矩形骨架线圈注塑模设计【线圈骨架】【一模两腔】【侧抽芯】【说明书+CAD】
矩形骨架线圈注塑模设计【线圈骨架】【一模两腔】【侧抽芯】【说明书+CAD】,线圈骨架,一模两腔,侧抽芯,说明书+CAD,矩形骨架线圈注塑模设计【线圈骨架】【一模两腔】【侧抽芯】【说明书+CAD】,矩形,骨架,线圈,注塑,设计,说明书,仿单,cad
河南机电高等专科学校学生毕业设计(论文)中期检查表学生姓名学 号指导教师选题情况课题名称骨架线圈注塑模设计难易程度偏难适中偏易工作量较大合理较小符合规范化的要求任务书有无开题报告有无外文翻译质量优良中差学习态度、出勤情况好一般差工作进度快按计划进行慢中期工作汇报及解答问题情况优良中差中期成绩评定:所在专业意见: 负责人: 年 月 日 河南机电高等专科学校毕业设计(论文)任务书系 部: 材料工程系 专 业: 模具设计与制造 学生姓名: 学 号: 设计(论文)题目: 骨架线圈注塑模设计 起 迄 日 期: 指 导 教 师: 2007年 3月 20日毕 业 设 计(论 文)任 务 书1本毕业设计(论文)课题来源及应达到的目的:本设计来源于生活中的骨架线圈塑料件,要求设计一套塑料模具成型此零件。要求该模具设计简单,成型容易,脱模容易,可以批量生成。要求有所设计模具的装配图和全部的零件图(非标准件),有一个典型零件的加工工艺卡。通过此设计,让学生理解塑料模具设计与制造的过程,为以后的学习和工作打下了一定基础。2本毕业设计(论文)课题任务的内容和要求(包括原始数据、技术要求、工作要求等):原始数据 内容: 1.模具工艺规程的编制 2.注塑模结构设计 3.模具的有关计算 4.模具加热和冷却系统的计算 5.模具闭合高度的确定 6.注塑机有关参数的校核 7.绘制模具总装图 8.模具的装配与调试 要求:1. 塑料制件结构工艺分析和注塑工艺方案确定2. 模具装配图及零件图的绘制3. 完成主要模具零件的工艺规程编制4. 编写设计说明书5. 用word文档形式打印出说明书所在专业审查意见:负责人: 年 月 日系部意见:系领导: 年 月 日河南机电高等专科学校毕业设计说明书毕业设计题目:骨架线圈注塑模设计系 部 材料工程系 专 业 班 级 学生姓名 学 号 指导教师 年 月 日河南机电高等专科学校毕业设计说明书 摘 要 本设计题目为线圈骨架注塑模设计,体现了骨架类塑料零件的设计要求、内 容及方向,有一定的设计意义。通过对该零件模具的设计,进一步加强了设计者 注塑模设计的基础知识,为设计更复杂的注塑模具做好了铺垫和吸取了更深刻的 经验。 本设计运用塑料成型工艺及模具设计的基础知识,首先分析了塑件的成分及 性能要求,为选取浇口的类型做好了准备;然后估算了塑件的体积,便于选取注 塑机及确定型腔数量;最后分析了塑件的特征,确定模具的设计参数、设计要点 及推出装置的选取。 线圈骨架类塑件,具有与一般小断面侧孔侧凹收缩和抽芯不同的特点,即在 整个侧表面周边的大面积抽芯,塑件的径向收缩不仅不对侧凹成型零件产生包紧, 反而会松开,但轴向收缩仍会使侧凹成型零件卡紧。这种塑件采用对和的两个哈 夫块。另外骨架类塑件的临界抽芯距,不一定总是等于侧孔或者侧凹的深度,需 看速件的具体的结构和侧面的形状而定。例如:若是圆形的骨架,那么临界的抽 芯距为 ,而不是 R(R,r 为大,小圆的半径) 。2rRSc 关键词:线圈骨架,临界抽芯, 脱模力。 河南机电高等专科学校毕业设计说明书 ABSTRACT The requirement ,content and direction of the design of the skeieton construction plastic parts are embodied on this injection mould design of the plastic parts of skeieton box. The designers foundation knowledge of the injection mould design is reinforced and is able to design more complex injection mould through the design. Through the foundation knowledge, firstly, the composion and the perfourmance of thr part is analyzed to choose the type of the gat advantagely. Secondly, the volume of the part is estimated to choose the injection molding machine and to determine the mould quantity conveniencely. Lastly the character of the part is analyzed to determine the mould design parameter and design point and choose the ejection assembly The radial shrinkage not only be in the wrong undercutting moulding part bring fold close,instead met loosen,but axial direction shrinkage still met enable undercutting moulding part chucking to in forth of the both loop skeleton genera model piece,possess and commonly light section side port undercutting shrinkage and loose core different point,namely at wholly lateral surface peripheral large area loose core, model piece.the crises loose core distance, not always equal side port or undercutting depth,require saw velocity piece specific structure and lateral shape whereas book of the the two half piece of the both such model piece adopt versus and. in addition skeleton genera model piece.as for example,:if yes rounded skeleton,those critical loose core distance , not R(R,r for large,small 2rSc circle radius) Keywords: dfaf, critical loose core , knockout press. 河南机电高等专科学校毕业设计说明书 目 录 摘要 . . 1 绪论 . 1 第 1章 模塑工艺规程的制定 . 4 1.1 塑件的工艺性分析 4 1.2 计算塑件的体积和质量. 5 1.3 塑件注塑工艺参数的确定. 5 1.4 塑料成型设备的选取 5 第 2章 注塑模的结构设计 . .6 2.1 分型面选择 . 6 2.2 浇注系统设计 . 7 2.3 确定型腔的数目及排列方式 . 7 2.4 抽芯机构设计 8 2.5 成型零件的设计 9 第 3章 模具的有关计算 11 第 4章 模具加热和冷却系统的设计 . 13 第 5章 结构与辅助零部件的设计 . 14 第 6章 模具闭合高度的确定 .16第 7章 注塑机有关参数的校 核.17 第 8章 注塑模具的安装和试模 . . 18 8.1 模具安装 . 19 8.2 试模 21 第 9章 绘制模具总装配图和非标准零件工作图.22 9.1 本模具总装图和非标零件工作图见附图.22 9.2 本模具的工作原理.22 第 10章 模具主要零件加工工艺规程的编制 .23 致谢. 26 参考文献. . 27 河南机电高等专科学校毕业设计说明书 河南机电高等专科学校毕业设计评语学生姓名: 班级: 学号: 题 目:骨架线圈注塑模模具设计 综合成绩: 指导者评语: 指导者(签字): 年 月 日毕业设计评语评阅者评语: 评阅者(签字): 年 月 日答辩委员会(小组)评语: 答辩委员会(小组)负责人(签字): 年 月 日骨架线圈注塑模设计绪 论随着工业的发展,工业产品的品种和数量不断增加。换型不断加快。使模具的需要补断增加。而对模具的质量要求越来越高。模具技术在国民经济中的作用越来越显得更为重要。模具是制造业的重要工艺基础,在我国,模具制造属于专用设备制造业。中国虽然很早就开始制造模具和使用模具,但长期未形成产业。直到20世纪80年代后期,中国模具工业才驶入发展的快车道。近年,不仅国有模具企业有了很大发展,三资企业、乡镇(个体)模具企业的发展也相当迅速。虽然中国模具工业发展迅速,但与需求相比,显然供不应求,其主要缺口集中于精密、大型、复杂、长寿命模具领域。由于在模具精度、寿命、制造周期及生产能力等方面,中国与国际平均水平和发达国家仍有较大差距,因此,每年需要大量进口模具。中国模具产业除了要继续提高生产能力,今后更要着重于行业内部结构的调整和技术发展水平的提高。结构调整方面,主要是企业结构向专业化调整,产品结构向着中高档模具发展,向进出口结构的改进,中高档汽车覆盖件模具成形分析及结构改进、多功能复合模具和复合加工及激光技术在模具设计制造上的应用、高速切削、超精加工及抛光技术、信息化方向发展。近年,模具行业结构调整和体制改革步伐加大,主要表现在,大型、精密、复杂、长寿命、中高档模具及模具标准件发展速度高于一般模具产品;塑料模和压铸模比例增大;专业模具厂数量及其生产能力增加;“三资”及私营企业发展迅速;股份制改造步伐加快等。从地区分布来看,以珠江三角洲和长江三角洲为中心的东南沿海地区发展快于中西部地区,南方的发展快于北方。目前发展最快、模具生产最为集中的省份是广东和浙江,江苏、上海、安徽和山东等地近几年也有较大发展。 模具成型具有优质,高产,低消耗,低成本的特点。因而,在国民经济各个部门得到了极其广泛的应用。在模具成型中,塑料成型占很大的比重。由于塑料具有化学稳定性好,电绝缘性强,力学性能高,自润滑,耐磨及相对密度小等独特的优异性能,成为工业部分必不可少的新型材料。 根据业内专家预测,今年中国塑料模具市场总体规模将增加13%左右,到2005年塑料模具产值将达到460亿元,模具及模具标准件出口将从现在的9000多万美元增长到2005年的2亿美元左右,产值在增长,也就意味着市场在日渐扩大。相当多的发达国家塑料模具企业移师中国,是国内塑料模具工业迅速发展的重要原因之一。中国技术人才水平的提高和平均劳动力成本低都是吸引外资的优势,所以中国塑模市场的前景一片辉煌,这是塑料模具市场迅速成长的重要因素所在。大学三年的学习即将结束,毕业设计是其中最后一个实践环节,是对以前所学的知识及所掌握的技能的综合运用和检验。随着我国经济的迅速发展,采用模具的生产技术得到愈来愈广泛的应用。 据悉目前全世界年产出模具约650亿美元,其中塑料模具约为260亿美元。我国1999年模具总产值245亿元其中塑料模具约为82亿元,2000年近100亿元。七类塑料模具中,注塑模具所占比例很大,约占全部塑料模具的80%左右。塑料模具的主要用户是家用电器行业、汽车、摩托车行业、电子音像设备行业、办公设备行业、建筑材料行业、信息产业及各种塑料制品行业等。目前国内年需塑料模具约130-140亿元,真中有30多亿元仍靠进口,进口量最多的塑料模具有汽车摩托车饰件模具、大屏幕彩电壳模具、冰箱洗衣机模具、通讯及办公设备塑壳模具、塑料异型材模具等。在完成大学三年的课程学习和课程、生产实习,我熟练地掌握了机械制图、机械设计、机械原理等专业基础课和专业课方面的知识,对机械制造、加工的工艺有了一个系统、全面的理解,达到了学习的目的。对于模具设计这个实践性非常强的设计课题,我们进行了大量的实习。经过在新飞电器有限公司、洛阳中国一拖的生产实习,我对于模具特别是塑料模具的设计步骤有了一个全新的认识,丰富了各种模具的结构和动作过程方面的知识,而对于模具的制造工艺更是实现了零的突破。在指导老师的协助下和在工厂师傅的讲解下,同时在现场查阅了很多相关资料并亲手拆装了一些典型的模具实体,明确了模具的一般工作原理、制造、加工工艺。并在图书馆借阅了许多相关手册和书籍,设计中,将充分利用和查阅各种资料,并与同学进行充分讨论,尽最大努力搞好本次毕业设计。 本次设计题目“骨架线圈的产品造型与模具设计”。该模具属于侧向抽芯的注射模。本说明书将分项阐述该塑件注射成型和模具设计的全过程。 由于本人设计水平有限,错误的不妥之处在所难免,肯请老师批评指正。 第1章 模塑工艺规程的制定1.1塑件的工艺性分析(1) 材料性能分析 骨架线圈选用ABS塑料成型,ABS是一种具有良好综合性能的工程塑料,它具有聚苯乙烯的良好成型性,聚丁二稀的韧性,聚丁烯腈的化学稳定性和表面硬度,其抗拉强度可达35-50MPa。ABS粘度适中,流动性好。它的另一个优点是耐气候性,其制品的使用温度范围为,适应性广。 ABS塑料具有一定的吸湿性,含水量为0.3%-0.8%,成型时在会在制品上产生斑痕、云纹、气泡等缺陷,在注塑成型之前应进行干燥处理。ABS粘度适中、流动性好。 ABS塑料密度1.08g/,弹性模量E=1.410MPa,成型收缩率=0.5%0.8%,泊松比。(2)注塑制件结构和尺寸精度及表面质量分析1结构分析 从零件图上分析,该零件总体形状为矩形,在上、下两端各有一个凸翼,其厚度为1.5mm,中间部分为16mm12mm11mm的矩形柱,因此,模具设计时必须设置侧向分型抽芯机构,该零件属于中等复杂程度。 2 尺寸精度 该零件各个尺寸均为注明公差,为提高经济效益,则按未注明公差尺寸来处理,根据表214查得ABS材料的适用未注公差等级为MT5级,对应的模具相关零件的尺寸加工容易保证。从塑件的壁厚来看,各处壁厚均为1.5mm,均匀一致,有利于零件成型。3零件质量的分析 零件表面及内腔要求没有缺陷、毛刺,内部不得有导电介质,没有其他特别的表面质量要求,故比较容易实现。 综上分析可以看出,注塑时在工艺参数控制较好的情况下,零件的成型要求可1.2计算塑件的体积和质量 计算塑件的质量是为了选用注塑机及确定模具型腔数。 计算塑件的体积:用体积分割法求得V=2522.514-1310.514-164.5112-22.54.5112=2153计算塑件的质量:根据设计手册查得ABS的密度为=1.0g/,故塑件的质量为:W=V =21531.0=2.2g1.3注塑模结构分析与注塑机的选用 根据以上计算,采用一模两件的结构设计,考虑其外形尺寸,注塑时所需压力和工厂现有设备等情况,初步选用注塑机YS-ZY-45型。1.4塑件注塑工艺参数的确定 查找相关文献和参考工厂实际应用的情况,ABS的成型工艺参数可作如下选择:(适模时,可根据实际情况作适当调整)预干燥温度:7080 时间:2h注塑温度:前段温度t选用200; 中段温度t选用220; 后段温度t选用190; 喷嘴温度:选用180;注塑压力:选用80MPa;注塑时间:选用15S;保 压:选用65 MPa;保压时间:选用10s;冷却时间:选用15s;第2章 注塑模的结构设计注塑模的结构设计主要包括:分型面的选择、模具型腔数目的确定、型腔的排列方式、冷却水道布局、模具工作零件的结构设计、侧向分型与抽芯机构的设计、推出机构的设计等内容。2.1分型面的选择 模具设计中,分型面的选择很关键,它决定了模具的结构。应根据分型面选择原则和塑件的成型来选择分型面.该塑料表面质量无特殊要求。但是在绕线的过程中,两端凸翼与工人的手指接触较多,因此两端应自然形成圆角;此外,该零件高度为14mm,且垂直于轴线的截面形状比较简单,可选用如下图所示的水平分型方式,即可降低模具的复杂程度,减少模具加工难度,又便于成型取件。型面选择如下图。2.2确定型腔的排列方式本塑件在注塑时采用一模两件,即模具需要两个型腔,综合考虑浇注系统、模具结构的复杂程度等因素,拟采用型腔布置图1所示的型腔排列方式。其最大优点是便于设置侧向分型抽芯机构,缺点是熔料进入型腔后到另一端的料流长度较长,但是塑件尺寸较小,故对成型没有太大的影响。 若采用其他的型腔排列方式,显然料流长度较短,但是会增大侧向抽的距离,势必会增大模具整体尺寸。2.3浇注系统设计(1)主流道的设计根据设计手册查得XSZ30型注塑机喷嘴的有关尺寸:喷嘴前端孔直径: =2mm;喷嘴前端球面半径:=12mm;根据模具主流道与喷嘴的关系:=+(12)mm D=+(0.51)mm取主流道球面半径R=14mm;主流道的小端直径d= 2.5mm.为了便于将凝料从主流道中拔出,将主流道设计成锥形,其斜度为。经换算得主流道大端直径D=4.5mm,为了使熔料顺利进入分流道,可在主流道出料端设计半径r=5mm的圆弧过渡。(2) 分流道设计分流道的形状及尺寸,应根据塑件的体积、壁厚、形状的复杂程度,注塑速度、分流道长度等因素来确定。本塑件形状简单对成,熔料填充型腔比较容易,根据型腔的排列方式,可知分流道长度较短,为便于加工起见,选截面形状为梯形的分流道,根据制件壁厚、体积和形状等,初确定梯形尺寸=4mm,=2.5mm,=1mm.(1) 浇口设计根据塑件的成型要求、型腔的排列方式及模具结构,拟选侧浇口较为理想,可使模具结构简单,浇口易去除,且不影响塑件外观。设计时考虑壁厚为1.3处进料,料由厚处往薄处流,而且再模具结构上采用镶拼式型腔、型芯,有利于填充,排气。采用截面为矩形的侧浇口,查表初选尺寸为(blh)1mm0.8mm0.6mm,试模时修正。2.4抽芯机构设计塑件的两端各有一个凸翼,他们均垂直于脱模方向,阻碍成型后塑件从模具脱出,因此成型小凸台的零件必须设计成活动的型芯,即须设置抽芯机构。本模具采用斜导柱机构。(1) 确定抽芯距抽芯距一般应大于成型孔(或凸台)的深度,本题中凸台高度为11.25mm,另加3mm的抽芯安全系数,可取抽拔距=15mm。(2) 确定斜销倾角斜导柱倾斜角是倾斜机构的主要技术数据之一,它与抽拔力与抽芯距有直接关系。一般取=1525,在这里选用20。(3) 确定斜销尺寸斜导柱的直径取决于抽拔力及其倾斜角度,按公式计算,取斜导柱直径d= 18mm,固定凸肩D=1.8d。斜导柱的长度根据抽芯距、固定端模板的厚度、斜销直径及斜角大小确定,其计算根据公式:=+由于上模座板的凸模固定板尺寸尚不确定,即=25mm,如果设计中有变化,则修正的长度,取D=32mm,取=92mm.(4)滑块与导滑槽设计(a)滑块与侧型芯的连接方式设计。本题侧向抽芯机构主要是用于成型零件的侧向孔合侧向凸台,拟采用整体式结构,具体结构见零件图01。(b)滑块的导滑方式。为使模具结构紧凑,降低模具装配复杂程度,拟采用整体式滑块和整体式导向槽的形式。其结构见装配图。(c)滑块的导滑长度和定位装置设计。导滑长度要保证侧向抽芯后,滑块与导滑槽的配合长度不小于其总长度的,滑块的定位装置采用弹簧滚珠形式(见装配图)。2.5成型零件设计(1) 凹模的结构设计本模具采用一模两件的结构设计,考虑加工难易程度和材料的价值利用等因素,凹模拟采用拼块式结构,滑块同时构成凹模型腔,其结构形式见下图(2) 凸模的结构设计凸模主要是与凹模相结合构成模具型腔,其结构形式见下图。第3章 模具设计的有关计算本例中成型零件工作尺寸计算时均采用平均尺寸、平均收缩率、平均制造公差和平均磨损量来进行计算。查表得ABS地收缩率S=0.50.8,故平均收缩率为0.5,考虑到工厂模具现有条件,模具制造公差取。1. 型腔、型芯工作尺寸计算类别序号模具零件名称塑件尺寸计算公式型腔或型芯工作尺寸型腔的计算1凹模滑块250.25222.50.223110.1641.50.16型芯的计算5主型芯130.16610.50.162压紧楔块的设计和计算为使注塑过程中凹模滑块能闭合紧密,避免侧向分型面产生毛刺以及使斜导柱免除型腔的侧向推挤力,拟采用压紧楔块对凹模滑块进行锁紧。本题因模具尺寸不大,所以采用将楔块与定模板设计为一整体的结构,为避免干涉撞击,楔块楔角按照下式选取式中:斜导柱楔角;:斜导柱与斜孔之间的间隙;:楔块压紧高度;=10mm。计算结果圆整为表81推荐值 ,取=。2. 型腔滑块底板厚度计算根据组合式型腔底板厚度计算公式进行计算:式中:=13mm;=40Mpa;=13mm;=125mm (根据模具初选外形尺寸确定) ;=160Mpa(底板材料选用45钢)。代入计算得:H=8.5mm。考虑模具整体结构的协调,取H=25mm。第4章 模具加热与冷却系统的计算 本塑件在注射过程中不要求有太高的模温,因而模具上可不开设加热系统,是否需要冷却系统可作如下计算。设定模具平均工作温度为65用20常温水作为模具冷却介质,其出口温度为25,产量为(处算2分钟一套),0.27/h。1求塑件在每小时释放的热量Q,查有关文献ABS单位若流量为3.98J/g.Q=WQ=0.273.98J/g=1.074610 J/2求冷却水的体积流量VV=0.8510m/min由体积流量V查表可知所需的冷却水管直径非常小。由上述计算可知,因为模具每分钟所需的冷却体积流量很小,故可不设冷却系统,依靠空冷的方式冷却模具即可。 第5章 结构与辅助零部件的设计1. 导柱的选用导柱选用带头导柱,由导柱直径与模板外形尺寸关系,其尺寸选用1610025,材料选用20钢。GB/T4169.4-1984其结构形式如下图1-5所示: 图1-5 导柱的结构形式 其导柱的安装时与模板之间的配合的公差取IT7级,安装沉孔直径比导柱直径大(12)。2.导套的选用导套选用直导套,与导柱的配合。尺寸选1640,材料选用20钢。GB/T4169.2-1984 其结构形式如下图1-6所示: 图1-6 导套的结构形式 导套与模板的安装孔径之间的配合公差IT7级,安装后下平面磨平。 该模具由于塑件的精度要求较低,可以采用两根导柱即可满足塑件的精度,两根导柱,导套尺寸选用相同直径,不对称布置。其布置形式如零件图定模固定板上所示。 第6章 模具闭合高度的确定在支撑和固定零件的设计过程中,根据经验确定:定模座板:=25mm,上固定板:=25mm,下固定板:=40mm,支撑板: =25mm动模座板6=25mm。根据推出行程和推出机构的结构尺寸确定垫块:=50mm因而模具闭合高度 + 6=25mm+25mm+40mm+25mm+50mm+25mm=185mm第7章 注塑机有关参数的校核本模具的外形尺寸为100mm125mm155mm. XSZ30型注塑机模板最大安装尺寸为200mm190mm,故能满足模具的安装要求。由上述计算模具的闭合高度=185mm,XSZ30型注塑机所允许模具的最小厚度=60mm,最大厚度=180mm,即模具满足的安装条件。经查资料XSZ30型注塑机的最大开模行程S=160mm,满足下式顶出塑件的要求:=14+35+10=59mm此外,侧向分型抽芯距不是很大,因此不会过大增加开模距离,注塑机的开模行程足够。经验证,XSZ30型注塑机能满足使用要求,故可采用第8章 塑料模的装配、试模与维修 1模具装配 模具设有斜滑块机构,先安装斜导柱,作为模具的装配基准,装配顺序如下;(1) 装配前按图检验主要工作零件及其零件的尺寸。(2) 将导柱8压入定模固定板10中,保证两导柱的对称度。(3) 装配型芯,将型芯固定在定模座板9上,保证垂直度。将座板9固定在固定板10上。(4) 将凹模压入动模固定板23中,保证垂直度。(5) 将侧滑块7装在固定板的导滑槽上。(6) 以凹模为基准,斜导柱起导向定位作用,将侧滑块装配在斜导柱上,使分型面密合。(7) 以凹模为基准将动模基准板26固定在动模故定板上。(8) 装配其他辅助零件。(9) 装配完成,试模。使配时以分型面密合作为模具的装配基准 2试模(1) 试模前,先对设备的油路,水路以及电路进行检查;(2)选取的原料必须合格,根据选用的工艺参数将料筒和喷嘴加热;(3)开始试模时,应该先选择选定的压力,温度和注塑时间的条件下成型,制品不符合要求然后按压力,注塑时间,温度, 这样的先后顺序变动,注意一次只改变一个参数;(4) 在试模过程中作出详细的记录,并将结果填入试模记录卡,注明模具是否合格,如果需要返修,提出返修意见;(5)通过不断的试模和返修,生产出合格的制件后,将模具清理干净,涂上防锈油,入库。3 试模可能产生的问题及改善措施试模中所获得的样件是对模具整体质量的一个全面反映。以检验样件来修正和验收模具,是塑料模具这种特殊产品的特殊性。首先,在初次试模中我们最常遇到的问题是根本得不到完整的样件。常因塑件被粘附于模腔内,或型芯上,甚至因流道粘着制品被损坏。这是试模首先应当解决的问题。3.1 粘着模腔制品粘着在模腔上,是指塑件在模具开启后,与设计意图相反,离开型芯一侧,滞留于模腔内,致使脱模机构失效,制品无法取出的一种反常现象。其主要原因是:(1) 注射压力过高,或者注射保压压力过高。(2) 注射保压和注射高压时间过长,造成过量充模。(3) 冷却时间过短,物料未能固化。(4) 模芯温度高于模腔温度,造成反向收缩。(5) 型腔内壁残留凹槽,或分型面边缘受过损伤性冲击,增加了脱模阻力。3.2 粘着模芯(1) 注射压力和保压压力过高或时间过长而造成过量充模。 (2) 冷却时间过长,制件在模芯上收缩量过大。(3) 模腔温度过高,使制件在设定温度内不能充分固化。(4) 机筒与喷嘴温度过高,不利于在设定时间内完成固化。(5) 可能存在不利于脱模方向的凹槽或抛光痕迹需要改进。3.3粘着主流道(1) 闭模时间太短,使主流道物料来不及充分收缩。(2) 料道径向尺寸相对制品壁厚过大,冷却时间内无法完成料道物料的固化。(3) 主流道衬套区域温度过高,无冷却控制,不允许物料充分收缩。(4) 主流道衬套内孔尺寸不当,未达到比喷嘴孔大0.51 。(5) 主流道拉料杆不能正常工作。一旦发生上述情况,首先要设法将制品取出模腔(芯),不惜破坏制件,保护模具成型部位不受损伤。仔细查找不合理粘模发生的原因,一方面要对注射工艺进行合理调整;另一方面要对模具成型部位进行现场修正,直到认为达到要求,方可进行二次注射。3.4 成型缺陷当注射成型得到了近乎完整的制件时,制件本身必然存在各种各样的缺陷,这种缺陷的形成原因是错综复杂的,一般很难一目了然,要综合分析,找出其主要原因来着手修正,逐个排出,逐步改进,方可得到理想的样件。下面就对度模中常见的成型制品主要缺陷及其改进的措施进行分析。(1) 注射填充不足所谓填充不足是指在足够大的压力、足够多的料量条件下注射不满型腔而得不到完整的制件。这种现象极为常见。其主要原因有:a. 熔料流动阻力过大这主要有下列原因:主流道或分流道尺寸不合理。流道截面形状、尺寸不利于熔料流动。尽量采用整圆形、梯形等相似的形状,避免采用半圆形、球缺形料道。熔料前锋冷凝所致。塑料流动性能不佳。制品壁厚过薄。b. 型腔排气不良这是极易被忽视的现象,但以是一个十分重要的问题。模具加工精度超高,排气显得越为重要。尤其在模腔的转角处、深凹处等,必须合理地安排顶杆、镶块,利用缝隙充分排气,否则不仅充模困难,而且易产生烧焦现象。c. 锁模力不足因注射时动模稍后退,制品产生飞边,壁厚加大,使制件料量增加而引起的缺料。应调大锁模力,保证正常制件料量。(2) 溢边(毛刺、飞边、批锋)与第一项相反,物料不仅充满型腔,而且出现毛刺,尤其是在分型面处毛刺更大,甚至在型腔镶块缝隙处也有毛刺存在,其主要原因有:a. 注射过量b. 锁模力不足c. 流动性过好d. 模具局部配合不佳e. 模板翘曲变形(3) 制件尺寸不准确初次试模时,经常出现制件尺寸与设计要求尺寸相差较大。这时不要轻易修改型腔,应行从注射工艺上找原因:a. 尺寸变大注射压力过高,保压时间过长,此条件下产生了过量充模,收缩率趋向小值,使制件的实际尺寸偏大;模温较低,事实上使熔料在较低温度的情况下成型,收缩率趋于小值。这时要继续注射,提高模具温度降低注射压力,缩短保压时间,制件尺寸可得到改善。b. 尺寸变小注射压力偏低、保压时间不足,制在冷却后收缩率偏大,使制件尺寸变小;模温过高,制件从模腔取出时,体积收缩量大,尺寸偏小。此时调整工艺条件即可。通过调整工艺条件,通常只能在极小范围内使尺寸京华,可以改变制件相互配合的松紧程度,但难以改变公称尺寸。 c.调整措施 调整时应注意调节进料速度,增加排气孔,正确设计浇注系统。注意控制成型周期。第9章 绘制模具总装图和非标准零件工作图本模具的总装图见装配图所示。非标准件工作图见零件图。本模具的工作原理:模具安装在注塑机上,定模部分固定在注塑机的定模板上,动模固定在注塑机的动模板上。合模后,注塑机通过喷嘴将熔料经流道注入型腔,经保压、冷却后塑件成型。开模时动模部分随动模板一起运动渐渐将分型面打开,与此同时在斜导柱的作用下侧滑块向两边分离并脱离塑件,完成侧向抽芯动作,当塑件完全脱离后,动模停止运动,在注塑机顶出装置作用下,推动推杆运动并驱动脱件板将塑件从型芯上脱出。合模时,随着分型面的闭合侧向滑块复位至型腔,同时复位杆也对推杆进行复位。第10章 注塑模主要零件加工工艺规程的编制1型芯机械加工工艺过程卡机械加工工艺过程卡片产品型号零(部)件图号01产品名称型芯零(部)件名称型芯共(2)第(1)页材料牌号45钢毛坯种类圆棒料毛坯外型尺寸30每个毛坯可制件数4每台件数4备注工序号工序名称工 序 内 容车间工段设备工 艺 装 备工时准终单件05下料锯割下料30120下料车间锯床0.510粗车车端面车削3680模具车间车床215精车车削至34.577.5模具车间车床220磨削磨削至34.0277.005模具车间磨床325钳钳工精修尺寸至要求工作表面抛光Ra0.1模具车间5.设计日期审核日期标准化日期会签日期标记记数更改文件号签字日期标记处数更该文件号2型腔机械加工工艺过程卡机械加工工艺过程卡片产品型号零(部)件图号02产品名称型腔零(部)件名称共(3)页第(3)页材料牌号 45钢毛坯种类钢板毛坯外型尺寸10每个毛坯可制件数1每台件数1备注工序号工序名称工 序 内 容车间工段设备工 艺 装 备工时准终单件05下料锯割下料1050下料车间锯床0.2510锻造锻至尺寸4015锻造车间空气锤215热处理退火至180HBS200HBS模具车间820车削粗车至3212同上车床225精车精车至30110同上车床230线切割切割18的孔同上线切割机835热处理成型部分淬火至要求同上8精修精修成型部分Ra0.2同上6设计日期审核日期标准化日期会签日期标记记数更改文件号签字日期标记处数更该文件号致 谢 塑料模具课程设计是塑料模具设计与制造课程重要的综合性与实践性教学环节。通过这次实际操作,使我能够综合运用塑料模具设计课程和其他先修课程的知识,分析和解决模具设计问题,进一步巩固、加深和拓宽所学知识。 通过设计实践,我逐步树立了正确的设计思想,增强了创新意识,熟悉掌握塑料模具设计的一般规律,培养了分析问题和解决问题的能力;通过设计计算、绘图以及运用技术标准、规范、设计手册等有关设计资料,进行了全面的塑料模具设计基本技能的训练。从陌生到开始接触,从了解到熟悉,这是每个人学习事物所必经的一般过程,我对模具的认识过程亦是如此。经过近三个月的努力,我相信这次毕业设计一定能为三年的大学生涯划上一个圆满的句号,为将来的事业奠定坚实的基础。在这次设计过程中得到了老师以及许多同学的帮助,特别是于智宏老师的悉心指导,使我受益匪浅。在此,对关心和指导过我各位老师和帮助过我的同学表示衷心的感谢! 参考文献 1. 杨占尧主编. 塑料注塑模结构与设计. 清华大学出版社. 2. 中国模具设计大典. 3. 王孝陪主编. 塑料成型工艺及模具简明手册. 机械工业出版社. 20004. 模具制造手册编写组. 模具制造手册. 机械工业出版社. 19965. 冯炳尧,韩泰荣,蒋文生主编. 模具设计与制造简明手册. 上海科学技术出版社,19986. 黄毅宏主编. 模具制造工艺. 机械工业出版社. 19997. 贾润礼,程志远主编. 实用注塑模设计手册. 中国轻工业出版社. 20008. 唐志玉主编. 模具设计师指南. 国防工业出版社. 19999. 屈华昌主编. 塑料成型工艺与模具设计. 机械工业出版社. 199510. 彭建声主编. 简明模具工实用技术手册. 机械工业出版社. 199327 编号: 毕业设计(论文)外文翻译(原文)院 (系): 国防生学院 专 业:机械设计制造及其自动化 学生姓名: 蔡秀滨 学 号: 1001020105 指导教师单位: 机电工程学院 姓 名: 郭中玲 职 称: 高级工程师 2014年 3 月 9 日Contents1.The Injection Molding12.Automated surface nishing of plastic injection mold steel with spherical grinding and ball burnishing processes14第 22 页 共 23 页 桂林电子科技大学毕业(论文)报告专用纸 The Injection Molding Alp Tekin Ergenc , Deniz Ozde KocaYildiz Tecnical University, Mechanical Engineering Department, IC Engines Laboratory, TurkeyThe Introduction of MoldsThe mold is at the core of a plastic manufacturing process because its cavity gives a part its shape. This makes the mold at least as critical-and many cases more so-for the quality of the end product as, for example, the plasticiting unit or other components of the processing equipment.Mold MaterialDepending on the processing parameters for the various processing methods as well as the length of the production run, the number of finished products to be produced, molds for plastics processing must satisfy a great variety of requirements. It is therefore not surprising that molds can be made from a very broad spectrum of materials, including-from a technical standpoint-such exotic materials as paper matched and plaster. However, because most processes require high pressures, often combined with high temperatures, metals still represent by far the most important material group, with steel being the predominant metal. It is interesting in this regard that, in many cases, the selection of the mold material is not only a question of material properties and an optimum price-to-performance ratio but also that the methods used to produce the mold, and thus the entire design, can be influenced.A typical example can be seen in the choice between cast metal molds, with their very different cooling systems, compared to machined molds. In addition, the production technique can also have an effect; for instance, it is often reported that, for the sake of simplicity, a prototype mold is frequently machined from solid stock with the aid of the latest technology such as computer-aided (CAD) and computer-integrated manufacturing (CIMS). In contrast to the previously used methods based on the use of patterns, the use of CAD and CAM often represents the more economical solution today, not only because this production capability is available pin-house but also because with any other technique an order would have to be placed with an outside supplier.Overall, although high-grade materials are often used, as a rule standard materials are used in mold making. New, state-of-the art (high-performance) materials, such as ceramics, for instance, are almost completely absent. This may be related to the fact that their desirable characteristics, such as constant properties up to very high temperatures, are not required on molds, whereas their negative characteristics, e. g. low tensile strength and poor thermal conductivity, have a clearly related to ceramics, such as sintered material, is found in mild making only to a limited degree. This refers less to the modern materials and components produced by powder metallurgy, and possibly by hot isocratic pressing, than to sintered metals in the sense of porous, air-permeable materials.Removal of air from the cavity of a mold is necessary with many different processing methods, and it has been proposed many times that this can be accomplished using porous metallic materials. The advantages over specially fabricated venting devices, particularly in areas where melt flow fronts meet, I, e, at weld lines, are as obvious as the potential problem areas: on one hand, preventing the texture of such surfaces from becoming visible on the finished product, and on the other hand, preventing the microspores from quickly becoming clogged with residues (broken off flash, deposits from the molding material, so-called plate out, etc.). It is also interesting in this case that completely new possibilities with regard to mold design and processing technique result from the use of such materials. A. Design rules There are many rules for designing molds. These rules and standard practices are based on logic, past experience, convenience, and economy. For designing, mold making, and molding, it is usually of advantage to follow the rules. But occasionally, it may work out better if a rule is ignored and an alternative way is selected. In this text, the most common rules are noted, but the designer will learn only from experience which way to go. The designer must ever be open to new ideas and methods, to new molding and mold materials that may affect these rules.B. The basic mold1. Mold cavity space The mold cavity space is a shape inside the mold, “excavated” in such a manner that when the molding material is forced into this space it will take on the shape of the cavity space and, therefore, the desired product. The principle of a mold is almost as old as human civilization. Molds have metals into sand forms. Such molds, which are still used today in foundries, can be used only once because the mold is destroyed to release the product after it has solidified. Today, we are looking for permanent molds that can be used over and over. Now molds are made from strong, durable materials, such as steel, or from softer aluminum or metal alloys and even from certain plastics where a long mold life is not required because the planned production is small. In injection molding the plastic is injected into the cavity space with high pressure, so the mold must be strong enough to resist the injection pressure without deforming.2. Number of cavities Many molds, particularly molds for larger products, are built for only cavity space, but many molds, especially large production molds, are built with 2 or more cavities. The reason for this is purely economical. It takes only little more time to inject several cavities than to inject one. For example, a 4-cavity mold requires only one-fourth of the machine time of a single-cavity mold. Conversely, the production increases in proportion to the number of cavities. A mold with more cavities is more expensive to build than a single-cavity mold, but not necessarily 4 times as much as a single-cavity mold. But it may also require a larger machine with larger platen area and more clamping capacity, and because it will use 4 times the amount of plastic, it may need a large injection unit, so the machine hour cost will be higher than for a machine large enough for the smaller mold.3. Cavity shape and shrinkage The shape of the cavity is essentially the “negative” of the shape of the desired product, with dimensional allowance added to allow for shrinking of the plastic. The shape of the cavity is usually created with chip-removing machine tools, or with electric discharge machining, with chemical etching, or by any new method that may be available to remove metal or build it up, such as galvanic processes. It may also be created by casting certain metals in plaster molds created from models of the product to be made, or by casting some suitable hard plastics. The cavity shape can be either cut directly into the mold plates or formed by putting inserts into the plates.C. Cavity and core By convention, the hollow portion of the cavity space is called the cavity. The matching, often raised portion of the cavity space is called the core. Most plastic products are cup-shaped. This does not mean that they look like a cup, but they do have an inside and an outside. The outside of the product is formed by the cavity, the inside by the core. The alternative to the cup shape is the flat shape. In this case, there is no specific convex portion, and sometimes, the core looks like a mirror image of the cavity. Typical examples for this are plastic knives, game chips, or round disks such as records. While these items are simple in appearance, they often present serious molding problems for ejection of the product. The reason for this is that all injection molding machines provide an ejection mechanism on the moving platen and the products tend to shrink onto and cling to the core, from where they are then ejected. Most injection molding machines do not provide ejection mechanisms on the injection side.Polymer Processing Polymer processing, in its most general context, involves the transformation of a solid (sometimes liquid) polymeric resin, which is in a random form (e.g., powder, pellets, beads), to a solid plastics product of specified shape, dimensions, and properties. This is achieved by means of a transformation process: extrusion, molding, calendaring, coating, thermoforming, etc. The process, in order to achieve the above objective, usually involves the following operations: solid transport, compression, heating, melting, mixing, shaping, cooling, solidification, and finishing. Obviously, these operations do not necessarily occur in sequence, and many of them take place simultaneously. Shaping is required in order to impart to the material the desired geometry and dimensions. It involves combinations of viscoelastic deformations and heat transfer, which are generally associated with solidification of the product from the melt. Shaping includes: two-dimensional operations, e.g. die forming, calendaring and coating; three-dimensional molding and forming operations. Two-dimensional processes are either of the continuous, steady state type (e.g. film and sheet extrusion, wire coating, paper and sheet coating, calendaring, fiber spinning, pipe and profile extrusion, etc.) or intermittent as in the case of extrusions associated with intermittent extrusion blow molding. Generally, molding operations are intermittent, and, thus, they tend to involve unsteady state conditions. Thermoforming, vacuum forming, and similar processes may be considered as secondary shaping operations, since they usually involve the reshaping of an already shaped form. In some cases, like blow molding, the process involves primary shaping (pair-son formation) and secondary shaping (pair son inflation). Shaping operations involve simultaneous or staggered fluid flow and heat transfer. In two-dimensional processes, solidification usually follows the shaping process, whereas solidification and shaping tend to take place simultaneously inside the mold in three dimensional processes. Flow regimes, depending on the nature of the material, the equipment, and the processing conditions, usually involve combinations of shear, extensional, and squeezing flows in conjunction with enclosed (contained) or free surface flows. The thermo-mechanical history experienced by the polymer during flow and solidification results in the development of microstructure (morphology, crystallinity, and orientation distributions) in the manufactured article. The ultimate properties of the article are closely related to the microstructure. Therefore, the control of the process and product quality must be based on an understanding of the interactions between resin properties, equipment design, operating conditions, thermo-mechanical history, microstructure, and ultimate product properties. Mathematical modeling and computer simulation have been employed to obtain an understanding of these interactions. Such an approach has gained more importance in view of the expanding utilization of computer design/computer assisted manufacturing/computer aided engineering (CAD/CAM/CAE) systems in conjunction with plastics processing. It will emphasize recent developments relating to the analysis and simulation of some important commercial process, with due consideration to elucidation of both thermo-mechanical history and microstructure development. As mentioned above, shaping operations involve combinations of fluid flow and heat transfer, with phase change, of a visco-elastic polymer melt. Both steady and unsteady state processes are encountered. A scientific analysis of operations of this type requires solving the relevant equations of continuity, motion, and energy (I. e. conservation equations).Injection Molding Many different processes are used to transform plastic granules, powders, and liquids into final product. The plastic material is in moldable form, and is adaptable to various forming methods. In most cases thermoplastic materials are suitable for certain processes while thermosetting materials require other methods of forming. This is recognized by the fact that thermoplastics are usually heated to a soft state and then reshaped before cooling. Theromosets, on the other hand have not yet been polymerized before processing, and the chemical reaction takes place during the process, usually through heat, a catalyst, or pressure. It is important to remember this concept while studying the plastics manufacturing processes and the polymers used. Injection molding is by far the most widely used process of forming thermoplastic materials. It is also one of the oldest. Currently injection molding accounts for 30% of all plastics resin consumption. Since raw material can be converted by a single procedure, injection molding is suitable for mass production of plastics articles and automated one-step production of complex geometries. In most cases, finishing is not necessary. Typical products include toys, automotive parts, household articles, and consumer electronics goods, Since injection molding has a number of interdependent variables, it is a process of considerable complexity. The success of the injection molding operation is dependent not only in the proper setup of the machine variables, but also on eliminating shot-to-shot variations that are caused by the machine hydraulics, barrel temperature variations, and changes in material viscosity. Increasing shot-to-shot repeatability of machine variables helps produce parts with tighter tolerance, lowers the level of rejects, and increases product quality ( i.e., appearance and serviceability). The principal objective of any molding operation is the manufacture of products: to a specific quality level, in the shortest time, and using a repeatable and fully automatic cycle. Molders strive to reduce or eliminate rejected parts, or parts with a high added value such as appliance cases, the payoff of reduced rejects is high. A typical injection molding cycle or sequence consists of five phases:1 Injection or mold filling2 Packing or compression3 Holding4 Cooling5 Part ejectionInjection Molding OverviewProcessInjection molding is a cyclic process of forming plastic into a desired shape by forcingthe material under pressure into a cavity. The shaping is achieved by cooling(thermoplastics) or by a chemical reaction (thermosets). It is one of the most commonand versatile operations for mass production of complex plastics parts with excellentdimensional tolerance. It requires minimal or no finishing or assembly operations. Inaddition to thermoplastics and thermosets, the process is being extended to suchmaterials as fibers, ceramics, and powdered metals, with polymers as binders.ApplicationsApproximately 32 percent by weight of all plastics processed go through injection moldingmachines. Historically, the major milestones of injection molding include the invention of thereciprocating screw machine and various new alternative processes, and the application of computersimulation to the design and manufacture of plastics parts.Development of the injection molding machineSince its introduction in the early 1870s, the injection molding machine has undergone significantmodifications and improvements. In particular, the invention of the reciprocating screw machine hasrevolutionized the versatility and productivity of the thermoplastic injection molding process.Benefits of the reciprocating screwApart from obvious improvements in machine control and machine functions, the majordevelopment for the injection molding machine is the change from a plunger mechanism to areciprocating screw. Although the plunger-type machine is inherently simple, its popularity waslimited due to the slow heating rate through pure conduction only. The reciprocating screw canplasticize the material more quickly and uniformly with its rotating motion, as shown in Figure 1. Inaddition, it is able to inject the molten polymer in a forward direction, as a plunger.Development of the injection molding processThe injection molding process was first used only with thermoplastic polymers. Advances in theunderstanding of materials, improvements in molding equipment, and the needs of specific industrysegments have expanded the use of the process to areas beyond its original scope.Alternative injection molding processesDuring the past two decades, numerous attempts have been made to develop injection moldingprocesses to produce parts with special design features and properties. Alternative processes derivedfrom conventional injection molding have created a new era for additional applications, more designfreedom, and special structural features. These efforts have resulted in a number of processes,including: Co-injection (sandwich) molding Fusible core injection molding) Gas-assisted injection molding Injection-compression molding Lamellar (microlayer) injection moldin Live-feed injection molding Low-pressure injection molding Push-pull injection molding Reactive molding Structural foam injection molding Thin-wall moldingComputer simulation of injection molding processesBecause of these extensions and their promising future, computer simulation of the process has alsoexpanded beyond the early lay-flat, empirical cavity-filling estimates. Now, complex programs simulate post-filling behavior, reaction kinetics, and the use of two materials with different properties, or two distinct phases, during the process.The Simulation section provides information on using C-MOLD products.Among the Design topicsare several examples that illustrate how you can use CAE tools to improve your part and molddesign and optimize processing conditions.Co-injection (sandwich) moldingOverviewCo-injection molding involves sequential or concurrent injection of two different butcompatible polymer melts into a cavity. The materials laminate and solidify. This processproduces parts that have a laminated structure, with the core material embedded betweenthe layers of the skin material. This innovative process offers the inherent flexibility ofusing the optimal properties of each material or modifying the properties of the moldedpart.FIGURE 1. Four stages of co-injection molding. (a) Short shot of skin polymer melt (shown in dark green)is injected into the mold. (b) Injection of core polymer melt until cavity is nearly filled, as shown in (c). (d)Skin polymer is injected again, to purge the core polymer away from the sprue.Fusible core injection moldingOverviewThe fusible (lost, soluble) core injection molding process illustrated below producessingle-piece, hollow parts with complex internal geometry. This process molds a coreinside the plastic part. After the molding, the core will be physically melted or chemicallydissolved, leaving its outer geometry as the internal shape of the plastic part.FIGURE 1. Fusible (lost, soluble) core injection moldingGas-assisted injection moldingGas-assisted processThe gas-assisted injection molding process begins with a partial or full injection ofpolymer melt into the mold cavity. Compre
收藏