HVAC Flap Sealing via Spring-Assisted Closure

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Solution Overview

Problem

Existing HVAC modules for vehicle passenger compartments face issues with flap sealing due to production and mounting tolerances, leading to noise, vibration, and reduced airflow control efficiency, particularly in the closed position.

Innovation Solution

Incorporating a spring element that assists the flaps during closure, compensating for production and mounting tolerances, and reducing the torque required for the adjustment mechanism, thereby enhancing sealing and reducing leakage and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If two flaps are arranged on a common shaft to control airflow in two channels, then cost is reduced and structure is simplified, but sealing performance deteriorates due to production tolerances causing angular offset

Engineering Contradiction:
Improvemanufacturing costVSAvoidsealing precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces a spring element that applies a closing force to the flaps, dynamically adjusting the flap position to compensate for manufacturing tolerances. This changes the operational parameter of the flap from a static position determined solely by the shaft to a dynamically adjusted position that maintains sealing contact despite angular offset caused by tolerance accumulation in the housing, flaps, shaft, and drive components.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the shaft length is increased to connect flaps spaced apart, then the adjustment mechanism can control both channels, but the required torsional strength of the shaft increases

Engineering Contradiction:
Improveadjustment rangeVSAvoidtorsional strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The spring element acts as an intermediary that provides local support and force application to the shaft at the flap location. This reduces the bending moment and torsional stress on the shaft by distributing the load, allowing the shaft to be lighter while still spanning the required distance between channels.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single drive controls both flaps on a common shaft, then the adjustment mechanism is simplified, but torque requirements increase due to static and dynamic airflow pressure

Engineering Contradiction:
Improveadjustment mechanism complexityVSAvoidtorque requirement
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The spring element provides a closing force that counteracts the airflow pressure acting on the flaps. By pre-tensioning the spring, the system creates a counterbalancing force that reduces the net torque the drive must exert to close and hold the flaps against the airflow pressure, effectively using the spring as a mechanical counterweight to the aerodynamic load.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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 spring element improves the sealing of flaps in the closed position, reduces leakage, and lowers production costs and weight by optimizing the adjustment mechanism, while maintaining flap contact pressure under airflow pressure.

Implementation Method 1

a spring element which acts upon the shaft in the closed position of the flaps is provided

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3317132B1Module for heating, ventilation and/or air conditioning of a passenger compartment of a motor vehicle
Publication Date: 2021.01.27 VALEO KLIMASYST
  • EP3317132B1 patent drawingFigure 1~2
  • EP3317132B1 patent drawingFigure 3~4b
  • EP3317132B1 patent drawingFigure 5a~5c

AI summary

Module for heating, ventilation and/or air conditioning of a passenger compartment of a motor vehicle A module (10) for heating, ventilation and/or air conditioning of a passenger compartment of a motor vehicle comprises a module housing (12), at least two channels (14) being formed therein, and an adjustment mechanism (18), in particular for controlling airflows (L) in the channels (14). The adjustment mechanism (18) comprises at least two flaps (22) arranged on a common shaft (20) as well as a drive, the shaft (20) being able to be adjusted thereby between a closed position in which each flap (22) closes a channel (14) and at least one open position in which each flap (22) at least partially opens a channel (14). A spring element (30) which acts upon the shaft (20) in the closed position is provided.