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FEDERAL RAILWAY TRANSPORT AGENCY

UDC 629.4.077

METHODOLOGICAL INSTRUCTIONS

for laboratory work No. 11

GENERAL DEVICE OF BRAKE EQUIPMENT FOR FREIGHT AND PASSENGER CARS

in the discipline "Wagons (general course)"

Compiled by: A.V. Pargachevsky,

G.V. Efimova, st. teacher;

M.N. Yakushkina, assistant

Irkutsk 2005

Laboratory work No. 11. General design of braking equipment for freight and passenger cars

Purpose of work: To study: the general structure of the brake system she; location of the main devices of autobraking equipment on freight and passenger cars; types of pneumatic brakes, their braking modes.

Brief information from the theory

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

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

There are 5 types of brakes used on railway rolling stock: parking (manual), pneumatic, electro-pneumatic, electric and magnetic rail. Freight cars of the general Ministry of Railways network use pneumatic brakes. The pneumatic brake system includes: a 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 and connecting sleeves with heads (Fig. 2). The brake line of each car included in the formed train must be connected to each other using connecting hoses, and the end valves are open.

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

The air distributor is connected to the brake line (M), the reserve reservoir 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 (BP), which must be closed if the car's automatic brake is faulty - the valve handle is located across the pipe.

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

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

A rod output regulator is installed on one of the brake linkage rods, which, as the brake pads wear, reduces the length of this rod and thereby compensates for the increase in gaps between the pads and the wheel rolling surfaces. A schematic diagram of the brake lever transmission of a two-axle freight car bogie is shown in Fig. 5.

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 steering wheel or handle.

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

Some types of passenger cars are equipped with an anti-skid device that automatically reduces the pressure in the brake cylinder to stop the wheel pair from slipping when the braked car moves.

2. Air brakes

Pneumatic brakes have a single-pass line (air line) laid along each locomotive and car for remote control of air distributors for the purpose of charging spare reservoirs, filling the brake cylinders with compressed air during braking and communicating them with the atmosphere during release. Pneumatic brakes used on rolling stock are divided into automatic and non-automatic, as well as passenger (with fast braking processes) and cargo (with slow braking processes).

Automatic brakes are those that, when a train or brake line ruptures, as well as when the stop valve is opened from any car, automatically come into action due to a decrease in air pressure in the line (when the pressure increases, the brakes are released). Non-automatic brakes, on the contrary, come into action when the pressure in the pipeline increases, and when air is released, the brake is released.

The operation of automatic brakes is divided into the following processes:

Charging - the air duct (main) and spare tanks under each unit of rolling stock are filled with compressed air;

Braking - the air pressure in the main line of the car or the entire train is reduced to activate the air distributors, and air from the reserve tanks enters the brake cylinders; the latter activate the brake linkage, which presses the pads to the wheels;

Overlap - after braking, the pressure in the line and the brake cylinder does not change;

Release - the pressure in the line increases, as a result of which the air distributors release air from the brake cylinders into the atmosphere, while at the same time the reserve reservoirs are recharged by connecting them with the brake line.

Let's look at the schematic diagrams of three groups of brakes.

Direct-acting non-automatic brake (Fig. 7). This type of brake is used on locomotives. The air is pumped by a compressor into the main tank 2, from where it flows through the supply line 3 to valve 4, which in its simplest form is a three-way plug valve. Each position of the tap handle 4 corresponds to a specific process.

Braking - the supply line 3 communicates with the brake line 5, and air enters the brake cylinders, moving the piston 7 with the rod 8 to the right, as a result of which the vertical lever rotates around the fixed point 9 and with its lower end presses the brake pad 10 to the wheel;

Overlap - the brake line 5 is disconnected from the supply line 3, the air pressure in the brake cylinders 6 remains unchanged.

Indirect automatic brake (Fig. 8). A brake of this type differs from a direct-acting non-automatic one in that on each unit of rolling stock, between the brake line 5 and the brake cylinder 7, a device 6, called an air distributor, and a spare reservoir 8 are installed. All passenger cars, electric and diesel trains are equipped according to this scheme. Compressor 1, main tank 2 and driver's valve are mounted on the locomotive.

Before the train departs, the brake is charged, for which the handle of the driver's tap 4 is placed in the release position I (Fig. 8, a), in which air from the main reservoir 2 along the supply line 3 through the driver's tap 4 enters the brake line 5 and then through the air distributor 6 - into the spare tank 8. In this case, the brake cylinder 7 is connected to the atmosphere Atm through the air distributor 6.

To brake the train, the operator's valve handle 4 is moved to brake position III (Fig. 8, b), the supply line 3 is turned off, and the brake line 5 communicates with the atmosphere Atm through valve 4. When the pressure in line 5 decreases, the air distributor 6 comes into action, disconnects the brake cylinder 7 from the atmosphere and communicates it with a spare tank 8 filled with compressed air. Under the influence of compressed air, the piston of the brake cylinder moves and, using a system of rods and levers, presses the brake pads to the wheels. To release the brake, the operator's valve handle 4 is placed in position I. The supply line 3 communicates with the brake line 5, as a result of which the pressure in it increases and the air distributor 6 communicates the brake cylinder 7 with the atmosphere, and the line 5 with the spare reservoir 8. In the case of opening in in the car crane for emergency braking (stop valve) 9 the brakes automatically come into action.

Rice. 8. Scheme of an indirect automatic brake: a-charging and releasing; b--braking

Shown in Fig. 8, the brake is called indirectly acting, or exhaustible, because during the braking process, the air distributor 6 disconnects the brake line from the reserve reservoir 8 and the brake cylinder 7, and if air leaks from the reserve reservoir or brake cylinder, the pressure in them is not restored.

Direct acting automatic brake (Fig. 9). This brake consists of the same main parts as the indirect brake. According to this scheme, the brakes of freight cars and locomotives with air distributors 5 No. 135, 270-002, 270-005-1 and 483-000 with flat and mountain release modes are made. Leaks from the reserve reservoir and brake cylinder are replenished automatically during service braking or the driver's supply valve is shut off. The fundamental difference between a direct-acting automatic brake and an indirect-acting one lies in the design of the air distributor 5.

Depending on the position of tap 3, the following occurs:

Charging and release - the brake line 8 (Fig. 9, a) communicates with the supply line 2 and the main reservoir, the brake cylinder 6 through the air distributor 5 with the atmosphere At, and the spare reservoir 4 through the check valve 7 with the brake line;

Braking - the pressure in the brake line 8 (Fig. 9, b) is reduced by releasing air via valve 3 into the atmosphere. At. Air distributor 5 comes into action, which disconnects

When braking, as well as during stepwise release, the air distributor 5, through the check valve 7, replenishes air leaks in the reserve tank 4 and the brake cylinder 6 directly (directly) from the line, therefore such brakes are called direct-acting.

By changing the air pressure in the brake line 8 by valve 5, stepwise braking and stepwise or stepless release are carried out.

3. Location and fastening of braking equipment

air brake freight car

Passenger carriages. Air distributor No. 292-001 and electric air distributor 12 No. 305-000 are installed on the bracket of the rear cover of the brake cylinder 13. Under the car there is also a main pipe 3 in diameter, end valves with inter-car connecting hoses 7 and a tee or dust trap 9. Isolation valve 10 is used to turn on and turning off the air distributor 11.

Each passenger car has at least three valves 5 for emergency braking (stop valves). The spare tank 15 is connected by a pipe with a diameter to the bracket of the rear cover of the brake cylinder 13. An outlet valve 14 is installed on the pipe from the spare tank or on the spare tank. On some types of cars, devices 10 and 12 are installed on a separate bracket, and the brake cylinder has a regular cover.

Fig. 10. Diagram of brake equipment of a passenger car

Freight cars (Fig. 11). The two-chamber tank 7 is attached to the frame of the car with four bolts and connected by pipes to a tee or dust trap 2, a spare tank 4 and a brake cylinder 10 in diameter through the auto mode 9. The main 6 and main 8 parts of the air distributor are attached to the tank 7.

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Rice. 11. Diagram of the brake equipment of a freight car

A 5-diameter disconnect valve is used to turn the air distributor on and off. On the main pipe there are end valves 3 and connecting hoses. The end valves are installed with a rotation of 60° relative to the horizontal axis. This improves the operation of the hoses in curved sections of the track and eliminates impacts of the hose heads when moving through hump retarders.

Stop valve 1 with the handle removed is installed only on cars with a brake platform.

4. Brake linkages

The lever transmission of a four-axle freight car (Fig. 12) has the following device.

The piston rod of the brake cylinder 10 and the dead center bracket 11 are connected by rollers with horizontal levers 15, which in the middle part are connected to each other by a tightening 16, and at the opposite ends are articulated by rollers with rods 6. The upper ends of the vertical levers 19 of both bogies are connected to rods 6, and the lower ends of the levers 3 and 19 are connected to each other by a spacer 24.

Fig. 12. Lever transmission of a freight car

The upper ends of the outermost vertical arms 3 are secured to the frames of the trolleys using earrings 4 and brackets.

Triangels 5, on which shoes 2 with brake pads are installed, are connected by rollers 18 to vertical arms 3 and 19.

Holes 12 in levers 15 are intended for installing tightening rollers 16 with composite pads, and holes 13 with cast iron pads.

To protect the triangels and spacers from falling onto the path in the event of their separation or breakage, safety squares 22 and brackets 23 are provided. The shoes 2 and the triangels 5 are suspended from the trolley frame on pendants 21 and rollers 20. The rods and horizontal levers near the brake cylinder are equipped with safety and supporting staples.

When braking, the body of the regulator 17 rests against lever 8, connected to horizontal lever 15 by tightening 9. Screw 7 is used to adjust size A. Gondola cars, platforms and tanks have a similar lever transmission, differing only in the dimensions of the horizontal levers. The action of the lever transmission of a four-axle car is similar to the action of the lever transmission discussed above. When braking, the rod (see Fig. 12) with the horizontal lever 15 and the tightening 16 moves to the left (according to the figure). At the same time, the other end of the lever 15, which has a roller inserted into the hole 12 or 13 as a fulcrum, moves together with the regulator 17, rod 6 and the upper end of the vertical lever 19 to the right. Vertical lever 19, having a support at the junction of the lower end with the puff 24, will press the brake pad to the wheel and the block will become the fulcrum, and the puff 24 will move to the left, pressing the block of the second axle. After pressing the blocks of the left trolley of the car, the tightening 16, having a fulcrum in the bracket 11, will move the horizontal lever 15, the rod 14 and the upper end of the vertical lever of the right trolley to the left, pressing the block to the wheel of the third axle, and then to the fourth.

The lever transmission of a passenger car differs from the transmission of freight cars in that instead of triangels, traverses 17 are used, on the axles of which shoes 15 with brake pads 21 are installed. Vertical levers 24 and puffs 23 are suspended from the frame on suspensions 22.

The brake pads are pressed on both sides; vertical levers are located in two rows on the sides near the wheels.

Rice. 13. Details of the traverse (beam) on the bogie of a passenger car: * traverses; 2 -- washer; 3 --- cotter pin; 4 --nut; 5 -- spring; " 6 - shoe suspension; 7 - driver pin; 8 - driver; 9 - shoe with bushings; 10 - pin; 11 - composite block.

Rice. 14. Parts of a triangel with a dead-fit shoe (GOST 4686--74) of a freight car bogie (the suspension assembly is shown in the left corner): 1—triangel; 2—bookmark; 3-shoe; 4—suspension; 5-safety tip; 6 - check; 7-cast iron block; 8 -- castle nut; 9 -- cotter pin; 10 -- bushing; 11 -- suspension roller; 12 --rubber bushing

Date of the lesson; subject; Objective; description and sketches of the main parts and assemblies of auto-braking equipment; operating diagrams of pneumatic brakes; answers to security questions.

Control questions

1. What is the purpose of auto braking equipment?

2. Location and fastening of the main brake equipment on freight and passenger cars.

3. The principle of operation of a direct-acting non-automatic brake.

4. The operating principle of an indirect non-automatic brake, the main difference from a direct non-automatic one.

5. The principle of operation of a direct-acting automatic brake. The main difference from direct-acting non-automatic.

6. Operating principle of the electro-pneumatic brake. How to act in case of failure of the electrical part of the brake.

7. Design of lever transmission of freight and passenger cars.

8. Name the power supplies in the train brake system and their purpose.

9. Name the control devices and their purpose.

10. Name braking devices and their purpose.

11. How is automaticity ensured in pneumatic brakes?

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The brakes of railway rolling stock are designed to regulate the speed of movement from the maximum possible to a complete stop, as well as to hold the train in place.

Classification of brakes and their main properties.

Brakes are classified according to the methods of creating braking force and the properties of the control part.

According to the methods of creating braking force, friction and dynamic brakes differ. Based on the properties of the control part, brakes are distinguished between automatic and non-automatic. Five types of brakes are used on the rolling stock of Russian railways:

Parking (manual) - they are equipped with locomotives, electric motor and self-propelled rolling stock, passenger and freight cars.
Pneumatic - all rolling stock is equipped with them using compressed air.
Electropneumatic - they are equipped with passenger cars and locomotives, electric motor rolling stock and diesel trains.
Electric (dynamic and reversible) - they are equipped with certain series of locomotives and electric trains.
Magnetic rail – high-speed trains are equipped with them.

They are used as additional to EPT and electric ones.

Parking hand brakes consist of a gearbox and a system of levers and (or) chains. They are activated manually and ensure that the movable unit is held in place during long periods of parking.

Pneumatic brake device.

Air brakes have:

— a single-wire line for providing compressed air and remote control of the operation of braking equipment;

— brake control devices;

— braking devices.

Pneumatic brakes used on rolling stock are divided into automatic And non-automatic, as well as passenger (with fast braking processes) and cargo (with slow braking processes).

Automatic are called brakes, which, when a train or brake line ruptures, as well as when the stop valve is opened from any car, automatically come into action due to a decrease in pressure in the line (when the pressure increases, the brakes are released).

Non-automatic the brakes, on the contrary, come into action when the pressure in the pipeline increases, and when the air is released, the brakes are released.

Based on the principle of action they are divided into:

— direct-acting non-automatic ;

—not direct acting automatic ;

—direct acting automatic.

Direct-acting non-automatic The brake is called because during the braking process the brake cylinders communicate with the power source, and if the train breaks or the connecting hoses are disconnected, it does not come into action. If there was air in the brake cylinders at that moment, it will immediately come out and release will occur. In addition, this brake is inexhaustible, since with the help of the driver’s tap it is always possible to increase the pressure in the brake cylinders, which has decreased due to air leaks.

Not direct acting automatic The brake differs from a direct-acting non-automatic one in that on each unit of rolling stock, an air distributor is installed between the brake line and the brake cylinder, connected to a reserve tank that contains a supply of compressed air. The brake is called non-direct acting because during the braking process the brake cylinders do not communicate with the power source (main reservoirs). During prolonged braking, due to the inability to replenish the reserve reservoirs with air through the brake line, the air pressure in the brake cylinders and reserve reservoirs decreases and therefore the brake becomes exhausted.

Direct acting automatic the brake consists of the same components as the indirect one. Thanks to the special design of the driver's tap and air distributor, the pressure in the brake line is automatically maintained, and the braking force on the train can be adjusted to increase and decrease within the required limits. If during braking the pressure in the brake cylinders decreases due to leaks, it will quickly be restored due to the supply of air from spare reservoirs. As soon as the pressure in the reserve reservoir becomes less than in the line, the check valve will open and air will replenish the reserve reservoir and then the brake cylinder. The brake line will in turn be automatically replenished through the driver's tap from the main reservoir. In this way, the pressure in the brake cylinder can be maintained for a long time. This is how an automatic non-direct acting brake differs from an automatic direct acting brake.

During the maintenance of wagons, work is performed to service the brake equipment. At the same time, the currently valid “Rules for the maintenance of automatic braking equipment and control of brakes of railway rolling stock” establish the following requirements:

REQUIREMENTS FOR IMPLEMENTATION OF TECHNICAL

MAINTENANCE OF BRAKE EQUIPMENT OF FREIGHT CARS.

During maintenance of each freight car it is necessary to:

— check the serviceability of the brake equipment;

— check the presence and serviceability of fasteners and safety (supporting) devices of the braking equipment;

— in the brake lever transmission, check the presence of axles, washers, cotter pins, their compliance and correct installation;

— check the condition, thickness of the brake pads and their location relative to the rolling surface of the wheels;

— check the adjustment of the brake cylinder rod outputs and the brake lever transmission;

— check that the air distributors are switched on correctly to the “Plain” or “Mountain” mode;

— check, depending on the presence or absence of auto mode on the car, the type of shoes (composite or cast iron), the loading of the car, the type and model of the car, whether the air distributor is switched correctly to the braking mode “Empty”, “Medium” or “Loaded”.

7 At freight train formation points and maintenance points at stations preceding steep, protracted descents, the operation of the parking (hand) brakes on cars must be checked.

8 When performing maintenance on a set of cars or a train, it is necessary to:

— check the connection of the brake line hoses between the cars, the train of cars and the locomotive - make sure that the connecting hoses are connected, the end valves between the cars, the train of cars and the locomotive are open, the tail end valve of the last car is closed;

— check that the brakes on the cars are turned on - make sure that the isolation valves on the supply pipes to the air distributors are open;

— control the density of the brake pneumatic network of the carriages, which must comply with established standards;

— check the action of the brake of each car during braking and release;

— check the output of the brake cylinder rod on each car.

9 All braking equipment must be securely fastened, loose fastening parts must be tightened, faulty and missing fastening parts and safety (supporting) devices must be replaced by serviceable fastening parts and safety (supporting) devices.

10 Rubber-textile tubes of connecting sleeves are not allowed to have delaminations, tears and deep cracks reaching the textile layer, or peeling of the outer or inner layer.

11 Vertical axles in the brake lever transmission must be installed with their heads up. Axles installed horizontally must have their washers facing outward from the longitudinal axis of the car. Horizontal axles located on the longitudinal axis of the car must have their heads facing the same direction.

Standard washers and cotter pins must be installed on the brake linkage axle. Both branches of the cotter pin must be set at an angle of at least 90º between them. If replacement is necessary, new cotter pins must be installed; reuse of cotter pins is prohibited.

The distance between the washer and the cotter pin in the hinge joints of the brake lever transmission should not exceed 3 mm. It is possible to adjust this size by installing no more than one additional washer of the required thickness, but not more than 6 mm, with the same hole diameter as the main washer.

The contact strip must be securely fastened to the support beam using fasteners.

Under the contact strip, adjustment strips can be installed, mounted on the support beam integrally with the contact strip. Welding adjustment strips on top of the contact strip is prohibited.

13 Brake pads must not have kinks or cracks and protrude beyond the edge of the outer edge of the wheel rim by more than 10 mm. On freight cars with passenger-type bogies, the pads are not allowed to extend beyond the edge of the outer edge of the wheel rim.

The minimum thickness of brake pads at which they must be replaced (thickness of extremely worn brake pads) is established depending on the length of the warranty section, but not less than:

— cast iron — 12 mm;

— composite with stamped metal frame — 14 mm;

- composite with mesh-wire frame - 10 mm.

Composite brake pads with a mesh-wire frame can be distinguished from composite brake pads with a stamped metal frame by the eye filled with a friction composite mass.

The thickness of the brake pad should be checked from the outside of the cart.

In case of wedge-shaped wear, the thickness of the brake pad should be checked at a distance of 50 mm from the thin edge of the pad.

If the side surface of the brake pads on the wheel flange side is worn, it is necessary to check the condition of the triangels, traverses (for freight cars with passenger-type bogies), brake shoes and their suspensions, and replace the brake pads.

The minimum thickness of a newly installed brake pad must be at least 25 mm, and wedge-shaped wear is not allowed.

14 It is prohibited to install composite brake pads on cars, the linkage of which is installed under cast iron pads (the tightening axes of the horizontal levers are located in the holes located further from the brake cylinder), and, conversely, it is not allowed to install cast iron brake pads on cars, the linkage of which is installed under composite pads.

The exception is service and diesel cars of refrigerated rolling stock, as well as freight cars with a diesel compartment of five-car refrigerated sections, the brake lever transmission of which is designed only for cast iron pads (horizontal brake levers have one hole for connection with a tightening). On such cars it is allowed to install composite brake pads, subject to the obligatory condition that the air distributors of these cars must be fixed to the “Empty” operating mode of the air distributor.

Cars with containers of 27 tons or more, including six- and eight-axle cars, are allowed to operate only with composite brake pads.

When replacing brake pads, the following conditions must be observed:

— blocks of the same type and design must be installed on one car;

— pads on the same axis should not differ in thickness by more than 10 mm.

15 With the brake linkage adjusted correctly:

— the output of the brake cylinder rod must be within the limits given in Table II.1 of these Rules.

The standards for the release of brake cylinder rods for cars with a brake lever transmission not equipped with regulators before steep, long descents are established by the technical and administrative document of the owner of the infrastructure;

— the distance from the end of the coupling of the protective pipe of the brake linkage regulator (hereinafter referred to as the regulator) to the connecting thread of its screw must be for regulators 574B, RTRP-675, RTRP-675-M at least 150 mm, for regulators RTRP-300 – at least 50 mm;

— the thrust lever of the regulator drive (stop) when the car brake is released should not touch the regulator body;

— the angles of inclination of the horizontal, intermediate and vertical levers must ensure the working condition of the brake lever transmission of the car until the brake pads wear out to the limit.

If adjustment is necessary, the brake linkage of cars equipped with a regulator must be adjusted to maintain the brake cylinder rod output at the lower limit of the established rod output standards.

Table II.1– Output of the brake cylinder rod of freight cars

	Rod output in mm.
			Maximum permissible in operation with full service braking (without regulator)

1	2	3	4
Freight car (including refrigerated) with one brake cylinder, with cast iron brake pads
Freight car (including refrigerated) with one brake cylinder, with composite brake pads
Freight car with two brake cylinders (with separate braking), with cast iron brake pads
Freight car with two brake cylinders (with separate braking), with composite brake pads

Note ()* for cars equipped with adapters.

16 All malfunctions identified during the maintenance of cars must be eliminated.

17 If faults are identified in a car that cannot be eliminated at a station that does not have a maintenance point, it is allowed to move the car as part of a train with the brakes off to the nearest maintenance point, provided that this does not threaten traffic safety.

18 Maintenance of the braking equipment of train cars of increased weight and length (freight trains of regular or special formation) and connected trains is allowed to be carried out in trains on different tracks with mandatory full testing of the automatic brakes in each train, subject to subsequent coupling when forming the train.

REQUIREMENTS FOR THE MAINTENANCE OF BRAKE EQUIPMENT OF LOCOMOTIVE-HAULED PASSENGER CARS AND PASSENGER-TYPE CARS

19 When performing maintenance on wagons, check:

— condition of components and parts of brake equipment for compliance with their established standards. Parts that do not ensure normal brake operation must be replaced;

— the correct connection of the hoses of the brake and supply lines, the opening of the end valves between cars and the isolation valves on the air supply lines, as well as their condition and reliability of fastening. The correctness of hanging the hose and the reliability of hanging and closing the end valve on the tail car. When coupling passenger cars equipped with two brake lines, hoses located on one side of the automatic coupler axis in the direction of travel must be connected;

— no contact between the electrical inter-car connections of the heads of the end hoses of the brake line, as well as unauthorized contact of the heads of the end hoses of the brake and supply lines with each other;

— correct activation of the air distributor modes on each car, taking into account the number of cars in the train;

— the density of the train’s brake network, which must comply with established standards;

— the effect of auto brakes on the sensitivity to braking and release, the effect of the electro-pneumatic brake with checking the integrity of the electrical circuit of the train, the absence of short circuit of the electro-pneumatic brake wires to each other and to the car body, voltage in the circuit of the tail car in braking mode. The operation of the electro-pneumatic brake is checked from a power source with a stabilized output voltage of 40 - 50 V, while the voltage drop in the electrical circuit of the electro-pneumatic brake wires in braking mode, in terms of one car of the train being tested, should be no more than 0.5 V for trains of up to 20 cars. inclusive and not more than 0.3 V for longer trains. Replace air distributors and electric air distributors that are operating unsatisfactorily with serviceable ones;

— action of the anti-skid device (if equipped). To check the mechanical anti-skid device, after performing full service braking, it is necessary to rotate the inertial load through the window in the sensor housing. In this case, air should be released from the brake cylinder of the trolley being tested through the relief valve. After the impact on the load ceases, it must return to its original position, and the brake cylinder must be filled with compressed air to the initial pressure, which is monitored by a pressure gauge on the side wall of the car body. The test must be carried out for each sensor.

To check the electronic anti-skid device, after performing a full service braking, it is necessary to check the functioning of the relief valves by running a test program. In this case, there should be a sequential release of air on the corresponding wheel pair and the activation of the corresponding indicators for the presence of compressed air pressure of this axle on board the car;

— action of the speed controller (if available). To check, after performing a full service braking, press the speed controller test button. The pressure in the brake cylinders should increase to the set value, and after stopping pressing the button, the pressure in the cylinders should decrease to the original value.

After checking, turn on the brakes of the cars to a mode corresponding to the upcoming maximum speed of the train;

— action of the magnetic rail brake (if equipped). To check, after emergency braking, press the magnetic rail brake test button. In this case, the shoes of the magnetic rail brake should lower onto the rails. After you stop pressing the button, all shoes of the magnetic rail brake should rise to the upper (transport) position;

— correct adjustment of the brake lever transmission. The lever transmission must be adjusted so that the distance from the end of the coupling of the protective tube of the autoregulator screw 574B, RTRP-675, RTRP-675M to the connecting thread on the autoregulator screw is at least 250 mm when leaving the point of formation and turnover and at least 150 mm when inspection at intermediate technical inspection points.

When using other types of auto-regulators, the minimum length of the regulating element of the auto-regulator when leaving the point of formation and turnover and when checking at intermediate technical inspection points must be indicated in the operating manual for a specific car model.

The angles of inclination of the horizontal and vertical arms must ensure normal operation of the lever transmission until the brake pads wear out to the limit. When the brake is released, the driving horizontal lever (the horizontal lever on the side of the brake cylinder rod) should be inclined towards the bogie;

— the output of the brake cylinder rods, which must be within the limits specified in Table III.1 of these Rules.

— the thickness of the brake pads (linings) and their location on the rolling surface of the wheels.

The thickness of brake pads for passenger trains must ensure the ability to travel without replacement from the point of formation to the point of turnover and back and is established by local rules and regulations based on experimental data.

The pads are not allowed to leave the tread surface beyond the outer edge of the wheel.

The minimum thickness of the pads at which they must be replaced is set depending on the length of the warranty section, but not less than: cast iron - 12 mm; composite with a metal back - 14 mm, with a mesh-wire frame - 10 mm (pads with a mesh-wire frame are determined by the ear filled with friction mass).

Check the thickness of the brake pad from the outside, and in case of wedge-shaped wear - at a distance of 50 mm from the thin end.

In case of wear on the side surface of the pad on the wheel flange side, check the condition of the yoke, brake shoe and brake shoe suspension, eliminate any identified deficiencies, replace the pad;

Metal-ceramic linings with a thickness of 13 mm or less and composite linings with a thickness of 5 mm or less along the outer radius of the linings must be replaced. The thickness of the pad should be checked at the top and bottom of the pad in the pad holder. The thickness difference between the top and bottom of the pad in the pad holder is allowed to be no more than 3 mm.

Table III.1— Rod output of brake cylinders of passenger cars, mm

Type of car and brake pads	Rod output in mm.
	When departing from a service point		When departing from a service point
	at full service braking	at the first stage of braking	When departing from a service point
1	2	3	4
Passenger car with cast iron brake pads
Passenger car with composite brake pads
Passenger carriage of RIC size with KE air distributors and cast iron brake pads
VL-RITS passenger car on TVZ-TsNII - M bogies with cast iron brake pads

Notes

1 The output of the brake cylinder rod with composite brake pads on passenger cars is indicated taking into account the length of the clamp (70 mm) installed on the rod.

2 The brake cylinder rod outlets for other types of cars are installed in accordance with their operating instructions.

On passenger cars with disc brakes, additionally check:

- the total gap between both pads and the disk on each disk. The gap between both pads and the disc should be no more than 6 mm. On cars equipped with parking brakes, check the clearances during release after emergency braking;

— no air passage through the check valve on the pipeline between the brake line and the additional feed tank;

— condition of the friction surfaces of the discs (visually with the broaching of the cars);

— serviceability of compressed air pressure indicators on board the car.

20 It is prohibited to install composite pads on cars, the lever transmission of which is rearranged under cast iron pads (i.e., the tightening axes of the horizontal levers are located in the holes located further from the brake cylinder), and, conversely, it is not allowed to install cast iron pads on cars, the lever transmission of which rearranged for composite blocks, with the exception of wheel pairs of passenger cars with gearboxes, where cast iron blocks can be used up to a speed of 120 km/h.

21 Passenger cars operated on trains with speeds above 120 km/h must be equipped with composite brake pads.

22 When inspecting a train at a station where there is a maintenance point, all faults in the brake equipment of the cars must be identified, and parts or devices with defects must be replaced with serviceable ones.

If a malfunction of the brake equipment of cars is detected at stations where there is no maintenance point, it is allowed to move the car with the brake off, provided that traffic safety is ensured to the nearest maintenance point.

23 At the points of formation and turnover of passenger trains, car inspectors are required to check the serviceability and operation of the parking (hand) brakes, paying attention to the ease of activation and pressing of the blocks to the wheels.

Car inspectors should carry out the same check of parking (hand) brakes at stations with maintenance points preceding steep, long descents.

24 Check the distance between the heads of the connecting hoses of the brake line with electric tips and the plug connectors of the inter-car electrical connection of the lighting circuit of the cars when they are connected. This distance must be at least 100 mm.

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Ministry of Railways of Russia

RUSSIAN STATE OPEN

TECHNICAL UNIVERSITY OF COMMUNICATIONS (RGOTUPS)

Test

in the discipline Fundamentals of Technical Diagnostics

"Braking equipment for freight cars"

Student Nesterov S.V.

Saratov - 2007

Braking equipment is used to reduce the speed of movement of the car and stop it at a given place.

The most important parameter for the efficiency of the braking system is its braking coefficient or the length of the path that a car moving at a given speed will cover from the moment the braking begins to a complete stop. The design of brake equipment is very diverse. However, if we consider it as an automated system, then we can distinguish a number of blocks combined into a single block diagram (Fig. 1).

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Rice.1. Structuralschemebrakeequipment

The brake system works as follows. Control unit 1 ensures that the brake system is charged with compressed air through the brake line (connection unit 2) and, if necessary, sends a signal to start braking or releasing. The control signal is received by the air distributor 3, which, using auto mode 4, activates the brake cylinder 5 with a lever transmission and auto-regulator 6. The force from the brake cylinder is transmitted to the friction pair 7, which ensures the absorption of kinetic energy of movement, i.e. car braking. The braking process of the wheelset 9 is controlled and regulated by the anti-skid device 8. Consequently, the efficiency of the braking system is ensured by the high-quality functioning of all units. Moreover, the predominantly sequential connection of blocks makes such a system very vulnerable, since the failure of one of the blocks leads to the failure of the entire system. This feature of the operation of brake equipment requires a clear organization of the diagnostic and maintenance system.

Functional diagnostics of the effectiveness of automatic brakes is carried out while the train is moving (after departure to the station) mainly on a flat straight section of the track at a speed of 40-60 km/h. To do this, the driver performs a test braking of the train, usually by reducing the pressure in the brake line by 0.03-0.04 MPa. If a sufficient braking effect is not obtained within 20-30 seconds in freight trains, then emergency braking is performed and other measures are taken to stop the train, since the brakes are not functioning properly. Experienced drivers can determine its braking coefficient by the rate at which the train decelerates.

For example, in the USA, the following system for diagnosing train brake systems began to be used on an experimental basis. Electronic units with microprocessors are installed on the last carriage of the train and in the driver’s cabin, which interact with each other via radio communication. According to the corresponding program, pressure and leaks from the brake line at the head and tail of the train, the braking process and the release are monitored. At the driver's request, this information is displayed on a display located in the driver's cabin.

In the carriage industry, at maintenance points, quasi-functional diagnostics of brake equipment based on structural parameters is widely used, which is called full and abbreviated testing of brakes. The essence of testing is as follows.

After charging the train's brake network to the set pressure, the density of the air line is checked. To do this, for example, on freight trains, the driver's crane is set to the position II and measure the time of pressure drop in the main tanks with the compressors turned off by 0.05 MPa. The time standard is set depending on the volume of the main tanks and the length of the train in the axes.

After checking the tightness of the train line, the functioning of the brakes is monitored. To do this, perform a braking step by reducing the pressure in the line by 0.06-0.07 MPa and set the driver's crane handle to the power supply shutoff position. All air distributors on the train must engage the brakes and not release spontaneously during the entire test period. The operation of the brakes is monitored by car inspectors, who assess the technical condition of the braking equipment using structural diagnostic parameters. The diagnostic parameters in this case are: the release of the brake cylinder rod, the pressing of the pads to the wheels, the correct location of the gear levers, the absence of intense air leaks in the elements of the brake equipment. If it is determined that the brake system has responded normally to braking, then a signal is given to release the brakes and the driver's valve is moved to the position II. The release of the brakes is monitored. The correct release is checked by the return of the rods to the cylinders, the brake pads moving away from the wheels, and the absence of intense leaks, in this case from the air distributors.

Rice. 2. Schemepointscentralizedtestingbrakes

At the end of the full testing of the brakes, fill out a certificate of brakes, form VU-45. Large VETs have centralized testing points for brake diagnostics (Fig. 2). Two point schemes have become widespread. In scheme A, all diagnostic equipment is located in the station premises, and pipelines with end valves 1, 2, 3, 4 are connected to Pita for connecting the brake network of the trains and the two-way loudspeaker communication column. The testing of train brakes is supervised by the operator of a centralized point, who performs it according to the algorithm described above.

In scheme B, autonomous semi-automatic machines 5, 6, 7, 8 are installed at each inter-track to diagnose auto brakes according to the corresponding program. The compressed air supply and cable lines are centralized, through which the diagnostic results are recorded on the equipment of point B. The operator of the point actually controls the actions of semi-automatic machines and car inspectors, and also makes a decision on the scope of repair work and keeps appropriate records. As can be seen from the described procedure for fully testing the brakes, the process is quite lengthy, which complicates the maintenance of trains, especially long-unit trains, and increases their downtime at technical maintenance stations. To shorten the process of diagnosing brakes, VNIIZhT researchers have proposed two methods. The essence of the first method is that it is recommended to control the line density by measuring the compressed air flow rate during the charging of the brake network. Indeed, as operating experience shows, air leaks in the composition are concentrated mainly in places where end valves, connecting hoses, tees, dust traps, and couplings are located. Therefore, the condition of the brake line is essentially characterized by transit flow caused by leaks concentrated in specified locations. Consequently, by measuring the air flow rate when charging the brake network, you can first observe a large flow rate used to charge the spare tanks, and then a gradual stabilization of the compressed air flow rate. This stabilized level of air flow actually goes to replenish leaks. By assessing it depending on the length of the train, it is possible to determine whether the density of the brake line corresponds to the established standards.

The second method is to check the brake line tightness after the braking stage. In this case, the air distributors of the cars are activated and disconnected from the brake line. Therefore, if you check for leaks 15-20 seconds after braking, they will characterize the density of the train’s brake line. This means that in this case, too, it is possible to combine two brake testing procedures and reduce the time of the entire diagnostic cycle.

With a short brake test, the diagnostic algorithm is significantly simplified. After charging the brake network, the braking stage is performed and the operation of the brakes of only the tail cars is monitored. If the brakes of the tail cars have worked, then the brakes are released and the quality of the release of the brakes of the tail cars is monitored. Consequently, during a shortened test of the auto brakes, they actually check the integrity and serviceability of the train’s brake line and, with some probability, the effect of all brakes when the brakes of the tail cars are activated.

Air distributors and auto modes

The method for diagnosing air distributors can be considered using the example of testing the devices of freight cars. On the test bench, four parameters of the functioning of the main part of the air distributor and three of the main part are monitored.

Moreover, tests of the main part being diagnosed, for example, are carried out together with the reference main part of the same type of air distributor. Subsets used as standards must meet the requirements of the factory instructions in all respects. During testing, the operation of the main part in a flat loaded mode is checked according to the following parameters: charging time of the spool chamber; softness of action; clarity of operation during braking and release. The main part of the air distributor is checked in mountain empty and loaded modes. In this case, the main attention is paid to monitoring the charging time of the reserve tank, the proper operation of the non-return feed valve, filling and releasing the brake cylinder (time and pressure). Currently, a test bench with automatic program control of the StVRG-PU type (St - stand, VRG - cargo air distributors, PU - with program control) is being introduced at auto braking control points.

The stand works as follows. The tested and reference parts of the air distributor are installed on the counter flanges of the stand and secured with pneumatic clamps. The stand is charged and the software control unit is turned on. The step finders of the program unit, which are in the initial position, turn on the corresponding electro-pneumatic measuring instruments and begin testing the air distributor according to the unconditional diagnostic algorithm. Electrical contact pressure gauges measure the pressure in the tanks and air distributor chambers, and time interval counters record the time (in seconds) when the tanks are filled or emptied. The memory unit remembers the information and stores it until the end of the test.

If at any stage of diagnosis the measured parameters go beyond the established standards, the tests automatically stop and the red signal lamp lights up. The display block indicates in which operation a defect was detected. This allows you to quickly determine which air distributor assembly is faulty.

freight car brake equipment

Auto modes.

Diagnosis of auto modes is carried out on a stand (Fig. 3). The stand consists of a pneumatic clamp, in which auto mode 1 is set and connected to reservoir 6 and through valve 2 to reservoir 3. Reducer 4, receiving power from compressed air line 7, maintains a given pressure in reservoir 3. In turn, the tank 6 is equipped with a tap 5 with a calibrated hole. Imitation of the operation of auto mode 1 at different car loads is carried out by cylinder 9 using tap 8.

Rice. 3. SchemestandFordiagnosingauto modes.

Diagnosis of auto mode is carried out in the following sequence. First, the reducer 4 sets a pressure of 0.3 - + 0.005 MPa in the tank 3, i.e. reservoir 3 will simulate the operation of the car brake air distributor. Auto mode 1 is set to work in empty mode, i.e. with a gap between the head and the cylinder rod 9 in the released state d? 1 mm. Tap 2 is opened, and compressed air from reservoir 3 through auto mode 1 enters reservoir 6, which plays the role of a brake cylinder. A pressure of 0.125 - 0.135 MPa should be established in the brake reservoir 6. This concludes the first stage of testing. At the second stage, valve 2 is closed, and compressed air from reservoir 6 is released into the atmosphere. Using valve 8, compressed air is supplied to cylinder 9 from line 7. Cylinder 9 is activated and retracts the auto mode head 1 by 24 - + 1 mm, i.e. switches its operation to medium mode. Next, reducer 4 sets the initial pressure in reservoir 3, opens valve 2 and measures the pressure in brake reservoir 6, which should be 0.3 MPa. The time it takes for the auto mode damper piston to move down when releasing air from cylinder 9 should be within 13-25 seconds. In the same order, the operation of the auto mode is controlled during other loadings of the car, as well as when simulating a leak from the brake cylinder by opening a calibrated hole in valve 5 of reservoir 6.

Automatic linkage regulators

The effectiveness of the braking system largely depends on the correct operation of the brake cylinder and linkage. The output of the brake cylinder rod must be within the limits prescribed by the instructions of the Ministry of Railways. An increase in the rod output above the established norm leads to a decrease in the effectiveness of the brake, since the pressure in the brake cylinder will be lower than the calculated value. Small rod outputs with indirectly acting brakes cause excessive pressure in the brake cylinder, which can cause wheel jamming.

The output of the brake cylinder rod depends not only on the wear of the brake pads, but also on the correct adjustment of the linkage and its rigidity. The brake linkage must be adjusted so that, when braked, the horizontal arms occupy a position close to perpendicular to the brake cylinder rod and rods. The vertical arms on the cart should have approximately the same slope, and the suspension and pads should form approximately a right angle between the suspension axis and the direction of the radius of the wheel passing through the center of the lower suspension joint.

The transmission rigidity should not be below normal. For example, on a freight car with a brake cylinder with a diameter of 14 and a gear ratio n рп = 11.3, the rod output in empty mode is 110 mm, in medium mode - ? 120 mm, and when loaded - ? 135 mm. To ensure automatic control of the lever transmission, autoregulators are used, for example, 536 M, 574 B, and the pneumatic regulator RB 3. The lever transmission regulators are checked on a bench (Fig. 4). The stand consists of a brake cylinder 1 connected to a lever transmission consisting of a horizontal lever 2, a tested regulator 4, a limiter 3, an elasticity simulator of the brake transmission 5, a vertical lever 6 with a brake shoe, a wheel simulator 7 with an adjusting screw 8. The output of the brake cylinder rod 1 is measured with instrument 9. By adjusting the position of the wheel simulator 7 with screw 8, the gap between the wheel and the block can be reduced. Consequently, the stand simulates the operation of a lever transmission on a carriage. The regulator is tested on a bench according to an algorithm.

Rice. 4. SchemestandFordiagnosingautoregulatorslevertransfers.

From the beginning, set the regulator to its original position, i.e. when the linkage is adjusted correctly and the adjuster should not operate either to loosen or tighten the gear. In this position, the size a from the protective pipe to the control mark on the screw shank should be in the range of 75 to 125 mm. After this, the positional stability of the regulator is checked. To do this, chalk a longitudinal line on the pipe and the rods of the regulator screw and simulate a series of successive braking and release cycles on the stand. For a working regulator, the protective tube in this position should not rotate relative to the screw, i.e. the size a should not change. Next, check the effect of the regulator for dissolution. To do this, by turning the control pipe, screw the regulator nut onto the screw 1-2 turns and thereby reduce size a. The braking process is simulated on the stand and the regulator should restore the original size a, and during subsequent braking it should not change. At the next stage, the tightening action of the regulator is checked. To do this, turn the adjusting nut 1-2 turns to increase size a, i.e. "dissolve" the transmission. After each braking, the size a should decrease, which is observed by the chalk line “measured by a device” marked on the protective pipe and rod.

Anti-anti-union devices

The main function of these devices is to prevent wheel sets from jamming during braking. The anti-skid device consists of an axial sensor installed on the axle box of the wheelset; a safety valve located on the car body and connected to the axial sensor with a flexible hose; exhaust valve located next to the brake cylinder. The devices operate as follows. When a wheel set jams, the axial sensor sends a signal to the safety valve, which works as an amplifier and actuates the exhaust valve. Through the release valve, the compressed air from the brake cylinder is released into the atmosphere and the brake is briefly released. As soon as the rotation speed of the wheelset is restored, the braking process resumes, and so on.

Three types of anti-skid devices are used on carriages: inertial type, improved for international carriages, and electronic. Anti-skid devices of the inertial type are triggered when the rotational movement of the wheel tread reaches a deceleration of 3-4 mm per second. Includes an advanced anti-skid device such as MWX includes 4 axial sensors MWX2, two actuation valves M.W.A15 and four safety valves. Thus, the devices control the rotation speed of all four wheel pairs of the car.

The electronic anti-skid device kit includes an electronic unit, four tachogenerators installed on each axle of the wheel pair, and four electro-pneumatic relief valves.

Rice. 5. SchemestandFordiagnosinganti-uniondevices.

Power is supplied from a rechargeable battery. Despite the design differences, all types of anti-skid devices actually have structurally similar designs and are controlled at the stand (Fig. 5). The stand for testing the anti-skid device includes: a base 1 on which an axle box 2 with an anti-skid device sensor 3 is fixed; brake pad 4 with cylinder 6, which is mounted on frame 5; rotator 7 with V-belt transmission; dump valve 8; air distributor 9; brake line 10; spare tank 11; a brake cylinder 12, and a lever transmission simulator 13, in the form of an elastic element. The diagnostic technique is as follows. The stand is turned on and, using a rotator 7 with a V-belt drive, the specified rotation speed of the wheel pair axle journal with the flywheel is reproduced. Compressed air is supplied to cylinder 6, which receives the brake pad 4 to the flywheel. The braking process begins. The anti-skid device is tested from the beginning under normal braking, i.e. slowing down the speed of rotation of the wheelset to less than 3 m/s 2. In this case, the anti-skid device should not operate. Next, the jamming of the wheelset is simulated, i.e. the process of stopping the flywheel occurs with a deceleration of more than 3-4 m/s 2 . In this case, the sensor 3 of the anti-skid device should operate to turn off the brake system and turn on the relief valve 8, which connects the brake cylinder 12 to the atmosphere. The pressure is released from cylinder 6 and the process of rotation of the wheelset axis is resumed. At this time, valve 8 closes and air distributor 9 connects the reserve reservoir 11 with the brake cylinder 12, simulating the braking process. Then the anti-skid sensor 3 is triggered again and so on.

It should be noted that the described stand consists of two parts: the first, which simulates the jamming of a wheel pair and the operation of the sensor, and the second, which reproduces the operation of conventional elements of brake equipment - an air distributor, a spare reservoir, a brake cylinder and a lever transmission.

Diagnosis is carried out according to the parameters of deceleration at which the sensor is triggered, the time of emptying and filling the brake cylinder, the consumption of compressed air from the reserve tank when the anti-skid device is activated repeatedly, and others. Anti-skid devices are adjusted so that they prevent the wheel pair from jamming with a minimal reduction in the braking efficiency of the entire system.

Magnetic rail brake

Such brakes are used mainly as additional brakes for emergency braking of high-speed trains. Electromagnetic shoes are located on both sides of the trolley in the space between the wheels. Each such shoe, when the brake is released, is held above the rails by springs mounted in vertical pneumatic cylinders with guides. The shoes are also equipped with shock absorbers and cross braces.

During emergency braking, compressed air is supplied to the cylinders, which lower the shoes onto the rails, and at the same time, current from the batteries is supplied to the windings of the shoe electromagnets. The electromagnets are attracted, and friction of the shoes on the rails occurs, which provides braking for the cars.

Rice. 6. SchemestandFordiagnosingmagnetic railbrakes.

The effectiveness of magnetic rail brakes is checked on a stand (Fig. 6). For testing, the magnetic rail brake unit 1 is installed on rotating metal circles 2, which imitate a moving rail track, and secured by connections 3 with fixed supports. A series of braking-release cycles is performed. Braking efficiency is measured by the power consumption of electric motors rotating circles 2. During testing, the response time of the shoes for braking and release is also measured, and the efficiency of the lifting devices, dampers and connections is monitored.

Occupational safety requirements when repairing brake equipment of freight cars

1. Repair of brake equipment must be carried out in accordance with the repair and technological documentation, the requirements of the Instructions for the repair of brake equipment of cars by specially trained mechanics under the control and guidance of a foreman or foreman.

2. Before changing air distributors, exhaust valves, parts of brake equipment, reservoirs, supply pipes to the air distributor, before opening the brake cylinders and adjusting the lever transmission, the air distributor must be turned off and the air from the spare two-chamber reservoir must be released.

3. Tightening the brake lever transmission; when adjusting it, it should be done using a special device. To align the holes in the rod heads and brake linkage arms, you must use a punch and a hammer. It is prohibited to check the alignment of the holes with your fingers.

4. When blowing the brake line, to avoid hitting the connecting hose, you should hold it with your hand near the connecting head.

5. Before disconnecting the connecting hoses, the end valves of adjacent cars must be closed.

6. To disassemble the piston after removing it from the brake cylinder, it is necessary to compress the spring with the brake cylinder cover so much that you can knock out the pin of the rod head and remove the cover, gradually releasing it until the spring is completely decompressed.

7. Before disconnecting the head of the brake cylinder piston rod and the horizontal lever, the air distributor must be turned off and the air from the spare and dual-chamber reservoir must be released. Removal and installation of the brake cylinder piston must be done using a special tool.

8. Before changing the end valve, it is necessary to disconnect the brake line of the freight car from the power source.

9. When repairing brake equipment under a freight car, it is prohibited to stand at the piston rod head of the brake cylinder on the rod exit side and touch the rod head.

10. It is prohibited to tap the reservoirs of the working chamber and air distributor when cleaning them, as well as to unscrew the plugs of brake devices and reservoirs under pressure.

11. Special installations and air outlets for testing car brakes and other purposes must be equipped with connecting heads. When testing auto brakes, it is prohibited to carry out repair work on the chassis of the frame or the auto-braking device for the brakes of freight cars.

12. When repairing equipment located under a freight car, it is prohibited to sit on the rail.

Literature

1. Sokolov M.M. Car diagnostics.

2. Sergeev K.A., Gotaulin V.V. Fundamentals of technical diagnostics.

3. Birger I.A. Technical diagnostics. M: Mechanical engineering.

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...

Purpose of brake equipment for freight cars. Braking equipment for a passenger car

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METHODOLOGICAL INSTRUCTIONS

for laboratory work No. 11

GENERAL DEVICE OF BRAKE EQUIPMENT FOR FREIGHT AND PASSENGER CARS

in the discipline "Wagons (general course)"

Compiled by: A.V. Pargachevsky,

G.V. Efimova, st. teacher;

M.N. Yakushkina, assistant

Irkutsk 2005

Laboratory work No. 11. General design of braking equipment for freight and passenger cars

Purpose of work: To study: the general structure of the brake system she; location of the main devices of autobraking equipment on freight and passenger cars; types of pneumatic brakes, their braking modes.

Brief information from the theory

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

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

The air distributor is connected to the brake line (M), the reserve reservoir 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 (BP), which must be closed if the car's automatic brake is faulty - the valve handle is located across the pipe.

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

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

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 steering wheel or handle.

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

Some types of passenger cars are equipped with an anti-skid device that automatically reduces the pressure in the brake cylinder to stop the wheel pair from slipping when the braked car moves.

Similar documents

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Air distributors and auto modes

The method for diagnosing air distributors can be considered using the example of testing the devices of freight cars. On the test bench, four parameters of the functioning of the main part of the air distributor and three of the main part are monitored.

Automatic linkage regulators

Rice. 4. SchemestandFordiagnosingautoregulatorslevertransfers.

Anti-anti-union devices

The electronic anti-skid device kit includes an electronic unit, four tachogenerators installed on each axle of the wheel pair, and four electro-pneumatic relief valves.

Rice. 5. SchemestandFordiagnosinganti-uniondevices.

Magnetic rail brake

Rice. 6. SchemestandFordiagnosingmagnetic railbrakes.

Occupational safety requirements when repairing brake equipment of freight cars

1. Repair of brake equipment must be carried out in accordance with the repair and technological documentation, the requirements of the Instructions for the repair of brake equipment of cars by specially trained mechanics under the control and guidance of a foreman or foreman.

3. Tightening the brake lever transmission; when adjusting it, it should be done using a special device. To align the holes in the rod heads and brake linkage arms, you must use a punch and a hammer. It is prohibited to check the alignment of the holes with your fingers.

4. When blowing the brake line, to avoid hitting the connecting hose, you should hold it with your hand near the connecting head.

5. Before disconnecting the connecting hoses, the end valves of adjacent cars must be closed.

6. To disassemble the piston after removing it from the brake cylinder, it is necessary to compress the spring with the brake cylinder cover so much that you can knock out the pin of the rod head and remove the cover, gradually releasing it until the spring is completely decompressed.

7. Before disconnecting the head of the brake cylinder piston rod and the horizontal lever, the air distributor must be turned off and the air from the spare and dual-chamber reservoir must be released. Removal and installation of the brake cylinder piston must be done using a special tool.

8. Before changing the end valve, it is necessary to disconnect the brake line of the freight car from the power source.

9. When repairing brake equipment under a freight car, it is prohibited to stand at the piston rod head of the brake cylinder on the rod exit side and touch the rod head.

10. It is prohibited to tap the reservoirs of the working chamber and air distributor when cleaning them, as well as to unscrew the plugs of brake devices and reservoirs under pressure.

11. Special installations and air outlets for testing car brakes and other purposes must be equipped with connecting heads. When testing auto brakes, it is prohibited to carry out repair work on the chassis of the frame or the auto-braking device for the brakes of freight cars.

12. When repairing equipment located under a freight car, it is prohibited to sit on the rail.

Literature

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