Drum Washing Machine Spin-Drying Control by Laundry Weight
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Solution Overview
Problem
Drum type washing machines face limitations in increasing their rate capacity due to size constraints, which restrict the length of vibration-absorbing springs, and struggle to efficiently manage spin-drying time based on varying laundry weights.
Innovation Solution
A method is introduced to control drum type washing machines by sensing laundry weight, executing a first spin-drying pattern for low weights and switching to a second pattern when the weight exceeds a certain threshold, with specific acceleration and maintenance stages tailored to each pattern to optimize spin-drying efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the rate capacity of the drum type washing machine is increased, then the washing capacity is improved, but the length of the spring for absorbing vibration must be increased which is limited by the cabinet size
Solution Approach 1:
The patent applies dynamics by making the spin-drying pattern adaptive rather than fixed. The control method dynamically adjusts drum rotation speeds, acceleration periods, and maintenance speeds based on sensed laundry weight, allowing the system to optimize vibration absorption characteristics for different load conditions without requiring physical modification of the spring system.
Solution Approach 2:
The patent changes operational parameters (drum rotation speed, acceleration rate, maintenance speed duration) based on laundry weight sensing. By adjusting these parameters, the system optimizes the spin-drying process for different load weights, effectively managing vibration within the fixed cabinet space without needing to change the spring length.
2Device complexity
If a single spin-drying pattern is used for all laundry weights, then the control system is simple, but the spin-drying time cannot be optimized for different weights
Solution Approach 1:
The control method transitions from a static single pattern to a dynamic multi-pattern system. Based on sensed laundry weight, the system automatically selects between a first spin-drying pattern (for lighter loads) and a second spin-drying pattern (for heavier loads), optimizing spin-drying time for each condition while maintaining manageable control complexity through weight-based decision logic.
Solution Approach 2:
The patent segments the spin-drying process into distinct patterns based on laundry weight thresholds. The first spin-drying pattern includes specific acceleration and maintenance stages optimized for lighter loads, while the second pattern is optimized for heavier loads. This segmentation allows time optimization for each weight category without creating an overly complex control system.
3Productivity
If the drum is accelerated to high speed immediately, then the spin-drying efficiency is improved, but vibration and unbalance may increase causing operational issues
Solution Approach 1:
The patent applies preliminary action by implementing an acceleration period with controlled target speeds before reaching the final maintenance speed. The drum is first accelerated to a first target speed, maintained for a first maintenance period, then accelerated to a second target speed. This staged approach allows the system to prepare for high-speed operation by gradually building momentum and allowing sensor systems to detect and compensate for developing unbalance, thereby reducing harmful vibrations while maintaining spin-drying efficiency.
Data Source
AI summary
A method of controlling a drum type washing machine is disclosed. The method includes sensing laundry weight to perform a washing cycle (a laundry weight sensing step), immediately executing a first spin-drying pattern without additional laundry weight sensing when a laundry weight value sensed at the laundry weight sensing step is equal to or less than A in a spin-drying cycle, and executing a second spin-drying pattern after sensing the laundry weight when the laundry weight value sensed at the laundry weight sensing step is greater than A in the spin-drying cycle. In a case in which the laundry weight is low, spin-drying is immediately performed without performing laundry weight sensing, whereby it is possible to reduce time necessary to sense the laundry weight.