| 摘要 |
PURPOSE:To simplify the construction and offer the arbitrary flow control characteristics by giving the pressure loss preventing function to a valve which has the flow drop characteristics, that is, executes the drooping function. CONSTITUTION:When the revolution speed of a pump 6 driven by an automobile engine is increased gradually, a spool valve 3 is moved to the right due to pressure difference between the front and the rear position of each of a fixed orifice 4c and other orifices 4d and 4e. When a flow return passage 7 is communicated with a supply passage 5, excess of flow is returned so that the quantity of fluid fed to a power steering device P.S is kept constant. A sleeve 12 is moved to the left due to the pressure difference between the front and the rear position of a limited flow passage 16. As a result, the sleeve 12 has each of the orifices 4d and 4e reduce in bore so that the pressure difference between the front and the rear position of each of the orifices 4c-4e is increased, on account of which the spool valve 3 is moved to the right to increase the quantity of return flow. The quantity of oil fed to the power steering device P.S may be reduced. |
