AUTOMATED CONTROL OF DRIVES FOR OPEN-PIT DRILLING RIGS

Abstract

Physical and moral aging of mining equipment, in particular drilling rigs is one of the main problems of the open method of mineral extraction in the quarries of Ukraine. The modernization of the existing park and the creation of a new generation of drilling rigs is an important scientific and applied problem, the success of which depends on the efficiency of the domestic mining industry. The teams of special design bureau of research institutes of Ukraine are engaged in the creation of domestic core drilling rigs. Along with the improvement of the hydromechanical equipment of drilling rigs, it is necessary to improve the drive systems, which must correspond to the achieved level in the global electrical engineering industry. Only in this case, it is possible to create a competitive drilling roller-cone bit at a whole. The issue of finding and choosing a rational way of controlling interconnected drive systems of rotation and feeding rod in the hole button zone is considered. An important issue in the development of rotation and feed drives is the choice of a method of mutual control. The control methods are analyzed in which one of the parameters is maintained at a constant level: the rotation frequency of the roller-cone bit, the moment of resistance on the roller-cone bit, the linear speed of the drilling rod movement, the axial pressure on the drilling rod, the power consumed by the rotation drive. Based on the energy criterion of stability of the roller-cone bit, the most rational way of controlling the drive of drilling rod rotation of the drilling rig was chosen. The roller-cone bit will have the greatest stability when its energy load is uniform, i.e. when maintaining a linear growth of rock destruction energy or when maintaining at a constant level the power released in the roller-cone bit and hole bottom contact zone. The proposed working ability criterion generalizes the known criteria because it automatically considers the strength and abrasiveness of the rock that is destroyed by the roller-cone bit. In the proposed method of controlling the feed drives and rotation of the drilling rod in the process by the roller-cone bit drilling, rigid mechanical characteristics are formed on the roller-cone bit when penetrating rocks with a strength of 10-13 units on the scale of Prof. M.M. Protodiakonov and soft mechanical characteristics – in stronger rocks. When drilling different strength of the rocks of physical and mechanical properties, the control method provides automatic selection of mechanical characteristics depending on the strength of the rock.