<p>A flow control apparatus returning a part of a fluid discharged from a pump to the suction side of the pump by sliding a flow regulating spool in a valve bore, and reducing inversely the flow quantity of the delivered fluid in a range of a large discharge quantity of the pump. A throttle housing is disposed in the valve bore and between the flow regulating spool and a delivering union to form a fixed throttle across which a pressure difference is generated by a pass of the fluid supplied from a discharge passage. A fluid passage bore and cylinder bore which are communicated with a delivery chamber through a respective throttle hole are formed in parallel in the throttle housing. A variable throttle is constituted by the throttle holes one of which is opened and closed by a throttle spool sliding in response to the pressure difference across the fixed throttle and the other of which has a predetermined area. The flow regulating spool is slid by a pressure difference generated across the variable throttle and by a pass of the fluid delivered to the delivery chamber, thereby distributing the fluid supplied from the discharge passage to a circulation passage and the delivery chamber. The throttle spool is urged by a coil spring toward the flow regulating spool, and a stopper is disposed which restricts the range of the sliding movement of the throttle spool toward the urging direction. A linear guide section and a folded blind hole section which is connected to the guide section are formed on the periphery wall of the throttle housing (or the stopper), and an engaging projection which is engaged with the folded blind hole section through the guide section is disposed on the periphery wall of the stopper (or the throttle housing). The engaging projection is kept engaged with the folded blind hole section by using the expansion pressure of the coil spring. <IMAGE></p>
