Van Doorne's Transmissie B.v.

Chi Chung Choi

Wilhelmus C Roovers

Emery F Hendriks

Bastiaan A d'Herripon

Bastiaan Andreas D'Herripon

Bastiaan A d`Herripon

Wilhelmus Johannes Van Wijk

The invention relates to a continuously variable transmission. The continuously variable transmission according to the invention is designed such that in operating conditions to be defined in more detail the transmission ratio is kept essentially constant, in particular for travelling through bends, on inclines, in case of an emergency stop and during a transmission overspeeding. The constant transmission ratio is obtained while the input r.p.m. of the transmission is changing.

Continuously variable transmission

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.

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.

Method and apparatus for controlling the transmission ratio of a

To obtain a flexible transmission system which can be adjusted to the meet the individual desires of a driver, the choice of the desired value of the rate of revolution of the primary axle in the system, based on the current position of an accelerator pedal, and based on the current rate of revolution of the secondary axle of the system, is influenced, whereby several sub ranges are composed from the range of possible desired rate of revolution values of the primary axle, so that the possible positional values of the accelerator pedal can be combined with one of the sub ranges, to choice. A sub range preferably serves as a model for a desired type of driving program. If desired, the boundary values of the sub range can be continuously adjusted through the use of potentiometers which are operated by the driver. To assist in the realization of a simple-to-implement digital construction, the sub range values are stored in a memory.

Method for influencing the driving behaviour of a vehicle with a

A device for optically providing information pertaining to the value of the quotient of the rates of revolution of two axles contains converters connected to the axles, which converters generate electrical signals which are a measure for the rate of revolution of the respective axles. At least one of the signals is fed to a ladder network of resistances which contains tap-off points which are connected to similar inputs of comparator circuits. The other inputs of the various amplifiers receive as input the signal which is a measure for the rate of revolution of the other axle. The comparator circuits are each coupled to light-emitting elements of which a few, depending upon the quotient of the revolution rates, illuminate. When applied in a vehicle which is provided with a continuously variable transmission, optical information pertaining to the current value of the transmission ratio is thus provided.

Display device

In a continuously variable transmission which is provided with a primary pulley and a secondary pulley, between which a driving belt is mounted, primary and secondary control systems, which are coupled to the respective pressure chambers of the axially translatable pulley discs, are employed to precipitate current pressure values, in dependence upon desired pressure values. To this end, the control system employs a regulator to which only the difference between the desired and the measured pressure-value is supplied, whereby the regulator nevertheless only has to regulate the relatively rapidly changing variation in a rest value supplied separately by a rest state device. This greatly improves the dynamic behaviour of the controller, so that rapid variations in the desired value of the entrant pressure can be effectively followed by the control system.

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Eindhoven, Netherlands

Chi Chung Choi