Piezo Dosing Nozzle Cooling for High-Precision Metering
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Solution Overview
Problem
Piezoelectric actuators in dosing systems generate significant heat, leading to thermally induced expansion and reduced precision in dosing accuracy due to temperature-dependent behavior, which existing cooling methods like compressed air circulation are insufficient to address.
Innovation Solution
A metering system with a cooling device that supplies a pre-cooled cooling medium directly to specific areas of the piezoelectric actuator and movement mechanism, using a selective and controlled cooling method to maintain precise dosing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If piezoelectric actuators are used for precise dosing control, then dosing precision is improved, but heat generation causes thermally induced expansion and reduced precision
Solution Approach 1:
The cooling system is divided into separate channels: a first cooling channel for cooling the piezoelectric actuator and a second cooling channel for cooling the movement mechanism. This segmentation allows independent cooling of different components with different thermal requirements, preventing thermal interference between them while maintaining dosing precision.
Solution Approach 2:
Different cooling strategies are applied to different components: the piezoelectric actuator receives cooling to prevent thermal expansion, while the movement mechanism receives cooling to reduce friction. This local differentiation of cooling quality ensures that each component is cooled according to its specific thermal characteristics and operational requirements.
2Temperature
If conventional cooling methods like compressed air circulation are used, then some cooling effect is achieved, but dosing precision is insufficiently maintained at high frequencies
Solution Approach 1:
The patent employs a liquid cooling system using a cooling medium (such as water or another liquid) circulated through channels in the actuator and movement mechanism. This hydraulic cooling approach provides superior heat removal capability compared to compressed air, enabling the system to maintain dosing precision at high operating frequencies by effectively managing thermal loads.
3Temperature
If cooling is applied to all components, then temperature control is improved, but cooling medium consumption increases
Solution Approach 1:
The cooling system is segmented into separate channels for different components, allowing cooling medium to be directed specifically where needed. This segmentation prevents unnecessary cooling of components that do not require it, thereby reducing overall cooling medium consumption while maintaining effective temperature control of critical components.
Solution Approach 2:
Cooling is applied locally to specific components based on their thermal requirements rather than uniformly to the entire system. The piezoelectric actuator receives cooling to prevent thermal expansion, while the movement mechanism receives cooling to reduce friction, optimizing cooling medium usage by targeting only the components that benefit from cooling.
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 effectively dissipates heat from temperature-sensitive components, ensuring consistent dosing precision and high-frequency operation even at elevated ambient temperatures, reducing the need for cooling other components and minimizing cooling medium consumption.
Implementation Method 1
an actuator unit coupled to the ejection element and/or the nozzle with a piezoelectric actuator
Implementation Method 2
a cooling device with a feed device for supplying a pre-cooled cooling medium into a housing of the dosing system
Data Source
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AI summary
The invention relates to a dosing system (1) for a dosing material, comprising a nozzle (40), a feed channel (44), a discharge element (31), an actuator unit (10) coupled to the discharge element (31) and/or the nozzle (40) and comprising a piezo actuator (60) and a cooling device (2). The cooling device (2) comprises a supply device (21, 24, 26) for feeding a precooled cooling medium into a housing (11) of the dosing system (1). The cooling device (2) is designed to directly cool at least one partial area of the piezoactuator (60) and/or at least a subregion of a movement mechanism (14) coupled to the piezoactuator (60) by means of the precooled cooling medium.