Dual-Spool Differential Pressure Sensing for Low-Pressure Accuracy
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Solution Overview
Problem
Existing differential pressure detection devices face instability and reduced accuracy when measuring low differential pressures due to unstable spring constants and limited sensitivity ranges, particularly with the use of non-linear and linear springs.
Innovation Solution
A differential pressure detection device is designed with a spool system where a lighter first spool and a heavier second spool, both with elastic members, are used to widen the measurement range, allowing accurate detection of low differential pressures by adjusting the urging forces and increasing the pressure receiving area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an unequal pitch spring (non-linear spring) is used to enable low flow rate detection, then detection capability during low differential pressure is improved, but the spring constant becomes unstable before the narrow pitch site comes into close contact, causing detection instability
Solution Approach 1:
The single spool is divided into two separate spools (first spool and second spool), each handling different pressure ranges. The first spool with lighter weight and smaller elastic force handles low differential pressure detection, while the second spool handles higher pressures, eliminating the instability issue of non-linear springs.
Solution Approach 2:
The invention changes the weight parameter of the spool and the elastic force parameter of the elastic member to optimize detection sensitivity. The first spool is designed to be lighter than the second spool, and the elastic force of the first elastic member is smaller than that of the second elastic member, enabling stable low differential pressure detection.
2Measurement precision
If the number of turns of a normal coil spring is increased to enable low differential pressure detection, then detection capability during low differential pressure is improved, but the length of the coil spring and closed height increase, reducing magnetic sensor sensitivity range and detection accuracy
Solution Approach 1:
The detection range is segmented between two spools with different characteristics. The first spool is optimized for low differential pressure with lighter weight, while the second spool handles higher pressures, allowing the magnetic sensor to operate within its optimal sensitivity range for both conditions.
Solution Approach 2:
The invention changes the weight parameter of the spool to optimize the balance between spring force and magnetic restoring force. By making the first spool lighter, the system achieves sensitive detection at low pressures without requiring excessive spring turns that would reduce sensor sensitivity range.
3Measurement precision
If the spool weight is minimized to improve low differential pressure detection sensitivity, then measurement range is widened, but the pressure receiving area must be maximized to compensate, requiring optimized spool design
Solution Approach 1:
The invention optimizes the weight parameter of the spool and the area parameter of the pressure receiving surface. The first spool is designed with lighter weight and the pressure receiving area is maximized to enhance sensitivity for low differential pressure detection while maintaining structural integrity.
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 device effectively measures differential pressures across a broader range, including low pressures, with improved accuracy and stability, enabling reliable operation in applications like hydraulic circuits and filtration systems.
Implementation Method 1
a magnetic field detection element provided inside the case... the magnetic field detection element is provided opposite to the magnet with a bottom surface of the sliding cavity interposed between the magnetic field detection element and the magnet
Implementation Method 2
an elastic member provided inside the sliding cavity... the elastic member includes a first elastic member provided in the first spool and configured to urge the first spool toward the space in the high pressure side, and a second elastic member provided in the second spool and configured to urge the second spool toward the space in the high pressure side
Data Source
AI summary
A differential pressure measurement range is widened and differential pressure can be measured particularly during low differential pressure. A first spool facing a space in a high pressure side is lighter than a second spool facing a space in a low pressure side in a state where a magnet is provided. Urging force of a first elastic member that urges the first spool toward the space in the high pressure side is smaller than urging force of a second elastic member that urges the second spool toward the space in the high pressure side, and the first elastic member and the second elastic member are disposed in series.