| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable displacement vane pump which improves fuel economy by reducing a relief amount while suppressing the increase of the pump workload. SOLUTION: The variable displacement vane pump has a metering orifice provided on a discharge passage connected to a discharge port, a high-pressure chamber where an upstream side pressure of the metering orifice is introduced, an intermediate-pressure chamber where a downstream side pressure is introduced, and a low-pressure chamber connected to a reservoir tank for storing working oil. The variable displacement vane pump has a pressure control means for controlling the pressure introduced into a first fluid pressure chamber or a second fluid pressure chamber, a relief valve which is provided between the downstream side of the metering orifice and the reservoir tank, opens the valve when it is at the predetermined pressure or more and discharges the pressure at the downstream side of the metering orifice to the reservoir tank side, and a variable throttle mechanism for reducing the sectional area of a flow passage of the metering orifice when at least the relief valve is opened. COPYRIGHT: (C)2009,JPO&INPIT
|
