摘要:
The invention relates to a fluidic actuator comprising a drive element (2) that can be supplied with a pressure fluid and a two-stage proportional position controller (3) controlling the supply with pressure fluid to the drive element, said actuator comprising an electro-fluidic pilot stage (10) of the position controller, exactly one electromechanical transducer (14) and exactly one proportional valve (16) actuated by said transducer and having a pressure fluid inlet (18), a control pressure outlet (19) and a discharge outlet (20). A fluidic power stage (11) of the position controller comprises two poppet valves (24, 25) having associated pressure-to-distance converters that are supplied by a common control chamber (34) which is connected to the control pressure outlet (19) of the pre-stage (10).
摘要:
The invention relates to a controlled three-way proportional valve unit comprising: a valve assembly with two individual valves; an actuating device actuating valves of the valve assembly; and a control unit acting upon the actuating device and having a control signal input, the valves of the valve assembly being designed as poppet valves arranged on opposite sides and having counter-rotatable valve spindles. The valve spindles are prestressed relative each other in opposite directions by a prestressing element such that, when the actuating unit is inactive, a first poppet valve is open and the second poppet valve is closed. The actuating device comprises an actuator common to both poppet valves, acts upon the two valve spindles and changes the position of the valve spindles counter to the effect of the prestressing element.
摘要:
The dunnage airbag inflation circuit of this invention includes a pilot valve that is controlled by a pressure sensing line in communication with the dunnage bag, and an arrangement of other valves to allow the dunnage bag to inflate up to a certain preset pressure. The pressure sensing line controls pilot air to various valves and ultimately to the main pilot valve allowing airflow to the dunnage bag until the dunnage bag reaches a certain preset pressure. The inflation circuit also includes (i) a safety pressure valve to stop airflow to the dunnage bag if for some reason the dunnage bag continues to be inflated past the preset pressure, and (ii) a stop valve that allows an operator to manually override the pressure valve and stop the airflow to the dunnage bag.
摘要:
A method and system for controlling the dynamics of an actuatable load functioning or operable within a servo or servo-type system, wherein the dynamics of the load are controlled by way of a unique pressure control valve configured to provide intrinsic pressure regulation. The pressure control valve comprises dual spools physically independent of one another and freely supported in a valve body to regulate the pressures acting within the overall system between the control or pilot pressure and the load or load pressure. The dual spools of the pressure control valve, although physically independent of one another, function in cooperation with one another in an attempt to maintain a state of equilibrium in the system, namely to keep pressure acting on or within the actuator (the load pressure), or the feedback force corresponding to the load pressure, the same as the control or pilot pressure.
摘要:
In corrective control system and method for a liquid pressure control apparatus for a control valve unit, fundamental maps are preset on the basis of a hysterisis characteristic, the hysterisis characteristic being exhibited in such a manner that an output liquid pressure actually measured value which takes along a first hysterisis loop when the current value is increased toward a larger value is different from that which takes along a second hysterisis loop when the current value is, in turn, decreased toward a smaller value from the larger value and each fundamental map is a map representing a relationship between the output liquid pressure actually measured value and a current average value, the current average value being an average between the current value in the first hysterisis loop and that in the second hysterisis loop with respect to each of the same output pressure actually measured values.
摘要:
A relief valve for hydraulic power transmission systems serves not only to limit the maximum system pressure, but also to limit the rate of pressure rise in the system when subjected to sudden transients which would otherwise cause large pressure overshoots before stabilizing at the designed pressure level. The valve is opened by system pressure reacting against a spring and has the spring normally set to permit valve opening at a small fraction of the designed maximum relief pressure. System pressure also reacts upon a spring loading piston of larger area which, when moved through its full stroke, brings the spring load up to the designed maximum limit. The rate of travel of this piston is regulated by a dashpot.
摘要:
A pressure multiplying apparatus for supplying, at a regulated pressure, a control fluid in a closed system to control a device such as a hydraulically operated valve. The system is used to control either 1; automatic blowout control devices around a drilling well or 2; to use such control equipment to control the pressure on the drill string used to drill the well. Such system includes a pump for supplying the control liquid to the valve being controlled at a pressure which is a constant factor greater than the pressure of the gas used to power the pump. Valve means are provided to bleed the pressure of the control fluid proportionally to the lowering of the pressure of the power gas. This includes a differential piston exposed on one side to the pressure of the power air and on the other side to the pressure of the control fluid from the pump. The two areas of the differential piston have approximately the same ratio as the multiplying pressure factor of the pump. Means are further provided so that a constant drill pipe pressure can be maintained by using the pressure of the fluid in the drill pipe to regulate the control fluid.