Parallel double gate valve

Abstract

The application discloses a parallel double-gate plate gate valve, which comprises a valve body, a valve cover, a valve rod, a hand wheel, two gate plates and two valve seats; the inner end of the valve rod is connected with the two gate plates through a linkage mechanism; the linkage mechanism comprises a connecting block, a follower seat and two groups of reset components; the follower seat is arranged at the lower end of the connecting block; the two gate plates are arranged on the two sides of the follower seat; a limiting block is arranged at the bottom of the cavity of the valve body; when the valve rod drives the connecting block to move axially, the follower seat has a closing movement process of going up under the action of the limiting block and an opening movement process of going down under the action of its own gravity after being separated from the limiting block; when the follower seat is in the closing movement process, the connecting block drives the two gate plates to move towards the direction of approaching the corresponding valve seats; when the follower seat is in the opening movement process, the two groups of reset components drive the two gate plates to move towards the direction of moving away from the corresponding valve seats. In the opening and closing process of the valve, there is no relative friction between the sealing surface of the gate plate and the sealing surface of the valve seat, and the service life of the valve can be remarkably prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valves, in particular to a parallel double-disc gate valve. BACKGROUND

[0002] The double-disc gate valve is a parallel gate valve, which is a full opening and closing type opening and closing device, mainly applied to the pipeline system of water, sewage, petroleum, chemical industry, pharmaceutical industry and power industry, and suitable for steam, water and oil media with a nominal pressure of ≤1.0 MPa. The valve is not allowed to be used for flow regulation and emptying, and its structure is designed with double-discs. The valve stem is driven by a pneumatic cylinder or a hand wheel to drive the disc to move vertically to achieve opening and closing. The spring pre-tightening force ensures the contact of the sealing surface. The closing process is divided into two stages, i.e. fast closing (100-20% opening, 10 seconds) and slow closing (20-0% opening, 40 seconds). When power is off, the mode can be automatically switched. Some models are equipped with electric devices to support local and remote control, and are also equipped with a valve stem locking device.

[0003] The utility model patent with the application number CN201621446424.1 discloses a large-diameter parallel double-disc gate valve, which comprises a double-disc, a valve seat, a valve body, a spring and a valve stem. The double-disc is composed of two parallel discs. One end of the disc is connected with the valve seat, and the other end is provided with a plurality of spring holes in the circumferential direction. The two parallel discs are provided with springs therebetween to realize the sealing of the disc and the valve seat. The valve stem is arranged in the middle of the double-disc to drive the double-disc to move up and down. The lower end of the valve stem is connected with the valve body. This scheme increases the number of springs to increase the pre-tightening force. The springs are evenly distributed on the circumference of the disc, so that the disc can be in close contact with the valve seat at any position. This can meet the requirement of the spring pre-tightening force of the large-diameter valve.

[0004] However, the above scheme increases the number of springs to increase the pre-tightening force, which presses the disc tightly against the valve seat to make the disc sealing surface tightly cooperate with the valve seat sealing surface. However, as the normal pressure between the disc and the valve seat increases, the friction between the disc sealing surface and the valve seat sealing surface also increases, which accelerates the wear of the disc sealing surface and the valve seat sealing surface, thereby reducing the service life of the valve. SUMMARY

[0005] The purpose of the present application is to provide a parallel double-disc gate valve. In the opening and closing process of the valve, there is no relative friction between the disc sealing surface and the valve seat sealing surface. The sealing is reliable, and the service life of the valve can be significantly improved.

[0006] To achieve the above object, the present application provides the following technical scheme: parallel double-gate plate gate valve, including valve body, valve cover, valve stem, hand wheel and two gate plates, the valve body is equipped with a middle cavity, the valve body two ends are equipped with a flow channel respectively, the valve cover is installed on the upper end of the valve body, the valve stem penetrates the valve cover, and the outer end of the valve stem is connected with the hand wheel, two gate plates are symmetrically installed on the inner end of the valve stem, the junction of the flow channel and the middle cavity is provided with a valve seat for sealing cooperation with the corresponding gate plate when the valve is closed; the inner end of the valve stem is connected with the two gate plates through a linkage mechanism, the linkage mechanism includes a connecting block, a follower seat and two sets of reset components, the connecting block is connected to the inner end of the valve stem, the follower seat is vertically slidably arranged at the lower end of the connecting block, the two gate plates are symmetrically arranged on both sides of the follower seat, the bottom of the valve body middle cavity is provided with a limiting block, when the connecting block is axially moved, the follower seat has a closing movement process of moving upward under the action of the limiting block and an opening movement process of moving downward under the action of its own gravity after leaving the limiting block, and when the follower seat is in the closing movement process, the connecting block drives the two gate plates to move towards the corresponding valve seat, when the follower seat is in the opening movement process, the two sets of reset components respectively drive the two gate plates to move away from the corresponding valve seat.

[0007] By adopting the above technical scheme, the opening and closing of the gate valve is completed in two steps, taking closing as an example, when the valve stem drives the two gate plates to move downward, first, the follower seat abuts against the limiting block to form limiting, so that the follower seat and the two gate plates no longer move downward, and at this time the two gate plates are arranged opposite to the corresponding valve seat, second, the connecting block continues to move downward relative to the follower seat and pushes the two gate plates to move towards the corresponding valve seat (axial movement), until the two gate plates abut against the two valve seats respectively, the opening process is the same. Since the gate plate and the corresponding valve seat do not produce relative sliding friction during the opening and closing process of the valve, not only the sealing is reliable, but also the service life of the valve can be significantly improved.

[0008] The present application further provides that the upper end of the follower seat is vertically provided with a movable cavity, the lower end of the connecting block extends into the movable cavity, and the part of the connecting block in the movable cavity is provided with a sliding part, the outer periphery of the sliding part is provided with a plurality of first pressure stabilizing grooves extending vertically, the outer circular surface of the sliding part is fitted with the inner circular surface of the movable cavity, and the position of the follower seat corresponding to the upper end of the movable cavity is threadedly connected with a limiting ring for limiting when abutting against the sliding part.

[0009] By adopting the above technical scheme, the axial relative movement connection structure of the connecting block and the follower seat can be realized, the connection structure is simple and reliable, and the disassembly and assembly are very convenient.

[0010] The application is further provided with a driving chamber opened vertically in the inner end of the movable cavity of the follower seat, a guide hole communicated with the driving chamber is opened on each side of the follower seat, a guide column is arranged on the side of the gate plate away from the corresponding valve seat, the guide column is movably arranged in the corresponding guide hole, a driving block is threadedly connected to the lower end of the connecting block, a driving slope is arranged on the lower end of the driving block for pushing the guide column to move towards the outer end of the guide hole when descending, a vertical stationary surface is arranged on the upper end of the driving slope for slidingly cooperating with the inner end of the guide column, and the gate plate abuts against the corresponding valve seat when the inner end of the guide column abuts against the vertical stationary surface of the driving block.

[0011] By adopting the above technical scheme, when the gate valve closing process reaches the second step, the driving slope on the driving block at the lower end of the connecting block cooperates with the guide column on the gate plate, the inner end of the guide column slides along the surface of the driving slope as the driving block descends, the gate plate is pushed outward, and when the inner end of the guide column slides onto the vertical stationary surface of the driving block, the guide column no longer moves outward, and at this time, the gate plate abuts against the corresponding valve seat, thereby when the follower seat moves relative to the connecting block, the gate plate is caused to move close to or away from the corresponding valve seat.

[0012] The application is further provided with a reset assembly including a reset rod and a first reset spring, a fixed block is threadedly connected to the inner end of the driving chamber, a spring cavity is arranged on the end of the guide column away from the valve seat, and a limiting pressure ring is threadedly connected to the outer end of the spring cavity, the reset rod penetrates through the limiting pressure ring, one end of the reset rod is threadedly connected to the side of the fixed block, the other end of the reset rod extends into the spring cavity, a guide flange with an outer circular surface abutting against the inner circular surface of the spring cavity is arranged on the end of the reset rod in the spring cavity, and the two ends of the first reset spring abut against the guide flange and the limiting pressure ring respectively.

[0013] By adopting the above technical scheme, when the driving block ascends and gradually moves away from the guide column, the reset spring of the reset assembly releases energy and pushes the limiting pressure ring on the guide column, so that the gate plate moves away from the corresponding valve seat, realizing the movement of the gate plate first axially moving away from the valve seat and then vertically lifting, and ensuring that the gate plate sealing surface and the valve seat sealing surface are free of friction during the opening process.

[0014] The application is further provided with a pressure relief assembly, the fixed block is provided with an upper hole and a lower hole with increasing diameters from top to bottom, the valve core penetrates the upper hole and the lower hole, the part of the valve core in the lower hole is provided with a guide part with an outer circular surface matched with the inner circular surface of the lower hole, the outer periphery of the guide part is provided with a plurality of second pressure stabilizing grooves extending vertically, the two ends of the second reset spring are respectively abutted with the valve core and the follow-up seat for applying an upward pre-tightening force to the valve core, so that the upper end of the valve core protrudes out of the upper hole when the driving block does not contact the valve core; the middle part of the gate plate is provided with a pressure relief outer hole axially connected with the spring cavity, the reset rod is provided with a pressure relief inner hole axially penetrating, and the outer circular surface of the guide flange is provided with a first sealing ring for sealing cooperation with the inner circular surface of the spring cavity, the end of the reset rod away from the gate plate is provided with a second sealing ring between the fixed block, the side part of the fixed block is provided with two flow holes for connecting the two pressure relief inner holes with the upper hole, the inner circular surface of the upper hole is respectively provided with a third sealing ring for sealing cooperation with the outer circular surface of the valve core at the positions above and below the flow holes, and the outer periphery of the valve core is provided with an annular switching groove, the annular switching groove connects the two flow holes when the driving block does not contact the valve core, and the annular switching groove is completely dislocated from the two flow holes and disconnects the two flow holes when the upper end of the valve core is completely pressed into the upper hole by the driving block.

[0015] By adopting the above technical scheme, the pressure relief assembly is additionally arranged, that is, at the moment of closing the valve, the driving block first abuts the gate plate on the corresponding valve seat to pre-close the valve, at this time, the two flow holes on the fixed block are connected by the annular switching groove on the valve core, and the upstream and downstream flow channels are still in the connected state, then the driving block continues to descend, the inner end of the guide column slides on the vertical static surface of the driving block, at the same time, the driving block presses the valve core, the upper end of the valve core is completely pressed into the upper hole of the fixed block, the annular switching groove on the valve core is completely dislocated from the two flow holes, so that the two flow holes are disconnected, at this time, the upstream and downstream flow channels are completely closed, and at the moment of opening the valve, the two flow holes are connected first to pre-press, then the gate plate is separated from the corresponding valve seat to completely open the valve, which reduces the fluid pressure received by the gate plate at the moment of opening and closing, and makes the opening and closing operation more easy.

[0016] The application is further provided with an inner hexagonal groove on the end of the reset rod close to the corresponding gate plate, and the cross-sectional area of the pressure relief outer hole is larger than that of the inner hexagonal groove.

[0017] By adopting the above technical scheme, the tool can pass through the pressure relief outer hole of the gate plate and be inserted into the inner hexagonal groove of the reset rod, the reset rod is rotated, and the reset rod is screwed into or out of the corresponding threaded groove on the fixed block, which facilitates the disassembly and assembly of the reset rod.

[0018] The application is further provided with a positioning groove in the lower end of the driving block, a silica gel block is arranged in the positioning groove, a locking screw is arranged in the upper end of the driving block, the lower end of the locking screw is threadedly connected with the upper end of the silica gel block, the silica gel block is locked in the positioning groove, and a gap groove is further arranged in the upper end of the driving block for embedding the head of the locking screw.

[0019] By adopting the above technical scheme, the silica gel block is arranged in the lower end of the driving block for cooperating with the upper end of the valve core, and the soft contact mode is adopted to avoid the bending damage of the valve core caused by frequent rigid impact.

[0020] The application is further provided with an operation part with a regular hexagon outer contour arranged on the outer periphery of the fixing block, and a silica gel pad is arranged between the operation part and the follow-up seat.

[0021] By adopting the above technical scheme, the fixing block is convenient to disassemble and assemble, the silica gel pad provides a pre-tightening force for the fixing block, the thread friction force borne by the fixing block is increased, and the firmness of the installation is improved.

[0022] The application is further provided with a screw rod part arranged in the lower end of the valve rod, a screw hole arranged in the upper end of the connecting block, the screw rod part is threadedly matched with the screw hole, and the connecting block is fixedly connected with the screw rod part through a bolt.

[0023] By adopting the above technical scheme, the connection structure of the two is simple and very firm.

[0024] The application is further provided with a limiting plate arranged between the lower end of the valve rod and the upper end of the connecting block, a guide block is arranged at the left end and the right end of the limiting plate respectively, a guide groove is arranged in the upper end of the gate plate on the side close to the corresponding valve seat in the transverse direction, the width of the guide groove is equivalent to the width of the guide block, and the lower end of the guide block always slides in the guide groove when the gate plate moves in the direction close to or away from the corresponding valve seat.

[0025] By adopting the above technical scheme, the travel of the gate plate is limited, the gate plate is guided, the gate plate does not rotate in the process of moving in the direction close to or away from the corresponding valve seat, and the stability of the movement of the gate plate is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural schematic view of the whole when the gate plate and the valve seat abut against each other.

[0027] Figure 2 It is an enlarged structural schematic view of a part when the gate plate and the valve seat abut against each other.

[0028] Figure 3 It is Figure 2 an enlarged structural schematic view of the A part in the middle.

[0029] Figure 4 Fig. 6 is a schematic view of the overall structure of the gate and the valve seat of the application;

[0030] Figure 5 Fig. 7 is a schematic view of the local enlarged structure of the gate and the valve seat of the application;

[0031] Figure 6 Fig. 8 is a schematic view of the enlarged structure of the middle B part. Figure 5

[0032] Fig. 1: valve body; 2, valve cover; 3, valve stem; 4, hand wheel; 5, gate; 6, middle cavity; 7, flow channel; 8, valve seat; 9, linkage mechanism; 10, connecting block; 11, follower seat; 12, reset assembly; 13, limiting block; 14, movable cavity; 15, sliding part; 16, first pressure stabilizing groove; 17, limiting ring; 18, driving chamber; 19, guide hole; 20, guide column; 21, driving block; 22, driving inclined surface; 23, vertical stationary surface; 25, reset rod; 26, first reset spring; 27, fixed block; 28, spring cavity; 29, limiting pressure ring; 30, guide flange; 31, pressure relief assembly; 32, valve core; 33, second reset spring; 34, upper hole; 35, lower hole; 36, guide part; 37, second pressure stabilizing groove; 38, pressure relief outer hole; 39, pressure relief inner hole; 40, first sealing ring; 41, second sealing ring; 43, overflow hole; 44, third sealing ring; 45, annular switching groove; 46, inner hexagonal groove; 47, positioning groove; 48, silica gel block; 49, locking screw; 50, accommodation groove; 51, operating part; 52, silica gel pad; 53, screw part; 54, screw hole; 55, bolt; 56, limiting plate; 57, guide block; 58, guide groove. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0034] Embodiment: as shown in the accompanying drawings Figures 1-6 ​The parallel double gate valve shown, including valve body 1, valve cover 2, valve stem 3, hand wheel 4 and two gate plates 5, the valve body 1 is provided with a cavity 6, the valve body 1 both ends are respectively provided with a flow channel 7, the valve cover 2 is installed on the upper end of valve body 1, the valve stem 3 penetrates through the valve cover 2, and the outer end of the valve stem 3 is connected with the hand wheel 4, two gate plates 5 are symmetrically installed on the inner end of the valve stem 3, the junction of the flow channel 7 and the cavity 6 is provided with a valve seat 8 for sealing cooperation with the corresponding gate plate 5 when the valve is closed, the valve seat 8 is an integral structure with the valve body 1, and can also be a welded structure; the inner end of the valve stem 3 is connected with the two gate plates 5 through a linkage mechanism 9, the two gate plates 5 are arranged in parallel, the linkage mechanism 9 includes a connecting block 10, a follow-up seat 11 and two sets of reset components 12, the connecting block 10 is connected to the inner end of the valve stem 3, the follow-up seat 11 is vertically slidably arranged at the lower end of the connecting block 10, the two gate plates 5 are symmetrically arranged on both sides of the follow-up seat 11, the bottom of the cavity 6 of the valve body 1 is provided with a limiting block 13, the limiting block 13 is an integral structure with the valve body 1, and can also be a welded structure, when the valve stem 3 drives the connecting block 10 to move axially, the follow-up seat 11 has a closing movement process of moving upward under the action of the limiting block 13 and an opening movement process of moving downward under the action of its own gravity after leaving the limiting block 13, and when the follow-up seat 11 is in the closing movement process, the connecting block 10 drives the two gate plates 5 to move towards the corresponding valve seat 8, when the follow-up seat 11 is in the opening movement process, the two sets of reset components 12 respectively drive the two gate plates 5 to move away from the corresponding valve seat 8. The opening and closing of the gate valve is completed in two steps, taking closing as an example, when the valve stem 3 drives the two gate plates 5 to move downward, first, the follow-up seat 11 abuts against the limiting block 13 to constitute limiting, so that the follow-up seat 11 and the two gate plates 5 no longer move downward, and at this time the two gate plates 5 are arranged opposite the corresponding valve seat 8, second, the connecting block 10 continues to move downward relative to the follow-up seat 11 and drives the two gate plates 5 to move towards the corresponding valve seat 8 (axial movement), until the two gate plates 5 abut against the two valve seats 8 respectively, the opening process is the same. Since there is no relative sliding friction between the gate plate 5 and the corresponding valve seat 8 during the opening and closing process of the valve, not only the sealing is reliable, but also the service life of the valve can be significantly improved.

[0035] As shown in the accompanying drawings Figure 2As shown, the upper end of the follow-up seat 11 is vertically provided with a movable cavity 14, the lower end of the connecting block 10 extends into the movable cavity 14, and the part of the connecting block 10 located in the movable cavity 14 is provided with a sliding part 15, the height of the sliding part 15 is less than the height of the movable cavity 14, the outer periphery of the sliding part 15 is provided with a plurality of first pressure stabilizing grooves 16 extending vertically to ensure that the sliding part 15 can move up and down smoothly, the outer circular surface of the sliding part 15 is fitted with the inner circular surface of the movable cavity 14, and the position corresponding to the upper end of the movable cavity 14 of the follow-up seat 11 is threadedly connected with a limiting ring 17 for limiting when the sliding part 15 abuts against it, that is, the outer circular surface of the limiting ring 17 has external threads, and the inner circular surface of the movable cavity 14 of the follow-up seat 11 has internal threads. This design can realize the axial relative movement of the connecting block 10 and the follow-up seat 11, and the connecting structure is simple and reliable, and very convenient to disassemble and assemble.

[0036] As shown in the accompanying drawings Figure 3 and the accompanying drawings Figure 6 As shown, the inner end of the movable cavity 14 of the follow-up seat 11 is vertically provided with a driving chamber 18, the two sides of the follow-up seat 11 are respectively provided with a guide hole 19 in communication with the driving chamber 18, the side of the gate plate 5 away from the corresponding valve seat 8 is provided with a guide column 20, the guide column 20 is movably arranged in the corresponding guide hole 19, the outer diameter of the guide column 20 is equivalent to the inner diameter of the guide hole 19, and the lower end of the connecting block 10 is threadedly connected with a driving block 21, that is, the lower end of the connecting block 10 has a threaded groove, and the upper end of the driving block 21 has external threads matched with the threaded groove, the lower end of the driving block 21 is provided with a driving inclined surface 22 for pushing the guide column 20 to move towards the outer end of the guide hole 19 when descending, that is, a large upper and small lower conical surface, and a vertical stationary surface 23 arranged at the upper end of the driving inclined surface 22 for slidingly matching with the inner end of the guide column 20, and when the inner end of the guide column 20 abuts against the vertical stationary surface of the driving block 21, the gate plate 5 abuts tightly against the corresponding valve seat 8. When the gate valve closing process proceeds to the second step, the driving inclined surface 22 on the driving block 21 at the lower end of the connecting block 10 cooperates with the guide column 20 on the gate plate 5, as the driving block 21 descends, the inner end of the guide column 20 slides along the surface of the driving inclined surface 22, and the gate plate 5 is pushed outward until the inner end of the guide column 20 slides to the vertical stationary surface 23 of the driving block 21, the guide column 20 no longer moves outward, and at this time the gate plate 5 abuts tightly against the corresponding valve seat 8. Thus, when the follow-up seat 11 and the connecting block 10 move relative to each other, the gate plate 5 is caused to move close to or away from the corresponding valve seat 8.

[0037] As shown in the accompanying drawings Figure 3 and the accompanying drawings Figure 6As shown, the reset assembly 12 comprises a reset rod 25 and a first reset spring 26, and a fixed block 27 is threadedly connected to the inner end of the drive chamber 18, that is, the inner end of the drive chamber 18 has a threaded groove, and the lower end of the fixed block 27 has external threads matched with the threaded groove, one end of the guide column 20 away from the valve seat 8 is provided with a spring cavity 28, and the outer end of the spring cavity 28 is threadedly connected with a limiting pressure ring 29, that is, the outer circular surface of the guide column 20 has external threads, and the limiting pressure ring 29 has internal threads matched with the external threads, the reset rod 25 penetrates through the limiting pressure ring 29, one end of the reset rod 25 is threadedly connected to the side of the fixed block 27, and the other end of the reset rod 25 extends into the spring cavity 28, and the end of the reset rod 25 in the spring cavity 28 is provided with a guide flange 30 with an outer circular surface matched with the inner circular surface of the spring cavity 28, and the two ends of the first reset spring 26 are respectively abutted against the guide flange 30 and the limiting pressure ring 29. When the drive block 21 moves upward and gradually away from the guide column 20, the reset spring of the reset assembly 12 releases energy and pushes the limiting pressure ring 29 on the guide column 20, so that the gate plate 5 moves away from the corresponding valve seat 8, realizing the movement of the gate plate 5 first axially away from the valve seat 8 and then vertically lifting, and ensuring that there is no friction between the sealing surface of the gate plate 5 and the sealing surface of the valve seat 8 during the opening process.

[0038] As shown in the accompanying drawings Figure 3 and the accompanying drawings Figure 6As shown, the gate valve further comprises a pressure relief assembly 31, the pressure relief assembly 31 comprising a valve core 32 and a second reset spring 33, the fixed block 27 being provided with an upper hole 34 and a lower hole 35 with increasing diameters from top to bottom, the upper hole 34 and the lower hole 35 being coaxially arranged, the valve core 32 penetrating the upper hole 34 and the lower hole 35, a guiding portion 36 with an outer circular surface being fitted with an inner circular surface of the lower hole 35 being arranged at a position of the valve core 32 in the lower hole 35, a plurality of second pressure stabilizing grooves 37 extending vertically being arranged on an outer periphery of the guiding portion 36 to ensure smooth up-and-down movement of the guiding portion 36, and two ends of the second reset spring 33 being respectively abutted with the valve core 32 and the follower seat 11 to apply an upward pre-tightening force to the valve core 32, so that the valve core 32 is partially extended out of the upper hole 34 when the driving block 21 is not in contact with the valve core 32; an outer pressure relief hole 38 communicating with the spring cavity 28 is arranged in a middle portion of the gate plate 5 along an axial direction, an inner pressure relief hole 39 is arranged on the reset rod 25 along an axial direction, a first sealing ring 40 for sealing cooperation with an inner circular surface of the spring cavity 28 is arranged on an outer circular surface of the guiding flange 30, a second sealing ring 41 is arranged between an end of the reset rod 25 away from the gate plate 5 and the fixed block 27, two flow-through holes 43 for connecting the two inner pressure relief holes 39 and the upper hole 34 are arranged on side portions of the fixed block 27, one third sealing ring 44 for sealing cooperation with an outer circular surface of the valve core 32 is arranged on the inner circular surface of the upper hole 34 corresponding to positions above and below the flow-through holes 43, and an annular switching groove 45 is arranged on an outer periphery of the valve core 32, the annular switching groove 45 connects the two flow-through holes 43 when the driving block 21 is not in contact with the valve core 32, and the annular switching groove 45 is completely misaligned with the two flow-through holes 43 to disconnect the two flow-through holes 43 when the driving block 21 completely presses the upper end of the valve core 32 into the upper hole 34. By adding the pressure relief assembly 31, the gate plate 5 is first pressed against the corresponding valve seat 8 by the driving block 21 to pre-close the valve at the moment of closing the valve, at this time, the two flow-through holes 43 on the fixed block 27 are connected by the annular switching groove 45 on the valve core 32, and the upstream and downstream flow passages 7 are still in a connected state, then the driving block 21 continues to move downward, the inner end of the guide column 20 slides on the vertical stationary surface of the driving block 21, at the same time, the driving block 21 presses the valve core 32 downward, the upper end of the valve core 32 is completely pressed into the upper hole 34 of the fixed block 27, the annular switching groove 45 on the valve core 32 is completely misaligned with the two flow-through holes 43, so that the two flow-through holes 43 are disconnected, at this time, the upstream and downstream flow passages 7 are completely closed, and the same is true at the moment of opening the valve, that is, the two flow-through holes 43 are first connected for pre-pressure relief, then the gate plate 5 is separated from the corresponding valve seat 8 to completely open the valve, which reduces the fluid pressure received by the gate plate 5 at the moment of opening and closing, and makes the opening and closing operation more convenient.

[0039] As shown in the accompanying drawings Figure 3 and the accompanying drawings Figure 6As shown, the reset rod 25 has an internal hexagonal slot 46 at one end near the corresponding gate plate 5, and the cross-sectional area of ​​the pressure relief outer hole 38 is larger than the cross-sectional area of ​​the internal hexagonal slot 46, that is, the orthographic projection of the internal hexagonal slot 46 is within the cross-sectional area of ​​the pressure relief outer hole 38. A tool can be inserted through the pressure relief outer hole 38 of the gate plate 5 and into the internal hexagonal slot 46 of the reset rod 25. By rotating the reset rod 25, it can be screwed into or out of the corresponding threaded groove on the fixing block 27, which facilitates the disassembly and assembly of the reset rod 25.

[0040] As attached Figure 3 and attached Figure 6 As shown, the lower end of the drive block 21 has a positioning groove 47, and a silicone block 48 is placed inside the positioning groove 47. The lower end of the silicone block 48 protrudes outside the positioning groove 47. The upper end of the drive block 21 is provided with a locking screw 49, which is an internal hexagon screw. The lower end of the locking screw 49 is threadedly connected to the upper end of the silicone block 48, locking the silicone block 48 in the positioning groove 47. That is, the drive block 21 has a through hole for the locking screw 49 to pass through, and the upper end of the silicone block 48 has a threaded hole for the locking screw 49 to be screwed in. The threaded hole does not penetrate the silicone block 48. The drive block 21 also has a relief groove 50 for the screw head of the locking screw 49 to be inserted. The silicone block 48 is provided at the lower end of the drive block 21 to cooperate with the upper end of the valve core 32, using a soft contact method to avoid the valve core 32 from being bent and damaged by frequent rigid impacts.

[0041] As attached Figure 3 and attached Figure 6 As shown, the fixing block 27 has an operating part 51 with a regular hexagonal outer contour on its outer periphery, and a silicone pad 52 is sandwiched between the operating part 51 and the follower seat 11. This design not only facilitates the installation and removal of the fixing block 27, but also provides a pre-tightening force to the fixing block 27 with the silicone pad 52, increasing the thread friction force on the fixing block 27 and improving its installation firmness.

[0042] As attached Figure 2 As shown, the lower end of the valve stem 3 is provided with a screw part 53, and the upper end of the connecting block 10 is provided with a screw hole 54. The screw part 53 is threadedly engaged with the screw hole 54, and the connecting block 10 and the screw part 53 are fixedly connected by a pin 55. The connection structure between the two is simple and very strong.

[0043] As attached Figure 2 and attached Figure 4As shown, the lower end of the valve rod 3 and the upper end of the connecting block 10 are clamped between a limiting plate 56, the left and right ends of the limiting plate 56 are respectively provided with a guide block 57, the upper end of the flashboard 5 close to the corresponding valve seat 8 side is provided with a guide groove 58 along the transverse direction, the width of the guide groove 58 is equivalent to the width of the guide block 57, and when the flashboard 5 moves close to or away from the corresponding valve seat 8, the lower end of the guide block 57 always slides in the guide groove 58. It can not only limit the stroke of the flashboard 5, but also guide the flashboard 5, so that it will not rotate during the movement close to or away from the corresponding valve seat 8, and the stability of the movement of the flashboard 5 is improved.

Claims

1. Parallel double gate plate gate valve, including valve body (1), valve cover (2), valve rod (3), hand wheel (4) and two gate plates (5), the valve body (1) is provided with middle cavity (6) inside, the valve body (1) is provided with one flow channel (7) at both ends respectively, the valve cover (2) is installed on the upper end of valve body (1), the valve rod (3) penetrates the valve cover (2), and the outer end of valve rod (3) is connected with hand wheel (4), two gate plates (5) are symmetrically installed on the inner end of valve rod (3), the junction of flow channel (7) and middle cavity (6) is provided with valve seat (8) for sealing cooperation with corresponding gate plate (5) when the valve is closed;Its characterized in that: The inner end of the valve rod (3) is connected with the two gate plates (5) through a linkage mechanism (9), the linkage mechanism (9) comprises a connecting block (10), a follower seat (11) and two sets of reset assemblies (12), the connecting block (10) is connected to the inner end of the valve rod (3), the follower seat (11) is vertically slidably arranged at the lower end of the connecting block (10), the two gate plates (5) are symmetrically arranged on the two sides of the follower seat (11), the bottom of the middle cavity (6) of the valve body (1) is provided with a limiting block (13), when the valve rod (3) drives the connecting block (10) to move axially, the follower seat (11) has a closing movement process under the action of the limiting block (13) and an opening movement process under the action of its own gravity after being separated from the limiting block (13), and when the follower seat (11) is in the closing movement process, the connecting block (10) drives the two gate plates (5) to move towards the corresponding valve seat (8) direction, when the follower seat (11) is in the opening movement process, the two sets of reset assemblies (12) respectively drive the two gate plates (5) to move away from the corresponding valve seat (8) direction; the inner end of the movable cavity (14) of the follower seat (11) is vertically provided with a driving chamber (18); the reset assembly (12) comprises a reset rod (25) and a first reset spring (26), the inner end of the driving chamber (18) is threadedly connected with a fixed block (27); further comprising a pressure relief assembly (31), the pressure relief assembly (31) comprises a valve core (32) and a second reset spring (33), the fixed block (27) is sequentially provided with an upper hole (34) and a lower hole (35) with increasing diameters from top to bottom, the valve core (32) penetrates the upper hole (34) and the lower hole (35), the part of the valve core (32) located in the lower hole (35) is provided with a guide portion (36) with an outer circular surface matched with the inner circular surface of the lower hole (35), the outer periphery of the guide portion (36) is provided with a plurality of second pressure stabilizing grooves (37) extending vertically, the two ends of the second reset spring (33) are respectively abutted with the valve core (32) and the follower seat (11) for applying an upward pre-tightening force to the valve core (32), so that when the driving block (21) does not contact the valve core (32), the upper end of the valve core (32) partially extends out of the upper hole (34); the middle part of the gate plate (5) is axially provided with a pressure relief outer hole (38) in communication with the spring cavity (28), the reset rod (25) is axially provided with a pressure relief inner hole (39), the side of the fixed block (27) is provided with two flow holes (43) for connecting the two pressure relief inner holes (39) and the upper hole (34), the outer periphery of the valve core (32) is provided with an annular switching groove (45), when the driving block (21) does not contact the valve core (32), the annular switching groove (45) connects the two flow holes (43), when the driving block (21) completely presses the upper end of the valve core (32) into the upper hole (34), the annular switching groove (45) is completely dislocated from the two flow holes (43) and disconnects the two flow holes (43).

2. The parallel double-disk gate valve of claim 1, wherein: The upper end of the follow-up seat (11) is vertically provided with a movable cavity (14), the lower end of the connecting block (10) extends into the movable cavity (14), and the part of the connecting block (10) in the movable cavity (14) is provided with a sliding part (15), the outer periphery of the sliding part (15) is provided with a plurality of first pressure stabilizing grooves (16) extending vertically, the outer circular surface of the sliding part (15) is fitted with the inner circular surface of the movable cavity (14), and the follow-up seat (11) is threadedly connected with a limiting ring (17) corresponding to the upper end of the movable cavity (14) to form limiting when abutting against the sliding part (15).

3. The parallel double-disk gate valve of claim 2, wherein: The two sides of the follow-up seat (11) are respectively provided with a guide hole (19) communicating with the driving chamber (18), the side of the flashboard (5) away from the corresponding valve seat (8) is provided with a guide column (20), the guide column (20) is movably arranged in the corresponding guide hole (19), the lower end of the connecting block (10) is threadedly connected with a driving block (21), the lower end of the driving block (21) is provided with a driving inclined surface (22) for pushing the guide column (20) to move towards the outer end of the guide hole (19) when descending, and a vertical stationary surface (23) is arranged at the upper end of the driving inclined surface (22) to form a sliding fit with the inner end of the guide column (20), and when the inner end of the guide column (20) abuts against the vertical stationary surface of the driving block (21), the flashboard (5) abuts tightly against the corresponding valve seat (8).

4. The parallel double-disk gate valve of claim 3, wherein: The end of the guide column (20) away from the valve seat (8) is provided with a spring cavity (28), the outer end of the spring cavity (28) is threadedly connected with a limiting pressure ring (29), the reset rod (25) penetrates through the limiting pressure ring (29), one end of the reset rod (25) is threadedly connected with the side of the fixed block (27), the other end of the reset rod (25) extends into the spring cavity (28), the end of the reset rod (25) in the spring cavity (28) is provided with a guide flange (30) with an outer circular surface fitted with the inner circular surface of the spring cavity (28), and the two ends of the first reset spring (26) abut tightly against the guide flange (30) and the limiting pressure ring (29) respectively.

5. The parallel double-disk gate valve of claim 4, wherein: The outer circular surface of the guide flange (30) is mounted with a first sealing ring (40) for sealing fit with the inner circular surface of the spring cavity (28), the second sealing ring (41) is arranged between the end of the reset rod (25) away from the flashboard (5) and the fixed block (27), and the inner circular surface of the upper hole (34) is respectively provided with a third sealing ring (44) corresponding to the positions above and below the overflow hole (43) for sealing fit with the outer circular surface of the valve core (32).

6. The parallel double-disk gate valve of claim 1, wherein: The end of the reset rod (25) close to the corresponding flashboard (5) is provided with an internal hexagonal groove (46), and the cross-sectional area of the pressure relief outer hole (38) is larger than that of the internal hexagonal groove (46).

7. The double parallel gate valve according to claim 1, characterized in that: The lower end of the driving block (21) is provided with a positioning groove (47), and a silica gel block (48) is arranged in the positioning groove (47); the upper end of the driving block (21) is provided with a locking screw (49), the lower end of the locking screw (49) is threadedly connected with the upper end of the silica gel block (48), the silica gel block (48) is locked in the positioning groove (47), and the driving block (21) is further provided with a gap groove (50) for embedding the screw head of the locking screw (49).

8. The parallel double-disk gate valve of claim 4, wherein: The outer periphery of the fixing block (27) is provided with an operation part (51) with a regular hexagonal outer contour, and the operation part (51) and the follow-up seat (11) are clamped with a silica gel pad (52) therebetween.

9. The double parallel gate valve according to claim 1, characterized in that: The lower end of the valve rod (3) is provided with a screw rod part (53), the upper end of the connecting block (10) is provided with a screw hole (54), the screw rod part (53) is threadedly matched with the screw hole (54), and the connecting block (10) and the screw rod part (53) are fixedly connected through a bolt (55).

10. The parallel double-disk gate valve of claim 9, wherein: The lower end of the valve rod (3) and the upper end of the connecting block (10) are clamped with a limiting plate (56), the left and right ends of the limiting plate (56) are respectively provided with a guide block (57), the upper end of the flashboard (5) close to the corresponding valve seat (8) is provided with a guide groove (58) in the transverse direction, the width of the guide groove (58) is equivalent to the width of the guide block (57), and when the flashboard (5) moves close to or away from the corresponding valve seat (8), the lower end of the guide block (57) always slides in the guide groove (58).

Images