| 摘要 |
1534628 Change-speed gear control GENERAL MOTORS CORP 9 Sept 1977 [13 Dec 1976] 37714/77 Heading F2D An automatic transmission has shift points controllable by pressure from an input governor 87 modified by a regulator valve 216, the valve 216 reducing the input governor pressure by a smaller amount in each successive ratio, as the transmission changes up, to provide a simulated output governor pressure. Shift signal valves 151, 1511, 151<11> are controlled by governor pressure and by TV pressure provided by a valve 126 to supply signal pressures to relay valves 176, 176<1>, 17611 which in turn effect ratio shifts. The transmission has four forward speeds and reverse. The signal pressures are also supplied to chambers 332, 333 and 334 of regulator valve 216 to modify the input governor pressure in accordance with ratio. The regulator valve 316 is deactivated unless pressure is supplied to a chamber 248. An output governor 93 may be provided, as shown, the highest of the modified input governor pressure and the output governor pressure controlling ratio through a valve 249. The torque converter 11 has a lock-up clutch. A manual selector valve 96 limits the highest ratio obtainable in normal driving by way of a hold regulator valve 111 although a higher ratio (i.e. 3rd or 4th with the selector valve in DR2) may engage in higher speed coasting. The input governor employs a pilot head and the output governor employs plural masses controlling a valve. The gearbox has three planetary gearsets, 16, 22 and 28. The sun gear 19 of gearset 16 and the ring gear 27 of gearset 22 are driven through a clutch 36 in all forward ratios. A brake 81 holds the ring gear 21 of gearset 16 in reverse and first gear. Brakes 63, 73 and a clutch 51 select the other three forward ratios. |
