Flat Tube Projections for Inner Insert Introduction

Solution Overview

Problem

The production of flat tubes for heat exchangers is costly due to end widenings and soldering-related issues, and existing methods either compromise wall thickness or require expensive continuous production processes.

Innovation Solution

Generating two projections at the flat tube ends that are bent down to serve as introduction bevels, allowing for the insertion of inner inserts without widenings, and subsequently cutting them off for secure connection to tube bottoms, reducing investment costs and improving quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If end widenings are produced to facilitate inner insert introduction, then ease of operation is improved, but manufacturing cost increases and wall thickness is reduced

Engineering Contradiction:

Improveintroduction of inner insertVSAvoidproduction cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The method creates preliminary forming elements (protrusions) on the flat tube end before inner insert insertion. These protrusions are formed by localized deformation of the tube wall and are subsequently removed after serving their purpose as introduction aids, enabling easy insert introduction without permanent structural modifications that would increase manufacturing cost or reduce wall thickness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention temporarily changes the geometric parameters of the flat tube end by forming protrusions that create an introduction bevel effect. After the inner insert is introduced, these protrusions are removed, restoring the original wall thickness and structural parameters, thus avoiding permanent reduction in wall thickness while still facilitating easy insert introduction.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If end widenings are produced to facilitate inner insert introduction, then ease of operation is improved, but manufacturing precision deteriorates due to soldering problems

Engineering Contradiction:

Improveintroduction of inner insertVSAvoidsoldering quality

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The method creates preliminary forming elements (protrusions) on the flat tube end before inner insert insertion. These protrusions are formed by localized deformation of the tube wall and are subsequently removed after serving their purpose as introduction aids, enabling easy insert introduction without permanent structural modifications that would increase manufacturing cost or reduce wall thickness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention temporarily changes the geometric parameters of the flat tube end by forming protrusions that create an introduction bevel effect. After the inner insert is introduced, these protrusions are removed, restoring the original wall thickness and structural parameters, thus avoiding permanent reduction in wall thickness while still facilitating easy insert introduction.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If continuous production method is used to produce flat tubes with inner inserts, then productivity is improved, but device complexity increases due to expensive rolling train investment

Engineering Contradiction:

Improveproduction volumeVSAvoidproduction line investment

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention separates the inner insert introduction process into distinct stages: first forming temporary protrusions on the flat tube end, then introducing the inner insert, and finally removing the protrusions. This segmentation allows standard production equipment to be used without requiring complex continuous production lines, making the method suitable for both small-scale and large-scale production while avoiding high investment costs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention temporarily changes the geometric parameters of the flat tube end by forming protrusions that create an introduction bevel effect. After the inner insert is introduced, these protrusions are removed, restoring the original wall thickness and structural parameters, thus avoiding permanent reduction in wall thickness while still facilitating easy insert introduction.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8713796B2Method for producing a flat tube with an inner insert

Publication Date: 2014.05.06 MODINE MFG CO

AI summary

A flat tube for use with a heat exchanger. The flat tube including wide sides, narrow sides, an inner insert, a wall that at least partially forms the wide sides and the narrow sides, and the wall is configured to be produced from a punched-out blank. The flat tube further includes an introduction bevel in order to facilitate introduction of the inner insert. The introduction bevel includes at least two bent-down projections at an end of the flat tube. The at least two projections extend over portions of at least one of the wide sides and the narrow sides, and it being possible for the at least two projections to be separated off after the introduction of the inner insert.