The paper suggests the design of the locking truck hydraulic valve with electro-hydraulic drive and braking, which eliminates the disadvantages of the known designs hydraulic valves. A mathematical model for the study of operating modes of the proposed design of hydraulic valve. As a result of research modes of pressure hydraulic valve is installed, it has a high-speed operation. The proposed design of the shut-off tractor hydraulic valve allows you to quickly make adjustment of the time of its operation during operation using the throttle is part of the hydraulic valve.
Робота присвячена дослідженню динамічних навантажень, що виникають у гідросистемі механізму затискання штаби двоконусного розмотувача рулонів ТЕЗА 159-529. Запропоновано математичну модель дослідження динамічних процесів у гідросистемі затискання штаби з урахуванням хвильових властивостей довгих гідромагістралей. В ході реалізації математичної моделі в середовищі Simulink MATLAB було проведено дослідження режимів роботи гідросистеми механізму затискання штаби. В результаті дослідження було показано, що в гідросистемі механізму затискання штаби двоконусного розмотувача виникають динамічні навантаження в кінці зворотного ходу. Запропоновано порядок роботи гідророзподільників із часом спрацьовування 0,16 сек. Це дозволяє значно зменшити динамічні навантаження в гідросистемі механізму затискання штаби розмотувача.
In the technological line for the production of small diameter pipes used segment un-winder staffs with a cantilever drum and additional support. The experience of its operation has shown that one of its main shortcomings is the unsatisfactory operation of the hydraulic system clamping staffs. In the hydraulic clamping system of the staffs there are increased dynamic loads, which lead to the failure of components and elements of the hydraulic system. The layout of the hydraulic clamping system of the headquarters is made for design and technological rea-sons, without taking into account the influence of pipeline lengths on the nature of dynamic processes in the hydraulic system. In addition, the hydraulic system uses spool hydrodistributors with electro-hydraulic control, the operation time of which is practically not subject to regulation. Based on the analysis of known mathematical models for the study of dynamic processes in hydraulic systems, it was concluded that as a mathematical model that takes into account the design and operation of the hydraulic clamping system staffs finite-difference method in a sys-tem of ordinary differential equations with boundary conditions described by algebraic equations. A basic dynamic model has been created, which allows to analyze with high relia-bility the behavior of the hydraulic system of the clamping mechanism of the staff in the segment unwinder of the rolls, which is exposed to different nature in a wide range of mode parameters. Simulink MATLAB software environment was used to effectively solve this problem. During the implementation of the mathematical model, a study of the modes of operation of the hydraulic system of the clamping mechanism of the staff was performed. It was found that at the end of the working and reverse strokes of the clamping mechanism of the roll in the end posi-tions there are dynamic loads in the hydraulic system that reach the maximum allowable values. In addition, it was found that during the acceleration of the piston of the hydraulic cylinder during operation and reverse, although there are no dangerous loads, but there are rapid fluctuations in pressure in the cavities of the hydraulic cylinder. Theoretical studies of the modes of operation of the hydraulic clamping system of the staff in the segment unwinder with different operating times of the control valve. As a result of the study of transients in the unwinding hydraulic system with different operating times of the hydraulic distributor, its ra-tional operating time was recommended, which is 0.20 seconds when opening and 0.15 sec-onds when closing.
В работе описаны базовые модели для анализа реакции защитных экранов на действие кумулятивных боеприпасов. С этой целью построены математические и тестовые численные модели механического взаимодействия боеприпаса в момент подлета к защитному экрану и в дальнейшем при взаимной деформации элементов созданной механической системы. Продемонстрировано влияние условий встречи боеприпаса с экраном на дальнейшее развитие сценария действия боеприпаса на бронепреграду. В частности, на примере решения тестовых задач исследовано влияние механических свойств материала решетчатого экрана и скорости встречи гранаты с экраном на разрушение элементов системы. На этой основе предложено создание виртуального испытательного стенда. Также на основе анализа полученных результатов предложено создать специализированную базу данных. Ключевые слова: механика сплошной среды, бронезащита, метод конечных элементов, защитный экран, кумулятивный боеприпас, легкобронированная машина
Each type of activity, each profession has its own specifics, its own characteristics and, accordingly, special requirements for professionals. To perform the tasks of the chosen profession, a person must be ready both physically and psychologically. The article investigates the level and dynamics of the mental working capacity of cadets-future police officers under the influence of physical training and sports. The study was conducted at the National Academy of Internal Affairs in 2017-2020. The study involved cadets (male) of the 1st-4th years of study (18-22 years old, n=152). Two groups were formed: experimental group (EG) – cadets who during studying were engaged in the sambo wrestling section of the academy (n=32); control group (CG) – cadets who studied according to the current program of the academic discipline "Special physical training" and did not attend additionally the sports sections of the academy (n=120). The dynamics of the cadets‟ thought processes was studied using the following methods: Bourdon-Anfimov‟s test, the "Operation with numbers" method, the "Complex associations" method. Research methods: analysis and generalization of literature sources, pedagogical testing, pedagogical observation, pedagogical experiment, methods of mathematical statistics. It was found that sambo wrestling classes are more effective, in comparison with the current program of physical training, contributes to the improvement of the thought processes among cadets-future police officers, which in general will contribute to the improvement of their future professional activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.