EPB - electric parking brake, electromechanical parking brake

The parking brake system, which fixes the car in place at the moment of parking, automatically or at the request of the user (driver), the mode of operation can be coded. A system that prevents the car from rolling back in any direction.

 

The device and principle of operation of the electromechanical parking brake (EPB)

• EPB functions
• EPB device
• The working principle of EPB
• Advantages and disadvantages of EPB compared to parking brake
• Features of maintenance and operation of cars with EPB.

 

 

EPB functions

The main functions of EPB include:

• keeping the vehicle in place when parking;
• emergency braking when the working braking system fails;
• preventing the car from rolling back when starting uphill.

 

 

EPB device

What is an Electromechanical Parking Brake (EPB) and how does it work? The principle of operation and why it is needed. Electromechanical parking brake (EPB) - a parking brake system that fixes the car in place at the moment of parking, preventing the latter from rolling back in any direction. An electromechanical type handle is installed on the rear wheels of the car.

The electromechanical handbrake is usually combined with the rear brakes of the car.

One of the EPB options is integration into the rear brake calipers. For example, Volkswagen, Audi, Škoda.

Structurally, it consists of the following elements:

Or mounted by a separate mechanism and connected to the parking brake by cables, Mercedes-Benz, BMW, Peugeot, Citroën.

 

• brake mechanism;
• occasion;
• electronic control system.
• the braking mechanism is represented by standard disc brakes of the car. Design changes affected only the working cylinders. The parking brake drive is installed on the caliper of the brake mechanism.

 

The electric handbrake actuator consists of the following parts located in one body:

• electric motor;
• belting;
• planetary gearbox;
• screw drive.

The electric motor drives the planetary gearbox with the help of a belt transmission. The latter, reducing the noise level and mass of the drive, affects the movement of the screw drive. The drive, in turn, is responsible for the translational movement of the piston of the brake mechanism.

The electronic control unit consists of:

• input sensors;
• control unit;
• executive mechanisms.

Input signals enter the control unit from at least three elements: from the handbrake activation button (located on the central console of the car), from the slope sensor (integrated into the control unit itself) and from the clutch pedal sensor (located on the clutch drive), which fixes the position and speed of releasing the clutch pedal.

The control unit affects the executive devices (such as the drive motor, for example) through sensor signals. Thus, the control unit directly interacts with the engine control and course stability systems.

 

 

The working principle of EPB

The principle of operation of the electromechanical parking brake is cyclic: it turns on and off.

 

EPB is activated using a button on the central tunnel in the car interior. The electric motor, with the help of a gearbox and a screw drive, pulls the brake pads to the brake disc. At the same time, the latter is rigidly fixed.

And the parking brake turns off when the car starts. This action happens automatically. Also, the electronic handbrake can be turned off by pressing the button while the brake pedal is already depressed.

In the process of turning off the EPB, the control unit analyzes such parameters as: the amount of slope, the position of the gas pedal, the position and speed of releasing the clutch pedal. Thanks to this, it becomes possible to turn off EPB in a timely manner, including shutdown with a time delay. This prevents the vehicle from rolling back when starting uphill.

 

Most cars equipped with EPB have an Auto Hold button next to the handbrake button. This is very convenient for cars with automatic transmission. This function is especially relevant in city traffic jams with frequent stops and starts. When the driver presses the "Auto Hold" button, there is no need to hold the brake pedal after stopping the car.

EPB turns on automatically if the position is stationary for a long time. The electric parking brake will also turn on automatically if the driver turns off the ignition, opens the door or unbuckles the seat belt.

 

 

 

Advantages and disadvantages of EPB compared to parking brake

For clarity, we will present the pros and cons of EPB compared to the classic towel in the form of a table:

 

ADVANTAGES OF EPB	DISADVANTAGES OF EPB
1. A compact button instead of a bulky lever	1. The mechanical parking brake allows you to adjust the braking force, which is not available for EPB
2. There is no need to adjust the EPB during operation	2. When the battery is completely discharged, it is impossible to "remove from the handle"
3. Automatic shutdown of EPB when starting the car	3. Higher cost
4. Absence of rollback of the car on the rise

 

 

 

Features of maintenance and operation of cars with EPB

To check EPB functionality, the car must be placed on a brake stand and braked with the parking brake. At the same time, the inspection must be carried out regularly.

Replacement of brake pads is carried out only when the parking brake is released. The replacement process takes place with the help of diagnostic equipment. The blocks are automatically set to the desired position fixed in the memory of the control unit.

Do not leave the car on the parking brake for a long time. When parked for a long time, the battery may discharge, as a result of which it will be impossible to remove the car from the handbrake.

Before carrying out technical work, it is necessary to put the car's electronics into service mode. Otherwise, the electric handbrake may turn on automatically when the vehicle is being serviced or repaired. This, in turn, can lead to damage to the car.

 

 

Editor's note:

The electromechanical parking brake frees the driver from the problem called "forgetting to remove the car from the handbrake". Thanks to EPB, this process happens automatically when you start driving. In addition, it facilitates the start of the car uphill and significantly simplifies the life of drivers in traffic jams.