A self-relieving bellows-sealed double disc gate valve

Abstract

The present invention relates to the technical field of double gate valve structures, and particularly relates to a self-relieving bellows-sealed double gate valve, which includes a valve seat, a valve stem and a gate. A through hole for the flowing medium is provided on the valve seat. The valve stem passes through the valve seat and drives the gate to move up and down for opening and closing the through hole. The gate is arranged as a double gate, including symmetrically arranged sealing plates. The sealing plates have a floating adjustment amount along the setting direction of the through hole. A self-relieving mechanism is arranged at the connection position between the gate and the valve stem. The self-relieving mechanism is used to squeeze the sealing plates from both sides, so that the sealing plates are respectively in contact with and sealed against the medium inlet end and the medium outlet end of the through hole. Through the cooperation of a push rod and a wedge block, the push rod is used to drive the sealing plate to move, so that the sealing plate is in contact with and sealed against the medium inlet end on the valve seat. Due to the tightening effect of the push rod, the sealing plate can better withstand the pressure of the medium.

Description

Technical Field

[0001] The present invention relates to the technical field of double gate valve structures, and particularly to a self-relieving bellows-sealed double gate valve. Background Art

[0002] Due to the special structure of the parallel double gate valve, it has the characteristics of good sealing performance, small opening and closing torque, long service life, etc., and is more and more applied in industries such as petroleum, chemical industry, and light industry.

[0003] The valve stem thrust of the parallel double gate valve is transmitted to the gate through the component forces inside the valve, causing the gate to automatically squeeze against the valve seat to form a forced seal. However, in some special cases where the temperature difference of the medium or the external environmental temperature changes greatly, when the valve is closed at a lower temperature, it may take several hours to open. Since there is medium in the valve cavity, if the medium temperature rises or the external temperature rises during the valve closing process, at this time, because the valve is in a sealed state, the medium in the valve cavity will expand in volume as the temperature rises, resulting in an abnormal increase in the internal pressure of the valve cavity, making the sealing specific pressure between the gate and the valve seat too large. At this time, a greater driving force is required to open the valve. In this case, it often leads to the valve being unable to be opened, and even damages the valve sealing surface or the valve body.

[0004] In addition, the gate located at the medium inlet end is subjected to the pressure of the medium acting on it, which will also easily cause the gate on this side to have poor sealing and leakage.

[0005] In the Chinese patent with the patent application number 201620961540.0 applied by the applicant on August 29, 2016, a valve core assembly on a gate valve is specifically disclosed. The valve core assembly is arranged in the valve cavity between the medium inlet flow channel and the medium outlet flow channel. The valve core assembly includes a wedge-shaped block, an expansion block, two sealing disks and two guide frames. The two sealing disks are arranged parallel to each other; the guide frames are arranged on the valve body above the sealing disks, and a guide track for guiding the sealing disks is formed between the two guide frames; the wedge-shaped block is connected to the inner end of the valve stem. A positioning shaft hole parallel to the medium flow channel is opened on the sealing disk, and a positioning shaft is arranged on the inner end side surface of the sealing disk, and the positioning shaft is arranged in the positioning shaft hole; the expansion block is located between the wedge-shaped block and the sealing disk, the lower end of the expansion block abuts against the inner end surface of the valve body, the expansion block is hung on the wedge-shaped block, and the wedge-shaped block and the expansion block are in inclined surface cooperation and abutment.

[0006] However, according to the applicant's reaction, when the above technical solution is used, due to the temperature difference, it is very easy to cause the abnormal increase in the internal pressure of the valve cavity as described above, making the sealing specific pressure between the gate and the valve seat too large. At this time, a greater driving force is required to open the valve. Summary of the Invention

[0007] In view of the above problems, the present invention provides a self-pressure relief bellows sealed double-disc gate valve, which cooperates with a push rod and a wedge block and utilizes the push rod to drive the sealing plate to move, so that the sealing plate and the medium inlet hole end on the valve seat are in contact and sealed. Due to the tightening effect of the push rod, the sealing plate can better withstand the pressure of the medium, and a pressure relief hole is provided on the sealing plate. When the push rod returns, the pressure relief hole opens and connects the two sides of the sealing plate to relieve pressure, so that the gate plate can be lifted more easily, solving the problems of the existing double-disc gate valve being unable to be opened due to high pressure and the gate plate being unable to be tightened and sealed due to the medium pressure during use.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A self-decompression bellows sealed double-disc gate valve, comprising a valve seat, a valve stem and a gate plate, wherein the valve seat is provided with a through hole for circulating a medium, the valve stem is inserted through the valve seat, and drives the gate plate to be lifted and lowered, and is used to open and close the through hole, the gate plate is provided with double gate plates, and comprises symmetrically arranged sealing plates, and the sealing plates have a floating adjustment amount along the setting direction of the through hole;

[0010] A self-pressure relief mechanism is provided at the connection position between the gate plate and the valve stem, and the self-pressure relief mechanism is used to squeeze the sealing plate at both sides so that the sealing plate is respectively in contact with the medium inlet end and the medium outlet end of the through hole for sealing;

[0011] The self-pressure relief mechanism includes a push rod and a wedge block, wherein the push rod is arranged between the two groups of sealing plates, and an inclined guide hole is provided on the push rod, and the wedge block is installed at the lower end of the valve stem, and the wedge block is inserted into the guide hole;

[0012] When the valve stem drives the gate plate to descend, the wedge block is staggered and matched with the guide hole, pressing the push rod to move toward the medium inlet end, and supporting the corresponding sealing plate to seal and match with the medium inlet end.

[0013] As an improvement, the top of the wedge block and the bottom of the valve stem are connected by interlacing and fitting;

[0014] A clamping block is arranged on the top of the wedge block, and a clamping groove is arranged on the bottom of the valve stem. The clamping block and the clamping groove are arranged in an interlaced manner to achieve rapid installation and cooperation between the wedge block and the valve stem.

[0015] As an improvement, the guide hole is arranged to be inclined toward the medium outlet hole end, and the bottom of the wedge block is arranged as an inclined block. When the wedge block moves downward, the wedge block is squeezed and matched with the inner wall of the guide hole, so that the push rod moves toward the medium inlet hole end, and the sealing plate is pressed toward the medium inlet hole end.

[0016] As an improvement, a pressure relief hole is provided on the sealing plate at the medium inlet end opposite to the ejector rod;

[0017] When the wedge block moves downward, the wedge block is in extrusion fit with the inner side wall of the guiding hole, so that while the ejector rod moves towards the medium inlet end, the ejector rod blocks the pressure relief hole;

[0018] When the wedge block moves upward, the ejector rod loses the limit of the wedge block, the ejector rod resets, and the pressure relief hole communicates with both sides of the sealing plate to relieve the pressure on the gate plate, solving the problem that the gate plate cannot be smoothly opened due to excessive sealing specific pressure.

[0019] As an improvement, a sealing ring corresponding to and cooperating with the ejector rod is provided at the top sealing position of the ejector rod and the pressure relief hole.

[0020] As an improvement, the self-pressure relief mechanism further includes a wedge-shaped block, and the wedge-shaped block is installed at the lower end of the valve stem;

[0021] On one side of the sealing plate corresponding to the wedge-shaped block, a swelling block cooperating with the wedge-shaped block is provided. Through the cooperation of the wedge-shaped block and the swelling block, the sealing plate moves towards the corresponding side and abuts and seals against the corresponding medium inlet end and medium outlet end respectively.

[0022] As an improvement, the wedge-shaped block includes an extrusion block arranged in a wedge shape and limiting blocks located on both sides of the extrusion block. When the extrusion block extrudes the swelling block, when the limiting blocks abut against the swelling block, the limiting blocks are used to limit the extrusion block.

[0023] As an improvement, the wedge-shaped block is provided with a mounting hole for the ejector rod to pass through, and the wedge-shaped block is further provided with a mounting groove for the wedge block to be installed. The wedge-shaped block and the wedge block are both driven by the valve stem to move synchronously.

[0024] As an improvement, the top of the wedge-shaped block and the lower end of the valve stem are connected by an insertion fit;

[0025] The top of the wedge-shaped block is provided with a convex-shaped clamping groove, and the lower end of the valve stem is provided with a clamping block corresponding to and cooperating with the clamping groove.

[0026] As an improvement, the outer side of the valve stem is coated with a corrugated pipe that expands and contracts as the valve stem moves.

[0027] The beneficial effects of the present invention are as follows:

[0028] (1) Through the cooperation of the ejector rod and the wedge block, the present invention drives the sealing plate to move by the ejector rod, so that the sealing plate abuts against and seals the medium inlet end on the valve seat. Due to the tightening action of the ejector rod, the sealing plate can better withstand the pressure of the medium, overcome the medium pressure, and solve the problem that the gate plate cannot be tightly sealed.

[0029] (2) By providing a pressure relief hole on the sealing plate, when the ejector rod tightly presses the sealing plate, the pressure relief hole is closed, and when the ejector rod returns, the pressure relief hole opens, connecting both sides of the sealing plate to play a pressure relief role, making it easier for the gate plate to be lifted, and solving the problem that the existing double gate valve cannot be smoothly opened due to excessive sealing specific pressure.

[0030] (3) By mutually cooperating the ejector rod, the wedge block and the wedge-shaped block, they are integrated together. Both the wedge block and the wedge-shaped block are driven by the valve stem to rise and fall. While driving the sealing plates of the gate plate to float and seal respectively, it also drives the ejector rod to move, and uses the ejector rod to tightly press the sealing plate, with a very compact and stable structure.

[0031] (4) By covering the outside of the valve stem with a corrugated pipe, the valve stem is wrapped and sealed by the corrugated pipe to prevent impurities from entering the space between the valve stem and the valve seat, resulting in wear of the valve stem, and providing effective protection.

[0032] In summary, the present invention has the advantages of stable sealing, stable structure, good pressure relief effect, etc., and is particularly applicable to the technical field of the double gate valve structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic partial cross-sectional structure diagram of the present invention;

[0034] Figure 2 is Figure 1 an enlarged schematic diagram of the structure at A in

[0035] Figure 3 is a schematic side view structure diagram of the wedge-shaped block of the present invention;

[0036] Figure 4 is a schematic front view structure diagram of the wedge-shaped block of the present invention;

[0037] Figure 5 is a schematic cross-sectional structure diagram of the guide ejector rod of the present invention Figure 1 ;

[0038] Figure 6 is a schematic cross-sectional structure diagram of the guide ejector rod of the present invention Figure 2 ;

[0039] Figure 7 is a schematic side view structure diagram of the wedge block of the present invention;

[0040] Figure 8Schematic diagram of the valve stem structure of the present invention;

[0041] Figure 9 Schematic diagram of the sealing plate structure of the present invention;

[0042] Figure 10 Schematic diagram of the bellows structure of the present invention. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0045] Embodiment:

[0046] As Figures 1 to 10 shown, a self-relieving bellows-sealed double-gate valve includes a valve seat 1, a valve stem 2 and a gate 3. A through hole 11 for flowing medium is formed on the valve seat 1. The valve stem 2 is inserted through the valve seat 1 and drives the gate 3 to move up and down for opening and closing the through hole 11. It is characterized in that:

[0047] The gate 3 is arranged as a double gate, including symmetrically arranged sealing plates 31, and the sealing plates 31 have a floating adjustment amount along the setting direction of the through hole 11;

[0048] A self-pressure relief mechanism 4 is provided at the connection position between the gate plate 3 and the valve stem 2. The self-pressure relief mechanism 4 is used to squeeze the sealing plates 31 from both sides, so that the sealing plates 31 are respectively in sealing contact with the medium inlet end 111 and the medium outlet end 112 of the through hole 11.

[0049] The self-pressure relief mechanism 4 includes a push rod 41 and a wedge block 42. The push rod 41 is arranged between the two groups of sealing plates 31. An inclined guide hole 411 is formed in the push rod 41. The wedge block 42 is installed at the lower end of the valve stem 2, and the wedge block 42 penetrates through the guide hole 411.

[0050] When the valve stem 2 drives the gate plate 3 to descend, the wedge block 42 is in misaligned cooperation with the guide hole 411, squeezing the push rod 41 to move towards the medium inlet end 111, and pressing against the corresponding sealing plate 31 to be in sealing cooperation with the medium inlet end 111.

[0051] Wherein, the top of the wedge block 42 and the bottom of the valve stem 2 are connected by an insertion fit.

[0052] A clamping block 421 is arranged at the top of the wedge block 42, and a clamping groove 21 is arranged at the bottom of the valve stem 2. The clamping block 421 and the clamping groove 21 are arranged in an insertion fit.

[0053] Furthermore, the guide hole 411 is inclined towards the medium outlet end 112. The bottom of the wedge block 42 is in the shape of an inclined block. When the wedge block 42 moves downward, the wedge block 42 is in extrusion cooperation with the inner side wall of the guide hole 411, so that the push rod 41 moves towards the medium inlet end 111.

[0054] Furthermore, a pressure relief hole 311 is arranged on the sealing plate 31 at the medium inlet end 111 opposite to the push rod 41.

[0055] When the wedge block 42 moves downward, the wedge block 42 is in extrusion cooperation with the inner side wall of the guide hole 411, so that when the push rod 41 moves towards the medium inlet end 111, the push rod 41 blocks the pressure relief hole 311.

[0056] When the wedge block 42 moves upward, the push rod 41 loses the limit of the wedge block 42, the push rod 41 resets, and the pressure relief hole 311 communicates with both sides of the sealing plate 31 to relieve pressure on the gate plate 3.

[0057] In addition, a sealing ring 312 corresponding to and cooperating with the push rod 41 is arranged at the top sealing position between the push rod 41 and the pressure relief hole 311.

[0058] It should be noted that the valve seat 1 is also provided with a driving mechanism for driving the valve stem 2 to move up and down. This driving mechanism can be an electric mechanism or a manual mechanism. Since this driving mechanism is a conventional mechanism, no further elaboration will be provided here. During operation, the driving mechanism drives the valve stem 2 to descend, and the wedge block 43 installed on the valve stem 2 also descends accordingly. The two side walls of the wedge block 43 catch the protruding mounting protrusions on the sealing plate 31, causing the sealing plate 31 to also descend, thereby sealing the through hole 11 on the valve seat 1, making the through hole 11 sealed and closing the valve. During the descent of the valve stem 2, the wedge 42 cooperates with the corresponding guiding hole and squeezes through the inclined surface, causing the ejector rod to move towards the medium inlet end 111 side, pressing the sealing plate 31 tightly against the medium inlet end 111, and the ejector rod 41 aligns with the pressure relief hole 311 for sealing and plugging. When opening the valve, the driving mechanism drives the valve stem 2 to lift. During the lift, the valve stem 2 drives the wedge 42 to lift. The ejector rod 41 loses the inclined surface extrusion of the wedge 42, and the ejector rod 41 is reset under the medium pressure, opening the pressure relief hole 311, enabling the two sides of the sealing plate 31 to communicate through the pressure relief hole 311, achieving the purpose of pre-pressure relief. Furthermore, the sealing plate floats, and the gate plate 3 is more easily driven by the valve stem 2 to lift, opening the through hole 11 and opening the valve.

[0059] As a more preferred embodiment, the self-pressure relief mechanism 4 further includes a wedge block 43, and the wedge block 43 is installed at the lower end of the valve stem 2;

[0060] On one side of the sealing plate 31 corresponding to the wedge block 43, a swelling block 313 is provided for cooperating with the wedge block 43. Through the cooperation of the wedge block 43 and the swelling block 313, the sealing plate 31 moves towards the corresponding side and abuts and seals against the corresponding medium inlet end 111 and medium outlet end 112 respectively.

[0061] Furthermore, the wedge block 43 includes an extrusion block 433 arranged in a wedge shape and limiting blocks 434 located on both sides of the extrusion block 433.

[0062] In addition, when the valve is closed, through the cooperation of the wedge block 43 and the swelling block 313, the sealing plate 31 moves towards the corresponding side simultaneously to seal the through hole 11, and the wedge block 43 is also driven by the valve stem 2 to move up and down.

[0063] As a preferred embodiment, the wedge block 43 is provided with a mounting hole 435 for the ejector rod 41 to pass through, and the wedge block 43 is also provided with a mounting groove 436 for the wedge 42 to be installed.

[0064] Furthermore, the top of the wedge block 43 and the lower end of the valve stem 2 are connected by an insertion fit;

[0065] A clamping groove 437 in a convex shape is arranged at the top of the wedge-shaped block 43, and a clamping block 22 corresponding to and cooperating with the clamping groove 437 is arranged at the lower end of the valve stem 2.

[0066] It should be noted that the wedge 42 is installed in the installation groove 436 of the wedge-shaped block 43, and the wedge 42 and the wedge-shaped block 43 move up and down synchronously. Moreover, an installation hole 435 for passing through the ejector rod 41 is formed in the wedge 42, and no interference will occur with the ejector rod 41.

[0067] As a preferred embodiment, a corrugated pipe 23 that contracts and expands as the valve stem 2 moves is wrapped around the outside of the valve stem 2. The corrugated pipe 23 is used to seal and protect the valve stem 2 to prevent medium impurities from entering the fitting space between the valve stem and the valve seat, resulting in wear of the valve stem.

[0068] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A self-relieving bellows-sealed double-gate valve, comprising a valve seat (1), a valve stem (2) and a gate (3). A through hole (11) for the flowing medium is provided on the valve seat (1). The valve stem (2) passes through the valve seat (1) and drives the gate (3) to move up and down to open and close the through hole (11). It is characterized in that: The gate (3) is arranged as a double gate, including symmetrically arranged sealing plates (31), and the sealing plates (31) have a floating adjustment amount along the setting direction of the through hole (11); A self-relieving mechanism (4) is arranged at the connection position between the gate (3) and the valve stem (2), and the self-relieving mechanism (4) is used to squeeze the sealing plates (31) on both sides, so that the sealing plates (31) are respectively in contact with and sealed with the medium inlet end (111) and the medium outlet end (112) of the through hole (11); The self-relieving mechanism (4) includes a push rod (41) and a wedge block (42). The push rod (41) is arranged between the two groups of sealing plates (31). An inclined guiding hole (411) is provided on the push rod (41). The wedge block (42) is installed at the lower end of the valve stem (2), and the wedge block (42) passes through the guiding hole (411); When the valve stem (2) drives the gate (3) to descend, the wedge block (42) is misaligned and matched with the guiding hole (411), squeezing the push rod (41) to move towards the medium inlet end (111), and holding the corresponding sealing plate (31) in sealing cooperation with the medium inlet end (111); The self-relieving mechanism (4) further includes a wedge-shaped block (43), and the wedge-shaped block (43) is installed at the lower end of the valve stem (2); On one side of the sealing plate (31) corresponding to the wedge-shaped block (43), a swelling block (313) matching with the wedge-shaped block (43) is provided. Through the cooperation of the wedge-shaped block (43) and the swelling block (313), the sealing plate (31) moves towards the corresponding side and is respectively in contact with and sealed with the corresponding medium inlet end (111) and medium outlet end (112).

2. The self-relieving bellows-sealed double-gate valve according to claim 1, characterized in that: The top of the wedge block (42) and the bottom of the valve stem (2) are connected by an interpenetrating fit; A clamping block (421) is provided at the top of the wedge block (42), and a clamping groove (21) is provided at the bottom of the valve stem (2). The clamping block (421) and the clamping groove (21) are arranged in an interpenetrating fit.

3. The self-relieving bellows-sealed double-gate valve according to claim 1, characterized in that: The guiding hole (411) is inclined and pointed towards the medium outlet end (112). The bottom of the wedge block (42) is arranged as an inclined block. When the wedge block (42) moves downwards, the wedge block (42) is in extrusion fit with the inner side wall of the guiding hole (411), so that the push rod (41) moves towards the medium inlet end (111).

4. The self-relieving bellows-sealed double-gate valve according to any one of claims 1-3, characterized in that: A pressure relief hole (311) is provided on the sealing plate (31) at the medium inlet end (111) opposite to the ejector rod (41). When the wedge block (42) moves downward, the wedge block (42) is in extrusion fit with the inner side wall of the guide hole (411), so that while the ejector rod (41) moves towards the medium inlet end (111), the ejector rod (41) blocks the pressure relief hole (311). When the wedge block (42) moves upward, the ejector rod (41) loses the limit of the wedge block (42), the ejector rod (41) resets, and the pressure relief hole (311) communicates with both sides of the sealing plate (31) to relieve the pressure on the gate plate (3).

5. The self-pressure-relieving bellows-sealed double-gate valve according to claim 4, characterized in that: A sealing ring (312) corresponding to and cooperating with the ejector rod (41) is provided at the top-sealing position of the ejector rod (41) and the pressure relief hole (311).

6. The self-pressure-relieving bellows-sealed double-gate valve according to claim 1, characterized in that: The wedge-shaped block (43) includes an extrusion block (433) arranged in a wedge shape and limit blocks (434) located on both sides of the extrusion block (433).

7. The self-pressure-relieving bellows-sealed double-gate valve according to claim 1, characterized in that: The wedge-shaped block (43) is provided with a mounting hole (435) for the ejector rod (41) to pass through, and the wedge-shaped block (43) is further provided with a mounting groove (436) for the wedge block (42) to be mounted.

8. The self-pressure-relieving bellows-sealed double-gate valve according to claim 1, characterized in that: The top of the wedge-shaped block (43) is connected to the lower end of the valve stem (2) by means of an insertion fit; The top of the wedge-shaped block (43) is provided with a convex-shaped engaging groove (437), and the lower end of the valve stem (2) is provided with an engaging block (22) corresponding to and cooperating with the engaging groove (437).

9. The self-pressure-relieving bellows-sealed double-gate valve according to claim 1, characterized in that: The outer side of the valve stem (2) is covered with a bellows (23) that contracts and expands as the valve stem (2) moves.

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