Node-Tube Joint Structure With Annular Gap for Flexible Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional methods for connecting tubes in space frame and monocoque structures, such as those used in automotive and marine applications, incur high manufacturing costs and design inflexibility due to the need for complex joint fabrication and high tooling costs.

Innovation Solution

The use of additively manufactured nodes with interconnects that include concentric portions forming an annular gap to connect tubes, allowing for efficient assembly and reducing post-processing needs, while also incorporating spacer structures and seals to prevent material reactions and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional welding methods are used to connect tubes in space frame structures, then strong connections can be achieved, but manufacturing costs and tooling costs increase significantly

Engineering Contradiction:

Improveconnection strengthVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The connection system is divided into separate components: nodes with connection features and tube ends with corresponding joining features. This segmentation allows each component to be manufactured independently using additive manufacturing, eliminating the need for expensive welding tooling while maintaining connection strength through mechanical interlocking and bonding mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the connection method from thermal welding to mechanical joining followed by bonding. The nodes incorporate connection features with specific geometric parameters that enable tube ends to be mechanically attached, and the use of bonding agents provides additional strength without requiring welding equipment or processes.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If complex joint fabrication is used to accommodate various tube geometries, then design flexibility is reduced, but connection reliability is improved

Engineering Contradiction:

Improveconnection reliabilityVSAvoiddesign flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The nodes are designed with universal connection features that can accommodate multiple tube geometries, angles, and configurations. The additive manufacturing process enables nodes to be produced with complex internal structures and connection features that can adapt to various tube arrangements, providing both reliability through consistent manufacturing and flexibility through design variability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The connection system utilizes composite construction combining additively manufactured node structures with bonding agents. This composite approach allows the nodes to incorporate multiple materials with different properties, enabling optimization for both structural reliability and design flexibility in accommodating various tube geometries.

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If dissimilar materials are used in node and tube construction, then design freedom increases, but galvanic corrosion becomes a problem

Engineering Contradiction:

Improvematerial selection freedomVSAvoidgalvanic corrosion

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The bonding agent serves as an intermediary between dissimilar node and tube materials, electrically isolating them to prevent galvanic corrosion. This allows the use of dissimilar materials such as aluminum nodes with steel tubes or titanium nodes with aluminum tubes, providing material selection freedom while protecting against corrosion through the protective barrier function of the bonding agent.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Manufacturing precision

If traditional manufacturing methods are used for joint members, then manufacturing precision can be maintained, but manufacturing time increases

Engineering Contradiction:

Improvejoint fabrication precisionVSAvoidmanufacturing time

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The nodes are additively manufactured with connection features already integrated into their structure before tube assembly. This preliminary incorporation of joining features eliminates subsequent machining or fabrication steps, maintaining manufacturing precision through controlled additive processes while significantly reducing overall manufacturing time compared to traditional sequential fabrication methods.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11174884B2Systems and methods for joining node and tube structures

Publication Date: 2021.11.16 DIVERGENT TECHNOLOGIES INC

AI summary

Connections between nodes and tubes are provided. An apparatus can include additively manufactured first and second nodes, a tube, and an interconnect connecting the tube to the first and second nodes. An apparatus can include a node having an end portion with inner and outer concentric portions forming an annular gap therebetween, and a tube having an end portion extending into the gap.