| 摘要 |
1,206,263. Controlling vehicles. FORD MOTOR CO. Ltd. 24 Jan., 1969 [21 Feb., 1968], No. 4072/69. Heading B7H. [Also in Division G3] Automatic speed control means in a motor vehicle comprise a governor valve 28 and a reference valve 44 which are relatively movable in a common valve chamber 54 and have cooperating lands 34, 50 and 32, 46 for controlling application of fluid pressure through respective conduits 134, 146 and 136, 142 to opposite faces of a land 128 on a throttle actuator 26 connected by a lever 20 and link 22 to the throttle 18 of the vehicle engine. The governor valve 28 is movable against spring-loading 84 by fluid pressure exerted on a land 30 through a conduit 182 extending from a governor which is driven from the output shaft 14 of the vehicle transmission 12 and produces a pressure signal proportional to the speed of the vehicle. The reference valve 44 is arranged to move with the governor valve 28 as the speed varies until it is locked in position at a desired speed by a drivercontrolled lock valve 92 so that subsequent movement of the governor valve 28 in response to a change of speed will cause the throttle actuator 26 to move the throttle 18 in the appropriate direction to restore the desired speed. The lock valve 92 is loaded by a spring 98 and has a stem 118 which engages the reference valve 44 when fluid pressure applied through a restriction 104 to beneath a land 94 is released through a vent 108 controlled by a valve element 110 actuated by a solenoid 114. The solenoid 114 is energized to open the vent 108 by a relay 212 in a control circuit, Fig. 2, including the ignition switch 190 of the vehicle, a switch 194 opened whenever the vehicle brake pedal is depressed, and a speed control setting switch 198. An override valve 154 is spring loaded into an exhaust position wherein the conduits 134, 136 leading to the throttle actuator 26 are connected to exhaust passages 172, 174 so that the speed control does not operate unless a conduit 100 which is supplied with pressure fluid only when the transmission 12 is operating at high ratio in automatic drive is put into communication across the engaged lock valve 92 with a conduit 180 which applies the pressure to the underside of the override valve 154 to move the valve into an operating position wherein the conduits 134, 136 are cutoff from the exhaust passages. To ensure that the throttle actuator 26 is rendered inoperative when the vehicle is braked even if opening of the switch 194 fails to disengage the lock valve 92, lands 36, 52 on the governor valve 28 and reference valve 44 form an exhaust opening from a conduit 178 which is fed through a restriction 216 from the conduit 180 and is connected to the upper end of the override valve 154 so that movement of the governor valve 28 as the vehicle is retarded closes the exhaust opening to create a pressure build-up in the conduit 178 and move the override valve to the exhaust position. To eliminate engine inertia effects on the response rate of the governor valve 28, a land 130 on the throttle actuator 26 forms a feedback chamber which communicates through the override valve 154 with the conduit 182 upstream of a restriction 186 so that a pressure rise or fall is produced in the conduit 182 when the throttle actuator moves in order to obtain an immediate response of the governor valve to the movement of the engine throttle. |
