Battery Pack Fastening Member Hooking Structure

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Solution Overview

Problem

Conventional battery pack fastening methods face challenges in accurately positioning the vehicle body fastening member due to thermal distortion during welding, leading to potential misalignment and instability in attaching the battery pack to the vehicle body frame.

Innovation Solution

A battery pack design featuring a vehicle body fastening member connected via a hooking structure to the case's side wall parts, allowing for independent positioning along the length direction and bonded using friction stir welding to prevent thermal distortion, ensuring accurate and stable fastening without deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the vehicle body fastening member is welded to the side surface of the casing, then the fastening strength is improved, but thermal distortion occurs in the casing causing positioning errors

Engineering Contradiction:

Improvefastening strengthVSAvoidpositioning precision

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

A positioning fixture is introduced as an intermediary tool during the welding process. The fixture holds the vehicle body fastening member in the correct position relative to the casing before welding, preventing thermal distortion from causing positioning errors. The fixture acts as a mediator that ensures precision while the welding process provides strength.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The vehicle body fastening member is positioned and fixed in place using the positioning fixture before the welding process begins. This preliminary positioning action ensures that when welding occurs, the member remains accurately positioned despite the thermal effects, preventing distortion-related positioning errors.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the vehicle body fastening member is welded to the side surface of the casing, then the connection reliability is improved, but the positioning becomes difficult due to thermal distortion

Engineering Contradiction:

Improveconnection reliabilityVSAvoidpositioning ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The positioning fixture serves as a mediator that simplifies the positioning process. It provides a straightforward mechanical means to locate and hold the fastening member in the correct position, making the manufacturing process easier while ensuring reliable welded connections.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The complex task of achieving accurate positioning despite thermal distortion is replaced by a simple mechanical positioning fixture. This substitution transforms a difficult positioning problem into an easy-to-implement mechanical solution, improving ease of manufacture while maintaining connection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the vehicle body fastening member is positioned after welding, then the positioning flexibility is improved, but the position may shift due to thermal distortion

Engineering Contradiction:

Improvepositioning flexibilityVSAvoidposition accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The positioning of the vehicle body fastening member is performed as a preliminary action before welding, not after. The positioning fixture establishes the correct position beforehand, and the subsequent welding process maintains this position without causing shifts, thereby preserving both positioning flexibility and accuracy.

Inventive Principle:

Principle #10Preliminary action

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

Enables easy and reliable positioning of the vehicle body fastening member at arbitrary positions, reducing the risk of thermal distortion and ensuring a stable fastening of the battery pack to the vehicle body frame, thereby improving the attachment process and maintaining structural integrity.

Implementation Method 1

the vehicle body fastening member is bonded to the case respectively by friction stir welding from at least one direction in a vertical direction of the case

Methodology Applied

Scientific EffectFriction stir welding: Friction Welding

Data Source

PatentUS11021070B2Battery pack and method of manufacturing battery pack

Publication Date: 2021.06.01 HONDA MOTOR CO LTD

AI summary

A battery pack includes a plurality of stacked single battery cells, a case for housing the plurality of stacked single battery cells, and a vehicle body fastening member for fastening the case to a vehicle body frame, wherein the vehicle body fastening member is provided separately from case, is connected to at least one of two side wall parts opposing each other in a width direction of the case by a hooking structure facing an upper surface and a lower surface of the side wall part, and is provided independently at a plurality of arbitrary positions along a length direction of the case.