Fuel Cell Stack Case Layout for Water Drainage and Seal Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing fuel cell stack designs face issues with water accumulation near the seal due to inclination, leading to potential seal deterioration from rainwater and splashback, which compromises airtightness.

Innovation Solution

The stack case is designed with a downward inclination in the stacking direction and an upward inclination of the upper surface towards the discharge pipe, combined with a draft angle and ribs on the upper surface, to facilitate water drainage and prevent puddle formation near the seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the stack case is disposed with downward inclination toward the discharge end to facilitate water discharge, then generated water can be easily discharged by gravity, but rainwater entering the upper surface accumulates near the lid and deteriorates the seal

Engineering Contradiction:

Improvewater dischargeVSAvoidseal deterioration from rainwater accumulation

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The upper surface of the case main body is given a specific inclination direction (opposite to the stacking direction inclination) in the region where rainwater accumulates, creating different surface characteristics in different locations. This local surface inclination change directs rainwater away from the seal while maintaining the overall downward inclination for water discharge

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of inclining the entire case uniformly for water discharge, the upper surface is inclined in the opposite direction (away from the discharge end) to prevent rainwater accumulation, while the stacking direction maintains its downward inclination. This inverted approach for the upper surface solves the rainwater problem without compromising water discharge

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If the stacking direction is inclined downward to discharge generated water, then water discharge efficiency is improved, but the upper surface inclination causes rainwater to flow toward the discharge end and accumulate near the lid

Engineering Contradiction:

Improvewater discharge efficiencyVSAvoidseal airtightness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The case main body is divided into functionally different surfaces: the stacking direction maintains downward inclination for water discharge, while the upper surface is independently inclined in the opposite direction to prevent rainwater accumulation. This segmentation of surface functions resolves the contradiction between discharge efficiency and seal protection

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If the case main body is made as a cast product with draft angle, then manufacturing is simplified, but the internal space geometry becomes complex to achieve proper water drainage

Engineering Contradiction:

Improvecase main body manufacturingVSAvoidinternal space geometry for water drainage

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The draft angle for manufacturing and the water drainage geometry are merged into a single integrated design. The internal space is shaped such that the draft angle itself creates the water drainage path, eliminating the need for separate complex geometric features while maintaining both manufacturability and drainage function

Inventive Principle:

Principle #5Merging (Combining)

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

This design effectively directs water away from the seal, preventing puddle formation and thus suppressing seal deterioration, ensuring improved airtightness and durability.

Implementation Method 1

By using gravity, the generated water can be easily discharged

Methodology Applied

Scientific EffectGravity: Gravitation

Implementation Method 2

the water accumulated on the upper surface of the stack case can be moved to an opposite end on an opposite side of the other end at which the opening is formed

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS12451506B2Stack case

Publication Date: 2025.10.21 TOYOTA JIDOSHA KK

AI summary

A stack case houses a plurality of fuel cells in a stacked state, and includes a case main body, a lid, and a seal. The stack case is configured to be disposed in a vehicle such that a stacking direction is inclined downward with respect to a horizontal direction as a distance to the discharge pipe decreases and an upper surface of the case main body is inclined upward with respect to the horizontal direction as a distance to the discharge pipe decreases.