OBRABOTKAMETALLOV Vol. 25 No. 1 2023 technology dependence of the pushing force on the contact temperature of the tool and the workpiece. It is convenient to interpret this through the introduction of the dependence – the strength limit of the processed metal under compression on the corresponding contact temperature. To determine this dependence, a series of experiments was carried out using the experimental setup STD.201-1, which involves adjusting the weighting coefficients to calculate the cutting temperature based on the values of the removed natural thermal EMF. The STD.201-1 installation was developed by American engineers to solve the problems of analyzing the dynamics of cutting processes on machines of the turning group. The setup allows measuring the forces and vibrations of the tool, spread out along the axes of deformation (see Figure 1), as well as the temperature in the cutting zone. The research methodology provides for a whole setup procedure, which includes a double measurement of the contact temperature, a measurement using a natural thermal EMF and measurements carried out next to the contact with a calibrated thermocouple. An example of connection for the case of measuring the effect of contact temperature on the expulsive force, for the case of Steel 45, is shown in Figure 7. As can be seen from Figure 7, the measuring unit, in addition to the STD201-1 stand, contains a specially prepared shaft made of Steel 45, which has a radiator working area, heated by a special circular heater that is put on the shaft. In addition, a tool is brought to the shaft with some effort, next to the contact, which has a thermocouple inserted into the shaft material that measures the real value of the contact temperature. The measurement results are presented by the system’s software interface, the appearance of which is shown in Figure 8. As shown in Figure 8, the interface of the stand STD201-1 provides for the possibility of the measuring subsystem calibration based on the measurement of the natural thermal EMF of the cutting zone. It was the calibration mode of this measuring stand that was used for the experiment to determine the dependence of the expulsive force on the contact temperature of the tool and the workpiece. Fig. 7. Experimental setup prepared to assess the effect of contact temperature on the expulsive force
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