A controller of a power transmission system for a vehicle includes an electronic control unit. When a difference between a secondary pressure set by use of a command pressure of the electromagnetic control valve for the secondary pulley, and an actual pressure obtained by a hydraulic pressure sensor, is larger than a predetermined pressure difference, the electronic control sets a primary pressure and the secondary pressure such that a speed ratio of a continuously variable transmission becomes substantially equal to a maximum value. The electronic control unit determines that there is an abnormality that an output pressure of the electromagnetic control valve for a secondary pulley is low, when the speed ratio is smaller than a predetermined first determination value, and determines that there is an abnormality in the hydraulic pressure sensor, when the speed ratio is larger than a predetermined second determination value.

In a control device of a vehicle including a first power transmission path transmitting a power through a belt-type continuously variable transmission and a second power transmission path transmitting a power through a reduction gear mechanism in parallel between an input shaft and an output shaft and including a dog clutch in series with the reduction gear mechanism in the second power transmission path, when the dog clutch is in an engagement transition state and a rotational speed change of the output shaft is equal to or greater than a predetermined value, the engagement transition state of the dog clutch is canceled to release the dog clutch.

A control apparatus for a vehicle drive-force transmitting apparatus that includes a gear mechanism and a continuously-variable transmission mechanism. The control apparatus determines whether there is a lower-gear-ratio setting request requesting a target gear ratio of the continuously-variable transmission mechanism to be set to a lower gear ratio that is lower than a highest gear ratio of the continuously-variable transmission mechanism. When it is determined that there is not a detection accuracy of a rotational speed of an output rotary member of the drive-force transmitting apparatus, the control apparatus sets the target gear ratio to the lower gear ratio if it is determined that there is the lower-gear-ratio setting request, and sets the target gear ratio to the highest gear ratio if it is determined that there is not the lower-gear-ratio setting request.

A continuously variable transmission is configured wherein an outer diameter of a first pulley 11 is smaller than an outer diameter of a second pulley 12, a first input shaft 1 and a second input shaft 2 have a parallel coaxial structure, the first input shaft 1 and a first output shaft 14 are linked via a LO clutch 3 and a first transmission gear assembly 8; and the second input shaft 2 and a second output shaft 15 are linked via a HI clutch 3 and a second transmission gear assembly 9. In-low-speed mode, a drive torque outputted from the second pulley 12 is transmitted to a differential via the second transmission gear assembly, a second low-speed gear 23, and a low final gear 16, whereas in high-speed mode, a drive torque outputted from the first pulley is transmitted to the differential via a high final gear 18.

Technologies relating to two channel transmissions are disclosed. A two channel transmission may comprise a differential or epicyclic gear train disposed inside a case, with input/output shafts extending out of case. A speed variator may link inputs and outputs of the differential or epicyclic gear train. The speed variator may comprise, inter alia, a continuously variable transmission (CVT) and a speed range gear. The CVT may link to an input/output shaft outside the case, and the speed range gear may link to an input/output shaft or carrier gear inside the case. In high-stability embodiments, the speed variator may be replaced by a belt or a set of gears.

A control apparatus for a drive-force transmitting apparatus that includes a transmission having primary and secondary pulleys. The control apparatus calculates a target thrust applied to the secondary pulley such that the target thrust is larger during a vehicle driven state than during a vehicle driving state. The control apparatus sets a first determination threshold of a drive-force related value used to determine whether it is the vehicle driving state or vehicle driven state and a second determination threshold of the drive-force related value used to switch from determination of the driven state to determination of the driving state, such that a difference of the first and second determination thresholds is larger and a range of the drive-force related value in which the driven state is determined is wider, when an automatic running-speed control is executed, than when the automatic running-speed control is not executed.

A control apparatus for a drive-force transmitting apparatus that includes a transmission having primary and secondary pulleys. When a detection accuracy of rotational speed of the primary and secondary pulley is not assured, the control apparatus sets each of (i) a secondary-thrust calculation thrust ratio value used for calculation of a secondary thrust that is to be applied to the secondary pulley and (ii) a primary-thrust calculation thrust ratio value used for calculation of a primary thrust that is to be applied to the primary pulley, such that each of the secondary-thrust calculation thrust ratio value and the primary-thrust calculation thrust ratio value is dependent on a result of a determination as to whether an actual gear ratio of the transmission is the highest gear ratio and a result of a determination as to whether an input torque inputted to the transmission is lower than a given torque value.

A dog clutch of a vehicle power transmission device includes a sleeve, the dog clutch connecting/disconnecting a first rotating shaft to/from a first gear by moving the sleeve between a neutral position at which inner circumferential teeth formed on an inner circumferential side of the sleeve are not meshed with outer circumferential teeth on a side surface side of the first gear and an engagement position at which the inner circumferential teeth are meshed with the outer circumferential teeth, the inner circumferential teeth and the outer circumferential teeth having inclined surfaces tooth thicknesses of which become larger as the inner circumferential teeth and the outer circumferential teeth approach each other, and when the sleeve is moved to an engagement position by a shift fork, the sleeve being held in contact with a side surface of the first gear.

A continuously variable transmission includes four shift elements to establish three forward driving ranges and one reverse driving range. Two of the forward driving ranges utilize recirculating power flow paths in which the power transmitted through the variator is much smaller than the power transmitted by the transmission. Both variator sheaves rotate about axes that are offset from the input axis such that neither sheave is partially submerged in transmission fluid.

A control apparatus for a vehicle drive-force transmitting apparatus which establishes selectively a first state in which a drive force is transmitted by a gear mechanism and a second state in which the drive force is transmitted by a continuously-variable transmission mechanism. The control apparatus executes a shift-up action requiring the first state to be switched to the second state, in (a) a case in which a state of the drive-force transmitting apparatus satisfies a first condition that a gear ratio of the continuously-variable transmission mechanism is not lower than a first gear ratio value and in (b) a case in which the state of the drive-force transmitting apparatus satisfies a second condition that a lap-down control is executed with the gear ratio of the continuously-variable transmission mechanism being not lower than a second gear ratio value that is lower than the first gear ratio value.