Variable-Thickness Air Spring Sleeve for Durable Vehicle Suspension

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Solution Overview

Problem

Existing air spring sleeves for vehicles require complex reinforcing fiber processes to achieve improved durability and rigidity, which complicates manufacturing and reduces efficiency.

Innovation Solution

The sleeve is designed with varying thicknesses along its longitudinal direction, allowing for improved rigidity and spring properties without the need for complex reinforcing fibers, and is manufactured in multiple sections via injection molding to enhance design freedom and manufacturing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex reinforcing fiber process is used to improve durability and rigidity, then the durability and rigidity of the sleeve are improved, but the manufacturing complexity increases and manufacturing efficiency deteriorates

Engineering Contradiction:
ImprovedurabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the physical parameters of the rubber material by controlling the expansion rate during molding to create a cellular structure with 30-70% porosity. This parameter change allows the rubber sleeve to achieve improved durability and rigidity through its cellular structure rather than through complex reinforcing fiber processes, thereby resolving the contradiction between reliability and manufacturing complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates local quality variations by forming a cellular structure with controlled porosity distribution in different regions of the sleeve. The expansion rate is controlled to create different cell densities in different sections, providing localized reinforcement where needed while maintaining manufacturing simplicity

Inventive Principle:
Principle #3Local quality

2Strength

If a complex reinforcing fiber process is used to improve rigidity, then the rigidity of the sleeve is improved, but the manufacturing efficiency deteriorates

Engineering Contradiction:
ImproverigidityVSAvoidmanufacturing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent extracts and eliminates the complex reinforcing fiber process from the manufacturing workflow entirely. Instead of adding fibers to the rubber, the invention uses a controlled expansion process that creates the desired rigidity through cellular structure formation, thereby improving manufacturing efficiency while maintaining rigidity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical reinforcing fiber system with a pneumatic/expansion-based cellular structure formation process. By controlling the expansion rate during molding, the desired mechanical properties are achieved through the cellular geometry rather than through fiber reinforcement, simplifying the manufacturing process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If the sleeve is designed with varying thicknesses for each section, then the spring property and rigidity are improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvespring propertyVSAvoiddesign complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent uses parameter changes in the expansion rate to achieve varying thicknesses and cellular structures in different sections of the sleeve. By controlling the expansion rate as a variable parameter during the molding process, the design achieves optimized spring properties without requiring complex multi-step manufacturing procedures

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4474178A1Sleeve for air spring for vehicle and air spring for vehicle including same
Publication Date: 2024.12.11 ILJIN CO LTD
  • EP4474178A1 patent drawingFigure 1
  • EP4474178A1 patent drawingFigure 2
  • EP4474178A1 patent drawingFigure 3

AI summary

A sleeve for an air spring for a vehicle includes at least an upper sleeve and a lower sleeve. An upper circumferential portion of the upper sleeve is coupled to a top mount, a lower circumferential portion of the lower sleeve is coupled to a piston portion, and one of the upper sleeve and the lower sleeve is formed to have different thicknesses for each section along a longitudinal direction.