Control device for multi-disc lock-up clutch

Patent metadata

Field	Value
Publication number	US-10173686-B2
Application number	US-201715440423-A
Country	US
Kind code	B2
Filing date	Feb 23, 2017
Priority date	Mar 4, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Lock-up clutch engagement hydraulic pressure learning control can be precisely performed by starting lock-up clutch engagement control and executing the lock-up clutch engagement hydraulic pressure learning control after execution of shift control is completed, in a case where the lock-up clutch engagement control is limited in a shift stage before execution of the shift control, when the shift control is executed in a state where a multi-disc lock-up clutch is released. Meanwhile, a decrease in fuel efficiency performance and a direct steering feeling is minimized by starting the lock-up clutch engagement control during shift control in a case where the lock-up clutch engagement control is not limited.

First claim

What is claimed is:

1. A control device for a multi-disc lock-up clutch provided in a transmission of a vehicle, the control device comprising
an electronic control unit configured to
i) perform shift control of the transmission,
ii) perform engagement control of the multi-disc lock-up clutch,
iii) a) start the engagement control of the multi-disc lock-up clutch and b) perform a process to learn an engagement hydraulic pressure of the multi-disc lock-up clutch that causes the multi-disc lock-up clutch to reach a state immediately before an engaged state by a target time, after execution of the shift control is completed, when the shift control is executed in a state where the multi-disc lock-up clutch is released while the electronic control unit limits the engagement control of the multi-disc lock-up clutch in a shift stage before the execution of the shift control, and
iv) start the engagement control of the multi-disc lock-up clutch and not perform the process to learn the engagement hydraulic pressure during the shift control when the shift control is executed in a state where the multi-disc lock-up clutch is released while the electronic control unit does not limit the engagement control of the lock-up clutch in a shift stage before the execution of the shift control.

2. The control device according to claim 1 ,
wherein the electronic control unit is configured to
v) release the multi-disc lock-up clutch after the engagement control of the multi-disc lock-up clutch is performed while the vehicle is traveling, and then
vi) limit the engagement control of the multi-disc lock-up clutch when a vehicle speed is lower than a predetermined speed.

3. The control device according to claim 2 ,
wherein the electronic control unit is configured to limit the engagement of the multi-disc lock-up clutch by prohibiting the engagement control of the multi-disc lock-up clutch.

Assignees

• Toyota Motor Co Ltd

Inventors

• Aratake Hironobu
• Tsukamoto Norihiro
• Asami Tomohiro

Classifications

• F16H45/02

  with mechanical clutches for bridging a fluid gearing of the hydrokinetic type (control of torque converter lock-up clutches F16H61/14) · CPC title

• F16D25/0638

  with more than two discs, e.g. multiple lamellae · CPC title

• B60W2710/10

  Change speed gearings · CPC title

• F16D2500/3108

  Vehicle speed · CPC title

• B60W2510/10

  Change speed gearings · CPC title