Stepped Speaker Grille Holes to Prevent Mold Pin Misalignment
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Solution Overview
Problem
Conventional speaker grilles with resin-molded through holes often suffer from misalignment and deformation of mold pins, leading to aesthetic defects such as burrs and clogging, due to slender mold pins and inadequate strength, which existing solutions have not fully addressed.
Innovation Solution
The speaker grille design features mold pins on both the stationary and movable sides of the mold, with distal end faces of different shapes and sizes to reduce misalignment and deformation, creating a stepped portion that prevents the appearance of burrs and enhances strength by ensuring consistent pressure and shape during resin injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the through holes in the speaker grille are small in size, then the number of through holes can be increased to improve sound quality, but the length of the mold pins becomes greater than their diameter making them slender and weak, which causes misalignment and deformation during injection molding
Solution Approach 1:
The mold pin structure is segmented into two separate mold pins from opposite sides (stationary half and movable half) that meet in the middle, rather than using one long mold pin. This segmentation reduces the length of each individual mold pin while still achieving the same through-hole formation function, thereby preventing deformation and misalignment.
2Manufacturing precision
If the mold pins are made longer to form small through holes, then the through holes can be formed properly, but the mold pins become slender and prone to misalignment and deformation, resulting in aesthetic defects such as burrs
Solution Approach 1:
The single long mold pin is segmented into two shorter mold pins positioned on opposite sides of the mold. Each shorter mold pin has sufficient strength and rigidity to resist deformation during injection, preventing burr formation while still achieving proper through-hole formation.
Solution Approach 2:
The distal end faces of the mold pins are designed with different sizes to create a stepped portion at the inner end of the through holes. This local structural variation prevents resin overflow and burr formation at critical locations while maintaining proper through-hole geometry.
3Object-generated harmful factors
If mold pins are used on both stationary and movable sides with different distal end face sizes, then the stepped portion prevents burrs and improves appearance, but the device complexity increases
Solution Approach 1:
The mold structure is divided into stationary and movable halves, each equipped with their own mold pins. This segmentation allows independent optimization of each mold pin's geometry and positioning, enabling the creation of the stepped portion feature while distributing the complexity across two separate, manageable components.
Data Source
AI summary
A speaker grille has a grille base, a plurality of front through holes formed on a front side of the grille base, and a plurality of back through holes formed on a back side of the grille base, each of the plurality of front through holes communicating with one of the plurality of back through holes at its inner end. The front through holes are smaller than the back through holes at the inner ends. Such speaker grille is formed by injection-molding a resin using a mold having a stationary half provided with a plurality of stationary side mold pins, and a movable half provided with a plurality of movable side mold pins. The stationary half is designed to form a front side of the speaker grille. The stationary mold pins have distal end faces that are smaller than distal ends faces of the movable mold pins.