Pneumatic Suspension Air Spring Control for Stroke End Prevention

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Solution Overview

Problem

Pneumatically sprung vehicle seats face limited residual spring travel due to design constraints and installation space limitations, leading to a high risk of reaching stroke end stops during uneven road conditions, which compromises seating comfort and operational reliability, especially for smaller drivers.

Innovation Solution

A pneumatic suspension system with a first control device that exhausts air after a first stroke end range and supplies air after a second stroke end range, and a second control device that shuts off air discharge during a predeterminable period after a first lifting stop, dynamically adjusting spring travel to prevent stroke end stops and optimize damping during strong vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the vehicle seat is adjusted to a lower seating position to accommodate smaller drivers, then the driver can reach the pedals, but the residual spring travel of the air spring is reduced, increasing the risk of reaching stroke end stops

Engineering Contradiction:
Improvedriver's ability to reach pedalsVSAvoidrisk of reaching stroke end stops
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control system dynamically adjusts the air spring characteristics based on real-time vibration detection. When strong vibrations are detected, the system modifies air supply/discharge behavior to prevent stroke end stops, transforming the static suspension system into a dynamic one that adapts to changing road conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses vibration sensors to detect oscillating movements and feeds this information back to the control device. Based on the feedback signal indicating strong vibrations, the control device adjusts air supply to the air spring to prevent reaching stroke end stops, creating a closed-loop control system

Inventive Principle:
Principle #23Feedback

2Reliability

If additional hydraulic dampers with hard damping are added to counteract oscillating movements, then stroke end stops are prevented, but the driver can still feel the vibration movements

Engineering Contradiction:
Improveprevention of stroke end stopsVSAvoidvibration discomfort to driver
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system uses pneumatic control of the air spring instead of traditional hydraulic dampers. By controlling air supply to the air spring, the system achieves both stroke end stop prevention and vibration damping, eliminating the need for separate hydraulic dampers and reducing vibration transmission to the driver

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If the available spring deflection is increased to compensate for strong oscillating movements, then stroke end stops are avoided, but the installation space requirements increase

Engineering Contradiction:
Improveavoidance of stroke end stopsVSAvoidinstallation space for suspension system
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The system changes the parameters of the air spring by dynamically adjusting air pressure and volume through controlled air supply. This allows the air spring to provide adequate stroke end stop prevention without increasing the physical dimensions of the suspension system, maintaining compact installation space

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

This solution dynamically adjusts the residual spring travel to prevent stroke end stops, enhancing seating comfort and operational reliability by optimizing spring deflection and damping, ensuring the driver experiences reduced vibration discomfort and maintains access to vehicle controls.

Implementation Method 1

at least one air spring (8), and in which a second control device (20) is arranged for supplying air into the air spring (8) and for shutting off the exhaust of air in the air spring (8) during a predeterminable first period of time after a first lifting end stop (54) has been reached

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2394843B1Pneumatic suspension system for vehicles and method for pneumatic suspension of vehicle sections
Publication Date: 2014.10.08 GRAMMER AG
  • EP2394843B1 patent drawingFigure 1
  • EP2394843B1 patent drawingFigure 2
  • EP2394843B1 patent drawingFigure 3

AI summary

The invention relates to a pneumatic suspension system for vehicles with at least a first and a second part (3, 4), wherein both parts (3, 4) are mounted relative to each other in a way that allows for vibration and pneumatic rebound by means of at least one air spring (8), wherein a first control device (10) is arranged for supplying and removing air to and from the air spring (8), which carries out the removal of air after a first stroke end region (62) of the suspension system, in which the air spring (8) is in a compressed state, has been reached, and which carries out the supply of air after a second stroke end region (63) of the suspension system, in which the air spring (8) is in an extended state, has been reached, wherein a second control device (20) is provided for supplying air to the air spring (8) and for switching off the removal of air from the air spring (8) during a predetermined first time period (61),after a first stroke end stop (58) has been reached for the first time in the first stroke end range (62), and/or a third control device (30) for removing air from the air spring (8) and for switching off the supply of air to the air spring (8) during a predetermined second time period, after a second stroke end stop has been reached for the first time in the second stroke end range (63).