Working brake. The device and the principle of operation of the vehicle brake system. So how does a hydraulic braking system work?

The brake system of a car (English - brake system) refers to active safety systems and is designed to change the speed of the car until it stops completely, including emergency, as well as to keep the car in place for a long period of time. To implement the listed functions, the following types of braking systems are used: working (or main), spare, parking, auxiliary and anti-lock braking (exchange rate stability system). The collection of all braking systems in a vehicle is called brake control.

Working (main) brake system

The main purpose of the service brake system is to regulate the speed of the vehicle until it comes to a complete stop.

The main braking system consists of a brake actuator and brakes. In passenger cars, a predominantly hydraulic drive is used.

Car brake system diagram

The hydraulic drive consists of:

• (in the absence of ABS);
• (in the presence of);
• working brake cylinders;
• working contours.

The brake master cylinder converts the force supplied by the driver to the brake pedal into the pressure of the working fluid in the system and distributes it to the working circuits.

To increase the force that creates pressure in the braking system, the hydraulic drive is equipped with a vacuum booster.

The pressure regulator is designed to reduce the pressure in the drive of the rear wheel brakes, which contributes to more effective braking.

Types of brake circuits

The brake system circuits, which are a system of closed pipelines, connect the master brake cylinder and the wheel brakes.

The contours can duplicate each other or perform only their functions. The most in demand is a two-circuit brake drive circuit, in which a pair of circuits operate diagonally.

Spare brake system

The spare brake system is used for emergency or emergency braking in case of failure or malfunction of the main one. It performs the same functions as a service braking system and can function both as part of a service system and as an independent unit.

Parking brake system

The main functions and purpose are:

• keeping the vehicle in place for a long time;
• elimination of spontaneous movement of the car on a slope;
• emergency and emergency braking in case of failure of the service brake system.

Vehicle brake system

Brake system

The brake system is based on brakes and their drives.

The braking mechanism is used to create the braking torque required to brake and stop the vehicle. The mechanism is mounted on the wheel hub, and its principle of operation is based on the use of frictional force. Brakes can be disc or drum.

Structurally, the brake mechanism consists of a static and rotating parts. The static part of the drum mechanism is the brake drum, and the rotating part is the brake pads with linings. In the disc mechanism, the rotating part is represented by a brake disc, while the stationary part is represented by a caliper with brake pads.

The drive controls the braking mechanisms.

The hydraulic drive is not the only one used in the braking system. So in the parking brake system, a mechanical drive is used, which is a combination of rods, levers and cables. The device connects the rear wheel brakes to the parking brake lever. There is also an electromechanical parking brake that uses an electric drive.

A variety of electronic systems can be included in the brake system with a hydraulic drive: anti-lock braking system, directional stability system, emergency braking amplifier,.

There are other types of brake drives: pneumatic, electric and combined. The latter can be represented as pneumohydraulic or hydropneumatic.

How the brake system works

The braking system works as follows:

1. When the brake pedal is depressed, the driver generates a force that is transmitted to the vacuum booster.
2. Then it increases in the vacuum booster and is transmitted to the brake master cylinder.
3. The GTZ piston pumps the working fluid to the wheel cylinders through the pipelines, due to which the pressure in the brake drive increases, and the pistons of the working cylinders move the brake pads to the discs.
4. Further pressing the pedal further increases the fluid pressure, due to which the brakes are activated, leading to a slowdown in the rotation of the wheels. The working fluid pressure can approach 10-15 MPa. The larger it is, the more effective the braking is.
5. Lowering the brake pedal causes it to return to its original position under the action of the return spring. The GTZ piston also returns to the neutral position. The working fluid also moves to the brake master cylinder. The pads release discs or drums. System pressure drops.

Important! The working fluid in the system must be changed periodically. How much brake fluid does one change need? Not more than a liter and a half.

The main malfunctions of the brake system

The table below lists the most common vehicle brake system malfunctions and how to fix them.

Symptoms	Probable cause	Elimination options
A whistling or noise is heard when braking	Wear of brake pads, their poor quality or defects; deformation of the brake disc or the ingress of a foreign object on it	Replacing or cleaning pads and discs
Increased pedal travel	Leakage of working fluid from wheel cylinders; air entering the brake system; wear or damage to rubber hoses and gaskets in the GTZ	Replacement of defective parts; bleeding the brake system
Increased pedal effort when braking	Failure of the vacuum amplifier; damaged hoses	Replacing the amplifier or hose
Braking of all wheels	Piston jamming in the GTZ; lack of pedal free play	Replacement of the GTZ; setting the correct freewheel

Conclusion

The braking system is the basis for safe driving. Therefore, close attention should always be paid to it. In the event of a malfunction of the service brake system, the operation of the vehicle is prohibited completely.

A car. You will also learn how to bleed the system correctly. Anti-lock braking designs will be considered. At the moment, no one can do without them quality car... We are talking, of course, about cars of the middle price category and above. Budget cars can be completed with this design, but it goes as additional option... In general, the braking systems of all cars are the same, they consist of identical elements.

A little theory about the brake system

As you can imagine, it is necessary in order to change the speed of the car. This can be signaled by either the driver's action or the electronic control system. It is also necessary to keep the car stationary while parked.

There are three types of braking systems. The first is, of course, the worker. It is necessary for the normal operation of the machine. With its help, braking is carried out at high or low speeds. The features of the "Niva-2121" brake system, the scheme of which is classic, will be discussed below.

The second type is parking. It is better known as a handbrake if you need to put the car on for a long time. In particular, if there is a slope in the road surface, this system is a must. The handbrake can be used during an emergency stop. And there are also systems of a spare type. They have recently begun to be used on cars. Most often they can be found on those cars that have an electric handbrake. Its main purpose is to enable the driver to stop the car if the working system fails. It is mounted on cars with an electric hand brake for one reason: the parking brake cannot be released if the vehicle speed is greater than zero.

Functioning principle

We are used to the fact that when you press the brake pedal, the car starts to slow down. But not everyone goes into the details of what processes take place at the same time. Not everyone knows how the VAZ-2109 brake system works, the diagram of which is given in this article. To put it simply, the car stops only due to the compression of the liquid in the pipes and hoses. The pressure is generated by the brake master cylinder, which is the main component of the system.

Everyone is used to seeing hydraulic brakes, but there are designs that use compressed air rather than fluid pressure. They are identical with hydraulic ones, only their reliability is much higher. Elements used in pneumatic brakesmust withstand very high pressure. True, it is comparable to that in the hydraulic drive. It is only necessary to introduce a compressed air receiver. There are also electromechanical brakes. They are driven by electric motors and special cables.

The braking system is one of the main mechanisms of the car's functioning. It is designed to stop the vehicle and reduce its speed. Also, it allows you to leave vehicle in a safe state of rest, do not allow it to spontaneously move during non-working hours.

The braking system consists of many mechanical elements that fulfill their specific function and role in the successful operation of the entire system. The working brake cylinder is one of the most important elements of the entire brake system.

In this way, working brake cylinder is a unique mechanism in the brake system that converts fluid pressure into a certain mechanical force, which, in turn, acts on the brake pads. It differs from the main brake cylinder in that it acts directly on the drum-type brake pads. In addition to the above definition, a slave cylinder is a brake piston that acts on disc type brake pads.

The service braking system, of which the slave cylinder is a direct part, is always used at any vehicle speed to slow down or stop the vehicle. The service brake system is activated by pressing the brake pedal by the driver. It is the most efficient of all types of braking systems.

1. The working brake cylinder - role in the brake system.

At the moment of braking, the driver directly acts on the brake pedal. This pressure, in turn, is transmitted by a special rod to the piston of the master cylinder. This piston itself acts on the brake fluid, as a result of which, it activates the working cylinders. At the same time, special pistons are extended from the working cylinders, which press the brake pads already against the discs or drums. Disc pads or drum pads at the brake system - it depends directly on the type of this brake system.

Any deficiency in the braking system can significantly reduce the effectiveness of the braking process. This, in turn, leads to undesirable consequences for all vehicles and drivers taking part in the movement. There is one element that, in most cases, becomes the cause of the malfunction of the working cylinder and, as a result, the complete or partial cessation of the entire brake system. This element is brake fluid. In addition, low quality and cheap parts can cause many different problems. Find out that the car needs repair of the working brake cylinder, up to its total replacement, may indicate the following signs:

1. When the car brakes, its subsequent movement will not be straightforward;

2. Reducing the level of brake fluid in the reservoir. To find out about this flaw, a special indicator, which is located on the instrument panel in the car, can help;

3. If you need to increase your effort to press the brake pedal if necessary, stop.

There are problems that are associated with parts that directly work together with the working cylinder. If the car "skids" when braking, and its movement is not straightforward, then the problem is the piston sticking. This breakdown occurs for several reasons: low-quality fluid, worn-out part or its breakage.

2. The design of the working brake cylinder.

The working brake cylinder is a piston that extends into a drilled hole in the caliper. The piston itself uses its pressure on the brake pad, due to the brake fluid. Also, for a better seal, a rubber ring is used, which is inserted into a recess located in the wall of the caliper (piston). The piston is most often in the form of a glass and is hollow. It is quite common to have a chrome plated piston to protect it from corrosion. To prevent dust and dirt from entering the working brake cylinder, a boot is used, which is fixed on the piston with one side and on the caliper with the other. The boot is made of heat resistant rubber.

Working cylinders of different diameters are usually used in multi-piston calipers - from 6 and more. This type of brake cylinder extends towards the rear of the caliper / piston. Thus, the back of the pad is pressed down much more strongly. This, in turn, allows for more even and uniform pad wear, as it distributes heat much more efficiently. In addition, when the vehicle is braking, the brake pad will wear off, resulting in the formation of dust. This dust accumulates towards the back of the pad.

3. Types of working brake cylinders.

The working brake cylinder is divided into two types, which, in turn, directly depend on the type of the entire brake system. So, in the automotive nature, the following types of working brake cylinders are distinguished: the first type of working cylinder is a device that acts on drum-type brake shoes, that is, a drum cylinder; the second type of the working brake cylinder is the brake piston, which acts on the brake disc pads, respectively, this type of the working brake cylinder is called the disc type.

The very type of this kind of cylinders is determined entirely by the brake system, disc or drum. Depending on the manufacturer, brand and model of the working brake cylinder, there are many of its varieties, which differ both in their essence and in terms of validity, the type and make of the car and the brake system. This is due to the fact that not all working brake cylinders are suitable for all drum-type and disc brake systems, since the development of automotive technology has brought many innovations and changes in the design and capacity of the brake system, as an integral part of the entire operation of a single automotive mechanism.

In addition to this classification, there is another, different classification, which is more related to cars of a domestic manufacturer. In order to identify and determine which type of working brake cylinder is used, in most cases it will be enough to look in the car's operating instructions, where every detail of the car should be described and indicated in detail.

If there is no such instruction, or it exists, but the model and type of the brake cylinder is not indicated in it, it is necessary to inspect the working brake cylinder with your own hands. Thus, there are such types of working brake cylinders, the main difference of which lies in different inner diameters: single-circuit type of working brake cylinder, double-circuit and three-circuit. So, the diameter of a single-circuit is - 25 mm, double-circuit - 22 mm, and three-circuit - 19 mm. As you can see, the diameter decreases with the addition of one contour by 3 mm.

Thus, the working brake cylinder is one of the main mechanisms for the functioning of the entire brake system of a car. Fulfilling its main task, which is to transform the fluid pressure by the effect on the brake pads, it is a completely original and necessary element of a single link in the functioning of the entire braking system of a car.

Engineers rightly call the braking system of a car the main component of any vehicle. The task of this device is while driving. Having a brake at his disposal, the driver can slow down in time, or stop the car completely. Additional systems actively help when driving and while parking vehicles. If you study purely mechanical components, you will not see anything complicated. It mainly consists of a drive and actuators. This principle applies to all brakes. But modern cars went much further. Manufacturers began to use assistive systems to improve the performance of the brakes.

A variety of modern braking systems.

Kinds

First you need to get acquainted with the types of braking systems that are used on vehicles. Brakes have been in use since the early days of cars. Then the design was extremely simple and primitive. But it was also enough to ensure due to the low maximum speed. But gradually the cars became faster. This forced manufacturers to develop more efficient and sophisticated brakes. If we talk about varieties, then the classification of brake systems for cars provides for several different solutions, depending on:

• destination;
• drive;
• working mechanisms.

Since a number of elements and units are involved in braking, you need to understand how the systems differ from each other.

Appointment

Let's start with the purpose and types of braking systems. Passenger cars provide for the use of the service and parking brakes. The backup and mountain braking systems act as additional devices. Working type passenger cars slows down the movement of vehicles and allows you to stop completely. A special feature is that the intensity of the speed reduction directly depends on how hard the driver presses the corresponding pedal. The name of the parking brake speaks for itself. With its help, the car blocks any possible movement while in the parking lot. The wheels are immobilized, and therefore arbitrary movement that may occur when the vehicle is on a slope is excluded.

Backup or emergency brakes serve as an auxiliary mechanism in case the main unit breaks down. Most passenger cars the emergency emergency brake is largely absent, and instead this role is transferred to the parking system. Mountain brakes are relevant to use in the design trucks... Such a system allows for forced dumping when a freight vehicle is moving down the mountain. This slows down the movement of the car without applying the main service brake. This is a useful solution as it avoids overheating and prevents possible failure of the main system.

Drive unit

Also, brake systems are distinguished depending on what type of drive is used on each of them. The task of the drive is to transfer the force of the working mechanisms, or to perform certain actions with the components of the system responsible for braking. The drive is:

• mechanical;
• hydraulic;
• pneumatic;
• combined.

In mechanical systems, the impact on the working units is carried out using rods, levers and special cables. This drive is practically not used in conventional brakes. But it often turns out to be part of the parking brake. Hydraulic drives are the most common in passenger car construction. The basis of its work is the physical property of a liquid, which consists in its incompressibility. With its help, the effort is quite easily transmitted to the working mechanisms, and therefore the driver does not have to press hard on the pedal.

The pneumatic drive is widely used in the design of trucks. The working fluid here is compressed air, which is forced through the use of a compressor. When the driver presses on the pedal, special channels open. Through them, air goes to the chambers directly connected with the working brakes. The combined drive is relevant for special equipment. A feature of the system is the simultaneous use of different drives. Not installed on passenger cars.

Working mechanisms

The working mechanism is needed in order to exert an impact on the car wheels, slowing down the speed of their rotation. Therefore, these are the main components of the entire system. They are divided into tape, disk and drum. Belt mechanisms are practically not used. The only exception is special equipment. The bottom line is that a drum with a belt is installed on the axle designed to transmit rotations to the wheels. When the driver brakes, the belt is tightened, and due to the frictional force, the speed of rotation of the drum decreases. Disc mechanisms have proven to be the most common among light vehicles. The main element is a disc that is rigidly fixed to the wheel hub.

The drive is directly connected to the caliper on the brake disc. There are friction-type pads here. When the pedal is depressed, the pad is pressed against the disc and the frictional force promotes deceleration. If the system is drum, then the place of the disc is occupied by a drum installed on the hub. Inside the drum there are a pair of pads that are shaped like a crescent moon. They are mounted on the fixed part of the hub. When braking occurs, this wire opens the pads, after which they begin to press against the drum, thereby slowing down the speed of its rotation.

Advantages and disadvantages

Since it makes no sense to talk about tape drives, it is worth discussing the strengths and weaknesses of disc and drum braking systems. The advantages of disk solutions include the following points:

• high level of efficiency;
• light weight;
• compact size;
• low temperature of the hydraulic fluid during operation;
• high reliability rates;
• stability.

At the same time, disc brakes are not well protected from dirt, which can negatively affect the performance of the entire system. As for the drum counterparts, their advantages are:

1. Great effort indicators. This makes it possible to effectively use drums on large cars and trucks, since their mass is impressive, and therefore it is more difficult to stop such vehicles with disc brakes.
2. Long service life. Dirt does not get inside the drive, and therefore the linings wear less intensely.
3. Affordable price. This applies to purchase and service.

But not everything is so perfect with drum brakes. Do not forget about the slow speed of the reaction to pressing the pedal, as well as the likelihood of sticking brake pads. This happens if the car is left in the street with the handbrake on in extreme heat or extreme cold.

Modern cars are equipped with additional equipment that is designed to improve safety and improve the efficiency of the main brakes. Many people know what an anti-lock braking system is and why it is needed. We first learned about it in practice in 1978, when Bosch developed a new product and launched it into production. The ABS braking system is designed to prevent car wheels from locking when the driver suddenly presses the pedal and brakes. This allows the machine to remain stable even in the event of an emergency stop. Plus ABS helps to maintain vehicle controllability. But current trends and increasing speeds have forced manufacturers to come up with new solutions to ensure adequate safety. In addition to ABS, which has already become a standard solution on all machines, several more new systems have been added. Namely:

• Brake Assist;
• Cornering Brake Control;
• Electronic Brake Force Distribution.

All of these auxiliary, but very useful additional braking systems are called BA (BAS or EBS), DBC, CBC and EBD for short.

BA

To increase efficiency, after the introduction of ABS, they began to use additional EBS braking systems. On some cars it is simply called BA or BAS. The essence does not change from the name. The system aims to reduce the time required for the braking system to operate. ABS maximizes braking performance when the brake pedal is fully depressed. But it is not activated when the pedal is pressed lightly. The amplifier works in certain situations and provides emergency braking if the driver presses the pedal sharply, but he fails to apply sufficient force. The system measures how quickly and with what force the pressure is applied. If necessary, the pressure inside the braking system is automatically and instantly increased to maximum values.

To implement such an idea, a speed sensor was installed in the pneumatic amplifiers, which monitors the movement of the rod, and an electromagnetic type of drive. When a signal is received from the sensor about a very fast movement of the rod, that is, the driver must press the pedal sharply, the electromagnet is activated and increases the amount of force acting on the rod. This is what makes it possible to reduce the braking time, sometimes saving the driver's life. Modern EBS systems are able to memorize the behavior of the driver's brakes in normal mode, thereby recognizing emergency braking. The presence of EBS is possible only if ABS is present on the car, since they closely interact with each other.

In short, the EBS is used to press the brake pedal, thereby activating the ABS system. But at the same time, EBS is not able to distribute the forces on different wheels. An improved version of this braking system is under active development, allowing it to work in conjunction with cruise control, automatically recognize obstacles in front and help to shorten the braking distance. Experts from Bosch are confident that the new product will be even more effective than the standard Brake Assist.

DBC

The authors of this braking system are the engineers of the German company BMW. The solution is somewhat similar to the previously considered BA. But the German system helps to accelerate and further increase the pressure build-up in the brake actuator of the car during an emergency stop. Even if the driver applies little effort, the braking distance is reduced to a minimum. The automatic system reads information about the rate of pressure increase and the force applied by the driver. This is how the computer determines if the situation is dangerous. If so, the pressure immediately rises to the maximum, which allows the car to brake faster.

In addition, the control unit reads data on the driving speed and the degree of brake wear. DBC is based on the principle of hydraulic amplification, in contrast to competitors, where the vacuum principle is applied. Practice shows that hydraulics contributes to better and more accurately distributed braking force during emergency and emergency stops of vehicles. The DBC electronics are directly linked to the stability control and ABS.

CBC

This system was also developed by Bavarian specialists from BMW back in 1997. When the car starts to brake, the rear wheels on the car are unloaded. If this braking occurs in a corner, the rear axle may skid as the load on the front increases. CBC is closely related to ABS. They work together to prevent possible rear axle drift when the driver starts to brake at the entrance to a turn. The system optimally distributes the braking forces. As a result, skidding does not occur, even if the driver firmly and sharply presses the brake pedal. The signals from the ABS sensors are transmitted to the CBC. The speed at which the wheels rotate is also determined. This data allows you to adjust the increase in braking force for each of the cylinders. This is done so that the build-up is more intense on the outer front wheel when viewed from the corner. This principle of action prevents drifts. On cars, the system works constantly, but it remains invisible to drivers. Although the benefits of such a solution are enormous.

EBD

Much is said about the EBD brake force distribution system, but not everyone understands exactly what it is. EBD stands for Electronic Brake Force Distribution. From this it already becomes approximately clear what functions and tasks the system performs. In cars, this solution is used in order to redistribute the forces from the brakes between the rear and front wheels. Plus, the brake force distribution system, or simply EBD, helps in competent automatic redirection between the left and right side of the vehicle, based not on the current driving conditions. The EBD is part of the traditional electronically controlled ABS system.

When the car moves in a straight line and starts to brake, the load is redistributed. Namely, the front wheels are loaded, and the rear ones, on the contrary, are unloaded. If the rear brakes have the same amount of force as the front, the likelihood of locking on the rear wheels will increase significantly. Using special speed sensors, the ABS electronic control unit detects the right moment and adjusts the force. In many respects, competent distribution depends on the mass of the transported cargo and how it is located.

The EBD is also useful when braking when entering corners. Then there is an increase in the load on the outer wheels relative to the turn and unloading the inner ones. This guarantees protection against possible blocking. The EBS is guided by the signals from the sensors installed on the wheels, as well as the deceleration or acceleration sensors. This allows the system to determine what conditions need to be created for safe braking. By combining different valves, the pressure of the working fluid is redistributed. As a result, each wheel marks different indicator pressure.

Modern brakes have retained their original operating principle. But new developments have managed to significantly increase their efficiency. Now the car can not just brake. She does this carefully, avoiding wheel blockages, skids and other troubles that may arise if you need to urgently slow down. Many people underestimate the importance of modern braking systems. Although it is they who largely help to feel confident on the roads, enter turns at solid speeds and stop in time in front of an obstacle that jumped out in front. The presence of all brake assistants is gradually becoming a prerequisite for the production and sale of new cars. And this is absolutely the right decision aimed at improving road safety and reducing the number of accidents or road accidents.

It is necessary to quickly change the speed or stop the car completely and keep it in place when parked.

To do this, the car has such types of braking systems as - working, parking, spare and auxiliary systems (retarder).

Service brake system always used at any vehicle speed to stop completely or to slow down. The service brake system begins to operate when the brake pedal is depressed. This system is most effective when compared with other species.

Spare brake system used in case of malfunction of the main system. A spare brake system can be in the form of an autonomous system or its function is performed as part of a serviceable service brake system.

Parking brake system is necessary to keep the car in one place for a certain time. The parking system completely eliminates the movement of the car spontaneously.

Auxiliary braking system used on vehicles with increased weight. The assist system is used for downhill braking. It often happens that on cars the role of an auxiliary system is played by the engine, where the exhaust pipe is blocked by a flap.

The braking system is an important vehicle for active safety. Different systems and devices are used on cars that increase the efficiency of the system during braking - these are anti-lock braking system, emergency braking booster, brake booster.

The braking system includes a brake drive and a braking mechanism.

Brakes hydraulic drive diagram:
1 - pipeline of the "left front-right rear brake" contour; 2-signal device; 3 - pipeline of the "right front - left rear brake" circuit; 4 - a tank of the main cylinder; 5 - the main cylinder of the hydraulic drive of the brakes; 6 - vacuum amplifier; 7 - brake pedal; 8 - rear brake pressure regulator; 9 - parking brake cable; 10 - rear wheel brake; 11 - adjusting tip of the parking brake; 12 - parking brake drive lever; 13 - front wheel braking mechanism.

Brake mechanism blocks the rotation of the wheels and, as a result, the emergence of braking force, which stops the vehicle. The brakes are located on the rear and front wheels.

In theory, it is logical to call all the brake mechanisms shoe. And already in turn, they can be divided by friction - disk and drum. The brakes of the main system are mounted in the wheel, and the parking system is located behind the transfer case or gearbox.

About drum and disc brakes

The braking mechanism usually consists of two parts, one rotating and one stationary. The rotating part of the drum mechanism is the brake drum, and the stationary part is the brake pads.

Drum brakes usually stand on the rear wheels. In the process of wear, the gap between the drum and the pad increases and there are mechanical adjusters to eliminate it.

Rear drum brake:
1 - cup; 2 - clamping spring; 3 - drive lever; 4 - brake shoe; 5 - upper clamping spring; 6 - spacer bar; 7 - an adjusting wedge; 8 - wheel brake cylinder; 9 - brake shield; 10 - bolt; 11 - rod; 12 - eccentric; 13 - pressure spring; 14 - lower clamping spring; 15 - clamping spring of the spacer bar.

On cars, brakes can have different combinations:

• two disc front, two drum rear;
• four disk;
• four drums.

In the disc brake mechanism - the disc rotates, and two pads are stationary, they are installed inside the caliper. There are working cylinders in the caliper, when braking, they press the brake pads against the disc, and the caliper itself is well fixed on the bracket. Ventilated discs are often used to improve heat removal from the work area.

Disc brake diagram:
1 - wheel stud; 2 - guiding pin; 3 - inspection hole; 4 - support; 5 - valve; 6 - working cylinder; 7 - brake hose; 8 - brake shoe; 9 - ventilation hole; 10 - brake disc; 11 - wheel hub; 12 - antisplash cap.

About brake drives

These types of brake drives are used in automotive brake systems:

• hydraulic;
• pneumatic;
• combined.
• mechanical;

Hydraulic drive received the most widespread use in the working brake system of a car. It includes:

• the main brake cylinder;
• brake pedal;
• wheel cylinders;
• brake booster
• hoses and pipelines (working circuits).

When the driver exerts pressure on the brake pedal, it transfers the force from the foot to the master brake cylinder. The brake booster generates additional force, thus making life easier for the driver. The vacuum brake booster is widely used in cars.

The brake master cylinder supplies brake fluid to the brake cylinders. Usually there is an expansion tank above the master cylinder, it contains brake fluid.

The wheel cylinder presses the brake pads against the brake drum or disc.

The work path is now the main and the auxiliary. For example, the entire system is in good working order, which means both work, but if one of them fails, the other will work.

Three basic layouts for dividing work paths are widely used:

• 2 + 2 connected in parallel - rear + front;
• 2 + 2 connected diagonally - right front + left rear and so on;
• 4 + 2, two front ones are connected to one circuit, and the brakes of all wheels are connected to the other.

Hydraulic drive layout diagram:
1 - the main brake cylinder with a vacuum booster; 2 - fluid pressure regulator in the rear brakes; 3-4 - working contours.

Progress does not stand still and now various electronic components are added to the hydraulic brake drive:

• emergency brake booster
• anti-lock braking system;
• anti-slip system;
• brake force distribution system;
• electronic differential lock.

Pneumatic drive used in the braking system of heavy vehicles.

Combined brake drive Is a combination of different drive types.

Mechanical drive used in the parking brake system. It includes a system of rods and cables, with the help of which it unites the system into one whole, usually has a drive for the rear wheels. The brake lever is connected by a thin cable to the brake mechanisms, where there is a device that activates the main or parking pads.

There are cars where the parking system works from a foot pedal. Now more and more often they began to use an electric drive in the parking system, which was named - electromechanical parking brake .

So how does a hydraulic braking system work?

It remains to consider the operation of the brake system, which we will do with the example of the hydraulic system.

When the driver presses the brake pedal, the load is transferred to the booster and it creates a force on the master cylinder. And in turn, the piston pumps fluid through the pipelines to the wheel cylinders. The pistons of the wheel cylinders from the pressure of the fluid move the brake pads to the discs or drums and the car is braked.

When the driver takes his foot off the brake pedal, the pedal from the action of the return spring returns to its original position. Also, the piston of the main brake cylinder returns to its position, and the springs take the pads away from the drums or discs.