| 摘要 |
An automatic pneumatic control system (30) for the air springs (16) of a semi-trailer air-ride trailing beam-type axle/suspension system (11). A plurality of conduits (38,42,44) and valves (32,35,41,43) of the control system pneumatically interconnect one or more sources of compressed air (31,39), the vehicle parking brakes (37) and the suspension air springs (16). The control system (30) incorporates a vented two-position two-way pilot valve (52) for controlling inflation and deflation of each air spring (16). The valve (52) closes when air pressures in a pair of control system sensor lines (45,51) differ, thereby enabling complete or nearly complete deflation of the air spring (16) it controls before the parking brake (37) is set, thereby minimizing or eliminating the problems of trailer drop and walk during loading of an empty trailer, heretofore caused by complete or nearly complete deflation of the air springs (16) only after the parking brakes (37) are already set. |
