Shanghai Daoqin Plastics Co., Ltd.

        一, 顶针布置原则

        (1)顶针布置应 make ejection force amount balanced. structure complex 部位 需 demolding force relatively large, 顶针数 amount versus increase.

        (2)顶针应设置于 has 效部位, 如骨位, 柱位, 台阶, metal parts, local thick and other structure complex 部位. 骨位, 柱位两侧 顶针应尽 amount for 称布置, and 骨位, 柱位 边间距 generally 取D=1.5mm, 如图5.5.8 示, another, amount ensure 柱位两侧顶针 in 心连线 through in 心.

        (3)避免跨台阶 or in upper 设置顶针, 顶针顶面应尽 amount 平缓, 顶针应布置于胶 parts force relatively good structure 部位. 如图5.5.9 示.

        (4) in parts relatively deep 骨位(deep degree ≥20mm) or difficult 于布置圆顶针时, use 扁顶针. need use 扁顶针时, 扁顶针处尽 amount using/adopting parts 形式以利于 processing. 如图5.5.10

        (5)避免尖钢, thin 钢, especially is 顶针顶面不 can front 模面. 如图5.5.11

        (6)顶针布置应考虑顶针 and water 道 边间距, effect/influence water processing and water. specific requirements 参见第十章10.2节.

        (7)考虑顶针 排 gas function, is ejection 时 排 gas, in easy formed true 空 部位应布置顶针. type relatively large 平面处, parts force relatively small, easy formed true 空, demolding force add large.

        (8) has appearance requirements parts, 顶针不 can in appearance upper, using/adopting its it ejection methods.

        (9) for/regarding transparent parts, 顶针不 can in light 部位.

        二.顶针 selection 原则

        (1) selection relatively large 顶针. in has ejection 位置 情况 lower, selection relatively large 直径, dimensions excellent 先 顶针.

        (2) selection specifications amount less. selection 顶针时, adjustment large small make dimensions specifications most less, meanwhile amount selection excellent dimensions series.

        (3) selection 顶针应 meet/satisfy ejection strong/high degree requirements. ejection 时, need relatively large pressure, is small bending deformation, 当顶针直径 small 于2.5mm时, selection has 托顶针.

         mold demolding difficult, easy pressure 断顶针 issues can through various ⼿段 decrease/reduce 但始终 is method 杜绝, rear 期维护费 use high, separation causes and 建议如 lower:

        1. production ring temperature degree high, formed fatigue, 顶针材 material from 而失效

        2. dimensions degree is combined use requirements

        3. force in.

        轴 in processing 台阶时容 easy in 直径变化突然 部位(other parts in 形状变化突然 部位)形 formed force in, from in use engineering in to outer force function (especially is toward force)时 cracking or fracture.

        4. hot 处理

         more 数顶针 in manufacturing process in need hot 处理, rear 不经 回火 or time product easy 出现, 如残留应 force more and other quality issues;

        5. surface treatment, is improve/increase wear resistance, relatively more using/adopting nitrogen 化处理, nitrogen process is specification, relatively high nitrogen temperature degree formed material 回火甚至退火而失效

        6. in use process in amount make 顶针径 toward force.

        7. in design mold 时考虑孔 变径部位 using/adopting 圆角 渡 or increase force 释放槽.  

        8. 装顶针 front 检查孔径 large small and coarse degree, if 顶针孔铰 rear 顶针装 upper very 松动, that 顶针孔 very easy material, 顶针就容 easy 断, if very 紧, in high temperature lower easy 烧死, therefore and 孔 配 combined degree must need good.

        9. mold day maintenance and process debugging

        每次装模时 add coating anti 卡油效果 more good, its in day maintenance main/primary is coating lubricated or 顶针油. mold 顶针都 is 3-5μ 间隙, ⼀般 lubricated coating rear most more can ⽀支持3~5天, 随 灰尘, mold scratch formed metal powder 末累积进入顶针, slip block, 斜顶隧道缝隙 inner formed combined 面缝隙越 越 small, light degree 越 越 low, most rear full 烧蚀卡死直至 fracture.

         therefore scratch 拭顶针 and 模面 污垢 heavy new coating dry lubricant. maintenance attention/notes and 顶针尽 amount coating high temperature resistance lubricated 膏, formed ⼀道 film can, use use force coating 抹, 否则极 easy formed 油污污染 injection molding parts

        10. more short cycle, will ejection and speed degree 设置 太 fast ultra- mold can force.

        11. demolding fast, product 底部进 gas 不足, formed negative pressure retardant 尼状态, increase demolding retardant force. 顶杆就会受 to large retardant force

        12. if comparison mono thin 话, easy loss bad.

        13. ejection retardant force large, 检查啤 parts has 无拉伤 deformation 方, improvement 出模斜 degree, front will mold opening time short, 一两秒即 can, is system issues, is product force large causes.

        14. machine rear cooling water 没关, mold temperature decline, pressure 第⼀模时, cooling time long force large, mold opening time shrink short

        15. 顶针 材质 issues, can selection new type material 瑞典SSAB钢 iron group Toolox44拓达钢 solution and hot issues, Toolox is world upper most hard hard 钢, 出⼚时预 hard to 45-48HRC, reduce hot 处理风险 and cycle, nitrogen property can excellent 秀, 几乎没 has force, deformation, ratio 传统材 material high 2-3倍 tough property, can resistant 640°C below/following high temperature, can solution fracture or deformation issues, is currently high temperature resistance stability property most material selection.