Since the object under test is a micro-torque coil spring, the stiffness measurement is performed as a static stiffness test. Static stiffness is defined as: k = M/H (1). To obtain the stiffness value, multiple torque measurements (M) and corresponding angular displacements (H) are collected and then processed through fitting calculations. For measuring torque (M), a direct measurement approach is used, where the torque sensor directly captures the torque value. This method minimizes errors introduced by intermediate steps, thereby improving the overall measurement accuracy. The angular displacement (H) is determined automatically by the program based on the step angle set for the stepper motor during its operation. During testing, each step of the motor is driven, and the corresponding torque (Mi) and angular displacement (Hi) for each step are recorded. A linear fit is then applied to calculate the static stiffness, with the least squares method being employed for this purpose. Let K represent the torsional static stiffness; the fitting formula for K is given by:
K = [nΣ(MiHi) - ΣMiΣHi] / [nΣ(Hi²) - (ΣHi)²] (2)
The test system design includes a detailed measurement scheme, as shown in <1>. The overall design of the test system focuses on evaluating the performance of the micro-torsion spring. The automatic testing device operates according to the principle outlined in the system diagram. Based on VC++6.0, a Windows-based test software was developed, enabling data acquisition from the torque sensor via an RS232 serial port. After processing the collected data, the system calculates the stiffness of the tested torsion spring. Additionally, the software supports automatic torque and angle measurements, as well as automated pure torque loading, as illustrated in <2>.
In terms of hardware design, the automated test system was developed in accordance with the selected test scheme and the specific requirements of the torsion spring testing device. The system controls a precision rotary table through a computer-regulated stepper motor, achieving highly accurate angular positioning with a resolution of 0.00125°. Under the influence of load torque, the spring undergoes rotational deformation, which is detected by a high-precision torque sensor and transmitted to the torque meter chromatography workstation software. The system achieves a torque measurement accuracy of up to 2×10â»â¶ Nm. The test results are visualized in the experimental curve shown in the figure.
The single measurement torque curve and five sets of torque-angle curves demonstrate the system's high accuracy and linearity. The test data for the micro-spring show consistent results across multiple measurements, indicating excellent repeatability. The system can perform fully automated testing, meeting all required specifications efficiently.
In conclusion, by addressing the challenges of micro-spring torsional stiffness testing, the system utilizes high-performance control devices and advanced measurement algorithms, achieving excellent performance in practical applications. The system is currently being used in production environments and has proven to be reliable and effective.
Low creep clay refractory bricks are made of selected high alumina clinker, mullite, combined with clay as the main raw materials, high pressure molding, high temperature sintering and become. The product has excellent high temperature physical properties and chemical corrosion resistance. According to the creep rate (0.2MPa, 1280 ℃, 25h) can be divided into ≤ 0.4%, 0.6%, 0.8% of the three series of low creep clay brick.
Customized Low Creep Refractory Brick,Customized Low Creep Refractory Bricks,Customized R&D is Available Refractory Bricks
Huixian Xinwei Refractories Co. , https://www.xinweirefractory.com