Washing Machine Wetting Control Using Hydrostatic Pressure Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing washing machine wetting processes fail to accurately and efficiently wet laundry batches of varying sizes, leading to incomplete wetting in large loads and prolonged wetting in small loads, with a lack of uniformity and timely recognition of laundry loads.
Innovation Solution
A method using a sensor to measure hydrostatic pressure and time gradient, allowing precise control of water filling until predetermined threshold values are reached, enabling quick and accurate recognition of laundry loads and optimizing the wetting phase duration and water amount based on absorption capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If water is filled into the tub during the wetting phase until a predetermined amount is reached, then the wetting process is simple to control, but complete and uniform wetting cannot be achieved for laundry batches of varying sizes
Solution Approach 1:
The patent implements feedback control by continuously measuring hydrostatic pressure during water filling and comparing it with predetermined threshold values. The control device adjusts the water supply based on these measurements, ensuring that wetting is adapted to the actual laundry load while maintaining simple process control through automated feedback loops.
Solution Approach 2:
The patent changes the control parameter from fixed water quantity to dynamic hydrostatic pressure threshold. By monitoring pressure changes over time and comparing with threshold values, the system adapts the wetting process to different laundry loads, achieving both simple control and uniform wetting results.
2Reliability
If the wetting phase duration is extended to ensure complete wetting of large laundry batches, then wetting completeness is improved, but the wetting time for small batches becomes excessively long
Solution Approach 1:
The patent makes the wetting phase duration dynamic by continuously monitoring hydrostatic pressure and its time gradient. The control device adjusts the water supply and drum operation in real-time based on pressure changes, allowing the wetting phase to be completed as quickly as possible for each specific load size, thus achieving complete wetting without unnecessary time loss.
Solution Approach 2:
The patent replaces mechanical timing-based wetting control with a sensor-based hydrostatic pressure measurement system. This substitution enables precise detection of wetting progress and automatic adjustment of the process, optimizing both completeness and time efficiency.
3Productivity
If the wetting phase is shortened to improve processing efficiency, then productivity increases, but complete and uniform wetting cannot be achieved
Solution Approach 1:
The patent uses feedback control to determine the precise endpoint of the wetting phase by monitoring hydrostatic pressure threshold values. This allows the wetting phase to be shortened to the minimum necessary duration while ensuring complete and uniform wetting, thereby improving productivity without sacrificing reliability.
4Device complexity
If fixed threshold values for hydrostatic pressure are used to control water filling, then the control process is simple, but accurate recognition of different laundry load quantities cannot be achieved
Solution Approach 1:
The patent implements feedback control by comparing measured hydrostatic pressure values with predetermined threshold values during water filling. This simple feedback mechanism enables accurate recognition of different laundry load quantities while maintaining control process simplicity through automated threshold comparison.
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
Ensures complete and uniform wetting of laundry with the optimal amount of water, allowing for efficient transition to the washing phase by accurately determining the laundry load and adjusting the wetting phase accordingly.
Implementation Method 1
a sensor for determining a height of the liquid in the tub (i.e. the hydrostatic pressure p)
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A method for treating laundry in a program-controlled washing machine with a sensor (15) for determining the height of a liquid in the liquor container (1), the sensor signal of which is recorded during the method, and a drum (2), characterized in that, in a wetting phase a) while the drum (2) is rotating, water is filled in until a specified threshold value (p1, p2, p3) is reached for the hydrostatic pressure p and until a specified threshold value ((p/t)1, (p/t)2, (p/t)3) is reached for the temporal gradient of the hydrostatic pressure p, and/or b), at a specified time (t1, t2, t3) in the method, the rotation of the drum (2) is stopped and the filling-in of water is ended, and the change in the hydrostatic pressure p because of the water running back is evaluated for determining a loading amount; as well as a washing machine suitable for carrying out the method.