Drivnig control device and method for vehicle

Abstract

In the case where a signal for coasting time downshifting is output while fuel cut is performed and fuel supply is stopped, and a hydraulic pressure PC1 of a low speed side frictional engagement device is being gradually increased and an engine speed NE is being increased, when the fuel cut is cancelled and the fuel supply is restarted, the hydraulic pressure PC1 is reduced to a hydraulic pressure value immediately before an amount of torque is applied to the low speed side frictional engagement device.

Description

technical field [0001] The present invention relates to a drive control device for a vehicle and a drive control method for a vehicle, in particular to downshift control during coasting (during coasting). Background technique [0002] There is known a drive control device for a vehicle, which includes (a) an engine that generates power by burning fuel, (b) an engine that establishes a plurality of frictional engagement devices by changing the engagement / disengagement (disengagement) states A transmission of gears with mutually different gear ratios, and (c) for disengaging a high-speed side frictional engagement device and applying torque to a low-speed side frictional engagement device when a transmission downshift is automatically performed during coasting, thereby causing the engine Downshift control device during coasting with increased rotational speed (see, for example, Japanese Patent Laid-Open Publication No. 11-287317 (claim 6 and FIG. 7)). [0003] Also widely use...

AI Technical Summary

Problems solved by technology

[0004] However, in the case where a transmission downshift signal is output when the fuel is cut while coasting, and then the engine speed is increased in accordance with the torque control of the low-speed side frictional engagement device by the downshift control device during coasting, if, for example, an auxiliary device such as an air conditioner When the operation of the engine is canceled (released) and the fuel cut is resumed to restore the fuel supply, the torque of the output shaft (the driving torque of the vehicle) will suddenly change due to the decrease of the engine load (engine braking force), which makes the driver feel uncomfortable.

In particular, since downshifting during coasting is automatically performed even when the driver does not want to change the torque (hereinafter referred to as downshifting during coasting), the driver will sensitively feel a shock (torque fluctuation), even if the shock is small , causing inconvenience

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