Towing Nut Positioning in Vehicle Bumper Assemblies

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Solution Overview

Problem

Existing bumper assemblies for vehicles face challenges in aligning shock absorption boxes and towing nuts for optimal performance, particularly when stylistic considerations require non-alignment, leading to potential deformation of the bumper beam during towing and modification of the shock absorption box's crushing behavior during impacts.

Innovation Solution

A bumper assembly design where the towing nut is positioned offset laterally relative to the shock absorption box with a distance between 5mm to 10mm, utilizing a light alloy bumper beam with a cylindrical towing nut that crosses through and is welded to the bumper beam, featuring a shoulder for bearing and weld beads for secure attachment, and positioned at the edge of one of the shock absorption boxes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the towing nut is positioned far from the shock absorption box for stylistic reasons, then the aesthetic appearance is improved, but the bumper beam may deform during towing

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidbumper beam deformation
Core Design Contradiction:
ShapeVSStability of the object's composition

Solution Approach 1:

The patent specifies precise distance parameters (5mm to 10mm) between the towing nut and shock absorption box, optimizing both aesthetic appearance and structural stability. This parameter optimization allows the bumper beam to maintain its shape during towing while achieving desired stylistic offset.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the towing nut is positioned too close to the shock absorption box, then structural stability is improved, but the towing nut may create a hard point during impact

Engineering Contradiction:
Improvebumper beam stabilityVSAvoidhard point creation during impact
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent establishes a minimum distance of 5mm between the towing nut and shock absorption box to prevent the towing nut from creating hard points during impact. This parameter control ensures that the towing nut does not interfere with the crushing behavior of the shock absorption box while maintaining structural stability.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If a light alloy bumper beam is used to reduce weight, then fuel efficiency is improved, but the bumper beam is more susceptible to deformation during towing

Engineering Contradiction:
Improvebumper beam weightVSAvoidbumper beam deformation resistance
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The patent optimizes the distance parameter between the towing nut and shock absorption box to 5mm-10mm, which provides sufficient support to prevent deformation of lightweight aluminum bumper beams during towing operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The shock absorption box acts as an intermediary support structure between the towing nut and the bumper beam, providing additional stabilization that prevents deformation of the lightweight aluminum beam during towing.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If the towing nut is rigidly fixed to the bumper beam, then towing strength is improved, but the shock absorption box operation is degraded during impact

Engineering Contradiction:
Improvetowing strengthVSAvoidshock absorption operation
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent positions the towing nut at a controlled distance (5mm to 10mm) from the shock absorption box, which provides sufficient clearance to allow the shock absorption box to operate properly during impact while maintaining adequate towing strength through proper welding of the towing nut to the bumper beam.

Inventive Principle:
Principle #35Parameter changes

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 design enhances the structural integrity and absorption capabilities while preventing deformation and hard points, ensuring effective shock absorption and towing performance within the constraints of stylistic and structural requirements.

Implementation Method 1

The towing nut is welded to the bumper beam. At least one spot weld or at least one weld bead is formed between the outer edge of said shoulder and the bumper beam.

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3085554B1Bumper assembly including a towing nut and vehicle including such a bumper assembly
Publication Date: 2019.09.11 PSA AUTOMOBILES SA
  • EP3085554B1 patent drawingFigure 1~4

AI summary

The present invention relates to a bumper assembly (2) for a vehicle, in particular for a motor vehicle, comprising a bumper beam (21) extending essentially along the transverse axis of the vehicle, a shock-absorbing housing (22) disposed behind the bumper beam (21), extending mainly along the longitudinal axis of the vehicle, and a tow nut (23) disposed along the bumper beam (21), extending mainly along the longitudinal axis of the vehicle and comprising a lateral projection that forms a bearing surface for the front of the tow nut (23) against the bumper beam (21), characterized in that the tow nut (23) is positioned laterally offset relative to the shock-absorbing housing (22), the distance between the tow nut (23) and the shock-absorbing housing (22) being less than 15 mm, preferably said distance being between 5mm and 10mm.