Druckregler, insbesondere Bremskraftregler

摘要

1,196,988. Fluid pressure brakes. WESTINGHOUSE BREMSEN-UND APPARATEBAU G.m.b.H. 7 March, 1968 [10 March, 1967], No. 11033/68. Headings F2F and F2V. A pressure regulator, for inclusion in the brake pipe between the brake valve and cylinder of an air pressure braking system for a vehicle, includes a differential piston 6, Fig. 1, with a smaller area exposed to the input pressure in chamber 4 than to the output pressure in chamber 14 and an auxiliary piston 5 acted on by the input pressure against the action of a spring 8, the arrangement being such that at input pressures below a predetermined input pressure the differential piston functions independently of the auxiliary piston to produce an output pressure which bears a constant ratio to the input pressure and at input pressures above the predetermined pressure the auxiliary piston and differential piston act together to produce an output pressure which bears a constant, but larger, ratio, than that previously, to the input pressure. As described, for zero braking force, the differential piston is in the position shown with the output chamber 3 connected to the atmosphere via aperture 15. When the brake valve is opened so that pressure is applied to input 2, the differential piston 6 moves downwards until the valve plate 12 closes aperture 15 and valve plate 11 moves away from valve seat 13 in the piston 6 so that the pressure in chamber 4 is communicated to chamber 14. At equilibrium the piston 6 is positioned so that the plate 11 closes valve seat 13 when the pressure in chamber 14 is in proportion to the pressure in chamber 4 in the ratio of the areas of the two sides of the piston. For these pressures the auxiliary piston 5 is held against movement by the spring 8. At the predetermined pressure the input pressure on the auxiliary piston becomes greater than the force on the spring 8 causing the auxiliary piston to be moved downwards until it contacts a stop 9 on the differential piston thereby moving the latter and displacing the valve plate from the seat 13. Above the predetermined pressure, equilibrium is established when the force on the underside of the differential piston due to the output pressure is equal to the force on the upperside of the piston together with the differential force on the piston 5, thus the output pressure is larger in proportion to the input pressure. The regulator is so arranged that at maximum input pressure, the output pressure is equal to the input pressure.