The article deals with the determination of the efficiency of a multi-bladed tool equipped with inserts made of oxide-carbide cutting ceramics, depending on the microstructural parameters of the tool material. The microstructural parameters of the oxide-carbide cutting ceramic, which affect the performance of the tool, are proposed to be determined according to the electrical resistance of the tool material. In order to implement the method for determining the working capacity of the instrument, a basic design of the device for measuring the electrical resistance of the material of the instrument is proposed. The device for measuring the electrical resistance of ceramic plates consists of a body made of a dielectric material, with channels for supplying a conductive material and a groove for installing a case with a test sample. During the test, the channels are filled with a liquid conductive material, which fills the cavity formed by the channel of the case, the groove of the case and the plate itself under test. To ensure uniform filling of the cavity, after the introduction of the liquid conductive material, metal balls are installed into the channels, which are made in such a size as to ensure free sliding along the channel, but not to let the liquid pass into the upper part of the channel. The tested ceramic plate is installed in the walls of the removable case. The walls of the removable case include electrodes, which, when the device is in operation, are inserted into a cavity with a liquid conductive material at one end, and are connected to an ohmmeter at the other. Using a device for measuring the electrical resistance of ceramic plates, it is possible to determine the operability of the tool and guarantee its operation without rejection for a certain period of time, which was confirmed by experimental research in the milling of workpieces of machine parts made of gray cast iron. Experimental studies in multi-edge machining with cutters with different values ​​of electrical resistance of ceramic plates made it possible to plot graphs of the dependence of the quality of machining during milling on the operability of the tool and on the time of the machining process.

Abstract. The article examines the main sources of technological deviations and local manufacturing defects in parts of mechanical systems. These flaws significantly affect the vibration characteristics of the system during its operation. The authors proposed a mathematical description of technological errors for further modeling and investigation of their influence on the vibration activity of a mechanical system. This allows one to evaluate the parameters of vibration processes along the symmetry axes of the rotating assembly of the mechanical system and to reveal the main places of concentration of disturbing effects in the form of dynamic reactions on the support elements and bearings IntroductionTechnological errors in the manufacture of machine parts are one of the main reasons for the occurrence of vibration effects in the nodes of mechanical systems.The technological process of manufacturing parts with high quality indicators -precision and strength -is extremely complex and difficult. To ensure sufficient quality of machine parts functioning, it is necessary to know the relative influence of individual structural elements on each other, thus, for example the influence of their mechanical properties, material properties and surface hardening methods on the accuracy of manufacturing parts. It is also necessary to have reliable methods for calculating and predicting the accuracy indexes of product quality.

Own fluctuations in the drives of technological equipment based on a three-mass model of fluctuating torsional chain system are analyzed. Differential equations of motion of a mechanical system with three degrees of freedom are obtained. An analysis of the forms of fluctuating processes in the system is conducted. Conditions of orthogonality of own torsional fluctuation forms are considered, dependencies of own frequencies on system rigidity coefficients are determined.

No abstract

The article describes the principles of building dynamic models of technological systems with concentrated parameters with a finite number of degrees of freedom. Dynamic properties of technological system are considered taking into account elastic and inertial parameters of its elements. The model of three-mass torsional chain system and the model with progressively moving masses are used for estimation of vibrational processes in drives of the technological equipment. According to the proposed mathematical model the analysis is carried out and the forms of natural oscillatory movements in the system are revealed. Oscillations of zero, first and second eigenfrequencies are determined, for each of which sets of form of the coefficients are found that describe the system configuration in the process of free oscillations.