Washing Machine Weight Sensing with Stable Load Cell Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing washing machine weight sensing methods, either using a driving motor or a load cell, face accuracy issues due to non-uniform pressure application and vibration-induced changes in spring position and posture, leading to inaccurate laundry weight measurement.
Innovation Solution
A weight sensing unit with a pressure distributing member that ensures point contact between the spring and load cell, and a surface contact portion for uniform pressure transfer, combined with a method of compensating sensed values from both direct and indirect weight measurements to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a load cell is used to directly sense laundry weight, then measurement precision is improved, but reliability deteriorates due to biased transformation and contact instability
Solution Approach 1:
A pressure distributing member is introduced as an intermediary component between the spring and load cell. This mediator ensures uniform pressure distribution across the load cell surface, preventing biased transformation while maintaining stable contact despite spring position variations due to vibration.
Solution Approach 2:
The pressure distributing member features a curved surface with specific geometric properties that concentrate pressure uniformly on the transformation portion of the load cell. The curved surface design ensures that pressure is applied locally and uniformly to the critical sensing area, improving both accuracy and stability.
2Device complexity
If spring pressure is applied directly to load cell, then device complexity is reduced, but manufacturing precision deteriorates due to non-uniform pressure application
Solution Approach 1:
The pressure distributing member serves as a simple intermediary component that corrects non-uniform pressure distribution without requiring complex sensing or control systems. The curved surface geometry inherently distributes pressure uniformly, achieving manufacturing precision improvement with minimal added complexity.
Solution Approach 2:
The pressure distributing member employs a curved surface geometry that naturally distributes spring pressure uniformly across the load cell. The specific curvature design ensures that pressure is applied evenly to the transformation portion, improving manufacturing precision through geometric design rather than complex control mechanisms.
3Ease of manufacture
If load cell posture is not stabilized, then ease of manufacture is improved, but measurement precision deteriorates due to vibration-induced position changes
Solution Approach 1:
The pressure distributing member acts as a stable intermediary that maintains consistent contact with the load cell despite spring position variations. This component ensures that the load cell posture remains stable during operation, preventing measurement errors caused by vibration-induced position changes while maintaining ease of assembly.
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 configuration stabilizes the load cell posture, prevents pressure-induced transformations, and allows for simultaneous direct and indirect weight sensing, resulting in more accurate laundry weight measurement.
Implementation Method 1
at least one spring installed between the tub and a frame of the cabinet, one end of the springs being coupled to the weight sensing unit
Implementation Method 2
The load cell which contacts the spring may be transformed due to pressure applied by the spring, and the laundry weight is sensed by electrically sensing a transformed level of the load cell based on strain gages
Data Source
AI summary
A washing machine having a weight sensing unit comprises a cabinet forming an appearance, a tub disposed within the cabinet, springs installed between the tub and a frame of the cabinet, and a weight sensing unit disposed on the frame of the cabinet, one end of the springs being coupled to the weight sensing unit. The weight sensing unit comprises a case coupled to the frame of the cabinet, a load cell supported with being received in the case, and a pressure distributing member mounted on the load cell to hold the spring thereon.