Why do big cars usually use air brakes instead of disc brakes?

1. The reaction speed of the air brake is relatively fast. Compared with the liquid, the circulation speed of the gas is faster, so there is no need to pump the oil to the brake, and the gas used is compressed air. , It’s just fine to discharge it directly into the air after use. There is no need to design a circuit like an oil brake, but also to recycle hydraulic oil. Generally speaking, it saves money and troubles, and also because it can exhaust
2. The braking force of the air brake is greater, because the air used by the air brake is compressed into the air tank and stored in advance, often up to 8 or 9 atmospheres. As long as the vent valve is opened, the air will be carried. These high-pressure energy quickly rushed to the brake chamber, and oil brakes are slightly inferior in these aspects.
3. The applicability of the gas brake is strong. If it is an ordinary truck, the oil sand is also oil sand. If it is a semi-trailer, the shortcomings of the oil sand can be fully exposed. The oil used in the oil brake is usually metal It is transported by pipeline, and the gas pipeline of the air brake can use a hose, so that when the semi-trailer only has the front of the vehicle, it is convenient to clean up and does not take up space, and there is no embarrassment of overturning when connected to the trailer.