1. In what measure deterioration of the tool is caused by the electromechanical phenomena at the set modes of processing and properties of materials of the detail and the tool?

2. How can current and EMF in contact the tool - a detail testify the deviations from normal work of the machine tool and possible malfunctions?

3. Whether automated management by process of cutting and maximization of resistance of the tool is possible by introduction in cutting zone of an additional current?

The purpose of carrying out the researches is search of ways to increase the resistance of the tool and quality of the processable surface at studying the electromechanical phenomena in contact with the tool - the detail.

Thus in the given work the following problems are investigated:

• To analyse the received results and to reveal interrelation of parameters of machining with the electromechanical phenomena.
• To develop a technique of carrying out the researches;
• To develop and create experimental installation for measurement of the both constant and variable component of EMF and the current of cutting;
• To carry out researches of EMF constant component and the current of cutting;
• To investigate EMF variable component and the current of cutting;
• To carry out statistical processing of the results research, the correlation and spectral analysis;
• To carry out experimental researches of cutting process with break of the circuit and with indemnification of the weak currents arising in a zone of cutting;

Sources of the electromechanical phenomena are investigated well enough. It is thermionic issue, exionic issue, Seebeck’s, Peltier’s and Thomson’s effects.

Influence arising in a circuit of contact a detail is the most evident - tool EDS is shown by the example of practical use of break of an electric circuit, for example, in devices V.A. Bobrovsky, at boring spindle drums at the Kiev factory of machine tools - automatic devices, at the Kharkov tool factory at drilling стружечных apertures in dies. In these cases the tool (or preparation) was isolated from the machine tool by special electroisolation structure. Practically in all cases resistance of the tool is raised in 1,5 - 2 times. Similar receptions, and also a method of indemnification of the current were applied in 1960-70 at other ways of processing.

On « Manufacturing Engineering » chair DonNTU experimental researches of the turning steel 20 by cutters with plates of firm alloy Т5К10 have been carried out. Researches were carried out with isolation of the tool and without isolation. Researches of wear have shown, that at identical modes of processing resistance of the electroisolated tool is higher, than non-isolated, and on the oscillogram approach of breakage of the tool is in a point of sharp difference of potentials EMF (рис 2.3):

Research of the connection of EMF with the roughness of the processed surface accepts special value at fair processing (turning, boring). Operating size EMF, it is possible to lower the roughness more considerably, than it manages to be made an increment of cutting speed. The majority of researchers consider, that the reason of reduction in microroughnesses at absence of a current (i.e. at indemnification EMF or isolation of the tool) is reduction of intensity and change of deterioration character of the tool. The question on direct influence of EMF on the roughness of the processed surface is debatable, and for studying of this question the further researches are required.

Two kinds of experiments were carried out for the research of EMF investigation: with reinstallation of preparations and the tool and without reinstallation of those; in the second case the electroisolated tool which for translation in a mode « without isolation » incorporated to the case of the tool holding device by the shielded shunt was initially established. The length of the way and modes of cutting were chosen proceeding from necessity of exception of the tool essential deterioration. As the varied parameter speed in a range 25 - 135 m / mines, i.e. in hill-formation zone was chosen. Other parameters were constant (s=0,22 rev/min, t=0,25 mm). At each mode oscillograms of potentials EMF were removed; the roughness was estimated by measurement and profilographing the processed surface. According to the results of the first types of experiences schedules of dependence of the roughness from speed of cutting were made up at processing not isolated and isolated by cutters.

Oscillograms at corresponding modes were statistically processed. Thus conclusions, that are made at processing by the isolated tool are:

1) The roughness of the processed surface is reduced in comparison with a variant « without isolation »;

2) The hill-formation zone is displaced in area of lower speeds of cutting;

3) Reduction of the roughness of the processed surface is connected with the increase in arithmetic-mean value of EMF and reduction of a dispersion and a root-mean-square deviation.

The second types of experiences confirm the given conclusions. Besides the correlation and spectral analysis of potentials EMF was made at turning of not isolated and isolated by tools on speeds of the specified range. The analysis was made with the purpose of more detailed studying of the given fluctuations EMF. As character of fluctuations does not vary in due course on one enough long record it is possible to determine statistical characteristics of process.

The carried out researches have shown deep connection of variable component EMF of cutting with deterioration of the tool and formation of a superficial layer of preparation. It opens prospects for creation of control systems by process by introduction in a zone of cutting of external pulses of a current. However first of all it is necessary to be determined with immediate prospects of researches. Among them we shall allocate:

- More detailed studying interrelation EMF with parameters of processing that assumes research of various contacting pairs on various modes of cutting;

- Development of phusical-statistical model of friction and wear process;

- Development of concrete recommendations on improvement of quality indicators of the processed surface.

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