Rapid downshift control device for electric vehicles

Abstract

By increasing accelerator opening APO from time t1 as shown in the drawing, kick-down shift is started at time t2. While the kick-down shift is carried out by changeover from a release element (direct clutch D / C) to an engagement element (high and low reverse clutch H&LR / C), a motor torque tTm that is increased as Tmo with an increase in accelerator opening APO is restricted as follows. In a shift initial stage from time t2 to inertia phase start time t3, motor torque tTm is restricted so as not to exceed upper limit value Tlimit (=Tmo2-Tip) obtained by subtracting an inertia phase progressing torque increment Tip from an inertia phase end outputtable maximum motor torque Tmo2 that is outputtable with motor rotation speed Nmo2 at inertia phase end time t4. During an inertia phase (t3-t4), the motor torque tTm is restricted to a value Tlimit+Tip (a value equal to Tmo2).

Description

technical field [0001] The present invention relates to a rapid downshift control device for an electric vehicle, such as an electric vehicle using only an electric motor as a power source, or a hybrid electric vehicle using an electric motor and an engine (internal combustion engine, etc.) as a power source, in particular It is an electric vehicle in which wheels are driven via an automatic transmission, and during electric travel (EV travel) by motor torque from an electric motor, a sudden downshift of the automatic transmission is performed favorably. Background technique [0002] As an electric vehicle equipped with an automatic transmission as described above, for example, an electric vehicle described in Patent Document 1 is conventionally known. [0003] The electric vehicle only has an electric motor as a power source, and an automatic transmission is interposed between the electric motor and the driving wheels, and the motor torque from the electric motor is shifted...

AI Technical Summary

Problems solved by technology

[0016] The reduction of the transmission input torque in the rapid downshift (in the inertia phase) has the following problems: In the reduction of the transmission input torque, the driver feels that the increase in the vehicle acceleration is not expected, and the rapid downshift (inertial phase) The progress of the stage) is delayed, and the shifting time is prolonged. During this long shifting time, the acceleration response will be greatly delayed.

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