Pressure Regulating Valve for Liquid Ejection Purging
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Solution Overview
Problem
Existing liquid ejection apparatuses face nozzle ejection failures due to viscous fluid, foreign matters, or air bubbles, and their purging mechanisms are ineffective in removing these obstructions, particularly when the open/close pressure differential of the pressure regulating valve is not optimally set.
Innovation Solution
A liquid ejection apparatus with a pressure regulating valve that can controllably regulate the open/close pressure differential, controlled by a controller to adjust the valve's opening based on suction pump operations during purging, allowing for effective removal of obstructions by varying the pressure differential between the fluid supply and the head units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the open/close pressure differential of the pressure regulating valve is set to a small value, then the valve opens early during purging operations, but this prevents creation of sufficient negative pressure for effective removal of obstructions from nozzles
Solution Approach 1:
The pressure regulating valve dynamically adjusts its open/close pressure differential based on operational mode. During purging operations, the controller increases the pressure differential threshold, allowing the valve to remain closed longer and maintain higher negative pressure for effective obstruction removal. During normal ejection, the valve operates at a lower threshold to maintain stable ink supply.
Solution Approach 2:
The system changes the pressure differential parameter of the valve based on operational requirements. The controller modifies the valve's pressure characteristics to match the current operation mode, enabling optimal performance for both purging and normal ejection by adjusting the pressure threshold at which the valve opens.
2Stress or pressure
If the open/close pressure differential is increased for effective purging, then greater negative pressure can be applied to nozzles, but the valve may fail to open timely during normal fluid ejection operations
Solution Approach 1:
The valve transitions from a static pressure threshold to a dynamic one, adjusting its opening characteristics based on the operational phase. During purging, the higher threshold is maintained for effective negative pressure. During normal operation, the controller adjusts the threshold downward to ensure timely valve response and maintain proper fluid flow speed.
Solution Approach 2:
The pressure regulating valve serves multiple functions by adapting its characteristics to different operational modes. It functions as a high-threshold valve during purging to maintain negative pressure, and as a low-threshold valve during normal ejection to ensure rapid response and appropriate fluid flow, making it universally applicable to both operations.
3Ease of operation
If a fixed pressure differential setting is used, then the valve operation is simple and stable, but it cannot adapt to different operational conditions requiring different pressure levels
Solution Approach 1:
The controller receives feedback regarding the operational mode (purging or normal ejection) and automatically adjusts the pressure regulating valve's differential setting accordingly. This feedback mechanism allows the system to maintain simple automatic operation while adapting the pressure characteristics to match current operational requirements, eliminating the need for manual intervention.
Solution Approach 2:
The system performs self-adjustment of the valve characteristics based on detected operational conditions. The controller automatically modifies the pressure differential threshold without requiring external intervention, enabling the valve to serve itself by adapting to different operational phases while maintaining ease of operation through automatic control.
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 solution enables effective purging by adjusting the pressure differential to suit the conditions of the nozzles, ensuring efficient removal of viscous ink, foreign matters, and air bubbles, thereby maintaining nozzle performance and reducing ink consumption.
Implementation Method 1
a suction pump is being operated to perform a first purging operation comprising creating a first negative pressure through suctioning by the suction pump to purge the fluid through the nozzle
Implementation Method 2
The pressure regulating valve is configured to open in response to an open/close pressure differential of the fluid across the pressure regulating valve
Data Source
AI summary
A liquid ejection apparatus is disclosed. One apparatus includes a nozzle through which fluid is ejected or purged, and a pressure regulating valve arranged upstream of the nozzle. The pressure regulating valve is configured to open in response to an open/close pressure differential of the fluid across the pressure regulating valve. The pressure regulating valve is configured to controllably regulate the open/close pressure differential. The apparatus further includes a controller configured to, when a suction pump is being operated to perform a first purging operation comprising creating a first negative pressure through suctioning by the suction pump to purge the fluid through the nozzle, control the pressure regulating valve to set the open/close pressure differential of the pressure regulating valve to a first value.