Patent ID: 6966300
Filing Date: 2005-11-22
Classification: F02D,F02M,Y10T

Abstract:
1. A valve opening degree control system comprising: a fluid drive means for drawing or pumping fluid; a valve that adjusts a degree of opening of a fluid passage, which conducts the fluid drawn or pumped by the fluid drive means, wherein a maximum adjusting performance of the valve is larger than a maximum performance of the fluid drive means; a control device that controls a degree of opening of the valve; and a flow rate change sensing means for sensing an amount of change in the flow rate of the fluid, which is conducted through the fluid passage, wherein: the control device includes a learning means; the learning means controls a valve control value, which is supplied to the valve to control the degree of opening of the valve; the learning means controls the valve control value in a manner that achieves one of: at the time of progressively increasing the degree of opening of the valve from the first preset value, when the amount of change in the flow rate of the fluid in the fluid passage, which is sensed by the flow rate change sensing means, becomes equal to or less than a corresponding predetermined value, the learning means obtains the current valve control value, which is currently supplied to the valve, as a maximum control value; at the time of progressively decreasing the degree of opening of the valve from the second preset value, when the amount of change in the flow rate of the fluid in the fluid passage, which is sensed by the flow rate change sensing means, becomes equal to or greater than a corresponding predetermined value, the learning means obtains the current valve control value, which is currently supplied to the valve, as the maximum control value; and the learning means learns that the fluid drive means attains the maximum performance at the maximum control value.