초록 ▼

An automatic speed ratio control system of the integration servo mechanism type for a stepless transmission of an automotive vehicle. Speed ratio is controlled by a hydraulic pump motor of variable displacement type, which in turn is controlled by an actuator having a piston and a cylinder to which

An automatic speed ratio control system of the integration servo mechanism type for a stepless transmission of an automotive vehicle. Speed ratio is controlled by a hydraulic pump motor of variable displacement type, which in turn is controlled by an actuator having a piston and a cylinder to which hydraulic oil is supplied. The system comprises a target value generator which produces a target value for an engine speed corresponding to a throttle opening or an output torque of an engine, or which produces a target value for an engine output torque corresponding to a throttle opening or an engine speed; a detector for producing a signal indicative of an engine speed or an output torque of an engine; a control signal generator for comparing the signal from the detector against the signal from the target value generator to produce a control signal in accordance with a deviation therebetween; and a controller responsive to the control signal to drive the actuator to change a speed ratio of the stepless transmission. The system is characterized by further comprising means for controlling a gain of the alteration rate of the speed ratio in response to a rotational speed of an output shaft of the stepless transmission to increase the alteration rate when the rotational speed of the output shaft is low and decrease the alteration rate when the rotational speed of the output shaft is high.

대표청구항 ▼

In an automatic speed ratio control system for a stepless transmission of an automotive vehicle, having a target value signal generator means which produce a target value signal for controlling operation of an engine on the automotive vehicle, a detector means for producing a signal indicative of op

In an automatic speed ratio control system for a stepless transmission of an automotive vehicle, having a target value signal generator means which produce a target value signal for controlling operation of an engine on the automotive vehicle, a detector means for producing a signal indicative of operation of the engine, a control signal generator means for comparing the signal from the detector means against the target value signal from the target value signal generator means to generate a deviation signal in accordance with a deviation therebetween and controller means responsive to the deviation signal from the control signal generator means to change a speed ratio of the stepless transmission, and these means construct an integration servo control system comprising, means for controlling a gain of an alteration rate of the speed ratio in response to a rotational speed of an output shaft of the stepless transmission to increase the alteration rate when the rotational speed is low and decrease the alteration rate when the rotational speed is high.