Zexel Gmbh

Hiroyuki Soda

Masuhiro Otsuka

Hiromi Kono

Yuji Satoh

Hiromi Kohno

Masuhiro Ohtsuka

Yusi Satoh

An automatic transmission which includes a clutch (6); a clutch actuator (7) for detecting and controlling a position of the clutch; a transmission (1); a transmission actuator (2) for driving the transmission; a vehicle speed detector (22) for detecting a vehicle speed; a throttle opening detector (11) for detecting a throttle opening; an automatic shift unit (30) including a gear shift map (30a, 30b) having a gear shift characteristic which is determined based on the vehicle speed and the throttle opening; a computer unit (30c) for computing an instant gear position of the transmission based on the vehicle speed and the throttle opening according to the gear shift map; a gear position selector (30d) for controlling the transmission actuator based on the instant gear position to upshift or downshift the transmission; a shift prohibit unit (40) for determining whether the instant gear position matches the previous gear position from a memory (40a) for a predetermined times in a predetermined period and, if they do not match for the predetermined times, invalidating the instant gear position and prohibiting any shift operation according to the gear shift map; and a shift determination unit (41) for establishing an upshift prohibit condition when the throttle opening is equal to or less than a predetermined value while releasing the upshift prohibit condition when the vehicle speed is low or the clutch is in a position toward disengagement from a half clutch position, or with a low-speed gears even if the throttle opening is equal to or less than the predetermined value.

Automatic transmission with upshift prohibit dependent on throttle and

In a method for correcting clutch data used for controlling the operation of a friction clutch connected with an electronically controlled transmission system, the clutch data includes meet position data stored in a memory and the stored meet position data is compared with a first learned meet position data obtained after power is applied to the transmission system. The old data stored in the memory is replaced with the first learned meet position data when the difference between the old data and the first learned meet position data is greater than a prescribed value. The old data is corrected by the use of the old data and the learned data when the difference is not greater than the prescribed value even if the learned data is the first learned meet position data.

Correcting method for data used for control operation of vehicular clutch

A transmission control system with gear shift failure detection includes a transmission (1), each gear of which is equipped with a synchromesh mechanism (1e); an actuator unit (2) consisting of a shift actuator (2a) for making a gear shift in a shift direction and a select actuator (2b) for making a gear shift in a select direction; a control unit (4) for calculating a target position signal (M) from an amount of pressdown of an accelerator pedal, a vehicle speed, and a set position of a gear selector to control not only the actuator unit so that a gear is set within a target range but also a clutch so that connection or disconnection is made according to an operation of the transmission; a position detector (2f, 2g) provided in each of the shift and select actuators for detecting a position of a piston rod (2c, 2d); a servo cylinder (2a, 2b) in response to a signal from the position detector to position the piston rod at a given position of each gear; a speed detector (4a) in response to a signal from the position detector of the shift actuator to detect an operational speed of the piston rod of the shift actuator; and a decision maker (4b) in response to a signal from the speed detector to decide that a gear shift is faulted if the operation speed is lower than a reference speed for a predetermined time outside a synchromesh mechanism operational range of the transmission.

Transmission control system with gear shift failure detection

In a system for controlling a clutch for vehicle having an automatic gear-transmission control system, the clutch is controlled so as to be disengaged when a gear of the transmission is in a prescribed low-speed gear position at which strong engine braking power can be expected and fuel-powered operation of an engine for powering the vehicle has stopped during the running of the vehicle, whereby it can be prevented to apply sudden engine braking power to the vehicle.

Method and apparatus for controlling a clutch for vehicles

An automatic transmission with an engine rpm sensor fault detector includes a starter switch (18); a clutch (6) for transmitting an output of an engine (8); a clutch control unit for controlling engagement of the clutch; a transmission (1); an engine rpm sensor (9); a an input shaft sensor (5a); a gear position sensor (40a) for detecting a gear position of the transmission; a control unit (4) for controlling the clutch control unit based on outputs of the respective detectors and enables the starter switch to operate when the transmission is in a neutral position. The control unit includes a starter switch detector (40b) for determining whether the starter switch is on and a fault determination unit (40c) for determining whether the first detector is faulty. The fault determination unit controls the clutch control unit to engage the clutch temporarily if there is no output from the first detector with the starter switch on and determines that the first detector is faulty if there is an output from the second detector.

Automatic transmission with sensor fault detector

A clutch control unit which includes a clutch (6); a first detector (9) for detecting a first rate of rotation of an input of the clutch; a second detector (5a) for detecting a second rate of rotation of an output of the clutch; a clutch learning unit (4b) for determining a clutch position at which both of the first and second rates of rotation meet predetermined conditions when said clutch is moved toward engagement from a preset learning starting point and storing a clutch characteristic; a signal generator (4c) for generating a learning underway signal indicating that the clutch learning unit is learning the clutch characteristic; and warning unit (16a) responsive to the learning underway signal to provide a warning display or sound.

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Saitama, Japan

Hiroyuki Soda