vehicle drive

Abstract

The invention provides a vehicle drive device. This vehicle driving device includes: an engine capable of variably adjusting the output rotational speed and output torque of an output shaft by controlling output power; a power train including a clutch and a transmission; and a control unit based on an operation amount of an accelerator pedal. The engine is controlled, and the control unit has: a load estimation unit that estimates a running load when the vehicle starts; a lower limit value setting unit that variably sets an output required to obtain a vehicle propulsion force corresponding to the estimated running load a lower limit value of at least one of the rotational speed and the output torque; and propulsion maintaining means for controlling the output power of the engine to increase when the output rotational speed decreases to reach the lower limit value. Accordingly, the output rotational speed and output torque of the engine are variably controlled in accordance with the magnitude of the running load when the vehicle is started, and reliable and quick start can always be performed.

Description

technical field [0001] The present invention relates to a vehicle drive device, and more specifically, to a vehicle drive device capable of reliably starting even when a running load such as an uphill road is heavy. Background technique [0002] A vehicle drive system is common that includes an engine, a clutch, and a transmission, and is controlled by an electronic control unit with a built-in microcomputer. In this vehicle drive device, the accelerator pedal does not function as means for operating the throttle valve of the engine, but functions as means for inputting the driver's starting and acceleration intentions to the electronic control device. The electronic control device detects the operation amount of the accelerator pedal, and sets the target value (speed and torque) of the engine output power through internal calculation, and controls the throttle valve to adjust the intake air amount and fuel supply amount. In addition, the electronic control unit not only co...

AI Technical Summary

Problems solved by technology

[0005] However, in Patent Document 1, the target rotational speed and target torque of the engine are calculated based on the accelerator operation amount, and the lockup clutch and the engine are controlled. However, there is a possibility that the vehicle cannot be started satisfactorily when a large torque is required.

In particular, if the driving load is large on an uphill road or an unpaved road with unevenness, the vehicle propulsion force will be insufficient in the target rotation speed and target torque based on the accelerator operation amount, and the output RPM often decreases

Moreover, if the output speed falls into the low rotation area of ​​the output torque characteristic of the engine, the output torque will also decrease with the reduction of the output speed, so the vehicle will not move forward, or even stall.

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