Wiring Harness Insulation Testing Under Vacuum for In-Line Detection
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Solution Overview
Problem
Existing methods for dielectric insulation detection of high-voltage wiring harnesses in electric vehicles are unsafe, time-consuming, and cannot perform in-line detection of finished products, requiring high test voltages and sample preparation.
Innovation Solution
An insulation withstand voltage detection method utilizing Paschen's law and Townsend's discharge theory, which applies a low test voltage under vacuum conditions to detect insulation breakdown in a sealed cavity, enabling nondestructive and rapid in-line detection of wiring harnesses using a conductive electrode and power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high test voltage is used for dielectric insulation detection, then detection accuracy is improved, but safety deteriorates and test time increases
Solution Approach 1:
The patent changes the physical parameter of the test environment by creating a vacuum condition (reducing air pressure) inside the detection cavity. According to Paschen's law, the breakdown voltage of gas is a function of pressure and electrode distance. By reducing the air pressure to a specific range (10Pa-1000Pa), the patent enables insulation detection at lower voltages (1kV-5kV) while maintaining detection accuracy, thus resolving the contradiction between detection accuracy and safety
Solution Approach 2:
The patent introduces a vacuum environment as an intermediary medium between the high-voltage electrode and the wiring harness. This vacuum medium modifies the electrical breakdown characteristics, allowing safe operation at reduced voltages while still enabling effective insulation detection. The vacuum acts as a controlled intermediary that facilitates accurate detection without requiring dangerous high voltages
2Measurement precision
If high test voltage is used for dielectric insulation detection, then detection accuracy is improved, but detection time increases
Solution Approach 1:
By changing the air pressure parameter to a vacuum state, the patent reduces the required test voltage to 1kV-5kV. This voltage reduction significantly decreases the time needed for voltage application and breakdown observation, while the controlled vacuum environment ensures detection accuracy is maintained through consistent electrical characteristics
3Ease of manufacture
If traditional detection methods are used, then sample preparation is simplified, but in-line detection capability deteriorates
Solution Approach 1:
The patent designs a universal detection cavity structure that can accommodate wiring harnesses in their actual delivery state without requiring special sample preparation. The cavity is equipped with adjustable electrodes and vacuum sealing capabilities that work with various wiring harness configurations, enabling both ease of operation and in-line detection integration
Solution Approach 2:
The detection system is designed to accept wiring harnesses directly in their delivery state, eliminating the need for external grounding copper meshes or conductive liquid media. The vacuum environment itself provides the necessary detection conditions, and the system automatically creates the test environment, reducing preparation steps while enabling in-line detection
4Ease of operation
If conductive liquid medium or external grounding copper mesh is used, then detection setup is simplified, but detection speed deteriorates and in-line detection becomes impossible
Solution Approach 1:
The patent replaces conductive liquid media and external grounding copper meshes with a vacuum environment as the intermediary medium. This simplifies the setup by eliminating the need for these additional materials while enabling faster detection through direct voltage application in the vacuum cavity, thus improving both ease of operation and detection speed
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 method achieves safe, rapid, and efficient in-line detection of wiring harness insulation, reducing test voltage by one-third, ensuring product safety and improving production efficiency by integrating the detection into the assembly line.
Implementation Method 1
a vacuum device (80), the air pressure in the enclosed cavity (21) is reduced by the vacuum device (80), so that a set vacuum degree is reached inside the enclosed cavity (21)
Implementation Method 2
when a high voltage applied between the electrodes under a certain vacuum degree reaches a certain level, gas ionization and conduction may occur, thereby realizing a glow discharge
Implementation Method 3
gas ionization and conduction may occur, thereby realizing a glow discharge
Implementation Method 4
By capturing and detecting the voltage or the leakage current, it may be judged whether a breakdown occurs
Data Source
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AI summary
The present disclosure provides an insulation withstand voltage detection method and detection device for a wiring harness, and an automobile wiring harness assembly line. The insulation withstand voltage detection method for the wiring harness includes: step S 10: placing a to-be-detected wiring harness in an enclosed cavity, in which a conductive electrode plate is disposed in the enclosed cavity, and the to-be-detected wiring harness has one end insulated and enclosed, and the other end connected to a power supply; step S20: reducing air pressure in the enclosed cavity; step S30: providing a test voltage by the power supply; and step S40: detecting a voltage of the to-be-detected wiring harness, and/or detecting a leakage current of the to-be-detected wiring harness. Through the present disclosure, it alleviates the technical problem in the prior art that the dielectric insulation detection of a high-voltage wiring harness cannot realize the in-line detection of finished products.