Browse Topic: Air brakes
Brake failures in the vehicles can cause hazardous accidents so having a better monitoring and emergency braking system is very important. So, this project consists of an autonomous brake failure detector integrated with Automatic Braking using Electromagnetic coil braking which detects the braking failure at the time and applied the combinations of the brakes, to overcome this kind of accidents. So, here the system comprises of IR sensor circuit, control unit and electromagnetic braking system. How it works: The IR sensor monitors the brake wire, and if the wire is broken, the control unit activates the electromagnetic brakes, stopping the vehicle in a safe manner. This system enhances vehicle safety by ensuring immediate braking action without driver intervention. Key advantages include real-time brake monitoring, reduced mechanical wear, quick response time, and an automatic failsafe mechanism. The system’s minimal reliance on hydraulic components also makes it suitable for harsh or variable conditions. The proposed system can be widely implemented in automobiles, especially those using drum brakes, as well as railway systems to prevent accidents due to brake failure. Future advancements in predictive maintenance, machine learning, and AI integration could further improve the reliability, adaptability, and overall efficiency of this advanced braking system.
Aircraft design is an example of complex engineering and actuation system is one of the critical and flight safety part of Fixed wing/Rotary wing aircraft. The application of Actuators in an aircraft is more and more varied and important. ASERDC, HAL- Lucknow division has expertise in design, testing, certification, and production of actuators for Civil and Military applications used for various roles that include operation of Undercarriage, Doors, Air Brakes, Yaw damper, Flight control rotor actuators and similar other applications. The various challenges and failures encountered during process of realization of these utility and flight control actuators with numerous learnings from design phase to certification phase and so on. These challenges and learnings are discussed in this paper through examples mainly through Flight control rotor actuators. This paper discusses about specification, development, and the testing aspects along with its functioning and architecture. It also covers several important points which need to be considered during design, manufacturing, testing and certification stages for these complex servo hydraulic actuators.
This SAE Standard is intended to establish uniform performance criteria and methods of testing push-to-connect tube fittings, with SAE J844 air brake tubing as used in vehicular air brake systems. The specific tests and performance criteria applicable to the tubing are set forth in SAE J844. The test values contained in this performance standard are for test purposes only. For environmental and usage limitations, refer to SAE J844.
This SAE Standard covers complete general and dimensional data for the manufacture of, T6061-T6 Aluminum cavities designed to receive Push To Connect threadless fittings known as “cartridges“, for air brake applications. This document is not intended to specify or recommend any style or manufacture of such cartridges but to establish uniform cavity dimensions for interchangeability purposes.
In an air brake system, compressed air is used as an energy medium for braking applications, ensuring a good seal between the components is critical. The sealing performance of gaskets are significant for the product with joint features as it affects functionality and can cause a breakdown of the entire system; hence, finite element simulation of the sealing performance of gaskets is important for any product development. To simulate fluid interacting with gasket, a fluid-structure interaction (FSI) simulation is necessary by co-simulating a computation fluid dynamics (CFD) and finite element analysis (FEA) solvers to capture complex behavior of seal deformation under dynamic conditions during leakage, but it is a time-consuming process. In this article, the sealing performance of gaskets is studied in detail only till the start of leakage. It is not necessary to simulate the dynamic behavior of the seal beyond leakage to validate the sealing performance; hence, static nonlinear analysis is performed in FEA to capture the seal behavior. But instead of simulating the interaction of fluid as a normal pressure load, a new technique called pressure penetration load is applied. This new technique can not only simulate the normal pressure on the seal and body but also simulate the penetration of fluid through the seal. The intensity of penetration depends on the contact pressure and exists at the interface between the seal and body, due to bolt torque. If the contact pressure is less, the fluid pressure can penetrate and open the contact. This method can predict the possibility of leakage efficiently, and the computation cost is less compared to FSI simulations involving two solvers. The contact pressure developed during the assembly process is simulated and confirmed with the Fuji film test—a pressure-indicating sensor film. Using pressure penetration load, the sealing performance is analyzed to ensure no leakage during extreme conditions. With this methodology, the gasket groove volume, number of bolts, bolt torque, and bolt locations can be optimized. This paper also discusses the sensitivity of various FEA parameters like element size, element type, and dependence of bolt modelling for the current simulation to reduce computation time. This methodology can be applied to validate various products with face-sealing gaskets. A design optimization study is done using this method to convert a metal cover into plastic material with topology optimization to save weight and overall cost of the product.
This Recommended Practice provides a road test procedure for trucks and buses, to evaluate their compliance with Federal Motor Vehicle Safety Standard (FMVSS) 121; Air Brake Systems. Units of measure are English in lieu of metric to be consistent with FMVSS 121.
This SAE Recommended Practice provides a road test procedure for truck-tractors, to evaluate their compliance with Federal Motor Vehicle Safety Standard (FMVSS) 121. Units of measure are English in lieu of metric to be consistent with FMVSS 121.
This SAE Recommended Practice is intended for qualification testing for brake drums used on highway commercial vehicles with air brakes using an inertia-dynamometer procedure. This document consists of two distinct tests: Part A, durability and speed maintenance test, and Part B, heat check drag sequence test. Each test can be considered to be an independent evaluation of the brake drum which tests different properties.
This SAE Recommended Practice is intended for measuring the static brake torque performance of a pnuematically actuated brake assembly, friction material, and drum/disc combination on an inertia brake dynamometer.
This SAE Information Report lists common port connection types used in truck, bus, truck-trailer, converter dolly, and multi-purpose vehicles with air brake systems at the time of publication. The purpose of the document is to give system designers and users a starting point for connector selection and a reference to the standards that govern these connector types. Also included are notes on common practices associated with these ports. CAUTION: Consult the relevant standard for the connector before making a decision on suitability for use in a specific application.
This SAE Recommended Practice applies to S-CAM, wedge, and disc air brake actuators where the stroke can be measured without disassembly from the brake.
The braking capacity of reducing the speed or even keeping the vehicle stoped is extremely important in the design of any brake system, as more than meeting legislation requirements; it directly affects the safe operation of the vehicle and its users. A fundamental component, which requires notable attention, is the friction material, which is designed to establish a compromise between mechanical properties, friction coefficient, noise propensity, deformation, wear, among others. However, braking capacity is a combined response for several of these friction material properties, along with the performance of other brake system components, such as the brake chamber, disc and caliper. This work aims to analyze firstly the influence of the friction material deformation and secondly the brake system deformation on the total stroke of the brake chamber. To the first one, three different formulations of friction material, applied to commercial vehicles, were selected. For these materials, compressibility measurements were performed, according to ISO 6310, and also subjected to static test for measuring the total stroke of the brake chamber, in an inertial dynamometer. The static test performed consists of a pressure ramp application on the brake pad with the measurement of the total chamber stroke for each of the pressures. To the second one, static test was performed using steel pads (copying the brake pad shape), with thickness simulating new and end-of-life pads. The friction material and the brake system showed a significant pressure sensitivity, with a small contribution at low pressures, increasing its contribution with pressure increase. More than it, this work allowed to understand that the formulation, pad compressibility, material thickness, brake system stiffness, temperature and chamfered pads show a significant influence on the performance, fuel consumption and reduction of pollutants), there are also improvements to be made on braking performance and reduction of early wear. These improvements must also be applied to commercial vehicles such as trucks and buses, where the brake system is subjected to heavy loads and long routes. For this type of vehicle is very important to obtain maximum brake pad durability, in order to reach customer satisfaction. For commercial vehicles, the use of disc brakes has been increasing gradually, once it is already widely applied in Europe and there is a gradual growth in North American and Asian markets. Brazil tends to follow the same path as Europe, only slower, due to drum brakes costs, which are much lower than disc brake costs. Disc brake system has greater advantages compared to the drum brake system, such as: higher braking efficiency, even on higher application temperatures; greater dissipative energy capacity during braking and, finally, greater comfort during brake pedal actuation [2]. Pedal force and displacement are important factors for the driver to modulate, regarding safety and braking efficiency. It shows that soft pedal feeling is not only unsafe due to lack of vehicle control and accidental brake lock, but can also generate longer stopping distances [3]. Technically, the term known as Pedal Sensitivity means the relationship between the force applied to the pedal, the pedal travel and the deceleration achieved by the vehicle. Normally, the vehicle's brake capacity is evaluated on a field test, considering different conditions of deceleration, force and chamber stroke.
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