Shift Valve A, B, and C
Shift Valve A, B, and COutline
^ Shift valves A, B, and C switch the oil passages. These valves switch the line pressure oil passage according to each shift solenoid operation and apply operation pressure (line pressure) to each clutch and brake.
Operation
First gear (engine brake operation not possible)
^ Each shift solenoid is set to first gear (engine brake operation not possible) mode. The pilot pressure is applied to the bottom end of every shift valve and each shift valve is positioned on the upper side. Line pressure (1) is applied to the low clutch passing through shift valve B (oil passage (35)). Line pressure (5) is applied to the reduction brake passing through shift valve B (oil passage (34)).
Second gear
^ Each shift solenoid is set to second gear mode. Pilot pressure is applied to the bottom end of shift valves A, B, and shift valves A, B are positioned on the upper side. Conversely, shift valve C is positioned on the down side by spring force. Line pressure (1) flows through shift valve B and is applied to the low clutch (oil passage (35)). Also, line pressure (1) flows through shift valve C and is applied to 2-4 brake acting through shift valve A (oil passage (37)). Line pressure (5) is applied to the reduction brake flowing through shift valve B (oil passage (34)).
Third gear
^ Each shift solenoid is set to third gear mode. Pilot pressure is applied to the bottom end of shift valve B and shift valve B is positioned on the upper side. Conversely, shift valves A and C is positioned on the down side by spring force. Line pressure (1) flows through shift valve B and is applied to the low clutch (oil passage (35)). Also, line pressure (1) flows through the shift valve C and acts through the shift valve A and is applied to the high clutch (oil passage (23)). Line pressure (5) flows through shift valve B and is applied to the reduction brake (oil passage (34)).
Forth gear
^ Each shift solenoid is set to forth gear mode. Pilot pressure is applied to the bottom end of shift valve C and positioned on the upper side. Conversely, shift valve A and B is positioned on the down side by spring force. Line pressure (1) flows through shift valve B and acts through the shift valve A and is applied the 2-4 brake (oil passage (37)). Conversely, line pressure (32) flows through shift valve C and acts through the shift valve A and is applied to the high clutch (oil passage (23)). Line pressure (5) flows through shift valve A and acts through shift valve B and is applied to the reduction brake (oil passage (38)).
Fifth gear
^ Each shift solenoid is set to fifth gear mode. Pilot pressure is applied to the bottom end of shift valves A, C and shift valves A, C are positioned on the upper side. Conversely, shift valve B is positioned on the down side by spring force. Line pressure (1) flows through shift valve B and acts through shift valve A and is applied to the direct clutch (oil passage (36)). Line pressure (32) flows through shift valve A and is applied to the high clutch (oil passage (23)). Also, line pressure (1) that flows through shift valve B goes to shift valve C and is applied to the 2-4 brake acting through shift valve A (oil passage (37)).
