Method and system for controlling sailing stop in vehicle

Patent metadata

Field	Value
Publication number	US-10449964-B2
Application number	US-201615758645-A
Country	US
Kind code	B2
Filing date	Oct 17, 2016
Priority date	Oct 19, 2015
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

Variator ( 20 ) and forward clutch (Fwd/C) disposed in series are provided between engine ( 1 ) having starter motor ( 15 ) and driving wheel ( 7 ). Sailing stop control that, on the basis of satisfaction of sailing entering condition, interrupts power transmission by frictional engagement element (Fwd/C), stops engine ( 1 ) and performs coast-travel is performed. When sailing entering condition is satisfied, coast-travel is started with rotation stop timing of variator ( 20 ) being delayed with respect to rotation stop timing of engine ( 1 ). When accelerator pedal depression operation intervenes after start of coast-travel, engine ( 1 ) is restarted by starter motor ( 15 ). When judged that input and output rotation speeds of frictional engagement element (Fwd/C) become synchronization rotation speed after restart of engine ( 1 ), frictional engagement element (Fwd/C) is reengaged. Shift response from coast-travel to normal travel is therefore improved at change-of-mind at which sailing quitting condition is satisfied during progress of automatic stop of engine.

First claim

The invention claimed is:

1. A method of sailing stop control of a vehicle, the vehicle having a transmission and a frictional engagement element that are disposed in series between an engine and a driving wheel, a starter motor that starts the engine and a torque converter having a lock-up clutch between the engine and the transmission, and the vehicle coast-travelling by the sailing stop control that, on the basis of satisfaction of a sailing entering condition, interrupts power transmission by the frictional engagement element, stops the engine and performs coast-travel of the vehicle, the method comprising:
when the sailing entering condition including a brake OFF condition is satisfied, starting release of the lock-up clutch, stopping fuel injection of the engine after completion of the release of the lock-up clutch and releasing the frictional engagement element after stop of the fuel injection of the engine;
when a sailing quitting condition is satisfied after the coast-travel is started, restarting the engine by the starter motor; and
when it is judged that input and output rotation speeds of the frictional engagement element become a synchronization rotation speed after the engine is restarted, reengaging the frictional engagement element.

2. A sailing stop control device of a vehicle comprising:
a transmission and a frictional engagement element that are disposed in series between an engine and a driving wheel;
a starter motor that starts the engine;
a torque converter having a lock-up clutch between the engine and the transmission; and
a sailing stop controller that, on the basis of satisfaction of a sailing entering condition, interrupts power transmission by the frictional engagement element, stops the engine and performs coast-travel of the vehicle, and
the sailing stop controller being configured to,
when the sailing entering condition including a brake OFF condition is satisfied, start release of the lock-up clutch, stop fuel injection of the engine after completion of the release of the lock-up clutch and release the frictional engagement element after stop of the fuel injection of the engine,
when a sailing quitting condition is satisfied after the coast-travel is started, restart the engine by the starter motor, and
when it is judged that input and output rotation speeds of the frictional engagement element become a synchronization rotation speed after the engine is restarted, reengage the frictional engagement element.

Assignees

• Jatco Ltd

Inventors

• Iwamoto Tadashi
• Takano Akira
• Nakasaki Masayoshi
• Nishihiro Yoshimasa
• Ootsuka Yukifumi

Classifications

• F02D17/00

  Controlling engines by cutting out individual cylinders; Rendering engines inoperative or idling (controlling or rendering inoperative by varying inlet or exhaust valve operating characteristics F02D13/00) · CPC title

• B60W2510/0241

  Clutch slip, i.e. difference between input and output speeds · CPC title

• B60W2710/06

  Combustion engines, Gas turbines · CPC title

• F02D29/00

  Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto · CPC title

• F16D48/02

  Control by fluid pressure · CPC title