Patent GB-1191916-A (GB)
Title: Automatic Shifting Device of Automatic Speed Change Gear for Automobiles
IPC: F16H47/08
Filed: 1967-11-15
Abstract: 1,191,916. Change speed control. NISSAN JIDOSHA K.K. 15 Nov., 1967 [15 Nov., 1966], No. 52063/67. Heading F2D. A manual range selector valve 106 of an automatic control system for a planetary change speed gear comprises an axially slidable valve spool 126 selectively supplying pressure liquid from a main supply line 144 to ducts 201 . . . 208 in a first part (214) of a two part valve casing (214, 215) having the two parts separated by a partition 213 with a plurality of holes 221... 228 interconnecting the ducts 201 ... 208 with ducts 150, 153, 209, 210 in the second part (215) and the operative ranges of the selector valve are modified by providing different partitions having selected holes 221 . . . 228 blocked. A partition having holes 221, 223 and 228 only provides a selector valve giving Park (P), Reverse (R), Neutral (N), Drive (D) and Low (L) ranges, the drive range permitting automatic shifts between all three ratios and the low range enforcing second ratio, permitting a normal 2-1 downshift and preventing a 1-2 upshift. A partition with holes 222, 224, 225 or 226 and 228 provides a valve giving Park, Reverse, Neutral, Drive (D), Second Drive (D 2 ) and Low ranges. The second drive range permitting automatic shifts between second and third ratios whilst preventing first ratio. A partition having holes 221, 224 and 227 only provides a selector valve giving Park, Reverse, Neutral, Drive Second Low (L 2 ) and First Low (L 1 ) ranges. The second low (L 2 ) range permits automatic shifts between first and second ratios whilst the first low range (L 1 ) downshifts at a higher vehicle speed than the normal low range. A partition with holes 221, 224, 226, 227 provides a selector valve giving Park, Reverse, Neutral, Drive, enforced second and low ranges. Fluid system components.-An engine driven pump 101 supplies pressure liquid to a regulator valve 103 which controls main line pressure 144 and is subject to throttle pressure modulation, reverse boost modulation and high output speed reduction. The regulator valve 103 also controls admission of regulated pressure to a torque converter 3 and to front and rear lubricating ducts 180, 184. An engine manifold depression servo 174 controls a primary throttle valve 114 supplying throttle variable (T.V.) pressure 159 to a secondary throttle valve 111. The reduced secondary T.V. pressure 160 is fed to an intensifier valve 186 to obtain T.V. pressure modulation of the regulator valve 103 and to a throttle pressure intensifier valve 115. The valve 115 supplies boosted T.V. pressure 161 to 1-2 and 2-3 shift valves 107, 108. The valves 107, 108 are shifted automatically in response to opposing boosted T.V. pressure and output speed responsive governor pressure 164 supplied by first and second governor valves 112, 113 rotating with the gear output shaft. A governor pressure loaded "cut-back" valve 109 supplies pressure through a pressure reducing valve 104 to the regulator valve 103 to reduce line pressure above a predetermined speed. A solenoid operated "kickdown" valve 134 supplies additional loading pressure 156 to both shift valves 107, 108 when the accelerator pedal is over depressed.