High-Voltage Junction Box Cover Interlock Without Sensor Switches

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Solution Overview

Problem

Existing high voltage junction boxes in electric vehicles face challenges with ergonomics, security, durability, reliability, and manufacturing complexity due to environmental conditions and varying operator skills, while requiring complex electromechanical switches for safety.

Innovation Solution

A high voltage junction box with an interlocking circuit that uses a watertight closing cover with an integrated interlocking extension or a separate interlocking part, eliminating the need for electromechanical detection switches, and allowing for manufacturing in insulating materials for enhanced design flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an electromechanical sensor switch is used to detect cover opening, then the interlocking function is achieved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveinterlocking functionVSAvoidelectromechanical switch complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the detection function from a separate electromechanical sensor switch and integrates it directly into the closing cover structure through interlocking parts. The cover itself becomes the detection element, eliminating the need for additional sensor components while maintaining the interlocking safety function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the cover structure with the detection function by incorporating interlocking parts directly into the closing cover. The cover and detection mechanism become a single integrated component, reducing overall device complexity while ensuring reliable detection of cover opening status.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If an electromechanical sensor switch is used for cover detection, then the safety function is provided, but the manufacturing cost and complexity increase

Engineering Contradiction:
Improvesafety functionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the separate electromechanical sensor switch from the system and extracts its detection function into the closing cover's interlocking parts. This eliminates the need for expensive sensor components and simplifies the manufacturing process while maintaining safety functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive electromechanical sensor switches with simple interlocking parts made from standard plastic materials. These interlocking parts are cost-effective to manufacture and integrate seamlessly into the cover molding process, significantly reducing overall manufacturing costs.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If a metal closing cover is used, then electromagnetic shielding is provided, but the cover cannot be made from insulating material

Engineering Contradiction:
Improveelectromagnetic shieldingVSAvoidmaterial selection flexibility
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent divides the closing cover into two functional parts: an insulating plastic cover body for structural purposes, and a separate metallic interlocking part for electromagnetic shielding. This segmentation allows each material to perform its optimal function while being integrated into a single component system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material construction by combining insulating plastic material for the cover body with metallic material for the interlocking parts. This composite approach provides both electrical insulation and electromagnetic shielding capabilities, offering versatility in material selection while meeting multiple functional requirements.

Inventive Principle:
Principle #40Composite materials

4Measurement precision

If complex electromechanical switches are used, then detection accuracy is achieved, but the durability under environmental conditions decreases

Engineering Contradiction:
Improvecover opening detectionVSAvoiddurability under environmental conditions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the electromechanical sensor switch system with a purely mechanical interlocking detection system. The interlocking parts provide direct mechanical detection of cover opening status through simple geometric engagement, eliminating complex electromechanical components that are susceptible to environmental degradation from vibrations, temperature changes, and humidity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4606655A1High voltage junction box with interlocking circuit of battery operated power system, and method for disassembling it
Publication Date: 2025.08.27 APTIV TECHNOLOGIES AG
  • EP4606655A1 patent drawingFigure 1~2
  • EP4606655A1 patent drawingFigure 3~4
  • EP4606655A1 patent drawingFigure 5~6

AI summary

Present disclosure relates to a high voltage junction box with an interlocking circuit (149), for high voltage battery operated systems especially electric vehicles. Junction box (1) comprises a protection cover (13) assembled on main housing (11). An interlocking part (18,18') is electrically connected, by insertion contact, shunting two interlocking terminals (145) fixed within the main housing. It cooperates with protection cover, that can not be removed without said interlocking part being extracted from interlocking terminals, thus providing a cover opening detection. A watertight closing cover (12) may have an integrated plastic interlocking extension (182), internally protruding through an opening of protection cover and having a cavity (180) containing a metallic one-piece interlocking shunt (185). Opening closing cover thus opens interlocking circuit. Alternatively, interlocking part (18') is separated from closing cover (12), with interlocking extension (182) protruding through protection cover (13), while being maintained outside it by maintaining portion (181). It thus has to be removed for opening protection cover.