| 摘要 |
A dynamic/friction brake blending control system in which a brake pipe pressure responsive control valve device provides a friction brake pressure that is connected to the vehicle brake cylinders via a blending relay valve device having a self-lapping piston valve assembly spring biased to a brake application position in which the friction brake pressure from the control valve device is relayed unmodulated to the brake cylinders in the absence of dynamic brake effort on the vehicle. A control piston of the piston valve assembly is subject to the friction brake pressure from the control valve, while a friction brake feedback piston is subject to the friction brake pressure connected from the blending relay valve to the brake cylinders. These pistons act on the piston assembly in opposite directions and have equal effective pressure areas. A dynamic brake feedback piston is subject to the feedback signal of the dynamic brake effort sensed by a pressure transducer and acts on the piston assembly in cooperation with the friction brake feedback piston, such as to modulate the friction brake pressure from the blending relay valve to the brake cylinders as the dynamic brake effort increases. |
