Passive Roll-Over Protection for Pivoting Axles

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Solution Overview

Problem

Agricultural vehicles with pivoting front axles face stability issues during rollover situations, particularly when power is lost, as existing anti-roll-over systems either require external energy or are not designed for pivoting front axles.

Innovation Solution

A passive roll-over protection system using a hydraulic cylinder connected via a steerable valve to an open oil reservoir or an accumulator, allowing the front axle to freely pivot in safe conditions and applying counterforce during rollover situations without energy input, with sensors to activate and deactivate the system based on rollover risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an active anti-roll-over system with hydraulic pump is used, then roll-over protection is provided, but the system fails when power is lost

Engineering Contradiction:
Improveroll-over protectionVSAvoidpower dependency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The hydraulic system uses the vehicle's own motion and gravity to generate the necessary hydraulic pressure for roll-over protection. The steering valve and hydraulic cylinder form a self-contained system that converts the vehicle's kinetic energy and gravitational force into stabilizing counterforces without requiring external power input.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention employs a hydraulic circuit with a steering valve and hydraulic cylinder to create a passive roll-over protection system. The hydraulic fluid transmits forces generated by the vehicle's motion and gravity to provide stabilizing counterforces during roll-over situations without requiring an active hydraulic pump.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of operation

If the hydraulic cylinder is connected to open oil reservoir, then the front axle can pivot freely for comfort and traction, but roll-over protection is not provided

Engineering Contradiction:
Improveaxle pivoting freedomVSAvoidroll-over protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The steering valve dynamically switches between two states: connected to the open oil reservoir allowing free axle pivoting for comfort and traction, and connected to the hydraulic cylinder providing roll-over protection. This dynamic switching enables the system to adapt to different operational conditions and provide both comfort and safety as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the hydraulic connection parameter of the cylinder by switching the steering valve position. When connected to the open reservoir, the system allows free movement; when connected to the hydraulic circuit, it provides resistive force for roll-over protection, thus changing the system's mechanical parameters based on operational needs.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a passive anti-roll-over system is used, then power loss does not affect operation, but it is not designed for pivoting front axles

Engineering Contradiction:
Improveoperation during power lossVSAvoidcompatibility with pivoting front axle
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The hydraulic cylinder serves multiple functions: it acts as a suspension system allowing free axle pivoting when connected to the open reservoir, and as a roll-over protection mechanism when connected to the hydraulic circuit. This multi-functionality makes the passive system adaptable to pivoting front axles while maintaining operation during power loss.

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

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

Provides enhanced stability and traction by allowing the front axle to pivot freely in safe conditions while effectively countering rollover without external energy, ensuring the system remains operational even when power is lost, and minimizing resonance and potential wheel lift during rollover.

Implementation Method 1

the hydraulic cylinder is fluid connected, via a steerable valve, to one of an open oil reservoir and an accumulator

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

When the anti roll-over state is activated, further pivoting of the axle will result in a pressure that is built up in the accumulator and cylinder which will act as a counterforce against further rotation of the axle

Methodology Applied
Scientific EffectHydraulic accumulation: Hydraulic Accumulator

Data Source

PatentEP2902221B1Roll-over protection system
Publication Date: 2021.06.02 CNH IND ITALIA SPA
  • EP2902221B1 patent drawingFigure 1
  • EP2902221B1 patent drawingFigure 2
  • EP2902221B1 patent drawingFigure 3~4

AI summary

Agricultural vehicle comprising a body to which a front axle is pivotally connected, wherein a hydraulic cylinder (7) is mounted as a suspension system between the body and the axle, wherein the hydraulic cylinder (7) is fluid-connected, via a steerable valve (20, 21), to one of an open oil reservoir (24) and an accumulator (25).