JP2007192374A - Butterfly valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a butterfly valve without separating a material and an insert, even when the material used for a valve box contracts, when molding the valve box, without requiring processing while finely adjusting a pitch of a bolt hole, even when opening the bolt hole for connecting a flange, without deforming the valve box in the vertical direction, when installing a valve element on an inner peripheral surface of a seat ring installed on an inner peripheral surface of the valve box. <P>SOLUTION: This butterfly valve has the valve box 1 forming a flow passage 8 inside, the seat ring 2 fitted to and installed on the inner peripheral surface 11 of the valve box 1 and the disk-like valve element 4 rotatably journaled by a valve stem 3 in the substantially right-angled direction to the axis of the flow passage 8 inside the flow passage 8 of the valve box 1, and has at least one substantially annular insert 5 formed of a construction material of higher rigidity than the valve box 1 inside the valve box 1, and is formed by arranging at least one continuous projection strip part 6 on an outer peripheral surface 10 of the insert 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a butterfly valve that is preferably used in piping lines for chemical factories, water and sewage systems, agriculture and fisheries, and more particularly to a butterfly valve having a large diameter.

  As shown in FIG. 8, the conventional butterfly valve has a valve box 31 having a flow path formed therein, a seat ring 32 fitted to the inner peripheral surface of the valve box 31, and a seat ring 32. A valve shaft supported by the valve box 31 and a disc-shaped valve element 33 rotatably supported by the valve shaft in a direction substantially perpendicular to the axial center of the flow path inside the valve box 31. In general, the valve body 33 is rotated by rotating the valve shaft so as to be pressed against and separated from the seat ring 32 to open and close the valve. When the valve body 33 is mounted on the inner peripheral surface side of the seat ring 32 fitted to the inner peripheral surface of the valve box 31, the valve body 33 crushes the seat ring 32 and keeps the sealing performance. The inner diameter and the outer diameter of the valve body 33 are substantially equal, and when the valve body 33 is mounted on the valve box 31 fitted with the seat ring 32, the valve body 33 is incorporated into the valve box 31 by applying a considerable force. Thus, a force acts to push the valve box 31 upward and downward. This force increases as the aperture increases. For this reason, the problem that the valve box 31 will deform | transform in the up-down direction occurred (refer FIG. 9). Therefore, when opening a bolt insertion hole 34 to be connected to a flange of a pipe or the like to be connected (hereinafter referred to as a flange), while adjusting the pitch of the hole 34 in anticipation of the deformation amount of the valve box 31, It was necessary to perform processing. The displacement of the pitch of the bolt insertion hole 34 can be improved by adjusting, but it is possible to improve the processing, but there is a large variation in processing, it takes time and effort, and the processing time becomes longer, which increases the processing cost. There was a problem.

  As a solution for preventing the deformation of the valve box, which is a problem of the above prior art, a norbornene-based monomer is subjected to reaction injection molding so as to cover the entire core material using the metal ring 36 as a core material, and the valve box is formed. A butterfly valve using a forming method is disclosed in Patent Document 1.

JP-A-11-153243 (page 1-10, FIG. 1)

  As described above, the valve box 35 of the butterfly valve obtained by using the reaction injection molding with the norbornene-based monomer and covering the entire core material with the metal ring 36 as the core material contains the core material. Therefore, the deformation as described above is suppressed as compared with the case without the core material. However, when the diameter of the valve is increased, the inner peripheral surface side of the seat ring 37 fitted to the inner peripheral surface of the valve box 35 is provided. Further, since the amount of deformation when the valve body is mounted on the valve body increases and the pitch of the flange bolt holes 38 slightly shifts, further improvement has been desired.

  Further, when the valve box 35 is formed so as to cover the entire core material with the resin layer, the resin shrinks toward the inner peripheral side of the valve box 35, and therefore the resin and metal on the inner peripheral side of the valve box 35 There is a possibility that peeling from the ring 36 may occur, and there is a problem that cracks may occur in the resin layer.

  The present invention has been made in view of the problems of the prior art as described above, and its purpose is to mount a valve body on the inner peripheral surface of a seat ring fitted to the inner peripheral surface of a valve box. Without opening the valve box in the vertical direction, it is not necessary to drill the bolt holes for connecting the flanges or to make fine adjustments to the pitch of the bolt holes, and when forming the valve box, It is to provide a butterfly valve which does not cause separation between the material and the insert even when the material used for the shrinkage.

  The configuration of the present invention will be described with reference to FIGS. 1 to 7. A valve box 1 having a flow path 8 formed therein, a seat ring 2 fitted to the inner peripheral surface 11 of the valve box 1, In a butterfly valve having a disc-like valve body 4 rotatably supported by a valve shaft 3 in a direction substantially perpendicular to the axis of the flow path 8 inside the flow path 8 of the valve box 1, 1 has at least one substantially annular insert 5 made of a material having higher rigidity than the valve box 1, and at least one continuous protrusion 6 is provided on the outer peripheral surface 10 of the insert 5. This is the first feature.

  A second feature is that the cross-sectional shape of the protrusion 6 is substantially trapezoidal, semicircular or rectangular.

  A third feature is that the insert 5 is provided with at least one through hole 7 penetrating the inner peripheral surface 9 and the outer peripheral surface 10 thereof.

  A fourth characteristic is that the material of the valve box 1 is a norbornene resin.

  Furthermore, a fifth feature is that the disc-like valve body 4 is rotated by any one of manual, electric and pneumatic driving.

  In the present invention, the shape of the insert 5 is not particularly limited as long as it is substantially annular, and may be a circular shape, a polygonal shape such as an octagonal shape or a hexagonal shape. Is preferred.

  Further, a plurality of continuous protrusions 6 provided on the outer peripheral surface 10 of the insert 5 may be formed, but it is preferable that the number is one for light weight and ease of manufacture.

  The cross-sectional shape of the ridge portion 6 of the insert 5 may be trapezoidal, semicircular or rectangular, and is not particularly limited, but is preferably trapezoid in view of strength and manufacturing surface.

  Further, the strength of the ridge 6 increases as the height increases, but if the ridge 6 becomes too high and interferes with the bolt hole 14 for flange connection, it becomes difficult to process the bolt hole 14, so about 5 to 20 mm. Is preferable.

  Moreover, although the intensity | strength increases, so that the width | variety of the protrusion 6 becomes large, when the surface of weight reduction and manufacturing cost is considered, it is preferable to set it as 50% or less with respect to the width | variety of the insert 5.

  The through hole 7 that penetrates the inner peripheral surface 9 and the outer peripheral surface 10 of the insert 5 is not particularly limited in size, but the strength decreases if the through hole becomes too large, and the material used for the valve box if it is too small. Therefore, the diameter of the through hole 7 is preferably about 10 to 30% with respect to the width of the insert 5.

  The number of the through holes 7 may be at least one, but it is preferable to provide ten or more in order to prevent the insert 5 and the material from peeling when the material contracts. The insert 5 may be made of metal such as cast iron, cast steel, carbon steel, stainless steel, titanium, or synthetic resin such as vinyl chloride (hereinafter referred to as PVC) or FRP, as long as the material is higher than that of the valve box 1. Good, not particularly limited. Of these, cast iron FCD450 is preferable because of its excellent cost and productivity.

  As the material of the valve case 1, polydicyclopentadiene (hereinafter referred to as PDCPD) or polypropylene (hereinafter referred to as PP) can be used, but if the strength and characteristics required for the valve case 1 are satisfied, Synthetic resins such as polyvinylidene fluoride (hereinafter referred to as PVDF), polyethylene (hereinafter referred to as PE), polyphenylene sulfide (hereinafter referred to as PPS), FRP, or metals such as stainless steel, copper, cast iron and cast steel good. The present invention is preferably used particularly in the case of a large diameter, but if it is made of a resin, it is much lighter than that of a metal and the working efficiency is improved, and it can be used for a corrosive fluid transportation line without any problem.

  The material of the valve shaft 3 of the present invention is not particularly limited as long as it has no problem in strength, such as cast iron, cast steel, carbon steel, stainless steel, and titanium. The material of the seat ring 2 of the present invention is preferably an elastic material, such as ethylene propylene rubber (hereinafter referred to as EPDM), acrylonitrile butadiene rubber (hereinafter referred to as NBR), rubber such as fluorine rubber, PVDF, etc. The synthetic resin is not particularly limited as long as it has no problem in strength and corrosion resistance.

  The butterfly valve of the present invention is mainly driven manually by attaching a handle to one end portion of the valve shaft 3 protruding from the valve box 1 or by attaching a handle via a gear box. There is no particular limitation, and it may be electric driving by air pressure or pneumatic driving by air pressure. In the case of the electric type, as shown in FIG. 7, instead of the handle or the gear box, the electric drive unit 27 is directly mounted on the top flange 19 or mounted via a mounting base, and is conducted to the upper part of the valve shaft 3. .

The butterfly valve according to the present invention has the above-described structure, whereby the following excellent effects can be obtained.
(1) Deformation of the valve box can be suppressed when the valve body is mounted on the inner peripheral surface of the seat ring fitted to the inner peripheral surface of the valve box. Therefore, when the bolt hole for connecting the flange is opened, it is not necessary to perform drilling while adjusting the pitch of the bolt hole in consideration of the deformation amount of the valve box. Further, there is no variation during processing, processing time is shortened, and increase in processing cost can be suppressed.
(2) Since the deformation of the valve box is reduced, the elastic force of the seat ring is sufficiently transmitted to the valve body, so that the sealing performance in the vicinity of the valve shaft portion can be improved.
(3) Since the insert is provided with a through-hole penetrating the inner peripheral surface and the outer peripheral surface, the materials used on the inner peripheral surface side and the outer peripheral surface side of the valve box are connected and integrated by the through-hole. When the box is molded, even if the material used shrinks toward the inner peripheral surface side of the valve box, the material used on the inner peripheral surface side does not peel off from the insert. Therefore, there is no possibility of cracks occurring in the resin layer.
(4) If the valve box and the valve body are made of norbornene-based monomer resin, the butterfly valve having a large diameter is light in weight, improving the workability, and can be used without problems even in the use of corrosive fluid.

  Hereinafter, the first embodiment of the present invention will be described with reference to the drawings, but it goes without saying that the present invention is not limited to this embodiment. FIG. 1 is a longitudinal sectional view showing the butterfly valve according to the first embodiment of the present invention when fully closed. FIG. 2 is a partially broken perspective view of the valve box of the present invention. FIG. 3 is a perspective view of the insert of the present invention. FIG. 4 is a cross-sectional view of the insert taken along line AA. 5 and 6 are sectional views taken along line AA showing another embodiment of the insert. FIG. 7 is a longitudinal sectional view of an electric drive type butterfly valve according to a second embodiment of the present invention.

  1 to 7, reference numeral 1 denotes a PDCPD valve box having a diameter of 1100 mm in which a flow path 8 is formed, and a seat ring 2 to be described later is fitted to an inner peripheral surface 11. A protrusion 13 is formed on the outer peripheral surface 12 of the valve box 1, and the diameter of the protrusion 13 is about 1400 mm. The bolt hole 14 for connecting with a flange here is formed at predetermined intervals along the circumferential direction.

  At the upper and lower portions of the valve box 1, substantially trapezoidal boss portions 15 and 16 are formed on the outer peripheral surface 12 at positions 180 degrees symmetrical, and bearing holes 17 and 18 are formed respectively. The shaft centers of these bearing holes 17 and 18 are substantially perpendicular to the shaft core of the flow path 8. A later-described valve shaft 3 for opening and closing the later-described valve body 4 is inserted into the bearing holes 17 and 18 and is held rotatably. Further, a valve bearing 20 is mounted below the boss portion 16 with bolts. Further, a substantially disk-shaped top flange 19 protruding from the boss portion 15 is provided at the upper portion. Further, grooves 21 and 22 for fitting the seat ring 2 are formed on both end surfaces in the axial direction of the flow path 8 of the valve box 1.

  2 is a seat ring made of EPDM, and a hollow cylindrical main body 23 and flange surfaces 24 on both side surfaces thereof are integrally formed. The outer periphery of the flange surface 24 is formed in a circular shape, and the ears 25 provided inwardly projecting from the upper end of the flange surface 8 are formed in fitting grooves 21 and 22 provided on both side surfaces of the valve box 1. The seat ring 2 is not moved by fitting.

  Reference numeral 3 denotes a valve shaft made of SUS403, which is supported by the valve box 1. The upper end portion of the valve shaft 3 is disposed so as to protrude from the center of the top flange 19 provided at the upper portion of the valve box 1. The central portion of the valve shaft 3 is tightly penetrated through the valve main body 1 and the seat ring 2 in a rotatable state.

  4 is a circular PP valve element disposed in the center of the valve box 1. A valve shaft hole 26 is provided in the center of the valve element 4, and the valve shaft 3 is rotated to the valve shaft hole 26. The valve shaft 3 is supported so as not to move.

  Reference numeral 5 denotes a substantially annular insert having a thickness of 25 mm, which is made of cast iron FCD450, and has bearing holes 17 and 18 formed in the vertical direction. The outer peripheral surface 10 of the insert 5 is provided with one continuous ridge 6, and its cross-sectional shape (transverse cross section along the line AA) is formed in a trapezoidal shape. The cross-sectional shape is preferably a trapezoidal shape, but is not limited to this and may be a semicircular shape or a rectangular shape. (See FIGS. 5 and 6). The width of the protrusion 6 is preferably about 80 mm and the height is about 8 to 15 mm. The insert 5 is preferably produced by casting using a sand mold and does not require machining, but may be produced by machining.

  Reference numeral 7 denotes a through hole, which is formed so as to penetrate the inner peripheral surface 9 and the outer peripheral surface 10 of the insert 5, and has a diameter of 40 mm. The twelve holes are provided radially at equal intervals and penetrate the center of the protrusion. ing. The through hole 7 is formed by casting using a sand core and does not require machining, but may be formed by machining.

  The insert 5 is embedded in the valve box 1 by insert molding, and the upper and lower parts of the insert 5 are formed in a substantially trapezoidal shape similar to the boss parts 15 and 16 of the valve box 1. The thickness of the resin layer of the valve box 1 covering the insert 5 is 18 mm, but 15 to 20 mm is a preferable range.

  Next, an electric drive butterfly valve according to a second embodiment of the present invention will be described.

  In FIG. 7, reference numeral 27 denotes an electric drive unit using a motor, which is directly attached to the top flange 19 of the butterfly valve. The drive of the electric drive unit 27 is transmitted to the upper part of the valve shaft 3, and the valve body is rotated by rotating the valve shaft 3 to open and close the valve. Instead of the electric drive unit 27, an air driven drive unit using air pressure may be provided. In that case, the pneumatic drive unit may be directly attached or via a mounting base.

  Next, a method for forming the butterfly valve of the first embodiment will be described.

  A reaction injection molding material mainly composed of a norbornene-based monomer, a metathesis catalyst and an aluminum-based activator, a liquid B composed of a norbornene-based monomer and a metathesis catalyst, and an A composed of the norbornene-based monomer and the aluminum-based activator. Divide into two stable liquids and put them in separate tanks.

  The temperature of the reaction stock solution composed of the A solution or the B solution is 20 to 80 ° C., and the viscosity of the reaction stock solution is, for example, about 5 cps to 3000 cps, preferably about 30 cps to 800 cps at 30 ° C.

  Molded by reaction injection molding using a sand mold. The sand mold is manufactured based on a wooden mold. At this time, the shrinkage ratio of the molded product is expected to be about 2/1000 to 16/1000.

  The insert 5 is placed in a sand mold that performs reaction injection molding. Since it is necessary to float and fix the insert 5 in the air, the insert 5 is provided with four protrusions. On the other hand, the sand mold is provided with a recess for fitting the protrusion. After the insert 5 is fixed, a sand mold is set up, and a reaction liquid is supplied into the cavity from the lower side of the sand mold to polymerize.

  In order to start reaction injection molding, the mixer is controlled to mix the liquid A and liquid B from the tank, and the mixed liquid is filled into the cavity as a reaction stock solution. The reaction stock solution filled in the cavite spreads inside the cavity.

The polymerization time may be appropriately selected, but is usually about 20 seconds to 20 minutes after the completion of the reaction liquid injection. The in-mold pressure is usually in the range of 0 to 100 Kg / cm ² . The injection pressure of the reaction stock solution is preferably 2 × 10 ^{5 to} 5 × 10 ⁵ Pa. The injection pressure should not be too low in order to obtain a molded body having a predetermined shape, and the injection pressure should not be too high in order to prevent the mold from becoming rigid and not economical.

  The material of the mold may be a mold instead of a sand mold. Alternatively, since reaction injection molding can be performed at a relatively low pressure, a synthetic resin or the like may be used.

  When molded by the above method, the resin is divided into the inner peripheral surface 9 and the outer peripheral surface 10 of the insert 5, and both the insert 5 and the resin shrink toward the inner peripheral surface 9, but on the outer peripheral surface 10 side of the insert 5 Since the resin has a contraction rate larger than that of the insert 5, the resin tends to adhere to the insert 5. On the other hand, since the resin on the inner peripheral surface 9 side of the insert 5 has a larger shrinkage rate than the insert 5, it easily peels off from the insert 5, but the insert 5 penetrates the inner peripheral surface 9 and the outer peripheral surface 10. Since the hole 7 is provided, the resin on the outer peripheral surface 10 side of the insert 5 and the resin on the inner peripheral surface 9 side are connected and integrated with each other through the through hole 7, thereby preventing the insert 5 and the resin from peeling off.

  In assembling the butterfly valve according to the first embodiment having the structure as described above, when the valve body 4 is mounted on the valve box 1 to which the seat ring 2 is fitted, the valve body 4 is applied with a considerable force. Since it is incorporated in the valve box 1, the valve box 1 is pushed up and down by the valve body 4. When the strength is insufficient, it is deformed in the vertical direction. However, since the protrusion 5 is provided in the insert 5, it is not deformed in the vertical direction. Therefore, since the bolt hole 14 of the valve box 4 opened before the valve body 4 is mounted does not shift, machining becomes easy, the time can be shortened, and variations during processing can be suppressed, Moreover, since the valve box 1 is not deformed, the sealing performance does not deteriorate.

  Next, the action of the insert 5 in the butterfly valve of the present invention was confirmed by the following test method.

(1) Confirmation of pitch deviation of bolt hole 14 of valve box 1 After the valve body 4 is mounted on the valve box 1, the pitch of the bolt hole 14 before the valve body 4 is mounted on the valve box 1 is measured. The pitch was compared with the pitch of the bolt holes 14.

(2) Confirmation of peeling of valve box 1 and insert 5 When the valve box 1 was molded, the valve box 1 and the insert 5 were cut and the peeling state between the internal resin and the insert 5 was visually confirmed. .

  In the first embodiment of the present invention, that is, the insert 5 provided with the protrusion 6 is insert-molded in the valve box 1, and the insert 5 is provided with a through hole 7 that penetrates the inner peripheral surface 9 and the outer peripheral surface 10. Using the butterfly valve having a diameter of 1100 mm, the pitch deviation of the bolt hole 14 opened in the valve box 1 when the valve body 4 is mounted on the valve box 1 and the peeling state of the resin and the insert 5 are checked. It was. The results are shown in Table 1.

[Comparative Example 1]
The pitch deviation of the bolt holes 14 was confirmed in the same manner as in Example 1 except that an insert of the type in which the protrusion 6 of the insert 5 was not provided was used.

[Comparative Example 2]
Except for using the type of insert in which the through-hole 7 is not provided in the insert 5, the separation of the resin and the insert was confirmed in the same manner as in Example 1.

  As can be seen from Table 1, in Example 1, no shift in the pitch of the bolt holes 14 was observed, and no separation of the insert 5 and the resin was observed. On the other hand, in Comparative Example 1, the pitch of the bolt holes 14 opened in the valve box 1 was shifted. In Comparative Example 2, the resin of the valve box 1 and the insert 5 were peeled off. From this result, it was confirmed that the butterfly valve of the present invention can eliminate the pitch shift of the bolt holes 14 and that the resin layer of the valve box 1 and the insert 5 do not peel off.

It is a longitudinal cross-sectional view which shows the time of full closure of the butterfly valve of this invention. It is a partially broken perspective view of the valve box of the present invention. It is a perspective view of the insert of the present invention. It is an AA line sectional view of an insert. It is an AA line sectional view showing other examples of an insert. It is an AA line sectional view showing other examples of an insert. It is a longitudinal cross-sectional view of the electric drive type butterfly valve which is the 2nd Embodiment of this invention. It is a front view of the conventional butterfly valve. It is a front view of the conventional butterfly valve. It is a partial longitudinal cross-sectional view of the conventional butterfly valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Valve box 2 ... Seat ring 3 ... Valve shaft 4 ... Valve body 5 ... Insert 6 ... Projection part 7 ... Through-hole 8 ... Channel 9 ... Inner peripheral surface 10 ... Outer peripheral surface 11 ... Inner peripheral surface 12 ... Outer peripheral surface 13 ... Projection part 14 ... Bolt hole 15 ... Boss part 16 ... Boss part 17 ... Bearing hole 18 ... Bearing hole 19 ... Top flange 20 ... Valve bearing 21 ... Fitting groove 22 ... Fitting groove 23 ... Body part 24 ... Flange Surface 25 ... Ear portion 26 ... Valve shaft hole 27 ... Electric drive 31 ... Valve box 32 ... Seat ring 33 ... Valve element 34 ... Hole 35 ... Valve box 36 ... Metal ring 37 ... Seat ring 38 ... Flange bolt hole

Claims (5)

A valve box having a flow path formed therein, a seat ring fitted to the inner peripheral surface of the valve box, a flow path of the valve box, and substantially perpendicular to the axis of the flow path A butterfly valve having a disc-like valve body pivotally supported by a valve shaft, and at least one substantially annular insert formed of a material higher in rigidity than the valve housing. A butterfly valve characterized in that at least one continuous protrusion is provided on the outer peripheral surface of the insert. 2. The butterfly valve according to claim 1, wherein a cross-sectional shape of the protrusion is substantially trapezoidal, semicircular, or rectangular. The butterfly valve according to claim 1 or 2, wherein the insert is provided with at least one through-hole penetrating the inner peripheral surface and the outer peripheral surface thereof. The butterfly valve according to any one of claims 1 to 3, wherein a material of the valve box is a norbornene resin. The butterfly valve according to any one of claims 1 to 4, wherein the disc-shaped valve body is rotated by any one of a manual type, an electric type, and a pneumatic type drive.

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