Fifth Wheel Coupling Force Measurement via Intermediate Element

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Solution Overview

Problem

Existing fifth wheel coupling systems fail to accurately measure the force flow due to interference from wear and aging of components like bearing inserts and damping elements, leading to incomplete and unreliable force measurements.

Innovation Solution

Incorporating an intermediate element with sensors between the bearing insert and coupling plate, which is designed to transmit force exclusively through the intermediate element, allowing for precise measurement of force flow independent of wear on other components, and using a metal construction for minimal deformation and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If force sensors are attached to the king pin to measure forces between the king pin and coupling plate, then part of the power flow can be measured, but the measurement is incomplete because power is also transmitted via frictional forces between the trailer and the coupling plate

Engineering Contradiction:
Improveforce measurement completenessVSAvoidpower flow information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The invention extracts the force measurement function from the traditional king pin attachment point and relocates it to the coupling plate itself. By integrating force sensors directly into the coupling plate structure, the system captures all force components (including frictional forces) that act on the coupling plate, providing complete power flow measurement without the information loss experienced in king pin-based measurements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The coupling plate serves multiple functions: it transmits power from the trailer, provides a mounting surface for the force sensors, and acts as the measurement platform itself. This multi-functional design allows the same component to both transmit forces and measure them, eliminating the need for separate measurement apparatus that would miss frictional force components.

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

2Measurement precision

If measuring elements are arranged between the mounting surface and the fifth wheel coupling to measure forces, then forces between the mounting plate and fifth wheel coupling can be measured, but the measurement is influenced by vehicle frame deformation at this location

Engineering Contradiction:
Improveforce measurement accuracyVSAvoidvehicle frame deformation influence
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the force measurement function from the mounting plate area (which is subject to frame deformation) and relocates it to the coupling plate. By measuring forces directly at the coupling plate where the trailer loads are applied, the system eliminates the harmful influence of vehicle frame deformation that plagues measurements taken at the mounting surface.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If force measurement is performed on the bearings of the clutch plate, then force flow can be measured, but the measurement is affected by the division of force flow between the bearing insert and damping element, and this division changes due to aging and wear

Engineering Contradiction:
Improveforce flow measurementVSAvoidmeasurement consistency over time
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The invention extracts the force measurement from the bearing structure (where force division between bearing insert and damping element creates measurement uncertainty) and relocates it to the coupling plate. By measuring forces directly on the coupling plate before the force flow divides into multiple paths, the system ensures consistent and reliable measurements that do not change with aging and wear of bearing components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The coupling plate acts as an intermediary measurement platform that captures the total force flow from the trailer king pin before it is distributed to various components (bearing insert, damping element). This intermediary position allows measurement of the complete force flow without being affected by how the force is subsequently divided and distributed to different components that are subject to wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If multiple sensors are arranged in the bearing structure of the fifth wheel coupling to measure force flow, then comprehensive force data can be obtained, but the system complexity increases significantly

Engineering Contradiction:
Improveforce flow measurement completenessVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention merges the force measurement function directly into the coupling plate structure itself. By integrating force sensors into the coupling plate, the system obtains comprehensive force flow data with a single measurement platform, eliminating the need for multiple distributed sensors in the bearing structure and significantly reducing system complexity while maintaining measurement completeness.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables accurate determination of force flow size and direction, ensuring long-term reliable measurements by isolating the force measurement from wear-related influences on the bearing insert and damping element, thus providing unadulterated force data for improved load monitoring and energy optimization in tractor-trailer systems.

Implementation Method 1

the intermediate element is made of metal, preferably steel... allows sufficient elastic deformation when a corresponding force acts on the intermediate element

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3792165B1Saddle coupling, method of detecting load, wear and/or strain conditions in a saddle coupling and/or in a trailer, and computer program for such a method
Publication Date: 2023.09.20 SAF HOLLAND GMBH
  • EP3792165B1 patent drawingFigure 1
  • EP3792165B1 patent drawingFigure 2
  • EP3792165B1 patent drawingFigure 3

AI summary

Fifth wheel coupling (1) for reversibly coupling a trailer to a tractor unit, comprising: - a coupling plate (20) for receiving a pin element of the trailer, - a bearing block (30) for pivoting the coupling plate (20) about a pivot axis (S) and - a bearing insert (21) which, in the assembled state, is arranged between the bearing block (30) and the coupling plate (30), wherein an intermediate element (40) is provided between the bearing insert (21) and the coupling plate (30), which includes at least one sensor for force detection.