Indoor Unit Inlet Panel Arm Retention With Guided Shaft Stopper

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Solution Overview

Problem

During maintenance or operation of an indoor unit, the fitting between arms and shafts may become disengaged due to the opening and closing of the inlet panel, leading to the potential coming-off of the inlet panel from the casing.

Innovation Solution

The indoor unit design includes a casing with arm accommodation portions that have upper and lower guide portions, a bearing portion with a recessed curved surface, and a stepped portion. The arms have a shaft portion that is guided by these features, and a stopper that restricts the turning of the shaft portion, preventing disengagement and coming-off of the inlet panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the inlet panel is made detachable for maintenance, then ease of operation is improved, but reliability deteriorates due to potential disengagement of arms from shafts

Engineering Contradiction:
Improveease of maintenanceVSAvoidfitting retention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by providing guide portions that preliminarily guide the shaft portion into the correct position before the final fitting is achieved. The guide portions ensure proper alignment during the attachment process, preventing misalignment that could lead to disengagement during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary mechanism by introducing a stopper that acts as a mediator between the shaft portion and the bearing portion. The stopper prevents excessive movement and ensures the shaft portion remains properly positioned within the bearing portion, thereby maintaining reliable fitting while allowing the inlet panel to be detachable for maintenance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the inlet panel can be opened for access, then ease of operation is improved, but the inlet panel may come off from the casing

Engineering Contradiction:
Improvepanel accessibilityVSAvoidpanel attachment stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The guide portions perform preliminary guidance to ensure the shaft portion is correctly positioned before the inlet panel is fully attached. This preliminary alignment action prevents instability during subsequent opening and closing operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stopper serves as an intermediary element that stabilizes the connection between the inlet panel and casing. It mediates the relationship by preventing the shaft portion from moving beyond the bearing portion, thereby maintaining attachment stability while still allowing the panel to be opened for access.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4187164B1Indoor unit
Publication Date: 2025.04.23 MITSUBISHI HEAVY IND THERMAL SYST
  • EP4187164B1 patent drawingFigure 1
  • EP4187164B1 patent drawingFigure 2
  • EP4187164B1 patent drawingFigure 3

AI summary

An indoor unit of the present disclosure includes a casing (1) having arm accommodation portions (52) recessed backward from a front surface (51), arms (8) each having arm main body (80) inserted to the arm accommodation portion (52) from the front and shaft portion (81) protruding in a width direction from back end of the arm main body (80), and an inlet panel (9) which is fixed to front ends of the arm main bodies (80) and covering the front surface (51) of the casing (1). The arm accommodation portions (52) each have upper and lower guide portions configured to guide the shaft portion (81) backward through an opening of the arm accommodation portion (52) in a manner of being sandwiched therebetween from above and below, a bearing portion that is provided on a back end side thereof and is able to hold the shaft portion (81) to be rotatable about an axis extending in the width direction, and a stepped portion that is provided between the upper guide portion and the bearing portion and has a stepped surface directed to a backward side. The arms (8) each further have a stopper (84) that abuts the stepped surface so as to restrict turning of the shaft portion (81) when the shaft portion (81) turns in a state in which the shaft portion (81) is positioned in front of the bearing portion.