Washer Drawer Door Sensing for Safe Drum Loading

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Solution Overview

Problem

Conventional top loading laundry treatment apparatuses risk wash water and laundry being discharged when the door is opened, lack user notification of door status, and may incorrectly determine door openness due to external signals like vibration.

Innovation Solution

Incorporation of a door sensing unit using magnetic force generators and sensors to accurately detect door openness and a drawer sensing unit to determine drawer insertion, with a display unit to notify the user, and a guide to prevent door interference during drawer discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a door is provided to open the introduction aperture in conventional top loading laundry treatment apparatuses, then laundry can be introduced into the drum, but the door may prevent the drawer from being discharged when opened in the state where the drawer is located inside the cabinet

Engineering Contradiction:
Improvedrawer dischargeVSAvoiddoor mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The door mechanism is segmented into multiple components: the door body, the guide structure, and the sensing unit. The guide is divided into a guide body and a guide arm that can rotate independently. This segmentation allows the door to perform its primary function of opening the introduction aperture while the guide arm can independently move to prevent interference with drawer discharge.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guide arm acts as an intermediary between the door and the drawer discharge mechanism. When the door is opened inside the cabinet, the guide arm rotates to block the drawer's path, preventing discharge. This intermediary structure resolves the conflict between door operation and drawer discharge by introducing a mediating element that can adapt its position based on door status.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If conventional laundry treatment apparatuses lack door status notification, then the structure remains simple, but users cannot check door status and may leave the door open

Engineering Contradiction:
Improvedoor status informationVSAvoidsensing and notification system
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

A feedback system is implemented consisting of a door sensing unit that detects door status and a display unit that notifies the user. The sensing unit includes a magnetic force generator and sensor that detect whether the door is opened or closed, and this information is fed back to the user through the display unit. This feedback mechanism ensures users are always aware of the door status without requiring them to physically check it.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The mechanical door status detection system is replaced with a magnetic field-based sensing system. Instead of using mechanical switches or contacts that require physical interaction, the door sensing unit uses magnetic force generators and sensors to detect door position non-contactually. This substitution improves reliability and reduces mechanical wear while providing accurate door status information.

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

3Measurement precision

If no sensing unit is provided, then the device is simpler, but there is no ability to accurately check whether the door is opened in the state where the drawer is located inside the cabinet

Engineering Contradiction:
Improvedoor openness detectionVSAvoiddoor sensing unit
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The door sensing unit replaces mechanical detection methods with magnetic field-based sensing. A magnetic force generator is attached to the door, and a magnetic sensor is positioned on the cabinet body. When the door moves, the magnetic field changes, and the sensor detects this change to determine door status. This non-contact method provides precise measurement of door position without mechanical wear or contact.

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

Solution Approach 2:

The magnetic field serves as an intermediary between the door and the sensing system. Instead of direct mechanical contact or line-of-sight optical detection, the magnetic field transmits information about door position to the sensor. This intermediary approach allows for accurate detection while maintaining a compact structure and avoiding direct mechanical coupling between moving and stationary parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If conventional apparatuses lack abnormality detection, then the system is simpler, but abnormalities in constituent elements cannot be assuredly checked

Engineering Contradiction:
Improveabnormality detectionVSAvoidabnormality checking system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The abnormality detection system uses feedback from the magnetic sensor to monitor the health of door-related components. The control unit continuously receives signals from the magnetic sensor and compares them against expected values. When deviations indicate potential failures or abnormal conditions, the system generates alerts or error messages. This continuous feedback mechanism enables real-time monitoring of component health without requiring manual inspection.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis by automatically monitoring its own components through the magnetic sensing mechanism. The same magnetic force generator and sensor used for door status detection also serve to detect abnormalities in their own operation. If the magnetic force generator fails or the sensor becomes misaligned, the system detects these conditions and notifies the user, enabling the system to monitor itself without external intervention.

Inventive Principle:
Principle #25Self-service

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

Prevents wash water and laundry discharge, ensures accurate door openness detection, allows safe drawer discharge, and eliminates incorrect door openness determination.

Implementation Method 1

a door sensing unit for determining whether or not the door to open the introduction aperture is opened in a state in which the drawer is inserted into the cabinet. The door sensing unit includes a first magnetic-force generator provided in any one of the cabinet and the door for generating magnetic force, and a first magnetic-force sensor provided in a remaining one of the cabinet and the door for sensing the magnetic force provided by the first magnetic-force generator.

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP3112516B1Laundry treatment apparatus
Publication Date: 2018.08.22 LG ELECTRONICS INC
  • EP3112516B1 patent drawingFigure 1
  • EP3112516B1 patent drawingFigure 2
  • EP3112516B1 patent drawingFigure 3

AI summary

Disclosed is a laundry treatment apparatus including a cabinet (2) having an introduction/discharge opening (21), a drawer (3) configured so as to be discharged from the cabinet through the introduction/discharge opening, a through-hole (351) formed in an upper surface of the drawer, a tub (4) provided inside the drawer for providing a space for storage of water, an introduction aperture (431) formed in an upper surface of the tub, the introduction aperture being located under the through-hole, a drum (5) rotatably provided inside the tub for receiving laundry supplied to the introduction aperture, a door (45) provided on any one of the drawer and the tub for opening and closing the introduction aperture, and a door sensing unit (97) for determining whether or not the door to open the introduction aperture is opened in a state in which the drawer is inserted into the cabinet.