In the manufacturing of New Energy Vehicle (NEV) motors, overmolding high-performance engineering plastics onto multiple stacked metal laminations (inserts) presents critical engineering challenges. During injection, the cumulative thickness tolerance of stacked steel laminations often leads to plastic flash or resin leakage. Furthermore, standard slider mechanisms are prone to scratching the delicate edges of the steel sheets. These microscopic defects can compromise insulation, degrade motor performance, and shorten the stator's operational lifetime.
To address these issues, we have engineered an innovative In-Mold Spring-Loaded Insert Technology. By incorporating a dynamic elastic compensation mechanism within the tooling, our system automatically self-adjusts for cumulative lamination tolerance variations during the clamping and injection cycles. This effectively seals the cavity, prevents flash, and eliminates slider-induced scratching, delivering clean, defect-free automotive overmolded parts.

1. Key Engineering and Technical Specifications

Molding a φ 87 * 67mm stator component with integrated inserts requires precise control over tolerances and material behavior:

• Stator Dimension and Geometries: Designed with a complex outer profile (φ 87 * 67mm), featuring an intricate undercut design that requires a stable demolding mechanism to ensure secure subsequent mechanical assembly.
• Overmolding Multi-Lamination Inserts: The component integrates multiple 0.2 mm ultra-thin steel laminations. Leveraging our hot-pressing process and customized tooling technology, the cumulative stack-up tolerance of these metal sheets is tightly controlled within ±0.5 mm.
• High-Performance Engineering Polymers: The stator uses PA66+GF15 (polyamide reinforced with 15% glass fiber). Compared to standard plastics, this material offers superior mechanical strength, dimensional stability, and long-term thermal resistance under harsh, high-vibration NEV operating conditions. thermal resistance under harsh, high-vibration NEV operating conditions.
  

  2. Custom Tooling and Engineering Solutions

  As an experienced china mold manufacturer, we implemented advanced design and processing methodologies to ensure high-yield, stable mass production:

• In-Mold Tolerance Compensation: Our design engineers developed a patented spring-loaded insert compensation mechanism. This system dynamically compensates for the variations in metal sheet thickness, preventing over-packing of the cavity and eliminating flash.
• Precision Slider Alignment: To protect the delicate edges of the 0.2 mm steel laminations, we engineered a high-precision slider guiding system. This ensures that the parting line interfaces close with minimal shear friction, completely preventing scratch marks on the inserts.
• Scientific Mold Flow Analysis: At the early stage of development, our engineering team conducted comprehensive mold flow simulations to locate gates and balance the injection pressure. This minimized internal stress on the thin-walled PA66+GF15 sections and prevented lamination displacement during the injection phase.
  

3. Proven Tooling Performance: Rapid Validation and Mass Production

Our robust engineering and precision machining processes have allowed us to bypass lengthy trial iterations and deliver immediate manufacturing readiness:

• High-Volume Production Approval at T3: The mold successfully passed all dimensional and functional criteria, transitioning directly to stable mass production after the T3 trial phase.
• Proven Automotive Track Record: This dynamic tolerance-compensation mold design has been successfully applied to a series of stator and rotor overmolded tools for global automotive brands, including Audi.
• Complete One-Stop Tooling Service: As a full-service china mold factory, we support automotive OEMs with collaborative DFM engineering, precision mold making, and advanced cleanroom molding services.
  
  If you are facing precision challenges in overmolding NEV structural or electrical components, partner with a premier china mold company dedicated to high-tolerance automotive manufacturing. Contact our engineering department today for a technical DFM review.
  Email: [email protected]
  Website: www.molds-maker.com