Junction Box Bolt Locking Structure for Vibration-Prone EV Terminals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric vehicles, the bolts connecting three-phase high voltage wiring terminals to busbar terminals can loosen due to vibration, leading to serious consequences such as electric arcs and motor failure.
Innovation Solution
An anti-loose bolt connection structure for a junction box is introduced, featuring non-circular bolt head portions and anti-loose assemblies, including anti-loose plates and locking pins, which prevent bolt rotation and ensure secure connections between terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If bolts are used to connect terminals, then the connection is simple and easy to assemble, but the bolts become loose due to vibration during vehicle operation
Solution Approach 1:
The bolt head is designed with an asymmetric non-circular shape (such as hexagonal or square) that corresponds to a matching non-circular opening in the anti-loose plate. This asymmetric geometry prevents the bolt from rotating once the anti-loose plate is installed, thereby eliminating loosening caused by vibration while maintaining ease of assembly during installation.
Solution Approach 2:
An anti-loose plate is introduced as an intermediary component between the bolt head and the terminal connection point. This plate serves as a mediator that converts the simple bolt connection into a secure anti-loose connection by providing a non-circular opening that matches the bolt head shape, thus preventing rotation without complicating the overall assembly process.
2Reliability
If anti-loose assemblies are added to prevent bolt loosening, then connection reliability is improved, but device complexity increases
Solution Approach 1:
The anti-loose plate is merged with the terminal structure or the junction box housing in many implementations. By integrating the anti-loose function into existing structural components rather than adding completely separate parts, the design improves connection reliability while minimizing the increase in device complexity.
Solution Approach 2:
The anti-loose plate serves multiple functions: it prevents bolt rotation, provides structural support, and can be integrated into the terminal or housing design. This multi-functionality reduces the need for additional dedicated anti-loose components, thereby improving reliability without significantly increasing overall structure complexity.
Data Source
AI summary
An anti-loose bolt connection structure for a junction box, comprising: a junction box main body; a first terminals disposed on the junction box main body, the first terminals being provided with a threaded hole; a second terminal for electrically connecting to the first terminals, the second terminals being provided with a through hole; a bolts, which each comprise having a bolt head portion; and an anti-loose assembly mounted on the junction box main body, the anti-loose assembly being cooperatively mounted with the bolt head portions for limiting the rotation of the bolts.