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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.

Lift axle is essentially provided in commercial vehicles to increase the vehicle’s load-carrying capacity. The axle is lowered in the case of a high payload and the load is evenly distributed among the wheels both on fixed axles and the lift axle. This ability to lift the axle implies better maneuverability in turns, better fuel consumption, and less wear and tear on the tires and brake shoes. Also, it will reduce the damage to the road surfaces. This lowering and lifting of the lift axle are controlled by a series of valves together called the Lift Axle Control System (LACS). This LACS must consider the vehicle load condition, the ignition state, and gear state to decide if the axle must be lifted or lowered. This paper deals with the modeling and simulation of the LACS system at the vehicle level and optimize the design for the respective desired design solution.

In recent days the usage of Electro - Hydraulic Control Unit (EHCU) is increased acutely in light passenger vehicle applications apart from the passenger cars. The main advantage of using electro - Hydraulic control unit (EHCU) is operational flexibility, consistent performance customization, increase durability and lower running cost. During running, the mechanical load is converted into the electronic signal by using transmitter. The electronic devices are highly responsive when compared with mechanical devices, so, it is necessary to reduce the Noise, Vibration and Harshness (NVH) in the system. As per the recent trend, the NVH pollution should be as low as possible in the vehicle. It is necessary to maintain the NVH in minimum level in the electronic device to meet the overall performance of the system. The vibrational isolator is one of the key components used in Electro – Hydraulic Control Unit to reduce the noise and vibration implication of the system.

Generally the brake system products are mounted on chassis with brackets which are subjected to dynamic loads due to road undulations. Exhaust brake is used to restrict the engine exhaust flow passage and thereby creates a back pressure in the engine for reducing the engine speed. This in turn reduces the vehicle speed. This is widely used in the vehicles operating in the hilly areas. This product is mounted on the exhaust passage and the air cylinder sub-assembly which actuates the exhaust brake is mounted on a bracket. Automotive industries perform durability tests on vehicles to reduce the failure on end-user environment. An assembly which has cleared the durability test got failed on addition of a spring into the assembly. The inclusion of spring is for enhancing the performance of the overall assembly.