Dual sealing pair and flow and pressure regulating valve

Abstract

The utility model discloses a double sealing pair and a flow and pressure regulating valve, and relates to the technical field of sealing of flow and pressure regulating valves, and the double sealing pair comprises a sealing ring and a metal wire sealing pair; the sealing ring is used for being arranged in a placing groove of a sliding sealing surface of the flow and pressure regulating valve; the metal wire sealing pair comprises an annular limiting protrusion and an annular conical metal sealing face which are coaxial, the annular conical metal sealing face is used for being arranged on the piston sleeve, the annular limiting protrusion is used for being fixedly arranged on the inner side wall of the valve seat, and the annular limiting protrusion and the annular conical metal sealing face are in annular linear sealing. The flow and pressure regulating valve comprises a valve body, a valve seat, a piston sleeve, a crank connecting rod mechanism and the double sealing pair. Double sealing is formed by the sealing ring and the metal wire sealing pair, so that the sealing performance is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the sealing technical field of flow and pressure regulating valve, especially to a double sealing pair and flow and pressure regulating valve. BACKGROUND

[0002] Under the current environment of water resource shortage, in order to effectively allocate and manage the water resources of the whole country, numerous water transfer projects are built in various places of the country. While ensuring the reasonable distribution of water resources, considering the more efficient utilization and allocation of water resources, many water transfer projects are more inclined to build in high terrain areas to obtain higher potential energy. However, with the change of seasons, the water level in the reservoir will also change during the dry season and flood season, and the pressure difference produced will have a great influence on the safe and stable operation of the pipeline. Not only is it easy to cause cavitation and cavitation problems, but it is also a waste of energy. The flow and pressure regulating valve is widely used in water transfer projects due to its good water level control, flow control function and pressure holding and pressure relief control function.

[0003] The main seal between the piston and the valve body of the current flow and pressure regulating valve is double sealing, which generally adopts metal and metal sealing pair + metal and rubber sealing to realize double sealing effect. The metal sealing pair usually adopts a conical surface sealing pair with the same taper angle. The rubber sealing ring in the non-metal sealing pair usually adopts EPDM rubber.

[0004] In actual water transfer project application, because the water supply source carries impurities such as microorganisms, silt and pollutants; the EPDM rubber sealing ring is easy to age, and once the silt and microorganisms in the water are adsorbed on the piston metal sealing surface or the valve seat metal sealing surface, the impurities are clamped between the two sealing surfaces when the valve is closed, which causes the sealing performance of the valve metal sealing pair to fail. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a double sealing pair and flow and pressure regulating valve to solve the problems existing in the prior art and improve the sealing performance.

[0006] To achieve the above-mentioned purpose, the utility model provides the following scheme:

[0007] The utility model provides a kind of double sealing pair, including sealing ring and metal wire sealing pair;The sealing ring is used to be placed in the deposit groove of the sliding sealing surface of flow-regulating pressure regulating valve, the sliding sealing surface is the sealing surface between the inner side wall of the opening of valve body end of flow-regulating pressure regulating valve and the inner side wall of valve seat at the opening and the outer side wall of piston sleeve of flow-regulating pressure regulating valve;The sealing ring has elasticity;The metal wire sealing pair includes annular limiting protrusion of coaxial line and annular conical metal sealing surface, the annular conical metal sealing surface is used to be arranged on the piston sleeve of flow-regulating pressure regulating valve, the annular limiting protrusion is used to be fixedly arranged on the inner side wall of valve seat of flow-regulating pressure regulating valve, the annular limiting protrusion is annularly linearly sealed with the annular conical metal sealing surface;And the sealing ring is located at the side of the metal wire sealing pair close to the valve body center of flow-regulating pressure regulating valve.

[0008] Preferably, the sealing ring is used for sealing the position material is high molecular polytetrafluoroethylene.

[0009] Preferably, the sealing ring includes ring outer sleeve and O-shaped ring;The ring outer sleeve includes C-shaped outer ring sleeve and first extension connecting part and second extension connecting part fixedly arranged at the opening of the C-shaped outer ring sleeve;The material of the ring outer sleeve is high molecular polytetrafluoroethylene;The opening of the C-shaped outer ring sleeve is directed away from the axis of the C-shaped outer ring sleeve;The O-shaped ring is used to be sleeved in the C-shaped outer ring sleeve;In natural state, the first extension connecting part and the second extension connecting part are in the attitude of being away from each other;And under the action of external force, the first extension connecting part and the second extension connecting part can be in the attitude of being close to each other and make the opening of the C-shaped outer ring sleeve be in closed state;The outer side of the first extension connecting part and the second extension connecting part is fixedly provided with a plurality of parallelly arranged anti-disengagement barbs.

[0010] The utility model discloses still provide a kind of flow regulating pressure regulating valve, including valve body, valve seat, piston sleeve, crank connecting rod mechanism and the double sealing pair as any described above;The valve body has first end opening, and the valve body has rotating valve stem in;The valve seat is fixedly arranged at the first end opening, and the piston sleeve is slidably arranged in the first end opening along the axis of the valve body;The piston sleeve has sliding sealing section and necked communication section, the sliding sealing section and the necked communication section are located at both ends of the piston sleeve respectively, the outer diameter of the necked communication section is less than the outer diameter of the sliding sealing section, and the necked communication section is provided with the flow regulating groove that penetrates on the side wall;The crank connecting rod mechanism is arranged in the valve body, the input end of the crank connecting rod mechanism is connected with the valve stem, and the output end of the crank connecting rod mechanism is drivingly connected with the piston sleeve, and the crank connecting rod mechanism is used to drive the piston sleeve to slide along the axis of the valve body;The inner side wall of the end opening of the valve body and the inner side wall of the valve seat jointly form sliding sealing surface, the sliding sealing surface is provided with the accommodating groove, and the sealing ring is placed in the accommodating groove;The annular taper metal sealing surface is located on the piston sleeve between the sliding sealing section and the necked communication section;The annular limiting protrusion is fixedly arranged on the inner side wall of the valve seat.

[0011] Preferably, the first end opening of the valve body is provided with a first annular half groove, and the valve seat is provided with a second annular half groove, and the first annular half groove and the second annular half groove jointly form the accommodating groove.

[0012] Preferably, when the sealing ring has the anti-falling barbs, the first annular half groove and the second annular half groove are provided with anti-falling inverted grooves corresponding to the positions of the anti-falling barbs.

[0013] Preferably, a flow guide cylinder is arranged in the valve body, and the sliding sealing section of the piston sleeve is slidably arranged in the flow guide cylinder.

[0014] Preferably, a guide rail is arranged on the inner wall of the flow guide cylinder, and the piston sleeve moves along the axis of the valve body on the guide rail.

[0015] Preferably, the necked communication section with the flow regulating groove is a squirrel cage, the sliding sealing section is a piston body, and the piston body is integrally formed with the squirrel cage; the outer diameter of the squirrel cage is less than the outer diameter of the piston body, and the variable-diameter connection between the outer side wall of the piston body and the outer side wall of the squirrel cage is connected through the annular taper metal sealing surface.

[0016] Preferably, a driving mechanism is connected to the valve stem, and the driving mechanism can drive the valve stem to rotate.

[0017] Compared with the prior art, the utility model has the following technical effects:

[0018] The double sealing pair is fixed on the inner side wall of the valve seat through the annular limiting protrusion, the annular conical metal sealing surface is arranged on the piston sleeve, and the two are annular linear sealing; the linear sealing structure can generate higher sealing specific pressure on smaller contact area, can effectively prevent fluid from leaking through the gap between the inner side wall of the valve seat and the piston sleeve even in a high-pressure environment, and can keep good sealing performance for a long time because of smaller relative sliding friction when the piston sleeve moves; and because of the particularity of the linear sealing, the distance between the annular limiting protrusion and the annular conical metal sealing surface is continuously reduced in the closing process, and in this process, the annular conical metal sealing surface can scrape off the adsorbed matter larger than the distance between the two in the closing process to a certain extent, so that the annular conical metal sealing surface has a certain scraping effect; the sealing ring is located on the side of the valve body center close to the metal linear sealing pair of the flow and pressure regulating valve, forming a double sealing structure, when fluid attempts to leak from the gap between the piston sleeve and the valve body, the fluid will first be blocked by the sealing ring, most of the fluid is blocked back by the sealing ring, even if a small amount of fluid passes through the sealing ring, the fluid will be blocked again by the outer metal linear sealing pair, further improving the reliability of the sealing, at the same time, the sealing ring can also protect the metal linear sealing pair to a certain extent, preventing it from being eroded and worn by impurity particles, prolonging the service life of the metal linear sealing pair, and thus improving the sealing performance of the flow and pressure regulating valve as a whole.

[0019] The utility model discloses still provide a kind of flow and pressure regulating valve, the sliding sealing section of piston sleeve and necked communication section and the flow regulating groove on necked communication section design, so that when piston sleeve slides along the valve body axis, the flow and pressure of fluid can be accurately controlled by changing the flow area between flow regulating groove and valve seat;The rotation of valve rod is converted into linear sliding of piston sleeve by crank connecting rod mechanism, this transmission mode can provide stable, reliable power transmission, and the sliding distance of piston sleeve can be accurately controlled by adjusting the rotation angle of valve rod, and then the opening of flow and pressure regulating valve is accurately controlled, realizes fine adjustment to flow and pressure;Double sealing pair including sealing ring and metal linear sealing pair is arranged, sealing ring is located on the side of valve body center close to metal linear sealing pair, can preliminarily seal fluid, prevent fluid from directly impacting metal linear sealing pair, annular limiting protrusion and annular conical metal sealing surface in metal linear sealing pair are annular linear sealing, further improve sealing effect, even in the case of high pressure, high speed fluid, fluid leakage can be effectively prevented, and the sealing performance of flow and pressure regulating valve is guaranteed. BRIEF DESCRIPTION OF DRAWINGS

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the flow regulating and pressure regulating valve provided by this utility model;

[0022] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0023] Figure 3 A cross-sectional schematic diagram of the sealing ring in the flow regulating and pressure regulating valve provided by this utility model in a free state before installation;

[0024] Figure 4 A cross-sectional structural diagram of the sealing ring in the working state after installation in the flow regulating and pressure regulating valve provided by this utility model;

[0025] Figure 5 A schematic diagram of the structure of the middle ring outer sleeve of the flow regulating and pressure regulating valve provided by this utility model in the open state before the O-ring is installed;

[0026] Figure 6 for Figure 5 Cross-sectional structural diagram;

[0027] Figure 7 A schematic diagram of the structure of the middle ring outer sleeve of the flow regulating and pressure regulating valve provided by this utility model in the closed state after the O-ring is installed;

[0028] Figure 8 for Figure 7 Cross-sectional structural diagram;

[0029] Figure 9 A schematic diagram of the piston sleeve in the flow regulating and pressure regulating valve provided by this utility model;

[0030] Figure 10 A schematic diagram of the valve body in the flow regulating and pressure regulating valve provided by this utility model;

[0031] Figure 11 for Figure 10 A magnified view of a section at point B in the middle;

[0032] Figure 12 This is a partial structural diagram of the valve seat in the flow regulating and pressure regulating valve provided by this utility model.

[0033] In the picture:

[0034] 10 - valve body; 11 - valve stem; 12 - guide cylinder; 13 - guide rail; 14 - crank connecting rod mechanism; 15 - first end opening; 16 - first annular half slot;

[0035] 20 - valve seat; 21 - annular limiting protrusion; 22 - second annular half slot;

[0036] 30 - piston sleeve; 31 - sliding sealing section; 32 - annular conical metal sealing surface; 33 - necked communication section; 331 - flow regulating groove;

[0037] 40 - sealing ring; 41 - ring outer sleeve seat; 411 - C-shaped outer ring sleeve; 412 - first extension connecting part; 413 - second extension connecting part; 414 - anti-falling thorn; 42 - O-ring. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0039] The present application aims to provide a double sealing pair and a flow and pressure regulating valve to solve the problems in the prior art and improve the sealing performance.

[0040] In order to make the above-mentioned purposes, features and advantages of the present application more apparent, obvious and easy to understand, the present application will be described in further detail below with reference to the drawings and specific embodiments.

[0041] Embodiment One

[0042] The present embodiment provides a double sealing pair, such as Figures 1-12As shown, including sealing ring 40 and metal wire sealing pair; sealing ring 40 is used to set in the valve body 10 end opening inside wall of the flow regulating pressure regulating valve and the sealing surface between the inside wall of the opening of the valve seat 20 and the outside wall of the piston sleeve 30 of the flow regulating pressure regulating valve; sealing ring 40 has elasticity; metal wire sealing pair includes coaxial annular limiting protrusion 21 and annular tapered metal sealing surface 32, annular tapered metal sealing surface 32 is arranged on the piston sleeve 30 of the flow regulating pressure regulating valve, annular limiting protrusion 21 is fixedly arranged on the inside wall of the valve seat 20, annular limiting protrusion 21 and annular tapered metal sealing surface 32 are annular linear sealing (annular limiting protrusion 21 cross section is trapezoidal, and the small diameter edge of the side slope close to the valve body 10 of annular limiting protrusion 21 and annular tapered metal sealing surface 32 are annular linear sealing, the side slope close to the valve body 10 forms a 50° taper surface with the horizontal plane; annular tapered metal sealing surface 32 is a taper surface with the horizontal plane at 45°, due to the angle difference between them, it forms annular linear sealing, so that in the closing process, the larger size of dirt can be removed to some extent); and sealing ring 40 is located on the side of the metal wire sealing pair close to the center of the valve body 10 of the flow regulating pressure regulating valve.

[0043] By fixing annular limiting protrusion 21 on the inside wall of the valve seat 20, annular tapered metal sealing surface 32 is arranged on the piston sleeve 30, and the two are annular linear sealing; this linear sealing structure can produce higher sealing specific pressure on smaller contact area, which can effectively prevent fluid from leaking through the gap between the inside wall of the valve seat 20 and the piston sleeve 30 even in high pressure environment, and because it is linear sealing, the relative sliding friction is small when the piston sleeve 30 moves, which is not easy to wear and can maintain good sealing performance for a long time; and due to the particularity of linear sealing, the distance between annular limiting protrusion 21 and annular tapered metal sealing surface 32 is constantly reduced during the closing process, which can scrape off the adsorbed matter on the annular tapered metal sealing surface 32 during the closing process to some extent, so it has a certain scraping effect; sealing ring 40 is located on the side of the metal wire sealing pair close to the center of the valve body 10 of the flow regulating pressure regulating valve, forming a double sealing structure, when fluid tries to leak from the gap between the piston sleeve 30 and the valve body 10, it will first encounter the blockage of sealing ring 40, most of the fluid is blocked back by sealing ring 40, even if a small amount of fluid passes through sealing ring 40, it will be blocked again by the outer metal wire sealing pair, further improving the reliability of the sealing, at the same time, sealing ring 40 can also protect the metal wire sealing pair to some extent, preventing it from being eroded and worn by impurity particles, prolonging the service life of the metal wire sealing pair, thereby improving the sealing performance of the flow regulating pressure regulating valve as a whole.

[0044] In the optional solution of the embodiment, preferably, the sealing ring 40 is made of polytetrafluoroethylene. The mechanical properties (such as tensile strength and elasticity) of the polytetrafluoroethylene material remain unchanged in water; the material has a low probability of degradation caused by microbial erosion after long-term immersion in water; the material has strong resistance to medium scouring and is not easy to wear; the friction coefficient of the material is only 0.05, which is one-tenth of the friction coefficient of EPDM rubber. During the valve flow regulating and pressure regulating or valve closing process, the friction torque between the piston sleeve 30 and the sealing ring 40 is small, and thus the torque for operating the valve is also low.

[0045] In the optional solution of the embodiment, preferably, as shown in Figures 2-8 the sealing ring 40 comprises an outer sleeve 41 and an O-ring 42; the outer sleeve 41 comprises a C-shaped outer sleeve 411 and first and second extension connecting portions 412 and 413 fixedly arranged at the two ends of the opening of the C-shaped outer sleeve 411; the material of the outer sleeve 41 is polytetrafluoroethylene; the opening of the C-shaped outer sleeve 411 faces away from the axis of the C-shaped outer sleeve 411; the O-ring 42 is arranged in the C-shaped outer sleeve 411; in a natural state, the first and second extension connecting portions 412 and 413 are in a posture away from each other; and under the action of an external force, the first and second extension connecting portions 412 and 413 can be in a posture close to each other and make the opening of the C-shaped outer sleeve 411 in a closed state; a plurality of anti-disengagement barbs 414 are fixedly arranged on the outer sides of the first and second extension connecting portions 412 and 413. The structure design of the C-shaped outer sleeve 411 makes it have a certain elasticity and deformation ability, and the opening faces away from the axis, which makes it more convenient to install the O-ring 42 and better adapt to different sizes of installation space and sealing requirements. When subjected to an external force, the opening of the C-shaped outer sleeve 411 can be closed to tightly wrap the O-ring 42, providing stable support and constraint to ensure that the O-ring 42 maintains a good sealing state during operation; the C-shaped structure of the outer sleeve 41 and the polytetrafluoroethylene material provide a stable installation environment and protection for the O-ring 42 to prevent displacement, distortion or excessive deformation of the O-ring 42 during operation, and at the same time, the cooperation of the two can better adapt to the slight deformation and unevenness of the sealing surface, further enhancing the sealing effect; the plurality of anti-disengagement barbs 414 on the outer sides of the first and second extension connecting portions 412 and 413 can enhance the fixing effect of the sealing ring 40 to ensure that it maintains stable sealing performance during long-term use.

[0046] Specifically, the O-ring 42 is a rubber O-ring.

[0047] Specifically, the first and second extension connecting portions 412 and 413 in the closed state are similar to a pagoda head structure.

[0048] Specifically, when the flow and pressure regulating valve plays a role of regulating the flow and pressure of water, the sealing ring 40 and the sealing surface of the piston sleeve 30 (i.e. the outer side wall of the sliding sealing section 31) are separated, and the outer sleeve seat 41 is in a free state under the elastic force of the O-ring 42; when the flow and pressure regulating valve plays a role of cutting off, the sealing ring 40 and the corresponding sealing surface of the piston sleeve 30 (i.e. the outer side wall of the sliding sealing section 31) are in contact and the sealing ring 40 is compressed, under the compression, the O-ring 42 is elastically deformed and applies elastic force to the outer sleeve seat 41, so that the sealing force formed by the corresponding sealing surface of the outer sleeve seat 41 and the piston sleeve 30 reaches the sealing specific pressure of the polytetrafluoroethylene material of the outer sleeve seat 41, and the sealing is realized.

[0049] Embodiment two

[0050] The embodiment provides a flow and pressure regulating valve, which comprises a valve body 10, a valve seat 20, a piston sleeve 30, a crank connecting rod mechanism 14 and a double sealing pair as in embodiment one. Figures 1-12 As shown in the figure, the valve body 10 has a first end opening 15, and the valve body 10 has a rotating valve rod 11 inside; the valve seat 20 is fixedly arranged at the first end opening 15 (the valve seat 20 is circumferentially provided with counterbores for corresponding connection with the end of the valve body 10, and connecting screws are arranged in each counterbore, and the valve body 10 is provided with connecting screw holes for threaded connection with the connecting screws), and the piston sleeve 30 is slidingly arranged in the first end opening 15 along the axis of the valve body 10; the piston sleeve 30 has a sliding sealing section 31 and a necked connecting section 33, the sliding sealing section 31 and the necked connecting section 33 are respectively located at two ends of the piston sleeve 30, the outer diameter of the necked connecting section 33 is smaller than that of the sliding sealing section 31, and the necked connecting section 33 is provided with a through flow regulating groove 331 on the side wall; the crank connecting rod mechanism 14 is arranged in the valve body 10, the input end of the crank connecting rod mechanism 14 is connected with the valve rod 11, and the output end of the crank connecting rod mechanism 14 is drivingly connected with the piston sleeve 30, and the crank connecting rod mechanism 14 is used to drive the piston sleeve 30 to slide along the axis of the valve body 10; the inner side wall of the end opening of the valve body 10 and the inner side wall of the valve seat 20 jointly form a sliding sealing surface, the sliding sealing surface is provided with a placing groove for placing the sealing ring 40; the annular tapered metal sealing surface 32 is located on the piston sleeve 30 between the sliding sealing section 31 and the necked connecting section 33; the annular limiting protrusion 21 is fixedly arranged on the inner side wall of the valve seat 20.

[0051] The sliding sealing section 31 and the necked communication section 33 of the piston sleeve 30 and the flow regulating groove 331 on the necked communication section 33 are designed so that when the piston sleeve 30 slides along the axis of the valve body 10, the flow and pressure of the fluid can be accurately controlled by changing the flow area between the flow regulating groove 331 and the valve seat 20; the crank linkage mechanism 14 converts the rotation of the valve stem 11 into the linear sliding of the piston sleeve 30, which can provide stable and reliable power transmission, and the sliding distance of the piston sleeve 30 can be accurately controlled by adjusting the rotation angle of the valve stem 11, thereby accurately controlling the opening of the flow and pressure regulating valve to achieve fine adjustment of the flow and pressure; a double sealing pair including a sealing ring 40 and a metal wire sealing pair is provided, the sealing ring 40 is located on the side of the metal wire sealing pair close to the center of the valve body 10, which can preliminarily seal the fluid to prevent the fluid from directly impacting the metal wire sealing pair, and the annular limiting protrusion 21 in the metal wire sealing pair and the annular tapered metal sealing surface 32 form a ring-shaped linear seal, which further improves the sealing effect, effectively prevents fluid leakage even under high pressure and high speed, and ensures the sealing performance of the flow and pressure regulating valve.

[0052] Among them, the related setting of the valve body 10 and the valve seat 20 is as follows:

[0053] In the optional scheme of the embodiment, preferably, as shown in Figure 2 and Figures 10-12 , the first end opening 15 of the valve body 10 is provided with a first annular half groove 16, and the valve seat 20 is provided with a second annular half groove 22, and the first annular half groove 16 and the second annular half groove 22 jointly form a placing groove. The placing groove is composed of two half grooves, when installing the sealing ring 40, the sealing ring 40 can be placed in one of the half grooves first, and then the valve body 10 and the valve seat 20 are assembled to combine the two half grooves to form a complete placing groove, which is more convenient to install, reduces the installation difficulty, and improves the installation efficiency; when the valve body 10 and the valve seat 20 are installed together, the two annular half grooves uniformly extrude the sealing ring 40, so that the sealing ring 40 can better fit the groove wall, effectively fill the possible gap, improve the sealing performance, and prevent fluid leakage from the sealing part.

[0054] In the optional scheme of the embodiment, preferably, as shown in Figures 10-12As shown, when the sealing ring 40 has the anti-disengagement barb 414, the first annular half-groove 16 and the second annular half-groove 22 are each provided with an anti-disengagement inverted groove corresponding to the position of each anti-disengagement barb 414. The anti-disengagement barb 414 and the anti-disengagement inverted groove cooperate with each other to effectively prevent the sealing ring 40 from being displaced axially during operation. When the flow-regulating pressure-regulating valve is in operation, the pressure of the fluid and the movement of the piston sleeve 30 can generate an axial force on the sealing ring 40. However, the anti-disengagement barb 414 is embedded in the anti-disengagement inverted groove to form a reliable mechanical limit, so that the sealing ring 40 can always be kept in the correct position to ensure the stability of the sealing effect.

[0055] In this embodiment, the piston sleeve 30 is provided with the following structures:

[0056] In the optional solution of this embodiment, preferably, as shown in Figure 9 As shown, the necked communication section 33 with the flow-regulating groove 331 is a squirrel cage, the sliding sealing section 31 is a piston body, and the piston body and the squirrel cage are integrally formed. The outer diameter of the squirrel cage is smaller than the outer diameter of the piston body, and the variable-diameter connection between the outer side wall of the piston body and the outer side wall of the squirrel cage is connected through the annular tapered metal sealing surface 32. The sliding sealing section 31 adopts the piston body and is integrally formed with the squirrel cage, thereby ensuring the integrity and sealing of the structure. The variable-diameter connection between the outer side wall of the piston body and the outer side wall of the squirrel cage is connected through the annular tapered metal sealing surface 32. Such a tapered sealing surface can form good adhesion with the corresponding sealing surface of the valve body 10 or the valve seat 20 when the piston sleeve 30 moves, thereby improving the sealing effect. The integrally formed piston body and squirrel cage structure reduces the connection points between parts, improves the strength and stability of the overall structure, can withstand higher pressure and impact force when the flow-regulating pressure-regulating valve is in operation, and is not prone to deformation or damage. At the same time, such a structure is also convenient for processing and manufacturing, reduces production costs, and improves production efficiency.

[0057] In this embodiment, the piston sleeve 30 is provided with the following structures:

[0058] In the optional solution of this embodiment, preferably, as shown in Figure 1 and Figure 10 As shown, the valve body 10 is provided with a flow guide cylinder 12, and the sliding sealing section 31 of the piston sleeve 30 is slidingly arranged in the flow guide cylinder 12. The flow guide cylinder 12 provides accurate guidance for the sliding of the piston sleeve 30 and limits the movement track of the piston sleeve 30, so that the piston sleeve 30 can only slide along the axial direction of the flow guide cylinder 12. This can avoid the piston sleeve 30 from deviating, shaking or tilting during movement, improve the stability and accuracy of the movement of the piston sleeve 30, and thus ensure the normal operation of the flow-regulating pressure-regulating valve.

[0059] In the optional solution of this embodiment, preferably, as shown in Figure 1 and Figure 10As shown, the guide rail 13 is arranged on the inner wall of the flow guide cylinder 12, and the piston sleeve 30 moves along the axis of the valve body 10 on the guide rail 13. The guide rail 13 provides a clear and accurate guide path for the movement of the piston sleeve 30, which can ensure that the piston sleeve 30 moves strictly along the axial direction of the valve body 10, avoiding deviation, swing or inclination, etc., thereby ensuring the stability and reliability of the flow and pressure regulating valve, making the valve adjustment more accurate, and improving the accuracy of flow and pressure control.

[0060] In the optional solution of the present embodiment, preferably, the valve rod 11 is connected with a driving mechanism, which can drive the valve rod 11 to rotate. By driving the valve rod 11 to rotate through the driving mechanism, the opening degree of the valve can be accurately controlled, different rotation angles correspond to different valve flow areas, thereby realizing accurate regulation of fluid flow and pressure to meet the use requirements under various working conditions.

[0061] Specifically, the flow and pressure regulating valve provided in the present embodiment is provided with other structures except the above-mentioned double sealing pair, which are all prior art, and will not be described in detail here.

[0062] The principle and implementation mode of the present application are described by applying specific examples in the present application, and the above embodiment is only used to help understand the method and core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present specification should not be understood as a limitation of the present application.

Claims

1. A dual seal pair, characterized by: The sealing ring and the metal wire sealing pair are provided. The sealing ring is arranged in a placing groove of a sliding sealing surface of the flow and pressure regulating valve, and the sliding sealing surface is a sealing surface between an inner wall of an opening of an end of a valve body of the flow and pressure regulating valve and an inner wall of a valve seat at the opening and an outer wall of a piston sleeve of the flow and pressure regulating valve. The metal wire sealing pair comprises a coaxial annular limiting protrusion and a ring-shaped tapered metal sealing surface. The ring-shaped limiting protrusion is arranged on the inner wall of the valve seat.

2. The dual seal pair of claim 1, wherein: The sealing ring is arranged on a side of the metal wire sealing pair close to a center of the valve body of the flow and pressure regulating valve.

3. The dual seal pair of claim 2, wherein: The material of the sealing ring is polytetrafluoroethylene. The sealing ring comprises an outer sleeve and an O-shaped ring. The outer sleeve comprises a C-shaped outer sleeve and first and second extension connecting parts arranged at two ends of an opening of the C-shaped outer sleeve. The material of the outer sleeve is polytetrafluoroethylene. The opening of the C-shaped outer sleeve is directed away from an axis of the C-shaped outer sleeve.

4. A flow and pressure regulating valve characterized by: The O-shaped ring is arranged in the C-shaped outer sleeve. In a natural state, the first and second extension connecting parts are away from each other. Under an external force, the first and second extension connecting parts are close to each other and the opening of the C-shaped outer sleeve is closed. The outer sides of the first and second extension connecting parts are provided with a plurality of parallel arranged anti-disengagement barbs. The valve body, the valve seat, the piston sleeve, the crank connecting rod mechanism and the double sealing pair are provided. The valve body has a first end opening. The valve seat is arranged at the first end opening. The piston sleeve is arranged in the first end opening along an axis of the valve body. The piston sleeve has a sliding sealing section and a necked connecting section. The crank connecting rod mechanism is arranged in the valve body. The input end of the crank connecting rod mechanism is connected with the valve rod. The output end of the crank connecting rod mechanism is drivingly connected with the piston sleeve. The valve body and the valve seat form a sliding sealing surface. The ring-shaped limiting protrusion is arranged on the inner wall of the valve seat.

5. The flow-regulating pressure-regulating valve according to claim 4, characterized in that: The first annular half-groove is arranged at the first end opening of the valve body, and a second annular half-groove is arranged on the valve seat, and the first annular half-groove and the second annular half-groove jointly form the accommodating groove.

6. The flow-regulating pressure-regulating valve according to claim 5, characterized in that: When the sealing ring has the anti-falling barbs, anti-falling inverted grooves are arranged at positions corresponding to the anti-falling barbs in the first annular half-groove and the second annular half-groove.

7. The flow-regulating pressure-regulating valve according to claim 4, characterized in that: The valve body is internally provided with a flow guide cylinder, and the sliding sealing section of the piston sleeve is slidingly arranged in the flow guide cylinder.

8. The flow-regulating pressure-regulating valve according to claim 7, characterized in that: A guide rail is arranged on the inner wall of the flow guide cylinder, and the piston sleeve moves along the guide rail along the axis of the valve body.

9. The flow-regulating pressure-regulating valve according to claim 4, characterized in that: The necked communication section with the flow regulating groove is a squirrel cage, the sliding sealing section is a piston body, the piston body is integrally formed with the squirrel cage, the outer diameter of the squirrel cage is smaller than the outer diameter of the piston body, and the variable-diameter connection between the outer side wall of the piston body and the outer side wall of the squirrel cage is connected through the annular tapered metal sealing surface.

10. The flow-regulating pressure-regulating valve according to claim 4, characterized in that: A driving mechanism is connected to the valve rod, and the driving mechanism can drive the valve rod to rotate.

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