A double-disc gate valve

Abstract

The present invention relates to the field of fluid control equipment, and more specifically, to a double-disc gate valve, comprising a valve body and a valve cover mounted on the valve body. The valve body is provided with a flow channel, with a liquid inlet and a liquid outlet at either end. The valve body is provided with a first gate plate and a second gate plate for connecting or blocking the flow channel. The first and second gate plates are connected and driven to rise and fall to connect or block the flow channel. The valve stem is mounted on the valve cover. The first and second gate plates are arranged parallel to each other. An annular valve seat is provided on the valve body below the first and second gate plates. A seal is mounted on the valve seat near the liquid inlet. The present invention solves the problems of easily worn sealing surfaces and insufficient strength in current gate valves.

Description

Technical Field

[0001] The present invention relates to the field of fluid control equipment, and in particular to a double-disc gate valve. Background Art

[0002] As a type of valve, the gate valve uses a gate as the opening and closing part. Its movement direction is perpendicular to the direction of the fluid. The gate valve is sealed by the contact between the valve seat and the gate. Its sealing surface is usually made of welded metal material to increase wear resistance. There are gate valves using sealing parts on the market. Its structure is as shown in the Chinese patent publication number CN 113494620. As shown in A, a gate valve is proposed, comprising a valve body, a valve cover fixedly connected to the valve body, a gate plate installed in the valve body, a valve stem and a handle fixedly connected to the valve stem, the valve body is provided with a main flow channel connected or blocked by the gate plate, the lower end of the valve stem is connected to a screw by a flat key, the lower part of the screw is threadedly connected to the gate plate to drive the gate plate to move up and down when the screw rotates, the gate valve also includes a double-layer valve seat adjustment device, the double-layer valve seat adjustment device includes: two adjustment chambers, symmetrically opened in the valve body and respectively located on both sides of the gate plate, each of the adjustment chambers is slidably connected to an outer valve seat and an inner valve seat, the inner valve seat is slidably fitted on the inner wall of the outer valve seat, a first chamber is formed between the end of the inner valve seat away from the gate plate and the inner wall of the adjustment chamber, the first chamber is provided with a first spring for pushing the inner valve seat to move toward the side away from the gate plate, the outer The cam is connected with the valve body through the cam, and the cam is connected with the valve stem in the cam, and the cam is connected with the valve body to the cam.

[0003] Wherein, the outer valve seat and the inner valve seat are both fixedly connected with a sealing ring on one side facing the gate plate.

[0004] However, this structure still has the disadvantages of traditional gate valves, that is, there is still relative friction between the gate and the valve seat, resulting in greater wear and tear, and the sealing surface is also easily worn. Summary of the Invention

[0005] Therefore, the present invention provides a double-disc gate valve, which solves the problems of easy wear of the sealing surface and insufficient strength of the current gate valve.

[0006] To achieve the above object, the present invention is achieved through the following technical solutions:

[0007] A double-disc gate valve comprises a valve body and a valve cover mounted on the valve body, wherein a flow channel is provided in the valve body, wherein the two ends of the flow channel are respectively a liquid inlet end and a liquid outlet end, a first gate plate and a second gate plate are mounted in the valve body for connecting or blocking the flow channel, the first gate plate and the second gate plate are connected and driven to rise and fall to connect or block the flow channel, the valve stem is mounted on the valve cover, the first gate plate and the second gate plate are arranged in parallel, a valve seat with an annular structure is provided on the valve body below the first gate plate and the second gate plate, and a sealing member is mounted on the valve seat on the side close to the liquid inlet end;

[0008] The second gate includes a fixed seat fixed to the valve stem, and a rotating portion rotatably mounted on the fixed seat, wherein a hook is provided on the rotating portion, and a convex portion extending along the flow channel is provided on the valve seat. When the second gate moves downward, the hook contacts the convex portion, and the rotating portion rotates around the convex portion. When the second gate descends to the bottom of the flow channel, the rotating portion is sealed with the sealing member.

[0009] The first gate plate is fixed on the fixing seat, and when the second gate plate descends to the bottom of the flow channel, the first gate plate supports the sealing member.

[0010] Preferably, the rotating part includes a first disk part and a second disk part, the first disk part is heavier than the second disk part, and when the hook part is not in contact with the protrusion, the rotating part rotates so that the first disk part is located below the second disk part.

[0011] Preferably, the thickness of the rotating portion gradually decreases from the first disc portion to the second disc portion.

[0012] Preferably, the cross-section of the seal is U-shaped, comprising a base fixed to the valve seat, a ring portion adhered to the inner surface of the valve body, and a free portion arranged at the end of the ring portion and parallel to the base. When the rotating portion contacts the seal, the free portion adheres to the surface of the rotating portion.

[0013] Preferably, the thickness of the free portion gradually decreases from the side close to the ring portion to the end thereof.

[0014] Preferably, the free portion below the rotating portion is provided with a retreat opening for facilitating the rotating portion to extend into a space between the free portion and the base.

[0015] Preferably, a retaining ring sealed with the first gate is installed in the valve body near the liquid inlet end, and a sealing ring is installed at the end of the retaining ring.

[0016] Preferably, both the outer surface and the inner surface of the retaining ring are provided with inclined surfaces for preventing the first gate from interfering with the first gate when the first gate moves downward.

[0017] By adopting the above technical solution, the beneficial effects of the present invention are:

[0018] This technical solution designs a double-gate structure. In use, as the valve stem moves, the hook on the rotating part of the second gate plate contacts and engages with the convex part on the valve seat inside the valve body, forming a rotatable structure. During the closing process of the gate valve, the second gate plate first has a gradual downward process. Then, after the hook contacts the convex part and as the gate plate gradually moves downward, the rotating part rotates. After rotating into place, it seals with the pre-installed seal to complete the valve closing action. The first gate plate serves as a structural support for the seal, forming a double sealing structure with the seal sandwiched between the first and second gate plates.

[0019] Structurally, the second gate plate rotates and contacts the seal to form a seal. The seal is offset toward the first gate plate under the extrusion and push of the second gate plate, forming a double-gate extrusion seal structure. Compared with the traditional double-gate structure, its sealing surface is concentrated and has good sealing performance, which is conducive to initial installation and later maintenance. Although the first gate plate and the second gate plate are both plate-shaped, their structures are different. The second gate plate cooperates with the seal in a rotating form, and the force applied to the seal is softer. It is also different from the straight up and down extrusion and friction form, avoiding the deformation of the seal in the thickness direction, and the first gate plate supports the seal to avoid displacement in the opposite direction of thickness, thereby ensuring the structural sealing between the first gate plate, the second gate plate and the seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the cross-sectional structure of embodiment 1 of the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram of the component change structure at position A in the middle;

[0022] Figure 3 Schematic diagram of the position change structure of the second gate in Example 1 of the present invention;

[0023] Figure 4 Schematic diagram of the structure of the second gate and the sealing member in the first embodiment of the present invention;

[0024] Figure 5 This is a schematic cross-sectional view of a second embodiment of the present invention;

[0025] Figure 6 for Figure 5 Schematic diagram of the local enlarged structure at point B in the middle.

[0026] Figure numerals: 1, valve body; 11, valve seat; 111, convex part; 2, valve cover; 21, valve stem; 3a, first gate plate; 3b, second gate plate; 31, fixed seat; 32, rotating part; 321, hook; 322, first disc part; 323, second disc part; 4a, liquid inlet end; 4b, liquid outlet end; 5, sealing member; 51, base; 52, ring; 53, free part; 531, retreat port; 6, retaining ring; 61, sealing ring; 62, inclined surface. DETAILED DESCRIPTION

[0027] The following will describe the implementation methods of the present invention in detail with reference to specific embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Example 1

[0028] refer to Figures 1 to 4 A double-disc gate valve comprises a valve body 1 and a valve cover 2 mounted on the valve body 1. A flow channel is provided in the valve body 1, and the two ends of the flow channel are respectively a liquid inlet end 4a and a liquid outlet end 4b. A first gate plate 3a and a second gate plate 3b are installed in the valve body 1 for connecting or blocking the flow channel. The first gate plate 3a and the second gate plate 3b are connected to drive the two to rise and fall to connect or block the flow channel. The valve stem 21 is mounted on the valve cover 2. The first gate plate 3a and the second gate plate 3b are arranged in parallel. A valve seat 11 with an annular structure is provided on the valve body 1 below the first gate plate 3a and the second gate plate 3b. The valve seat 11 near the liquid inlet end 4a is provided. 1 is mounted with a sealing member 5; wherein, the sealing member 5 is overall C-shaped, with its opening facing the second gate plate 3b, and a U-shaped cross section; the sealing member 5 comprises a base portion 51 fixed to the valve seat 11, a ring portion 52 affixed to the inner surface of the valve body 1, and a free portion 53 provided at the end of the ring portion 52 and arranged parallel to the base portion 51; when the rotating portion 32 contacts the sealing member 5, the free portion 53 affixes to the surface of the rotating portion 32; in a normal state, the free portion 53 affixes to the surface of the base portion 51; when the rotating portion 32 penetrates between the free portion 53 and the base portion 51, the free portion 53 is pushed outward to contact the first gate plate 3a.

[0029] Among them, the sealing member 5 is made of rubber, and its free portion 53 needs to have a certain elasticity to meet the offset action of its fitting on the rotating portion 32; and in the design, the thickness of the free portion 53 gradually decreases from the side close to the ring portion 52 to its end, so that when the free portion 53 fits on the rotating portion 32, the end portion on the side with smaller thickness can fit as much as possible with the rotating portion 32 to improve the sealing of both.

[0030] The second gate plate 3b includes a fixed seat 31 fixed to the valve stem 21 and a rotating portion 32 rotatably mounted on the fixed seat 31. The fixed seat 31 is welded to the end of the valve stem 21, and the rotating portion 32 is connected to one side of the fixed seat 31. The rotating portion 32 has a hook 321 formed on the rotating portion 32. The valve seat 11 has a protrusion 111 extending along the flow channel. When the second gate plate 3b moves downward, the hook 321 contacts the protrusion 111, and the rotating portion 32 rotates around the protrusion 111. When the second gate plate 3b descends to the bottom of the flow channel, the rotating portion 32 is sealed with the sealing member 5. The fixed seat 31 is cylindrical in shape, similar to the valve stem 21, with a rotating shaft passing through its lower end. The rotating portion 32 is sleeved on the rotating shaft to form a rotating structure.

[0031] The first gate plate 3a is fixed to the fixed seat 31, and when the second gate plate 3b drops to the bottom of the flow channel, the first gate plate 3a supports the seal 5. This technical solution designs a double gate structure. In use, as the valve stem 21 moves, the hook 321 on the rotating part 32 of the second gate plate 3b contacts and engages with the protrusion 111 on the valve seat 11 inside the valve body 1, forming a rotatable structure. During the closing process of the gate valve, the second gate plate 3b first has a gradual downward process, and then after the hook 321 contacts the protrusion 111, and as the gate plate gradually moves downward, the rotating part 32 rotates. After rotating into place, it seals with the pre-installed seal 5 to complete the valve closing action, and the first gate plate 3a serves as a structural support for the seal 5, forming a double sealing structure in which the first gate plate 3a and the second gate plate 3b sandwich the seal 5.

[0032] Structurally, the second gate plate 3b rotates and contacts the seal 5 to form a seal. The seal 5 is pushed toward the first gate plate 3a by the extrusion of the second gate plate 3b, forming a double-gate extrusion seal structure. Compared with the traditional double-gate structure, its sealing surface is concentrated and has good sealing performance, which is beneficial for initial installation and later maintenance. Although the first gate plate 3a and the second gate plate 3b are both plate-shaped, their structures are different. The second gate plate 3b cooperates with the seal 5 in a rotating form, and the force applied to the seal 5 is softer. It is also different from the straight up and down extrusion and friction form, avoiding the seal 5 from forming deformation in the thickness direction, and the first gate plate 3a supports the seal 5 to avoid displacement in the opposite direction of thickness, thereby ensuring the structural sealing between the first gate plate 3a, the second gate plate 3b and the seal 5.

[0033] In this embodiment, the rotating part 32 includes a first disk part 322 and a second disk part 323. The weight of the first disk part 322 is greater than that of the second disk part 323. When the hook part 321 is not in contact with the protrusion 111, the rotating part 32 rotates so that the first disk part 322 is located below the second disk part 323. During the design, by designing different weight ratios of the first disc portion 322 and the second disc portion 323, a structure is formed in which the rotating portion 32 can rotate and reset according to its own weight, that is, when the rotating portion 32 is in a free state (the hook portion 321 is not in contact with the protrusion 111, and the rotating disc is only under the limit of the rotating shaft), it can form an adaptive rotation (the second disc portion 323 moves downward, that is, the first disc portion 322 moves upward) under the action of the weight difference between the first disc portion 322 and the second disc portion 323; in this way, when the valve stem 21 rises and drives the second gate plate 3b to rise, the rotating portion 32 adaptively rotates to adapt to the cavity between the valve body 1 and the valve cover 2 and gradually rises. Therefore, during the design, the cavity here between the valve body 1 and the valve cover 2 must be sufficient to ensure that the rotating portion 32 has sufficient rotation space.

[0034] Structurally, the thickness of the rotating portion 32 gradually decreases from the first disc portion 322 to the second disc portion 323. This structural design allows the second disc portion 323, which is thinner in thickness, to be relatively sharp when the second gate plate 3b moves downward, facilitating insertion into the fluid. This also facilitates the end portion from penetrating the interior of the seal 5. Compared to conventional gate plates with uniform thickness, this design reduces the reaction force of the fluid on the second gate plate 3b. This reduced force can, in turn, extend the lifespan of the gate plate and its associated connection structure.

[0035] To ensure proper rotation, the free portion 53 below the rotating portion 32 is provided with a recess 531 to facilitate insertion of the rotating portion 32 between the free portion 53 and the base 51. Specifically, the recess 531 is located directly below the second disc portion 323 on the rotating portion 32. The lower end of the second disc portion 323 is also suitably smaller and thinner to facilitate insertion of the end of the second disc portion 323. Subsequently, when the rotating portion 32 rotates, the entire portion is ensured to be inserted between the base 51 and the free portion 53 on the sealing member 5.

[0036] Moreover, during the design, the rotating portion 32 does not contact the annular portion 52 on the seal 5, and there is a certain gap between the two. On the one hand, the rotating portion 32 will not squeeze the seal 5, thereby preventing the gate from exerting force on the seal 5 and affecting its life. On the other hand, the gap between the two can accommodate some impurities, thereby preventing impurities from accumulating on the free portion 53 and affecting the sealing between it and the rotating portion 32.

[0037] Structurally, the flow channel has an elliptical cross-section, while the cross-sections of the valve cover 2 and the valve body 1 at their installation locations are both C-shaped. This C-shaped cross-section gives the valve cover 2 and valve body 1 an elliptical appearance after installation, with sufficient clearance inside to accommodate the lifting and lowering of the valve stem 21 and the rotation of the gate. The design was tailored to the dimensions and shape of the second gate 3b, simulating the rotation of the gate at this location on the valve body 1 during installation. Furthermore, the valve body 1 opening in this structure is sufficiently large to facilitate installation of the valve seat 11 and seal 5, reducing installation difficulty and facilitating demolding during casting. Example 2

[0038] refer to Figure 5 、 Figure 6 Compared to Example 1, a retaining ring 6 is installed within the valve body 1 near the liquid inlet end 4a, sealingly connected to the first gate plate 3a. A sealing ring 61 is installed at the end of the retaining ring 6. Compared to Example 1, this structure adds a sealing structure at the internal end of the pipeline on the liquid inlet end 4a side, forming multiple seals between the valve seat 11 and it, further improving the sealing performance of the valve. Furthermore, compared to the structure of Example 1, the structural support provided by the first gate plate 3a for the sealing element 5 is more stable. Furthermore, the first gate plate 3a can also be the first to block the flow path, thereby reducing the pressure of the internal fluid on the second gate plate 3b and the sealing element 5.

[0039] Structurally, both the outer and inner surfaces of the retaining ring 6 are provided with inclined surfaces 62 to prevent interference with the first gate 3a during downward movement. This ensures that the first gate 3a does not interfere with the retaining ring 6 during downward movement, reducing the requirements for installation precision. The sealing ring 61 is positioned in a pre-defined groove below the inclined surfaces 62.

[0040] In this embodiment, the retaining ring 6 and the valve body 1 are integrally formed, but it can also be a separate installation structure.

[0041] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A double-disc gate valve, comprising a valve body (1) and a valve cover (2) mounted on the valve body (1), wherein a flow channel is provided in the valve body (1), and the two ends of the flow channel are respectively a liquid inlet end (4a) and a liquid outlet end (4b), and characterized in that: A first gate plate (3a) and a second gate plate (3b) for connecting or blocking the flow channel are installed in the valve body (1); the first gate plate (3a) and the second gate plate (3b) are connected to drive a valve stem (21) to lift and lower the first gate plate (3a) and the second gate plate (3b) to connect or block the flow channel; the valve stem (21) is installed on the valve cover (2); the first gate plate (3a) and the second gate plate (3b) are arranged in parallel; a valve seat (11) with an annular structure is provided on the valve body (1) below the first gate plate (3a) and the second gate plate (3b); a sealing member (5) is installed on the valve seat (11) on the side close to the liquid inlet end (4a); The second gate plate (3b) comprises a fixed seat (31) fixed on the valve stem (21), and a rotating portion (32) rotatably mounted on the fixed seat (31); a hook portion (321) is provided on the rotating portion (32); a convex portion (111) extending along the flow channel is provided on the valve seat (11); when the second gate plate (3b) moves downward, the hook portion (321) contacts the convex portion (111), and the rotating portion (32) rotates around the convex portion (111); and when the second gate plate (3b) descends to the bottom of the flow channel, the rotating portion (32) is sealed and connected to the sealing member (5); The first gate plate (3a) is fixed to the fixing seat (31), and when the second gate plate (3b) descends to the bottom of the flow channel, the first gate plate (3a) supports the sealing member (5); The cross section of the sealing member (5) is U-shaped, and comprises a base portion (51) fixed to the valve seat (11), a ring portion (52) affixed to the inner surface of the valve body (1), and a free portion (53) provided at the end of the ring portion (52) and arranged parallel to the base portion (51). When the rotating portion (32) contacts the sealing member (5), the free portion (53) affixes to the surface of the rotating portion (32).

2. A double-disc gate valve according to claim 1, characterized in that: The rotating portion (32) includes a first disk portion (322) and a second disk portion (323), the first disk portion (322) being heavier than the second disk portion (323), and when the hook portion (321) is not in contact with the convex portion (111), the rotating portion (32) rotates so that the first disk portion (322) is located below the second disk portion (323).

3. A double-disc gate valve according to claim 2, characterized in that: The thickness of the rotating portion (32) gradually decreases from the first disc portion (322) to the second disc portion (323).

4. A double-disc gate valve according to claim 1, characterized in that: The thickness of the free portion (53) gradually decreases from the side close to the ring portion (52) toward the end thereof.

5. The double-disc gate valve according to claim 1, characterized in that: The free portion (53) located below the rotating portion (32) is provided with a retreat opening (531) that facilitates the rotating portion (32) to extend into the space between the free portion (53) and the base (51).

6. A double-disc gate valve according to any one of claims 1 to 5, characterized in that: A retaining ring (6) sealedly connected to the first gate plate (3a) is installed in the valve body (1) on the side close to the liquid inlet end (4a), and a sealing ring (61) is installed at the end of the retaining ring (6).

7. A double-disc gate valve according to claim 6, characterized in that: Both the outer surface and the inner surface of the retaining ring (6) are provided with inclined surfaces (62) for preventing the first gate plate (3a) from interfering with the first gate plate (3a) when the first gate plate (3a) moves downward.

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