Drum Washing Control Using Dirt Feedback and Variable Spin Speed

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional drum-type washing machines face issues with non-uniform washing, high power consumption, and inefficient detergency due to fixed high-speed rotating operations regardless of laundry quality or detergent amount, leading to poor energy saving and removal efficiency.

Innovation Solution

A drum-type washing machine with a state detector to monitor laundry conditions, controlling rotational speed in washing and centrifugal cleaning steps based on detected dirt levels and detergent amounts, and adjusting operations to optimize washing efficiency and energy usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a predetermined-high-speed rotating operation is performed regardless of the degree of dirt of the laundry, then the removal efficiency of dirt is improved, but unnecessary electric power is consumed

Engineering Contradiction:
Improveremoval efficiency of dirtVSAvoidelectric power consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the drum rotational speed adjustable based on detected dirt levels. The controller dynamically changes the rotational speed from a predetermined high speed to a lower speed when the dirt level is determined to be low, optimizing both cleaning efficiency and energy consumption according to actual washing conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using a detector to monitor the dirt level of laundry during the washing process. The controller receives this feedback information and adjusts the drum rotational speed accordingly, creating a closed-loop control system that prevents unnecessary high-speed rotation when dirt levels are already low.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If a predetermined-high-speed rotating operation is performed regardless of an amount of loaded detergent, then the removal efficiency of dirt is improved, but unnecessary electric power is consumed

Engineering Contradiction:
Improveremoval efficiency of dirtVSAvoidelectric power consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent uses feedback from a detector that monitors detergent amount to control drum rotational speed. When the detector determines that a sufficient amount of detergent is present, the controller reduces the rotational speed, preventing unnecessary energy consumption while maintaining effective cleaning.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the operational parameter (rotational speed) based on the detected detergent amount. The controller adjusts the drum speed from a predetermined high speed to a lower speed when adequate detergent is detected, optimizing the washing process efficiency and energy consumption.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If beat washing is subjected to chemical-fiber clothes, then the washing process is simplified, but the removal efficiency of dirt is low due to low water content and light weight

Engineering Contradiction:
Improvewashing process complexityVSAvoidremoval efficiency of dirt
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by adjusting the drum rotational speed based on the detected quality of laundry. When chemical-fiber clothes are detected, the controller increases the rotational speed to generate sufficient centrifugal force for effective cleaning, rather than using a fixed low-speed beat washing mode.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the rotational speed parameter according to the detected laundry type. For chemical-fiber clothes with low water content and light weight, the controller increases the rotational speed to provide adequate mechanical action for dirt removal, optimizing cleaning effectiveness for different fabric types.

Inventive Principle:
Principle #35Parameter changes

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 machine achieves low power consumption with optimal detergency by varying rotational speeds according to laundry quality and detergent levels, enhancing cleaning efficiency and energy saving performance.

Implementation Method 1

rotating the drum at a high speed which stick the laundry to an inner peripheral wall surface of the drum to discharge washing water from the laundry by centrifugal force

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2752515B1Drum-type washing machine
Publication Date: 2019.05.08 PANASONIC HOLDINGS CORP
  • EP2752515B1 patent drawingFigure 1
  • EP2752515B1 patent drawingFigure 2
  • EP2752515B1 patent drawingFigure 3A

AI summary

A drum-type washing machine includes a drum drive unit (4) that rotationally drives a drum (3), and a controller (30) that receives an output from a dirt detector (18) serving as a state detector that detects a state of laundry in the drum for which dirt of the laundry in the drum is detected, and sequentially controls steps including washing, rinsing, and spin-drying steps. The washing step includes an agitating step for rotating the drum (3) at a low speed which does not stick the laundry to the inside of the drum (3), and a centrifugal cleaning step for rotating the drum (3) at a high speed which stick the laundry to an inner peripheral wall surface of the drum (3) to discharge washing water from the laundry by centrifugal force, and the controller (30) changes a rotational speed of the drum in the centrifugal cleaning step according to the output from the dirt detector (18).