Deck Cross-Member With Segmented Pipes and Joint Member

Solution Overview

Problem

Existing deck cross-members, while attempting to enhance rigidity to support steering units, face challenges in reducing weight and material limitations due to the difficulty in expanding or contracting aluminum pipes, which restricts the freedom in material selection for lightweight designs.

Innovation Solution

A deck cross-member configuration comprising a first pipe with a uniform cross-section, a joint member with a receptacle unit, and a second pipe, allowing them to be coupled without deformation, enabling the use of aluminum pipes and expanding material options, thereby reducing weight and manufacturing costs while maintaining rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the cross section of the deck cross-member is increased to enhance rigidity, then the rigidity is improved, but the weight increases

Engineering Contradiction:

ImproverigidityVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The deck cross-member is divided into multiple pipes with different cross-sectional sizes arranged along the axial direction. The first pipe has a larger cross section to provide rigidity near the steering unit, while the second pipe has a smaller cross section to reduce weight. This segmentation allows different parts of the structure to have different structural characteristics optimized for their specific functional requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the deck cross-member are given different cross-sectional properties according to their functional needs. The region closer to the steering unit (first pipe) has a larger cross section for rigidity, while the region farther away (second pipe) has a smaller cross section for weight reduction. This local differentiation of structural properties resolves the contradiction between overall rigidity and weight.

Inventive Principle:

Principle #3Local quality

2Weight of moving object

If aluminum pipes are used to reduce weight, then the weight is reduced, but the difficulty in expanding or contracting the pipes limits material selection freedom

Engineering Contradiction:

ImproveweightVSAvoidmaterial selection freedom

Core Design Contradiction:

Weight of moving objectVSEase of manufacture

Solution Approach 1:

The deck cross-member is divided into multiple pipes with different cross-sectional sizes arranged along the axial direction. The first pipe has a larger cross section to provide rigidity near the steering unit, while the second pipe has a smaller cross section to reduce weight. This segmentation allows different parts of the structure to have different structural characteristics optimized for their specific functional requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the deck cross-member are given different cross-sectional properties according to their functional needs. The region closer to the steering unit (first pipe) has a larger cross section for rigidity, while the region farther away (second pipe) has a smaller cross section for weight reduction. This local differentiation of structural properties resolves the contradiction between overall rigidity and weight.

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If pipes with different cross sections are coupled by expanding or contracting diameter, then the coupling is achieved, but the manufacturing complexity increases

Engineering Contradiction:

Improvecoupling capabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A joint member is introduced as an intermediary component to couple the first pipe and second pipe. The joint member has a receptacle unit that receives the second pipe, and protrusions that fit into recesses of the first pipe. This intermediary structure enables coupling of pipes with different cross sections without requiring expansion or contraction operations, thereby reducing manufacturing complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The second pipe is inserted into the receptacle unit of the joint member, creating a nested arrangement. The joint member itself is inserted into the first pipe, forming a nested structure of nested doll type. This nesting approach allows pipes of different sizes to be coupled without deformation while simplifying the manufacturing process.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS7458625B2Deck cross-member and method of manufacturing a deck cross-member

Publication Date: 2008.12.02 MITSUBISHI MOTORS CORP

AI summary

A deck cross-member comprises a first pipe, a joint member, and a second pipe. The first pipe is configured to support a steering unit. The first pipe has a cross section that is uniform along the axial direction as viewed in a plane perpendicular to the axial direction. The joint member is inserted in the first pipe and secured to the first pipe. The joint member incorporates a receptacle unit. The second pipe is inserted in the receptacle unit of the joint member, thus secured to the joint member. The second pipe has a cross section that is uniform along the axial direction as viewed in a plane perpendicular to the axial direction.