Negative Pressure Valve Layout for Ink Air and Debris Purging

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Solution Overview

Problem

Existing inkjet recording apparatuses face challenges in maintaining high print quality due to residue of air and solid matter in the outflow-side pressure chamber, which affects the ink ejection state.

Innovation Solution

A negative pressure regulation valve with an inflow-side and outflow-side pressure chamber, a communication hole, and a valve member that adjusts flow path resistance to efficiently discharge air and solid matter during the suction purge process, using first and second outflow holes with different diameters to manage fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single outflow hole is used in the outflow-side pressure chamber, then the structure is simple, but air and solid matter residue efficiently cannot be discharged

Engineering Contradiction:
Improvedischarge efficiency of air and solid matterVSAvoidstructure of outflow holes
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The outflow-side pressure chamber is divided into multiple outflow holes (first outflow hole and second outflow hole) positioned at different locations. This segmentation allows different substances (air and solid matter) to be discharged through different holes, improving discharge efficiency while maintaining reasonable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different outflow holes are given different characteristics (different positions, different flow path resistances) to suit different discharge needs. The first outflow hole has lower flow path resistance for efficient liquid discharge, while the second outflow hole is positioned to facilitate air and solid matter removal, creating local quality differences that solve the overall discharge problem

Inventive Principle:
Principle #3Local quality

2Productivity

If the first outflow hole has low flow path resistance for efficient liquid discharge, then liquid flow is improved, but air and solid matter may accumulate

Engineering Contradiction:
Improveliquid discharge efficiencyVSAvoidair and solid matter discharge
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The discharge function is segmented between two outflow holes: the first outflow hole handles liquid discharge with low flow path resistance for high productivity, while the second outflow hole handles air and solid matter discharge, ensuring both functions are performed effectively without interference

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first outflow hole is designed with specific local qualities (lower flow path resistance, positioned below the communication hole) to optimize liquid flow, while the second outflow hole has different local qualities (higher flow path resistance, positioned above the communication hole) to facilitate air and solid matter discharge, allowing each hole to excel at its specific function

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If the valve member closes the communication hole completely, then pressure regulation is precise, but air and solid matter become trapped in the outflow-side pressure chamber

Engineering Contradiction:
Improvepressure regulation precisionVSAvoidair and solid matter discharge
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The valve member provides precise closure of the communication hole for accurate pressure regulation, while the separately positioned second outflow hole (above the communication hole) remains accessible for air and solid matter discharge. This creates local quality differentiation where pressure control and contaminant discharge functions are spatially separated, allowing both to perform optimally

Inventive Principle:
Principle #3Local quality

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 suppresses the residue of air and solid matter, ensuring efficient ink discharge and reducing the risk of clogging, thereby maintaining consistent ink ejection and improving print quality.

Implementation Method 1

The valve member is inserted in the communication hole and movable, in accordance with change of pressure inside the outflow-side pressure chamber, between a closing position for closing the communication hole and an opening position for opening the communication hole

Methodology Applied
Scientific EffectPressure change: Pressure Gradient

Implementation Method 2

In a case where a first fluid flows out from the outflow-side pressure chamber via the first outflow hole and the second outflow hole, a first flow path resistance generated when the first fluid passes through the first outflow hole is lower than a second flow path resistance generated when the first fluid passes through the second outflow hole

Methodology Applied
Scientific EffectFlow path resistance: Drag

Data Source

PatentEP4624168A1Negative pressure regulation valve and inkjet recording apparatus including the same
Publication Date: 2025.10.01 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4624168A1 patent drawingFigure 1~2
  • EP4624168A1 patent drawingFigure 3~4
  • EP4624168A1 patent drawingFigure 5~6

AI summary

A negative pressure regulation valve (31) includes an inflow-side pressure chamber (50), an outflow-side pressure chamber (51), a communication hole (54), and a valve member (52). The valve member (52) is inserted in the communication hole (54) and movable, in accordance with change of pressure inside the outflow-side pressure chamber (51), to a closing position for closing the communication hole (54) and an opening position for opening the communication hole (54). The outflow-side pressure chamber (51) includes, as a liquid outflow hole (51a, 51b), a first outflow hole (51a) formed below the communication hole (54) and a second outflow hole (51b) formed above the communication hole (54). In a case where a first fluid flows out from the outflow-side pressure chamber (51) via the first outflow hole (51a) and the second outflow hole (51b), a first flow path resistance (R1) generated when the first fluid passes through the first outflow hole (51a) is lower than a second flow path resistance (R2) generated when the first fluid passes through the second outflow hole (51b).