Brake system nodes. Hydraulic brake drive

The hydraulic brake drive of the car is hydrostatic, i.e., in which the power transmission is carried out by fluid pressure. The principle of operation of the hydrostatic drive is based on the property of the liquid incubability, which is alone, transmit the pressure created at any point to all other points during a closed volume.

Schematic diagram of the working brake system of the car:
1 - brake disc;
2 - brake mechanism brake mechanism;
3 - front contour;
4 - main brake cylinder;
5 - a tank with an emergency drop sensor of the brake fluid level;
6 - vacuum amplifier;
7 - pusher;
8 - brake pedal;
9 - Brake light switch;
10 - brake pads rear wheels;
11 - brake cylinder rear wheels;
12 - rear contour;
13 - the casing of the rear axle;
14 - Load Spring;
15 - pressure regulator;
16 - rear cables;
17 - equalizer;
18 - front (central) cable;
19 - parking brake lever;
20 - alarm emergency drop in the level of the brake fluid;
21 - Parking brakes warning switch;
22 - Brake Shoe Front Wheel

The brake hydraulic scheme is shown in the figure. The drive consists of the main brake cylinder, the piston of which is associated with the braking pedal, the wheel cylinders of the front and rear wheels, pipelines and hoses connecting all cylinders, control pedals and the driving force amplifier.
Pipelines, internal cavities of the main brake and all wheeled cylinders are filled with brake fluid. The brake forces controller and modulator shown in the figure and the anti-lock system modulator, when they are installed on the car, are also included in the hydraulic line.
When the pedal is pressed, the piston of the main brake cylinder displaces the liquid into pipelines and wheeled cylinders. In the wheeled cylinders, the brake fluid makes all the pistons move, as a result of which the brake shods are pressed against the drums (or disks). When the gaps between the pads and drums (discs) are selected, the displacement of the liquid from the main brake cylinder into the wheels will become impossible. With a further increase in the pressing force on the pedal in the drive, the fluid pressure increases and the simultaneous braking of all wheels begins.
The greater the force is applied to the pedal, the higher the pressure generated by the piston of the main brake cylinder to the liquid and the greater the force acts through each piston of the wheel cylinder onto the block of the brake mechanism. Thus, the simultaneous response of all brakes and the constant ratio between the strength on the brake pedal and the drive forces of the brakes is provided by the principle of operation of the hydraulic line. Modern drives have a fluid pressure during emergency braking can reach 10-15 MPa.
When the brake pedal is released, it is moving to its original position under the action of the return spring. In the original position of its spring, the piston of the main brake cylinder is also returned, the tie springs of the mechanisms are removed from the drums (disks). The brake fluid from the wheeled cylinders through the pipelines is displaced into the main brake cylinder.
Advantages of hydraulic drive are the speed of triggering (due to the incomprehensibility of the liquid and the high stiffness of pipelines), high efficiency, since the loss of energy is connected mainly with the movement of low-grade fluid from one volume in another, simplicity of design, small mass and dimensions due to large drive pressure, convenience of layout of devices drives and pipelines; The possibility of obtaining the desired distribution of brake efforts between the axes of the car due to the various diameters of the pistons of wheel cylinders.
The disadvantages of the hydraulic line are: The need for a special brake fluid with a high boiling point and low thickening temperatures; the possibility of failure during depressurization due to leakage of fluid during damage, or failure in the drive of air (the formation of steam plugs); a significant reduction in efficiency at low temperatures (below minus 30 ° C); Difficulty use on road trains to directly control trailer brakes.
For use in hydraulic drives, special fluids are produced, called brakes. Brake fluids are manufactured on different bases, such as alcohol, glycolic or oily. They cannot be mixed with each other due to the deterioration of the properties and formation of flakes. To avoid the destruction of rubber parts, the brake fluids obtained from petroleum products are allowed to be used only in hydraulic references, in which seals and hoses are made of oil resistant rubber.
When using the hydraulic drive, it is always performed by two-circuit, and the performance of one contour does not depend on the state of the second. With such a scheme, with a single malfunction, not all the drive fails, but only a faulty contour. A good circuit plays the role of a spare brake system with which the car stops.

Methods for separating the brake drive into two (1 and 2) independent contours

Four brake mechanism and their wheeled cylinders can be separated into two independent circuits in various ways, as shown in the figure.
In the diagram (Fig. 5a), the first section of the main cylinder and the wheel cylinders of the front brakes are combined into one circuit. The second outline is formed by the second section and cylinders of the rear brakes. Such a diagram with axial separation of contours is used, for example, on WEZ-3160 cars, GAZ-3307. A diagonal contour separation scheme (Fig. B) is considered to be more effective, in which the wheel cylinders of the right front and left rear brakes are combined, and in the second circuit - the wheeled cylinders of the two other brake mechanisms (VAZ-2112). With this scheme, in the event of a malfunction, you can always brake one front and one rear wheel.
In the remaining schemes presented in Fig. 6.15, after the failure, three or all four brake mechanisms retain the performance, which further increases the efficiency of the spare system. So, the hydraulic engine of the car brakes of Moskvich-21412 (Fig. B) is made using a two-position caliper of the disk mechanism on the front wheels with large and small pistons. As can be seen from the scheme, if one of the contours is refused, the serviceable contour of the spare system is operating either only on large pistons of the front brake caliper, or on the rear cylinders and small pistons of the front brake.
In the scheme (Fig. D), one of the contours that combines the wheeled cylinders of two front brakes and one rear (VOLVO car) remains good. Finally, in fig. 6.15D shows a diagram with full duplication (ZIL-41045), in which any of the contours carries out the braking of all wheels. In any scheme, the presence of two independent main brake cylinders is obligatory. Constructively most often this happens a dual main cylinder of tandem type, with sequentially arranged independent cylinders in one case and drive from the pedal with one rod. But on some cars, two ordinary main cylinders are used, installed in parallel with the drive from the pedal through the equalistic lever and the two stems.

Each motorist should do everything so that his car does not imagine any danger, both its owner and other road users. It is clear that, first of all, the driver must comply with the rules of movement on the roads, but at the same time, the motorist should not forget about the control of the technical condition of the car, because even the smallest malfunction can lead to a road accident capable of carrying human life. It is especially important that in perfect condition there was a brake system of the car.

Surely, everyone understands that defective brakes can lead to the very rapid result. That is why it is important to monitor all the details of the brake system and in time to conduct their technical inspection. This approach will be a guarantee of your safety when driving on a car.

Causes of faults in the car brake system

Mainly malfunction in the braking system appears due to long service and wear of certain elements of the system. In addition, the malfunction in this node may occur due to the installation of details of low or dubious quality, so we advise you not to save on spare frequent for the brake system. Also, the malfunction may occur due to the use of poor-quality brake fluid, and no one cancels the effect of external factors on the car as a whole and on the brake system in particular.

In order to identify a malfunction in the brake system, it is necessary to conduct inspections at maintenance stations and independently perform the diagnostics of this important node. But, after all, you should not forget about the professional inspection, since only a hundred there is special equipment that can show the need to replace some hidden parts of the brake system.

Signs of failure of the brake system

You should be alert if when you click on the brake pedal, you will hear whistle or creak, which was previously never before. Also, if the brake pedal began to fall out strange or you feel that the car in braking begins to enter when such symptoms are advised to immediately go to check the elements of the braking system.

When inspecting the car, it is worth paying special attention to brake discs. The working surface of the disks should be without cracks, and the wheels themselves must be permissible thickness. Pay attention to the uniform wear of the disk surface. Also get time to check the brake line. You may find leak. If your brake hoses are in perfect condition, but they are already more than five years, we advise them to replace them. Be sure to change the brake fluid on time, because with prolonged use of its properties may well change for the worse, and this may well lead to emergency situations.

In conclusion I would like to say that it is better to check the work of your car better, since it directly depends not only your life, but also the lives of other participants in the movement.

Video: "Car brake system"

The hydraulic type of the brake system is used on passenger cars, SUVs, minibuses, small-sized trucks and special equipment. The working medium is the brake fluid, 93-98% of which are polyglycols and ethers of these substances. The remaining 2-7% are additives that protect fluids from oxidation, and parts and components from corrosion.

Scheme of hydraulic brake system

Composite elements of the hydraulic brake system:

• 1 - brake pedal;
• 2 - central brake cylinder;
• 3 - tank with liquid;
• 4 - vacuum amplifier;
• 5, 6 - transport pipeline;
• 7 - Caliper with a working hydraulic cylinder;
• 8 - brake drum;
• 9 - pressure regulator;
• 10 - manual brake lever;
• 11 - central hand brake cable;
• 12 - side cables of manual brakes.

To understand the work, consider in more detail the functionality of each element.

Brake pedal

This is a lever whose task is to transfer efforts from the driver to the pistons of the main cylinder. Pressing power affects the pressure in the system and the speed of stopping the car. To reduce the required effort, there are brake amplifiers on modern cars.

Chief cylinder and liquid tank

The central brake cylinder is a hydraulic type assembly, consisting of a housing and four cameras with pistons. Cameras are filled with brake fluid. When you click on the pedal, the pistons increase the pressure in the chambers and the force is transmitted through the pipeline to the calipers.

Above the main brake cylinder is a tank with a reserve "TORROSUhi". If the brake system flows, the level of fluid in the cylinder is reduced and the liquid from the tank begins to enter it. If the level of "TORROSUhi" falls below the critical mark, the manual brake indicator will flash on the dashboard. The critical level of fluid is fraught with the failure of the brakes.

Vacuum amplifier

The brake amplifier became popular thanks to the introduction of hydraulics in brake systems. The reason is to stop the car with hydraulic brakes you need more effort than in the case of pneumatics.

The vacuum amplifier creates a vacuum using an intake manifold. The resulting medium presses on the auxiliary piston and significantly increases the pressure. The amplifier facilitates braking, makes driving comfortable and easy.

Pipeline

In hydraulic brakes, four highways are one for each caliper. In the pipeline, the liquid from the main cylinder enters the amplifier, which increases the pressure, and then in separate circuits is supplied to the calipers. Metal tubes with calipers connect flexible rubber hoses that need to bind movable and fixed knots.

Stopping support

The node consists of:

• hull;
• work cylinder with one or more pistons;
• pumping fitting;
• planting pads;
• fasteners.

If the node is movable, then the pistons are located on one side of the disk, and the second block presses the movable bracket, which moves on the guides. The immobile pistons are located on both sides of the disk in a solid building. The caliper is attached to the hub or to a swivel fist.

Rear brake caliper with manual brake system

The liquid enters the working cylinder of the caliper and squeezes the pistons, pressing the pads to the disk and stopping the wheel. If you release the pedal, the fluid returns, and since the system is hermetic, pulls up and returns to the place of pistons with pads.

Brake discs with pads

Disc - the brake element, which is attached between the hub and the wheel. The disk is responsible for stopping the wheel. Pads are flat parts that are located on the landing places in the caliper on both sides of the disk. Pads stop the disk and the wheel with the help of friction force.

Pressure regulator

Pressure regulator or, as they are called in the people, "sorcerer" is an insuring and regulating element that stabilizes the car during braking. The principle of work - when the driver sharply presses the brake pedal, the pressure regulator does not allow all the wheels of the car to slow down at the same time. The element transmits an effort from the main brake cylinder to the rear brake nodes with a small delay.

This principle of braking provides better stabilization of the car. If all four wheels will slow down at the same time, a car with a lot of probability will bring. The pressure regulator does not allow to go into uncontrollable skid even with a sharp stop.

Manual or parking brake

The hand brake holds the car while stopping on an uneven surface, for example, if the driver stopped on the slope. The mechanism of the handbrake consists of a handle, the central, right and left cables, the right and left levers of the manual brake. Manual brakes are usually connected to the rear brake nodes.

When the driver pulls behind the handbrake lever, the central cable pulls the right and left cables that are attached to the brake nodes. If the rear brakes are drum, then each cable is attached to the lever inside the drum and presses the pads. If the brakes are disc, the lever is attached to the shaft of the manual brake inside the piston of the caliper. When the handbrake lever in the working position, the shaft is extended, presses the rolling part of the piston and presses the pads to the disk, blocking the rear wheels.

These are the main points that you should know about the principle of operation of the hydraulic brake system. The remaining nuances and features of the functioning of hydraulic brakes depend on the brand, model and vehicle modifications.

1. Remove the panel closing the brake pedal assembly.

2. Remove the protective flap.

3. Disconnect the brake pedal position sensor sensor shoe from the pedal node.

4. Remove the spop and remove the finger connecting the pusher of the vacuum amplifier with the brake pedal.

5. Unscrew and throw three nuts that are fixing the brake pedal node to the body panel.

6. Separate the brake pedal assembly and remove it from the car.

Note: Do not further disassemble if the node is removed only to facilitate access.

7. Release and remove the brake pedal position sensor from the socket.

8. Remove the sensor socket from the brake pedal brake.

9. Remove the return spring of the brake pedal.

10. Unscrew the two nuts and remove the two bolts of the return spring bracket to the brake pedal node. Remove the springs bracket.

Assembly

1. Install the return spring bracket to the brake pedal assembly, insert the fastening bolts, screw the nuts on them and tighten them from the moment 10 N · m.

2. Connect the return spring with the bracket pedal and set it the pedal position sensor.

3. Install the pedal node on the body panel, screw new nuts and tighten them with a torque of 26 N · m.

ATTENTION: Nuts connecting the vacuum amplifier with a kraxnoe pedal should be re-tightened after 30 minutes.

4. Install the brake pedal position sensor into the socket, connect the wire block to its connector and secure it in the nest.

5. Connect the pusher with the pedal, insert the finger and set the pin in it.

6. Make sure that the sensor is in contact with the pedal protrusion when the pedal is in the raised position.

7. Replace the protective shield.

Details of the car interior, repair work, lower control panel casing.

8. Replace the panel, which closes the brake pedal node.

Details of the car interior, repair work, the lower shield of the control panel - the side of the passenger.

(fire station node)

In the book "School of Mountaineering", this node is written as follows: "UIAA assembly (node \u200b\u200bof the International Union of Alpine Associations) is used for dynamic insurance only on a soft, elastic rope. On the rigid rope he is not applicable. The main thing is to properly lay the joke of the node in the carbine, given the direction of the possible jerk. "

In the Brochure "Carabinous knots" of the authors of Mikhail Zorguguev and Svetlana Sitnikova: "The node is applied in situations when it is necessary to dry rope in two sides. The node is used for dynamic insurance, better on soft rods. Sometimes it is used as a braking device during the descent of vertical periodiles, but in this case it spoils the launching of the rope, especially on domestic hard rods. " Someworthy in the text: "When changing the direction of the movement of the rope, the node will turn over to the carbine, saved] drawing, and will work in the other direction."

Almost constantly using the UIAA node during the works of industrial mountaineering, I came to the following conclusions:

1. The node is very convenient when used as a "brake device" on the descent of vertical periodiles.

2. The node is really spoils the rope felling, but much less than other brake devices.

3. The node can be applied on a rigid rope.

4. Indeed, the main thing is to properly lay the coil of the node in the carbine. The main load in the node comes to the first round so that the node worked normally, this round should be accurately in the karabina inflection. Therefore, the statement that "when changing the direction of the movement of the rope, the node will turn over in Carabin, retaining the drawing, and will work in the other direction." wrong.

"Three clicks"

(Carabiner in combination with the brake node "Three Click")

Knot Garda

(Loop Garda)

Zode T Garda is an excellent tool for insurance. Practically indispensable for vertical transportation of the victim. Easy knits. Delivered at any condition of the rope.

Fig. 79 A, \u200b\u200bB, B, G.

The node is convenient when picked up any cargo, in the above case, when it is necessary when you easily choose a rode to quickly block its slippage in the opposite direction. Sometimes applicable when tightening the hinged crossing instead of a grab (holding) node.

In an unlocking loop of a fixed rope, two identical carabis clutches in one direction in both Karabarba is a trimmer, which is carried out by insurance of a victim or some cargo. Further, the indigenous end of the four carbine is made by one slog, and the second slog is made only through one carbine in such a way that the chosen end of the rope takes place between the Karabins.

Carabinine brake

(Carabinine Cross)

Carabinine brake - a system of carbines and ropes, intended mainly for rescue work, when it is necessary to ensure the etching of loaded rods by the forces of one-piece man.

The bracket brake device is as follows: two carbine are used, one - as a brake frame, and the other -Close movable cross. The cross is served to create strong friction. Friction, as is known, depends on the area of \u200b\u200brubbing surfaces and pressure on these surfaces. Due to the movable crossbar, the carbine pressure can be adjusted to the rope, i.e. Adjust the magnitude of the friction.

Carabiner is mounted on the insurance loop. It carries out the role of the guide. Used for convenience, you can do without it if necessary. The second carbine is embedded in this carbine and is closed. This carbine performs the function of the brake frame, through it the rope loop, which will be insurance will be carried out. The third carbine is embedded in the formed loop, it is also fastened at the end of the rope, designed under load. The third carbine plays the role of cross. Carabinine brake assembled. It is necessary to sentence all carbines. The carbine that performs the role of moving crossbar, the coupling should be from the back side of the second carbine. Rope when moving should not touch this coupling.

In the extreme situation, the carabiner, which performs the role of crosslinor, can be replaced with a rock hammer or ice ax (see Fig. 81).

Here it is necessary to make a slight digression. Many tourists satisfied the possibilities of climbing Carabi-1 new and the use of brake nodes. In this regard, several inventions were made at once. Different brake devices were invented. Inventors proceeded from the following considerations. The degree of braking depends on the friction developed in the places of the support of the rope (cable) and in brake devices, as well as from the effort of the tourist holding ("etching") unloaded free end of the rope.

Fig, 81 A, b.

Various methods of braking rope and brake devices (devices) of various structural complexity were invented.

In fig. 82. The most simple ways of braking rope are shown:

A - through the rocky protrusion (a), with loop and carbine (b);

B - through carbine, hung on a single hook (a) and hook with loop (b);

B - through the ice ax.

Fig. 82 A, B, V.

In fig. 83. Showing: Descent on the rope

a - in a sporty way (on the slopes of the average steepness);

b - on steep slopes;

b - with braking, in the Dulfe (through the thigh).

Depending on how it is wound on a person's body (laid), the rope will be appropriate and braking.

Fig. 83 A, B

The braking of the rope, in which only the housing of the person and hands take part, is used for insurance over the shoulder and lower back; Sometimes as an additional insurance during the descent of sports ("Svan") in the way and classical "dulfe-rum". Braking of rope through the housing and hands in combination with brake fixtures is used during dynamic insurance and various ways to descend along the rope.

The use of brake devices gave tourists the ability to adjust the speed of descent on the rope.

D. Brake Device (Devices)

First, brake fixtures were invented without the possibility of blocking the rope: the puck of the Schticht,

"Frog" and "Eight" (without knecht).

If necessary, fix the fixed place on the rope, tourists accounted for special bonds; That was not always reliable, comfortable and safe. Therefore, almost immediately the brake devices were invented by blocking rope: "petal" ("Soldatik"), Munter Bougel,

Fig. 85 (a) Fig. 86 (b).

"Bukashki" Cook "Eight" (with Knecht).

Brake device, not blocking a rope, such as "Eight".

The rope form a loop, which is formed into a large "eight" ring and is embedded in carbine or attacked on the "eight" neck. To increase friction, the rope is additionally driven through the knecht. In order to fix on the Relief stationary, you need to wind the rope first to be coached on Knecht, and then, making a loop and selling it to a big ring "Eights", also throw on Knecht. The use of brake devices blocking the rope increases the safety of the descents and therefore it is preferable.

The third group of brake fixtures is automatically blocked by friction devices. These are the devices of Petzla, Serafimov and the like it.

Fig. 89. Fig. 90.

E.. Captures (clamps)

Catching nodes were also found replacement. Began to apply capturesvarious designs, i.e. Devices and devices intended for fastening to the rope (cable) of the strapping of the safety tourist, cargo, as well as for transmitting effort. Captures freely slide without load and automatically fix their position on the rope (cable) when it is applied or jerk. Apply to create support points when driving on steep or sheer slopes, self-insurance, organization of insurance, during transportation rescue work. As captures use various devices. Term Saleva (see Fig. 69 (B)).

Clamps of one-sided action without handle.

Clips one-sided actionwithout pens(Clip Gorenmuk): a - open position for laying a rope; b.- Working position of fixation.

Fig. 92 A, b.

Captures with a handle - for the convenience of movement (Zhura).

Two-way clips that allow free movement along the rope in both directions.

Block brakes of eccentric, wedge and lever systems.

Fig. 95 A, b.

To secure the cable applycable and unique silenteccentric clamps.

Fig. 96 A, b.

In the 1980s, seizures were developed and began to be used, structurally combined with friction brake devices into a single shielding device.

At first glance, it may seem that everything outlined in this section to the nodes of the direct relationship does not have. But let's turn to the sensible dictionary V. Del, what does the word "node" mean? We read: "Knot - translation of flexible end and tightening them, tie. The nodes kide various rendering. " "Translation is to blame (binding or crifry, releasing, applying brake fixtures and grips, we wake up a rope on anything or pay something, or put it in a certain way. Rope in combination with fixtures forms a node ( Compare the term "node" in mechanical engineering). All nodes (acclating) used with brake fixtures and with captures refer to the class special, and therefore are considered in this section.

Rope fixing scheme in the brake device type "Frame" ("Butterfly")

All brake devices considered here have a variety of modifications. For example, the "eights" are of different sizes, with knechts and without knechtov, with a double knecht. "Petals" are right and left. By the way, the "petals" made of aluminum alloys are very fragile, and therefore are dangerous in use. Ii approve of the actions of your friend tourist, who coming out the first day to work in one of the Turklo bov, the hammer broke the whole box of aluminum "petals", which saved many lives of young tourists, and their boss from trouble. I know from tourists that in Krasnodar one time someone made a batch of titanium "petal" - here they meet the requirements of strength.

"Frames" used in industrial mountaineering, also have a variety of designs. I met more than JO various forms. I propose the form of "Frames", in my opinion, the most convenient for work. Taking her as a basis, anyone can refine it under itself.

The form represents from itself as a dual "eight" with | Knechti. Carabins are embedded in small holes. Descent is carried out in two trimps. Two ropes, first, guarantee security, and secondly, allow the movement of the pendulum. Alternately, encroaching the right or left rope, you can go on the wall to the left or right. Ropes are attached to the top carbins of the "Frames", for example, the UIA assembly, and are fixed by loops on the knecht. You can use the "frame" and as the usual "eight". A gazebo is attached to the lower carbins of the "frame". "Butterflies" are indispensable when conducting rescue work. They are very simple and easy to use. I suggested this design by Vladimir Zaitsev. I suggest this technical device Nazvagn "Butterfly" Zaitsev.