Piezoelectric Dispenser Valve Stroke Calibration
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Solution Overview
Problem
Piezoelectric liquid dispensers face challenges in maintaining uniform dispensing quality due to changes in operation stroke caused by assembly tolerance and component abrasion, leading to variations in discharge amount and potential leakage.
Innovation Solution
A piezoelectric dispenser system that includes a lever and valve rod connected via a hinge axis, with piezoelectric actuators controlling the stroke, and a displacement measurement sensor to detect and adjust the operation stroke by calibrating the voltage applied to the actuators, ensuring the stroke remains within a preset initial value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a piezoelectric actuator is used to control the valve rod stroke, then the dispensing speed is improved, but the stroke varies due to assembly tolerance and component wear
Solution Approach 1:
The patent implements a feedback mechanism where a position sensor detects the actual position of the valve rod, and the control unit compares this with the expected position to calculate stroke variations. The system then adjusts the piezoelectric actuator voltage to compensate for assembly tolerance and wear, maintaining consistent dispensing performance while preserving fast dispensing speed.
Solution Approach 2:
The patent dynamically changes the voltage parameter applied to the piezoelectric actuator based on detected stroke variations. By adjusting the voltage magnitude in response to wear or assembly variations, the system maintains the desired valve rod stroke length, thereby ensuring consistent dispensing precision without sacrificing the high speed enabled by piezoelectric actuation.
2Quantity of substance
If the valve rod stroke is increased to compensate for wear, then the dispensing amount is maintained, but leakage occurs
Solution Approach 1:
The position sensor provides continuous feedback on the valve rod's actual position, allowing the control unit to detect when the stroke has increased due to wear. The system then reduces the actuator voltage to bring the stroke back to the optimal level, preventing both under-dispensing and leakage caused by excessive stroke.
Solution Approach 2:
The patent makes the stroke length dynamic rather than fixed. The control unit continuously adjusts the piezoelectric actuator's output based on real-time position feedback, allowing the stroke to adapt to component wear while maintaining optimal dispensing parameters and preventing leakage.
3Object-generated harmful factors
If the first position is adjusted to shorten the stroke, then leakage is prevented, but the dispensing amount decreases
Solution Approach 1:
The patent precisely controls the voltage parameter of the piezoelectric actuator to achieve the optimal stroke length. By dynamically adjusting the voltage magnitude, the system maintains the stroke short enough to prevent leakage while ensuring it is long enough to deliver the required dispensing amount, thus resolving the contradiction between leakage prevention and dispensing volume.
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 system maintains uniform dispensing quality by calibrating the operation stroke of the valve rod, reducing the impact of assembly tolerance and component wear, thereby preventing leakage and ensuring consistent discharge.
Implementation Method 1
at least one piezoelectric actuator configured to expand and shrink along a second axis in response to a voltage signal applied to the at least one piezoelectric actuator
Data Source
AI summary
A piezoelectric dispenser having a uniform dispensing quality of a viscous liquid by calibrating an operation stroke of a valve rod discharging a viscous liquid (vertical operation displacement of the valve rod) by setting the operation stroke of the valve rod to an initial value during use, and a method of calibrating the operation stroke of the piezoelectric dispenser. Accordingly, a uniform dispensing accuracy of viscous liquid may be maintained, and degradation of the dispensing quality of a viscous liquid due to abrasion of components may be reduced.