| 摘要 |
<p>An improvement in and method of operating a load sensing system in which a variable displacement, pressure compensated pump delivering hydraulic fluid to a fluid operating device through a directional control valve is controlled by a load-sensing system pressure limiter which is set so that the system operates at the maximum continuous system operating pressure. By also setting pump destroke pressure slightly higher than the necessary operating pressure for the load, optimum performance of the pump is realized. The load-sensing system pressure limiter is configured as a poppet which is placed inside of the body of the directional control valve and is biased by an adjustable spring force to the closed position. Preferably, the poppet connects the load sensing core of the directional control valve to an exhaust passage therein so as to require minimal modification of the directional control valve. In a preferred embodiment, the poppet has a bleed-down orifice extending therethrough to unload the load pressure signal when work has been completed or diminished.</p> |
