Test bench for investigating the sowing seeders’ characteristics

Наведено конструкції однозернового апарата висівання насіння і три конструкції стендів для дослідження характеристик висівних апаратів сівалок. Наведено аналітичні залежності для визначення силових і кінематичних параметрів апаратів точного висівання насіння, а також технічні характеристики стендів і можливості їх застосування. Дано практичні рекомендації виробництву щодо проектування висівних однозернових апаратів сівалок і стендів для дослідження їх характеристик і захисту насіння від пошкоджень і подрібнень.The structure of corn seed sowing unit and three structures of posters for investigating the seeding machines’ characteristics are proposed. The analytical dependences for determining the power and kinematic parameters of precision sowing seeds machines are developed as well as the technical characteristics of posters and the possibility of their usage. The practical recommendations for manufacturing the design of sowing corn planters and the posters for investigating their characteristics concerning the protection of seeds against damage and grinding are given

Calculation of holder sectional cone clamping machine tools

Наведено конструкцію і принцип роботи оправки затискної конусної для метало- різальних верстатів і технологічного оснащення. Виведено аналітичні залежності для визначення сумарної сили затиску заготовки по внутрішньому діаметру, конструктивних і технологічних параметрів. Дано практичні рекомендації для проектування даних оправок.Reduced construction and working principle opravky Tightening conic for metal cutting machine tools and manufacturing equipment. Analytical dependences for determining the total force to clamp the workpiece inner diameter, structural and technological parameters. These practical recommendations for designing data opravok

The mathematical model of single-seeding by disk sowing device

Розроблено математичну модель однозернового висіву насіння дисковим комірчастим апаратом, який встановлено вертикально. Представлено розрахункову схему для визначення сили виштовхування зернин з висівного апарата й наведено аналітичні залежності для визначення складових сил виштовхування, сил тертя, обертового моменту, а також швидкість виштовхування зернин з висівного апарата визначено за формулою згідно з планом швидкостей.Cereals, spikes and industrial crops play an important role in the structure of the crop sector of Ukraine supplying population with the foodstuff and industry with primary products. Wide use of high productivity variants of drain crops and organs of grain crops, introduction of the efficient and resource-saving cultivation is very important at the stage of setting up the agricultural sector. For the last seven years in Ukraine the average gross grain harvest equaled 29.2 million tons with the total demand of 40 - 45 million tons. Therefore, at the current stage of the national agricultural reform reestablishment the varying use of high productivity sorts of crops and the introduction of intensive and energy-saving technologies of their cultivation is very important. The dynamic model of single-seeding by the vertically installed disk cell machine is proposed. The essence of the design is that in the middle of the outer cylindrical part of the removable ring for different seed sizes being replaced while changing the sowing seeds, in the radial direction the ring groove, the depth of which being equal to or greater than the maximum size of grain, is made. The seeds interact with the pushing surface of the wedge mounted rigidly in the stationary body with the possibility of being relatively replaced. The sharp ring of the wedge is set under the cell disk at the angle towards the direction of the disk rotation, its position being adjusted. The essential feature of the sell disk is the fact that on the external diameter of the basis the external removable ring is set rigidly, which is changed dependently on the size of the sowing material seeds. The calculation scheme for finding the seeds pushing power from the sowing machine is developed. The analytical dependences for finding the pushing forces components: friction forces, torque are presented as well as seed pushing speed from the sowing machine is found according to the formula of the speeds plan. The analytical dependence for finding the productivity of the seeding machine and the seeder in general is proposed. Taking advantage of the precise single-seeding the method will make possible to decrease more than in two times the sowing seeds portion and to increase the productivity by 10 - 15% due to the creation of the efficient conditions of the plants feeding during the sprouting and growing

The results of experimental investigation of technological vibration-centrifugal processing of details

Наведено результати експериментальних досліджень технологічного процесу вібраційно-відцентрової обробки. Визначено дискретність зміни шорсткості оброблюваної поверхні та шляхи її усунення. Запропоновано конструктивну схему установки для автоматизації технологічного процесу вібраційно-відцентрової обробки, на яку отримано деклараційний патент України.The construction of vibration-centrifugal device with complex angular vibration and gimbal suspension, which is placed inside the working chamber, for machine parts treatment with low rigidity and complex profile, was presented. Besides, the machine tool is equipped with a device for smooth change of the angular vibration value and rotation frequency control. Block diagram for the control of the vibration-centrifugal treatment process, which allows to avoid the discrete nature of the change of machined surfaces roughness and reduces the time of obtaining a certain or minimum value of surfaces hardness and provides reliable performance of treatment technological process of complex profile and very low rigidity parts. The objective of the work is to study the influence of structural kinematic parameters of chamber inside which parts are machined on the quality of the vibration-centrifugal treatment of parts with complex configuration and low hardness. The results of experimental investigations of the vibration-centrifugal treatment, were presented. The experimental investigations for determining the changes of the parameters of treated surfaces by vibration-centrifugal treatment were done on unhardened samples after turning and milling of steels 40, 40X, Steel 20, St3, brass LS 59-1 with different initial stiffness, cylindrical and prismatic shape. It was found that during the first 15 minutes of treatment there is intensive reduction of microirregularities, the next 15 minutes the intensity of decreasing the heterogeneity is negligible. Within 30 .. 45 minutes the hardness increases, but the roughness parameters Ra being not higher than the initial. The change of the arithmetic deviation of profile stiffness depending on the duration of treatment with different initial stiffness for the above materials was determined. Practical recommendation on the choice of technological parameters of the process of treatment and choice of design parameters settings are presented

Technical and economical substantiation of the use of resetting the conductors with rotating hubs

Наведено конструкції універсальної багатошпиндельної свердлильної головки та універсального кондуктора для свердління отворів в деталях машин, які забезпечують підвищення гнучкості виробництва та довговічності кондукторних втулок. Наведено теоретичні залежності зношення поверхні кондукторних втулок від конструктивних параметрів і параметрів взаємодії свердло–кондукторна втулка. Підраховано економічну доцільність удосконалених конструкцій.The constructions of universal multi-spindle milling head and the universal conductor for milling the holes in machines’ details are proposed. These constructions are proved to increase the flexibility of production and durability of conductor hubs. The theoretical dependences of the wear of conductor hubs’ surface on the structural parameters and the parameters of interaction of milling-conductor hub are developed. The economical expediency of the improved constructions is calculated

Quantitative measurements of inequality in geographic accessibility to pediatric care in Oita Prefecture, Japan: Standardization with complete spatial randomness

<p>Abstract</p> <p>Background</p> <p>A quantitative measurement of inequality in geographic accessibility to pediatric care as well as that of mean distance or travel time is very important for priority setting to ensure fair access to pediatric facilities. However, conventional techniques for measuring inequality is inappropriate in geographic settings. Since inequality measures of access distance or travel time is strongly influenced by the background geographic distribution patterns, they cannot be directly used for regional comparisons of geographic accessibility. The objective of this study is to resolve this issue by using a standardization approach.</p> <p>Methods</p> <p>Travel times to the nearest pediatric care were calculated for all children in Oita Prefecture, Japan. Relative mean differences were considered as the inequality measure for secondary medical service areas, and were standardized with an expected value estimated from a Monte Carlo simulation based on complete spatial randomness.</p> <p>Results</p> <p>The observed mean travel times in the area considered averaged 4.50 minutes, ranging from 1.83 to 7.02 minutes. The mean of the observed inequality measure was 1.1, ranging from 0.9 to 1.3. The expected values of the inequality measure varied according to the background geographic distribution pattern of children, which ranged from 0.3 to 0.7. After standardizing the observed inequality measure with the expected one, we found that the ranks of the inequality measure were reversed for the observed areas.</p> <p>Conclusions</p> <p>Using the indicator proposed in this paper, it is possible to compare the inequality in geographic accessibility among regions. Such a comparison may facilitate priority setting in health policy and planning.</p