Bottom valve

Abstract

The invention relates to a bottom valve (1) constructed such that when the holes (6a) of the filter screen (6) receive the flow of water into the valve box (2), the disc of the valve element (5) moves to one side along the central axis of the valve box (2) and contacts the cylinder (9) of the bearing (4), part of the water flows between the levers (10) through between the valve element (5) and the foot (12) of the bearing (4), and the other part of the water flows between the levers (10) through between the valve element (5) and the inner surface of the valve box (2).

Description

Foot valve

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a foot valve used to store fluid on the suction side of a pump.

[0002] A conventional foot valve of this type will be described with reference to FIG. 10 (see, for example, Patent Document 1).

[0003] FIG. 10 is a cross-sectional view of a conventional foot valve.

[0004] As shown in Figure 10, in the vertical cross section of the foot valve, a piping joint 102 is provided above a hollow cylindrical valve box 101, and inside the foot valve, a cylinder 105 is fitted into the valve box 101 so as to guide a valve stem 104 which is formed integrally with the valve body 103 or separately from the valve body 103 as shown.

[0005] Arms 106 are arranged radially from the cylinder 105 in a plan view, and a guide 107 is formed at the center of the arms 106, into which the valve stem 104 is fitted and slides.

[0006] A female thread 108 is formed in the lower part of the valve box 101, and a valve seat 109 is provided in the center of the valve box 101. A partition plate 110 with an opening on the inside is screwed onto the female thread 108. A strainer 111 is screwed into the lower part of the partition plate 110.

[0007] Japanese Utility Model Application Publication No. 58-9983

[0008] In such conventional foot valves, when the valve disc moves upward due to the pressure of the water being pumped up, the gap between the cylinder and the valve disc and the opening between the arms arranged toward the cylinder become flow paths. Conventional foot valves have the problem that because this flow path is narrow, pressure loss increases and the pump performance deteriorates.

[0009] The present disclosure reduces pressure loss in a foot valve.

[0010] a strainer having a plurality of holes provided on the other side of the valve box in the direction of the central axis, wherein the valve box has: a cylindrical valve box; a cylindrical discharge port provided on one side of the valve box in the direction of a central axis; a bearing portion held by being sandwiched between the discharge port and the valve box; a valve portion supported on the bearing portion so as to be movable in the vertical direction, the valve portion having a valve stem and a disc portion; and a strainer having a plurality of holes provided on the other side of the valve box in the direction of the central axis, wherein the valve box has: a first annular support portion protruding inward from an inner circumferential surface of the valve box; and a second annular support portion protruding inward from the inner circumferential surface of the valve box, on the other side of the valve box in the direction of the central axis of the first support portion, and the bearing portion has: a cylindrical portion that movably supports the valve stem of the valve portion; a plurality of rod-shaped arm portions extending radially from a side circumferential surface of the cylindrical portion; and an annular portion connecting the respective tip ends of the arm portions. and a plurality of leg portions protruding from the annular portion to the other side in the central axis direction of the valve box, the bearing portion is arranged so that outer peripheral surfaces of the plurality of leg portions contact the inner peripheral surface of the valve box, the surface of the annular portion on one side in the central axis direction of the valve box contacts an end of the discharge port, the ends of the plurality of leg portions on the other side in the central axis direction of the valve box contact the first support portion of the valve box, and when water flows into the valve box from the discharge port, the valve portion moves to the other side in the central axis direction of the valve box and comes into contact with the second support portion of the valve box, When water flows into the valve box through the plurality of holes in the strainer, the disc portion of the valve portion moves to one side in the central axial direction of the valve box and comes into contact with the cylindrical portion of the bearing portion, and a portion X of the water flows between the plurality of arm portions through a gap between the valve portion and the leg portion of the bearing portion, and another portion Y of the water flows between the plurality of arm portions through a gap between the valve portion and the inner circumferential surface of the valve box.

[0011] According to the present disclosure, a larger flow path can be ensured and pressure loss can be reduced compared to conventional foot valves.

[0012] Figure 1 is a piping system diagram illustrating the positional relationship between the pumping pump, foot valve, and water surface. Figure 2 is an exploded perspective view of the foot valve of this embodiment. Figure 3 is a cross-sectional view of the foot valve when the pumping pump is not operating. Figure 4 is a cross-sectional view of the foot valve when the pumping pump is operating. Figure 5 is a cross-sectional view of the foot valve. Figure 6 is a perspective view of the bearing part of the foot valve seen from diagonally above. Figure 7 is a perspective view of the bearing part of the foot valve seen from diagonally below. Figure 8 is a detailed view of the cylindrical part of the bearing part of the foot valve. Figure 9 is a detailed view of the leg part of the bearing part of the foot valve. Figure 10 is a cross-sectional view of a conventional foot valve.

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0014] (Embodiment 1) Fig. 1 is a piping diagram illustrating the positional relationship between a water pump 20, a foot valve 1, and a water surface.

[0015] As shown in FIG. 1, it is assumed that a water pump 20 is used to pump water in a water storage tank 21 from a level L1 to a different level L2.

[0016] In this case, a suction pipe 22 is connected to the upstream side of the water pump 20 , a discharge pipe 23 is connected to the downstream side of the water pump 20 , and a foot valve 1 is connected to the end of the suction pipe 22 .

[0017] The foot valve 1 is installed at the end of a suction pipe 22 that draws water from a water source such as a water storage tank 21, and is always submerged in water.

[0018] When using a pumping pump 20 to pump water from a water storage tank 21 from level L1 to a different level L2, if the water source is located lower than the pumping pump 20, the water level in the suction pipe 22 will drop when the operation of the pumping pump 20 is stopped, causing an air layer to form in the suction pipe 22. If an air layer forms in the suction pipe 22, the pumping pump 20 will run idle the next time it is operated, and will not be able to pump up water. For this reason, a foot valve 1 is often provided at the end of the suction pipe 22 to prevent the water in the suction pipe 22 from running out after operation is stopped.

[0019] Fig. 2 is an exploded perspective view of the foot valve 1. Fig. 3 is a vertical cross-sectional view of the foot valve 1 when the water pump 20 is not operating. Fig. 4 is a vertical cross-sectional view of the foot valve 1 when the water pump 20 is operating.

[0020] As shown in FIGS. 2, 3, and 4, the foot valve 1 has a valve box 2, a discharge port 3, a bearing portion 4, a valve portion 5, and a strainer 6.

[0021] A valve element 5 is arranged inside the foot valve 1 so that it can move up and down, and as shown in Figure 4, when the pump is operating, the pressure of the water being pumped up pushes the valve element 5 upward, forming a flow path 15. On the other hand, as shown in Figure 3, when the pump stops, the pressure of the water flowing back inside the foot valve 1 moves the valve element 5 downward, thereby stopping the water flow.

[0022] The valve box 2 is cylindrical, with a female thread 2a formed on the upper part (one side of the valve box 2 in the central axis direction) and a male thread 2b formed on the lower part (the other side of the valve box 2 in the central axis direction).

[0023] The valve box 2 has a first annular support portion 7 that protrudes inward from the inner surface of the valve box 2, and a second annular support portion 8 that protrudes inward from the inner surface of the valve box 2 below the first support portion 7 (the other side in the central axial direction of the valve box 2). The interiors of the first annular support portion 7 and the second annular support portion 8 form part of a flow path 15.

[0024] An outlet 3 is connected to the top of the valve box 2 .

[0025] The discharge port 3 is cylindrical and has a male thread 3a formed at its bottom (on the valve box 2 side). The male thread 3a of the discharge port 3 is threadedly engaged with the female thread 2a of the valve box 2, connecting the discharge port 3 to the top of the valve box 2. The gap between the valve box 2 and the discharge port 3 is sealed with an O-ring, sealing tape, adhesive, or the like to prevent water leakage.

[0026] Inside the valve box 2 , a bearing portion 4 is held between the valve box 2 and the discharge port 3 .

[0027] A suction pipe 22 extending from a water pump 20 is connected to the upper part of the discharge port 3 .

[0028] The strainer 6 is a cylindrical member having a bottom and an open top side, and has a plurality of holes 6a on its circumferential side, for removing foreign matter.

[0029] When the water pump 20 is operated, water flows into the strainer 6 through the holes 6a, so that foreign matter larger than the holes 6a does not flow into the strainer 6.

[0030] A female thread 6b is formed on the opening side of the strainer 6. The female thread 6b of the strainer 6 and the male thread 2b of the valve box 2 are threadedly engaged with each other, and the strainer 6 is connected to the lower part of the valve box 2.

[0031] Fig. 6 is a perspective view of the bearing unit 4 as seen obliquely from above. Fig. 7 is a perspective view of the bearing unit 4 as seen obliquely from below. Fig. 8 is a detailed view of the cylindrical portion 9 of the bearing unit 4. Fig. 9 is a detailed view of the leg portion 12 of the bearing unit 4.

[0032] As shown in FIGS. 2, 6, 7, 8, and 9, the bearing portion 4 has a cylindrical portion 9, a plurality of arm portions 10, an annular portion 11, and a plurality of leg portions 12.

[0033] The cylindrical portion 9 is cylindrical and movably supports the valve unit 5. The central axis of the cylindrical portion 9 is aligned with the central axis of the valve box 2.

[0034] The arm portions 10 are each rod-shaped and extend radially at equal intervals from the side circumferential surface of the cylindrical portion 9 in a plan view. Openings 10a between adjacent arm portions 10 form flow paths 15. The lower end of the cylindrical portion 9 protrudes downward further than the arm portions 10 (see FIG. 7 ).

[0035] The annular portion 11 is annular and connects the respective tip ends of the multiple arm portions 10. In other words, the shape of the annular portion 11 connecting the respective tip ends of the multiple arm portions 10 is a shape in which multiple openings 10a are arranged at equal intervals in the circumferential direction of a disk.

[0036] Each of the leg portions 12 has a generally plate shape and protrudes downward from the annular portion 11, i.e., toward the strainer 6 (the other side in the central axial direction of the valve box 2). The cylindrical portion 9, the arm portion 10, the annular portion 11, and the leg portions 12 are integrally formed.

[0037] The bearing portion 4 is arranged so that the outer peripheral surfaces of the multiple leg portions 12 contact the inner peripheral surface of the valve box 2.

[0038] 3 and 4, the valve unit 5 is supported by the bearing unit 4 so as to be able to move up and down, and is housed in the valve box 2. The valve unit 5 is composed of a disk-shaped gasket 5a that functions to stop water, and a valve stem 5b that moves up and down within the cylindrical portion 9 of the bearing unit 4. The gasket 5a and the valve stem 5b may be integral. In the valve unit 5, the valve stem 5b extends on the central axis from the center of the gasket 5a.

[0039] 4, when the water pump 20 is operated, water flows into the valve box 2 through the multiple holes 6a in the strainer 6, and the valve unit 5 moves toward the discharge port 3 (one side in the direction of the central axis of the valve box 2), causing the disk portion of the valve unit 5 to come into contact with the cylindrical portion 9 of the bearing unit 4. As a result, the valve unit 5 moves away from the second support portion 8 of the valve box 2, forming a flow path 15. At this time, the upper end of the gasket 5a (more precisely, the disk portion) of the valve unit 5 is positioned above the lower end of the leg portion 12 of the bearing unit 4.

[0040] FIG. 5 is a detailed cross-sectional view of the foot valve 1.

[0041] 5, when water flows into the valve box 2 through the multiple holes 6a in the strainer 6, a region A is formed between the valve unit 5 and the second support portion 8. A portion X of the water that flows into region A flows between the multiple arm portions 10 via the gap between the valve unit 5 and the leg portion 12 of the bearing portion 4 (region B), and another portion Y of the water that flows into region A flows between the multiple arm portions 10 via the gap between the valve unit 5 and the inner surface of the valve box 2 (region C).

[0042] The distance (area C) between the valve portion 5 and the inner surface of the valve box 2 is greater than the distance (area B) between the valve portion 5 and the leg portion 12 of the bearing portion 4. In other words, the flow path 15 in area C is wider than the flow path 15 in area B.

[0043] In this way, in the present disclosure, not only the area B having the leg portion 12 but also the area C not having the leg portion 12 becomes a flow path, thereby ensuring a wider flow path 15 and reducing pressure loss in the foot valve 1.

[0044] The height of the cylindrical portion 9, which determines the contact position between the bearing portion 4 and the valve portion 5, is set so that none of the regions A, B, and C become extremely small.

[0045] 3, when the pumping pump 20 stops operating, the water in the suction pipe 22, the pumping pump 20, and the discharge pipe 23 flows downward (toward the foot valve 1). When water flows into the valve box 2 from the discharge port 3, the valve element 5 moves toward the strainer 6 (the other side in the direction of the central axis of the valve box 2), and the gasket 5a of the valve element 5 comes into contact with the second support part 8 of the valve box 2, thereby stopping the water from flowing through.

[0046] Furthermore, as shown in FIG. 6 , the sum of the distances between adjacent leg portions 12 in the circumferential (inner circumferential) direction of the valve box 2 is characterized in that it is greater than the sum of the dimensions of the multiple leg portions 12 in the inner circumferential (circumferential) direction of the valve box 2.

[0047] As a result, the amount of water portion Y that flows between the multiple arm portions 10 (area C in FIG. 5 ) via the gap between the valve portion 5 and the inner surface of the valve box 2 is greater than the amount of water portion X that flows between the multiple arm portions 10 (area B) via the valve portion 5 and the leg portions 12 of the bearing portion 4. This ensures a flow path 15 and reduces pressure loss in the foot valve 1. Note that although the leg portions 12 are provided in three locations in this embodiment, the multiple leg portions 12 may be equally spaced in the circumferential direction (in a plan view), as long as there are three or more of them.

[0048] The number of leg portions 12 is the same as the number of arm portions 10, and each of the leg portions 12 protrudes downward from annular portion 11 located toward the tip of each of the arm portions 10 extending radially from cylindrical portion 9. In other words, each leg portion 12 and each arm portion 10 is disposed on the same plane including the central axis of cylindrical portion 9.

[0049] In this example, region B between the valve unit 5 and the leg portion 12 of the bearing unit 4 is located below the arm portion 10. In this way, compared to when region B between the valve unit 5 and the leg portion 12 of the bearing unit 4 is located below the opening 10a between adjacent arm portions 10, water is more likely to flow into the opening 10a when region B between the valve unit 5 and the leg portion 12 of the bearing unit 4 is located below the arm portion 10.

[0050] Furthermore, the outer surfaces (facing the valve box 2) of the plurality of leg portions 12 are curved surfaces that follow the inner peripheral surface of the valve box 2, and the inner surfaces (facing the cylindrical portion 9) of the leg portions 12 have inwardly bulging expansion portions 14 (see Figure 9). When the bearing portion 4 is viewed from the discharge port 3 side, the expansion portions 14 of the plurality of leg portions 12 are configured to overlap with the arm portions 10.

[0051] As a result, when water hits the expanding portion 14, it guides the water to the left and right of the arm portion 10, i.e., to the opening 10a, improving the flow of water and reducing pressure loss in the foot valve 1.

[0052] As shown in Figures 7 and 8, the bearing portion 4 has a plurality of reinforcing portions 13 that extend from one side (upper side) of the surface of the arm portions 10 in the central axis direction of the valve box 2 to the side periphery of the cylindrical portion 9 of the bearing portion 4.

[0053] This allows the width of the arm portion 10 to be narrowed, which means that the flow path 15 can be widened, thereby reducing the pressure loss in the foot valve 1.

[0054] Furthermore, the multiple reinforcing portions 13 extend along the side periphery of the cylindrical portion 9 toward one side (upper side) of the central axis direction of the valve box 2 beyond the cylindrical portion 9 of the bearing portion 4 .

[0055] In this way, by configuring the positional relationship when operation is stopped so that the tops of the reinforcing parts 13, the valve part 5, and the cylindrical part 9 are located in descending order of height (see FIG. 3), debris flowing in from the suction pipe 22 when operation is stopped flows through the spaces between the reinforcing parts 13 into the opening 10a of the bearing part 4. This makes it possible to prevent debris from accumulating on the bearing part 4 and the valve part 5 when operation is stopped. This makes it possible to prevent deterioration of the bearing part 4 and the valve part 5 over time and reduce the frequency of replacement.

[0056] Furthermore, by making the height of the reinforcing portion 13 higher than the height of the cylindrical portion 9, when the bearing portion 4 is installed upside down, the reinforcing portion 13 comes into contact with the upper surface of the disk of the valve portion 5, and the bearing portion 4 is installed at a higher position, making it impossible to sufficiently tighten the discharge port 3. This contributes to preventing problems when assembling the bearing portion 4.

[0057] The foot valve 1 according to the present disclosure has been described above based on the embodiment, but the present disclosure is not limited to the embodiment. As long as it does not deviate from the spirit of the present disclosure, various modifications conceivable by a person skilled in the art to the present embodiment and configurations constructed by combining components of different embodiments are also included within the scope of the present disclosure.

[0058] A pump equipped with a foot valve according to the present disclosure is useful because it can be operated more efficiently than a pump equipped with a conventional foot valve.

[0059] REFERENCE SIGNS LIST 1 Foot valve 2 Valve box 2a Female thread 2b Male thread 3 Discharge port 3a Male thread 4 Bearing portion 5 Valve portion 5a Gasket 5b Valve stem 6 Strainer 6a Hole 6b Female thread 7 First support portion 8 Second support portion 9 Cylinder portion 10 Arm portion 10a Opening 11 Annular portion 12 Leg portion 13 Reinforcement portion 14 Expansion portion 15 Flow path 20 Lifting pump 21 Water storage tank 22 Suction pipe 23 Discharge pipe 101 Valve box 102 Joint portion 103 Valve disc 104 Valve stem 105 Cylinder 106 Arm 107 Guide 108 Female thread 109 Valve seat portion 110 Partition plate 111 Strainer L1, L2 Level A, B, C area

Claims

1. A valve box having a cylindrical shape; a cylindrical discharge port provided on one side of the valve box in a central axis direction; a bearing portion held between the discharge port and the valve box; a valve portion supported on the bearing portion so as to be movable in the vertical direction and having a valve stem and a disk portion; and a strainer having a plurality of holes provided on the other side of the valve box in the central axis direction, wherein the valve box has: a first support portion shaped like an annular ring protruding inwardly from an inner circumferential surface of the valve box; and a second support portion shaped like an annular ring protruding inwardly from the inner circumferential surface of the valve box, on the other side of the valve box in the central axis direction than the first support portion, and the bearing portion has: a cylindrical portion shaped like a cylinder that movably supports the valve stem of the valve portion, a plurality of rod-shaped arm portions extending radially from a side circumferential surface of the cylindrical portion, a circular ring portion connecting each tip end of the arm portions, and a plurality of leg portions protruding from the circular ring portion to the other side in the central axis direction of the valve box, a first support portion of the valve box and a second support portion of the valve box, the first support portion being arranged so that the first support portion of the valve box and the second support portion of the valve box face each other in the direction of the central axis of the valve box, and a second support portion of the valve box and the second support portion being arranged so that the first support portion of the valve box and the second support portion are arranged so that the first support portion of the valve box and the second support portion are arranged so that the second ...

2. A foot valve as described in claim 1, wherein the sum of the distances between adjacent ones of the leg portions in the inner circumferential direction of the valve box is greater than the sum of the dimensions of the leg portions in the inner circumferential direction of the valve box.

3. A foot valve as described in claim 2, wherein the number of said leg portions is the same as the number of said arm portions, and each of said leg portions protrudes from said annular portion located toward the tip of each of said arm portions radially extending from said cylindrical portion.

4. A foot valve as described in claim 3, wherein the outer surfaces of the multiple leg portions are curved surfaces that conform to the inner peripheral surface of the valve box, the inner surfaces of the multiple leg portions have inwardly expanding expansion portions, and when the bearing portion is viewed from the discharge port side, the expansion portions of the multiple leg portions overlap with the multiple arm portions.

5. A foot valve as set forth in claim 3, further comprising a plurality of reinforcing portions extending from the surface of said one side in the central axial direction of said valve box to a side circumference of said cylindrical portion of said bearing portion.

6. A foot valve as described in claim 5, wherein the plurality of reinforcing portions extend along the side circumference of the cylindrical portion and extend further toward the one side in the central axial direction of the valve box than the cylindrical portion of the bearing portion.

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