| 摘要 |
1,085,421. Change speed control. SOC. ANON ANDRE CITROEN. Feb. 8, 1966 [Feb. 22, 1965], No. 5482/66. Heading F2D. In a motor vehicle change speed gear, such as described in Specification 1,061,379, wherein, for upshift, automatic actuation of a relay 5 responsive to engine speed and torque energizes a solenoid valve 12 to engage an hydraulically actuated friction clutch 3 and simultaneously energizes a solenoid 15 to close an auxiliary throttle valve 16 for engine torque reduction, a piston 13b in a cylinder 13a is acted on against a spring 13c by the hydraulic pressure effecting clutch engagement, the arrangement being such that only when the clutch is completely engaged is said pressure high enough for the piston to open, by its rod 13d, contacts 14 in the circuit of the solenoid 15 and thereby reopen the auxiliary throttle valve. A range-shift lever 1 selects Neutral, PM; Low Range, GB, for 1-2 automatic shift; and High Range, GH, for 3-4 automatic shift. In 1st and 3rd gear, drive is through an hydraulic converter/coupling (not shown) the turbine of which is connected to a shaft 2. In 2nd and 3rd gear, drive is through the hydraulically actuated friction clutch 3. In operation, with the vehicle stationary the hydraulic converter/coupling drives the shaft 2 at idling speed and a vehicle-stop detector switch 7 is closed. On shifting the lever 1 to Low Range, GB, closure of a shift lever switch 6 energizes a relay 8 through the closed switch 7 to open a solenoid valve 9 to apply an hydraulic brake 10a, 10b to the shaft 2 to enable 1st gear to be engaged. As soon as the vehicle travels at a predetermined speed, the switch 7 opens, the brake 10a, 10b being needed only for starting. On actuation of the automatic relay 5, a relay 11 effects the abovementioned clutch and auxiliary throttle valve operation. On continued vehicle acceleration, the lever 1 is shifted to High Range, GH, and drive is firstly in 3rd gear, through the hydraulic converter/ coupling, the relay 5 opening to effect exhaust of hydraulic pressure to disengage the clutch 3 and return of the piston-rod 13d in readiness for 3-4 shift. |
