Battery Pack Box Structure to Prevent Bottom Deflection

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Solution Overview

Problem

The existing methods for fixing battery packs at the bottom of vehicles face structural strength challenges, leading to safety issues and increased weight distribution difficulties, resulting in complex and costly designs with low energy density and unsightly appearances.

Innovation Solution

A battery pack design featuring a lower box body with a first connecting portion and an upper box body with a second connecting portion, where the first connecting portion has a protrusion protruding upward and the second connecting portion has a corresponding recess, allowing for a concave-convex fit to enhance structural strength and prevent downward deflection, thereby enabling reliable fixation at the vehicle's bottom.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If fixing points are provided only at the peripheries of the battery pack box body, then the design is simple, but the structural strength is insufficient and the battery pack cannot withstand the challenges of larger sizes

Engineering Contradiction:
Improvestructural strengthVSAvoiddesign complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention divides the box body into upper and lower sections with multiple connecting portions (first connecting portion at the bottom, second connecting portion at the top, and third connecting portion at the side). This segmentation allows strength to be distributed across multiple locations rather than relying on a single complex structure, resolving the contradiction between strength and design simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention adds vertical dimension to the fixing points by providing connecting portions at both the bottom (first connecting portion) and top (second connecting portion) of the box body. This multi-dimensional distribution of connection points enhances structural strength without requiring overly complex peripheral designs.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If the box body is made strong enough to distribute weight to each fixing point, then the strength is sufficient, but the design difficulty increases and the cycle is long due to constant simulation

Engineering Contradiction:
Improveweight distribution strengthVSAvoiddesign ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The box body is segmented into multiple standard connecting portions (first, second, and third connecting portions) with standardized structures. This segmentation allows weight distribution to be achieved through simple replication of standard components rather than complex custom designs, significantly reducing design difficulty and simulation requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses standardized geometric parameters for the connecting portions (protrusions and recesses with defined dimensions). By changing from complex custom designs to standardized parameters, the design process becomes simpler and more repeatable, reducing the need for constant simulation while maintaining sufficient strength.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the box body is made strong enough to support the battery pack, then the strength is sufficient, but the weight increases which reduces energy density

Engineering Contradiction:
Improvesupport strengthVSAvoidbox body weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The box body is divided into upper and lower sections connected by multiple lightweight connecting portions. This segmentation allows the use of thinner, lighter materials in each section while maintaining overall strength through the distributed connection structure, reducing total weight compared to a single thick-walled box body.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention distributes structural support across multiple dimensions (bottom, top, and side connecting portions) rather than relying on increased wall thickness in a single dimension. This multi-dimensional support system achieves sufficient strength with lighter materials, improving energy density.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Device complexity

If fixing points are arranged around the outside of the box body, then the structure is simple, but the appearance becomes unsightly

Engineering Contradiction:
Improvestructural simplicityVSAvoidappearance
Core Design Contradiction:
Device complexityVSShape

Solution Approach 1:

The connecting portions (protrusions and recesses) are integrated into the box body structure itself, with the fixing points nested within the box body walls rather than protruding outward. This nesting approach maintains structural simplicity while achieving a cleaner, more aesthetically pleasing appearance.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3886199B1Battery pack
Publication Date: 2023.11.01 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3886199B1 patent drawingFigure 1~2
  • EP3886199B1 patent drawingFigure 3
  • EP3886199B1 patent drawingFigure 4

AI summary

The present invention is provided with a battery pack, including a first battery module, a second battery module and a box body, where the first battery module and the second battery module are housed in the box body; the box body including a lower box body configured to support the first battery module and the second battery module, and an upper box body fitting with the lower box body. The lower box body includes a first connecting portion, and the first connecting portion is located between the first battery module and the second battery module. The upper box body includes a second connecting portion, where the first connecting portion and the second connecting portion are fixed and connected. In the battery pack of the present invention, the first connecting portion is located between the first battery module and the second battery module, and the first connecting portion and the second connecting portion are fixed and connected, such that the strength of portions between the first battery module and the second battery module of the lower box body are improved. Therefore the problem of downward deflection of the lower box body is avoided and the strength of the battery pack is improved, so that the battery pack is suitable to be fixed at the bottom of the vehicle.