Multi-Part Valve Position Sensor Lever for Large-Stroke Accuracy
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Solution Overview
Problem
Conventional position sensors for control valves require large installation space and suffer from impaired accuracy with increasing stroke amplitude, particularly in the closed position, due to the mechanical limitations of lever travel and disproportionate sliding movement.
Innovation Solution
A sensor device with a multi-part lever arm design, comprising translationally movable sections, converts linear stroke movements into rotary transmissions using a pivot point, allowing precise measurement even with large strokes, and incorporates magnetoresistive sensors with systematic linearity adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional position sensor with a lever arm is used to detect the position of the actuating rod, then the sensor can measure the stroke movement, but the installation space required becomes large and the measurement accuracy deteriorates with increasing stroke amplitude
Solution Approach 1:
The patent replaces the conventional mechanical lever arm system with a magnetic field-based detection system. Magnets are attached to the actuating rod, and a magnetic sensor (such as a Hall effect sensor or magnetoresistive sensor) mounted on the lever arm detects the position by sensing the magnetic field changes. This substitution eliminates the need for mechanical contact and large lever arm movements, significantly reducing installation space while maintaining or improving measurement accuracy across the full stroke range
Solution Approach 2:
The patent makes the lever arm rotatable about a pivot point, allowing it to dynamically adjust its position as the actuating rod moves. This rotational movement enables the lever arm to track the position changes throughout the entire stroke amplitude without requiring excessive installation space. The dynamic configuration allows the sensor to maintain optimal detection geometry across all positions, preserving measurement accuracy while minimizing the stationary space required
2Measurement precision
If a lever arm with large stroke amplitude is used, then the measurement range is increased, but the measurement accuracy in the closed position deteriorates due to disproportionate sliding movement
Solution Approach 1:
The patent replaces the mechanical sliding contact between the lever arm and actuating rod with a magnetic field-based detection system. Magnets are attached to the actuating rod, and a magnetic sensor mounted on the lever arm detects position through magnetic field changes without mechanical contact. This eliminates the disproportionate sliding movement that occurs in conventional systems during large lever travel, maintaining consistent measurement accuracy throughout the entire stroke range, particularly in the closed position where precision is most critical
Solution Approach 2:
The patent transitions from a one-dimensional mechanical sliding measurement to a two-dimensional magnetic field sensing approach. The magnetic sensor detects changes in magnetic field strength and/or direction as the actuating rod moves, providing position information through multiple dimensional variations in the magnetic field. This dimensional change allows for consistent measurement accuracy across the full stroke amplitude without the mechanical limitations of conventional lever 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
The solution provides high measurement accuracy and compact size, especially in the closed position, with enhanced resolution and reduced installation space, while compensating for assembly tolerances and ensuring compatibility with various position controllers.
Implementation Method 1
The sensor device includes a magnetoresistive sensor that detects the position of the actuating rod based on magnetic field changes
Implementation Method 2
The displacement sensor uses a Hall effect sensor arranged between two stationary magnetic poles
Data Source
Figure 1~3
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Figure 5
AI summary
In a sensor device (1) for an actuating valve (11) of a processing plant, such as a chemical plant, a power plant, a food processing plant, or the like, comprising an (in particular, magneto-resistive) position sensor (3) and a lever arm (4) which is rotationally movable about a stationary pivot point (31) of the sensor device (1) for converting a linear stroke movement of an actuating rod (5) of the actuating valve (11) into a corresponding (in particular, rotational) transmission movement mapped at the position sensor (3), it is provided that the lever arm (4) comprises a coupling (45) for positionally accurate, rotationally movable connection of the lever arm (4) to a reference point (54) of the actuating rod (5), and that the lever arm (4) comprises at least one first lever portion (41) and at least one second lever portion (43) which is movable relative to the first lever portion (41).