Hydraulic control apparatus for a continuously variable transmission

Claim 2

A hydraulic control apparatus for controlling a RPM of an engine in a motor vehicle using a continuously variable transmission, the transmission having a driving pulley mounted on an input shaft, the driving pulley comprising a fixed member and a moveable member, said moveable member being actuated by a hydraulic cylinder to form a V-shaped opening between said moveable member and said fixed member, a driven pulley mounted on an output shaft, the driven pulley comprising another fixed member and another moveable member, said another moveable member being similarly actuated by another hydraulic cylinder supplied with a line pressure to form another V-shaped opening between said another moveable member and said another fixed member, and an endless belt member spanning the driving and driven pulleys so that an effective diameter of the pulleys can be varied with regard to each other so that different speed ratios can be obtained comprising: first detecting means for detecting a first phase of a frequency component of an input torque on the input shaft of the driving pulley generated by the power stroke of the engine, and for outputting an input torque signal, said first detecting means being in communication with said input shaft; second detecting means for detecting a second phase of a frequency component of an output torque on the output shaft of the driven pulley generated by the power stroke of the engine, and for outputting an output torque signal, said second detecting means being in communication with said output shaft; a control circuit including: first calculating means in communication with said first and second detecting means for receiving the input and output torque signals for calculating first differences at a plurality of points in time between the first phase detected by the first detecting means and the second phase detected by the second detecting means, the first calculating means outputting at least a first calculated signal having a maximum value of the first differences between the first and second phases and a second calculated signal having a minimum value of the first differences between the first and second phases; second calculating means in communication with said first calculating means for receiving the first and second calculated signals from the first calculating means, and calculating a second difference between the maximum value of the first calculated signal and the minimum value of the second calculated signal, the second calculating means outputting a third calculated signal, the third calculated signal being indicative of the second difference; memory means for storing a predetermined value; comparison means in communication with said memory means and said second calculating means for receiving the third calculated signal and the predetermined value, and for comparing the second difference of the third calculated signal with the predetermined value stored in the memory means, the comparison means outputting a comparison signal indicative of the result of the comparison; and hydraulic fluid control means for receiving said comparison signal and for controlling the line pressure supplied to said another hydraulic cylinder of the driven pulley in accordance with the comparison signal, whereby said control means decreases the line pressure when the second difference of the third calculated signal is less than said predetermined value and increases the line pressure when the second difference of the third calculated signal is greater than said predetermined value.

Claim 3

The hydraulic control apparatus of claim 1, further comprising a flow control valve which functions to supply the hydraulic cylinder of the driving pulley with hydraulic fluid.

Claim 4

The hydraulic control apparatus of claim 1, wherein each of said first and second detecting means comprises a non-contact type torque sensing device having a first portion and a second portion.

Claim 5

The hydraulic control apparatus of claim 3, wherein detected variation in a magnetic field created between said first and second portions correspond to an amount of torque.

Claim 8

The method of claim 5, wherein the first predetermined value is greater than zero and less than 180°.

Claim 9

The method of claim 5, wherein said step of determining a new input voltage for the regulator valve comprises adding the compensated feedback voltage value to a previously used input voltage for the regulator valve.

Claim 10

A hydraulic control apparatus for controlling a RPM of an engine in a motor vehicle using a continuously variable transmission, the transmission having a driving pulley mounted on an input shaft, the driving pulley comprising a fixed member and a moveable member, said moveable member being actuated by a hydraulic cylinder to form a V-shaped opening between said moveable member and said fixed member, a driven pulley mounted on an output shaft, the driven pulley comprising another fixed member and another moveable member, said another moveable member being similarly actuated by another hydraulic cylinder supplied with a line pressure to form another V-shaped opening between said another moveable member and said another fixed member, and an endless belt member spanning the driving and driven pulleys so that an effective diameter of the pulleys can be varied with regard to each other so that different speed ratios can be obtained, comprising: first detecting means for detecting a first phase of a frequency component of an input torque on the input shaft of the driving pulley generated by the power stroke of the engine, and for outputting an input torque signal, said first detecting means being in communication with said input shaft; second detecting means for detecting a second phase of a frequency component of an output torque on the output shaft of the driven pulley generated by the power stroke of the engine, and for outputting an output torque signal, said second detecting means being in communication with said output shaft; a control circuit including: first calculating means in communication with said first and second detecting means for receiving the input and output torque signals and for calculating first differences at a plurality of points in time between the first phase detected by the first detecting means and the second phase detected by the second detecting means, the first calculating means outputting at least a first calculated signal having a maximum value of the first differences between the first and second phases and a second calculated signal having a minimum value of the first differences between the first and second phases; second calculating means in communication with said first calculating means for receiving the first and second calculated signals from the first calculating means, and calculating a second difference between the maximum value of the first calculated signal and the minimum value of the second calculated signal, the second calculating means outputting a third calculated signal, the third calculated signal being indicative of the second difference; memory means for storing a predetermined range of values representing an acceptable range for the calculated second difference between the first phase detected by the first detecting means and the second phase detected by the second detecting means; comparison means in communication with said memory means and said second calculating means for receiving the third calculated signal and the predetermined range of values, and for comparing the second difference of the third calculated signal with the predetermined range stored in the memory means, the comparison means outputting a comparison signal indicative of the result of the comparison; and hydraulic fluid control means for receiving said comparison signal and for controlling the line pressure supplied to said another hydraulic cylinder of the driven pulley in accordance with the comparison signal, whereby said control means increases the line pressure to cause said actual value to be within said predetermined range of values when the second difference of the third calculated signal is greater than said predetermined range of values and decreases the line pressure to cause said actual value to be within said predetermined range of values when the second difference of the third calculated signal is less than said predetermined range of values.

Claim 11

A hydraulic control apparatus for controlling a RPM of an engine in a motor vehicle using a continuously variable transmission, the transmission having a driving pulley mounted on an input shaft, the driving pulley comprising a fixed member and a moveable member, said moveable member being actuated by a hydraulic cylinder to form a V-shaped opening between said moveable member and said fixed member, a driven pulley mounted on an output shaft, the driven pulley comprising another fixed member and another moveable member, said another moveable member being similarly actuated by another hydraulic cylinder supplied with a line pressure to form another V-shaped opening between said another moveable member and said another fixed member, and an endless belt member spanning the driving and driven pulleys so that an effective diameter of the pulleys can be varied with regard to each other so that different speed ratios can be obtained, comprising: first detecting means for detecting a first phase of a frequency component of an input torque on the input shaft of the driving pulley generated by the power stroke of the engine, and for outputting an input torque signal, said first detecting means being in communication with said input shaft; second detecting means for detecting a second phase of a frequency component of an output torque on the output shaft of the driven pulley generated by the power stroke of the engine, and for outputting an output torque signal, said second detecting means being in communication with said output shaft; a control circuit including: first calculating means in communication with said first and second detecting means for receiving the input and output torque signals and for calculating first differences at a plurality of points in time between the first phase detected by the first detecting means and the second phase detected by the second detecting means, the first calculating means outputting at least a first calculated signal having a maximum value of the first differences between the first and second phases and a second calculated signal having a minimum value of the first differences between the first and second phases; second calculating means in communication with said first calculating means for receiving the first and second calculated signals from the first calculating means, and calculating a second difference between the maximum value of the first calculated signal and the minimum value of the second calculated signal, the second calculating means outputting a third calculated signal, the third calculated signal being indicative of the second difference; memory means for storing a predetermined range of values representing an acceptable range for the calculated second difference between the first phase detected by the first detecting means and the second phase detected by the second detecting means; comparison means in communication with said memory means and said second calculating means for receiving the third calculated signal and the predetermined range of values, and for comparing the second difference of the third calculated signal with the predetermined range stored in the memory means, the comparison means outputting a comparison signal indicative of the result of the comparison; and hydraulic fluid control means for receiving said comparison signal and for controlling the line pressure supplied to said another hydraulic cylinder of the driven pulley in accordance with the comparison signal, whereby said control means increases the line pressure to cause said actual value to be within said predetermined range of values when the second difference of the third calculated signal is greater than said predetermined range of values and decreases the line pressure to cause said actual value to be within said predetermined range of values when the second difference of the third calculated signal is less than said predetermined range of values.

Claim 12

The hydraulic control apparatus of claim 8, further comprising a flow control valve which functions to supply the hydraulic cylinder of the driving pulley with hydraulic fluid.

Claim 13

The hydraulic control apparatus of claim 8, wherein each of said first and second detecting means comprises a non-contact type torque sensing device having a first portion and a second portion.

Claim 14

The hydraulic control apparatus of claim 10, wherein detected variations in a magnetic field created between said first and second portions correspond to an amount of torque.

Claim 15

The hydraulic control apparatus of claim 8, wherein said predetermined value is between -180° and +180°.