Liquid Supply Unit Outer Wall Geometry for Carriage Connection Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional liquid jetting devices face issues with securing a sufficient frictional force between the outer peripheral wall and the sealing member, leading to unstable connections between the liquid supply and introduction parts, particularly during carriage movement.

Innovation Solution

The design enhances the frictional force by modifying the outer peripheral wall geometry, including protrusions and contact areas, and adjusting the dimensions of the carriage and liquid supply unit components to ensure proper engagement and alignment, thereby stabilizing the connection between the liquid supply and introduction parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the outer peripheral wall is designed with conventional geometry, then the device structure is simple, but the frictional force between the outer peripheral wall and sealing member is insufficient, causing unstable connection during carriage movement

Engineering Contradiction:
Improveconnection stabilityVSAvoidouter peripheral wall geometry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The outer peripheral wall is designed with non-uniform cross-sectional geometry, creating different surface characteristics at different locations. Specifically, the wall has a first cross-section near the liquid supply part and a second cross-section away from it, where at least one cross-section features a curved surface with a specific radius of curvature. This local variation in geometry increases the contact area and frictional force between the outer peripheral wall and sealing member at critical locations, thereby improving connection stability without requiring complete redesign of the entire structure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The outer peripheral wall incorporates curved surfaces with specific radii of curvature (first radius R1 and second radius R2) at different cross-sections. These curved geometries provide better contact compatibility with the sealing member, increasing the frictional force and preventing relative displacement during carriage movement. The curved surfaces replace conventional flat or simple geometric shapes, creating optimal contact conditions for maintaining reliable liquid supply connection

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Reliability

If the outer peripheral wall area is increased to enhance frictional force, then the connection stability improves, but the device size increases

Engineering Contradiction:
Improveconnection stabilityVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

Instead of uniformly increasing the outer peripheral wall area throughout the entire structure, the invention applies increased surface area and curved geometry only at specific cross-sections where the wall contacts the sealing member. The first and second cross-sections have optimized curved surfaces with specific radii, while other portions of the structure maintain compact dimensions. This localized approach increases frictional force and connection stability without proportionally increasing the overall device volume

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

This configuration ensures a stable and secure connection between the liquid supply and introduction parts, preventing shifting and ensuring reliable ink supply during carriage movement, while also allowing for a more compact device design.

Implementation Method 1

a frictional force generated between an outer peripheral wall and a sealing member enables to suppress displacement of connection between a liquid supply part and a liquid introduction part

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3381695B1Liquid supply unit and liquid ejection device
Publication Date: 2023.01.04 SEIKO EPSON CORP
  • EP3381695B1 patent drawingFigure 1
  • EP3381695B1 patent drawingFigure 2
  • EP3381695B1 patent drawingFigure 3

AI summary

A liquid supply unit includes a first wall part to a seventh wall part. The first wall part includes a liquid supply part and an outer peripheral wall surrounding the liquid supply part and protruding in a direction from the second wall part toward the first wall part so as to come into contact with a sealing member of a carriage. The liquid supply part has a filter for supplying liquid to a liquid introduction part upon coming into contact with the liquid introduction part. A distance between the third wall part and the fourth wall part is larger than a distance between the fifth wall part and the sixth wall part. In a plan view in a direction from the first wall part toward the second wall part, a length of the outer peripheral wall in a first direction from the third wall part toward the fourth wall part is larger than a length in a second direction from the fifth wall part toward the sixth wall part. In a state of the liquid supply unit mounted on the carriage, the first direction is set along a moving direction of the carriage.