Zexel Gmbh

Masuhiro Otsuka

Hiromi Kono

Hiroyuki Soda

Yuji Satoh

Hiromi Kohno

Tsutomu Takahashi

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 an engine starting system for a vehicle with an automatic transmission system including a clutch operated by an actuator, the system comprises a detector for detecting whether an engine has stalled for a reason other than that an ignition switch has been turned off, and a control signal for disengaging the clutch is supplied to the actuator when the ignition switch is turned to its start position in the case where it is detected by the detector that the engine has stalled. After this, the current necessary for activating the starter motor is supplied to the starter motor irrespective of the position selected by a selector whenever the ignition switch is turned to the start position. The clutch needs not necessary be disengaged and it is possible to drive the starter motor with the clutch engaged.

System for starting an internal combustion engine for powering vehicles

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

In a method for controlling the gear-shift operation of a gear transmission for a vehicle in accordance with the running speed of the vehicle, in response to a command for shifting the transmission from its neutral position, the transmission is first shifted into a prescribed high gear position to detect the actual vehicle running speed and a target gear position is determined on the basis of the resulting detected vehicle running speed, whereafter the transmission is shifted into the target position.

Method for controlling gear transmission for vehicle

A clutch control unit includes a clutch learning unit (4b) for determining a clutch connection characteristic (M) based on the clutch position at which the number of revolutions of an output shaft of the clutch reaches a predetermined value when the clutch is moved toward connection from a predetermined learning starting point and a clutch off detector (4c) for determining a clutch off point at which the number of revolutions of the output shaft is zero by moving the clutch toward disconnection and taking as a new learning starting point the clutch off point or a point made by adding a small offset value to the clutch off point, thereby controlling the clutch based on the clutch connection characteristic (M).

Clutch control unit

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.

Growing community of inventors

Saitama, Japan

Masuhiro Otsuka