Control apparatus for vehicle

Patent metadata

Field	Value
Publication number	US-9821806-B2
Application number	US-201515318460-A
Country	US
Kind code	B2
Filing date	Jul 7, 2015
Priority date	Jul 7, 2014
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

When neutral control is started by placing a CVT drive clutch in a semi-engaged state while a vehicle is decelerating in a state where a second power transmission path is established, a clutch mechanism that is semi-engaged in neutral control while the vehicle is decelerating is changed from the CVT drive clutch to a forward clutch before a stop of the vehicle, so it is possible to continue the neutral control until a stop of the vehicle. At a stop of the vehicle, a power transmission path is already changed to a first power transmission path that establishes a gear ratio (EL) higher than a highest gear ratio (γmax) that can be established by the second power transmission path. Thus, right after a stop of the vehicle, it is possible to execute idle stop control.

First claim

What is claimed is:

1. A control apparatus for a vehicle, the vehicle including
an engine,
a drive wheel, and
a power transmission system including
an input rotating member to which power of the engine is transmitted,
an output rotating member configured to output the power to the drive wheel,
a continuously variable transmission provided between the input rotating member and the output rotating member,
a gear mechanism provided in parallel with the continuously variable transmission between the input rotating member and the output rotating member, the gear mechanism including a gear stage, and
a clutch mechanism configured to selectively change a power transmission path between a first path and a second path, the clutch mechanism including a first clutch and a second clutch, the first path being a path configured to transmit the power of the engine to the drive wheel via the gear mechanism when the first clutch is engaged, the second path being a path configured to transmit the power of the engine to the drive wheel via the continuously variable transmission when the second clutch is engaged, a speed ratio at a time when the power of the engine is transmitted by the first path being a low vehicle speed gear ratio higher than a lowest vehicle speed gear ratio at a time when the power of the engine is transmitted by the second path, the control apparatus comprising:

at least one electronic control unit configured to
i) execute neutral control for limiting transmission of power through the power transmission path by placing the clutch mechanism in a semi-engaged state and idle stop control for temporarily stopping the engine during a stop of the vehicle based on a predetermined condition, and
ii) when the neutral control for the second path is started by placing a engaged second clutch in a semi-engaged state while the vehicle is decelerating in a state where the power is being transmitted via the second path, shift into the neutral control for the first path by releasing the second clutch and placing a released first clutch in a semi-engaged state before a stop of the vehicle.

2. The control apparatus according to claim 1 , wherein
the electronic control unit is configured to, when a vehicle speed is lower than or equal to a predetermined vehicle speed while the neutral control for the second path is being executed, shift from the neutral control for the second path to the neutral control for the first path.

3. The control apparatus according to claim 1 , wherein
the electronic control unit is configured to, when the idle stop control is executed after a stop of the vehicle, cancel the neutral control for the first path.

4. The control apparatus according to claim 1 , wherein
the electronic control unit is configured to, in a state where a speed ratio of the continuously variable transmission mechanism is a speed ratio smaller than the highest vehicle speed gear ratio that is established by the continuously variable transmission mechanism, shift from the neutral control for the second path to the neutral control for the first path.

5. The control apparatus according to claim 4 , wherein
the electronic control unit is configured to, after shifting from the neutral control for the second path to the neutral control for the first path, change the speed ratio of the continuously variable transmission toward the highest vehicle speed gear ratio.

Assignees

• Toyota Motor Co Ltd

Inventors

• Shimazu Takuro
• Fukao Mitsuhiro
• Nitani Hiromitsu
• Hino Akira
• Kondo Hiroki
• Ayabe Atsushi

Classifications

• B60W2520/10

  Longitudinal speed · CPC title

• B60W2710/1005

  Transmission ratio engaged · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W30/181 Primary

  Preparing for stopping · CPC title

• B60W2520/105

  Longitudinal acceleration · CPC title