What is the working principle of an exhaust brake?
2 Answers
The principle of exhaust braking is to transform the engine, originally a power output device, into an air compressor that becomes a power-consuming device. Application areas of exhaust braking: Exhaust braking is widely used in large diesel vehicles. It involves installing a regulating valve on the engine exhaust pipe. The closing of this valve increases the pressure during the exhaust stroke, utilizing the generated negative pressure to obtain braking force. The regulating valve is generally controlled by compressed air or vacuum, driven by a mechanism, and in most cases, it shares the same power source as the main brake. Precautions for using exhaust braking: Engine braking cannot replace service braking for emergency braking, nor can it be used for parking braking. Engine braking can be used simultaneously with service braking. The throttle pedal should be at the zero position.
The exhaust brake is something I find quite handy, especially when driving diesel vehicles. The principle is simple: there's an exhaust valve in the vehicle. When you turn on the exhaust brake switch, this valve closes, blocking the exhaust. As a result, the engine's exhaust gases can't escape, backpressure increases, and the engine has to work harder to rotate, effectively turning into an air compressor that absorbs energy, which slows the vehicle down. There are many benefits, such as on long downhill slopes, where you don't have to worry about frequent braking causing the brake pads to overheat. The exhaust brake helps control speed, extending the lifespan of the brake pads. Of course, it's not a replacement for the main brakes but rather an auxiliary tool—just press a button to activate it, making operation simple and safe, especially suitable for trucks or large vehicles to avoid loss of control. Overall, it makes driving easier and more energy-efficient, with lower maintenance costs. Just check the valve condition during regular car washes.
