Electrostatic Paint Nozzle Control for Uniform Droplet Atomization
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Solution Overview
Problem
Deviation in the positions of the coating target and conductor can hinder the uniformity of paint particle size, leading to a deterioration in coating quality during electrostatic atomization coating.
Innovation Solution
A coating device and method that measures the supplied current and controls the voltage applied to the nozzle based on this measurement to maintain a consistent electric field, using a coating device with insulated flow passages to minimize leakage current and ensure a constant current flow between the nozzle and the coating target.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the voltage applied to the nozzle is controlled according to the distance between the nozzle and the conductor, then the particle size of the paint can be made uniform, but deviation in the positions of the coating target and conductor will cause lower voltage to be applied, resulting in an electric field with strength lower than intended and non-uniform particle size
Solution Approach 1:
The patent employs feedback control by measuring the supplied current and adjusting the voltage applied to the nozzle based on this measurement. The controller increases the voltage when the supplied current is lower than expected, and decreases the voltage when the supplied current is higher than expected, thereby maintaining a consistent electric field strength despite positional deviations between the nozzle and conductor.
Solution Approach 2:
The patent dynamically changes the voltage parameter applied to the nozzle based on real-time current measurements. By adjusting the voltage parameter in response to current feedback, the system compensates for positional deviations and maintains uniform paint particle size and consistent coating quality.
2Reliability
If the voltage is increased to compensate for positional deviation, then the electric field strength can be maintained, but this may cause excessive current flow and energy loss
Solution Approach 1:
The feedback control mechanism precisely adjusts the voltage based on actual current measurements, increasing voltage only when necessary to maintain electric field strength while avoiding excessive voltage application. This prevents energy loss from excessive current flow while ensuring consistent coating quality.
Solution Approach 2:
The system dynamically adjusts the voltage parameter in real-time based on current feedback, optimizing the balance between maintaining electric field strength and minimizing energy consumption. The voltage is increased only to the extent necessary to compensate for positional deviation, not beyond.
3Manufacturing precision
If current measurement and voltage control based on current measurement are implemented, then non-uniformity in the electric field caused by positional deviation can be suppressed, but this increases device complexity
Solution Approach 1:
The patent implements feedback control using current measurement to adjust voltage, which suppresses electric field non-uniformity caused by positional deviation. The controller uses the measured supplied current as feedback to dynamically adjust the voltage, maintaining consistent coating quality despite added control system complexity.
Solution Approach 2:
The patent replaces mechanical positioning precision requirements with an electrical control system. Instead of relying on precise mechanical positioning of the nozzle relative to the conductor, the system uses electrical feedback control to maintain the desired electric field strength, trading mechanical simplicity for electrical control complexity.
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 approach suppresses non-uniformity in the electric field due to positional deviations, stabilizing the size and discharge speed of paint droplets, thereby enhancing coating quality.
Implementation Method 1
Electrostatic atomization coating is a coating method in which paint is turned into fine droplets by the action of an electric field which is formed between an electrically charged nozzle and a conductor arranged opposing the nozzle
Implementation Method 2
a measuring unit configured to measure a supplied current
Implementation Method 3
a controller configured to control the voltage applied to the nozzle, based on a measurement value of the measuring unit
Data Source
AI summary
A coating device for atomizing a paint having an electrical resistivity of 20 MΩ·cm or less using an action of an electric field, and includes a nozzle to which a voltage is applied, a flow passage along which the paint flows, a measuring unit that measures a supplied current, and a controller that controls the voltage applied to the nozzle, based on a measurement value of the measuring unit.