Drum Washer Load Detection Without Cloth Rubbing Damage

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Solution Overview

Problem

Drum washing machines often cause cloth damage during load quantity detection due to the dry state of washings and the rotation of the drum and its associated rotating body, which increases friction and wear.

Innovation Solution

A drum washing machine design that allows the drum and rotating body to integrally rotate at the same speed during load quantity detection, using a driving part with different operating modes to minimize friction and wear by adjusting rotating speeds and incorporating a braking mechanism to loosen washings before detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the drum and rotating body rotate at different speeds to improve washing performance, then detergency is improved, but cloth damage occurs during load quantity detection due to friction between the rotating body and dry washings

Engineering Contradiction:
Improvewashing performanceVSAvoidcloth damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The driving part can operate in different driving forms: first driving form for washing/rinsing where drum and rotating body rotate at different speeds to provide detergency, and second driving form for load quantity detection where they integrally rotate at the same speed to avoid cloth damage. This dynamic switching resolves the contradiction between washing performance and cloth protection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotating speed relationship between the drum and rotating body is changed based on the operational phase. During load quantity detection, the rotating speed of the rotating body is adjusted to match the drum's rotating speed, eliminating relative motion and friction that would damage dry cloth, while during washing the speeds are differentiated to maintain effective detergency.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the load quantity is detected before water supply when washings are dry, then detection can be performed, but friction coefficient increases causing cloth damage

Engineering Contradiction:
Improveload quantity detectionVSAvoidcloth damage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The load quantity detection is performed as a preliminary action before water supply, but the patent introduces a protective measure (integral rotation of drum and rotating body) to prevent cloth damage during this preliminary detection phase, allowing both early detection and cloth protection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The function of the rotating body is temporarily extracted or deactivated during load quantity detection by making it rotate at the same speed as the drum, effectively removing its stirring action that would cause friction and damage to dry washings, while allowing detection to proceed.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the rotating body rotates to provide mechanical force for washing, then detergency improves, but it causes rubbing and cloth damage during dry rotation

Engineering Contradiction:
ImprovedetergencyVSAvoidcloth damage from rubbing
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The rotating body dynamically adjusts its rotating speed based on the operational phase. During washing, it rotates at different speeds than the drum to provide effective mechanical action for detergency. During load quantity detection, it rotates at the same speed as the drum to eliminate relative motion and prevent rubbing damage to dry cloth.

Inventive Principle:
Principle #15Dynamics

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

This design prevents cloth damage during load quantity detection by ensuring the washings are not rubbed by the rotating body, allowing for precise detection and improved washing performance without wear on the garments.

Implementation Method 1

the load quantity is detected according to a rotating load applied to the drum when the drum rotates at a rotating speed at which the washings are attached to an inner circumferential surface of the drum

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3187638B1Drum washing machine
Publication Date: 2020.05.27 HAIER ASIA INT CO LTD
  • EP3187638B1 patent drawingFigure 1
  • EP3187638B1 patent drawingFigure 2
  • EP3187638B1 patent drawingFigure 3

AI summary

Provided is a drum washing machine (1) capable of preventing washings from generating cloth damage while detecting load quantity. The drum washing machine (1) includes: an outer tank (20), configured in a shell (10); a drum (22), configured in the outer tank (20) and capable of rotating by using a horizontal shaft or an inclination shaft inclining relative to a horizontal direction as a center; a rotating body (24), configured at a rear part of the drum (22) and having protruding parts (24a) in contact with washings on a surface of the rotating body (24); a driving part (30), capable of operating in a first drying form and a second driving form, wherein the first driving form refers to a driving form which enables the drum (22) and the rotating body (24) to rotate at different rotating speeds, and the second driving form refers to a driving form which enables the drum (22) and the rotating body (24) to rotate integrally at the same rotating speed; and a control part (801). Herein, the control part (801) detects the load quantity of the washings in the drum (22), and enables the driving part (30) to operate in a uniaxial driving form while detecting the load quantity (S13 and S14).