Electromechanical Brake Lock for Push Trailers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electromechanical brake systems for electrically driven push trailers with mechanical overrun brakes face challenges in ensuring safe braking, particularly during abrupt emergency braking, due to high friction between pawls and racks, which can lead to failure in locking the drawbar and preventing overrun brake function.

Innovation Solution

The system employs an electromagnetic coil that supplies energy to a controller, using an electromagnetically activatable actuating rod to transfer thrust from the chassis to the drawbar apparatus, eliminating the need for racks and pawls, and ensuring the actuating force exceeds the motor thrust force, with diodes and power semiconductors managing current flow for safe operation during braking and overrun.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanically operated pawl locks against a rack during push operation, then the drawbar can be locked, but during abrupt emergency braking the high friction between pawl and rack prevents safe release of the pawl, causing the overrun brake to fail

Engineering Contradiction:
Improvebraking safetyVSAvoidfriction between pawl and rack
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes the rack and pawl mechanism entirely from the system. Instead of using a mechanical pawl-rack locking system, the invention employs an electromagnetic coil that directly acts on the drawbar apparatus through an electromagnetically activatable actuating rod, eliminating the harmful friction between pawl and rack that prevented reliable release during emergency braking.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical pawl-rack locking system with an electromechanical system. The electromagnetic coil generates electromagnetic force to actuate the drawbar apparatus, substituting the mechanical friction-based pawl-rack interaction with an electromagnetic field-based actuation mechanism that allows for more reliable and controlled operation during braking.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Force

If the electromagnetic coil is dimensioned to provide sufficient actuating force during thrust, then the actuating force exceeds the motor thrust force, but this may cause unwanted action from the electromagnetic coil during braking

Engineering Contradiction:
Improveactuating forceVSAvoidunwanted action during braking
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent makes the electromagnetic coil's operation dynamic by controlling its energization state based on the operational phase. During thrust, the coil is energized to provide actuating force; during braking, the coil is de-energized to prevent unwanted action. This dynamic control allows the same electromagnetic component to serve different functions in different operational states without generating harmful effects.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electromagnetic coil operates periodically - energized during thrust phases and de-energized during braking phases. This periodic on/off operation pattern allows the system to utilize the electromagnetic force when needed while avoiding its harmful effects during braking, achieving both sufficient actuating force and prevention of unwanted actions.

Inventive Principle:
Principle #19Periodic action

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 enhances braking safety by preventing unwanted actions from the electromagnetic coil during braking and allows for efficient engine braking and recuperation without interfering with engine control, applicable to various electric drives using direct current sources.

Implementation Method 1

an electromagnetically activatable actuating rod (10) being activated by an electromagnetic coil (7) during propulsion in order to transfer the thrust from the chassis (1) into the part that is movable relative to it of the drawbar apparatus (2)

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP3981654B1Electromechanical brake lock for an electrically driven pushing trailer
Publication Date: 2022.11.30 THIEL KARL
  • EP3981654B1 patent drawingFigure 1~5

AI summary

For push trailers with an electric drive motor (4), an electromechanical locking mechanism is suitable, provided that it is ensured that this locking mechanism is reliably released when the drive motor (4) is de-energized. For this purpose, an electromagnetic coil (7) is inserted into the current flowing from the battery (5) through the controller (8). During push operation, the current flowing through the coil moves an electromagnetically activated actuating rod (10) to initiate the motor's thrust into the movable part of the drawbar assembly (2) relative to the chassis (1), thus pushing the towing vehicle. After the drive is switched off, the coil (7) is de-energized, and the actuating rod (10) can be easily pushed back through the drawbar assembly (2) without obstruction from racks or pawls to release the brake.