Electrostatic Coating Gunhead Dynamic Speed Control

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Solution Overview

Problem

Electrostatic coating handguns with rotating heads face challenges in achieving both improved coating efficiency and safety, as increased voltage can cause paint to scatter towards protective covers, reducing efficiency and posing safety risks.

Innovation Solution

The electrostatic coating handgun controls the output voltage of the high voltage generator and rotational speed of the rotating head based on the distance between the operator and the object being coated, using a voltage control device to reduce voltage and a motor control device to adjust speed, ensuring paint is directed towards the object and preventing accidental contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective cover is provided outside the rotating head, then safety is improved, but coating efficiency deteriorates due to paint scattering toward the protective cover

Engineering Contradiction:
ImprovesafetyVSAvoidcoating efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent removes the protective cover from the system, extracting the harmful element that caused paint scattering. By eliminating this component, the invention resolves the contradiction between safety (which would be improved by a cover) and coating efficiency (which deteriorated due to paint scattering toward the cover).

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces dynamic control of the rotating head's rotational speed based on real-time detection of operator proximity. When the operator approaches, the rotational speed is reduced; when the operator moves away, the rotational speed increases. This dynamic adjustment maintains safety without requiring a protective cover, as the controlled rotation prevents accidental contact while maintaining coating efficiency.

Inventive Principle:
Principle #15Dynamics

2Productivity

If increased voltage is applied to the paint, then coating efficiency is improved, but paint scattering toward the protective cover increases, reducing coating efficiency

Engineering Contradiction:
Improvecoating efficiencyVSAvoidpaint scattering
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent dynamically adjusts the rotational speed of the rotating head based on the operator's proximity. When the operator is close, the rotation speed is reduced, which stabilizes the paint flow and reduces scattering. When the operator moves away, the rotation speed increases, improving coating efficiency. This dynamic control allows the system to optimize between paint application efficiency and paint scattering reduction.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the rotating head rotates at high speed, then coating efficiency is improved, but the risk of contacting the operator increases

Engineering Contradiction:
Improvecoating efficiencyVSAvoidcontact risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a detection device that continuously monitors the operator's proximity to the rotating head and provides feedback to the control device. Based on this feedback, the control device adjusts the rotational speed in real-time: reducing speed when the operator is close to prevent contact, and increasing speed when the operator moves away to maintain coating efficiency. This closed-loop feedback system resolves the contradiction between high-speed rotation for efficiency and safety.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements dynamic rotational speed control that adapts to real-time operating conditions. The rotating head operates at high speed when safe, but automatically reduces speed when the operator approaches, creating a dynamic balance between coating efficiency and safety that eliminates the need for protective covers.

Inventive Principle:
Principle #15Dynamics

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 enhances coating efficiency by directing paint effectively and ensures safety by reducing the risk of the rotating head contacting the operator or object, while also eliminating the need for protective covers, thus improving both efficiency and safety.

Implementation Method 1

electrostatic coating handguns and electrostatic coating methods for spraying electrically charged atomized paint onto an object to be coated

Methodology Applied
Scientific EffectElectrostatic coating: Electrostatics

Implementation Method 2

a rotating head having on a tip end of the rotating head a groove through which the paint is discharged; a motor configured to apply rotational power to the rotating head

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4049760B1Electrostatic coating handgun and electrostatic coating method
Publication Date: 2023.06.14 TOYOTA JIDOSHA KK
  • EP4049760B1 patent drawingFigure 1~2
  • EP4049760B1 patent drawingFigure 3
  • EP4049760B1 patent drawingFigure 4

AI summary

An electrostatic coating handgun sprays electrically charged atomized paint onto an object to be coated. The electrostatic coating handgun includes: a rotating head (20); a motor that applies rotational power to the rotating head (20); a high voltage generator (40) that applies a voltage to the paint; a housing (10) supporting the rotating head (20) with a tip end of the rotating head (20) being exposed, and housing the motor and the high voltage generator (40); and a grip portion (13) to be held by an operator. When a current value discharged from the rotating head (20) increases due to movement of the rotating head (20) caused by an operation by the operator (YES in S2), a voltage control device (5) reduces an output voltage of the high voltage generator (40) (S7) and a motor control device (7) reduces a rotational speed of the motor (S8).