Research on the characteristics of the pneumatic measuring system in the process of controlling cylindrical parts
Students Name: Lukach Oleh Andriiovych
Qualification Level: magister
Speciality: Computer Engineering in Mechanical Engineering
Institute: Institute of Mechanical Engineering and Transport
Mode of Study: full
Academic Year: 2025-2026 н.р.
Language of Defence: ukrainian
Abstract: The master’s thesis is devoted to the research, design and justification of the parameters of an automated control and sorting system for measuring the geometric parameters of carbide teeth of drill bits. Products of this type are critical elements of cone drill bits, and therefore high precision control of their mounting diameter and ovality directly affects the reliability of the drilling tool and the safety of subsequent technological processes. The first chapter provides a comprehensive scientific and research analysis of pneumatic means of controlling the linear parameters of parts. The principles of operation of rotametric and manometric measuring systems, their functional capabilities, limitations and sensitivity to external factors are considered. It is shown that although rotametric systems provide ease of visual control, they are not suitable for automation due to difficulties in reading the float position and relatively low accuracy in non-differential circuits. Manometric pneumatic measuring systems are analysed in detail, and mathematical dependencies describing the air flow through the measuring nozzles and the formation of the measuring pressure are given. Special attention is paid to the study of a pneumatic measuring clamp used to control parts that cannot be mounted on a rigid measuring base. The paper presents conclusions describing the formation of measuring pressure at the total gap of a two- nozzle clamp, and evaluates the results of experiments on the effect of part displacement along the clamp axis on measurement accuracy. The work experimentally determines the errors of the pneumatic clamp when controlling samples of different diameters and different adjustment conditions (according to a flat and cylindrical standard). Generalised graphical dependencies of the error on the displacement of the axes are constructed, which allows for a quantitative assessment of the accuracy of the system and the selection of optimal parameters for the nozzles and operating modes. An analysis of the dynamic and static components of the measurement process during tooth rotation was carried out, the required rotation frequency for ovality control was determined, and the compliance of the system parameters with the control accuracy requirements (±0.005 mm) was confirmed. Based on the graphs constructed for selecting the optimal clearance and sensitivity, recommendations for the practical application of the system were formed. The second section is devoted to the development of the design of an automated control and sorting complex for sorting drill bits into three categories: suitable, minor defects, and major defects. The process of the machine’s operation is described, a cycle diagram of its functioning is constructed, and its productivity is determined. Taking into account the duration of the processes of feeding the part, its rotation, control and sorting, a working cycle of 3.2 seconds is established, which corresponds to a productivity of more than 1100 pieces per hour. A kinematic diagram of the machine has been developed, which includes: a part feeding and orientation system, a pneumatic measuring clamp, a tooth rotation drive, part position adjustment mechanisms, an electromagnetic sorting module, and receiving trays. The diagram provides for the adjustment of the pneumatic clamp position in two coordinates, compensation for part displacement, and conditions for simultaneous control of diameter and ovality. The results of the research show that the differential manometric pneumatic system in combination with a two-nozzle pneumatic clamp provides the necessary accuracy and is suitable for automating the control of large-scale production. The proposed design of the automatic control and sorting machine allows for stable control of the dimensions of drill teeth with an accuracy of ±0.005 mm, automatic sorting of parts, and a significant increase in the efficiency of the production process. The results of the work are of practical importance for enterprises that manufacture drilling tools or other critical cylindrical parts, where non-contact high- precision control of geometric parameters and automation of measurement operations are required. Key words: Pneumatic measuring systems, pneumatic clamp, diameter and ovality control, automated control and sorting complex, carbide teeth for drill bits, non-contact measuring methods.