【作者】 张巍；

【导师】 祝铁丽；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2015， 硕士

【摘要】 微小塑料机构的模内装配注塑成型关键技术研究,目的是使该类型产品摆脱目前高投入、低产出的困境,为市场亟需的微小塑料机构产品铺平从实验室到工厂规模化生产之路。从设备环节降低高端注塑机的高昂成本,从模具制造环节创新设计思路,从生产环节减少二次装配工作量和用工成本。本课题基于微小塑料铰链的模内装配注塑成型初步研究,进一步拓展和深化,对极冷策略的实现进行有益的探索。研制了基于半导体制冷技术对微细型芯进行冷却的极冷系统,以期在与实际注塑生产条件相同的注塑成型周期内即能消除微小塑料铰链的孔、轴配合接触面的粘附现象。首先,对孔、轴配合结构的微小塑料铰链成型顺序和配合间隙的已有研究进行了比较,根据对同种聚合物材料在模内装配注塑成型塑料机构的成功案例进行分析,探讨将极冷策略应用于同种聚合物模内装配注塑成型微小塑料铰链的可能性与难点。其次,通过将半导体制冷片嵌入模具核心位置、以热管为导热媒介,以及合理设计隔热部件及散热机构,提出了一种实用性强、能够极度降低模具微细型芯的温度从而使与其接触的聚合物熔体表面被迅速冷却的成型方案,设计了一套用于在单料筒微注塑机上以同种注塑材料进行模内组装微小塑料铰链的关键位置控温系统,在极冷策略应用在模具机构设计中引入ANSYS Workbench稳态热分析进行方案优化。再次,将极冷系统应用于在单料筒注塑机上使用同种聚合物材料(HDPE)进行模内装配注塑成型微小塑料铰链的模具,以双流道转换浇注系统进行微孔塑件和微轴塑件的分阶段注塑成型实验,通过反复摸索各项成型参数,消除了影响成型质量的各种缺陷。最后,对使用高密度聚乙烯材料完成同种聚合物模内装配注塑成型微小塑料铰链的实验制件进行检验,观察转动机构的表面形态,测量微孔塑件和微轴塑件的关键尺寸。测量结果表明,利用极冷系统在与实际注塑生产条件相同的注塑成型周期内得到的微小塑料铰链,能够保证微小塑料机构的成型质量和配合间隙,实现了有效缩短微小塑料机构的模内组装成型周期。更多还原

【Abstract】 For the key technology research on in-mold assembly injection of micro plastic hinge, the purpose is to make this type of products break away the strait of high cost, in order to smooth out the way of the micro plastic mechanics from laboratory research to practical application. The methods include reducing equipment costs by avoiding the high-end injection molding machine, innovating the product design and the mold design, reducing production steps by avoiding the secondary treatment of assembly work after demoulding. Based on preliminary research of in-mold assembly technology, this thesis made further study on inducing the ice cold trick into the injection mold of micro plastic revolute joint. By using the semiconductor refrigeration technology, an ice cold system was developed to make the tiny core rapidly cool down, in order to eliminate adhesion of the contact areas between the micro plastic hole and the micro plastic pin which compose the micro plastic hinge while shortening the producing cycle time greatly.At first, the thesis summed up previous research about molding sequence and the fit clearance of parts composing the micro plastic hinge. After analyzing successful application of the ice cold trick to in-mold assembly of micro plastic mechanics whose components are made of the same polymer material, both possibility and difficulty about using the ice cold trick for in-mold assembly of a micro plastic hinge which is also made of the same polymer material are discussed.Secondly, a practicable program was proposed which can extremely cool the tiny core and then make polymer melt touching the tiny core rapidly cool down. This program includes inlaying the semiconductor refrigerating chip into the key location of the mold, using the heat pipe as heat-conducting approach, and properly designing insulation structure and the cooling unit. A temperature control system was designed for in-mold assembly of a micro plastic hinge which is made of the same polymer material from a single cylinder injection machine. Temperature distribution was calculated by means of ANSYS Workbench steady state thermal analysis and design of the ice cold system was optimized.Thirdly, the ice cold system was installed into the mould for a micro plastic hinge which is made of the same polymer material (HDPE). In the running system, double flow channels were used for conversion between molding processes of the micro plastic hole and the micro plastic pin. Through many tests by trial and error, quality defects of the plastic parts were eliminated.Finally, experimental products of the micro plastic hinge made of the same polymer material (HDPE) were disassembled, and the micro plastic holes and the micro plastic pins were observed. Measuring of the key dimensions showed that the micro plastic hinge produced with ice cold system had reliable quality and reasonable fit clearance, and at the same time the injection molding cycle times was shortened effectively.更多还原