Modular Rear Suspension Structure for Twist or Rigid Axle Layouts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current motor-vehicle suspension systems lack a modular structure that can easily switch between twist axle and rigid axle configurations, making it difficult to adapt to design changes such as those required for vehicles with internal combustion engines versus electric traction, where space for batteries may necessitate different suspension configurations.

Innovation Solution

A motor-vehicle rear suspension system with a main tubular element and longitudinal arms that can be rigidly connected in two positions: coaxially with wheel supports for a rigid axle suspension or at intermediate positions for a twist axle suspension, using auxiliary tubular elements and a stabilizing bar to define the configurations, allowing for a simple and cost-effective switch between the two types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a suspension system is designed as a fixed configuration (either twist axle or rigid axle), then the structural design is simple and manufacturing is straightforward, but the system cannot adapt to different vehicle traction types and design requirements

Engineering Contradiction:
Improveconfiguration adaptabilityVSAvoidstructural complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The suspension system is divided into modular components: longitudinal arms with mounting plates, auxiliary tubular elements, and a main tubular element. These segmented components can be independently positioned and connected to create different suspension configurations, enabling adaptability without requiring complete structural redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The longitudinal arms are designed with universal mounting features that can accommodate both twist axle and rigid axle configurations. The mounting plates and auxiliary tubular elements serve multiple functions depending on their positioning, allowing a single structural design to fulfill different suspension requirements for various vehicle types.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If different suspension configurations are designed separately for different vehicle types, then each configuration is optimized for its specific use, but production costs increase and manufacturing complexity increases

Engineering Contradiction:
Improveproduction simplicityVSAvoidconfiguration flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The longitudinal arms are pre-equipped with mounting plates and positioning features during manufacturing that enable both suspension configurations. This preliminary preparation allows for easy reconfiguration later without requiring complex modifications, simplifying production while maintaining configuration flexibility.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The suspension system incorporates dynamic reconfigurability through movable mounting plates and selectable connection positions. The structure can transition between fixed and flexible states, allowing manufacturers to produce standardized components that can be adapted to different vehicle requirements without increasing production complexity.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the main tubular element is rigidly connected to longitudinal arms at intermediate positions for twist axle configuration, then the suspension provides better traction and stability, but the structure becomes more complex and expensive

Engineering Contradiction:
Improvesuspension stabilityVSAvoidconnection structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The auxiliary tubular elements are nested within or connected to the longitudinal arms, with the main tubular element connecting to these auxiliary elements. This nested arrangement provides stable intermediate-position connections for twist axle configuration while maintaining a compact and relatively simple overall structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The auxiliary tubular elements serve as intermediary components between the main tubular element and the longitudinal arms. These intermediaries enable stable intermediate-position connections without requiring direct complex connections between the main element and arms, simplifying the overall connection structure while maintaining reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Volume of moving object

If the main tubular element is rigidly connected to longitudinal arms at coaxial positions for rigid axle configuration, then the suspension provides better space efficiency for battery housing, but the structure loses configurability

Engineering Contradiction:
Improvespace utilizationVSAvoidconfiguration switching capability
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The connection structure is segmented into discrete mounting plates and auxiliary elements that can be positioned at different locations. This segmentation allows the same components to achieve both coaxial (space-efficient) and intermediate (configurable) arrangements, maintaining adaptability while optimizing space utilization when needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mounting plates and auxiliary tubular elements are designed with universal positioning capabilities that enable them to function in both rigid axle and twist axle configurations. The same structural components can be arranged to provide either coaxial connections for space efficiency or intermediate connections for configurability, eliminating the need for separate designs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3858648B1Motor-vehicle rear suspension system having a modular structure which can be configured as a twist axle suspension or as a rigid axle suspension
Publication Date: 2024.11.13 STELLANTIS EUROPE SPA
  • EP3858648B1 patent drawingFigure 1A
  • EP3858648B1 patent drawingFigure 1B
  • EP3858648B1 patent drawingFigure 1C

AI summary

A motor-vehicle rear suspension system comprises a pair of longitudinal arms (10), and a cross-member in the form of a tubular element (90). These components are configured so that the tubular element (90) can be rigidly connected to the longitudinal arms (10) in any of two selectable mounting positions. In a first mounting position, the tubular element (90) is rigidly connected to the longitudinal arms (10) at a position substantially coaxial with the wheel supports (60), so as to define a rigid axle suspension. In a second mounting position, the tubular element (90) is rigidly connected to the longitudinal arms (10) at an intermediate position between the front and rear ends of the longitudinal arms (10), so as to define a twist axle suspension.