JP2020153419A - Valve device - Google Patents

Abstract

To provide a valve device capable of improving durability of a diaphragm while supporting high pressure and large flow rate situation.SOLUTION: Since a metal diaphragm 15 has a curved part 155 that is convexly curved toward a valve closing side, stress is more likely to be dispersed throughout the metal diaphragm as compared to a configuration in which the metal diaphragm is convexly curved toward a valve opening side. Therefore, even when the metal diaphragm 15 is configured by using a highly rigid metal thin plate material to support high pressure situation and a stroke of a valve body 13 is lengthened to support large flow rate situation, it is possible to suppress damage to the metal diaphragm 15, and improve durability.SELECTED DRAWING: Figure 2

Description

The present invention relates to a valve device including a valve body forming a valve chamber, a valve body provided in the valve chamber, and a diaphragm for sealing the valve chamber.

Conventionally, in a valve device used for, for example, a refrigeration and air conditioner, a metal diaphragm has been used as a sealing member for sealing the valve chamber. (See, for example, Patent Document 1). In the valve device (diaphragm valve) described in Patent Document 1, the outer peripheral edge of the metal diaphragm is held by the body (valve body), and the shaft portion of the disc (valve body) is inserted and connected to the central portion thereof. Has been done. That is, when the disc is brought into contact with the valve seat, the diaphragm is deformed as the disc moves.

Japanese Unexamined Patent Publication No. 8-219303

In a valve device provided with a diaphragm as described in Patent Document 1, when a high-pressure fluid is used, it is necessary to construct the diaphragm using a metal having high rigidity. On the other hand, in such a valve device, an increase in the flow rate may be required, and in this case, it is necessary to lengthen the stroke (movement amount) of the valve body. When the stroke of the valve body is lengthened, the displacement amount of the diaphragm becomes large, and stress concentration tends to be easy especially when a highly rigid metal is used. When stress concentration occurs in the diaphragm, it causes stress cracking and reduces durability. That is, it has been difficult to improve the durability of the diaphragm while dealing with high pressure and large flow rate.

An object of the present invention is to provide a valve device capable of improving the durability of a diaphragm while supporting high pressure and high flow rate.

The valve device of the present invention is a valve device including a valve body forming a valve chamber, a valve body provided in the valve chamber, and a diaphragm for sealing the valve chamber, and the valve body is a shaft. The diaphragm has an insertion hole through which the shaft portion is inserted, and is formed in an annular shape. The inner peripheral edge portion thereof is fixed to the shaft portion, and the outer peripheral edge portion thereof is the valve. It is fixed to the main body and is characterized in that it is convexly curved toward the valve closed side between the inner peripheral edge portion and the outer peripheral edge portion from the maximum valve open state to the valve closed state.

According to the present invention as described above, since the diaphragm is curved convexly toward the valve closing side, stress concentration can be suppressed when the valve body is brought into contact with the valve seat. That is, in the configuration in which the diaphragm is curved convexly toward the valve opening side, the stress tends to be concentrated in the vicinity of the inner peripheral edge portion, whereas in the present invention, the stress tends to be dispersed in the entire diaphragm. Therefore, by constructing the diaphragm using a highly rigid metal, it is possible to cope with high pressure, and even when the stroke of the valve body is lengthened to cope with a large flow rate, damage to the diaphragm is suppressed and durability is maintained. Can be improved.

At this time, the diaphragm in the natural state has a cross section along the axial direction of the valve body having an inner arc-shaped portion on the inner peripheral edge side and an outer arc-shaped portion on the outer peripheral edge side. It is preferable that the curvature of the inner arcuate portion is larger than the curvature of the outer arcuate portion.

According to this configuration, stress concentration in the diaphragm can be further suppressed and durability can be improved. In the diaphragm, stress tends to concentrate in the vicinity of the shaft portion (inner peripheral edge side). At this time, in this configuration, when the valve body comes into contact with the valve seat, the diaphragm is easily deformed in the outer arcuate portion having a small curvature, and the stress can be dispersed to the outer peripheral edge portion side.

Further, it is preferable that the diaphragm has an inner connecting portion extending along a plane intersecting the axial direction of the valve body and being connected to the shaft portion at the inner peripheral edge portion. According to this configuration, the inner connecting portion can be easily connected to the shaft portion by overlapping the valve opening side, and the diaphragm can be easily curved convexly toward the valve closing side.

According to the valve device of the present invention, since the diaphragm is curved convexly toward the valve closing side, the durability of the diaphragm can be improved while dealing with high pressure and large flow rate.

It is sectional drawing which shows the valve device which concerns on embodiment of this invention. It is an enlarged cross-sectional view which shows the main part when the valve device is in the maximum valve open state. It is an enlarged cross-sectional view which shows the main part when the valve device was put into a valve closed state. It is sectional drawing which shows the diaphragm of the valve device. It is sectional drawing which shows the dimension of the diaphragm. It is an enlarged cross-sectional view which shows the main part when the valve device of the comparative example is in the maximum valve open state. It is an enlarged cross-sectional view which shows the main part when the valve device was put into a valve closed state. It is sectional drawing which shows the diaphragm of the valve device. It is a graph which shows the characteristic of the maximum stress generated in the diaphragm in the valve device which concerns on this invention, and the diaphragm in the valve device of a comparative example.

The valve device according to the embodiment of the present invention will be described with reference to FIGS. 1 to 5. The valve device of the present embodiment includes a metal diaphragm which is a displaceable sealing member. FIG. 1 is a cross-sectional view showing a diaphragm valve 10 which is a valve device of the embodiment. FIG. 2 is an enlarged cross-sectional view showing a main part when the diaphragm valve 10 is in the maximum valve open state. FIG. 3 is an enlarged cross-sectional view showing a main part when the diaphragm valve 10 is in the valve closed state. FIG. 4 is a cross-sectional view showing the metal diaphragm 15 of the diaphragm valve 10. FIG. 5 is a cross-sectional view showing the dimensions of the metal diaphragm 15.

As shown in FIG. 1, the diaphragm valve 10 rotates to move the valve body (body) 12 having the valve chamber 11 inside, the valve body 13 provided in the valve chamber 11, and the valve body 13 forward and backward. It is a manual opening / closing type valve including an operating unit 14 to be operated and a metal diaphragm 15 for sealing the inside of the valve chamber 11. The valve body 12 includes a first member 12a and a second member 12b that are screwed together, and an outer peripheral edge portion 152 of the metal diaphragm 15 is sandwiched between the facing portions of the first member 12a and the second member 12b. ..

The first member 12a of the valve body 12 has an inflow port 12c that opens to one end side and communicates with the valve chamber 11, an outflow port 12d that opens to the other end side and communicates with the valve chamber 11, and an inflow port 12c. A valve port 12e, which is an opening opened in the valve chamber 11, is provided. The second member 12b of the valve body 12 is formed in a cylindrical shape as a whole, and is configured to rotate and support the shaft portion 14b of the operation portion 14 and to be screwed with the male screw portion of the shaft portion 14b.

As shown in FIGS. 2 and 3, the valve body 13 has a cylindrical valve body case 13a having flanges at the top and bottom, a valve member 13b held inside the valve body case 13a, and an upper side of the valve member 13b. It is configured to have a connecting member 13c held in the valve body case 13a. The valve member 13b is a packing made of resin or rubber, and is configured to be seated on the valve port 12e and hermetically sealed. The connecting member 13c has a columnar shaft portion 13d extending upward from the valve body case 13a, a metal diaphragm 15 is fixed to the upper surface 13e of the shaft portion 13d, and the shaft portion 14b of the operating portion 14 is attached to the upper surface 13e. It is connected.

The metal diaphragm 15 is made of one whole circular plate-shaped (dish-shaped) metal thin plate material, and an insertion hole 15a through which the shaft portion 13d of the valve body 13 is inserted is formed in the central portion. In the metal diaphragm 15, the inner peripheral edge portion 151 of the insertion hole 15a is welded and fixed to the shaft portion 13d of the valve body 13, and the outer peripheral edge portion 152 is sandwiched between the first member 12a and the second member 12b of the valve body 12. By doing so, it is fixed to the valve body 12. Further, the metal diaphragm 15 flexes in the out-of-plane direction due to its own elasticity to support the valve body 13 so as to be vertically movable, and the upward urging force due to the elasticity of the metal diaphragm 15 acts on the valve body 13. Is supported at a valve opening position where the valve member 13b is separated from the valve port 12e. The metal diaphragm may be composed of a plurality of thin metal plates.

In such a diaphragm valve 10, when the handle of the operating portion 14 is rotated, the male threaded portion of the shaft portion 14b is guided by the female threaded portion of the second member 12b, and the operating portion 14 moves up and down. Is transmitted to the valve body 13. When the operating portion 14 moves downward due to the closing operation of the handle, the valve body 13 moves downward while bending the metal diaphragm 15 downward in the out-of-plane direction due to the pressing force, and the valve member 13b is seated on the valve port 12e. When the operation unit 14 moves upward due to the opening operation of the handle, the valve member 13b moves upward due to the elastic force (restoring force) that the metal diaphragm 15 tries to return to the initial position, and the valve member 13b separates from the valve port 12e. Sit down. In this way, the valve member 13b moves back and forth between the valve opening position and the valve closing position in accordance with the operation of the handle of the operation unit 14.

Next, the detailed shape of the metal diaphragm 15 will be described with reference to FIGS. 2 to 4. In the following, the valve port 12e side will be the valve closing side and the opposite side will be the valve opening side with reference to the metal diaphragm 15. Further, the shape of the metal diaphragm 15 described below is a shape in a natural state unless otherwise specified. The metal diaphragm 15 has an inner connecting portion 153 on the inner peripheral edge portion 151 and an outer connecting portion 154 on the outer peripheral edge portion 152. The inner connecting portion 153 and the outer connecting portion 154 extend along a plane substantially orthogonal to the axis L direction of the valve body 13. The inner connecting portion 153 is overlapped and fixed on the valve opening side with respect to the upper surface 13e of the valve body 13. The outer connecting portion 154 is sandwiched between the first member 12a and the second member 12b of the valve body 12 as described above.

The metal diaphragm 15 has a curved portion 155 that is convexly curved toward the valve closing side between the inner connecting portion 153 and the outer connecting portion 154. The curved portion 155 maintains a convex shape toward the valve closing side from the maximum valve opening state shown in FIG. 2 to the valve closing state shown in FIG. The metal diaphragm 15 may or may not be slightly deformed from the natural state in the maximum valve open state.

The curved portion 155 has an inner region A1 on the inner peripheral edge side and an outer region A2 on the outer peripheral edge portion side, and the curvature of the convex shape is different between the inner region A1 and the outer region A2. Specifically, the metal diaphragm 15 has an inner arcuate portion 156 on the inner peripheral edge portion 151 side and an outer arcuate portion 157 on the outer peripheral edge portion 152 side in a cross section along the axis L direction of the valve body 13. The curvature of the inner arcuate portion 156 is larger than the curvature of the outer arcuate portion 157 (the radius of curvature of the inner arcuate portion 156 is smaller than the radius of curvature of the outer arcuate portion 157).

The apex portion 158 of the metal diaphragm 15 located on the valve closing side is closer to the boundary portion 159 between the inner region A1 and the outer region A2 (between the inner arcuate portion 156 and the outer arcuate portion 157). It is located on the outer peripheral edge 152 side.

Here, an example of a method of setting the cross-sectional shape of the curved portion 155 of the metal diaphragm 15 will be described with reference to FIG. First, based on the dimensions of each part of the diaphragm valve 10, the width of the curved portion 155 (dimension in the direction orthogonal to the axis L direction) W1, the distance H1 between the inner connecting portion 153 and the outer connecting portion 154 in the axis L direction, and Is decided. Next, the protrusion dimension H2 of the curved portion 155 from the outer connecting portion 154 to the valve closing side and the radius of curvature r1 of the outer arc-shaped portion 157 are appropriately set, and the first arc C1 is drawn. At this time, the first arc C1 passes through the reference point B1 at the outer connecting portion 154 and has the horizontal line indicating the protruding dimension H2 as the tangent line. By drawing in this way, the center O1 of the first arc C1 becomes. It will be decided naturally.

Next, the second arc having a radius of curvature r2 is in contact with both the vertical line passing through the reference point B2 at the inner connecting portion 153 (corresponding to the side surface of the shaft portion 13d of the valve body) and the first arc C1. Draw C2. At this time, the center O2 of the second arc C2 has a height lower than the inner connecting portion 153 in the axis L direction (located below), and the inner connecting portion 153 by the radius of curvature r2 in the direction orthogonal to the axis L direction. It will be located away from. Further, the first arc C1 and the second arc C2 are smoothly continuous (at the point A3 where they overlap, the tangent line of the first arc C1 and the tangent line of the second arc C2 coincide with each other). As a result, with the point A3 as the boundary portion 159, the portion of the second arc C2 from the boundary portion 159 to the inner connecting portion 153 becomes the inner region A1 (inner arc-shaped portion 156), and the boundary portion 159 of the first arc C1. The portion from the outer connecting portion 154 to the outer connecting portion 154 becomes the outer region A2 (outer arc-shaped portion 157). At this time, since the tangent line at the upper end of the inner arcuate portion 156 is along the axis L direction, the inner arcuate portion 156 is along the side surface of the shaft portion 13d.

Next, the maximum stress generated in each of the metal diaphragm 15 of the present embodiment and the metal diaphragm 100 of the comparative example shown in FIGS. 6 to 8 will be described. The metal diaphragm 100 has an insertion hole 101 through which the shaft portion 13 is inserted, and is formed in an annular shape. The inner peripheral edge portion 102 thereof is fixed to the shaft portion 13, and the outer peripheral edge portion 103 thereof is the valve body 12. From the maximum valve open state shown in FIG. 6 to the valve closed state shown in FIG. 7, the inner peripheral edge portion 102 and the outer peripheral edge portion 103 are curved convexly toward the valve open side. Further, as shown in FIG. 8, the metal diaphragm 100 is convexly curved toward the valve opening side even in the natural state.

FIG. 9 shows a simulation result of the maximum stress generated in each metal diaphragm when the valve closing degree is changed by using the metal diaphragm 15 of the present embodiment or the metal diaphragm 100 of the comparative example. The horizontal axis in FIG. 9 is the ratio (valve closing degree) obtained by dividing the displacement amount based on the maximum valve open state of the valve body 13 by the maximum displacement amount (valve closing degree), and the vertical axis is each metal. The maximum stress generated in the diaphragm is shown as a ratio (ratio) divided by the maximum stress generated in the metal diaphragm 100 of the comparative example. Further, as a condition of the simulation, a constant pressure acts on the diaphragm from the maximum valve open state (valve closing degree 0%) to the valve closed state (valve closing degree 100%), and even in the maximum valve opening state, it is predetermined. It is assumed that stress is generated.

Regardless of whether the metal diaphragm 15 or the metal diaphragm 100 is used, the maximum stress generated in each metal diaphragm increases as the valve closing degree increases. In the maximum valve open state (valve closing degree 0%), the maximum stress generated in the metal diaphragm 15 of the present embodiment is about 50% of the maximum stress generated in the metal diaphragm 100 of the comparative example. Further, in the valve closed state (valve closing degree 100%), the maximum stress generated in the metal diaphragm 15 of the present embodiment is about 30% of the maximum stress generated in the metal diaphragm 100 of the comparative example. At any valve closing degree, the maximum stress generated in the metal diaphragm 15 of the present embodiment is smaller than the maximum stress generated in the metal diaphragm 100 of the comparative example. As described above, in the metal diaphragm 15 of the present embodiment, the stress is dispersed in the entire metal diaphragm as compared with the metal diaphragm 100 of the comparative example, and as a result of the decrease in the maximum stress, the durability is improved. It gets higher.

According to the above embodiment, the metal diaphragm 15 has a curved portion 155 that is convexly curved toward the valve closing side, so that the metal diaphragm 15 is compared with a configuration in which the metal diaphragm is convexly curved toward the valve opening side. As a result, the stress is easily dispersed over the entire metal diaphragm, and the maximum stress is lowered, resulting in higher durability. In addition to this, in the case where the metal diaphragm is curved convexly toward the valve opening side, tensile stress is applied to the diaphragm, whereas in the case of the present embodiment, compressive stress is applied to the diaphragm. In general, metals are more durable against compressive stress than tensile stress, so it is considered that the durability is higher not only by the magnitude of maximum stress but also by the difference in the type of stress. Therefore, even when the metal diaphragm 15 is configured by using a highly rigid metal thin plate to cope with high pressure and the stroke of the valve body 13 is lengthened to cope with a large flow rate, the metal diaphragm 15 Damage can be suppressed and durability can be improved.

Further, in the metal diaphragm 15, the curvature of the inner arcuate portion 156 is larger than the curvature of the outer arcuate portion 157, so that the stress concentration in the metal diaphragm 15 can be further suppressed and the durability can be improved.

Further, since the metal diaphragm 15 has an inner connecting portion 153 along a plane orthogonal to the axis L direction, the inner connecting portion 153 can be overlapped and connected to the upper surface 13e of the shaft portion 13d, and the metal diaphragm 15 can be connected. The curved portion 155 can be easily curved convexly toward the valve closing side.

The present invention is not limited to the above embodiment, but includes other configurations and the like that can achieve the object of the present invention, and the following modifications and the like are also included in the present invention. For example, in the above-described embodiment, a manual opening / closing type valve is exemplified as the valve device, but the valve device of the present invention can also be applied to an electric valve driven by a motor, a valve having another opening / closing type, and the like. Is.

Further, in the above embodiment, the metal diaphragm 15 has two arcuate portions 156 and 157, and the curvature of the inner arcuate portion 156 is larger than the curvature of the outer arcuate portion 157. It may have one arcuate portion, or may have three or more arcuate portions. Further, when the diaphragm has a plurality of arcuate portions, the relationship of these curvatures may be appropriately set according to, for example, the dimensions of each portion, the stroke length of the valve body, and the like so as to avoid stress concentration.

Further, in the above embodiment, the metal diaphragm 15 has an inner connecting portion 153 along a plane orthogonal to the axis L direction, but the diaphragm has an appropriate portion on the inner peripheral edge side thereof as a shaft portion of the valve body. It should be connected to. For example, the portion corresponding to the inner arcuate portion 156 in the above embodiment may be connected to the shaft portion of the valve body.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the design changes, etc. within the range not deviating from the gist of the present invention, etc. Even if there is, it is included in the present invention.

10 Diaphragm valve (valve gear)
11 Valve chamber 12 Valve body 13 Valve body 13d Shaft 15 Metal diaphragm 15a Insertion hole 151 Inner peripheral edge 152 Outer peripheral edge 156 Inner arcuate part 157 Outer arcuate part 153 Inner connection part

Claims (3)

A valve device including a valve body forming a valve chamber, a valve body provided in the valve chamber, and a diaphragm for sealing the valve chamber.
The valve body has a shaft portion and has a shaft portion.
The diaphragm has an insertion hole through which the shaft portion is inserted, and is formed in an annular shape. The inner peripheral edge portion thereof is fixed to the shaft portion, and the outer peripheral edge portion thereof is fixed to the valve body. The valve device is characterized in that the valve device is convexly curved toward the valve closing side between the inner peripheral edge portion and the outer peripheral edge portion from the maximum valve open state to the valve closed state. The diaphragm in a natural state has a cross section along the axial direction of the valve body having an inner arc-shaped portion on the inner peripheral edge side and an outer arc-shaped portion on the outer peripheral edge side.
The valve device according to claim 1 or 2, wherein the curvature of the inner arcuate portion is larger than the curvature of the outer arcuate portion. The first or second aspect of the present invention, wherein the diaphragm has an inner connecting portion extending along a plane intersecting the axial direction of the valve body and being connected to the shaft portion at the inner peripheral edge portion. Valve device.

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