JP2007032683A - Butterfly valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a butterfly valve capable of reducing its weight without impairing strength of a valve element, and having superior sealing property. <P>SOLUTION: In this butterfly valve 1, an elastic seat ring 3 is mounted on an inner peripheral face of a short cylindrical body 2, and a disc-shaped valve element 10 opened and closed, or controlled by the rotation of a stem 8 is mounted in the seat ring 3. An outer peripheral portion 20 of the valve element 10 is thicker than a flat portion 17 of the valve element 10. Further the valve element 10 is provided with a vertical rib 21 and a horizontal rib 22, the vertical rib 21 is joined to upper and lower boss portions 18, 19 mounted in the vertical direction of the valve element 10. The horizontal rib 22 is horizontally mounted from a center position of the valve element 10 and joined to the outer peripheral portion 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a butterfly valve used to open and close a flow of a fluid such as gas, cold / hot water, and oil and to control the flow rate, and particularly relates to a valve body of a butterfly valve that achieves stable sealing and weight reduction. .

  The butterfly valve has a simple structure, is compact, has good operability, etc., so that it can be used as a stop valve or as a flow control valve, depending on the purpose and application, as a water supply / drainage, air conditioning equipment, various industrial plants, factory processes Widely used in In general, a butterfly valve is constructed by attaching an elastic seat ring to the inner peripheral surface of the valve body and fixing a disc-shaped valve body to a stem that is rotatably mounted at the diameter position of the main body. By operating, the outer peripheral surface of the valve body is brought into contact with and separated from the inner peripheral surface of the seat ring, and the fluid passage in the valve body is opened and closed or the flow rate is controlled.

  By the way, when this butterfly valve closes the fluid passage in the valve body, a large fluid pressure is applied to the disc-shaped valve body. Due to the action of the stress based on the fluid pressure, a change in shape (distortion) occurs in the valve body. Due to this change in shape, a deviation occurs in the sealing position between the valve body and the seat ring, which is likely to cause leakage.

  In order to deal with the above problem, a method has been adopted in which the entire valve body is made thick so as to ensure sufficient strength that does not cause a shape change. Since it increases, the operating torque of the valve body increases and the operability is poor. Therefore, various techniques have been proposed in order to reduce the weight while ensuring the strength of the valve body.

For example, Japanese Patent Application Laid-Open No. 2004-239343 (hereinafter referred to as Patent Document 1) provides a valve rod hole boss portion that bulges outward in the Y axis direction, which is the valve axis direction of the valve body, A plurality of horizontal ribs extending in the secondary direction from the boss portion on the nozzle side surface, and a plurality of horizontal ribs extending in the primary side direction from the boss portion rotated about 180 degrees around the Y axis on the orifice side rear surface of the valve body, respectively. By providing these ribs, the strength of the valve body is improved, and the thickness of the valve body is reduced to reduce the weight. Further, as can be seen in Japanese Patent No. 3356511 (hereinafter referred to as Patent Document 2), the valve body has a thin wall shape except for the shaft hole forming portion, and has a substantially S-shape when viewed from the valve body axial hole direction. The body is known.
JP 2004-239343 A Japanese Patent No. 3356511

  However, as in Patent Document 1, a valve body provided with a plurality of ribs hardly changes in shape (distortion) in the vicinity of the ribs during pressure reception, but it is not possible to suppress the occurrence of distortion at locations where there are no ribs. In order to obtain a sufficient strength that does not cause distortion in the entire valve body, it is necessary to further increase ribs. Therefore, it is impossible to achieve the strength and weight reduction of the valve body at the same time. On the other hand, in the substantially S-shaped valve body shown in Patent Document 2, in order to obtain the required strength, the valve body must be thickened after all. In the first place, the structure of the valve body is to minimize the fluid resistance when the valve is opened, and cannot be a technique for reducing the weight while ensuring the strength.

  The present invention has been developed as a result of earnest research in view of the above-mentioned problems, and the object of the present invention is to realize weight reduction without impairing the strength of the valve body and to achieve excellent sealing. An object of the present invention is to provide a butterfly valve having the characteristics.

  In order to achieve the above object, the invention according to claim 1 is a disk in which an elastic seat ring is mounted on the inner peripheral surface of a short cylindrical body, and is opened / closed or controlled by rotation of a stem in the seat ring. In the butterfly valve provided with a valve-like valve body, the outer periphery of the valve body is formed thicker than the flat part of the valve body, and the valve body is provided with a reinforcing rib.

  According to a second aspect of the present invention, the rib comprises a vertical rib and a horizontal rib, the vertical rib is joined to a boss portion provided above and below in the vertical direction of the valve body, and the horizontal rib is the center of the valve body. It is a butterfly valve provided in the horizontal direction from the position and joined to the outer peripheral portion.

  The invention according to claim 3 is a butterfly valve in which the vertical rib and the horizontal rib intersect with each other at the thickest part, and the flat portion of the valve body has a uniform and thin thickness.

  The invention according to claim 4 is the butterfly valve in which the vertical rib and the horizontal rib are drawn with a large parabola with the central portion of the valve body as a vertex so as to have a uniform stress in the cross section of the rib.

  According to the first aspect of the present invention, for example, by forming the outer peripheral portion in which the range from the outer peripheral surface to the inner diameter direction of 2 to 7 mm is 2 to 5 mm thicker than the flat portion, the sealing surface with the seat ring is increased. , Stable sealing becomes possible. In addition, the sealing position can be changed in a wide range, and the adjustment can be easily performed.

  According to the invention of claim 2, the vertical rib plays a role of suppressing bending with the upper and lower stems as fulcrums, while the horizontal rib suppresses bending with the valve body center as a fulcrum with respect to the horizontal direction of the valve body. Take a role. The displacement of the entire valve body can be suppressed, and the thickness of the inner flat portion can be extremely reduced.

  According to the invention of claim 3, the vertical rib is joined to the upper and lower bosses, the horizontal rib is joined to the thick outer peripheral part, and the vertical rib and the horizontal rib are crossed at the thickest part. The displacement of the entire valve body can be suppressed, and the thickness of the inner flat portion can be extremely reduced.

  According to the fourth aspect of the present invention, the ribs pass in two directions, vertical and horizontal, from the center of the valve body, and the two ribs each take an average strength beam, and the cross-section of the rib has a uniform stress. Since such a large parabola is drawn, the thickness of the rib is not wasted and a shape having an efficient strength against stress was realized.

  Hereinafter, embodiments of a butterfly valve according to the present invention will be described in detail with reference to the drawings. Note that this embodiment is a particularly useful form in which the present invention is implemented, and the present invention is not limited to that form. FIG. 1 is a cross-sectional view showing an example of a butterfly valve according to the present invention. 2 is a perspective view showing a valve body constituting the present invention, FIG. 3 is a front view of the valve body in FIG. 2, and FIG. 4 is a partially cutaway plan view of the valve body constituting the present invention. FIG. 5 is a side view of the valve body constituting the present invention.

  In FIG. 1, a butterfly valve 1 has a seat ring 3 made of an elastic material such as rubber on the inner peripheral surface of a cylindrical body 2 (valve box). An upper stem 8 and a lower stem 9 are rotatably mounted in the formed stem holes 4 and 5 via bearings 6 and O-rings 7a and 7b. The stems 8 and 9 are fixed to a disc-like valve body 10 fitted in the seat ring 3 so that the fluid passage is opened and closed by the valve body 10 or the flow rate is controlled. In this embodiment, the body 2 employs an aluminum casting that is die-molded by die casting, and the valve body 10 employs a stainless steel casting. However, the present invention is not limited to this. Select any material.

  A mounting flange 11 is provided above the stem hole 4, and an electric, hydraulic, or pneumatic actuator mounted on the upper surface of the mounting flange 11 via a fixing member such as a bolt, as shown in FIG. The operation unit 13 such as a gear mechanism having the handle 12 is connected. In this example, a manual force via the handle 12 is transmitted to the upper stem 8 of the butterfly valve 1 via a gear unit in the casing 14 to enable the valve body 10 to be manually rotated.

  The lower stem hole 5 is covered with a holding body 15 made of an elastic material such as a synthetic resin material or rubber, and the lower stem 9 is rotatable and prevented from coming off. The holding body 15 includes a substantially cylindrical bearing tube portion 15 a that pivotally supports the lower stem 9 and a tapered locking portion 15 b that expands toward the end, and the locking portion 15 b is provided on the body 2. The structure is easy to assemble and excellent in workability, in which the bearing holder of the lower stem 9 can be mounted only by the holding body 15 and is engaged with the engaging portion 2a. Also, holding rings 16 and 16 are attached to the body contact surface of the seat ring 3 to prevent twisting of the seat ring 3 caused by rotation of the stems 8 and 9 and sliding of the valve body 10, and when the valve body rotates. Improves stability. The said structure is an example and is not limited to this. In this example, the holding body 15 made of an elastic material such as rubber is used. However, for example, a holding body (not shown) formed by processing a metal leaf spring may be used.

  As shown in FIGS. 2 and 3, the disc-shaped valve body 10 according to the present invention is composed of a flat portion 17 that is formed uniformly and thinly, and an upper boss portion is positioned at a position opposite to the flat portion 17 in the vertical direction. 18 and a lower boss portion 19 project. As shown in FIG. 1, insertion holes 18a and 19a for inserting and fixing the upper stem 8 and the lower stem 9 are formed in the boss portions 18 and 19, respectively. Of these, the upper insertion hole shown in FIG. An appropriately shaped stopper surface portion (in this example, two surface portions 18b) that restricts the rotation of the upper stem 8 is formed in 18a, and the valve body 10 can be rotated as the upper stem 8 rotates.

  A thick outer peripheral portion 20 is formed over the entire outer peripheral edge including the upper and lower boss portions 18 and 19. For example, in the case of a 100 A valve body, a thick region is formed in which the range from the outer peripheral surface to 3.5 mm in the inner diameter direction is 3.0 mm thicker than the flat portion 17. The formation of the outer peripheral portion 20 is most effective in reducing the weight of the entire valve body while ensuring a sufficient strength that does not cause a shape change due to fluid pressure, and the valve body 10 and the seat ring 3. And functions to ensure a stable sealing property. In addition, the sealing position can be changed in a wide range, and the adjustment can be easily performed.

  As shown in FIGS. 4 and 5, a gentle round (arc-shaped) 20 a is formed at the corner in the width direction of the outer peripheral portion 20, and the incoming contact with the seat ring 3 during the rotation of the valve body is smooth. Become. If this round 20a is formed to have a desired curvature, the surface pressure with the seat ring 3 can be set to a surface pressure according to the implementation. In addition, since the boss surfaces of the upper and lower boss portions 18 and 19 are wide, the curvature of the radius 20a is changed from that of the other outer peripheral portion 20, and in this example, the radius 20a is set large so that the valve body is rotated. The structure prevents the rubber (seat ring) from accumulating. Thereby, while ensuring optimal sealing performance with low torque, the durability of the seat ring 3 is greatly improved.

  As shown in FIG. 5, the upper boss portion 18 and the lower boss portion 19 are connected by vertical ribs 21 on both surfaces (primary side and secondary side) of the valve body 10, and the central portion of the vertical ribs 21. Horizontal ribs 22 are provided from the outer peripheral portion 20 to the thick wall shape. The vertical rib 21 plays a role of suppressing bending with the upper and lower stems 8 and 9 as fulcrums, while the horizontal rib 22 plays a role of suppressing bending with the valve body center as a fulcrum with respect to the horizontal direction of the valve body 10. Is responsible. If the strength of the vertical ribs 21 is weak, the entire ribs undergo a shape change, and the entire valve body is affected by this, so the thickness of the vertical ribs 21 is set to be thicker than the horizontal ribs 22.

  Further, the vertical rib 21 and the horizontal rib 22 intersect each other at the thickest part. As described above, the thickness of the intersecting portion (valve element center portion) between the vertical rib 21 and the horizontal rib 22 is maximized, so that an optimum effect of reinforcing the stress is exerted in the valve center portion where the generated stress is high. In addition to realizing the thickness and taking into account the average strength of the vertical and horizontal ribs 21 and 22, a large parabola with the center of the valve body as the apex, which is a uniform stress in all rib sections, is drawn. It has a thickness that is not wasteful and lightweight, and does not increase fluid resistance. An organic combination of the thick outer peripheral portion 20, the vertical ribs 21 and the horizontal ribs 22 realizes a high-strength and lightest valve body 10 in which a reinforcing effect against stress is spread over the entire valve body. is doing.

  In this embodiment, a particularly useful seat ring is employed in combination with the valve body constituting the present invention. FIG. 6 is a schematic explanatory view showing a sealing start state. The seat surface 3a of the seat ring 3 shown in this example has a flat convex surface 3b having a flat surface. When the valve body 10 rotates, the outer peripheral surface of the valve body contacts and separates from the seat ring 3 The seat ring 3 can be escaped, and the minimum amount of crushing is realized. As a result, an optimum sealing performance is ensured with a lower torque than in the prior art, and the durability of the seat ring 3 is greatly improved. In addition, the gentle radius 20a formed at the corner in the width direction of the outer peripheral portion 20 makes the incoming contact with the seat ring 3 smooth when the valve body rotates, and if this radius 20a is formed to a desired curvature, The surface pressure with the seat ring 3 can be set to a desired surface pressure according to the implementation. In this example, the sealing position is set to 3 °, but the sealing point between the valve body 10 and the seat ring 3 may be set to a desired position according to the implementation.

  The seat surface 3a of the seat ring 3 may be provided with a stretchable texture (not shown). In this case, the texture functions to partially reduce the contact surface pressure with the valve body 10. That is, the sealing surfaces of the valve body 10 and the seat ring 3 are made in a dotted contact, and particularly the resistance (restarting torque) at the time of separation is reduced. Thereby, even if it has the structure which expanded the sealing surface with a valve body, friction resistance is reduced and the stable light operation torque is ensured.

  In forming the texture, if the texture is rougher than necessary, leakage may occur between the textures. For this reason, the roughness of the texture is preferably set to 60 μm or less. In addition to the formation of such wrinkles, it is also an effective means to modify the sheet surface 3a, for example, by subjecting the sheet surface 3a to a halogenation treatment as a surface hardening treatment. The seat surface having a reduced frictional resistance (particularly torque during sliding) realizes a stable light operation torque.

  According to the present invention, it is possible to provide a butterfly valve that achieves weight reduction without impairing the strength of the valve body, and also has excellent sealing properties, as a stop valve or as a flow control valve, It is possible to meet various specifications such as air conditioning equipment, various industrial plants, and factory processes.

It is sectional drawing which showed an example of the butterfly valve in this invention. It is the perspective view which showed the valve body which comprises this invention. It is the front view which showed the valve body which comprises this invention. It is the partially notched top view which showed the valve body which comprises this invention. It is the side view which showed the valve body which comprises this invention. It is the schematic explanatory drawing which showed the sealing start state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Butterfly valve 2 Body 3 Seat ring 8 Upper stem 9 Lower stem 10 Valve body 17 Flat part 18 Upper boss part 19 Lower boss part 20 Outer peripheral part 21 Vertical rib 22 Horizontal rib

Claims (4)

  In a butterfly valve in which an elastic seat ring is mounted on the inner peripheral surface of a short cylindrical body, and a disc-shaped valve body that is opened and closed or controlled by rotation of a stem is provided in the seat ring, the outer periphery of the valve body The butterfly valve is characterized in that the portion is formed thicker than the flat portion of the valve body, and a reinforcing rib is provided on the valve body.   The rib includes a vertical rib and a horizontal rib, the vertical rib is joined to a boss portion provided above and below in the vertical direction of the valve body, and the horizontal rib is provided in the horizontal direction from the center position of the valve body. The butterfly valve according to claim 1, wherein the butterfly valve is joined to the outer periphery.   The butterfly valve according to claim 1 or 2, wherein the vertical rib and the horizontal rib intersect with each other at the thickest portion, and the flat portion of the valve body has a uniform and thin thickness. The butterfly valve according to any one of claims 1 to 3, wherein the vertical rib and the horizontal rib draw a large parabola with the central portion of the valve body as an apex so that the stress is uniform in the cross section of the rib.

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