Two-Stage Calibrating Jetting Valve for Precision Dispensing
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Solution Overview
Problem
Conventional pneumatic mechanical dispensing valves lack precision in fluid material dispensing due to variations in air pressure and elastic fatigue, making it difficult to set calibrating parameters according to the fluid material's characteristics. Additionally, piezoelectric jetting valves face limitations in providing a wide range of calibration due to small-scale displacement of piezoelectric elements and material expansion coefficients at varying temperatures.
Innovation Solution
A jetting valve with a two-stage calibrating structure that includes a piezoelectric actuating unit, a displacement amplifying element, a sensing unit, and a control unit. This configuration allows for precise adjustment of the voltage applied to the piezoelectric actuating unit, enabling accurate control of the nozzle's open and close speed and thus achieving precise calibration and dispensing of fluid materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a piezoelectric element is used to actuate the nozzle, then the response speed and processing speed are improved, but the displacement range is limited due to the small-scale displacement of the piezoelectric element
Solution Approach 1:
A linkage mechanism serves as an intermediary between the piezoelectric element and the nozzle. The linkage includes a first linkage arm connected to the piezoelectric element and a second linkage arm connected to the nozzle, with a pivot point that amplifies the small displacement into a larger effective movement range for the nozzle actuation.
Solution Approach 2:
The patent introduces a rotational degree of freedom through the pivot point of the linkage mechanism. The piezoelectric element moves linearly with small displacement, but this motion is converted into rotational movement of the linkage arms, which then produce larger linear displacement of the nozzle in a different dimensional space.
2Adaptability or versatility
If the piezoelectric element displacement is amplified, then the calibration range is improved, but the manufacturing precision becomes more difficult to control
Solution Approach 1:
The patent incorporates a feedback mechanism where the actual position of the nozzle is detected and fed back to the control system. This feedback information is used to adjust the voltage applied to the piezoelectric element, creating a closed-loop control system that compensates for manufacturing tolerances and ensures precise nozzle positioning despite the amplification mechanism.
Solution Approach 2:
The system dynamically adjusts the voltage parameter applied to the piezoelectric element based on feedback from the nozzle position. By changing the voltage parameter in real-time, the system compensates for variations in the amplification mechanism and maintains precise control over the nozzle position and displacement.
3Device complexity
If air pressure and spring rebound force are used to dispense fluid material, then the device complexity is reduced, but the manufacturing precision deteriorates due to variations in air pressure and elastic fatigue
Solution Approach 1:
The patent replaces the pneumatic-mechanical actuation system (using air pressure and spring rebound) with a piezoelectric actuation system. The piezoelectric element converts electrical signals directly into mechanical displacement, eliminating the need for complex pneumatic components and spring mechanisms, thereby achieving both simplified device architecture and high manufacturing precision.
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 two-stage calibrating structure enables high-frequency jetting (greater than 500 Hz) with a time resolution of 1 μs, allowing for precise control over the jetting amount, droplet size, and width. This results in improved accuracy and reliability of fluid material dispensing, overcoming the limitations of conventional technologies.
Implementation Method 1
The actuating principle of the piezoelectric jetting valve is to apply voltage to a piezoelectric element of the piezoelectric jetting valve, cause the piezoelectric element to move a linkage up and down
Data Source
AI summary
A jetting valve with two stage calibrating structures is disclosed, the jetting valve includes: a casing having an accommodating space; a piezoelectric actuating unit disposed on one side of the accommodating space; a spraying unit disposed on the other side of the accommodating space; a displacement amplifying element is arranged at the bottom of the accommodating space and leans against on the spraying unit, the bottom end of the piezoelectric driving unit is in contact with the displacement amplifying element; a sensing unit is arranged on the periphery of the displacement amplifying element to sense the movement of the spraying unit; a control unit, connected to the sensing unit and the piezoelectric actuating unit, adjusting the voltage supplied to the piezoelectric driving unit according to data obtained by the sensing unit; and a liquid supply unit connected to the spraying unit. In accordance with the present invention, a dispenser may be corrected its starting position for dispensing by large-range and small-range correction, and achieve the effect of rapid and accurate spraying calibration.