To appropriately control the engagement torque of a friction engagement type clutch upon switching from 2WD traveling to 4WD traveling, thereby suppressing the feeling of discomfort due to a deceleration shock during synchronization control and the occurrence of unstable vehicle behavior due to a long synchronization time.SOLUTION: When switching from 2WD traveling to 4WD traveling is performed, an allowable deceleration Ga is set on the basis of a vehicle acceleration/deceleration G (S4). The engagement torque of a friction engagement type clutch is controlled so that the deceleration of a vehicle during synchronization control increasing the rotational speed of a front propeller shaft or the like becomes equal to the allowable deceleration Ga (S9), so that the synchronization control is appropriately performed according to the vehicle acceleration/deceleration G. In other words, during traveling with a small vehicle acceleration/deceleration G, the allowable deceleration Ga is small, so that a deceleration shock is suppressed. During traveling with a large vehicle acceleration/deceleration G in which the deceleration shock is hardly felt, the allowable deceleration Ga is made large, and a synchronization time is shortened, so that shifting to four-wheel-drive traveling is promptly performed. Thus, the disturbance of vehicle behavior due to a slip or the like is suppressed.SELECTED DRAWING: Figure 6
【課題】2WD走行から4WD走行へ切り換える際の摩擦係合式クラッチの係合トルクを適切に制御し、同期制御時の減速ショックで違和感を生じさせたり、同期時間が長くて車両挙動が不安定になったりすることを抑制する。【解決手段】2WD走行から4WD走行へ切り換える際に、車両加減速度Gに基づいて許容減速度Gaを設定し(S4)、フロントプロペラシャフト等の回転速度を上昇させる同期制御時の車両の減速度が許容減速度Gaになるように摩擦係合式クラッチの係合トルクを制御するため(S9)、車両加減速度Gに応じて適切に同期制御が行なわれる。すなわち、車両加減速度Gが小さい走行時は許容減速度Gaが小さくて減速ショックが抑制される。減速ショックを感じにくい車両加減速度Gが大きい走行時は許容減速度Gaが大きくされ、同期時間が短縮されて速やかに4輪駆動走行へ移行し、スリップ等による車両挙動の乱れが抑制される。【選択図】図6
DRIVE STATE SWITCHING DEVICE OF FOUR-WHEEL-DRIVE VEHICLE
4輪駆動車両の駆動状態切換装置
2019-02-21
Patent
Electronic Resource
Japanese
IPC: | B60K Anordnung oder Einbau von Antriebseinheiten oder von Kraft- bzw. Drehmomentübertragungen in Fahrzeugen , ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES |
European Patent Office | 2018
|CONTROL DEVICE OF FOUR-WHEEL DRIVE VEHICLE AND FOUR-WHEEL DRIVE VEHICLE
European Patent Office | 2016
|