| 摘要 |
<p>A simple, operationally reliable and not-overly-sensitive level control in a generally known form of self-pumping hydropneumatic spring leg or strut is of such a construction that a delayed adjust-down control action can be achieved when a control opening is opened upon reaching a certain level. For that purpose, a sleeve is fitted as or as part of a throttle arrangement between the control opening of a hollow pump rod and a suction valve arranged at the end of the pump rod, the sleeve allowing oil to flow with a delay from the high pressure chamber which controls the level, by way of the control opening of the pump rod to the pump rod bore, the bore communicating with a low pressure chamber from which oil is normally pumped to the high pressure chamber. By removing the throttling responsibility from the control opening, size restrictions on the control opening are removed, thus facilitating sizing the control opening so as to preclude clogging. The throttling and delay functions can be accomplished by appropriately sizing the length and cross section of a duct defined in part by the sleeve, or by a throttle opening defined in part by the suction valve. In the latter arrangement, a self clearing action is achieved when the suction valve lifts from its seat.</p> |
