Nissan Motor Company Limited

Jun Amemiya

Munetoshi Ueno

Noboru Kudo

Hiroyuki Ashizawa

Hiroki Matsui

Yoshinori Yamamura

Yutaka Takamura

Hiromichi Murata

Tatsuya Uchida

A hybrid electric vehicle comprises an internal combustion engine and an electric motor/generator connected via a first clutch. In response to a system stop request in a vehicle stop state, a rotation speed of the internal combustion engine is decreased to a predetermined rotation speed higher than a predetermined resonance frequency band by a negative torque applied to the internal combustion engine from the electric motor/generator via the first clutch. Then, the disengagement of the first clutch starts. The rotation speed of the engine falls below the predetermined resonance frequency band within a predetermined period from the start of the disengagement. As a consequence, the required period from a stopping operation of the internal combustion engine until actual operation stop thereof in a vehicle stationary state is reduced.

Drive control device and drive control method for hybrid electric vehicle

In a hybrid electric vehicle in which an internal combustion engine and an electric motor/generator are connected via a clutch, the controller performs the following processing before the operation of the internal combustion engine stops in a stationary state of the vehicle while the clutch is engaged. Specifically, it is determined whether or not the clutch can be disengaged within a predetermined time period. If the clutch can be disengaged within a predetermined time period, the clutch is disengaged. If the clutch cannot be disengaged within the predetermined time period, a driving torque of the internal combustion engine is lowered to an engine stoppable torque set in advance while the clutch is engaged. Then, the operation of the internal combustion engine stops. Through this control, it is possible to prevent a vibration sound or an abnormal sound that may be generated when a driver turns off the ignition button.

Driving control device and driving control method in hybrid electric vehicle

A hybrid vehicle control device includes an engine, a motor/generator, an automatic transmission in which the gear ratio can be fixed by the driver's intention; and a drive wheel. The control device has an assist traveling mode and an engine generation traveling mode as hybrid modes in which the engine and the motor/generator are drive sources. The control device includes a rotational speed limit setting unit which sets a value that exceeds the upper rotational speed limit, at which the motor/generator can carry out a torque output, as the rotational speed limit of the engine motor rotational speed, and a rotational speed limit control unit for reducing the rotational speed limit to the rotational speed limit at which the motor/generator can carry out a torque output, when the engine motor rotational speed has reached the rotational speed limit and there is a torque output request of the motor/generator.

Device for controlling hybrid vehicle

A vehicular driving torque control apparatus, comprising: a limitation variation rate setting section included in a driving torque control section and configured to set, in a form of a limitation variation rate, a low torque side limitation variation rate used in a low torque side until the target driving torque reaches to a torque variation rate switching threshold value and a high torque side limitation variation rate used in a high torque side exceeding the torque variation rate switching threshold value and to execute a limitation suppression variation rate setting process in which the low torque side limitation variation rate is set to be larger than the high torque side limitation variation rate until the target driving torque reaches to the torque variation rate switching threshold value.

Vehicle driving-torque control device

When there is a requirement on switching from the electrically driven drive mode to the hybrid drive mode by changing an accelerator position opening, the torque capacity is generated for the first clutch to start the engine. However, as torque capacity is at &#x3b2;, the engine rotational speed is quickly increased to the high-speed region free of the influence of the compressive reactive force of the engine; once the engine rotational speed becomes the high-speed region, the engine rotational speed is decreased as torque capacity and is at &#x3b2;. Consequently, it is possible to quickly pass through the low engine rotational speed region as the engine rotational speed torque is increased under the influence of the compressive reactive force, and avoiding the poor acceleration, as can be seen from the smooth variation of the time sequence increase of the transmission output rotational speed as indicated by &#x3b2;, is possible.

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Atsugi, Japan

Jun Amemiya