Design of two⁃step demolding injection mould for door inner panel of new energy vehicles

doi:10.19491/j.issn.1001-9278.2025.06.018

Abstract

Abstract:

This work presents the development of a large⁃scale injection mold incorporating sequential valve⁃gated hot runner （SVGHR） technology. There are two key challenges addressed， which included high clamping force and demolding complexity. A two⁃stage ejection system resolved excessive clamping force on the horn mesh structure and facilitated reliable part release. Integrated support columns within the part geometry eliminated the deformation caused by inclined ejector pin forces during demolding. SVGHR control ensured uniform filling of the large mold cavity， mitigating flow⁃related defects. A multi⁃channel cooling system with 24 interconnected circuits， including through⁃type， angled， and baffle⁃cooled wells， achieved rapid， balanced cooling through optimized vertical/horizontal routing. Production trials confirmed the dimensional accuracy of molded parts meeting MT3 standards according to the national standard GB/T14486—2008. Cycle time was reduced by 10 % compared to conventional molds.

Key words: new energy vehicles, door inner panel, supersized injection mould, two?stap demolding, sequential valve gate technology, the core pulling mechanism, positioning column

CLC Number:

TQ320.66⁺2

LI Qingan, ZHANG Weihe. Design of two⁃step demolding injection mould for door inner panel of new energy vehicles[J]. China Plastics, 2025, 39(6): 105-109.

Figures/Tables 9

Fig.1. Door inner panel of new energy vehicles

Fig.2. Injection mold stracture of the vehicles door inner panel

Fig.3. Mold formed parts

客户名称	E	F	C	D
佛吉亚	170	180	190	220
铃木	160	170	170	190
伟世通	140	150	150	180
实验模具	90	100	100	120

Tab.1. Reference size of the mold strength of automobile door inner plate

Fig.4. Hot runner gating system with ten gates

Fig.5. The core pulling mechanism

Fig.6. Cooling system of the injection mold

Fig.7. Mold guidance positioning system and two⁃stap demolding mechanism

Fig.8. Exhaust system of the injection mould

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