The car engine is working, how to brake?

As can be seen from your question, you want to know why the car won't stall when I step on the brakes when the engine is working. In fact, I had doubts about this when I first learned to drive. We know that the engine will stall if you step on the brakes too hard or too hard, but automatic cars will not have this problem. The automatic car allows us to stop the car with one foot and the car will not stall. So how does the engine brake when it is working?

As we know, the engine provides power for the car to move forward or backward, while the brake provides resistance. When we hit the brakes, the brakes will stop the car and slow down. Nowadays, hydraulic disc brakes are widely used in family cars, commonly known as disc brakes. It mainly pushes the hydraulic oil and the brake piston by stepping on the brake pedal, and the brake piston pushes the brake pad to clamp the brake disc, thus generating braking force. Of course, I have omitted the detailed braking process here, and a series of braking actions are probably this principle.

When the engine of our vehicle is running, we step on the brakes at this time. We know that the engine provides forward force and the brake provides backward force. If the power transmission route between the engine and the wheels is hard connected, the engine and the brakes will start to compete, either the brakes are damaged or the engine will stall. The current vehicle setting is that the engine will be turned off. Of course, this is for cars with manual transmission, so in order not to turn off the engine, we are required to step on the clutch and disconnect the power transmission route between the engine and the wheels when braking suddenly.

For an automatic car, this problem does not exist, because if it is an AT gearbox with a torque converter as a buffer, the engine will not stall. If it is a dual clutch gearbox, the gearbox controller will automatically downshift, or even directly disconnect the clutch to cut off the power transmission of the engine. The principle is the same as driving a manual gear and stepping on the clutch, except that the clutch is controlled by computer.

In short, whether it is a manual transmission, a dual-clutch automatic gearbox, an AT automatic gearbox or a continuously variable gearbox, the braking principle is the same, and the difference lies in the control principle of the gearbox.