Trailer Control System Sequence for Tire Protection

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Solution Overview

Problem

Motor vehicle trailers with air suspension, service brake, and parking brake often face issues where the trailer is driven away without the air suspension being raised to the intended level, leading to potential tire damage and inaccurate brake pressure due to incomplete pneumatic system operation.

Innovation Solution

A control system that secures the service brake, parking brake, and air suspension in a specific order, ensuring the air suspension is operational before the parking brake is released, using overflow valves and switching valves to maintain the correct pressure and operational sequence, preventing tire damage and ensuring accurate brake pressure adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the parking brake is released before the air suspension is fully pressurized, then the trailer can be driven away faster, but the tire sidewalls may be damaged by contact with the fenders and the brake pressure will be inaccurate

Engineering Contradiction:
Improvetrailer departure speedVSAvoidtire integrity and brake accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary pressurization of the air suspension system before allowing the parking brake to be released. The sequence control ensures that the air suspension reaches the required pressure level first, then the parking brake release is enabled, preventing tire damage and ensuring accurate brake pressure from the outset

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A sequence control valve acts as an intermediary between the air suspension system and the parking brake system. This valve mediates the pressure distribution, ensuring that the air suspension is pressurized first and only after reaching the correct pressure can the parking brake system access the required air pressure for release

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the air suspension is pressurized to the correct level before departure, then the chassis is properly positioned and brake pressure is accurate, but the system requires more time to reach operational state

Engineering Contradiction:
Improveoperational accuracyVSAvoidsystem preparation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The pneumatic system is segmented into separate circuits with different pressure requirements - the air suspension circuit and the brake circuit. The sequence control valve divides the air supply to ensure proper pressurization sequence, allowing the system to reach operational state efficiently without unnecessary delays

Inventive Principle:
Principle #1Segmentation

3Device complexity

If a single pneumatic system supplies both the air suspension and parking brake, then the system structure is simpler, but the pressure required for brake release may not be available if the suspension is not yet pressurized

Engineering Contradiction:
Improvepneumatic system structureVSAvoidbrake release reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A sequence control valve is introduced as an intermediary component in the pneumatic system. This valve maintains system simplicity while ensuring reliable operation by controlling the sequence of air distribution - it prevents the parking brake from accessing air pressure until the air suspension has been properly pressurized first

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures the trailer is raised to the intended level and the brake pressure is adjusted correctly, preventing tire damage and ensuring safe operation by ensuring the air suspension is operational before the parking brake is released.

Implementation Method 1

an overflow valve is arranged in a line leading to the air spring bellows and in a line leading to the parking brake cylinder units, with the overflow valve in the line leading to the parking brake cylinder units being set to a comparatively higher opening pressure

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2058188B9Control system for vehicle trailers with service brake, parking brake and air suspension
Publication Date: 2012.03.14 HALDEX BRAKE PROD GMBH
  • EP2058188B9 patent drawingFigure 1
  • EP2058188B9 patent drawingFigure 2
  • EP2058188B9 patent drawingFigure 3

AI summary

The system (1) has a driving brake (8) provided with a control valve and an operating brake cylinder (12). A hand brake (10) is provided with a hand brake valve (31) and hand brake cylinder units (30). A pneumatic spring (9) is provided with a level regulating valve (26) and air suspension bellows (24). The driving brake, the hand brake and the pneumatic spring are secured against each other such that the driving brake, the pneumatic spring and the hand brake are transferred in an operative condition when filling the control system with compressed air. An independent claim is also included for a method for operating a control system for motor vehicle trailers.