Patent ID: 7997117
Filing Date: 2011-08-16
Classification: F15B,F16K,G01F

Abstract:
1. A method of calibrating an electrically controlled hydraulic valve having a known relationship between flow rate through the valve and displacement of a valve element, comprising: pumping hydraulic fluid from a fluid source through a first electrically controlled hydraulic valve, and through a second electrically controlled hydraulic valve to be calibrated; actuating the second electrically controlled hydraulic valve to be calibrated to move the valve element to a position adjacent an inlet port so that the valve just opens enough to permit flow through the inlet port; ascertaining a first current level for actuating the second electrically controlled hydraulic valve to move the valve element to the position adjacent the inlet port, and a first displacement of the valve element responsive to the first current level; actuating the second electrically controlled hydraulic valve to move the valve element to a position permitting flow through the inlet port; ascertaining a second current level for actuating the second electrically controlled hydraulic valve to move the valve element from the position adjacent the inlet port to the position permitting flow through the inlet port; ascertaining a first flow rate through the first electrically controlled hydraulic valve to determine a second flow rate through the second electrically controlled hydraulic valve; correlating the determined second flow rate through the second electrically controlled hydraulic valve with a second displacement of the valve element thereof based on the known relationship between flow rate through the valve and displacement of the valve element; and establishing a relationship between current and displacement associated with the second electrically controlled hydraulic valve based on at least the first and the second current levels and the first and the second displacements.