improved luftsteuerrelais in luftbremssystemen for motor vehicles

摘要

1,127,256. Fluid-pressure brakes. SANWA SEIKI MFG. CO. Ltd. 28 Nov., 1966 [11 Dec., 1965], No. 53165/66. Heading F2F. In an air brake system for automotive vehicles having a control valve 1 operative in response to actuation of a pedal 2, a relay valve 4 is disposed in a brake piping leading to the front wheels and/or rear wheels of the vehicle, the relay valve comprising a volume chamber 40 having a relatively large volume and an orifice 41 of small diameter providing communication between the volume chamber and an air feed passage through the valve, the volume chamber and the orifice being so interrelated with each other that pressure build up in the volume chamber to reach pressure equilibrium under a pressure differential therebetween of 1 kg. per sq. cm. is delayed by 0À01 to 0À05 of a second and the relay valve is operative to provide a pressure peak at the beginning of the compressed air filling operation whereby to effect a quick braking action. As shown in Fig. 1, a reservoir 16 fed by an air compressor 15, supplies compressed air via the pedaloperated control valve 1 and lines 17, 18, 21a, 21aSP1/SP to the front wheel brakes cylinders 5, 5SP1/SP of the vehicle through a quick-release valve 3. At the same time air is supplied via lines 20, 21b, 21bSP1/SP to the rear wheel brake cylinders 6, 6SP1/SP through the improved relay valve 4 shown in Fig. 3. The relay valve has a chamber 36 fed with a control fluid-pressure supply via a port 35 such that when the pressure in the line 20 is increased, a diaphragm 29 is urged downwardly to allow an exhaust valve member 34 to lift a spring-loaded feed valve member 43 off its seat 46SP1/SP and allow air pressure from the reservoir 16 to pass through the inlet port 48 and into the air feed port 42 leading to the rear wheel brake cylinders 6, 6SP1/SP. At the same time, air pressure is fed slowly into the variable volume chamber 40 below the diaphragm 29 at a metered rate via the orifice 41. The pressure built up in the volume chamber 40 is delayed for the required time and the diaphragm 29 is urged upwardly by the combined action of the spring 37 and the pressure in the chamber 40 to move the exhaust valve member 34 back to the position shown in Fig. 3 wherein the supply from the inlet port 48 to the air feed port 42 is cut off and the air in the brake cylinders is allowed to escape to atmosphere via passages 42, 24 and 49. An alternative embodiment is disclosed in the Specification (Fig. 2, not shown) wherein a relay valve is disposed in the brake lines leading to the front wheels in addition to the relay valve disposed in the brake lines leading to the rear wheels of the vehicle.