| 摘要 |
A vehicle brake control system (10) comprises a hydraulic pump (12), a sump (14), a left manually operated brake member (16), a right manually operated brake member (18), a left hydraulic brake unit (20), and a right hydraulic brake unit (22). A left brake valve (30) is operatively coupled to the left manually operated brake member (16). The left brake valve (30) has a left pressure responsive pilot (32) acting in opposition to the left manually operated brake member (16). A supply port (36) is connected to the hydraulic pump (12). A return port (38) is connected to the sump (14). A left work port (39) is connected to the left hydraulic brake unit (20). A right brake valve (40) is operatively coupled to the right manually operated brake member (18). The right brake valve (40) has a right pressure responsive pilot (42) acting in opposition to the right manually operated brake member (18). A supply port (46) is connected to the hydraulic pump (12). A return port (48) is connected to the sump (14). A right work port (49) is connected to the right hydraulic brake unit (22). A solenoid operated normally closed balance valve (70) has a left port (72) connected to the left hydraulic brake unit (20) and to the left work port (39) of the left brake valve (30), and has a right port (74) connected to the right hydraulic brake unit (22) and to the right work port (49) of the right hydraulic brake valve (40). A brake member lock (24) has a locking position wherein the left and right manually operated brake members (16, 18) operate in unison and an unlocked position wherein the left and right manually operated brake members (16, 18) operate independently. |
