Lined butterfly valve and method for manufacturing a lined butterfly valve

Abstract

The present application provides a lined butterfly valve and a manufacturing method thereof, which is excellent in chemical resistance and heat resistance, and even if set to a large diameter, ensures a sufficient thickness of a liner layer with respect to a metal core without setting the metal core of a valve body with high precision, and prevents penetration and permeation of a fluid. A valve body (2) in which a metal core (20) is covered with a liner layer (22) is set to be rotatable within a valve body (3) by means of a valve stem (5). The liner layer (22) has front and back liner portions (32) provided on the front and back sides of the metal core, respectively, and an outer peripheral liner portion (33) provided on the outer peripheral side of the metal core, the front and back liner portions being set to have, on each of the front and back sides of the metal core, assuming no warping of the metal core, a thickness (T1) that is the sum of a predetermined liner thickness and a thickness that is the same as the maximum warping amplitude that can be assumed on the valve wing side of the metal core, and the thickness of the outer peripheral liner portion from the outer peripheral end of the metal core to the outer peripheral end of the valve body is a thickness (T2) that is the sum of a predetermined liner thickness and a predetermined crush thickness.

Description

TECHNICAL FIELD

[0001] The present application relates to a lined butterfly valve in which a resin liner is applied to the valve body and the inner peripheral surface of the valve case, and a manufacturing method for the lined butterfly valve. BACKGROUND

[0002] For example, in the case where a butterfly valve for a flow path related to food is used in a factory where a highly corrosive fluid such as a chemical is flowing, a so-called lined butterfly valve in which a metal core of a valve body is provided with a resin liner and a resin seat ring is fitted to the inner peripheral surface of a valve case is often used. In such a valve, a fluororesin having excellent chemical resistance and heat resistance is generally used as a liner material, and the fluororesin is subjected to a lining process with a certain degree of thickness in order to prevent penetration and permeation of a special fluid such as a medicine. On the other hand, the fluororesin also has a property of lacking elasticity, so it is necessary to particularly sufficiently ensure the sealing property of the vicinity of a sealing portion on the valve wing side and the valve case side of the valve body at the time of valve closing, and it is even necessary to prevent leakage throughout the entire circumference of the sealing portion on the outer peripheral side of the valve body.

[0003] As a lined butterfly valve, for example, the butterfly valve of Patent Literature 1 has been filed by the present applicant. In the valve body of this valve, a disc-shaped liner based on a fluororesin is applied to a metal core, and the disc-shaped liner has gentle inclined surfaces on both sides, and a tapered surface having a predetermined angle is formed on the end side of the valve wing in continuity with the inclined surfaces. A sealing portion that is pressed and sealed by a sheet-shaped liner at the time of valve closing is provided between the tapered surfaces of the both sides. These inclined surfaces, tapered surfaces, and sealing portion are formed from the metal core with substantially the same wall thickness, and high sealing surface pressure is exerted at the time of valve closing to prevent leakage.

[0004] On the other hand, the valve body of the butterfly valve of Patent Literature 2 is covered with a liner layer on the outside of a metal core for reinforcement, and a sealing portion having a two-layer structure of a low-pressure sealing portion having a small curvature radius and a medium-pressure or high-pressure sealing portion having a large curvature radius is formed on the outer periphery of the liner layer. With this sealing portion, only the low-pressure sealing portion is pressed against the seat ring at a small degree at the time of low pressure, and the low-pressure sealing portion and the medium-pressure or high-pressure sealing portion are pressed against the seat ring at a large degree at the time of high pressure, whereby the burden on the cover member is reduced.

[0005] In the case where a resin liner is applied to the metal core of the lined butterfly valve of Patent Literatures 1 and 2, the lining is generally performed by a liner forming mold. In general, when the lining process is performed by the liner forming mold, the metal core is supported horizontally inside the forming mold, and a liner material is then poured into the cavity in this state, whereby the entire surface including the front and back surfaces of the metal core is subjected to the lining process to produce the valve body.

[0006] Patent Literature 1: Japanese Patent No. 6495243

[0007] Patent Literature 2: Japanese Patent No. 3086783

[0008] However, in the case of making the lining type butterfly valve of Patent Literatures 1 and 2 large-diameter, the metal core of the valve body also becomes large-diameter and increases in weight, and the metal core is likely to warp with the valve wing side as the center at the time of casting, and the valve wing vicinity is likely to be deflected downward by the weight when the lining is formed at the metal core with the lining forming mold supporting the metal core. In lining forming, the metal core is arranged inside the resin mold to supply resin to be formed, so the metal core with warping and deflection is arranged inside the resin lining of constant outer shape. Thus, it is difficult to apply the lining to both sides of the metal core equally, and in particular, there is a possibility that the lining thickness is insufficient on one side of the metal core with the valve wing vicinity and the metal core is exposed to the surface, and the lining thickness is formed more than necessary on the other side. In this case, there is a possibility that fluid penetrates or passes through the portion where the lining layer is insufficient.

[0009] In these valves, the inclined surface, the tapered surface, and the sealing portion for the sheet type lining on the front and back sides of the metal core are provided with substantially the same thickness, and in order to form these thicknesses to the same wall thickness, the metal core needs to be formed with high precision. However, unevenness is likely to occur in the formation of the resin when the resin lining layer is covered on the surface of the metal core, and in particular, it is difficult to form a predetermined sealing width near the outer periphery of the metal core. Thus, the outer peripheral sealing surface is formed in a manner extending from the front and back surfaces near the outer periphery of the metal core, and in this case, in order to make the outer peripheral sealing surface a uniform predetermined width, the shape of the metal core needs to be finely set, and the excess extension of the outer peripheral sealing portion needs to be cut with high precision on the basis of the crushing allowance of the outer peripheral sealing surface.

[0010] Thus, there is a demand for a lining type butterfly valve having a valve body that can simply form a thickness that can prevent penetration or passage of a drug or the like without setting the metal core with high precision in the case of setting the lining type butterfly valve to be large-diameter, and ensure sealing performance at the time of valve closing throughout the entire circumference. SUMMARY

[0011] The present application has been developed to solve the problems of the related art, and aims to provide a lining type butterfly valve and a manufacturing method thereof, which are excellent in chemical resistance and heat resistance, and ensure a lining layer of sufficient thickness with respect to a metal core without setting the metal core of the valve body with high precision even in the case of setting to be large-diameter, and prevent penetration or passage of fluid.

[0012] To achieve the above object, the invention according to claim 1 is a lining type butterfly valve characterized in that, in a butterfly valve in which a valve body in which a metal core is covered with a lining layer is rotatably disposed in a valve body by means of a valve shaft, the aforementioned lining layer has a front and back lining portion disposed on the front and back sides of the aforementioned metal core, an outer peripheral lining portion disposed on the outer peripheral side of the aforementioned metal core, the aforementioned front and back lining portion is disposed so as to have, on each of the front and back sides of the metal core assuming no warping, at least at the outer peripheral end position of the aforementioned metal core, a thickness obtained by adding a predetermined lining thickness to a thickness identical to the maximum warping amplitude conceivable on the valve wing side of the aforementioned metal core, the thickness of the end sealing surface of the aforementioned outer peripheral lining portion from the outer peripheral end of the aforementioned metal core to the outer peripheral end of the aforementioned valve body is a thickness obtained by adding a predetermined crush thickness to a predetermined lining thickness, the aforementioned predetermined lining thickness is the minimum thickness of the lining layer necessary so as not to allow fluid to permeate to the aforementioned metal core, the aforementioned maximum warping amplitude conceivable on the valve wing side of the aforementioned metal core is the amplitude of deviation from the designed value of the end portion of the aforementioned metal core in the case of the maximum warping occurring in the range of anticipation with respect to the warping centered on the vicinity of the valve wing that can occur when casting the aforementioned metal core, and the aforementioned predetermined crush thickness is the amount of irreversible crushing that occurs when the sealing portion of the aforementioned valve body is crushed repeatedly in contact with the sheet lining at the time of opening and closing of the aforementioned valve body.

[0013] The invention according to claim 2 is a lining type butterfly valve characterized in that, in the outer peripheral lining portion, a convex portion projecting toward the outer peripheral side of the valve body is connected to the outer peripheral side of the valve body to be formed in a substantially ring shape, and the outer peripheral side end surface of the convex portion is an end sealing surface having a predetermined sealing width.

[0014] The invention according to claim 3 is a lining type butterfly valve characterized in that the metal core has an outer peripheral side surface portion at the outermost periphery thereof, the outer peripheral side surface portion having a width capable of facing the central portion in the thickness direction of the convex portion provided in the outer peripheral lining portion even when the metal core warps by the maximum warping amplitude conceivable on the valve wing side of the metal core.

[0015] The invention according to claim 4 is a lining type butterfly valve characterized in that each side surface portion of the convex portion facing the end sealing surface is formed by an inclined surface having an angle of 10° or less with respect to the crimping sealing direction of the end sealing surface.

[0016] The invention according to claim 5 is a lining type butterfly valve characterized in that a set of gaskets facing each other in the insertion direction of the valve shaft is fitted in the shaft fitting portion of the valve shaft, the set of gaskets being composed of a combination of substantially identical uneven shapes capable of occurring when the surface pressure applied from the valve shaft side to the boss portion formed at the valve body deviates and inclines between the valve shaft and the valve body.

[0017] The invention of technical solution 6 is a lining type butterfly valve in which the gasket is composed of a convex gasket having a convex spherical surface and a concave gasket having a concave spherical surface for contacting the convex spherical surface, and the convex gasket and the concave gasket are assembled in a pushing state in a direction toward each other by the repulsive force of a spring assembled in the shaft mounting portion.

[0018] The invention of technical solution 7 is a lining type butterfly valve characterized in that, in a butterfly valve in which a valve body in which a metal core is covered with a lining layer is rotatably disposed in a valve body by a valve shaft, the aforementioned lining layer has a front and back lining portion disposed on the front and back sides of the aforementioned metal core, and an outer peripheral lining portion disposed on the outer peripheral side of the aforementioned metal core, the aforementioned front and back lining portion has at least a predetermined lining thickness on the front and back sides of the aforementioned metal core, and at least at the outer peripheral end position of the aforementioned metal core, the front and back sides have a thickness that is twice the thickness of the predetermined lining thickness plus the thickness of the maximum warping amplitude that can be assumed on the valve wing side of the aforementioned metal core, and the thickness of the outer peripheral end of the aforementioned metal core to the end sealing surface of the outer peripheral end of the aforementioned valve body of the aforementioned outer peripheral lining portion is the thickness of the predetermined lining thickness plus the predetermined crushing thickness, the aforementioned predetermined lining thickness is the minimum thickness of the lining layer necessary to prevent fluid from penetrating into the aforementioned metal core, the aforementioned maximum warping amplitude that can be assumed on the valve wing side of the aforementioned metal core is the deviation amplitude from the design value of the end portion of the aforementioned metal core in the case of the maximum warping occurring in the range of the warping centered on the vicinity of the valve wing that can occur when casting the aforementioned metal core, and the aforementioned predetermined crushing thickness is the amount of irreversible crushing that occurs when the sealing portion of the aforementioned valve body is crushed repeatedly by the sheet lining when the aforementioned valve body is opened and closed.

[0019] The invention of technical solution 8 is a manufacturing method of the lining type butterfly valve described in any one of the aforementioned technical solutions 1 to 7, in which, at the metal core, a valve shaft or a valve shaft jig is inserted into a valve shaft insertion hole provided at opposite positions of the valve wing portion of the metal core, the metal core and the valve shaft or the valve shaft jig are fixed to each other, the metal core is arranged in a molding space of a mold for forming a lining layer, and by introducing a material for forming a lining layer into the molding space while maintaining the upper and lower valve shafts or the upper and lower valve shaft jigs in a state in which the metal core is fixed without moving, the lining layer is formed on the surface of the metal core.

[0020] Inventive Effects

[0021] According to the invention of the technical solution 1, it is a butterfly valve of the lining type which is excellent in chemical resistance and heat resistance, the front and back lining portions of the valve body are provided so that, on each side of the front and back sides of the metal core assuming no warping, at least at the outer peripheral end position of the metal core, there is a thickness which is the thickness of the predetermined lining thickness plus the thickness of the maximum warping amplitude which can be assumed at the valve wing side of the metal core, so that in the case where warping actually occurs at the metal core, at least the predetermined lining thickness is ensured at the front and back sides of the valve body, and on the other hand, the outer peripheral lining portion is of a thickness which is the predetermined lining thickness plus the predetermined crushing thickness, so that at least the predetermined lining thickness is ensured at the outer peripheral side of the valve body. Therefore, even in the case where a large diameter is provided, a lining layer of sufficient thickness can be ensured with respect to the metal core to prevent penetration and permeation of fluid. Thus, the front and back lining portions and the outer peripheral lining portion can be formed in predetermined shapes without finely setting the shape of the metal core, and in particular, it is easy to form the outer peripheral side in a predetermined thickness and a predetermined width which has the thickness and the sealing width necessary to ensure sealing, whereby sealing can be exerted over the entire circumference of the valve body to prevent leakage from the outer peripheral side of the valve body at the time of valve closing.

[0022] According to the invention of the technical solution 2, a protrusion is formed in the outer peripheral lining portion, the outer peripheral side end surface of the protrusion is a terminal sealing surface having a predetermined sealing width, whereby the outer peripheral lining portion can be formed in the necessary thickness regardless of the outer diameter and thickness of the metal core, and the predetermined sealing width necessary for sealing is provided in the protrusion, so that even in the case where the valve is large in diameter, a necessary minimum outer peripheral sealing portion can be formed, and processing is easy.

[0023] According to the invention of the technical solution 3, in order to make the protrusion of the outer peripheral lining portion exert good sealing, it is preferable that the outer peripheral portion of the metal core serves as a support, and therefore, even if the metal core warps, at least the outer peripheral side surface of the metal core faces the center of the protrusion. In particular, it has a width which can face the central portion in the thickness direction of the protrusion provided in the outer peripheral lining portion, so that even if the metal core warps, the protrusion and the outer peripheral side surface of the metal core can be made to face each other surely, and the sealing of the protrusion can be ensured.

[0024] According to the invention of the technical solution 4, each side surface portion is formed by an inclined surface having an angle of 10° or less with respect to the pressing sealing direction of the terminal sealing surface, whereby unevenness in the sealing width after lining formation is suppressed, and an outer peripheral sealing portion of uniform sealing width can be easily formed at the outer periphery of the valve body. At the time of valve closing sealing, the outer peripheral sealing portion exerts a constant sealing surface pressure over the outer periphery of the valve body, and fluid leakage is surely prevented.

[0025] According to the invention of the technical solution 5, even if the valve body side and the valve stem side are tilted or moved in the state of applying fluid pressure, the assembly state of the valve body side and the valve stem side is maintained by means of a set of gaskets, and smooth rotation operability is maintained. In this case, the gaskets are composed of a combination of concave-convex shapes, and the boss portions of the valve body are applied with the same surface pressure as before the tilting or movement occurs from the valve stem side, thereby ensuring the sealing property of these boss portions and the valve body side, and leakage is effectively prevented even if the valve body side and the valve stem side are tilted or moved.

[0026] According to the invention of the technical solution 6, even if the convex gasket and the concave gasket are tilted or displaced with respect to each other, the convex spherical surface and the concave spherical surface are tightly contacted by means of the spring opening force, thereby exerting uniform surface pressure on the contact positions in a wide range, and excellent sealing property of the boss portions and the valve body side is exhibited.

[0027] According to the invention of the technical solution 7, it is a lining type butterfly valve which is excellent in chemical resistance and heat resistance, and the lining portions of the front and back sides of the valve body are provided so that, on each side of the front and back sides of the metal core assuming no warping, at least at the outer peripheral end position of the metal core, a thickness obtained by adding a predetermined lining thickness to a thickness equivalent to the maximum warping amplitude assumed on the valve wing side of the metal core is provided, so that in the case where warping actually occurs at the metal core, at least a lining portion having the predetermined lining thickness is ensured on the front and back sides of the valve body, and on the other hand, the outer peripheral lining portion has a thickness obtained by adding a predetermined crushing thickness to the predetermined lining thickness, so that at least a lining portion having the predetermined lining thickness is ensured on the outer peripheral side of the valve body. Therefore, even in the case where a large diameter is provided, a lining layer having a sufficient thickness with respect to the metal core can be ensured to prevent penetration and permeation of fluid. Thus, the front and back lining portions and the outer peripheral lining portion can be formed in a predetermined shape without finely setting the shape of the metal core, and in particular, the outer peripheral side having a thickness and a sealing width necessary to ensure the sealing property can be easily formed in a predetermined thickness and a predetermined width, so that the sealing property can be exhibited over the entire circumference of the valve body while preventing leakage from the outer peripheral side of the valve body at the time of valve closing.

[0028] According to the invention of the technical solution 8, the valve stem or the valve stem clamp is inserted into the metal core in advance to fix it, the metal core is fixed in the molding space of a mold (metal mold) for forming a lining layer in such a manner that the metal core is not moved by holding the valve stem or the valve stem clamp, and a material of the lining layer is introduced into the molding space to form the lining layer, so that in the lining layer having an outer shape determined in advance by the mold (metal mold), the metal core can be arranged at a correct position, and thus a lining layer having a thickness necessary to prevent penetration of fluid even if warping occurs in the metal core can be effectively formed. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a central longitudinal sectional view showing an embodiment of the lining type butterfly valve of the present invention.

[0030] Figure 2 (a) is a partial cutaway perspective view of the valve body. Figure 2

[0031] Figure 3 Figure 2 (b) is an enlarged sectional view of A portion of (b).

[0032] Figure 4

[0033] Figure 5 Figure 1

[0034] Figure 6 DETAILED DESCRIPTION

[0035] Hereinafter, an embodiment of the lined butterfly valve of the present application will be described in detail based on the drawings. Figure 1 Figure 2 (a) of (b) indicates a valve body, Figure 2 Figure 3 Figure 2 (b) is an enlarged sectional view of A portion of (b).

[0036] In the drawings, the lined butterfly valve (hereinafter, referred to as valve body 1) is provided, for example, as a large-diameter valve having a nominal diameter of about 350A to 600A, and is used as a part of a pipeline in a factory for manufacturing semiconductors, a food-related pipeline, and the like. The valve body 1 is provided with a valve body 2, a substantially cylindrical valve body 3, a sheet-type liner 4, and a valve stem 5 composed of an upper valve stem 5a and a lower valve stem 5b.

[0037] The valve body 3 is formed, for example, of cast iron such as malleable cast iron, is provided in a manner capable of being divided into an upper valve body 3a and a lower valve body 3b, and is provided so as to be integrally fixed by means of bolts, not shown in the drawings. The valve body 3 is provided with a flow path opening 10 and a flange 11, and the inner peripheral side of the valve body 3 including them is covered with the sheet-type liner 4. A shaft mounting portion 12 is formed on the shaft mounting side of the valve stem 5 of the upper valve body 3a and the lower valve body 3b, a shaft mounting hole 13 is provided inside the shaft mounting portion 12, and the upper valve stem 5a and the lower valve stem 5b are fitted to the respective shaft mounting holes 13. A polygonal square portion 5c is formed on the lower portion of the upper valve stem 5a.

[0038] ​​​​​​​​​The valve body 2 has a substantially circular plate-shaped metal core 20 formed of a metal material such as stainless steel alloy on the center side, which is covered with a liner layer (liner portion) 22 having a front and back liner portion 32 provided on the front and back sides of the metal core 20, and an outer peripheral liner portion 33 provided on the outer peripheral side of the metal core 20.

[0039] A valve stem insertion hole 23 is formed on the top and bottom sides of the valve body 2, and particularly, a square hole portion 24 into which a square portion 5c of the valve stem 5 can be fitted is formed in the valve stem insertion hole 23 on the top side. The upper valve stem 5a is inserted into the valve stem insertion hole 23 on the top side in such a manner that the square portion 5c is fitted into the square hole portion 24, and the lower valve stem 5b is inserted into the valve stem insertion hole 23 on the bottom side. Thus, the valve body 2 is fitted into the valve body 3 in a state of being axially installed by the upper and lower valve stems 5a and 5b, and the flow path in the valve body can be opened and closed by rotation of the upper valve stem 5a.

[0040] The liner portion (liner layer) 22 is provided, for example, with a resin material such as fluororesin such as PFA (polyfluoroalkyl vinyl ether copolymer), and has, in addition to the front and back liner portion 32 and the outer peripheral liner portion 33, a boss portion 30 and a shaft cylinder liner portion on the upper and lower sides (top and bottom sides). The liner portion 22 is integrally covered on the outer periphery of the front and back surfaces of the metal core 20 by a communication portion 21 formed at an appropriate position of the metal core 20, and is formed in a state of being prevented from being separated from the metal core 20.

[0041] The sealing portion of the valve body 2 of the liner portion 22 and the sheet-type liner 4 is constituted by the boss portion 30 near the top and bottom sides and the valve wing portion 31 as a portion other than the boss portion 30, the sealing property with the sheet-type liner 4 from the open to closed state of the valve is ensured by the boss portion 30, and the sealing property with the sheet-type liner 4 on the valve wing side in the closed state of the valve is ensured by the valve wing portion 31. In this way, the sealing property with the sheet-type liner 4 is exerted on the entire inner peripheral surface by the boss portion 30 and the valve wing portion 31 in the closed state of the valve.

[0042] Here, in the case where the liner portion 22 is formed, the valve main body 1 (metal core 20) is large in diameter, and therefore, more warping is likely to occur on the valve wing side of the metal core 20 at the center of the axis of rotation at the time of casting, and the metal core 20 is likely to be deformed by being deflected downward due to its own weight near the valve wing side at the time of the subsequent liner processing.

[0043] In contrast to this, Figure 2 , Figure 3 In this case, the front and back liner portion 32 is provided so as to have a thickness T1 that is the sum of a predetermined liner thickness and a thickness that is the same as the maximum warping amplitude that can be assumed on the valve wing side of the metal core 20, at least on the outer peripheral side of the metal core 20 on each of the front and back sides of the metal core 20 in which warping is not assumed to occur. By this front and back liner portion 32, the front and back surfaces of the metal core 20 on the valve wing side are both covered in a reliable manner. This front and back liner portion 32 is formed in a state of being prevented from being separated from the metal core 20.Figure 2 and Figure 3 A drawing showing a so-called ideal state in which no warping occurs at the metal core 20, in fact, there are cases in which warping occurs at the metal core 20 from such a state. Regarding the manner in which warping occurs at the metal core 20, the following is described later. Also, in this example, the same thickness of the front and back liner portions 32 is provided on the front and back sides of the metal core 20, but this is not necessarily limited thereto. It is also possible that warping of the metal core 20 easily becomes large toward the valve wing side, so the thickness is increased accordingly toward the valve wing side. Figure 4

[0044] Specifically, in the case of a large-diameter butterfly valve of such a nominal diameter 350A to 600A or so in this example, the respective predetermined liner thicknesses of the front and back sides of the metal core 20 are preferably at least 3 mm or more, and in this example, are set to about 3 mm. On the other hand, the same thickness as the maximum warping amplitude that can be assumed on the valve wing side of the metal core 20 is, the maximum warping amplitude near the valve wing centered on the rotation axis of the metal core 20 is assumed to be 2 mm, and corresponding thereto, about 2 mm is provided on the front and back sides of the metal core 20, respectively. Thereby, the front and back liner portions 32 are provided on each of the front and back sides of the metal core 20, which is assumed not to have warping, according to the sum of the predetermined liner thickness 3 mm and the thickness 2 mm that is the same as the maximum warping amplitude that can be assumed on the valve wing side of the metal core, that is, a thickness Tl of about 5 mm.

[0045] On the other hand, the outer peripheral liner portion 33 is provided on the outer peripheral side of the metal core 20 according to a thickness T2 from the outer peripheral end of the metal core 20 to the end seal surface 41 of the outer peripheral end of the valve body 2, which is constituted by adding a predetermined liner thickness on the outer peripheral side of the metal core 20 and a predetermined crush thickness, and by means of this outer peripheral liner portion 33, the outer peripheral side of the metal core 20 is covered.

[0046] Specifically, the predetermined liner thickness on the outer peripheral side of the valve body 2 is set to about 3 mm, and to this predetermined liner thickness, a predetermined crush thickness is added, thereby constituting the outer peripheral liner portion 33. In this example, the predetermined crush thickness is set to about 1 mm, and according to these predetermined liner thickness and predetermined crush thickness, a necessary thickness is ensured as a thickness of pressure bonding with the sheet liner 4 and a crush allowance on the outer peripheral side of the valve body 2.

[0047] ​Here, the "predetermined liner thickness" is the minimum thickness of the liner layer necessary to prevent the fluid that the valve body 2 can contact from permeating to the metal core 20, and differs depending on the material of the liner layer and the kind of the fluid. In addition, the "minimum thickness" need not be a value that is proven by theory, experiment, or the like, but can be a value that is conventionally necessary to prevent permeation of the fluid on the basis of experience of those skilled in the art. Further, the "predetermined crush thickness" is the amount of irreversible crushing that can occur when the sealing portion of the valve body 2 is repeatedly brought into contact with the sheet liner 4 and crushed when the valve body 2 is opened and closed. The "predetermined crush thickness" can be set in consideration of the size of the valve body 2, the material of the liner portion 22, the amount of pressing of the sealing portion, and the like.

[0048] Further, the "maximum warping range that can be assumed near the valve wing of the metal core 20" is the range of deviation from the designed value of the end portion of the metal core 20 in the case where the maximum warping occurs in the range expected with respect to warping that can occur in casting or the like of the metal core 20, which is centered on the vicinity of the valve wing.

[0049] On the sealing side of the outer peripheral liner portion 33, a convex portion (annular convex portion 40) is provided at a predetermined height, the annular convex portion 40 protrudes to the outer peripheral side of the valve body 2, is connected to the outer periphery of the valve body 2, and is formed in a substantially annular shape, and a terminal sealing surface 41 is formed on the outer peripheral side end surface of the valve body 2 of the annular convex portion 40. The terminal sealing surface 41 is provided at a predetermined sealing width W.

[0050] In this case, the annular convex portion 40 is also set to a predetermined height (predetermined crush thickness) that enables maintenance of sufficient sealing performance in consideration of irreversible leakage that occurs as a result of contact between the sheet liner 4 and the valve seat. As a result, in the outer peripheral liner portion 33, a layer having a predetermined liner thickness is formed on the outer peripheral side of the metal core 20, and the annular convex portion 40 having a predetermined crush thickness is formed on the outer peripheral side thereof. According to such a configuration, it is possible to reliably ensure the predetermined liner thickness on the outer peripheral side of the metal core 20 and also to form the outer peripheral sealing portion to the necessary minimum.

[0051] The aforementioned predetermined sealing width W means a large width of the terminal sealing surface 41 of the annular convex portion 40, which is the main sealing portion of the sheet liner 4, that is necessary to obtain sufficient sealing performance. The predetermined sealing width W can be set to a value that is conventionally used by those skilled in the art.

[0052] The annular convex portion 40 of the present example is formed to a height of about 1 mm in accordance with a predetermined sealing width W of about 3 mm, and the entire outer peripheral liner portion 33 is provided to a thickness of about 4 mm, which is the sum of the predetermined liner thickness (3 mm) and the predetermined crush thickness (1 mm).

[0053] Figure 3In the cross-sectional view of the valve body 20, side surfaces 42 are provided on both sides (upper and lower sides in the drawing) of the annular protrusion 40 toward the end sealing surface 41, and each side surface 42 is formed by an inclined surface inclined with respect to the press-sealing direction of the end sealing surface 41. The angle θ with respect to the press-sealing direction of the end sealing surface 41 is set to 10° or less.

[0054] That is, when the liner layer (liner portion 22) is formed at the metal core 20, the annular protrusion 40 is formed much higher than the predetermined height (larger on the right side in the drawing) before the forming of the liner portion 22, and after the forming, the annular protrusion 40 can be cut at a position of the necessary height. At this time, if the angle θ is 10° or less, the side surfaces 42 of the annular protrusion before the cutting become close to each other in parallel, the width between the side surfaces 42 can be made less variable at the cutting position, and thus the necessary sealing width W can be formed at the end sealing surface 41. Figure 3

[0055] Figure 3 In the present embodiment, the thickness (thickness from the surface of the metal core 20 to the outer surface of the liner portion 22) of the front and back liner portions 32 is larger than the thickness of the outer peripheral liner portion 33, but more preferably, the thickness of the liner portion from the front and back liner portions 32 to the annular protrusion 40 can be uniform. If the thickness of the liner portion is not uniform, a difference in shrinkage can occur due to the difference in thickness at the time of forming of the liner portion, and stress can be concentrated at the thinnest portion, which can become a portion that is likely to be broken. In particular, the root of the annular protrusion 40 is a portion where stress is likely to be concentrated, but by making the thickness from the front and back liner portions 32 to the annular protrusion 40 uniform via the outer peripheral liner portion 33, stress concentration due to the difference in thickness is less likely to occur, and breakage of the liner portion 22 and the like can be easily suppressed.

[0056] The C-surface portion 45 is formed in a ring shape between the end sealing surface 41 and the side surfaces 42, and by providing the C-surface portion 45 (C chamfer), excessive force applied to a portion of the annular protrusion 40 when the annular protrusion 40 comes into contact with the gasket 4 can be prevented. Furthermore, by appropriately setting the size and angle of the C-surface portion 45, the sealing width W of the end sealing surface 41 can also be set to an arbitrary size.

[0057] By forming the above-described liner portion 22 at the valve body 2, when warping or flexing occurs at the metal core 20, the thickness Tl of the front and back liner portions 32 and the thickness T2 of the outer peripheral liner portion 33 and the sealing width W are set to sizes that can reliably exert the sealing property at the time of valve closing, and at this time, the outer peripheral liner portion 33 is suppressed to a thickness that is necessary to maintain the sealing property to the minimum.

[0058] Hereinafter, with reference to the drawings, Figure 4 a case where warping or flexing occurs at the metal core 20 will be described. In this drawing, a partial cross-sectional view of the valve body is shown, Figure 4 ​(a) indicates the warped state without a metal core in this embodiment. Figure 4 (b) indicates a warped state at the metal core in this embodiment. Figure 4 (c) indicates a comparative example.

[0059] Figure 4 In (a), the front and back lining portions 32 are formed with a uniform thickness relative to the front and back sides of the metal core 20, indicating that the outer peripheral lining portion 33 is formed with a uniform thickness on the outer peripheral side. In this case, these front and back lining portions 32 and the outer peripheral lining portion 33 are ensured to have sufficient thickness.

[0060] like Figure 4 As shown in (b), when warping upwards, the front and back lining portions 32 have a thickness equal to the predetermined lining thickness plus the maximum warping amplitude of the pre-conceived metal core 20. Therefore, the front and back lining portions 32 on the upper surface side of the metal core 20 at least ensure the predetermined lining thickness, and the outer peripheral lining portion 33 also at least ensures the predetermined lining thickness. By means of these, fluid penetration and permeation are prevented, and the sealing performance of the sheet lining 4 when the valve is closed is ensured.

[0061] Figure 4 In the case of the lining portion 25 provided in comparative example (c), the lining thickness is not added to both sides of the metal core 20, which is the same as the maximum conceivable warpage on the valve wing side, and the lining thickness with a predetermined sealing thickness is not added to the outer periphery of the metal core 20. In this case, the predetermined lining thickness is insufficient on both sides of the upper surface lining portion. In particular, in this example, the metal core 20 is exposed from the upper part of the lining portion 25 on both sides, so it cannot prevent fluid penetration and permeation. The thickness of the outer periphery lining portion is insufficient, so it is difficult to ensure the sealing performance when the valve is closed.

[0062] When the valve body 2 of this embodiment is applied to a butterfly valve, the annular protrusion 40 is crushed between itself and the sealing surface on the valve body side, thus achieving a seal. In this case, to obtain a good seal, the outer peripheral side surface 20a of the metal core 20 can be reliably positioned opposite the annular protrusion 40. Therefore, it is preferable that the annular protrusion 40 is supported by the metal core 20. Furthermore, as mentioned above, the larger the diameter, the easier it is for warping and deflection to occur at the metal core 20. However, if the outer peripheral side surface 20a of the metal core 20 deviates from the annular protrusion 40 due to warping or deflection, it is possible that a sufficient seal cannot be obtained.

[0063] Therefore, in this example, the outer peripheral side surface portion 20a of the metal core 20 has a width that enables the central portion of the thickness direction of the annular protrusion 40 to be faced even when the metal core 20 is warped by a maximum warp amplitude that can be assumed on the valve wing side. For example, in the case where the metal core 20 is assumed to be warped by a maximum of about 2 mm, the width of the outer peripheral side surface portion 20a is preferably greater than 4 mm. Even if the metal core 20 is warped by a maximum of 2 mm, the central portion of the annular protrusion 40 is positioned to face the outer peripheral side surface portion 20a of the metal core 20, so that a decrease in sealing performance due to warping or flexing of the metal core 20 can be prevented.

[0064] The valve body 2 in which the liner portion 22 is provided on the surface of the metal core 20 described above can be manufactured, for example, as follows. Figure 6 is a schematic diagram of a molding metal mold for a butterfly valve, and although not shown, a valve stem or valve stem clamp is inserted into a valve stem insertion hole, and the valve stem or valve stem clamp is held by a lower metal mold.

[0065] First, the metal core 20 is prepared, and the valve stem 5 or an upper and lower valve stem clamp (not shown) that is the same shape as the valve stem, or the like is inserted into the valve stem insertion hole 23 of the upper valve stem 5a and the lower valve stem 5b of the metal core 20, and the metal core 20 is fixed (the valve stem insertion hole 23 of the metal core 20 is described with reference to Figure 1 and the like).

[0066] Next, while the upper and lower valve stems 5a, 5b or the upper and lower valve stem clamps (hereinafter, valve stem clamps) are held, the metal core 20 is disposed in a predetermined resin molding forming region D of a lower metal mold 100b of a mold (metal mold) 100 for forming. At this time, the upper and lower valve stems 5a, 5b or the valve stem clamps are fixed by a holding member or the like so that the metal core 20 does not move in the rotational direction. Here, the holding member can be fixed by any method as long as the metal core 20 does not rotate, and for example, can be a holding member that is fixed in a manner in which the upper and lower valve stems 5a, 5b or the valve stem clamps are sandwiched from both sides, or can be a holding member that is integral with the metal mold by providing a recess or the like for holding the valve stem at the metal mold.

[0067] Next, the metal mold 100 is fixed by a fixing member (not shown) or the like by covering the upper metal mold 100a from above the lower metal mold 100b. At this time, a space S for forming the liner portion 22 is provided around the metal core 20 between the upper metal mold 100a, the lower metal mold 100b, and the region in which the metal core 20 is disposed.

[0068] Figure 6In this case, after the kettle 200 is filled with the resin material 300, the resin material 300 is extruded by the extrusion member 201, and the resin material 300 is injected (introduced) into the space S from the injection port 100c provided in the metal mold 100, and the resin material 300 is hardened to form the liner portion 22 covering the metal core 20.

[0069] Further, the annular layer portion 100d is provided in the metal mold 100. The resin material 300 is pressed into the annular layer portion 100d, and the annular protrusion 40 is formed on the outer circumferential side of the liner portion 22 of the metal core 20.

[0070] After the resin material is sufficiently hardened, the metal core 20 on which the liner portion is formed is taken out of the metal mold 100, and the unnecessary portion is cut off at the annular protrusion 40 formed on the outer circumference of the valve body, and the liner-type butterfly valve having the end sealing surface 41 having a predetermined sealing width W can be manufactured.

[0071] Further, in the above-described method, if the upper and lower valve stems 5a and 5b or the valve stem clamp or the like is fixedly held, the metal core 20 can be arranged at the correct position in the molding area D in the metal mold 100, and thus the inclination or deviation of the liner portion 22 when the liner portion is formed can be prevented, and the liner portion 22 having a necessary thickness can be easily formed.

[0072] In this case, particularly in the case of a large-diameter butterfly valve, there is a tendency that the metal core 20 is easily warped or deflected compared to a small-diameter butterfly valve, and the shape of the liner portion 22 is set to satisfy a predetermined condition, so that the liner portion 22 having a necessary thickness can be formed even if the metal core is warped or deflected, and it is particularly important that the position of the metal core 20 in the molding area in the metal mold is correctly aligned when the liner portion 22 is formed. According to the above-described method, the upper and lower valve stems 5a and 5b or the valve stem clamp or the like fixedly held at the metal core 20 can be correctly aligned in the metal mold 100.

[0073] Figure 5 In this case, the boss portions 30 of the top side and the bottom side of the valve body are arranged in a press-sealed state, and the boss surfaces 4d formed on the top side and the bottom side of the sheet-type liner 4 fitted to the valve body 3, and the sealing of the boss portions from the valve opening to the valve closing state is ensured by the boss portions 30 and the boss surfaces 4d.

[0074] Figure 1In the present embodiment, the sheet-type liner 4 is provided with a predetermined wall thickness by the same material as the liner portion 22 of the valve body 2, i.e., a resin material such as PFA, and covers the inner peripheral side of the valve body 3 as described above, and is configured to exhibit high corrosion resistance and heat resistance. The sheet-type liner 4 has an annular portion 4a fitted to the inner peripheral side of the valve body 3, flange portions 4b protruding from the outer peripheral edges of both ends of the annular portion 4a, and cylindrical liner portions 4c, 4c protruding in the mounting direction of the valve stem 5 at the fitting positions of the upper and lower valve stems 5a, 5b, and are integrally formed. The cylindrical liner portions 4c are fitted to the upper and lower valve stems 5a, 5b.

[0075] The valve stems inserted into the shaft mounting portions 12 on the upper and lower sides of the valve body 3 are respectively provided with a washer 51, a ring body 52, a sealing bush 53, an O-ring 54, and a cylindrical bearing 55. Further, a spring 56 composed of a coil spring is fitted to each of the shaft mounting portions 12 on the upper and lower sides. The valve body 2 is rotatably mounted in the valve body 3 in a state where the upper and lower sides are covered by the liner portion 22 and are axially sealed by the shaft mounting portions 12.

[0076] In each of the shaft mounting portions 12 on the upper and lower sides, a set of washers 51 facing each other in the insertion direction of the upper valve stem 5a and the lower valve stem 5b is fitted. The set of washers 51 is composed of a combination of concave-convex shapes, and the combination of concave-convex shapes is configured such that, even when a surface pressure applied to the boss portion 30 of the valve body 2 from the valve stem 5 (the upper and lower valve stems 5a, 5b) is deviated or inclined between the valve stem 5 and the valve body 2, the state is substantially the same as a state in which the surface pressure is not deviated or inclined.

[0077] Specifically, the washer 51 is composed of a convex washer 60 and a concave washer 61. In the convex washer 60, a convex spherical surface 62 is provided on one side, and in the concave washer 61, a concave spherical surface 63 that contacts the convex spherical surface 62 is provided on one side. The convex washer 60 and the concave washer 61 are fitted in a pressed state in a direction facing each other by the repulsive force of the spring 56 fitted in the shaft mounting portion 12. The mounting structure of the washer 51 is provided in a symmetrical fitting state in the upper and lower shaft mounting portions 12.

[0078] When fluid pressure is applied to the valve body 2, the valve body 2 moves in that direction, and thus it is considered that the valve stem 5 (the upper and lower valve stems 5a, 5b) is inclined with the center position of each bearing 55 as the center. Therefore, from the viewpoint of sliding on the spherical surface along the inclination of the valve stem 5, the center position of the sphere is made the center position of the upper and lower bearings 55, and the imaginary spherical surface formed in the position of the washer 51 is made to coincide with the facing spherical surfaces of the convex washer 60 and the concave washer 61.

[0079] The valve stem 5 is inclined at the maximum to the space on the valve body 2 side existing around the end portion side, so the convex spherical surface 62 and the concave spherical surface 63 are formed in a shape to the extent that they can correspond to the inclination. For example, in the case where the valve stem 5 is inclined at an angle of 1° at the maximum, the convex spherical surface 62 and the concave spherical surface 63 are set in a spherical surface shape corresponding to the inclination at an angle of 1° at the maximum.

[0080] The radius of the spherical surface assumed in this example is set to 110 mm, and the convex spherical surface 62 and the concave spherical surface 63 are formed by this radius. Thereby, even if the valve stem 5 (the upper valve stem 5a, the lower valve stem 5b) is inclined and a deviation or an inclination occurs between the valve stem 5 and the valve body 2, the face pressure of the inclination of the bearing 55 is uniformly transmitted from the convex spherical surface 62 to the concave spherical surface 63.

[0081] The convex spherical surface 62 and the concave spherical surface 63 are preferably formed in a manner that they easily slide with respect to each other, and in this embodiment, the inner and outer circumferential diameters of the convex washer 60 are set to be slightly smaller than those of the concave washer 61, and appropriate spaces (not shown) are provided on the inner and outer circumferential sides of the convex washer 60. Therefore, the convex washer 60 can easily swing in the circumferential direction with respect to the concave washer 61.

[0082] The bearing 55 is arranged between the spring 56 and the ring body 52, and by this bearing 55, the upper valve stem 5a and the lower valve stem 5b are rotatably supported in the vicinity of the O-ring 54 and in a self-aligning state, respectively.

[0083] The ring body 52 is provided in a cylindrical shape by a stainless steel material so as to strongly push the position of the outer circumference of the boss portion 30 of the valve body 2 from the upper side, the valve body 2 is in a rotatable state, and the ring body 52 is provided so that the opening force of the spring 56 can be transmitted to the valve body 2 side through the bearing 55.

[0084] On the upper side of the upper valve body 3a, a bearing member 70 rotatably supporting the upper valve stem 5a is arranged in a state of being caught by a retaining ring 71, and by this bearing member 70, the spring 56 is held in a state of being able to open downward.

[0085] On the other hand, on the lower valve body 3b side, a block member 72 is arranged in a state of being caught by the retaining ring 71, a bearing member 73 rotatably supporting the lower valve stem 5b is overlapped on the block member 72, and the spring 56 is held in a state of being able to open upward by passing through the bearing member 73. By the aforementioned bearing members 70, 73 and the block member 72, the springs 56, 56 are respectively opened in the direction of the valve body 2. O-rings 74, 74 for dust and water prevention are fitted on the inner and outer circumferences of the bearing members 70, 73 and the block member 72, respectively.

[0086] The sealing bush 53 is formed of a resin material such as PTFE (polytetrafluoroethylene) containing carbon fibers, and is provided as a sealing portion between the ring body 52 and the liner portion 22 and the gasket liner 4. An annular flange portion 53a is formed in the lower side of the sealing bush 53 in a manner bent outward in the circumferential direction. The end face side of the ring body 52 is provided so as to abut against the flange portion 53a, whereby the ring body 52 pushes the gasket liner 4 of the boss portion 30 at the top and bottom of the valve body 2 through the flange portion 53a.

[0087] With the above structure, in the valve body 1, Figure 1 the gasket liner 4 of the boss portion 30 at the top and bottom of the valve body 2 is pushed through the ring body 52 by the spring opening force of the spring 56 provided in the shaft mounting hole 13 of the valve stem 3, whereby the sealing properties of the top and bottom portions are ensured, respectively.

[0088] Further, in the above embodiment, the thickness of the portions of the front and back liner portions 32 and the outer peripheral liner portion 33 corresponding to the warping of the metal core 20 can be further thickened, and the thickness corresponding to the maximum warping amplitude that can be assumed can be added to the entire surface of the metal core 20.

[0089] The gasket 51 can also be disposed at an arbitrary position of the shaft mounting portion 12, and a conical shape other than a spherical shape, or the positional relationship of the upper and lower portions in reverse can be provided as long as the convex gasket and the concave gasket can slide with respect to each other. Further, the gasket can be provided in a manner that does not swing the set of gaskets.

[0090] A coil spring is used as the spring 56, but the present application is not limited thereto, and for example, a disc spring or the like can be used.

[0091] Next, the effects of the above embodiment of the liner type butterfly valve of the present application will be described. Figures 1-3 In the above embodiment, the valve body 1 is provided with the liner portion 22, the liner portion 22 is provided with the front and back liner portions 32 and the outer peripheral liner portion 33, and the metal core 20 is covered by the liner portion 22, so the chemical resistance and heat resistance can be maintained even when the valve body 1 is made large in diameter to a nominal diameter of 350A to 600A or so.

[0092] In this case, the front and back liner portions 32 are each provided with a thickness Tl of 5 mm, which is the predetermined liner thickness of 3 mm plus a thickness of 2 mm corresponding to the maximum warping amplitude that can be assumed on the valve wing side of the metal core 20, and thus even when warping occurs at the metal core 20 at the time of casting, or the valve wing side is deformed by being deflected downward by the weight when the liner is processed by the liner forming mold, Figure 6 the necessary liner thickness can be applied to the front and back surfaces of the metal core 20, and the penetration and permeation of fluid can be prevented by the liner portions 32, whereby the chemical resistance and heat resistance can be ensured.

[0093] On the other hand, the outer peripheral lining portion 33 is set to a thickness T2 of 4 mm, which is the sum of a predetermined lining thickness of 3 mm and a predetermined crushing thickness of 1 mm on the outer peripheral side of the metal core 20. An annular protrusion 40 is formed on the sealing side of the outer peripheral lining portion 33. Therefore, the shape of the metal core 20 is not precisely set, and it is not limited to the thickness or tapered shape of the outer peripheral end side of the metal core 20. It is possible to easily form an outer peripheral sealing portion with the necessary sealing width W.

[0094] The predetermined sealing width W of the annular protrusion 40 is set to the width necessary for the valve body 2 of the size in this embodiment, which is 3 mm. Therefore, when the valve is closed, the outer peripheral lining portion 33 including the annular protrusion 40 is pressed by the outer peripheral surface of the metal core 20, and the end sealing surface 41 of the annular protrusion 40 is pressed against the annular sealing surface 43 of the inner periphery of the sheet lining 4 to effectively prevent leakage.

[0095] Furthermore, the outer peripheral side surface 20a of the metal core 20 has a width such that even if the metal core 20 warps at the valve wing side with the maximum conceivable warping amplitude, it can face the central portion of the annular protrusion 40 in the thickness direction. Therefore, even if the warping of the metal core 20 becomes maximum, the outer peripheral side surface 20a and the central portion of the annular protrusion 40 will always face each other. Thus, even if the metal core 20 warps or flexes, the decrease in sealing performance can be prevented.

[0096] Furthermore, by using an inclined surface with an angle θ of 10° relative to the pressing and sealing direction of the end sealing surface 41, the side portions 42 of the annular protrusion 40 are parallel to each other in relation to the pressing and sealing direction of the end sealing surface 41. Therefore, the annular protrusion 40 is formed relatively long in advance during molding, and by cutting off its excess portion, it becomes easy to process into a predetermined sealing width W.

[0097] like Figure 5 As shown, a set of washers 51, consisting of a convex washer 60 and a concave washer 61, is assembled within the upper and lower shaft-mounted portions 12, in a state where the convex spherical surface 62 and the concave spherical surface 63 are pressed together by the spring force of the spring 56. Thus, even when the valve body 2 moves and tilts at the valve stem 5, the convex spherical surface 62 slides relative to the concave spherical surface 63, the convex washer 60 tilts together with the valve stem 5, while the predetermined orientation of the concave washer 61 is maintained. Therefore, even if the pushing force of the spring 56 is applied in a way that the tilt of the valve stem 5 is relative to the boss surface 4d, it is converted into a force perpendicular to the boss surface 4d by the washer 51. Without this washer 51, the pushing force of the spring 56 is applied tilted to the boss surface 4d, so the pushing force towards the circular boss surface 4d is inconsistent in the circumferential direction, and leakage may occur in the weakened portion. In contrast, with the help of washer 51, the pushing force is converted to be perpendicular to the boss surface 4d, so that the force is applied evenly in the circumferential direction of the boss surface 4d.

[0098] According to the above, the tightness of both the boss portion side and the valve wing portion side other than the boss portion of the valve body 2 is ensured at the time of valve closing, and for example, even in the case where the valve main body 1 is made large in diameter to a nominal diameter of 350A to 600A or so, the sealing can be improved throughout the entire circumference of the valve body 2.

[0099] The above describes embodiments of the present application in detail, but the present application is not limited to the above-described embodiments, and various modifications can be made within the scope of the present application recited in the claims without departing from the spirit of the present application.

[0100] Explanation of Reference Numerals

[0101] 1 Valve main body

[0102] 2 Valve body

[0103] 3 Valve stem

[0104] 4 Split liner

[0105] 5 Valve stem

[0106] 5a Upper valve stem

[0107] 5b Lower valve stem

[0108] 12 Shaft attachment portion

[0109] 20 Metal core

[0110] 20a Outer peripheral side surface portion

[0111] 22 Liner portion (liner layer)

[0112] 23 Valve stem insertion hole

[0113] 30 Boss portion

[0114] 32 Front and back side liner portion

[0115] 33 Outer peripheral liner portion

[0116] 40 Annular convex portion (convex portion)

[0117] 41 Tip sealing surface

[0118] 42 Inclined surface (side surface portion)

[0119] 51 Gasket

[0120] 56 Coil spring (spring)

[0121] 60 Convex gasket

[0122] 61 Concave gasket

[0123] 62 Convex spherical surface

[0124] 63 concave spherical surface

[0125] 100 mold for molding (metal mold)

[0126] 100a upper metal mold

[0127] 100b lower metal mold

[0128] T1, T2 thickness

[0129] W predetermined sealing width

[0130] θ angle

Claims

1. A lining type butterfly valve characterized in that, in a butterfly valve in which a valve body covered with a lining layer is rotatably disposed in a valve body by a valve shaft, the aforementioned lining layer has a front and back lining portion disposed on the front and back sides of the aforementioned metal core, an outer peripheral lining portion disposed on the outer peripheral side of the aforementioned metal core, the aforementioned front and back lining portion is disposed so as to have, on each side of the front and back sides of the metal core assuming no warping, at least at the outer peripheral end position of the aforementioned metal core, a thickness that adds a predetermined lining thickness to a thickness that is the same as the maximum warping amplitude that can be assumed on the valve wing side of the aforementioned metal core, and the thickness of the aforementioned outer peripheral lining portion from the outer peripheral end of the aforementioned metal core to the end sealing surface of the outer peripheral end of the aforementioned valve body is a thickness that adds a predetermined crush thickness to the predetermined lining thickness, the aforementioned predetermined lining thickness is the minimum thickness of the lining layer necessary so that fluid does not permeate to the aforementioned metal core, the aforementioned maximum warping amplitude that can be assumed on the valve wing side of the aforementioned metal core is the deviation amplitude from the designed value of the end portion of the aforementioned metal core in the case of the maximum warping occurring in the range of warping that can occur around the valve wing when the aforementioned metal core is cast, the aforementioned predetermined crush thickness is the amount of irreversible crushing that occurs when the sealing portion of the aforementioned valve body is crushed repeatedly by the sheet lining when the aforementioned valve body is opened and closed.

2. The lining type butterfly valve according to claim 1, characterized in that, in the aforementioned outer peripheral lining portion, a protruding portion that protrudes toward the outer peripheral side of the aforementioned valve body is connected to the outer peripheral side of the aforementioned valve body to be formed in a substantially ring shape, and the outer peripheral side end surface of the aforementioned protruding portion is the aforementioned end sealing surface having a predetermined sealing width.

3. The lining type butterfly valve according to claim 2, characterized in that, the aforementioned metal core has an outer peripheral side surface portion at the outermost periphery thereof, the outer peripheral side surface portion having a width that is able to face the central portion in the thickness direction of the aforementioned protruding portion provided in the aforementioned outer peripheral lining portion even when the metal core on the valve wing side of the aforementioned metal core warps by the maximum warping amplitude that can be assumed.

4. The lining type butterfly valve according to claim 2, characterized in that, each side surface portion of the aforementioned protruding portion that faces the aforementioned end sealing surface is formed by an inclined surface having an angle of 10° or less with respect to the direction of the press contact seal of the aforementioned end sealing surface.

5. The lining type butterfly valve according to claim 3, characterized in that, each side surface portion of the aforementioned protruding portion that faces the aforementioned end sealing surface is formed by an inclined surface having an angle of 10° or less with respect to the direction of the press contact seal of the aforementioned end sealing surface.

6. The lining type butterfly valve according to any one of claims 1 to 5, characterized in that, a set of gaskets that face each other in the insertion direction of the aforementioned valve shaft are fitted in the shaft fitting portion of the aforementioned valve shaft, the set of gaskets is composed of a combination of concave-convex shapes that are able to make the surface pressure applied to the boss portion formed at the aforementioned valve body from the side of the aforementioned valve shaft substantially the same even when a deviation or inclination occurs between the aforementioned valve shaft and the aforementioned valve body.

7. The lining type butterfly valve according to claim 6, characterized in that, The aforementioned gasket is composed of a convex gasket having a convex spherical surface and a concave gasket having a concave spherical surface for contacting the aforementioned convex spherical surface, and the aforementioned convex gasket and the aforementioned concave gasket are assembled in a pushing state in a direction toward each other by the springing force of a spring assembled in the aforementioned shaft mounting portion.

8. A lined butterfly valve characterized by In a butterfly valve in which a valve body covered with a liner layer is rotatably disposed in a valve body by a valve shaft, the aforementioned liner layer has a front and back liner portion disposed on the front and back sides of the aforementioned metal core, and an outer peripheral liner portion disposed on the outer peripheral side of the aforementioned metal core, the aforementioned front and back liner portions have at least a predetermined liner thickness on the front and back sides of the aforementioned metal core, and at least at the outer peripheral end position of the aforementioned metal core, the front and back sides have a thickness that is the predetermined liner thickness plus a thickness that is the same as the maximum warping amplitude that can be assumed on the valve wing side of the aforementioned metal core, and the thickness of the aforementioned outer peripheral liner portion from the outer peripheral end of the aforementioned metal core to the end sealing surface of the outer periphery of the aforementioned valve body is a thickness that is the predetermined liner thickness plus the predetermined crush thickness, The aforementioned predetermined liner thickness is the minimum thickness of the liner layer necessary to prevent fluid from penetrating into the aforementioned metal core, The aforementioned maximum warping amplitude that can be assumed on the valve wing side of the aforementioned metal core is the warping that can occur in the vicinity of the valve wing when the aforementioned metal core is cast, and the deviation from the design value of the end of the aforementioned metal core in the case of the maximum warping in the assumed range, The aforementioned predetermined crush thickness is the amount of irreversible crushing that occurs when the sealing portion of the aforementioned valve body is crushed repeatedly by the sheet liner when the aforementioned valve body is opened and closed.

9. A manufacturing method for a lined butterfly valve, the manufacturing method being the manufacturing method for a lined butterfly valve according to any one of claims 1 to 8, characterized by At the aforementioned metal core, a valve shaft or a valve shaft jig is inserted into a valve shaft insertion hole disposed at a position facing the valve wing portion of the metal core, the metal core and the valve shaft or the valve shaft jig are fixed to each other, the aforementioned metal core is disposed in a molding space of a mold for molding the aforementioned liner layer, and by maintaining the state in which the upper and lower valve shafts or the upper and lower valve shaft jigs are fixed to the aforementioned metal core without moving, the material for forming the aforementioned liner layer is introduced into the aforementioned molding space, whereby the aforementioned liner layer is formed on the surface of the aforementioned metal core.

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