Development of a High-precision Digital Display Torque Wrench

Abstract

Thread connection is widely used in mechanical connection. Torque wrench can feedback tightening torque in real time, and can apply more accurate tightening torque, which is widely used in engineering. Some assembly lines in aerospace or military field the tightening accuracy need to reach 0.1%, comparing with the only 1% accuracy of ordinary working wrench, the high precision torque wrench is needed to apply the high accuracy torque in aerospace or military field. Two methods are introduced to improve the measurement accuracy of the torque wrench. One is to design the transducer with pure torsional transformation when it is used. The other is to apply linearity correction to the transducer by circuit software. The results shows the accuracy of the torque wrench is 0.1%, which is much higher than ordinary work wrench.

New Concepts in the Design of an IoT Electric Torque Wrench Based on a Smart Meter Chip

“…In the signal processing system, a waveform tracking strategy based on a phase-locked loop was proposed to obtain a stable phase difference and improve the robustness of echo time calculation. Xu et al [6]. developed a digital display wrench and described two methods to improve the measurement accuracy of a torque wrench.…”

“…By measuring the voltage difference at the output of the bridge, the torque value can be obtained, thereby enabling torque control. Due to the inevitable influence of axial stress on the cross-section where the resistance strain gauges are attached, in order to eliminate the impact of stress on torque measurement [6], the resistance strain gauges should be attached to the elastic shaft at a 45-degree angle to the axis to counteract the axial stress. This is shown in Figure 4.…”

“…As shown in Figure 12, the control system of the tool consists of two main parts: the main controller and the IoT-HMI [6]. These two parts are connected via USART communication and interact using the Modbus protocol.…”

Design and Optimization of High-Power and Low-Frequency Broadband Transducer with Giant Magnetostrictive Material

“…Piezoelectric ceramic materials are currently the most commonly used smart materials [ 3 , 4 , 5 ] in the field of aerospace engineering. The piezoelectric transducers are used in active vibration and noise suppression sensors for plate structures [ 6 ], vibration energy collection sensors [ 7 ], high-precision digital torque wrenches [ 8 ], mechanical strain measurement sensors [ 9 ], structural health monitoring (SHM) [ 10 , 11 ], and flaw detectors [ 12 , 13 ] et al Piezoelectric is suitable for small sensors and high output power [ 14 ]. However, sometimes, some performance flaws of piezoelectric ceramic materials, such as a small size range, low frequency that is difficult to achieve [ 15 ], high voltage intolerance, high driving voltage [ 16 ], and material fading polarization [ 17 ], limit its application in the sensing system to a certain extent.…”