A minimum flow valve for a pump outlet

Abstract

This invention relates to the field of regulating valve technology, and more particularly to a minimum flow valve for pump outlet, comprising a valve body and a valve seat. The valve body has media channels on both sides of the inner arc surface bottom cavity. The valve seat is connected to the junction of the two media channels. A valve screen head is movably inserted into the middle of the upper surface of the valve seat. Through the force linkage between the hook extension section, the flange and the outwardly expanding flexible edge, an approximately triangular support and sealing structure can be formed under the impact of the media. This structure helps to disperse the impact load generated at the junction of the two media channels, alleviate the problem of force concentration at the sealing part, thereby enhancing the local support effect and sealing stability between the valve screen head and the valve seat. At the same time, it plays a front-end buffering role against the impact of the media from the converging flow channel, reducing the direct scouring intensity of the fluid on the sealing edge. After the valve screen head is separated from the valve seat, the outwardly expanding flexible edge can rely on its own elasticity to restore the outward expansion arc, which plays a certain guiding role for the subsequent flowing media.

Description

Technical Field

[0001] This invention relates to the field of regulating valve technology, and more particularly to a minimum flow valve for pump outlet. Background Technology

[0002] Minimum flow valves are a type of control component commonly used in pump outlet pipelines. They are mainly used to automatically or in conjunction with other systems to open the bypass circuit when the flow rate in the main delivery circuit decreases or approaches the shut-off condition. This ensures that the pump can maintain the necessary minimum circulating flow rate under low flow conditions, avoiding problems such as pump overheating, cavitation, increased vibration, and mechanical seal damage caused by prolonged low flow operation. Therefore, the sealing reliability, opening and closing stability, and durability of the minimum flow valve in complex fluid scouring environments directly affect the operational safety and service life of the pump system.

[0003] A Chinese invention patent, CN107314118B, discloses a novel condensate recirculation regulating valve, comprising a valve body, a valve seat, and a valve core. A hollow first sleeve is connected to the valve seat. The first sleeve includes a first part and a second part. The first part is located close to the valve seat, and the second part is located at the end of the first part away from the valve seat. The first part has multiple channels connecting its inner and outer walls, each channel having at least one bend. The second part has multiple radial through holes. The valve core is located within the hollow cavity of the first sleeve and can move axially along the inner wall of the first sleeve. When the valve core moves along the inner wall of the first sleeve, it can adjust the communication state between the inlet and outlet channels. The regulating valve of this invention has excellent pressure reduction and anti-cavitation effects. It can not only achieve precise adjustment of small opening and small flow rate but also respond quickly to large opening and large flow rate changes with zero leakage. The valve has a long service life and is easy to maintain.

[0004] However, in practical applications, the valve core or sealing parts in existing technologies usually adopt a rigid contact seal or single-stage seal fit structure with the valve seat. Although this type of structure can meet the basic sealing requirements, it is prone to problems such as local stress concentration, insufficient sealing fit, and decreased compensation performance after wear when the pump outlet medium pressure fluctuates greatly, the fluid scouring is strong, or the opening and closing frequency is high. This affects the overall sealing effect of the valve. Especially when the medium on both sides of the flow channel converges and impacts the valve seat area, if the sealing structure lacks corresponding buffer and deformation compensation design, the leakage risk will further increase, which is not conducive to the long-term stable operation of the valve. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a minimum flow valve for pump outlet.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The valve includes a valve body and a valve seat. The valve body has media channels on both sides of its inner arc surface bottom cavity. The valve seat is connected to the junction between the two media channels. A valve screen head is movably inserted into the middle of the upper surface of the valve seat. A sealing guide edge is provided on the outer arc surface of the valve screen head near the valve seat. An annular groove is formed on the upper surface of the sealing guide edge. A buffer flexible body is snapped into the sealing guide edge through the annular groove. Sealing rings are connected to both the upper and lower ends of the buffer flexible body. A valve stem is fixedly connected to the upper surface of the valve screen head. The valve stem is rotatably connected to the valve body. A column is connected to the valve stem near the valve screen head. An N-shaped sliding groove is formed on the outer arc surface of the column. An inner sleeve column is movably connected to the inner arc surface of the column through a rotating shaft. The valve stem and the inner sleeve column are rotatably connected inside the column.

[0007] Preferably, the sealing guide edge includes an outwardly expanding flexible edge and a bendable sealing edge, wherein the outer arc surface of the outwardly expanding flexible edge is movably inserted into the inner arc surface of the valve seat.

[0008] Preferably, a molding cavity is formed between the outwardly expanding flexible edge and the corner sealing edge, and a hook extension section is provided near the top of the outwardly expanding flexible edge on the corner sealing edge. The outer arc surface of the hook extension section is located at the inlet and outlet ends of the media channels on both sides, and one end of the hook extension section is bent into the molded cavity.

[0009] Preferably, the inner arc surface of the corner seal is provided with a flange in the middle, the outer surface of the flange is provided with an outer convex ring, the bottom of the outer arc surface of the flange abuts against one end of the hook extension section, and the top corner of the inner arc surface of the corner seal is provided with a nose, the surface of the nose abuts against the outer convex ring.

[0010] Preferably, the buffer flexible body has an outwardly expanding structure and is on the same horizontal plane as the sealing guide edge, and the buffer flexible body is sleeved on the outside of the valve screen head.

[0011] Preferably, the valve stem has elastic pins on both sides of its outer arc surface, and the inner sleeve has linear grooves on both sides near the elastic pins, with the elastic pins slidably connected to the inner walls of the linear grooves.

[0012] Preferably, there are four N-shaped grooves, which are distributed in a circular array on the surface of the cylinder, and the four N-shaped grooves are connected end to end.

[0013] Preferably, the column is positioned near the valve stem and the valve screen head, and the inner sleeve is housed inside the column and rotatably connected to the column.

[0014] Preferably, the valve screen head forms a sealing structure by cooperating with the valve seat through a sealing guide edge, a buffer flexible body, and a sealing ring.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. Through the force linkage between the hook extension section, flange, and outwardly expanding flexible edge, an approximately triangular support and sealing structure can be formed under the impact of the medium. This structure helps to disperse the impact load generated at the intersection of the two medium cavities, alleviate the problem of force concentration at the sealing part, thereby enhancing the local support effect and sealing stability between the valve screen head and the valve seat. At the same time, it plays a front-end buffering role against the impact of the medium from the converging flow channel, reducing the direct scouring intensity of the fluid on the sealing edge. After the valve screen head separates from the valve seat, the outwardly expanding flexible edge can rely on its own elasticity to restore the outward expansion arc, which plays a certain guiding role for the subsequent flowing medium, thereby helping to reduce the impact of fluid turbulence and improve the repeatability stability of the sealing structure.

[0016] 2. Through the linkage between the column, N-shaped slide, elastic pin, and inner sleeve, the valve stem drives the valve screen head to rotate circumferentially in addition to axial lifting during the opening and closing process. As a result, the position of the valve screen head and its sealing parts in contact with the main impact surface of the medium can change each time, thereby avoiding long-term scouring and wear in the same area, improving the wear resistance and service life of key sealing components. The combination of adaptive sealing compensation structure and deflection positioning guide structure enhances the sealing reliability of the valve under complex flow impact conditions on the one hand, and reduces the local failure problem caused by long-term repeated opening and closing and single-point scouring on the other hand. Therefore, it can better meet the long-term stable operation requirements of the pump outlet minimum flow valve under high-frequency opening and closing, pressure fluctuation and continuous scouring conditions.

[0017] 3. The angled sealing edge compresses the internal space of the molding cavity when subjected to media impact, driving the hook extension section to retract and the flange to move in tandem. This causes the convex nose and the outer convex ring to engage, thereby controlling the flange to press against the outwardly expanding flexible edge, forming a dynamic compensation seal. This structure can automatically adjust the sealing contact state under the impact of media flow, which helps to improve the fit of the sealing surface and reduce the risk of leakage. 4. By setting a sealing guide edge, a buffer flexible body, and a sealing ring on the outside of the valve screen head, and forming a composite sealing structure with the valve seat, compared with the traditional rigid contact or single-stage sealing method, the adaptability of the sealing part can be improved under the working conditions of large pump outlet pressure fluctuation and frequent media scouring, reducing the problems of local rigid collision and unstable fit, thereby improving the overall sealing performance of the valve. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view of the overall pump structure for a minimum flow valve at the pump outlet proposed in this invention. Figure 2 This is a schematic diagram of the overall connection of the valve screen head of a minimum flow valve for pump outlet proposed in this invention; Figure 3 This is a partial cross-sectional view of the sealing guide edge of a minimum flow valve for pump outlet proposed in this invention; Figure 4 This is a schematic diagram showing the disassembly of the valve screen and valve seat of a minimum flow valve for pump outlet proposed in this invention. Figure 5 This is a side sectional view of the outwardly expanding flexible edge and the bend-corner sealing edge of a minimum flow valve for pump outlet proposed in this invention; Figure 6 This is a schematic diagram of the buffer flexible body structure of a minimum flow valve for pump outlet proposed in this invention; Figure 7 This is a schematic diagram of the disassembled cylindrical structure of a minimum flow valve for pump outlet proposed in this invention; Figure 8 This is a schematic diagram of the beveled edge sealing structure of a minimum flow valve for pump outlet proposed in this invention; Figure 9 This is a schematic diagram of the elastic pin rotation process structure of a minimum flow valve for pump outlet proposed in this invention.

[0019] In the diagram: 1. Valve body; 2. Valve seat; 3. Medium passage; 4. Valve screen head; 5. Sealing guide edge; 51. Outwardly expanding flexible edge; 52. Folded sealing edge; 511. Molded cavity; 521. Hook extension section; 522. Flange; 523. Outer convex ring; 524. Lug nose; 6. Buffer flexible body; 7. Sealing ring; 8. Valve stem; 81. Elastic pin; 9. Column; 91. N-shaped slide groove; 10. Inner sleeve column; 101. Straight slide groove. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] The terms used in this invention, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0022] Reference Figures 1-9A minimum flow valve for pump outlet includes a valve body 1 and a valve seat 2. The valve body 1 has media channels 3 on both sides of the inner arc surface bottom cavity. The valve seat 2 is connected to the junction between the two media channels 3. A valve screen head 4 is movably inserted into the middle of the upper surface of the valve seat 2. A sealing guide edge 5 is provided on the outer arc surface of the valve screen head 4 near the valve seat 2. An annular groove is opened on the upper surface of the sealing guide edge 5. A buffer flexible body 6 is snapped into the sealing guide edge 5 through the annular groove. Sealing rings 7 are connected to both the upper and lower ends of the buffer flexible body 6. A valve stem 8 is fixedly connected to the upper surface of the valve screen head 4. The valve stem 8 is rotatably connected to the valve body 1. A column 9 is connected to the valve stem 8 near the valve screen head 4. An N-shaped sliding groove 91 is opened on the outer arc surface of the column 9. An inner sleeve column 10 is movably connected to the inner arc surface of the column 9 through a rotating shaft. The valve stem 8 and the inner sleeve column 10 are rotatably connected inside the column 9.

[0023] In the embodiments of the above technical solution, when the valve screen head 4 descends and contacts the valve seat 2, the sealing guide edge 5 first mates with the inner arc surface of the valve seat 2, wherein the outwardly expanding flexible edge 51 abuts against the corresponding mating surface of the valve seat 2, playing an initial guiding and basic fitting and sealing role. Since the buffer flexible body 6 is clamped to the upper surface of the sealing guide edge 5 through the annular groove, and both the upper and lower ends of the buffer flexible body 6 are provided with sealing rings 7, when the valve screen head 4 is pressed against the valve seat 2, the buffer flexible body 6 can play an elastic buffering and auxiliary sealing role for the surrounding area of ​​the sealing guide edge 5, so as to reduce the rigid collision between the valve screen head 4 and the valve seat 2 and improve the fitting stability during the sealing process.

[0024] Furthermore, when the medium flows through the media cavities 3 on both sides and impacts the area where it intersects with the valve seat 2, the corner seal 52 in the sealing guide edge 5 first bears the impact load from the medium. Since a plastic cavity 511 is formed between the outwardly expanding flexible edge 51 and the corner seal 52, the corner seal 52 can undergo elastic deformation in the direction of the plastic cavity 511 when impacted by water flow or other media, and compress the internal space of the plastic cavity 511. As the space of the plastic cavity 511 is compressed, the hook extension section 521 set at the top of the corner seal 52 contracts inward under the action of fluid pressure, thereby playing the role of guiding and unloading the impacting medium and avoiding the medium from directly concentrating on a single sealing part.

[0025] During the aforementioned deformation process, the hook extension section 521 contracts inward and further compresses and transmits pressure to the central flange 522, causing the flange 522 to undergo a linkage displacement. Since the outer surface of the flange 522 is provided with an outer convex ring 523, and the corner seal 52 has a nose 524 at the top corner of the inner arc surface, when the corner seal 52 deforms under pressure, the nose 524 gradually contacts and presses against the surface of the outer convex ring 523. With the mutual abutment between the nose 524 and the outer convex ring 523, the flange 522 can be controlled to move downward toward the outward flexible edge 51, so that a stable support and sealing state is formed between the flange 522 and the outward flexible edge 51.

[0026] A molding cavity 511 is provided between the outwardly expanding flexible edge 51 and the corner sealing edge 52. The corner sealing edge 52 is provided with a hook extension section 521 near the top of the outwardly expanding flexible edge 51. The outer arc surface of the hook extension section 521 is located at the inlet and outlet ends of the media channels 3 on both sides. One end of the hook extension section 521 is bent into the molded cavity 511. A flange 522 is provided in the middle of the inner arc surface of the corner sealing edge 52. An outer convex ring 523 is provided on the outer surface of the flange 522. The bottom of the outer arc surface of the flange 522 abuts against one end of the hook extension section 521. A nose 524 is provided at the included angle of the top of the inner arc surface of the corner sealing edge 52. The surface of the nose 524 abuts against the outer convex ring 523.

[0027] Because the hook extension section 521, flange 522, and outwardly expanding flexible edge 51 form an interconnected force relationship after being impacted by the medium, the sealing guide edge 5 locally forms an approximately triangular stable support structure. This state can, on the one hand, disperse the impact load from the intersection of the two medium cavities 3, and on the other hand, enhance the local support strength and fit of the sealing guide edge 5 and the valve seat 2 mating area, thereby improving the sealing reliability between the valve screen head 4 and the valve seat 2 and reducing the risk of leakage due to uneven local force. Furthermore, during the continuous flushing of the medium, the hook extension section 521 can act as a front-end buffer to mitigate the fluid impact, while the flange 522 is pressed against the surface of the outwardly expanding flexible edge 51 under the action of deformation transmission. The convex nose 524 and the outer convex ring 523 are used to guide and limit the displacement direction of the flange 522, so that the flange 522 is protected by the medium impact. The downward-expanding flexible edge 51 generates a compensating pressing effect to achieve dynamic compensation sealing. When the valve screen head 4 is separated from the valve seat 2, the area where the corner seal 52, the outward-expanding flexible edge 51, and the plastic cavity 511 are located loses the impact load and pressing load of the external medium. Under the elastic recovery of the material itself, its flexible structure returns to its original shape. At this time, the outward-expanding flexible edge 51 re-forms an arc-shaped outward expansion state, which not only helps the valve screen head 4 to quickly form a guiding fit with the valve seat 2 when it is pressed down again, but also plays a certain guiding role for the fluid when the medium flows through again, so as to achieve reuse (the cavity depth, wall thickness and flexible parameters of the plastic cavity 511 and the corner seal 52 are matched and set according to the valve design pressure, medium flow rate and material elastic recovery performance, so that the deformation of the corner seal 52 in the working state is within the recoverable elastic range).

[0028] Both sides of the outer arc surface of the valve stem 8 are provided with elastic pins 81. Both sides of the inner sleeve column 10 near the elastic pins 81 are provided with straight grooves 101. The elastic pins 81 are slidably connected to the inner wall of the straight grooves 101. There are four N-shaped grooves 91, which are distributed in a ring array on the surface of the column cylinder 9. The four N-shaped grooves 91 are connected end to end. The column cylinder 9 is located near the valve screen head 4 of the valve stem 8. The inner sleeve column 10 is housed inside the column cylinder 9 and is rotatably connected to the column cylinder 9. The valve screen head 4 forms a sealing structure with the valve seat 2 through the sealing guide edge 5, the buffer flexible body 6 and the sealing ring 7.

[0029] Reference Figure 2 , Figure 7 and Figure 9 The valve stem 8 is fixedly connected to the valve screen head 4 and passes through the inside of the column cylinder 9 along the axial direction. The inner sleeve 10 is housed in the inner cavity of the column cylinder 9, and the inner sleeve 10 and the column cylinder 9 are connected to each other by a rotating shaft. Elastic pins 81 are respectively provided on both sides of the outer arc surface of the valve stem 8. The inner sleeve 10 is provided with a straight groove 101 corresponding to the position of the elastic pin 81. The elastic pin 81 is embedded in the straight groove 101 and maintains a sliding fit with its groove wall. This allows the valve stem 8 to slide relative to the inner sleeve 10 during axial lifting and lowering. At the same time, the constraint of the straight groove 101 on the elastic pin 81 restricts the valve stem 8 from disorderly swinging or excessive radial displacement, so that the movement of the valve stem 8 is always kept within the predetermined guide range.

[0030] The outer arc surface of the column 9 is provided with an N-shaped groove 91. The N-shaped groove 91 forms a circumferential guide trajectory with a broken line guide feature. When the valve stem 8 drives the valve screen head 4 to move up or down, the elastic pin 81 slides axially in the straight groove 101 on the one hand, and moves synchronously along the groove trajectory of the N-shaped groove 91 under the cooperation of the relative movement between the column 9 and the inner sleeve column 10. Since the N-shaped groove 91 does not simply extend along the axial direction, but has a guide path that combines axial section and circumferential offset section, the elastic pin 81 will experience a composite motion state of axial linear movement, oblique transition, circumferential deflection and then axial movement during the sliding process.

[0031] Specifically, in the initial stage when the valve stem 8 begins to rise, the elastic pin 81 first slides relatively stably along the straight slide groove 101. At this time, the valve stem 8 mainly drives the valve screen head 4 to disengage from the valve seat 2, and the overall movement is linear, with each component inside the cylinder 9 in the initial guiding state. When the elastic pin 81 continues to move to the turning guide area of ​​the N-shaped slide groove 91, due to the change in the direction of the groove wall profile, the elastic pin 81, under the limiting and guiding effect of the groove wall, begins to change from a single axial sliding to a composite sliding state with both axial and circumferential directions. At this time, the elastic pin 81 generates a certain elastic compliance under the compression of the groove wall and transmits the guiding displacement to the valve stem 8 and the valve screen head 4, causing the valve screen head 4 to gradually deflect circumferentially during the rising process.

[0032] When the valve switches from the open state to the closed state, the valve stem 8 moves downward along the axis and drives the valve screen head 4 to move downward toward the valve seat 2. In the initial stage of the downward movement of the valve screen head 4, the outwardly expanding flexible edge 51 in the sealing guide edge 5 first contacts the inner arc surface of the valve seat 2. The outwardly expanding flexible edge 51 plays a pre-guiding and preliminary positioning role in the contact process, so that the valve screen head 4 can be stably pressed down along the predetermined mating position of the valve seat 2, reducing the possibility of misalignment and collision between the valve screen head 4 and the valve seat 2.

[0033] As the valve stem 8 continues to descend, the valve screen head 4 presses further against the valve seat 2. The buffer flexible body 6 and sealing ring 7 located at the sealing guide edge 5 are compressed, thus forming a pre-sealed state between the valve screen head 4 and the valve seat 2. At this time, the valve screen head 4 and the valve seat 2 have not yet completely achieved final sealing through rigid contact. Instead, the buffer flexible body 6 and sealing ring 7 first absorb part of the contact impact and improve the flexibility of the sealing contact. When the valve screen head 4 continues to press down and approaches the final closed position, the medium in the medium channels 3 on both sides exerts pressure on the sealing guide at the confluence area. The fluid impact generated by edge 5, after acting on the corner seal 52, causes the corner seal 52 to undergo controlled elastic deformation towards the molding cavity 511, creating a compression clearance space inside the molding cavity 511. At the same time, the deformation of the corner seal 52 causes the hook extension section 521 to contract inward, further transmitting the force to the flange 522. Due to the cooperation between the convex nose 524 and the outer convex ring 523, the flange 522, after being subjected to force, is pressed towards the outwardly expanding flexible edge 51 in a predetermined direction, thereby pushing the outwardly expanding flexible edge 51 to fit more tightly against the inner arc surface of the valve seat 2. Thus, a stable linkage support relationship is formed between the outwardly extended flexible edge 51, the flange 522, and the hook extension section 521, and an approximately triangular force support structure is formed locally. Through this structure, the impact force of the medium is converted into a compensating clamping force on the sealing guide edge 5, so that the valve screen head 4 can not only complete the axial clamping seal at the closing end, but also achieve dynamic compensation seal under the action of the medium, thereby completing the sealing state.

[0034] When the valve switches from the closed state to the open state, the valve stem 8 moves upward along the axis, causing the valve screen head 4 to disengage from the valve seat 2. In the initial stage of the upward movement of the valve stem 8, the valve screen head 4 first releases the pressure contact between itself and the valve seat 2. The buffer flexible body 6 and the sealing ring 7 are then gradually unloaded. The pressure of the medium on the corner seal 52 is reduced, and the compression state inside the molding cavity 511 is gradually released. As the external pressure and the local impact state of the fluid decrease, the corner seal 52 tends to return to its initial position by its own elasticity. The hook extension section 521 returns to its outward position from the inward state. After the flange 522 is released from the pressure by the cooperation of the nose 524 and the outer ring 523, it gradually returns to its original position. The outward expansion flexible edge 51 also returns to its original outward expansion shape. Thus, the sealing guide edge 5 as a whole completes the transition from the pressure compensation state to the natural reset state, providing deformation release conditions for the smooth opening of the valve screen head 4.

[0035] As the valve stem 8 continues to move upward, the elastic pins 81 set on both sides of the valve stem 8 slide upward along the straight groove 101 on the inner sleeve column 10. When the elastic pins 81 move to the turning guide area of ​​the N-shaped groove 91 on the column cylinder 9, under the guidance of the groove wall, the movement of the elastic pins 81 changes from a single axial upward movement to a composite movement combining axial displacement and circumferential deflection. Under this guiding action, the valve stem 8 continues to rise while driving the valve screen head 4 to rotate circumferentially.

[0036] During one opening process, the valve screen head 4 can deflect from its original position by a predetermined angle, for example, about 45°. In this way, the valve screen head 4 completes its rotation and repositioning while rising and disengaging from the valve seat 2, changing its circumferential position in contact with the main impact zone of the medium when it closes next time. This serves to alternate the erosion surface and prevent the sealing guide edge 5 and local areas of the valve screen head 4 from being subjected to erosion in the same direction for a long time. At this point, the valve completes its opening action. When the valve switches back from the open to the closed state, the valve stem 8 moves downward along the axis again, and the elastic pin 81 moves in the opposite direction along the N-shaped slide 91. Under the limiting cooperation of the straight slide 101, it drives the valve screen head 4 to rotate in the opposite direction or continue to change position, so that the valve screen head 4 returns to the corresponding closed engagement posture. Since the N-shaped slide 91 has a segmented guide trajectory, the elastic pin 81 can complete the circumferential position switching according to the preset path during the reset process. Thus, when the valve screen head 4 approaches the valve seat 2 again, the sealing guide edge 5 enters the sealing position with a different circumferential contact surface than before. Subsequently, the valve screen head 4 repeats the above closing and sealing process, that is, the outwardly expanding flexible edge 51 first guides the contact, the buffer flexible body 6 and the sealing ring 7 form a pre-seal, and the angled sealing edge 52 compresses the plastic cavity 511 under the impact of the medium and drives the hook extension section 521 and the flange 522 to move, finally completing the compensation and compression sealing.

[0037] As the elastic pin 81 continues to move along the N-shaped slide groove 91, its movement trajectory gradually completes the predetermined angle rotation and repositioning under the guidance of the column cylinder 9. In a preferred embodiment, the valve screen head 4 can deflect about 45° relative to its original position during a single lifting process. During this deflection process, the straight slide groove 101 continuously plays a linear limiting role on the elastic pin 81, so that the elastic pin 81 will not deviate from the predetermined trajectory due to unilateral force. At the same time, the inner sleeve column 10 provides internal support for the valve stem 8 to ensure that the deflection action and the lifting action are carried out synchronously and smoothly.

[0038] As the valve stem 8 continues to move upward to the open position, the elastic pin 81 moves to another stable area corresponding to the N-shaped groove 91. At this time, the valve screen head 4 has completed the corresponding angle deflection and repositioning and maintains a new circumferential posture. When the medium flows again, the parts of the valve screen head 4 and its external sealing guide edge 5 that face the impact of the medium will change relative to the previous working condition, thereby dispersing the fluid scouring position to different circumferential areas, avoiding long-term concentrated scouring of the same surface, and improving the wear resistance and service life of the valve screen head 4 and the sealing structure. During the downward reset process of the valve stem 8, the elastic pin 81... Sliding in the opposite direction along the N-shaped slide groove 91, and returning to another predetermined position under the cooperation and limiting of the straight slide groove 101, the elastic pin 81 also undergoes a transition from the circumferential guide section to the axial guide section, so that the valve screen head 4 completes the corresponding adjustment in the process of approaching the valve seat 2, and cooperates with the valve seat 2 in a new circumferential position. That is to say, every time the valve stem 8 completes one opening and closing cycle, the elastic pin 81 completes one guide repositioning in the N-shaped slide groove 91, thereby driving the valve screen head 4 to produce one circumferential surface changing action, so that the impact surface of the valve screen head 4 changes periodically.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A minimum flow valve for pump outlet, comprising a valve body (1) and a valve seat (2), characterized in that: The valve body (1) has media channels (3) on both sides of the inner arc surface bottom cavity, and the valve seat (2) is connected to the intersection of the two media channels (3); A valve screen head (4) is movably inserted into the middle of the upper surface of the valve seat (2). A sealing guide edge (5) is provided on the outer arc surface of the valve screen head (4) near the valve seat (2). An annular groove is provided on the upper surface of the sealing guide edge (5). A buffer flexible body (6) is snapped into the sealing guide edge (5) through the annular groove. A sealing ring (7) is connected to both the upper and lower ends of the buffer flexible body (6). A valve stem (8) is fixedly connected to the upper surface of the valve screen head (4). The valve stem (8) is rotatably connected to the valve body (1). A column (9) is connected to the valve stem (8) near the valve screen head (4). An N-shaped groove (91) is opened on the outer arc surface of the column (9). An inner sleeve column (10) is movably connected to the inner arc surface of the column (9) through a rotating shaft. The valve stem (8) and the inner sleeve column (10) are rotatably connected inside the column (9).

2. The minimum flow valve for a pump outlet according to claim 1, characterized in that, The sealing guide edge (5) includes an outwardly expanding flexible edge (51) and a corner sealing edge (52), and the outer arc surface of the outwardly expanding flexible edge (51) is movably inserted into the inner arc surface of the valve seat (2).

3. A minimum flow valve for a pump outlet according to claim 2, characterized in that, A molding cavity (511) is provided between the outwardly expanding flexible edge (51) and the corner sealing edge (52). The corner sealing edge (52) is provided with a hook extension section (521) near the top of the outwardly expanding flexible edge (51). The outer arc surface of the hook extension section (521) is located at the inlet and outlet ends of the media channels (3) on both sides. One end of the hook extension section (521) is bent into the interior of the molding cavity (511).

4. A minimum flow valve for a pump outlet according to claim 3, characterized in that, The inner arc surface of the corner seal (52) is provided with a flange (522) in the middle, and the outer surface of the flange (522) is provided with an outer convex ring (523). The bottom of the outer arc surface of the flange (522) abuts against one end of the hook extension section (521). The top corner of the inner arc surface of the corner seal (52) is provided with a nose (524), and the surface of the nose (524) abuts against the outer convex ring (523).

5. A minimum flow valve for a pump outlet according to claim 1, characterized in that, The buffer body (6) has an outward expansion structure and is on the same horizontal plane as the sealing guide edge (5). The buffer body (6) is sleeved on the outside of the valve screen head (4).

6. A minimum flow valve for a pump outlet according to claim 1, characterized in that, The valve stem (8) has elastic pins (81) on both sides of its outer arc surface. The inner sleeve (10) has linear grooves (101) on both sides near the elastic pins (81). The elastic pins (81) are slidably connected to the inner wall of the linear grooves (101).

7. A minimum flow valve for a pump outlet according to claim 1, characterized in that, There are four N-shaped grooves (91), which are distributed in a ring array on the surface of the cylinder (9), and the four N-shaped grooves (91) are connected end to end.

8. A minimum flow valve for a pump outlet according to claim 1, characterized in that, The column (9) is located near the valve stem (8) and the valve screen (4). The inner sleeve column (10) is housed inside the column (9) and is rotatably connected to the column (9).

9. A minimum flow valve for a pump outlet according to claim 1, characterized in that, The valve screen head (4) forms a sealing structure with the valve seat (2) through the sealing guide edge (5), the buffer flexible body (6) and the sealing ring (7).

Images