WO2001098694A1 - A steep-like throttling and reducing valve - Google Patents

Abstract

A throttling and reducing valve comprises a valve seat like a conical tube and a valve element with a plurality of steps. Every step corresponds to a grade of pressure reduction. The throttling area of each grade is formed of a clearance between the step seat and the step of the valve element. By determining the match sizes and the shapes of the valve seat and the valve element, the distribution relationship of all the throttling area can be determined. So that a well-distributed pressure ratio is gained, specially a small opening protecting function of the valve seal surface is gained.

Description

 Stepped multi-stage throttle decompression threshold Technical field

 The present invention relates to a multi-stage throttle pressure reducing valve, and more particularly to a shape of a multi-stage throttle pressure reducing valve spool valve seat.

Background technique

 The existing multi-stage throttle valve is composed of a multi-stage throttle assembly of any size and shape and a sealing surface for regulating flow and shutting off. The disadvantage brought by this is that the uneven partial pressure is particularly prominent in the case of small openings, which causes cavitation damage to the sealing surface, resulting in damage to expensive valves. In addition, the structure of the existing multi-stage throttle is complicated and the manufacturing cost is high.

Summary of the Invention

 An object of the present invention is to provide a multi-stage throttle pressure reducing valve, which achieves a mode of uniform partial pressure reduction through the shape matching of the valve seat and the valve core. And the design according to the present invention can simultaneously improve the cavitation damage problem in the prior art when the sealing surface of the multi-stage throttle pressure reducing valve is small.

 In addition, the multi-stage throttle pressure reducing valve of the present invention is simpler in mechanical processing, so that the processing cost can be significantly saved.

 The above-mentioned object according to the present invention can be achieved by such a stepped multi-stage throttle pressure reducing valve, which includes a generally tapered tube-shaped valve seat and a stepped valve core that cooperates with the valve seat. The closed loop-shaped throttling surfaces formed by the gap between each step of the stepped valve core and the cone-shaped valve seat are respectively opposed to a throttling pressure reducing stage.

According to an advantageous structural design of the present invention, the valve seat may have different slopes or curvatures according to the requirements of different situations. In addition, the same generally tapered valve seat can also have different slopes or curvatures at different stages to meet different requirements.

 The spool is shown as a number of circles of varying diameters in the horizontal view, but in a stepped shape in the vertical section. This shape makes the machining of the spool and valve seat easier and facilitates the machining with higher accuracy. Of course, according to different situations and requirements, such as flow characteristics, fluid morphology, and noise reduction requirements, the closed-loop throttle surface can be any shape in the horizontal cross-sectional view, such as oval, square, rectangle, diamond, triangle, or Other shapes to suit a wider range of machining conditions and other conditions.

 The ratio of the area of each throttle surface corresponds to the partial pressure proportional relationship. When the pressure difference between the front and back of the valve is constant, the differential pressure is allocated to each throttle decompression stage according to the partial pressure ratio determined by each throttle area, thereby achieving the function of multi-stage partial pressure decompression. According to different conditions, by properly selecting the shape of the valve seat and the valve core or the direction of its outer contour, the gap value between each pressure reducing stage and the cone-shaped valve seat can be selected and determined. The partial pressure proportional relationship can be further selected and determined, Can make the valve in the effective throttle decompression stroke, especially in the small stroke (full stroke

Within 15%) or a very small stroke (within 1% of the full stroke), a partial pressure ratio that approaches 1 and has a small change with the stroke can be obtained. In other words, it is possible to obtain a more uniform partial pressure ratio on a stroke section with a smaller opening and a larger pressure difference, thereby achieving a uniform partial pressure and pressure reduction method. This makes it possible for each throttle decompression stage to effectively perform partial pressure decompression with the sealing surface in a small stroke and a small stroke range, and protect the sealing surface from cavitation damage under the condition of small opening.

 In addition, the use of a stepped valve core, using the reaction force of the fluid when it rushes to the frontal obstacle, increases the resistance of the fluid flow, strengthens the decompression effect, and can further reduce the effect of the fluid on the valve seat and the valve core. Erosion.

Claims

Drawings fan  Hereinafter, the principle of the present invention will be described with reference to a schematic diagram.  The structure of the valve seat and the spool of the stepped multi-stage throttle pressure reducing valve according to the present invention is shown in a sectional view in the only one of the drawings. Wherein, the reference numeral 1 indicates the valve core, and the reference numeral 2 indicates the valve seat surrounding the valve core. The fluid flows upward from the lower side of the drawing through the multi-stage throttling surface (stage) and flows into the low-pressure side after multi-stage partial pressure. Each step on spool 1 represents a throttled partial pressure stage.  The gap between each throttling pressure reducing stage and the valve seat is appropriately selected, that is, the ratio of the throttling area of each throttling pressure reducing stage is selected, so that the partial pressure proportional relationship can be selected and determined. And the size of the valve seat and the valve core are selected in such a way that when the stroke of the valve core is small or small, the partial pressure ratio approaches 1.  The stepped multi-stage throttling pressure reducing valve mentioned in the present invention is a kind of valve internals, which is suitable for the existing actuators of various power types, various flow characteristics, fluid forms, and noise reduction requirements. In principle, the multi-stage throttle pressure reducing valve according to the present invention can be applied to any flow range and differential pressure range.