breaks and pneumatics

7/24/2019 Breaks and Pneumatics

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RS Training ManualLevel - I ROLLING STOCK

DELHI METRO RAIL CORPORATION LIMITEDRevision No: A2 ISO 9001:2008

Date: 01.09.2012 BRAKES & PNEUMATICS

Page 1 of 20For Rolling Stock Personnel Only

BRAKES AND PNEUMATICS

Brake System

Type of Brakes;

1. Service Brake: Electric Regenerative brake and Electro-Pneumatic (EP) friction brablending, Load weighed and Jerk Controlled

2. Emergency Brake: EP friction brake, Load weighed

3. Parking Brake:Spring applied, air-release parking brake

4. Holding Brake:EP friction brake

5. BP (Brake pipe)-back up brake: Pneumatic friction brake

Service Brake-Priority of braking effort;

- Electric Regenerative brake controlled by C/I of Motor car

- EP friction brake controlled by BECU of Driving trailer car

- EP friction brake controlled by BECU of Motor car (In the beginning and end ofservice braking)

- EP friction brake of Driving Trailer car & Motor car (In case of failure of electricbrake)

Brake Blending - The Electric brake of each Motor car is used in preference to the pneumatbrake, as it works without wearing either brake blocks and is therefore more economical. Thelectric brake is controlled by the C/I (Converter/ Inverter),


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In case that the Electric Regenerative brake cannot provide the braking effort as demanded by thmaster controller of the driver, the missing brake effort will be supplied by the pneumatic brak

This feature is called blending.The M car BECU on a two-car basis controls the brake blending. Blending is carried out betweeMotorcar and Driving trailer car of a unit.

Emergency BrakeThe train set is equipped with an emergency brake loop wire. The emergency brake loop connected to the emergency brake magnet valve, which is opened when de-energized and closewhen energized (Fail-safe system).

So, in case the emergency brake magnet valve is de-energized by interrupting emergency brakloop, the emergency brakewill be applied automatically.

Holding brake-The holding brake is provided to prevent the train from rolling backwards on a rising gradient anthe train from moving at the station.

The holding brake is released when C/I sends the signal Reset Holding Brake to the BECU. Thtractive effort, which is applied when the signal Reset Holding Brake Request is initiated, shensure that the train will not roll backwards at a slope. The holding brakes are 70% of full servicbrakes.

Parking Brake

Parking brake is used for parking the train in depot and these are installed at Driving trailer cand Motor cars (1 set per axle).

Parking brake can be applied manually or these may apply automatically also when the Mpressure is low. To apply parking brake put Mode Selector at Standby position and press ParkinBrake On Push Button. To release press Parking Brake OFF Push Button.

Parking brakes are automatically applied in the event of loss of the main reservoir pipe pressure.

Parking Brake Manual Release - When MR pressure is low, it is possible to release individu

parking brake manually from track level by; pulling out the manual release device installed at thparking brake cylinder.


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Operation of parking brake is monitored through the parking brake lamp installed at drivers des

and TIMS screen.

When the parking brake is applied the parking brake lamp will be illuminated and the applicatiocan be read through TIMS screen also.

Load WeighingThe load dependent pressure limiting valve (B3.C) is used to limit the supply reservoir air pressuaccording to the actual car load.

At the same time the average load signal is electrically fed to the BECU from the T pressutransducer on the EP-BCU. This signal is used for load compensation of the propulsion and a

conditioning system.

Wheel Slide Protection (Anti-skid control)-Wheel slide protection is used to optimize the stopping distance and to avoid the wheel flats undewheel sliding conditions. Wheel slide protection is active in service brake and emergency brake.

The wheel slide protection acts per bogie on each car by the dump valves (G2). Wheel-slidprotection is operational at all speeds down to 3 km/h.

Speed sensor mounted on the cover of each axle box, detects the speed of the associated whee

When a potential wheel-slide event is detected, the BECU will release/apply the brakes througenergizing/ de-energizing the magnets of the dump valves.

Wheel slip/slide is also controlled by CI during electric regenerative braking and powering.


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BP-back up Brake-Additional BP (Brake pipe) controlled back-up brake system is provided in order to take over th

brake control function in case of failure of individual electronic or electrical control elements. Thdriver can continue to control the pneumatic friction brake by using the drivers brake valve.

The driver is able to apply or release the pneumatic brake by operating the drivers brake valvinstalled at the drivers cab.

By the brake valve the brake pipe (BP) pressure can be reduced or increased depending on thtime the brake lever is maintained at braking or driving. During the normal service brakoperation, the drivers brake valve lever shall be maintained at driving.


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Brake Application Flow DiagramDBV TBCEBPB PBPB

ON/OFF

BECU

DistributorAnalog

ConverterEMVCheck

Valve

Brake Pipe

Relay

Valve

Load Limiting

Valve

PBMV

Relay valve

Two

way

Bogie-2 CylinderBogie-1 brake cylinder

BCU

100 lt.Supply

Reservoir

Reservoirs

MR Pipe


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Pneumatic Air Distribution System-

GeneralThe complete compressed air supply system in each two car (DT & M car) unit consisting of:

- Piston type air compressor VV120- Dual chamber air dryer unit type LTZ015- Oil separator- Micro oil filter- Auxiliary compressor-Reservoirs, Pressure governors and switches, Pipe system, Automatic coupling actuatinequipment

Main CompressorThe compressor is a cylinder piston compressor powered by a 415 V AC, 50Hz motor and it has capacity of approximately 900 L/min free air at 10 bar.

The main air-compressor unit is controlled by one relay contact of BECU in the software to 8.0 bafor cut in and 10 bar for cut out. The second pressure switch (A9) set to 7.5 bar for cut in and 1bar for cut out is provided as hardwired back-up in case of failure of BECU. Based on thelectrical signals of the pressure switch A9 and pressure transducer A10 the main motor contactis controlled.

In normal service operation the air compressors of each DT car is controlled individually by threlevant BECU at that trailer car. The BECU in turn communicates with all other BECU installed the train consist to determine which air compressor should be operated.


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Fig. Main Compressor


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Air Dryer and Filtration

Moisture in compressed air systems often causes the pneumatic equipment to malfunction andwear prematurely as a result of corrosion and freezing.

The compressed air supplied by the main air compressor is filtered by oil separator and dried bythe air dryer unit and filtered by the oil micro filter.

The air dryer unit consists of two chambers with a adsorptive desiccant. While the main air flow being dried in one chamber (I), the desiccant of the other chamber (I) is being regenerated by threversed air flow.

Fig. Air Dryer Unit


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19 Tower 34.15 KNORR K-ring 71 Valve head forbypass valve

19.7 Desiccant 34.17 KNORR K-ring A Drainage port19.11 Oil separator bowlwith

Raschig rings

43 Valve Magnet O.. Exhaust port50 Regeneration choke P1 Air supply port

24 Valve cone for checkvalve

55 Piston for precontrolvalve

P2 Air pipe connectionto main reservoir

25 Bracket 56 KNORR K-ring34 Duplex piston valve 70 KNORR K-ring V.. Valve seat

Main ReservoirAir supply system is provided with main air reservoirs (A7) with a capacity of 200 liters & located each DT Car.

Fig. Main Reservoir

Auto Drain Valve

The automatic drain valve is used for automatic drainage (with manual drain also) of condensatefrom compressed air reservoirs and oil/water separators. The drain valves are operatedpneumatically by the magnet valve A17.

1 Body 4.1 Valve stem P Inlet port

2Body 5 Manual drainvalve V Conicalvalve sea

3 Spring 6 Sealing ring Z Control aiport

3.1 Spring A Sump O Exhaust p

4 Valve E Drain bore


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Fig Auto Drain ValveThe MR pipe feeds air to the following subsystems:

1. Brake system2. Air suspension equipment3. Pantograph4. Pneumatic signaling equipment5. Automatic couplers

Isolating Cocks

It is possible to isolate the compressed air supply system to the consumers such as asuspension equipment, pantographs, air horns and automatic couplers by operating the isolatio

cocks with/ without a vent and an electrical switch. The isolation cocks with/ without a vent and aelectrical switch are located on the under frame adjacent to the bogie.

Fig Isolating Cock

1 Housing 4 Handle I Supply port

2 Spherical plug 5 Stop washer II Consumerport

3 Ball valve 6 O-ring


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Single Protection Valve

The single protection valve (B26) is installed in front of the main reservoir (MR) air hose of eachend of the car. The valve shuts off the air supply through the hose in the event of a break ordamage to the hose or the main piping, maintaining the main reservoir air pressure in the system

Fig. Single Protection Valve

Auxiliary Air Distribution System-In the event that the MR pipe is not charged, the required air pressure for pantograph operation supplied by the auxiliary motor-compressor unit (U01).

The unit includes a single-stage compressor driven by a 110 VDC motor.


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Brake Control Equipment

Brake Electronic Control Unit

The BECU commands the brake system and implement anti-skid functions by evaluating the spoints for the brake value out of various input signals (e.g. brake demand signals, speed signaor load signals.).

BECU calculates the required brake force according to brake demand and send electrical signal the BCU. Every car has its individual BECU.

To achieve a comfortable ride in all braking modes, load correction and wheel slide control an

jerk control are active.

Equipment Layouts

Brake Electronic Control Unit

The BECU consists of the following PCBs

1. MB04B Card - MB04B is a main board. It is loaded with application software. It consists

a main board MB03B and a man machine interface (MMI).

2. EB01B Card - EB01B is an extension board in the ESRA system. The board is used enhance the input and output operations of the main board. The EB01B extension boaprovides relay outputs, and optocoupler inputs and outputs. EB01B interfaces with thperipherals


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3. CB07A Card - CB07A is a communication board in the ESRA system. The boatransforms messages between the internal BECU bus and an external RS485 bus.

4. PB03A Card - PB03A is used to power the BECU. It meets the demands of both theelectronic boards and the sensors and actuators.

Brake Control UnitOne pneumatic brake control unit (B3) is provided in every car. The BCU has following macomponents

a. Analog Converterb. Emergency Brake Valvec. Double Check Valved. Pressure Transducere. Load Limiting Valvef. Relay Valve

The analogue converter (B3.A) in converts the electric friction brake demand signal frothe BECU (B15) into a proportional pre-control pressure (Cv).

The analogue converter is equipped with a charging magnet valve, a venting magnet valvand a feedback pressure transducer Cv for a closed control circuit.

C

STV

R

C

Cv

RCv Aw4.1

Kr6

T

A1A2

A3A4

Cv1

Cv2

T

E

M A

C

D

Brake ControlUnit

A1A2

A3A4

IP

E

B

R1

IP

F

J

L

N

G

R

C

Cv

RCv

A1A2

A3A4

E

R

R

C

Cv

RCv

Brake Control Unit (BCU)

The signal of the pressure transducer Cv indicates the actual pressure level in the control unit.

The relay valve provides a large volume air flow a the specific pressure level, pre-controlled by thanalogue converter, to actuate the brake cylinders.


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The Cv-pressure sensor B3.G is used to indicate the emergency brake pressure level generateby the emergency brake magnet valve (system pressure 8 to 10 bar).

The double check valve B3.B is used to change-over between normal service brake and back-ubrake operation by the distributor valve type STV (B41).

The isolating cocks with electrical switch (B4.3) in the brake cylinder pipe isolate the brake pbogie and allow the air-applied brake cylinders to be released on a per bogie basis.


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Equipment LayoutAlmost of all brake equipments including the Main air compressor, Air dryer, Auxiliary a

compressor, BCU and etc are located at the under frame.

The following items are installed at the drivers cab, interior end part or interior saloon or bogpart as followings.

Location of Equipment Items

Drivers cabDrivers brake valve (B61), Relay valve (B62), Magnetvalve (B63), BPCON cock (B69)

Interior end part BECU (B15), Isolation cocks (U10 and U12)

Interior saloon Isolation cocks (B4.3A, B4.3B)

Bogie partBlock brake units (C2 and C3), Air hoses (C4 and C5),Pole wheel (G4), Air spring (L9)

Air Pipe Descriptions Colour

BP Brake Pipe Green (G)MR Main Reservoir Pipe White (W)

BC Brake Cylinder Pipe Red (R)

AS Air Suspension Pipe Yellow (Y)

PB Parking Brake Pipe Black (B)

SR SR gauge Pipe Yellow (Y)

PANTO Panto Pipe Yellow (Y)

UNCOUPLE Uncoupling Pipe Yellow (Y)


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Isolating Cock and Air Pipe

Name plate DescriptionsColour

of Cock handle

MRP Main Reservoir Pipe White (W)

BP Brake Pipe Green (G)

CM Compressor Motor White (W)

SR Supply Reservoir Red (R)

EPIC EP Brake Isolation Cock Red (R)

BIC Brake Isolation Cock Red (R)

PARK Parking Isolation Cock Black (B)

AS Air Suspension Yellow (Y)

ASCO Air Suspension Cut-Out Yellow (Y)

HORN Air Horn White (W)

UNCOUPLE Uncoupling Yellow (Y)

BPIC BP Isolation Cock White (W)

BPCON BP Brake Control Green (G)

BPMR Brake Pipe to MR pipe Green (G)

PANTO PANTOGRAPH Yellow (Y)

VCB Vacuum Circuit Breaker Yellow (Y)


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APPLICATION OF BRAKES BY DBV

DBV B61) Handle on Position V application)

Brake Application

Brake Pressure to Brake Cylinder

Control pressure to relay Valve B03D)

Control Pressure to Load Limiting valve

B03C)

Relay valve vents the BP pressure

Control Pressure of Relay Valve reduces

Distributor Valve B41) Activates

Air Pressure between Relay Valve B62) and DBV Vents


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APPLICATION OF PNEUMATIC SERVICE BRAKE

Brake Demand from TBC

Pneumatic Brake Demand from BECU

Brake Application

Analog Converter (B 03R)

Conversion of Electrical Signal to Pneumatic Signal(Hot redundant)

Emergency Brake Valve (B 03F)

Check Valve (B 03 B)

Electric Load signal from BECU to Pressure Transducer (B 03F)

Control Pressure to Relay Valv3e (B 03 R)

B

C

U


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APPLICATION OF EMERGENCY BRAKE

Emergency Brake Loop Interrupted

Emergency Brake Signal from BEC

Emergency Magnet Valve (B 03 E)

Load Limiting Valve (B 03 C)

B

C

U


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Page 20 of 20

Brake Cylinder

Emergency Brake Application

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