Wyniki wyszukiwania - BazTech

1

Method of calculating the design parameters of a modulator anti-lock braking system with a high flow of working fluid

Zhilevich Mikhail, Ermilov Sergey, Kapski Denis, Vovk Yuriy, Lyashuk Oleg, Vovk Iryna

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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z. 110

199--210

EN

The design dimensions of the executive hydraulic cylinders of the brake system of heavy-duty mining dump trucks cause high fluid flow during the braking process. Therefore, dimensions of the anti-blocking system modulator spool pair require unique electromagnets or hydraulic amplifiers to control. These solutions do not allow the required modulator performance. Thus, a modulator scheme with a division of the flow of fluid from the source to the brake cylinders was developed. This scheme allows during emergency braking passing, an additional amount of fluid to cylinders through the valve, installed parallel to the main valve upon pressure increase phase and controlled by the pressure difference. The task is to develop a method for calculating the main structural dimensions of a modulator. The calculation of the valve of the second cascade, installed in parallel to the main stage, is carried out for the emergency braking mode with the maximum flow rate to ensure the required performance of the braking system. The balance of fluid flows equations is compiled at the key points. The flow rate of the fluid through each of the valves is determined by the Torricelli formula, and the pressure difference across the valves is assuned equal. The obtained relations allows building a family of Q-p curves, which can be used to select the diameter and stroke of the additional valve depending on the flow rate in the brake system.

2

Blending control of the trolleybus traction and brake drives to enhance the braking efficiency of a vehicle

Safonau Andrei, Vovk Yuriy, Lyashuk Oleg, Khudobei Roman

Journal of Sustainable Development of Transport and Logistics

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2020

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Vol. 5, No. 2

49--61

EN

Widespread usage of emission free public transport is the preferred strategy in many cities to reduce a congestion and pollution from the road traffic. The trolleybus is a kind of urban public transport, i.e. a fully electric vehicle, which is considered as a promising tool to enhance the efficiency of public transport and to attain the goals of sustainable development and quality of city life. The operation control of service brake system and secondary brake system (the braking torque of traction electric motor) is realized with help of one pedal in the trolleybus. Thus, there are modes of the joint operation for these systems during the braking process. Authors focus on the development of rule-based algorithm for the blending control of traction electric motor and anti-lock braking system to enhance the overall braking efficiency of a vehicle. The mathematical model of the trolleybus braking dynamics was developed for this purpose. Test bench and ride tests on different road surfaces were carried out to determine the parameters of vehicle braking efficiency and to validate the developed mathematical model. The corresponding experimental data were used to analyse the efficiency of proposed rule-based strategy for the blending control of traction electric motor and anti-lock braking system of the trolleybus. As a result, the availability of proposed control algorithm is confirmed, which secures the required braking efficiency and provides a high braking stability of the vehicle.

3

Influence of ABS system use on aviation brake temperature

Paprzycki I.

Journal of KONES

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2014

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Vol. 21, No. 4

381--388

EN

The main functions of an aviation brake system are to slow the speed of the vehicle, to perform stable deceleration, and to hold the vehicle stationary after it stopped. They must perform safely under a variety of operating conditions such as slippery, wet and dry runways, full or light load of the vehicle, new or worn brake linings, novice or experienced pilot, etc. The experimental tests show that about 95% of friction energy is converted into thermal energy by plastic deformation of brake linings surface layers and other deformations. The friction materials temperature growth is caused by this energy transformation. The influence of braking temperature is very important to the tribology characteristics, durability and reliability of friction brakes. Landing Gear Department Laboratory performed many experimental tests on full-scale brakes and also on friction material samples. It was performed on the special laboratory test rigs. During the Anti Lock Braking system test, the Landing Gear Department Laboratory workers performed the brake linings temperature measurements. Author observed a positive influence of ABS system use on temperature curve. The aim of this article is to compare the test results of braking with ABS system applied to braking without ABS.

4

Antilock brake system of trolleybus

Safonau A.

Archive of Mechanical Engineering

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2012

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Vol. LIX, nr 1

21-30

EN

The antilock brake system (ABS) was developed, which coordinates actions of auxiliary and working braking systems of a trolleybus. A trolleybus type 321 "Belkommunmash", equipped with the proposed ABS was tested in road conditions. The results of tests confirmed compliance of the trolleybus with requirements of the rules UN EEC No 13. Decrease in slippage of the driving wheels, improved stability, roadability and traffic safety of the trolleybus was noted.

PL

Opracowano przeciwpoślizgowy system hamulców (ABS), który koordynuje działanie dwu systemów hamowania trolejbusu: roboczego i pomocniczego. Trolejbus typu "Belkommunmash 321", wyposażony w proponowany system ABS, był testowany w warunkach drogowych. Wyniki testów potwierdziły zgodność trolejbusu z wymaganiami normy UN EEC No 13. Odnotowano zmniejszenie poślizgu kół napędzanych, poprawę stabilności trolejbusu, lepsze trzymanie się drogi i lepsze bezpieczeństwo w ruchu.

5

The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

Hadryś D., Węgrzyn T., Miros M.

Transport Problems

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2008

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T. 3, z. 1

85-94

EN

In this article has been presented the influence of various pressures in pneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking declaration, maximum value of deceleration, braking distances.

PL

W pracy przedstawiono wpływ zamian ciśnienia powietrza w ogumieniu pojazdu osobowego Fiat Panda 1,3 JTD wyposażonego w układ ABS na wybrane parametry procesu hamowania: przebieg opóźnienia hamowania, maksymalną wartość opóźnienia hamowania, drogę hamowania.

6

Material and legal criteria of vehicle braking process

Dudziak M., Lewandowski A.

Zeszyty Naukowe Politechniki Poznańskiej. Maszyny Robocze i Transport

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2002

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Nr 54

67-74

EN

The article discusses the material and legal criteria of the car braking process decisive for the safety of use of a passenger car. The results of proving ground testing are presented. The tests were carried out with a passenger car equipped with anti-lock braking system (ABS), with which emergency braking was performed using various summer and winter tyres, in summer conditions, as well as on dry and wet (artificially sprayed) carriageway. Based on the total number of 160 braking tests within speed range between 60 and 120 km/h it was found out that the use of winter tyres in summer in a car equipped with an ABS guarantees effective braking of the vehicle' on dry, as well as on wet pavements. The braking process was analysed in terms of slip velocities of wheels and the effect of this parameter on the values of mean fully developed deceleration.