The braking system of any car consists of pneumatic and mechanical parts. The pneumatic part of the brake system of a freight car includes: an air distributor, a brake cylinder, a reserve reservoir and an automatic pressure regulator in the brake cylinder (auto mode). The mechanical part includes: brake cylinder, brake linkage (horizontal levers, tightening horizontal levers, rods), automatic brake linkage adjuster and hand parking brake.

Figure: The pneumatic part of the freight car brake.

In the figure, the numbers indicate: 1 - connecting hoses, 2 - tee-bracket of the brake line, 3 - end valves, 4 - reserve tank, 5 - isolation valve, 6,7,8 - air distributor (two-chamber tank 7 with main 8 and main 6 parts), 9 - auto mode, 10 - brake cylinder.

Figure: Car brake system.

The figure shows the braking system of the car, the location of the braking equipment on the frame, and the numbers indicate: 1 - head link, 2 - automatic brake linkage adjuster, 3 - head horizontal lever, 4 - tightening of horizontal levers, 5 - brake line, 6 - rear horizontal lever, 7 - tee bracket, 8 - spare tank, 9 - platform for auto mode, 10 - rear thrust, 11 - release valve leash, 12 - air distributor, 13 - brake cylinder, 14 - brake cylinder rod, 15 - automatic drive regulator TRP, 16 - safety brackets.

The principle of operation of the brake system: when the brake line is discharged, the air distributor responds to braking, while connecting the reserve reservoir to the brake cylinder. Under the action of compressed air pressure, the brake cylinder rod comes out, while turning the head horizontal lever relative to the dead center. The tightening of the horizontal arms moves in the same direction as the stem and pulls the rear horizontal arm. The automatic brake linkage adjuster moves into the actuator, the brake linkage is reduced. The rods pull the vertical levers of the brake linkage of the bogies towards the center of the car and press the brake pads fixed in the triangel shoes to the rolling surface of the wheels.

When the pressure in the brake line rises, the air distributor is released, connects the reserve reservoir with the brake line, and the brake cylinder with the atmosphere. Under the action of the return spring, the piston with the rod moves to the brake cylinder cover, the horizontal levers move the rods towards the bogies, the brake pads move away from the rolling surface of the wheels.

A hand parking brake is used to secure cars at stations or steep slopes.

Figure: Hand parking brake diagram.

The hand parking brake consists of a drive 2 with a handwheel 1, a worm gear, a mechanism with an eccentric 4 and a thrust 5. To bring the brake into working position, the handwheel with a drive is tilted away from its initial position) so that it is perpendicular to the longitudinal axis of the car. Then the worm gear engages with the rotary mechanism, which, turning, pulls the thrust along with it. The rod with its second end is attached by means of a roller to the head horizontal arm. When moving it towards the hand parking brake drive, the head horizontal lever turns relative to the dead center and removes the piston rod from the brake cylinder, thereby bringing the brake lever transmission to the braking position. The second end of the handbrake rod, connected to the head horizontal lever, is made in the form of an eyelet, that is, it has an elliptical opening, the length of which provides free movement of the fastening roller when the brake cylinder rod comes out during the operation of the brake system.

The pneumatic part of the brake equipment (Fig. 1) includes a brake line (air line) b with a diameter of 32 mm with end valves 4 of valve or spherical type and connecting inter-car hoses 3; a two-chamber reservoir 7, connected to the brake line b by a drain pipe with a diameter of 19 mm through an isolation valve 9 and a dust trap - tee 8 (valve 9 has been installed in tee 5 since 1974); spare tank 11; brake cylinder 1; air distributor No. 483 m with main 12 and main 13 parts (blocks); auto mode No. 265 A-000; stop valve 5 with the handle removed.

Auto mode serves to automatically change the air pressure in the brake cylinder, depending on the degree of loading of the car - the higher it is, the greater the pressure in the brake cylinder. If there is an auto mode on the car, the handle of the air distributor load mode switch is removed after the air distributor mode switch is set to loaded mode with cast iron brake pads and medium mode with composite brake pads. Refrigerated cars do not have an automatic mode. The reserve tank has a volume of 78 liters for four-axle cars with a brake cylinder with a diameter of 356 mm and 135 liters for an eight-axle car with a brake cylinder with a diameter of 400 mm.
The reservoir 7, the spool and working chambers of the air distributor of the reserve reservoir 11 are charged from the brake line 6 with the disconnecting valve 9 open. The brake cylinder is connected to the atmosphere through the main part of the air distributor and auto mode 2. When braking, the pressure in the brake line decreases through the driver's valve and partly through the air distributor, which, when triggered, disconnects the brake cylinder 1 from the atmosphere and communicates it with the reserve reservoir 11 until the pressure in them is equalized with full service braking.
The brake linkage of freight cars is made with one-sided pressing of brake shoes (except for six-axle cars, in which the middle wheelset in the bogie has a double-sided pressure) and one brake cylinder, bolted to the center beam of the car frame. At present, in an experimental manner, some eight-axle tanks without a backbone are equipped with two brake cylinders, from each of which the force is transmitted to only one four-axle tank carriage. This is done to simplify the design, facilitate the brake linkage, reduce power losses in it and improve the efficiency of the brake system.
The brake linkage of all freight cars is adapted to the use of cast iron or composite brake shoes. Nowadays, all freight cars have composite shoes. If it is necessary to switch from one type of shoe to another, it is only necessary to change the gear ratio of the brake linkage by rearranging the tightening rollers and horizontal levers (to the hole located closer to the brake cylinder with composite shoes and, conversely, with cast iron shoes). The change in the gear ratio is due to the fact that the coefficient of friction of the composite shoe is approximately 1.5-1.6 times higher than that of the standard cast iron shoes.
In the brake linkage of a four-axle freight car (Fig. 2), the horizontal levers 4 and 10 are pivotally connected to the rod b and the bracket 7 on the rear cover of the brake cylinder, as well as to the rod 2 and the automatic regulator 3 and to the rod 77. They are connected to each other by tightening 5 , holes 8 of which are intended for the installation of rollers with composite pads, and holes 9 - with cast iron brake pads.

The rods 2 and 77 are connected to the vertical levers 7 and 72, and the levers 14 are connected to the shackles 13 of the dead points on the pivot beams of the bogies. The vertical levers are interconnected by spacers 75, and their intermediate holes are pivotally connected with spacers 17 of triangels with brake shoes and pads, which are connected by suspensions 16 to the brackets of the side frames of the bogie. Protection against falling onto the track of parts of the brake linkage is provided by special tips 19 triangels located above the shelves of the side frames of the bogie. The gear ratio of the brake linkage, for example, of a four-axle gondola car with horizontal levers of 195 and 305 mm and vertical levers of 400 and 160 mm is 8.95.
The brake linkage of an eight-axle car (Fig. 3, a) is basically similar to the transmission of a four-axle car, the only difference is in the presence of a parallel transmission of force to both four-axle bogies on each side through the link 1 and balancer 2, as well as the upper arm of the vertical levers.
In the linkage of a six-axle car (Fig. 3.5), the transfer of force from the brake cylinder to the triangels in each bogie is not parallel, but sequential.

Freight cars are equipped with a main air duct 6 (fig. 11) 32 mm diameter with end valves 4 valve type No. 190 and connecting sleeves 8 No. Р17.

Two-chamber tank 7, mounted on the car frame, is connected to the main air line by an outlet 10 with a diameter of 19mm through the release valve 9 and tee dust trap 8 (since 1974 crane 9 installed in the tee before the outlet 10, so that you can turn off not only the air distributor, but also the outlet in the event of a break).

Pipes with a diameter of 19 mm tank 7 also connected to a storage tank 11 and brake cylinder 1. The main line is attached to the tank 7 12 and the main 13 parts of the air distributor. On new freight cars, only air distributors No. 483 are installed. A freight auto mode is connected between the air distributor and the brake cylinder. 2 No. 265-002 (if installed). If there is an auto mode in the braking equipment of cars, the handle of the load mode switch is removed from the air distributor. If the car is equipped with composite blocks and auto mode, then the air distributor is fixed to medium braking mode.

Figure: 11. Diagram of the braking equipment of a freight car.

With the switched on position of the release valve 9 the air distributor communicates with the brake line, when it is off - with the atmosphere.

Emergency brake valve 5 with the handle removed, it is installed only on cars with a brake platform.

On four-axle cars, the volume of the reserve tank is 78 liters with a brake cylinder 356 mm in diameter. Eight-axle cars have a similar braking system, all of them have a parking brake; a spare tank is used with a volume of 135 liters (or two tanks 78 and 55 liters), a brake cylinder with a diameter of 406 mm.

Refrigerated cars are equipped according to the diagram in Fig. 11, but without auto mode.

Charging the spool and working chambers of the air distributor, reservoir 7 and a reserve tank 11 carried out from the main 6. Brake cylinder 1 communicated at this time with the atmosphere through auto mode 2 and the main part of the air distributor. When braking, the pressure in the line decreases, the air distributor engages, turns off the brake cylinder 1 from the atmosphere and communicates it with a spare tank 11. With full braking, the pressure in the storage tank and the brake cylinder is equalized.

Passenger cars are equipped with an electro-pneumatic brake with an electric air distributor 17 (fig. 12) No. 305-000 and air distributor 17 No. 292-001 mounted on the camera 10, which is located on the brake cylinder bracket 16 with a diameter of 356 mm.

Figure: 12. Diagram of the brake equipment of a passenger car.

Brake line 15 with a diameter of 32 mm connected by a bend 8 through tee 7 and isolation valve 9 with air diffuser 17, and also with a camera 10, brake cylinder 16 and a spare tank 13 volume of 78 liters. Exhaust valve 12, located on the reserve tank or on the pipe to it, has a drive drive, brought out on both sides outside and inside the car.

The air ducts between the brake line, the air distributor, the storage tank and the brake cylinder are made of pipes with a diameter of 25.4 mm (from the isolation valve Shto the air diffuser with a diameter of 32 mm).

End valves are located on the brake line 2 and connecting sleeves 1 No. 369A with electrical contacts, suspended on insulated hangers 14. Linear electrical wires of the electro-pneumatic brake are laid in a steel pipe 5 and brought to the connecting sleeves through end two-pipe boxes 3 No. 316-000-7. From the middle three-pipe box 6 No. 317-000-7 leads to the camera 10 electric air distributor 11.

The pneumatic part of the brake equipment (Fig. 7.11) includes a brake line (air line) b with a diameter of 32 mm with end valves 4 of valve or spherical type and connecting inter-car hoses 3; two-chamber reservoir 7, connected to the brake line b by a drain pipe with a diameter of 19 mm through an isolation valve 9 and a dust trap - tee 8 (valve 9 has been installed in tee 5 since 1974); spare tank 11; brake cylinder 1; air distributor No. 483 m with main 12 and main 13 parts (blocks); auto mode No. 265 A-000; stop valve 5 with the handle removed.

Auto mode serves to automatically change the air pressure in the brake cylinder, depending on the degree of loading of the car - the higher it is, the greater the pressure in the brake cylinder. If there is an auto mode on the car, the handle of the air distributor load mode switch is removed after the air distributor mode switch is set to loaded mode with cast iron brake pads and medium mode with composite brake pads. Refrigerated cars do not have an automatic mode. The reserve tank has a volume of 78 liters for four-axle cars with a brake cylinder with a diameter of 356 mm and 135 liters for an eight-axle car with a brake cylinder with a diameter of 400 mm.

The reservoir 7, the spool and working chambers of the air distributor of the reserve reservoir 11 are charged from the brake line 6 with the disconnecting valve 9 open. The brake cylinder is connected to the atmosphere through the main part of the air distributor and auto mode 2. When braking, the pressure in the brake line decreases through the driver's valve and partly through the air distributor, which, when triggered, disconnects the brake cylinder 1 from the atmosphere and communicates it with the reserve reservoir 11 until the pressure in them is equalized with full service braking.

The brake linkage of freight cars is made with one-sided pressing of brake shoes (except for six-axle cars, in which the middle wheelset in the bogie has a double-sided pressure) and one brake cylinder, bolted to the center beam of the car frame. At present, in an experimental manner, some eight-axle tanks without a backbone are equipped with two brake cylinders, from each of which the force is transmitted to only one four-axle tank carriage. This is done to simplify the design, facilitate the brake linkage, reduce power losses in it and improve the efficiency of the brake system.

The brake linkage of all freight cars is adapted to the use of cast iron or composite brake shoes. Nowadays, all freight cars have composite shoes. If it is necessary to switch from one type of shoe to another, it is only necessary to change the gear ratio of the brake linkage by rearranging the tightening rollers and horizontal levers (to the hole located closer to the brake cylinder with composite shoes and, conversely, with cast iron shoes). The change in the gear ratio is due to the fact that the coefficient of friction of the composite shoe is approximately 1.5-1.6 times higher than that of the standard cast iron shoes.

In the brake linkage of a four-axle freight car (Figure 7.12), the horizontal levers 4 and 10 are pivotally connected to the rod b and the bracket 7 on the rear cover of the brake cylinder, as well as to the rod 2 and the automatic regulator 3 and to the rod 77. They are connected to each other by tightening 5 , the holes 8 of which are intended for the installation of rollers with composite pads, and holes 9 - with cast-iron brake pads.

The rods 2 and 77 are connected to the vertical levers 7 and 72, and the levers 14 are connected to the shackles 13 of the dead points on the pivot beams of the bogies. The vertical levers are interconnected by spacers 75, and their intermediate holes are pivotally connected with spacers 17 of triangels with brake shoes and pads, which are connected by suspensions 16 to the brackets of the side frames of the bogie. Protection against falling onto the path of parts of the brake linkage is provided by special tips 19 triangels located above the shelves of the side frames of the bogie. The gear ratio of the brake linkage, for example, of a four-axle gondola car with horizontal levers of 195 and 305 mm and vertical levers of 400 and 160 mm is 8.95.

The brake linkage of an eight-axle car (Fig. 7.13, a) is basically similar to the transmission of a four-axle car, the only difference is in the presence of a parallel transmission of force to both four-axle bogies on each side through the link 1 and balancer 2, as well as the upper arm of the vertical levers.

In the linkage of a six-axle car (Fig. 7.13.5), the transfer of force from the brake cylinder to the triangels in each bogie occurs not in parallel, but in series.

for students of the specialty "Carriages"

in the discipline "Wagons (general course)"

to laboratory work No. 11

GENERAL DEVICE OF BRAKE EQUIPMENT

FREIGHT AND PASSENGER CARS

Irkutsk 2005

UDC 629.4.077

Compiled by A.V. Pargachevsky, st. teacher;

G.V. Efimova, Art. teacher;

M.N. Yakushkina, assistant

Department of Carriages and Carriage Facilities

Reviewers: P.A. Golets, Head of the Technical Department of the Railroad Car Service Service of the Russian Railways, a branch of Russian Railways;

candidate of technical sciences G.S. Pugachev, Associate Professor of the Department of Carriages and Carriage Facilities.

Laboratory work No. 11

GENERAL BRAKE EQUIPMENT

FREIGHT AND PASSENGER CARS

Objective: Study: the general arrangement of the car brake system; location of the main devices of auto-brake equipment on freight and passenger cars; types of pneumatic brakes, their braking modes.

1. Summary of theory

The braking equipment of the cars is designed to create and increase the resistance forces to the moving train. The forces creating artificial resistance are called braking forces.

Braking forces and forces of resistance to movement extinguish the kinetic energy of a moving train. The most common means of obtaining braking force is shoe brake, in which braking is carried out by pressing the shoes against the rotating wheels, due to which frictional forces between the block and the wheel.

On the rolling stock of railways, 5 types of brakes are used: parking (hand), pneumatic, electro-pneumatic, electric and magnetic rail.

Pneumatic brakes are used on freight cars of the general network of the Ministry of Railways. The pneumatic brake system includes: brake line (M), which is located relative to the longitudinal axis of symmetry of the car (Fig. 1). The brake line is attached to the car body in several places and at the end beam of the car frame it has end valves, connecting sleeves with heads (Fig. 2). The brake line of each car entering the formed train must be connected by means of connecting sleeves to each other, and the end valves must be open. The end valve of the tail car of the train must be closed.

From the brake line on each car there are branches through tees to the air distributor (BP) and, in some cases, to stop valves (Fig. 1). The air distributor (BP) and the reserve tank (ZR) are fastened to the brackets mounted on the car frame with bolts. In the main types of cars, the air diffuser and the storage tank are located in the middle of the frame. In some types of specialized freight cars, the air diffuser and the reserve tank are installed in the cantilever part of the car frame.

The air distributor is connected to the brake line (M), the storage tank and the brake cylinder using pipes (fig. 3).

An isolation valve is installed on the pipe between the brake line (M) and the air distributor (ВР), which should be closed in case of a faulty autobrake of the car - the valve handle is located across the pipe.

The brake cylinder is bolted to the brackets mounted on the car frame and connected to the air distributor using a pipe (Fig. 4).

When braking, the force from the rod of the brake cylinder (TC) is transmitted through the horizontal levers and the tightening of the horizontal levers to the rods connected to the brake linkage of the bogie.

On one of the rods of the brake linkage, a rod exit regulator is installed, which, as the brake pads wear out, reduces the length of this rod and thereby compensates for the increase in gaps between the pads and the rolling surfaces of the wheels.

A schematic diagram of the brake linkage of a two-axle bogie of a freight car is shown in Fig. five.

To secure a single standing freight car from spontaneous departure, it has a parking (hand) brake, the main elements of which are shown in Fig. 6. A similar device has a parking brake for passenger cars. These brakes are activated manually by turning the handwheel or handle.

In addition to these units, the braking equipment of some types of freight cars has an auto mode - this is a device that automatically regulates the air pressure in the brake cylinder, depending on the load of the car. Installed between the air distributor and the brake cylinder.

In some types of passenger cars, an anti-skid device is installed that provides automatic pressure reduction in the brake cylinder to stop the wheelset slipping when the car is in motion.