Abstract: A control device for controlling a continuously variable transmission (5) is disclosed. The control device has an oil pressure control unit (100) which supplies an oil pressure to a primary pulley (10) and secondary pulley (11) based on a command signal indicative of a target speed-reduction ratio, a sensor (26) which detects a rotation speed (Np1) of the primary pulley (26), and a controller (20) which transmits the command signal indicative of the target speed-reduction ratio to the oil pressure control unit (100).

Abstract: Disclosed are a control system and a control method for an automatic transmission, in which a judgment is made whether or not a range selector (31) has been switched to a reverse range during forward traveling of the vehicle. When it is determined that the range selector (31) has been switched to the reverse range during forward traveling of the vehicle, a judgment is made whether or not the vehicle speed is lower than a first vehicle speed and whether or not the period of time that has elapsed until switching from the forward to the reverse range is shorter than a predetermined judgment time. When the vehicle speed is lower than the first vehicle speed and the period of time that has elapsed until switching from the forward to the reverse range is shorter than the predetermined judgment time, a forward/backward changeover mechanism (4) is switched to a reverse mode. Otherwise, the switching of the forward/backward changeover mechanism (4) to the reverse mode is delayed.

Abstract: Disclosed is a control device for controlling a two-way linear solenoid valve (60) including a pressure regulating port (60p) which communicates with a hydraulic circuit side, a drain port (60d) which communicates with a drain side, a plunger (61) which controls the state of communication between the pressure regulating port and drain port, and a coil (70) which drives the plunger in accordance with an exciting current. The control device has a current generator (65) which supplies the coil with the exciting current corresponding to a duty signal; and a microcomputer (1). The microcomputer determines whether or not a preset foreign matter removal starting condition for removing foreign matter accumulated in the ports has been established.

Abstract: A control system for an automatic transmission (5) includes an oil pressure control mechanism (100) for supplying an oil pressure to the transmission (5), and sensor (28, 29) for detecting the oil pressure supplied from the oil pressure control mechanism (100) to the transmission (5). System controller (20, 21) calculates a maximum torque transmittable by the transmission (5) based on a speed ratio of the transmission (5) and the detected oil pressure; calculate an engine torque reduction amount from the difference between the torque being inputted into the transmission (5) and the maximum transmittable torque; and reduce the torque of an engine (1) according to the engine torque reduction amount.

Abstract: A clutch engagement control device controls the engagement of a forward clutch (32) and reverse clutch (33) in an automatic transmission connected to an engine (70) in a vehicle. An inhibitor switch (56) outputs a range signal in accordance with a position range of a select lever (51). A manual valve (57) supplies oil pressure selectively to one of the forward clutch (32) and the reverse clutch (33) by changing position in accordance with the position range of the select lever (51). A controller (60) of the clutch engagement control device determines whether an unmatching range condition occurs in which the range of the select lever (51) indicated by the range signal and the range of the manual valve (57) do not match, when the range of the select lever (51) indicated by the range signal is a drive range or reverse range; and suppress an increase in engine rotation speed prior to engagement of the forward clutch or reverse clutch when the unmatching range condition occurs.

Abstract: A controller (50) controls the supply of oil pressure to a primary pulley (41) and a secondary pulley (42) of a belt-drive continuously variable transmission (1) in accordance with the depression amount of an accelerator pedal (81) of a vehicle. When slippage is detected in a V-belt (43) that is wrapped around the primary pulley (41) and secondary pulley (42), the controller (50) reduces the output torque of an engine (70) of the vehicle to stop the V-belt (43) from slipping. Meanwhile, damage to the V-belt (43) caused by slippage is prevented by reducing the oil pressure supply to the secondary pulley (42).

Abstract: A vehicle engine (70) is connected with a belt-type continuously variable transmission (1) via a clutch (32). The transmission (1) transmits torque via a belt (43) between a pair of pulleys (41, 42), and varies the transmission torque according to a supply of oil pressure. The clutch (32) 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 (10, 44, 45, 46) supplies the oil pressure required to transmit torque between the belt (43) and the pulleys (41, 42), and the oil pressure for engaging the clutch (32). Slippage between the belt (43) and the pulleys (41, 42) is prevented during engagement of the clutch (32) by restricting the output torque of the engine (70) over a predetermined period of time.

Abstract: A hydraulic clutch (12, 13) transmits driving torque in a power train of a vehicle. An oil pressure supply unit (35) which supplies oil pressure for engagement to the clutch (12, 13) and a controller (40) which controls the unit (35) are provided. The controller (40) causes the unit (35) prior to engagement of the clutch (12, 13) to precharge the interior of the clutch (12, 13) with hydraulic fluid. The controller (40) counts an elapsed time since the last release of the clutch (12, 13) and shortens the precharge period as the elapsed time decreases, thereby optimizing the precharge state of the clutch (12, 13).

Abstract: In a system for controlling an automatic transmission, at the time of ultra-low temperature start with the oil temperature of −20° C. or less, control is carried out such that when the state that the actual line pressure is equal to or greater than an ultra-low set value continues for a period longer than a line-pressure low-pressure control command set time, it is determined that the line pressure is under regulation, maximizing an indicated value of the line pressure.

Abstract: Hydraulic control system and method for a belt-drive continuously variable transmission (CVT). The system includes an oil pump operative to produce an oil pressure and an oil flow amount which are supplied to the CVT, a pressure regulator valve operative to regulate the oil pressure, an oil supply passage for supplying oil to the belt on a downstream side of the pressure regulator valve, means for detecting an engine operating condition and generating a signal indicative of the engine operating condition detected, and a controller programmed to calculate a CVT input torque based on the signal, calculate a required belt lubricating oil flow amount to be supplied to the belt on the basis of the signal and the CVT input torque, determine a minimum speed of the oil pump based on the required belt lubricating oil flow amount, and control the oil pump at the minimum speed.

Abstract: A shift control system for an automatic transmission which has a gear ratio control means for controlling gear ratio of the automatic transmission comprises a lower limit setting device provided in said gear ratio control means and setting a lower limit for inhibiting a gear ratio from changing to a gear ratio of an upshift side; and a lower limit variable control means in which a lower limit of said gear ratio can be changed to a downshift side or to an upshift side by an operation of a driver.

Abstract: A shift control system for a continuously variable transmission CVT) has a gear ratio controller for controlling the gear ratio of CVT by determining a target gear ratio from a drive point determined on the basis of at least a throttle opening and a vehicle speed. The shift control system also has a vehicle distance controller for maintaining a proper vehicle distance by controlling the throttle opening of an engine. A shift speed control device provided in the gear ratio controller increases the shift speed from the shift speed established at the time the vehicle distance is not controlled by the vehicle distance controller, when the vehicle distance is controlled by the vehicle distance controller.

Abstract: A driving force control device, which controls a driving force by changing a gear ratio of an automatic transmission, comprises: a virtual throttle opening converter for converting a target driving force into a virtual throttle opening by using a target driving force characteristic and a detected vehicle speed; a throttle opening information selector for selecting the virtual throttle opening from the virtual throttle opening converter as throttle opening information when the driving force is controlled, and selecting an actual throttle opening from the throttle opening sensor as throttle opening information when the driving force is not controlled; and a target input revolutionary speed calculator 123d that calculates the target input revolutionary speed according to the selected throttle opening information, the detected vehicle speed and one shift map. The Continuously variable transmission determines an achievable gear ratio according to the target input revolutionary speed.

Abstract: A shift control system for an automatic transmission which has a gear ratio control means for controlling gear ratio of the automatic transmission comprises a lower limit setting device provided in said gear ratio control means and setting a lower limit for inhibiting a gear ratio from changing to a gear ratio of an upshift side; and a lower limit variable control means in which a lower limit of said gear ratio can be changed to a downshift side or to an upshift side by an operation of a driver.

Abstract: A shift control system for a continuously variable transmission which has a gear ratio control means for controlling gear ratio of said continuously variable transmission by determining a target gear ratio from a drive point determined on the basis of at least a throttle opening and a vehicle speed, and a vehicle distance control means for maintaining a proper vehicle distance by controlling a throttle opening of an engine, comprises: a shift speed control device provided in said gear ratio control means and making a shift speed higher than a shift speed established at the time when of a vehicle distance is not controlled by said vehicle distance control means, when a vehicle distance is controlled by said vehicle distance control means.

Abstract: A driving force control device, which controls a driving force by changing a gear ratio of an automatic transmission, comprises: a virtual throttle opening converter for converting a target driving force into a virtual throttle opening by using a target driving force characteristic and a detected vehicle speed; a throttle opening information selector for selecting the virtual throttle opening from the virtual throttle opening converter as throttle opening information when the driving force is controlled, and selecting an actual throttle opening from the throttle opening sensor as throttle opening information when the driving force is not controlled; and a target input revolutionary speed calculator 123d that calculates the target input revolutionary speed according to the selected throttle opening information, the detected vehicle speed and one shift map. The Continuously variable transmission determines an achievable gear ratio according to the target input revolutionary speed.

Abstract: In a vehicle transmission wherein plural speed change ratios from a largest speed change ratio to a smallest speed change ratio are selectively applied according to a command input by a driver, a real speed change ratio of the transmission is detected. It is determined whether or not the transmission is performing a shift-down based on the input command and the real speed change ratio. A shift-down limit speed change ratio is determined based on the speed change ratio before the shift-down operation is performed, and when the engine brake of the vehicle is operating, the transmission is controlled so as not to apply a speed change ratio larger than this shift-down limit speed change ratio. Due to this, the driver does not experience an excessive engine braking sensation even when an extreme speed change command is issued.

Abstract: In a vehicle provided with a continuously variable transmission, when a target speed change ratio sharply decreases due to the release of an accelerator pedal from depression, a real speed change ratio of the continuously variable transmission which follows the target speed change ratio may undershoot the target speed change ratio. Due to this undershoot, the engine rotation speed may temporarily fall below a permitted level. Therefore, the variation rate of the speed change ratio of the transmission is decreased in the terminal phase of the shifting process of the speed change ratio.

Abstract: A shift control apparatus outputs a command transmission ratio to a continuously variable transmission (CVT) to control a real transmission ratio of the CVT. The shift control apparatus comprises a shift mode determining section determines whether an actually selected shift mode is an automatic upshift or a power-down upshift (foot-release upshift), on the basis of the result of a previously selected shift mode, a difference between a final objective transmission ratio and a transient objective transmission ratio and a rate of change in the transmission ratio per time. The dynamic characteristic selecting section determines the dynamic characteristic according to the determined shift mode.

Abstract: A speed ratio controller for a continuously variable transmission of a vehicle is provided which sets a target speed ratio according to a vehicle speed and degree of accelerator pedal depression, sets a command speed ratio according to the target speed ratio and a predetermined dynamic characteristic, and controls the transmission so as to obtain the target speed ratio while a real speed ratio follows the command speed ratio. This speed ratio controller computes a deviation between the command speed ratio and target speed ratio, and determines whether an upshift characteristic is an auto upshift, foot release upshift or foot return upshift based on the speed ratio deviation, degree of accelerator pedal depression, and variation amount of the target input shaft rotation speed. The dynamic characteristic of the command speed ratio is set according to the determination result, and the response characteristics of the transmission are thereby modified.