РАСЧЕТ ДИНАМИЧЕСКИХ КОНТАКТНЫХ НАПРЯЖЕНИЙ В ПРОЦЕССЕ ПРЕРЫВИСТОГО РЕЗАНИЯ

МАШИНОСТРОЕНИЕ

Abstract

The existing theoretical and experimental research in the sphere of fragile solidity of carbide wedge within and out of the contact zone ( T. N Loladze, M. F. Poletika, A. I. Betaneli, etc) have an approximate character . An essential drawback of the latter is that they do not take into consideration the impact phenomena arising in the transient process of inserting a cutting wedge into the material being processed. The results of the known research show that
tail destructions of the cutting wedge basically take place out of the contact zone. This can be facilitated by the peak of stresses on the front surface of the tool in the area of the contact with the chips which can be explained by the delay between the increase of the “tool-chips” contact and the increase in the dynamic component of the cutting force, as the force of the impact reaches its maximum value before the total cross section of the cut is reached on the front surface of the tool. The experimental studies we conducted, considering the requirements for converting and recording the equipment for measuring fast processes, show that in the intermittent cutting mode, when the tool enters the material to be processed, a shock jump of the cutting force occurs, which, depending on the parameters of the cutting regime, the type of the processed material and the rigidity of the of the MDID system(Machine-tool-DeviceInstrument-Detail system), can exceed the forces of the cutting process by 2,2 times which certainly must be taken into consideration in solidity calculations of the carbide wedge. The article deals with the issues of solidity of carbide tools in the contact zone of the cutting wedge with intermittent cutting. For the first time, an attempt has been made to determine the contact loads considering the shock force for the case of distribution of contact dynamic stresses according to the parabolic law.