Motor Valve Rotor Speed Control for Quiet Stop Positioning
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Solution Overview
Problem
Electric vehicles' motor operated valves produce impact noise when the rotor approaches the reference position, which is perceived as abnormal noise due to the quiet operation of electric vehicles.
Innovation Solution
A motor operated valve control device with a rotation detecting unit and a rotation control unit that adjusts the rotor's speed when approaching the reference position, lowering the speed when close and increasing it when farther away, to minimize noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the rotor rotates at high speed to reach the reference position quickly, then the response time is improved, but impact noise increases
Solution Approach 1:
The patent applies periodic action by dividing the rotation process into distinct phases: a first rotation at high speed for most of the行程, and a second rotation at low speed near the reference position. This periodic speed variation allows the system to maintain overall efficiency while eliminating impact noise at the critical moment of reaching the reference position.
Solution Approach 2:
The patent implements dynamics by making the rotation speed variable rather than constant. The rotation control unit dynamically adjusts the speed based on the rotor's position relative to the reference position, transitioning from high speed to low speed as the rotor approaches the target. This dynamic speed control optimizes both response time and noise reduction.
2Object-generated harmful factors
If the rotor rotates at low speed near the reference position, then impact noise is reduced, but the overall response time increases
Solution Approach 1:
The patent applies local quality by applying different speed characteristics to different portions of the rotation行程. The high-speed rotation is applied to the majority of the行程 where noise is not an issue, while low-speed rotation is applied locally near the reference position where noise reduction is critical. This localized speed differentiation resolves the contradiction between overall response time and local noise reduction.
Solution Approach 2:
The patent segments the rotation process into two distinct phases: a first rotation phase at high speed and a second rotation phase at low speed. This segmentation allows the system to optimize each phase independently - maximizing speed during the first phase and minimizing noise during the second phase - thereby resolving the contradiction between response time and impact noise.
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
The solution effectively reduces the impact noise produced by the motor operated valve, enhancing the quietness of the valve's operation and improving user experience.
Implementation Method 1
A magnetic sensor is arranged to axially face the sensor magnet. The rotational movement of the rotor is converted into the axial movement of the valve element by a feed screw mechanism. A change of magnetic flux with the rotation of the rotor is sensed by the magnetic sensor, which enables detection of the rotation angle of the sensor magnet
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3D
AI summary
A motor operated valve control device (202) is connected with a motor operated valve (1) that adjusts a valve opening degree by rotating a rotor (60). The motor operated valve control device (202) includes a rotation detecting unit (216) that detects a rotation angle of the rotor (60), and a rotation control unit (218) that moves the rotor (60) toward a predetermined initial position (stop position) (Q) by providing instructions on a rotating speed and a rotating direction of the rotor (60). In control of movement of the rotor (60) to the initial position (Q), the rotation control unit (218) lowers the rotating speed of the rotor (60) when a difference between a rotation angle at an origin position (P0) of the rotor (60) and a detected rotation angle of the rotor (60) is sufficiently small.