SPEED-CHANGE CONTROL DEVICE FOR CAR

PURPOSE:To improve the performance of running by determining the non-operation of a lockup mechanism provided in a transmission gear box on the basis of the will of a driver and operating the lockup mechanism automatically in accordance with the driving state when the driver desires. CONSTITUTION:When a car is started, a microcomputer memorizes various data from a speed sensor 16, an accelerator opening sensor 17, and a range switch 19, and looks up the map of lockup control pattern based on the car load and the running range. Then, it reads out the data indicating a standard speed to distinguish the lockup area, and decides whether the present running state satisfies the lockup conditions by comparing the data with the actual car speed. When ''yes'', an indicator lamp 23 is lit. In this construction, a step is cut in to decide the on/off state of the switch 18 at every fixed time. When the switch 18 is on, a signal to cancel a lockup solenoid 14 is outputted.