| 摘要 |
1,253,731. Valves. ROBERT BOSCH G.m.b.H. 17 Jan., 1969 [17 Jan., 1968], No. 2758/69. Heading F2V. [Also in Divisions G2-G3] A flow regulator for controlling the flow from pump 1 to a steering cylinder 10 has a spool 12 provided with a lateral metering orifice 19 and biased leftwards by spring 17 such that, at low pump speeds, by-pass port 6 is closed and work port 8 is open to receive fluid passing through orifice 19. When the pressure drop across orifice 19 reaches a certain level, the spool begins to open port 6 so as to allow bypass flow, and the flow rate to cylinder 10 will then rise, fall or remain constant with increasing pump delivery according to the angle at which orifice 19 is disposed relative to port 6. This angle can be adjustable or maintained constant by preventing spool rotation such as by anchoring spring 17, by using a conical spring or by a guide pin. There may be a pair of orifices 19 and these or a single orifice may be embodied in an adjustable and removable end of the spool. Relief ball 27 vents chamber 23 to allow total by-pass when excess load pressures arise. A damping bleed orifice 15 feeds chamber 23. In Fig. 6, not shown, grooves (34) in the spool replace orifice 15. |
