Battery Safety Valve Structure for Accurate Pressure Venting

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Solution Overview

Problem

Lead storage batteries in vehicles generate gases during charging and discharging, leading to increased pressure and a fire risk due to gas accumulation, necessitating a safety valve that can effectively discharge gas to maintain constant pressure.

Innovation Solution

A safety valve with a simple structure comprising a main body, sub body, cap membrane, and cover, featuring a protrusion for line contact and a 'c' shaped cross-section cap membrane that discharges gas when pressure exceeds a set point, ensuring constant pressure in the battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional safety valve structure is used, then gas discharge function is provided, but the structure is complex and operating pressure error is large

Engineering Contradiction:
Improvevalve structure complexityVSAvoidoperating pressure accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The safety valve is divided into functionally independent segments: the cap membrane (with protrusion) handles pressure sensing and activation, the sub body provides structural support and gas passage, and the main body contains the discharge mechanism. This segmentation allows each component to be optimized for its specific function, reducing overall complexity while improving reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cap membrane is designed with a specific 'C' shape cross-section and protrusion geometry that changes the mechanical parameters of the valve. The protrusion contact area with the sub body outer surface is precisely controlled to achieve accurate operating pressure threshold, reducing pressure error while maintaining simple structure.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the cap membrane covers the sub body completely, then sealing is improved, but gas discharge efficiency is reduced

Engineering Contradiction:
Improvesealing performanceVSAvoidgas discharge efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The cap membrane is designed with non-uniform properties: the main body has a 'C' shape cross-section that provides sealing contact with the sub body, while the protrusion at the end portion creates a localized contact point with the sub body outer surface. This local quality differentiation ensures sealing in critical areas while maintaining gas discharge pathways in other areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The protrusion acts as an intermediary element between the cap membrane and sub body. It provides a controlled contact point that maintains sealing pressure while allowing gas to pass through designated pathways, thus mediating between the conflicting requirements of sealing and discharge efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the protrusion contact area is increased, then sealing is improved, but operating pressure error increases

Engineering Contradiction:
Improvesealing performanceVSAvoidoperating pressure precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The protrusion geometry is precisely controlled with specific dimensional parameters. The contact area between the protrusion and sub body outer surface is optimized to provide sufficient sealing force while maintaining a small, well-defined contact region that ensures accurate operating pressure threshold, preventing pressure error.

Inventive Principle:
Principle #35Parameter changes

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 safety valve effectively discharges gas to maintain constant pressure, improving battery function and lifespan with minimal operating pressure error.

Implementation Method 1

The cap membrane is formed so that a cross section is formed in a 'c' shape to cover an upper portion of the sub body due to a weight of the cap membrane

Methodology Applied
Scientific EffectWeight: Gravitation

Implementation Method 2

a protrusion is formed on an end portion of the cap membrane to be in line contact with an outer surface of the sub body

Methodology Applied
Scientific EffectLine contact sealing:

Implementation Method 3

a safety valve configured to maintain a constant pressure in a battery cell by discharging gas to the outside when a pressure in the battery cell reaches a set pressure

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4329071A1Safety valve
Publication Date: 2024.02.28 MODEL SOLUTION
  • EP4329071A1 patent drawingFigure 1
  • EP4329071A1 patent drawingFigure 2
  • EP4329071A1 patent drawingFigure 3

AI summary

A safety valve having a simple structure and a small operating pressure error and configured to maintain a constant pressure in a battery by effectively discharging gas in the battery is provided. A safety valve according to one aspect of the present invention, which is mounted on a battery and operates to maintain a predetermined internal pressure in the battery when the predetermined pressure or more is applied to the battery, includes a main body, a sub body, a cap membrane, and a cover, and a protrusion is formed on an end portion of the cap membrane to be in line contact with an outer surface of the sub body. The main body has a hollow structure formed so that a top communicates with a bottom and a discharge hole in one side surface of an upper portion. The sub body is formed to protrude from an inner circumferential surface of the main body, and a through hole is formed in one side surface of a lower portion of the sub body. The cap membrane is formed so that a cross section is formed in a "c" shape to cover an upper portion of the sub body due to a weight of the cap membrane. A cover opens or closes the upper portion of the main body. The protrusion is formed on the end portion of the cap membrane to be in line contact with the outer surface of the sub body.