| 摘要 |
<p>1,045,613. Valves. DANFOSS A.S. Feb.19, 1964 [Feb. 20, 1963], No. 6996/64. Heading F2V. Fuel is supplied to a nozzle connected to a port D, Fig. 3, of a cut-off valve 16 from a pump connected to a port P of a pressureregulating valve 14; some of the pump output is returned to the input via a conduit R and a port S. The valve 14 has a piston closuremember 17 loaded by an adjustable spring 18 in opposition to the pressure in a chamber 20 open to the port P so that the member 17 assumes a position in which one face 21 controls the opening of port S and hence the quantity of fuel fed to the nozzle. The chamber 20 leads to the cut-off valve 16 which consists of a fixed seat 23 having a parallel port 29, Fig. 4, merging into a tapered port 30 and over which is slidable a spring- urged ring 31, Fig. 3; a piston 25 loaded by an adjustable spring 27 embodies a flexible insert 24 that co-operates with the end of the tapered port 30 to control flow through the seat 23 to the port D. The conduit R opens into the chamber 37 behind the piston 25. Upon starting the pump the ring 31 and an abutting sleeve 34 are moved a distance Y, Fig. 4, which causes the piston 25, Fig. 3, to travel a smaller distance X on to a stop 28; however, the sleeve 34 continues to move with the ring 31 until axial slots 35 therein open into chamber 37. If the ring 31, Fig. 4, is moved further into the dotted-line position by the fuel pressure the fuel flows through an orifice 32 between the ring and tapered port 30 to the port D as well as through the slots 35 to the conduit R and port S. The ring 31 adjusts itself in dependence on the pressure difference thereacross. Should the quantity of oil decrease the pressure drop across the orifice 32 is reduced and the valve is closed by the spring 27 urging the piston 25 to the left, which piston carries with it the sleeve 34 since the latter are frictionally coupled.</p> |
