Check valve for water supply system

Abstract

The objective is to provide a check valve for water supply systems that can prevent or reduce wear on the valve body during opening and closing. [Solution] The check valve 1 for water supply equipment comprises a valve body 2 provided with a valve hole 2a through which water can pass, a valve element 3 housed in the valve body 2 that moves between a closed position that closes the valve hole 2a and an open position that opens the valve hole 2a, and a spring 4 that biases the valve element 3 to the closed position. One end 4a of the spring 4 is connected to the head 31 or shaft 32 of the valve element 3 in a state where circumferential rotation is restricted, and the other end 4b is connected to the valve body 2 in a state where circumferential rotation is restricted.

Description

Technical Field

[0001] The present invention relates to a check valve for water supply facilities installed in the middle of a water supply pipe to prevent backflow of water.

Background Art

[0002] Conventionally, a check valve for water supply facilities installed in the middle of a water supply pipe, such as near a water meter, to prevent backflow of water is known.

[0003] For example, Patent Document 1 discloses a check valve having an annular valve seat portion provided with a fluid inlet, a valve body, and a support portion that supports the valve body so as to be linearly movable between a closed position where the valve body abuts against the valve seat portion to close the fluid inlet and an open position where the valve body is separated from the valve seat portion. The support portion has a cylindrical portion that faces the valve seat portion with a gap in the linear movement direction of the valve body and protrudes toward the valve seat portion in the linear movement direction. The valve body includes a valve portion located between the valve seat portion and the cylindrical portion, a shaft portion that passes through the cylindrical portion and is in sliding contact with the inner peripheral surface of the cylindrical portion, and a valve body side cylindrical portion that surrounds the cylindrical portion from the outer peripheral side and is in sliding contact with the outer peripheral surface of the cylindrical portion.

[0004] Patent Document 2 discloses a check valve having a valve box having a liquid inlet and a liquid outlet, a valve body housed in the valve box to open and close the liquid inlet, and an annular flange protruding from the outer peripheral side of the valve box. In the check valve installed with the flange sandwiched between a primary side pipe and a secondary side pipe constituting a liquid circulation pipe and the valve box inserted into the liquid circulation pipe, the check valve has an annular first elastic member that elastically deforms between the flange and the primary side pipe to liquid-tightly seal the flange and the primary side pipe, and a first end surface of the flange facing the primary side pipe side has a first contact portion that can be in surface contact with the primary side pipe when the first elastic member elastically deforms between the primary side pipe and the flange.

[0005] Patent Document 3 discloses a unit-type check valve for use in water pipes, comprising: an annular valve seat member forming a central fluid inlet; a housing coupled to the valve seat member and having an open shape that allows the passage of fluid flowing in from the inlet; and a valve body provided within the housing and pressed against the valve seat member by a biasing means, wherein the valve seat member is formed of a metal ring and a rubber covering integrally formed on the ring so as to cover at least the surface of the ring that engages with the valve body, the inner diameter surface, and the outer end surface facing outward, wherein a compressible rubber buffer member protruding outward is provided on the outer surface of the outer end surface covering portion of the covering that covers the outer end surface of the ring. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-80767 [Patent Document 2] Japanese Patent Publication No. 2017-9026 [Patent Document 3] Japanese Patent Application Publication No. 9-72442 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, conventional check valves for water supply systems all consist of a valve body with a valve hole through which water can pass, a valve element supported inside the valve body that moves between a closed position that closes the valve hole and an open position that opens the valve hole, and a biasing spring that biases the valve element to the closed position. However, when the valve element opens and closes due to the water flow, it rotates around its axis, causing friction between the valve element and the valve body (especially the part that supports the valve element), which can lead to wear and damage of the valve element.

[0008] The present invention has been made in view of the above-mentioned problems, and aims to provide a check valve for water supply equipment that can prevent or reduce wear of the valve body when opening and closing. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides a check valve for water supply equipment comprising: a valve body provided with a valve hole through which water can pass; a head for opening and closing the valve hole; a shaft provided on the head; a valve body housed inside the valve body and moving axially between a closed position that closes the valve hole and an open position that opens the valve hole; and a biasing spring that biases the valve body to the closed position of the valve hole in a manner through which the shaft of the valve body is inserted, wherein one end of the biasing spring is connected to the head or shaft of the valve body in a manner that restricts circumferential rotation, and the other end is connected to the valve body in a manner that restricts circumferential rotation.

[0010] According to this, since the valve body is mounted on the valve casing via a biasing spring with its axial rotation restricted, the rotation of the valve body around its axis relative to the valve casing can be restricted, making it possible to prevent or reduce wear on the valve body during opening and closing.

[0011] Furthermore, the biasing spring may be connected with one end fitted into a valve-side recess provided on the valve body. This allows one end of the biasing spring to be connected to the valve body easily and reliably, facilitating the disassembly and assembly of the check valve for water supply equipment during maintenance work.

[0012] Furthermore, the valve body may have a plurality of valve body-side recesses arranged along the circumferential direction. This allows for easy and reliable connection of one end of the biasing spring to the valve body, even if the valve body rotates around its axis when attaching the biasing spring to the valve body, as one end of the biasing spring can face any of the valve body-side recesses.

[0013] Furthermore, the valve body may have multiple protrusions arranged radially on its shaft, with the spaces between each protrusion forming the valve body-side recesses. This allows for a simple configuration in which multiple valve body-side recesses can be provided along the circumferential direction of the valve body.

[0014] Further, the biasing spring may be connected while the other end portion thereof is fitted into a valve box side recess provided in the valve box. According to this, the other end portion of the biasing spring can be easily and reliably connected to the valve box, and disassembly and assembly of the check valve for water supply facilities in maintenance work or the like become easy.

[0015] Further, the biasing spring may be connected while the other end portion thereof is hooked on the valve box. According to this, the other end portion of the biasing spring can be easily and reliably connected to the valve box, and disassembly and assembly of the check valve for water supply facilities in maintenance work or the like become easy.

Advantages of the Invention

[0016] According to the present invention, since the valve body is provided in a state where the axial rotation thereof is restricted by the biasing spring with respect to the valve box, it is possible to restrict the valve body from rotating about the axis with respect to the valve box, and it becomes possible to prevent or reduce wear when the valve body opens and closes.

Brief Description of the Drawings

[0017] [Figure 1] It is a cross-sectional view of a check valve for water supply facilities according to an embodiment of the present invention. [Figure 2] It is a (a) rear view, (b) side view, and (c) front view of the check valve for water supply facilities of FIG. 1. [Figure 3] It is an exploded view of the check valve for water supply facilities of FIG. 1. [Figure 4] It is a (a) rear view and (b) side view of the valve body. [Figure 5] It is a partial cross-sectional view showing the operation of the check valve for water supply facilities of FIG. 1. [Figure 6] It is a (a) rear view and (b) side view of a check valve for water supply facilities according to another embodiment.

Modes for Carrying Out the Invention

[0018] Next, the check valve for water supply facilities according to an embodiment of the present invention (hereinafter referred to as the present check valve 1) will be described with reference to FIGS. 1 to 6. In this specification, the right side of FIG. 1 is referred to as the "upstream side", and the left side of FIG. 1 is referred to as the "downstream side".

[0019] As shown in FIGS. 1 and 5, the present check valve 1 is installed at the position of the joint J connecting the upstream pipe P1 and the downstream pipe P2 connected to the water meter, and water W flows in from the inlet R1 on the upstream side and flows out from the outlet R2 on the downstream side.

[0020] As shown in FIGS. 1 to 3, the present check valve 1 includes a valve box 2 provided with a valve hole 2a through which water W can pass between the inlet R1 and the outlet R2, a valve body 3 housed inside the valve box 2 and moving between a closed position for closing the valve hole 2a and an open position for opening the valve hole 2a, and a coiled spring (biasing spring) 4 for biasing the valve body 3 to the closed position where the valve body 3 closes the valve hole 2a.

[0021] As shown in FIGS. 1 to 3, the valve box 2 is composed of a check valve body 21 in which the valve body 3 is housed, a valve body presser 22 that presses the valve body 3 housed in the check valve body 21 from the upstream side, a valve seat packing 23 provided on the valve body 3 side of the valve body presser 22, and a meter packing 24 provided on the upstream side of the valve body presser 22 and the check valve body 21.

[0022] The check valve body 21 includes a cylindrical body main body 211 extending in the axial direction, a flange portion 212 provided at the upstream end portion 211a of the body main body 211 and extending radially outward, an intermediate portion 213 provided at the downstream end portion 211b of the body main body 211 and extending in the axial direction (downstream direction), an annular portion 214 provided at the downstream end portion 213a of the intermediate portion 213 and extending radially inward, and a cylindrical portion 215 provided at the radially inner end portion 214b of the annular portion 214 and extending in the axial direction (upstream direction).

[0023] The aforementioned body 211 has a recess 211c formed on its inner circumferential surface that corresponds to the projection 221c of the valve retainer 22, which will be described later. The valve retainer 22 is fitted into the body 211 from the upstream end 211c, and the projection 221c and the recess 211c engage during this fitting.

[0024] The flange portion 212 is formed in an annular shape extending radially with a predetermined thickness and is covered by the meter packing 24.

[0025] The intermediate sections 213 are columnar members extending in the axial direction, and four of them are arranged in a row at equal intervals along the circumferential direction at positions along the outer circumferential surface of the main body 211. In addition, outlets R2 for the outflow of water W are formed between adjacent intermediate sections 213.

[0026] The annular portion 214 is provided with radially protruding radially, with three or four radially outer ends 214a connected to the intermediate portion 213 arranged in the circumferential direction. Furthermore, the annular portion 214 is provided with a valve body side recess 214c on the upstream side surface of the radially inner end 214b, into which the other end 4c of the spring 4 (described later) is fitted and connected. This allows the other end 4c of the spring 4 to be easily and reliably connected to the valve body 2, making it easy to disassemble and assemble the check valve 1 during maintenance work.

[0027] The cylindrical portion 215 is inserted axially into the interior of the other end 4b side of the spring body 4a of the spring 4.

[0028] The valve body retainer 22 comprises a cylindrical retainer body 221 extending in the axial direction and a flange portion 222 extending radially outward at the upstream end 221a of the retainer body 221.

[0029] The retaining body 221 is provided with an inlet R1 for allowing water W to flow in through the inner circumferential surface of its upstream end 221a.

[0030] The retaining body 221 has a projection 221c formed on its outer circumferential surface that corresponds to the recess 211c of the body 211. Furthermore, the retaining body 221 is reduced in diameter at its downstream end 221b, and this downstream end 221b is fitted into the upstream end 23a of the valve seat packing 23.

[0031] The flange portion 222 is formed to extend radially with a predetermined thickness. When the valve retainer 22 is fitted into the body 211 of the check valve body 21, the flange portion 222 is positioned along the upstream side of the flange portion 212 of the check valve body 21 and is covered by the meter packing 24.

[0032] The valve seat packing 23 is formed in a ring shape from a synthetic resin such as silicone. The valve seat packing 23 is formed such that the downstream end 23b becomes thinner towards the downstream side, and the downstream end 23b flexibly deforms in accordance with the seating and unseating of the valve body 3. The valve hole 2a is provided by the inner circumferential surface of the downstream end 23b of this valve seat packing 23.

[0033] The meter packing 24 is made of rubber or the like and includes an upstream portion 24a positioned along the upstream side of the flange portion 222, a downstream portion 24b positioned along the downstream side of the flange portion 212, and a connecting portion 24c that connects the radially outer surfaces of the upstream portion 24a and the downstream portion 24b on the outside of the flange portion 212 and the flange portion 222, and covers the flange portion 212 of the check valve body 21 and the flange portion 222 of the valve body retainer 22.

[0034] As shown in Figure 4, the valve body 3 comprises a head 31 formed in the shape of an umbrella that protrudes upstream, and a shaft portion 32 provided downstream of the head 31 and formed in a manner that extends in the axial direction. When the pressure of the water W is less than a predetermined value, the valve is biased to the closed position by the spring 4, as shown in Figure 5(a). When the pressure of the water W is greater than or equal to the predetermined value, the valve is pushed to the open position by the water W against the biasing force of the spring 4, as shown in Figure 5(b).

[0035] The head portion 31 is provided such that the upstream side surface 31a is curved toward the upstream side, while the downstream side surface 31b is provided in a planar shape perpendicular to the axial direction, and an axially symmetric recess 31c is formed on the downstream side surface 31b.

[0036] The shaft portion 32 is formed to have an axial length of 10 to 50 mm and a diameter of 1 to 10 mm, with its upstream end 32a connected to the center of the recess 31c of the head portion 31. This shaft portion 32 is inserted into the cylindrical portion 215 of the check valve body 21 and is supported so as to be movable in the axial direction by the inner circumferential surface of the cylindrical portion 215. Therefore, in the closed position of the valve body 3 shown in Figure 5(a), the downstream end 32b of the shaft portion 32 protrudes relatively small downstream from the radially inner end 214b of the annular portion 214, while in the open position of the valve body 3 shown in Figure 5(b), the downstream end 32b protrudes relatively large downstream from the radially inner end 214b of the annular portion 214. Furthermore, the shaft portion 32 is inserted axially into the spring 4, so that its outer circumferential surface 32c is surrounded by the spring 4.

[0037] Furthermore, the shaft portion 32 has a plurality of valve body-side recesses 32e provided along the circumferential direction at its upstream end 32a. Specifically, the shaft portion 32 has a plurality of projections 32d arranged radially within the recess 31c of the head portion 31, and the space between each projection 32d forms the valve body-side recess 32e. This allows for a simple configuration in which a plurality of valve body-side recesses 32e can be provided along the circumferential direction of the valve body.

[0038] Furthermore, the shaft portion 32 is connected to the valve body side recess 32e formed between the protrusions 32d, with one end 4b of the spring 4 (described later) fitting into it. This allows the one end 4b of the spring 4 to be easily and reliably connected to the valve body 3, making it easy to disassemble and assemble the check valve 1 during maintenance work. Also, when attaching the spring 4 to the valve body 3, even if the valve body 3 rotates around its axis, the one end 4b of the spring 4 (described later) can face either of the valve body side recesses 32e, thus allowing the one end 4b of the spring 4 to be easily and reliably connected to the valve body 3.

[0039] As shown in Figure 3, the spring 4 comprises a spiral spring body 4a formed in its natural state with an axial length of 10 to 60 mm, an outer diameter of 3 to 15 mm, and a wire diameter of 0.2 to 1 mm; one L-shaped end 4b at the upstream end of the spring body 4a, which extends in the direction of the center of the spring body 4a and then bends and extends downstream by about 0.5 to 3 mm; and the other end 4c at the downstream end of the spring body 4a, which extends downstream by about 2 to 10 mm.

[0040] The spring 4 is configured such that one end 4b is deeply fitted into the valve body-side recess 32e within the valve body 3 and connected to the valve body 3, while the other end 4c is deeply fitted into the valve casing-side recess 214c and connected to the valve casing 2. This configuration causes the spring 4 to be contracted by a predetermined length from its natural state, thereby biasing the valve body 31 to the closed position of the valve hole 2a.

[0041] Thus, one end 4b of the spring 4 is connected to the head 31 or shaft 32 of the valve body 3 in a manner that restricts its circumferential rotation, and the other end 4c is connected to the valve casing 2 in a manner that restricts its circumferential rotation, and the valve body 3 is provided on the valve casing 2 via the spring 4 in a manner that restricts its axial rotation.

[0042] Next, the operation of this check valve 1 will be explained with reference to Figure 5.

[0043] First, as shown in Figure 5(a), when no water W is flowing through the upstream piping P1 or when the pressure of the water W is below a predetermined level, the valve body 3 is biased upstream by the spring 4 and positioned in a closed position, in close contact with the valve seat packing 23.

[0044] Then, as shown in Figure 5(b), when the pressure of the water W flowing in from the inlet R1 exceeds a predetermined value, the pressure of the water W causes the valve body 3 to be strongly pushed downstream against the biasing force of the spring 4, and it moves to an open position a predetermined distance away from the valve seat packing 23. The water W that flowed in from the inlet R1 then passes through the valve hole 2a, which has been opened when the valve seat packing 23 has moved to the open position, and then flows out through the inside of the valve body 2 to the downstream piping P2 from the outlet R2.

[0045] Then, as shown in Figure 5(a), when the pressure of the water W flowing in from the inlet R1 falls below a predetermined value again, the spring 4 biases the valve body 3 upstream against the pressure of the water W, returning it to the closed position in close contact with the valve seat packing 23.

[0046] In this manner, the valve body 3 moves along the axial direction due to the pressure of the water W. However, since the valve body 3 is mounted on the valve casing 2 via a spring 4, its rotation around the axis relative to the valve casing 2 can be restricted, thereby preventing or reducing wear of the valve body 3 (especially the shaft portion 32) during opening and closing.

[0047] In the above embodiment, the valve body 3 was described as having a valve body-side recess 32e formed between a plurality of protrusions 32d, but it is not limited to this, and the valve body-side recess 32e may be formed by other configurations.

[0048] Furthermore, although the biasing spring 4 has been described as being a coil-shaped spring, it is not limited to this and may be a leaf spring or other type of biasing spring.

[0049] Furthermore, although the biasing spring 4 has been described as being connected by fitting one end 4b or the other end 4c into the valve body side recess 32e or the valve casing side recess 214c, it is not limited to this and may be connected by other methods.

[0050] For example, as shown in Figure 6, the biasing spring 4 may be connected with its other end 4c hooked onto the valve body 2 (the outer surface of the annular portion 214). Even in this case, the other end 4c of the biasing spring 4 can be easily and reliably connected to the valve body 2, making it easy to disassemble and assemble the check valve during maintenance work.

[0051] In this case, the other end 4c may rotate circumferentially relative to the valve body 2. In this specification, "circumferential rotation is restricted" means that the rotation is restricted to a range of 90° in the circumferential direction, preferably to a range of 45° in the circumferential direction, and more preferably to a range of 5° in the circumferential direction. However, it is preferable that the biasing spring 4's circumferential rotation is suppressed by friction between the other end 4c and the outer circumferential surface of the annular portion 214.

[0052] Although embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiments within the same scope as the present invention, or within an equivalent scope. [Explanation of Symbols]

[0053] 1… Check valve 2…Lever box 2a...Valve hole 21... Check valve body 211... Torso 211a...Upstream end 211b...Downstream end 211c…recess 212... Guard section 213...Middle section 213a...Downstream end 214... Ring section 214a...Radially outer end 214b...Radially inner end 214c... Recess on the valve body side 215...Cylindrical section 22... Valve body retainer 221...Presser body 221a...Upstream end 221b...Downstream end 221c…Protrusion 222... Guard section 23... Valve seat packing 24... Meter packing 24a…Upstream side 24b… Downstream side 24c...Connection part 3… Valve body 31...Head 31a... Upstream side 31b... Downstream side 31c... indentation 32... Shaft 32a...Upstream end 32b...Downstream end 32c...Outer surface 32d…Protrusion 32e... Valve body side recess 4... Spring (biasing spring) 4a... Spring body 4b...One end 4c...Other end P1... Upstream piping P2... Downstream piping J... Fitting R1…Inlet R2…outlet W…Water

Claims

1. A valve body provided with a valve opening through which water can pass, A valve body having a head that opens and closes the valve hole, and a shaft provided on the head, housed inside the valve casing, and moving axially between a closed position that closes the valve hole and an open position that opens the valve hole, A check valve for water supply equipment, comprising a biasing spring that biases the valve body to the closed position of the valve hole in a manner through which the shaft portion of the valve body is inserted, The check valve for water supply equipment is characterized in that one end of the biasing spring is connected to the head or shaft of the valve body in a manner that restricts its circumferential rotation, and the other end is connected to the valve body in a manner that restricts its circumferential rotation.

2. The check valve for water supply equipment according to claim 1, wherein one end of the biasing spring is connected to the valve body by fitting into a valve body-side recess provided on the valve body.

3. The check valve for water supply equipment according to claim 2, wherein the valve body is provided with a plurality of valve body-side recesses along the circumferential direction.

4. The check valve for water supply equipment according to claim 3, wherein the valve body has a plurality of projections arranged radially on its shaft, and the space between each projection is formed as a recess on the valve body side.

5. The check valve for water supply equipment according to claim 1, wherein the biasing spring is connected with its other end fitted into a recess on the valve body side provided in the valve body.

6. The check valve for water supply equipment according to claim 1, wherein the biasing spring is connected with its other end hooked onto the valve body.

Images