Ventilation member
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Solution Overview
Problem
Conventional ventilation members for housings with electronic components are prone to cracking on the inner circumferential surface of the insertion portion at the root, leading to potential detachment from the housing.
Innovation Solution
The ventilation member design includes a support with a vent hole and an air-permeable membrane, featuring a leg portion with insertion portions separated by slits and receding portions between the inner and outer circumferential surfaces at the root, which reduces stress concentration and prevents cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insertion portions are elastically deformed radially inwardly and inserted into the opening for fixation, then the ventilation member can be securely attached to the housing, but the inner circumferential surface of the insertion portion may crack due to stress concentration
Solution Approach 1:
The insertion portion is segmented by forming a slit that divides it into multiple insertion regions. This segmentation allows the material to deform more uniformly during insertion, distributing the stress and preventing stress concentration at any single point on the inner circumferential surface, thereby preventing cracks while maintaining secure attachment.
Solution Approach 2:
A receding portion is formed locally at the root of the insertion portion, creating a stepped structure where the thickness varies. This local quality change provides a stress relief zone that prevents stress concentration at the critical root area, reducing the risk of cracking during elastic deformation and insertion while preserving the necessary attachment strength.
2Ease of manufacture
If the insertion portion is made with uniform thickness for ease of manufacture, then production is simpler, but stress concentrates at the root causing cracks
Solution Approach 1:
Instead of maintaining uniform thickness throughout, a receding portion is introduced at the root of the insertion portion, creating a localized thickness variation. This stepped structure provides stress relief at the critical root area, preventing cracks during installation while the rest of the insertion portion maintains sufficient thickness for secure attachment. The design balances manufacturing feasibility with reliability.
Solution Approach 2:
The insertion portion is divided into segments by forming a slit, which creates multiple thinner regions that are less prone to stress concentration. This segmentation approach allows the structure to flex more easily during insertion without developing cracks, while still providing adequate attachment strength through the distributed structure.
3Strength
If the insertion portion is made thinner to reduce stress, then crack risk decreases, but attachment strength is reduced
Solution Approach 1:
The receding portion creates a stepped thickness profile where the root area has reduced thickness for stress relief and crack prevention, while the main body of the insertion portion maintains sufficient thickness for secure attachment. This local quality variation optimizes both crack resistance and attachment strength simultaneously.
Solution Approach 2:
By dividing the insertion portion into multiple segments through slits, the effective thickness at any single location is reduced, lowering stress concentration and crack risk. However, the cumulative attachment surface area and distributed structure compensate for the reduced local thickness, maintaining overall attachment security.
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 design effectively prevents cracks on the inner circumferential surface of the insertion portion at the root, ensuring secure attachment and reduced risk of detachment while maintaining airflow through the housing.
Implementation Method 1
the receding portion recedes from an imaginary circumferential end surface in a direction away from the slit and recedes from an imaginary inner circumferential surface toward the outer circumferential surface, the stress is less likely to concentrate on the inner circumferential surface of the insertion portion at the root thereof
Implementation Method 2
the insertion portions being adapted to be elastically deformed radially inwardly when the insertion portions are inserted into the opening and then to be fixed to the opening
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The ventilation member (10) of the present invention includes: a support (4); and an air-permeable membrane (2) disposed on the support (4). The support (4) includes: a base portion (11) supporting the air-permeable membrane (2); and a leg portion (12) extending from the base portion (11) toward the interior space (22) of a housing (20) and adapted to fix the ventilation member (10) to the opening (21) of the housing (20). The leg portion (12) includes: insertion portions (31) separated from each other in a circumferential direction by slits (32) formed between the insertion portions (31) in an insertion start side of the leg portion (12), the insertion portions (31) being adapted to be elastically deformed radially inwardly when the insertion portions (31) are inserted into the opening (21) and then to be fixed to the opening (21); and receding portions (33) in the insertion portions (31). In a region between an edge of an inner circumferential surface (31C) of the insertion portion (31) and an edge of an outer circumferential surface (31E) of the insertion portion (31) at a root (31A) of the insertion portion (31), the receding portion (33) recedes from an imaginary circumferential end surface (Q) in a direction away from the slit (32) and recedes from an imaginary inner circumferential surface (R) toward the outer circumferential surface (31E), when the imaginary circumferential end surface (Q) is defined as an imaginary end surface including a central axis (O) of the support (4) and a first reference line (P) parallel to the central axis (O) and passing through the edge of the outer circumferential surface (31E) and the imaginary inner circumferential surface (R) is defined as an imaginary surface extending in the circumferential direction from the edge of the inner circumferential surface (31C) toward the slit (32).