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This paper presents a systematic procedure for design and evaluation of snap fit for Quadruple System Protection Valve (QSPV) piston assembly. The QSPV piston is assembled with housing by means of snap joint. Snap joints are a very simple, economical and rapid way of joining two different components. All types of snap joints have in common the principle that a protruding part of one component, e.g., a hook, stud or bead is deflected briefly during the joining operation and catches in a depression (undercut) in the mating component. After the joining operation, the snap-fit features should return to a stress-free condition. The joint may be separable or inseparable depending on the shape of the undercut; the force required to separate the components varies greatly according to the design. It is particularly important to bear the following factors in mind when designing snap joints: Mechanical load during the assembly operation and force required for assembly.

Braking system components generally are safety critical products. Commercial vehicles braking systems are of highly safety critical as they pose a serious threat to life and property. Therefore, a system must be designed and validated to minimize the effects of component failure of these portfolios of products. In order to avoid accidents due to brake failures, this paper mainly focuses on analysis of loss of pneumatic fluid pressure in the components of the braking systems. Leakage of pneumatic fluid pressure through the sealing in braking system is one of the major reasons for the failure of the brakes in the vehicles. The aim of the present study is to simulate the lab failure and improve the design using finite element analysis. Also, the optimized design is validated by experimentally. A finite element model is developed in Ansys Workbench to study the behavior of the sealing ring under assembly conditions.

Air Supply Unit (ASU) serves as the pneumatic source for the air suspension system in the passenger car segment. The ASU is an electrically driven oil-free compressor with integrated air dryer to deliver dry air to the suspension system. Solenoid valve, Height Sensor and ECU adjusts the pressure in bellow based on the vehicle load condition. During the lab test, pressure was not building up in the compressor due to delivery valve failure. The type of valve in asu is reed valve type, it is mostly used in the micro compressors due to its low cost, simple structure and light weight configuration. The reed movement is based on the pressure difference between the inlet and the compression chamber. Failure analysis is carried out based on the finite element analysis to identify the root cause, the root cause identified is optimized to prevent the failure.

Reliable sealing solutions are extremely important in commercial vehicle industry because sealing failures can cause vehicle breakdown, damage of equipment or even accident, incurring expenses that are substantially higher than the costs of just replacing the damaged seals. Consequently, new seal designs must be experimentally verified and validated before they can be implemented. In this study, Mooney - Rivlin hyper elastic material model is used to simulate the sealing behavior during dynamic conditions. The seal under study is a large diameter lip seal made of Neoprene® rubber (NBR) A finite element model to study the response of the seal under dynamic conditions was developed. The analysis took into account the mating parts dimensions and the lip seal parameters. Three designs were proposed and verified. The seal design is optimized using non-linear FEA and validated. Results include contact pressure, deflection and strain experienced by the seal during actuation.

Pneumatic valves are widely used in heavy commercial vehicles’ air braking systems. These valves are mainly used in the braking system layout to maintain the vehicle stability during dynamic conditions. Rubber components are inevitable in valves as a sealing element, and it is very difficult to predict the behavior due to its nonlinear nature. Basically, this valve efficiency is defined in terms of performance and response characteristics. These characteristics are determined in the concept stage itself using 1D simulation software. AMESim software has a variety of elements to use in a unique way for performance and response behavior prediction. For pneumatic valves, 1D analysis is an effective method and it gives good correlation with actual test results. During the modelling of pneumatic valves, some of the contacts between rubber and metals are controlled by various parameters such as damping, contact stiffness and desired phase angle.