Influence of cutter tool wear on the efficiency of the road cutter

BACKGROUND: Road cutters are widely used for removing the top layers of asphalt concrete pavements. The cutting elements of a road cutter are subject to uneven wear. This kind of wear mostly develops in different ways on the entire set of cutting elements located along the entire width of the milling drum. AIM: Defining the cutting resistance forces that occur when milling asphalt concrete pavements with road cutters, taking into account different types of wear of cutting elements. The experimental data obtained make it possible to conduct a comparative analysis of the forces acting on worn cutting elements in comparison with a new cutting element. MATERIALS AND METHODS: The worn cutting elements selected for the study are divided into the following types: correct wear; excessive wear; uneven wear of the cutter body and the tip; deformation of the washer and the fixing sleeve. Experimental studies were conducted on samples of asphalt concrete pavement with a nominal mineral aggregate size of 16.0 mm. This material is widely used for roads with normal traffic conditions. Experimental studies were conducted with a pendulum bench. RESULTS: It is noted that improper wear of the cutting element can lead to an increase in cutting resistance forces by more than three times compared to the forces that arise on a new cutting element. The analysis made it possible to identify the most unfavorable types of wear of the cutting elements of road cutters. The data obtained will make it possible to predict changes in loads on the working body of road milling machines during operation. This, in turn, allows developing more advanced designs of road milling equipment. CONCLUSION: For the machines being developed, it becomes possible to provide the necessary safety margin for the elements of the milling drum and to justify the power reserve of its drive. The obtained data also make it possible to choose the replacement interval for cutting elements during the operation of milling equipment reasonably. These measures together will lead to an increase in the specific productivity of the equipment and will improve the quality of the milled surface. The achieved results also make it possible to make changes in the existing mathematical models and the calculation methods of milling machines, taking into account the wear factor of cutting elements.