JP6636281B2 - Seat liner and butterfly valve for lining type butterfly valve - Google Patents

Description

The present invention relates to a sheet liner and butterfly valves mounted to the body inner peripheral surface of the lining type butterfly valve.

  Conventionally, as a butterfly valve with chemical resistance and corrosion resistance used for flowing highly corrosive fluids and high-temperature fluids in plants for the chemical industry and for food-related flow paths, resin on the inner peripheral surface of the valve box A so-called lining type butterfly valve in which a sheet liner made of a resin is attached and a metal core body of a valve body is covered with a resin lining layer is often used.

For example, Patent Document 1 discloses a lining type butterfly valve of this type. In this butterfly valve, the inner periphery of the body and the outer periphery of the valve body are provided in a lining structure in which a resin such as PFA is coated.
In the butterfly valve of Patent Document 2, a seat liner used for a butterfly valve having a lining structure is disclosed. On the inner peripheral surface of this seat liner, a concave ridge is formed to closely contact the outer peripheral edge of the valve body so as to extend in the circumferential direction. A flexible portion protruding from the valve body is formed, and the flexible portion is provided with a spindle portion forming a top-side sealing surface with the valve body.

  In such a butterfly valve, it is particularly important to secure the sealing performance with the valve body to reliably prevent leakage, and to suppress torque at the time of operating the valve body to improve operability. For this reason, the top and bottom sealing surfaces of the seat liner are provided in a concave spherical shape, and the valve top and bottom sides are provided with a structure in which the valve body top surface is surface-sealed on the concave spherical surface, like the support shaft portion of Patent Document 2. General.

When the sheet liner is provided in such a shape, usually, the sheet liner is formed by die molding. For example, the liner member 2 is formed by transfer molding in a die 1 as shown in FIG. The mold 1 includes an upper mold section 3, a lower mold section 4, and a cylindrical split mold section 5, and a cavity section 6 for molding the liner member 2 is formed inside by combining these. The upper mold part 3 is provided in a lid shape and can be fitted from the outer peripheral side of the split mold part 5. The split mold part 5 is provided so as to be splittable into two parts, and on one side, a bar-shaped ridge part 8 for forming a stem insertion hole 7 in the liner member 2 is formed. A cylindrical projection 10 having an insertion hole 9 into which the projection 8 can be inserted is formed on the lower mold 4 at an upper side.
When the liner member 2 is formed, as shown in the figure, the split mold portions 5 are placed on the lower mold portion 4 while being combined from the left and right, and the upper mold portion 3 is mounted from above, and the mold 1 is assembled. Then, a resin material is injected into the cavity 6 in this state. In this case, the mold 1 is often provided in such a manner that the liner member 2 is molded with a substantially constant thickness in order to prevent defects in molding.

JP-A-61-119881 JP 2012-219819 A

However, in the butterfly valve of Patent Literature 1, when the thickness of the liner portion 2 is provided to be substantially constant as shown in FIG. 8A, the inner diameter end portion 11 on the flow path side has a shape that is enlarged toward the opening side. In order to form the enlarged diameter portion, the portion of the lower mold portion 4 becomes the convex portion 12 whose diameter is increased toward the inner diameter end portion 11 side. For this reason, the upper mold part 3 and the split mold part 5 are removed from the lower mold part 4, and when the liner member 2 is released from the lower mold part 4 in FIG. The concave spherical surface 13 is hooked and becomes difficult to pull out. If the liner member 2 is forcibly pulled out in this state, the concave spherical surface 13 of the liner member 2 is pushed out from the edge side by the convex portion 11 and deformed, or as shown in FIGS. 9 (a) and 9 (b). There is a possibility that the concave spherical surface 13 may be crushed by the convex portion 12 and may be damaged. In this case, after the liner member 2 is mounted on the valve, the sealing performance with the valve body and the torque performance are adversely affected, and these functions are not performed. May not be able to be fully exhibited.
Further, as the nominal diameter of the liner member 2 becomes smaller, for example, 50A or 65A, it becomes more difficult to spread the liner member 2 at the time of release from the mold.

As a countermeasure, if the thickness of the entire liner member 2 is reduced, the releasability can be improved. However, there is a new problem that the fluid permeability resistance is reduced as the entire liner member 2 becomes thinner. For example, when chlorine is flowed as a fluid, when chlorine permeates the liner member 2 and comes into contact with water. Due to the change to hydrochloric acid, the body of the valve, such as ductile cast iron, may be corroded.
On the other hand, in order to improve the releasability, it is conceivable to increase the thickness of the entire liner member 2 to reduce the amount of diameter expansion of the convex portion 12, but when the entire liner member 2 is thickened, Sometimes the resin shrinks and defects such as shrinkage tend to occur.

  Further, in Patent Document 2, a flexible portion around a shaft hole of a seat liner is protruded in a plane toward an inner peripheral surface. However, this flexible portion deflects a support shaft portion toward a valve body. It is intended to ensure airtightness with the valve body, and does not describe or suggest preventing forcible removal of the seat liner.

The present invention has been developed in order to solve the conventional problems, and its object is to improve the mold releasability from the mold without making the entire body thinner or thicker. A lining type butterfly valve with excellent chemical and corrosion resistance that can be formed while preventing deformation and damage due to contact, and that ensures sealing with the valve near the stem mounting side and low torque during valve operation. It is to provide a seat liner and butterfly valves.

In order to achieve the above object, an invention according to claim 1 includes a liner main body formed of a fluororesin material and an inner peripheral seal provided on a valve seat surface along an inner periphery of a cylindrical flow path of the liner main body. And a concave spherical portion serving as a top and bottom sealing surface with the valve body is provided following the inner peripheral sealing surface, and at least one of the liner main body opening end sides with the outer periphery of the concave spherical portion as a peak. A substantially flat portion having a chordal cross section is provided up to the flow channel end toward the flow channel end direction, and the substantially flat portion is provided substantially parallel to the flow channel and at a substantially constant width. in the flow path direction of the end edge portion of the substantially flat portion of the rectangular position and length of a chord which is provided in the circumferential direction, the maximum diameter and equal to or of the concave spherical surface portion, slightly shorter form the lining form Butterfly valve seat liner.

The invention according to claim 2 is a lining type butterfly valve using the seat liner.

According to the first aspect of the present invention, the substantially flat portion having a chordal cross section is provided in the vicinity of the concave spherical portion, so that the whole is not thinned or thickened at the time of molding, and is provided at the end of the flow path. Since the projecting portion of the mold is not located, forcible removal with the mold is eased, the releasability is improved, and molding can be performed while preventing contact with the mold. As a result, there is no possibility that the concave spherical portion is deformed or damaged, and the concave spherical portion can be disposed in a well-balanced manner without affecting the spherical seal of the concave spherical portion. It is possible to provide a resin-made sheet liner that has excellent chemical resistance and corrosion resistance while ensuring low torque at the time. In addition, the length of the chord is equal to or slightly shorter than the maximum diameter of the concave spherical part, and the size of the substantially flat part is kept to a minimum while securing the size of the substantially flat part and eliminating forcible removal As a result, it is possible to suppress molding defects in the substantially flat portion, suppress the influence on the concave spherical portion, and secure the sealing performance of the concave spherical portion with the valve element and low torque during operation of the valve element. Further, by providing the substantially flat portion with a uniform width in the flow path direction, it is possible to improve the releasability while suppressing defects such as shrinkage of the resin during molding.

  According to the second aspect of the present invention, the length of the chord is equal to or slightly shorter than the maximum diameter of the concave spherical portion, so that the size of the substantially flat portion is ensured, and the forcible removal is eliminated, and Part is minimized to suppress molding defects in the substantially flat part, and the effect on the concave spherical part is suppressed, ensuring the sealing performance of the concave spherical part with the valve element and low torque during operation of the valve element. ing.

According to the second aspect of the present invention, it is possible to provide a resin-lined butterfly valve having excellent chemical resistance and corrosion resistance capable of ensuring the accuracy of the concave spherical portion and ensuring the sealing property and the low torque property at the time of operating the valve body.

It is a longitudinal section showing the butterfly valve using the seat liner of the lining type butterfly valve of the present invention. It is a longitudinal cross-sectional view of FIG. It is a perspective view showing the seat liner of the lining type butterfly valve of the present invention. It is a partially expanded sectional view of a seat liner. (A) is a partial expanded sectional view of the upper part of a sheet liner. (B) is a partially enlarged sectional view of a lower portion of the seat liner. It is AA sectional drawing of FIG.4 (b). It is the schematic model which showed the comparative example of the substantially plane part. FIG. 3 is a longitudinal sectional view showing a molding apparatus of the seat liner. It is a longitudinal section showing the conventional metallic mold. FIG. 9 is an enlarged sectional view showing a main part of the mold of FIG. 8.

  An embodiment of a seat liner of a lining type butterfly valve and a butterfly valve using the seat liner according to the present invention will be described below in detail with reference to the drawings. 1 and 2 are sectional views of a butterfly valve using the seat liner of the present invention, and FIG. 3 is a perspective view of the seat liner. Here, the “lining type” of the present invention includes not only a case where a metal core material is covered and molded with a resin material or the like but also a case where it is molded with a resin material or the like alone.

  The butterfly valve (hereinafter, referred to as a valve body 20) shown in FIGS. 1 and 2 is provided, for example, with a small diameter of about 50A to 65A in nominal diameter, and is used in a chemical industry plant, a food-related pipeline, and the like. . The valve body 20 according to the present embodiment is provided with a nominal diameter of 65A and includes a seat liner (hereinafter, referred to as a liner body 21), a substantially cylindrical valve body 22, a valve body 23, and an upper stem 24. The main body 21 is molded by a molding device described below (hereinafter, referred to as an apparatus main body 25) and is incorporated into the body 22.

  The liner main body 21 shown in FIGS. 3 to 5 is formed of, for example, a fluororesin material such as PFA (tetrafluoroethylene / perfluoroalkylvinyl ether copolymer) so as to exhibit high corrosion resistance and heat resistance. It is mounted on the inner peripheral surface 29 so as to be able to seal with the valve body 23. The liner body 21 has a cylindrical flow path 26 and a valve seat surface 27 with the valve element 23 on the inner periphery of the flow passage 26. The valve seat surface 27 has an inner peripheral seal surface 28 and a concave spherical portion 30. , 31. The flow path 26 of the liner main body 21 is formed so as to be inclined toward the opening side at an inclination angle α = 5 ° with respect to the axis P as shown in FIG. A concave bag-like portion 32 is provided on the lower side of the liner body 21, and a tubular portion 33 is formed on the upper side so as to extend upward.

As shown in FIGS. 3 and 4 , the inner peripheral sealing surface 28 is provided on an arc-shaped valve seat surface along the inner peripheral surface of the cylindrical flow passage of the liner main body 21. Thus, concave spherical portions 30 and 31 are provided on the top and bottom sealing surfaces with the valve body 23 on the upper (top) side and the lower (ground) side, respectively.

  In the vicinity of the concave spherical portions 30, 31, substantially flat portions 40, 41 having a chordal cross section are provided so as to be adjacent to each other. Only locally thickened compared to other parts. The substantially flat portions 40 and 41 are provided on at least one end in the flow path 26 direction, that is, at least on the drawing end 21a side of the liner main body 21 of the molding die 42 of the apparatus main body 25 described later in FIG. I just need. In the present embodiment, as shown in FIG. 4, substantially flat portions 40 and 41 are provided on both upper and lower ends of the liner body 21, whereby the liner body 21 is provided in a symmetrical shape.

  The substantially flat portions 40 and 41 are formed from the concave spherical portions 30 and 31 on the top and bottom sides of the liner main body 21 to the vicinity of the end 26a of the flow path 26, and chords 45 and 46 are formed in the circumferential direction of the substantially flat portions 40 and 41. Each is configured. That is, the continuum of the strings 45 and 46 in the flow path direction becomes the substantially flat portions 40 and 41. In this case, the lengths L1 and L2 of the chords 45 and 46 at the ends of the substantially flat tops 40 and 41 shown in FIG. 3 are the maximum diameters of the concave spherical portions 30 and 31 at the top and bottom shown in FIG. Are respectively equal to or slightly shorter than the outer diameters φdW1 and φdW3.

  In the valve body 20 having a nominal diameter of 65 A according to the present embodiment, the concave spherical portion 30 on the upper side has a large diameter and the concave spherical portion 31 on the lower side has a small diameter. The length L1 is long, and the length L2 of the lower string 46 is short. In this case, the relationship between the outer diameter φdW1 of the upper concave spherical portion 30 and the inner diameter φdW2 of the concave spherical portion 30 which is the hole diameter of the upper stem 24 is as follows: the inner diameter φdW2 of the concave spherical portion 30 <the length L1 of the string 45 ≦ the concave shape. The relationship between the outer diameter φdW3 of the concave spherical portion 31 on the lower side and the inner diameter φdW4 of the concave spherical portion 31 is set such that the outer diameter φdW1 of the spherical portion 30 is smaller than the inner diameter φdW4 of the concave spherical portion 31 <length of the chord 46. It is set so that L2 ≦ the outer diameter φdW3 of the concave spherical portion 31.

  Further, the substantially flat portions 40 and 41 are formed such that the thickness of the liner body 21 on the concave spherical portions 30 and 31 side in the direction of the axis P of the flow path 26 gradually decreases in the mounting direction of the valve body 23. Is done. Specifically, the concave spherical portions 30 and 31 are formed so as to be inclined in the axial direction of the valve element 23, and the back surfaces of the concave spherical portions 30 and 31 are formed substantially parallel to the axis P of the flow path 26. By doing so, the thickness is gradually reduced.

  Moreover, the substantially flat portions 40 and 41 are formed by inclined surfaces having an inclination angle β toward the end 26a of the flow path 26 with the outer circumferences 30a and 31a of the concave spherical portions 30 and 31 as peaks. Therefore, the strings 45 and 46 according to the present invention include not only a general straight line connecting both ends of a circle or an arc on a curved surface, but also a slightly curved shape with a middle height. In this case, since the continuum of the strings 45 and 46 in the flow direction becomes the substantially flat portions 40 and 41, these substantially flat portions 40 and 41 have a gentle curved surface toward the centripetal direction of the liner body 21. . This makes it possible to further alleviate the forcible removal of the concave spherical portions 30 and 31 from the mold near the most easily damaged central portion while minimizing the thickened portion.

  In addition, as shown in FIG. 5, the substantially flat portions 40 and 41 are preferably provided substantially in parallel with the flow path axis P and at a substantially constant width. In this case, as shown in FIG. 4, the substantially flat portions 40 and 41 have a gentle slope toward the flow path end 26a of the liner main body 21 with the outer peripheral portions of the concave spherical portions 30 and 31 as peaks. And is configured as a part of the flow path 26.

  At this time, in FIG. 4, the inner diameter φD formed by the substantially flat portions 40 and 41 is larger than the diameter φdH1 formed by the outer diameter φdW1 of the concave spherical portion 30 and the outer diameter φdW3 of the concave spherical portion 31. Is less than or equal to the diameter φdH2 formed by the inner diameter φdW2 of the concave spherical portion 31 and the inner diameter φdW4 of the concave spherical portion 31, and the substantially flat portions 40, 41 are within the range from the diameter φdH1 to the diameter φdH2 so that the concave spherical portions 30, 31 , And is formed to be inclined toward the annular flow path end surface, and has a gentle curved surface. Due to the shapes of the substantially flat portions 40 and 41, the continuous body of the strings 45 and 46 also has a gentle curve slightly curved toward the flow path.

  In this case, the substantially flat portions 40 and 41 have a constant width in the direction of the flow channel axis P, that is, the lengths L1 and L2 of the chords 45 and 46 in the range from the flow channel end 26a to the concave spherical portions 30 and 31 are set. It is desirable to provide a fixed length. In the liner body 21 of the present embodiment, for example, as shown in the lower part of FIG. 5, the inclination angle β of the substantially flat portion 41 is set in a range of 3 ° to 8 ° with respect to the inclination angle α of the flow path 26. Thus, the substantially flat portion 41 has a constant width in the direction of the flow path axis P, that is, the length L2 of the chord 46 is constant. In the figure, the inclination angle β is set to 3 °.

  Here, FIG. 6 shows a comparative example of a substantially flat portion, and more specifically, FIG. 6A shows that the substantially flat portion is directed toward the flow path end 26a shown in FIGS. 6 (b) shows a case where the substantially flat portion is tapered toward the flow channel end 26a.

In the case of FIG. 6A, the length L2 ′ of the chord of the substantially flat portion 41 on the lower side is longer than the outer diameter φdW3 of the concave spherical portion 31. In this case, the area of the thick portion of the flow path end 26a of the liner main body 21 increases, so that defects such as shrinkage of the resin during molding easily occur, and the length L2 ′ of the chord increases. The flow path 26 in FIG. 2 is also narrowed.
6B, the length L2 "of the chord is shorter than the outer diameter φdW3 of the concave spherical portion. In this case, the diameter of the liner body 21 is increased toward the opening at the flow path end 26a. Partially remain, and the improvement of the releasability (without forcing) becomes insufficient.
In this example, the concave spherical portion 31 and the flat portion 41 on the lower side of the liner body 21 have been described, but the same applies to the upper side.

  1 and 2, the body 22 of the valve body 20 is formed by dividing an upper body 22a and a lower body 22b using cast iron such as ductile cast iron as a material, and these upper body 22a and lower body 22b are combined. These side portions are integrally fixed by fixing bolts 47. An inner peripheral surface 29 of the body 22 is covered with a liner body 21 in a substantially annular shape, and a valve body 23 is mounted in the seat liner 21 via an upper stem 24. A shaft casing 50 is formed on the upper part of the body 22, and a mounting cylinder 51 is formed on the lower part. A ring body 52, a flange 53, an O-ring 54, and a bearing 55 are mounted in the shaft casing 50.

  The valve body 23 has a substantially disk-shaped metal core 60 made of a stainless alloy on the center side, and a lining layer 61 of resin lining is provided on the outer periphery of the metal core 60. A stem fitting portion 62 for fitting and fixing the upper stem 24 is provided on the upper side of the cored bar 60. The upper stem 24 is inserted into the stem fitting portion 62, and the valve body 23 is 22 is mounted rotatably.

  On the lower side of the cored bar 60, a projecting portion 63 which is short and cylindrical and can be inserted into the bag-shaped portion 32 of the liner body 21 is provided integrally. The outer diameter of the projecting portion 63 is set to be smaller than the outermost diameter of the upper stem 24, and the lining layer 61 is provided on the core 60 around the front and back surfaces including the projecting portion 63. Can be

  The lining layer 61 is formed with a thickness of about 3 mm around the outer periphery of the front and back surfaces of the cored bar 60 using a resin material such as a fluororesin such as PFA similarly to the liner main body 21. Is provided with a bottom stem portion 64 in which the projecting portion 63 is covered with the lining layer 61. The bottom stem portion 64 is pivotally supported in a non-penetrating state on the side of a mounting cylinder 51 formed below the body 22, whereby the valve body 23 is mounted on the body 22 in a so-called cantilevered manner by the upper stem 24. You.

The resin lining 61a provided on the bottom stem portion 64 side of the valve body 23 described above is located outside the sealing portion with the concave spherical portion 31 of the liner main body 21, so that there is no danger of liquid contact and the resin lining 61a is resistant to permeation. There is no need to consider sex. For this reason, the thickness of the resin lining 61 a may be set smaller than the thickness of the lining layer 61 near the outer periphery of the front and back surfaces of the cored bar 60.
This is the same for the liner main body 21 described above, and the thickness of the bag-shaped portion 32 may be formed thinner than other portions.

  A holding body 65 is attached to a lower portion of the bottom stem portion 64, and the holding body 65 is provided in a substantially columnar shape using, for example, a metal material such as stainless steel. A concave portion 66 is formed in the upper portion of the holding body 65, and the bag-like portion 32 is fitted in the concave portion 66. The bottom stem portion 64 is mounted on the body 22 in a state where the bottom stem portion 64 is rotatably supported in a non-penetrating state by being fitted to the bag-shaped portion 32, and the valve body 23 is rotatably held in this state. After the bottom stem portion 64 is mounted, a slight gap is provided in the axial direction between the bottom stem portion 64 and the bag-shaped portion 32, and between the bag-shaped portion 32 and the concave portion 66, respectively.

A lower spring 70 made of a coil spring is mounted on the back side of the holding body 65, and the holding body 65 is pressed by the elastic force of the lower spring 70, and the lower part of the liner main body 21 is moved by the holding body 65 to the valve body 23. Pressed to the side.
On the other hand, a bearing 55 is mounted on the shaft casing 50 above the body 22, and an upper spring 71 is mounted on the back side of the bearing 55.

  A ring body 52 and a collar member 53 are provided on the back side above the valve body 23. The ring body 52 is formed in a cylindrical shape from a metal material such as stainless steel, and is provided on the shaft casing 50 so as to be sandwiched between the bearing 55 and the liner main body 21. The elastic force of the upper spring 71 is transmitted to the ring body 52 via the bearing 55, and the elastic force is transmitted from the ring body 52 to the liner main body 21, and the lining layer 61 of the concave spherical portion 30 and the valve body 23 is formed. Thus, the sealing property between the resins is ensured, and the shaft sealing state is held by the ring body 52 from the outer peripheral side.

The above-described liner body 21 is not limited to the cantilever support structure having the bag-shaped portion 32, but is provided in a structure in which the top and bottom sides of the valve body 23 are supported by upper and lower stems, that is, a so-called double-support structure. You may.
Further, although the lining layer 61 of the liner body 21 and the valve body 23 is formed of PFA, it may be formed of other fluororesin, for example, PTFE (polytetrafluoroethylene) or other various resin materials. .

Subsequently, a sheet liner forming apparatus will be described.
FIG. 7 shows an apparatus main body 25, which has a lining mold 42, and the above-described liner main body 21 is molded by the mold 42.

  The molding die 42 includes an upper die 80, a lower die 81, and a split mold 82 that can be divided between the upper die 80 and the lower die 81. A cavity 83 is formed therein, and a resin material is charged into the cavity 83 so that the liner main body 21 can be molded.

  The upper die 80 is formed in a substantially cylindrical shape, and a concave portion 84 capable of forming a flange portion on one side of the liner main body 21 is formed on the bottom surface side of the upper die 80. At an appropriate position of the upper mold 80, a pot into which a material is to be charged and a material injection port communicating with the cavity 83 from the pot are formed (not shown).

  The lower die 81 has a disc-shaped base 85 and a columnar portion 86 protrudingly provided at the center of the base 85, and a substantially flat portion is formed on the outer periphery of the columnar portion 86 on the liner body 21. An uneven surface 87 for forming the valve seat surface 27 including 40 and 41 is formed. On the upper surface side of the base 85, a concave portion 88 capable of forming a flange portion on the other side of the liner main body 21 is formed.

A communication hole 89 is formed at the center of the columnar portion 86 in parallel with the base 85. In addition, the columnar portion 86 has at least an outer diameter portion forming the flow path end portion 26 a on the drawing end portion 21 a side of the liner main body 21 smaller than an outer diameter portion forming the inner diameter of the concave spherical portions 30 and 31. Is provided. Thus, after the liner body 21 is formed, the substantially flat portions 40 and 41 having the chordal cross section are formed in a state where the inner diameter sides of the concave spherical portions 30 and 31 are larger than the flow path end portion 26a. .
In the present embodiment, the columnar portion 86 is provided in a shape capable of forming the substantially planar portions 40 and 41 toward both ends of the liner main body 21, whereby the liner main body 21 is formed into a symmetrical shape.

The split mold 82 is formed in a substantially cylindrical shape that can be divided into two parts in a plan view, and a bar 90 is formed on one side of the split mold 82 in the direction of insertion into the communication hole 89 of the lower mold 81. The split mold 82 is placed on the base 85 of the lower mold 81 while being integrated from the left and right while the rod-shaped portion 90 is inserted into the communication hole 89. After being attached to the lower die 81, the rod-shaped portion 90 penetrates the columnar portion 86, and the cylindrical portion 33 and the bag-shaped portion 32 are provided so that they can be formed when the material is charged.
In this state, the upper mold 80 is mounted from above the split mold 82 and the lower mold 81, and these are integrally assembled to form the molding mold 42.

When the liner main body 21 is formed by the above-described apparatus main body 25, the liner main body 21 is formed by a transfer molding method. The transfer molding method has advantages such as that the lining layer can be formed with high dimensional accuracy with uniform quality and uniform mass can be easily mass-produced with high work efficiency even in a complicated shape, as compared with the compression molding method.
In this case, a predetermined amount of preheated resin material is put into a pot, and after a plunger is inserted into the pot through a predetermined heating step by a compression molding machine (not shown) and pressurized, the plasticized resin material in the pot is removed. The liner main body 21 is formed by press-fitting into the cavity 83 from the inlet.

After the liner body 21 is formed, the liner body 21 is removed from the molding die 42, and if necessary, excess flesh and burrs formed so as to cover a flow path called “cull” are removed. Post-processing such as applying
In this embodiment, the liner body 21 is formed by the transfer molding method, but may be formed by another molding method.

  As described above, the lower columnar portion 86 of the apparatus main body 25 has at least an outer diameter portion forming the flow path end portion 26a on the drawing end portion 21a side and an outer diameter portion forming the inner diameter of the concave spherical portions 30 and 31. The liner main body 21 formed by the apparatus main body 25 has a substantially flat portion 40 having a chordal cross section in the direction of the flow path end 26a adjacent to the concave spherical diameter portions 30 and 31. 7A, the end of the columnar portion 86 does not project toward the opening of the liner main body 21 in FIG.

  7B and 7C, when the liner main body 21 is released from the lower die 81 after the upper die 80 and the split die 82 are removed from the lower die 81, the columnar portions 86 are removed. The concave spherical portions 30 and 31 are not caught on the end side of the, and the liner main body 21 can be pulled out without difficulty while preventing the concave spherical portions 30 and 31 from being deformed or damaged. Therefore, when the liner main body 21 after release is mounted on the valve main body 20, the valve body 23 can be opened and closed while ensuring the sealing performance and the torque performance, and the chemical resistance and corrosion resistance can be maintained.

  Moreover, the substantially flat portions 40 and 41 are formed from the concave spherical portions 30 and 31 to the vicinity of the end 26a of the flow path 26, and the lengths L1 and L2 of the chords 45 and 46 at the end portions of the substantially flat portions 40 and 41 are adjusted. The substantially flat portions 40 and 41 are secured to a predetermined size by being formed to be equal to or slightly shorter than the maximum diameters of the concave spherical portions 30 and 31, respectively. , While suppressing the influence on the concave spherical portions 30 and 31.

  More specifically, the substantially flat portions 40 and 41 are provided to be substantially parallel to the flow path 26 and to have a substantially constant width, and the lengths L1 and L2 of the strings 45 and 46 at the end portions of the substantially flat portions 40 and 41. Are provided longer than the inner diameters φdW2 and φdW4 of the concave spherical portions 30 and 31, so that the withdrawn end 21a side of the columnar portion 86 protrudes toward the inner peripheral sides of the cylindrical portion 33 and the bag-like portion 32 of the liner body 21. Therefore, it is possible to reliably prevent the pulling end 21a from being caught, thereby ensuring the ease of release.

  Further, since the lengths L1 and L2 of the strings 45 and 46 are set to be equal to or less than the outer diameters φdW1 and φdW3 of the concave spherical portions 30 and 31, the thickness outside the concave spherical portions 30 and 31 is increased unnecessarily. And suppresses molding defects such as shrinkage. In addition, by suppressing the length of the strings 45, 46, the size of the flow path 26 can be ensured without the substantially flat portions 40, 41 reaching the inner peripheral sealing surface 28, and the inner peripheral sealing surface 28 The sealing performance with the valve body 23 by the spherical portions 30 and 31 is maintained.

  Since the substantially flat portions 40 and 41 have a chordal cross section and a gentle curved surface toward the centripetal direction of the seat liner, they form a part of the substantially spherical shape, and the strength is improved. The substantially flat portions 40, 41 can support the concave spherical portions 30, 31, and even if a downstream force is applied to the valve body 23 by the fluid pressure when the valve is closed, the concave spherical portions 30, 31 are deformed. To maintain the up-and-down sealing performance of the valve seat surface. When more importance is attached to the top and bottom sealing properties, a so-called fleshy portion is provided on the back surface of the liner main body 21 facing the ring body 52 so that the liner main body 21 is partially removed while improving the releasability. The thickness may be reduced.

In addition, the liner main body 21 after molding is locally thickened only in the vicinity of the portion where the substantially flat portions 40 and 41 are provided, thereby preventing the overall thickness from being increased. Defects such as shrinkage due to resin shrinkage can be suppressed to achieve high quality molding. On the other hand, since the liner body 21 is not made thin, fluid permeation resistance is ensured and corrosion of the body 22 and the like can be prevented.
As described above, the liner body 21 can be easily released from the lower die 81 without impairing the functionality of the liner body 21, and the processing accuracy after the transfer molding can be maintained.

Further, by increasing the thickness of the periphery of the concave spherical portions 30 and 31 by the substantially flat portions 40 and 41, even if a force that pushes the valve shaft seal portion to the downstream side due to fluid pressure when the valve is closed is applied. Deformation can also be prevented.
When the substantially flat part is provided in a curved shape, the overall strength of the substantially flat part is improved while forcible removal with the mold is eased, and sealing is performed by preventing deformation of the concave spherical part when the valve body is mounted after molding. It is also possible to operate the valve body while maintaining the torque and low torque.

  In this embodiment, since the liner main body 21 is provided in a symmetrical shape, the material shrinks at the time of molding evenly in the left and right directions, so that the concave spherical portions 30 and 31 required for the top and bottom seals can be formed uniformly.

DESCRIPTION OF SYMBOLS 20 Valve main body 21 Liner main body 22 Valve body 23 Valve body 25 Device main body 26 Flow path 26a Flow path end part 27 Valve seat surface 29 Inner peripheral surface 30, 31 Concave spherical surface part 40, 41 Substantially flat part 42 Mold 46, 46 chord 80 upper die 81 lower die 82 split die 83 cavity 86 columnar part L1, L2 chord length φdW1, φdW3 outer diameter (maximum diameter) of concave spherical part

Claims (2)

A liner main body formed of a fluororesin material, and an inner peripheral sealing surface provided on a valve seat surface along a cylindrical flow path inner periphery of the liner main body; A concave spherical portion serving as a top and bottom sealing surface with the body is provided, and the outer periphery of the concave spherical portion is set as a peak toward at least one of the liner main bodies toward the flow path end toward the flow path end to the flow path end. A substantially flat portion having a chordal cross section is provided, and the substantially flat portion is provided substantially parallel to the flow path and at a substantially constant width, and a rectangular substantially flat portion is provided at an end position of the substantially flat portion in the flow direction. at the end side, and the length of the chord that is provided in the circumferential direction, the concave spherical surface portion maximum diameter and or equivalent, slightly shorter form lining type butterfly sheet liner valve, characterized in that the.   A lining type butterfly valve using the seat liner according to claim 1.

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