阅读说明：本技术 一种压力补偿式阀芯组件、直动式溢流阀和先导式溢流阀 (Pressure compensation type valve core assembly, direct-acting overflow valve and pilot operated overflow valve ) 是由 王振耀 刘银水 吴德发 庞浩 程谦 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种压力补偿式阀芯组件、直动式溢流阀和先导式溢流阀。所述压力补偿式阀芯组件包括阀芯、阀座和补偿节流元件；其中,所述补偿节流元件连接于阀芯底部,所述阀芯与阀座之间形成第一级阀口和第二级阀口,所述补偿节流元件的出口位于第一级阀口和第二级阀口之间,所述补偿节流元件与第一级阀口呈并联状态；以使得液体同时流经补偿节流元件和第一级阀口后从第二级阀口流出。本发明基于两级阀口节流结构的特点,在阀芯上安装有补偿节流元件,与第一级阀口形成并联状态,可以重新分配第一级和第二级阀口两端的压差,从而进一步降低流场中的介质最大流速以及出现空化气蚀的可能性。(The invention discloses a pressure compensation type valve core assembly, a direct-acting overflow valve and a pilot-operated overflow valve. The pressure compensation type valve core assembly comprises a valve core, a valve seat and a compensation throttling element; the compensating throttling element is connected to the bottom of the valve core, a first-stage valve port and a second-stage valve port are formed between the valve core and the valve seat, an outlet of the compensating throttling element is positioned between the first-stage valve port and the second-stage valve port, and the compensating throttling element and the first-stage valve port are in a parallel connection state; so that fluid flows through the equalizing restriction element and the first-stage port simultaneously and then flows out of the second-stage port. Based on the characteristics of the two-stage valve port throttling structure, the compensation throttling element is arranged on the valve core and forms a parallel connection state with the first-stage valve port, and the pressure difference between two ends of the first-stage valve port and the second-stage valve port can be redistributed, so that the maximum flow velocity of media in a flow field and the possibility of cavitation and cavitation erosion are further reduced.)

1. A pressure compensated valve core assembly is characterized by comprising a valve core (9), a valve seat (5) and a compensation throttling element (13);

the compensating throttling element (13) is connected to the bottom of the valve core (9), a first-stage valve port (15) and a second-stage valve port (14) are formed between the valve core (9) and the valve seat (5), an outlet of the compensating throttling element (13) is positioned between the first-stage valve port (15) and the second-stage valve port (14), and the compensating throttling element (13) and the first-stage valve port (15) are in a parallel state; so that the liquid flows out of the second-stage valve port (14) after simultaneously flowing through the compensation throttling element (13) and the first-stage valve port (15).

2. The pressure compensated spool assembly of claim 1, wherein the compensating restriction element (13) comprises a split flow opposed restriction element, a labyrinth restriction element, a thin-walled orifice restriction element, or an elongated orifice restriction element.

3. The pressure compensated spool assembly according to claim 1 or 2, wherein the bottom of the spool (9) is funnel-shaped, a receiving hole for receiving the compensation throttling element (13) is formed in the central position of the bottom of the spool (9), and a through hole perpendicular to the receiving hole is formed at the end of the receiving hole and is an outlet of the compensation throttling element (13).

4. The pressure compensated spool assembly according to claim 3, wherein the compensating restriction element (13) penetrates into the receiving hole and is screwed to the bottom of the spool (9), and the through hole perpendicular to the receiving hole is two symmetrically arranged through holes.

5. The pressure compensated spool assembly of claim 1, wherein a seal ring is circumferentially disposed on an outer wall of the valve seat (5).

6. The pressure compensated spool assembly of claim 1, wherein the first-stage valve port (15) is a cone valve.

7. A direct-acting relief valve including a pressure-compensated spool assembly according to any one of claims 1-6.

8. A pilot operated relief valve including a pressure compensated spool assembly as claimed in any one of claims 1 to 6.

9. The direct-acting overflow valve according to claim 7, further comprising a valve body (3), a pressure regulating assembly and a pressing plug (6), wherein the valve body (3) is provided with an overflow valve inlet (7) and an overflow valve outlet (4);

the pressure regulating assembly comprises a spring (8), a spring seat (12), a pressure regulating screw rod (1), a limiting ring (11) and a gland (2), wherein the spring (8) is abutted against the valve core (9) and the spring seat (12), the gland (2) is connected to the top of the valve body (3) through a screw, and the gland (2) is used for axially positioning the valve core assembly;

a control upper cavity (10) is formed between the valve core (9) and the valve seat (5), and the control upper cavity (10) is communicated with the overflow valve outlet (4) through a small hole in the valve core (9);

and the compression plug (6) is abutted against the bottom of the valve seat (5) and is used for compressing the valve core assembly.

10. The direct overflow valve of claim 9 wherein the inner bore of the valve body (3) is a through hole with the same diameter, and the gland (2) and the spring seat (12) are provided with sealing rings.

Technical Field

The invention belongs to the technical field of overflow valves, and particularly relates to a pressure compensation type valve core assembly, a direct-acting overflow valve and a pilot operated overflow valve.

Background

The overflow valve is a pressure control valve and is normally open. The overflow valve can be used for setting the working pressure of the system or serving as a safety valve to protect the whole system, and the safety of components and parts caused by overhigh pressure of the system is prevented. When the overflow valve works under high pressure, the opening degree of a valve port of the overflow valve is small, the flow rate of a medium passing through the valve port is extremely high, the local pressure at the position of the valve port is lower than the vaporization pressure of the medium, and a large amount of bubbles are generated after the medium is vaporized, namely cavitation phenomenon. When the bubbles move to the downstream of the valve port along with the medium, the bubbles can collapse under the external pressure, and the process can not only generate larger noise, vibration and impact, but also cause each part of the overflow valve to be damaged by cavitation, thereby seriously restricting the service life of the overflow valve.

The typical direct-acting overflow valve or pilot-operated overflow valve mostly adopts a single-stage throttle valve port structure, all pressure and energy are released at the valve port, and serious cavitation can be generated under the condition of high pressure difference. In order to reduce the pressure difference between the two ends of the valve port and thus reduce the cavitation strength, a two-stage valve port throttling mode can be considered, and the two valve ports are used for sharing pressure loss and energy loss together so as to inhibit the generation of cavitation and cavitation. However, when the through-flow diameter difference of the two-stage valve ports is large and the working pressure of the overflow valve is high, most of the pressure difference and energy will be lost at the first-stage valve port, the flow rate of the medium in the flow field of the valve port of the overflow valve is still high, and the cavitation and cavitation phenomena at the valve port of the overflow valve are still serious.

Based on the above reasons, there is a need in the art to design a high-pressure relief valve with a brand-new structure based on two-stage valve port throttling and capable of evenly distributing differential pressure across two-stage valve ports.

Disclosure of Invention

In view of the above-mentioned drawbacks or needs for improvement in the prior art, the present invention provides a pressure compensation type spool assembly, a direct-acting overflow valve, and a pilot-operated overflow valve, which are based on the characteristics of a two-stage valve port throttling structure, and aims to provide a spool having a compensation throttling element mounted thereon, which is connected in parallel with a first-stage valve port, and which can redistribute the pressure difference between both ends of the first-stage and second-stage valve ports. Thereby further reducing the maximum flow velocity of the medium in the flow field and the possibility of cavitation.

To achieve the above object, according to one aspect of the present invention, there is provided a pressure compensated valve core assembly comprising a valve core, a valve seat and a compensating throttling element; the compensating throttling element is connected to the bottom of the valve core, a first-stage valve port and a second-stage valve port are formed between the valve core and the valve seat, an outlet of the compensating throttling element is positioned between the first-stage valve port and the second-stage valve port, and the compensating throttling element and the first-stage valve port are in a parallel connection state; so that fluid flows through the equalizing restriction element and the first-stage port simultaneously and then flows out of the second-stage port.

Preferably, the compensating restriction element comprises a split flow opposed restriction element, a labyrinth restriction element, a thin-walled orifice restriction element, or an elongated orifice restriction element.

Preferably, the compensating restriction member is threadably attached to the bottom of the valve spool.

Preferably, the bottom of the valve core is funnel-shaped, a containing hole for containing the compensation throttling element is formed in the central position of the bottom of the valve core, a through hole perpendicular to the containing hole is formed at the end of the containing hole, and the through hole is an outlet of the compensation throttling element.

Preferably, the compensating throttling element penetrates into the accommodating hole and is connected to the bottom of the valve core through threads, and the through holes perpendicular to the accommodating hole are two through holes which are symmetrically arranged.

Preferably, a sealing ring is circumferentially arranged on the outer wall of the lower end of the valve seat.

Preferably, the first-stage valve port is a cone valve.

According to another aspect of the present invention, a direct-acting relief valve is provided that includes the above-described pressure-compensated spool assembly.

According to yet another aspect of the present invention, a pilot operated relief valve is provided that includes the above-described pressure compensated spool assembly.

Preferably, the direct-acting overflow valve further comprises a valve body, a pressure regulating assembly and a pressing plug, and the valve body is provided with an overflow valve inlet and an overflow valve outlet; the pressure regulating assembly comprises a spring, a spring seat, a pressure regulating screw, a limiting ring and a gland, wherein the spring is abutted against the valve core and the spring seat, the gland is connected to the top of the valve body through a screw, and the gland is used for axially positioning the valve core assembly; a control upper cavity is formed between the valve core and the valve seat and is communicated with the outlet of the overflow valve through a small hole on the valve core; the pressing plug is abutted against the bottom of the valve seat and used for pressing the valve core assembly.

Preferably, the inner hole of the valve body is a through hole with the same diameter, and the gland and the spring seat are provided with sealing rings.

In general, at least the following advantages can be obtained by the above technical solution contemplated by the present invention compared to the prior art.

(1) The invention is based on a two-stage valve port throttling structure, a compensation throttling element is arranged between an inlet of an overflow valve and a second-stage valve port, the compensation throttling element and the first-stage valve port form a parallel connection state, and a liquid medium can simultaneously pass through the first-stage valve port and the compensation throttling element and then pass through the second-stage valve port, so that the pressure difference between the two ends of the first-stage valve port and the second-stage valve port is redistributed. The adoption of the compensation throttling element can enable the first-stage valve port and the second-stage valve port to evenly distribute the total pressure difference between the inlet and the outlet of the overflow valve, thereby further reducing the maximum medium flow rate in a flow field and further reducing the possibility of cavitation and cavitation erosion.

(2) The compensation throttling element may generate structural damage due to cavitation erosion, but the function of the compensation throttling element is not affected, so that the compensation throttling element has extremely long service life, and the compensation throttling element is connected with the valve core through threads, so that the compensation throttling element is simple to assemble and disassemble and easy to replace.

(3) The compensation throttling element is arranged on the valve core, so that the volume of the valve core assembly is not obviously increased, and the manufacturing and assembling processes are simple.

Drawings

FIG. 1 is a direct relief valve having a pressure compensated spool assembly according to the present invention;

FIG. 2 is an enlarged partial view of the direct relief valve with the pressure compensating spool assembly of FIG. 1 including a compensating restriction element.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein:

1-pressure regulating screw rod, 2-gland, 3-valve body, 4-overflow valve outlet, 5-valve seat, 6-pressing plug, 7-overflow valve inlet, 8-spring, 9-valve core, 10-control upper cavity, 11-limit ring, 12-spring seat, 13-compensation throttling element, 14-second valve port and 15-first valve port.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The invention analyzes the principle of the two-stage valve port, and finds that the medium flow rate at the position of the first-stage valve port is always larger than that at the position of the second-stage valve port because the through-flow diameter of the first-stage valve port is always smaller than that of the second-stage valve port. When the through-flow diameter difference of the two-stage valve ports is large and the working pressure of the overflow valve is high, most of pressure difference and energy will be lost at the first-stage valve port, the flow rate of media in the flow field of the valve port of the overflow valve is still high, and the cavitation and cavitation phenomena at the valve port of the overflow valve are still serious. If a two-stage valve port structure is reformed by a certain method, so that the first-stage valve port and the second-stage valve port can averagely share the total pressure difference between the inlet and the outlet of the overflow valve, the highest flow velocity of media in a valve port flow field of the overflow valve can be further reduced, and the possibility of cavitation and cavitation erosion is reduced.

Based on the above analysis, please refer to fig. 1 and fig. 2, for example, the embodiment of the present invention uses a direct-acting type relief valve with a pressure compensation type valve core assembly to describe a detailed process of reducing occurrence of cavitation and cavitation in the technical solution of the present invention, but the embodiment does not limit the technical solution of the present invention.

The direct overflow valve with the pressure compensation type valve core assembly provided by the embodiment of the invention comprises a valve body 3, the valve core assembly, a pressing plug 6 and a pressure regulating assembly. The valve core assembly comprises a valve core 9, a valve seat 5 and a compensating throttling element 13. The valve core assembly is arranged in the valve body 3, the inner hole of the valve body 3 is a through hole with the same diameter, and the valve core assembly can be assembled and disassembled from two ends of the valve body 3 in the assembling and disassembling process of the valve core assembly. The valve core assembly is axially positioned through the gland 2 and is compressed through the compression plug 6. The compensation throttling element 13 is connected to the bottom of the valve core 9, a first-stage valve port 15 and a second-stage valve port 14 are formed between the valve core 9 and the valve seat 5, an outlet of the compensation throttling element 13 is positioned between the first-stage valve port 15 and the second-stage valve port 14, and the compensation throttling element 13 is connected with the first-stage valve port 15 in parallel; so that the liquid flows out of the second-stage valve port 14 after passing through the compensating throttling element 13 and the first-stage valve port 15 simultaneously, thereby forming a two-stage throttling effect.

The valve body 3 is provided with an overflow valve inlet 7 and an overflow valve outlet 4. A control upper cavity 10 is formed between the valve core 9 and the valve seat 5. The control upper cavity 10 is directly connected with the overflow valve outlet 4 through a small hole on the valve core 9. The compensating restriction member 13 is threadedly mounted to the spool 9 for movement with movement of the spool 9. The inlet of the compensation throttling element 13 is communicated with the inlet 7 of the overflow valve, and the outlet of the compensation throttling element 13 is directly communicated with the inlet of the second-stage valve port 14 through a flow passage.

The bottom of the valve core 9 is funnel-shaped, a containing hole for containing the compensation throttling element 13 is formed in the central position of the bottom of the valve core 9, a through hole perpendicular to the containing hole is formed at the end of the containing hole, and the through hole is an outlet of the compensation throttling element 13. The compensation throttling element 13 penetrates into the accommodating hole and is connected to the bottom of the valve core 9 through threads, and the through holes perpendicular to the accommodating hole are two through holes which are symmetrically arranged.

The invention is not limited to the compensation throttling element, and any throttling element with throttling effect can be used as the compensation throttling element 13 in the structure of the invention, including but not limited to a shunt counter-flushing throttling element, a labyrinth throttling element, a thin-wall small hole throttling element or an elongated hole throttling element. The overflow valve port is in the structural form of a cone valve.

The pressure regulating assembly comprises a spring 8, a spring seat 12, a pressure regulating screw rod 1, a limiting ring 11 and a gland 2, wherein the spring 8 is contained in the upper control cavity 10 and is abutted against the valve core 9 and the spring seat 12. The gland 2 is mounted on the upper part of the valve body 3 through screws. The maximum set pressure of the relief valve can be controlled by the stop collar 11. The lower part of the valve seat 5 is provided with a sealing ring to effectively isolate the overflow valve inlet 7 from the outside, so that the compression plug 6 bears a part of hydraulic pressure, the upward hydraulic pressure is reduced, and the pressure of the valve seat 5 on the gland 2 is reduced. And a sealing ring is arranged on the valve seat 5 to reliably isolate the inlet 7 and the outlet 4 of the overflow valve. And sealing rings are arranged on the gland 2 and the spring seat 12 to effectively isolate the overflow valve outlet 4 from the outside.

The invention is based on a two-stage valve port throttling structure, the compensating throttling element 13 is arranged between the inlet 7 of the overflow valve and the second-stage valve port 14, and medium can simultaneously pass through the first-stage valve port 15 and the compensating throttling element 13 and then pass through the second-stage valve port 14, so that the pressure difference between the first-stage valve port 15 and the second-stage valve port 14 is redistributed. After the compensation throttling element 13 is reasonably designed, the total pressure difference between the inlet 7 and the outlet 4 of the overflow valve can be evenly distributed by the first-stage 15 and the second-stage valve port 14, so that the maximum medium flow rate in a flow field is further reduced, and the possibility of cavitation and cavitation erosion is further reduced; the compensating throttle element 13 may be structurally damaged by cavitation, but does not affect the function of the compensating throttle element 13, so that the compensating throttle element 13 itself has a very high service life. Disposing the compensating restriction member 13 on the spool 9 does not significantly increase the volume of the spool assembly.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.