Liquid Ejecting Apparatus Pressure Control Valve Ink Circulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid ejecting apparatuses, such as inkjet printers, the use of pigment inks leads to pigment particle settling in the liquid flow channel, causing concentration imbalances and pressure fluctuations, which can result in ink accumulation and potential system failures like tube disengagement or rupture due to repeated pressure changes.
Innovation Solution
A configuration that includes a pressure control valve, a check valve, a circulating pump, and a return flow channel to manage pressure fluctuations, with optional liquid reservoirs to hold ink in a pressurized state, ensuring that ink is circulated and returned effectively, preventing pressure buildup and maintaining stable ink flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a tube pump is used to agitate ink in the liquid flow channel, then ink circulation and agitation are improved, but pressure fluctuations cause ink to flow into the circulating flow channel from the liquid supply source via the check valve, leading to gradual ink accumulation and pressure rise
Solution Approach 1:
A pressure control valve is introduced as an intermediary component between the liquid supply source and the circulating flow channel. This valve mediates the pressure fluctuations generated by the tube pump, preventing excessive pressure buildup while maintaining effective ink circulation and agitation. The pressure control valve opens when pressure drops and closes when pressure rises, thereby regulating the pressure in the circulating flow channel.
2Device complexity
If the circulating flow channel is formed by connecting multiple tubes, then the system becomes more complex, but the connections between tubes can become disengaged or tubes can rupture due to repeated pressure changes
Solution Approach 1:
The pressure control valve serves as a protective intermediary that prevents excessive pressure fluctuations from reaching the tube connections. By regulating pressure before it enters the circulating flow channel, the valve protects the connections between tubes from disengagement and prevents tube rupture, thereby improving reliability without compromising the multi-tube configuration.
Solution Approach 2:
The pressure control valve provides beforehand cushioning by preemptively regulating pressure fluctuations before they can cause damage to the tube connections. This protective mechanism anticipates and mitigates the harmful effects of pressure changes, preventing connection disengagement and tube rupture before they occur.
3Quantity of substance
If pigment ink is supplied through a long liquid flow channel, then the channel can accommodate more ink, but pigment particles sink in the ink carrier, causing concentration imbalances and tint changes
Solution Approach 1:
The system employs dynamic pressure control through the pressure control valve and tube pump to create continuous flow variations in the liquid flow channel. This dynamic operation prevents pigment particles from settling by maintaining constant motion and pressure variations, thereby preserving concentration uniformity even in long channels that can accommodate larger ink volumes.
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 suppresses pressure rises in the circulating flow channel, preventing ink accumulation and system failures, ensuring consistent ink supply and extending the lifespan of the apparatus by managing pressure fluctuations and maintaining ink homogeneity.
Implementation Method 1
a check valve that is provided in the first liquid flow channel closer to the liquid supply source than the pressure control valve and that prevents backflow from the pressure control valve side toward the liquid supply source side
Implementation Method 2
a circulating pump that is provided in the second liquid flow channel and that causes the liquid to flow in one direction in the circulating flow channel
Implementation Method 3
a pressure control valve that is provided in the first liquid flow channel and that opens as a result of a drop in pressure on the liquid ejecting head side
Data Source
AI summary
A liquid ejecting apparatus includes a liquid ejecting head, an ink supply tube that supplies ink to the liquid ejecting head, a pressure control valve that opens as a result of depressurization on the liquid ejecting head side, a check valve provided upstream from the pressure control valve, an ink circulation tube that is connected at both ends to the ink supply tube between the pressure control valve and the check valve, and a tube pump provided in the ink circulation tube; in this configuration, by providing at least one of an ink return tube and a liquid reservoir portion that is capable of holding liquid in a liquid flow channel in a pressurized state, a rise in pressure within a circulating flow channel caused by pump operations can be suppressed.