Battery Pack Underguard Rib Structure for Underbody Impact Protection

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Solution Overview

Problem

Battery packs mounted in the floor of a vehicle cabin are susceptible to impact from below due to uneven road surfaces, which can damage the battery and its cooling system.

Innovation Solution

A vehicle-mounted structure for a battery pack that includes a bottom plate with integrated cooling pipes and a plate-shaped underguard with alternately arranged upwardly and downwardly protruding ribs, where the underguard is attached to the housing such that the cooling pipes face the downwardly protruding ribs, providing protection from impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a battery pack is mounted in the floor of a vehicle cabin, then the center of gravity is lowered and weight distribution is improved, but the battery pack becomes vulnerable to impact from below due to uneven road surfaces

Engineering Contradiction:

Improveweight distributionVSAvoidimpact from below

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The underguard is installed beforehand below the battery pack to cushion and absorb impact forces from road unevenness before they can reach the battery pack. The ribbed structure of the underguard is specifically designed to deform and absorb impact energy, protecting the cooling pipes and battery components from damage.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The underguard acts as an intermediary protective structure between the road surface and the battery pack. It absorbs and dissipates impact forces through its ribbed design, preventing direct transmission of harmful forces to the cooling pipes and battery components while maintaining the floor-mounted configuration benefits.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If cooling pipes are installed inside the battery pack for liquid cooling, then heat dissipation efficiency is improved, but the cooling pipes become more vulnerable to impact damage

Engineering Contradiction:

Improveheat dissipationVSAvoidimpact damage to cooling pipes

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The underguard serves as an intermediary protective barrier that absorbs impact forces before they can reach the cooling pipes. The ribbed structure of the underguard is specifically designed to deform and absorb impact energy, preventing direct transmission of forces to the cooling pipes while maintaining their functionality for heat dissipation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The underguard is positioned beforehand below the battery pack to cushion impact forces before they reach the cooling pipes. This pre-positioned protective structure ensures that the cooling pipes are protected from impact damage while maintaining their heat dissipation function.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the underguard is attached directly to the bottom plate, then structural simplicity is improved, but the cooling pipes may come into contact with the underguard and suffer damage during impact

Engineering Contradiction:

Improvestructural complexityVSAvoidcontact between underguard and cooling pipes

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The bottom plate is designed with locally differentiated properties: certain areas have increased thickness or reinforced structures specifically at locations where cooling pipes are positioned. This local reinforcement creates protective spacing between the cooling pipes and the underguard without requiring complex overall structural changes to the entire bottom plate.

Inventive Principle:

Principle #3Local quality

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 structure effectively absorbs impact from below, protecting the battery pack and its cooling system, while maintaining efficient heat exchange and ensuring reliable operation.

Implementation Method 1

cooling pipes provided inside or on a surface of the bottom plate for circulating coolant

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

coolant circulates in cooling pipes

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

underguard having upwardly protruding ribs and downwardly protruding ribs that are alternately arranged

Methodology Applied

Scientific EffectImpact absorption: Damping

Implementation Method 4

the underguard is attached to the housing such that an upper plate of the upwardly protruding ribs and a bottom surface of the bottom plate are spaced apart from each other

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentEP4299352B1Vehicle-mounted battery pack structure

Publication Date: 2025.01.22 NISSAN MOTOR CO LTD

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AI summary

A battery pack (1) is mounted in the floor of a vehicle cabin. A plate-shaped underguard (2) is provided below a bottom plate (10b) of a housing (10) of the battery pack (1). The underguard (2) has a shape in which upwardly protruding ribs (20) and downwardly protruding ribs (30) are alternately arranged. Cooling pipes (12) provided inside (or on the surface of) the bottom plate (10b) of the housing (10) are arranged facing the downwardly protruding ribs (21). The underguard (2) is attached to the housing (10) such that a top plate (20a) of the upwardly protruding ribs (20) and a bottom plate (10b) of the housing (10) are spaced apart.