Left/right drive torque adjusting apparatus for vehicle and left/right drive torque adjusting method for vehicle

A left/right drive torque adjusting apparatus for a vehicle, the apparatus being arranged between a left-wheel axle and a right-wheel axle in the vehicle to permit transfer of drive torque between the left-wheel and right-wheel axles so that drive torques for left and right wheels of the vehicle can be adjusted, the apparatus comprising:

• input means for receiving drive torque from an engine of the vehicle;
• a differential mechanism for transmitting the drive torque, which has been received by said input means, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle;
• a speed change mechanism connected to a side of at least one of the left-wheel and right-wheel axles, whereby a rotational speed of said at least one axle is shifted at a predetermined constant shift ratio;
• a torque transmission mechanism, of a variable transmitted capacity control type, interposed between a side of an output portion of the speed change mechanism and a side of said input means so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles;
• running state detection means for detecting a running state of the vehicle;
• control means for controlling an operation state of the torque transmission mechanism, on the basis of information detected by said running state detection means, so that torque of a desired capacity can be transferred between the left-wheel and right-wheel axles;
• rotational speed ratio judging means for judging whether or not a rotational speed ratio .alpha., of the left wheel to the right wheel obtained based on the detected running state of the vehicle, is greater than a threshold value Smax across which a predetermined high/low relationship between a rotational speed of the output portion of the speed change mechanism and a rotational speed of the other axle changes;
• and
• large-difference-rotation-time control means arranged in association with said control means, for, when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged to be greater than the threshold value Smax by said rotational speed ratio judging means, cancelling transfer of torque by the torque transmission mechanism to discontinue drive torque transmission control.

A left/right drive torque adjusting apparatus for a vehicle, the apparatus being arranged between a left-wheel axle and a right-wheel axle in the vehicle to permit transfer of drive torque between the left-wheel and right-wheel axles so that drive torques for left and right wheels of the vehicle can be adjusted, the apparatus comprising:

• input means for receiving drive torque from an engine of the vehicle;
• a differential mechanism for transmitting the drive torque, which has been received by said input means, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle;
• a speed change mechanism connected to a side of said input means, whereby a rotational speed on the side of said input means is shifted at a predetermined constant shift ratio;
• a torque transmission mechanism, of a variable transmitted capacity control type, interposed between a side of at least the other one of the left-wheel and right-wheel axles and a side of an output portion of the speed change mechanism so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles;
• running state detection means for detecting a running state of the vehicle;
• control means for controlling an operation state of the torque transmission mechanism, on the basis of information detected by said running state detection means, so that torque of a desired capacity can be transferred between the left-wheel and right-wheel axles;
• rotational speed ratio judging means for judging whether or not a rotational speed ratio .alpha., of the left wheel to the right wheel obtained based on the detected running state of the vehicle, is greater than a threshold value Smax across which a predetermined high/low relationship between a rotational speed of said output portion of the speed change mechanism and a rotational speed of the other axle changes;
• and
• large-difference-rotation-time control means arranged in association with said control means, for, when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged to be greater than the threshold value Smax by said rotational speed ratio judging means, cancelling transfer of torque by the torque transmission mechanism to discontinue drive torque transmission control.

A left/right drive torque adjusting apparatus for a vehicle, the apparatus being arranged between a left-wheel axle and a right-wheel axle in the vehicle to permit transfer of drive torque between the left-wheel and right-wheel axles so that drive torques for left and right wheels of the vehicle can be adjusted, the apparatus comprising:

• a combination of speed change mechanisms connected to the left-wheel and right-wheel axles, respectively, whereby rotational speeds on sides of the left-wheel and right-wheel axles are shifted at a predetermined constant shift ratio;
• a combination of torque transmission mechanisms, each of a variable transmitted capacity control type, interposed between sides of the left-wheel and right-wheel axles and sides of an output portion of the speed change mechanisms, respectively, so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles;
• running state detecting means for detecting a running state of the vehicle;
• control means for controlling an operation state of the torque transmission mechanisms, on the basis of information detected by said running state detection means, so that torque of a desired capacity can be transferred between the left-wheel and right-wheel axles;
• wheel slip judging means for judging a slipping state of the left and right wheels;
• and
• setting means for setting amounts of control of the combined torque transmission mechanisms so that, when one of the left and right wheels is judged to be slipping by said wheel slip judging means, one of the torque transmission mechanisms, said one torque transmission mechanism being the one opposite to the one which would be coupled if the direction of transfer of torque were based upon a desired capacity, is coupled.

A left/right drive torque adjusting apparatus for a vehicle, the apparatus being arranged between a left-wheel axle and a right-wheel axle in the vehicle to permit transfer of drive torque between the left-wheel and right-wheel axles so that drive torques for left and right wheels of the vehicle can be adjusted, the apparatus comprising:

• input means for receiving drive torque from an engine of the vehicle;
• a differential mechanism for transmitting the drive torque, which has been received by said input means, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle;
• a combination of speed change mechanisms connected to the left-wheel and right-wheel axles, respectively, whereby rotational speeds on sides of the left-wheel and right-wheel axles are shifted at a predetermined constant shift ratio;
• a combination of torque transmission mechanisms, each of a variable transmitted capacity control type, interposed between sides of an output portion of the speed change mechanism and a side of said input means, respectively, so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles;
• running state detection means for detecting a running state of the vehicle;
• control means for controlling an operation state of the torque transmission mechanism, on the basis of information detected by said running state detecting means, so that torque of a desired capacity can be transferred between the left-wheel and right-wheel axles;
• wheel slip judging means for judging a slipping state of the left and right wheels;
• and
• setting means for setting amounts of control of the combined torque transmission mechanisms so that, when one of the left and right wheels is judged to be slipping by said wheel slip judging means, one of the torque transmission mechanisms, said one torque transmission mechanism being the one opposite to the one which would be coupled if the direction of transfer of torque were based upon a desired capacity, is coupled.

A left-right drive torque adjusting apparatus for a vehicle, the apparatus being arranged between a left-wheel axle and a right-wheel axle in the vehicle to permit transfer of drive torque between the left-wheel and right-wheel axles so that drive torques for left and right wheels of the vehicle can be adjusted, the apparatus comprising:

• input means for receiving drive torque from an engine of the vehicle;
• a differential mechanism for transmitting the drive torque, which has been received by said input means, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle;
• a speed change mechanism connected to a side of said input means, whereby a rotational speed on the side of said input means is shifted at a predetermined constant shift ratio;
• a combination of torque transmission mechanisms, each of a variable transmitted capacity control type, interposed between the sides of the left-wheel and right-wheel axles and sides of an output portion of the speed change mechanisms, respectively, so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles;
• running state detection means for detecting a running state of the vehicle;
• control means for controlling an operation state of the torque transmission mechanism on the basis of detected information outputted from said running state detection means so that torque of a desired capacity can be transferred between the left-wheel and right-wheel axles;
• wheel slip judging means for judging a slipping state of the left and right wheels;
• and
• setting means for setting amounts of control of the combined torque transmission mechanisms so that, when one of the left and right wheels is judged to be slipping by said wheel slip judging means, one of the combined torque transmission mechanisms, said one torque transmission mechanism being the one opposite to the one which would be coupled if the direction of transfer of torque were based upon a desired capacity, is coupled.

A left/right drive torque adjusting method for a vehicle, the vehicle having a speed change mechanism and a torque transmission mechanism of the variable transmitted capacity control type between a left-wheel axle and a right-wheel axle, the speed change mechanism being connected to a side of at least one of the left-wheel and right-wheel axles to shift a rotational speed of the at least one axle at a predetermined constant shift ratio, and the torque transmission mechanism being interposed between a side of at least the other one of the left-wheel and right-wheel axles and a side of an output portion of the speed change mechanism so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles, the method including controlling a coupling state of the torque transmission mechanism of the variable transmitted capacity control type, thereby transferring drive torque between the left-wheel and right-wheel axles to adjust drive torques for the left and right wheels, the method comprising the steps of:

• i) detecting a running state of the vehicle;
• ii) judging whether or not a rotational speed ratio .alpha., of the left wheel to the right wheel obtained based on the detected running state of the vehicle, is greater than a threshold value Smax across which a predetermined high/low relationship between a rotational speed on a side of the output portion of the speed change mechanism and a rotational speed of the other axle changes;
• and
• iii) controlling an operation state of the torque transmission mechanism of the variable transmitted capacity control type so that, when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged not to be greater than the threshold value Smax, the torque transmission mechanism is coupled based on information about the detected running state of the vehicle to transfer torque of a desired capacity between the left-wheel and right-wheel axles, and when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged to be greater than the threshold value Smax, the transfer of torque by the torque transmission mechanism is cancelled to discontinue the drive torque transmission control.

A left/right drive torque adjusting method for a vehicle, the vehicle having an input device, a differential mechanism, a speed change mechanism and a torque transmission mechanism of the variable transmitted capacity control type, all between a left-wheel axle and a right-wheel axle, [said]the input device being adapted to receive drive torque from an engine of the vehicle, the differential mechanism being adapted to transmit the drive torque, which has been received through the input device, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle, the speed change mechanism being connected to a side of at least one of the left-wheel and right-wheel axles to shift a rotational speed on a side of the one axle at a predetermined constant shift ratio, and the torque transmission mechanism being interposed between a side of an output portion of the speed change mechanism and a side of the input device so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles, the method including controlling a coupling state of the torque transmission mechanism of the variable transmitted capacity control type, thereby transferring drive torque between the left-wheel and right-wheel axles to adjust drive torques for the left and right wheels, the method comprising the steps of:

• i) detecting a running state of the vehicle;
• ii) judging whether or not a rotational speed ratio .alpha., of the left wheel to the right wheel obtained based on the detected running state of the vehicle, is greater than a threshold value Smax across which a predetermined high/low relationship between a rotational speed on a side of the output portion of the speed change mechanism and a rotational speed of the other axle changes;
• and
• iii) controlling an operation state of the torque transmission mechanism of the variable transmitted capacity control type so that, when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged not to be greater than the threshold value Smax, the torque transmission mechanism is coupled based on information about the detected running state of the vehicle to transfer torque of a desired capacity between the left-wheel and right-wheel axles, and when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged to be greater than the threshold value Smax, the transfer of torque by the torque transmission mechanism is cancelled to discontinue the drive torque transmission control.

A left/right drive torque adjusting method for a vehicle, the vehicle having an input device, a differential mechanism, a speed change mechanism and a torque transmission mechanism of the variable transmitted capacity control type, all between a left-wheel axle and a right-wheel axle, the input device being adapted to receive drive torque from an engine of the vehicle, the differential mechanism being adapted to transmit the drive torque, which has been inputted through the input device, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle, the speed change mechanism being connected to a side of the input device to shift a rotational speed on the side of the input device at a predetermined constant shift ratio, and the torque transmission mechanism being interposed between a side of at least one of the left-wheel and right-wheel axles and a side of an output portion of the speed change mechanism so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles, the method including controlling a coupling state of the torque transmission mechanism of the variable transmitted capacity control type, thereby transferring drive torque between the left-wheel and right-wheel axles to adjust drive torques for the left and right wheels, the method comprising the steps of:

• i) detecting a running state of the vehicle;
• ii) judging whether or not a rotational speed ratio .alpha., of the left wheel to the right wheel obtained based on the detected running state of the vehicle, is greater than a threshold value Smax across which a predetermined high/low relationship between a rotational speed on a side of the output portion of the speed change mechanism and a rotational speed of the other axles changes;
• and
• iii) controlling an operation state of the torque transmission mechanism of the variable transmitted capacity control type so that, when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged not to be greater than the threshold value Smax, the torque transmission mechanism is coupled based on information about the detected running state of the vehicle to transfer torque of a desired capacity between the left-wheel and right-wheel axles, and when the rotational speed ratio .alpha. of the left wheel to the right wheel is judged to be greater than the threshold value Smax, the transfer of torque by the torque transmission mechanism is cancelled to discontinue the drive torque transmission control.

A left/right drive torque adjusting method for a vehicle, the vehicle having a combination of speed change mechanisms and a combination of torque transmission mechanisms of the variable transmitted capacity control type between a left-wheel axle and a right-wheel axle in the vehicle, the speed change mechanisms being connected to the left-wheel and right-wheel axles to shift rotational speeds on the sides of the axles at a predetermined constant shift ratio, and the torque transmission mechanisms being interposed between the sides of the left-wheel and right-wheel axles and a side of an output portion of the speed change mechanisms so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles, the method including controlling coupling states of the torque transmission mechanisms of the variable transmitted capacity control type, thereby transferring drive torque between the left-wheel and right-wheel axles to adjust drive torques for the left and right wheels, the method comprising the steps of:

• i) judging slipping states of the left and right wheels;
• ii) setting amounts of control of the torque transmission mechanisms so that, when one of the left and right wheels is judged to be slipping in step i), one of the combined torque transmission mechanisms, the one torque transmission mechanism being the one opposite to the one which would be coupled if the direction of transfer of torque were based upon a desired capacity, is coupled;
• and
• iii) controlling operation of the torque transmission mechanisms of the variable transmitted capacity control type on the basis of the amounts of control set in step ii).

A left/right drive torque adjusting method for a vehicle, the vehicle having an input device, a differential mechanism, a combination of speed change mechanisms and a combination of torque transmission mechanisms of the variable transmitted capacity control type, all between a left-wheel axle and a right-wheel axle in the vehicle, the input device being adapted to receive drive torque from an engine of the vehicle, the differential mechanism being adapted to transmit the drive torque, which has been received through the input device, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle, the speed change mechanisms being connected to the left-wheel and right-wheel axles, respectively, to shift rotational speeds on sides of the axles at a predetermined constant shift ratio, and the torque transmission mechanisms being interposed between sides of an output portion of the respective speed change mechanisms and a side of the input device so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles, the method including controlling coupling states of the torque transmission mechanisms of the variable transmitted capacity control type, thereby transferring drive torque between the left-wheel and right-wheel axles to adjust drive torques for the left and right wheels, the method comprising the steps of:

• i) judging slipping states of the left and right wheels;
• ii) setting amounts of control of the torque transmission mechanisms so that, when one of the left and right wheels is judged to be slipping in step i), one of the combined torque transmission mechanisms, the one torque transmission mechanism being the one opposite to the one which would be coupled if the direction of transfer of torque were based upon a desired capacity, is coupled;
• and
• iii) controlling operation of the torque transmission mechanisms of the variable transmitted capacity control type on the basis of the amounts of control set in step ii).

A left/right drive torque adjusting method for a vehicle, said vehicle having an input device, a differential mechanism, a combination of speed change mechanisms and a combination of torque transmission mechanisms of the variable transmitted capacity control type, all between a left-wheel axle and a right-wheel axle in the vehicle, the input device being adapted to receive drive torque from an engine, the differential mechanism being adapted to transmit the drive torque, which has been received through the input device, to the left-wheel and right-wheel axles while permitting differential motion between the left-wheel and right-wheel axles in the vehicle, the speed change mechanisms being connected to a side of the input device to shift a rotational speed on the side of the input device at a predetermined constant shift ratio, and the torque transmission mechanisms being interposed between sides of the axles and the speed change mechanisms, respectively, so that, when coupled, drive torque is transferred between the left-wheel and right-wheel axles, the method including controlling coupling states of the torque transmission mechanisms of the variable transmitted capacity control type, thereby transferring drive torque between the left-wheel and right-wheel axles to adjust drive torques for the left and right wheels, the method comprising the steps of:

• i) judging slipping states of the left and right wheels;
• ii) setting amounts of control of the torque transmission mechanisms so that, when one of the left and right wheels is judged to be slipping in the i), one of the combined torque transmission mechanisms, the one torque transmission mechanism being the one opposite to the one which would be coupled if the direction for transfer of torque were based upon a desired capacity, is coupled;
• and
• iii) controlling operation of the torque transmission mechanisms of the variable transmitted capacity control type on the basis of the amounts of control set in step ii).