Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
DYNAMIC LOADS ANALYSIS FOR SPRING BRAKE PADS APPLIED ON COMMERCIAL VEHICLES
Submission Author:
Juliana Favero , RS
Co-Authors:
Juliana Favero, Diego Antunes, Luciano Rodrigues Maia
Presenter: Luciano Rodrigues Maia
doi://10.26678/ABCM.COBEM2021.COB2021-0516
Abstract
The proper acting of a brake system depends on different components and accessories despite of the brake pads and caliper. Most of these accessories are metallic and contribute to the application, installation and assembling, therefore they need to be correctly designed trough specifics tests and measurements. During the vehicle’s application, the various conditions and imperfections of the roads generate different dynamic loads, mainly accelerations, that are transmitted directly to the brake system, which has no suspension attenuation. Vibrations affect directly brake pads, which can be associated as an inertial mass inside the caliper, been free to move undesirable. Thus, high importance components on the brake pads field application are the brake springs – defined as elastic elements responsible for the elastic energy storage –. Springs applied on commercial vehicles equipped with disc brakes are usually installed on the top of the backing plates. In order to keep the springs under compression during field application, the pad retainer compresses them against to caliper housing. The various functions of this type of component are: compensating system's clearance; decreasing vibration when going through obstacles; and avoiding misalignments during movement of the brake actuation. The present study aims to understand the dynamic loads to which the springs are exposed in field applications, allowing to perform the correct design of bench tests used for their evaluation, as well as to create specifications of minimum mechanical properties requirements for this component, thus reducing the time cycle for developing a new brake pad. Results of an instrumented route of urban bus are shown, where vehicle data was acquired, as: axle acceleration, pad temperatures, brake pressure, among others, and also spring data was acquired: temperature and extensometry. All this data from field was correlated with data from bench tests, in order to define the levels of force to which the spring is exposed during application. It was possible to correlate the spring clamp force with the inertial brake pads force, when peaks of acceleration occurred due to road imperfections. Also, the application of urban bus evaluated, did not show to be a critical route in terms of spring temperature, brake pressure and spring acceleration.
Keywords
spring brake pad, commercial vehicle, dynamic loads, road mapping
