Electric Vehicle Battery Pack H-Shaped Case Stiffness

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Solution Overview

Problem

Existing battery packs face challenges in ensuring water tightness and high stiffness while minimizing the number of parts, and there is a need to improve cooling performance and compactness.

Innovation Solution

A battery pack design featuring a first case with an H-shaped section, integrated flange portions, and fin structures for enhanced stiffness, water tightness, and cooling, along with multiple cases and bus bars for efficient battery stacking and component integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate members (annular supporting frame and supporting plate) made of different materials are used, then water tightness can be ensured, but the number of parts increases and stiffness is reduced

Engineering Contradiction:
Improvewater tightnessVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the annular supporting frame and supporting plate into a single integrated case structure. The case is formed as one piece with a bottom wall and side walls that continuously connect, eliminating the need for separate members and reducing the total number of parts while maintaining structural integrity and water tightness

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If separate members (annular supporting frame and supporting plate) made of different materials are used, then water tightness can be ensured, but stiffness is reduced

Engineering Contradiction:
Improvewater tightnessVSAvoidstiffness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent merges the annular supporting frame and supporting plate into a single integrated case structure. The case is formed as one piece with a bottom wall and side walls that continuously connect, eliminating the need for separate members and reducing the total number of parts while maintaining structural integrity and water tightness

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The case is made from a composite material comprising a thermoplastic resin and a fiber reinforcement. The fiber reinforcement (such as glass fiber or carbon fiber) embedded in the thermoplastic resin matrix provides enhanced stiffness and strength to the integrated case structure, compensating for the elimination of separate structural members

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If conventional housing structure is used, then manufacturing is simple, but cooling performance is insufficient

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcooling performance
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent introduces cooling fins on specific portions of the case (such as on the side walls or bottom wall) to locally enhance heat dissipation capability. These fins are strategically positioned areas where heat generation is highest, providing improved cooling performance without requiring complete redesign of the entire housing structure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent incorporates a cooling passage through which cooling fluid flows to remove heat from the battery pack. The cooling fluid circulates through channels formed within or on the case structure, efficiently transferring heat away from the battery components while maintaining a relatively simple overall manufacturing process

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

The design achieves high stiffness, water tightness, improved cooling performance, and compact battery packaging, suitable for electric vehicles.

Implementation Method 1

a first fin provided on an outer circumferential surface of the first case main body... by providing the first fin on the outer circumferential surface of the first case main body, it becomes possible to increase a heat dissipation area and improve cooling performance

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

increase a heat dissipation area and improve cooling performance

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4629420A1Battery pack and electric vehicle
Publication Date: 2025.10.08 YAMAHA MOTOR CO LTD
  • EP4629420A1 patent drawingFigure 1
  • EP4629420A1 patent drawingFigure 2
  • EP4629420A1 patent drawingFigure 3

AI summary

An electric two-wheeled vehicle 10 includes a battery pack 40 supported by a body frame 12. The battery pack 40 includes a first case 66. The first case 66 includes a first case main body 76 having a wall portion 82 which has an H-shaped section constituted by a cylindrical portion 84 having two open ends and a partitioning portion 90 dividing an inside of the cylindrical portion 84 into a first storage portion 86 and a second storage portion 88; a first flange portion 78 formed at an outer circumference of a first end of the first case main body 76; and a second flange portion 80 formed at an outer circumference of a second end of the first case main body 76. A first plate member 72 is fixed to the first flange portion 78 to close the first storage portion 86. A second plate member 74 is fixed to the second flange portion 80 to close the second storage portion 88. First assembled batteries 126 are housed in the first storage portion 86 and second assembled batteries 128 are housed in the second storage portion 88.