Swing check valve

Abstract

To provide a swing check valve that can be made compact while ensuring a predetermined flow rate. [Solution] The swing check valve 1 has a body 10 which has an intermediate passage 20 that forms a passage between the inlet passage 11 and the outlet passage 12, a valve body 30 which is pivotably supported within the intermediate passage 20 and is provided with a stopper portion 35 which abuts against the inner wall surface 20a of the intermediate passage 20 to restrict the valve body 30 to a fully open position, and a disc-shaped valve body 31 which can close the inlet opening 11a. The body 10 has a shorter inter-face distance than the inter-face distance between the inlet opening 11a and the outlet opening 12a so that the inner wall surface 20a of the intermediate passage 20 does not interfere with the valve body 31 when the valve body 30 is fully open, and is provided with a pair of relief portions 25 which bulge out from the inside to the outside in the interference region with the valve body 31 so that both sides 31a of the valve body 31 which interfere with the inner wall surface 20a of the intermediate passage 20 when the valve body 30 is fully open can escape.

Description

Technical Field

[0007] , , ,

[0001] The present invention relates to a swing check valve, and particularly to a swing check valve in which a valve body is rotatably supported in an intermediate flow path connecting an inlet-side flow path and an outlet-side flow path.

Background Art

[0002] Conventionally, in a pipe for transporting a fluid such as a liquid or a gas, a check valve for preventing the fluid from flowing backward is provided to keep the flow of the fluid in a certain direction. Such check valves are used in a plurality of types according to the application. For example, in a fluid transportation environment where the backflow pressure is low, a swing check valve with a simple structure is frequently used.

[0003] For example, Patent Document 1 describes a swing check valve that enhances the water-stopping performance by strengthening the adhesion between a sheet packing attached to a top and the sheet surface using magnetic attraction.

[0004] Further, Patent Document 2 describes a swing check valve that significantly reduces the pressure loss during forward flow and effectively functions to suppress power loss and prevent valve seat damage.

[0005] By the way, such a swing check valve is required not only to ensure a predetermined flow rate but also to achieve further compactification.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the swing check valve described in Patent Document 1, when attempting to reduce the distance between the inlet and outlet openings of the body to make it more compact while ensuring a predetermined flow rate, that is, when the valve body is opened at a predetermined swing angle corresponding to the flow rate, there was a risk that the valve body portion, which is the main body of the valve, would interfere with the inner wall surface near the outlet opening of the valve body. In such cases, for example, it is possible to prevent the valve from interfering with the inner wall surface of the body by bulging the inner wall surface of the body outward around its entire circumference. However, if the distance between the body surfaces is reduced, the inner wall surface of the body that is bulging around its entire circumference would require the flow path cross-section to be abruptly reduced towards the outlet opening, which would adversely affect the fluid flow and potentially make it difficult to secure the required flow rate.

[0008] Furthermore, in the swing check valve described in Patent Document 2, when the flow along the ventral surface of the valve body moves away from the downstream end of the valve body when the valve is fully open, the flow vector becomes approximately parallel to the pipe axis, forming a nearly parallel and equally spaced flow path between the lower bottom of the valve body and the ventral surface of the valve body when the valve is fully open. For this reason, if the distance between the inlet and outlet openings of the body is reduced, it becomes difficult to secure a nearly parallel flow path. Consequently, the swing check valve described in Patent Document 2 has a configuration that makes it difficult to make it compact.

[0009] The present invention was developed to solve the problems of the past, and its objective is to provide a swing check valve that can avoid interference between the valve body and the inner wall surface of the intermediate flow path, while ensuring a predetermined flow rate and achieving a compact design. [Means for solving the problem]

[0010] To achieve the above objective, the invention according to claim 1 is a swing check valve having a body that forms a flow path between an inlet-side flow path and an outlet-side flow path, and an intermediate flow path that is connected to the outlet-side flow path by gradually narrowing the flow path cross section perpendicular to the outlet-side flow path toward the outlet opening, a valve body that is pivotably supported within the intermediate flow path, and a stopper portion that abuts against the inner wall surface of the intermediate flow path to restrict the valve body to a fully open position, and a disc-shaped valve body that can close the inlet opening of the inlet-side flow path at a fully closed position, wherein the body has a distance between the faces of the inlet opening and the outlet opening that is shorter than the distance between the faces of the inlet opening and the outlet opening that does not interfere with the valve body when the valve body is in a fully open position, and a pair of relief portions that bulge outwards from the inside to the outside of the interference region with the valve body so as to allow both sides of the valve body that interfere with the inner wall surface of the intermediate flow path to escape when the valve body is in a fully open position.

[0011] The invention according to claim 2 is a swing check valve in which the inner wall surfaces of a pair of relief portions have a curved shape that smoothly guides the fluid flowing on the back side of the valve body when it is fully open toward the outlet side flow path.

[0012] The invention according to claim 3 is a swing check valve in which a pair of relief portions are provided in positions that do not overlap with the inlet opening and the outlet opening when viewed from the front side of the inlet opening and the outlet opening.

[0013] The invention according to claim 4 is a swing check valve in which stopper portions are provided on both sides of the valve body, and abutment surfaces are formed on the inner wall surfaces of a pair of relief portions for abutting against the stopper portions. [Effects of the Invention]

[0014] According to the invention of claim 1, the body is configured such that, when the valve body is fully open, the distance between the inlet and outlet openings is shorter than the distance between the inlet and outlet openings such that the inner wall surface of the intermediate passage does not interfere with the valve body, and a pair of relief portions are provided that bulge outwards from the inside to the outside of the interference region with the valve body so as to allow the sides of the valve body that interfere with the inner wall surface of the intermediate passage when the valve body is fully open to escape. As a result, when the valve body is fully open according to a predetermined flow rate, the sides of the valve body located on the side of the body that is less likely to affect the fluid flow become the parts that interfere with the inner wall surface of the intermediate passage, and relief portions are provided in these interference portions to allow the sides of the valve body to escape. This makes it possible to avoid interference between the valve body and the inner wall surface of the intermediate passage, and to make the device more compact while ensuring a predetermined flow rate.

[0015] According to the invention of claim 2, the inner wall surfaces of the pair of relief portions have a curved shape that smoothly guides the fluid flowing on the back side of the valve body when it is fully open toward the outlet flow path. As a result, the fluid flowing on the back side of the valve body when it is fully open is also smoothly guided toward the outlet flow path by the inner wall surfaces of the pair of relief portions, thus preventing a decrease in flow rate due to the provision of the pair of relief portions.

[0016] According to the invention of claim 3, the pair of relief sections are provided in positions that do not overlap with the inlet and outlet openings when viewed from the front side of the body's inlet and outlet openings. This minimizes the influence of the pair of relief sections on the flow in the region where the inlet and outlet openings face each other, which is the main flow of fluid that flows into the body from the inlet opening and flows out from the outlet opening.

[0017] According to the invention according to claim 4, the stopper portions are provided on both side portions of the valve body main body, respectively, and abutment surfaces for abutting the stopper portions are formed on the inner wall surfaces of the pair of relief portions, so that in the fully open state, the stopper portions are provided so as to be disposed near the pair of relief portions, and by forming the abutment surfaces on the inner wall surfaces of the relief portions, the stopper portions can be abutted at a position close to the inner wall surface of the body, so that the stopper portions can be set low, and as a result, the influence of the fluid flow on the stopper portions can be suppressed to a small extent.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view of a swing check valve according to an embodiment of the present invention. [Figure 2] (a) is a cross-sectional view taken along line A-A of the swing check valve shown in FIG. 1, and (b) is an enlarged view of the vicinity of the relief portion of the swing check valve shown in (a). [Figure 3] It is a view in which the valve body of the swing check valve shown in FIG. 2(a) is omitted. [Figure 4] It is a cross-sectional view taken along line B-B of the swing check valve shown in FIG. 1. [Figure 5] It is a cross-sectional view taken along line C-C of the swing check valve shown in FIG. 1. [Figure 6] (a) is a view of the outlet opening of the swing check valve seen from the front, and (b) is a view of the inlet opening of the swing check valve seen from the front. [Figure 7] It is a cross-sectional view taken along line D-D of the swing check valve shown in FIG. 1. [Figure 8] It is a perspective view of a swing check valve showing a modified example of the relief portion. [Figure 9] (a) is a cross-sectional view taken along line A-A of the swing check valve shown in FIG. 8, and (b) is an enlarged view of the vicinity of the relief portion of the swing check valve shown in (a). [Figure 10] (a) is a cross-sectional view of a swing check valve showing a modified example of the stopper portion, and (b) is a view of the outlet opening of the swing check valve shown in (a) seen from the front. In FIG. 5, the valve body is not shown in cross-section, and only the valve body main body and its vicinity are shown.

Best Mode for Carrying Out the Invention

[0019] Embodiments of the swing check valve according to the present invention will be described in detail based on FIGS. 1 to 7. Note that the present disclosure is not limited by the embodiments shown below. Also, the drawings are schematic, and it should be noted that the dimensional relationships of each element, the ratios of each element, etc. may differ from reality. Furthermore, there may be portions where the dimensional relationships and ratios of each other are different even between the drawings. FIG. 1 is a perspective view of a swing check valve 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line A-A of the swing check valve 1 shown in FIG. 1, where (a) is the cross-sectional view and (b) is an enlarged view of the vicinity of the relief portion 25 of the swing check valve 1 shown in (a). FIG. 3 is a view of the swing check valve 1 shown in FIG. 2(a) with the valve body removed. FIG. 4 is a cross-sectional view taken along line B-B of the swing check valve 1 shown in FIG. 1. FIG. 5 is a cross-sectional view taken along line C-C of the swing check valve shown in FIG. 1. FIG. 6 is a front view of the outlet opening 12a of the swing check valve 1, where (a) is the front view and (b) is a front view of the inlet opening of the swing check valve 1. FIG. 7 is a cross-sectional view taken along line D-D of the swing check valve 1 shown in FIG. 1. The swing check valve 1 according to an embodiment of the present invention is, for example, arranged between water pipes (not shown) to prevent backflow. This swing check valve 1 has a body 10, a valve body 30 provided swingably within the body , and a cap 40 closing the upper opening 10a of the body 10.

[0020] <Regarding the body 10> The body 10 has an inlet-side flow path 11 through which water flowing in the water pipe flows in, an outlet-side flow path 12 through which the water that has flowed in from the inlet-side flow path 11 and passed through the inside of the body 10 flows out, and an intermediate flow path 20 forming a flow path between the inlet-side flow path 11 and the outlet-side flow path 12. The inlet-side flow path 11 and the outlet-side flow path 12 are configured to have a diameter dimension corresponding to the diameter of the water pipe to which they are to be connected and to be connectable to the water pipe.

[0021] In this embodiment, the body 10 is configured such that, when the valve body 30 is fully open according to a predetermined flow rate, the distance between the inner wall surface 20a of the intermediate flow path 20 (described later) is shorter than the distance between the inlet opening 11a and the outlet opening 12a, so as not to interfere with the valve body 31. In the case of a swing check valve structure like this embodiment, the fully open position of the valve body 30, which is necessary to secure the desired flow rate when fully open, is mainly determined by the cross-sectional area of ​​the flow path required for the main flow path. This cross-sectional area of ​​the flow path is larger when the valve body 30 is close to being parallel to the flow path axis, but if the cross-sectional shape of the intermediate flow path 20 is gradually narrowed, the valve body 30 will eventually hit the inner wall surface 20a as the opening position is increased. A stopper 35 is provided to prevent such interference between the valve body 30 and the inner wall surface 20a, and this stopper 35 restricts the fully open position of the valve body 30. To maximize the flow rate when fully open, if we try to set a large opening angle for the valve body 30, we would need to either increase the cross-sectional area of ​​the intermediate flow path 20 itself, or increase the distance from the inlet opening 11a to the outlet opening 12a (face-to-face distance), which would increase the overall size of the swing check valve 1. In the body 10 of this embodiment, when the valve body 30 is fully opened to obtain a predetermined flow rate, the minimum inter-face distance that prevents the valve body 30 from interfering with the inner wall surface 20a is set. However, in this embodiment, the inter-face distance is smaller than this minimum inter-face distance. In other words, in the body 10 of this embodiment, the inter-face distance is such that the valve body 30 would come into contact with the inner wall surface 20a unless the relief portion 25, which will be described later, is provided. In this embodiment, the inter-face distance of the body 10 is set, for example, as follows. First, the cross-sectional area of ​​a predetermined intermediate flow path 20 is set, and a predetermined flow rate is set when the valve body 30 is fully open in that flow path cross-sectional area. Once these conditions are set, the required opening degree of the valve body 30 under those conditions is determined. Then, under those conditions, the minimum inter-face distance that does not interfere with the inner wall surface 20a of the intermediate flow path 20 when the valve body 30 is fully open is derived, and an inter-face distance smaller than this is set as the inter-face distance of the body 10. For example, as in the body 10 of this embodiment, by providing a relief portion 25 to prevent the inner wall surface 20a of the intermediate flow path 20 from interfering with the valve body 30, it is possible to maintain a similar flow rate even if the distance between the faces of the body 10 is reduced by about 7 to 10% compared to when the relief portion 25 is not provided.

[0022] <Regarding the intermediate flow path 20 of body 10> The intermediate channel 20 forms an enlarged internal space compared to the inlet channel 11 and the outlet channel 12, and has a main channel 21 through which water flowing in from the inlet opening 11a of the inlet channel 11 mainly flows, and a secondary channel 23 connected to the main channel 21 from a direction substantially perpendicular to the inlet channel 11 and the outlet channel 12.

[0023] The main flow path 21 mainly forms the space between the inlet opening 11a of the inlet-side flow path 11 and the outlet opening 12a of the outlet-side flow path 12, which face each other. The main flow path 21 is provided with a valve closed position restricting wall portion 22, which, when back pressure is applied, abuts against the valve body 31 of the valve body 30, restricting it to the valve closed position.

[0024] The valve closed position regulating wall 22 is provided in the intermediate flow path 20 at an angle to the direction perpendicular to the central axis C of the body 10 connecting the inlet opening 11a and the outlet opening 12a, and has an opening 22a that further introduces water that has flowed into the intermediate flow path 20 from the inlet opening 11a into the intermediate flow path 20. The valve body 31 abuts against the surface bordering the opening 22a of the valve closed position regulating wall 22, thereby closing the opening 22a and preventing water from flowing back into the inlet opening 11a. In other words, in this embodiment of the swing check valve 1, the valve closed position regulating wall 22 functions as a valve seat.

[0025] The secondary channel 23 forms a space that separates from the main channel 21 by connecting a roughly cylindrical wall portion 24 to the main channel 21 from above. The sub-channel 23 is provided with a pivot 27 for the valve body 30. The valve body 30 is pivotally supported by the pivot 27 so as to be able to swing freely, and when tilted at its full opening degree around the pivot 27, most of the valve body 30 is housed within the sub-channel 23. In other words, when the valve body 30 is fully open, most of the valve body 30 is positioned in the secondary channel 23, which is away from the main channel 21 and has less impact on the water flow.

[0026] Such an intermediate flow path 20 forms a flow path between the inlet flow path 11 and the outlet flow path 12, and the flow path cross section perpendicular to the outlet flow path 12 is gradually reduced toward the outlet opening 12a of the outlet flow path 12 and connected to the outlet opening 12a. In other words, as shown in Figure 2(a), the intermediate channel 20 connects to the outlet channel 12 such that the cylindrical wall portion 24 forming the sub-channel 23 gradually widens downwards.

[0027] <About Escape Club 25> The intermediate passage 20 is provided with a relief section 25 that allows the valve body 30, when fully open, to avoid interfering with the inner wall surface 20a of the intermediate passage 20, thereby accommodating the portion that would interfere with the inner wall surface 20a. More specifically, the relief section 25 is provided on both sides 10b, 10b of the body 10, corresponding to both sides 31a, 31a, so as to allow relief for both sides 31a, 31a of the valve body 31 that interfere with the inner wall surface 20a of the intermediate flow path 20 when the valve body 30 is fully open according to a predetermined flow rate. The relief portion 25 is provided to bulge outwards from the inside to the outside, thereby venting the interference area with each side portion 31a, 31a of the valve body 31. Therefore, the relief section 25 is formed with a concave shape on the inner wall surface 20a side of the intermediate flow path 20 and a convex shape on the outer wall surface 20b side.

[0028] The swing check valve 1, by providing a pair of relief portions 25 in the intermediate flow path 20 that allow the sides 31a, 31a of the valve body 31 to escape, ensures that even if the intermediate flow path 20 is connected to the outlet side flow path 12 by gradually narrowing the flow path cross-section perpendicular to the outlet side flow path 12 toward the outlet opening 12a, the inner wall surface 20a of the intermediate flow path 20 does not interfere with the sides 31a, 31a of the valve body 31 when the valve body 30 is tilted to a predetermined full opening degree. This allows the distance between the inlet opening 11a and the outlet opening 12a to be reduced compared to when these relief portions 25 are not provided.

[0029] For example, if an intermediate flow path 20 is formed so that its flow path cross-section gradually narrows toward the outlet opening 12a of the outlet flow path 12, and the distance between the faces of the inlet opening 11a and the outlet opening 12a is reduced without providing a relief portion 25, then, as shown by the dashed line L in Figure 5, the inner wall surface 20a of the intermediate flow path 20 will interfere with both sides 31a, 31a of the valve body 31.

[0030] Each escape section 25 is formed in the sub-channel 23, although a portion of it is formed in the main channel 21. The portion formed in the main channel 21 is also located in a position within the main channel 21 that is less likely to affect the water flow. Furthermore, a position within the main channel 21 that is less likely to affect the water flow is a position that does not overlap with the inlet opening 11a and the outlet opening 12a when viewed from the front side of the inlet opening 11a and the outlet opening 12a (see Figures 6(a) and 6(b)). More specifically, as shown in Figure 7, each relief section 25 is formed on the inner wall surface 20a outside the line L extending inward from the respective opening edges of the inlet opening 11a, more specifically the opening 22a and the outlet opening 12a, into the intermediate flow path 20.

[0031] In other words, each escape section 25 is located in a part that is less likely to affect the flow of water passing through the body 10. The reason why each escape section 25 can be placed in a location that does not significantly affect the water flow is due to the inventors' discovery of the following points. In other words, as described above, the inventors have found that when the distance between the inlet opening 11a and the outlet opening 12a of the body 10 is reduced, the inner wall surface 20a of the intermediate flow path 20, which is connected to the outlet side flow path 12 with a gradually reducing flow path cross-section, interferes with both sides 31a, 31a of the valve body 31 at its fully open position. Furthermore, they have found that by having both sides 31a, 31a of the valve body 31 at its fully open position located on the side 10b, 10b of the body 10, which is less affected by the water flow, and by providing a relief section 25 in a position that is less affected by the water flow, the influence on the fluid flow can be reduced, and the inner wall surface 20a of the intermediate flow path 20 can not interfere with the valve body 31.

[0032] Each relief section 25 has an inner wall surface 25a, 25b that has a curved shape that smoothly guides the fluid flowing on the back side of the valve body 31 toward the outlet side flow path 12 when the valve is closed.

[0033] Furthermore, each relief portion 25 has a contact surface 26 that abuts against the stopper portion 35, which will be described later and is provided on the valve body 31. This abutting surface 26 utilizes a portion of the inner wall surfaces 25a and 25b of a relief portion 25 that is formed in a concave shape on the inner wall surface 20a of the intermediate flow path 20, so that the upper end surface 35a of the stopper portion 35 provided on both sides 31a of the valve body 31 abuts against it when it is fully open. The relief section 25 is a portion of the intermediate flow path 20 where the inner wall surface 20a is formed in a concave shape to allow the sides 31a, 31a of the valve body 31, which is tilted when fully open, to escape. In particular, as shown in Figure 5, in the downstream side where the flow path cross-section becomes smaller, the bottom surface 25a of the recess becomes deeper, and the distance between the bottom surface 25a of the recess and the inner wall surface 20a of the intermediate flow path 20 near the relief section 25 increases, forming a wide recessed side surface 25b between the bottom surface 25a of the recess and the inner wall surface 20a of the intermediate flow path 20 near the relief section 25. The abutting surface 26 is provided so that the stopper portion 35 abuts against the recessed side surface 25b of the wide relief portion 25. Therefore, the abutment surface 26 is more likely to function as an abutment surface for the stopper portion 35, and the fully open position of the valve body 31 is stabilized.

[0034] <Regarding valve body 30> The valve body 30 is pivotally supported within the intermediate flow path 20 so as to be able to swing between a fully closed position and a fully open position. The valve body 30 has a shaft portion 32 that is pivotally supported by a pivot support portion 27 provided in the intermediate flow path 20, a valve body 31, and an arm portion 33 that connects the valve body 31 and the shaft portion 32.

[0035] The valve body 31 is disc-shaped and capable of closing the opening 22a of the valve closed position regulating wall 22. It is provided with a stopper portion 35 that abuts against the inner wall surface 20a of the intermediate flow path 20, more specifically, against the abutment surface 26 formed on the recessed side surface 25c of the relief portion 25, thereby regulating the valve body 30 to an inclination of full opening degree according to a predetermined flow rate.

[0036] The stopper portions 35 are provided on both sides 31a, 31a of the valve body 31. In other words, each stopper portion 35 is provided at a position corresponding to a pair of relief portions 25 that are provided so that both sides 31a, 31a of the valve body 31 do not interfere with the inner wall surface 20a of the intermediate flow path 20. Therefore, each stopper portion 35 can abut against the inner wall surface 25c of the relief portion 25 which is formed in a concave shape on the inner wall surface 20a of the intermediate flow path 20. In other words, in this embodiment, the swing check valve 1 is positioned so that not only the relief portion 25 but also the stopper portion 35 is in a location that does not significantly affect the flow of water.

[0037] Furthermore, stopper portions 35 are provided on both sides 31a, 31a of the valve body 31, and a portion of the inner wall surface of the relief portion 25, which is provided to allow the valve body 31a to move, is made into a butt surface 26. By doing so, the stopper portion 35 and the abutment surface 26 can be positioned closer together. In other words, the swing check valve 1 allows the height of the stopper portion 35 protruding from the valve body 31 to be kept low, thereby minimizing the influence of the stopper portion 35 on the fluid flow. Furthermore, each stopper portion 35 is positioned to abut against a contact surface 26 formed on the downstream side surface 25b of the recess 25, where the distance between the bottom surface 25a of the recess and the inner wall surface 20a of the intermediate flow path 20 near the relief portion 25 is large. In other words, each stopper portion 35 is positioned to abut against a contact surface 26 formed on the recess side surface 25b of the relief portion 25, which has a sufficient area for abutting. Thus, the swing check valve 1 effectively utilizes the recessed side surface 25b of the relief portion 25, which is provided in a concave shape to avoid interference with the valve body 31, and furthermore, the recessed side surface 25b, whose area is enlarged on the downstream side, as the abutment surface 26 of the stopper portion 35.

[0038] <About Cap 40> The cap 40 is detachably attached to the upper opening 10a of the body 10 and seals the upper opening 10a. The swing check valve 1 allows for the assembly of components such as the valve body 30 into the body 10 or for maintenance of the inside of the body 10 by removing the cap 40 from the body 10.

[0039] <Regarding the opening and closing operation of the valve body 30> The opening and closing operation of the valve body 30 will be described below. When water is flowing normally without back pressure, the water pressure from the water flowing in from the inlet side channel 11 causes the valve body 31 to open, and if the water pressure is high enough, it is held at a fully open angle. More specifically, when fully open, the valve body 30 is oscillated by water pressure so that the valve body 31 tilts towards the outlet side flow path 12 around the shaft portion 32, and the stopper portions 35 provided on both sides 31a of the valve body 31 abut against the abutment surface 26 which is the inner wall surface 20a of the intermediate flow path 20, more specifically the recessed side surface 25c of the relief portion 25, and is held at a tilt that ensures a predetermined flow rate.

[0040] When the valve body 30 is fully open, both sides 31a, 31a of the valve body 31 are moved into the relief portions 25 formed in the intermediate flow path 20. Therefore, in the case where the intermediate flow path 20 of the body 10 is connected to the outlet flow path 12 by gradually reducing the flow path cross section perpendicular to the outlet flow path 12 toward the outlet opening 12a of the outlet flow path 12, even if the distance between the faces of the inlet opening 11a and the outlet opening 12a is reduced, the inner wall surface 20a of the intermediate flow path 20 does not interfere with the valve body 31, and the valve body 30 is held at a predetermined fully open angle.

[0041] On the other hand, if backflow pressure acts on the water flowing through the water pipe due to a pump malfunction or the like, the valve body 30 swings from its fully open position to a fully closed position, tilting the valve body 31 towards the inlet flow path 11 around the shaft 32, and the valve body 31 closes the opening 22a, which serves as the inlet opening of the valve closed position regulating wall 22. This prevents backflow of water.

[0042] <Comparative evaluation of inter-face distance and Cv value> Next, the following table will be used to explain the comparative evaluation results of the face-to-face distance and Cv value of the swing check valve 1 of this embodiment and swing check valves with other configurations. Table 1 shows the comparative evaluation results of the face-to-face distance and Cv value of the swing check valve 1 of this embodiment and swing check valves with other configurations. In Table 1, the comparative product compared with the swing check valve 1 of this embodiment (product of this embodiment) is a swing check valve with a larger overall body size, including the distance between the faces of the inlet and outlet openings, and a structure in which the inner wall surface of the body does not interfere with the valve body even without providing a relief section. Table 1 shows the face-to-face distance and Cv value for each nominal diameter of 1 / 2 inch, 1 inch, and 2 inches for the comparative product and the product of this embodiment.

[0043] [Table 1]

[0044] As shown in Table 1, for all nominal diameters of 1 / 2 inch, 1 inch, and 2 inches, the Cv value of this embodiment is approximately equal to or slightly greater than that of the comparative product, despite the face-to-face distance of this embodiment being significantly smaller than that of the comparative product. In other words, this embodiment was found to be more compact than the comparable product while maintaining a flow rate of the same or slightly higher than the comparable product, and it was confirmed that the fluid flow, especially the flow in the sub-channel 23, is not obstructed even with the provision of the relief section 25.

[0045] <Effects of the Embodiment> As described above, according to the swing check valve 1 of the embodiment, the body 10 is designed so that when the valve body 30 is fully open, the distance between the faces of the inlet opening 11a and the outlet opening 12a is shorter than the distance between the faces of the inlet opening 11a and the outlet opening 12a so that the inner wall surface 20a of the intermediate passage 20 does not interfere with the valve body 31, and a pair of relief portions 25, 25 are provided that bulge out from the inside to the outside in the interference region with the valve body 31 so that the sides 31a, 31a of the valve body 31 that interfere with the inner wall surface 20a of the intermediate passage 20 when the valve body 30 is fully open can be relieved. As a result, when the valve body 31 is fully open according to a predetermined flow rate, the sides 31a, 31a of the valve body 31, which are located on the side 10b of the body 10 and are less likely to affect the fluid flow, become the parts that interfere with the inner wall surface 20a of the intermediate flow path 20. By providing a relief section 25 in this interference section to allow the sides 31a, 31a of the valve body 31 to escape, it is possible to avoid interference between the valve body 31 and the inner wall surface 20a of the intermediate flow path 20, and to make the design more compact while ensuring a predetermined flow rate.

[0046] Furthermore, according to the swing check valve 1 of the embodiment, the inner wall surfaces 25a, 25b, and 25c of the pair of relief portions 25, 25 have a curved shape that smoothly guides the fluid flowing on the back side of the valve body 31 in the fully open state toward the outlet flow path 12. As a result, the fluid flowing on the back side of the valve body 31 in the fully open state is also smoothly guided toward the outlet flow path 12 by the inner wall surfaces 25a, 25b, and 25c of the pair of relief portions 25, 25, thus preventing a decrease in flow rate due to the provision of the pair of relief portions 25, 25.

[0047] Furthermore, according to the swing check valve 1 of the embodiment, the pair of relief portions 25, 25 are positioned so as not to overlap with the inlet opening 11a and outlet opening 12a when viewed from the front side of the inlet opening 11a and outlet opening 12a of the body 10. This minimizes the influence of the pair of relief portions 25, 25 on the flow in the region where the two openings, inlet opening 11a and outlet opening 12a, face each other, which is the main flow of fluid that flows into the body 10 from the inlet opening 11a and flows out from the outlet opening 12a.

[0048] Furthermore, according to the swing check valve 1 of the embodiment, the stopper portions 35, 35 are provided on both sides 31a, 31a of the valve body 31, and abutment surfaces 26 are formed on the recessed side surfaces 25c of the pair of relief portions 25, 25, against which the stopper portion 35 abuts. As a result, when the valve is fully open, each stopper portion 35 is positioned near the pair of relief portions 25, 25, and by forming abutment surfaces 26 on the recessed side surfaces 25c of the relief portions 25, 25, the stopper portion 35 can abut against the inner wall surface 20a of the body 10 at a position close to it. This allows the stopper portion 35 to be set lower, and consequently, the influence of the fluid flow on the stopper portion 35 can be minimized.

[0049] (Variation 1) Here, a modified example of the relief section 25 will be explained with reference to Figures 8 and 9. Figure 8 is a perspective view of the swing check valve 2 showing a modified example of the relief portion 25. Figure 9 shows (a) a cross-sectional view of the swing check valve 2 shown in Figure 8 along the line A-A, and (b) an enlarged view of the area around the relief portion 55 of the swing check valve 2 shown in (a). In this modified example 1, the same reference numerals are used for parts identical to those in the embodiment, thus omitting redundant explanations.

[0050] The relief portion 55 of this modified example 1 has substantially the same shape as the relief portion 25 of the embodiment on the outer wall side, but differs from the relief portion 25 of the embodiment in that the abutment surface 56 provided on the inner wall side is formed by a surface that protrudes from the inner wall surface 20a of the body 10.

[0051] In this modified example 1, the relief section 55 does not have abutment surfaces formed on the recess bottom surface 55a, the recess top surface 55b, and the recess side surface 55c, which form the inner wall surface of the relief section 55, but an abutment surface 56 is formed on the inner wall surface 20a of the intermediate flow path 20.

[0052] (Modification 2) Next, a modified example of the stopper portion 35 will be explained with reference to Figure 10. Figure 10 shows (a) a cross-sectional view of the swing check valve 3 showing a modified example of the stopper portion 35, and (b) a front view of the outlet opening 12a of the swing check valve 3 shown in (a). In this modified example 2, the same reference numerals are used for parts identical to those in the embodiment, thus omitting redundant explanations.

[0053] The stopper portion 65 in this modified example 2 differs from the stopper portion 35 in the embodiment in that it is provided in only one place on the back of the portion of the valve body 31 that faces the outlet opening 12a of the body 10 when it is fully open.

[0054] In this modified example 2, the stopper portion 65 abuts against abutment portion 70 protruding from the inner wall surface 20a of the intermediate flow path 20 of the body 10, thereby holding the valve body 31 at an inclination of the fully open degree that ensures a predetermined flow rate.

[0055] While embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from its spirit.

[0056] In the above embodiment, a swing check valve used in a water pipe was given as an example, but it may also be applied to piping systems other than water pipes.

[0057] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The embodiments described above may be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0058] 1, 2, 3 Swing check valve 10 Body 11 Inlet side flow path 11a Entrance opening 12 Outlet side flow path 12a Exit opening 20 Intermediate channel 20a Inner wall surface 25, 55 Escape Club 25a, 55a Recessed bottom surface (inner wall surface) 25b, 55b Recessed side surface (inner wall surface) 30 valve body 31 Valve body 31a Side 35, 65 Stopper part

Claims

1. A swing check valve having a body that forms a passage between an inlet passage and an outlet passage, and an intermediate passage that connects to the outlet passage with a passage cross-section perpendicular to the outlet passage that gradually narrows toward the outlet opening, a valve body pivotably supported within the intermediate passage, and a stopper portion that abuts against the inner wall surface of the intermediate passage to restrict the valve body to a fully open position, and a disc-shaped valve body that can close the inlet opening of the inlet passage at a fully closed position, The body is characterized in that, when the valve body is in the fully open position, the distance between the faces of the inlet opening and the outlet opening is shorter than the distance between the faces of the inlet opening and the outlet opening so that the inner wall surface of the intermediate flow path does not interfere with the valve body, and the body is provided with a pair of relief portions that bulge outwards from the inside to the outside in the interference region with the valve body so as to give way to both sides of the valve body that interfere with the inner wall surface of the intermediate flow path when the valve body is in the fully open position.

2. The swing check valve according to claim 1, wherein the inner wall surfaces of the pair of relief portions have a curved shape that smoothly guides the fluid flowing on the back side of the valve body in the fully open state toward the outlet side flow path.

3. The swing check valve according to claim 1 or 2, wherein the pair of relief portions are provided in a position that does not overlap the inlet opening and the outlet opening when viewed from the front side of the inlet opening and the outlet opening.

4. The stopper portion is provided on both sides of the valve body, The swing check valve according to claim 1 or 2, wherein abutment surfaces are formed on the inner wall surfaces of the pair of relief portions for abutting against the stopper portion.

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