US 7,393,299 B2
Hydraulic control apparatus and hydraulic control method for automatic transmission
Yuji Inoue, Nisshin (Japan); Atsushi Tabata, Okazaki (Japan); Atsushi Honda, Seto (Japan); Akiharu Abe, Toyota (Japan); Kazutoshi Nozaki, Aichi-gun (Japan); Hirofumi Ota, Toyota (Japan); and Atsushi Kamada, Toyota (Japan)
Assigned to Toyota Jidosha Kabushiki Kaisha, Toyota-shi (Japan)
Filed on Apr. 04, 2006, as Appl. No. 11/396,459.
Claims priority of application No. 2005-136639 (JP), filed on May 09, 2005.
Prior Publication US 2006/0252593 A1, Nov. 09, 2006
Int. Cl. F16H 31/00 (2006.01)
U.S. Cl. 475—123 8 Claims
OG exemplary drawing
 
1. A hydraulic control apparatus for an automatic transmission which includes a hydraulic power transmission device with a lock-up clutch, and in which a plurality of hydraulic engagement devices are selectively engaged to achieve any one of a plurality of shift speeds which have different speed ratios, the hydraulic control apparatus comprising:
a first solenoid valve that controls an engagement pressure of a first engagement device that is engaged at a first predetermined shift speed, and that is disengaged at a second predetermined shift speed;
a second solenoid valve that controls an engagement pressure of a second engagement device that is disengaged at the first predetermined shift speed, and that is engaged at the second predetermined shift speed; and
at least one oil-passage selection device which selects between a first oil passage used to control an engagement pressure of the first engagement device and a second oil passage used to control a torque capacity of the lock-up clutch, and supplies a first control hydraulic pressure output from the first solenoid valve to the selected oil passage, and which selects between a third oil passage used to control an engagement pressure of the second engagement device and the second oil passage, and supplies a second control hydraulic pressure output from the second solenoid valve to the selected oil passage.