Sealing enhancement type knife gate valve

Abstract

The utility model discloses a sealing enhancement type knife gate valve. According to the technical scheme, the gate valve is characterized by comprising two half valve bodies connected oppositely, a U-shaped sealing strip limited between the two half valve bodies, a gate plate capable of making contact with the sealing strip, a valve rod driving the gate plate to move, a handle used for driving the valve rod to move and filler allowing the gate plate to penetrate through and located at ports of the half valve bodies. The two half valve bodies are provided with sealing grooves for jointly containing the sealing strip, the face, attached to the sealing strip, of the gate plate is provided with a sealing part protruding towards the sealing strip, and the sealing strip is provided with an attaching groove partially matched with the sealing part. The sealing part is partially inserted into the attaching groove and tightly attached to the inner wall of the attaching groove, so that the sealing part cannot move in the axis direction of the half valve body relative to the attaching groove, and the problems that in the prior art, opening and closing are difficult, the needed torque is large, and leakage is generated due to the fact that a gate plate is prone to deviation are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of gate valves, and more specifically to a sealing enhanced knife gate valve. Background Art

[0002] The wafer-type knife gate valve is widely used in many low-pressure pipeline transportation systems due to its many advantages such as short structure length, light weight, easy installation and maintenance. The existing technology usually uses hard sealing for the seal between the gate and the valve body, that is, the edge of the gate fits tightly with the inner wall of the valve body. After the edge of the gate touches the inner wall of the valve body for many times, the edge of the gate and the inner wall of the valve body are damaged, thus affecting the sealing performance. There is a Chinese patent with application number 201020542406X that discloses a wafer-type gate valve, which has a sealing groove on the inner wall of the valve body and a soft sealing strip installed in the sealing groove. The sealing strip is U-shaped and can fit with the edge of the gate. Although it solves the problem of easy wear between the edge of the gate and the inner wall of the valve body, However, there are still defects. First, the peripheral wall of the gate and the inner wall of the sealing strip are both flat, so the contact area between the gate and the sealing strip is large. This will cause the friction on both sides of the gate to be large when the gate moves up and down relative to the sealing strip, resulting in increased torque required for the handle, affecting the opening and closing efficiency of the gate. At the same time, the handle or the valve stem is easily damaged due to the increased force, shortening the service life of the knife gate valve; second, the peripheral wall of the gate and the inner wall of the sealing strip are both flat in design, so there is a situation where one side of the gate is subjected to force and deviates relative to the sealing strip, causing the gate and the sealing strip to be misaligned and leak. Utility Model Content

[0003] In view of the deficiencies in the prior art, the utility model aims to provide a knife gate valve which is easy to open and close and has stable sealing.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a sealing enhanced knife gate valve, comprising two half valve bodies connected in opposite directions, a U-shaped sealing strip limited between the two half valve bodies, a gate plate capable of contacting the sealing strip, a valve stem for driving the gate plate to move, a handle for driving the valve stem to move, and a packing for the gate plate to pass through and located at the port of the half valve body, the two half valve bodies are both provided with a sealing groove for accommodating the sealing strip, a sealing portion convex toward the sealing strip is provided on the surface of the gate plate that fits with the sealing strip, the sealing strip is provided with a fitting groove that matches a part of the sealing portion, and the sealing portion is partially inserted into the fitting groove and fits tightly with the inner wall of the fitting groove so that the sealing portion cannot move relative to the fitting groove along the axial direction of the half valve body.

[0005] As a further improvement of the present invention, the cross section of the sealing portion in the direction of the U-shaped profile of the sealing strip is trapezoidal or triangular.

[0006] As a further improvement of the utility model, the edges of the two sealing grooves adjacent to the gate plate are beveled to form drainage surfaces parallel to the corresponding side surfaces of the sealing portion.

[0007] As a further improvement of the utility model, the two surfaces of the sealing strip connected to the opening edge of the fitting groove are both arc-shaped and protrude toward the gaps between the two drainage surfaces and the corresponding side surfaces of the sealing part.

[0008] As a further improvement of the present invention, a sealing layer which can be clamped between the two half valve bodies and has the same profile as the sealing strip is arranged on the outer wall of the sealing strip.

[0009] As a further improvement of the present invention, two connection layers are arranged on the outer wall of the sealing layer, the two connection layers are respectively arranged adjacent to the two ends of the sealing layer, and both of the two connection layers are provided with a plurality of through holes for connecting bolts to pass through.

[0010] As a further improvement of the utility model, it also includes a sealing ring that can be passed through by the gate plate and is located below the packing. The sealing ring is fixedly connected to the sealing strip and the height of the sealing ring is less than or equal to the height of the two ends of the sealing strip.

[0011] As a further improvement of the utility model, a V-shaped debris containing groove with a tip far away from the gate plate is provided on the inner wall of the sealing ring.

[0012] As a further improvement of the utility model, a dust cover for accommodating a gate plate or a valve stem is arranged above the two half valve bodies.

[0013] As a further improvement of the utility model, an indicator is provided on the portion of the valve stem located in the dust cover, and an observation hole parallel to the moving track of the indicator is opened on the dust cover.

[0014] The beneficial effects of the utility model are as follows: the sealing part is partially inserted into the fitting groove and fits tightly with the inner wall of the fitting groove, so that the sealing part cannot move relative to the fitting groove along the axis direction of the semi-valve body. Compared with the prior art, such a design can partially insert the gate plate and the sealing strip together, thereby reducing the contact area between the gate plate and the sealing strip, thereby reducing the resistance generated when the gate plate moves relative to the sealing strip, and the torque required for the handle is reduced, which is convenient for the rapid opening and closing of the gate plate, reduces the deformation of the handle or the valve stem, and extends the service life of the handle and the valve stem; during the movement of the gate plate, one side of the gate plate is subjected to force and cannot be offset relative to the sealing strip, ensuring that the bottom end part of the gate plate can be smoothly inserted into the sealing strip, ensuring the structural stability and closing accuracy of the gate plate; when the gate plate is in a closed state, one side of the gate plate is subjected to force and cannot be offset relative to the sealing strip, which increases the tightness between one side of the sealing part and the sealing strip, thereby improving the sealing performance and improving the blocking effect of the gate plate in the closed state. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0016] Figure 2 for Figure 1 Exploded diagram of

[0017] Figure 3 It is the front view of the utility model;

[0018] Figure 4 for Figure 3 Cross-sectional view at AA in the middle;

[0019] Figure 5 This is a state diagram of the gate plate and the sealing strip in the utility model when they are attached;

[0020] Figure 6 This is a cross-sectional view of the utility model when the gate plate and the sealing strip are attached;

[0021] Figure 7 It is a three-dimensional diagram of the sealing strip in the utility model.

[0022] Figure numerals: 1. half valve body; 11. sealing groove; 12. drainage surface; 2. sealing strip; 21. fitting groove; 22. sealing layer; 23. connecting layer; 24. through hole; 3. gate; 31. sealing part; 4. valve stem; 41. indicator; 5. handle; 6. packing; 7. sealing ring; 71. debris containing groove; 8. dust cover; 81. observation hole. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, wherein the same components are indicated by the same reference numerals.

[0024] Reference Figures 1 to 7 As shown, a sealing enhanced knife gate valve of this embodiment comprises two half valve bodies 1 connected to each other, a U-shaped sealing strip 2 limited between the two half valve bodies 1, a gate plate 3 capable of contacting the sealing strip 2, a valve stem 4 for driving the gate plate 3 to move, a handle 5 for driving the valve stem 4 to move, and a packing 6 for the gate plate 3 to pass through and located at the end of the half valve body 1. The two half valve bodies 1 are fixedly connected together by bolts and nuts, and the two half valve bodies 1 are both provided with a sealing groove 11 for accommodating the sealing strip 2 together.

[0025] Based on the above-mentioned prior art, the end surface edges of the gate plate 3 facing the two half valve bodies 1 are beveled to form a trapezoidal or triangular sealing portion 31, the sealing portion 31 is U-shaped, and the tip of the sealing portion 31 faces the sealing strip 2. A concave fitting groove 21 matching the tip of the sealing portion 31 is processed on the surface where the sealing strip 2 and the edge of the gate plate 3 fit together. When the gate plate 3 blocks the flow of the medium, the tip of the sealing portion 31 is inserted into the fitting groove 21 and fits tightly with the inner wall of the fitting groove 21. When the gate plate 3 is opened or closed, the tip of the sealing portion 31 on both sides of the gate plate 3 is always fitted with the fitting groove 21.

[0026] Compared with the prior art, such a design can partially plug the gate plate 3 and the sealing strip 2 together, thereby reducing the contact area between the gate plate 3 and the sealing strip 2, thereby reducing the resistance generated when the gate plate 3 moves relative to the sealing strip 2, and the torque required for the handle 5 is reduced, which is convenient for the rapid opening and closing of the gate plate 3, reduces the deformation of the handle 5 or the valve stem 4, and prolongs the service life of the handle 5 and the valve stem 4; during the movement of the gate plate 3, one side of the gate plate 3 is subjected to force and cannot be offset relative to the sealing strip 2, ensuring that the bottom end of the gate plate 3 can be smoothly inserted into the sealing strip 2, ensuring the structural stability and closing accuracy of the gate plate 3; when the gate plate 3 is in a closed state, one side of the gate plate 3 is subjected to force and cannot be offset relative to the sealing strip 2, which increases the tightness between one side of the sealing portion 31 and the sealing strip 2, thereby improving the sealing performance and improving the blocking effect of the gate plate 3 in the closed state;

[0027] Preferably, the shape of the sealing portion 31 is designed to be an isosceles trapezoid. Compared with the triangular design, the trapezoidal design can reduce the cutting effect of the tip on the sealing strip 2, thereby ensuring the structural stability of the sealing strip 2 and extending the service life of the sealing strip 2; compared with the non-isosceles trapezoidal design, the isosceles trapezoidal design has a more balanced force on the sealing portion 31 and is easy to use.

[0028] As a specific implementation method of the improvement, refer to Figure 4 As shown, the edges of the two sealing grooves 11 adjacent to the gate plate 3 are beveled to form a drainage surface 12, and the two drainage surfaces 12 are respectively parallel to the two inclined side surfaces of the sealing portion 31, and a gap is formed between the drainage surface 12 and the corresponding side surfaces of the sealing portion 31. After the gate plate 3 cuts off the flow of the medium, the medium on one side of the gate plate 3 will enter the gap formed by the corresponding drainage surface 12 and the sealing portion 31, and the medium applies pressure to the sealing strip 2 along the gap. The sealing strip 2 is locally compressed and elastically deformed, so that it can fit more closely with the sealing portion 31, thereby further improving the sealing performance of the sealing portion 31 and the sealing strip 2, and ensuring the ability of the gate plate 3 to block the medium; at the same time, compared with the design of the sharp-angled edge of the sealing groove 11 adjacent to the gate plate 3, it can not only play a role in drainage guidance, but also reduce the wear degree of the side surface of the sealing portion 31 and the edge of the sealing groove 11 when the sealing strip 2 loses its elasticity over the years and the gate plate 3 deviates under the action of the medium and contacts the edge of the sealing groove 11.

[0029] As a specific implementation method of the improvement, refer to Figure 4 and Figure 6 As shown, the surface where the sealing strip 2 fits with the gate plate 3 is designed to be arc-shaped and convex toward the gate plate 3, and then a fitting groove 21 is opened in the middle of the arc convex surface of the sealing strip 2, so that there are unprocessed arc convex surfaces on both sides of the opening of the fitting groove 21, and the two arc convex surfaces respectively protrude toward the gap between the two drainage surfaces 12 and the corresponding side surfaces of the sealing portion 31. When the arc convex surface is subjected to medium pressure, the two sides of the arc convex surface will move to both sides and fit tightly with the sealing portion 31 and the inner wall of the sealing groove 11 respectively. Compared with the design in which the surfaces of the sealing strip 2 located on both sides of the opening of the fitting groove 21 are made into flat or concave surfaces, such a design can improve the local pressure resistance of the sealing strip 2 and avoid the local elastic failure or damage of the sealing strip 2. At the same time, the arc convex surface is subjected to medium pressure and is tightly fitted with the sealing portion 31 faster, ensuring the tight fit between the sealing portion 31 and the sealing strip 2 at the first time to prevent medium leakage.

[0030] As a specific implementation method of the improvement, refer to Figures 4 to 7 As shown, a sealing layer 22 having the same contour as the sealing strip 2 and capable of being clamped between the two half-valve bodies 1 is integrally formed on the outer wall of the sealing strip 2. The thickness of the sealing layer 22 is less than that of the sealing strip 2. Compared with the prior art design of simply fitting the two half-valve bodies 1 tightly, such a design can use a soft seal instead of a hard seal, thereby avoiding the phenomenon of structural looseness or leakage caused by the presence of a gap between the two half-valve bodies 1 due to uneven processing.

[0031] As a specific implementation method of the improvement, refer to Figure 2 , Figure 5 and Figure 7 As shown, two connecting layers 23 are integrally formed on the outer wall of the sealing layer 22. The two connecting layers 23 are respectively arranged adjacent to the two ends of the sealing layer 22. Both connecting layers 23 are provided with a plurality of through holes 24 for connecting bolts to pass through. During the assembly process, the plurality of through holes 24 are respectively matched with the holes on the half valve body 1 for the connecting bolts to pass through. After the two half valve bodies 1 clamp the connecting layer 23 and the sealing layer 22, the connecting bolts are used to successively penetrate the half valve body 1, the connecting layer 23 and the other half valve body 1, and then a nut is screwed on one end of the connecting bolt to fix the two half valve bodies 1 together. In this design, the connecting bolts are used to further limit the sealing strip 2, the sealing layer 22 and the sealing layer 23 as a whole, so as to avoid the sealing strip 2 moving or falling out of the sealing groove 11 due to the traction of the sealing strip 2, the sealing layer 22 and the sealing layer 23 as a whole during heating or the movement of the gate plate 3, thereby ensuring the connection stability of the sealing strip 2.

[0032] As a specific implementation method of the improvement, refer to Figure 2 , Figure 5 and Figure 7 As shown, it also includes a sealing ring 7 that can be passed through by the gate plate 3 and is located below the packing 6. The material of the sealing ring 7 is the same as that of the sealing strip 2. The sealing ring 7 and the sealing strip 2 are integrally formed or bonded together through a process. The height of the sealing ring 7 is less than or equal to the height of the two ends of the sealing strip 2. Grooves for accommodating the sealing ring 7 are processed on the inner walls of the two half valve bodies 1. The height of the sealing ring 7 is lower than the height of the packing 6. When the gate plate 3 is in a state of blocking the flow of the medium, the sealing ring 7 and the packing 6 form a double seal together. Such a design can further improve the sealing between the gate plate 3 and the valve body to avoid medium leakage. At the same time, the sealing ring 7 can also wipe off the dust on the surface of the gate plate 3 or the attached liquid medium, so as to clean the gate plate 3.

[0033] As a specific implementation method of the improvement, refer to Figure 6 and Figure 7 As shown, a V-shaped debris containing groove 71 with a tip away from the gate plate 3 is provided on the inner wall of the sealing ring 7. Such a design can not only reduce the contact surface between the sealing ring 7 and the gate plate 3, thereby reducing the torque required by the handle 5, but also the sealing ring 7 wipes the surface of the gate plate 3 twice. The dust or medium generated by the second wiping will remain in the debris containing groove 71 and move downward along the inner wall slope of the debris containing groove 71, and then fall back into the valve body.

[0034] As a specific implementation method of the improvement, refer to Figures 1 to 3 As shown, a dust cover 8 for accommodating the gate 3 or the valve stem 4 is arranged above the two half valve bodies 1, and the dust cover 8 is located between the handle 5 and the half valve body 1. When the gate 3 is in a state of blocking the medium, the portion of the valve stem 4 below the handle 5 is in the dust cover 8. During the opening process of the gate 3, the valve stem 4 gradually withdraws from the dust cover 8, and the gate 3 gradually withdraws from the valve body and gradually enters the dust cover 8. The design of the dust cover 8 can prevent external dust from adhering to the gate 3 and affecting the subsequent closing operation of the gate 3 when the valve is in an open state.

[0035] As a specific implementation method of the improvement, refer to Figure 3As shown, an indicator 41 is fixedly connected to the position where the valve stem 4 is connected to the gate plate 3 or the position where the valve stem 4 is adjacent to the gate plate 3, and an observation hole 81 is opened on the dust cover 8, the length direction of which is parallel to the valve stem 4, and the observation hole 81 is opposite to the indicator 41. The indicator 41 can be a bolt or a rod partially inserted into the observation hole 81. When the handle 5 is rotated to drive the gate plate 3 to move, the indicator 41 will move along the observation hole 81. Two marks can be added at both ends of the observation hole 81 or on the edge of the observation hole 81 to correspond to the open and closed positions of the gate plate 3 respectively. Such a design allows the operator to more conveniently observe whether the valve is in a closed state or an open state, and also facilitates the operator to observe the opening or closing process of the gate plate 3 while operating, thereby avoiding excessive closure of the gate plate 3 to damage the sealing strip 2 or the gate plate 3 not being fully opened to cause low medium flow.

[0036] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A seal-enhanced knife gate valve, comprising two valve halves (1) connected to each other, a U-shaped sealing strip (2) limited between the two valve halves (1), a gate (3) capable of contacting the sealing strip (2), a valve stem (4) for driving the gate (3) to move, a handle (5) for driving the valve stem (4) to move, and a packing (6) for the gate (3) to pass through and located at the end of the valve halves (1), wherein the two valve halves (1) are both provided with a sealing groove (11) for accommodating the sealing strip (2), and characterized in that: A sealing portion (31) convex toward the sealing strip (2) is provided on the surface where the gate plate (3) and the sealing strip (2) are in contact, and the sealing strip (2) is provided with a contact groove (21) partially matching the sealing portion (31). The sealing portion (31) is partially inserted into the contact groove (21) and is tightly contacted with the inner wall of the contact groove (21), so that the sealing portion (31) cannot move relative to the contact groove (21) along the axial direction of the half valve body (1).

2. A seal-enhanced knife gate valve according to claim 1, characterized in that: The cross section of the sealing portion (31) in the direction of the U-shaped profile of the sealing strip (2) is in a trapezoidal or triangular shape.

3. A seal-enhanced knife gate valve according to claim 2, characterized in that: The edges of the two sealing grooves (11) adjacent to the gate plate (3) are beveled to form drainage surfaces (12) parallel to the corresponding side surfaces of the sealing portion (31).

4. A seal-enhanced knife gate valve according to claim 3, characterized in that: The two surfaces of the sealing strip (2) connected to the opening edge of the fitting groove (21) are both arc-shaped and protrude toward the gaps between the two drainage surfaces (12) and the corresponding side surfaces of the sealing portion (31).

5. A seal-enhanced knife gate valve according to claim 1, 2, 3 or 4, characterized in that: The outer wall of the sealing strip (2) is provided with a sealing layer (22) which can be clamped between the two half valve bodies (1) and has the same profile as the sealing strip (2).

6. A seal-enhanced knife gate valve according to claim 5, characterized in that: Two connecting layers (23) are arranged on the outer wall of the sealing layer (22). The two connecting layers (23) are respectively arranged adjacent to the two ends of the sealing layer (22). Both connecting layers (23) are provided with a plurality of through holes (24) for connecting bolts to pass through.

7. A seal-enhanced knife gate valve according to claim 1, 2, 3 or 4, characterized in that: It also includes a sealing ring (7) that can be passed through by the gate plate (3) and is located below the filler (6). The sealing ring (7) is fixedly connected to the sealing strip (2) and the height of the sealing ring (7) is less than or equal to the height of the two ends of the sealing strip (2).

8. A seal-enhanced knife gate valve according to claim 7, characterized in that: The inner wall of the sealing ring (7) is provided with a V-shaped impurity containing groove (71) with the tip thereof being away from the gate plate (3).

9. A seal-enhanced knife gate valve according to claim 1, 2, 3 or 4, characterized in that: A dust cover (8) for accommodating a gate plate (3) or a valve stem (4) is arranged above the two half valve bodies (1).

10. A seal-enhanced knife gate valve according to claim 9, characterized in that: An indicator (41) is provided on the portion of the valve stem (4) located inside the dust cover (8), and an observation hole (81) parallel to the moving track of the indicator (41) is provided on the dust cover (8).

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