Insulating Caps for Motor Vehicle Bus Bar Screw Protection

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Solution Overview

Problem

Current solutions fail to prevent short circuits and injuries during the assembly and use of motor vehicle battery packs due to the risk of accidental contact between fixing screws and metallic elements, particularly at high voltage connections.

Innovation Solution

A busbar protection and insulation system that uses electrically insulating caps to cover the protruding screw bodies and a protective cover to isolate the busbar ends, ensuring no conductive contact and providing a simple, economical solution to prevent short circuits and injuries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fixing screws are used to connect busbar to electrodes, then secure electrical connection is achieved, but risk of accidental contact and short circuit increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidshort circuit risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An electrically insulating cap is introduced as an intermediary element between the conducting screw body and the external environment. This cap covers the protruding portion of the screw body, allowing the screw to maintain its mechanical fastening function while preventing electrical contact with surrounding metallic elements, thus eliminating the short circuit risk without compromising connection reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The screw assembly is segmented into two functional parts: the conducting screw body (for mechanical fastening and electrical connection) and the insulating cap (for electrical isolation). This segmentation allows each part to perform its specific function independently - the screw provides secure connection while the cap prevents harmful electrical contact with surrounding elements

Inventive Principle:
Principle #1Segmentation

2Reliability

If insulating protective covers are added to busbar ends, then electrical insulation is improved, but device complexity increases

Engineering Contradiction:
Improveelectrical insulationVSAvoidprotective cover structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulating cap serves multiple functions simultaneously: it provides electrical insulation, protects the screw threads, prevents accidental contact, and can be easily removed for maintenance or replacement. This multi-functionality reduces the need for additional separate protective components, thereby maintaining simplicity while improving insulation reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Strength

If fixing screws protrude under the busbar, then secure mechanical fastening is achieved, but electrical contact risk with metallic elements increases

Engineering Contradiction:
Improvemechanical fastening strengthVSAvoidelectrical contact hazard
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The insulating cap acts as a mediator that allows the screw body to protrude for mechanical fastening while preventing electrical contact. The cap covers the protruding portion of the screw body, enabling the screw to maintain its mechanical function of securing the busbar to the electrode while simultaneously preventing electrical contact with surrounding metallic elements

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3682492B1System for protecting and insulating a bus bar of a motor vehicle
Publication Date: 2021.11.17 PSA AUTOMOBILES SA
  • EP3682492B1 patent drawingFigure 1~4

AI summary

The invention relates to a system for protecting and insulating a bus bar, comprising a bus bar (3) and at least one fastening screw (4) that has a body (5) and a screw head (4), for fastening said cable (3) to an electric power source, the bus bar (3) having an opening through which the body (5) of each screw (4) can pass, and the part of the body (5) of the screws (4) which protrudes from the bus bar (3) being entirely covered by an electrically insulating cap (6). The invention also relates to a motor vehicle comprising such a system for protecting and insulating a bus bar.