Railway Vehicle Collision Energy Absorption Structure

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Solution Overview

Problem

Existing collision energy absorption devices in railway vehicles often result in high collapse loads during collisions, leading to potential impacts on passengers and crew due to the large amount of energy absorption, which can cause initial impact during the collapse process.

Innovation Solution

A railway vehicle design incorporating a collision energy absorption structure with a collapse area (crushable zone) and non-collapse area, featuring energy absorption devices and strategically placed beams that absorb impact through plastic deformation, distributing the force to prevent increased collapse loads and protect passengers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a collision energy absorption device is provided to absorb large amount of collision energy, then the collision energy absorption capacity is improved, but the collapse load becomes large causing impact to passengers

Engineering Contradiction:
Improvecollision energy absorption capacityVSAvoidcollapse load
Core Design Contradiction:
Loss of energyVSForce

Solution Approach 1:

The underframe is divided into a collapse area with collapsible beams (first end floor, first frame, second frame) and a non-collapse area that maintains rigidity. This segmentation allows the collapse area to absorb energy through controlled deformation while the non-collapse area prevents excessive collapse load transmission to passengers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the underframe are given different mechanical properties: the collapse area is designed with lower rigidity to enable plastic deformation and energy absorption, while the non-collapse area maintains high rigidity to protect passengers. This local differentiation of structural properties resolves the contradiction between energy absorption and collapse load control.

Inventive Principle:
Principle #3Local quality

2Strength

If the underframe has high rigidity to maintain structural integrity, then the structural strength is improved, but plastic deformation for absorbing collision energy cannot occur

Engineering Contradiction:
Improvestructural rigidityVSAvoidcollision energy absorption capacity
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The underframe is segmented into collapse beams that are permitted to deform and non-collapse beams that maintain rigidity. This allows the structure to simultaneously exhibit both plastic deformation capability and structural integrity in different regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The collapse area is designed with specific structural characteristics (collapsible beams with predetermined collapse positions) that enable energy absorption through controlled plastic deformation, while the non-collapse area maintains high rigidity. This local quality differentiation resolves the contradiction between overall structural strength and localized energy absorption.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If energy absorption devices are designed to absorb large collision energy, then the energy absorption amount is improved, but the initial collapse impact affects passengers

Engineering Contradiction:
Improvecollision energy absorption amountVSAvoidinitial collapse impact on passengers
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The underframe is divided into collapse area and non-collapse area, where the collapse area absorbs energy through progressive deformation of multiple beams while the non-collapse area acts as a barrier to prevent impact transmission to passengers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The non-collapse area serves as an intermediary structure between the collapse area and the passenger compartment. It absorbs and redistributes the collapse loads, preventing direct transmission of initial collapse impact to passengers while allowing the collapse area to perform its energy absorption function.

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

The design effectively relieves impact during collisions by distributing collision energy through plastic deformation of specific structural components, reducing the risk of injury to passengers and crew while maintaining structural integrity, ensuring safe evacuation routes.

Implementation Method 1

plastic deformation of a part of the railway vehicle when the railway vehicle collides against an obstacle

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3181425B1Railway vehicle provided with collision energy absorption structure
Publication Date: 2019.02.13 HITACHI LTD
  • EP3181425B1 patent drawingFigure 1
  • EP3181425B1 patent drawingFigure 2
  • EP3181425B1 patent drawingFigure 3

AI summary

A collision energy absorption device that absorbs a large collision energy has a drawback in that a large collapse load tends to occur, and that passengers tends to receive impact during initial collapse of the collision energy absorption device. A railway vehicle provided with a collision energy absorption structure configured to absorb collision energy is provided, wherein a body of the railway vehicle includes an underframe constituting a floor surface, side structure bodies having entrances on both end portions in a width direction of the underframe, a first end portion floor disposed at an end portion in a longitudinal direction of the underframe, a gangway frame standing on an upper surface at a front end portion of the first end portion floor, a horseshoe-shaped first frame standing on an upper surface of the first end portion floor at a center portion side in the longitudinal direction of the underframe of the gangway frame, and a horseshoe-shaped second frame standing on an upper surface of the underframe at a center portion side in the longitudinal direction of the underframe of the first frame, wherein the railway vehicle includes an entrance provide on the side structure body adjacent to the second frame, a first beam group connecting an upper portion of the gangway frame and an upper portion of the first frame, a second beam connecting an upper portion of the first frame and an upper portion of the second frame, and a collapse area provided on the side structure body on an upper portion of the entrance.