| 摘要 |
<p>A brake pipe sensing unit (800) may be used with a universal pneumatic brake control unit (100) of a rail vehicle. The brake pipe sensing unit includes a control reservoir (803), an auxiliary reservoir (802), a three state valve (811), a quick service valve (812), a brake pipe transducer (804) and a transmission device (805). The control reservoir is used as a volume in which gas under pressure may stored and from which gas under pressure may be supplied. The auxiliary reservoir communicates with a supply port of the universal unit and with a first and a second route of the brake pipe sensing unit. The three state valve has a first pilot port in communication with a brake pipe of the rail vehicle, a second pilot port in communication with the control reservoir, and first and second exhaust ports both of which connect to atmosphere. The three state valve operates in an apply position, a release position and a lap position depending on the pressure bearing on the first and second pilot ports. The quick service valve connects within the first route and has a service pilot port in communication with both the auxiliary reservoir and the supply port. The quick service valve closes the first route when pressure at the service pilot port exceeds a preselected level. The brake pipe transducer converts pressure within the brake pipe to an electrical signal. The transmission device communicates the electrical signal received from the brake pipe transducer to a brake control bus on the rail vehicle.</p> |
