Large and Complex Mold Design for Robot Vacuum Cleaners

A robot vacuum cleaner, also known as an automatic cleaning machine, intelligent vacuum, or robotic vacuum, is a type of smart home appliance. It uses artificial intelligence technology to automatically complete floor cleaning tasks indoors. Robot vacuums typically clean by brushing and vacuuming, sucking debris from the floor into a built-in dustbin to achieve floor cleaning. Due to their ease of operation and convenience, robot vacuum cleaners have become widely popular and are commonly used smart appliances in modern homes and office environments.

Part Appearance Requirements and Structural Analysis

The figure below shows the part drawing of a robot vacuum cleaner’s foot cover from a renowned brand. The material is ABS, classified as a cosmetic component. Part dimensions: Ø327.5 × 61.3 mm. Key features include:

1. Appearance Requirements: The cosmetic surface must be free of defects such as spots, sink marks, weld lines, and flash.
2. Undercut Design: One undercut exists on the inner side of the part, necessitating a slider or angled lifter mechanism.
3. Structural Complexity: The large part contains multiple shut-offs, pin holes, and ribs, requiring extensive use of inserts in the core/cavity.

Gating System Design

• Layout: 1×1 cavity arrangement with a four-point sub-gate system.
• Gate Details: Three gates transition from sub-gates to main gates (commonly termed “sub-to-main gate conversion”), while one gate is directly positioned on the part’s outer surface. Gates are located at the parting line and shut-off surfaces to ensure balanced filling.

Side Core-Pulling Mechanism Design

• Undercut Resolution: The undercut on the inner side (fixed mold half) is addressed using an internal slider mechanism.
• Slider Design Considerations:
  • The angle pin must fully seal against plastic leakage.
  • A tapered front edge on the angle pin prevents flash formation due to injection pressure.

Results and Discussion

This mold employs an innovative “fixed mold internal slider” structure, offering significant reference value for similar designs. Key outcomes include:

• Smooth demolding and reliable mechanical motion during long-term production.
• Stable part dimensions and seamless assembly post-molding.
• High customer satisfaction due to consistent quality and economic efficiency.