Jatco Corporation

Jihoon Kang

Yasutaka Kawamura

Hirofumi Okahara

Tatsuo Ochiai

Donggyun Park

Hiroyasu Tanaka

Shigeki Shimanaka

Yoshichika Hagiwara

Toshiyasu Yamaguchi

Takeshi Oohori

An abnormal oil pressure reduction determining device has an oil pressure sensor which detects a real oil pressure, a sensor which detects a vehicle running state, and a controller which sets an oil pressure command value for an oil pressure control mechanism. The controller computes the lower limiting oil pressure which is possible in the present vehicle running state, and when the real oil pressure is less than this lower limiting oil pressure and the pressure difference between the real oil pressure and oil pressure command value exceeds a reference value, determines that there is an abnormal pressure reduction due to a fault in the oil pressure control mechanism. Even if the oil pressure of the transmission has dropped abnormally due to some reason, the abnormal oil pressure reduction determining device determines the situation without fail.

Abnormal oil pressure reduction determination device for vehicle transmission

A vehicle is provided with an engine (), an automatic transmission () connected to the engine (), a detection device () which detects an operating state of the transmission (), and a torque regulating mechanism () which regulates a torque of the engine. When the operating state of the transmission () is in a predetermined drive state and the torque of the engine () is to be reduced, a selection is made, based on the operating state of the transmission (), between a first torque reduction control whereby the torque of the engine () is reduced rapidly and temporarily, and a second torque reduction control whereby the torque of the engine () is reduced continuously, and more smoothly than in the first torque reduction control. The torque of the engine () is then reduced by the selected one of the first torque reduction control and the second torque reduction control.

Control apparatus for vehicle provided with an automatic transmission, and method of controlling the same

There is provided an engine torque control apparatus that is comprised of a torque-down amount calculating section to which the throttle valve opening and the engine speed are inputted and which calculates the torque-down amount based on the inputted values, an inertia correction amount calculating section that calculates the correction amount for inertia of each component part (inertia discharged torque), a friction correction amount calculating section that calculates the correction amount for friction generated by a belt CVT (friction discharged torque), a torque-down amount correcting section that corrects the torque-down amount based on the calculated correction amounts, and an engine torque control section that controls engine torque. Since the engine torque is controlled with inertia and friction discharged torque of each component part being taken into account, the upper limit of the torque inputted to an automatic transmission can be accurately controlled to the value of the allowable input torque of the automatic transmission.

Engine torque control apparatus

An engine torque control apparatus for controlling the output torque of an engine () connected to a transmission () in a vehicle has a temperature sensor () for detecting the temperature of oil used by the transmission (), and a controller () for limiting the output torque of the engine to an engine torque limit or less. The controller () functions to compare the oil temperature with a specific temperature, to set the engine torque limit to a first limiting value when the oil temperature is equal to or less than the specific temperature, and to increase the engine torque limit at a predetermined increase rate when the oil temperature exceeds the specific temperature.

A vehicle engine () is connected with a belt-type continuously variable transmission () via a clutch (). The transmission () transmits torque via a belt () between a pair of pulleys (), and varies the transmission torque according to a supply of oil pressure. The clutch () engages by means of oil pressure supplied as a shift lever is changed over from a neutral range to a drive range. An oil pressure supplying device () supplies the oil pressure required to transmit torque between the belt () and the pulleys (), and the oil pressure for engaging the clutch (). Slippage between the belt () and the pulleys () is prevented during engagement of the clutch () by restricting the output torque of the engine () over a predetermined period of time.

Prevention of slippage in belt-type continuously variable transmission

A control system for an automatic transmission ( ) includes an oil pressure control mechanism ( ) for supplying an oil pressure to the transmission ( ), and sensor ( ) for detecting the oil pressure supplied from the oil pressure control mechanism ( ) to the transmission ( ). System controller ( ) calculates a maximum torque transmittable by the transmission ( ) based on a speed ratio of the transmission ( ) and the detected oil pressure; calculate an engine torque reduction amount from the difference between the torque being inputted into the transmission ( ) and the maximum transmittable torque; and reduce the torque of an engine ( ) according to the engine torque reduction amount.

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Fuji, Japan

Jihoon Kang