Model of Filling the Internal Structure of Workpiece with Curved Layers for 3D Printing

This paper presents a solution to the problem of filling the internal structure of the workpiece with curve layer in 3D printing. A generalized model of filling the internal structure of workpiece with curve layer is designed. The results are presented for solving the problem on the example of curved layers of a conical shape with filling along a helical line. The research results can be in demand in the development of algorithms and software for technological equipment. They allow to ensure the formation of the internal structure of products in curved layers during 3D printing.

Investigation of the Operational and Technological Reliability of the Small-size Internal Threading Process

The article presents the results of research in the direction of improving technological equipment for internal threading of parts in a flexible automated production. Methods for assessing the operational and technological reliability of a flexible manufacturing module (FMM) of thread processing are considered, which can be used as the basis for the developed method of synthesis of its elements. It is proposed to consider the technological system of the flexible manufacturing module (FMM) of thread processing as a system in which transitions from state to state occur under the action of the simplest flows with parameters of the transition probabilities of a continuous Markov chain. The developed mathematical model describing the state of the FMM taking into account the failures of the functioning of its elements, parametric failures, as well as taking into account the recovery after these types of failures, makes it possible to reflect the influence on the operation of the module of the parameters of the flows of failures and restorations of the tool, machine tool, fixture, loading device. The solution of the obtained systems of equations of final probabilities allows for given (or experimentally obtained) intensities of failure streams (functioning and parametric) for FMM threading to obtain the values of the probability of failure-free operation, as well as the probabilities of finding the system in an inoperative state due to corresponding failures. The measures taken make it possible to solve the synthesis problem at the level of structural and layout optimization, so that at the stage of parametric synthesis to determine the elements that are vulnerable according to the developed criterion, the improvement of which will lead to the creation of the most efficient system.

RTI metoda jako způsob digitalizace kulturního dědictví

Current technological developments offer an inexhaustible number of procedures for digitization. However, technological equipment intended for teams in professional laboratories reaches price levels that cultural institutions often do not have enough finances. Procedures and methods using equipment, which institutions often already own or are not so expensive to acquire, come to the fore. One of them is the RTI (Reflectance Transformation Imaging) method, which creates a spatial relief composed of a sequence of images with visible lighting. The RTI method is very successful in depicting illegible or wiped details and is already widely used in archaeology.

Measurements of PM10 particles made in the Rosia of Jiu quarry as a result of the use of Komatsu PC4000-11 hydraulic excavator

This paper studies the Roșia Jiu quarry area in Romania. This research highlights the working method of hydraulic excavators and the values of particles released into the atmosphere by them. Improving technological equipment not only helps build a better world, but also restores and preserves the environment. The measurements were made during 2020, using DSM501A sensors, which were located at four points in the quarry, namely in the north, southeast and west of the quarry.

A model for determining the time of pointing a grip-cutting device of feller buncher machines on a growing tree

Исследование посвящено нахождению аналитической математической модели по определению времени наведения захватно-срезающего устройства на растущее дерево. В качестве известных параметров используются конструктивные размеры технологического оборудования, снятые с компоновочно-кинематических схем валочно-пакетирующих машин, требуемая высота пня и среднее расстояние между деревьями пасики. Поиск требуемой модели кратко можно разделить на несколько последовательных этапов: нахождение пути, который пройдет шток гидроцилиндра привода стрелы, и по известной формуле скорости перемещения поршня гидроцилиндра находится время на подвод стрелы к дереву; нахождение пути, который пройдет шток гидроцилиндра привода рукояти; нахождение пути, который пройдет шток гидроцилиндра привода наклона захватно-срезающего устройства; нахождение пути, который пройдет шток гидроцилиндра привода рычагов захвата в процессе раскрытия. Сумма времени на подвод каждого из элементов технологического оборудования и есть время на наведение, присущее неопытному оператору, в случае опытного оператора время на наведение захватно-срезающего устройства к дереву определяется максимальным временем одного из компонентов. The research is devoted to finding an analytical mathematical model for determining the aiming time of a feller head on a growing tree. As the known parameters are used. The design dimensions of the technological equipment, taken from layout and kinematic diagrams of feller-buncher machines, the required stump height and the average distance between the trees of the windrow. The search for the required model can be briefly divided into several successive steps: finding the path that the hydraulic cylinder rod of the boom drive will take and by the known formula of speed of movement of the hydraulic cylinder piston is time to bring the boom to the tree; finding the way which the rod of the hydraulic cylinder of the arm drive; to find the path which the hydraulic cylinder rod of the tilt of the feller head; finding the path which the hydraulic cylinder rod for the arm actuator will take during the opening. The sum of the time for supplying each of the elements of technological equipment is the time required for the orientation, which is characteristic for a nonexperienced operator. In case of an experienced operator the time for setting the feller head to the tree is determined by the maximum time of one of the components.

Implementation of reengineering technology to ensure the predefined geometric accuracy of a light aircraft keel

The subject of this research is the technology of reengineering and control of parts of aircraft objects (AOs) and technological equipment for their manufacture. The predefined accuracy of the keel of a light aircraft and molding surfaces of technological equipment for its manufacture has been ensured by using reengineering technology and CAD systems. A portrait of the actual physically existing keel of a light aircraft was built in the *.stl file format using the software Artec Studio (USA). The control and comparison of the geometry of the shapes of the analytical standard with the actual physically existing keel of a light aircraft based on its portrait have been implemented. The methods used are the analysis and synthesis of the experimental geometry of shapes, the method of expert evaluations. The following results were obtained: based on the analysis and synthesis, the presence of significant errors in the accuracy of the manufacture of the keel for a light aircraft in the range from −5.26 mm to +5.39 mm was detected. It has been shown that the key factor is the keel's relative plane indicator, which is outside the tolerance margin and is 85 %. It was decided to fabricate new technological equipment from another material – organic plastics. Control of the technological equipment made from organic plastics for the keel of a light aircraft showed that the shape-forming surfaces of the equipment have appropriate shapes and sizes corresponding to the existing analytical standard and are devoid of inaccuracies that occurred in the previous version. The range of keel margins that was made using the new technological equipment from organic plastics is from –0.51 mm to +0.34 mm while the relative plane of the keel outside the tolerance margin does not exceed 15 %. The study results showed the adequacy of the decisions taken, ensuring the predefined accuracy for the keel of a light aircraft and molding surfaces of technological equipment for its manufacture.

Modeling of formation regularities of conical surfaces

The scheme of processing conical surfaces by grinding them to a flat tool is considered and a technical solution for the implementation of such processing is proposed. Using the created device allows implementing the group method of forming conical parts with a deviation of the generatrix of the cone from straightness of not more than ± 0.00012 mm. A mathematical model of the patterns of removal of stock from a conical part with a flat tool is developed. A formula is obtained for calculating the modulus of the sliding velocity at any point on the processed conical surface, which implements engineering methods for controlling the shaping of conical parts without conducting preliminary labor-intensive experimental studies. An optimization technique for the adjustment parameters of technological equipment was proposed. The most effective axicon processing modes were revealed at the stages of preliminary, medium and fine grinding, as well as at the polishing stage, depending on the technological heredity of the workpiece from the point of view of distribution of the stock to be removed over its surface. It has been established that changes in the eccentricity between the axes of rotation of the tool and the faceplate as well as the amplitudes of the reciprocating rotational movements of the latter practically do not affect both accuracy and processing productivity, therefore, in practice, these parameters can not be optimized, but their average values can be assigned. The operating modes of the basic lever grinding and polishing machine are established, at which the required accuracy of the working surface of the tool is provided, which directly affects the straightness of the generatrix of the cone. Studies of the regularities of the shaping of the side surface of a conical lens in the conditions of free grinding are carried out and the adjustment parameters of technological equipment that affect the quality and productivity of the processing process are determined.

Diamond Grinding Technology of Flexural Strength Test Pieces of Super hard, Brittle, Composite-ceramic Materials and Technological Equipment

At the present stage of the revolutionary development of technologies, scientists from the leading countries of the world are working intensively to create qualitatively new materials whose physical-mechanical, electrical, thermal or other properties far exceed the basic constructions, armament or other metals used. Such materials are surface, brittle, composite ceramic materials (based on oxide and carbide ceramics, state-of-the-art surface compositions, polycrystalline diamond + Si  SiC and etc.). A progressive process for diamond grinding test samples from composite ceramic materials to determine the bending strength is discussed. The proposed technological process is based on an original and effective method for polishing the flat surfaces of articles made of difficult-to-process and composite materials - low-temperature precision grinding (LPG). Based on the results of many years and multilateral studies in the field of diamond processing of various non-metallic, composite and ceramic materials, optimum conditions for diamond polishing of mentioned materials have been determined and recommended. Technological equipment and equipment for processing composite and ceramic materials are also disclosed.