New energy battery upper cover is a core protective structural part of battery modules, integrating multiple functions such as sealing, fixing, insulation and safety protection. The product has a large overall size and complex structural details. In the formal injection molding process, various embedded parts such as metal nuts, reinforcing steel sheets and conductive copper sheets need to be pre-embedded. The positioning accuracy of embedded parts directly determines the sealing performance, locking strength and electrical safety of battery module assembly. Traditional molds generally adopt simple positioning structures. Under the combined influence of high-pressure melt scouring, long-term mold opening and closing vibration and manual placement errors, embedded parts are prone to offset, floating, inclination and excessive depth deviation. These defects seriously restrict the mass production yield and operation stability. Through comprehensive optimization of positioning structure, limiting mode, material coordination and anti-floating mechanism, the positioning deviation defects of embedded parts can be effectively solved, and the mold stability, durability and mass production adaptability can be improved to meet the high-precision manufacturing requirements of new energy industry.
1. Common Positioning Defects of Embedded Parts in Battery Cover MoldsMost battery upper covers are made of flame-retardant modified engineering plastics. There are many types of embedded parts with scattered distribution, which put forward high requirements for the universality and precision of mold positioning structures. The traditional single pin positioning has weak limiting ability. After long-term friction and impact, the matching gap gradually increases, resulting in inclination and left-right offset of embedded parts, further leading to eccentric mounting holes and poor assembly locking effect. The lateral thrust generated by high-pressure injection makes the thin positioning structure unable to resist deformation, causing embedded parts to sink or retreat, and resulting in excessive wrapping glue and local flash. The lack of profiling limit and auxiliary locking structure leads to low efficiency of manual placement, and frequent problems such as misplacement, shallow placement and missing placement. In addition, special-shaped thin embedded parts are easy to twist and deform during filling, and the aging and wear of positioning inserts will increase the frequency of mold maintenance.
2. Core Design Concept of Embedded Parts Positioning Optimization
The optimization design takes high-precision positioning, impact resistance and anti-floating, wear resistance and convenient operation as the core. Abolishing the old single-point positioning mode, an integrated optimization scheme of composite limit, profiling wrapping, elastic locking and wear-resistant matching is adopted. On the premise of controlling mold modification cost and not greatly changing the main structure of the original mold, multi-dimensional constraint of up-down, left-right and front-back directions is strengthened to buffer the instantaneous impact force of melt injection. The human-computer operation adaptability is optimized to reduce the difficulty and error rate of manual placement. The overall scheme takes into account structural stability and later maintenance convenience, adapts to long-term continuous production, and reserves space for automatic transformation to meet the intelligent production development trend of new energy industry.
3. Key Optimization Scheme of Positioning Structure3.1 Step-type Composite Limiting Structure
The traditional straight-through positioning pin is replaced by double-layer stepped positioning inserts. The lower section adopts micro-gap sliding fit to control lateral deviation, and the upper section is provided with limit steps to fit the contour of embedded parts. The step surface resists lateral melt pressure in a rigid manner to restrict floating and deflection, ensuring the verticality and flatness of embedded parts and avoiding threaded hole inclination.
3.2 Profiling Wrapping Limit for Special-shaped Embedded Parts
Integrated profiling wrapping inserts are customized for thin steel sheets and conductive copper sheets. Reasonable avoiding gaps are reserved to ensure smooth picking and placing. The semi-enclosed limit restrains bending and twisting deformation. The integrated processing reduces splicing gaps and prevents flash and mold jamming caused by melt penetration.
3.3 Elastic Tightening Anti-retreat Auxiliary Mechanism
Small spring tightening components are added on the non-appearance side. The elastic force keeps the embedded parts tightly positioned after placement to offset the vibration displacement during mold opening and closing. The elastic structure buffers the injection load, reduces the rigid wear of positioning parts, and features compact layout and low replacement cost.
3.4 High-precision Wear-resistant Matching and Material Upgrade
All positioning parts are made of high-hardness wear-resistant mold steel with heat treatment and precision grinding. The matching gap is standardized and controlled to ensure smooth placement and stable positioning. Guide chamfers are optimized to reduce scratching and pressing damage of embedded parts and improve embedding quality.
4. Practical Effect after OptimizationAfter the optimization of positioning components, the abnormal problems such as offset, floating and deformation of embedded parts are completely improved. The dimensional accuracy of key positions is stable and up to standard. The rigid limit and elastic buffer composite design slow down the wear rate of inserts, reduce shutdown maintenance and rework costs. The standardized limit structure reduces human errors, stabilizes production rhythm, and ensures the assembly performance and safety of battery upper covers. The optimized design has strong universality and can provide effective reference for the structural upgrading of similar embedded molds for new energy parts.
