Analytical determination of energy intensity of critical deep cutting of soils by multi-scraper trench excavators

The object of research is the processes of interaction of the cutters of the working body of the chain trench excavator on the basis of the semi-blocked critical depth mode of soil cutting. One of the most problematic places is that the known analytical and experimental models of interaction of multi-scraper chain trench excavators with soil do not determine the parameters and modes of their operation based on critical depth cutting of soils. Therefore, the design of work equipment for given conditions on the basis of such dependencies does not provide the minimum energy consumption and maximum productivity of the work process. The research used the method of analytical calculation of parameters of installation of soil-developing elements and determination of energy performance of multi-scraper chain working body of trench excavator on the basis of semi-blocked critical-depth soil cutting regime. The proposed calculation method allows to determine the parameters of installation of the working body and placement of soil development elements and to quantify the energy performance of multi-scraper chain working body of the trench excavator based on semi-blocked critical depth of soil cutting mode. The obtained method of calculation, in contrast to existing empirical estimates, allows developing options for improving the parameters of multi-scraper chain working body. As a substantiation of this conclusion the conceptual variant of technical realization of the working equipment is offered, namely, allows to prove expediency of the choice of the semi-blocked scheme of arrangement of cutters of critical deep cutting of soil of a working body of a trench multi-scraper excavator. The conducted energy analysis showed that it is more expedient to use a multi-scraper chain working body of a trench excavator on the basis of a semi-blocked critical-depth regime of soil cutting. For example, for soil semi-solid clay with blocked cutting, cutting angle αc=20–30°, cutter width b=0.02 m the energy intensity of the working process varies within E=191–233 kJ/m3; for semi-blocked cutting under the same conditions – E=187–191 kJ/m3, which is 2–18 % less.