Heat Exchanger Rim Segmentation for Joining Strength

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Solution Overview

Problem

Existing heat exchanger designs require significant material and force for joining the base and cover, resulting in low joining forces due to elastic deformation, making them inefficient and costly to produce.

Innovation Solution

A heat exchanger design featuring multiple caulks along the rim of the base and cover, which are embossed from sheet metal blanks with a w- or ω-shape, allowing for a strong and symmetrical joint with reduced material usage, and enabling high-pressure resistance through soldering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the rim is formed by a continuous bracket and bent or folded to fix base and cover, then the joining forces between base and cover are increased, but a large amount of material and high forces are required for bending or folding

Engineering Contradiction:
Improvejoining forcesVSAvoidmaterial usage
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The continuous bracket rim is segmented into multiple discrete caulkings distributed along the longitudinal direction. This segmentation reduces the total material required while maintaining joining strength, as each caulking acts as an independent joining point rather than requiring a continuous high-strength bracket throughout the entire length.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of uniformly strengthening the entire rim, the invention applies localized caulkings at specific positions where joining is needed. The caulkings concentrate material and forming effort only at critical joining points, reducing overall material usage while achieving sufficient local joining strength.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If the rim is formed by isolated tabs and bent or folded to fix base and cover, then the material usage is reduced, but the joining forces between base and cover are low due to stretching of the material and elastic deformation of the rim

Engineering Contradiction:
Improvematerial usageVSAvoidjoining forces
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The invention changes the geometric parameters of the caulkings, specifically their cross-sectional shape (W-shape or omega-shape) and dimensions. These parameter changes enable the caulkings to achieve high joining strength through their embossed geometry rather than relying on material volume, thus reducing material usage while maintaining or improving joining forces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The caulkings feature curved W-shaped or omega-shaped cross-sections rather than straight tabs. This curvature provides mechanical advantage by distributing stresses more effectively and creating interlocking geometry between base and cover, thereby increasing joining strength without proportionally increasing material usage.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Strength

If the rims of the base are bent over the entire length to fix base and cover, then the joining forces are increased, but the construction complexity and production cost are increased

Engineering Contradiction:
Improvejoining forcesVSAvoidconstruction complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The full-length bent rim is segmented into discrete caulkings spaced at intervals along the longitudinal direction. This segmentation simplifies the forming process by requiring localized deformation at specific points rather than continuous bending, reducing construction complexity and tooling requirements while maintaining adequate joining strength through distributed attachment points.

Inventive Principle:
Principle #1Segmentation

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

The design achieves a powerful and reliable joining of the base and cover with minimal material usage, ensuring high-pressure resistance and efficient production, suitable for use in CO2 refrigerant circuits.

Implementation Method 1

the joining forces that prevail after bending or folding between the bottom and the lid being low due to elastic deformation of the rim

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The base and the cover are advantageously soldered to one another

Methodology Applied
Scientific EffectSoldering: Soldering

Data Source

PatentEP2467665B1Heat exchanger
Publication Date: 2015.10.14 MAHLE BEHR GMBH & CO
  • EP2467665B1 patent drawingFigure 1~2
  • EP2467665B1 patent drawingFigure 3~5

AI summary

The invention relates to a heat exchanger (2), in particular gas cooler, having at least one collecting tank (6) which extends in a longitudinal direction (4) and which comprises a plate (8) and a cover (10), wherein the plate (8) has, at at least one of its edge regions (12) running in the longitudinal direction (4), a rim (18) by means of which the plate (8) engages at the outside over an edge region (12), which runs in the longitudinal direction (4), of the cover (10), or wherein the cover (10) has, at at least one of its edge regions (12) running in the longitudinal direction (4), a rim (18) by means of which the cover (10) engages at the outside over an edge region, which runs in the longitudinal direction (4), of the plate (8). Said heat exchanger is characterized in that the respective rim (18) has, in the longitudinal direction (4), a multiplicity of calked portions (20) by means of which said rim, in the region of each individual calked portion (20), is deformed in the direction of the collecting tank centre and fixes the plate (8) and the cover (10) to one another.