What is the difference between electronic handbrake and electronic parking?

Ten years ago, I remember when Xiao Bian was learning to drive, the coach was a pickup or pickup. It seemed that the radio on the center console was electronic except for the mechanical structure. The coach's teaching is: a step (clutch), two hung (block), three dozen steering (lights), four horn, five loose hand brake, six step on the throttle, the car started ... ... that was the most difficult to grasp Beginning of the ramp, how can we master the timing of loose handbrake, pine early fire, loose late car forward, there is no old driver that kind of steady dangdang feeling. If you see the word “ABS” in the rear of the car, it will be attributed to the “high-end car”.

Today, with the development and maturity of automotive technology, ABS has become the standard, and even the mechanical hand brake has been replaced by a small button in many cars, and named as Electronic Handbrake (EPB). And many times, you don't even have to worry about starting the ramp down, because you have an AUTO HOLD, also called an auto park, and these two features are the most used for our daily car use. What are the specific principles of the two functions? What are the advantages?

First of all, the Electronic Handbrake (EPB), as the name suggests, its biggest bright spot is on the word “electronics”, and its function is exactly the same as the mechanical handbrake. But to operate it, you no longer have to use your arms, sleeves, teeth, or mechanical handles, but you can easily handle them by gently lifting the buttons.

So, how does this electronic handbrake work? There are now two types of electronic handbrake. One of the electronic hand brakes is to control a motor to drive the reel through a switch, and the rear wheel is locked by tightening the pull wire. This is basically the same as the principle of the traditional mechanical handbrake, except that the mechanical handle is replaced by an electronic button, and the rear wheel is suitable for both caliper parking and drum parking. It is also easy to arrange, but the disadvantage is that the function is too single. Basically eliminated or applied on some low-end models.

There is also an electronic hand brake that uses an integrated caliper, that is, the motor is integrated directly on the brake caliper, and no zip-lock mechanism is used. The hydraulic brake is used in the normal driving brake, and the motor brake is used in the parking brake. In principle, this form requires an electronic circuit to intervene in the rear brake system. The structure is relatively complex but it is very easy to use.

The integrated caliper consists of four parts, namely, a DC motor, a deceleration mechanism, a screw nut mechanism, and a disc brake. When parking brake, the motor starts after receiving the signal from the ECU, the output torque, the torque reaches the deceleration mechanism and deceleration. After the moment is increased, it is transmitted to the screw nut mechanism to push the brake piston against the brake disk to complete the parking brake effect.

Let me talk about the electronic parking (AUTO HOLD), in many cases, the electronic hand brake button and the electronic parking button or "neighbors", its role is to go on a stop and stop the road to temporary parking. For example, if you stop at a red light in front of you, and you release the brake pedal, the automatic parking system will start quietly and lock the wheels. When you press the accelerator pedal again, the electronic parking will automatically unlock the wheels. It is much faster than pressing the electronic handbrake.

In addition to ease of use, E-parking can also prevent slipping, as the E-parking function is developed through the ESP module. During the parking process, the ECU determines the levelness of the car body through sensors installed in the car. And the torque needed for the wheel brakes, thus making a decision on whether it is necessary to take a brake to prevent the car from slipping. Moreover, the braking force exerted by the electric parking horse wheel will not be so great that it will just stop the wheel from moving so that the vehicle will not squat forward when the accelerator is stepped on again. However, after the vehicle parks for more than a certain time limit, the electronic parking will open the electronic handbrake, and when the vehicle goes forward again, the electronic system will judge whether to release the brake according to the accelerator pedaling force and the stroke of the manual transmission type clutch pedal.

At present, these two functions are basically on the high-end models. The benefits to the user are not only convenient and quick, but also the two "behavior", but also in extreme cases, such as brake pedal fracture, the driver lost consciousness, etc., once the electronic hand brake is pulled up, the ESP control unit at high speed A hydraulic brake will be applied to all four wheels with a force that is slightly less than the full force of the brakes, thus providing an effect of emergency braking, stopping the brakes in critical situations. Some people may ask, ordinary mechanical hand brake is not also able to brake the car? In fact, under the condition of medium and high speeds, the braking force provided by ordinary mechanical handbrake is far from enough, and it is only braking on the rear wheels, and the vehicles are easily out of control.

From this point of view, these two small buttons are indeed very simple, not only convenient, but also a layer of functions, such electronic systems, the more naturally the better in the car.