Electric valve control device, electric valve device, and method for controlling electric valve
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Solution Overview
Problem
Existing electric valve control devices fail to accurately determine if the rotor can rotate normally due to issues like foreign matter interference or stopper wear, leading to improper valve operation.
Innovation Solution
Implementing a system to detect rotor rotation restrictions using stopper mechanisms and pulse counting within specific ranges, determining normal operation by comparing input pulse numbers to design and upper limit numbers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the initialization number is set to a number greater than the design number to ensure the rotor reaches the reference position, then the rotor positioning reliability is improved, but the device cannot detect abnormal rotation conditions caused by foreign matter or stopper wear
Solution Approach 1:
The control device counts the actual number of pulses input to the stepping motor during initialization and compares it with the predetermined design number. This feedback mechanism allows detection of rotation abnormalities (such as foreign matter interference or stopper wear) by identifying deviations between the actual pulse count and the expected design number, while still using a sufficient initialization number to ensure proper rotor positioning.
2Duration of action of stationary object
If the stopper mechanisms are made durable to withstand repetitive contact, then the device lifespan is improved, but wear accumulation causes the rotor to rotate past the reference position and fail to position accurately
Solution Approach 1:
The control device performs initialization operation before normal operation to position the rotor at the reference position. During this preliminary action, the control device also counts the pulses and compares them with the design number to detect any wear-related deviations. This allows the durable stopper mechanisms to function throughout their lifespan while the system periodically checks for positioning accuracy degradation due to wear.
3Measurement precision
If the control device continuously monitors rotor position to detect abnormalities, then the detection capability is improved, but the device complexity increases
Solution Approach 1:
The control device utilizes the pulse signals already being sent to the stepping motor for control purposes and simply counts them during initialization. The existing pulse generation and control infrastructure serves dual purposes: both actuating the motor and providing data for abnormality detection. This self-service approach enables rotation monitoring without adding separate sensors or complex monitoring hardware.
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 the rotor operates within the appropriate range by restricting rotations with stopper mechanisms, allowing for accurate determination of normal operation through pulse number comparison.
Implementation Method 1
a stepping motor that includes a rotor, a valve member that moves toward the valve port when the rotor rotates in a first direction and moves away from the valve port when the rotor rotates in a second direction
Data Source
AI summary
An electric valve control device inputs pulses to a stepping motor to rotate a rotor in a second direction; inputs pulses to the stepping motor to rotate the rotor in a first direction when the electric valve is in a second-direction-rotation restricted state; obtains the number of pulses (an input number (Xi)) input to the stepping motor from the second-direction-rotation restricted state to a first-direction-rotation restricted state when the electric valve is in the first-direction-rotation restricted state while the rotor rotates in the first direction; determines that the rotor can rotate normally when the input number (Xi) is greater than or equal to a design number (Xd) and is smaller than or equal to an upper limit number (Xu); and determines that the rotor cannot rotate normally when the input number (Xi) is smaller than the design number (Xd) or is greater than the upper limit number (Xu).