Abstract: A positional determination device which is drived according to the pulse signals output to a stepping motor 1 and displaces a nut 2 to a position corresponding to the degree of rotation. In order to adjust the initializing position of a feed mechanism, the stepping motor 1 is rotated and the nut 2 displaces until it reaches the limiting position (LimA) defined by the stopper 3a. When initializing, the pattern of temporarily stopping the stepping motor 1 for a period corresponding to a pulse number (N2) at each pulse number (N1) and rotating is repeated. As a result the rotations of the stepping motor 1 become gentle and even if the nut 2 were to collide with the stopper 3a at the limiting position, the reverse rotation of the stepping motor 1 can be prevented and accurate adjustment of the initializing device can be performed.

Abstract: A speed change ratio of a continuously variable transmission comprising a V-belt looped around a pair of variable pulleys for varying the speed change ratio according to a first and second oil pressures. A speed change control valve converts a first oil pressure from an oil pressure supply unit to a second oil pressure based on a speed change ratio command value. The speed change ratio command value is calculated by a microprocessor according to a real speed change ratio and dynamic characteristics of the transmission. By calculating the dynamic characteristics according to the real speed change ratio and the first oil pressure, a set response of the transmission is always obtained regardless of fluctuations of the first oil pressure.

Abstract: A method for controlling the transmission ratio of a belt variator in a transmission unit for a motor vehicle is provided. The method at least provides for a control manner whereby the transmission ratio is controlled as a function of gear change signals given by a driver of the motor vehicle. The control is carried out according to what is called a variogram which is defined by a plurality of predetermined fixed control lines (A-B-C-D-E-F) via following the control lines. The control lines are determined so that, when gearing up and gearing down, respectively, large rotational speed differences in each successive transition between the control lines (A-B-C-D-E-F) are avoided.

Abstract: A transmission control system for a vehicle 10 is disclosed comprising a continuously variable transmission (CVT) 14 whose transmission ratio is varied by a CVT controller 20. When the selector lever 24 is in drive D, the CVT controller 20 varies the transmission ratio in a continuous manner but, if a stepped down-shift is selected using a down-shift button DS on the steering wheel 36, a hybrid mode may be entered to allow a user to perform stepped down-shifts to provide engine braking. In the hybrid mode, stepped down-shifts can be selected but the vehicle 10 is accelerated by varying the transmission ratio in a continuous manner.

Abstract: A control system comprises a line pressure control section which controls a line pressure applied to pulleys of a CVT according to an input load from the engine. When the input load is temporally increased, the line pressure is temporally increased by a pressure increasing section. After the line pressure is held for a predetermined time, the temporally increased line pressure is slowly decompressed by a step amount which is set small according to the increase of a transmission ratio of the CVT. This slow decompression of the line pressure suppresses the generation of vibrations of a drive system. Further, when an anti-skid control apparatus is operating or when a start clutch is engaged by the increase of the line pressure, the slow decompression is cancelled to smoothly execute their operations.

Abstract: A shift control apparatus of a continuously variable transmission for a vehicle comprises sensors for detecting operating conditions of the transmission and a motor connected to the transmission. A controller of the shift control apparatus stores different shift maps and employs one of them according to a driver's command or vehicle driving condition. The controller decides a target value of an input rotation speed of the transmission from an output rotation speed of the transmission and the load condition of a motor on the basis of the shift map and continuously changes a gear ratio of the transmission so that the transmission input rotation speed is adjusted to the target value. The controller can change the rate of the shift speed according to a driver's command.

Abstract: A power train for use in motor vehicles has an infinitely variable transmission with two adjustable sheaves, an endless flexible torque transmitting element trained over the sheaves, and at least one hydraulic adjusting unit for each of the sheaves. The adjusting units receive pressurized fluid from a pump and the pressure of such fluid, and hence the extent of frictional clamping engagement between the sheaves and the flexible element, is regulated by a torque sensor including a plenum chamber with an outlet having an effective cross-sectional area which is variable in dependency upon variations of torque being applied to the torque sensor by the engine of the vehicle. The energy of fluid leaving the plenum chamber is used to operate a jet pump which draws fluid from a source for lubrication and/or cooling of the transmission and/or one or more clutches forming part of the power train.

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.

Abstract: A vehicle power shift transmission (PST) is controlled by a transmission control system which implements a control method. The PST is part of the driveline of the vehicle and is shifted by an actuating mechanism. The driveline includes an engine, the PST, a clutch, a synchronized shift transmission that can be shifted by a shift lever and driven vehicle wheels. In order to simplify the operator's tasks, during the shift of the synchronized shift transmission the gear of the PST is automatically shifted so that the resulting difference in the gear ratio of the complete transmission before and after the shift is minimized. The gear of the PST is selected and shifted automatically so that the rotational speeds on both sides of the clutch differ as little as possible.

Abstract: A manual operation mode specifying a fixed speed change ratio by manual operation is set in a continuously variable transmission for a vehicle which continuously varies a speed change ratio to an arbitrary target speed change ratio. The manual operation mode defines for example first speed-fourth speed. While a driver is accelerating at the specified speed change ratio, the speed change ratio is decreased when a predetermined vehicle speed is reached. A difference of speed change ratio when the driver performs a shift-up operation after this decrease is thereby reduced. As a result, there are fewer drops of engine rotation speed due to shift-up, and acceleration performance is improved.

Abstract: A continuously variable transmission control system determines the desired speed ratio for a continuously variable transmission from various input data received from the vehicle and operator. The desired speed ratio is compared with a commanded speed ratio to provide an error signal which establishes a new commanded speed ratio for the continuously variable transmission. The comparing process of desired speed ratio to commanded speed ratio is repeated until the error signal is substantially null. Also, the control provides an adaptive modifier for the actuator of the continuously variable transmission such that a comparison of actual transmission ratio to commanded speed ratio will determine if an adaptive modification is necessary. The control further provides a step control function which is operable when the ratio of the continuously variable transmission is moving toward an underdrive ratio.

Abstract: A method for regulating a belt variator type transmission unit for motor vehicles, and which includes a belt variator, a reversing unit and a hydraulically controlled engine drive coupling that controls the reversing unit to provide forward and reverse drive connection between the engine and variator. The drive coupling comprises a forward coupling and a reverse coupling including fluid driven clutches which may be operated via a pressure regulating unit that provides an adjustable clutch actuating pressure. The clutch actuating pressure is hydraulically regulated both as a function of engine Pitot pressure which is representative of the engine speed, and as a function of a regulated pressure which is set by an electronically controlled valve.

Abstract: A process for regulating continuously variable transmissions in motor vehicles by means of a controller includes a first control circuit as a speed controller for regulating the transmission input speed as the product calculated from the transmission output speed and the transmission ratio, and a second control circuit post-connected to the first control circuit as a speed gradient controller for regulating the time derivative of the transmission input speed. A correction value, dependent on the functional value of a correcting function and obtained from a correction element, is added to the summation element at the controller input of one of the two control circuits. The correction value is obtained such that the regulating ranges are specified, respectively, with a different control behavior of the controller.

Abstract: A shift shock reducing apparatus installed in a vehicle which is equipped with a power train constituted by a continuously variable transmission (CVT) and an engine. The shift shock reducing apparatus comprises a calculating section which calculates an inertia torque caused by a shifting from a rate of change in a CVT ratio per time and an output torque correcting section which corrects a toque inputted to the CVT on the basis of the calculated inertia torque so as to cancel the inertia torque. Therefore, shift shocks due to the inertia torque is suppressed without generating a shift delay.

Abstract: An infinitely variable transmission has a gear neutral (GN) point and serves as an output member by torque circulation. When a pulley ratio thereof is within a predetermined range from the GN point, a coasting state occurs which may hinder smooth torque transmission based on the transmission efficiency and generate a great engine braking effect (failure in the transmission resulting from the coasting state) based on a large gear ratio. When the pulley ratio assumes a predetermined value that may cause failure in transmission resulting from the coasting state, upon release of the accelerator pedal, an electronic throttle system performs control such that the engine outputs a predetermined torque. Thus a positive driving state is always established. In this state, the continuously variable transmission (CVT) is shifted in the upshift direction to escape rapidly from a range defined by the pulley ratio of the predetermined value.

Abstract: The up-shift is discriminated to be in any one of a first up-shift mode in which the throttle opening degree remains nearly constant, a second up-shift mode accompanying the operation for nearly fully closing the throttle or a third up-shift mode accompanying the operation for closing the throttle to a half opened state. On the other hand, the down-shift is discriminated to be either in a first down-shift mode which accompanies the operation for opening the throttle or in a second down-shift mode accompanying the decrease in the vehicle speed. The rate of changing the speed is set for each of the speed change modes, and the speed change ratio of the continuously variable transmission is so controlled that the actual speed change ratio is gradually brought to the basic speed change ratio based upon said rate of changing the speed.

Abstract: A device for controlling the gear ratio of a continuously variable transmission. The theoretical rotational speed or transmission ratio is fed to the signal input of a set-value filter (44). The time constant (T.sub.-- RS) of the set-value filter (44) is adaptively controlled so that the change in transmission ratio takes place in accordance with a transition function whose limit is defined by a maximum variation speed. The principal advantage of the invention is that the vehicle is not slowed when shifting down to lower transmission ratios.

Abstract: A continuously variable transmission control system employs a gear ratio control map which has a step-wise control zone of driving condition where engine speed is controlled to repeat alternate gradual increase and rapid decrease with an increase in vehicle speed so as thereby to vary step-wise a gear ratio and a continuous control zone of driving conditions where engine speed is controlled to increase approximately linearly with an increase in vehicle speed so as thereby to continuously vary a gear ratio, the step-wise control zone of driving condition based on which the gear ratio control is performed being narrowed when a driving condition is judged to be within a specified unstable zone.

Abstract: A work vehicle having an improved transmission control circuit, that is responsive to a shuttle shift lever and associated switch that generates a forward signal, a reverse signal and a neutral signal, whereby the transmission control circuit engages the transmission in a forward gear ratio on receipt of the forward signal, a reverse gear ratio on receipt of the reverse signal and places the transmission in neutral on receipt of the neutral signal, and further wherein the transmission control circuit further places the transmission in neutral whenever it receives both a forward and neutral signal, or both a reverse and neutral signal.

Abstract: A method and apparatus for controlling a transmission for use with an automotive vehicle including an engine. The transmission coupled to the engine for transmitting a torque inputted thereto from the engine to produce an output torque at a continuously variable speed ratio. A target value for the speed ratio is calculated based on vehicle operating conditions. A rate at which the speed ratio changes to the calculated target value is calculated. An upper limit for the rate is calculated to satisfy such a condition that the output torque is substantially equal to or greater than zero. The rate of change of the speed ratio is limited to the upper limit when the calculated rate of change of the speed ratio is greater than the upper limit.

Abstract: A continuously variable transmission control system determines the desired speed ratio for a continuously variable transmission from various input data received from the vehicle and operator. The desired speed ratio is compared with a commanded speed ratio to provide an error signal which establishes a new commanded speed ratio for the continuously variable transmission. The comparing process of desired speed ratio to commanded speed ratio is repeated until the error signal is substantially null. Also, the control provides an adaptive modifier for the actuator of the continuously variable transmission such that a comparison of actual transmission ratio to commanded speed ratio will determine if an adaptive modification is necessary. The control further provides a step control function which is operable when the ratio of the continuously variable transmission is moving toward an underdrive ratio.

Abstract: A continuously variable transmission in a motor vehicle is regulated using a controller comprising a first control circuit as a speed controller for regulating the transmission input speed as the product calculated from the transmission output speed and the transmission ratio, complete with a summation element at the controller input as well as with a control element, and a second control circuit post-connected to the first control circuit as a speed gradient controller for regulating the time derivative of the transmission input speed, complete with a summation element at the controller input.

Abstract: A control system of a vehicular continuously variable transmission having a manual transmission mode comprises speed ratio changing when a manual transmission mode is chosen and a speed range is manually selected for changing a speed ratio of the selected speed range in the up-shift direction as the engine speed becomes high on the side of low speed ranges and in the down-shift direction as the vehicle speed becomes high on the side of high speed ranges. Further, in the manual transmission mode, when the engine speed reaches a lower limit value without making a down-shift, the speed ratio is controlled so as to hold the engine speed at the lower limit value. Thus constituted continuously variable transmission provides a vehicle with miscellaneous advantages such as an easy handling, smooth acceleration/deceleration performance, extended maximum speed and the like when the manual transmission mode is selected.

Abstract: A hydraulic control apparatus for a continuously variable transmission which can produce stable drive pulley pressure and driven pulley pressure and also control the speed change time. The line pressure regulated by the regulator valve 22 is supplied to the control valve 24.sub.DR of the drive pulley 5 and to the control valve 24.sub.DN of the driven pulley 7. These control valves regulate the line pressure according to the PB pressure and the PC pressure output from the solenoid valves SOL-B, SOL-C, respectively, and produce the drive pulley pressure P.sub.DR and the driven pulley pressure P.sub.DN. When the PB pressure and the PC pressure are both zero, and P.sub.DR =P.sub.DN, the control apparatus maintains the same gear ratio. When the PB pressure is increased from zero while keeping the PC pressure at zero, i.e. P.sub.DR >P.sub.DN, the gear ratio changes toward the high-speed overdrive. When the PC pressure is increased from zero while holding the PB pressure at zero, i.e. P.sub.DR <P.sub.

Abstract: A shift control apparatus for use with a continuously variable transmission operable at a speed ratio changed in a plurality of steps for transmitting a drive from the engine to the vehicle wheels. The shift control apparatus is operable in the manual shift control mode for producing an upshift command in response to a driver's upshift demand and a downshift command in response to a driver's downshift demand. An upshift is produced from a current speed ratio to another speed ratio one step higher than the current speed ratio in response to the upshift command and a downshift from the current speed ratio to another speed ratio one step lower than the current speed ratio in response to the downshift command. The transmission speed ratio is corrected to keep the engine speed at or below a predetermined acceptable value. An upper vehicle speed limit value is set for each of the speed ratios to provide a greater first upper vehicle speed limit value for a higher speed ratio.

Abstract: A speed change ratio of a continuously variable transmission for converting the rotation of the output shaft of an engine in a stepless manner and transmitting it to a drive shaft of a vehicle is controlled to a target speed change ratio. A target vehicle speed at a predetermined future time is estimated based on a real vehicle speed, and the target speed change ratio is calculated based on the estimated vehicle speed. By controlling a real speed change ratio to this target speed change ratio, the response of the transmission is enhanced. Preferably, a feedback vehicle speed is calculated by processing the estimated vehicle speed with a predetermined lag element. By integrating a difference between the real vehicle speed and feedback speed so as to estimate the vehicle speed at the predetermined future time, hunting of the speed change ratio in the speed change ratio control is suppressed.

Abstract: The invention is directed to a system for determining gear ratio change in an automatic transmission in a vehicle having an accelerator pedal actuated by a driver of the vehicle. The system includes a first sensor for detecting the position (DK) of the accelerator pedal as a first variable and a second sensor for detecting the straight-line speed (V.sub.x) of the vehicle as a second variable. An adaptation variable (BZ) is determined in dependence upon at least one of the following: the instantaneous driving behavior of the driver, the environmental conditions to which the vehicle is subjected and the driving situation in which the vehicle is. A gear ratio change function includes a characteristic field for receiving the first and second variables (DK, V.sub.x) as first and second input variables (DK, V.sub.x), respectively. At least one of the first and second input variables (DK, V.sub.x) is changed in dependence upon the adaptation variable (BZ).

Abstract: A powertrain control method applied to a lean burn engine coupled to a continuously variable transmission for minimizing engine out emissions selects one or more control parameters from a plurality of parameters that may be precisely controlled to provide for acceptable powertrain control with minimized emissions. Lean burn engine operation is maintained under low brake mean effective pressure conditions by modulating powertrain output power through transmission drive ratio variation. Fuel and air per cylinder may further be varied with the drive ratio when low emissions can be provided with minimum sacrifice to fuel economy. Lean burn operation is suspended under high brake mean effective pressure conditions by driving air/fuel ratio toward the stoichiometric ratio to exploit the efficiency of an included three-way catalytic treatment device while lowering engine speed to stabilize combustion.

Abstract: A basic speed change ratio is set on the basis of vehicle speed and throttle valve opening, and a control target speed change ratio is made to gradually approach the basic speed change ratio in accordance with a speed change speed. Feedback control is then carried out so that the actual speed change ratio coincides with the control target speed change ratio. When there is an up-shift requirement with a rate of change in throttle valve opening equal to or less than a predetermined value, and a rate of change in the basic speed change ratio, which is set on the basis of operating conditions, equal to or less than a predetermined value, the speed change speed is faster than at the time of an up-shift requirement with throttle valve closure.

Abstract: An automatic transmission having a multiple ratio gearset arranged in series with an overdrive gearset wherein ratio upshifts and downshifts are effected by separate reaction brakes for each gearset, each brake being independently controlled to achieve an enhancement of shift quality using closed loop control of reaction brake pressure and high ratio clutch pressure as a function of turbine speed, output shaft speed, brake drum speed for the multiple ratio gearset and input shaft speed in establishing control of upshifts and downshifts.

Abstract: An external disturbance compensating output computing unit comprising a low pass filter is provided in a speed change controller of a continuously variable transmission. A real speed change ratio, and an actuator position signal or a speed change ratio command value are input to the external disturbance compensating output computing unit. The actuator position signal or speed change ratio command value of a speed change mechanism control unit are selectively assigned to a value input to the low pass filter according to a difference between the real speed change ratio and a target speed change ratio. When the difference between the real speed change ratio and target speed change ratio is small, non-linear characteristics of the speed change mechanism are compensated, and when the difference is large, the non-linear characteristics of the speed change mechanism are not compensated. In this way, a desired speed change response is obtained regardless of driving conditions.

Abstract: A method of controlling a vehicle driveline including an engine, a continuously variable ratio transmission (CVT) and a final drive in which over a working range of engine speed, the engine is constrained to work to a performance map correlating each value of engine speed to a particular value of engine torque wherein a demand by a driver for a increase in vehicle speed initiates a quick increase in engine speed to a predetermined engage speed without any substantial rise in the final drive speed and then increasing both engine speed and drive speed by a predetermined function until a selected engine speed limit is reached which is commensurate with the driver's demand, and finally maintaining the selected engine speed limit despite further changes in the final drive speed whereby the ratio range of the CVT is extended by providing two regimes of operation with a synchronous ratio between those regimes and the predetermined function is graphically represented as a straight line slope which corresponds to the

Abstract: A multiple ratio transmission having a main gear unit with at least three forward driving ratios and a single reverse drive ratio and a simple planetary gear unit in series with the main gear unit, the simple planetary gear unit being downshifted and the main gear unit being upshifted on an upshift from a first intermediate ratio to a higher intermediate ratio, the simple planetary gear unit being upshifted and the main gear unit being downshifted on a downshift from the higher intermediate ratio to the first intermediate ratio, the initiation of the inertia phase of the upshifting mean gear unit on an overall automatic transmission ratio upshift triggering the beginning of the release of a reaction element of said simple planetary gear unit upon downshifting of said simple planetary gear unit.

Abstract: A method and apparatus for controlling a transmission for use with an automotive vehicle including an engine. The transmission coupled to the engine for transmitting a torque inputted thereto from the engine to produce an output torque at a continuously variable speed ratio. A target value for the speed ratio is calculated based on vehicle operating conditions. A rate at which the speed ratio changes to the calculated target value is calculated. An upper limit for the rate is calculated to satisfy such a condition that the transmission input torque is less than a maximum value below which there is no danger of damaging the transmission. The rate of change of the speed ratio is limited to the upper limit when the calculated rate of change of the speed ratio is greater than the upper limit.

Abstract: A method of controlling an electronically controlled, continuously variable transmission (3), according to which an electronic control device (15) determines a parameter K1 (24) on the basis of input variables, for example driving activity and topography. The parameter K1 (24) brings about a variation of an operating point.

Abstract: A rotation ratio of a continuously variable transmission for a vehicle provided with a pair of variable pulleys whereof the diameter of a contact part with a V-belt is made to vary according to an oil pressure, is controlled according to the running state of a vehicle. An oil pressure control valve is therefore provided to control the oil pressure. A rotation ratio command value is computed from a target rotation ratio set according to the vehicle running state and a control variable set for each rotation ratio according to the dynamic characteristics of the transmission. By inputting a signal based on this rotation ratio command value to the oil pressure control valve, a desirable speed change response is obtained.

Abstract: A steady state transmission ratio Base i is computed from a vehicle speed VPS and a throttle opening TVO (S1). An output shaft revolution speed No of the transmission and a current transmission ratio i are detected (S2, S3). A coefficient TTINR is computed from a difference or a ratio or the like between the steady state transmission ratio Base i and the current transmission ratio i (S4). Then, from the current transmission ratio i, the output shaft revolution speed No and the coefficient TTINR, a shift speed SV=TTINR/(IE.times.i.times.No) is computed (S5). Then a shift control is performed in accordance with the shift speed SV so as to approach to the steady state transmission ratio Base i (S6.about.S9). Thus, the shift speed during shifting in a continuously variable transmission is controlled in consideration of inertia torque.

Abstract: A control system for an engine-CVT drivetrain conducts conversion of speed ratio command to displacement command of an input element of a ratio control mechanism of the CVT beyond limits of a predetermined displacement range that corresponds to a predetermined speed ratio window having, as a lower limit, a lowest speed ratio and, as an upper limit, a highest speed ratio, providing improved driveability upon moving from a standstill and improved fuel economy. The speed ratio command is given by subtracting a disturbance compensated speed ratio from a dynamic characteristic compensated speed ratio.

Abstract: A power transmitting mechanism for use in a hybrid vehicle includes first and second continuously variable transmissions connected to an output shaft of a vehicle's engine. The first continuously variable transmission causes left and right wheels to rotate via a starting clutch, differential gear and vehicle's axle. The second continuously variable transmission drives a generator/motor and also drives pulleys that are provided for actuating auxiliaries such as an air-conditioning compressor and power-steering compressor. In acceleration of the vehicle, the generator/motor operates as an electro motor so that the axle can be driven by a combination of the output power of the engine and generator/motor. In deceleration of the vehicle, the generator/motor operates as a power generator so as to effectively collect, from the axle, decreasing energy of the vehicle.

Abstract: A continuously variable transmission, in particular for a motor vehicle, provided with a control for the transmission ratio of the transmission, which control in a first operating mode controls the transmission ratio on the basis of one or more input signals and in a second operating mode controls the transmission ratio, for example on the basis of an external signal originating from the driver of the motor vehicle, along one or more control curves of one or more sets of control curves, possibly within rotational speed limits imposed on the input speed of the transmission. One or more control curves and/or one or more rotational speed limits are a function of the input speed of the transmission in such a way that, in accordance with those functions, the input speed of the transmission is not zero for a notional output speed of the transmission of zero. In this way the drive characteristics of the transmission are appreciably improved, coupled with improved efficiency and optimum power.

Abstract: A method and apparatus for controlling a continuously variable transmission having an input and output shaft for use with an automotive vehicle. The transmission is operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft. A target value for the speed of rotation of the input shaft of the transmission is calculated based on the sensed vehicle operating conditions including vehicle acceleration (deceleration). A correction factor per predetermined unit time is calculated based on the vehicle acceleration (deceleration) when the vehicle acceleration (deceleration) exceeds a threshold value with the accelerator pedal being released. The correction factor is used to correct the target input shaft speed value at intervals of the predetermined unit time. The speed ratio is controlled to bring the input shaft speed into coincidence with the corrected target value.

Abstract: In order to optimize the speed change control of a continuously variable transmission, a necessary minimum primary pressure (Ppmin) for achieving a target speed change ratio is computed, and also a necessary minimum line pressure (Plmin) for the non occurrence of slippage between a secondary pulley 5 and a belt 6 is computed, and a required speed change ratio line pressure (Plratio) which can realize a target speed change ratio without slippage on the primary pulley 4 side is computed. The highest of these is then selected. The selected line pressure (Pl base) is then corrected by a transition line pressure (Pl add) determined from engine torque (TQ.sub.ENG) and speed change speed (SV), to obtain a final output line pressure (Plprs) which is then used to control a secondary pulley actuator 5a. In this way, speed change control can be optimized, for example by controlling slipping of the belt 6 at the time of rapid speed change.

Abstract: By a controller which controls a speed-change control valve for switching a hydraulic pressure to be supplied to each of cylinder chambers of each of pulleys of a continuously variable vehicular transmission, the speed reduction ratio is controlled such that the engine revolution speed becomes a target revolution speed which is set depending on the running conditions of a vehicle. When an accumulated time of high-speed operation at which Ne becomes higher than a predetermined first set revolution speed exceeds a first set time, an upper limit value of Ne or the target revolution speed is corrected to decrease. Further, when the duration time of a low-speed revolution below a predetermined second set revolution speed which is smaller than the first set revolution speed exceeds a second set time, the upper limit value of Ne is corrected to increase or the correction to decrease the target revolution speed is stopped.

Abstract: A transmission ratio control apparatus for a friction-wheel CVT requires no feedback of the offset of a friction wheel and performs stable transmission ratio control. A control circuit is provided for controlling the offsetting of the friction wheel to change transmission ratio. A first unit of the control circuit determines a target input rotational speed based on the throttle valve opening and the vehicle speed. A second unit determines target transmission ratio corresponding to the target input rotational speed. A third unit determines an rotational angle instructional value for a motor to achieve the target input rotational speed. A fourth unit determines a changing rate of actual transmission ratio based on the input rotational speed and the vehicle speed. A fifth unit corrects the motor rotational angle instructional value to reduce changes in transmission ratio as the transmission ratio changing rate increases, and outputs the corrected instructional value to the motor.

Abstract: A method for controlling the transmission ratio (input speed/output speed) of a continuously variable transmission, in particular for a motor vehicle. The transmission can be set to a second operational state as a result of energization by an activation signal. In the second operational state, the transmission ratio increases or decreases in the event of a decrease of increase, respectively, in the output speed of the transmission. In the second operational state, the transmission ratio is controlled using a control line, which intersects a point determined by the instantaneous input speed and instantaneous output speed of the transmission at the instant of commencement of said second operational state and also intersects a starting point determined by an input speed equal to zero and an output speed notionally less than zero. The invention also relates to an apparatus for carrying out the method.

Abstract: A basic speed change ratio is set on the basis of vehicle speed and throttle valve opening, and a control target speed change ratio is made to gradually approach the basic speed change ratio in accordance with a speed change speed. Feedback control is then carried out so that the actual speed change ratio coincides with the control target speed change ratio. When there is an up-shift requirement with a rate of change in throttle valve opening equal to or less than a predetermined value, and a rate of change in the basic speed change ratio, which is set on the basis of operating conditions, equal to or less than a predetermined value, the speed change speed is faster than at the time of an up-shift requirement with throttle valve closure.

Abstract: A speed change controlling apparatus and method for a non-stage change-gear system of the V-belt type or CVT are disclosed, wherein control is performed based particularly on the torque of a non-stage change-gear to meet with a high degree of accuracy requirements in which importance is attached to the fuel cost of a vehicle or the power performance and the time for development of a speed change schedule is avoided. A torque of a change-gear is estimated and speed change control is performed based on a targeted drive shaft torque so that the necessity for a speed change schedule map is eliminated and accurate speed change control based on the torque is performed. Consequently, an object speed change characteristic can be produced readily with a high degree of accuracy. Because matching need not be performed for each vehicle, the development man-hours can be reduced remarkably.

Abstract: In a shifting device such as generally used in automatic transmissions, a regulating device (15) is provided by the swiveling of which to a shifting gate (13) the automatic multiplication stages can be preselected. Besides, the regulating device can be transferred to a second shifting gate (14) via a transverse gate (17). According to the invention, in the second shifting gate (14) a characteristic field (1) is influenced by a continuously variable incremental or decremental change of individual operation parameters or a combination of at least two parameters. The operation parameters consist of the engine speed, the transmission ratio and the output speed.

Abstract: In a control apparatus for controlling a gear shift ratio of a continuously variable transmission mounted in an automotive vehicle as an automatic power transmission, a gear shift ratio command value is calculated using a control constant corresponding to a dynamic characteristic determined for each instantaneous gear shift ratio of the continuously variable transmission so as to achieve a target gear shift ratio response characteristic.

Abstract: With the present invention, it is possible for a vehicle to run on an uphill road at substantially the same throttle opening as on a horizontal road.When the road is uphill (hill-climbing resistance R.theta.>0), a maximum acceleration Amax for a full throttle opening is obtained according to a vehicle speed, and a maximum driving force Fmax=m.multidot.Amax+RL is calculated based on the mass of the vehicle m and the rolling and air resistance RL of the vehicle. Then, a correction coefficient HOS is obtained according to a throttle opening to calculale a required driving force Ftgt=Fmax.multidot.HOS. According to the required driving force Ftgt, hill-climbing resistance R.theta., and vehicle speed VSP, a target horsepower Ptgt=(Ftgt+R.theta.).multidot.VSP is calculated. To attain the target horsepower Ptgt, a target speed change ratio "itgt" for a continuously variable transmission is calculated to control the transmission.