Control device for continuously variable transmission

Patent metadata

Field	Value
Publication number	US-2016290503-A1
Application number	US-201415036140-A
Country	US
Kind code	A1
Filing date	Dec 10, 2014
Priority date	Dec 11, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

In a control apparatus for a continuously variable transmission with a sub transmission, a primary solenoid valve ( 118 ) installed at an oil passage midway position from a mechanical oil pump ( 10 ) to a primary pulley ( 21 ) and configured to control a hydraulic pressure to the primary pulley ( 21 ) and a transmission controller ( 12 ) which outputs a primary current command value (PriSOL/I*) to primary solenoid valve ( 118 ) are provided. The transmission controller ( 12 ) outputs primary current command value (PriSOL/I*) which previously closes an oil passage from the mechanical oil pump ( 10 ) to the primary pulley ( 21 ) to the primary solenoid valve ( 118 ) before a rise in engine revolution number (Ne) due to at least a re-start of the engine, when a coast stop control/an idle stop control is carried out.

First claim

1 .- 5 . (canceled)

6 . A control apparatus for a continuously variable transmission, comprising:
an engine; a continuously variable transmission mechanism intervened between the engine and driving wheels and configured to transmit a torque by means of a belt pressed in grooves of hydraulic pressure driven primary pulley and secondary pulley; a starting clutch installed in a drive train in which the continuously variable transmission mechanism is intervened; a mechanical oil pump driven by the engine and configured to supply a hydraulic pressure to the primary pulley, the secondary pulley, and the starting clutch; engine stop control means for stopping the engine when a predetermined start condition is established and for terminating an engine stop control and re-starting the engine when a predetermined end condition is established; a primary solenoid valve installed at an oil passage midway position from the mechanical oil pump to the primary pulley and configured to control the hydraulic pressure to the primary pulley; and transmission control means for outputting a primary current command value to the primary solenoid valve, wherein the transmission control means outputs the primary current command value, which previously closes an oil passage from the mechanical oil pump to the primary pulley from an engine stop control end time point to a line pressure generation time point, to the primary solenoid valve, when a time point at which a line pressure equal to or above a predetermined value is generated due to a rise in a revolution number according to the re-start of the engine after the engine stop control end is said to be the line pressure generation time point.

7 . The control apparatus for the continuously variable transmission as claimed in claim 6 , wherein the transmission control means sets the primary current command value to a closed circuit current value which can close an oil passage from the mechanical oil pump to the primary pulley overcoming a biasing force of a spring in spite of a position of a valve spool.

8 . The control apparatus for the continuously variable transmission as claimed in claim 7 , wherein the transmission control means gradually reduces the primary current command value from the closed circuit current value to a current value in accordance with a target speed ratio, when a determination that a time has reached to the line pressure generation time point is made.

9 . The control apparatus for the continuously variable transmission as claimed in claim 6 , wherein a sub transmission mechanism having a plurality of gear positions is provided in the drive train in which the continuously variable transmission mechanism is intervened and the starting clutch is a low brake engaged at a forward 1 st speed from among frictional engagement elements which change the gear positions of the sub transmission mechanism.

Assignees

• Jatco Ltd

Inventors

• Kawamoto Yoshinobu
• Utagawa Tomohiro
• Eguchi Takashi

Classifications

• B60W30/18018

  Start-stop drive, e.g. in a traffic jam · CPC title

• B60W10/107

  with endless flexible members · CPC title

• B60W10/11

  Stepped gearings · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• F16H2312/14

  Going to, or coming from standby operation, e.g. for engine start-stop operation at traffic lights · CPC title