Fan Guide Cover Assembly to Prevent Rotation and Air Leakage

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Solution Overview

Problem

Existing fan cover mounting structures are prone to rotation due to engine vibration and applied forces, leading to potential detachment and leakage of cooling air.

Innovation Solution

A fan guide unit with a fan guide featuring a fitting portion and protrusions that intersect the circumferential direction, and a fan cover with corresponding through-holes, ensuring secure attachment and preventing rotation by aligning the protrusions and through-holes in the same radial direction, enhancing mounting workability and rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fan cover is attached to a fan guide by fitting a projected portion to a pinch portion (Patent Document 1), then the fan cover can be mounted, but when a strong force is applied in the rotation direction, the fitting portion may ride on the periphery of the recess portion and rotate

Engineering Contradiction:
Improvemounting easeVSAvoidrotation resistance
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The invention introduces asymmetric protrusions on the fan guide and corresponding asymmetric through-holes on the fan cover. These asymmetric features prevent rotational movement by ensuring that the components can only be assembled in a specific orientation, thereby solving the rotation resistance problem while maintaining ease of mounting through the straightforward protrusion-through-hole fitment mechanism.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention adds a rotational constraint dimension to the mounting structure. By incorporating protrusions that extend in a direction intersecting the circumferential direction and corresponding through-holes, the design transforms a two-dimensional fitting problem into a three-dimensional constraint system that simultaneously addresses both mounting ease and rotation prevention.

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

2Ease of operation

If a fan cover is attached to a fan guide by fitting a fitting portion to stoppers (Patent Document 2), then the fan cover can be mounted, but when a force is applied in the rotation direction, the bulging portion may come off from the mounting hole and rotate

Engineering Contradiction:
Improvemounting easeVSAvoidattachment security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The asymmetric protrusion-through-hole configuration provides both mounting ease and rotational constraint in a single integrated feature, eliminating the need for separate stoppers and bulging portions. This asymmetric design ensures that the fan cover cannot rotate once mounted, as the protrusions would conflict with the fan guide structure in any rotated position.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention merges the mounting function and the rotation prevention function into a single integrated structure. The protrusions serve dual purposes: facilitating easy mounting through the through-holes and preventing rotation by their asymmetric configuration, thereby combining multiple functions that were previously separated into different components.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If protrusions are provided on the fitting portion to prevent rotation, then rotation suppression is improved, but the device complexity increases

Engineering Contradiction:
Improverotation resistanceVSAvoidstructure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention applies local quality by adding protrusions only at specific locations on the fitting portion where rotational constraint is needed, rather than complicating the entire structure. The protrusions are localized features that provide rotational resistance without requiring changes to the overall fan cover or fan guide design, thus minimizing the increase in device complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The rotation prevention function is segmented into discrete protrusion features that can be independently designed and manufactured. This segmentation allows the protrusions to be added as simple extrusions or molded features on the fitting portion, avoiding the need for complex integrated designs and keeping the overall device complexity low.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3859132B1Fan guide unit
Publication Date: 2024.04.17 TOKYO RADIATOR MFG CO LTD
  • EP3859132B1 patent drawingFigure 1
  • EP3859132B1 patent drawingFigure 2A
  • EP3859132B1 patent drawingFigure 2B

AI summary

A fan guide unit for a heat exchanger of the present disclosure includes a fan guide (5) having a fitting portion (10) provided along a circumferential direction on a periphery of an opening portion and at least one protrusion (11) provided on the fitting portion (10) and protruding in a direction intersecting the circumferential direction and a fan cover (6) having a fitted portion (13) provided corresponding to the fitting portion (10) of the fan guide (5). The fitted portion (13) of the fan cover (6) is provided with at least one through-hole (14) provided corresponding to the protrusion (11) of the fan guide (5).