Flow Path Unit O-Ring Sealing Against Contamination-Induced Leakage
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Solution Overview
Problem
Existing flow path units in liquid ejection apparatuses are prone to liquid leakage due to foreign substances entering between the O-ring and the contact surface, leading to compromised sealing performance.
Innovation Solution
A flow path unit design featuring a first and second flange with an O-ring annularly surrounding the flow path, a contact surface with recessed portions, and a liquid gasket disposed on the contact surface to wrap around foreign substances, enhancing sealing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an O-ring and contact surface are provided at the coupling portion of flanges, then sealing function is achieved, but liquid leakage occurs when foreign substances enter between the O-ring and contact surface
Solution Approach 1:
A liquid gasket is introduced as an intermediary substance between the O-ring and the contact surface. This liquid gasket fills the gaps and prevents foreign substances from compromising the sealing function, thereby resolving the contradiction between achieving sealing and preventing leakage when foreign substances are present.
2Reliability
If a liquid gasket filling groove is formed around the fitting groove, then sealing is improved, but the fitting groove and liquid gasket filling groove are separately formed at positions separated from each other, leaving vulnerability to foreign substances
Solution Approach 1:
The contact surface and liquid gasket filling groove are merged into a single integrated structure. The liquid gasket filling groove is formed as part of the contact surface itself, eliminating the need for separate grooves and ensuring continuous sealing protection against foreign substances while simplifying the overall structure.
3Ease of manufacture
If the contact surface is made flat for simple manufacturing, then manufacturing ease is improved, but gaps occur when foreign substances enter between the O-ring and contact surface
Solution Approach 1:
While maintaining an overall flat contact surface for ease of manufacturing, a liquid gasket filling groove is locally formed at the critical sealing position. This localized modification provides gap-filling capability where needed without requiring the entire contact surface to be complex, thus balancing manufacturing simplicity with sealing reliability.
Data Source
AI summary
A flow path unit includes a first flange including a part of a flow path, and a second flange detachably coupled to the first flange and including a part of the flow path, wherein the first flange includes a facing surface that faces the second flange when the second flange is coupled to the first flange, the facing surface is provided with an O-ring annularly surrounding the flow path, a contact surface being in contact with the O-ring annularly surrounding the flow path, and a liquid gasket disposed on the contact surface, and the contact surface is provided with at least one recessed portion.