Design Of A New Type Of Torque-axis Sensor And Parameters Measurement Of Composite Vibration Extrusion Tapping

With higher and higher demands placed on the properties of the materials by industrialproducts, titanium alloy is widely used in machining process. But because of its low modulusof elasticity and high intensity, elastic recovery and hardening easily appear on the machinedsurface, which can increase the torque in the tapping process. It is a considerably difficult,especially in the tapping process under the M6. So the process of small-aperture internalthreads to titanium alloy is a bottleneck in titanium alloy processing techniques. A tappingmachine designed by professor YANG could realize the composite vibration incircumferential and axial direction. The machine can be used to tap the difficult-to-machinematerials. In order to make the testing prototype produced as early as possible, the effects tothe torque of composite vibration extrusion trapping in different working parameters wereconducted. The main points of view in the paper are listed as follows:(1) A new type of four-beam torque-axis sensor was designed. In order to improve thesensor’s sensitivity, the measuring requirements of torque and axis force in the tappingprocess were met. Four stiles and four flat-beams combined were designed for themeasurement of torque and force, which could realize the purpose of simultaneousmeasurement of small range torque and force.(2) To determine the optimal design parameters of structure, the mathematical modelwas built on sensitivity as the objective function, and the structure parameters were optimized.As the sensor was used in the state of vibration, modal analysis which can calculate naturalfrequency of vibration modes was made to prevent resonance.(3) NI USB-9237data acquisition module was used to collect data and form testingchannels. Also the graphical program LabVIEW was used to develop testing proceduresincluding data acquirement, signal processing, data storage, curve fitting and so on.(4) The calibration of sensor was done, then the influence between torque and axis forcewas tested.(5) Measurement of the torque and axis force with the sensor was carried out on thematerials of Aluminum, Copper, stainless steel, Titanium alloy. By changing vibration frequency, spindle speed, the influence for torque was tested. Then the relationship helpful indetermining the parameters of tapper between the torque and axis force was summarized.The experiment results show that the designed torque and axis force sensor canaccurately measure the signal of torque and axis force, and its high sensitivity can meet themeasurements of torque and axis force for vibration tapping and vibration drilling. Complexvibration extrusion tapping can effectively decrease the tapping torque. At length, the relationderived from the tapping torque and axis force will provide reliable criterion for determiningthe parameters of the tapper.