Ink Delivery Backpressure Control With Passive Valve and Pump
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inkjet printing systems face challenges in maintaining consistent ink pressure across multiple printheads, leading to high costs due to the need for expensive diaphragm pumps and electronically-controlled pressure regulators, while passive pressure regulating valves suffer from hysteresis and limited flow rates.
Innovation Solution
A pressure regulating valve design featuring a diaphragm-controlled second valve member with a spring bias, which passively controls fluid flow through an orifice without sealing or shut-off functions, allowing for linear regulation of flow rates and minimizing hysteresis, combined with a solenoid-actuated first valve member for shut-off operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If expensive diaphragm pumps and electronically-controlled pressure regulators are used, then ink pressure control precision is improved, but system cost increases
Solution Approach 1:
The pressure regulating valve uses a spring-biased diaphragm mechanism that automatically regulates ink pressure without external control systems. The diaphragm responds directly to pressure changes, opening or closing the orifice to maintain constant pressure, eliminating the need for expensive electronic sensors and actuators while achieving reliable pressure control
Solution Approach 2:
The invention replaces complex electronic pressure control systems with a simple mechanical pressure-regulating valve. The spring-biased diaphragm mechanism provides passive pressure regulation through purely mechanical means, substituting electronic controllers with a self-regulating mechanical device that is both cheaper and more reliable
2Device complexity
If passive pressure regulating valves with sealing mechanisms are used, then system cost is reduced, but hysteresis and pressure fluctuation increase
Solution Approach 1:
The invention extracts the sealing function from the pressure regulation function. The first valve member with compliant plug handles sealing when the printhead is idle, while the second valve member with rigid surfaces handles only pressure regulation during printing. This separation eliminates the hysteresis caused by sealing mechanisms during pressure regulation
Solution Approach 2:
The second valve member uses rigid non-sealing surfaces that progressively open and close the orifice during printing operations. This dynamic regulation without sealing contact eliminates hysteresis and pressure fluctuations, providing stable pressure control throughout the printing cycle
3Stress or pressure
If sealing valve members are used for pressure control, then pressure regulation is achieved, but flow rate is limited and hysteresis occurs
Solution Approach 1:
The invention segments the valve into two distinct valve members: the first valve member for shut-off operations and the second valve member for pressure regulation. This segmentation allows each component to be optimized for its specific function, enabling high flow rates during printing while maintaining pressure control
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 provides cost-effective, localized pressure control for inkjet printheads, maintaining consistent ink pressure across multiple printheads without the high costs associated with traditional systems and minimizing issues of hysteresis and flow rate limitations.
Implementation Method 1
an ink tank connected to a valve inlet of the pressure regulating valve, the ink tank being positioned above the pressure regulating valve and the printhead, the ink tank having an air vent open to atmosphere for suppling ink to the pressure regulating valve under gravity
Implementation Method 2
a pump connected to a printhead outlet port, wherein: a level of ink in the ink tank is at a height h1 above the orifice; the orifice is positioned at a height h2 relative to the printhead; and the backpressure of ink supplied to the printhead is controlled by: h1, h2, a position of the valve member relative to the orifice and a pump speed of the pump
Data Source
AI summary
An ink delivery system for supplying ink to an inkjet printhead at a predetermined backpressure. The ink delivery system includes: a pressure regulating valve connected to a printhead inlet port; an ink tank connected to a valve inlet of the pressure regulating valve; and a pump connected to a printhead outlet port. The backpressure of ink supplied to the printhead is controlled by: a height h1 of ink in the ink tank relative to a valve orifice, a height h2 of the valve orifice relative to the printhead, a position of a valve member relative to the orifice and a pump speed of the pump.