Multi-Rate Dishwasher Flow-Path Switching with Motor-Current Diagnostics
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Solution Overview
Problem
Conventional dishwashers lack an efficient method to determine the position and state of the flow path switching unit, which affects the washing performance and reliability of the appliance.
Innovation Solution
A control method for a dishwasher that measures the current supplied to the motor while the impeller rotates, comparing it to reference current amounts to determine the position and state of the flow path switching unit, and notifies the user of malfunctions through an alarm system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dishwasher includes multiple flow paths with different flow rates to improve washing performance, then the washing ability is improved, but the device complexity increases due to the need for a flow path switching unit and multiple communication holes
Solution Approach 1:
The flow path switching unit is divided into multiple communication holes (first, second, and third communication holes) that correspond to different flow paths. Each communication hole can be independently opened or closed by the switching unit, allowing selective activation of different flow paths based on washing needs, thus managing complexity through modular segmentation
Solution Approach 2:
The flow path switching unit serves multiple functions: it switches between different flow paths (first, second, third flow paths) with different flow rates, monitors the operational state of the flow paths, and provides diagnostic information about system malfunctions. This multi-functionality reduces the need for separate components
2Adaptability or versatility
If the dishwasher uses a flow path switching unit to sequentially open communication holes based on washing water supply, then the adaptability to different washing conditions is improved, but the difficulty of detecting and measuring the switching unit position increases
Solution Approach 1:
The system uses current sensing to detect the position of the flow path switching unit. The control unit measures the current consumed by the motor that operates the switching unit, and based on the current characteristics, determines which communication hole is currently opened. This feedback mechanism enables automatic adaptation without complex position sensors
Solution Approach 2:
The patent replaces complex mechanical position detection mechanisms with electrical current measurement. Instead of using mechanical switches, optical sensors, or positional encoders to detect the switching unit position, the system uses the electrical current characteristics of the motor to infer the switching unit state, simplifying the detection system
3Measurement precision
If the dishwasher measures current supplied to the motor to determine flow path switching unit position, then the measurement precision is improved, but the reliability decreases due to potential current measurement errors and malfunction detection challenges
Solution Approach 1:
The control unit is programmed with predetermined current values that correspond to known positions of the flow path switching unit. Before normal operation, the system can perform diagnostic checks by comparing actual current measurements against these predetermined values to detect potential malfunctions. This preliminary validation prevents unreliable operation
Solution Approach 2:
The system establishes predetermined current values for each flow path position in advance during system design and calibration. These reference values are stored and used during operation to quickly and accurately determine the switching unit position without requiring complex real-time calculations, improving both precision and reliability
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 method enhances washing ability by ensuring proper operation of the flow path switching unit, improving washing performance and user awareness of potential issues.
Implementation Method 1
a water supply pump configured to supply washing water to the chamber through an impeller rotated by a motor
Implementation Method 2
measuring an amount of current supplied to the motor while the motor rotates the impeller to supply washing water to the chamber
Data Source
AI summary
A control method of a dishwasher that includes at least two flow paths having different flow rates, a chamber having communication holes that each communicate with a respective flow path, a water supply pump configured to supply washing water to the chamber through an impeller rotated by a motor, and a flow path switching unit located within the chamber and configured to sequentially open the communication holes is described. The control method includes the actions of measuring an amount of current supplied to the motor while the motor rotates the impeller to supply washing water to the chamber, and determining a position of the flow path switching unit by comparing the amount of current supplied to the motor with reference current amounts that are each designated as an amount of current supplied to the motor when the motor rotates the impeller to supply washing water to the respective flow path.