Swaged Bumper Stay Joining With Axial Elastic Compression

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Solution Overview

Problem

Unintended deformation of rubber and bumper stays occurs due to non-axial forces applied during the swaging process, leading to improper joining of structural components.

Innovation Solution

A joining method where the support surface on the die is perpendicular to the axial direction of the elastic member, preventing non-axial forces from acting on the rubber, and using a core member that tapers towards the end to facilitate insertion and positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the front inclined wall applies force to the rubber during compression, then the rubber expands outward to join the bumper stay to the bumper beam, but the rubber deforms unintentionally in an oblique direction

Engineering Contradiction:
Improvejoining strengthVSAvoiddeformation control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

A support member is introduced as an intermediary element between the die and the rubber. This support member has a support surface that applies force to the rubber in the axial direction only, preventing oblique deformation while allowing the rubber to expand outward for joining. The support member mediates the compression process to eliminate harmful oblique forces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The support surface of the support member counteracts the oblique force component generated by the front inclined wall. By providing a reaction force in the axial direction, the support surface balances the harmful oblique forces and prevents unintended deformation of the rubber during compression.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Manufacturing precision

If the support surface is perpendicular to the axial direction of the elastic member, then non-axial forces are prevented from acting on the rubber, but the joining process requires additional support member structure

Engineering Contradiction:
Improvedeformation controlVSAvoiddie structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The support member serves multiple functions: it provides the perpendicular support surface to prevent oblique deformation, acts as a positioning element for the rubber, and distributes the compressive force uniformly. This multi-functionality justifies the additional structure by consolidating several requirements into a single component.

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

3Strength

If rubber is compressed axially to expand and deform the bumper stay, then the joining strength is improved, but the rubber may deform unintentionally in oblique directions

Engineering Contradiction:
Improvejoining strengthVSAvoidrubber shape stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The support member acts as a mediator that guides the compression process. Its support surface perpendicular to the axial direction ensures that compressive force is transmitted uniformly to the rubber without introducing oblique components, thereby maintaining rubber shape stability while achieving the desired axial expansion for joining.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Prevents unintended deformation of the structure, allowing for precise fitting and improved joining strength between bumper beam and stay components.

Implementation Method 1

the plunger driven by a press device applies a compressive force in the axial direction of the bumper stay and elastically deforms the rubber outward from the axis

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4104947B1Method for producing structure
Publication Date: 2025.11.19 KOBE STEEL LTD
  • EP4104947B1 patent drawingFigure 1
  • EP4104947B1 patent drawingFigure 2
  • EP4104947B1 patent drawingFigure 3

AI summary

A joining method of a structure 1 includes preparing a first member 10 including a first portion 14 provided with a first hole 14a and a second portion 12 provided with a second hole 12a, a second member 20, a die 30, and an elastic member 40, inserting the second member 20 into the first hole 14a of the first member 10, inserting the elastic member 40 into the second member 20, in a state where one end of the second member 20 in an axial direction is located between the first portion 14 and the second portion 12 of the first member 10, compressing and expanding the elastic member 40 in the axial direction, thereby expanding and deforming the second member 20 at a portion passing through the first hole 1a of the first member 10 to be swaged and joined to the first portion 14. The die 30 includes a support surface 30a for applying a compressive force from the die 30 to the elastic member 40 through the second hole 12a. The support surface 30a is perpendicular to an axial direction of the elastic member 40.