Resin Molded Component Flange Weld Line Suppression
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Solution Overview
Problem
Resin-molded components with through-holes face challenges in achieving reduced weight and high rigidity due to the formation of weld lines during the molding process, which can lead to reduced rigidity and increased weight.
Innovation Solution
Forming concave portions on the flange surface upstream of the weld line with a greater thickness at the bottom portion compared to the thinnest wall portion, allowing more molten resin to flow into the periphery of the through-hole, thereby reducing or eliminating the weld line and enhancing rigidity while minimizing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the thickness of resin material is reduced to form concave portions, then weight is reduced, but rigidity is compromised at the weld line
Solution Approach 1:
The patent applies local quality by creating a thickness variation within the concave portion: the bottom portion has a first thickness while the wall portion has a second thickness that is smaller than the first. This localized thickness differentiation allows weight reduction in the wall area while maintaining sufficient material at the bottom to support the weld line and preserve rigidity.
2Weight of moving object
If concave portions are formed by reducing resin thickness, then weight is reduced, but weld line formation is exacerbated
Solution Approach 1:
The patent addresses weld line formation through local quality by making the bottom portion of the concave portion thicker than the wall portion. This localized thickness control modifies the resin flow pattern, allowing sufficient material to reach the weld line area and reducing the harmful effects of weld line formation while still achieving weight reduction through the thinner wall portions.
3Weight of moving object
If the resin material flow amount is small in certain portions, then weight is reduced, but the weld line rigidity is further reduced
Solution Approach 1:
The patent resolves this contradiction by implementing local quality with differentiated thicknesses: the bottom portion of the concave portion has a first thickness that ensures sufficient resin flow and weld line integrity, while the wall portion has a smaller second thickness for weight reduction. This localized thickness control ensures that critical areas receive adequate material flow while non-critical areas are optimized for weight.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively suppresses the formation of weld lines, increasing the rigidity of the resin-molded component while reducing its weight, even in configurations where the likelihood of reduced rigidity is high, such as with glass fiber-reinforced resin materials.
Implementation Method 1
pressurized molten resin material is injected into a die
Implementation Method 2
After the resin material has hardened
Data Source
AI summary
A resin molded component includes a flange having a through-hole. A concave portion is formed on the surface of the flange that faces the component on which the flange is fitted. Flows of a molten resin material meet each other at a meeting portion in a region around the through-hole during a molding process, and a weld line is formed at the meeting portion. The concave portion is formed upstream of the meeting portion at which the flows of the molten resin material meet each other, and in the vicinity of the through-hole. The thickness of the resin material in the bottom portion of the concave portion is greater than the thickness of the resin material in the thinnest portion of the wall of the concave portion.