| 摘要 |
PURPOSE:To obtain a pressure flow control device having smaller occupying space in a machinery constitution using a single type of machines, when the discharge pres sure exceeds a set value, by generating an electric control signal corresponding to it, so that the rotating speed control of a fixed delivery pump can be carried out. CONSTITUTION:The discharge of a fixed delivery pump 2 is output into a main pipe line 8 via a check valve 11, and is supplied to a load. When a pressure detector 7 (a plurality of settings are possible) detects that the discharge pressure in the main pipe line 8 has exceeded a set value, the output thereof is input into a control circuit 9. Therein, control signals such as those for the on-off control of the fixed delivery pump 2 or for the multistage control of discharge quantity are output. By the output, via a converter 10, an electric motor 1 is driven variably in its rotating speed by a prescribed voltage or a frequency signal. Accordingly, by the on-off control of the fixed delivery pump 2 and the multistage control of discharge quantity, the difference between the output of the fixed delivery pump 2 and the load power is reduced to restrain the power less. Thus, the generation of heat is decreased to reduce the deterio ration of oil, and the volume of each oil tank 3 can be significantly decreased, so that the occupying space can be reduced.
|
