Physical-mathematical model of ground adhesion on the surface of the excavating parts of earthmoving machines

A large number of domestic and foreign scientists were engaged in the wear of the surfaces of the excavating parts of earthmoving machines during their interaction with the ground, as well as the problem of the adhesion of soils on the surface of the working excavating parts of machines and methods of struggle. It is known that the classical theory of digging is based on empirical dependencies obtained experimentally. They allow, basically, to reveal the essence of the process of dredging, but they differ from each other, both in their description and in the number of results. In this article, the authors propose, on the basis of probability theory, theoretical studies of the process of dredging and the interaction of the excavating part with the soil. The authors of previous studies confirm the obtained results. The developed physical model of the interaction of soil particles with the surface of the excavating part during adhesion allows us to reveal the physical cause of the process of wear of the surface of the excavating parts.

Calculation of the Amount of Work on a Typical Technological Parking Area Lot of an Excavator for Building an Information Model

Постановка задачи. Построение информационных моделей строительных процессов невозможно без точного вычисления объема работ, выполняемого на типовой технологической стоянке (захватке). Цель работы состоит в разработке системы автоматизации вычислительных процедур, применяемых при определении объема земляных работ на типовой технологической стоянке экскаватора, которая используется в 4D- и 5D-BIM-моделях. Результаты. Получены аналитические уравнения для вычисления объема земляных работ на одной технологической стоянке экскаватора с учетом технических характеристик землеройных машин, а также условий производства работ (категорий грунта по величине угла внутреннего трения). Выводы. Аналитические зависимости объема работ на одной типовой технологической стоянке экскаватора от технических характеристик и условий производства работ (категорий грунта) могут применяться для формирования процедур автоматического вычисления объема работ, продолжительности и стоимости устройства котлованов. Величина объема работ на одной технологической захватке может применяться для формирования, оценки и выбора траектории движения экскаватора при устройстве котлована. Statement of the problem. The construction of information models of construction processes is impossible without an accurate calculation of the amount of work performed on a typical technological parking lot (gripper). The aim of the work is to automate the computational procedures used to calculate the amount of excavation work on a typical technological excavator parking lot, which is used in 4D and 5D BIM models. Results. Analytical equations are obtained for calculating the volume of earthworks at one technological site of an excavator, taking into account the technical characteristics of earthmoving machines, as well as the conditions of work (the category of soil according to the value of the internal friction angle). Conclusions. The analytical dependences of the volume of work on one typical technological site of an excavator on the technical characteristics and operating conditions (the category of soil) can be used to form procedures for automatically calculating the volume of work, the duration and cost of the construction of pits. The amount of work on a single technological gripper can be used to form, evaluate and select the trajectory of the excavator during the construction of the pit.

General Characteristics for Loading the Working Elements of Drilling and Milling Machines when Moving in the Clay Solution

The article is devoted to influence of the clay thixotropic solutions on the strength of resistance to movement of the earthmoving machines' working elements. The forces of resistance to the movement of a flat plate, a smooth cylinder and real working bodies in a clay solution for various modes of solution flow (bingamian, pseudo-laminar and turbulent) are established. Mathematical models of movement of the earthmoving machines working elements in clay solution are developed and investigated. Dynamics of the working element of an earthmoving machine movement in a clay solution is studied. Dependence of the feed force, torque and dynamic coefficient on the resistance forces, acting on the working body from the clay solution, is established.

Determination of dynamic properties of the caterpillar drive of hydraulic reclamation machines and the method of articulated attachment of the working body of the trenchless pipelayer

Objective. The objective of the study is to determine the requirements for various devices of hydraulic reclamation machines, which are widely used in the construction of canals and drains, to maintain a given slope, as well as the calculation of the executive mechanism that serves to eliminate the oscillating movement of the working body relative to the line of the specified slope.Methods. A mathematical description of the vibrations of the working body for caterpillar hydraulic reclamation machines with mounted working bodies is given.Results. The article presents the results of research to identify the main factors affecting the oscillations of the working body of caterpillar reclamation machines. As a result of theoretical and experimental studies, it was found that when a caterpillar machine with a rigid undercarriage crosses single and multiple irregularities, the movement of the cutting edge of the rigidly mounted working body is graphically depicted by sinusoidal curves. The obtained dependencies allow conducting calculations of the automatic system of maintaining the specified slope and establish the area of stable modes of system operation. A geometric method for optimizing the hinge linkage of the working body of trenchless pipelayer is presented.Conclusion. The proposed methods of improving the performance of caterpillar hydraulic reclamation machines with mounted working bodies when moving on uneven ground surfaces can be used to create a wide class of mounted earthmoving machines, both with passive and active working bodies.

PROBLEMS, DIRECTIONS, AND HORIZONS IN THE CREATION AND MODERNIZATION OF SPECIALIZED CONTINUOUSLY OPERATING EARTHMOVING MACHINES

The article addresses directions and horizons in the creation of highly efficient specialized continuously operating earthmoving machines and provided a technical proposal for the multipurpose earthmoving machine. Study subject: continuously operating earthmoving machines. Objective: To create a power-efficient special-purpose earthmoving machine. Study method: experimental. Existing dimension-types of trenching excavators allow digging lengthy excavations of the assigned profile with minor deviations from their nominal width and depth. Creating of excavations of different profiles is being achieved via machine re-equipment with different implements. A sustainable solution is to create multipurpose earthmoving machines that are capable to perform lengthy excavations of various widths and depths with the same implement and without constructional alterations. There are known machine designs for trenching on the basis of a wheeled tractor with a mounted chain-bucket implement that is able to perform the lateral oscillatory displacements in relation to the vertical axis on the hull back of the tractor. Alteration of the implements oscilative motion amplitude allows to excavate the tranches of differnt width. This is the essence of the multipurpose earthmoving machine. The existing kinematics chain sections of the implement in relation to the tractore can't ensure the consistency of the machine load due to inconsistency of the borings along the width of excavation. This leads to significant pulsation of the load on the implement, loss of the longitudinal stability and, in the end, reduces the potential productivity of the machine by half. We have performed a set of studies in creating of the multipurpose earthmoving machines (MEM). As the experimental study objects we've used physical models of the MEM implements and full-size prototypes of the machines. Results of the study experimentally confirm the possibility to create a highly productive MEM with rotary implement, which efficiently performs trenches as well as wide construction pits in the mode of reciprocating approach of the rotary implement to excavation by means of equalization and minimization of power load parameters values. KEYWORDS: EARTHMOVING MACHINE, ENERGY INTENSITY, KINEMATICS, PRODUCTIVITY, SOIL

Actuality of development of new means of ground cutting spatially oriented knifes of dynamic action when working with earth machines

Using the sources of patent documentation, a patent search was conducted to determine the relevance of the problem of cutting the soil with spatially oriented knives when working with earthmoving machines and further analysis of the proposed technical solutions. As a result of the study, we found that the topic remains relevant for the period under consideration. It was found that different types of persons were involved in this area: individuals, scientific and educational institutions, research institutes and equipment manufacturing organizations, in particular by Caterpillar, Komatsu and John Deere, which indicates the relevance and importance of this problem. The study of cutting soils with spatially oriented knives of dynamic action is relevant for achieving a decrease in the energy consumption of the process of cutting soils. The proposed research direction is a continuation of the scientific schools of the Department of Construction Machines KNUBA, namely, dynamic cutting and creation of cutting elements of earth-moving machines with spatial orientation.

HYDROSTATIC SYSTEMS FOR ENERGY RECUPERATION IN EARTHMOVING MACHINES

The first part of the paper contains the results of a study into the change in the energy parameters of earthmoving machines during manipulation tasks. The results of the research show that during certain operations of manipulation tasks, in the stop phase, the required energy of the machines has negative values. Modern earthmoving machines have hydrostatic drive systems that accumulate potential negative energy by recuperation and, if necessary, return it to the drive system of the machine for use in other operations of a manipulation task. In the second part of the paper, the analysis of the concepts of hydrostatic drive systems of earthmoving machines that enable energy recuperation is performed in detail.

Structural Parameters and Working Range Estimation of Excavator Backhoe Mechanism

Earthmoving machines like excavators and loaders characteristics such as productivity, weight, reliability depend on their backhoe mechanism. For that, the backhoe mechanism has to deliver the desired working range, digging forces and stability which are dependent on structural parameters like components length and joint angles. This paper describes the method of developing a backhoe mechanism for the desired working range which constitutes cutting heights and reaches by using structural parameters. This requires to develop forward kinematical model by considering the backhoe mechanism as a mechanical manipulator. A computer algorithm was developed, that uses the forward kinematic model, to estimate the working range. Also, a relationship is established between joint angles and cylinder lengths. Results of Virtual prototype, modeled and simulated in MSC ADAMS along with the testing results of BEML designed Physical prototype were used to validate the working range and structural parameters. This research provides a solid foundation for analyzing the effect of structural parameters on digging forces and stability.