| 摘要 |
PURPOSE:To easily change input horsepower without changing a program and a data by winding an auxiliary coil on an internal spool constituting a pressure control means, and allowing an auxiliary current to flow in the coil from a power supply through a variable resistor to adjust a setting position of the internal spool. CONSTITUTION:An auxiliary coil 19 is wound onto an end part 10a of an internal spool, which constitutes a pressure control means 10, to connect one end part of the coil 19 to a power supply 21 by an electric circuit of inserting a variable resistor 20 and the other end part to an earth 22. In this way, when the variable resistor 20 is adjusted, a position of the end part 10a of the internal spool is moved even when a current value, output to the pressure control means 10 from a controller 11, is equal. According to the above, an output secondary pressure of the pressure control means 10 is changed to move a position of the spool 7 thus to move also a servo piston 4, and a tilt rotary amount of a main variable displacement oil hydraulic pump 1 is controlled. Accordingly, input horsepower of the main variable displacement oil hydraulic pump 1 can be adjusted by adjusting the variable resistor without changing a program of a microcomputer. |
