注塑模顶出机构的计算机辅助设计

介绍塑料注射模具实用顶出系统的计算机辅助设计。使用该软件可设计不同形式的顶出系统。     

汽车吸尘器封盖注射模设计

汽车吸尘器封盖使用聚碳酸酯(PC)/丙烯腈-丁二烯-苯乙烯塑料(ABS)合金注塑成型,结合塑件结构特点和无卤阻燃PC/ABS改性塑料的特性,采用二维计算机辅助设计平面排位设计方法设计了一副单个点浇口三板模具用于塑件的注射成型。为简化模具结构,模具定模一侧使用2个导动楔紧块驱动滑块机构观察孔和倒扣边的成型和脱模,并通过三板模开模动力进行驱动,动模一侧使用倒扣顶杆+顶针二次顶出抽芯机构实施基座外壁倒扣的成型和脱模,也通过模具动模的开模运动来进行驱动,有效简化了模具结构,降低了模具制造成本。二次顶出机构中,简化为依靠挡位块定位进行分离驱动,即动模打开后下行一定距离,注射机顶杆顶住第二次顶出板而使塑件获得第一次共同顶出,随着顶出的继续上行,动模模脚上开设的侧凹挡住第一次顶出板边上的挡块而迫使第一次顶出停止顶出,而第二次顶出板则可以继续顶出完成塑件的第二次完全顶出脱模,从而获得了变形较小的注塑成品。浇注系统使用点浇口+侧浇口复合式浇注系统,便于对塑件模腔浇口位置的灵活选择,保证了模腔充填的可靠性。     

专利文摘

变频与微机控制的橡胶平板硫化机本变频与微机控制的橡胶平板硫化机由机架,锁模、顶出、移模油缸,开合模拉杆,上固定模板,上、下加热器,动模板,定量泵,电动机,控制箱组成。控制箱内有电气、液压控制系统,液压控制系统由比例压力阀与电磁换向阀A、B、C构成,电磁换向阀A、B、C与定量泵连接,又与锁模、顶出、移模油缸连接,比例压力阀与定量泵连接,在锁模、顶出、移模油缸处分别有合模、顶出、移模行程开关;电气控制系统由微机和变频控制器构成,变频控制器分别与微机、电动机连接,微机与合模、顶出、移模行程开关连接。它改变现有液压系统的…     

提高顶装焦炉装煤除尘系统安全性的技术改进

通过分析近年来关于顶装焦炉装煤除尘系统发生的安全事故,分析装煤除尘操作过程中装煤口—除尘管道—装煤除尘器三环节存在的安全风险,总结出提高六米顶装焦炉装煤除尘系统安全性的关键点。通过增加信号联锁,设备改造等手段,改进了六米顶装焦炉装煤除尘系统安全性。     

汽车冷却风扇面罩热固性压缩模设计

针对风扇面罩SMC热固性塑料压缩成型的需要,设计了其模一模一腔两板模结构热固性压缩成型模具,模具由成型件、加热系统、顶出系统等机构件组成;模具的加料方式采用机械手条料加料方式,并对条料进行分割均布以保证塑件成型的饱满性;模具上、下模温度控制采用油温控制,模腔成型工艺参数为:温度控制在150℃,成型压力为41 MPa,成型时间1. 2 min/mm,脱模取件温度为80℃;模具的顶出机构采用4个油缸驱动顶出板及顶针平衡顶出。模具结构简单,布局合理,便于制造和生产。     

汽车主副驾饰板顺序阀热流道注塑模具设计

结合某汽车主副驾饰板的结构特点,设计了一副“1+1”模腔布局的注塑模具。利用Moldflow软件进行模流分析,模具浇注系统采用“热流道+冷流道”组合形式,热流道采用顺序阀技术2点进料,解决了塑件表面熔接痕和色泽不一致等成型问题。针对塑件内部倒扣众多,且有多处倒扣形状不规则,空间狭窄,倒扣脱模方向不一致的问题,为保障倒扣顺利脱模,每个模腔设计了1个滑块和10个斜顶机构。塑件内表面还有较多筋位,大量蜂窝结构,多个boss柱,需要的脱模力较大,脱模系统还需要设计顶针、司筒、直顶和二次顶出结构。该模具由于直顶和斜顶数量较多,模具底板和顶出板上需要留有较多空间来安装直顶杆和斜顶,导致注塑机顶棍无法为模具提供脱模动力,需要设计油缸为顶出系统提供动力。模具投产后,运行平稳,实践表明,结构合理可靠,满足客户要求,为类似模具设计提供借鉴。     

双脱模模具结构设计

分析了洗发液瓶盖塑料件的成型工艺。为保证顺利脱模,模具设计采用了双脱模机构,即定模采用杠杆、推杆顶出机构,动模采用推管二级顶出机构。浇注系统凝料的脱出采用了斜拉孔、球形拉料杆自动脱料机构。     

精密塑料成型模具的潜伏式浇口

<正>本实用新型公开了一种精密塑料成型模具的潜伏式浇口,包括流道顶出机构、流道、压板、顶出块、顶出弹簧、切刀、产品顶出机构和型腔,流道位于动模和定模之间,流道的底部设置有流道顶出机构、压板,压板的底部安装有顶出块,顶出块的底部安装有顶出弹簧,压板、顶出块、顶出弹簧均位于动模的方槽内,型腔位于动模内,切刀位于     

一种多面填埋的注塑夹具

正本实用新型公开了一种多面填埋的注塑夹具,包括模具座和气动顶出装置,模具座的底部设有定位螺栓、H形板和承重弹簧,气动顶出装置安装在模具座的顶部,气动顶出装置包括顶出座、顶出柱、顶块、顶出弹簧、支撑柱和模具,顶出座的底部固定连接模具座的上表面,顶出柱的一端连接顶块;本多面填埋的注塑夹具,通     

齐鲁石化工程有限公司开发出异戊橡胶胶乳脱气气体分离工艺及系统

<正>山东齐鲁石化工程有限公司开发出一种异戊橡胶胶乳脱气气体分离工艺及系统。它是将除掉脱气气体夹带胶粒后的气体降温至60℃,全部冷凝为液体;将冷凝液降温至45℃,然后再进行己烷、异戊二烯和水的分离。分离系统包括脱气釜、釜顶过滤器、分离塔,釜顶过滤器通过管线连接脱气釜顶部,釜顶过滤器通过管线连接釜顶冷凝器,釜顶冷凝器通过管线连接粗溶剂油冷却器,粗溶剂油冷却器通过管线连     

文丘里液体喷射技术在真空系统的工业应用

介绍了以文丘里液体喷射抽真空技术在炼油厂常减压系统的工业运行情况。用一级液体喷射取代原来的三级蒸汽喷射。工业装置的运行及标定结果表明,文丘里液体喷射抽真空技术在低于蒸汽喷射抽真空技术能耗的前提下,真空度高于蒸汽喷射抽真空技术。用于喷射的液体采用装置自产的减一线油,运行结果表明,用于炼厂常减压装置的文丘里液体喷射系统流程设计合理,塔顶压力低于蒸汽喷射真空系统,加热炉出口温度、减一线产品质量、减一及减二线的产量等未受到影响。     

Ejection force modeling for stereolithography injection molding tools

Stereolithography (SL) molds have proven effective for short injection molding runs. However, they are susceptible to failure because of their poor mechanical properties, especially at elevated temperatures. A majority of these failures occur during the ejection stage, as a result of excessive ejection forces. An ejection force model was developed by combining the effects of thermal shrinkage and mechanical interlocking due to stair‐steps on the surface of SL tools. Finite element analyses were performed to validate and complement the ejection force equation. Measured forces and temperatures from injection molding experiments indicated that the ejection force model is valid for SL molds of both circular and non‐circular shape. The average differences between measured and predicted ejection forces were approximately 10%.     

An ejection system for firing a small high-temperature tunnel kiln

Conclusions An ejection system for firing a tunnel kiln differs from an ejection system for firing metallurgical and machine building industry furnaces.Investigations were conducted on a model of the ejection equipment of small high temperature kilns.Results were obtained on the change in the coefficient of ejection in relation to the geometric parameters of the ejectors and the burners, the distance between them, the pressure in the ejection channel and the working space of the kiln, and the temperature of the air ejected.A method of calculation of ejectors used in tunnel kilns is proposed.Translated from Ogneupory, No. 2, pp. 40–43, February, 1984.     

Calculation of ejection force of hollow,thin walled,and injection moulded cones

Abstract

As far as products of open or closed hollow cones or cylinders are concerned, the moulded parts grip the mould cores after mould opening because of differential thermal contraction. To strip the parts from the mould core, most injection and compression moulds have systems to eject the moulded parts automatically. The ejection force is defined as the force needed to strip the moulded parts from the mould cores. An injection mould with changeable cavities and cores has been designed. Using different configurations of the mould cavities and cores, open (or closed), hollow, thin walled cones in various thicknesses, diameters, lengths, and cone angles were injected. The ejection force was measured using a tensile machine and a specially designed tool. The dependence of the ejection force on the size, wall thickness, cone angle, elastic modulus, Poisson's ratio of the moulded parts, and the friction coefficient between steel and plastics are considered and a new method for calculating the ejection force in an acceptably accurate way is presented. The relationship between the ejection force and plastics properties as well as mould configuration is discussed. The calculation formula of the ejection force indicates that: the ejection force is directly proportional to the thickness and length of the part and has little relationship with the radius of the part; the thermal contraction strain and Young's modulus of the plastics impose considerable influence on the ejection force; a high friction coefficient f leads to a high ejection force; and for a cone angle of 2α, moulded parts can drop down from the core automatically without ejection when tan α ≥ f.     

Experimental study of shrinkage and ejection forces of reinforced polypropylene based on nanoclays and short glass fibers

This study presents the influence of nanoclays and glass fibers on the shrinkage and ejection forces of polypropylene‐based composites for tubular parts produced by injection molding. An instrumented mold was used to measure cavity pressure, surface temperature and ejection forces in the tubular parts during the injection cycle. The materials used for the study were polypropylene homopolymer Domolen 1100L, nanoclays for polyolefin nanocomposites (P‐802 nanoMax, used in percentages of 2%, 6%, and 10%) and reinforced polypropylene homopolymer with a content of 10% and 30% glass fiber (Domolen P1‐013‐V10‐N and Domolen P1‐102‐V30‐N, respectively). Part shrinkage was measured 48 h after production. The results show that the incorporation of nanoclays reduces shrinkage and ejection forces while glass fibers decrease shrinkage and increase ejection forces due to an increase in elastic modulus. Nanoclays decrease the ejection forces when compared to glass fibers and pure PP. The effects of nanoclays are less pronounced than those of glass fibers. Moldings produced with different materials were also analyzed to assess the effect of mold temperature on the ejection forces. Shrinkage rises slightly by increasing the mold temperature while the ejection force decreases. POLYM. ENG. SCI., 58:55–62, 2018. © 2017 Society of Plastics Engineers     

油缸浮动顶出脱模机构结构优化与注塑模具设计

针对中间深度凹陷产品扣帽盖的横向脱模,设计了含油缸浮动顶出与侧边油缸推出组合机构的注塑模具。通过侧边顶出脱模机构的优化设计,利用模架模板将侧边推出机构顶起,以增强顶出机构的稳定性及使用寿命。详述了通过注塑模具的三步动作,实现产品横向顶出侧型芯脱模,确保塑料件的脱模质量。     

Evaluation of the die wall friction during tablet ejection

Coulomb's equation for the friction between solids has been applied to the friction between a tablet and a die wall during the tablet ejection process. An apparatus has been developed to measure the ejection forces with varying radial forces for the tablets compressed at a definite compressive force. The tablet of lactose granulate or blended mixture is compressed in a die at a definite compressive force apart from the apparatus. The ejection forces are determined under various radial forces produced by recompression or relaxation of the tablet in the die. In the series of measurements of the ejection forces, a linear relation between the ejection and radial forces has been obtained. The coefficient of friction can be estimated from the slope of the straight line and the adhesive force from the intercept. A good correlation is observed between the adhesive force and the binding characteristics of the tablets on both a physical testing instrument and an actual rotary tablet machine.     

不同放汽阀流量特性对弹射过程的影响规律

研究对象为某型蒸汽弹射装置,建立了系统的热力过程数学模型和飞机的力学模型,建立弹射装置的仿真模型并对其进行了可靠性验证,对分别选用快开阀、线性阀、抛物线阀、对数阀的蒸汽弹射装置动态性能进行了仿真研究。仿真计算结果表明：当其他参数均一致,选用具有不同流量特性的阀门时,弹射耗汽量相差不大,均在560 kg左右,弹射过程时间：快开阀<线性阀<抛物线阀<对数阀,且弹射时间均在3 s以内,选用线性阀与抛物线阀时,汽缸内压力曲线更为平稳,飞机最大加速度也较小,分别为40.97与42.80 m/s²,飞机最终起飞速度均大于75 m/s。     

Draft angle and surface roughness effects on stereolithography molds

Stereolithography (SL) is a rapid prototyping process, which allows one to build complex shapes quickly. Current research investigates the possibilities of using this process to make injection molds. This would allow designers to manufacture and test molds easily and rapidly. One of the main issues with this technique is the effects of its surface on the part. Molds built by SL have high roughness. This gives rise to a high friction force between the part and the mold, and increases the ejection force needed to eject the part from the mold. High ejection forces often lead to damage or breakage of the part and the mold. Research was undertaken on the effects of draft angle and roughness on ejection forces. It was found that increasing the draft angle does not necessary assist the ejection of the part. As the draft angle increases, the roughness and hence the friction force between the part and the mold also increase. There is a trade‐off between draft angle and roughness. A model based on Glanvill's equation was developed to predict ejection force and was consistent with experimental results.     

磁场测试仪外壳定模斜顶机构家族注塑模设计

为了满足磁场测试仪外壳4个塑件同步成套注射成型的需要,设计了一副1模4腔家族注塑模.4个腔的浇口都采用矩形浇口,截面积优化配置为12:12:3:1.为了解决塑件型腔侧倒扣的脱模,设计了拉杆驱动式定模滑块抽芯机构和弹簧顶出式定模斜顶机构.在弹簧顶出式定模斜顶机构中,采用弹簧驱动定模斜顶实施顶出,并由动模板驱动定模复位杆进...