The article deals with the problem of creating machines and units for the prevention and suppression of forest ground fire. The purpose of the study is to increase the efficiency of the working ...process of the soil-throwing machine by substantiating the parameters of the energy-saving hydraulic drive of the rotor-thrower. The rational values of the pre-charging pressure and the working volume of the pneumohydraulic accumulator have been established, which ensure the reduction to a minimum of the number of operation of the safety valves when the rotor-thrower meets obstacles. The optimum charging pressure of the pneumohydraulic accumulator is 6 ... 7 MPa, the working volume is 5 ... 8 dm3, while the energy-saving hydraulic drive stores energy of about 15 ... 17 kJ during the working cycle, pressure surges do not exceed 13.3 MPa, and the recovered energy at density of obstacles up to 200 pcs / km due to the reduction in the number of operation of safety valves can be about 3000 kJ per 1 km of strip laying. The productivity of the forest fire ground-throwing machine with a new energy- saving hydraulic drive increases by 16-22% while reducing energy consumption by 7-8%.
The research analysis of dynamics of technological machine work processes has been carried out. The aim of the work is improvement of work processes of the grapple slewing gear in forest transport ...machines by justification of energy saving hydraulic drive parameters. It enables to reduce dynamic loading and power consumption of the carried-out technological process. The computer program including the design data of new power-saving hydraulic drive of the grapple slewing gear affecting the efficiency of working processes is developed on the basis of a mathematical model of work process. As a result of computer experiments it is established that the energy-saving hydraulic drive with optimum parameters reduces the maximum pressure of actuating fluid during column braking. The pressure becomes equal to 3MPa. Recovery energy when turning the column is 25% of the spent energy. Amplitude of load swinging with a frequency of 0.8-1.5 Hz with the sharp change of the column movement mode decreases in 2-3 times.
Abstract
The article considers the possibility of increasing the efficiency of manipulator-type machines when harvesting wood by increasing the productivity, energy efficiency and reliability of the ...hydraulic equipment used. A combined method of transporting timber from logging sites by road and water transport using equipment with an improved hydraulic drive of the manipulator is proposed. The issue has not been worked through before. Using the example of the Northwestern Federal District, the author considers the development of forest areas located in the upper reaches of small and medium rivers. For the first time, original hydromechanical dampers and energy-saving devices are used in hydraulic drives of manipulators of forest machines to reduce dynamic loads and energy consumption for loading and unloading timber. This increases the efficiency of the use of manipulator-type machines, creating mobility, reducing equipment costs, the time spent waiting for unloading on sites for further rafting or shipment. The development of forest areas in a combined way will reduce capital investments for the construction of transport routes at the border of waterways by at least 3 times. All this will reduce the cost of harvesting in general and eliminate the use of additional loaders.
One of the main difficulties in combating forest fires with conventional water-based methods is the difficult topography and the fact that there are usually no accessible roads to bring firefighting ...techniques closer to the fire site. Today, a large number of scientific teams are working on the topic of extinguishing the edge of a forest fire with soil. The aim of the study is to increase the efficiency of forest fire prevention and extinguishing by ground-throwing machines by removing the upper combustible layer of forest soil, the formation of a loosened soil shaft from the mineralized layers of forest soil and throwing soil into the edge of a forest ground fire. The paper briefly describes the technical means for extinguishing forest fires using soil. The analysis of the structures of soil-throwing machines has been carried out. The promising directions for improving the technology and working bodies of fire-fighting ground launchers are described, the advantages and disadvantages of its designs are revealed, and ways of further improvement are outlined. A promising design of a strip-laying soil gun with a hydraulic drive of working bodies for preventing and extinguishing forest fires is presented. A distinctive feature of the developed design of the strip-laying soil launcher is the use of an auger to remove the upper fire-hazardous cover, consisting of plant residues, and cut spherical discs to improve the quality of loosening the soil shaft. As a result of the conducted studies of the working process of the strip-laying machine, it was found that the share of the soil covers with combustible materials in the soil flow decreased from 40 to 7%, and the quality of soil shaft loosening increased by 17%, due to which the average distance of soil ejection increased from 10 to 15 m and the power consumption of the rotor-thrower is reduced from 12 to 10 kW.
The article is devoted to the reduction of dynamic loads on hydraulic drive by optimization of hydraulic cylinder for boom lifting and parameters of new damping device. A mathematical model of the ...working process of the boom lifting mechanism of serial hydraulic manipulator LV-184A has been solved. The optimal position of the hydraulic cylinder, in which the fluid pressure is reduced from 12.4 MPa to 11.3 MPa, has been found. It takes into account the forces of inertia and compliance of hydraulic drive. Connecting a new damper reduces the maximum pressure in the piston cavity of the hydraulic cylinder by 47%. The minimum of maximum values of the working fluid pressure is achieved when the damper throttle channel diameters are in the range of 4.0-4.5 mm. The aim (reduction of dynamic loads) is achieved by optimizing the configuration of the boom lift cylinders and the parameters of new damper. It significantly increases reliability of hydraulic drive elements and efficiency of manipulator-type machines in forestry complex.
This paper provides an overview and analysis of existing tools and machinery for fighting ground forest fires. The paper examines theoretical issues of applying soil-thrower machine to extinguish ...forest fires. In the paper, the information database on the usage of existing technology in modern conditions is studied in order to evaluate the effectiveness of the usage of new technology. The design of the presented machine makes it a universal one, replacing two technological units and thereby reducing the material consumption of technological process of extinguishing fire with soil and laying firebreaks; it increases the amount of ground to extinguish the fire, increasing efficiency in the fight against fire, as well as the traveling speed of the unit and its performance.
Abstract
The article describes the use of mulcher technology in forestry for the care of forest crops, removal of overgrowth under power lines, in the right-of-way of gas and oil pipelines, railways ...and highways. With the help of mulchers, they create fire strips in the forest, make clearings. Mulchers clean fallen trees after fires, floods and hurricanes. They are involved in landscaping and agricultural work. The article examines the work of the PT-400 self-propelled tillage mulcher for the surface crushing of logging waste on the utilized poplar plantations of the Oryakhovsky state forestry in Bulgaria. The work of the Rotor Ferri S stump grinder was studied when crushing poplar stumps with a diameter of up to 50 cm. The hourly productivity of these machines at various operations was determined, and also the process of crushing stumps and felling residues by fractional composition was studied. The work of the mulcher was compared with the bulldozer technology and the mounted tractor stump grinder Rotor Ferri S. It was concluded that the mounted stump grinder Rotor Ferri S is the most suitable machine for grinding poplar stumps of any diameter, since its productivity significantly exceeds that of the PT-400 mulcher/tiller. The load on the tractor is minimal, which saves energy. At the same time, mulching technology is very effective and in demand.
The article presents a technological scheme of the operation process of a soil-throwing unit, which has a milling-throwing working body and a guiding casing, and a developed simulation model of the ...process of movement in the air of a directed flow of soil particles supplied by a soil launcher when extinguishing a forest fire. The aim of the study is to assess the influence of soil and air flow parameters on the indicators of its suitability for extinguishing a ground forest fire by using simulation modeling of the process. The study of this work covers the process of flow, which received the necessary impulse from the milling cutters of the soil launcher. The theoretical description of this direction of research is complex, since it considers both the packing of flying particles and individually detached spherical elements that come into contact with air particles, also presented in the form of discrete elements. As a result of modeling the movement of soil in the air, a vertical cut of the system of fragments of soil and air, graphs of dependences on time, the average distance between soil elements and the average resistance force of the air environment were obtained.
The analysis of the work processes of technical equipment used for forest fire control and preventive activities has revealed that they do not meet the requirements of the process flows. The aim of ...the work was to increase the efficiency of the work processes of new forest fire-fighting soil-thrower by optimizing the parameters of the milling thrower. The optimization task has been to search for the values of the length and width of the milling thrower blades. These values should provide the highest productivity and smallest supplied power with the average range of soil displacement. Based on the optimization results, the optimal blade length of the milling thrower was revealed in the range of 200-230 mm, and the width of the blade was 150-220 mm. With optimal parameters of the working body, a fire-fighting machine throws soil into the fire zone at a distance of up to 21 m. It consumes no more than 38 kW of power, and its productivity is 0.22 m3/s on the average.
Abstract
The article presents the results of a study of the process of operation of the Mounty 4000 machine in mountain conditions. The main goal of the research is to establish production rates for ...harvesting when using Mounty 4000 machines in mountainous areas. The need for research in this direction is due to the lack of such data in the current regulations, as well as in the scientific literature. To study the operation of the Mounty 4000, a passive production experiment was carried out in the mountainous regions of Bulgaria. The obtained data on the rates of output and operating time of the Mounty 4000 allows you to make scientifically based decisions in the selection of effective technical means from a large number of alternatives for forest harvesting technologies in mountainous areas.
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