Integrally Molded Foam Body with Localized Thickness Variation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vehicle interior members, such as door trims, face challenges in achieving high design quality due to uneven geometries resulting from insert members, which can be concealed only by increasing product thickness, thereby compromising weight and practicality.
Innovation Solution
An integrally-molded body with a sheet-shaped molded foam and an insert member, where the insert member's extension portion is buried in the foam, and the foam includes a thicker first portion and a thinner second portion with a groove along their boundary, manufactured using a method involving a first and second mold where the foamed resin is vacuum suctioned to expand and form a gap, allowing the insert member to be buried without protruding on the design surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the thickness of the molded body is increased to conceal uneven geometry from insert members, then the design quality is improved, but the weight of the product increases
Solution Approach 1:
The molded foam has different thicknesses in different regions: a first thickness in the region corresponding to the insert member and a second thickness in other regions, where the first thickness is greater than the second thickness. This local variation in thickness conceals the uneven geometry caused by the insert member only where needed, while maintaining overall lightweight design.
Solution Approach 2:
The invention addresses the surface unevenness problem by adding thickness in the thickness dimension rather than increasing overall product dimensions. By creating a localized thick portion that protrudes toward the first surface, the uneven geometry is concealed without increasing the product's planar footprint.
2Ease of manufacture
If a single-wall body structure is used, then the manufacturing process is simplified, but uneven geometry from insert members appears on the design surface
Solution Approach 1:
The single-wall molded foam structure incorporates a localized thick portion with greater thickness in the region corresponding to the insert member. This local thickness variation conceals the uneven geometry on the design surface while maintaining the simplicity of a single-wall structure throughout the rest of the body.
3Manufacturing precision
If the thickness of the molded foam is increased to conceal uneven geometry, then the design quality is improved, but the material consumption increases
Solution Approach 1:
The molded foam has different thicknesses in different regions: a first thickness in the region corresponding to the insert member and a second thickness in other regions. This localized thickening conceals uneven geometry only where needed, minimizing overall resin consumption compared to uniformly increasing thickness.
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 approach prevents the exposure of uneven geometries on the design surface, maintaining high design quality while keeping the product lightweight and practical by using foamed resin, which allows for increased thickness without weight penalties.
Implementation Method 1
the foamed resin is vacuum suctioned by both of the first and second molds in a state where the first and second molds are close to each other to provide a gap greater than a thickness of the foamed resin between the first and second molds and accordingly is expanded to a thickness of the gap
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to a method for manufacturing a structure that is provided, it is possible to prevent creases on a skin sheet when the skin sheet and a molten resin sheet are integrally molded using a mold. The method provided by the present invention is a method for manufacturing a structure including the step of integrally molding a skin sheet and a molten resin sheet using a mold. The molding is performed with the skin sheet under tension.