Refrigerator Inner Casing Shelf Support to Reduce Thermal Cracking
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Solution Overview
Problem
The manufacturing method of refrigerator inner casings using acrylonitrile butadiene styrene (ABS) sheets is prone to cracking due to thermal contraction stress, especially at the middle height of the storage space, which can lead to deformation and damage during cooling cycles.
Innovation Solution
The use of shelf seating protrusions and separate shelf seating members strategically positioned on the inner casing to distribute the load and reduce thermal contraction stress, with the protrusions formed at shorter lengths and the members being longer to support the shelf assemblies effectively, thereby reducing the risk of cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the inner casing is made thin to reduce material usage and cost, then manufacturing cost is reduced, but the inner casing becomes prone to cracking under thermal contraction stress
Solution Approach 1:
The support structure is segmented into multiple shelf seating protrusions distributed at different heights on the inner casing. This segmentation distributes the thermal contraction stress across multiple localized support points rather than concentrating it, allowing the casing to be thinner while maintaining cracking resistance.
2Adaptability or versatility
If shelf seating protrusions are formed at multiple heights to support shelves, then shelf support functionality is improved, but the inner casing thickness is reduced at these locations causing cracking
Solution Approach 1:
The inner casing is designed with varying local qualities - thicker at the shelf seating protrusion locations to provide structural support and resistance to thermal stress, and thinner in other areas to reduce material usage. This localized thickness variation maintains both strength where needed and material efficiency elsewhere.
3Temperature
If the storage space is cooled to below-zero temperatures to achieve freezing functionality, then refrigeration performance is improved, but thermal contraction stress increases causing cracking
Solution Approach 1:
The shelf seating protrusions are pre-formed during the molding process to provide structural reinforcement before the refrigerator undergoes cooling cycles. This preliminary structural preparation prevents the casing from developing cracks when thermal contraction stress occurs during subsequent freezing operations.
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 reduces the risk of cracking and deformation of the inner casing by distributing the load and managing thermal contraction stress, ensuring the structural integrity and longevity of the refrigerator.
Implementation Method 1
thermal contraction of the inner casing may occur during cooling, and stress concentrated at a specific area may cause cracking
Data Source
AI summary
A refrigerator has a shelf seating protrusion and a separate shelf seating member. The shelf seating protrusion is not formed at an approximate mid-point, height wise, of a storage space defined by an inner casing. The shelf seating member may be coupled to the inner casing to support a shelf assembly. An arrangement of the shelf seating protrusions and the shelf seating member is configured to reduce deformation and cracking of the inner casing due to thermal impact in a manufacturing process or when items are stored on the shelf assembly.