JP2006132743A - Metal seat butterfly valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide smooth water cut-off performance without causing reduction of a communication area. <P>SOLUTION: In the metal seat butterfly valve V, a thin elastic metal made cylindrical valve body seat 6 is provided in an inner face of a valve body 1, and contact and separation of a valve element 3 is carried out with respect to the valve body seat 6. In the valve body seat 6, its both ends 7 whole circumferences are cross sectionally U-shaped, and it is housed in a recessed part 4 of the valve body inner face. By this housing, a protruding amount to the valve body inner face due to installation of the valve body seat can be minimized, and reduction of the communication area is prevented. If both ends 7 are U-shaped, when the valve element 3 abuts on a substantially center of the valve body seat 6 (when the valve is closed), moment protrusively bending a center part from the U-shaped ends toward a valve body center acts like a statically indeterminate beam with respect to the abutting force, the moment enhances the abutting force of the valve element, and the water cut-off performance becomes high. Water cut-off into the recessed part 4 is carried out by an O-ring 8, and abutting force during deformation absorption of the valve body and valve closing is eased by elastic rubber 9 of recessed part 4 both ends. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metal sheet butterfly valve which prevents water leakage due to deformation of a valve box.

Conventional technology

The metal seat butterfly valve consists of a metal seat for both the valve seat (valve seat) and the valve seat (valve seat). Therefore, the durability of the valve seat (seat) when the valve is opened and closed high. For this reason, it is an advantageous valve in terms of maintenance.
However, since a normal metal sheet butterfly valve has a valve box sheet integrated with the valve box, when the valve box is deformed by an external force, the valve box sheet is also deformed. to degrade. For this reason, the actual situation is that the valve box is not used as a valve which is likely to be deformed, for example, a valve embedded in the ground.

Under such circumstances, a metal sheet butterfly valve having a structure in which the valve box and the valve box sheet are separated has been proposed. The valve box seat support structure of this valve supports both ends of the valve box seat with stoppers and interposes an elastic body such as an O-ring between the valve box seat and the inner surface of the valve box. The valve box sheet is not deformed by the presence of a gap between the valve box sheet and the inner surface of the valve box, and therefore, the valve box sheet is kept in contact with the valve body sheet in a watertight manner without causing water leakage. The valve body is not restrained by deformation. (See Patent Document 1, paragraphs 0007 and 0014 of FIG. 3). Incidentally, the O-ring is used as a sealing material for preventing water from flowing into the gap, and this seal prevents water from flowing through the gap to the downstream side (paragraph 0009 in the patent document 1).
Japanese Patent Laid-Open No. 2002-3152

Further, as an improvement of the above technique, the stopper is used as a support ring, and the end of the support ring and the valve box sheet is watertightly welded to make the gap between the valve box sheet and the valve box inner surface watertight. There is also. In this case, when the valve is closed, the valve box sheet is bent to allow contact of the valve body (see FIG. 4 of Patent Document 2).
JP 2003-185033 A

Since the valve box seats of the both metal sheet butterfly valves are flat in the cylinder axial direction, the bending due to the contact of the valve body takes the form of a simple beam, and the bending degree depends only on the material. For this reason, the water stoppage due to the contact with the valve body based on the degree of deflection is dependent on the material, and the valve box sheet is vigorous and expensive to obtain its smooth contact (waterstop). Will be used.
In addition, since all of the valve box sheets are supported by a stopper or a support ring protruding from the inner surface of the valve box, the valve box sheet and the valve box sheet protrude into the valve box, thereby causing a reduction in the flow area.

  This invention makes it the 1st subject to obtain a smooth water stop, and makes the 2nd subject to reduce the reduction | decrease of a distribution area as much as possible.

In order to achieve the first object, the present invention has a valve box sheet having a U-shaped cross section in which the entire circumference of both end portions is curved outward and curved toward the other side.
When both end parts are U-shaped, when the valve body comes into contact with the approximate center of the valve box sheet (when the valve is closed), the contact force is like an indefinite beam fixed at both ends. A moment force that curves the valve box seat in a convex shape from the U-shaped end portion toward the center of the valve box acts on the center portion, and the moment force increases the contact force with the valve body. As a result of this action, the water stoppage becomes high and the contact force is eased by the retreat of the valve box seat to the recess. Is less.
Further, even if an external force acts on the valve box and the valve box is deformed, the valve box sheet is bent so that the U-shaped end portions thereof are narrowed and the deformation is absorbed, so that the deformation is hardly deformed. Even if it is deformed, at the time of contact with the valve body, the valve box sheet bends so as to compensate for the deformation due to the bending of the both ends of the U-shape, thereby ensuring the water stoppage.

Next, in order to achieve the second problem, according to the present invention, a recess is formed on the inner surface of the valve box and the valve box sheet is accommodated therein.
If it does in this way, the protrusion amount to the valve case inner surface by installation of a valve case sheet | seat can be decreased as much as possible.

  Since the present invention can effectively obtain the contact force with the valve body due to the presence of the U-shaped end portion of the valve box seat as described above, the valve box seat is more expensive than the above prior art. There is no need to use a material, and a smooth water-stopping action can be obtained. Moreover, since the valve box sheet is accommodated in the concave part of the valve box, the reduction of the flow area can be minimized.

  As an embodiment of the present invention, in the metal seat butterfly valve in which a cylindrical valve box sheet made of a thin elastic metal material is provided on the inner surface of the valve box and the valve body is brought into contact with and separated from the valve box sheet, the valve box is opened and closed. The entire circumference of both ends of the seat is curved outward and has a U-shaped cross section curved toward each other, and the valve box seat is formed on the inner surface of the valve box so that the U-shaped end is on the outside. The provided configuration can be employed.

In this configuration, a recess for storing the valve box sheet is formed on the entire inner periphery of the valve box, and the valve box sheet is stored in the recess so that the U-shaped end is on the back side. It is preferable to minimize the amount of protrusion to the inner surface of the valve box.
Also, due to the contact of the valve body, both ends of the valve box sheet are pressed against the inner surface of the valve box to prevent water from entering the valve box sheet, but there is an elastic seal between the end part and the inner surface of the valve box. It is preferable to prevent the water from entering through the material. When the valve box sheet is stored in the recess, an elastic sealing material is interposed between the side surfaces of both ends of the valve box sheet and the side surfaces of the recess.

An elastic rubber is interposed between the end of the valve box seat and the inner surface of the valve box to reduce the contact force with the valve body of the valve box sheet, and when the valve box is deformed by an external force or the like. The deformation can be absorbed. At this time, the elastic strength (elastic modulus) of the elastic rubber is appropriately determined in consideration of the waterstop and deformation absorbability.
When the valve box sheet is stored in the recess, elastic rubber is interposed between the end of the valve box sheet and the bottom surface of the recess.

In this configuration, if the elastic rubber on the front side in the valve closing direction of the valve body is made to have a lower elastic strength (softer one) than the elastic rubber on the rear side, the valve body is in sliding contact with the valve box seat. When the valve is closed, the contact force (repulsive force from the valve box seat) is gradually increased to close the valve, so that the valve closing operation is smooth.
Also, if a partition wall is formed between the elastic rubbers to position them, the action of one elastic rubber is less affected by the action of the other elastic rubber, and both elastic rubbers individually absorb the deformation. Such an action is performed to ensure the action.

One embodiment is shown in FIG. 1 and FIG. 2, and this embodiment is a metal sheet butterfly valve V interposed in the buried water pipe D, and the valve rod 2 penetrates in the center of the valve box 1 in a watertight manner, A butterfly valve body 3 is provided on the valve stem 2. Around the valve body 3, a metal valve body sheet 3a is provided.
A concave portion 4 is formed on the entire inner periphery of the inner surface of the valve box 1, and the concave portion 4 has grooves 5 on the entire circumference at both ends. A valve box sheet 6 is accommodated in the recess 4.

The valve box sheet 6 is made of a thin elastic metal material having an appropriate elasticity with respect to the pressure contact of the valve body 3, for example, a steel material such as stainless steel. The U-shaped end 7 is curved toward the back, and the U-shaped end 7 is housed in the recess 4 so as to be on the back side.
An O-ring 8 is interposed between the both end portions 7 of the valve box sheet 6 and the side surface of the recess 4, and the O-ring 8 reliably prevents water from entering the recess 4.

Further, elastic rubbers 9 and 9 are accommodated in the grooves 5 of the recesses 4 desired by the both end portions 7 of the valve box sheet 6, respectively. The contact force is relaxed and the deformation of the valve box 1 is absorbed. At this time, the elastic strength of the elastic rubber 9 is appropriately determined in consideration of the water stoppage due to the contact between the valve box sheet 6 and the valve body 3, and the elastic rubber 9 on the front side in the valve closing direction of the valve body The elastic strength of the elastic rubber 9 is made lower. In this embodiment, in FIG. 1, the left side elastic rubber 9 is the front side, and the upper side is the right side elastic rubber 9 on the front side. The strength is changed.
The elastic rubber 9 is mechanically joined to the inner surface of the groove 5, adhesively bonded including baking, or similar mechanically bonded to the valve box sheet end 7 or adhesively bonded including baking.

  This embodiment has the above-described configuration. As shown by a chain line in FIG. 1, the valve body 3 is opened by being in the central axis direction (flow direction) of the valve box 1, and as shown by the solid line in FIG. The body 3 is rotated in the direction orthogonal to the central axis of the valve box 1 as shown by an arrow, and the valve body sheet 3a is brought into contact with the valve box sheet 6 and closed with a metal sheet.

When the valve is closed, since both end portions 7 of the valve seat 6 are U-shaped, when the valve body 3 (valve seat 3a) contacts the substantially center of the valve seat 6, the contact force As shown by the arrows in FIG. 2, the valve box seat 6 has a moment that curves from the U-shaped end 7 to the center of the valve box 1 in a convex manner, as shown by the arrows in FIG. A force acts, and the moment force increases the contact force with the valve body 3. For this reason, the waterstop is high.
Further, even if an external force is applied to the valve box 1 and the valve box 1 is deformed, the valve box sheet 6 is bent so that the U-shaped end portions 7 are narrowed therebetween to absorb the deformation. Even if deformed, the valve box sheet 6 bends to compensate for the deformation due to the bending of the U-shaped end portions 7 at the time of contact with the valve body 3 to ensure water-stopping.

Furthermore, since the elastic strength of the front elastic rubber 9 is lower than that of the rear elastic rubber 9 in the valve closing direction of the valve body 3, the valve body 3 slides against the valve box seat 6 to close the valve. At that time, the contact force is gradually increased from a low point to close the valve, and the valve closing operation is smooth.
Further, between the elastic rubbers 9 and 9, a valve box portion sandwiched between the grooves 5 and 5 serves as a partition wall 10 for positioning both of them. The action of the rubber 9 is less affected by the action of the other elastic rubbers 9, and both the elastic rubbers 9 individually perform actions such as the above-described deformation absorption, so that the action is ensured.

  In the above embodiment, the valve box sheet 6 is accommodated in the recess 4. However, when the recess 4 is not formed, the valve box sheet 6 is placed at a required position on the inner surface of the valve box 1 by a stopper as shown in Patent Document 1 described above. To support. At this time, the O-ring 8 can be interposed between the stopper and the end 7, and the elastic rubber 9 can be interposed between the end 7 and the inner surface of the valve box. Moreover, the partition wall 10 can also be provided by fixing a partition member to the valve box inner surface.

Cutting plan view of one embodiment 1 is an enlarged view of the main part of FIG.

Explanation of symbols

D Water pipe V Metal seat butterfly valve 1 Valve box 2 Valve stem 3 Valve body 3a Valve body seat (valve valve seat)
4 Recess 5 Groove 6 Valve box seat (valve box valve seat)
7 U-shaped end of valve box sheet 8 O-ring 9 Elastic rubber 10 Partition wall

Claims (6)

In the metal sheet butterfly valve V which is provided with a cylindrical valve box sheet 6 made of a thin elastic metal material on the inner surface of the valve box 1 and opens and closes the valve body 3 by contacting and separating the valve body 3 from the valve box sheet 6,
The entire circumference of both end portions 7 of the valve box seat 6 is curved outward and curved toward the other side, and the valve box seat 6 has the U-shaped end 7 on the outside. A metal sheet butterfly valve characterized by being provided on the inner surface of the valve box 1 as described above.   A concave part 4 for accommodating the valve box sheet 6 is formed on the entire inner periphery of the valve box 1, and the valve box sheet 6 is accommodated in the concave part 4 so that the U-shaped end 7 is on the back side. The metal sheet butterfly valve according to claim 1.   3. The metal sheet butterfly valve according to claim 2, wherein an elastic sealing material 8 is interposed between the side surfaces of both ends 7 of the valve box sheet and the side surfaces of the recess 4.   4. The metal seat butterfly valve according to claim 2, wherein elastic rubber 9 is interposed between both end portions 7 of the valve box sheet 6 and the bottom surface of the recess 4.   5. The metal sheet butterfly valve according to claim 4, wherein the elastic strength of the front elastic rubber is lower than that of the rear elastic rubber in the valve closing direction of the valve body.   The metal sheet butterfly valve according to claim 4 or 5, wherein a partition wall (10) for positioning both of the elastic rubbers (9, 9) is formed between the elastic rubbers (9, 9).

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