Air Spring Composite Part for Strength and Gas Tightness

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Solution Overview

Problem

Existing air spring components for motor vehicles face challenges in achieving both sufficient strength for force transmission and tightness, particularly in air spring pots, which are critical for connecting to vehicle parts and maintaining gas integrity.

Innovation Solution

A composite component comprising a first element made of die-cast aluminum for strength and a second element made of glass fiber-reinforced thermoplastic for tightness, connected through material bonding and overmolding, ensuring both strength and tightness by forming a weld seam under an inert atmosphere.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a single material is used for the air spring component, then the manufacturing process is simple, but it cannot achieve both sufficient strength for force transmission and sufficient tightness for gas retention

Engineering Contradiction:
Improvestrength for force transmissionVSAvoidtightness for gas retention
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies composite materials by combining a thermoplastic base material with glass fiber reinforcement. The thermoplastic matrix provides gas tightness and sealing properties, while the glass fiber reinforcement enhances mechanical strength and stiffness. This composite structure enables the single-component air spring element to simultaneously achieve both sufficient strength for force transmission and sufficient tightness for gas retention, resolving the technical contradiction between these two requirements.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes parameter changes by controlling the crystallization behavior of the thermoplastic material during injection molding. By adjusting cooling rates and processing parameters, the material achieves optimal crystalline structure that enhances both mechanical properties and sealing characteristics. This parameter optimization allows the material to simultaneously deliver required strength and tightness without requiring multiple materials or components.

Inventive Principle:
Principle #35Parameter changes

2Strength

If metal materials are used for the air spring component, then strength for force transmission is sufficient, but gas tightness and corrosion resistance are insufficient

Engineering Contradiction:
Improvestrength for force transmissionVSAvoidcorrosion and gas tightness
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces traditional metal components with a thermoplastic-based composite that, while having different service life characteristics, provides superior corrosion resistance and gas tightness. The thermoplastic material does not rust or corrode like metal, eliminating a major harmful factor. Although thermoplastics may have different durability characteristics under certain conditions, they provide adequate service life for air spring applications while avoiding corrosion issues entirely.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If plastic materials are used for the air spring component, then corrosion resistance and gas tightness are sufficient, but strength for force transmission is insufficient

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidstrength for force transmission
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent employs composite materials by incorporating glass fiber reinforcement into the thermoplastic matrix. The glass fibers provide enhanced mechanical strength, stiffness, and dimensional stability, while the thermoplastic matrix maintains corrosion resistance and gas tightness. This composite construction allows the material to overcome the inherent weakness of pure plastics in force transmission applications while preserving their corrosion-resistant properties.

Inventive Principle:
Principle #40Composite materials

4Strength

If multi-component construction is used for the air spring component, then both strength and tightness can be achieved, but the manufacturing process becomes complex and post-processing is extensive

Engineering Contradiction:
Improvestrength for force transmissionVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges multiple functions and material properties into a single injection-molded component. Instead of assembling separate metal and plastic parts to achieve both strength and tightness, the composite thermoplastic material with glass fiber reinforcement is formed as one integrated piece through injection molding. This single-component construction eliminates the need for complex assembly processes, reduces the number of parts, and minimizes post-processing requirements while maintaining both structural strength and gas tightness.

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

The composite component achieves enhanced strength and tightness, allowing for effective force transmission and gas retention, while reducing weight and requiring minimal post-processing, thus improving the performance and durability of air spring components.

Implementation Method 1

heating and/or melting or plasticizing the joining areas (72) and subsequently pressing the joining areas (72) together to create a material bond, in particular a weld seam (70), under an inert atmosphere

Methodology Applied
Scientific EffectOxidation prevention: Oxidation

Data Source

PatentEP3242806B2Composite part and air spring component containing such a composite part
Publication Date: 2025.07.16 VIBRACOUSTIC SE
  • EP3242806B2 patent drawingFigure 1~2
  • EP3242806B2 patent drawingFigure 3~4
  • EP3242806B2 patent drawingFigure 5

AI summary

The invention relates to a composite part (10) for an air spring component of a motor vehicle, comprising a first element (14) made of a first material and a second element (16) made of a second material, wherein the second element (16) at least partially surrounds the first element (14). The invention also relates to an air spring component comprising such a composite part (10) and a second component which are bonded to each other.