Ink Jet Head Maintenance via Selector Valve and Low-Viscosity Liquid
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Solution Overview
Problem
Ink jet systems face issues with poor fluidity due to high viscosity, leading to inefficient maintenance and wasteful consumption of expensive ink, along with air entrainment and bubble formation during pressure changes, which affect ejection performance.
Innovation Solution
A novel structure with a selector valve and flow passage block that minimizes the length of communication passages between the liquid changing-over mechanism and the ink jet head, allowing for selective supply of ink, cleaning liquid, or pressurized air to facilitate efficient maintenance, using a low-viscous liquid to fill the ink jet head and remove air bubbles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If ink containing solid components is used, then the ink provides necessary pigment content, but the fluidity becomes poor due to high viscosity and filling time increases
Solution Approach 1:
A low-viscous liquid is introduced as an intermediary substance to facilitate ink filling. The low-viscous liquid is supplied through the liquid supply passage to the ink jet head, enabling smooth filling while the ink is subsequently supplied through the ink supply passage. This intermediary approach resolves the contradiction by allowing high-pigment ink to be filled efficiently without compromising fluidity.
2Ease of operation
If maintenance is performed with the cap removed after negative pressure generation, then the cap can be accessed, but air pressure abruptly changes causing ink oscillation and air bubble entrainment
Solution Approach 1:
The equalization hole is provided in advance within the cap structure, allowing air pressure to equalize between the cap interior and exterior before the cap is removed. This preliminary action prevents abrupt pressure changes that would cause ink oscillation and air bubble entrainment, thereby maintaining ejection performance reliability while still allowing cap accessibility for maintenance.
3Adaptability or versatility
If a long flow passage is used between the liquid changing-over mechanism and the ink jet head, then the mechanism can be positioned remotely, but ink wastage increases and maintenance time extends
Solution Approach 1:
The flow passage is segmented into multiple sections with the liquid changing-over mechanism divided into first and second parts positioned at different locations. The first liquid supply passage connects to the first part while the second liquid supply passage connects to the second part, allowing flexible positioning while minimizing overall passage length. This segmentation resolves the contradiction by enabling remote positioning without excessive ink wastage or maintenance time.
4Force
If the cap is made to closely contact the nozzle surface, then sealing is improved and suction force increases, but any misalignment causes air leakage and insufficient suction
Solution Approach 1:
The cap is designed with a curved surface that locally adapts to the nozzle surface geometry. The equalization hole is positioned at a specific location on the cap where it can effectively equalize pressure while maintaining close contact. This local quality approach ensures consistent suction force while preventing air leakage, resolving the contradiction between sealing effectiveness and suction reliability.
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 approach reduces ink wastage and maintenance time, ensuring reliable ink ejection performance by using a low-viscous liquid to fill the ink jet head and remove air bubbles before filling with ink, thus enhancing the maintainability and efficiency of the ink jet head.
Implementation Method 1
a low-viscous liquid to fill the ink jet head and remove air bubbles
Implementation Method 2
a negative pressure suction pump is operated to cause a negative pressure suction force to act on the nozzle surface of the ink jet head
Data Source
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AI summary
Object: To provide an ink jet ejection head and an apparatus including the ink jet ejection head, which are suitable for realizing maintenance of an ink jet head in such a manner as restoring ink ejection performance and ensuring satisfactory application free from an ejection failure in one or more nozzles. Solving Means: An ink jet ejection head of a liquid material application apparatus, comprising an ink jet head, a head holding member for holding the ink jet head in a detachable manner, and a changing-over mechanism connected to a liquid supply passage and a pressurized air supply passage, wherein the changing-over mechanism selectively supplies one of a liquid and pressurized air to the ink jet head. The liquid material application apparatus includes the ink jet ejection head.