JP7361863B2 - Anti-freeze damage type air valve - Google Patents

Description

The present invention relates to a pneumatic valve, in particular, which can easily be both a freeze-damage prevention type and an easily disassembled type, and can also be easily used for a cap, and which is used in cold regions, winter, etc. Regarding the type of rapid air valve.

In general, rapid intake/exhaust type air valves are installed at appropriate locations in pipes such as water mains and water pipes, and collect air caused by air bubbles that occur in the pipes, causing the internal float to float and sink. The fluid is automatically discharged to the outside to maintain the fluid transfer capacity of the piping.

The structure of this type of air valve includes a valve body, a lid body with a large air hole, a float valve body housed in the valve body, a floating valve body with a small air hole, and a guide member that guides them. This structure allows it to handle rapid large-volume exhaust when filling the pipe with water, as well as rapid large-volume intake during draining. In addition, in order to maintain its function, appropriate maintenance is required, such as removing dust that has adhered to the inside, cleaning, and inspection. It requires a structure that can be taken out for cleaning, inspection, and replacement. Patent Documents 1 to 3 have been proposed as such a simple disassembly type rapid air valve.

In Patent Document 1, a floating valve body and a float valve body having small air holes are compactly housed in a guide cylinder that guides them, and this guide cylinder is set in a valve box and a removable lid is attached from above. By simply fixing the pneumatic valve to the valve box via the fixing means, the pneumatic valve can be properly positioned and held within the valve box by the guide pedestal and side guides even though it is in a loosely fitted state, making it extremely easy to use the pneumatic valve. In particular, the detachable lid can be engaged with or released from the upper part of the valve box by simply inserting the radially protruding arm engagement piece into the guide part and rotating it, making it extremely easy to attach and detach even within a compact space. Disassembly and assembly of the air valve, which is necessary for maintenance, is extremely easy.

Further, Patent Document 2 discloses an air valve that can be used regularly by integrating a cap and a removable lid, and this air valve can be used immediately as a fire hydrant water supply, pipe washing, water pressure test site, etc. without the need for a separate cap. It is possible. Patent Document 3 also discloses a simple disassembly type air valve, but in the case of the lid body of the same document, a fixing means is used in which two cam levers on the left and right are tilted down and locked.

On the other hand, the problem of freeze failure has been known for this type of pneumatic valves as well. When an air valve is used in a cold region or in winter, the water used as a fluid may freeze inside the air valve, and the water expands in volume as it freezes. As this volume expansion progresses, movable parts such as floats and frozen ice blocks housed in the valve box are pushed upwards and press against the floating valve body, or the internal pressure inside the valve box increases. This may result in malfunction or damage to the component parts, which may cause damage or failure of the air valve. Moreover, since freeze damage progresses gradually depending on the outdoor environment, it is difficult to predict its occurrence, and therefore an air valve that can reliably prevent it is required.

On the other hand, many air valves have been proposed in the past that can deal with the problem of freeze damage by adopting a structure that can appropriately absorb the volumetric expansion deformation caused by such pushing up. Examples of this type of air valve include Patent Documents 4 to 6. For example, in FIG. 2 of Patent Document 4, a piston that has a large air hole in the lid body and is resiliently sprung by a disc spring is covered with the upper part of the air valve. A lid-fixed structure is disclosed. With this structure, even if the floating valve body etc. is pushed up or the internal pressure of the valve box increases due to volume expansion due to freezing as described above, the movement is absorbed by the piston while being elastically biased by the disk spring. Even if volumetric expansion of water occurs within the valve box, freezing damage to the air valve as described above can be prevented.

Japanese Patent Application Publication No. 2013-190084 Japanese Patent Application Publication No. 2015-117827 Japanese Patent Application Publication No. 2009-121678 Utility Model Publication No. 62-153482 Utility Model Publication No. 60-35978 Publication No. 55-31072

However, first of all, there is no prior art that combines the conventional freeze damage prevention structure (Patent Documents 4 to 6) with the conventional simple disassembly type air valve (Patent Documents 1 to 3). Considering the conventional freeze damage prevention structure, even if such a combination structure existed, such a structure would at least require that the lid body be firmly fixed to the valve body with bolts, etc. Must be a structure.

For example, specifically, between the overlapped flange parts, a bolt is inserted vertically into the valve box to create a lid structure in which a piston body is stored in an elastic state from the back side of the lid body using a disc spring. A structure in which it is fixed to the top is considered. Furthermore, in such a structure, the piston body can only be housed inside the valve box by tightening this bolt. This is because such a fixing structure is adopted in at least all of Patent Documents 4 to 6.

However, it is clear that such a pneumatic valve completely loses the features and advantages of the easily disassembled type described above. In other words, in the air valve having such a structure, the lid must be attached and removed by fixing and removing bolts, and at least the workability of attaching and removing the lid is completely impaired. In this case, a structure is adopted in which the floating valve body, float valve body, and guide body, as the minimum components required for maintenance, can be stored inside the valve box in a manner that allows for extremely easy removal and installation. The structure does not take advantage of the advantages of the conventional simple disassembly type. This is because the air valve structure can be easily disassembled only if these internal storage parts can be taken out and stored extremely easily.

Therefore, in the conventional technology, the simple disassembly type (Patent Documents 1 to 3) may require reliable measures against freeze damage, while the freeze damage prevention type (Patent Documents 4 to 6) requires simple disassembly. There is a problem that it cannot be used as a type. Therefore, it is desired to develop an air valve that has both of these performances. In many cases, it is also necessary to have a cap that is compact and convenient and can also be used as an air valve. However, a patent document disclosing such a technique has not yet been proposed despite its high demand.

Therefore, the present invention was developed to solve the above-mentioned problems, and its purpose is to maintain easy disassembly without complicating the structure or assembly work, while preventing freeze damage. To provide a freeze-damage prevention type air valve which is capable of reliably responding to air valves, is extremely easily applicable to existing air valves, and has a structure that can be immediately used for caps of fire hydrants and the like.

In order to achieve the above object, the invention according to claim 1 provides an inlet provided at the lower part of the valve box, a float valve body housed inside a guide cylinder arranged in the valve box, and an upper part of the float valve body. The valve body is equipped with a floating valve body having a small air hole, and a freeze damage prevention unit is removably attached to the opening provided in the upper part of the valve body via a fixing means. A cylindrical part that has a hole opened at the center of the cover body connected to the cover body, a large air hole provided at the top of the piston that biases the spring, and the outer peripheral surface of the cylindrical part and the fixed cylinder. It is integrated into a unit consisting of an expansion and absorption chamber that houses a spring between them, a receiving part that elastically biases the upper part of the spring against the cover body, and a base that communicates with the cylindrical part provided at the upper part of the cover body. This is a freeze damage prevention type air valve.

According to the invention set forth in claim 1, by attaching a freeze damage prevention unit having a cap to the valve box, an existing air valve can be easily provided with a freeze damage prevention function. The large air holes in the unit allow water to pass through without the need for a separate cap. Therefore, there is no need to carry separate parts to the installation location of the air valve; simply remove the guide cylinder housing the float valve element and floating valve element, and attach/remove the freeze damage prevention unit to the valve box. You can easily switch between using it as an air valve or as a fire hydrant.
Moreover, this unit allows the diameter of the large air hole to be greatly expanded, and the opening of the base is provided so that it can communicate with the large air hole of the cylindrical part, so it is possible to secure a predetermined amount of air and It can be used as a fire hydrant that can obtain a sufficient flow rate of tap water by simply attaching a fire hydrant hose to the mouthpiece, and its useful value is extremely high.

FIG. 1 is a longitudinal cross-sectional view of a first embodiment of the air valve of the present invention. It is a perspective view showing a floating valve body and a float valve body. FIG. 1 is a longitudinal cross-sectional view of a freeze damage prevention unit according to a first embodiment of the present invention. FIG. 3 is a schematic plan view showing a fixed lid. It is a longitudinal cross-sectional view of the freeze damage prevention unit of 2nd Embodiment of this invention. FIG. 7 is a longitudinal sectional view showing an example of a state in which the piston is raised in the second embodiment of the air valve of the present invention. FIG. 2 is an isolated cross-sectional view in FIG. 1. FIG.

EMBODIMENT OF THE INVENTION Below, embodiment of the air valve in this invention is described in detail based on drawing. In FIG. 1, a first embodiment of the pneumatic valve of the present invention is shown.

As shown in FIG. 1, the air valve of the present invention includes a valve box 1, a guide cylinder 2, a float valve body 3, a floating valve body 4, a unit 61, and a fixed lid 7. It is installed in the main pipe line, etc., and is installed so that air bubbles and air pockets contained in tap water can be discharged to the outside. Further, as a freeze damage prevention type air valve, the unit 61 is used in an environment where water in the valve box 1 may freeze while the air valve is in use, such as in a cold region or during winter. Particularly preferred installation locations include the top of the pipe when the slope of the pipe changes, every fixed interval (for example, 300 to 500 m) along a straight horizontal pipe, the center of the water pipe, and the pipe. There are places where air needs to be supplied and exhausted before and after the valve.

In FIG. 1, a valve box 1 is made of, for example, ductile cast iron, and houses a float valve body 3 made of resin such as ebonite, and a floating valve body 4 made of resin such as polypropylene. A guide cylinder 2 made of a resin such as ABS resin is disposed, and an opening 6 is formed above the valve box 1. A unit 61, which will be described later, is permanently fixed in this opening 6 via appropriate fixing means 11, and this unit 61 is provided with a large air hole 12. In this air valve, the guide cylinder 2 housing the unit 61, the float valve body 3, and the floating valve body 4 is taken out from the opening 6 of the valve box 1 as needed, and the valve box 1 is taken out. A unit 61 having a large air hole 12 is fixed to the opening 6 of.

In FIG. 1, the valve box 1 is formed into a substantially cylindrical shape, and has an opening 6 at the top, an inlet 20 at the bottom, and a storage chamber 21 between them. A fitting part 22 having a diameter smaller than that of the opening 6 is formed on the side of the opening 6 of the valve box 1, and an annular groove 23 is formed in the upper part of the fitting part 22. A U packing 24 made of, for example, a cylinder material is attached to the annular groove 23. A step 25 is provided between the opening 6 and the fitting portion 22, a thrust ring 26 is attached to the step 25, and a male thread 28 of a bolt member 27 is screwed onto the upper surface of the opening 6. Female threads 29 for attachment are provided at multiple locations by centering processing.

In FIG. 1, the inflow port 20 at the bottom of the valve box 1 is provided so as to ensure a predetermined inflow area, and the inflow port 20 is provided with a predetermined inflow area around the inflow port 20, for example. Protrusions 30 are formed protrudingly at intervals of approximately 90°. The protrusion 30 is provided on the inner diameter side than the diameter of the float valve body 3 and the floating valve body 4, and by locking the float valve body 3 and the floating valve body 4 to this protrusion 30, it is possible to prevent mistakes during cleaning or inspection. Even if they are dropped, they will be prevented from falling. A flange 31 is provided on the lower outer periphery of the valve box 1, and a repair valve (not shown) or the like is removably provided via the flange 31.

The storage chamber 21 is provided with an inner diameter that can accommodate the guide cylinder 2, and a guide pedestal 32 for mounting the guide cylinder 2 is formed at the lower part of the storage chamber 21 to protrude inward. A plurality of side guides 33 are formed protrudingly on the inner circumferential side of the storage chamber 21, and these side guides 33 are made of suitable materials that can come into contact with the outer periphery of the guide cylinder 2 so as to guide the guide cylinder 2 in a centered state. installed at a height of

The guide cylinder 2 has an upper part disposed on the lower surface side of the unit 61, a lower part thereof so as to be placed on the guide pedestal 32, and is inserted into the storage chamber so as to be sandwiched between the guide pedestal 32 and the lower end surface of the unit 61. It is stored in 21. A plurality of communication parts 35 for communicating fluid are formed in the upper part of the guide cylinder 2, and a hole 36 of a predetermined diameter is provided at a substantially central position on the bottom surface side. The communication portions 35 are provided at equal intervals by a plurality of cutout portions, and the area during fluid passage is determined by the communication portions 35.

The temporary connecting parts 62 and 63 shown in FIG. 1 are provided in a structure that can connect and hold the unit 61 and the guide cylinder 2, and when the temporary connecting parts 62 and 63 are separated, the unit 61 is taken out from the opening 6. At this time, the guide cylinder 2 housing the float valve body 3 and the floating valve body 4 along with the unit 61 can be pulled up and taken out.

The structure of the temporary connecting parts 62 and 63 is such that it can support and hold the weight of the guide cylinder 2 housing the float valve body 3 and the floating valve body 4, and after it is taken out from the opening 6, the unit 61 and the guide cylinder are It has a structure that has a holding force that allows it to be easily removed from the body 2.

Specifically, in FIG. 1, the temporary connecting parts 62 and 63 are uneven parts that can be connected while centering with a press-fit structure provided on the lower inner periphery of the fixed cylinder 64 of the unit 61 and the upper outer periphery of the guide cylinder 2. These parts can be attached and detached by fitting these temporary connecting parts 62 and 63 together. In this embodiment, a convex portion 14 is formed in the upper portion by a plurality of notches 13 arranged at the upper portion of the guide cylinder 2 as the uneven portion constituting the temporary connecting portions 62 and 63. Thereby, the unit 61 can be easily engaged and detached by utilizing the elasticity of the plurality of convex portions 14.

In FIG. 2, a perspective view of the float valve body 3 and the floating valve body 4 shown in FIG. 1 is shown. As shown in the separated perspective view of FIG. 2(a), both the float valve body 3 and the floating valve body 4 are provided in a short cylindrical and flat shape, and as shown in the stacked state of FIG. A floating valve body 4 is disposed inside the cylinder body 2 above the float valve body 3 and is removably provided.

A small air hole 37 passing vertically is formed at an eccentric position of the floating valve body 4, and air can move through the small air hole 37 having the eccentric structure. A seal ring 38 is attached to the upper surface of the floating valve body 4 and is capable of contacting and sealing the lower end surface of the unit 61 when the floating valve body 4 floats up. The floating valve body 3 and the floating valve body 4 receive buoyancy according to the water level in the valve box 1 and are guided by the guide cylinder body 2 so that they can move up and down smoothly. is discharged outside the air valve.

1 and 3, the freeze damage prevention unit 61 of the present invention has a large air hole 12 and an expansion absorption chamber 65, and includes a piston 66 having the large air hole 12 and an upper outer periphery of the piston 66. A spring (disc spring 68) is housed in an expansion absorption chamber 65 surrounded by a provided piston case 67, and a fixing means 11 is provided on the lower outer periphery of the fixed cylinder 64 of the piston case 67 to be attached to the opening 6. It consists of

In FIGS. 1 and 3, the piston case 67 is formed by concentrically joining a substantially cylindrical cover body 69 and a fixed cylinder 64. The female screw portion and the male screw portion provided on the outer peripheral surface of the upper end portion of the fixed cylinder 64 are screwed together. The cover body 69 has a hole 70 opened at the center of the upper surface side, into which the upper end of the piston 66 can be slidably fitted. An O-ring 71 is provided at the sliding portion. An expansion/absorption chamber 65 is secured on the inner periphery of the cover body 69 and is surrounded and formed between the outer periphery of the piston 66 and a disk is installed in the expansion/absorption chamber 65 as a spring that elastically biases the piston 66. A spring 68 is housed so as to surround the outer periphery of the piston 66, and one end of the disc spring 68 springs against the receiving portion 72 of the cover body 69.

In FIGS. 1 and 3, the fixed cylinder 64 is formed into a substantially cylindrical shape, and has an engaging portion on the upper inner circumferential step surface on the side to be joined with the cover body 69, which locks the elastic movement of the piston 66. 73 is formed, and the inner circumferential surface of the lower side having a substantially circular cross section can be slidably fitted to the outer circumferential surface of the cylindrical portion 74 of the substantially cylindrical piston 66. Furthermore, an arm engaging piece 50 that engages with a mounting groove 52 of the valve box 1 is formed on the lower outer periphery of the fixed cylinder 64, and constitutes a fixing means 11 to be described later. Furthermore, the above-mentioned temporary connection part 62 is provided at the lower end, and can be connected to the guide cylinder 2.

1 and 3, the piston 66 has a substantially cylindrical shape with a large air hole 12 of a predetermined diameter penetrating straight through the inside thereof, and is fitted concentrically into the piston case 67 in the unit 61. A flange-like receiving portion 75 is formed on a part of the outer circumferential surface of the piston 66 to receive the other end of the spring of the disc spring 68. It is possible to engage with the joint portion 73. Furthermore, an O-ring 76 is provided in a part of the outer circumferential surface of the cylindrical portion 74 in an annular mounting groove, which serves as a sealing member when fitting and sliding on the inner circumferential surface of the fixed cylinder 64.

1 and 3, when the piston 66 is fixed to the air valve as the unit 61, the lower end surface 77 of the piston 66 can serve as a valve seat surface of the large air hole 12 on which the floating valve body 4 can be seated closely. As shown in FIG. It becomes a receiving surface that comes into contact and absorbs movement. In this way, in the unit 61, the expansion/absorption chamber 65 secured inside the cover body 69 is a space surrounded by the upper outer periphery of the piston 66 on the inside and the inner periphery of the cover body 69 on the outside. , a disc spring 68 is housed so as to surround the piston 66.

The guide cylinder 2 is not directly fixed to the unit 61 using bolts or the like, but the guide cylinder 2 is removable from the valve body 1 together with the float valve body 3 and the floating valve body 4 when removed. There is. At that time, if necessary, the guide cylinder 2 housing the unit 61, the float valve body 3, and the floating valve body 4 is taken out from the opening 6, and the large air hole 12 is inserted into the taken out opening 6. It becomes possible to fix the unit 61 that has.

In FIGS. 1 and 4, the fixing means 11 of this example has a locking part 50 protruding from the outer periphery of a fixing tube 64 provided on the lower outer periphery of the piston 66, and this locking part 50 is installed in the opening 6. It is locked in the groove 52, and is locked and fixed by the locking portion 50 and a stopper 54 protruding in the centripetal direction of the opening 6.

1 and 4, this fixing means 11 includes a stepped portion 25 provided on the valve body 1, an arm engaging piece 50 as a locking portion provided on the lower outer periphery of the fixed cylinder 64, and an inner periphery of the opening 6. It has a mounting groove 52 formed toward the side, a stopper 53, and a lock pin device (stopper) 54, by which a fixed cylinder 64 is removably installed in the valve box 1. The arm engaging pieces 50 are formed to protrude from the lower side surface of the fixed cylinder 64 at equal intervals, and are provided so as to be able to come into contact with the stepped portion 25 .

In FIG. 4, the stopper 53 is formed to protrude from the lower surface side of the fixed lid 7 so that it can be fitted into the mounting groove 52 when the fixed lid 7 is covered with the upper surface 1a of the valve box 1, as will be described later. In this example, three locations are provided at intervals of 120 degrees in the circumferential direction to match the arm engagement pieces 50. A steeply sloped surface 53a facing the circumferential direction and a gently sloped surface 53b facing inward are formed on the side surface of the stopper 53 so as to match the shape of the arm engaging piece 50. The outer circumferential surface of the mounting groove 52 matches the shape of the inner circumferential surface of the mounting groove 52 .

Although not shown in the drawings, since one stopper 53 is actually sufficient, a fixed lid may be used in which the stopper 53 shown in FIG. 4 is formed at only one of the three locations.

On the other hand, the arm engaging piece 50 is formed with different inclination angles on the front and rear sides, with a gently inclined surface 50b formed on one side and a steeply inclined surface 50a formed on the other side. These different inclination angles make it possible to rotate the fixed cylinder 64 while moving the pin of the lock pin device 54 in the retracting direction on the gently sloped surface 50b, while on the steeply sloped surface 50a, the lock pin device When the pin 54 completely protrudes in the centripetal direction of the opening 6 and the two engage, the fixed cylinder 64 becomes unable to rotate. Note that FIG. 4 shows a state in which the gently inclined surface 50b of the arm engaging piece 50 is close to and opposed to the gently inclined surface 53b of the stopper 53, and the rotation of the arm engaging piece 50, which will be described later, is , it will be locked in such a state.

In FIGS. 1 and 4, the lock pin device 54 is attached to the valve box 1, and is provided so that it can be engaged with the fixed cylinder 64 by the biasing force of a spring (not shown), so that the fixed cylinder 64 can be mounted in a predetermined position. The lock pin device 54 is grasped with fingers and pulled outward to release the lock from the fixed cylinder 64, and by rotating the fixed cylinder 64 in this state, the unit 61 can be attached and detached from the valve box 1. There is.

The fixed lid 7 shown in FIG. 4 is attached to the upper surface 1a of the valve box 1 so that the fixed cylinder 64 can be positioned and fixed. A hole 55 is formed in the center of the fixed lid 7, and a fixed cylinder 64 can be inserted into this hole 55. A through hole 56 is formed in the fixed lid 7 at a position corresponding to the female thread 29. A notch-shaped mounting groove 52 through which the arm engagement piece 50 passes is formed on the inner circumferential side of a part of the hole 55, and a stopper 53 that protrudes downward is formed following the mounting groove 52. The stopper 53 sets the rotation range of the fixed cylinder 64.

The fixed lid 7 is placed on the upper surface 1a of the valve box, and the bolt member 27 is fixed to the valve box 1 by screwing the screw 28 into the female thread 29 from the through hole 56. In this case, since the female thread 29 is centered, the fixed lid 7 is fixed in a state where misalignment is prevented.

Further, as shown in FIG. 1, a flange piece 78 is attached to the lower end of the cover 60 that surrounds the upper side of the valve case 1, and a mounting piece 79 provided on the valve case 1 is attached via bolts 80 to allow the cover 60 to be attached and detached. It is attached to. The cover 60 is made of metal such as stainless steel, and is formed to bulge upward so that it can surround the upper part of the valve box 1, and communicates the large air hole 12 of the unit 61 with the atmosphere. It is removably provided on the upper part of the unit 61 or the upper part of the valve box 1 so as to cover the state.

In FIG. 1, a flange piece 78 is provided on the outer periphery of the lower end of the cover 60 at a position where the lock pin device 54 can be hidden, and by fixing this flange piece 78 to a mounting piece 79 of the bracket 81, It can be attached at the upper outer circumferential position of the valve box 1. The bracket 81 is formed of a thin plate into a substantially annular shape and can be installed on the upper surface of the fixed lid 7, and has mounting pieces 79 bent downward and having a substantially L-shaped cross section formed at two locations on its outer periphery. . Furthermore, the flange piece 78 of the cover 60 has the function of covering and protecting an opening/closing cock that communicates with the inside of the valve box 1 (not shown) by covering the side surface of the valve box 1 from above.

In FIG. 1, the bracket 81 is disposed on the fixed lid 7 at the upper part of the valve box 1, and is positioned and fixed to the valve box 1 together with the fixed lid 7 by bolt members 27. In this state, the flange piece 78 is placed on the mounting piece 79 to position the cover 60 on the upper part of the valve box 1, and the flange piece 78 and the tip side of the attachment piece 79 are screwed together with bolts 80. Thereby, the cover 60 is fixed to the outer peripheral side of the valve box 1 via the bracket 81, and the upper side of the valve box 1 can be covered with the cover body 60. Although not shown, the collar piece 78 is formed with a screw hole into which the head of the bolt 80 can be inserted and removed. A guide hole in the shape of a thin elongated hole is formed.

In this case, when attaching and detaching the cover 60 to and from the valve box 1 using the bracket 81, it can be attached only to the outer peripheral side of the valve box 1, and there is no need to handle the upper surface side of the cover 60. On the other hand, although not shown, it is also possible to fix the cover 60 to the valve box 1 using bolts or the like in the upper surface area, but in such a case, a support member for supporting the upper surface of the cover on the upper surface side of the valve case 1 is unavoidable. Therefore, the air valve structure becomes complicated accordingly, and in the second embodiment described below, there is a risk that problems may occur when connecting or disconnecting a fire hose, etc. to the cap 84 after removing the cover 60. . For example, when connecting a female fire hose (not shown) to the male Machino type cap 84, the female socket is large on the outside diameter side, so if a support member is provided, it may interfere with the socket. Otherwise, you may not be able to connect. On the other hand, in the case of the attachment/detachment structure of the cover 60 using the bracket 81 of this example, such interference can be avoided. Furthermore, it is possible to prevent the bolts provided on the top side from being removed by mistake.

Furthermore, since there is no need to provide a support section between the upper part of the cover 60 and the upper part of the member (unit 61) covered by this, the distance between them can be kept to a minimum, and therefore the length of the cover 60 can be kept to a minimum. Alternatively, this cover 60 can suppress the height of the air valve under the cover. Furthermore, by fixing the collar piece 78 at a position where the lock pin device 54 is hidden, weather resistance can be improved even when the lock pin device 54 is made of resin.

Further, although not shown, an opening/closing cock communicating with the inside may be provided on the side surface of the valve box 1. The cock is provided to release residual pressure when the air valve is disassembled.

Further, a repair valve (not shown) may be attached to the lower part of the valve box 1 of the air valve to perform the water flow function. In this case, the repair valve may be any commonly used one, for example, a ball valve, which can be opened and closed by rotating the stem of the ball valve through 90 degrees. The ball valve is attached to the flange 31 with mounting bolts, for example, but the ball valve may be attached to a portion other than the flange. When using a ball valve, it is desirable that the diameter of the ball be approximately the same as the diameter of the internal flow path of the air valve.

Furthermore, as shown in FIGS. 1 and 4, in this example, the unit 61 and the float valve body 3 are attached to the valve box 1 to which the fixed lid 7 is fixed via the fixing means 11 by rotating the unit 61. Although the guide cylinder 2 housing the floating valve body 4 is detachable, the guide cylinder 2 and the like may be housed using other attachment/detachment structures (fixing means) of the unit 61.

For example, although not shown, an integrated unit (fixed cylinder) having a concave engagement groove, and a valve box having a rotatable lever having an engagement part and an operating part that can be engaged with the engagement groove. Then, with the fixed cylinder temporarily attached to the valve box, rotate the lever to press the engagement part into the engagement groove, or rotate the lever from this state to press the engagement part into the engagement groove. By separating from the valve body, the unit in which the guide body containing the float valve element and the floating valve element is temporarily attached can be attached to and detached from the valve box. This lever-based attachment/detachment structure between the engagement part and the engagement groove allows them to be attached and detached with one touch, and if a gasket or O-ring is installed between the unit and the guide, this gasket Alternatively, the O-ring and the like can also be attached and detached together with the fixed tube and the like. Furthermore, in this case as well, the cap and the unit can be provided integrally as described above.

Furthermore, the freeze damage prevention unit 61 of the present invention can also be used for air valves that do not have the fixing means 11 (installation groove 52) as described above. By simply providing a fixing means, it is possible to easily make the air valve anti-freeze damage type. That is, by providing mutually removable fixing means (engaging, fitting, crimping, screwing, etc.), either integrally or separately, on the opening on the valve box side and the lower part of the unit on the unit side. , it becomes possible to provide the freeze damage prevention unit 61 of the present invention with the function of a large air hole.

The above-mentioned air valve is installed in the water main pipe line and discharges the air contained in the tap water, but the target fluid may be a liquid other than tap water, and the excess air contained in this liquid may be discharged. Air can also be exhausted. This air valve is suitable, for example, for pipe washing, pressure measurement, temporary water supply, etc.

Next, the structure of a second embodiment of the air valve of the present invention will be described. FIG. 5 is a longitudinal cross-sectional view of the freeze damage prevention unit 85 applied to this second embodiment, and FIG. 6 is a longitudinal sectional view of the freeze damage prevention unit 85 applied to this second embodiment, and FIG. FIG. 3 is a vertical cross-sectional view showing an example of a raised state.

In this example, the structure of the freeze damage prevention unit 85 is different from the first embodiment. By installing the communicating cap 84, the air valve of this example is designed to prevent damage due to freezing due to the integrated cap. Although not shown in FIG. 6, when the piston 90 is elastically biased by the disk spring 87 and is locked in the engaging portion 95, the guide cylinder 2 is moved into the storage chamber 21, as in FIG. It will be housed in the same position as in Figure 1. The same parts as in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

5 and 6, similarly to the structure of the unit 61 described above, the freeze damage prevention unit 85 of this example also has a piston case 86 that includes a substantially cylindrical cover body 86a and a fixed cylinder 88 concentrically joined. However, in this example, a male threaded portion provided on the outer circumferential surface of the cover body 86a and a female threaded portion provided on the upper inner circumferential surface of the fixed cylinder 88 are screwed together. The cover body 86a has a hole 89 opened at the center, into which the upper end of the piston 90 can be slidably fitted. An O-ring 91 is provided at the sliding portion. An expansion absorption chamber 92 is secured on the inner periphery of the cover body 86a, and is surrounded by and formed between the outer periphery of the piston 90, and a disk is installed in the expansion absorption chamber 92 as a spring that elastically biases the piston 90. A spring 87 is housed so as to surround the outer periphery of the piston 90, and one end of the disc spring 87 springs against the receiving portion 93 of the cover body 86a.

5 and 6, a mounting portion 82 to which a base 84 is attached is formed on the cover body 86a of this example. The mounting portion 82 is formed in an annular shape to protrude upward from the cover body 86a, and surrounds the hole 89 concentrically. The lower outer circumferential side of the cap 84 is joined by screwing or fitting. The inner diameter of the mounting portion 82 is provided to match the diameter of this cap 84.

In FIGS. 5 and 6, the fixed cylinder 88 is formed into a substantially cylindrical shape, and has an engaging portion on the inner circumferential step on the upper side, which is the joint side with the cover body 86a, for locking the elastic movement of the piston 90. 95 is formed in an annular shape, and the inner circumferential surface of the lower side having a substantially circular cross section can be slidably fitted to the outer circumferential surface of the cylindrical portion 96 of the substantially cylindrical piston 90. Further, as in the first embodiment described above, on the lower outer periphery of the fixed cylinder 88, an arm engaging piece 97 (in FIG. 4, a steeply inclined surface 97a, a gently inclined surface 97a, a gently inclined surface A surface 97b is shown) forming the fixing means 11. Furthermore, the above-mentioned temporary connection part 98 is provided at the lower end, and can be connected to the guide cylinder 2.

5 and 6, the piston 90 has a substantially cylindrical shape with a large air hole 83 of a predetermined diameter penetrating straight through the inside thereof, and is fitted concentrically into the piston case 86 in the unit 85. A receiving portion 99 for receiving the other resilient end of the disc spring 87 is protruded in a part of the outer circumferential surface of the piston 90 in an annular shape. It is possible to engage with the joint portion 95. Further, an O-ring 100 is provided on a part of the outer circumferential surface of the cylindrical portion 96 and serves as a sealing member when the fixed tube 88 fits and slides on the inner circumferential surface of the fixed cylinder 88 .

5 and 6, when the piston 90 is fixed to the air valve as the unit 85, the lower end surface 101 of the piston 90 can serve as the valve seat surface of the large air hole 83 on which the floating valve body 4 can be seated closely. It is formed as an annular flat surface with a predetermined wall thickness, and comes into contact with the floating valve body 4, etc., which rises due to the volumetric expansion of water in the storage chamber 21 and the accompanying expansion of the water in the storage chamber 21, in the freeze damage prevention function described later. It becomes a receiving surface that absorbs movement. In this way, in the unit 85, the expansion/absorption chamber 92 secured inside the cover body 86a is a space surrounded by the upper outer periphery of the piston 90 on the inside and the inner periphery of the cover body 86a on the outside. , a disc spring 87 is housed so as to surround the piston 90.

On the other hand, a large air hole 83 is formed penetrating through the center of the base of the cap 84, and is provided so that fluid such as air can be sucked and discharged into the valve box 1 through the large air hole 83. The cap 84 belongs to, for example, a coupling fitting for a fire hose (not shown), and if it is the Machino type cap described above, it is constructed using a fitting 102 and a push ring 103, as shown in FIGS. 5 and 6.

These fittings 102 and push ring 103 are both made of metal such as stainless steel, for example. The push ring 103 is vertically movably mounted in an outer circumferential groove 104 formed between the outer periphery of the insert 102 and the attachment portion 82 into which the insert 102 is screwed. The upper end of the attachment portion 82 constituting the outer circumferential groove 104 has a function of retaining the position of the push ring 103, which corresponds to a retaining ring that determines the downward position of the push ring 103. An operation space for the push ring 103 is formed between the push ring 103 held at the upper end of the mounting portion 82 and the fixed lid 7. When removing the fire hose from the cap 84, the operator can remove the hose by putting his hand into the operation space and pushing up the push ring 103.

In FIGS. 5 and 6, the cap 84 does not necessarily need to be provided separately from the attachment portion 82, and may be provided integrally with it. In this case, in addition to integrally molding the cap and the mounting portion, for example, the mounting portion and the cap may be provided so that they can be assembled by screwing or fitting, and the O-ring 94 may be installed or not installed between them. In the omitted state, these can be sealed with adhesive. Further, the inner diameter of the insert 102 is larger than the outer diameter of the piston 90 in order to enable the upper end of the piston 90 to protrude from the hole 89 in the antifreeze function described later.

Next, the operation and assembly/disassembly operation of the air valve according to the first embodiment of the present invention will be explained. The air valve of this example has a guide cylinder body 2 housing a float valve body 3 and a floating valve body 4 in a valve body 1, and a large air hole 12 in an upper opening 6 of the valve body 1. The unit 61 for preventing freeze damage is permanently fixed via an appropriate fixing means 11, and the guide cylinder 2 housing the unit 61, the float valve body 3, and the floating valve body 4 is fixed as necessary. Since the unit 61 is taken out from the opening 6 of the box 1 and has a large air hole 12 fixed to the opening 6, it is possible to prevent the valve box 1 from increasing in size and the internal structure from becoming complicated. Without increasing the number of parts, it is possible to maintain the performance of an easily disassembled type while maintaining the air valve function as a freeze damage prevention type.

When removing the float valve body 3, floating valve body 4, and guide cylinder body 2 from the air valve of this example, first, the flow path from the flow channel to the air valve is shut off. At this time, since there is residual pressure inside the air valve, the unit 61 is pushed up and comes into close contact with the bottom side of the fixed lid 7, and rotation is prevented. If a cock (not shown) provided in the valve box 1 is opened from this state, the residual pressure inside the air valve is released, and the pushing force on the unit 61 is released, allowing it to be disassembled.

Next, the cover 60 is removed from the valve box 1. In this case, after loosening the bolt 80, which is a hexagonal screw, using a screwdriver or the like, rotate the cover 60 along the guide hole so that the bolt hole is aligned with the head of the bolt 80. 60 can be removed by pulling it upward.

When removing the freeze damage prevention unit 61, the fixing tube 64 (unit 61) is rotated by a predetermined angle in the removal direction while grasping and pulling the lock pin 54 to release the lock from the steeply sloped surface 50a. In this case, since the arm engaging piece 50 is supported by the thrust ring 26 while in contact with the stepped portion 25, rotation becomes smooth. When the steeply inclined surface 50a of the arm engaging piece 50 comes into contact with the steeply inclined surface 53a of the stopper 53 of the fixed lid 7, the fixed cylinder 64 (unit 61) can be pulled up.

At this time, the unit 61 and the guide cylinder 2 are connected and held through the temporary connecting parts 62 and 63, and when the unit 61 is taken out from the opening 6 at the time of separation, the float valve body 3 and the floating valve body 4 are connected together with the unit 61. Since the guide cylinder body 2 containing the can be pulled up and taken out, there is no need to separately remove the unit 61, the guide cylinder body 2, the float valve body 3, and the floating valve body 4 from the valve box 1, and the procedure is simple. These can be removed together. In this state, it is sufficient to remove dust from each part and perform cleaning and inspection. There is no need to remove the fixed lid 7 during this cleaning and inspection.

FIG. 7 shows that the air valve of this example is disassembled as described above, and the guide cylinder body 2 housing the cover 60, freeze damage prevention unit 61, and the float valve body 3 and floating valve body 4 is removed from the valve. FIG. 2 is an exploded cross-sectional view showing a state separated from the box 1; As shown in the figure, in the air valve of the present invention, the freeze damage prevention unit has a function as a lid member of the valve box with large air holes, so that the minimum amount necessary for maintenance of the float member, etc. This is a simple disassembly type air valve that allows efficient replacement of limited components.

On the other hand, when attaching the unit 61 to the valve box 1, the float valve body 3 and the floating valve body 4 are first housed in the guide cylinder 2, and the guide cylinder 2 is fitted into the fixed cylinder 64. Link. At this time, the temporary connecting parts 62 and 63 connect the lower inner periphery or lower outer periphery of the fixed cylinder 64 and the upper outer periphery or upper inner periphery of the guide cylinder 2 by a press-fit structure that can be attached and detached with one touch. It is easy to attach and detach, the wobbling between them is suppressed, and the guide cylinder 2 is attached to the fixed cylinder in a stable state, so the wobbling of the floating valve body 4 and the float valve body 3 is also relatively suppressed. Operation becomes stable.

Next, the unit 61 is placed over the valve box 1, and the fixed cylinder 64 is inserted while aligning the steeply inclined surface 50a of the arm engaging piece 50 and the mounting groove 52 (steeply inclined surface 53a of the fixed lid 7), and the stopper The fixed cylinder 64 (unit 61) is rotated by a predetermined angle in a direction in which the arm engaging piece 50 is engaged with the arm engaging piece 53. By this rotation, the arm engaging piece 50 (locking portion) becomes locked in the mounting groove 52, and the lock pin 54 is automatically moved in the retracting direction by the gently inclined surface 50b of the arm engaging piece 50. When the fixed cylinder 64 (unit 61) reaches the set position, the steeply inclined surface 50a reaches the position of the lock pin 54, and the lock pin 54 protrudes by the biasing force of the spring and engages with the steeply inclined surface 50a. . At this time, since the gently inclined surface 50b collides with the gently inclined surface 53b of the stopper 53, the arm engaging piece 50 is sandwiched from both sides and held fixed.

In addition, in the case of a separate structure that does not have the temporary connecting parts 62 and 63, the float valve body 3 and the floating valve body 4 are housed in the guide cylinder 2 before fixing the unit to the valve box, and the guide The cylindrical body 2 may be inserted through the opening 6 and then stored in the storage chamber 21.

This makes it possible to form the unit 61 so as to greatly expand the diameter of the large air hole 12. For example, it is possible to form the unit 61 so as to greatly expand the diameter of the large air hole 12. Compared to the case where the entrance side of the air hole 12 is 42 mm in diameter, when the temporary connecting parts 62 and 63 have a press-fit structure, the entrance side of the large air hole 12 can be provided while expanding the diameter to about 44 mm. As a result, the pressure loss can be reduced by making the inflow part gentle, thereby increasing the fluid discharge efficiency.

Furthermore, since the press-fit structure can be set to approximately the same height as the circumferential seal portion of the U packing 24, there is no need to shift the temporary coupling portions 62, 63 from the circumferential seal position. It is possible to suppress the dimension from increasing in the height direction by the amount of . Therefore, the valve box 1 can be formed low while maintaining the same height of the guide cylinder 2, and the entire air valve can be made more compact.

As a result, the guide cylinder body 2 housing the float valve body 3 and the floating valve body 4 together with the unit 61 is attached to a predetermined position of the valve box 1. When the arm engaging piece 50 engages with the stopper 53, the base of the fixed cylinder 64 is fitted into the fitting part 22, and the unit 61 is prevented from coming off in the valve box 1. After the unit 61 is attached, the U packing 24 is attached to the outer periphery of the base of the fixed cylinder 64, thereby preventing leakage between the valve box 1 and the unit 61. The unit 61 is attached to and detached from the fixed lid 7 by rotating within a range of 60 degrees, for example.

Furthermore, since the air valve of the present invention has a unitized freeze damage prevention function, it can be easily disassembled without impairing the ease of disassembly compared to existing easy disassembly type air valves as shown in Patent Documents 1 and 2, for example. It is also possible to very easily provide the air valve with a freeze-damage protection function. Although not shown, in the case where the valve box of an existing air valve is covered from above by a lid body having a structure different from the unit of the present invention via the above-mentioned fixing means, the lid body When attempting to install the unit 61 of the present invention after removing the valve body from the valve box and taking out the float body etc. inside the valve box, the unit 61 will be in the state shown in FIG. The air valve can be provided with a freeze damage prevention function simply by fixing it to the air valve via the fixing means 11.

When used as an air valve, first, as shown in FIG. 1, when there is no water in the valve body 1, the float valve body 3 and the floating valve body 4 descend to a state in which the large air hole 12 is opened, and from this state, the valve body 1 rapidly closes. Exhaust and rapid intake operations are performed. In this case, both the float valve body 3 and the floating valve body 4 have a short cylindrical shape and a flat shape, so that the contact resistance against the inner periphery of the guide cylinder body 2 is reduced, so that they fall reliably.

Rapid exhaust is an operation when a large amount of air in the pipe is rapidly exhausted through the large air hole 12 when the pipe of a water main (not shown) is filled with water. During rapid exhaust, both the floating valve body 4 and the float valve body 3 are located below the guide cylinder body 2 without floating up, so the large air hole 12 is fully opened and the air in the pipe is pumped through the air valve. Efficiently discharged to the outside.

Rapid intake is an operation in which a large amount of air is rapidly sucked into the pipe through the air valve when water in the pipe is discharged. During rapid intake, the floating valve body 4 and the float valve body 3 are in a lowered state. In this case, the large air hole 12 is opened, and air is efficiently taken in through the large air hole 12 to quickly drain the inside of the pipe. At this time, water accumulated in the guide cylinder 2 is also drained from the hole 36. During this rapid intake, the float valve body 3, the floating valve body 4, and the guide cylinder body 2 do not rise. These rapid exhausts and suctions allow operations such as initial water supply to the water mains and drainage from the water mains to be carried out in a short time.

When the air valve is completely filled with water, the pipe line is full of water, and the valve box 1 is filled with water, the float valve body 3 and the floating valve body 4 rise due to buoyancy, and the floating valve The seal ring 38 of the body 4 closely contacts the lower end surface of the piston 66 to close the large air hole 12, and the float valve body 3 closes the small air hole 37 of the floating valve body 4. As a result, the inside of the valve box 1 is completely shielded, and water is prevented from flowing outside.

Under this pressure during water filling, air mixed in the water main pipe gradually collects at the air valve and accumulates in the valve box 1. When this amount of air reaches a certain level, first, only the float valve body 3 descends, and the small air hole 37 of the floating valve body 4 becomes open. This is because the floating valve body 4 does not separate from the lower end surface of the piston 66 having the large air hole 12 due to the size relationship between the diameters of the large air hole 12 and the small air hole 37, and as a result, the floating valve body 3 only falls due to its own weight.

At that time, as shown in FIG. 2, since the small air hole 37 of the floating valve body 4 is arranged at an eccentric position of the float valve body 3, first, the small air hole 37 where the negative pressure is generated is opposite to the small air hole 37 where the negative pressure is generated. The float valve body 3 descends from the side, and a force in the direction of inclination is applied to the float valve body 3.Furthermore, as the float valve body 3 has a short cylindrical shape and a flat shape as described above, the contact resistance against the inner circumference of the guide cylinder 2 is reduced. Less is. For these reasons, the float valve body 3 is easily inclined with respect to the floating valve body 4, and can be reliably lowered away from the floating valve body 4. This prevents the float valve body 3 and the floating valve body 4 from adhering to each other, and allows the air inside the air valve to be smoothly discharged to the outside from the small air hole 37 of the floating valve body 4 that is opened. Furthermore, by forming the lower corner portion of the float valve body 3 in a rounded shape, the float valve body 3 is more likely to incline and descend.

When the amount of air in the valve box 1 decreases due to air discharge, the float valve body 3 rises and closes the small air hole 37 again. By repeating the above operations, the air accumulated in the main pipe is automatically discharged to the outside of the valve via the air valve.

In this case, as described above, the guide cylinder 2 is held in the fixed cylinder 64 by the temporary connecting parts 62 and 63, and is further surrounded by the guide pedestal 32, the side guides 33, and the unit 61 on the top, bottom, left, and right sides. This prevents the valve body 1 from shifting from the center. In addition, since the force is applied evenly at the upper part of the cylindrical part, for example, when compared with a guide body with a clamping flange on the upper side (not shown), bending stress is less likely to be applied, and it is more resistant to impact loads caused by water hammer etc. It has a very strong shape.

Next, the freeze damage prevention effect in this example will be explained. When water passage structures such as faucets and water passage pipes are used in cold regions or in winter, there is a problem of so-called freeze damage, and this problem has been known for air valves as well. Water has the property of expanding in volume as it freezes. For example, when it freezes outdoors at 0 degrees Celsius under 1 atmosphere, the volume expands discontinuously by about 9% before and after freezing.

In the conventional general air valve structure, when the air is stored before freezing, the floating valve body tightly closes the large air hole, and the floating valve body also floats on the water surface and closes the small air hole. Although it is tightly closed, if freezing progresses from near the water surface in this state, the float valve body will gradually become surrounded by frozen solids and will lose its float function while being restrained near the water surface. As the volume expands due to freezing, it is gradually pushed upward, and the float valve body, which was in close contact with the small air hole, immediately pushes up the floating valve body. Inside the valve box, the only escape area for this volume expansion due to freezing is the air pocket space, so regardless of the progress of freezing, the float valve body is pushed up according to the amount of freezing, and this Along with this, the floating valve body is also pushed up, and the internal pressure of the air pocket may also increase. Alternatively, the ice block itself in the valve box may hit and press the floating valve element or the inner wall as the ice cube expands in volume, or push up the lid or the guide member and press the floating valve element or the inner wall.

However, the pushing up force at this time, that is, the volumetric expansion pressure, is so strong that it is used, for example, in concrete crushing technology.For example, the volumetric expansion pressure from about 10 degrees to about -0.5 degrees is about 24.1 Mpa ( It is known that the pressure increases to a maximum of about 209 MPa at -22.3 degrees. Therefore, in the conventional air valve structure, where there is virtually no deformation allowance (expansion absorption allowance) for the deformation pressure of the internal structure, even a slight deformation (expansion) causes an extremely strong There is a risk of stress acting on it and causing destruction (freeze damage). In contrast, the freeze damage prevention unit of the present invention has the function of absorbing the deformation and load-induced movement within the valve box caused by such expansion to prevent damage to the air valve. Because it is a standardized ASSY, the air valve's anti-freeze damage prevention function can be easily handled independently at any time for replacement, maintenance, etc.

In the air valve of this example, under normal usage conditions in which air is stored, that is, in a stable state for a long period of time where the water inside the valve box 1 may freeze, when the water freezes, the structure inside the valve box 1 changes accordingly. The lifting movement of the parts and the increase in the internal pressure of the air pocket occur, and as a result, an upward force is applied to the lower end surface 77 of the floating valve body 4 and the piston 66 that are in close contact with the large air hole 12. It turns out.

On the other hand, the lower end surface 77 of the unit 61 receives such a pushing up force, and thereby a rising force acts on the piston 66. Since the piston 66 is in a state of being resiliently pushed into the storage chamber 21 by the disc spring 68 while being locked by the engaging portion 73, this upward force is caused by the biasing force of the disc spring 68 and the own weight of the piston 66. When the force exceeds this and reaches a force that causes the piston 66 to slide upward, the piston 66 slides upward while compressing the disc spring 68, and this causes the upward force acting on the floating valve body 4 to be released into the storage chamber. Movement of components and internal pressure within the storage chamber 21 are absorbed, and freezing damage to the components within the storage chamber 21 and the valve box 1 can be prevented. The elastic force of the disc spring 68 and the stroke of the piston 66 act as deformation margins as described above, thereby ensuring sufficient characteristics to prevent freeze damage of the air valve.

Next, the operation and assembly/disassembly operation of the air valve according to the second embodiment of the present invention will be explained. In the air valve of this example, the freeze damage prevention unit 85 can be attached and removed, or the lid body and freeze damage prevention unit can be replaced with the existing simple disassembly type air valve that is covered with a lid body of a different structure. The associated disassembly/assembly operations of the air valve, rapid intake/exhaust, function as an air valve, and freeze damage prevention function are the same as in the first embodiment described above.

Note that FIG. 6 shows an example of the freeze damage prevention effect of the present invention. For example, the float valve body 3 may be moved approximately parallel to the floating valve body 4 due to the action of ice blocks (not shown) or internal pressure in the storage chamber 21. In this posture, the small air hole 37 is tightly closed, and the seal ring 38 of the floating valve body 4 is also tightly attached to the lower end surface 101 of the piston 90, closing the large air hole 83, and these also close the piston 90 near the top dead center. It shows the state where it has been pushed up. In this state, the receiving part 99 of the piston 90 is separated from the engaging part 95 of the cover body 86a, and the disc spring 87 is compressed. It protrudes from the hole 89 by the amount of rise and is accommodated in the inner peripheral side of the cap 84. When the outer circumferential surface of the piston 90 slides at this time, an O-ring 91 is provided between the inner circumference of the hole 89 and an O-ring 100 is provided between the inner circumferential surface of the fixed cylinder 88 and the lower inner circumferential surface of the fixed cylinder 88 . As described above, such a piston raising action is the same in the unit 61 of the first embodiment shown in FIGS. 1 and 3.

As shown in FIG. 6, when the piston 90 moves up and down, the length of the cylindrical part 96 that is guided by the inner peripheral surface of the fixed cylinder 88 is the maximum stroke of the up and down movement (the length of the engaging part 95 in the figure). Since the piston 90 has a sufficient length with respect to the distance from the receiving portion 99), the piston 90 can move smoothly when moving up and down, and a reliable effect of preventing freeze damage can be obtained. This also applies to the cylindrical portion 74 of the piston 66 in the first embodiment shown in FIGS. 1 and 3.

5 and 6, in addition to the functions and operations described above, in this example, a cap 84 is further used to construct an air valve that can also be used as a cap, as described below.

When the air valve of this example is used for pipe washing or as a temporary fire hydrant through the mouthpiece 84, it is placed in the valve box 1 from which the float valve body 3, the floating valve body 4, and the guide cylinder body 2 have been extracted in advance. A freeze damage prevention unit 85 having a cap 84 is attached. In this case, the fixed cylinder 88 is inserted from above the valve box 1, and while aligning the arm engagement piece 97 and the mounting groove 52, the fixed cylinder 88 is inserted and rotated by a predetermined angle. Due to this rotation, the lock pin 54 is automatically moved in the retracting direction by the gently inclined surface 97b of the arm engaging piece 97. When the fixed cylinder 88 reaches the set position, the steeply inclined surface 97a reaches the position of the lock pin 54, and the lock pin 54 protrudes by the biasing force of the spring and engages with the steeply inclined surface 97a. At this time, since the gently inclined surface 97b collides with the gently inclined surface 53b of the stopper 53, the arm engaging piece 97 is sandwiched from both sides and fixedly held.

By attaching the unit 85 having the cap 84 to the valve box 1 in this way, the large air hole 83 of the unit 85 can perform the water flow function without requiring a new cap separate from this unit 85. . Therefore, there is no need to carry separate parts to the installation location of the air valve, and you can easily switch between an air valve and a fire hydrant by attaching and detaching the float valve body 3, floating valve body 4, and guide cylinder body 2 to the valve box 1. It can be used as At this time, compared to a fire hydrant with a general globe-shaped valve structure, which has a large pressure loss, the air valve of this embodiment has a straight flow path, which makes it easier to use when used as a fire hydrant. Pressure loss can be reduced.

A hose or the like can be connected to the base 84 of the unit 85, and the inside of the pipe can be washed through the hose or used as a temporary fire hydrant. Furthermore, it can be used for various purposes such as measuring water pressure in pipes. When the unit 85 is attached and used as a fire hydrant, the cap 84 can ensure a flow rate equivalent to, for example, a fire hydrant according to Japan Water Works Association standard JWWA B 103 (underground fire hydrant for water supply).

Furthermore, when a ball valve is provided on the flange 31 as a repair valve, it is possible to provide a valve suitable for pipe washing or a temporary fire hydrant while ensuring a flow path by opening and closing the repair valve. At this time, by providing the guide pedestal 32 at the lower part of the valve box 1, the jet flow flowing through the repair valve hits the guide pedestal 32 and is prevented from directly jetting out of the valve.

In the above embodiment, an example of an air valve in which the flange 31 is integrally provided at the lower part of the air valve has been described, but an air valve in which a ball valve for opening and closing a flow path is integrally provided at the lower part of the air valve is also described. It may also be an air valve called a so-called air valve with a ball valve, and in this case also the same function as above can be achieved.

Furthermore, the present invention is not limited to the description of the embodiments described above, including the materials, etc., and various changes can be made without departing from the gist of the invention as set forth in the claims of the present invention. It is something.

1 Valve box 2 Guide cylinder 3 Float valve body 4 Floating valve body 6 Opening 11 Fixing means 12 83 Large air hole 20 Inflow port 37 Small air hole 50 97 Arm engaging piece (locking part)
52 Mounting groove 54 Lock pin device (stop)
60 Cover 61 85 Freeze damage prevention unit 64 88 Fixed tube 65 92 Expansion absorption chamber 66 90 Piston 67 86 Piston case 68 87 Belleville spring
78 Flange piece 79 Mounting piece 80 Bolt 82 Mounting part 84 Base

Claims (1)

an inlet provided at the bottom of the valve box, a float valve body housed inside a guide cylinder disposed in the valve box, and a floating valve body having a small air hole above the float valve body; A freeze damage prevention unit is removably attached to an opening provided in the upper part of the valve box via a fixing means, and the freeze damage prevention unit is connected to a cover body connected to a cylindrical fixed tube and the center of the cover body. a cylindrical part having a hole opened at a certain position, a large air hole provided at the top of a piston for resiliently biasing the spring, and a cylindrical part having the spring housed between the outer peripheral surface of the cylindrical part and the fixed cylinder. It is characterized by being integrated into a unit with an expansion absorption chamber, a receiving part for urging the upper part of the spring toward the cover body, and a base communicating with a cylindrical part provided at the upper part of the cover body. Freeze damage prevention type air valve.

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