Header Box Cap With Retaining Lug for Compact Heat Exchangers

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Solution Overview

Problem

Existing plugs for heat exchangers are too bulky for compact cooling systems, making them difficult to install and require manual handling, which is challenging in confined spaces, and lack effective mechanisms to prevent slipping or popping during degassing and emptying.

Innovation Solution

A cap with a retaining lug that is elastically deformable, allowing it to be retained in an intermediate position within the header box, featuring a helical ramp for quarter-turn mounting and a rotation locking pin to prevent rotation, along with a seal and screwdriver slot for easy handling and secure operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a traditional plug is used for the collector box, then the sealing function is achieved, but the plug is too bulky for compact cooling systems and difficult to install in confined spaces

Engineering Contradiction:
Improveplug sizeVSAvoidinstallation difficulty
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The plug is segmented into distinct functional zones: a head portion for sealing, an intermediate portion with radial ribs for mounting, and a tail portion for manipulation. This segmentation allows each part to be optimized independently, reducing overall bulk while maintaining installation ease in confined spaces

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The plug design transitions from traditional linear dimensions to incorporate rotational dimensionality through the helical ramp mechanism. The quarter-turn rotational mounting allows the plug to be installed in a compact space by exploiting the rotational degree of freedom rather than requiring linear insertion space

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the plug is rotated to open position for purging or draining, then the passage is cleared, but the cap may slip or pop out due to lack of retention mechanism

Engineering Contradiction:
Improvedraining operationVSAvoidcap retention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A retaining tab acts as an intermediary element between the plug tail and the collector box opening. This tab engages with a corresponding feature in the opening to prevent the plug from slipping or popping out during draining operations, while still allowing controlled rotation to the open position

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The retention mechanism applies a preliminary counteracting force to prevent the harmful action of the plug slipping or popping out. The retaining tab is positioned and dimensioned to engage before any unwanted movement can occur, providing continuous retention during the draining operation

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If manual insertion of screw-on cap is required, then sealing is achieved, but it is not always possible to reach in to manually insert the cap in confined engine compartments

Engineering Contradiction:
Improvesealing functionVSAvoidaccessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The plug design incorporates self-aligning and self-retaining features that eliminate the need for manual positioning and insertion. The helical ramp automatically guides the plug into the correct rotational position, and the retention mechanism secures it without requiring hand access to confined spaces

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The manual screw-on mechanism is replaced with a rotational snap-fit system actuated by a tail mechanism. This substitution eliminates the need for threaded engagement that requires manual rotation, replacing it with a simpler rotational motion that can be initiated with minimal access

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

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

Enables secure, space-efficient installation and operation in compact environments, preventing cap slipping or popping, and facilitating easy handling and degassing of heat exchangers.

Implementation Method 1

This retaining tab (30) is elastically deformable so as to be able to take a retaining position and a clear position allowing the cap to be moved into the opening of the collection box when the cap is put in place

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

This plug includes a ramp having a substantially helical side arranged to allow mounting, in particular by quarter turn, of the plug in an opening of the collector box

Methodology Applied
Scientific EffectHelical motion: Helix

Implementation Method 3

the ramp includes a rotation locking pin arranged to cooperate with a stop of the collector box to lock the plug in rotation when it is in the intermediate position

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Data Source

PatentEP3794301B1Cap for a header box
Publication Date: 2022.02.23 VALEO SYST THERMIQUES SAS
  • EP3794301B1 patent drawingFigure 1
  • EP3794301B1 patent drawingFigure 2~3
  • EP3794301B1 patent drawingFigure 4~5

AI summary

The invention relates to a cap (20) for a header box of a heat exchanger (1), particularly for a motor vehicle, particularly a radiator, said cap comprising: a head (21); a shank (22) comprising at least one assembly slope (23), said shank being between the head and a free end of the cap; and a particularly elastically deformable retaining lug (30) arranged so as to retain the cap in an opening (10) of the header box in an intermediate position of the cap, a position in which the cap leaves a passage free while still being retained in the opening, said retaining lug being formed on the shank.