Gate valve

Abstract

The invention relates to the technical field of valves, and particularly discloses a gate valve which comprises a valve body, a gate plate assembly and a pressure relief part, a valve cavity and two medium flow channels are formed in the valve body, valve ports correspondingly communicated with the two medium flow channels are formed in the two sides of the valve cavity respectively, and the gate plate assembly is installed in the valve cavity in a sliding mode. The pressure relief part comprises a first channel arranged in the gate plate assembly, a pressure relief sliding shaft installed in the first channel in a sliding mode, two second channels communicating with the valve cavity and two pressure relief openings formed in the two sides of the gate plate assembly, and each pressure relief opening can communicate with the first channel and the medium flow channel on the corresponding side. The two ends of the pressure relief sliding shaft are provided with pressure relief structures respectively, each second channel is provided with a connector connected with the corresponding first channel, and when the pressure relief sliding shaft seals the pressure relief opening in the outlet side, a space communicated with the valve cavity is formed between the pressure relief sliding shaft and the pressure relief opening in the inlet side. According to the gate valve, when the sealing direction of the gate valve is changed, the pressure relief direction is automatically switched, and the middle cavity pressure relief function is achieved.

Description

Technical Field

[0001] The invention relates to the field of valves, in particular to a gate valve. Background Art

[0002] For gate valves with good sealing on both sides, in some cases, the pressure in the middle cavity will increase abnormally, that is, when high-temperature and high-pressure fluid is blocked in the middle cavity of the valve, if the temperature of the fluid on the upstream side increases, the fluid in the middle cavity will be heated synchronously by heat transfer. Since the volume of the middle cavity cannot be expanded, the fluid blocked in the middle cavity may quickly vaporize when it changes from cold to hot, causing a sharp increase in pressure, and the pressure increase is often geometric. This problem has become a major potential source of danger in thermal power plants. If it is not taken seriously and handled, it will have a serious impact on the safety of pressure pipelines.

[0003] To solve the problem of abnormal increase in the pressure in the middle cavity, the commonly used method is to connect the middle cavity of the gate valve with the inlet side of the valve to release the pressure to the inlet side. Although this solution solves the risk caused by overpressure in the middle cavity, since the high-pressure gate valve usually produces a seal on the sealing surface on the outlet side of the gate, when the gate valve is reversely pressurized, the medium will flow to the inlet side through the connecting pipe or the pressure relief holes on the valve seat and gate, and the gate valve loses its two-way sealing function. This type of gate valve cannot be used in situations where two-way sealing is required.

[0004] Moreover, at the moment the valve is closed or opened, the sealing surface of the valve seat and the sealing surface of the gate will produce a certain amount of wear. After long-term use, the sealing performance of the valve closing will deteriorate, which may easily lead to leakage and reduce the service life of the valve.

[0005] Based on this, the present application designs a gate valve. Summary of the invention

[0006] The object of the present invention is to provide a gate valve which can not only realize overpressure protection of the middle cavity (i.e. the valve cavity described below), but also automatically realize the middle cavity pressure relief function without manual switching of the pressure relief direction when the sealing direction of the gate valve changes (i.e. the medium flow direction changes).

[0007] In order to solve the above technical problems, the present invention provides a gate valve, including a valve body, a gate assembly and a pressure relief part, wherein a valve cavity and two medium flow channels are respectively located on both sides of the valve cavity along a first direction, the valve cavity has valve ports communicated with the medium flow channels on the corresponding sides on both sides along the first direction, the gate assembly is slidably installed in the valve cavity, and the pressure relief part comprises a first channel arranged in the gate assembly and extending along the first direction, a pressure relief sliding shaft slidably installed in the first channel, two second channels both arranged in the gate assembly and communicated with the valve cavity, and two pressure relief ports respectively formed on both sides of the gate assembly along the first direction, each pressure relief port can be communicated with the first channel and the medium flow channel on the corresponding side, the two ends of the pressure relief sliding shaft respectively have pressure relief structures, and the two pressure relief ports are The pressure relief structures are arranged in one-to-one correspondence with the two pressure relief ports, and each pressure relief structure has a sliding section, a pressure relief section and a sealing section in sequence along the direction toward its corresponding pressure relief port. The sliding section is slidably installed in the first channel, and the outer diameters of the pressure relief section and the sealing section are both smaller than the outer diameter of the sliding section. The sealing section can be sealed with the corresponding pressure relief port. Each second channel has a connecting port connected to the first channel. The pressure relief sliding shaft can move toward the pressure relief port on the outlet side under the action of the medium pressure of the pressure relief port on the inlet side until the sealing section on the outlet side seals the pressure relief port on the outlet side. When the sealing section on the outlet side seals the pressure relief port on the outlet side, the orthographic projections of the pressure relief section and the sliding section on the inlet side on the plane where the inlet side connecting port is located overlap with the connecting port respectively, and the sealing section on the inlet side is located in the first channel.

[0008] Furthermore, a truncated cone-shaped guide transition structure is provided at the end of the sliding section facing the corresponding pressure relief section.

[0009] Furthermore, when the sealing section on the outlet side seals the pressure relief port on the outlet side, the orthographic projection of the guide transition structure on the inlet side on the plane where the inlet side connecting port is located at least partially falls into the connecting port.

[0010] Furthermore, it also includes a valve stem, one end of the valve stem has a connecting block, the gate assembly is slidably installed in the valve cavity along the second direction, the gate assembly is provided with a gate cavity and a hanging groove connected to the gate cavity, the connecting block is slidably installed in the hanging groove along the second direction, and the hanging groove has a first groove wall and a second groove wall that limit the position of the connecting block relative to the gate assembly, the pressure relief part also includes an auxiliary rod and two limit units, one end of the auxiliary rod is arranged on the connecting block, the limit unit includes a connecting rod, a limit slider and a limit block, the two limit blocks are fixed on the pressure relief sliding shaft and are located between the two pressure relief structures, the limit slider is slidably installed in the gate cavity along the first direction, and a limit slider is formed extending along the first direction A limiting through hole and a pressure relief through hole connected with the limiting through hole, the two limiting through holes together constitute a first channel, the pressure relief through hole constitutes a second channel, the connecting rod is rotatably connected to the auxiliary rod and the corresponding limiting slider respectively, when the connecting block abuts against the second groove wall and the gate assembly seals the two valve ports, the two limiting sliders respectively fit correspondingly with the inner cavity walls on both sides of the gate cavity along the first direction, and at least one limiting slider is away from the corresponding limiting block, when the connecting block abuts against the first groove wall, each limiting slider abuts against the corresponding limiting block, when the connecting block abuts against the first groove wall and the gate assembly seals the two valve ports, there is a space between each sealing section and the corresponding pressure relief port for medium to pass through and communicate with the valve cavity.

[0011] Furthermore, a return spring is arranged between the connecting block and the groove wall of the suspension groove.

[0012] Furthermore, the gate assembly includes a gate frame and two sealing plates, the two sealing plates are arranged in a one-to-one correspondence with the two valve ports, each sealing plate is used to seal with the corresponding valve port, the two sealing plates are respectively detachably mounted on both sides of the gate frame along the first direction and are symmetrically arranged relative to the gate frame, a sealing through hole extending along the first direction is formed on the sealing plate, a pressure relief port is provided on the sealing through hole, a gate cavity is jointly formed between the gate frame and the two sealing plates, when the connecting block abuts against the second groove wall and the two sealing plates respectively seal the corresponding valve ports, each limit slider fits with the sealing plate on the corresponding side.

[0013] The cam is provided with two push plates, each of which is symmetrical with respect to the gate plate frame, and a push slide groove is provided on the push plate, which extends along the second direction and is slidably matched with the gate slide groove. The push slide groove has a first slide groove wall and a second slide groove wall that limit the position of the push plate relative to the gate plate frame, and the second slide groove wall is located on the side of the first slide groove wall away from the limiting projection, and the push surface is gradually inclined toward the gate plate frame along the direction toward the limiting projection. The bottom wall of each push plate on the limiting projection along the second direction at least partially falls on the top surface of the limiting projection, and the sealing plate has a sealing sliding hole that cooperates with the gate slide groove, and the two sealing plates are respectively located on the side of the two push plates away from the gate plate frame, and are slidably installed on the gate slide groove along the first direction. When the two push plates abut against the limiting projection and the gate slide groove abuts against the first slide groove wall, each sealing plate seals the valve port on the corresponding side respectively.

[0014] Furthermore, the sealing sliding hole and the pressure relief port are coaxially arranged.

[0015] Furthermore, a limiting plate is fixed on the sealing plate, a positioning through hole is provided on the gate frame, and the gate assembly also includes a positioning unit, the positioning unit includes a positioning stud and two positioning sleeves, the positioning stud is at least partially arranged in the positioning through hole, the positioning sleeve is a stepped shaft structure composed of a large diameter section and a small diameter section, a step surface is formed between the large diameter section and the small diameter section, the outer diameter of the large diameter section is larger than the aperture of the positioning through hole, the small diameter section is slidably matched with the positioning through hole, the two positioning sleeves are respectively installed on both ends of the positioning stud by threaded connection, the limiting plate is located between the step surface and the gate frame, and the projections of the limiting plate and the step surface on the gate frame along the axial direction of the positioning through hole overlap.

[0016] Furthermore, the sealing section has an arc-shaped sealing surface, and the pressure relief port has a truncated cone-shaped inner surface matching the spherical sealing surface.

[0017] The beneficial effects of the present invention are:

[0018] After the valve is closed, the medium pressure on one side pushes the pressure relief slide to move toward the outlet side and seals the pressure relief port on the other side. At the same time, the pressure relief port on one side is connected to the valve cavity to realize the pressure relief of the middle cavity. When the medium flows in the reverse direction and the gate valve is closed, the medium flow channel on the other side constitutes a new inlet side medium flow channel and pushes the pressure relief slide to move to one side. Therefore, the gate valve of the present invention can meet the automatic middle cavity pressure relief function after closing the valve when the medium flows forward and reversely. According to the flow direction of the medium, the sealing direction of the pressure relief port can be automatically switched to realize the pressure relief port sealing and middle cavity overpressure protection functions.

[0019] In addition, during the opening and closing process of the valve, the friction between the gate assembly and the sealing surface of the valve port side wall is small, and the service life is long. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a cross-sectional view of a gate valve in a closed state in one embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A magnified schematic diagram of part A;

[0023] Figure 3 is an exploded view of a valve stem, a gate assembly and a pressure relief portion in one embodiment of the present invention;

[0024] Figure 4 yes Figure 3 A magnified schematic diagram of part B;

[0025] Figure 5 It is a front view of a gate assembly in a state one in one embodiment of the present invention, wherein the state one is the state of the gate assembly when the connecting block abuts against the second slot wall and the gate slider abuts against the first slot wall;

[0026] Figure 6 The gate assembly in one embodiment of the present invention is along Figure 5 Cross-sectional view of line CC in;

[0027] Figure 7 The gate assembly in one embodiment of the present invention is along Figure 6 A cross-sectional view of the DD line in FIG.

[0028] Figure 8 It is a front view of a gate assembly in a state 2 in one embodiment of the present invention, wherein the state 2 is a state of the gate assembly when the connecting block abuts against the first slot wall and the gate slider abuts against the second slot wall;

[0029] Fig. 9 The gate assembly in one embodiment of the present invention is along Figure 8 A cross-sectional view of line EE in FIG.

[0030] Fig.10 1 is a cross-sectional view of a gate valve when the gate assembly is in state 2 in one embodiment of the present invention.

[0031] In the figure: 1 is a valve body, 11 is a valve cavity, 111 is a valve port, 12 is a medium flow channel, 13 is a limiting boss, 2 is a gate assembly, 21 is a gate frame, 211 is a hanging groove, 2111 is a first groove wall, 2112 is a second groove wall, 212 is a first cavity, 2121 is a first opening, 213 is a second cavity, 2131 is a second opening, 214 is a gate slider, 22 is a sealing plate, 221 is a sealing through hole, 2211 is a pressure relief port, 222 is a sealing sliding hole, 223 is a limiting plate, 2231 is a semicircular groove, 23 is a push plate, 23 1 is a push slide, 2311 is a first slide wall, 2312 is a second slide wall, 232 is a push surface, 24 is a positioning stud, 25 is a positioning sleeve, 3 is a pressure relief part, 31 is a pressure relief slide shaft, 311 is a sliding section, 3111 is a guide transition structure, 312 is a pressure relief section, 313 is a sealing section, 314 is a limit block, 32 is an auxiliary rod, 33 is a connecting rod, 34 is a limit slider, 341 is a limit through hole, 342 is a pressure relief through hole, 343 is a connecting port, 35 is a reset spring, 4 is a valve stem, 41 is a connecting block, and 411 is an auxiliary slide. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Figure 1 is a cross-sectional view of a gate valve in a closed state in one embodiment of the present invention; Figure 2 yes Figure 1 A magnified schematic diagram of part A; Figure 3 is an exploded view of a valve stem, a gate assembly and a pressure relief portion in one embodiment of the present invention; Figure 4 yes Figure 3 A magnified schematic diagram of part B;

[0034] Figure 5 It is a front view of a gate assembly in a state one in one embodiment of the present invention, wherein the state one is the state of the gate assembly when the connecting block abuts against the second slot wall and the gate slider abuts against the first slot wall; Figure 6 The gate assembly in one embodiment of the present invention is along Figure 5 Cross-sectional view of line CC in; Figure 7 The gate assembly in one embodiment of the present invention is along Figure 6 A cross-sectional view of the DD line in FIG. Figure 8It is a front view of a gate assembly in a state 2 in one embodiment of the present invention, wherein the state 2 is a state of the gate assembly when the connecting block abuts against the first slot wall and the gate slider abuts against the second slot wall; Fig. 9 The gate assembly in one embodiment of the present invention is along Figure 8 A cross-sectional view of line EE in FIG. Fig.10 1 is a cross-sectional view of a gate valve when the gate assembly is in state 2 in one embodiment of the present invention.

[0035] like Figure 1 and Figure 2 As shown, the present invention provides a gate valve, including a valve body 1, a gate assembly 2 and a pressure relief portion 3. The valve body 1 is formed with a valve cavity 11 and two valves located in the valve cavity along a first direction (such as Figure 1 The valve cavity 11 has a medium flow channel 12 on both sides along the first direction (shown as the left and right direction), and the valve cavity 11 has valve ports 111 connected to the medium flow channel 12 on the corresponding side on both sides along the first direction. The valve cavity 11 has a medium flow channel 12 on both sides along the second direction (shown as the left and right direction). Figure 1The first direction is shown as extending in the up and down direction, and the second direction is perpendicular to the first direction. The gate assembly 2 is slidably installed in the valve cavity 11. The pressure relief portion 3 includes a first channel arranged in the gate assembly 2 and extending along the first direction, a pressure relief sliding shaft 31 slidably installed in the first channel, two second channels both arranged in the gate assembly 2 and connected to the valve cavity 11, and two pressure relief ports 2211 respectively formed on both sides of the gate assembly 2 along the first direction. Each pressure relief port 2211 can be connected to the first channel and the medium flow channel 12 on the corresponding side. Both ends of the pressure relief sliding shaft 31 have pressure relief structures respectively. The two pressure relief structures are arranged in a one-to-one correspondence with the two pressure relief ports 2211, and each pressure relief structure has a sliding section 311, a pressure relief section 312 and a sealing section 313 in sequence along the direction toward its corresponding pressure relief port 2211. The sliding section 311 is slidably installed in the first channel, and the outer diameters of the pressure relief section 312 and the sealing section 313 are both smaller than the outer diameter of the sliding section 311, and the sealing section 313 can be sealed with the corresponding pressure relief port 2211. Each second channel has a connecting port 343 connected to the first channel, and the pressure relief sliding shaft 31 can move toward the pressure relief port 2211 on the outlet side under the medium pressure of the pressure relief port 2211 on the inlet side until the sealing section 313 on the outlet side seals the pressure relief port 2211 on the outlet side. When the sealing section 313 on the outlet side seals the pressure relief port 2211 on the outlet side, the orthographic projections of the pressure relief section 312 and the sliding section 311 on the inlet side on the plane where the inlet side connecting port 343 is located have overlapping areas with the connecting port 343, and the sealing section 313 on the inlet side and the pressure relief section 314 on the inlet side are both located in the first channel. At this time, an annular pressure relief channel is formed between the inlet side sealing section 313, the inlet side pressure relief section 314 and the side wall of the first channel, and the valve cavity is connected with the medium flow channel 12 on the inlet side through the second channel, the pressure relief channel and the pressure relief port on the inlet side. The pressure relief port 2211 on the outlet side is closed by the sealing section 313 on the outlet side, and the pressure relief port 2211 on the outlet side is not connected with the first channel, so that the medium flow channel 12 on the outlet side is not connected with the valve cavity 11.

[0036] According to some embodiments of the present invention, a truncated cone-shaped guide transition structure 3111 is provided at the end of the sliding section 311 facing the corresponding pressure relief section 312 .

[0037] According to one embodiment of the present invention, when the sealing section 313 on the outlet side seals the pressure relief port 2211 on the outlet side, the orthographic projection of the guide transition structure 3111 on the inlet side on the plane where the inlet side connection port 343 is located at least partially falls into the connection port 343. Such a design ensures that the medium at the connection port 343 and the pressure relief port 2211 can act on the guide transition structure 3111, and ensures that the sealing section 313 can have sufficient pressing force to press on the pressure relief port 2211.

[0038] like Figures 1 to 9As shown, according to some embodiments of the present invention, the gate valve further includes a valve stem 4, one end of the valve stem 4 has an inverted T-shaped connecting block 41, the gate assembly 2 is slidably installed in the valve cavity 11 along the second direction, the gate assembly 2 is provided with a gate cavity and a hanging groove 211 connected to the gate cavity, the connecting block 41 is slidably installed in the hanging groove 211 along the second direction, and the hanging groove 211 has a first groove wall 2111 and a second groove wall 2112 that limit the position of the connecting block 41 relative to the gate assembly 2, the first groove wall 2111 is located on the side of the second groove wall 2112 facing the pressure relief sliding shaft 31, the pressure relief part 3 further includes an auxiliary rod 32 and two limiting units, and one end of the auxiliary rod 32 is arranged on the connecting block 41. In this embodiment, an auxiliary sliding groove 411 (such as 2111) perpendicular to the second direction and the first direction is formed at the bottom of the connecting block 41. Figure 4 The auxiliary rod 32 is slidably arranged in the auxiliary slide groove 411. This arrangement facilitates the installation of the auxiliary rod 32 on the connecting block 41. Of course, in other embodiments, the auxiliary rod 32 can also be fixed to the bottom of the connecting block 41 in other ways. The limiting unit includes a connecting rod 33, a limiting slider 34 and a limiting block 314. Both limiting blocks 314 are fixed on the pressure relief slide shaft 31 and are located between the two pressure relief structures. In this embodiment, the two limiting blocks 314 are an integrated structure, and the two limiting blocks 314 are integrally formed and connected to the pressure relief slide shaft 31. In other embodiments, the two limiting blocks 314 can also be arranged at intervals, and the limiting blocks 314 can also be installed on the pressure relief slide shaft 31. The limit slider 34 is slidably installed in the gate cavity along the first direction. The limit slider 34 is formed with a limit through hole 341 extending along the first direction and a pressure relief through hole 342 connected to the limit through hole 341. The two limit through holes 341 together constitute the first channel. The pressure relief through hole 342 constitutes the second channel. The two ends of the connecting rod 33 are rotatably connected to the auxiliary rod 32 and the corresponding limit slider 34 through a pin shaft. When the connecting block 41 abuts against the second groove wall 2112 and the gate assembly 2 seals the two valve ports 111, the two limit sliders 34 are respectively corresponding to the inner cavity walls on both sides of the gate cavity along the first direction or there is only a small gap of 3mm between the limit sliders 34 and the inner cavity walls on the corresponding side, and at least one limit slider 34 is always away from the corresponding limit block 314. Preferably, at this time, the two limit sliders 34 are respectively corresponding to the inner cavity walls on both sides of the gate cavity along the first direction, and the two limit sliders 34 are away from the corresponding limit block 314. When the connection block 41 abuts against the first groove wall 2111, each limit slider 34 abuts against the corresponding limit block 314. When the connection block 41 abuts against the first groove wall 2111 and the gate assembly 2 seals the two valve ports 111, there is a space between each sealing section 313 and the corresponding pressure relief port 2211 for the medium to pass through and communicate with the valve cavity 11.

[0039] According to some embodiments of the present invention, a return spring 35 is provided between the connection block 41 and the groove wall of the suspension groove 211. Specifically, a first spring groove is provided at the end of the connection block 41 facing the suspension groove 211. A second spring groove corresponding to the first spring groove is provided on the groove wall of the suspension groove 211. The two ends of the return spring 35 are respectively provided in the first spring groove and the second spring groove. When the connection block abuts against the first groove wall 2111, the return spring 35 is in a natural state or a slightly compressed state.

[0040] According to an embodiment of the present invention, four first spring grooves are arranged on the connecting block 41 , four second spring grooves are arranged on the groove wall of the suspension groove 211 , and the number of the return springs is four.

[0041] According to some embodiments of the present invention, the gate assembly 2 includes a gate frame 21 and two sealing plates 22, and the gate assembly 2 is provided with a frame cavity and a hanging groove 211. Specifically, the frame cavity has a first cavity 212 extending along a first direction and having first openings 2121 at both ends, and a second cavity 213 extending along a second direction and communicating with the hanging groove 211. The first cavity 212 is communicated with the pressure relief port 2211 through the first opening 2121, and the first cavity 212 is communicated with the second cavity 213. The limiting slider 34 is slidably installed in the first cavity 212. The second cavity 213 has second openings 2131 on both sides along the first direction. The provision of the second opening 2131 facilitates the installation of the auxiliary rod 32, the connecting rod 33, etc., and the second cavity 213 is communicated with the valve cavity 11 through the hanging groove 211. One end of the auxiliary rod 32 is provided on the connecting block 41, and the other end extends into the second cavity 213. Two sealing plates 22 are arranged in one-to-one correspondence with two valve ports 111, and each sealing plate 22 is used to seal with the corresponding valve port 111. The two sealing plates 22 are detachably mounted on both sides of the gate frame 21 along the first direction and are symmetrically arranged relative to the gate frame 21. The sealing plate 22 is formed with a sealing through hole 221 extending along the first direction, and the sealing through hole 221 is provided with a pressure relief port 2211. The space between the sealing plate 22, the cavity wall of the first cavity 212, and the cavity wall of the second cavity 213 constitutes the gate cavity. When the connecting block 41 abuts against the second groove wall 2112 and the two sealing plates 22 seal the corresponding valve ports 111 respectively, each limiting slider 34 fits with the sealing plate 22 on the corresponding side.

[0042] According to one embodiment of the present invention, a limiting boss 13 is provided on the bottom wall of the valve cavity 11 along the second direction, and the gate assembly 2 further includes two push plates 23 symmetrically arranged relative to the gate frame 21. The gate frame 21 has gate sliders 214 on both sides along the first direction, and the two gate sliders 214 are symmetrically arranged relative to the gate frame 21. The push plate 23 is provided with a push slide 231 extending along the second direction and slidingly matched with the gate slider 214. The push slide 231 has a first slide wall 2311 and a second slide wall 2312 that limit the position of the push plate 23 relative to the gate frame 21. The second slide wall 2312 is located on the side of the first slide wall 2311 away from the limiting boss 13. The push plate 23 has a push surface 232 on the side facing the gate frame 21, and the push surface 232 gradually tilts toward the gate frame 21 along the direction toward the limiting boss 13. The gate frame 21 has an inclined surface that matches the push surface 232. The projection of the bottom wall of each push plate 23 along the second direction at least partially falls on the top surface of the limiting boss 13, and the sealing plate 22 has a sealing sliding hole 222 that cooperates with the gate slider 214. The two sealing plates 22 are respectively located on the side of the two push plates 23 away from the gate frame 21, and are slidably installed on the gate slider 214 along the first direction. When the two push plates 23 abut against the limiting boss 13 and the gate slider 214 abuts against the first slide groove wall 2311, each sealing plate 22 seals the valve port 111 on the corresponding side. Through the arrangement of the connecting rod 33 and the limiting slider 34, after the sealing plate 22 moves toward the valve port, the limiting slider 34 moves toward the sealing plate 22, so that the pressure relief port 2211 of the sealing plate 22 and the gate cavity can basically only be connected through the first channel, so that the medium in the pressure relief port 2211 pushes the pressure relief sliding shaft 31 to move toward the outlet through the first channel.

[0043] According to some embodiments of the present invention, the gate slider 214 is composed of a long slider section and a cylindrical slide shaft section. The slider section is installed on the push slide groove 231 along the second direction. The slide shaft section is slidably matched with the sealing slide hole 222.

[0044] According to one embodiment of the present invention, the first opening 2121, the sealing slide hole 222 and the pressure relief port 2211 are coaxially arranged. When the two push plates 23 abut against the limiting boss 13 and the gate slider 214 abuts against the first slide groove wall 2311, the gate assembly 2 seals the two valve ports 111. When the connecting block 41 abuts against the second groove wall 2112 and the gate assembly 2 seals the two valve ports 111, the two limiting sliders 34 respectively fit against the two sealing plates 22.

[0045] According to some embodiments of the present invention, a limiting plate 223 is fixed on the sealing plate 22, a positioning through hole is provided on the gate frame 21, and the gate assembly 2 further includes a positioning unit, the positioning unit includes a positioning stud 24 and two positioning sleeves 25, the positioning stud 24 is at least partially disposed in the positioning through hole, the positioning sleeve 25 is a stepped shaft structure consisting of a large diameter section and a small diameter section, a step surface is formed between the large diameter section and the small diameter section, the outer diameter of the large diameter section is larger than the aperture of the positioning through hole, the small diameter section and the positioning through hole are slidably matched, and the two positioning sleeves 25 are respectively installed at both ends of the positioning stud 24 by threaded connection. The limiting plate 223 is located between the step surface and the gate frame 21, and the top of the limiting plate 223 has a semicircular groove 2231. The small diameter section of each positioning sleeve 25 passes through the semicircular groove 2231 and then extends into the positioning through hole. And the projection of the limiting plate 223 and the step surface on the gate frame 21 along the axial direction of the positioning through hole overlaps. The position of the sealing plate 22 is limited by the limiting plate 223 to prevent the sealing plate 22 from being separated from the gate slider 214.

[0046] According to some embodiments of the present invention, the sealing segment 313 has an arc-shaped sealing surface, and the pressure relief port 2211 has a truncated cone-shaped inner surface matching the spherical sealing surface.

[0047] The operation flow of the gate valve in the embodiment of the present invention is as follows:

[0048] In the valve closing step, the valve stem 4 moves downward in the second direction, driving the gate assembly 2 to move downward. Since the squeezing force between the sealing plate 22 and the inner cavity wall of the valve body 1 at the valve port 111 is small, the friction force between the sealing plate 22 and the inner cavity wall of the valve body 1 is small. The gate assembly 2 moves downward until the two push plates 23 abut against the limiting boss 13. Fig.10As shown; the valve stem 4 continues to move downward, driving the gate frame 21 to move downward relative to the push plate 23. Due to the cooperation between the push surface 232 of the push plate 23 and the gate frame 21, in the process of the gate frame 21 driving the sealing plate 22 to move downward, the push plate 23 moves toward the valve port 111 on the corresponding side and pushes the sealing plate 22 to move toward the valve port 111. When the gate slider 214 on the gate frame 21 abuts against the first slide groove wall 2311 of the push plate 23, the sealing plate 22 abuts against the inner cavity wall of the valve body 1 and closes the valve port 111; the valve stem 4 continues to descend, the gate frame 21 remains stationary due to the restriction of the push plate 23, the valve stem 4 compresses the reset spring 35, and at the same time drives the auxiliary rod 32 downward The auxiliary rod 32 drives the two limit sliders 34 to move to both sides through the connecting rod 33, so that the two limit sliders 34 no longer abut against the limit block 314, and the valve stem 4 descends until the connecting block 41 abuts against the second groove wall 2112. At this time, the limit sliders 34 are respectively fitted with the two sealing plates 22, and the medium at the inlet enters the first channel through the sealing through hole 221 at the inlet and pushes the pressure relief sliding shaft 31 to move to the outlet side until the pressure relief port 2211 at the sealing outlet is sealed. The hole wall of the limit through hole 341 on the inlet side and the sealing section 313 and the pressure relief section 312 together form a pressure relief channel, and the valve cavity 11 is connected with the medium flow channel 12 on the inlet side through the second channel and the pressure relief channel to achieve pressure relief. Figure 1 As shown, when the medium flows forward (to the right) and the gate valve is closed, the valve cavity 11 is connected to the medium flow channel 12 on the left; similarly, when the medium flows reversely (to the left) and the gate valve is closed, the valve cavity 11 is connected to the medium flow channel 12 on the right. The gate valve of this embodiment can meet the function of automatic middle cavity pressure relief after the valve is closed when the medium flows forward and reversely, and can automatically switch the sealing direction of the pressure relief port 2211 according to the flow direction of the medium, so as to realize the sealing of the pressure relief port 2211 and the overpressure protection function of the middle cavity.

[0049] In the valve opening step, the valve stem 4 moves upward in the second direction. Due to the gravity of the gate assembly 2 and the elastic force of the return spring 35, the gate assembly 2 remains stationary, and the valve stem 4 drives the auxiliary rod 32 to rise. The auxiliary rod 32 drives the two limit sliders 34 to move inward through the connecting rod 33, thereby driving the limit block 314 on the outlet side to move inward. The limit block 314 no longer abuts against the sealing plate 22. The medium flow channel 12 on the outlet side is connected to the medium flow channel 12 on the inlet side through the sealing through hole 221, the distance between the limit slider 34 and the sealing plate 22, and the valve cavity 11, so as to achieve pressure balance of the inlet and outlet medium flow channels 12. The valve stem 4 rises until the connection block 41 abuts against the first groove wall 2111. Then the valve stem 4 continues to rise and drives the gate frame 21 and the seal to rise. The push rod remains stationary due to gravity, and the gate frame 21 no longer applies pressure in the first direction to the sealing plate 22 through the push rod. The friction between the sealing plate 22 and the inner wall of the valve body 1 is reduced, thereby reducing the wear of the sealing surface between the sealing plate 22 and the valve body 1. When the gate frame 21 rises to the point where it abuts against the second slide groove wall 2312 of the push plate 23, as shown in FIG. Fig.10 As shown, the gate frame 21 drives the push plate 23 to rise together until the valve port 111 is fully opened.

[0050] The above disclosures are only several preferred embodiments of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A gate valve, characterized in that: The invention comprises a valve body (1), a gate assembly (2) and a pressure relief portion (3), wherein the valve body (1) is formed with a valve cavity (11) and two medium flow channels (12) respectively located on both sides of the valve cavity along a first direction, wherein the valve cavity (11) has valve ports (111) respectively on both sides along the first direction and connected to the medium flow channels (12) on the corresponding sides, the gate assembly (2) is slidably mounted in the valve cavity (11), and the pressure relief portion (3) comprises a first channel arranged in the gate assembly (2) and extending along the first direction, a valve port (111) slidably mounted on the first channel, and a valve port (111) connected to the medium flow channels (12) on the corresponding sides. A pressure relief slide shaft (31) is provided in the gate assembly (2), two second channels both arranged in the gate assembly (2) and communicating with the valve cavity (11), and two pressure relief ports (2211) are respectively formed on both sides of the gate assembly (2) along the first direction, each of the pressure relief ports (2211) can be communicated with the first channel and the medium flow channel (12) on the corresponding side, and both ends of the pressure relief slide shaft (31) have pressure relief structures, the two pressure relief structures are arranged in a one-to-one correspondence with the two pressure relief ports (2211), and each of the pressure relief structures is arranged along the direction toward its corresponding The pressure relief port (2211) has a sliding section (311), a pressure relief section (312) and a sealing section (313) in sequence. The sliding section (311) is slidably installed in the first channel. The outer diameters of the pressure relief section (312) and the sealing section (313) are both smaller than the outer diameter of the sliding section (311). The sealing section (313) can be sealed with the corresponding pressure relief port (2211). Each of the second channels has a connecting port (343) connected to the first channel. The pressure relief sliding shaft (31) can be connected to the pressure relief port (2211) at the inlet side. Under the action of the medium pressure of the pressure port (2211), the pressure port (2211) moves toward the pressure relief port (2211) on the outlet side until the sealing section (313) on the outlet side seals the pressure relief port (2211) on the outlet side. When the sealing section (313) on the outlet side seals the pressure relief port (2211) on the outlet side, the orthographic projections of the pressure relief section (312) and the sliding section (311) on the inlet side on the plane where the connecting port (343) on the inlet side is located overlap with the connecting port (343), and the sealing section (313) on the inlet side is located in the first channel.

2. A gate valve according to claim 1, characterized in that: A truncated cone-shaped guide transition structure (3111) is provided at the end of the sliding section (311) facing the corresponding pressure relief section (312).

3. A gate valve according to claim 2, characterized in that: When the sealing section (313) on the outlet side seals the pressure relief port (2211) on the outlet side, the orthographic projection of the guide transition structure (3111) on the inlet side on the plane where the connecting port (343) on the inlet side is located at least partially falls into the connecting port (343).

4. A gate valve according to any one of claims 1 to 3, characterized in that: The valve stem (4) further comprises a valve stem (4), one end of which has a connecting block (41), the gate assembly (2) is slidably mounted in the valve cavity (11) along a second direction, the gate assembly (2) is provided with a gate cavity and a hanging groove (211) connected to the gate cavity, the connecting block (41) is slidably mounted in the hanging groove (211) along the second direction, and the hanging groove (211) has a first groove wall (2111) and a second groove wall (2112) for limiting the position of the connecting block (41) relative to the gate assembly (2), and the pressure relief valve (211) is provided with a valve stem (4), one end of which has a connecting block (41), and the gate assembly (2 ...) The part (3) further comprises an auxiliary rod (32) and two limiting units, one end of the auxiliary rod (32) is arranged on the connecting block (41), the limiting unit comprises a connecting rod (33), a limiting slider (34) and a limiting block (314), the two limiting blocks (314) are both fixed on the pressure relief sliding shaft (31) and are located between the two pressure relief structures, the limiting slider (34) is slidably installed in the gate cavity along the first direction, and the limiting slider (34) is formed with a limiting through hole (341) extending along the first direction and a through hole (341) connected to the limiting through hole (341) The connecting block (41) is connected to the second groove wall (2112) and the gate assembly (2) seals the two valve ports (111). The two limiting through holes (341) together constitute the first channel, and the pressure relief through hole (342) constitutes the second channel. The connecting rod (33) is rotatably connected to the auxiliary rod (32) and the corresponding limiting slider (34). When the connecting block (41) abuts against the second groove wall (2112) and the gate assembly (2) seals the two valve ports (111), the two limiting sliders (34) are respectively in contact with the inner cavity walls on both sides of the gate cavity along the first direction. The valve body (111) and the valve gate assembly (2) are connected to each other, and at least one of the limit sliders (34) is away from the corresponding limit block (314); when the connecting block (41) abuts against the first groove wall (2111), each of the limit sliders (34) abuts against the corresponding limit block (314); when the connecting block (41) abuts against the first groove wall (2111) and the gate assembly (2) seals the two valve ports (111), a space for medium to pass through and communicate with the valve cavity (11) is provided between each sealing section (313) and the corresponding pressure relief port (2211).

5. A gate valve according to claim 4, characterized in that: A return spring (35) is arranged between the connecting block (41) and the groove wall of the hanging groove (211).

6. A gate valve according to claim 4, characterized in that: The gate assembly (2) comprises a gate frame (21) and two sealing plates (22). The two sealing plates (22) are arranged in a one-to-one correspondence with the two valve ports (111). Each sealing plate (22) is used for sealingly cooperating with the corresponding valve port (111). The two sealing plates (22) are respectively detachably mounted on both sides of the gate frame (21) along the first direction and are symmetrically arranged relative to the gate frame (21). A sealing through hole (221) extending along the first direction is formed on the sealing plate (22). The pressure relief port (2211) is provided on the sealing through hole (221). The gate frame (21) and the two sealing plates (22) jointly form the gate cavity. When the connecting block (41) abuts against the second groove wall (2112) and the two sealing plates (22) respectively seal the corresponding valve ports (111), each limiting slider (34) fits with the sealing plate (22) on the corresponding side.

7. A gate valve according to claim 6, characterized in that: A limiting boss (13) is provided on the bottom wall of the valve cavity (11), the gate frame (21) is provided with the hanging groove (211), and the gate frame (21) has gate sliders (214) on both sides along the first direction respectively. The gate assembly (2) also includes two push plates (23) symmetrically arranged relative to the gate frame (21), and the push plate (23) is provided with a push slide groove (231) extending along the second direction and slidably matched with the gate slider (214), and the push slide groove (231) has a first slide groove wall (2311) and a second slide groove wall (2312) for limiting the position of the push plate (23) relative to the gate frame (21), and the second slide groove wall (2312) is located on the side of the first slide groove wall (2311) away from the limiting boss (13), and the push plate (23) is oriented toward the gate frame One side of the push plate (21) has a pushing surface (232), and the pushing surface (232) gradually inclines toward the gate frame (21) along the direction toward the limiting boss (13). The projection of the bottom wall of each push plate (23) along the second direction at least partially falls on the top surface of the limiting boss (13). The sealing plate (22) has a sealing sliding hole (222) that cooperates with the gate slider (214). The two sealing plates (22) are respectively located on the side of the two push plates (23) away from the gate frame (21), and are slidably installed on the gate slider (214) along the first direction. When the two push plates (23) abut against the limiting boss (13) and the gate slider (214) abut against the first slide groove wall (2311), each sealing plate (22) respectively seals the valve port (111) on the corresponding side.

8. A gate valve according to claim 7, characterized in that: The sealing sliding hole (222) and the pressure relief port (2211) are coaxially arranged.

9. A gate valve according to claim 7, characterized in that: A limiting plate (223) is fixed on the sealing plate (22), a positioning through hole is provided on the gate frame (21), and the gate assembly (2) further comprises a positioning unit, the positioning unit comprises a positioning stud (24) and two positioning sleeves (25), the positioning stud (24) is at least partially disposed in the positioning through hole, the positioning sleeve (25) is a stepped shaft structure consisting of a large diameter section and a small diameter section, a step surface is formed between the large diameter section and the small diameter section, the outer diameter of the large diameter section is larger than the aperture of the positioning through hole, the small diameter section is slidably matched with the positioning through hole, the two positioning sleeves (25) are respectively mounted on the two ends of the positioning stud by means of threaded connection, the limiting plate (223) is located between the step surface and the gate frame (21), and the limiting plate (223) and the step surface are overlapped in projection on the gate frame (21) along the axial direction of the positioning through hole.

10. A gate valve according to claim 6, characterized in that: The sealing section (313) has an arc-shaped sealing surface, and the pressure relief port (2211) has a truncated cone-shaped inner surface that matches the spherical sealing surface.

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