Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Yoshikazu Nemoto

Yoshiharu Saito

Yasushi Inagawa

Kazuhiko Kitano

Takanori Kon

Masamitsu Fukuchi

Atsuhiro Sakai

Masahide Saito

Toshiaki Tane

Satoshi Kato

Shinsaku Mayumi

An automatic transmission capable of improving stability and reliability of connection operation of a synchronization mechanism when pre-shift control is executed, thereby making it possible to prolong the service life of the mechanism and improve marketability thereof. To change the speed position of a vehicle, one of two power transmission paths from an internal combustion engine to drive wheels is switched to the other, and pre-shift control is executed before switching the path. In doing this, when conditions for executing the pre-shift control are satisfied, whether or not a motive power fluctuation state of the engine occurs after satisfaction of the execution conditions is determined. If the motive power fluctuation state occurs, delay control for delaying the start of the pre-shift control is executed, whereas if the same does not occur, the pre-shift control is executed without executing the delay control.

Automatic transmission

An in-gear oil pressure correcting section corrects engagement control oil pressure set up by an oil pressure supply control section over the entire range to be reduced by first predetermined pressure. An engagement determining section determines, on the basis of a torque converter slip ratio calculated by a calculating section, whether a frictional engagement element of a destination gear starts to engage or not. An addition correcting control section corrects the corrected engagement control oil pressure to add second predetermined pressure thereto in the case where engagement of the frictional engagement element has not been started yet when a timer measures first predetermined time. The addition correcting control section further corrects the corrected engagement control oil pressure to add third predetermined pressure thereto in the case where the engagement of the frictional engagement element has not been started yet when the timer measures second predetermined time.

Hydraulic control device for automatic transmission

A system for controlling an automatic transmission of a vehicle, wherein if the change of the destined gear GB (i.e., the target gear SH) is required when the jumping shift, i.e., two-gear downshifting is in progress, the input/output rotational speed ratio GRATIO (indicative of degree of shift progress) is compared with the predetermined input/output rotational speed ratio &num;GRCN312 or &num;GRCN423, and based on the result of comparison, how the shift to establish or effect the required destined gear GB, i.e., the shift mode QATNUM is determined, thereby enabling to improve or enhance the response to the change of the destined gear GB during two-gear downshifting. It can also prevent the clutch from being degraded in such a shifting.

Control system for automatic vehicle transmissions

The lock-up clutch control apparatus is provided with reference values for operating variations of the accelerator pedal predetermined for respective gear positions. The lock-up clutch control apparatus comprises a tightening permission judgement device 25 for judging whether it is appropriate to permit or prohibit tightening of the lock-up clutch, based on comparison between a reference value and an operating variation at present car conditions. Thereby, the lock-up clutch control apparatus is capable of reflecting the driver's intention to accelerate or reduce the car speed and is capable of enhancing drivability as well.

Lock-up clutch control apparatus

A lubricating oil supply apparatus for a hydraulically operated vehicular transmission has a lubricating oil passage for supplying oil discharged from a discharge port of a pressure control valve which is provided in a hydraulic control circuit of the transmission to lubricating portions thereof as lubricating oil. The lubricating portions are divided into a plurality of groups depending on a change in a required amount of lubricating oil due to a temperature of the transmission. The lubricating oil passage is branched into a plurality of branches corresponding to the groups. The lubricating oil supply apparatus has a choke type of throttle which is disposed in at least one of the branches of the lubricating oil passage.

Growing community of inventors

Wako, Japan

Yoshikazu Nemoto