Rail Car Body Partial Differential Design for Weight Reduction

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Solution Overview

Problem

The integral construction method for aluminum rail vehicle car bodies results in higher weight due to oversizing in areas with lower loads, leading to inefficient material use, as further lightweight optimizations reach the limits of feasibility.

Innovation Solution

A partial differential design incorporating single-shell and double-shell areas with differential components acting as reinforcements, connected at specific levels to enhance rigidity and reduce material usage, allowing for localized stiffening and tolerance compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If integral construction is used for aluminum car bodies, then manufacturing cost is reduced due to fewer parts and joining connections, but weight increases due to over-dimensioning in low-load areas

Engineering Contradiction:
Improvemanufacturing costVSAvoidcar body weight
Core Design Contradiction:
Ease of manufactureVSWeight of moving object

Solution Approach 1:

The car body is divided into integral components with single-shell areas and double-shell areas. The longitudinal structures are segmented into regions with different shell configurations based on local load requirements, allowing lightweight construction in low-load areas while maintaining strength where needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different shell configurations (single-shell vs. double-shell) are applied to different areas of the car body based on local load conditions. High-load areas receive double-shell construction for enhanced strength, while low-load areas use single-shell construction to reduce weight, optimizing material distribution throughout the structure.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If wall thickness is reduced for lightweighting, then car body weight decreases, but manufacturing feasibility reaches limits

Engineering Contradiction:
Improvecar body weightVSAvoidmanufacturing feasibility
Core Design Contradiction:
Weight of moving objectVSEase of manufacture

Solution Approach 1:

The structure is segmented into single-shell and double-shell areas, allowing thin-walled single-shell sections in low-load areas to achieve lightweighting while double-shell sections in high-load areas maintain structural integrity and manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The car body uses a composite construction combining single-shell and double-shell aluminum profiles in different areas. This composite approach allows optimization of wall thickness in each region, achieving overall weight reduction while maintaining manufacturability of individual components.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If differential components are added to single-shell structure for stiffening, then rigidity improves, but weight increases due to additional components and joining operations

Engineering Contradiction:
Improvecar body rigidityVSAvoidcar body weight
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The stiffening function is merged into the integral components themselves through the double-shell areas, eliminating the need for separate differential stiffening components. The double-shell longitudinal structures provide inherent stiffness while maintaining a streamlined single-shell appearance in other areas.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stiffening function is extracted from separate differential components and integrated directly into the integral component design through double-shell areas, reducing the number of parts and joining operations while maintaining rigidity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Weight of moving object

If differential construction is used, then weight is reduced compared to integral construction, but manufacturing complexity increases due to more parts and joining connections

Engineering Contradiction:
Improvecar body weightVSAvoidconstruction complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The car body is segmented into single-shell and double-shell integral components, creating a partial differential construction that reduces weight through strategic material distribution while avoiding the full complexity of traditional differential construction with numerous separate parts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The integral components serve multiple functions: they provide the car body structure, local stiffening through double-shell areas, and load-bearing capacity. This multi-functionality reduces the need for separate specialized components, simplifying the overall construction despite the partial differential design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4344975A1Wagon body with partially differential construction
Publication Date: 2024.04.03 SIEMENS MOBILITY GMBH
  • EP4344975A1 patent drawingFigure 1
  • EP4344975A1 patent drawingFigure 2
  • EP4344975A1 patent drawingFigure 3

AI summary

The invention relates to a car body 10 in partial differential construction, in particular of a rail vehicle 1, comprising at least one integral component 200, comprising at least one single-shell area 210 and at least one double-shell area 220, wherein the car body 10 is designed in partial differential construction and has at least one differential component 100, which is connected to the single-shell area 210 by at least one first connection 302 and to the double-shell area 220 by at least one second connection 304.