Foot valve

Abstract

To reduce pressure loss inside a foot valve used at a terminal of a suction pipe of a pump.SOLUTION: When water flows into a valve box 2 through a plurality of holes 6a of a strainer 6, a valve part 5 moves to one side in a central axial direction of the valve box 2 and comes into contact with a cylindrical portion 9 of the bearing part 4, where some of the water flows between a plurality of arm portions 10 through a gap between the valve part 5 and a leg portion 12 of the bearing part 4, and some of the water flows between the plurality of arm portions 10 through the gap between the valve portion 5 and an inner surface of the valve box 2. With this structure, it is possible to reduce pressure loss and suppress deterioration in characteristics of a pump.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a foot valve used to store fluid on the suction side of a pump. [Background technology]

[0002] A conventional foot valve of this type will be described with reference to FIG. 10 (see, for example, Patent Document 1). As shown in Figure 10, in the vertical cross section of the foot valve, a hollow cylindrical valve body 101 has a piping joint 102 above it, and inside, either integrally or separately as shown, a cylinder 105 is fitted into the valve body 101 to guide the valve stem 104 of the valve disc 103, and arms 106 are arranged radially from the cylinder 105, with a guide 107 at the centre into which the valve stem 104 fits and slides. A female thread 108 is engraved into the bottom of the valve body 101, and a partition plate 110 with a valve seat 109 in its centre and an open interior is screwed into the female thread 108. A strainer 111 is screwed into the bottom of the partition plate 110. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 58-9983 Summary of the Invention [Problem to be solved by the invention]

[0004] 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 an issue in that the flow paths are narrow, resulting in large pressure losses and a deterioration in the pump performance.

[0005] SUMMARY OF THE PRESENT DISCLOSURE ... The present invention is devised to solve the above-mentioned problems in the conventional art, and has an object to reduce the pressure loss in the foot valve. [Means for solving the problem]

[0006] In order to achieve this object, the foot valve according to the present invention comprises: A cylindrical valve box; a cylindrical discharge port provided on one side of the valve box in a central axis direction; a bearing portion that is sandwiched and 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; a strainer having a plurality of holes provided on the other side of the valve box in the central axis direction, The valve box comprises: a first support portion having an annular shape and projecting inwardly from an inner surface of the valve box; a second support portion having an annular shape and projecting inwardly from an inner surface of the valve box, the second support portion being disposed on the other side of the valve box in the central axis direction than the first support portion, The bearing portion is A cylindrical portion that movably supports a valve stem of the valve portion; A plurality of rod-shaped arm portions extending radially from a side peripheral surface of the cylindrical portion; a ring portion that connects the tip ends of the plurality of arm portions; a plurality of leg portions protruding from the annular portion toward the other side in the central axis direction of the valve box; The bearing portion is disposed such that an outer peripheral surface of the leg portion contacts an inner peripheral surface of the valve box, a 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 other end of the leg portion in the central axis direction of the valve box contacts the first support portion of the valve box, 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 multiple holes in the strainer, the valve portion moves to one side in the direction of the central axis 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 multiple arm portions through between the valve portion and the leg portion of the bearing portion, and a portion Y of the water flows between the multiple arm portions through between the valve portion and the inner surface of the valve box, thereby achieving the desired object. Effect of the Invention

[0007] According to the present invention, a larger flow passage can be ensured and pressure loss can be reduced as compared with conventional foot valves. [Brief description of the drawings]

[0008] [Figure 1] A piping diagram showing the relative positions of the water pump, foot valve, and water surface [Diagram 2] FIG. 2 is an exploded perspective view of the foot valve according to the embodiment; [Diagram 3] Cross-sectional view of the foot valve when the water pump is stopped [Figure 4] Cross-sectional view of the foot valve when the water pump is operating [Diagram 5] Cross-sectional view of the foot valve [Figure 6] FIG. 2 is a perspective view of the bearing portion of the foot valve as viewed obliquely from above. [Figure 7] FIG. 2 is a perspective view of the bearing portion of the foot valve as viewed obliquely from below. [Figure 8] A detailed view of the cylindrical part of the bearing of the foot valve. [Figure 9] Detailed view of the leg part of the bearing of the foot valve [Figure 10] Cross-sectional view of a conventional foot valve DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (Embodiment 1) As shown in FIG. 1, when using a lifting pump 20 to pump water in a water storage tank 21 from a level L1 to a different level L2, a suction pipe 22 is connected to the upstream side of the lifting pump 20 and a discharge pipe 23 is connected to the downstream side, and a foot valve 1 is connected to the end of the suction pipe 22. The foot valve 1 is installed at the end of the suction pipe 22 that draws water from a water source such as a water storage tank 21, and is always submerged. When using the lifting pump 20 to pump water in a water storage tank 21 from a level L1 to a different level L2, if the water source is located lower than the lifting pump 20, the water level in the suction pipe 22 drops when the operation of the lifting pump 20 is stopped, and an air layer is generated. If an air layer is generated in the suction pipe 22, the lifting pump 20 will run idly the next time it is operated and will not be able to draw up water, so a foot valve 1 is often provided to prevent the water in the suction pipe 22 from becoming empty after the operation is stopped. (See, for example, Patent Document 1).

[0010] Fig. 2 is an exploded perspective view of the foot valve, Fig. 3 is a vertical cross-sectional view of the foot valve when the pumping pump is not operating, and Fig. 4 is a vertical cross-sectional view of the foot valve when the pumping pump is operating.

[0011] As shown in FIGS. 2, 3, and 4, the foot valve 1 includes a valve box 2, a discharge port 3, and It has a bearing portion 4, a valve portion 5, and a strainer 6. Inside the foot valve 1 is the valve portion 5, which is configured so that when the pump is operating, it is pushed by the pressure of the water being pumped up to form a flow path 15, and when the pump stops, the water is stopped by the valve portion 5 due to the pressure of the water flowing back into the foot valve.

[0012] The valve box 2 is cylindrical and has a female thread 2a formed at its upper part (one side of the valve box 2 in the central axial direction) and a male thread 2b formed at its lower part (the other side of the valve box 2 in the central axial direction). The valve box 2 has a first annular support part 7 that protrudes inwardly from the inner surface of the valve box 2, and a second annular support part 8 that protrudes inwardly from the inner surface of the valve box 2 below the first support part 7 (the other side of the valve box 2 in the central axial direction). The insides of the first annular support part 7 and the second annular support part 8 form part of a flow path 15. A discharge port 3 is connected to the upper part of the valve box 2.

[0013] The discharge port 3 is cylindrical and has a male thread 3a formed at its lower part (on the valve box 2 side). The male thread 3a of the discharge port 3 screws into the female thread 2a of the valve box 2, and the discharge port 3 is connected to the upper part 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. A bearing 4 is held inside the valve box 2, sandwiched between the valve box 2 and the discharge port 3. A suction pipe 22 extending from a water lifting pump 20 is connected to the discharge port 3.

[0014] The strainer 6 is a cylinder with a bottom that is open on one side, and has multiple holes 6a on its circumferential side for removing foreign matter. When the water pump 20 is operated, water flows into the strainer 6 through the multiple holes 6a, so that foreign matter larger than the multiple holes 6a does not flow into the strainer 6. The strainer 6 has a female thread 6b formed on the open side. The female thread 6b of the strainer 6 and the male thread 2b of the valve box 2 screw together, and the strainer 6 is connected to the bottom of the valve box 2.

[0015] Fig. 6 is a perspective view of the bearing portion 4 as seen obliquely from above. Fig. 7 is a perspective view of the bearing portion 4 as seen obliquely from below. Fig. 8 is a detailed view of the cylindrical portion 9 of the bearing portion 4. Fig. 9 is a detailed view of the leg portion 12 of the bearing portion 4.

[0016] As shown in FIGS. 2, 6, 7, 8 and 9, the bearing portion 4 has a cylindrical portion 9, an arm portion 10, an annular portion 11 and a leg portion 12. As shown in FIG.

[0017] The cylindrical portion 9 is cylindrical and movably supports the valve portion. The central axis of the cylindrical portion 9 is aligned on the same line as the central axis of the valve box 2.

[0018] The multiple arm portions 10 are rod-shaped and extend radially at equal intervals from the side peripheral surface of the cylindrical portion 9. Openings 10a between adjacent arm portions 10 form flow paths 15. The lower end of the cylindrical portion 9 protrudes downward beyond the multiple arm portions 10.

[0019] The ring portion 11 is annular and connects the tip ends of the multiple arm portions 10. In other words, the shape of the ring portion 11 connecting the tip ends of the multiple arm portions 10 is a circular plate with multiple openings 10a arranged at equal intervals in the circumferential direction.

[0020] The multiple leg portions 12 are generally plate-shaped and protrude downward from the annular portion 11, i.e., toward the strainer 6 side (the other side in the central axial direction of the valve box). The cylindrical portion 9, arm portion 10, annular portion 11, and leg portions 12 are integrally formed. The bearing portion 4 is disposed so that the outer peripheral surface of the leg portions 12 contacts the inner peripheral surface of the valve box 2.

[0021] The valve portion 5 is supported by the bearing portion 4 so as to be vertically movable, and is housed in the valve box 2. The valve portion 5 is composed of a disk-shaped gasket 5a that serves to stop water, and a valve stem 5b that moves vertically on the cylindrical portion 9 of the bearing portion 4. The gasket 5a and the valve stem 5b may be integrated. In the valve portion 5, the valve stem 5b extends on the central axis from the center of the gasket 5a.

[0022] 4, when the water pump 20 is operated, water flows into the valve box 2 through the multiple holes in the strainer 6, and the valve portion 5 moves to the discharge port 3 side (one side in the central axial direction of the valve box 2) and comes into contact with the cylindrical portion 9 of the bearing portion 4. As a result, the valve portion 5 moves away from the second support portion 8 of the valve box 2, forming a flow path 15. The upper end of the gasket 5a of the valve portion 5 is located above the lower end of the leg portion 12 of the bearing portion 4.

[0023] FIG. 5 is a detailed cross-sectional view of the foot valve. As shown in FIG. 5, when water flows into the valve box 2 from the multiple holes 6a of the strainer 6, an area A is formed between the valve portion 5 and the second support portion 8. A part X of the inflowing water flows between the multiple arm portions 10 via the area B between the valve portion 5 and the leg portion 12 of the bearing portion 4, and a part Y of the water flows between the multiple arm portions 10 via the area C between the valve portion 5 and the inner surface of the valve box 2. The distance (area C) between the valve portion 5 and the inner surface of the valve box 2 is wider 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 the area C is wider than the flow path 15 in the area B. In this way, not only the area B having the leg portion 12 but also the area C not having the leg portion 12 serves as a flow path, so that a wider flow path 15 can be secured and the pressure loss of the foot valve 1 is reduced. Moreover, the height dimension 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 becomes excessively small.

[0024] 3, when the pumping pump 20 stops operating, the water in the suction piping 22, the pumping pump 20, and the discharge piping 23 flows downward (toward the foot valve 1). When water flows into the valve box 2 from the discharge port 3, the valve portion 5 moves toward the strainer 6 (the other side in the central axial direction of the valve box 2), and the valve portion 5 comes into contact with the second support portion 8 of the valve box 2, thereby stopping the water flow.

[0025] 6, the sum of the distances between adjacent leg portions 12 in the circumferential direction of the valve box 2 is greater than the sum of the dimensions of the multiple leg portions 12 in the inner circumferential direction of the valve box 2. As a result, the amount of water Y that flows between the multiple arm portions (area C) through the valve portion 5 and the inner surface of the valve box 2 is greater than the amount of water X that flows between the multiple arm portions 10 (area B) through the valve portion 5 and the leg portions 12 of the bearing portion 4, ensuring a larger flow path 15 and reducing pressure loss in the foot valve. In this embodiment, three leg portions 12 are provided, but it is sufficient to provide three or more equally spaced points.

[0026] The number of leg portions 12 is the same as the number of arm portions 10, and each leg portion 12 protrudes from an annular portion 11 toward the tip of each arm portion 10 extending radially from the cylindrical portion 9. Each leg portion 12 and each arm portion 10 are arranged on the same plane including the central axis of the cylindrical portion 9. An area B between the valve portion 5 and the leg portion 12 of the bearing portion 4 is located below the arm portion 10. As a result, water flows more easily into the opening 10a when the area B between the valve portion 5 and the leg portion 12 of the bearing portion 4 is located below the arm portion, compared to when the area B between the valve portion 5 and the leg portion 12 of the bearing portion 4 is located below the opening 10a between adjacent arm portions 10.

[0027] In addition, the outer surfaces (on the valve box 2 side) of the multiple leg portions 12 are curved surfaces that conform to the inner peripheral surface of the valve box 2, and the inner surfaces (on the cylindrical portion side) of the leg portions are expanded portions that bulge inward. When looking at the bearing part 4 from the discharge port 3 side, the expanded parts 14 in the multiple leg parts 12 overlap the arm part 10. As a result, when water hits the expanded parts 14, it guides the water to the left and right of the arm part 10, i.e., to the opening 10a, improving the water flow. This reduces the pressure loss of the foot valve 1.

[0028] As shown in Figs. 7 and 8, by having a plurality of reinforcing parts 13 extending from one side surface of the plurality of arm parts 10 in the central axis direction of the valve box 2 to the side circumference of the cylindrical part 9 of the bearing part 4, the width of the arm part 10 can be narrowed. In other words, the flow path 15 can be widened, and the pressure loss of the foot valve 1 can be reduced. In addition, the plurality of reinforcing parts 13 extend along the side circumference of the cylindrical part 9 and extend from the cylindrical part 9 of the bearing part 4 to one side in the central axis direction of the valve box 2. By setting the positional relationship at the time of operation shutdown to the top of the reinforcing part 13, the top of the valve part 5, and the top of the cylindrical part 9 in descending order, dust flowing in from the suction pipe 22 at the time of operation shutdown flows between the plurality of reinforcing parts 13 into the opening 10a of the bearing part 4, and it is possible to prevent dust from accumulating on the bearing part 4 and the valve part 5 at the time of operation shutdown. This makes it possible to prevent deterioration of the bearing part 4 and the valve part 5 over time, and to reduce the frequency of replacement. By making the height of the reinforcing part 13 greater than that of the cylindrical part 9, when the reinforcing part 13 is attached in the reverse direction, it comes into contact with the upper surface of the disk of the valve part 5, and the fitting position of the bearing part 4 becomes higher, so that the discharge port 3 cannot be tightened satisfactorily, which contributes to preventing assembly problems of the bearing part 4.

[0029] The foot valve according to the present invention has been described above based on the embodiment, but the present invention is not limited to the embodiment. As long as it does not deviate from the spirit of the present invention, various modifications conceivable by a person skilled in the art to the present embodiment and configurations constructed by combining components in different embodiments are also included within the scope of the present invention. [Industrial Applicability]

[0030] A pump equipped with a foot valve according to the present invention is useful because it can operate more efficiently than a pump equipped with a conventional foot valve. [Explanation of symbols]

[0031] 1 Foot valve 2 Valve box 2a Female thread 2b Male thread 3 outlet 3a Male thread 4 Bearing section 5 Valve section 5a Gasket 5b Valve stem 6 Strainer 6a hole 6b Female thread 7 First support part 8 Second support part 9 Cylindrical part 10 Arm part 10a opening 11 Ring section 12 Legs 13 Reinforcement part 14 Expansion section 15 Flow Path 20 Water Pump 21 Water Tank 22 Suction pipe 23 Discharge piping 101 Valve box 102 Joint 103 Valve body 104 Valve stem 105 Cylinder 106 Arm 107 Information 108 Female thread 109 Valve seat 110 Partition 111 Strainer

Claims

1. A cylindrical valve box; a cylindrical discharge port provided on one side of the valve box in a central axis direction; a bearing portion that is sandwiched and 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; a strainer having a plurality of holes provided on the other side of the valve box in the central axis direction, The valve box comprises: a first support portion having an annular shape and projecting inwardly from an inner surface of the valve box; a second support portion having an annular shape and projecting inwardly from an inner surface of the valve box, the second support portion being disposed on the other side of the valve box in the central axis direction than the first support portion, The bearing portion is A cylindrical portion that movably supports a valve stem of the valve portion; A plurality of rod-shaped arm portions extending radially from a side peripheral surface of the cylindrical portion; a ring portion that connects the tip ends of the plurality of arm portions; a plurality of leg portions protruding from the annular portion toward the other side in the central axis direction of the valve box; The bearing portion is disposed such that an outer peripheral surface of the leg portion is in contact with an inner peripheral surface of the valve box, a 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 other end of the leg portion in the central axis direction of the valve box contacts the first support portion of the valve box, 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, a valve member that is disposed between the first and second arm portions and that is connected to the strainer through a hole in the strainer and that is in contact with the cylindrical portion of the bearing portion; a valve member that is disposed between the first and second arm portions and that is connected to the strainer through a hole in the strainer;

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

3. the number of said leg portions is equal to the number of said arm portions; 3. The foot valve according to claim 2, wherein each of said leg portions projects from said annular portion toward a distal end of each of said arm portions which extend radially from said cylindrical portion.

4. The outer surfaces of the leg portions are curved surfaces that conform to the inner circumferential surface of the valve box, The inner surfaces of the plurality of leg portions have inwardly expanding portions, 4. The foot valve according to claim 3, wherein, when the bearing portion is viewed from the discharge port side, the expanded portions of the plurality of leg portions overlap with the plurality of arm portions.

5. 4. The foot valve according to claim 3, further comprising a plurality of reinforcing portions extending from one side surface of a plurality of the arm portions in the central axial direction of the valve box to a side periphery of the cylindrical portion of the bearing portion.

6. The plurality of reinforcing portions include extending along a periphery of the cylindrical portion; 6. The foot valve according to claim 5, wherein the bearing portion extends from the cylindrical portion to one side in a central axis direction of the valve box.

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