DISPOSITIVO DE IMANES Y CORRIENTES DE FOUCAULT PARA EL MANDO DE LOS CAMBIOS DE MARCHA EN FUNCION DE LA VELOCIDAD DE UN VEHICULO

摘要

1,105,782. Change-speed gear control. REGIE NATIONALE DES USINES RENAULT. 23 March, 1965 [27 March, 1964], No. 12334/65. Heading F2D. Automatic shifts in a stepped transmission 30 of a motor vehicle in response to vehicle speed and engine accelerator depression, with synchronization by engine speed control, are controlled by a device wherein rotation, at a speed proportional to vehicle speed, of a permanent magnet 7 in a coaxial cup 12 on a shaft 13 generates eddy currents in the cup which apply a torque thereto to turn the shaft 13 against a spiral spring 14 to successively engage arms 15 with respective contacts 16 to initiate ratio changes, the magnet 7 being axially movable on a ball spline relative to the cup 12 by the engine accelerator pedal linkage acting at F to reduce the eddy current strength as the pedal is depressed. When an arm 15 engages its contact 16, a magnet associated therewith tends to retain the arm, in opposition to spring 14, so that downshifts will occur at lower speeds than the corresponding upshifts. Each arm 15 remains on its contact 16 while higher gears are engaged. For synchronizing shifts by controlling engine speed during shifts, vehicle and engine speeds are compared by a pair of cups 19, 21 secured on a common shaft 20 biased to a neutral position by a spiral spring 26, a permanent magnet 6 being rotated in the cup 19 at a speed proportional to vehicle speed, and a permanent magnet 22 being rotated in the opposite sense at a speed proportional to engine speed. The axial position of the ball-splined magnet 22 is set in accordance with the gear ratio to be engaged in the transmission 30. During shifts, with coincidental clutch actuation by means not described, this device acts to synchronize the new ratio. If the engine runs too fast, the torque on cup 21 predominates, and an arm 27 on shaft 20 is moved away from a fixed contact 28 to reduce engine speed, while if the engine speed is too low, the torque on cup 19 predominates, causing the engine to be speeded up. Clutch control may be as described in Specification 1,105,781, and automatic double-declutching by unspecified means may be provided. In a modification, the cups 12, 21 may be axially movable instead of the magnets 7, 22.