Air Conditioner Shutter Sealing Using Discharge Air Pressure

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Solution Overview

Problem

Conventional indoor air conditioner units face challenges in reliably sealing the shutter due to the reliance on elastic forces or constant motor-driven mechanisms, leading to air leakage and inefficiency.

Innovation Solution

An indoor air conditioner unit with a rotatably movable shutter that is kept closed by the pressure of the air flow generated by a centrifugal fan, utilizing a stepper motor for precise control and a stopper for alignment, reducing the need for constant drive force and enhancing sealing reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shutter is closed by the elastic force of a spring during cooling, then the shutter can be held in the closed position, but the sealing is unreliable because the shutter cannot completely close against the pressure of discharged cooled air

Engineering Contradiction:
Improveshutter sealing reliabilityVSAvoidforce required to keep shutter closed
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The shutter utilizes the pressure of the discharged air flow itself to maintain the closed state, rather than requiring external spring force or continuous motor drive. The air pressure differential created during operation automatically seals the shutter against the discharge passage wall.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical spring-based closing mechanism with a pressure-based sealing system. Instead of using elastic force to overcome air pressure, the system allows the air flow pressure to directly maintain the closed state, eliminating the need for continuous mechanical counteraction.

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

2Reliability

If a motor or electric drive device is used to keep the shutter closed, then the shutter can remain sealed, but rotational drive force must constantly be exerted on the shutter, increasing energy consumption and device complexity

Engineering Contradiction:
Improveshutter sealing reliabilityVSAvoidenergy consumption of shutter drive
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The motor operates periodically rather than continuously - it provides rotational drive force only during the transition to the closed state, then stops. The shutter remains sealed during operation due to air pressure, eliminating the need for constant energy input.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses the operational air flow to maintain the closed state without continuous external energy input. The shutter serves itself by utilizing the pressure differential created during air discharge to maintain sealing, rather than requiring continuous motor power.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the shutter is positioned inside a concavity away from the air flow, then the shutter can be kept open without pressure application, but the shutter may not reliably close when needed

Engineering Contradiction:
Improveshutter open state stabilityVSAvoidshutter closing reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The shutter is preliminarily positioned in a concavity during the open state, and the motor is activated in advance to rotate the shutter to the closed position before air discharge begins. This ensures the shutter is already sealed when the high-pressure air flow starts, rather than relying on the air flow to push it closed.

Inventive Principle:
Principle #10Preliminary action

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 solution effectively maintains a closed shutter state using air pressure, improving sealing and reliability while reducing the drive force required, preventing natural closure and ventilation loss, and allowing for efficient air discharge configurations during heating and cooling.

Implementation Method 1

a centrifugal fan for generating a flow of air that passes through the indoor heat exchanger and is blown out of the discharge passages

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

the shutter is kept in a closed state by the pressure of the air flow

Methodology Applied
Scientific EffectAir pressure: Pressure Increase

Data Source

PatentEP1975520B1Indoor unit for air conditioner
Publication Date: 2017.04.19 DAIKIN INDUSTRIES LTD
  • EP1975520B1 patent drawingFigure 1~2
  • EP1975520B1 patent drawingFigure 3
  • EP1975520B1 patent drawingFigure 4

AI summary

An object of the present invention is to provide a highly reliable indoor unit of an air conditioner in which the sealing of a shutter is improved. An indoor unit (1) of an air conditioner includes an indoor heat exchanger (3), a body (2), a centrifugal fan (4), and a shutter (5). A plurality of discharge passages (P2, P3) for discharging air that has passed through the indoor heat exchanger (3) are formed in the body (2). The centrifugal fan (4) generates a flow of air that passes through the indoor heat exchanger (3) and is blown out of the discharge passages (P2, P3). The shutter (5) is provided to at least one discharge passage (P3) of the plurality of discharge passages (P2, P3). The shutter (5) is kept in a closed state by the pressure of the air flow.