Aisin Aw Co., Ltd.

Masayuki Kuwata

Kenji Suzuki

Masao Saitou

Hiroshi Tsutsui

Masao Saito

Muneo Kusafuka

Masatoshi Taguchi

Mitsunori Nakane

Masaharu Chiba

Masayuki Tsugawa

Kazuo Koumura

Kaoru Ootsuki

A sensor generates a continuous signal in response to operation of a shift lever, and a range is determined for each of the various control operations by comparing the output value of the signal with a range determination pattern set arbitrarily for each of the control operations. Accordingly, each of the control operations can be performed appropriately by using optimal range information.

Range determination apparatus, range determination method, and program therefor

In an automatic transmission having a torque converter interposed between an engine and a transmission mechanism, the torque converter includes a lock-up clutch capable of directly coupling an output shaft of the engine and an input shaft of the transmission mechanism. A speed difference detector is provided for detecting a difference between engine rotational speed and input shaft rotational speed. An engine speed controller means is also provided for controlling the engine speed to cause the speed difference to converge within a predetermined range. By detecting the speed difference, it is possible to precisely detect the actual vehicle state, and to reliably and smoothly engage the lock-up clutch without generating shift shock in any vehicle state. With this structure, the lock-up clutch can be reliably engaged and the engine brake can be secured.

Lock-up control apparatus in automatic transmission

A hydraulic control unit of an automatic transmission calculates deceleration during a coasting downshift, and calculates a piston play offsetting time, that is, the lag time that elapses between a shift decision and the start of the shift, on the basis of a correction value determined in accordance with the lag time learned from the previous shift. Based on the rate of deceleration and the piston play offsetting time, the downshift line in the speed shift map is corrected, that is, advanced in timing. Using this timing-advanced shift line, the control unit makes an earlier shift decision such that the shift starts in a proper state of operation, thus reducing shift shock during a coasting downshift and preventing excessive engine speed during a high-speed upshift.

Hydraulic control apparatus of automatic transmission

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Anjo, Japan

Masayuki Kuwata