Semi-Trailer Loading with Rear Axle Suspension Control

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Solution Overview

Problem

Existing methods for increasing the payload of semi-trailers within legal limits are either costly, unsafe, or not adaptable for semi-trailers, as they often require adding an additional axle which increases the length and reduces agility.

Innovation Solution

A method for loading a trailer with at least two axles connected by independently adjustable suspension systems, where the load on the kingpin is maintained at or below a threshold by adjusting the suspension parameters of the rearmost axle during loading, allowing for increased payload without exceeding legal limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If an additional axle is added to increase payload, then the load capacity is improved, but the production cost and servicing cost increase

Engineering Contradiction:
Improvepayload capacityVSAvoidproduction cost
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent changes the suspension parameter (air pressure) of the rearmost axle to redistribute load from the kingpin to the trailer axles. By adjusting the suspension stiffness through pressure control, the system achieves increased payload capacity without adding physical axles, thereby avoiding the manufacturing and servicing costs associated with additional components.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If an additional axle is added to increase payload, then the load capacity is improved, but the trailer length increases and agility is reduced

Engineering Contradiction:
Improvepayload capacityVSAvoidtrailer length
Core Design Contradiction:
Quantity of substanceVSLength of moving object

Solution Approach 1:

The patent uses suspension parameter adjustment (air pressure control) to achieve load redistribution without physically extending the trailer. By modifying the suspension characteristics of existing components rather than adding new structural elements, the trailer maintains its original length and agility while still increasing payload capacity.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the threshold load on the kingpin is exceeded to increase payload, then the payload capacity is improved, but the safety and legal compliance deteriorate

Engineering Contradiction:
Improvepayload capacityVSAvoidsafety
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent implements a feedback control system where the suspension parameter adjustment is based on the actual load measured on the kingpin. The control unit continuously monitors the kingpin load and adjusts the rearmost axle suspension pressure accordingly, ensuring the kingpin load remains at or below the threshold while maximizing payload capacity, thus maintaining safety and legal compliance.

Inventive Principle:
Principle #23Feedback

4Quantity of substance

If the suspension parameter is adjusted to relieve kingpin load, then the payload capacity is improved, but the device complexity increases

Engineering Contradiction:
Improvepayload capacityVSAvoidsuspension control system
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent employs a self-regulating suspension system where the control unit automatically adjusts the rearmost axle suspension pressure based on kingpin load measurements without requiring external intervention. The system uses readily available components (air suspension, pressure regulators, load sensors) and performs self-adjustment, minimizing the need for complex external control mechanisms while achieving increased payload capacity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4556264A1Trailer loading method
Publication Date: 2025.05.21 VOLVO TRUCK CORP
  • EP4556264A1 patent drawingFigure 1~2
  • EP4556264A1 patent drawingFigure 3
  • EP4556264A1 patent drawingFigure 4

AI summary

Method (1000) for loading a trailer comprising: providing (1100) a trailer having at least two axles connected to a trailer chassis by independently adjustable suspension systems, the at least two axles including a frontmost axle and a rearmost axle, the trailer further comprising a kingpin configured to be removably connected to a fifth wheel of a tractor; a first loading step (1400) comprising loading the trailer until a threshold load is reached on the kingpin; and then a second loading step (1500) comprising: loading (1510) the trailer further; and adjusting (1520) a suspension parameter of the rearmost axle to ensure that the load on the kingpin remains at or below the threshold load.