Butterfly valve with elastic butterfly plate

Abstract

The utility model discloses a butterfly valve with an elastic butterfly plate, relates to the technical field of butterfly valves, and solves the problems of abrasion, jamming, poor durability and the like in the prior art. The whole butterfly plate is in a plate sheet shape and is made of an elastic metal material, the butterfly plate comprises an inner disc part located in the center and a contact part located on the periphery of the inner disc part, the section of the contact part is in a bent shape, and the outline trend of the contact part is that the contact part is gradually away from the valve rod firstly and then bent inwards to approach the valve rod; and the valve seat is in sealing fit with the contact part. A plate-shaped butterfly plate structure integrally formed by an elastic metal material is adopted, and the contact part of the butterfly plate generates radial expansion deformation during closing through the elasticity of the material, so that a sealing surface gap caused by machining errors, thermal expansion and medium impurities is adaptively compensated, and the dependence on the assembly precision is remarkably reduced; the section of the contact part adopts a bent profile which firstly gets away from the valve rod and then gets close to the valve rod, the elastic deformation capacity is enhanced, and the contact pressure of the sealing surface can be gradually enhanced in the rotating closing process of the butterfly plate.

Description

Technical Field

[0001] The utility model relates to the technical field of butterfly valves, in particular to a butterfly valve with an elastic butterfly plate. Background Art

[0002] Traditional butterfly valves usually consist of a valve body, a valve stem and a rigid butterfly plate, and the opening and closing control is realized by the rotation of the butterfly plate around the axis of the valve stem. However, the butterfly valves in the prior art still have significant defects in terms of sealing performance and service life. For example, the conventional rigid butterfly plate and the valve seat are in rigid contact, which requires extremely high machining accuracy and assembly requirements. When the pipeline system vibrates, problems such as local wear and jamming of the sealing surface are likely to occur, resulting in an increased risk of leakage or an increased opening and closing torque. Especially in high-temperature or pressure fluctuation working conditions, the thermal expansion difference of metal materials will further exacerbate the risk of sealing failure.

[0003] Some improved butterfly valves in the prior art improve the sealing effect by adding elastic sealing rings such as rubber at the edge of the butterfly plate. However, such structures have obvious shortcoming. The elastic sealing ring is easily aged and torn due to long-term scouring by the medium, and its durability is insufficient, so it needs to be frequently replaced and maintained; and under high-pressure working conditions, the elastomer is easily extruded into the flow channel to form protrusions, which instead increases the flow resistance and vortex vibration. Summary of the Utility Model

[0004] The purpose of the utility model: In order to overcome the defects of the prior art, the utility model provides a butterfly valve with an elastic butterfly plate, which solves the problems of wear, jamming, poor durability, etc. existing in the prior art.

[0005] The technical solution of the utility model: It includes a butterfly plate, a valve seat, a valve body and a valve stem. The valve seat is located in the valve body, the valve stem penetrates into the valve body and is connected with the butterfly plate. The butterfly plate is in the shape of a plate as a whole and is made of elastic metal material. The butterfly plate includes an inner disc part at the central position and a contact part at the peripheral position of the inner disc part. The cross-section of the contact part is in a curved shape, and its contour trend is to gradually move away from the valve stem first, and then bend inward and approach the valve stem; the valve seat forms a sealing fit with the contact part.

[0006] By adopting the above technical solution, the plate-shaped butterfly plate structure integrally formed by elastic metal material is used to replace the traditional rigid butterfly plate or the setting of additional rubber sealing rings. Through the elasticity of the material, the contact part of the butterfly plate generates radial expansion deformation when closed, so as to adaptively compensate for the sealing surface gap caused by machining errors, thermal expansion and medium impurities, and significantly reduce the dependence on assembly accuracy; the cross-section of the contact part adopts a curved contour that first moves away from and then approaches the valve stem, which enhances the elastic deformation ability, can gradually increase the contact pressure of the sealing surface during the rotation and closing process of the butterfly plate, avoid the local wear and jamming problems caused by rigid contact, and at the same time simplify the manufacturing process. Reliable sealing can be achieved without a complex multi-eccentric structure, fundamentally solving the defects of easy aging of the elastic sealing ring and increased flow resistance under high pressure in the background art.

[0007] In a possible design, the inner disk portion is in the shape of a curved surface that is concave toward one side of the valve stem, and its cross-sectional profile is in the shape of an arc with gently expanding edges and a shallow concave center, and its outer edge and the contact portion have a smooth transition.

[0008] With the above design, the structure disperses pressure and enhances elasticity through arc surfaces. When subjected to medium pressure, the stress can be evenly dispersed to the entire butterfly plate to avoid the risk of plastic deformation caused by local stress concentration. The smooth transition between the outer edge and the contact part and the arc profile can also guide the medium to flow evenly through the butterfly plate surface along the tangential direction, thereby optimizing the flow field distribution when the fluid passes through the butterfly plate, reducing turbulence and vibration, and reducing flow resistance while improving seal durability, which is especially suitable for high flow rate conditions.

[0009] In a possible design, there is a gap between the rear disc surface of the inner disc and the valve stem, and the inner disc is pressed and deformed to abut against the valve stem.

[0010] With the above design, the gap ensures that the butterfly plate has no contact friction with the valve stem under normal conditions. When the medium pressure increases, the inner disc is elastically deformed under pressure and abuts against the valve stem. The valve stem limits excessive deformation of the butterfly plate, preventing sealing failure caused by excessive bending of the butterfly plate, thereby achieving a balance between sealing performance and structural reliability.

[0011] In a possible design, a protrusion protruding outward is provided at the center of the front disc surface of the inner disc portion.

[0012] With the above design, the raised structure in the center of the front disk surface of the inner disk is similar to a fluid mechanics guide cone, which can guide the medium to flow evenly to both sides of the valve cavity and reduce the static pressure gradient in the central area; at the same time, it forms a local reinforcement effect to avoid excessive deformation of the inner disk and maintain the shape accuracy of the sealing surface.

[0013] In a possible design, a lug is integrally provided on the rear disk surface of the inner disk portion, and the valve stem penetrates into the lug and is fixedly connected to the lug via a pin.

[0014] With the above design, the keyless design omits the complicated processing steps of the traditional key connection and improves the assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the appearance structure of the utility model;

[0016] Figure 2 It is a cross-sectional view of the utility model;

[0017] Figure 3 This is a schematic diagram of the structure of the butterfly plate and valve stem of the utility model;

[0018] Figure 4 It is a cross-sectional view of the butterfly plate and valve stem of the utility model;

[0019] Among them, 1 is the butterfly plate; 11 is the inner disc part; 12 is the contact part; 13 is the protrusion; 14 is the lug; 2 is the valve seat; 3 is the valve body; 4 is the valve stem; 41 is the gap; 42 is the pin. Specific implementation manner

[0020] As Figures 1 - 4 shown, a butterfly valve with an elastic butterfly plate includes a butterfly plate 1, a valve seat 2, a valve body 3 and a valve stem 4. The valve seat 2 is located on the inner wall of the valve body 3, and the valve stem 4 passes through the shaft holes on both sides of the valve body 3 to form a connection with the butterfly plate 1. The butterfly plate 1 is entirely in the shape of a plate and is made of an elastic metal material. The butterfly plate 1 includes an inner disc part 11 at the central position and an annular contact part 12 at the outer peripheral position of the inner disc part 11. The cross-section of the contact part 12 is in a curved shape, and its contour trend is: starting from the outer edge of the inner disc part 11, then extending outward in a large-radius arc away from the axis of the valve stem 4 to the maximum outward expansion point, and then bending inward in a small-radius arc and approaching the valve stem 4 direction, so that the contact part 12 contacts and forms a sealing fit with the valve seat 2 in the valve closed state. The butterfly plate 1 can be formed by stamping with a metal material having a certain elasticity such as austenitic stainless steel or nickel-based alloy, and is selected according to the cost and the required elastic modulus. The bending contour of the contact part 12 that first moves away from and then approaches the valve stem 4 makes the butterfly plate 1 more elastic, and can be elastically attached to the valve seat 2 through structural deformation, improving the sealing ability. When the butterfly plate 1 rotates around the valve stem 4 to open and close, the elastic bending structure of the contact part 12 can adapt to the surface curvature of the valve seat 2, and undergoes radial elastic deformation under the action of the medium pressure, with a deformation amount of about 0.3 - 0.5 mm, forming a dynamic sealing specific pressure, and realizing a low-leakage sealing performance without relying on high-precision machining. When the medium impacts or the pipeline vibrates, energy can be absorbed through structural deformation, avoiding jamming or fracture caused by rigid collision and extending the service life.

[0021] The inner disc part 11 is in the shape of a curved surface that is concave toward the valve stem 4 side, similar to the shallow concave shape of a radar dish. Its cross-sectional contour is an arc shape with a gently expanding outer edge and a shallow concave center, and its outer edge is smoothly transitioned with the contact part 12 through a large curvature radius. When the butterfly plate 1 is pressed in the positive direction, it contracts uniformly in the radial direction, and the inner disc part 11 bends inward, driving the outer part of the contact part 12 to squeeze and contact the valve seat 2. When the butterfly plate 1 is pressed in the reverse direction, it expands uniformly in the radial direction, and the inner disc part 11 bends outward, driving the inner part of the contact part 12 to squeeze and contact the valve seat 2.

[0022] A gap of 0.3 - 0.8 mm, namely gap 41, is reserved between the rear disk surface of the inner disk part 11 and the surface of the valve stem 4, and when the inner disk part 11 is deformed under pressure, it is in contact and cooperation with the valve stem 4. According to the actually measured data of experiments, when the medium pressure is lower than 4 MPa, the butterfly plate 1 realizes sealing only through the elastic deformation of the contact part 12; when the pressure rises above 6 MPa, the inner disk part 11 is bent and deformed towards the valve stem 4 under pressure, and the rear disk surface contacts the surface of the valve stem 4 to form an abutting support, thereby preventing the problem of excessive torque caused by excessive deformation of the butterfly plate 1.

[0023] A convex 13 with a bulging, mound-shaped diversion structure protruding outward is integrally stamped at the center position of the front disk surface of the inner disk part 11. Similar to a hydrodynamic diversion cone, it can guide the medium to be evenly diverted to the outside of the inner cavity of the valve body 3. At the same time, the connection area between the root of the convex 13 and the inner disk part 11 adopts a variable thickness design to form radially radiating reinforcing ribs.

Claims

1. A butterfly valve with an elastic butterfly plate, comprising a butterfly plate (1), a valve seat (2), a valve body (3) and a valve stem (4), wherein the valve seat (2) is located in the valve body (3), and the valve stem (4) penetrates into the valve body (3) to form a connection with the butterfly plate (1), characterized in that: The butterfly plate (1) is in the shape of a plate and is made of an elastic metal material. The butterfly plate (1) comprises an inner disc portion (11) at a central position and a contact portion (12) at a peripheral position of the inner disc portion (11). The cross section of the contact portion (12) is curved, and its contour first gradually moves away from the valve stem (4), then bends inward and approaches the valve stem (4); the valve seat (2) forms a sealing fit with the contact portion (12).

2. The butterfly valve with elastic butterfly plate according to claim 1, characterized in that: The inner disk portion (11) is in the shape of a curved surface that is recessed toward one side of the valve stem (4), and its cross-sectional profile is in the shape of an arc with gently expanding edges and a shallow concave center, and its outer edge smoothly transitions to the contact portion (12).

3. The butterfly valve with elastic butterfly plate according to claim 2, characterized in that: A gap (41) is provided between the rear disc surface of the inner disc portion (11) and the valve stem (4), and when the inner disc portion (11) is deformed under pressure, it abuts against the valve stem (4).

4. The butterfly valve with elastic butterfly plate according to claim 2, characterized in that: The inner disk portion (11) has a protrusion (13) protruding outward at the center of the front disk surface.

5. The butterfly valve with elastic butterfly plate according to claim 1 or 2, characterized in that: The rear disk surface of the inner disk portion (11) is integrally provided with a lug (14), and the valve stem (4) penetrates into the lug (14) and is fixedly connected to the lug (14) via a pin (42).

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