Design of Two⁃stage Side Core⁃pulling Injection Mold for Special⁃shaped Parts with Four Sides and Six Undercuts

doi:10.19491/j.issn.1001-9278.2021.02.017

Abstract

Abstract:

Aim at the difficulty in the large area of undercut in all four sides of the supporting shell in the mold design， we design a scheme to divide all of the side areas into 6 sliders S₁~S₆ for molding according to the demolding direction. Owing to two sliders on the right side of the product， S₂ and S₃， with inconsistent stripper directions and large molding areas， a two-stage sequential core-pulling mechanism with an inclined guide column + hydraulic cylinder was designed. The left side of the product was formed by slider S₅， and a local round hole was formed by the tunnel slider S₆， which was located in the main slider S₅. When the mold was opened， the core?pulling delay was caused by the gap between the holes of the slider angle pin in the slider S₅. After the core?pulling action was completed by the spring?driven slider S₆， the slider S₅ starts to move. The sequential structure of the spring+slider angle pin simplified the secondary core?pulling mechanism. Finally， a single parting hot runner injection mold was designed with a longitudinal layout of one mold and two cavities， a latent gate feeding， and an oblique pushing out. The lateral movement of all the sliders was completed by a single opening of the mold. The mold has a simple structure with a good stability in operation and a high degree of automation.

Key words: shell, undercut, slider, secondary core pulling, hydraulic cylinder, spring, delay

CLC Number:

TQ320.66⁺2

XIONG Yi, WANG Wei. Design of Two⁃stage Side Core⁃pulling Injection Mold for Special⁃shaped Parts with Four Sides and Six Undercuts[J]. China Plastics, 2021, 35(2): 101-106.

Figures/Tables 9

Fig.1. Structure of the product

Fig.2. Main parting of the mold

Fig.3. Side parting

Fig.4. Secondary core?pulling mechanisms of S2 and S3

Fig.5. Secondary core?pulling mechanisms of S5 and S6

Fig.6. Gating system

Fig.7. Ejection layout

Fig.8. The cooling system

Fig.9. Structure of the mold

References 15

1	齐卫东. 塑料模具设计与制造［M］. 2版. 北京：高等教育出版社， 2008： 206.
2	郑伶俐，王乾. 复杂盖板塑料件模具创新优化设计［J］. 工程塑料应用， 2017， 45（8）：84⁃87.
	ZHENG L L， WANG Q. Innovative Optimal Design of Mould for Complex Cover Plastic Part［J］. Engineering Plastics Application， 2017， 45（8）：84⁃87.
3	张强，李国富，王正才. 一种斜孔弯销三次抽芯机构的设计［J］. 工程塑料应用， 2017， 45（1）：76⁃79.
	ZHANG Q， LI G F， WANG Z C. Design of Three Inclined⁃Hole Angular Cam Core⁃Pulling Mechanism［J］.Engineering Plastics Application， 2017， 45（1）：76⁃79.
4	韩宝菊. 强力电锤仿生手柄注塑模具设计［J］. 工程塑料应用， 2016， 44（5）：60⁃64，98.
	HAN B J. Injection Mould Design of Strong Hammer Boionic⁃Handle［J］. Engineering Plastics Application， 2016， 44（5）：60⁃64，98.
5	刘鑫，冯刚. 四面内抽斜顶的圆盖塑料模设计［J］. 塑料工业， 2014， 42（12）：49⁃51.
	LIU X， FENG G. Four Sides Inner Loose Core and Lifter round Cover Plastic Mould Design［J］. China Plastics Industry， 2014， 42（12）：49⁃51.
6	唐晖. 一种新型自动自锁液压抽芯机构设计［J］. 塑料科技， 2016， 44（6）：76⁃80.
	TANG H. Design of a New Type of Automatic Self⁃Locking Hydraulic Core Pulling Mechanism［J］. Plastics Science and Technology， 2016， 44（6）：76⁃80.
7	陈黎明，熊建武，沈忠良.内壁六面包围框形塑料件脱模机构及模具设计［J］.工程塑料应用，2019（9）：87⁃93.
	CHEN L M ，XIONG J W ，SHEN Z L.Design of Compound Core⁃pulling Mechanism and Injection Mold for Six⁃bread Frame⁃Shaped Parts with Inner Wall［J］.Engineering Plastics Application，2019（9）：87⁃93.
8	卞平，肖国华. 除尘器手柄特殊滑块抽芯机构及其注塑模具设计［J］. 塑料， 2017， 46（3）：69⁃73，78.
	BIAN P， XIAO G H. Core Pulling Mechanism and Injection Mold Design of Special Slide Block of Dust Collector［J］. Plastics， 2017， 46（3）：69⁃73，78.
9	陈吉平，丁智平，陈宏洲. 一种多元组合抽芯机构注射模设计［J］. 工程塑料应用， 2016， 44（6）：76⁃79.
	CHEN J P， DING Z P， CHEN H Z. Injection Mould Design for Core⁃Pulling Mechanism of a Multiple Combination［J］. Engineering Plastics Application， 2016， 44（6）：76⁃79.
10	谭伟，程芳. 具有多抽芯机构的转向器壳体压铸模设计［J］. 特种铸造及有色合金， 2017， 37（8）：873⁃874.
	TAN W， CHENG F. Design of Die⁃Casting Die for Steering Gear Housing with Multi Core Pulling Mechanism［J］. Special Casting & Nonferrous Alloys， 2017， 37（8）：873⁃874.
11	梅益，朱春兰，宋沛毅，等. 短固定手柄套多侧向抽芯注塑模具设计［J］. 工程塑料应用， 2018， 46（4）：75⁃79.
	MEI Y， ZHU C L， SONG P Y， et al. Design of Injection Mould with Multi Side Core⁃Pulling for Short Fixed Handle Sleeve［J］. Engineering Plastics Application， 2018， 46（4）：75⁃79.
12	高瑾，周建军. 微型电机罩壳多类型抽芯机构及前后模顶出注塑模具设计［J］. 塑料工业， 2016， 44（11）：83⁃87.
	GAO J， ZHOU J J. Design of Injection Mould for Micro Motor Shell with Multi⁃Type Core Pulling Mechanism and Mould Front⁃back Ejector Mechanism［J］. China Plastics Industry， 2016， 44（11）：83⁃87.
13	张建卿. 洗涤机屏蔽盖双滑动三次抽芯注塑模脱模机构设计［J］. 塑料科技， 2016， 44（1）：87⁃89.
	ZHANG J Q. Demoulding Mechanism Design for the Injection Molding of Washing Machine Shield Cover with Thrice Slide⁃Drawing and Double T⁃Grooves［J］. Plastics Science and Technology， 2016， 44（1）：87⁃89.
14	刘庆东. 热流道复杂抽芯斜顶出双色注塑模具设计［J］. 中国塑料， 2018， 32（10）：138⁃142.
	LIU Q D. Design of Bi⁃Color Inj Ection Mould with Hot Runner， Complex Slides and Inclined Ej Ector［J］. China Plastics， 2018， 32（10）：138⁃142.
15	申开智. 塑料成型模具［M］. 3版. 北京：中国轻工业出版社， 2013： 79.

[1]	XU Yonglin, ZHANG Weihe, FENG Guoshu, SONG Dongyang, DU Hai, WANG Jing, WEI Haitao. Design of injection mold with complex core pulling and conformal cooling channel for smart kettle shell [J]. China Plastics, 2022, 36(6): 137-141.
[2]	GONG Meihua, ZHANG Xiaojuan, WEN Bianying. Research Progress in Preparation of Polypyrrole/Inorganic Nanoparticle Composites and their Electromagnetic Shielding Performance [J]. China Plastics, 2021, 35(5): 126-134.
[3]	LIU Hongyan. Design of Hot Runner Injection Mold with Two Types of Multiple Core⁃pulling Mechanisms for Booster Cylinder [J]. China Plastics, 2021, 35(1): 103-109.
[4]	Ligang DING, Guofei CHENG, Wenqiang WEI, Siqiao HU, Kaixiang GUO. Design of Front Mold Core Pulling Injection Mold with S⁃type Valve Chamber [J]. China Plastics, 2020, 34(8): 95-100.
[5]	Zhinan DONG, Fengxiang XU, Wei GUO, Lin HUA, Jianjun SU. Analysis of Opening Plate Injection⁃Molded by Short⁃Fiber⁃Reinforced Thermoplastic Composites Based on Mori⁃Tanaka Method [J]. China Plastics, 2020, 34(7): 61-68.
[6]	Fangfang LIU, Weihe ZHANG. Design of Large Precision Injection Mold for Rearview Mirror Base of Automobile [J]. China Plastics, 2020, 34(6): 87-91.
[7]	. Designof Hot-runner Bicolor Injection Mold for Valve Body Parts of Automobile [J]. China Plastics, 2019, 33(3): 93-96.
[8]	. Kinetic Study of Isothermal Melt and Non-isothermal Cold Crystallization of sPS/PBA-aPS Blends [J]. China Plastics, 2017, 31(7): 23-29 .
[9]	. Effect of Lacquer-seed-shell-fiber Content on Mechanical and Tribological Properties of Polyoxymethylene/Basalt Fiber Composites [J]. China Plastics, 2017, 31(4): 40-44 .
[10]	. Design of Injection Moulds with Antecedent Pushing out in Sloping Inserts of Core Molds for Printer Shells [J]. China Plastics, 2016, 30(12): 103-106 .
[11]	. Design of Injection Moulds for Blender’s Shells [J]. China Plastics, 2016, 30(10): 97-101 .
[12]	. Numerical Simulation and Experiment of the Influence of Delay Time on Gas Penetration in Gasassisted Injection Molding [J]. China Plastics, 2016, 30(08): 70-74 .
[13]	. Studies on Compatibility and Dispersibility of sPS/PBA-aPS Blend [J]. China Plastics, 2016, 30(04): 61-68 .
[14]	. Channelgroove Coupling Melting Model for Single Screw Extruders with a Grooved Melting Zone [J]. China Plastics, 2015, 29(10): 88-93 .
[15]	. Crystallization and Melting Behavior of sPS/PBA-aPS Blends [J]. China Plastics, 2015, 29(07): 46-52 .