Compact Rear Chassis Frame with Extendible Underrun Guard

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Solution Overview

Problem

Existing commercial vehicle chassis designs fail to efficiently manage load distribution and comply with underrun protection regulations, particularly when loading and unloading containers, leading to potential safety issues and increased production costs.

Innovation Solution

A compact rear chassis frame design with an underrun protection bar connected via multiple elements, allowing for flush rear loading and unloading while improving load distribution and adhering to legal underrun protection standards using a minimal number of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a compact rear chassis frame design is used to position the payload close to the rear axle, then load distribution is improved and compliance with safety regulations is enhanced, but the ability to load and unload containers flush with the rear is compromised

Engineering Contradiction:
Improveload distributionVSAvoidcontainer loading and unloading
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The rear cross member is designed to be displaceable relative to the longitudinal members, allowing the chassis frame to dynamically adjust its configuration. During transport, the rear cross member positions close to the rear wheels for optimal load distribution. During loading/unloading operations, the rear cross member can be displaced to extend the chassis frame rearward, enabling containers to be positioned flush with the rear of the vehicle.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the rear cross member extends above rear wheels to provide locking mechanisms, then payload securing capability is improved, but compliance with underrun protection regulations becomes difficult

Engineering Contradiction:
Improvepayload lockingVSAvoidunderrun protection compliance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The solution addresses the spatial conflict by utilizing the vertical dimension. The underrun protection bar is positioned below the rear cross member and rear wheels, creating a separate protective element in the lower dimension. This allows the rear cross member to extend upward for locking mechanisms while the underrun protection bar provides the required protective barrier at ground level, satisfying both requirements simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Stability of the object's composition

If multiple connecting elements are used to connect the underrun protection bar to the rear cross member, then structural stability is improved, but device complexity increases

Engineering Contradiction:
Improveunderrun protection stabilityVSAvoidnumber of connecting elements
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Instead of uniformly distributing connecting elements along the entire length of the underrun protection bar, the invention applies connecting elements at specific critical locations. The bar is connected to the rear cross member via connecting elements positioned to provide adequate structural stability and load distribution, rather than using excessive numbers of connections throughout the structure.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3398810B1Compact rear end of utility vehicles with extendible rear end
Publication Date: 2020.08.19 FAHRZEUGWERK BERNARD KRONE GMBH & CO KG
  • EP3398810B1 patent drawingFigure 1
  • EP3398810B1 patent drawingFigure 2
  • EP3398810B1 patent drawingFigure 3

AI summary

The invention describes a commercial vehicle chassis 1 with a chassis frame comprising wheel axles with associated wheels 2, longitudinal crossmembers 4, and transverse crossmembers 5, one of which, a rear transverse crossmember 5.1 closing off the rear of the chassis frame, forms part of a chassis frame rear 7. The rear transverse crossmember 5.1 and at least one further transverse crossmember 5 have locking elements 5.2 for locking a payload 10, in particular a container. The chassis frame rear 7 comprising the rear transverse crossmember 5.1 is designed as a compact rear section with an underride guard arranged below the rear transverse crossmember 5.1, which has a beam 9. The rear transverse crossmember 5.1 with its locking elements 5.2 extends at least partially above the rear wheels 2 and/or the wheel covers 3 associated with the rear wheels 2.The beam 9 of the underride guard is arranged in certain areas directly behind the rear wheels 2 and/or behind the wheel covers 3 associated with the rear wheels 2. (Fig. 3).