JP3788647B2 - Butterfly valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a butterfly valve that performs opening / closing and flow rate control of various fluids, and more particularly to a butterfly valve that reduces costs by minimizing processing steps.
[0002]
[Prior art]
Conventionally, as a butterfly valve with little finishing and low manufacturing cost, there is a butterfly valve in which a valve plate is formed by pressing a metal plate as disclosed in, for example, Japanese Patent Laid-Open No. 62-63279.
[0003]
In this butterfly valve, the valve box is formed with a double structure of an inner shell and an outer shell, and the inner shell is formed of a thin-walled cylindrical body made of steel plate, leaving the center as it is, and forming a flow path. The packing accommodating portion is formed by being expanded into an S shape by pressing. Also, the outer shell is a thin-walled cylindrical body made of a steel plate, fitted into the outer periphery of the inner shell, and welded to both ends of the inner shell formed in an S shape on both sides. The valve stem is pivotally supported by a cylindrical bearing welded to the upper and lower diameter positions of the inner shell of the valve box via a bush. And the flange which attaches a drive means is welded to the upper end part of this upper side bearing. Further, in the flow path of the valve box, a valve body whose edge is covered with an elastic member is fixed to the valve rod, and the valve body is rotated by rotating the valve rod to open and close the flow path.
[0004]
[Problems to be solved by the invention]
The above-mentioned conventional butterfly valve has a two-layer structure of an inner shell and an outer shell, and there are a large number of parts, such as the need for bearings that support the valve stem on both the upper and lower sides, inevitably increasing the number of welding points, There was a limit to cost reduction.
[0005]
The present invention reduces the number of parts to reduce the manufacturing cost due to the production of dies, etc., and even when press-molding from a metal plate like the above butterfly valve, the manufacturing cost is minimized and the manufacturing cost is reduced. An object of the present invention is to provide a butterfly valve having a low cost and a novel structure capable of suppressing the above.
[0006]
[Means for Solving the Problems]
To achieve the above object, the present invention is provided with a valve body, a seat ring attached to the inner peripheral surface of the valve body , a disc rotating inside the seat ring, and a diameter direction of the disc. A butterfly valve comprising a stem and opening and closing a disc by rotating the stem has the same shape as a shape obtained by dividing the valve body into two on a plane that passes through the center of the stem and is perpendicular to the flow path direction. In this pair of divided bodies, a seat ring clamping gap having an opening on the joining surface side and an inner wall inside the gap are formed on the pair of divided bodies, and the pair of divided bodies are joined. In this case, the seat ring is press-fitted and held in the gap and the inner wall, and a bearing for pivotally supporting the stem is provided on the outer periphery in the diameter direction of the seat ring to fit the stem. And to prevent twisting and misalignment of the seat ring location, a butterfly valve so as to ensure the sealing property.
[0007]
The split body is formed so as to have the same shape as the split shape of the valve body in a plane that passes through the center of the stem and is perpendicular to the flow path direction. One valve body can be formed. Attachment of the seat ring to the valve body is performed by sandwiching the seat ring between the divided bodies when the divided bodies are joined, so that the attachment of the seat ring is easy. In addition, since the disc is inserted into the seat ring before the seat ring is attached to the divided body, the insertion is easy and the position of the disc can be easily adjusted.
[0008]
In addition, when a cylindrical portion is protruded at the diameter position of the seat ring penetrating the stem and this cylindrical portion is protruded outward in the diameter direction from the gap portion of the divided body, the twist of the seat ring due to the rotation of the disc is prevented. Without being affected, the stem is sealed with the cylindrical portion and the seat ring is prevented from being displaced.
[0009]
Moreover, when a connection pipe is provided on the end face between the faces of the valve body, the pipe body can be piped using a joint such as a clamp joint.
[0010]
Further, a bearing is interposed between the valve body and the stem, and a cylindrical portion is protruded at a diameter position of a seat ring that penetrates the stem, and one end of the bearing is fitted to the cylindrical portion. In the case where the inner diameter of the portion is increased, the influence of the twist of the seat ring is eliminated more than in the case where only the cylindrical portion is provided in the seat ring, and the shift of the seat ring is prevented.
[0011]
Further, even when a reinforcing ring is interposed between the outer peripheral surface of the seat ring and the valve body, and a protruding portion is inserted through the stem at the diameter position of the reinforcing ring, the seat ring is prevented from being displaced. Can do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the butterfly valve of the present invention will be described in detail with reference to the drawings. In the figure, 1 is a valve body comprising a pair of divided bodies 2 and 3, 3 is a substantially annular seat ring having an annular surface which is the inner peripheral surface of the flow path, 4 is a stem, and 5 is integrally formed with the stem 4. In addition, a substantially disk-shaped disc, 6 is an annular elastic gasket, and 7 to 9 are substantially cylindrical bearings.
[0013]
The valve body 1 is formed by joining a pair of divided bodies 2 and 2, and is provided with a short cylindrical portion 10 for clamping and fixing the seat ring 3, and a diametrical direction projecting from the outer peripheral surface of the short cylindrical portion 10, It has a shaft cylinder portion 11 penetrating the stem 4 and is made of a resin such as a stainless steel casting (lost wax, shell casting, lost foam) or a high-strength engineer plastic having a high corrosion resistance.
[0014]
As shown in FIG. 2, the divided body 2 has a shape in which the valve body is divided into two at a surface 2 b (hereinafter referred to as a joint surface) that passes through the center of the rotation axis of the stem 4 and is perpendicular to the flow path direction. Since the short cylinder part 20 of the divided body 2 is formed, the width between the faces is half of the short cylinder part 10 when the valve body 1 is formed, and the shaft cylinder part 21 of the divided body 2 is the axis when the valve body 1 is formed. It becomes a substantially semi-cylindrical shape which is half of the cylindrical portion 11.
[0015]
A fitting groove 12 is formed along the inner periphery of the inter-plane end face 2a (hereinafter referred to as an end face) of the short cylinder portion 20, and the gasket 6 is fixed to the fitting groove 12. Further, a step portion 15 is formed on the side opposite to the diameter position where the shaft tube portion 21 of the short tube portion 20 is provided. The step portion 15 sandwiches the bearing 9 for pivotally supporting the lower end portion 4 c of the stem 4.
[0016]
Further, in the shaft tube portion 21, step portions 13 and 14 are formed which sandwich the bearings 7 and 8 for pivotally supporting the upper end portion 4 a and the center portion 4 b of the stem 4. And a flange portion 18 for fixing a valve drive mechanism (not shown) at the tip.
[0017]
Further, as shown in FIG. 3, a plurality of joint portions 16 are provided around the short tube portion 20 and the shaft tube portion 21 as viewed from the front, and the divided bodies 2 and 2 are connected to the joint portion 16. A bolt for fixing the joint is passed through or a piping bolt is brought into contact with the circular arc surface 16a of the joint 16 to center the pipe to be piped. The joining means is not limited to the case of joining with bolts as in this example, but may be a joining means such as a clip.
[0018]
On the joint surface 2b of the split body 2, an annular gap portion 17 that is concentric with the short cylindrical portion 20 opens the joint surface 2b side so that the seat ring 3 is sandwiched between the pair of split bodies 2 and 2. Is formed. The gap portion 17 is formed by connecting the inner wall 17a that forms the gap portion 17 to the bonding surface 2b so that the inner peripheral surface of the seat ring 3 is exposed when the seat ring 3 is sandwiched between the pair of divided bodies 2 and 2. It is formed so as to be separated from the end face 2a side. Therefore, in the short cylinder portion 10 of the valve body 1 where the pair of divided bodies 2 and 2 are joined, a cavity is formed in an annular shape, and a groove connected to the cavity is formed on the inner peripheral surface.
[0019]
The seat ring 3 is a substantially annular member made of an appropriate elastic material, for example, another known polymer material such as EPDM, NBR, PTFE. An annular press-fit portion 31 having a substantially triangular cross section projects from the inter-surface end surface 3a of the seat ring 3, and the annular ridge 31a having a semicircular cross section is formed on the surface of the press-fit portion 31. Is protruding. In addition, a through hole 33 that allows the stem 4 to pass through is provided at the diameter position of the seat ring 3, and a cylindrical tube portion 34 having an axial hole 34a from the outer peripheral surface of both diameter positions toward the outside in the diameter direction. Projectingly provided, annular grooves 35 into which the bearings 8 and 9 are inserted are respectively formed along the roots of both the cylindrical portions 34 and 34.
[0020]
The bearing 7 that pivotally supports the upper end portion 4a of the stem 4 has a cylindrical shape and is formed using an engineering plastic material such as a POM resin. The bearings 8 and 9 that pivotally support the central portion 4b and the lower end portion 4c of the stem 4 are formed of a suitable material such as steel, iron, an alloy, or a synthetic resin into a cylindrical shape and are provided at the diameter position of the seat ring 3 The inner diameter of one end is enlarged so that it can be fitted to the portions 34 and 34. Note that all or some of these bearings 7, 8, 9 may be omitted, and a semi-cylindrical bearing portion (not shown) may be formed at an appropriate position of the divided body 2 instead.
[0021]
Hereinafter, an example of assembly of the above-described butterfly valve will be described. The stem 4 is inserted into the through hole 33 of the seat ring 3 and the shaft hole 34 a of the cylindrical portion 34, and the disc 5 is fitted inside the seat ring 3. The bearings 8 and 9 are fitted to the central portion 4b and the lower end portion 4c of the stem 4, and the diameter-expanded one end portions of the bearings 8 and 9 are fitted to the cylindrical portions 34 and 34 of the seat ring 3. The tips of the expanded one end portions are fitted into the annular grooves 35 and 35 at the bases of the cylindrical portions 34 and 34. The press-fit portions 31, 31 projecting from the inter-surface end surfaces 3 a, 3 a of the seat ring 3 are fitted into the gap portion 17 formed in the divided body 2 and are formed in the shaft tube portion 21 of the divided body 2. The parts 13 and 14 and the bearings 7 and 8 and the stepped part 15 formed on the short cylinder part 20 and the bearing 9 are fitted to each other, the pair of divided bodies 2 and 2 are joined, and fixed using bolts and nuts.
[0022]
Thereby, in the short cylinder part 10 of the valve body 1 formed by the divided bodies 2 and 2 sandwiching the seat ring 3, the inner peripheral surface of the flow path is formed by the exposed inner peripheral surface of the seat ring 3, A stem 4 is rotatably inserted into the shaft tube portion 11. The head of the stem 4 protrudes from the flanges 18 and 18 at the tips of the shaft cylinders 21 and 21 of the divided bodies 2 and 2 and can be connected to a valve drive mechanism (not shown) fixed to the flanges 18 and 18. Become.
[0023]
In addition, when joining and fixing a pair of division | segmentation bodies 2 and 2, using a bolt and a nut which fasten the flange provided in the edge part of the pipe body (not shown) connected with the both sides of the valve body 1, The divided bodies 2 and 2 may be clamped and fixed.
[0024]
Here, as shown in FIG. 5, by connecting the connecting tube 22 integrally to the end surface 2a of the split body 2, the connecting tube 22 and the tube can be easily connected using a clamp joint or the like. . Furthermore, a thread may be formed at both ends of the connecting pipe 22 and the pipe body so that they can be screwed together. In this case, the gasket 6 is not used. In addition, since others are the same as the butterfly valve mentioned above, description is abbreviate | omitted.
[0025]
Moreover, as shown in FIG. 6, you may shape | mold the short cylinder part 10 and the axial cylinder part 11 of the valve body 1 separately. In this case, the valve body 1 is formed by a cylindrical shaft cylinder 19 and a pair of divided bodies 24 and 24. The shaft cylinder 19 is formed with a flange portion 19a by expanding the upper end of the cylindrical tube member, and by forming a step portion 19b with which the bearing 27 is fitted by expanding the diameter under the flange portion 19a. The lower end of the fitting portion 19c is enlarged to form a substantially prismatic fitting portion 19c, and a slit 19d is formed on the opposing surface of the fitting portion 19c from the opening end of the lower end toward the upper end. The valve drive mechanism can be fixed, and a rectangular plate member 29 for fixing the bearing 27 is fixed to the flange portion 19a. Further, the divided body 24 is formed in substantially the same manner as the short tube portion 20 shown in FIG. 3, but the fitting portion 19c of the shaft tube body 19 is fitted at a position where the shaft tube portion 21 is projected. A fitting recess 24a having a prismatic cross section is formed.
[0026]
In this case, a rectangular bearing 28 fitted to the fitting portion 19c of the shaft cylinder 19 is used. The bearing 28 has a shaft hole 28a through which the stem 4 is inserted, and further, a cylindrical portion 28b that fits into the annular groove 35 of the seal ring 3 is projected from an end surface on the seal ring side, and an inner diameter on the cylindrical portion 28b side. Is formed so that it can be fitted to the cylindrical portion 34 of the seal ring 3.
[0027]
【The invention's effect】
As described above in detail, the butterfly valve according to the present invention forms a valve body with a pair of divided bodies, so that the mold is half, and the seat ring that penetrates the stem and is fitted with a disc is divided into the divided bodies. Because it can be manufactured simply by sandwiching between the two, production efficiency is good and inexpensive. Moreover, since the disassembly is easy, maintenance such as replacement of the seat ring is easy.
[0028]
Further, since the seat ring is sandwiched in the valve body, there is a heat insulating effect, and condensation can be prevented.
[0029]
By joining a pair of split bodies, the seat ring is clamped and held between the gap and the inner wall, and the seat ring is held by a bearing that pivotally supports the stem. Without being affected, it is possible to secure the sealing performance with the disc and the stem and to prevent the seat ring from being displaced.
[0030]
Furthermore, since the divided body is formed in a shape divided by a plane perpendicular to the flow path, it is possible to form a divided body having a connecting pipe with one mold. For this reason, a butterfly valve suitable for piping using a clamp joint or the like can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a butterfly valve of the present invention.
FIG. 2 is an exploded explanatory view of the butterfly valve.
FIG. 3 is a front view showing a divided body of the butterfly valve.
4 is a cross-sectional view taken along the line AA in FIG.
FIG. 5 is a cross-sectional view showing another embodiment of the butterfly valve of the present invention.
FIG. 6 is a partial cross-sectional explanatory view showing another embodiment of the butterfly valve of the present invention.
[Explanation of symbols]
1 Bas Rububodi
2 Split body
3 Seat ring
4 Scan Temu
5 Di disk <br/> 8, 9 Bearing <br/> 1 7 Between gap section 17 a Inner wall <br/> 2 2 Consolidated tube 3 1 Pressure join the club 34 cylindrical portion

Claims (4)

It consists of a valve body, a seat ring attached to the inner peripheral surface of the valve body, a disc rotating inside the seat ring, and a stem provided in the diameter direction of the disc, and by rotating the stem In the butterfly valve that opens and closes the disc, the split body is formed so as to have the same shape as the split shape of the valve body in a plane that passes through the center of the stem and is perpendicular to the flow path direction. The body is formed with a gap portion for holding the seat ring having an opening on the joint surface side and an inner wall inside the gap portion, and when the pair of divided bodies are joined, the seat ring is connected to the gap portion. Torsion and displacement of the seat ring at the position where the stem is fitted by providing a bearing that press fits on the inner wall and supports the stem on the outer periphery in the diameter direction of the seat ring. Butterfly valve, characterized in that preventing and adapted to ensure the sealing property. The stem of the cylindrical portion projecting from the diameter position of the seat ring through which the butterfly valve of the protruding allowed claims 1 Symbol mounting the cylindrical portion from the gap of the split body outward in the diameter direction. The butterfly valve according to claim 1 or 2 , wherein an inner diameter of one end portion of the bearing is expanded to fit the cylindrical portion and the bearing . The butterfly valve according to any one of claims 1 to 3, wherein a connecting pipe is integrally formed on an end surface between the surfaces of the divided body.

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