Liquid Discharging Head With Dynamic Flow Path Area Adjustment

Solution Overview

Problem

Existing liquid discharging heads face clogging issues due to particles in the liquid, particularly at the narrow cross-sectional areas of individual flow paths, which restrict efficient discharge and require restrictive particle size and concentration limits to prevent clogging.

Innovation Solution

Incorporating an adjustment portion with leaf springs in the relay flow paths that changes the cross-sectional area of the flow path based on pressure differences between the common liquid chamber and pressure chamber, allowing for increased flow area during pressurization and reduced area during discharge to prevent particle accumulation and ensure reliable liquid discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the cross-sectional area of the individual flow path is narrowed, then the liquid discharge efficiency is improved, but particles in the liquid may stay and clog the flow path

Engineering Contradiction:

Improveliquid discharge efficiencyVSAvoidflow path clogging

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies the dynamics principle by introducing an adjustment portion with a movable wall that can dynamically change the cross-sectional area of the flow path. The movable wall is positioned to be movable between a first position and a second position, allowing the flow path cross-sectional area to be adjusted from a first area to a second area. This dynamic adjustment capability resolves the contradiction by enabling the system to optimize for discharge efficiency when needed while preventing clogging when particle accumulation becomes an issue.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the cross-sectional area of the flow path is increased to prevent particle accumulation, then clogging is reduced, but liquid discharge efficiency decreases

Engineering Contradiction:

Improveparticle accumulation preventionVSAvoidliquid discharge efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The adjustment portion with the movable wall enables dynamic optimization of the flow path cross-sectional area. When particle accumulation is detected or anticipated, the movable wall can be positioned to increase the cross-sectional area to the second area, preventing clogging. When high discharge efficiency is the priority and particle accumulation is not an issue, the wall can be positioned to maintain the smaller first area, optimizing flow velocity and discharge performance.

Inventive Principle:

Principle #15Dynamics

3Productivity

If a fixed narrow flow path is used, then discharge efficiency is maximized, but the system cannot adapt to varying liquid conditions with different particle concentrations

Engineering Contradiction:

Improvedischarge efficiencyVSAvoidadaptability to different liquid conditions

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The adjustable flow path cross-sectional area provides adaptability to different liquid conditions. The movable wall can be repositioned based on the particle concentration and size in the liquid being discharged. For liquids with high particle concentrations, the wall can be moved to increase the cross-sectional area to prevent clogging. For liquids with low particle concentrations, the wall can be positioned to maintain the narrower cross-sectional area for optimal discharge efficiency.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameter of the flow path cross-sectional area to adapt to different operating conditions. By varying this physical parameter, the system can optimize performance for different liquid types and particle concentrations, transforming a fixed-parameter system into a variable-parameter system that responds to changing conditions.

Inventive Principle:

Principle #35Parameter changes

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 reduces the likelihood of clogging by adjusting the flow path area dynamically, enabling the use of liquids with larger particles and higher concentrations, and ensures reliable discharge from the nozzle by preventing pressure escape and maintaining efficient flow.

Implementation Method 1

When a pressure of the liquid inside the common supply flow path is higher than a pressure of the liquid inside the pressure chamber, the adjustment portion changes the cross-sectional area to be a first cross-sectional area when a pressure difference, which is a difference between the pressure of the liquid inside the common supply flow path and the pressure of the liquid inside the pressure chamber, is a first pressure difference, and changes the cross-sectional area to be a second cross-sectional area larger than the first cross-sectional area when the pressure difference is a second pressure difference larger than the first pressure difference.

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentUS11780225B2Liquid discharging head and liquid discharging apparatus

Publication Date: 2023.10.10 SEIKO EPSON CORP

AI summary

When a pressure of the liquid inside the common supply flow path is higher than a pressure of the liquid inside the pressure chamber, the adjustment portion changes the cross-sectional area to be a first cross-sectional area when a pressure difference, which is a difference between the pressure of the liquid inside the common supply flow path and the pressure of the liquid inside the pressure chamber, is a first pressure difference, and changes the cross-sectional area to be a second cross-sectional area larger than the first cross-sectional area when the pressure difference is a second pressure difference larger than the first pressure difference.