Deformable Door Handle Plunger Impact Energy Absorption

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Solution Overview

Problem

Vehicle door handles often fracture and transfer compressive force to the passenger compartment during side impacts, posing a risk to occupants due to the lack of effective energy absorption mechanisms.

Innovation Solution

A deformable metal plunger with engineered corrugations is integrated into the door handle, designed to bend and absorb impact energy without transferring it to the passenger compartment, utilizing the ductility of metals to absorb large amounts of energy through deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid plunger is used to transfer motion from the handle to the bell crank, then the handle can effectively release the door latch, but during side impact the plunger transfers compressive force to the passenger compartment causing injury risk

Engineering Contradiction:

Improvedoor latch release functionVSAvoidcompressive force transfer to passenger compartment

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The plunger is designed with variable bending strength along its length, creating a gradient from low bending strength at the base portion to high bending strength at the distal portion. This parameter change allows the plunger to deform and absorb impact energy at the base while maintaining structural integrity for operational function at the distal end

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The plunger is divided into functionally distinct segments: a base portion with low bending strength that acts as a crumple zone for energy absorption, and a distal portion with high bending strength that maintains operational integrity. This segmentation allows different regions to serve different purposes during impact and normal operation

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If the plunger is designed to be deformable to absorb impact energy, then compressive force transfer to the passenger compartment is reduced, but the plunger may deform excessively during normal operation affecting door latch release

Engineering Contradiction:

Improvecompressive force transfer to passenger compartmentVSAvoiddoor latch release function

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

Different portions of the plunger are given different mechanical properties: the base portion has low bending strength optimized for energy absorption during impact, while the distal portion has high bending strength optimized for reliable operation during normal door opening. This local differentiation ensures each region performs its intended function without compromising the other

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If a deformable plunger with crumple zones is used to absorb impact energy, then occupant safety is improved, but the device complexity increases due to the need for engineered corrugations and variable bending strength

Engineering Contradiction:

Improveoccupant injury riskVSAvoidplunger structure with corrugations and variable bending strength

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The plunger incorporates engineered corrugations that create variable bending strength along its length through geometric parameter changes rather than material changes. This allows the complex energy absorption function to be achieved through shape design alone, simplifying manufacturing while maintaining the desired mechanical properties

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

The deformable plunger effectively absorbs and dissipates impact energy, reducing the risk of injury to occupants by preventing the transfer of compressive forces into the passenger compartment during side impacts.

Implementation Method 1

Metals are an example of a preferred material due to the ductility of metals and their ability to absorb large amounts of energy via deformation without fracturing

Methodology Applied

Scientific EffectDuctility: Plasticity

Implementation Method 2

The deformable metal plunger may be designed/engineered with a series of corrugations (deformation triggers) where it will bend/deform and absorb the incoming impact energy

Methodology Applied

Scientific EffectDeformation: Deformation

Implementation Method 3

The present invention combines these material properties with an engineered crumple zone with corrugations that initiate bending/deformation at the desired level of impact energy

Methodology Applied

Scientific EffectCrumple zone deformation: Deformation

Data Source

PatentUS10563433B2Deformable outside handle rear hook or plunger

Publication Date: 2020.02.18 FORD GLOBAL TECH LLC

AI summary

A handle for doors of motor vehicles includes an outer portion that can be grasped by a user, and an inwardly-extending plunger or hook that operably interconnects the handle to the door latch via a bell crank (that is part of the handle base or chassis depending on the type of handle architecture used). The plunger is made of a ductile material such as metal, and includes a crumple zone that causes the plunger to deform axially and/or bend sidewardly in the event an axial and/or a bending impact load.