Dishwasher Closure Element Position Sensing via Recirculation Pump Load
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Solution Overview
Problem
The existing methods for detecting the position of a closure element in a dishwasher's reversing device are complex and costly, requiring additional sensors and complex structures, which increase manufacturing costs and assembly effort.
Innovation Solution
A method where the closure element is actively controlled to a defined reference position, allowing its position to be determined quickly and reliably by monitoring power values of the circulating pump, eliminating the need for additional sensors and simplifying the device structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a speed sensor on the circulating pump is used to detect the position of the closure element, then the position can be determined based on pump speed, but the device structure becomes very complex and manufacturing costs increase
Solution Approach 1:
The patent removes the speed sensor from the circulating pump and extracts the position detection function from the mechanical domain to the electrical domain. The closure element position is detected by monitoring the electrical current consumption of the circulating pump motor, which varies depending on the water flow resistance created by different closure element positions. This eliminates the need for mechanical sensors and complex guiding structures.
Solution Approach 2:
The patent introduces electrical current consumption as an intermediary parameter to indirectly detect the closure element position. Instead of directly measuring mechanical position or pump speed, the system uses the electrical characteristics (current draw) of the pump motor as a mediator that reflects the hydraulic conditions caused by different closure element positions, thereby simplifying the overall device structure.
2Measurement precision
If additional sensors are arranged in the circulating pump area to detect closure element position, then position detection is possible, but manufacturing costs and assembly effort increase
Solution Approach 1:
The circulating pump motor serves a dual function: it not only pumps water but also acts as its own sensor for position detection. The motor's electrical characteristics (current consumption) automatically provide information about the closure element position without requiring separate sensing components. This self-service approach eliminates additional sensors and reduces manufacturing complexity.
Solution Approach 2:
The circulating pump motor is given multiple functions: water pumping and position detection. By monitoring the electrical parameters of the motor during operation, the system simultaneously achieves both hydraulic function and sensing function, thereby eliminating the need for dedicated sensors and reducing overall system cost and complexity.
3Reliability
If the closure element position is detected after a fault using active control and power value monitoring, then the position can be determined quickly and reliably, but the method requires active intervention
Solution Approach 1:
The control device continuously monitors the electrical current consumption of the circulating pump motor during normal operation, maintaining readiness to detect closure element position even after faults. This preliminary monitoring ensures that when a fault occurs, the system already has electrical characteristic data that can be used to determine the closure element position without requiring complex post-fault sensing systems.
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 approach reduces manufacturing costs, simplifies the device structure, and enables quick and reliable detection of the closure element's position after a fault, allowing for efficient resumption of the program sequence without additional alignment steps.
Implementation Method 1
the control device determines at least one signal value of the circulating pump. The signal value can be a power value of the circulating pump, for example pressure, load angle or vibration.
Data Source
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AI summary
The present invention relates to a method and device for detecting the position of a closure element (38) of a movement reversal device (32) in a dishwasher (10), wherein a predefined reference position of the closure element (38) is determined by means of a signal value of the recirculation pump (30).