Foot valve

Abstract

To provide a foot valve capable of simplifying maintenance.SOLUTION: A foot valve includes: a cylindrical valve box 2 to an upper end side of which a suction pipe 6 is connected, and on a lower end side of which a valve box valve seat 7 is provided; a valve body 3 that is brought into contact with the valve box valve seat 7 by a head pressure f1 of liquid in the suction pipe 6, to block the lower end side of the valve box 2, and is separated from the valve box valve seat 7 by a suction head pressure f2 of the liquid flowing upward through the suction pipe 6; a screen member 4 that is provided at the lower part of the valve box 2 and removes debris from the liquid flowing upward through the suction pipe 6; and a cleaning member 5 that is provided so as to be relatively movable along the outside surface of the screen member 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a foot valve provided at the end of a suction pipe. [Background technology]

[0002] In water purification works such as ponds, fish farms, hydroelectric power plants, etc., water is pumped up through a suction pipe equipped with a lifting pump. A foot valve is attached to the end (bottom end) of this suction pipe to prevent water from falling into the suction pipe when the lifting pump is stopped.

[0003] When pumping water with this foot valve, debris may be sucked in along with the water, which may cause the pump to break down. In addition, debris may get caught in the valve body of the foot valve, causing water to fall into the suction pipe, making it necessary to prime the pump before it can be put back into operation, which can be cumbersome work.

[0004] For this reason, as shown in the following Patent Documents 1 and 2, for example, a screen member that functions as a strainer (see strainer 3 in Patent Document 1 and strainer 8 in Patent Document 2) is provided at the suction port of the foot valve to prevent debris from being sucked into the inside of the foot valve. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 56-67383 [Patent Document 2] Japanese Utility Model Application Publication No. 62-190875 Summary of the Invention [Problem to be solved by the invention]

[0006] In the configurations disclosed in Patent Documents 1 and 2, the screen member needs to be maintained periodically to ensure the suction volume of the foot valve. However, it is troublesome to pull the foot valve, which is submerged in water, out of the water for maintenance.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a foot valve that can simplify maintenance. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides: A cylindrical valve box having an upper end connected to a suction pipe and a valve box seat provided at a lower end; a valve body that contacts the valve body valve seat by a head pressure of liquid in the suction pipe to close the lower end side of the valve body, and that separates from the valve body valve seat by a suction lift pressure of liquid flowing upward through the suction pipe; A screen member provided at the bottom of the valve box for removing dust particles from the liquid; a cleaning member provided along an outer surface of the screen member so as to be relatively movable; A foot valve having the above structure was constructed.

[0009] In this way, dust adhering to the surface of the screen member can be smoothly removed by the relative movement between the screen member and the cleaning member, thereby simplifying the maintenance of the foot valve.

[0010] In the above configuration, it is preferable to further include a link member interposed between the valve body and the cleaning member, and the link member moves the cleaning member in conjunction with the opening and closing operation of the valve body. In this way, dust is removed from the surface of the screen member during normal opening and closing operation of the valve body, thereby reducing the frequency of maintenance of the foot valve.

[0011] In the configuration having the link member, it is preferable that the link member is a guide shaft fixed to the valve body that guides the valve body in the axial direction, and that the cleaning member moves axially together with the valve body and the guide shaft. Since this guide shaft is an existing part of the foot valve in which the valve body moves axially, it is possible to configure a cleaning member movement mechanism without increasing the number of parts.

[0012] In each of the above configurations, it is preferable that the screen member and the cleaning member are cylindrical, a slit extending over the entire axial direction is formed in a part of the circumferential direction of the cleaning member, and the cleaning member is provided with a slit width adjustment mechanism for changing the width of the slit. In this way, the size of the radial gap between the screen member and the cleaning member can be appropriately adjusted, and it is possible to achieve both the performance of removing dust adhering to the surface of the screen member and the smoothness of the relative movement between the screen member and the cleaning member. Effect of the Invention

[0013] In this invention, by providing a cleaning member in the foot valve that can move relatively along the outer surface of the screen member, the relative movement between the screen member and the cleaning member can smoothly remove dust adhering to the surface of the screen member, thereby simplifying maintenance of the foot valve. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a foot valve according to the present invention (first embodiment) in a closed state. [Diagram 2] FIG. 2 is a cross-sectional view showing the foot valve shown in FIG. 1 in an open state. [Diagram 3] FIG. 2 is a perspective view of a cleaning member of the foot valve shown in FIG. [Figure 4] FIG. 2 is a cross-sectional view showing a foot valve according to the present invention (second embodiment) in a closed state. [Diagram 5] FIG. 5 is a cross-sectional view showing the foot valve in an open state shown in FIG. [Figure 6] FIG. 2 is a front view showing another example of the cleaning member of the foot valve shown in FIG. 1; [Figure 7] FIG. 11 is a cross-sectional view showing a foot valve according to a third embodiment of the present invention in a closed state. [Figure 8] FIG. 8 is a cross-sectional view showing the foot valve shown in FIG. 7 in an open state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A first embodiment of a foot valve 1 according to the present invention will be described with reference to the drawings. This foot valve 1 is a device that is installed underwater to pump up water in water purification work such as in ponds, fish farms, hydroelectric power plants, etc., and as shown in Figure 1, its main components are a valve box 2, a valve body 3, a screen member 4, and a cleaning member 5.

[0016] The valve box 2 is cylindrical, with a suction pipe 6 connected to its upper end and a valve box valve seat 7 at its lower end. A water pump (not shown) for sucking up water is provided midway along the suction pipe 6.

[0017] The valve disc 3 is provided inside the valve box 2 so as to be able to move towards and away from the valve box seat 7. A closing spring 8 is provided inside the valve box 2. The upper end of this closing spring 8 abuts against the inner surface at the upper end of the valve box 2, and its lower end abuts against the upper surface of the valve disc 3. As shown in Figure 1, when the valve disc 3 is pressed against the valve box seat 7 by the head pressure f1 of the water in the suction piping 6 and the biasing force of the closing spring 8 trying to extend, the foot valve 1 is brought into a closed state.

[0018] On the other hand, as shown in Figure 2, when the suction head pressure f2 of water (see arrow w in Figure 2) flowing upward through the suction piping 6 causes the valve disc 3 to separate from the valve body valve seat 7 against the biasing force of the closing spring 8, the foot valve 1 enters an open state. A guide shaft (hereinafter denoted by the same reference symbol as the link member 9) serving as a link member 9 interposed between the valve disc 3 and the cleaning member 5 is provided coaxially on the lower end side of the valve disc 3.

[0019] The screen member 4 is a punched metal with a bottomed cylindrical shape provided at the bottom of the valve box 2. The water pumped up from the foot valve 1 is configured to pass through this screen member 4, and dust contained in the water is removed by this screen member 4. In this embodiment, the screen member 4 is configured from punched metal, but it can also be configured from a member of another shape, such as a mesh material. The hole diameter of the punched metal can be determined appropriately as long as it does not interfere with the operation of the lifting pump.

[0020] The cleaning member 5 is a punched metal having a bottomed cylindrical shape and provided radially outside the screen member 4. The hole diameter of this punched metal is relatively larger than the hole diameter of the punched metal constituting the screen member 4.

[0021] The cleaning member 5 is provided so as to be relatively movable in the axial direction along the outer surface of the screen member 4. The lower end of the cleaning member 5 is fixed by a fixing member 10 which fixes the lower end of the guide shaft 9. That is, the valve body 3, the guide shaft 9, the fixing member 10, and the cleaning member 5 are integrated, and when the valve body 3 moves in the axial direction (up and down direction) in conjunction with the opening and closing of the valve, the cleaning member 5 also moves in the axial direction accordingly. As the cleaning member 5 moves in the axial direction, dust adhering to the outer surface of the screen member 4 is removed.

[0022] As shown in Fig. 3, a slit 11 is formed in a portion of the circumferential direction of the cleaning member 5, and extends over the entire axial direction of the cleaning member 5. Near the slit 11, slit width adjustment mechanisms 12 for changing the width of the slit 11 are provided at two locations. The slit width adjustment mechanism 12 has a bolt fixing plate 12a provided on one side of the slit 11, a bolt 12b provided on the bolt fixing plate 12a, and a tension spring 12c having one end fixed to the bolt 12b side and the other end fixed to the other side of the slit 11. The slit width can be appropriately changed by adjusting the amount of screwing of the bolt 12b into the bolt fixing plate 12a to adjust the biasing force of the tension spring 12c.

[0023] An anti-twist mechanism 13 is provided at the upper end of the slit 11. The anti-twist mechanism 13 has a guide member 13a provided on one side of the slit 11, and a guide rail 13b provided on the other side of the slit 11 for guiding the guide member 13a. By providing the anti-twist mechanism 13, it is possible to prevent the cleaning member 5 from becoming twisted due to the axial positions of both ends of the slit 11 being misaligned from each other when the slit width is adjusted by the slit width adjustment mechanism 12.

[0024] It should be noted that the slit width adjustment mechanism 12 and the twist prevention mechanism 13 shown in FIG. 3 are merely examples, and other configurations may be adopted as long as they can fulfill their respective functions.

[0025] A second embodiment of the foot valve 1 according to the present invention will be described with reference to the drawings. As shown in Figure 4, like the foot valve 1 according to the first embodiment, this foot valve 1 mainly comprises a valve box 2, a valve element 3, a screen member 4, and a cleaning member 5, and the functions of each component are also the same, but the position at which the closing spring 8 is provided is different.

[0026] In the second embodiment, a closing spring 8 is provided coaxially with a guide shaft 9 inside the screen member 4. This closing spring 8 is stored in a storage member 14 fixed to the screen member 4. The upper end side of the closing spring 8 abuts against the inner surface of the upper end part of the storage member 14, while the lower end side is engaged by a spring presser 15 (washer) fixed to the guide shaft 9.

[0027] As shown in Figure 4, when the valve disc 3 is pressed against the valve box seat 7 by the head pressure f1 of the water in the suction piping 6 and the biasing force of the closing spring 8 trying to extend, the foot valve 1 is in a closed state. On the other hand, as shown in Figure 5, when the valve disc 3 is separated from the valve box seat 7 against the biasing force of the closing spring 8 by the suction head pressure f2 of the water flowing upward through the suction piping 6 (see arrow w in Figure 5), the foot valve 1 is in an open state.

[0028] The slit width adjustment mechanism 12 and the twist prevention mechanism 13 described in the foot valve 1 according to the first embodiment can also be used in the foot valve 1 according to the second embodiment.

[0029] In each of the above embodiments, the cleaning member 5 is made of a punched metal having a hole diameter larger than that of the screen member 4, but the cleaning member 5 can also be made of a member of another shape, such as a mesh material, as long as it is possible to minimize blocking of the holes in the punched metal of the screen member 4 in the open valve state. Also, as shown in Figure 6, the cleaning member 5 can be a scraper-shaped member in which a plurality of annular members are arranged coaxially in the axial direction and are movable together in the axial direction.

[0030] In addition, in each of the above embodiments, the screen member 4 and the cleaning member 5 are configured to move relative to each other in the axial direction, but they can also be configured to move relative to each other in the circumferential direction as the valve body 3 moves axially, or they can be configured to move relative to each other in both the axial and circumferential directions (diagonally relative to the axial direction).

[0031] In the above first embodiment, the closing spring 8 is provided inside the valve box 2, and in the second embodiment, it is provided inside the screen member 4. However, if a sufficient sealing state can be ensured by the weight of the valve body 3 and the head pressure f1, for example, it may be possible to omit this closing spring 8.

[0032] In addition, in each of the above embodiments, the valve body 3 and the cleaning member 5 are connected via the guide shaft 9, but it is possible to configure the valve body 3 and the cleaning member 5 to be connected by another type of link member 9.

[0033] A third embodiment of the foot valve 1 according to the present invention will be described with reference to the drawings. As shown in Figure 7, like the foot valves 1 according to the first and second embodiments, this foot valve 1 mainly comprises a valve box 2, a valve disc 3, a screen member 4, and a cleaning member 5, and the functions of each component are also the same, but the configurations of the valve disc 3, link member 9, etc. are different.

[0034] In the third embodiment, the valve disc 3 is configured to open and close by swinging about a horizontal swing axis 16. As shown in Fig. 7, when the valve disc 3 is pressed against the valve body valve seat 7 by the head pressure f1 of the water in the suction piping 6 and the weight of the valve disc 3, the foot valve 1 is in a closed state. On the other hand, as shown in Fig. 8, when the valve disc 3 is separated from the valve body valve seat 7 against the weight of the valve disc 3 by the suction head pressure f2 of the water flowing upward through the suction piping 6 (see arrow w in Fig. 8), the foot valve 1 is in an open state.

[0035] The screen member 4 is a cylindrical member provided at the bottom of the valve box 2 and formed with multiple slits extending in the axial direction. A bottom plate 17 that is disk-shaped in plan view is provided at the lower end side of the screen member 4. A spring seat 18 is formed in the center of the upper surface side of the bottom plate 17, and standing members 19 are provided facing upward at predetermined angles (90 degrees in this embodiment) in the circumferential direction. The standing members 19 are formed with long holes 20 that extend in the axial direction (up and down direction).

[0036] The cleaning member 5 is a cylindrical punched metal provided so as to be movable in the axial direction relative to the outer surface of the screen member 4. On the outer circumferential surface of this cleaning member 5, fixing pins 21 are provided at predetermined angle intervals (90 degrees in this embodiment) in the circumferential direction.

[0037] A link member 9 having vertical pieces 22 extending in the axial direction (up and down direction) and horizontal pieces 23 extending horizontally at 90 degree intervals in the circumferential direction is provided inside the screen member 4. The upper end of the vertical pieces 22 abuts against the lower surface of the valve body 3 by the biasing force of a biasing member 30 described later.

[0038] The vertical piece 22 and each horizontal piece 23 are provided with link protrusions 24, 25. The link protrusion 25 provided on the horizontal piece 23 is capable of moving up and down within a long hole 20 formed in the standing member 19. In addition, a fixing pin 21 provided on the cleaning member 5 is inserted into a through hole 26 formed at the end of the horizontal piece 23.

[0039] A lever 28 is provided inside the screen member 4, one end of which is supported to be swingable by a horizontal swing shaft 27. The other end of this lever 28 passes through the screen member 4 and the cleaning member 5 and protrudes outward. A long hole 29 is formed in the lever 28, extending along the extension direction thereof, and the link protrusion 24 provided on the vertical piece 22 is inserted into this long hole 29.

[0040] A biasing member 30 is provided on the spring seat 18 formed on the bottom plate 17. This biasing member 30 is a coil spring, and biases the link member 9 upward. The biasing force of this biasing member 30 is just enough to bring the upper end of the vertical piece 22 of the link member 9 into contact with the lower surface of the valve body 3 (a relatively weak biasing force), and this biasing force is not enough to swing the valve body 3 upward against its own weight.

[0041] When the valve body 3 swings as it opens and closes, the link member 9 that abuts against the underside of the valve body 3 moves up and down due to the biasing force of the biasing member 30. At this time, each link protrusion 25 provided on the horizontal piece 23 is guided by the long hole 20 formed in each upright member 19, and the horizontal state of the horizontal piece 23 is maintained. When the link member 9 moves up and down, the cleaning member 5 moves in the axial direction together with the fixing pin 21 inserted into the through hole 26 formed at the end of the horizontal piece 23. As a result, dust adhering to the outer surface of the screen member 4 is removed.

[0042] Furthermore, by manually moving the tip of lever 28 up and down, the link member 9 can be moved up and down via the link protrusion 24 inserted into a long hole 29 formed in lever 28. Therefore, maintenance of the foot valve 1 can be performed by moving the cleaning member 5 in the axial direction regardless of whether the valve body 3 is opened or closed.

[0043] The foot valve 1 according to each of the above embodiments can simplify its maintenance because the relative movement between the screen member 4 and the cleaning member 5 allows dust particles adhering to the surface of the screen member 4 to be smoothly removed. In particular, a link member 9 is interposed between the valve body 3 and the cleaning member 5, and this link member 9 moves the cleaning member 5 in conjunction with the opening and closing of the valve body 3. As a result, dust particles are removed from the surface of the screen member 4 during the normal opening and closing of the valve body, and the frequency of maintenance of the foot valve 1 can be reduced.

[0044] The foot valve 1 in each of the above embodiments has a slit 11 formed in a portion of the circumferential direction of the cylindrical cleaning member 5, which extends over the entire axial direction, and is provided with a slit width adjustment mechanism 12 for changing the slit width.This makes it possible to appropriately adjust the size of the radial gap between the screen member 4 and the cleaning member 5, thereby achieving both the performance of removing dust adhering to the surface of the screen member 4 and the smooth relative movement between the screen member 4 and the cleaning member 5.

[0045] In particular, in the slit width adjustment mechanism 12 employing the tension spring 12c as described above, even if dust gets caught on the outer surface of the screen member 4 and cannot be removed by the cleaning member 5, the tension spring 12c expands and contracts the cleaning member 5, allowing it to overcome the dust caught in the screen member 4. This makes it possible to prevent the cleaning member 5 from getting caught on the trapped dust and causing problems in the relative movement between the screen member 4 and the cleaning member 5.

[0046] The above describes the function of the cleaning member 5 to remove dust adhering to the outer surface of the screen member 4. However, depending on the hole diameter of the punched metal and the size of the slits, it may be possible for the cleaning member 5 itself to have the same dust removal function as the screen member 4.

[0047] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. Therefore, the scope of the present invention is defined by the claims, not by the above description, and is intended to include the meaning equivalent to the claims and all modifications. [Explanation of symbols]

[0048] 1 Foot valve 2 Valve box 3 Valve body 4 Screen material 5 Cleaning materials 6 Suction piping 7 Valve body and seat 8 Closing spring 9 Link member (guide shaft) 10 Fixing member 11 Slit 12 Slit width adjustment mechanism 12a Bolt fixing plate 12b Bolt 12c Extension spring 13 Anti-twist mechanism 13a Guide member 13b Guide rail 14 Storage materials 15 Spring holder 16 Horizontal swing axis 17 Bottom plate 18 Spring seat 19 Standing member 20 long hole 21 Fixing pin 22 Vertical piece 23 horizontal piece 24, 25 Link protrusions 26 Through hole 27 Horizontal swing axis 28 Lever 29 long hole 30 Urging member f1 Head pressure f2 Suction head pressure

Claims

1. a cylindrical valve box (2) having an upper end connected to a suction pipe (6) and a valve box valve seat (7) at a lower end; a valve body (3) that abuts against the valve box valve seat (7) due to a head pressure (f1) of liquid in the suction pipe (6) to block the lower end side of the valve box (2), and that moves away from the valve box valve seat (7) due to a suction head pressure (f2) of liquid flowing upward through the suction pipe (6); A screen member (4) provided at the bottom of the valve box (2) for removing dust particles from the liquid; a cleaning member (5) provided so as to be relatively movable along an outer surface of the screen member (4); A foot valve having a

2. 2. The foot valve as described in claim 1, further comprising a link member (9) interposed between the valve body (3) and the cleaning member (5), and configured so that the cleaning member (5) moves in association with the opening and closing operation of the valve body (3) by the link member (9).

3. 3. A foot valve as described in claim 2, wherein the link member (9) is a guide shaft (9) fixed to the valve body (3) for guiding the valve body (3) in the axial direction, and the cleaning member (5) is configured to move axially together with the valve body (3) and the guide shaft (9).

4. 4. A foot valve as claimed in any one of claims 1 to 3, wherein the screen member (4) and the cleaning member (5) are cylindrical in shape, a slit (11) is formed in a part of the circumferential direction of the cleaning member (5) and extends over the entire axial direction thereof, and the cleaning member (5) is provided with a slit width adjustment mechanism (12) for changing the width of the slit (11).

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