NEW YORK AIR BRAKE CORPORATION

Transcription

1 NEW YORK AIR BRAKE CORPORATION A KNORR BRAKE COMPANY 748 Starbuck Avenue, Watertown, New York C.W. 307 COMPONENT WRITE-UP OF CCB-26 LOCOMOTIVE BRAKE SYSTEM ISSUE NO. 1 C.W. 307 GENERAL The CCB-26 system is a microprocessor based electronic air brake system designed to function as a direct replacement for an AAR freight 26L system, with an added pneumatic penalty brake function with provisions for pipes #3 (suppressible) & #10 (non-suppressible). This system is not intended for locomotives that have a locomotive computer and/or screen interface requirements. CCB-26 does not require an interface for cab electronics or screen displays. Instead, the engineers interface contains the basic two duplex gauges for pressure display and rotary selectors for mode selection. This system contains simple electronic modules that enable full closed loop pressure control, which allow for full time diagnostic health and performance monitoring and can take action to make a safe stop if system failure is detected. Equalizing reservoir, brake pipe control and IA&R pipe control are managed by computer electronics. Brake cylinder control is fully pneumatic and actuating pipe control is electro-pneumatic. This system does not include passenger mode (graduated release) functionality. The system performs several diagnostic functions like self test, calibrations, and a fault flagging via PTU software typically run on a laptop. Faults are detected and displayed on an LCD screen mounted on the driver s brake valve (EBV). A one wrench maintenance philosophy allows for rapid replacement of failed modules based upon the displayed fault information. This system contains only the main reservoir transducer back up mode. LOCOMOTIVE EQUIPMENT The CCB-26 consists of three major parts: The Electronic Brake Valve, the Relay Control Portion (intelligent), and the Electro-Pneumatic Control Unit which is comprised of eight line replaceable units (LRU s). The eight LRU s are the Brake Pipe Control Portion (intelligent), the Equalizing Reservoir Control Portion (intelligent), the DB Triple Valve, the 16 Pipe Control Portion, the 20 Pipe Control Portion (intelligent), the Brake Cylinder Control Portion, the 13 Pipe Control Portion, and the Power Supply / Junction Box. The LRU s labeled intelligent contain a control node. Control nodes are microprocessors that form the distributed brain of the system and monitor each others health and running health of the brake system. 1

2 A. The Electronic Brake Valve (EBV), Fig. 1 The EBV is a microprocessor controlled unit that communicates with the rest of the system via the network. This is the operator interface. It contains the automatic and independent brake handles, mode select switch, feed valve adjustment switch, and the message display. The mode select switch allows for Lead Cut-In, Lead Cut-Out and Trail. The feed valve adjustment switch is spring-centered and allows an increase or decrease of the ER release set pressure. It contains a pneumatic vent valve which mechanically initiates an emergency brake pipe vent when the automatic handle is placed into the emergency position. The display screen is a two-line LCD unit that allows for crew advisory messaging and display of diagnostic information. It advises the operator when a penalty or emergency is enforced and how to reset. It also gives instantaneous feedback for every handle movement. A Real Time Clock logs dates and times of any detected faults. Fig. 1 - EBV 2

3 B. The Relay Control Portion (RCP), Fig. 2 This intelligent unit is mounted on the EPCU, and provides discrete signal interface to locomotive controls. The wire connections of previous brake systems were wired to pressure switches for sanding, PCS, IBS, etc. This system has the wire connections wired to the RCP providing logic controlled electro-mechanical relays in lieu of less reliable pressure switches. A new printed wiring board is used to mount the computer controlled electro-mechanical relays. FIG. 2 RCP PORTION 3

4 C. The Electro-Pneumatic Control Unit (EPCU), Fig. 3 This unit is typically mounted in the locomotive brake bay and contains the valves that control the air pressures necessary for operation of the air brake system. There are eight LRU s: FIG. 3 - EPCU 4

5 1. The Brake Pipe Control Portion (BPCP), Fig. 4 This intelligent LRU s primary function is the supply, exhaust, maintaining and cut-off of brake pipe. It monitors and controls brake pipe pressure and flow with a pneumatic flowmeter. The BPCP determines emergency detection and contains emergency-initiating magnet valves. It controls cut-in and cut-out of brake pipe charging, brake pipe charging relay valve, break-intwo detection and brake pipe pressure sensing. Fig. 4 BPCP PORTION 5

6 2. The Equalizing Reservoir Control Portion (ERCP), Fig. 5 This intelligent LRU s primary function is for control of brake pipe relay. It controls pressure in the equalizing reservoir using pulse-width modulated, proportional, closed loop control technology. This also includes valving to accomplish fully pneumatic penalty override. The ERCP also contains the dead engine regulator and cut-off selector as well as the brake cylinder pressure transducer. The pneumatics are modified to emulate the #3, #10 & #26 pipes of the 26L system and require an electrical signal (transducer) to the node indicating penalty status. Fig. 5 ERCP PORTION 6

7 3. The DB Triple Valve (DBTV), Fig. 6 This LRU is a purely pneumatic valve which develops brake cylinder pressure during service brake applications in response to reduction of brake pipe pressure. It contains the direct release valve and the Dynamic Brake Interlock (DBI) magnet for the DBI type 2 systems. FIG. 6- DBTV PORTION 7

8 4. The 16 Control Portion (16CP), Fig. 7 This LRU contains service and emergency limiting valves, as well as emergency brake cylinder assurance valves to charge brake cylinders from main reservoir during emergency. The 16CP controls service bail-off, emergency bail-off and service & emergency limiting. This portion can be adapted for passenger use by replacement with the CCB II 16CP. FIG. 7-16CP PORTION 8

9 5. The 20 Control Portion (20CP), Fig. 8 This intelligent LRU contains a relay valve for charging the IA & R pipe, as well as the pulse-width modulated, proportional, closed loop control valves for control. It provides independent application and release pipe pressure. The 20CP control node controls the relays for the lead / trail function of bailoff. Fig. 8 20CP PORTION 9

10 6. The Brake Cylinder Control Portion (BCCP), Fig. 9 This LRU s primary function is to control brake cylinder pressure using 20 pipe or 16 pipe pressure as a pilot pressure signal. The 20CP is a relay valve that allows the system to achieve full braking pressures even when powered off on a dead locomotive in trail. It replaces the 26L J relay valves. Fig. 9 BCCP PORTION 10

11 7. The 13 Control Portion (13CP), Fig. 10 This LRU s primary function is to supply main reservoir pressure to the trainline for bail-off of automatic brake cylinder pressure. It controls the actuating pipe (bail off) function for service, emergency or power up applications. FIG CP PORTION 11

12 8. The Power Supply / Junction Box (PSJB), Fig. 11 This LRU provides system power to the EPCU and is a junction point for system signals and network connections. The PSJB accepts the locomotive power (74 VDC) as an input and conditions it for output (24 VDC) to the rest of the brake system. It also serves as the cable connection point for the EBV, RCP, and the EPCU LON cables as well as portable test unit (PTU) access. FIG. 11 PSJB PORTION 12

13 Penalty Brake Function A penalty brake function was implemented with the addition of the #3 & #10 pipes. When a penalty occurs, the brakes are automatically applied. There are five types of penalties: 1. Non-suppressible This penalty occurs when called for regardless of handle position. 2. Suppressible 3. Power up This penalty can be avoided / prevented with the automatic brake handle. This non-suppressible penalty is enforced when the system is turned on. 4. Fault or System This non-suppressible penalty is a diagnostic action that is computer controlled. A system penalty is declared by the RCP. A system / fault penalty is declared by the ERCP. 5. Loss of power This non-suppressible penalty is enforced when the system is turned off or a power malfunction occurs. The penalty brake function operates through the #3, #10 and #26 pipes. Pipe #3 is the suppressible penalty pipe. The application of a penalty can be prevented with brake cylinder pressure or the pressurization of pipe #26 (suppression pipe) which occurs with automatic handle movement. Pipe #10 is the non-suppressible penalty pipe. It bypasses all computer controls to apply the penalty brake when requested. This penalty application cannot be prevented. Penalty reset functions are provided by the EBV. Support tools There are three support tools for this system: 1. Self test When self-test is applied, the system performs a test on the running capability of all computer locomotive equipment. 2. Flow calibration When flow calibration is applied, the system calibrates the flowmeter. 3. Fault Summary When fault summary is applied, the system provides a list of all occurring faults in the system past and present. 13

14 REVISION PAGE ISSUE NO. 1 Original Issue 14