Foamable Sealing Structure for Electronic Device Waterproofing
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Solution Overview
Problem
Conventional electronic devices face issues with waterproofing and airtightness due to unstable sealing performance, particularly when exposed to water or low-temperature environments, as existing sealing rings are affected by cross-sectional shape and compression ratio, leading to potential damage from water ingress or temperature extremes.
Innovation Solution
A protective structure comprising a first and second housing member with a blocking unit that includes a sealing member and a foamable material, such as flexible ethylene vinyl acetate copolymer, which is compressed and undergoes a secondary foaming process to fill and seal the slits between the housing members, ensuring watertight, airtight, and dustproof properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing ring is positioned between housing shells to provide waterproofing and airtightness, then sealing function is provided, but the sealing performance is unstable and may be affected by cross-sectional shape and compression ratio
Solution Approach 1:
The patent changes the physical state of the sealing material from solid (traditional sealing ring) to foamable material that transitions from compressed state to expanded state. The foamable material undergoes parameter changes in volume and density through foaming, allowing it to adapt to different compression ratios and fill irregularities in the sealing space, thereby achieving stable sealing performance regardless of housing shell tolerances.
Solution Approach 2:
The sealing structure transitions from a static sealing ring to a dynamic foamable material system. The material dynamically adjusts its volume and shape during the foaming process, expanding to fill the sealing space and conform to the housing shell surfaces. This dynamic adaptation eliminates the need for precise cross-sectional shape control and compression ratio optimization.
2Reliability
If a traditional sealing ring is used, then the structure is simple, but water may penetrate into the electronic device through slits formed between the sealing ring and housing shells
Solution Approach 1:
The patent employs foamable material that creates a porous or cellular structure during foaming. This porous structure allows the material to expand and fill all voids, gaps, and slits between the housing shells and sealing member, creating a comprehensive barrier against water penetration while maintaining flexibility and seal integrity.
Solution Approach 2:
The sealing structure uses composite construction combining a sealing member (such as an O-ring) with foamable material. This composite system leverages the compression resistance of the sealing member and the gap-filling expansion capability of the foamable material, creating a multi-layered defense against water infiltration that addresses both primary sealing and secondary gap sealing requirements.
3Force
If the sealing ring compression ratio is increased to improve sealing, then sealing force is improved, but the sealing ring may deform or the housing shells may be damaged
Solution Approach 1:
The foamable material serves as a cushioning element between the sealing member and the housing shells. During assembly, the material is in a compressed low-volume state that allows easy insertion, then expands in-place to provide gradual, distributed sealing force. This beforehand cushioning prevents sudden high-force contact that could deform the sealing ring or damage the housing shells, while still achieving adequate sealing pressure.
Solution Approach 2:
The foamable material undergoes parameter changes in density and volume during the foaming process. The material transitions from a dense compressed state during assembly to a less dense expanded state after assembly, allowing the sealing force to be applied gradually as the material expands. This parameter change enables adequate sealing force without requiring high initial compression that could damage the housing shells.
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
The solution effectively enhances the sealing performance by completely sealing the slits between the housing members, improving the reliability of electronic devices against water, dust, and temperature-related damage, ensuring stable operation in harsh conditions.
Implementation Method 1
a first foamable material corresponding to the sealing member and implementing a primary foaming process to the first foamable material; connecting the first and the second housing members and compressing the sealing member and the first foamable material by the first and second housing members; and implementing a secondary foaming process to the first foamable material
Data Source
AI summary
A protective structure and an electronic device using the same are disclosed. The electronic device includes a first housing member, a second housing member, a blocking unit, and an operating module. The second housing member faces the first housing member, wherein a slit is located at the periphery of an enclosure disposed between the first and second housing members. The blocking unit, having a shape compatible with the shape of the slit, is disposed therein and includes a sealing member and a first foamable material. The sealing member is compressed by the first and second housing members, and the first foamable material is formed in the slit along an extending direction of the sealing member.