Extruded Chassis Edge Beam for Narrow Rail Vehicle Underframes

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Solution Overview

Problem

Conventional high-speed EMUs designed for domestic use face challenges in meeting the diverse mounting space and structural requirements of foreign rail vehicles, particularly due to large and heavy under-vehicle apparatuses, leading to insufficient space for bogies and under-vehicle components.

Innovation Solution

An underframe side beam with a laminated aluminum alloy profile structure featuring multiple cavities and integrated design, allowing for flexible adaptation to varying vehicle widths and enabling mounting of extra-large apparatuses by partial cavity removal and alternative bolt arrangements, while maintaining structural integrity and reducing welding stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional high-speed EMUs are designed with standard underframe structures for domestic use, then the vehicle body structure is simple and manufacturing is easier, but the mounting space for under-vehicle apparatus is insufficient when accommodating extra-large apparatus in foreign markets

Engineering Contradiction:
Improvemounting space for under-vehicle apparatusVSAvoidunderframe structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The underframe side beam is divided into multiple cavities (first cavity, second cavity, third cavity) that can be selectively removed or retained. This segmentation allows the structure to be customized for different mounting space requirements while maintaining a standardized base design, resolving the contradiction between mounting space and structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The underframe structure is designed to be dynamically configurable through selective removal of cavities. The same side beam design can be adapted to different vehicle width limits and apparatus sizes by removing specific cavities, enabling the structure to respond to different foreign market requirements without redesigning the entire underframe.

Inventive Principle:
Principle #15Dynamics

2Length of moving object

If the vehicle body width is reduced to meet foreign country limit requirements, then the vehicle can operate on foreign lines, but the mounting space for bogies and under-vehicle apparatus becomes insufficient

Engineering Contradiction:
Improvevehicle body widthVSAvoidmounting space for bogies and apparatus
Core Design Contradiction:
Length of moving objectVSArea of stationary object

Solution Approach 1:

The invention utilizes the vertical dimension by creating multi-layered cavities within the side beam structure. Instead of expanding horizontally (which would increase vehicle width), the design provides mounting space through vertical cavity layers that can be selectively removed, allowing adequate mounting space within a narrow vehicle width constraint.

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

Solution Approach 2:

Multiple cavities are nested within the side beam cross-section, with the first, second, and third cavities arranged in layers. This nesting arrangement maximizes the use of available space within the narrow vehicle width while providing sufficient mounting volume for under-vehicle apparatus.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Strength

If welding is used to connect underframe components, then structural strength is improved, but welding stress and fatigue damage increase

Engineering Contradiction:
Improveunderframe structural strengthVSAvoidwelding stress and fatigue damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The side beam is designed as an integrally extruded piece that combines multiple functional cavities and mounting features into a single component. This merging eliminates the need for welding between multiple separate components, reducing welding stress while maintaining structural strength through the integrated extrusion design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The side beam utilizes aluminum alloy material with composite cavity structures that provide both strength and mounting functionality. The extruded aluminum alloy profile integrates structural load-bearing functions with apparatus mounting features, reducing reliance on welded connections.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4365054B1Chassis edge beam, chassis structure and rail vehicle
Publication Date: 2026.02.18 CRRC QINGDAO SIFANG CO LTD
  • EP4365054B1 patent drawingFigure 1~2
  • EP4365054B1 patent drawingFigure 3~4
  • EP4365054B1 patent drawingFigure 5~6

AI summary

A chassis edge beam, a chassis structure and a rail vehicle. The chassis edge beam is an aluminum alloy profile structure that is integrally extruded and formed, and comprises a first-layer cavity, a second-layer cavity, a third-layer cavity and a fourth-layer cavity, which are sequentially stacked from top to bottom, wherein the top of the first-layer cavity is provided with a profile insertion structure, which is configured to be inserted in and welded to a side wall of a vehicle body; a profile lap-joint structure with an opening facing an inner side of the vehicle body is formed at an upper edge of an inner side face of the second-layer cavity; and the third-layer cavity has two square-shaped cavities arranged side by side, and a transverse wall of the bottom of each square-shaped cavity is thickened, so as to be used to form a planar structure for mounting an under-vehicle apparatus, an anti-yaw damper and an under-vehicle apparatus compartment, and for connecting a bogie to the vehicle body. The chassis edge beam can meet limiting requirements of different vehicle limits at home and abroad for the outer contour of a vehicle body structure, and can be flexibly fit with vehicle body structures having different vehicle widths.