摘要:
A shift control system for an automatic transmission, comprising a shift unit for selecting by manipulating a shift lever an automatic shift mode, in which a gear stage is determined on the basis of a running state of a vehicle, and a manual shift mode in which a gear state is determined from an output signal based on the manipulation. The shift unit has a drive range capable of setting a plurality of forward gear stages and a plurality of range positions arrayed and includes: a first shift path for guiding the shift lever into the range positions; a second shift path intersecting the first shift path for guiding the shift lever; two third shift paths formed at the two end portions of the second shift path, the third shift paths having at their individual end portions gear stage positions for indicating the forward gear stages in the automatic shift mode and for guiding the shift lever; and a manual shift instructor for outputting a signal instructing a gear stage corresponding to the gear stage position when the shift lever is moved to the gear stage position. The shift control system comprises a gear stage setter for setting the gear stage which is instructed by the output signal of the manual shift instructor.
摘要:
A shift control system for an automatic transmission, includes: a plurality of frictional engagement elements adapted to be hydraulically engaged for setting a plurality of gear stages; and a shift lever for switching between an automatic mode, in which a gear stage is set on the basis of the running state of a vehicle, and a manual mode in which a gear stage is selected by manipulating the shift lever. A shift detector detects that a gear stage should be selected for the shift in the manual mode state and a shift start timing adjuster, if the shift in the manual mode state is detected, the switching rate of the frictional engagement elements which are switched for executing the detected shift.
摘要:
In an automatic transmission according to the present invention, a coast brake cutoff valve is arranged between a range-pressure-producing manual valve and shift valves and, when changed over, selectively feeds oil to hydraulic engine brake servomotors. An engine brake solenoid valve is on/off controlled by a shifting output signal from a CPU, whereby the coast brake cutoff valve is selectively changed over. A lockout valve is arranged between the coast brake cutoff valve and the manual valve and is connected to one of shifting solenoid valves. The automatic transmission can therefore be operated without trouble even when an electrical problem occurs in the shifting solenoid valves and/or the engine brake solenoid valve.
摘要:
In order to control the engine output timing always properly irrespective of the aging of an automatic transmission, the present invention provides a shift control system for a vehicular automatic transmission, which system comprises: release end detecting means for detecting the release end of a frictional engagement element for a higher gear stage, at a shifting time from higher to lower gear stages; synchronism detecting means for detecting the synchronism between an engine R.P.M. and a rotating element in the automatic transmission at the lower gear stage; and engine output control means for controlling the output of the engine. The aforementioned engine output control means starts the rise control of the engine output, when the release end of the frictional engagement element for the higher gear stage is detected by the release end detecting means, and ends the rise control of the aforementioned engine output when the synchronism between the engine R.P.M. and the rotating element in the automatic transmission at the lower gear stage is detected by the synchronism detecting means.
摘要:
A shift device includes a shift lever with an operating knob provided on the top thereof, a gate plate that defines shift patterns for an automatic shift mode and a manual shift mode, and a first rotational center shaft and a second rotational center shaft for allowing the shift lever to be rotated in a front-to-rear direction and in a right-to-left direction, respectively, in accordance with the shift pattern of the gate plate. The gate plate is disposed apart from the knob of the shift lever, with the rotational center shafts passing between the gate plate and the knob. The length of the shift lever can be reduced so as to achieve a short stroke and a large shift lever pivot angle.
摘要:
A control system for an automatic transmission including a fluid transmission unit and a lockup clutch arranged in the fluid transmission unit. A running state sensor(s) detects the running state of the vehicle and outputs signals to an electronic control unit for deciding a shift and outputting a shift signal and for deciding lockup clutch ON/OFF and outputting a lockup ON/OFF signal. A hydraulic control unit selectively actuates a plurality of solenoid valves, in response to the output signals from the electronic control unit, to selectively apply/release a plurality of frictional engagement elements, to establish a new gear stage, and the lockup clutch. The electronic control unit (ECU) has stored in memory therein, a lockup diagram having a first hysteresis region defined by a lockup OFF line and a first lockup ON line, and a second hysteresis region defined by a second lockup ON line formed in the first hysteresis region and the first lockup ON line. The ECU compares the output signals of the running state sensor(s) against the lockup diagram to decide lockup clutch OFF, if the running state is in a region below the lockup OFF line, lockup clutch ON, if the running state is over the first lockup ON line, and lockup clutch ON if the running state is in the second hysteresis region. The ECU also outputs a lockup signal to a predetermined one of the solenoid valves to apply/release the lockup clutch in accordance with the results of the comparison.
摘要:
A lockup clutch of an automatic transmission is controlled so that no shock is produced while the vehicle is running within a predetermined gear stage. The automatic transmission includes a fluid coupling; a lockup clutch provided in the fluid coupling; a shift selector for selecting a range; a vehicle speed sensor for detecting vehicle speed, and a throttle opening sensor for detecting throttle opening. A control unit determines a gear stage in accordance with the selected range, the vehicle speed and the throttle opening, decides a shift, produces a shifting output signal, decides ON or OFF for the lockup clutch in accordance with the selected range, the vehicle speed and the throttle opening, and produces a lockup ON/OFF output signal. An oil pressure circuit actuates solenoid valves in response to the shifting output signal and the lockup ON/OFF output signal of the control unit. The solenoid valves, in turn, control engagement and release of frictional engagement elements to achieve the decided gear stage and control engagement and release of the lockup clutch. The control unit includes, stored in memory, a lockup diagram set with an ON/OFF hysteresis area; a comparator for deciding whether or not the vehicle speed and the throttle opening, at the time of a shifting output signal is produced, are within the ON/OFF hysteresis area of the lockup diagram; and a lockup output signal generator for turning the lockup output ON if the vehicle speed and the throttle opening are within the ON/OFF hysteresis area when the shifting output signal is produced.
摘要:
A transmission unit includes a belt type continuously variable transmission (CVT) having a first pulley arranged on a first shaft with a stationary sheave, a movable sheave and a hydraulic actuator for the movable sheave. The second pulley of the CVT is mounted on a second shaft and also has a stationary sheave, a movable sheave and a hydraulic actuator. A belt is mounted around the first and second pulleys. The transmission unit further includes a synchronous transmission for connecting a first rotary member arranged on the first shaft and a second rotary member arranged on the second shaft at a constant speed ratio, an output gear for transmitting power to the wheels and a planetary gear unit. The planetary gear unit is mounted on the second shaft and includes at least first, second and third rotary elements. The first rotary element is connected to the second rotary member, the second rotary element to the second pulley, and the third rotary element to the output gear. The first shaft is connected through the CVT to the second rotary element and through the synchronous transmission to the first rotary element. The hydraulic actuators are arranged on opposite sides of the belt.
摘要:
A continuously variable transmission is switchable between the low and high modes by changing engagement between two clutches. A sensor shoe which moves in association with a movable sheave of a primary pulley is provided with an indent and a protrusion formed at different locations on the sensor shoe. In addition, indents are formed on a spool of a low-high control valve. An interlock rod is provided between the sensor shoe and the low-high control valve. In a predetermined pulley-ratio region in the low and high modes, for example, on a low pulley-ratio side, as the movable sheave moves to the O/D side a base end of the interlock rod rides on the upper surface of the sensor shoe while its opposite end is engaged within one of the indents, thus mechanically locking the low-high control valve. In this way, switching between the low and high modes due to selective engagement of the low and high clutches can be inhibited.
摘要:
When a driver depresses an accelerator pedal to request a shift such as a downshift or the like, a maximum shift target changing rate (shift speed) of a CVT having a belt-type continuously variable shift apparatus is set based on the shift inertia of the CVT and the like. An assist torque is set by subtracting the normal torque of an internal combustion engine from a torque needed to achieve the maximum shift target changing rate. The assist torque and the torque outputtable from an electric motor based on the characteristic of the motor are compared. If the assist torque is greater than the motor torque, the target changing rate is restricted by an assist possible rate based on the ratio between the assist torque and the motor torque. The shift of the CVT is controlled by the target changing rate (shift speed). Thus, the apparatus allows a quick speed by assisting with a motor torque and, in a case where the assist torque from the motor is insufficient in quantity, allows a shift at a speed in accordance with the case, thereby resolving the degradation of acceleration feel caused by the shift inertia of the CVT.