Fuel Cell Layout Using Low-Voltage Rear Placement in Vehicles

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Solution Overview

Problem

In fuel cell vehicles, mounting the fuel cell in the lower rear seat area necessitates raising the floor, which narrows the occupant space and poses electrical safety concerns, particularly in collision scenarios.

Innovation Solution

The fuel cell is positioned in the rear portion of the vehicle with a DC voltage of less than 60 V, allowing it to be disposed in a crushable zone without requiring protective measures, while the battery is placed in the front, maintaining occupant space and ensuring electrical safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the fuel cell is mounted in the lower portion of the rear seat arrangement portion, then the fuel cell can be installed in the vehicle, but the floor surface must be raised which narrows the occupant space

Engineering Contradiction:
Improvefuel cell installation spaceVSAvoidoccupant space
Core Design Contradiction:
Volume of moving objectVSArea of stationary object

Solution Approach 1:

The patent transitions from horizontal mounting (under the floor) to vertical mounting (on the rear side of the front seat). This dimensional change allows the fuel cell to be installed in the lateral space between the front and rear seats rather than requiring floor elevation, thereby preserving occupant space while accommodating the fuel cell.

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

2Volume of moving object

If the fuel cell is mounted in the lower portion of the rear seat arrangement portion, then the fuel cell can be installed, but additional protective measures are required which increase device complexity

Engineering Contradiction:
Improvefuel cell installation spaceVSAvoidprotective measures
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent extracts the fuel cell from the high-voltage category by selecting a low-voltage model (less than 60V). This extraction from the high-voltage system eliminates the requirement for complex protective measures such as reinforced collision zones and specialized safety structures, thereby reducing device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Power

If a high voltage fuel cell is used, then power generation capability is improved, but electrical safety risks increase requiring additional protective measures

Engineering Contradiction:
Improvepower generation capabilityVSAvoidelectrical safety
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent changes the voltage parameter of the fuel cell from high voltage to low voltage (less than 60V). This parameter change maintains sufficient power generation capability for the vehicle while dramatically reducing electrical safety risks, thereby eliminating the need for additional protective measures and improving overall system reliability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3670242B1Fuel cell vehicle
Publication Date: 2024.03.06 NISSAN MOTOR CO LTD
  • EP3670242B1 patent drawingFigure 1
  • EP3670242B1 patent drawingFigure 2
  • EP3670242B1 patent drawingFigure 3(a)~3(b)

AI summary

In the fuel cell vehicle provided with the motor and configured to drive the motor with power of at least one of the fuel cell 1 and the battery, the fuel cell having a DC voltage of less than 60 V is disposed in the rear portion of the vehicle and the battery is disposed in the front relative to the fuel cell.