Friction-free parallel double-gate-plate control gate valve

Abstract

A friction-free parallel double-gate-plate control gate valve comprises a valve body, a valve rod and a valve seat are arranged in the valve body, the valve rod is connected with a gate plate, the gate plate is matched with the valve seat in a sealing mode, the gate plate frame is in threaded connection with the valve rod, the gate plate is installed on the gate plate frame, and the gate plate frame comprises a wedge block with a wedge angle A; two round holes are machined in the positions, perpendicular to the inclined planes, of the two center points of the two inclined planes of the wedge block, the two round holes intersect at the centers, an inclined column table and a spherical ejector core are installed in the two round holes respectively, the inclined column table and the spherical ejector core are in clearance fit with the round holes, and the inclined column table and the spherical ejector core can freely swing in the round holes within a certain range. A step is arranged on the gate plate frame, a limiting block is arranged on the step, a first inclined face is milled on the limiting block, a wedge angle B is formed by the first inclined face of the limiting block, and the wedge angle B is equal to two wedge angles A. According to the gate valve, in the opening and closing process, a sealing pair has no friction, and the metal sealing faces of the valve seat and the gate plate are effectively protected; and during closing, the flashboard and the sealing surface of the valve seat can be pushed to be automatically aligned and sealed through the inclined column table and the spherical ejector core, only the respective planeness and smoothness of the sealing plane of the valve seat and the sealing plane of the flashboard need to be guaranteed during machining, all flashboards of the same specification can be freely exchanged and universally used, and other flashboard frames, limiting blocks, ejector cores, inclined column tables and the like are universally used.

Description

Technical Field

[0001] This invention relates to the field of valve technology, specifically to a frictionless parallel double gate valve. Background Technology

[0002] Existing double-gate flat gate valves are difficult to manufacture, require high machining precision, and are prone to friction during opening and closing, which can easily scratch the sealing surface. During opening, the gate is prone to disintegration, and the working position requires the valve stem to be perpendicular to the ground, relying on gravity to push the loosely assembled gate assembly into the valve body groove. However, during this process, the gate sealing surface is subjected to vibration from the medium, constantly impacting the valve seat and limiting mechanism, leading to premature damage to the gate seal. The preload is achieved using wedge thrust, but the wedge thrust mechanism is prone to inconsistencies between the wedge angle of the gate holder and the wedge angle of the thrust block. Furthermore, the contact surface between the thrust block and the gate is planar, transmitting thrust and positional relationships. If there are errors in the machining of the two wedge angles, it can easily lead to incomplete contact between the gate sealing plane and the valve seat sealing plane, resulting in sealing leakage. The oblique angle (α1) of the wedge groove formed by the two thrust blocks and the oblique angle (α2) of the gate frame wedge block have machining deviations (e.g., the design angle is 15°, but the actual wedge groove is 14.95° and the wedge block is 15.05°), resulting in only partial line contact during contact, and inability to achieve full oblique contact. As a result, the force transmitted to the gate sealing surface and the valve seat sealing surface is biased and uneven, which can easily lead to oblique gaps on the sealing surface. In addition, the surfaces forming the two wedge surfaces are not parallel, which means that the two wedge surfaces cannot be completely contacted, and the force transmitted to the gate sealing surface and the valve seat sealing surface cannot be completely contacted either.

[0003] Currently, the solution to this problem involves trial assembly, applying color markings to check the fit between the valve seat and the gate sealing surface, as well as the fit of the two wedges. Then, repeated manual grinding is performed to correct any dimensional errors. This method only achieves a sealing effect for a single unit after manual grinding, but it is inefficient and difficult to assemble and grind. Furthermore, gates for valves of the same specification are not interchangeable, lacking compatibility. If the gate is damaged after long-term use on the pipeline, it cannot be repaired by simply replacing the gate, leading to overall valve failure. These numerous drawbacks have prevented the widespread adoption of this type of parallel double-gate valve. Only by optimizing the structural design to address all its shortcomings can widespread application be achieved. Summary of the Invention

[0004] To address the technical deficiencies of existing technologies, this invention provides a frictionless parallel double-gate control valve.

[0005] The technical solution adopted in this invention is: a frictionless parallel double-gate control valve, including a valve body, a valve stem and a valve seat, a gate connected to the valve stem, the gate and the valve seat being sealed together, and a gate frame, the gate frame being threadedly connected to the valve stem, the gate being mounted on the gate frame, the gate frame including a wedge block with a wedge angle A, two circular holes being machined perpendicularly to the two center points of the two inclined surfaces of the wedge block, the two circular holes intersecting at the center, an inclined column and a spherical top core respectively installed in the two circular holes, the inclined column and the spherical top core being clearance-fitted with the circular holes, the inclined column and the spherical top core being able to swing freely within a certain range within the circular holes, the gate frame having a step, the step having a limiting block, the limiting block having a first inclined surface milled on its upper part, the first inclined surface of the limiting block forming a wedge angle B, and the wedge angle B = 2wedge angle A.

[0006] The gate includes a left gate and a right gate, which are symmetrically arranged. One side of each of the left and right gates is set as a sealing plane, and the center of the other side is a second inclined plane with an angle of A / 2. After the left and right gates are installed and fitted together, they form a wedge angle A.

[0007] The gate is provided with grooves at its upper and lower ends, and the inner edge of the groove is milled with a third inclined surface with an angle of B / 2. The left and right gates are fitted together to form a wedge angle B.

[0008] The upper end face of the gate is also provided with a disc spring, which is located between the upper end face of the gate and the valve stem, and a washer is also provided between the disc spring and the gate.

[0009] Both the left and right gate plates are provided with spherical set screws at their bottoms. The bottoms of the left and right gate plates are provided with countersunk holes and threaded holes. After the spherical set screws are installed in the countersunk holes and threaded holes, they are spot welded to prevent loosening.

[0010] The bottom surfaces of the inclined column platform and the spherical top core within the two circular holes protrude from the wedge surface of the gate frame's wedge block. A gap D exists between the wedge surface of the gate frame and the inclined surface on the gate plate. The bottom surfaces of the spherical top core and the inclined column platform form a surface-to-surface contact with the inclined surface of the gate plate. The inclined surface of the inclined column platform and the spherical surface of the spherical top core make contact and fit together, providing clamping force during the gate's closing process. Furthermore, the contact between the spherical surface of the spherical top core and the inclined surface of the inclined column platform allows for free swinging, enabling the gate plates pushed on both sides to swing freely as well. During the swinging process, the gate sealing surface completely adheres to the valve seat sealing surface.

[0011] The inclined column is provided with a keyway, and a key is provided in the circular hole where the inclined column is installed. The inclined column and the circular hole are connected by the key and the keyway. There is a gap between the keyway and the key. The inclined column can swing within the circular hole by the cooperation of the keyway and the key.

[0012] The gate frame is cross-shaped, and guide ribs are milled at both ends of the gate frame. The valve body is provided with guide grooves, and the guide ribs and guide grooves are guided and matched.

[0013] There is a gap E between the two sides of the gate and the valve seat, and there is a gap F between the guide groove and the guide rib. The gap E is greater than 3 times the gap F.

[0014] The beneficial effects of this invention are as follows: This invention provides a frictionless parallel double-gate control valve, including a valve body, a valve stem and a valve seat inside the valve body, a gate connected to the valve stem, the gate and the valve seat being sealed together, and a gate frame, which is threadedly connected to the valve stem. The gate is mounted on the gate frame, which includes a wedge with a wedge angle A. Two circular holes are machined perpendicularly to the two center points of the two inclined surfaces of the wedge, and the two circular holes intersect at the center. An inclined column and a spherical core are respectively installed in the two circular holes, which are clearance-fitted with the circular holes. The inclined column and the spherical core can move freely within a certain range within the circular holes. The gate valve of this invention features a swing mechanism with a step on the gate frame and a limiting block on the step. The limiting block has a first inclined surface milled on its upper part, forming a wedge angle B, which is equal to 2wedge angles A. During the opening and closing process, the sealing surfaces of the gate valve of this invention do not experience friction, effectively protecting the metal sealing surfaces of the valve seat and the gate. When closed, the gate valve can be automatically aligned and sealed with the valve seat sealing surface by pushing the inclined column and the spherical top core. It is only necessary to ensure the flatness and smoothness of the valve seat sealing surface and the gate sealing surface during processing. All gate valves of the same specifications can be interchanged and used interchangeably. Other gate frames, limiting blocks, top cores, inclined columns, etc., are also universal. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the valve structure of the present invention.

[0017] Figure 3 for Figure 2 Enlarged view of section I in the middle.

[0018] Figure 4 This is a schematic diagram of the valve in the closed state of the present invention.

[0019] Figure 5 This is a schematic diagram of the valve in the open state of the present invention.

[0020] Wherein, 1-valve body, 2-valve stem, 3-gate, 4-gate frame, 11-guide groove, 31-left gate, 32-right gate, 33-groove, 34-disc spring, 35-washer, 36-spherical set screw, 41-wedge block, 42-round hole, 43-slanted column, 44-spherical core, 45-limiting block, 46-key, 47-guide rib. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] A frictionless parallel double gate valve includes a valve body 1, a valve stem 2 and a valve seat inside the valve body 1, a gate 3 connected to the valve stem 2, the gate 3 and the valve seat being sealed together, and a gate frame 4, the gate frame 4 being threadedly connected to the valve stem 2, so that the gate frame and the valve stem form a rigid integral unit. The gate plate 3 is mounted on the gate plate frame 4. The gate plate frame 4 includes a wedge block 41 with a wedge angle A. Two circular holes 42 are machined on the vertical inclined surfaces at the two center points of the two inclined surfaces of the wedge block 41. The two circular holes 42 intersect at the center. An inclined column 43 and a spherical top core 44 are respectively installed in the two circular holes 42. The inclined column 43 and the spherical top core 44 are clearance-fitted with the circular holes 42. The inclined column 43 and the spherical top core 44 can swing freely within a certain range within the circular holes 42. The gate plate frame 4 is provided with a step. A limiting block 45 is provided on the step. The limiting block 45 is milled with a first inclined surface. The first inclined surface of the limiting block 45 forms a wedge angle B, and the wedge angle B = 2wedge angle A.

[0023] The gate 3 includes a left gate 31 and a right gate 32, which are symmetrically arranged. One side of the left gate and the right gate is set as a sealing plane, and the center of the other side is a second inclined surface with an angle of A / 2. After the left gate and the right gate are installed and fitted together, a wedge angle A is formed.

[0024] The gate is provided with grooves 33 at its upper and lower ends. The inner edge of the groove 33 is milled with a third inclined surface with an angle of B / 2. The left and right gates are fitted together to form a wedge angle B.

[0025] The upper end face of the gate is also provided with a disc spring 34, which is located between the upper end face of the gate and the valve stem 2. A washer 35 is also provided between the disc spring 34 and the gate. After the washer is installed, the gate is also prevented from rotating by itself under the force of the disc spring.

[0026] Both the left and right gates are provided with spherical set screws 36 at their bottoms. The bottoms of the left and right gates are provided with countersunk holes and threaded holes. After the spherical set screws 36 are installed in the countersunk holes and threaded holes, they are spot welded to prevent loosening.

[0027] The bottom surfaces of the inclined column platform 43 and the spherical top core 44 within the two circular holes 42 protrude from the wedge surface of the wedge block 41 of the gate frame 4. There is a gap D between the wedge surface of the gate frame 4 and the inclined surface on the gate plate. The bottom surface of the spherical top core 44 and the bottom surface of the inclined column platform form a surface-to-surface contact with the inclined surface of the gate plate. The inclined surface of the inclined column platform 43 and the spherical surface of the spherical top core 44 make contact and fit together, providing a clamping force during the gate closing process. The contact between the spherical surface of the spherical top core 44 and the inclined surface of the inclined column platform 43 can swing freely, allowing the gate plates pushed on both sides to swing freely as well. During the swinging process, the gate sealing surface and the valve seat sealing surface automatically align and fit together completely.

[0028] The inclined column 43 is provided with a keyway, and a key 46 is provided in the circular hole 42 where the inclined column 43 is installed. The inclined column 43 and the circular hole 42 are tightly fitted together by the key and the keyway to form an integral unit. There is a gap between the keyway and the key. The inclined column 43 can swing within the circular hole 42 by the cooperation of the keyway and the key, but it cannot rotate in the inclined plane direction of the inclined column.

[0029] The gate frame 4 is cross-shaped, with guide ribs 47 milled at both ends. The valve body 1 has a guide groove 11 inside, and the guide ribs and guide grooves are guided and fitted together. Since the guide grooves on the valve body are machined and welded onto the valve body during assembly, the gap F between the guide grooves and the guide ribs of the gate frame can be made very small. This allows the gate frame to be fixed to the center plane of the left and right sealing surfaces of the valve seat on the valve body.

[0030] There is a gap E between the two sides of the gate and the valve seat, and there is a gap F between the guide groove and the guide rib. The gap E is greater than the gap F.

[0031] Description of the valve plate assembly, valve stem installation process, and overall assembly: First, install the left and right limit blocks onto the two steps of the gate frame using screws, and spot weld the threaded ends to prevent loosening. Two V-shaped grooves with an angle of B are formed at the upper and lower parts of the gate frame. Next, install the inclined column and keyway into the gate frame in the direction of the keyway groove. Also install the spherical top core into the gate frame. Then, push the gate plates horizontally into the center of the gate frame along the V-groove direction, forming a V-shaped interlock between the upper and lower parts. Next, install washers and a set of disc springs on the upper part of the gate plates and gate frame. Then, screw the threaded hole of the valve stem head into the threaded fit at the top of the gate frame. The thread engagement force compresses the disc spring assembly, and the two gate plates are simultaneously pushed downwards by the washers. Because they are hung in the upper and lower V-grooves, the two gate plates contract inwards. After contracting to a certain extent, they simultaneously clamp the inclined column and spherical top core. At this time, the spherical top core and the inclined column protrude a certain distance D from the wedge surface of the gate frame. The wedge surface of the gate frame does not contact the inclined surface on the gate plate; instead, the bottom surface of the spherical top core and the bottom surface of the inclined column are in contact, forming a surface-to-surface contact. The inclined surface of the inclined column contacts the spherical surface of the spherical top core, providing clamping force during closure. The contact between the spherical surface and the plane allows for free swinging, enabling the gate plates on both sides to swing freely as well. During this swinging process, the gate sealing surface automatically aligns and fully engages with the valve seat sealing surface. Additionally, a spherical top screw is installed at the bottom of the gate, further enhancing its flexibility and providing greater freedom of movement. After the gate assembly, disc spring, valve stem, etc., are installed, they are inserted into the valve body. At this point, the gap E between the gate and the valve seat is kept uniform; paper sheets or soft pads of equal thickness can be inserted. Then, guide grooves are installed at the guide ribs at both ends of the gate frame. After ensuring a uniform gap F between the guide grooves and the guide ribs, the guide grooves are welded to the valve body. This welding process ensures precise positioning of the guide ribs and guide grooves, facilitating control that the distance E is greater than the distance F. Generally, E is greater than 3F, ensuring that there is absolutely no friction between the gate and the valve seat during valve opening and closing. Before the gate assembly is closed to the bottom of the valve body, the gap between the gate sealing surface and the valve seat is always maintained at a distance of E minus F. Since E is greater than 3F, a gap of more than 2F is always maintained to ensure that there is no frictional movement between the gate and the valve seat during the opening and closing process. When the gate is pushed to contact the bottom platform of the valve body, the spherical surface of the spherical set screw installed at the bottom of the gate first contacts the bottom platform and stops its downward movement. At this time, the gate frame drives the spherical set screw and the inclined column to continue to move downward, opening the gate horizontally and pressing it against the valve seat plane. Since the inclined surface of the inclined column contacts the spherical surface of the spherical set screw, it can swing freely, causing the two gates to swing freely and press against the valve seat sealing surface, providing a forced sealing pre-tightening force to ensure the positive pressure sealing force of the hard sealing surface, making the seal very reliable.The valve opening process involves the valve stem moving upwards under the actuator's influence, causing the gate assembly, spherical top core, and inclined column to move upwards together. The gate, held in place by the disc spring assembly, cannot move upwards and can only move horizontally within the V-groove formed by the gate assembly and the gate itself, contracting inwards. When a gap E is formed between the gate and the valve seat, the gate, gate assembly, and disc spring assembly are compressed into a single unit and begin to move upwards, opening the valve. Throughout this process, the gate sealing surface and the valve seat sealing surface maintain a distance of gap E, resulting in a frictionless opening process. Therefore, the valve maintains a non-contact state between the valve seat and the gate sealing surface during both closing and opening, achieving a frictionless switching operation. The valve's structure ensures the precise positioning of the gate assembly through the valve body guide groove, maintaining the relative stability of the gap E between the gate sealing surface and the valve body / valve seat seal in its free state. This ensures that sliding friction does not occur between the gate sealing surface and the valve seat seal, preventing wear. In reality, the friction between the gate frame guide and the valve body guide groove during the opening and closing process protects the sealing pair from friction. Therefore, E is greater than 3F, leaving a wear allowance between the guides greater than 2F to protect the sealing pair from friction wear.

[0032] The advantages of this invention are primarily the universality of the gate; any gate of the same specification can be used interchangeably, solving the problem of poor manufacturability in the past, where only individual sealing surfaces could be ground, and the two valve seats of the same gate valve could not be installed in reverse with the mating surfaces, otherwise leakage would occur. The main solution lies in the oscillating effect generated by the spherical core and the inclined column platform's spherical and planar mating mechanism. The spherical set screw at the bottom of the gate provides more degrees of freedom to further assist in solving this problem. Simultaneously, the invention comprehensively addresses this issue by controlling the clearance of key dimensions, such as the size of the mounting holes for the spherical core and inclined column platform, and controlling the distance D between them and the inclined surface of the gate.

[0033] Secondly, the frictionless switching process is achieved through the angular relationship between the V-angles A and B formed by the disc spring assembly and the gate assembly. This allows for a large gap E in the free state. Furthermore, in the free state, the two gates are firmly pressed against the hooks formed by the two V-grooves of the gate frame by the disc spring, preventing vibration and movement between components. The separately machined guide grooves are welded during assembly, solving the problem of a sufficiently small guide gap F. A gap E greater than 3F achieves a relatively ideal switching gap, realizing frictionless switching and ensuring the longevity of the sealing surface. Therefore, this structure addresses the product's manufacturability and component compatibility. Good manufacturability and compatibility reduce manufacturing costs and long-term maintenance costs, while the frictionless switch solves the problem of long valve lifespan.

[0034] Please note to all technical personnel: Although the present invention has been described according to the specific embodiments above, the inventive concept of the present invention is not limited to this invention. Any modifications that utilize the inventive concept will be included within the scope of patent protection of this patent.

[0035] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A frictionless parallel double-gate control valve, comprising a valve body (1), wherein a valve stem (2) and a valve seat are provided inside the valve body (1), and a gate (3) is connected to the valve stem (2), wherein the gate (3) is in a sealing fit with the valve seat, characterized in that, It also includes a gate frame (4), which is threadedly connected to the valve stem (2). The gate (3) is mounted on the gate frame (4). The gate frame (4) includes a wedge (41) with a wedge angle A. Two circular holes (42) are machined on the vertical inclined surfaces at the two center points of the two inclined surfaces of the wedge (41). The two circular holes (42) intersect at the center. An inclined column (43) and a spherical top core (44) are respectively installed in the two circular holes (42). The inclined column (43) and spherical top core (44) are fitted with the round hole (42) with a clearance. The inclined column (43) and spherical top core (44) can swing freely within a certain range within the round hole (42). The gate frame (4) is provided with a step, and the step is provided with a limiting block (45). The limiting block (45) is milled with a first inclined surface. The first inclined surface of the limiting block (45) forms a wedge angle B, and the wedge angle B = 2 wedge angle A.

2. The frictionless parallel double-gate control valve according to claim 1, characterized in that, The gate (3) includes a left gate (31) and a right gate (32). The left gate and the right gate are symmetrically arranged. One side of the left gate and the right gate is set as a sealing plane, and the center of the other side is a second inclined plane with an angle of A / 2. After the left gate and the right gate are installed and fitted together, a wedge angle A is formed.

3. The frictionless parallel double-gate control valve according to claim 2, characterized in that, The upper and lower ends of the gate are also provided with grooves (33), and the inner edge of the groove (33) is milled with a third inclined surface, the angle of which is B / 2. The left gate and the right gate are combined to form a wedge angle B.

4. The frictionless parallel double-gate control valve according to claim 1, characterized in that, The upper end face of the gate is also provided with a disc spring (34), the disc spring (34) is located between the upper end face of the gate and the valve stem (2), and a washer (35) is also provided between the disc spring (34) and the gate.

5. The frictionless parallel double-gate control valve according to claim 2, characterized in that, The bottom of the left and right gates is provided with spherical set screws (36), and the bottom of the left and right gates is provided with countersunk holes and threaded holes. The spherical set screws (36) are installed in the countersunk holes and threaded holes and then spot welded to prevent loosening.

6. The frictionless parallel double-gate control valve according to claim 1, characterized in that, The bottom surfaces of the inclined column platform (43) and the spherical top core (44) in the two circular holes (42) protrude from the wedge surface of the wedge block (41) of the gate frame (4). There is a gap D between the wedge surface of the gate frame (4) and the inclined surface on the gate. The bottom surface of the spherical top core (44) and the bottom surface of the inclined column platform form a surface-to-surface contact with the inclined surface of the gate. The inclined surface of the inclined column platform (43) and the spherical surface of the spherical top core (44) are in contact and cooperate to provide clamping force during the gate closing process. The contact between the spherical surface of the spherical top core (44) and the inclined surface of the inclined column platform (43) can swing freely, so that the gate pushed on both sides can also swing freely. During the swing, the sealing surface of the gate is completely in contact with the sealing surface of the valve seat.

7. The frictionless parallel double-gate control valve according to claim 1, characterized in that, The inclined column (43) is provided with a keyway, and a key (46) is provided in the round hole (42) where the inclined column (43) is installed. The inclined column (43) and the round hole (42) are connected by the key and the keyway. There is a gap between the keyway and the key. The inclined column (43) can swing in the round hole (42) by the cooperation of the keyway and the key.

8. The frictionless parallel double-gate control valve according to claim 1, characterized in that, The gate frame (4) is cross-shaped, and guide ribs (47) are milled on the left and right ends of the gate frame (4). The valve body (1) is provided with a guide groove (11), and the guide ribs and guide grooves are guided and matched.

9. The frictionless parallel double-gate control valve according to claim 1, characterized in that, There is a gap E between the two sides of the gate and the valve seat, and there is a gap F between the guide groove and the guide rib. The gap E is greater than 3 times the gap F.

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