SETTING OF SPEED STAGE IN SHIFT-DOWN IN AUTOMATIC TRANSMISSION

• Main Author: KUZE TAKASHI
• Format: Patent
• Language: English
• Published: 19.02.1988
• Subjects: BLASTING; CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; THERMAL INSULATION IN GENERAL; TRANSPORTING; VEHICLES IN GENERAL; WEAPONS

PURPOSE:To reduce the speed change shock by determining the optimum speed stage corresponding to the car speed and detecting the car speed at that time in shift-down operation and setting the optimum speed stage corresponding to the car speed as the speed stage in shift-down operation. CONSTITUTION:The revolution speed Nd for judging shift-down in the case when the signals outputted from a throttle sensor 11 are S1-S3 is set beforehand, and compared with the revolution speed N1 of the output shaft of a torque converter 3 which is detected by a sensor 8, and it is judged that shift-down is to be executed, when N1>Nd. In a controller 13, a data table which shows the relation between the speed change stage S and the revolution speed N2 of the output shaft of a transmission is built in. Therefore, when it is judged that shift-down is to be executed, the speed stage corresponding to the revolution speed N2 at that time is determined. For example, when the optimum speed stage is determined at F2 in the traveling with the speed stage F5, shift-down F5 F2 is executed, skipping the intermediate stages. Therefore, the car speed and the speed stages are speedily matched, and the speed change shock can be reduced.