Dishwasher Filling Sequence Using Pump Concentricity Check
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Solution Overview
Problem
Commercially available dishwashers often fail to accurately dispense the desired amount of washing liquid during filling, leading to potential noise issues due to air suction by the circulating pump when the liquid level is low.
Innovation Solution
A dishwasher with a control device that implements a primary filling phase based on a default time for the nominal amount of washing liquid, followed by a concentricity check to ensure the circulating pump operates correctly, and continues filling if necessary to achieve the required amount, using a simple inlet valve and concentricity monitoring unit to manage the filling sequence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple time-based filling method is used, then the device complexity is reduced, but the manufacturing precision of the washing liquid quantity is insufficient
Solution Approach 1:
The patent implements feedback control by monitoring the actual washing liquid quantity during filling and comparing it with the target quantity. The control device adjusts the inlet valve based on this feedback to achieve precise filling while maintaining relatively simple device structure.
Solution Approach 2:
The patent performs preliminary concentricity checking of the circulating pump before finalizing the filling quantity. This preliminary action ensures that the pump is properly positioned, allowing for more accurate quantity control in subsequent filling operations.
2Loss of time
If the inlet valve remains open during concentricity checking, then the filling time is reduced, but the reliability of concentricity detection deteriorates due to changing liquid levels
Solution Approach 1:
The patent dynamically adjusts the inlet valve state based on the filling phase. During concentricity checking, the valve is temporarily closed to stabilize liquid level and ensure reliable detection. After successful detection, the valve is reopened to continue filling, optimizing the balance between time and reliability.
3Reliability
If the washing chamber is filled to a high liquid level, then the circulating pump operates more reliably, but the filling time increases
Solution Approach 1:
The patent fills the washing chamber to a slightly higher liquid level than the minimum required for pump operation. This partial excessive filling ensures the pump operates reliably without requiring complete chamber filling, thereby reducing overall filling time while maintaining pump reliability.
Data Source
AI summary
A dishwasher includes a control device controlling a dishwashing cycle for cleaning items to be washed, a dishwashing chamber for the items to be washed, an inlet valve for controlled filling the washing chamber with washing liquid, and a circulating pump for circulating the washing liquid in the dishwashing chamber. The inlet valve is opened during a primary filling phase having a duration sufficient to fill the dishwashing chamber with a nominal amount of washing liquid and allowing the circulating pump running to run concentrically at a rated speed. A concentricity monitoring unit performs a concentricity check at the end of the primary filling phase to ascertain whether the circulating pump is running concentrically at the rated speed. The filling sequence is terminated when the circulating pump is running concentrically, whereas the filling sequence is continued when the circulating pump is not running concentrically.