Radiator Tube Bushings for Brazing-Free Mechanical Joining

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Solution Overview

Problem

Traditional radiator production methods for heating plants, such as towel warmers, are limited by the need for specialized kilns and brazing processes, which restrict material choice to steel, limit size variability, and result in high production costs for non-standard sizes.

Innovation Solution

A method involving hollow cylindrical bushings with O-rings and washers, used in conjunction with an expanding device, allows for mechanical joining of vertical and horizontal tubes without brazing, enabling the use of various materials and flexible size options, while eliminating the need for kilns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If brazing process with kiln is used to join radiator elements, then permanent joints are formed, but material choice is limited to steel and production costs increase

Engineering Contradiction:
Improvejoint permanenceVSAvoidmaterial choice
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the thermal brazing process with a mechanical expansion system. An expanding device is inserted through the bushing and against the stop, applying mechanical force to deform the bushing radially outward, creating a friction fit that secures the radiator elements without requiring brazing or kilns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The bushing acts as an intermediary component between the radiator elements. It provides a standardized interface that accommodates different materials (steel, aluminum, stainless steel) and enables mechanical connection through expansion, eliminating the need for material-specific brazing processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If brazing process with kiln is used to join radiator elements, then permanent joints are formed, but production costs increase for non-standard sizes

Engineering Contradiction:
Improvejoint permanenceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the thermal brazing process with a mechanical expansion system. An expanding device is inserted through the bushing and against the stop, applying mechanical force to deform the bushing radially outward, creating a friction fit that secures the radiator elements without requiring brazing or kilns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The connection system is segmented into distinct components: bushing, expanding device, and stop. This modular approach allows for standardized production of radiator elements that can be assembled through simple mechanical operations, reducing manufacturing complexity and cost for both standard and custom sizes.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If brazing process is used, then steel elements can be joined, but other materials cannot be used

Engineering Contradiction:
Improvematerial compatibilityVSAvoidprocess complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The bushing is designed as a universal connector that works with multiple materials (steel, aluminum, stainless steel). The expanding mechanism provides a material-independent connection method, allowing the same assembly process to be used regardless of the radiator element material, thereby simplifying manufacturing across different material types.

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

4Productivity

If standard kiln process is used, then standard size radiators can be produced, but custom sizes are limited and expensive

Engineering Contradiction:
Improveproduction efficiencyVSAvoidsize customization
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The connection system is segmented into distinct components: bushing, expanding device, and stop. This modular approach allows for standardized production of radiator elements that can be assembled through simple mechanical operations, reducing manufacturing complexity and cost for both standard and custom sizes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system allows for parameter changes in radiator dimensions without changing the fundamental connection process. By adjusting the bushing and element dimensions while maintaining the same expansion mechanism, manufacturers can efficiently produce custom-sized radiators using the same standardized assembly process.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces production costs, expands material options beyond steel, and allows for customizable radiator sizes, enhancing production efficiency and flexibility.

Implementation Method 1

the slim tracts 24 are deformed so that a solid joint is achieved

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

the bushing 2, which is hollow and cylindrical and which externally exhibits two recesses 21 for housing O-rings 5

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1941226B1Production method for radiators
Publication Date: 2009.02.25 K DELTA T
  • EP1941226B1 patent drawingFigure 1~1b
  • EP1941226B1 patent drawingFigure 2~6
  • EP1941226B1 patent drawingFigure 7

AI summary

Production method for radiators comprising a vertical tubular element (1) with holes (11) in which bushings (2) house, the bushings (2) being provided with 0-rings (4) inserted in recesses (21', 23 a) afforded therein. An expanding element provided with a internal stem (41) and an external expandable tubular element (42) exhibiting longitudinal flutes (421) which expands the external tubular element (42) when the stem (41) is moved axially internally of the tubular element (42) , whereby a terminal slim tract (24) of the bushing (2) is thus enlarged and belling out to strike against walls of the holes (11) . The bushing (2) is then unremovably inserted into a horizontal tubular element (3) , a washer (R) housing in a recess (22) of the bushing (2) being crushed between an internal wall of the tubular element (3) and the bushing (2) , eliminating possibility of sliding of the horizontal tubular element (3) .