| 摘要 |
A suspension for the boom of a loading vehicle includes a hydraulic cylinder for raising and lowering, or for extending and retracting (in the case of a telescopic cylinder), a boom. A direction control valve is provided for selectively routing hydraulic oil to and from at least a head-end chamber of the cylinder. A position sensor senses the position of the hydraulic piston rod, at the start of operation, and sends a sends a target signal representing this beginning position to a control unit which determines the difference between the target signal and a signal representing a current position of the piston rod. When this difference equals a preset difference threshold, a pressure-limiting unit, in the form of a valve or choke, is activated so as to control fluid flow to and from the head-end chamber so as to return the piston rod to its initial position which generated the target signal. Different embodiments have different valve component arrangements for influencing the reaction time of the suspension and/or for adapting the circuitry for use with single-acting, double-acting or telescopic boom cylinders.
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