Abstract: This paper analyzes thin tube slender tube-type plastic pieces of the structural characteristics of the And in accordance with the characteristics described in detail tube plastic parts injection mold structure and its working process， to determine a reasonable way of injection and mold Key words: Process; gating system; ribbed tube; Injection Mold 1 Introduction In the mold design process， often encountered in long thin tube-type injection parts， such parts of the larger aspect ratio， and shape permit must have the Injection molding of such parts， there are often non-uniform tube wall thickness， surface with flow defects such as marks and Therefore in the design of injection molds need to consider the casting mold system， exhaust system， cooling system， the introduction of the At the same time should also be considered loaded mold mold mold height and open Mold structure as far as possible， compact， open-mode trip 2， process analysis Shown in Figure 1 for the plastic tube size Materials for the PS (polystyrene) We can see from the parts belong to the shape of thin elongated tube-type injection parts， die design and die in the process to determine the structure needed to be Fig know by the size， wall thickness 5mm， the outer diameter size! 24mm， length 150mm， there is at the bottom of tube M24 × 30mm outer thread of the Product requirements of uniform wall thickness， internal and external cavity surface smooth， burr-free edge Because of long thin tube-type injection parts， such parts of the larger aspect ratio， it focuses on mold design and injection molding Demoulding selection on the Because of thin-walled tube， and筒身longer， it had not yet reached the molten plastic in the entire cavity is likely to occur before condensation and should not make a complete injection molding In addition such slender parts by injection mold machine and therefore can not be away from the conventional way of Demoulding D Injection molding machine according to the selection of production conditions in the SCZ-125-type injection Their specific parameters are: a high degree of loading mode: 150 ~ Open-mode distance: The level of column spacing: Vertical column spacing: A maximum injection capacity: 3， mold design Three die structure using one mold plate structure Plastic parts to determine the shrinkage rate of 3% Demoulding gradient plastic parts in accordance with the molding process characteristics and the characteristics of plastic parts selection Demoulding cavity gradient 6 °， angle core Demoulding identified as 5 °， Figure 2 shows Demoulding add gradient plastic parts after various parts of the material thick-size Because of plastic parts at the bottom there is the outer M24 × 30mm thread， it must die structure using fractal lateral Injection Mold through the spring and the role of lock block to complete block of lateral Hough fractal core-pulling Injection Mold Design Demoulding manner shown in figure Push the board to adopt the way the introduction of plastic And to reduce the top of the distance from the injection molding machine using a direct role in the top bar at the push Greatly reduces the loading height 翻译：摘要：分析了螺纹管细长筒薄类塑料件的工艺结构特点并根据特点详细论述了螺纹管塑料件注射模具结构及其工作过程，确定了合理的注射及脱模方式 关键词：成型工艺；浇注系统；螺纹管；注射模 1、引言 在模具设计过程中，经常会遇到细长筒薄类注射零件，这类制件的长径比较大，且外形允许有一定的锥度。注射成型这类零件时，常常出现筒壁厚度不均匀，表面带有流痕及烧焦等缺陷。因此在设计注射模具时需要综合考虑模具的浇注系统、排气系统、冷却系统、推出系统。同时还要考虑模具的装模高度及开模行程。尽量使模具结构紧凑，开模行程短。 2、工艺分析 图1 所示为螺纹管塑件尺寸图。材料为PS(聚苯乙烯) 。由零件形状可知属于细长筒薄类注射零件，在模具设计及模具结构的工艺确定中需加以考虑。由尺寸图所知，壁厚5mm，其外径尺寸为!24mm，长度为150mm，在筒底部有M24×30mm 的普通外螺纹。产品要求壁厚均匀一致，内外型腔表面光滑，无飞边毛刺。 由于细长筒薄类注射零件，这类制件的长径比较大，故模具设计的重点在于注射成型和脱模方式的选择上。由于筒壁较薄，而筒身较长，故熔融塑料在还未达到整个型腔前就有可能出现冷凝而使得注射零件不能完整成型。另外这类细长零件受注射机的开模距离的限制而不能以常规的脱模方式进行脱模。 注射机的选择根据生产条件要求安排在SCZ-125 型注射机。其特定参数为:装模高度：150～300mm。开模距离：300mm。水平柱间距：400mm。垂直柱间距：400mm。一次最大注塑量：125g。 3、模具设计 模具结构采用三板式1 模4 件结构。 塑件的收缩率确定为3%。脱模斜度根据塑件的成型工艺特点及塑件的特性型腔选择脱模斜度6°，型芯脱模斜度确定为5°，图2 所示为加脱模斜度后塑件各部分的料厚尺寸图。 由于塑件底部有M24×30mm 的外螺纹，故模具结构必需采用侧向分形机构。注射模具通过弹簧和锁块作用来完成哈夫块的侧向分形抽芯动作。 注射模脱模方式的设计如图3 所示。采用推板推出塑件的方式。而为减少顶出距离，采用注塑机顶出杆直接作用在推板上。大大减少了装模高度。
