Introduction to Automotive Engineering

Chapter 5Braking System

5.1 Introduction

The continual adjustment of speed in response to the road condition and traffic density ensures the safety of the driver in a ground transport. This requirement can be effectively met by the braking system, the effective design of which completely ensures the vehicle safety and its reliability. An effective braking system should assure a smooth stop within the shortest possible distance in an emergency situation. Also, the braking should enable the driver to operate the vehicle safely in hilly and muddy terrains without any discomfort to the passengers. For example, a statistical report published points out that braking problems have been observed in approximately 31.4% of the heavy trucks involved in fatal accidents in the state of Michigan [2]. Based on these requirements and operating conditions, braking systems are commonly classified as service brakes, emergency brakes and parking brakes. The various elements of a brake system are incorporated such that they perform all the aforesaid functions effectively. The braking action can be obtained commonly by following modes (i) By mounting brakes on the respective wheels (ii) By employing brakes on the transmission lines. The former are called foundation brakes whereas the latter are termed retarders. Retarders provide higher braking force on wheels whereas they can only provide minimal braking torque at low speeds, due to which they are used in addition to the foundation brakes. This ...