Railway Vehicle Shock Absorbing Structure for Collision Energy Management

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Solution Overview

Problem

Railway vehicles face challenges in ensuring doorways remain functional as escape routes during collisions, as existing shock-absorbing structures often crush doorways at car ends, obstructing passenger evacuation.

Innovation Solution

A railway vehicle design with doorways arranged astride a crushable region and a survival region, where the crushable region absorbs impact by crushing under high loads, while the survival region maintains its structure to serve as an escape port, utilizing a shock-absorbing device with a fixed and movable member to control crushing behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the shock absorbing structure is made with sufficient strength to resist small loads during coupling operations, then the structure can endure normal operational forces, but it cannot effectively absorb impact energy during collision

Engineering Contradiction:
Improvestrength of shock absorbing structureVSAvoidimpact energy absorption
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The end structure is divided into multiple members including vertical members, horizontal members, and diagonal members, each with different strength characteristics. The diagonal members are designed with lower strength to crush preferentially, while vertical and horizontal members maintain higher strength to preserve doorway integrity and support coupling loads.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the structure are assigned different strength properties: the diagonal members have reduced strength for energy absorption, while the vertical and horizontal members surrounding the doorway maintain high strength to ensure passenger escape routes remain intact during collision.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If the car end structure is designed to crush during collision to absorb shock, then impact energy is absorbed, but the doorways at the car ends are crushed and cannot serve as escape routes

Engineering Contradiction:
Improvecollision energy absorptionVSAvoiddoorway functionality as escape route
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The structure implements spatially varying strength properties where diagonal members are designed to crush at lower loads to absorb energy, while vertical and horizontal members forming the doorway framework maintain high strength to remain intact and functional as escape routes during collision.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The end structure is segmented into energy-absorbing components (diagonal members) and survival components (vertical and horizontal members around doorways), allowing differentiated behavior during collision to simultaneously achieve energy absorption and preserve escape routes.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If the shock absorbing structure is designed to crush under high load during collision, then impact is absorbed, but it may also crush under small loads during coupling operations

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidcoupling operation
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The structure uses members with different strength characteristics: diagonal members are designed with lower strength to crush during high-load collision, while vertical and horizontal members maintain high strength to support normal coupling operations without excessive deformation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The end structure employs a composite configuration of members with different mechanical properties, combining high-strength members for structural support and low-strength members for energy absorption, allowing the structure to respond appropriately to different load levels.

Inventive Principle:
Principle #40Composite materials

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

Ensures passengers can evacuate through the nearest doorway by maintaining the survival region's integrity and width, effectively absorbing collision energy and relieving shock without crushing critical escape routes.

Implementation Method 1

a crushable region (shock absorbing region) for absorbing impact (collision energy) by actively plastically deforming a certain portion of the railway vehicle during collision

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

utilizing a shock-absorbing device with a fixed and movable member to control crushing behavior

Methodology Applied
Scientific EffectImpact force absorption: Impact Force

Data Source

PatentEP2371651B1Railway vehicle having shock absorbing structures
Publication Date: 2014.02.26 HITACHI LTD
  • EP2371651B1 patent drawingFigure 1
  • EP2371651B1 patent drawingFigure 2
  • EP2371651B1 patent drawingFigure 3

AI summary

The invention provides a shock absorbing structure of a railway vehicle capable of ensuring a doorway (escape port) region while absorbing collision energy during collision. The impact caused when a railway vehicle experiences collision is transmitted via an end structure (30) constituting the railway vehicle, a roof structure end section (42), an underframe end section (52) and a second doorway frame (74) to an upper third doorway frame (76a) and a lower third doorway frame (76b). When the impact exceeds a predetermined level, the roof structure end section (42), the underframe end section (52), the upper doorway frame (76a) and the lower doorway frame (76b) disposed in the crushable region (200) are crushed and plastically deformed in the longitudinal direction of the railway vehicle (1), absorbing the shock during the process. A width (L1) of the doorway section (60) after absorbing shock becomes smaller than a width (L0) of the doorway section (60) prior to absorbing shock, but the first doorway frame (72,72a,72b), the roof structure (40) and the underframe (50) disposed in the survival region (100) are not crushed, so that the doorway width (L1) can be ensured as an escape port.