Hybrid vehicle engine start control system

摘要

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 β1, 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 β2. 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 β3, is possible.

主权项

1. An engine start control system of a hybrid vehicle, the hybrid vehicle having an engine and an electrically driven motor as the power sources, a first clutch provided between the engine and the electrically driven motor for changing a transmission torque capacity between the engine and the electrically driven motor, and a second clutch provided between the electrically driven motor and at least one drive wheel for changing a transmission torque capacity between the electrically driven motor and the at least one drive wheel, the engine start control system comprising at least one controller programmed to:
select an electrically driven running mode by shutting down the engine, releasing the first clutch and engaging the second clutch; select a hybrid running mode by engaging both the first clutch and the second clutch; control the first clutch and the engine by increasing a torque capacity of the first clutch to increase an engine rotational speed to a high-speed region within a prescribed time period to ignore an increase in the engine rotational speed caused by an engine compressive reactive force upon determining progressive engagement of the first clutch during a running mode switch from the electrically driven running mode to the hybrid running mode,
wherein the prescribed time period is a time period during which an engine experiences a normal compressive reactive force during engine shutdown, the prescribed time period being based on engine compressive reactive force,wherein the engine compressive reactive force is determined based on an engine shutdown time; decrease the torque capacity of the first clutch upon determining the engine rotational speed having reached the high-speed region; and calculate a torque value of the first clutch for increasing the engine rotational speed or a time sequence variation of the engine rotational speed based on engine compressive reactive force, upon determining the engine rotational speed having reached the high-speed region within the prescribed time period.