的相关尺寸，需确保Zmax=0.26mm。在凹模刃口磨损的基础上，外形尺寸100-0.140+0.140mm，60-0.120+0.120mm, 7-0.0580mm将会逐渐增大，属于A类尺寸。可由公式（4-2）取自文献2P38中的式（2-12）来计算。A=Amax-x0+/4 （4-2）式中： A超声换能器弧形盖片的基本尺寸，单位mm；x磨损系数； 超声换能器弧形盖片公差，单位mm。据文献1P16中的表2-13可得本设计的磨损系数x1=x2=x3=1取=4。故：A1=Amax-X10+/4=(100.140-10.140)0+0.140/4=1000+0.035 A2=Amax-X20+/4=(60.120-10.120)0+0.120/4=600+0.030 A3=Amax-X30+/4=(7-10.058)0+0.058/4=6.9420+0.0145=7-0.058-0.0444.3冲裁工序力冲裁工序力由多种工序力构建，所以需分析该模具所需冲裁工序力有几种，并将相关工序力计算出来，最后相加得到冲裁工序力。4.3.1冲裁公序力分析基于弹性卸料分析超声换能器弧形盖片冲裁模具的具体结构和冲裁工艺，确定超声换能器弧形盖片冲裁模设计所需工序力，如图4.3所示。图4.3 冲裁工序力示意图4.3.2冲裁力冲裁力为冲压设备在冲裁超声换能器弧形盖片时提供的力，一般用Fc表示。可由公式（4-3）取自文献2P40中的式（2-15）来计算。Fc =KLtb （4-3）式中： Fc 冲裁力, 单位KN；K 修正系数，一般取K=1.3；L 冲裁周边长度, 单位mm；t 材料厚度, 单位mm； b 材料抗剪强度, 单位MPa。由SolidWorks可得图4.4冲裁面弧形长度。图4.4 冲裁面弧形长度由表2.1可知08钢的抗剪强度 b=255353MPa，本设计取抗剪强度 b=304则：L=L1+L2=255.30+463.14=330.66mm Fc=KLtb=1.3330.662304=261353.664(N)=261.354(KN)4.3.3卸料力卸料力是指将冲头上的超声换能器弧形盖片和圆形废料卸掉所需要的力，一般表示可用Fx。可由公式（4-4）取自文献2P40中的式（2-17）来计算。Fx=KxFc （4-4）式中：Fx 卸料力，单位KN；Kx 卸料力系数；Fc 冲裁力，单位KN。据文献1P22表2-20可知Kx为0.040.05，取Kx=0.05故：Fx=KxF=0.05261.354=13.068 (KN) 4.3.4推件力推件力是指将凹模型腔内的超声换能器弧形盖片和圆形废料推出的力，一般用Ft来表示。可由公式（4-5）取自文献2P40中的式（2-18）来计算。Ft=nKtFC （4-5）式中：Ft推件力，单位N； Fc冲裁力，单位N； Kt推件力系数； n同时卡在凹模内的超声换能器弧形盖片数量，n=h/t； t超声换能器弧形盖片厚度，单位mm； h凹模型腔的直刃壁高度，单位mm。注：超声换能器弧形盖片冲裁模设计以连续冲裁模为冲裁方案，废料出口方式为下落，以此来确定直通式为本次设计的刃口形式。基于超声换能器弧形盖片的厚度，确定刃口高度，因为超声换能器弧形盖片的厚度在0.5mm5mm区间，故取刃口高度h为8mm，则同时卡在凹模内的冲落部分制件数量n=4。据文献1P22表2-20可知Kt=0.05。故：Ft=nKtFC=40.05261.354=52.271(KN)4.3.5冲裁工序力的确定该超声换能器弧形盖片冲裁模设计所需工序力为冲裁力、卸料力和推件力，工序力之和就是冲裁工序力。可由公式（4-6）取自文献2P41中的式（2-21）来计算。F=Fc+Fx+Ft （4-6）式中:F 冲裁工序力，单位KN；Fc 冲裁力，单位KN； Fx 卸料力，单位KN。 Ft 推件力，单位KN故： F=Fc+Fx+Ft=261.354+13.068+52.271=326.693(KN)4.4冲裁压力中心计算超声换能器弧形盖片冲裁模具作工时零件不发生偏移、降低磨损和提高使用寿命期限的前提需要将压力机滑块的中心线与冲裁模具的压力中心重合。故合理合据的冲裁压力中心对确保制件精度和质量的意义十分重大。a、以超声换能器弧形盖片的中心为原点建立坐标系xOy，将超声换能器弧形盖片冲裁模的冲裁轮廓分成5部分，如图4.5冲裁压力解析图所示。图4.5 冲裁压力中心解析图b、确定各线段长度，因落料凹模关于对称，直接为0，其余列入表4.1。表4.1计算数据列表轮廓长度中心坐标XYL2=18.8439.20L3=18.8462.243L4=18.8462.2-43L5=18.8485.20c、可由公式（4-7）和公式（4-8）取自文献2P43的公式（2-24）和（2-25）来计算压力中心。xc=L1x1+L2x2+L9x9L1+L2+L9 （4-7） yc=L1y1+L2y2+L9y9L1+L2+L9 （4-8）式中:(xc ,yc) 压力中心坐标；(x，y) 各线段压力中心坐标；L 各线段长度。则：xc=L1x1+L2x2+L9x9L1+L2+L9=18.8439.2+18.8462.2+18.8462.2+18.8485.218.844=62.2 yc=L1y1+L2y2+L9y9L1+L2+L9=18.840+18.8443-18.8443+18.84018.844=0 故工件的冲裁压力中心为C（62.20，0.00）。使用SolidWorks建模测量压力中心坐标如图4.6所示。图4.6 SolidWorks所测压力中心值因计算值与软件值相等，故正确。4.5本章小结本章主要有四个部分，第一部分是在切合工件所需的基础上，通过查找相关文献确定冲裁间隙；第二部分是在实际经验计算公式中选择合适的计算方法来确定凸、凹模刃口尺寸；第三部分是通过分析本次设计的冲裁工序力有几种，并将相关工序力计算出来，最后相加得到冲裁工序力；第四部分确定超声换能器弧形盖片冲裁模的压力中心。 第五章 超声换能器弧形盖片冲裁模零部件结构设计超声换能器弧形盖片冲裁模的零部件结构多种多样。为了符合经济利用价值和实际应用情况的需求，以及超声换能器弧形盖片的技术要求，需通过分析和计算，选择适合本设计的标准件，以此来最大可能的满足产品需要。5.1凹模的结构设计因目前凹模的结构式样较多，为了符合本设计的使用性能及成本价值的体现需求，故要确保凹模结构设计的合理性。首先确定凹模结构及刃口形式，然后在切合实际应用情况需求的基础上计算出凹模的外形尺寸，最后选取符合工艺需求的材料。5.1.1确定凹模结构形式本设计基于凹模结构分类，可分为镶拼式凹模、组合式凹模和整体式凹模。本次超声换能器弧形盖片冲裁模设计因成本控制需求和故障维修操作过程的简练，确定整体式为本次超声换能器弧形盖片冲裁模设计中的凹模结构形式。5.1.2确定凹模刃口形式因超声换能器弧形盖片冲裁模设计以连续冲裁模为冲裁方案，并且该超声换能器弧形盖片冲裁模是下出料，为了凹模刃口强度在一定基础上较好，本次超声换能器弧形盖片冲裁模设计可采用直筒式刃口，如图5.1所示。图5.1 直筒式刃口基于超声换能器弧形盖片的厚度，确定刃口高度。因超声换能器弧形盖片的厚度在0.5mm5mm区间，故取刃口高度h为8mm。5.1.3凹模外形尺寸凹模的外形形式多样，为了能使超声换能器冲裁模的凹模在强度和刚度上有一定的确保，且修磨量在一定基础上有所保留，本次超声换能器弧形盖片冲裁模设计采用凹模外形为矩形。a、凹模高度：公式（5-1）选自文献2P51中的式（2-30） H=30.1F （5-1）式中: F 冲裁工序力，单位KN； H 凹模高，单位mm。故；H=30.1F=30.1326.69310331.968mmb、凹模壁厚：公式（5-2）选自文献2P41中的式（2-31）C=1.32.0H (5-2)式中：H凹模高，单位mm；C凹模壁厚，单位mm。故：C=1.32.0H=1.32.031.968=41.55863.936mm则可取H=32、36、40、45mm、C=59mm。c、凹模宽度： B=2C+b2 (5-3)式中：B凹模宽度，单位mm；C凹模壁厚，单位mm；b2工件与送料方向垂直的最大长度单位mm。故：B=2C+b2=259+100=218mmd、凹模长度： L=2C+b1+b12 （5-4）式中：L凹模长度，单位mm；C凹模壁厚，单位mm；b1工件在送料方向上的最大宽度，mm；故：L=2C+b1+b12=259+122.2+61.1=301.3mm 据文献4P149表6-20，可得本次超声换能器弧形盖片冲裁模设计的矩形凹模长度L=400mm、凹模宽度B=250mm、凹模高度H=40mm。5.1.4凹模的材料材料和技术要求超声换能器弧形盖片冲裁模设计中的凹模所需材料为Cr12。为了保证该设计中凹模刃口的锋利性，以及减少倒钝现象在工作中出现的概率，本设计决定将凹模进行淬火处理，使其硬度达到60-64HRC。 5.2定位装置的设计在冲裁模工作过程中，为了确保条料和半成品在冲裁模中位置的正确性，以及保证工件的质量和模具生产进行的连续性，需要定位装置的存在。本次超声换能器弧形盖片冲裁模设计采用两销一板，两销为挡料和导正，一板为导料。5.2.1挡料销超声换能器弧形盖片冲裁模在工作中，为了减少带材送进时产生的位置误差，从而设计挡料销，以此来保证准确度。本次超声换能器弧形盖片冲裁模设计采用A型固定挡料销且材料采用45钢制造。可据文献7P469表15.49确定尺寸，如图5.2所示。图5.2 挡料销因条料厚度t=2mm据文献1P33表2-28可确定挡料销高度， 本次超声换能器弧形盖片冲裁模设计中h挡为3毫米。5.2.2导正销导正销在超声换能器弧形盖片冲裁模中主要用于带材的精确定位，使得超声换能器弧形盖片的四个6mm的圆孔与弧形相对位置的准确性得到保准。本设计中的导正销高度需略高于超声换能器弧形盖片冲裁模凸模的高度，从而达到以先导正后冲裁的目的。本次超声换能器弧形盖片冲裁模设计的导正销的材料采用45钢，并需要经过淬火处理。可通过文献7P469表15.54及表15.55确定尺寸，如图5.3所示。图5.3 导正销5.2.3导料板导料板的存在价值是为了对带材行进方向进行限制，因超声换能器弧形盖片冲裁模工作过程中需要保证带材行进的通畅性，在带材宽度的基础上，导料板之间的距离设计定大2mm，以及厚度设计要高于带材厚度2mm。本次超声换能器弧形盖片冲裁模设计采用分离式导料板，且材料采用45钢，如图5.4所示。图5.4 导料板5.3卸料装置的设计卸料装置的存在，是为了减去卸下凸模外面的板料或超声换能器弧形盖片的人力投入。本次超声换能器弧形盖片冲裁模的卸料装置是利用弹性元件提供的弹性进行卸料。5.3.1弹性单元的设计充分考虑弹性单元的承载负荷、成本和安装操作的难易程度，从而确定本次超声换能器弧形盖片冲裁模的弹性单元为橡胶。（1）橡胶自由高度：S工作=t+4+S修磨 （5-5）式中：S工作橡胶工作行程，单位mm；t工件厚度，单位mm；S修磨模具修磨量，单位mm，取S修磨=5mm。故：S工作=t+4+S修磨=2+4+5=11mmH自由=3.54.0S工作 （5-6）式中：S工作橡胶工作行程，单位mm；H自由橡胶自由高度，单位mm。故：H自由=3.54.0S工作=3.54.011=38.544mm（2）根据橡胶自由高度计算其装配高度：H装配=0.850.9H自由 （5-7）式中：H自由橡胶自由装配高度，取H自由=40mm；H装配橡胶装配高度，单位mm。故：H装配=0.850.9H自由=0.850.940=3436mm， H装配取35。（3）橡胶总断面面积计算：A=FxP （5-8）式中：Fx卸料力，单位mm；P橡胶压缩量有关的单位压力，取P =2.1；A模具所需要的橡胶总断面面积，单位mm2。故：A=FxP=13.0681032.1=6.223103mm2（4）橡胶外形尺寸一般需切合0.5H/D1.5。0.540D1.5 （5-9）故：26.67D80据文献1P245表8-47取D=45mm,d=12.5mm，橡胶的外形尺寸如图5.5所示。图5.5 橡胶外形尺寸（5）橡胶的数量：n=AA1 （5-10）式中：A模具所需要的橡胶总断面面积，单位mm2；A1橡胶实际总断面面积，单位mm2；n橡胶数量。故：n=AA1=6.2231033.1422.52-6.2524.249则本次超声换能器弧形盖片冲裁模设计所需橡胶的数量为6（个）。5.3.2卸料板的设计在超声换能器弧形盖片冲裁模具工作完成后，以弹性单元（橡胶）的弹性使卸料板工作。本次超声换能器弧形盖片冲裁模决定将Q235作为卸料板的首要材料。卸料板的厚度可通过以下公式计算：Hx=0.81.0Ha （5-11）式中：Ha凹模厚度，单位mm；Hx卸料板厚度，单位mm。故：Hx=0.81.0Ha=0.81.040=3240mm，取Hx=36mm。5.4固定板的设计固定板的外形除高度以外皆与凹模的外形一致。本次超声换能器弧形盖片冲裁模决定将45钢作为固定板的首要材料。固定板厚度的计算：Hg=0.80.9Ha （5-12）式中：Ha凹模厚度，单位mm；Hg固定板厚度，单位mm。故：Hg=0.80.9Ha=0.80.940=3236mm，取Hg=34mm。5.5凸模的结构设计凸模是超声换能器弧形盖片冲裁模设计中模具的主要部件之一。在超声换能器弧形盖片冲裁模工作时，可以将板料按规定轮廓进行分离变形。 因目前凸模的结构式样较多，为了符合本设计的使用性能及成本价值的体现需求，故要确保凸模结构设计的合理性。5.5.1确定凸模结构形式由于超声换能器弧形盖片的结构简单，尺寸不大，以及本次超声换能器弧形盖片冲裁模设计中的成本控制需求和故障维修操作过程的简练，确定整体式为本次超声换能器弧形盖片冲裁模设计中的凸模结构形式。5.5.2确定凸模固定方法本次超声换能器弧形盖片冲裁模设计通过台阶式去固定凸模，以便由于冲头在超声换能器弧形盖片冲裁模在冲裁工作中产生损坏而进行的维修。5.5.3凸模长度计算凸模的长度可由公式（5-13）选自文献2P48中的式（2-28）来计算。 L=Hg+Hx+t+A （5-13）式中：L凸模长度，单位mm；Hg凸模固定板厚度，单位mm；Hx弹性卸料板厚度，单位mm；A自由尺寸， A相对要长一些，要考虑弹性单元的压缩量，本设计取A=37mm。故：L=Hg+Hx+t+A=34+36+2+37=109mm5.5.4凸模的材料和技术要求超声换能器弧形盖片冲裁模设计中的凸模所需材料为Cr12。为了保证该设计中凸模刃口的锋利性，以及减少倒钝现象在工作中出现的概率，本设计决定将凸模进行淬火处理，使其硬度达到58-62HRC。5.6固定零件的设计超声换能器弧形盖片冲裁模中的各结构部件都需要连接，故需要通过分析与计算，选择适合本次设计的标准件。5.6.1模柄据文献7P435表15.18，本次超声换能器弧形盖片冲裁模设计采用压入式模柄（A型），如下图5.6所示，图取自文献1P46表2-35。其固定部分与上模座成H7/m6配合，此结构能较好地保证模柄垂直度要求，长期使用模柄稳定可靠，不会松动，因此在多工位级进模中是较好的一种模柄，应用最多。本次超声换能器弧形盖片冲裁模设计的模柄材料采用Q235。图5.6 压入式模柄5.6.2垫板超声换能器弧形盖片冲裁模在工作中，会产生巨大的压力，从而对模座造成一定的损伤。为了减轻或扩散部分压力，可通过垫片来实现。因本设计选取的压力机较大，所以取垫片的厚度H垫板=12mm。本次超声换能器弧形盖片冲裁模垫板的材料采用淬火硬度为4045HRC的45钢。5.6.3紧固件超声换能器弧形盖片冲裁模模具决定以螺栓和销钉作为紧固件。螺栓的选择：超声换能器弧形盖片冲裁模设计中的上模座采用内六角紧固螺钉，直径为M304；超声换能器弧形盖片冲裁模设计中的下模座与上一致，不过直径为M364；卸料螺钉据文献8P472表8-58选择LLB（防松型）螺钉，直径为M126。 5.6.4模架基于上述，可据文献8P377表8-1，本次超声换能器弧形盖片冲裁模设计选择标准冲模滑动导向模架四导柱模架。如图5.7所示，图取自文献1P67表2-45。图5.7 四导柱模架据文献8P394表8-14，结合上述章节的相关计算，可得表5.1四导柱模架所示：表5.1 四导柱模架项目规格数量材料凹模周界400250闭合高度（参考）245-280上模座400250501Q235下模座400250601Q235导柱40230420Cr导套4012548420Cr模具闭合高度为： H闭=H上+H垫+L+Ha+H下-h （5-14） 式中：H闭超声换能器弧形盖片冲裁模的闭合高度，单位mm；H上上模座的高度，单位mm；H垫垫板的高度，单位mm；L凸模长度，单位mm；Ha凹模的厚度，单位mm；H下下模座的厚度，单位mm；h凸模进入凹模的距离，单位mm。故：H闭=H上+H垫+L+Ha+H下-h =50+12+111+40+60-3=270mm5.7导向零件超声换能器弧形盖片冲裁模在冲裁时，会产生一定的往复行进工作。为了确保模具在工作中运动的相对性，以及减少冲裁工作中偏移现象出现的次数，本次超声换能器弧形盖片冲裁模设计决定通过利用导柱与导套之间的滑动进行导向。5.7.1导柱的选择导柱规格基于模架标准，查文献7P445表15.25，选择B型导柱如图5.8所示，图取自文献1P41表2-30。本次超声换能器弧形盖片冲裁模的导柱材料采用淬火硬度为5660HRC的20钢。图5.8 B型导柱5.7.2导套的选择导套规格基于模架标准，查文献7P440表15.22，选择B型导套如图5.9所示，图取自文献1P42表2-31。本次超声换能器弧形盖片冲裁模的导套材料采用淬火硬度为5660HRC的20钢。图5.9 B型导套5.8本章小结本章是对超声换能器弧形盖片冲裁模零部件结构的设计，重点对凸凹模的结构、定位装置、卸料装置、导向装置和固定装置进行分析计算，且在冲裁工作零部件的标准上选择适合该超声换能器弧形盖片冲裁模的零部件。第六章 冲压设备参数的分析冲压设备又可以被称为压力机，属于一种特种设备。为了确保冲裁出质量合格的超声换能器弧形盖片，并达到检验模具结构及尺寸、精度要求的目的，需要适合各项参数的冲压设备。6.1压力机的技术参数据前述相关参数选择压力机型号为 J23-40开式可倾式曲柄，其参数可列表6.1。表6.1 压力机技术参数型号J23-80公称压力/ kN400到达工称压力时滑块距下止点的距离/mm7滑块行程/ mm100行程次数（次/分钟）80最大封闭高度/ mm300封闭高度调节量/ mm80滑块中心到床身距离/mm220工作台尺寸/mm前后630左右420工作台孔尺寸/mm前后300左右150直径200立柱间距离/ mm300模柄孔尺寸（直径深度）/ mm25070工作台板厚度/ mm80倾角/（）306.2相关技术参数的校核为保证压力设备能满足超声换能器弧形盖片冲裁模的实际需要，对该冲压设备的参数进行校核，以此达到检验模具结构、尺寸及精度要求的目的。6.2.1冲裁力的校核压力机公称压力需要大于冲裁工序力，即： Fp1.2F (6-1)式中：FP冲压设备公称压力，单位kN；F冲裁工序力，单位kN.故：Fp=4001.2F=392.032kN，故冲裁力的检验合格。6.2.2模具闭合高度的校核超声换能器弧形盖片冲裁模模具的H闭=270mm，本次设计所选冲压设备的H闭max=300mm，而该设备的封闭调节量为80mm，则H闭min=220mm。模具的闭合高度应符合：Hmin+10H闭Hmax-5 (6-2)式中：H闭冲裁模闭合高度，单位mm；Hmax最大封闭高度，单位mm；Hmin最小封闭高度，单位mm。由于H闭Hmin+12，则超声换能器弧形盖片冲裁模闭合高度的检验合格。6.2.3压力机工作台尺寸的校核因压力机与模具之间需要固定，所以压力机的工作台除去模座所占区域要留有余地。通过计算可知本次设计中压力机工作台每边留下的位置大于85mm，符合实际需要，则该检验成功。 6.3本章小结本章是对超声换能器弧形盖片冲裁模设计所需冲压设备的确定，且对相关参数进行一定的校核，以此达到检验模具结构及尺寸、精度要求的目的，从而确保冲裁出质量合格的超声换能器弧形盖片。第七章 结论通过对超声换能器弧形盖片进行了分析与计算，完成了超声换能器弧形盖片冲裁模的设计，可为超声换能器研制提供一定参考。（1）在满足实际超声换能器弧形盖片技术要求的基础上，对超声换能器弧形盖片的弧形结构及所采用的08钢材料进行工艺分析。基于精度等级为IT10，确定超声换能器弧形盖片零件的尺寸公差，并据材料厚度确定断面粗糙度为Ra12.5。最后明确超声换能器弧形盖片冲裁模设计将先冲孔后落料的连续冲裁模作为冲裁工艺方案。（2）根据材料厚度为2mm确定搭边值，并以此为基础对送料进距和条料的宽度进行分析计算，确定了最大材料利用率为68.6%的超声换能器弧形盖片排样形式，并绘制排样图。（3）在超声换能器弧形盖片冲裁模只需冲孔落料工序的基础上，确定初始双边间隙取最小间隙为0.22mm，最大间隙为0.26mm，以此为基础完成对凸凹模刃口尺寸的相关计算。通过分析计算所需冲裁工序力，确定冲裁工序力为326.693(KN)。最后是对压力中心分析计算，并通过Solidworks三维软件验证，确定工件的冲裁压力中心为C（62.20，0.00）。对超声换能器弧形盖片冲裁模零部件结构的设计中，对凸凹模的结构、定位装置、卸料装置、导向装置和固定装置进行分析计算，在冲裁工作零部件的标准上选择适合该超声换能器弧形盖片冲裁模的零部件。（4）通过分析选定冲压设备的压力机型号为 J23-40开式可倾式曲柄压力机，且对该冲压设备的参数进行校核，以此达到检验模具结构、尺寸及精度要求的目的。(5)在超声换能器弧形盖片冲裁模分析设计基础上，利用绘图软件完成了超声换能器弧形盖片冲裁模设计的零件图和装配图。超声换能器弧形盖片冲裁模具的设计工作，已经初步运用于课题组超声换能器的研制，达到了基本技术指标要求。参考文献1王芳.冷冲压模具设计指导M.北京: 机械工业出版社,1998.102田光辉.林红旗.模具设计与制造M. 北京:北京大学出版社,2009.3林承全,胡绍平.冲压模具课程设计指导与范例M.北京:化学工业出版社,2008.4杨占尧.最新模具标准应用手册.M.北京:机械工业出版社,2011.5廖伟.冲模设计技法典型实例解析M.北京:化学工业出版社,2012.6王伯平.互换性与测量基础M.北京：机械工业出版社.2008.017郝滨海.冲压模具简明设计手册M.北京：化学工业出版社.2007.108陈炎嗣.冲压模具设计手册（多工位级进模）M.北京：化学工业出版社.2013.03致谢时间总在悄悄逝去，我也最终完成了大学的最后一门课，毕业设计。不可否认的是，在此期间出现了很多问题，让人苦恼且愤恨。幸运的是，指导老师的细微指导、同组同学的信息共享和家人的体谅与理解，使我克服了所有的问题，且将毕业设计较为圆满的完成。你们的随手而为或许微不足道，可对于我的毕业设计来说，确是不小的助力。同时，特别感谢国家自然科学基金(11574399)的支持。附录1 英文文献原文An intelligent planning aid for the design of progressive diesAbstract:The design of progressive dies is a highly iterative planning process in which the designer attempts to select a die conzguration which will produce a part most efficiently by minimizing material, tooling and maintenance costs while achieving the required part speciji- cations. The planning process involves a considerable amount of human cognitive skills such as pattern recognition and matching (as in punch shape recognition) and spatial planning (as in nesting and staging of die processes) based on the geometrical features of the part. This paper describes an intelligent planning aid which can assist the die designer in planning progressive dies. The highly automated and yetflexible planning aid is developed by linking together a CAD (computer aided design) system, a knowledge-based system and a library of numerical routines.Key words: Progressive die design, CAD/CAM, knowledge-based expert systems1 INTRODUCTIONProgressive die design is an important component of tool engineering. A progressive die combines two or more types of dies into a single tool in an attempt to perform as many operations as possible in a single stroke of the press. In a progressive die, workpieces are passed along from one die (station) to the next. At each press stroke, work is carried out on a strip resulting, in most cases, with a finished component being deposited every time the machine ram rises, on a stack ready for the assembly shop. Products made by progressive dies can be found in almost all modern household appli- ances, office and computer equipment, car components, radio and television sets, clocks and watches and other mass-produced goods. Waller (1) identified four factors which are essential contributions to first-class presswork: (a) good operation planning,(b) excellent tool design,(c) accurate toolmaking, (d) knowledgeable press setting. The first three factors pertain to progressive die design. Modern CAD/CAM technology has contributed signifi- cantly to the second and third factors making the manufacture of precision parts possible. However, there are limited computer aids to assist in planning the die operations. A review of the academic and institutional research efforts in the field of CAD/CAM (computer aided design/manufacture) of progressive dies by Nee and Foong (2) shows that many of the systems are able to assist the designer by automating the tasks related to calculation of forces and centre of pressures, flat- patterning of formed parts, calculation of spring-back, retrieval of catalogue and library data of standard die components and the generation of NC (numerical control) data. In other words, these systems merely help to improve the productivity of the designer by automa- ting the procedural tasks after the operational plans have been decided. In most cases, the designers are required to plan the die operations manually and input the plan into the computer system using interactive graphical tools. The total cost of making a product is a function of material usage, tooling costs and die maintenance costs. In most cases, it is impossible to ascertain the total cost of making a product until the entire planning process is completed. Furthermore, the sub-optimal solution from each of the planning stages may not necessarily result in the cheapest die. This can be illustrated by a simple example. Two possible plans to mass-produce a part are shown in Fig. 1. Most nesting algorithms would select plan A, the single-row opposite arrangement. This is because this arrangement results in minimum material wastage. However, in a progressive notch and bend die, pilots are required to guide the positioning of the strip as it passes through the die. If plan B is chosen, a single-row arrangement, pilot holes can be located on the scrap material. On the other hand, plan A would require a wider strip (width = W,) to accommodate the pilot holes. Depending on the relative sizes of the flat pattern and pilot holes, the single-row opposite arrangement may no longer be more economical in terms of material usage. Furthermore, the resulting die for plan A would require the inclusion of an additional bending station and additional notching operations as compared to plan B. This means that the die would be more complex (and expensive) to build and maintain. The designer can only make the final decision after all the operational and costing implications of the various design alterna- tives have been explored.Fig. 1 Strip layout and piloting scheme affecting the cost of making a productThis example illustrates that a seemingly good solu- tion found during the planning stage may turn out to be a poor design. The complexity of the planning process makes it very difftcult to define a set of parameters that would help converge the various planning stages towards an optimum solution; hence it is almost impos- sible to fully automate the operation planning process in die design. What is needed is a set of planning aids that would automate each of the planning stages while the designer retains control over the planning process in the search for the optimum solution.Existing CAD/CAM systems for progressive dies are not able to assist the designer in evaluating alternative plans. This is mainly due to the fact that the design rules and the geometrical processing tasks associated with the planning process are very difficult to program into computer codes using a conventional approach. IAPDie, an intelligent aid to support the operation planning process for progressive die design, has been developed at the National University of Singapore (NUS). IAPDie is developed by integrating a knowledge-based system and a library of numerical rou- tines for the processing of geometrical data with a CAD system. In this way, efficient tools are provided for the user to search through the die design rules and heuris- tics, to process the geometrical information associated with the part and tooling arrangements, and to control interactively the planning steps and modify the plans. It is believed that the proposed system would constitute a crucial link towards an integrated computer tool for progressive die design as the results produced by the planning process are stored in the computer as CAD/CAM entities which can be accessed directly by conventional CAD/CAM systems.2 OPERATION PLANNING FOR DIE DESIGNAfter developing the flat pattern of a part, the main planning stages in the design of the progressive die are: nesting, selection of the piloting scheme, tool selection and operation staging design. All of these stages require decisions to be made based on the geometry of the part and interpretation of plans from each of the stages which are graphical in nature. IAPDie uses the follow- ing approaches to handle each of these planning steps. 2.1 Nesting Nesting is a well-researched subject matter (3-5). IAPDie rotates a part through a range of selected angles, and at each angle an identical part is placed along the advance direction such that they are closest together without overlapping. The stock utilization ratio (defined as the area of the developed shape divided by the area of rectangle formed by the advance and the width of the strip) for each angle is calculated. The nested arrangement is selected from the orientation which has a maximum stock utilization ratio. 2.2 Selection of piloting scheme Pilots are used to guide a strip in position before a die operation is executed. The strip must be positioned accurately in each station so that the operation can be performed in the proper location. IAPDie provides the following piloting scheme. 2.2.1 Direct piloting This consists of piloting in holes pierced in the part at an earlier station. IAPDie is able to identify the holes that are suitable as direct pilot holes and select the best pilot holes for the die. A hole is considered to be suit- able for use as a pilot hole if it satisfies the following conditions : 1. It is circular in shape. 2. The specified tolerance is not high. 3. It is big enough for use as a pilot hole. 4. It does not lie on the folded portion of the work- 5. It is not too close to the edge of the workpiece. 6. It is not too close to another hole on the workpiece. From the list of suitable pilot holes, the best piloting holes are selected based on the following priority: piece. 1. If only one hole is available, it will be considered in the first instance. 2. If there are a number of holes, select the two largest holes (which are equal in diameter) and the distance between them in the direction perpendicular to the feed direction is greater than a minimum preset dis- tance. The holes must be located on the opposite sides of the part3. Select the two largest holes (the diameters of which are within a preset percentage of each other) that satisfy the earlier conditions. 4. Select the hole that is nearest to the centroid of the part. 2.2.2 Semi-direct piloting In cases where a part has closely toleranced holes which invalidate the use of direct piloting, IAPDie would recommend the use of semi-direct piloting. The short- listing and selection criterion for semi-direct pilot holes is similar to direct piloting except that closely toler- anced holes can be short-listed for selection as semi- direct piloting holes. The operation of a semi-direct piloting scheme is similar to a direct piloting scheme. The differences are the pilot hole diameters which will now be made slight- ly smaller than the actual holes to be pierced and the actual holes will be pierced over the piloting holes in the last station. In this way, the distortions to the hole sizes caused by the actions of the pilots will not affect the final dimensions of the actual holes. 2.2.3 Indirect pilotingIndirect piloting involves locating the pilots in the scrap section. IAPDie provides two different schemes for indi- rect piloting: 1. Locating pilots on the scrap sections formed by the notching operations to stamp out the external profile of the part. Here, the system will identify the two notching punches which are furthest apart in the direction perpendicular to the feed direction. It will then calculate the largest possible pilot hole diam- eters in these two regions. Finally, it will use the cal- culated dimensions to select the desired pilot diameters from preferred sizes specified by the user in the tools library supported by the system. 2. Locating pilots on the side scrap-strip carrier. In cases where it is not feasible to locate pilots on the scrap sections formed by the notching operations, the user can elect to locate the pilots on the side scrap- strip carrier. The disadvantage of this piloting scheme is that the strip width may need to be increased to accommodate the pilot holes. 2.3 Tool selection IAPDie is able to automatically select the tools required to manufacture a part from its geometrical description. 2.3.1 Pierce and blank punchesA piercing or blanking punch, P, can be described by the following function:p =f（S,M,L）Where:S = punch shape M = mounting method L = length of the puncThe cost of constructing a die can be greatly reduced when as many standard punches as possible are used. IAPDie attempts to achieve this by decomposing the external and internal geometries of the part into smaller and less complex regions. By converting the geometrical data of these regions into two-dimensional primitive features and matching them with the predefined features of standard punch shapes, IAPDie is able to recognize up to 30 standard punch shapes from the catalogue of a commercial die component manufacturer (6). The fea- tures of the predefined shapes are arranged in a tree network according to the number of edges. A rule-based hierarchical search algorithm is used to reduce the number of tasks required to perform the pattern- matching process for punch shape recognition. For example, the number of features needed to match a four-sided polygon is fewer than that required to match a twelve-sided polygon. Hence, only the respective fea- tures required for a match are computed by the system as and when they are needed by the pattern-matching process. A more thorough treatment of the punch shape recognition and decomposition process adopted by IAPDie can be found in reference (7). After recognizing the punch shapes required to stamp out the profile of the part, IAPDie will define the envel- oping shape for each and every punch; depending on the aspect ratio of the punch shape, the enveloping shape can be circular or rectangular. The enveloping shape (in lieu of the actual punch shape) is used for interference checking of the subsequent spatial planning stages. This would simplify the interference checking algorithm and reduce the time taken to stage the die operations. Also, the enveloping shape will define the mounting method of the punch on the punch plate (Fig. 2).Fig. 2 Relationship between punch shape, envelope shape and mount type 2.3.2 Bending punches IAPDie is able to handle 23 D bending operations. By examining the geometrical features of both the plan and side elevation of the bend portion, IAPDie is able to classify the bending operation required to form the feature into any of the four predefined bending configu- rations shown in Fig. 3. The enveloping rectangle required to mount the corresponding bending tools is also derived. The enveloping rectangle provides the necessary spatial information for planning the staging operation.Fig. 3 Bending operations supported by IAPDie (bend angle not necessarily90)2.4 Staging the die operations The staging process is the planning stage in which the die operations are sequenced in a progressive manner such that, when the strip is subjected to all the shearing and forming operations in the progressive die, the required part is produced at the last stage. IAPDie will automatically stage the die operations in the following order:1. Piercing operations on pilot holes are staged first.2. Piercing operations on other internal holes are staged next.3. Notching operations of external profiles are staged next.4. Notching operations of external profiles used to accommodate indirect pilot holes (if any) are staged next. 5. Bending operations are staged next.6. Cam operations (on precise holes on bend features of the part) are staged next.7. Cam operations (on precise holes on bend features of the part) are staged next. Finally, the cut-off operation(s) and internal holes used as semi-piloting holes (if any) are staged.When planning the stages of a progressive die, IAPDie ensures that the die components will not interfere with each other when they are assembled together. It will also ensure that holes (for example in the punch plate) are sufficiently far apart to ensure that the die com- ponents are strong enough to withstand the forces during operation3 DESCRIPTION OF IAPDieA knowledge-based approach was initially used to develop a computer system to automate the progressive metal stamping die design process (7- 9). This approach extracts the topological information of a part from its constructive solid geometry (CSG) representation. A rule-based and object-oriented approach was used to generate the solid model representation of the die from information extracted from the part. The resulting system is able to design progressive dies for reasonably complex two-dimensional metal stamping parts. More importantly, it helps to test the validity of some of the design heuristics and illustrate the limitations of some of the approaches used to handle the die design problem. While it is possible to achieve a high degree of design automation of progressive stamping dies, it was noted that the solutions recommended by the system tend to be sub-optimal in some cases. Hence, it was decided that an intelligent planning aid would be of greater value to the die designer. In this way, personal design preference of the die designer can be catered for. It was also noted that the use of the CSG representation of the part to provide the topological information has its limi- tations. Firstly, more computer resources are required to manipulate solid models, and in a PC (personal computer) environment, the system performance suffers drastically. Secondly, the extraction of topological infor- mation of a three-dimensional formed part from its solid model would not be easy to implement. The die operation planning system requires the support of the following types of computing tools. Firstly, a set of numerical routines are required to process the geometrical data of the part and the associ- ated tools to assist in shape- and spatial-related plan- ning tasks. Secondly, a rule-based system is needed to search through the design rules and heuristics devel- oped to produce the plans automatically. Finally, inter- active graphical aids are to be provided for the designer to manipulate the geometrical model of the part and to interactively control the planning process and modify the plans generated by the system. IAPDie is a PC-based intelligent planning aid for the die designer. It is developed by integrating AutoCAD, Kappa-PC and a library of specially developed C+ + routines under the Microsoft Windows operating environment. AutoCAD is a computer aided design and drafting (CADD) package while Kappa-PC is an object- oriented knowledge-based development system. The integration is achieved by adopting the following meth- odology : 1. Shallow coupling the numerical and symbolic com- puting routines (10, 11). Die operation planning is inherently a mixed computational (numeric and heuristic) problem: numeric processing and analysis of part and tooling geometry, generation of the geo- metrical description of the plans and symbolic analysis of the die design rules and heuristics. In IAPDie, numerically intensive routines (for example external shape decomposition, interference checking, etc.) are coded in C+ + programming language, compiled as dynamic link libraries (DLLs) and regis- tered in Kappa-PC as kappa application language (KAL) functions. These routines are able to extract geometrical data from the respective object attributes in Kappa-PC. The outputs from these routines will depend on the nature of their tasks. They may create new objects in Kappa-PC (for example the decom- posed punch shapes) or provide attributes with values (for example the distance between the edge of an internal hole and the nearest edge of the part). If they are required to support a decision process initi- ated from Kappa-PC, the outputs will be presented as propositional logical expressions so that they can be formalized as well-formed formulae (WFFs) for logical interpretation by the knowledge-based system. 2. Adopting a model-based reasoning (MBR) (12) approach for the modelling of part and tooling com- ponents and the generation of plans. IAPDie obtains its problem definition in the form of part geometry and topology extracted from the AutoCAD database and places them into an object- oriented plan model in Kappa-PC. Monitors (or daemons) are used to synthesize additional geometri- cal or topological data when needed by the planning routines. Furthermore, rules are used to automate the synthesis of die sub-assemblies and components from the functional requirements specified by the plan.Figure 4 shows the simplified relationships between the CADD database, the plan model and the product model. Consider a hole to be pierced identified as IntShapel ; IAPDie extracts the geometrical data of the line or arc segments describing the shape and stores them as instances belonging to sub-class IntShapel. Monitors are built into the respective objects to derive additional attributes as and when they are needed by the planning routines. For example, the shape recognition routine will fire the monitors to extract the relevant shape features. The objects in the plan model will provide sufficient infor- mation for the system to develop the various plans for die design. After the plan is accepted by the user, it can be used to synthesize the various die com- ponents and sub-assemblies required to build the die. Hence, the piercing action required to stamp out IntShapel as specified by the plan will trigger off the synthesis rules leading to the generation of the objects belonging to the sub-class PunchSubAssembly 1.Fig. 4 Symbolic relationship between entities in the CADD database, the plan model and product model3. Dynamically linking graphics entities in AutoCAD with objects in Kappa-PC using Windows dynamic data exchange (DDE) capability (13). IAPDie pro- vides the designer with a high degree of control in the planning process by allowing the designer to access the object-oriented plan model by inter- actively manipulating graphics entities in AutoCAD. Similarly, the tools selected and plans generated in Kappa-PC can be automatically represented graphi- cally in AutoCAD. In other words, AutoCAD entities representing the part, the tools and the associated plans behave as intelligent objects having properties and attributes. This hot link provides instantaneous feedbacks between the designer and the knowledge-based system via AutoCAD. Changes made by the user in AutoCAD will immediately be updated in Kappa-PC after the system has checked the relevant rules to ensure that the changes requested are valid. For example, if a designer decides to select a specific hole as a direct piloting hole, IAPDie will check whether it satisfies the criteria associated with direct piloting before updating the knowledge base. Otherwise, it will reject the designers decision and explain the rules that have been violated. Similarly, when the designer decides to move an operation from one station to another, commands are provided by the system to check whether the spatial requirements of that particular operation to be introduced into the new station will interfere with the spatial require- ments of the other operations already staged.It is the ease of communication provided by this dynamic link that makes IAPDie an effective plan- ning aid. Using menu commands in AutoCAD, the designer can step through the planning stages. The designer can also interactively modify the plans sug- gested by the system. With the built-in checking rou- tines, the designer can be sure that the changes made are consistent with the functional and/or spatial requirements of the plan. IAPDie is able to automatically perform the process planning operations described earlier. However, addi- tional commands are provided for the user to inter- actively assist the decision-making process and to modify or over-rule the decisions made by the system. Some of the controls provided by the system are: 1. Instead of relying on the system to perform punch shape recognition, the user can opt to select the stan- dard punch shape and its dimensions interactively via an icon-based menu system (Fig. 5). This can reduce the processing time for punch shape recogni- tion. In addition, it allows the user to specify stan- dard shapes which otherwise are not recognizable by the shape recognition capabilities of the system.Fig. 5 Icon menu for standard punch shapes2. The punch shapes used to stamp out the external shape of a part are obtained by projecting horizontal or vertical strips from an edge of the external profile to the next identical part. The resulting punch pro- files are rather simplistic in shape. The end result from the automatic decomposition process may not be satisfactory in some cases. The user can inter- actively combine some of these elementary shapes into more complex shapes which are more suitable.3. The user can specify the piloting scheme to be used and also change the pilot holes selected by the system.4. The user can also interactively change the die oper- ations at the various stages selected by the system. Idle stations can also be inserted.5. The user can interactively change the configuration of the die components and sub-assemblies recom- mended by the system. For example, the user can interactively combine a cut-off operation with a bending operation. 6. The user can back-step to any point of the planning process, make certain changes and continue the plan- ning process along a different path. Hence, the final die designs provided by IAPDie are not constrained by the rules programmed into the system. The ease of control provided by the system permits the user to explore design alternatives conve- niently. In this way, creative and cost effective solutions can be obtained in the shortest possible time. 4 A CASE STUDYTo illustrate the functioning of IAPDie, the steps involved in planning the operations required to produce a part as shown in Fig. 6 will be presented as a case study:Fig. 6 Part to be manufactured1. The designer uses menu-driven commands to input and modify the geometrical features (such as holes, bend profiles and external profile) of the part for input into the object-oriented database in Kappa- PC. Manufacturing information (such as strip and part data) are input via dialogue boxes.2. The system recommends the use of the slug cut-off method to separate the finished part from the stock. It also generates the piercing, notching and bending punches required to form the part. The direct pilot- ing holes are also selected. The piercing and notching punches and the piloting holes generated by the system are shown in Fig. 7. Fig. 7 Punches and pilots selected by the system3. On visual inspection, the user decides to change some of the notching punches recommended by the system. The final punches selected by the user are shown in Fig. 8. In the figure, punch profiles in dashed linetype are those selected by the user after modifying the initial profiles selected by the system. The catalogue names of the standard punch profiles recognized by the system are also assigned to the punches.Fig. 8 Punches selected by the user4. Next, staging of the die operation is carried out. Figure 9 shows the final stagkg accepted by the user. This is derived from the original staging plan pro- vided by the system, except that the user can inter- actively move notching operation ExtP15, which is originally assigned to station 1 by the system, to station 2. This is to reduce overcrowding of punches in station 1.Fig. 9 Stages selected by the system and modified by user5. Finally, the system automatically produces the strip layout (Fig. 10) for visual inspection.Fig. 10 Strip layout generated by the systemConsider a situation where changes to the product specification requires the removal of the two circular holes on the unfolded portion of the part. When the die designer receives these changes, the original model can still be used to develop the new plans. The steps are as follows:1. Using menu-driven commands in AutoCAD, the designer will re-initialize the plans in the existing knowledge base. The designer will also remove Hole1 and Hole4 from the product description. 2. With the absence of internal circular holes on the flat portion, an indirect piloting scheme needs to be adopted. To avoid the need to use wider stock, the designer attempts to identify suitable piloting holes to be located on the scrap sections formed by the notching operations to stamp out the external profile of the part. However, after examining several alterna- tive solutions, the designer is unable to develop a satisfactory staging plan. This is because notching of the external profiles of a feature must be done before it can be bent. Hence, the notching operations associ- ated with the piloting holes have to be staged very early. Once the notching operations are executed, there will no longer be any scrap space to accommo- date the piloting holes.3. Hence, the piloting holes must be located on the side scrap-strip carrier. This will necessitate the use of wider stock and more complex notching punches Using the interactive aids provided, the user modifies the profiles of three of the punches and selects the piloting holes as shown in Fig. 11. The designer also increases the width of the stock.Fig. 11 Punch arrangement to accommodate indirect pilots on carrier strip4. After the tools are selected, the system will generate the staging plan and strip layout as shown in Figs 12 and 13 respectively.Fig. 12 Staging plan for the indirect piloting schemFig. 13 Strip layout for the indirect piloting schemeThis case study shows the capability of IAPDie in performing the various operation planning stages auto- matically. However, the solutions obtained at each stage may not meet the expectation of the designer as it is impossible to program all the rules involved in deriving the optimal solution. Hence, interactively, the designer can modify the initial plans provided by the system to meet the formers personal preference. This case study also shows how IAPDie can be used to modify existing plans to meet changing design specifications. The benefits of such a designers aid would be greater when designing progressive dies to manufacture parts of more complex geometry. This is because the designer can experiment with the various punch combinations and piloting schemes and examine the resulting plans in detail before making a final decision. The dynamic link between AutoCAD and Kappa-PC will ensure that decisions made by the user will always be consistent with the underlying basic design rules and heuristics and are geometrically accurate. This is because the system will always check with the rules and the geo- metrical information stored in the knowledge-based system before executing a command.5 DISCUSSIONSA designers aid such as that described above would be most useful as it allows the designer to examine many design alternatives easily using built-in rules. In this way, the designer can concentrate on the more impor- tant aspects that cannot be handled by the system. With full control over the design process, the creativity of the designer will not be constrained. In practice, when a die designer develops the oper- ation plans to manufacture a particular part, it may be discovered that certain minor modifications of the part may result in a simpler die design leading to cost savings. The die designer would recommend to the product designer that these changes be made if they do not affect the intended functions and performance of the part. In other instances, while the die designer is in the midst of designing the die, the product designer may inform the die designer of last minute changes to part specifications that may invalidate all the latters current efforts. This system reduces the time and effort required to implement the required changes. In essence, the overall die layout can be obtained once the staging of the die operation has been decided. The next step in the automation of the die design is the construction and assembly of the various die com- ponents from the staging plan. In an earlier attempt in building a CAD system for progressive stamping dies, a rule-based and object-oriented approach was used by the authors to generate the solid modelling description of the die from the punches selected and staging plan. This approach produces satisfactory results for progres- sive stamping dies. However, the process is time consuming as each and every component has to be generated from first scratch.6 FUTURE WORKIAPDie is intended to serve more than just stamping operations. Ultimately, it will be able to support most of the 2 and 24 D die operations such as bending, shaving, embossing, etc. As such, the actual die and the associated components will be more complex as addi- tional die operational and maintenance issues need to be addressed. For example, clearance for carrying formed features at later stations must be provided to ensure that the formed parts will not catch any of the die components and hence jam the entire die. In prac- tice, most die designers would refer to their past experi- ence and recall earlier cases of good and proven designs and try to adopt them to suit their current problem. Hence, a case-based planning approach appears to be an appropriate technique for automating the die con- figuration process from staging plans. The challenge is therefore to develop a set of semantics such that the staging plans can be expressed as goals for input to the case-based planner. A die description language needs to be developed to translate the geometrical description of good dies into cases for storage and retrieval in the case-based system. The performance of IAPDie can be further enhanced by adding a module to estimate the cost of constructing the die associated with a selected plan. This can be done by coding the price list of the manufacturers die com- ponent catalogue into the system. For non-standard components, empirical formulae and rules can be devel- oped to estimate the cost of their fabrication based on material used and the amount and degree of difficulties of machining required. Hence, as the designer examines the various alternative plans, the associated costs of constructing the die can be estimated immediately. The designer will no longer need to rely on personal experi- ence to estimate the cost or perform tedious cost calcu- lations to decide on which plan is more economical to adopt. IAPDie can also be used as a computer-based learn- ing aid for trainees in the tool and die trade if an expla- nation module can be added. In this way, the trainees can quickly learn the basic rules associated with die- making. In addition, since IAPDie permits them to explore many designs in a short time, their die-making experience can be developed in a much shorter time compared with conventional training approaches. 7 CONCLUSIONAn intelligent planning aid for progressive die design has been developed using PC development tools. The knowledge-based design system is built using Microsoft Windowss DDE and DLL capabilities to integrate AutoCAD, Kappa-PC and a library of numerical rou- tines. The system is able to perform operation planning tasks that are usually done manually by die designers. By providing the user with interactive aids to control and modify the planning tasks, the system is able to allow the user to specify more complex design needs which are difficult to program into the system. In addi- tion, the system can also serve as a useful training aid for the tool and die trade. 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AutoCAD Inc., 1993, pp. 97-124.附录2 英文文献翻译用于级进模设计的智能规划助手摘要：级进模设计是一项高度迭代的规划过程，在该过程中，设计人员试图选择一种模具配置，在达到所需零件规格的同时，能通过最小化材料、工具和维护成本，最有效地生产零件。根据零件的几何特征，规划过程涉及大量的人类认知技能，例如模式识别和匹配（例如在冲头形状识别中）和空间规划（例如在模具过程的嵌套和过渡中）。本文介绍了一种智能规划辅助工具，可以帮助模具设计人员规划级进模。通过将CAD（计算机辅助设计）系统，基于知识的系统和数字例程库共同开发了高度自动化且灵活的计划辅助工具。关键词：级进模设计，CAD / CAM，基于知识的智能系统1 介绍级进模设计是模具工程的重要组成部分。级进模将两种或两种以上的模具组合成一个模具，以尝试在压力机的单个行程中执行尽可能多的操作。在级进模中，工件从一个模具（工位）传递到下一个模具（工位）。在每个冲压行程中，工作都是在带材上进行的，在大多数情况下，每次机器压头上升时，成品零件都会被堆放在准备组装车间的堆垛上。在几乎所有现代家用设备，办公和计算机设备，汽车部件，广播电视，钟表和其他大量生产的产品中都可以找到用级进模具制造的产品。沃勒（1）确定了对一流印刷业必不可少的四个因素：(a) 良好的运营计划，(b) 出色的工具设计，(c) 精确的工具制作,(d) 知识渊博的新闻界。前三个因素与级进模设计有关。现代CAD / CAM技术对导致精密零件制造的第二和第三因素做出了重大贡献。但是，有限的计算机辅助工具可帮助您规划模具操作。Nee和Foong对级进模的CAD / CAM（计算机辅助设计/制造）领域的学术和机构研究工作进行的回顾（2）表明，许多系统都可以通过使相关任务自动化来帮助设计人员计算：力和压力中心、成形零件的平面图案、回弹的计算、标准模具零件的目录和库数据的检索以及NC（数控）数据的生成。换句话说，这些系统只是帮助在确定运营计划后，通过自动执行程序任务来提高设计人员的生产率。在大多数情况下，设计人员需要手动计划模具操作，并使用交互式图形工具将计划输入计算机系统。制造产品的总成本取决于材料使用，工具成本和模具维护成本。在大多数情况下，只有在完成整个计划过程之后才能确定制造产品的总成本。此外，每个计划阶段的次优解决方案不一定会导致“最便宜”的失败。这可以通过简单的例子说明。图1显示了两种可能的批量生产零件的计划。大多数嵌套算法将选择平面A，单行相反的布置。这是因为这种布置导致最小的材料浪费。然而，在渐进式切口和弯曲模具中，当带材通过模具时，需要导杆引导带材的定位。如果选择了计划B，则可以在废料上找到单排布置的导向孔。另一方面，方案A需要一个较宽的带（宽度= W，）来容纳导向孔。根据平面图案和导向孔的相对尺寸，单排相对的布置在材料使用方面可能不再经济。此外，与计划B相比，计划A的最终模具将需要包括额外的弯曲工位和额外的开槽操作。这意味着模具的制造和维护将更加复杂（且昂贵）。只有在探索了各种设计替代方案的所有运营和成本影响之后，设计师才能做出最终决定。图1 带钢布局和试点方案影响产品制造成本该示例说明，在计划阶段发现的看似好的解决方案可能证明设计不佳。计划过程的复杂性使得很难定义一组参数来帮助收敛各个计划阶段寻求最佳解决方案；因此，几乎不可能使模具设计中的操作计划流程完全自动化。所需要的是一组计划辅助工具，这些工具可以使每个计划阶段自动化，同时设计人员可以在寻找最佳解决方案的过程中保持对规划过程的控制。现有的用于级进模的CAD / CAM系统无法帮助设计人员评估替代计划。这主要是由于以下事实：使用常规方法很难将与规划过程相关的设计规则和几何处理任务编程为计算机代码。新加坡国立大学（NUS）开发了IAPDie，它是一种智能辅助工具，用于支持级进模设计的操作规划过程。IAPDie是通过集成一个基于知识的系统和一个用于使用CAD系统处理几何数据的数字例程库而开发的。以这种方式，为用户提供了有效的工具，以搜索模具设计规则和试探法，以处理与零件和工具布置相关的几何信息，并交互地控制计划步骤和修改计划。据信，由于计划过程产生的结果存储在计算机中，因此拟议的系统将构成通往进行模具设计的集成计算机工具的关键链接，可以由常规CAD / CAM系统直接访问的CAD / CAM实体。2 模具设计作业计划在开发出零件的平面图案之后，级进模的设计的主要计划阶段是：套料，试点方案的选择，工具选择和操作阶段设计。所有这些阶段都需要根据零件的几何形状做出决定，从本质上讲是图形化的每个阶段对计划进行解释。IAPDie使用以下方法来处理所有这些计划步骤。2.1套料嵌套是一个很好研究的主题（3-5）。IAPDie通过一系列选定的角度旋转零件，在每个角度上，并沿前进方向放置相同的零件，以使它们最靠近在一起而不会重叠。计算每个角度的库存利用率（定义为展开形状的面积除以由进给形成的矩形的面积和带材的宽度）。嵌套排列是从具有最大库存利用率的方向中选择的2.2选择试行方案在执行模具操作之前，导杆用于引导带材就位。带材必须准确定位在每个工位，以便在适当的位置进行操作。IAPDie提供了以下试验方案。2.2.1直接导向这包括在较早的位置引导零件上打孔的孔。IAPDie能够识别适合作为直接导向孔的孔，并为模具选择最佳导向孔。如果满足以下条件，则认为该孔适合用作导向孔：1. 它是圆形的。2. 指定的公差不高。3. 它足够大，可以用作导向孔。4. 它不位于工件的折叠部分上。5. 它不太靠近工件边缘。6. 它不太靠近工件上的另一个孔。从合适的导向孔列表中，根据以下优先级选择最佳的导向孔：1. 如果只有一个孔，则将首先考虑。2. 如果有多个孔，请选择两个最大的孔（直径相等），并且在垂直于进给方向的方向上，两个孔之间的距离大于最小预设距离。孔必须位于零件的相对侧。3. 选择满足较早条件的两个最大孔（直径互不超过预设的百分比）。4. 选择最接近零件质心的孔。2.2.2半直接导向如果零件上的孔有严格的公差，则无法使用直接引导，IAPDie建议使用半直接导向。半直接导向孔的简短列出和选择标准与直接导向相似，不同之处在于可以将公差极高的尖孔列出来选择作为半直接导向孔。半直接引导方案的操作类似于直接引导方案。区别在于先导孔的直径现在将略微小于实际要打孔的孔，而实际孔将在最后一个工位的先导孔上打孔。这样，由引燃器的作用引起的孔尺寸的变形将不会影响实际孔的最终尺寸。2.2.3间接导向间接导向包括将引航员定位在废料区。IAPDie提供了两种不同的间接试点方案：1. 将定位器定位在通过开槽操作形成的废料部分上，以冲压出零件的外部轮廓。在此，系统将识别出在垂直于进给方向的方向上相距最远的两个开槽冲头。然后，它将计算这两个区域中最大的导向孔直径。最后，它将使用计算得出的尺寸从用户在系统支持的工具库中指定的首选尺寸中选择所需的导向直径。2. 将飞行员定位在侧面废钢条运输船上。如果在通过开槽操作形成的废料段上放置导向器是不可行的，则用户可以选择将导向器定位在侧边废料条运输机上。该引导方案的缺点在于，可能需要增加带材宽度以容纳引导孔。2.3工具选择IAPDie能够根据其几何描述自动选择制造零件所需的工具。2.3.1冲孔和落料冲头冲孔或落料冲头P可用以下公式描述：P =f(S, M,L) 式中：S =冲头形状M =安装方法L =冲头长度当使用尽可能多的标准冲头时，模具的制造成本可以大大降低。IAPDie试图通过将零件的外部和内部几何结构分解为更小更不复杂的区域来实现这一点。通过将这些区域的几何数据转换为二维原始特征并将其与标准冲头形状的预定义特征进行匹配，IAPDie可以从商业模具组件制造商的目录中识别多达30种标准冲头形状（6）。预定义形状的特征根据边缘的数量排列在树形网络中。基于规则的分层搜索算法用于减少执行模式匹配过程以进行打孔形状识别所需的任务数量。例如，匹配四边形多边形所需的要素数量少于匹配十二边形多边形所需的要素数量。因此，当模式匹配过程需要它们时，系统仅计算出匹配所需的各个特征。IAPDie对冲头形状识别和分解过程的更彻底的处理可以在参考文献（7）中找到。识别出冲压出零件轮廓所需的冲头形状后，IAPDie将为每个冲头定义包络形状；取决于冲头形状的长宽比，包络形状可以是圆形或矩形。包络形状（代替实际的冲头形状）用于后续空间规划阶段的干涉检查。这将简化干扰检查算法，并减少进行芯片操作的时间。而且，包络的形状将定义冲头在打孔板上的安装方法（图2）。图2 凸模形状、包络形状与安装方式的关系2.3.2弯曲冲头IAPDie能够处理“2D”弯曲操作。通过检查弯曲部分的平面图和侧面图的几何特征，IAPDie可以将形成特征所需的弯曲操作分类为图3所示的四个预定义弯曲配置中的任何一个。安装相应的弯曲工具也是可以得到的。包围矩形为计划分期操作提供了必要的空间信息。图3 由IAPDie支持的弯曲操作（弯曲角度不一定为90）2.4进行模具操作分阶段过程是计划阶段，在该阶段中，模具操作以渐进方式进行排序，这样，当带材在渐进式模具中进行所有剪切和成型操作时，所需的零件将在最后一个阶段生产。IAPDie将按照以下顺序自动进行模具操作：1. 先进行先导孔的穿孔操作。2. 接下来进行其他内部孔的穿孔操作。3. 接下来进行外部配置文件的刻槽操作。4. 接下来进行用于容纳间接导向孔（如果有）的外部轮廓的开槽操作
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