Low-Floor Bus Chassis Assembly Modular Frame Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional low-floor bus chassis assemblies are excessively heavy and have poor workability due to their build-up body structure, making it difficult to assemble and modify components like the front and center frames, and the capacity of three-axis air springs is insufficient for double-decker electric buses.

Innovation Solution

A running bare chassis assembly for a low-floor bus is designed with a front frame, rear frame assembly, and center frame connected through welding and bolting engagements, allowing for improved stress distribution and easier assembly, featuring independent suspension and rigid axle configurations, and a center bridge to prevent deformation, with components like air tanks and battery carriers strategically mounted for efficient assembly and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a build-up body structure is used for the low-floor bus, then the body structure can be constructed, but the body weight becomes excessive and workability becomes very disadvantageous

Engineering Contradiction:

Improvebody structureVSAvoidbody weight

Core Design Contradiction:

ShapeVSWeight of moving object

Solution Approach 1:

The chassis is divided into separate modular components including front frame, center frame, and rear frame that can be manufactured independently and assembled together. This segmentation allows each component to be optimized separately and reduces overall weight while maintaining structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent combines the frame structure with the body structure to create an integrated running bare chassis assembly, eliminating the need for separate build-up body structure while reducing weight and improving workability.

Inventive Principle:

Principle #5Merging (Combining)

2Stability of the object's composition

If the front frame and center frame are connected using a longitudinal member in conventional ultra-low-floor frame assembly, then the frames can be connected, but assembling work becomes impossible and the length of the center frame is not easily changed

Engineering Contradiction:

Improveframe connectionVSAvoidassembling work

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The chassis is divided into separate modular components including front frame, center frame, and rear frame that can be manufactured independently and assembled together. This segmentation allows each component to be optimized separately and assembled easily, while maintaining structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The center frame length can be easily adjusted by modifying the number and position of connection points between the center frame and longitudinal members, providing flexibility in design without compromising connection stability.

Inventive Principle:

Principle #15Dynamics

3Strength

If the center frame, rear frame, and longitudinal member are integrally manufactured, then the structure is stable, but assembling work becomes impossible and the length of the center frame is not easily changed

Engineering Contradiction:

Improvestructural stabilityVSAvoidlength adjustment

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The chassis is divided into separate modular components including front frame, center frame, and rear frame that can be manufactured independently and assembled together. This segmentation allows each component to be optimized separately and assembled easily, while maintaining structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The center frame is designed with universal connection points that can accommodate different lengths and configurations, allowing the same basic component to serve multiple functions and adapt to different vehicle requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Shape

If a build-up body structure is applied, then the body can be constructed, but the capacity of the three-axis air spring of the double-decker electric bus is insufficient (less than or equal to 6,700 kg)

Engineering Contradiction:

Improvebody structureVSAvoidair spring capacity

Core Design Contradiction:

ShapeVSForce

Solution Approach 1:

The chassis is divided into separate modular components including front frame, center frame, and rear frame that can be manufactured independently and assembled together. This segmentation allows each component to be optimized separately and assembled easily, while maintaining structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The running bare chassis design changes the structural parameters and weight distribution, enabling the three-axis air spring capacity to exceed 6,700 kg by optimizing the chassis configuration and component placement.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11708118B2Running bare chassis assembly for low-floor bus and manufacturing method thereof

Publication Date: 2023.07.25 HYUNDAI MOTOR CO LTD

AI summary

An embodiment running bare chassis assembly includes a front frame on which a front suspension is mounted, a rear frame assembly on which a battery carrier is mounted, wherein the rear frame assembly comprises, a first rear frame on which a rear suspension is mounted, a second rear frame coupled to the first rear frame and on which a radiator is mounted, and a battery carrier frame on which the battery carrier is mounted and which is coupled to the first rear frame through a second engagement, and a center frame coupled to the front frame and the rear frame assembly through a first engagement, wherein a stress distribution due to the first engagement is greater than a stress distribution due to the second engagement.