Liquid Ejection Head Sealing via Segmented Reinforcement Plate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to maintain high sealability in liquid ejection heads with increased size and filler content, which affects the negative pressure and weldability, leading to potential liquid return and supply issues.
Innovation Solution
The design incorporates a hollow casing with a lid member and liquid guide grooves on both the lid member and casing, allowing fluid communication to enhance sealing reliability, using a vibration welding method to join the components and minimize air gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the mixing amount of filler in the resin is increased to strengthen the casing and improve recording speed, then the strength and stiffness of the casing is improved, but the weldability between the casing and lid member is lowered, resulting in insufficient sealability to maintain negative pressure
Solution Approach 1:
The patent introduces a separate reinforcement plate that is welded to both the casing and the lid member. This segmentation approach allows the filler content to be optimized for strength while the reinforcement plate provides the necessary weldability and sealability, resolving the contradiction between strength and ease of manufacture.
Solution Approach 2:
The patent uses a composite structure combining the resin material (with optimized filler content for strength) and the reinforcement plate (made of weldable material). This composite approach allows each material to contribute its advantageous properties: the resin provides strength and stiffness, while the reinforcement plate provides weldability and sealability.
2Productivity
If the liquid ejection head is increased in size to improve recording speed, then the liquid ejection amount per unit time is increased, but the negative pressure required for smooth liquid supply is large, requiring sealing with higher reliability
Solution Approach 1:
The reinforcement plate is welded to both the casing and the lid member, creating multiple sealing interfaces. This segmentation approach distributes the sealing requirement across multiple locations, enhancing overall sealing reliability to maintain the higher negative pressure needed for increased liquid ejection capacity.
Solution Approach 2:
The composite structure of the reinforcement plate welded to the casing and lid member creates a more robust sealing system. This composite approach provides higher reliability sealing that can maintain the increased negative pressure required for high-volume liquid ejection.
3Strength
If the mixing amount of filler is increased to further increase the strength of the casing, then the stiffness and strength are improved, but the sealability that can maintain predetermined negative pressure cannot be obtained
Solution Approach 1:
The reinforcement plate creates additional sealing interfaces between the casing and lid member. This segmentation allows the filler content to be optimized for strength while the reinforcement plate ensures sealability by providing multiple points of sealing that can maintain the required negative pressure.
Solution Approach 2:
The composite structure combines the strength-providing resin material with the sealability-providing reinforcement plate. This composite approach resolves the contradiction by allowing each material to optimize for its primary function while working together to achieve both strength and sealability.
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 effectively maintains negative pressure and prevents liquid return, ensuring reliable liquid supply and improved sealing even with increased size and filler content, maintaining the meniscus to cover air gaps and prevent leakage.
Implementation Method 1
liquid in an amount equivalent to an amount of liquid having been ejected is supplied by negative pressure from a liquid container (liquid tank) to the liquid ejection head
Implementation Method 2
a first liquid guide groove formed in an upper surface of the member which is a surface onto which the liquid supplied through the liquid supply port is to be dropped, and the casing has a second liquid guide groove formed in a side wall inner surface of the casing
Implementation Method 3
the casing and the lid member are joined to each other by, for example, an ultrasonic welding method or a vibration welding method
Implementation Method 4
maintaining the meniscus to cover air gaps and prevent leakage
Data Source
AI summary
A liquid ejection head includes: a casing, which is hollow, and has an opening at one end; a lid member, which is fixed to an end portion of the opening of the casing; and a member arranged inside the casing. The lid member has a liquid supply port. The member has a first liquid guide groove, and the casing has a second liquid guide groove. The second liquid guide groove extends from the end portion of the opening to a side opposite to the opening in the side wall inner surface of the casing, the first liquid guide groove extends to a side surface of the member which is in contact with or close to the side wall inner surface of the casing, and the first liquid guide groove and the second liquid guide groove are located so as to allow fluid communication therebetween.