Engine start control apparatus for hybrid electrical vehicle

Abstract

An engine start control apparatus for a hybrid electrical adopts a small-sized storage battery and guarantees engine start response performance when the engine starts in a low-temperature state. An engine start control apparatus, in a drive system, has an engine (Eng), a motor / generator (MG), a normally-open first clutch (CL1) disposed between the generator and the motor / generator, and is equipped with an engine start control unit (Fig.4) which, when the ignition switch (23) is switched to an ON state, is configured to crank the engine by using the motor / generator as a starter motor while the clutch (CL1) is slip-engaged when the discharge pressure from a mechanical oil pump (M-O / P) is ensured by driving the motor / generator, and at the same time engine power output is performed. In the hybrid electrical vehicle, when the engine stops after an ignition switch (23) is switched to an OFF state, the engine start control unit (Fig.4), using the motor / generator, enables the mechanical oil pump to be driven at no load at a predetermined time (steps S4 to S8).

Description

technical field [0001] The invention relates to an engine start control device for a hybrid vehicle. The hybrid vehicle uses an electric motor for driving provided in a driving system as a starter motor, and connects a normally open hydraulic clutch provided between the engine and the electric motor to perform engine start. PTO. Background technique [0002] Conventionally, a hybrid drive system is known in which a drive system includes an engine, an electric motor, and a normally open hydraulic clutch interposed between the engine and the electric motor (for example, refer to Patent Document 1). [0003] In this hybrid drive system, when the engine is started according to the engine start request after the ignition switch is turned on, the following procedure is performed. [0004] (1) Rotate the electric motor to ensure the clutch oil pressure generated based on the discharge pressure from the oil pump driven by the electric motor; [0005] (2) Using the electric motor a...

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Problems solved by technology

[0011] Also, a defoamer is mixed in the operating oil to eliminate air bubbles, but the defoaming effect becomes weaker as the oil deteriorates due to the distance traveled

In particular, when the temperature of the working oil is low, various reasons such as increased friction, decreased battery voltage, and difficulty in defoaming air bubbles will occur at the same time. As a result, the oil pressure rise time of the oil pump is delayed until the oil pressure rises. a long time

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