Liquid Supply Unit Valve Mechanism for Inkjet Printers
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Solution Overview
Problem
Conventional liquid supply units for inkjet printers face challenges in preventing ink leakage and ensuring stable ink supply to the ejection head, particularly when the negative pressure in the supply passage decreases, leading to inefficient ink distribution and potential clogging.
Innovation Solution
A liquid supply unit with a first and second chamber system, where the second chamber is set to negative pressure, utilizing a pressing member with a pivot fulcrum and a flexible film to adjust the opening/closing valve based on pressure changes, ensuring continuous ink flow and preventing backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional liquid supply unit uses a pressing plate directly attached to a flexible film to press a movable valve, then the structure is simple, but the valve cannot be reliably opened when negative pressure decreases, causing ink supply instability
Solution Approach 1:
The pressing member is designed to rotate about a pivot fulcrum, transforming the flexible film's linear displacement into rotational motion that amplifies the pressing force on the opening/closing member. This dynamic mechanism ensures reliable valve opening when negative pressure decreases, solving the ink supply stability problem while maintaining reasonable structural complexity
Solution Approach 2:
The solution transitions from a direct linear pressing arrangement to a rotational mechanism with a pivot fulcrum. By adding the rotational dimension, the system amplifies the displacement force from the flexible film and ensures sufficient pressing force on the opening/closing member to overcome biasing forces and open the valve reliably
2Object-generated harmful factors
If the negative pressure degree in the pressure chamber increases to prevent ink leakage, then ink leakage is suppressed, but the movable valve cannot open to replenish ink, causing supply interruption
Solution Approach 1:
The flexible film acts as a pressure-sensitive feedback element that automatically detects when negative pressure decreases (indicating ink depletion). The film's displacement triggers the pressing member to rotate and open the valve, allowing ink replenishment. This feedback mechanism dynamically balances leak prevention with timely replenishment
Solution Approach 2:
The system uses the pressure differential itself to activate the replenishment mechanism. When negative pressure decreases, the flexible film naturally displaces and drives the pressing member to open the valve, enabling the system to self-regulate ink flow without external control
3Reliability
If a biasing member is used to bias the opening/closing member toward closing posture, then the valve remains sealed under normal conditions, but insufficient pressing force prevents reliable opening when needed
Solution Approach 1:
The pressing member rotates about a pivot fulcrum, creating a mechanical advantage that amplifies the relatively small displacement force from the flexible film into a large pressing force on the opening/closing member. This dynamic leverage ensures the pressing force suffices to overcome the biasing member's closing force and reliably open the valve
Solution Approach 2:
By introducing rotational motion about a pivot fulcrum, the system transforms a linear displacement into a rotational lever action. This dimensional change creates mechanical advantage, multiplying the pressing force applied to the opening/closing member while maintaining reliable sealing when the valve is closed
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 manages pressure differences to prevent ink leakage and ensure stable ink supply to the ejection head, maintaining efficient printing operations and reducing the risk of clogging.
Implementation Method 1
The flexible film member is displaced based on a negative pressure generated as the liquid in the second chamber decreases
Implementation Method 2
The pressing member includes a pivot fulcrum, a pressure receiving portion configured to receive the displacement force from the flexible film member and a pressing portion configured to press the opening/closing member against a biasing force of the biasing member. The pressing member rotates about the pivot fulcrum when the pressure receiving portion receives the displacement force
Data Source
AI summary
A liquid supply unit includes a first chamber communicating with a liquid storage container, a second chamber communicating with a liquid ejection head, a communication opening allowing communication between the both chambers, an opening/closing member configured to open and close the communication opening, a biasing member configured to bias the opening/closing member in a direction toward the closing posture, a pressing member capable of pressing the opening/closing member in a direction toward the opening posture, and a flexible film member configured to be displaced based on a negative pressure. The pressing member includes a pivot portion, a pressure receiving portion configured to receive the displacement force from the flexible film member and a pressing portion configured to press the opening/closing member. The pivot portion is arranged on one end side of the pressing member, and the pressing portion is arranged on the other end side of the pressing member.