Crash Buffer Deformation Tube for Impact Protection

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Solution Overview

Problem

Existing shock absorbers, such as those used in ships and rail vehicles, face challenges in effectively managing high kinetic energy impacts, leading to potential damage when the damping capacity is exceeded, and known solutions often result in increased size and complexity.

Innovation Solution

A compact shock absorber design featuring a buffer tappet with a tappet sleeve and buffer plate, incorporating a clamping sleeve that releases at a critical impact force, allowing a destructive energy-absorbing deformation tube to dissipate energy through plastic deformation, while maintaining a regenerative damping device for normal operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a regenerative damping device is integrated in the side buffer, then normal driving impacts are dampened effectively, but high impact forces exceeding the buffer stroke are transmitted undamped to the vehicle undercarriage

Engineering Contradiction:
Improveprotection against damageVSAvoidbuffer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The buffer is divided into two functional segments: a regenerative damping element for normal operation and a destructive energy-absorbing element for extreme impacts. This segmentation allows each element to be optimized for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A coupling device is introduced as an intermediary between the regenerative damping element and the destructive energy-absorbing element. This coupling device selectively engages the destructive element only when the regenerative element's stroke is exhausted, enabling seamless transition between damping modes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If a destructive energy-absorbing element is added to the side buffer, then high impact energy can be dissipated, but the overall size and complexity of the buffer increases

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidbuffer housing volume
Core Design Contradiction:
Loss of energyVSVolume of stationary object

Solution Approach 1:

The destructive energy-absorbing element is nested within the buffer housing, concentric to the regenerative damping element. This nested arrangement allows both elements to share the same axial space, minimizing the overall volume increase while maximizing energy absorption capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The buffer elements are arranged concentrically in the radial dimension rather than sequentially in the axial dimension. This dimensional change allows both regenerative and destructive elements to occupy overlapping axial spaces, reducing the total buffer length and housing volume.

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

3Use of energy by moving object

If the buffer stroke is increased to absorb more impact energy, then the damping capacity is improved, but the buffer becomes longer and more complex

Engineering Contradiction:
Improveimpact energy dissipationVSAvoidbuffer stroke length
Core Design Contradiction:
Use of energy by moving objectVSLength of moving object

Solution Approach 1:

The coupling device acts as a mediator that activates the destructive energy-absorbing element precisely when the regenerative damping element's stroke is exhausted. This ensures optimal use of the regenerative element's travel while engaging the destructive element only when necessary, maximizing energy dissipation without extending the buffer stroke.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer system transitions between two distinct energy absorption parameters: regenerative damping for normal loads and plastic deformation for extreme loads. This parameter change allows the system to handle a wide range of impact energies without requiring a proportionally increased buffer stroke.

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 solution enables efficient energy dissipation during high-impact events without compromising the compactness of the shock absorber, preventing unwanted deformation and maintaining effective damping properties, thus protecting the underlying structure from extreme loads.

Implementation Method 1

at least one second end area of the tappet sleeve opposite the first end area of the tappet sleeve is received telescopically in the buffer housing... a destructive energy-absorbing element, which is designed in particular in the form of a deformation tube... with simultaneous plastic deformation of the energy dissipation element is displaced relative to the buffer sleeve

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

a regenerative damping device... serve to dampen tensile and impact forces occurring during normal driving operation in a regenerative manner

Methodology Applied
Scientific EffectElastic damping: Elasticity

Data Source

PatentEP2687417B1Impact protection, in particular in the form of a crash buffer
Publication Date: 2015.03.04 VOITH PATENT GMBH
  • EP2687417B1 patent drawingFigure 1
  • EP2687417B1 patent drawingFigure 2a~2b
  • EP2687417B1 patent drawingFigure 3a~3b

AI summary

The device (1) has a deformation pipe (23) clamped between an end region of a clamping sleeve and an end region of a buffer case (21). The sleeve together with the pipe is displaced by plastic deformation of the pipe relative to the buffer case, and a connection between another end region of the sleeve and the end region of the buffer case is released when a critical impact force introduced into the device is exceeded. A plunger case (11) is formed as cylindrical bodies such that an outer diameter of the plunger case is constant from an end region up to another end region of the plunger case.