TECHNICAL SEMINAR ONDISK BRAKE SYSTEM

By Kashyap prakash .B

Introduction

Most modern cars have disc brakes on the front wheels, and some have disc brakes on all four wheels.

This is the part of the brake system that does the actual work of stopping the car.

The most common type of disc brake on modern cars is the single-piston floating caliper.

Types of disc breaks Mechanical disc brakes work on the same principle as rim brake, The pads bear on the wheel rim. They require relatively

frequent adjustment to keep them working effectively.

Hydraulic disc brakes Single-piston floating caliper. systems are the most basic, with only one ‘active’

brake pad and one static Dual-piston floating caliper. systems equalize the braking forces on both sides

of the rotor and are generally much more effective

The main components of a disc brake are:

1. The brake pads ,

2. The caliper,

3. The rotor, which is mounted

to the hub.

Primary System

Rear Axle

Secondary System

Front Axle

Front/rear Hydraulic Split

How a disc break works

Bicycle brakes have a caliper, which squeezes the brake pads against the wheel and in turn the brake pads squeeze the rotor and the force is transmitted hydraulically, Friction between the pads and the disc slows the disc down.

A moving car has a certain amount of kinetic energy, and the brakes have to remove this energy from the car in order to stop it.

How do the brakes do this? Each time you stop your car, your brakes convert the kinetic energy to heat energy by the friction between the pads and the disc. Most of the rotors of disc brakes are vented , because to remove the heat from the disc

TEMPERATURE VARIATION A quick stop from 60 mph can easily

push the rotor temperature up 150 or more degrees.

Several hard stops in quick succession can push brake temperatures into the 600, 700 or even 800 degree range.

Remember, the heavier the vehicle, the more heat it creates when it brakes.

BRAKE FADE When brake temperatures get too high, the

pads and rotors lose their ability to create any additional friction.

As the driver presses harder and harder on the brake pedal, he feels less and less response from his overheated brakes

How to over come brake Semi-metallic linings can usually take more

heat than nonasbestos organic Vented rotors can dissipate heat more rapidly

than nonvented solid rotors. But if the brakes get hot enough, even the best ones will fade.

Emergency Brakes•In cars with disc brakes on all four wheels, an emergency brake has to be actuated by a separate mechanism than the primary brakes in case of a total primary brake failure. Most cars use a cable to actuate the emergency brake.

Some cars with four-wheel disc brakes have a separate drum brake integrated into the hub of the rear wheels. This drum brake is only for the emergency brake system, and it is actuated only by the cable; it has no hydraulics. Other cars have a lever that turns a screw, or actuates a cam, which presses the piston of the disc brake.

Servicing Your Brakes The most common type of service required for brakes is changing the pads. Disc brake pads usually have a piece of metal on them called a wear indicator. When enough of the friction material is worn away, the wear indicator will contact the disc and make a squealing sound. This means it is time for new brake pads. There is also an inspection opening in the caliper so you can see how much friction material is left on your brake pads.

Sometimes, deep scores get worn into brake rotors. This can happen if a worn-out brake pad is left on the car for too long. Brake rotors can also warp; that is, lose their flatness. If this happens, the brakes may shudder or vibrate when you stop. Both of these problems can sometimes be fixed by refinishing (also called turning or machining) the rotors. Some material is removed from both sides of the rotors to restore the flat, smooth surface.

. You need it only if they are warped or badly scored. In fact, refinishing the rotors more often than is necessary will reduce their life.. All brake rotors have a specification for the minimum allowable thickness before they need to be replaced.

What is the difference between disc brakes and drum brakes?

First, they dissipate heat better (brakes work by converting motion energy to heat energy).

Under severe usage, such as repeated hard stops or riding the brakes down a long incline, disc brakes take longer to lose effectiveness (a condition known as brake fade).

Disc brakes also perform better in wet weather, because centrifugal force tends to fling water off the brake disc and keep it dry, whereas drum brakes will collect some water on the inside surface where the brake shoes contact the drums.

Assembly Section View

Exploded View

Kinetic energy Vs Speed

Kinetic Energy as a Function of Speed and Mass

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290 kg