Abstract: The vehicle comprises a continuously variable transmission and traction control system (TCS) which controls a driving force. When the TCS is not operating, a controller computes a final target ratio based on a sensor detected vehicle speed. When the TCS is operating, the final target ratio is computed based on an estimated vehicle speed, and the final target ratio is limited by a speed ratio upper limiting value computed based on the sensor detected vehicle speed. The controller controls a speed change actuator so that a real speed ratio approaches the final target ratio.

Abstract: An alarm is emitted when a vehicle attempts to start when the speed ratio of a toroidal continuously variable transmission is small. A sensor (63. 67. 73) detects that the speed ratio is smaller than a predetermined range. A microprocessor (61) controls an alarm (68) to operate when an ignition switch (66) is in a position for starting an engine, while the speed ratio is smaller than the predetermined range.

Abstract: A first switch (2) which can select a manual mode, and a second switch (5, 6) which can select one of an upshift and a downshift, are provided. A microprocessor (1) varies a speed ratio of an automatic transmission (10) according to the specification of the second switch (5, 6) when the first switch (2) has previously selected the manual mode, and the second switch (5, 6) subsequently specifies one of the upshift and the downshift (S20, S21, S33, S40, S41, S34, S36, S37, S53, S54, S55). On the other hand, variation of the speed ratio of the automatic transmission (10) according to the specification of the second switch (5, 6) is prohibited when the second switch (5,6) specifies one of the upshift and the downshift at a timing not later than a timing at which the manual mode is selected by the first switch (2) (S20, S22, S33, S40, S38, S34, S36, S38, S53, S54, S56).

Abstract: A speed change control device for an automatic transmission wherein the speed ratio is automatically varied according to a running state when an automatic shift mode is selected, and the speed ratio is varied based on a manual operation when the manual shift mode is selected. When there is a change-over from the automatic shift mode to the manual shift mode, a speed ratio immediately after the change-over is set to a speed ratio such that a transmission input rotation speed after the change-over increases by at least a predetermined rotation speed compared to the transmission input rotation speed before the change-over. In this way, the effectiveness of engine braking is enhanced immediately after a change-over to the manual shift mode, or a downshift for acceleration can be definitively performed.

Abstract: When a slip control system starts operating, a vehicle speed VSP used for speed change control is simultaneously changed over from a sensor detected vehicle speed VSPSEN to an estimated vehicle speed VSPFL. On the other hand, when the slip control system has stopped, it is first determined whether a speed ratio variation amount, due to the change-over of the vehicle speed used for speed change control from the estimated vehicle speed VSPFL to the sensor detected vehicle speed VSPSEN, is less than a permissible amount. When it is determined that the speed ratio variation amount is smaller than the permissible amount, the vehicle speed used for speed change control is changed over from the estimated vehicle speed VSPFL to the sensor detected vehicle speed VSPSEN. By performing this change-over, a sharp variation of the vehicle speed used for speed change control is suppressed, and a sharp variation of the speed ratio leading to shocks or slipping is suppressed.

Abstract: A starting shift control system for a continuously variable transmission is provided which includes a control unit having a high start judgement device for judging whether or not a high start in a high speed side gear ratio is caused on the basis of a comparison between the generated number of the input rotation pulses and the generated number of the output rotation pulses from the time a first vehicle starting operation is performed after start of a prime mover, and a high start control device for restricting downshifting from the high speed side gear ratio to a target gear ratio when a start of the vehicle is judged to be the high start. A starting shift control method is also provided.

Abstract: A controller determines whether or not the vehicle dynamics controller is operating, and when it is determined that it is operating, a speed change operation by an actuator which changes over a gear position of the automatic transmission is prohibited. This speed change prohibition is continued for a predetermined time even when the vehicle dynamics controller has stopped. In this way, control performance of the vehicle dynamics controller is prevented from becoming unstable due to a speed change of the automatic transmission.

Abstract: When a slip control system is not operating, a speed ratio control device uses a sensor detected vehicle speed for speed ratio control, and when the slip control system is operating, it uses an estimated vehicle speed for speed ratio control. It is determined whether a variation amount of the estimated vehicle speed is greater than a threshold set to a variation amount which could not be obtained when there is no error. When the variation amount of the estimated vehicle speed is greater than the threshold, it is determined that the estimated vehicle speed is abnormal, and use of the estimated vehicle speed for speed ratio control is prohibited.

Abstract: A lock-up torque converter is equipped with a lock-up clutch. The lockup clutch may engage even when the vehicle is coasting (lock-up coasting). When an accelerator pedal is depressed in a stepwise manner during lock-up coasting, the lock-up clutch is temporarily disengaged. By setting the threshold value used for determination so that it is easier to determine that the accelerator pedal was depressed in a stepwise manner the lower the vehicle speed, the dual objectives of vibration suppression of the drive system and improvement of fuel cost-performance are realized.

Abstract: In a vehicle continuously variable transmission, an engine rotation speed, input rotation speed of the transmission and an output rotation speed of the transmission are respectively detected by sensors (64, 65, 68). Based on the output signals from these rotation speed sensors (64, 65, 68), a controller (61) controls a speed ratio of the transmission within a predetermined speed ratio range. The controller (61) also determines if any of the rotation speed sensors (64, 65, 68) has an abnormality based on the output signals from these sensors (64, 65, 68) and narrows the predetermined speed ratio range (S234) when any of the sensors has been determined to have an abnormality, so as to prevent an extraordinary speed ratio control from being performed.

Abstract: In a toroidal continuously variable transmission for a vehicle, either of an automatic operation mode and a manual operation mode is selected by a driver via a selector lever (59). A speed ratio grade in the manual operation mode is also designated via the selector lever (59) by the driver. A controller (61) is programmed to control a speed ratio of the transmission to a target speed ratio corresponding to the designated speed ratio grade. The controller (61) is further programmed to prevent the speed ratio from varying after an input torque to the transmission has changed. This control may be realized by setting different target speed ratios for an identical speed ratio grade according to the input torque of the transmission.

Abstract: A first final target input rotation speed is calculated according to a throttle opening and a vehicle speed, and a second final target input rotation speed is calculated by applying an upper limit to the first final target input rotation speed. The upper limit is determined so as to reduce noise outside the vehicle. A second final target speed ratio is set from the vehicle speed and second final target input rotation speed, and a time constant of a speed ratio variation is determined from the vehicle speed and first final target input rotation speed. By transiently controlling the speed ratio variation using the second final target speed ratio and time constant thus obtained, an excessive increase of engine rotation speed is prevented while retaining a desirable feeling of acceleration when there is a kickdown operation of the vehicle.

Abstract: In a vehicle continuously variable transmission, a controller (61) determines the transient target speed ratio Ratio0. A real speed ratio Ratio is detected by sensors (64, 65). The controller (61) calculates a feedback correction amount FBrto based on a deviation RtoERR of the real speed ratio Ratio from the transient target speed ratio Ratio0. The controller (61) then calculates a command value DsrSTP from the transient target speed ratio Ratio0 and feedback correction amount FBrto. The controller (61) applies a specific limitation to the command value DsrSTP when the real speed ratio Ratio is out of a predetermined range, so as to prevent the real speed ratio Ratio from exceeding the mechanical operation limit of the transmission. The limitation is based on the command value DsrSTP calculated in the preceding control cycle.

Abstract: A controller (61) calculates a transient target speed ratio based on a final speed ratio set according to a vehicle running condition and second order delay time constant gains (75, S99), and control a speed ratio of a continuously variable transmission to the transient target speed ratio via an actuator (4) (87, S103). The controller (61) also calculates the deviation between the final target speed ratio and transient target speed ratio (74, S95), and determines the second order delay time constant gains based on the deviation (74, S98). Preferably, the gains are determined so that the response rate is slower the larger the deviation (74, S134, S135, S136, S137, S139, S140, S141).

Abstract: In a vehicle automatic transmission, a controller (61) feedback controls a speed ratio command signal by proportional/integral/differential (PID) control so as to minimize a deviation between a transient target speed ratio and a real speed ratio. When a difference between the command signal and that of the preceding control cycle is larger than a predetermined value, the controller (61) prohibits the increase of an integral correction amount of the PID control in the next control cycle. In this way, continuous increase of the feedback correction amount while the transmission can not follow the command signal is suppressed.

Abstract: A speed ratio controller for a continuously variable transmission comprises a sensor (66) for detecting the activation of a catalyst purifying the exhaust gas of the engine, a sensor (62) for detecting an engine load, a sensor (63) for detecting a vehicle speed and a microprocessor (61) for controlling the transmission. The microprocessor (61) stores a first speed change map defining a speed ratio of the transmission according to the vehicle speed and engine load, and a second speed change map defining a larger speed ratio than the speed ratio defined in the first speed change map in a range where the vehicle speed is lower than a predetermined vehicle speed and the engine load is lower than a predetermined engine load. In order to determine the speed ratio of the transmission, the microprocessor (61) applies the first speed change map until the catalyst is activated and the second speed change map after the catalyst is activated.

Abstract: A speed ratio of a toroidal continuously variable transmission is varied by a step motor (4). The step motor (4) is responsive to a command signal Astep which a controller (61) outputs corresponding to a target speed ratio. The controller (61) is programmed to initialize the command signal Astep when it is activated while the vehicle is running (S152) such that the command signal coincides with an actual operation position of the step motor (4). The controller (61) is further programmed to limit the command signal, after performing this initialization, within a first limiting range which is narrower than a second limiting range corresponding to a physical operation limit of the step motor (4) (S168, S170). By applying such a limitation to the command signal, the command signal is prevented from exceeding the operation limit of the step motor (4) even when a torque shift error is introduced into the command signal by the initialization while the vehicle is running.

Abstract: A lockup control apparatus for use with an automotive vehicle having an engine, an automatic transmission and a torque converter operable in a coast lockup mode having a lockup capacity to provide a controlled degree of mechanical connection between the engine and the automatic transmission when the vehicle is coasting. The apparatus employs a memory having a desired value for the lockup capacity stored therein. A first signal is produced when a slip rotation occurs in the torque converter and a second signal is produced when the coast lockup mode is released. The desired lockup capacity value is updated with a greater value in response to the first signal. A frequency at which either of the first and second signals occurs is measured. The desired lockup capacity value is updated with a smaller value when the measured frequency exceeds a reference value.

Abstract: An agent for improving surface quality of paper comrising an acrylamide resin composition obtained by hydrolyzing an acrylamide resin which is obtained by polymerizing an acrylamide monomer in the presence of a urea compound, or copolymerizing an acrylamide monomer and an acrylonitrile monomer; an acrylamide monomer and a cross-linking agent; or an acrylamide monomer, an acrylnitrile monomer and a cross-linking agent in the presence of a urea compound. This agent provides paper with excellent surface strength, tensile strength and internal strength far better than conventional paper quality improving agents.

Abstract: A novel additive for papermaking is disclosed. The additive comprises an aqueous solution of a copolymer obtained by reacting (a) an acrylamide, (b) a vinyl monomer which is copolymerizable with component (a) and has a cationic group, (c) at least one of vinyl monomers which are copolymerizable with component (a) and (b) and have 2, 3 or 4 carboxyl groups in a molecule thereof and/or a salt thereof, optionally (e) a nonionic monomer which is copolymerizable with components (a), (b) and (c) if desired, and (d) a cross-linking compound, in the presence of (f) at least one of ethylene glycol, diethylene glycol, diethanolamine and glycerin.This novel additive for papermaking is able to achieve excellent freeness and retention in the process of papermaking and provides paper with increased strength.