| 摘要 |
1346615 Compressed air braking systems KNORR-BREMSE GmbH 20 April 1971 [20 April 1970] 10253/71 Heading F2F In a compressed air brake system for a rail vehicle a pressure control valve 25 provides a quick release of the vehicle brakes after a brake application by introducing a pressure surge into the train pipe 2. Brake application.-A drivers valve 20 is moved to allow pressure in a pipe 22 connected to a reservoir 21 to pass to atmosphere. The pressure in a chamber 13 of a relay valve 1 is thereby lowered enabling the pressure existing in a chamber 11, connected through an orifice 17 of a wall 10 separating the chamber from a further chamber 3, to move a piston 12 rightwardly causing air to pass through a tubular piston-rod 14 to atmosphere. Pressure in a train pipe 2 connected to chamber 3 is thereby lowered to apply the brakes. Thereafter as the pressure in chamber 11 falls piston 12 is caused to move leftwardly allowing a valve seat 15 thereto to rest against a valve plate 7. Brake release.-The release valve 25 has a piston 26 separating upper and lower spaces 24, 28 connected respectively through a pipe 19 to a pressure reducing valve 18 and to the reservoir 21. Plunger 35 is manually depressed and the difference in pressure between the spaces 24, 28 is sufficient to allow piston 26 to remain in a lowered position, abutting stops 42, in which space 28 is connected to a chamber 31 and pipe 22 by way of a passage 40 in a slide 37. Chamber 33 is connected by way of a pipe 34 to the chamber 11 of valve 1 and by way of a passage 41 in slide 37 to atmosphere. Chamber 11 is thereby vented and piston 12 moves leftwardly lifting valve plate 7 to connect train pipe 2 to a reservoir pipe 4 to charge the train pipe. The charging period is limited by the cross-section of a nozzle 27 in piston 26 which causes pressure in space 24 to be gradually lowered to that in space 28 so that piston 26 and valve slide move upwardly to cut off chamber 33, and hence chamber 11 from atmosphere. Air pressure then tends to equalize between chambers 11, 3 through throttle 17 and piston 12 moves rightwardly to seat valve plate 7. |
