JP7164321B2 - air valve - Google Patents

Description

The present invention relates to an air valve, and in particular, an air valve that can easily be both a freeze damage prevention type and a simple disassembly type, and can also be easily used for a mouthpiece, and is used in cold regions and in winter. type rapid air valve.

In general, rapid intake/exhaust type air valves are installed at appropriate locations in pipelines such as water supply mains and water pipes, and collect air caused by air bubbles generated in the pipelines to prevent the floating and sinking action of the float inside. automatically discharges to the outside to maintain the fluid transfer capability of the piping.

The structure of this type of air valve includes a valve body, a lid body having a large air hole, a float valve body housed in the valve body, a floating valve body having a small air hole, and a guide member for guiding them. This structure can be used for rapid large-volume exhaust when filling a pipe with water, and rapid large-volume suction when draining water. In addition, in order to maintain its function, it is necessary to perform appropriate maintenance such as cleaning and inspection of dust adhering to the inside of the valve body. A structure that can be taken out for cleaning, inspection, and replacement is required. Patent Documents 1 to 3 propose such a simple disassembly type rapid air valve.

In Patent Document 1, a floating valve body having a small air hole and a float valve body are compactly housed in a guide cylinder that guides them. By simply fixing the air valve to the valve box via the fixing means, the air valve can be properly positioned and held in the valve box while being loosely fitted by the guide pedestal and the side guides, so that the air valve can be used very easily. In particular, the detachable cover can be engaged with or released from the upper part of the valve body simply by inserting the arm engaging piece formed to protrude in the radial direction into the guide portion and rotating it. The disassembly and assembly of the air valve required for maintenance is extremely easy.

In addition, Patent Document 2 discloses an air valve that integrates a mouthpiece and a detachable lid and can be used normally, and this air valve does not require a separate mouthpiece and can be used immediately as a water supply for fire hydrants, a site for washing pipes, a water pressure test, etc. It is possible. Patent document 3 also discloses a simple disassembly type air valve, but in the case of the cover body of this document, fixing means for locking by tilting two left and right cam levers is taken.

On the other hand, freeze fracture problems are also conventionally known for this type of air valve. When the air valve is used in cold regions or in winter, the water used as the fluid may freeze inside the air valve, and the water expands in volume along with this freezing. As this volumetric expansion progresses, the expansion causes movable members such as floats and frozen ice blocks housed in the valve box to rise upward and press against the floating valve body, or increase the internal pressure in the valve box. As a result, there is a risk that component parts will malfunction or be damaged, resulting in damage or failure of the air valve. Moreover, since freezing damage progresses gradually according to the outdoor environment, it is difficult to predict its occurrence. Therefore, an air valve that can reliably prevent such damage is required.

In contrast, many conventional air valves have been proposed that can deal with the problem of freeze damage by adopting a structure capable of appropriately absorbing volumetric expansion deformation due to such push-up. This type of air valve is disclosed in, for example, Patent Documents 4 to 6. For example, in FIG. 2 of Patent Document 4, a large air hole is provided in the lid body, and a piston that is elastically ejected by a disc spring is attached to the upper portion of the air valve. A lid-fixed structure is disclosed. With this structure, even if the floating valve body is pushed up or the internal pressure of the valve box rises due to the volume expansion due to freezing as described above, the movement is absorbed by the piston elastically urging it with the disc spring. Even if the volume of water expands in the valve box, it is possible to prevent the air valve from freezing damage as described above.

JP 2013-190084 A JP 2015-117827 A JP 2009-121678 A Japanese Utility Model Laid-Open No. 62-153482 Japanese Utility Model Laid-Open No. 60-35978 Japanese Utility Model Laid-Open No. 55-31072

However, first of all, there is no prior art that combines a conventional freeze damage prevention structure (Patent Documents 4 to 6) with a conventional easily disassembled air valve (Patent Documents 1 to 3). In view of the conventional freezing damage prevention structure, even if such a combination structure exists, such a structure would at least have the lid firmly and tightly fixed to the valve body with bolts or the like. Must be structure.

For example, specifically, a valve body structure in which a bolt is vertically inserted through a lid body structure in which a piston body in an elastic state is accommodated from the back side of the lid body by a disk spring (spring) between the superimposed flange portions is inserted into the valve body. A structure fixed to the upper part is conceivable. Moreover, in such a structure, the piston body is completely housed inside the valve box only after the bolt is tightened. This is because at least each of Patent Documents 4 to 6 employs such a fixing structure.

However, it is clear that such an air valve completely loses the features and advantages of the simple disassembly type described above. That is, in the air valve having such a structure, the lid must be attached and detached by fixing and removing the bolt, and at least the attachment and detachment workability of the lid is impaired. In this case, as the minimum necessary components for maintenance, the floating valve body, the float valve body, and the guide body are each housed inside the valve body in such a manner that they can be removed and assembled very easily. This is a structure that does not make use of the advantages of the conventional simple disassembly type. This is because the easy disassembly type air valve structure can only be achieved when these internal storage parts can be removed and stored extremely easily.

Therefore, in the prior art, the simple disassembly type (Patent Documents 1 to 3) may require reliable countermeasures against freezing 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, disclosure of an air valve having these performances is desired. In many cases, it is also necessary to have a base that can be compactly and conveniently combined with an air valve. However, no patent document disclosing such a technique has yet been proposed despite its high demand.

Therefore, the present invention has been developed to solve the above-mentioned problems, and its object is to maintain easy disassembly without complicating the structure and assembly work, while preventing freezing damage. To provide an air valve having a structure capable of surely coping with a problem, being extremely easily applicable to an existing air valve, and being immediately usable for a mouthpiece of a fire hydrant or the like.

In order to achieve the above object, the invention according to claim 1 provides an inlet provided in the lower part of a valve body, a float valve body housed inside a guide cylinder arranged in the valve body, and a float valve body above the float valve body. A floating valve body having a small air hole in the air valve, wherein a freeze damage prevention unit is detachably attached to the opening provided in the upper part of the valve box via a fixing means, and the freeze damage prevention unit The unit is provided with a cylindrical fixed cylinder, the outer peripheral surface of a cylindrical portion provided on a piston having a large air hole is slidably fitted to the lower inner peripheral surface of the fixed cylinder, and further, The diameter of the fixed cylinder is expanded to form a stepped engaging portion, and the upper end opening of the fixed cylinder and the cylindrical cover body form a piston case, which encloses the piston case and the outer peripheral surface of the piston. An expansion absorption chamber is formed, a spring is housed in the expansion absorption chamber, and a receiving portion protruding from the outer circumference of the piston is provided so as to be able to engage with the stepped engaging portion, and when a pushing force acts on the piston, , the piston is lifted while compressing the spring at the receiving portion of the piston, and the lower end of the receiving portion of the piston is held in an engaged state with the engaging portion in a state in which the spring is elastically biased at the receiving portion of the piston in normal times. It is an air valve that

In the invention according to claim 2, a mouthpiece communicating with a large air hole is attached to a cylindrical mounting portion provided on a cover body of a freeze damage prevention unit to form a mouthpiece integrated freeze damage prevention air valve. This is an air valve in which the upper end side of the piston is vertically movable along the inner peripheral side .

According to a third aspect of the invention, the fixing means has an engaging portion projecting from the outer circumference of a fixed cylinder provided on the lower outer circumference of the piston, and this engaging portion is engaged with a mounting groove provided in the opening. The air valve is locked and fixed by a locking portion and a stopper projecting in a centripetal direction of an opening.

In the invention according to claim 4 , a flange piece is formed at the lower end of the cover that surrounds the upper side of the valve body, and the cover is detachably attachable to and detached from the flange piece and the mounting piece provided on the valve body through bolts. is an air valve attached to the

According to the first aspect of the invention, the unit for preventing freezing damage, which has a large air hole and an expansion absorption chamber in an opening provided in the upper part of the valve body, is detachably attached to the valve body via fixing means. As a result, the freeze damage prevention function for the air valve can be unitized separately as an ASSY, and the air valve having the corresponding fixing means can be extremely easily provided with the freeze damage prevention function. , it is possible to utilize the existing state without exchanging the air valve itself. Therefore, the freeze damage preventing unit can be easily attached and detached without impairing the characteristic performance of the easily disassemble air valve, and the easily disassemble air valve having the freeze damage preventive unit can be obtained.
The unit for preventing freezing damage has a stepped engagement portion formed by expanding the diameter of the fixed cylinder, and a piston case formed by the upper end opening of the cylindrical fixed cylinder and the cylindrical cover body, An expansion absorption chamber is formed by enclosing the piston case and the outer peripheral surface of the piston with large air holes, and by storing the spring in the expansion absorption chamber, a large air hole is formed inside the piston for rapid exhaust and rapid intake. By providing an expansion absorption chamber on the upper side of the fixed cylinder while securing a flow path for the freezing damage prevention unit, the lower part of the freeze damage prevention unit can be inserted into the opening of the valve box and detachable. It is possible to suppress the increase in size.
Moreover, since the receiving portion protruding from the outer circumference of the piston is provided so as to be able to engage with the stepped engaging portion, when a pushing force acts on the piston, the spring is held at the upper end of the receiving portion of the piston. The piston is lifted while being compressed, and the lower end of the receiving portion of the piston is held in engagement with the engaging portion in a state in which the spring is elastically biased by the receiving portion of the piston in normal times, thereby restricting the movement of the piston. Therefore, even when the freeze damage prevention function is exhibited, the function of the air valve can be reliably maintained by securing a flow path through which the air in the valve box can be sucked and discharged by the large air hole provided in the piston.

According to the second aspect of the present invention, the air valve is an air valve integrated with a base for preventing freeze damage by attaching a base communicating with a large air hole to a mounting portion provided on the top of the unit for preventing freeze damage. Therefore, it is unnecessary to prepare and manage a separate mouthpiece for each air valve as a mouthpiece type air valve, and the convenience as a mouthpiece application such as fire hydrant water supply in an emergency is greatly enhanced.
Moreover, the mouthpiece is provided so as to be able to communicate with the large air hole of the piston. When the anti-freezing effect is exerted, the upper end of the piston inserted through the hole 89 protrudes from the hole by an amount corresponding to the rise and is housed on the inner peripheral side of the mouthpiece. , a predetermined amount of air can be secured.

According to the third aspect of the invention, the fixing means has an engaging portion projecting from the outer circumference of the fixed cylinder provided on the lower outer circumference of the piston, and this engaging portion is engaged with the mounting groove provided in the opening. Since the locking portion and the stopper projecting in the centripetal direction of the opening are locked and fixed, there is no space for the fixing means on the outer peripheral side of the air valve, and the fixing means consists of the locking portion and the mounting groove. Since the height of the air valve is minimized, the air valve can be configured compactly. In addition, since the fixed cylinder is simply engaged with or disengaged from rotation, the workability of attaching and detaching the freeze damage prevention unit to and from the valve box is improved.

According to the fourth aspect of the invention, a flange piece is formed at the lower end of the cover that surrounds the upper side of the valve body, and the cover is attached to the cover by connecting the flange piece and the mounting piece provided on the valve body with bolts. Since it is attached detachably, the cover can be attached to the valve body only on the outer circumference of the lower end of the cover.Therefore, there is no need for a mounting structure such as bolts on the upper surface of the cover. In addition, when used as a base, there is no fear that a base connecting member such as a fire hydrant will interfere with the mounting member and make connection impossible.

1 is a longitudinal sectional view of a first embodiment of an air valve of the present invention; FIG. FIG. 4 is a perspective view showing a floating valve body and a float valve body; 1 is a vertical cross-sectional view of a freeze damage prevention unit according to a first embodiment of the present invention; FIG. FIG. 3 is a schematic plan view showing a fixed lid; FIG. 6 is a vertical cross-sectional view of a freeze damage prevention unit according to a second embodiment of the present invention; FIG. 10 is a vertical cross-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 a separated cross-sectional view in FIG. 1;

An embodiment of an air valve according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a first embodiment of the air valve of the present invention.

As shown in FIG. 1, the air valve of the present invention has a valve body 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 provided in a pipeline of a main pipe, etc., and is provided so as to be able to discharge air due to air bubbles and air stagnation contained in tap water to the outside. Also, as a freeze-damage prevention type air valve, the unit 61 is used in an environment where the water in the valve box 1 may freeze during use of the air valve, such as in cold regions or in winter. In addition, particularly preferable installation locations are the highest point when the laying gradient of the pipeline changes, the center of the water pipeline at regular intervals (for example, 300 to 500 m) with respect to the straight horizontal pipeline, the pipeline There are places where air must be supplied and exhausted before and after the valve.

In FIG. 1, a valve body 1 is made of, for example, ductile cast iron, and accommodates 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 resin such as ABS resin is disposed, and an opening 6 is formed above the valve body 1 . A unit 61, which will be described later, is always fixed to the opening 6 via an appropriate fixing means 11, and the unit 61 is provided with a large air hole 12. As shown in FIG. In this air valve, the unit 61 and the guide cylinder 2 containing the float valve body 3 and the floating valve body 4 are taken out from the opening 6 of the valve body 1 as necessary, and the valve body 1 in the taken-out state 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 in a substantially cylindrical shape, provided with an opening 6 at the top, an inlet 20 at the bottom, and a storage chamber 21 between them. A fitting portion 22 having a diameter smaller than that of the opening 6 is formed on the side of the opening 6 of the valve body 1 , and an annular groove 23 is formed in the upper portion of the fitting portion 22 . A U-packing 24 made of, for example, a cylinder material is attached to the annular groove 23 . A stepped portion 25 is provided between the opening portion 6 and the fitting portion 22. A thrust ring 26 is attached to the stepped portion 25, and an external thread 28 of a bolt member 27 is screwed onto the upper surface of the opening portion 6. A plurality of internal threads 29 for attachment are provided by centering.

In FIG. 1, the inflow port 20 in the lower part of the valve box 1 is provided so as to secure a predetermined inflow area. Projections 30 are formed at approximately 90° intervals. The projection 30 is provided on the inner diameter side of the diameter of the float valve body 3 and the floating valve body 4. By locking the float valve body 3 and the floating valve body 4 to this projection 30, it is possible to prevent an accident during cleaning or inspection. Even if they are dropped, they are prevented from falling. A flange 31 is provided at the lower part of the outer circumference of the valve body 1, and a repair valve (not shown) or the like is detachably provided through the flange 31. As shown in FIG.

The housing chamber 21 is provided with an inner diameter capable of housing the guide cylinder 2, and a guide base 32 for mounting the guide cylinder 2 is formed at the lower part of the housing chamber 21 so as to protrude inward. A plurality of side guides 33 are protrudingly formed on the inner peripheral side of the storage chamber 21 . is set at the height of

The guide cylinder 2 has an upper portion arranged on the lower surface side of the unit 61 and a lower portion arranged so as to be mountable on the guide pedestal 32 . 21 is housed. A plurality of communication portions 35 for communicating fluid are formed in the upper portion of the guide cylinder 2, and a hole 36 having a predetermined diameter is provided at a substantially central position on the bottom side. The communicating portions 35 are provided at equal intervals by a plurality of notch portions, and the communicating portions 35 determine the area when the fluid passes.

The temporary connecting portions 62 and 63 shown in FIG. 1 are provided in a structure capable of connecting and holding the unit 61 and the guide cylinder 2. When the temporary connecting portions 62 and 63 are separated, the unit 61 is removed from the opening 6. In this case, the guide cylinder 2 containing the float valve body 3 and the floating valve body 4 together with the unit 61 can be pulled up and taken out.

The structure of the temporary connecting portions 62 and 63 is such that the guide cylinder 2 containing the float valve element 3 and the floating valve element 4 can be supported and held by its own weight. It has a structure with a holding force that allows the body 2 to be easily removed.

Specifically, in FIG. 1, the temporary connecting portions 62 and 63 are provided on the inner periphery of the lower portion of the fixed cylinder 64 of the unit 61 and the outer periphery of the upper portion of the guide cylinder 2 by means of a press-fit structure. It is detachable by fitting these temporary connecting portions 62 and 63 together. In the present embodiment, the convex portions 14 are formed at the upper portion by a plurality of notch portions 13 arranged in the upper portion of the guide cylinder 2 as the uneven portions constituting the temporary connecting portions 62 and 63 . This makes it possible to easily engage and disengage the unit 61 by utilizing the elasticity of the plurality of convex portions 14 .

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

A small air hole 37 penetrating vertically is formed at an eccentric position of the floating valve body 4, and air can move through the small air hole 37 having an eccentric structure. A seal ring 38 is attached to the upper surface of the floating valve body 4 so as to contact and seal the lower end surface of the unit 61 when the floating valve body 4 floats. The float 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 2 to smoothly move up and down. 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, a piston 66 having the large air hole 12, and a A spring (disc spring 68) is housed in an expansion absorption chamber 65 surrounded by a piston case 67, and a fixing means 11 to be attached to the opening 6 is provided on the lower outer periphery of the fixed cylinder 64 of the piston case 67. Configure.

1 and 3, the piston case 67 is formed by joining a substantially cylindrical cover body 69 and a fixed cylinder 64 concentrically. The female threaded portion and the male threaded 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 at the center of the upper surface thereof. The upper end of the piston 66 can be slidably fitted in the hole 70, and the inner periphery serves as a sealing member during sliding. An O-ring 71 is provided at the sliding portion of the . An expansion absorption chamber 65 is formed on the inner circumference of the cover body 69 and surrounded by the outer circumference of 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 the receiving portion 72 of the cover body 69 .

In FIGS. 1 and 3, the fixed cylinder 64 is formed in a substantially tubular shape, and has an engaging portion for locking the elastic movement of the piston 66 on the upper inner peripheral stepped surface on the joint side with the cover body 69. 73 is formed, and the inner peripheral surface having a substantially circular cross section on the lower side can be slidably fitted to the outer peripheral surface of the tubular portion 74 of the substantially cylindrical piston 66 . Further, an arm engaging piece 50 that engages with the mounting groove 52 of the valve body 1 is formed on the lower outer periphery of the fixed cylinder 64 to constitute fixing means 11, which will be described later. Further, the lower end portion is provided with the above-described temporary connection portion 62 so that it 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 having a predetermined diameter extending straight through the interior thereof, and in the unit 61, is concentrically fitted in the piston case 67. As shown in FIG. A part of the outer peripheral surface of the piston 66 is formed with a flange-like receiving portion 75 for receiving the other end of the repulsion of the disc spring 68 , and the receiving portion 75 engages the fixed cylinder 64 in a stepped portion. It can be engaged with the joining portion 73 . In addition, an O-ring 76 serving as a seal member when fitting and sliding on the inner peripheral surface of the fixed cylinder 64 is provided in an annular mounting groove on a part of the outer peripheral surface of the cylindrical portion 74 .

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 the valve seat surface of the large air hole 12 on which the floating valve element 4 can be seated in close contact. As described above, it is formed as an annular flat surface with a predetermined thickness. It becomes a receiving surface that abuts and absorbs movement. As described above, 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 as an inner side and the inner periphery of the cover body 69 as an outer side. , 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, and the guide cylinder 2 can be detached from the valve casing 1 together with the float valve body 3 and the floating valve body 4 when the unit 61 is removed. there is At that time, the unit 61 and the guide cylinder 2 housing the float valve body 3 and the floating valve body 4 are taken out from the opening 6 as necessary, and the large air hole 12 is formed in the opening 6 in the taken-out state. It becomes possible to fix the unit 61 having.

In FIGS. 1 and 4, the fixing means 11 of this embodiment has a locking portion 50 protruding from the outer periphery of a fixed cylinder 64 provided on the lower outer periphery of the piston 66, and the locking portion 50 is provided at the opening 6. It is engaged with the groove 52 , and is engaged and fixed by this engaging portion 50 and a stopper 54 projecting in the centripetal direction of the opening 6 .

1 and 4, the 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 circumference of the fixed cylinder 64, and an inner circumference of the opening 6. It has a mounting groove 52 formed toward the side, a stopper 53, and a lock pin device (stopper) 54, whereby the fixed cylinder 64 is detachably attached to the valve box 1. As shown in FIG. The arm engaging pieces 50 are formed to protrude from the lower side surface of the fixed cylinder 64 at regular intervals and are provided so as to be able to contact the stepped portion 25 .

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

In addition, although not shown, one stopper 53 is substantially sufficient, so a fixed lid in which the three stoppers 53 shown in FIG. 4 are formed only at one of them may be used.

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 on one side and a steep inclined surface 50a on the other side. Due to these different inclination angles, it is possible to rotate the fixed cylinder 64 while moving the pin of the lock pin device 54 in the retracting direction on the gently inclined surface 50b, while on the steeply inclined surface 50a, the lock pin device When the pin 54 completely protrudes in the centripetal direction of the opening 6 and both are engaged, the fixed cylinder 64 cannot be rotated. 4 shows a state in which the gently sloping surface 50b of the arm engaging piece 50 faces the gently sloping surface 53b of the stopper 53 in close proximity. , will be locked in such a state.

1 and 4, the lock pin device 54 is attached to the valve body 1, and is provided so as to engage with the fixed cylinder 64 by the urging force of a spring (not shown) so that the fixed cylinder 64 can be mounted in a predetermined positioning state. The lock pin device 54 is grasped with fingers and pulled outward to release the engagement with the fixed cylinder 64. In this state, the fixed cylinder 64 is rotated to allow the unit 61 to be detached from the valve body 1. there is

The fixed lid 7 shown in FIG. 4 is provided so as to be attachable to the upper surface 1a of the valve body 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 the fixed cylinder 64 can be inserted into the hole 55. As shown in FIG. A through hole 56 is formed at a position corresponding to the internal thread 29 of the fixed lid 7 . A notch-shaped mounting groove 52 for the arm engaging piece 50 to pass through is formed in a part of the hole portion 55 on the inner peripheral side, and a stopper 53 is formed following the mounting groove 52 and protruding downward. The rotation range of the fixed cylinder 64 is set by the stopper 53 .

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

Further, as shown in FIG. 1, a brim piece 78 and a mounting piece 79 provided on the valve body 1 are attached to the lower end of the cover 60 surrounding the upper side of the valve body 1, and the cover 60 is detachably attached via bolts 80. attached to the The cover 60 is made of metal such as stainless steel, and is formed to bulge upward so as to be able to surround the upper portion of the valve body 1, and communicates the large air hole 12 of the unit 61 with the atmosphere. It is detachably provided on the upper part of the unit 61 or the upper part of the valve body 1 so as to cover the state.

In FIG. 1, a flange piece 78 is provided on the outer circumference of the lower end of the cover 60 at a position where the lock pin device 54 can be hidden. It can be attached at the upper peripheral position of the valve body 1. The bracket 81 is formed of a thin plate in a substantially annular shape so that it can be installed on the upper surface of the fixed lid 7. At two positions on the outer periphery of the bracket 81, mounting pieces 79 bent downward to have a substantially L-shaped cross section are formed. . Further, the flange piece 78 of the cover 60 has the function of covering and protecting the opening/closing cock communicating with the inside of the side surface of the valve body 1 (not shown) from above.

In FIG. 1, the bracket 81 is arranged on the fixed lid 7 on the upper part of the valve body 1 and is positioned and fixed to the valve body 1 with the bolt member 27 together with the fixed lid 7 . In this state, the flange piece 78 is placed on the mounting piece 79 to position the cover 60 on the upper portion of the valve body 1 , and the flange piece 78 and the tip side of the mounting piece 79 are screwed together with the bolt 80 . As a result, the cover 60 can be fixed to the outer peripheral side of the valve body 1 via the bracket 81 , and the upper side of the valve body 1 can be covered with the cover body 60 . Although not shown, the flange piece 78 is formed with a screw hole into which the head of the bolt 80 can be inserted and removed. A thin elongated guide 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 on the outer peripheral side of the valve box 1, and there is no need to handle the upper surface side of the cover 60 at all. On the other hand, although not shown, the upper surface region of the cover 60 can be fixed to the valve body 1 with bolts or the like. Therefore, the structure of the air valve is complicated accordingly, and in the second embodiment described later, there is a risk that trouble will occur when connecting or removing a fire hose or the like to or from the mouthpiece 84 after the cover 60 is removed. . For example, when connecting a female fire hose (not shown) to the male Machino mouthpiece 84, since the female socket is large on the outer diameter side, if a support member is provided, it will interfere with it. connection may not be possible. On the other hand, in the case of the detachable 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 upper surface side from being pulled out by mistake.

Furthermore, since there is no need to provide a support portion between the upper portion of the cover 60 and the upper portion of the member (unit 61) covered by the cover 60, the distance between them can be minimized. The height of the air valve under the lid can be suppressed with this cover 60. Moreover, by fixing the flange 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 . A cock is provided to release residual pressure when the air valve is disassembled.

Also, a repair valve (not shown) may be attached to the lower portion of the valve box 1 of the air valve so as to exhibit the function of passing water. In this case, a commonly used repair valve may be used, and for example, a ball valve can be used. In this case, opening and closing can be performed by rotating the stem of the ball valve by 90 degrees. The ball valve is attached, for example, to the flange 31 with an attachment bolt, but the ball valve may be attached to a portion other than the flange. If a ball valve is used, it is desirable that the diameter of the ball is 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 rotated by rotating the unit 61 to the valve body 1 to which the fixed lid 7 is fixed via the fixing means 11. Although the guide cylinder 2 housing the floating valve body 4 is detachable, the guide cylinder 2 and the like may be housed by 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, an engagement portion that can be engaged with the engagement groove, and a valve box having a rotatable lever having an operation portion. With the fixed cylinder temporarily attached to the valve body, the lever is rotated to engage the engagement portion with the engagement groove in a press-contact state, or the lever is rotated from this state to engage the engagement groove. By separating from the valve box, the unit to which the guide body containing the float valve body and the floating valve body is temporarily attached can be attached to and detached from the valve box. Such a structure for attaching and detaching the engaging portion and the engaging groove by means of the lever makes it possible to attach and detach them with one touch. Alternatively, the O-ring or the like can also be attached and detached integrally with the fixed cylinder or the like. Also in this case, the mouthpiece and the unit can be integrally provided in the same manner as described above.

In addition, the freezing damage prevention unit 61 of the present invention can also be applied to air valves that do not have the fixing means 11 (mounting grooves 52) as described above, as well. It is also possible to easily make the air valve anti-freeze damage by simply providing fixing means. That is, by providing detachable fixing means (engagement, fitting, crimping, screwing, etc.) to the opening on the valve body side and the lower part of the unit on the unit side, either integrally or separately. , the freeze damage prevention unit 61 of the present invention can be provided with the function of large air holes.

The above-mentioned air valve is provided in the plumbing line of the water main pipe and discharges the air contained in the tap water, but the target fluid may be a liquid other than tap water, and the excess contained in this liquid may be discharged. Air can also be discharged. This pneumatic valve is suitable, for example, for cleaning pipes, pressure measurement, temporary water supply and the like.

Next, the structure of the second embodiment of the air valve of the present invention will be described. FIG. 5 is a vertical cross-sectional view of a freezing damage prevention unit 85 applied to this second embodiment, and FIG. FIG. 4 is a vertical cross-sectional view showing an example of an elevated state;

In this example, the structure of the freeze damage prevention unit 85 is different from that in the first embodiment. In this example, a mounting portion 82 is provided on the upper portion of the unit 85, and the mounting portion 82 includes a large air hole 83 and a large air hole 83. By mounting the communicating mouthpiece 84, the air valve of this embodiment is made to be a mouthpiece-integrated type for preventing freezing damage. Although not shown in FIG. 6, when the piston 90 is elastically biased by the coned disc spring 87 and engaged with the engagement portion 95, the guide cylinder 2 is positioned in the storage chamber 21 as in FIG. It is stored in the same position as in FIG. The same reference numerals are given to the same parts as in the first embodiment, and the description thereof will be omitted.

5 and 6, in the freezing damage prevention unit 85 of this embodiment, the piston case 86 concentrically joins a substantially cylindrical cover body 86a and a fixed cylinder 88 in the same manner as the unit 61 described above. In this example, a male threaded portion provided on the outer peripheral surface of the cover body 86a and a female threaded portion provided on the upper inner peripheral surface of the fixed cylinder 88 are screwed together. The cover body 86a has a hole 89 at its 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 absorbing chamber 92 is formed on the inner circumference of the cover body 86a to surround it with the outer circumference of the piston 90. In this expansion absorbing chamber 92, a disc is provided as a spring for elastically urging 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 the receiving portion 93 of the cover body 86a.

5 and 6, a mounting portion 82 for mounting a base 84 is formed on the cover body 86a of this example. The mounting portion 82 is annularly formed to protrude upward from the cover body 86 a and concentrically surrounds the hole portion 89 . The outer peripheral side of the lower portion of the mouthpiece 84 is joined by screwing or internally fitting. The inner diameter of the mounting portion 82 is provided to match the diameter of the mouthpiece 84 .

In FIGS. 5 and 6, the fixed cylinder 88 is formed in a substantially cylindrical shape, and has an engaging portion that locks the resilient movement of the piston 90 on the inner peripheral stepped portion on the upper side, which is the joint side with the cover body 86a. 95 is formed in an annular shape, and the inner peripheral surface having a substantially circular cross section on the lower side can be slidably fitted to the outer peripheral surface of a cylindrical portion 96 of the substantially cylindrical piston 90 . As in the first embodiment described above, an arm engaging piece 97 (a steeply inclined surface 97a and a gently inclined surface 97a in FIG. surface 97b) is formed and constitutes the fixing means 11. As shown in FIG. Further, the lower end portion is provided with the above-described temporary connection portion 98 so that it 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 having a predetermined diameter extending straight through the interior thereof. In the unit 85, the piston case 86 is fitted concentrically. A part of the outer peripheral surface of the piston 90 is annularly provided with a receiving portion 99 for receiving the other end of the elastic force of the disc spring 87 . It can be engaged with the joining portion 95 . An O-ring 100 is provided on a portion of the outer peripheral surface of the cylindrical portion 96 as a sealing member when fitting and sliding on the inner peripheral 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 element 4 can be seated in close contact. As described above, it is formed as an annular flat surface with a predetermined thickness, and contacts the floating valve body 4, etc., which rises due to expansion of the volume of water in the storage chamber 21 and the accompanying expansion of the water in the storage chamber 21 in the action of preventing freezing damage, which will be described later. It becomes a receiving surface that absorbs movement. Thus, 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 as the inner side and the inner periphery of the cover body 86a as the outer side. , a disc spring 87 is housed so as to surround the piston 90 .

On the other hand, a large air hole 83 is formed through the center of the base of the mouthpiece 84, and a fluid such as air is provided in the valve box 1 through the large air hole 83 so as to be able to be sucked and discharged. The mouthpiece 84 belongs to, for example, a fitting for a fire hose (not shown), and in the case of the above-mentioned Machino style mouthpiece, it is constructed using a fitting 102 and a push ring 103 as shown in FIGS.

The fitting 102 and the 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 peripheral groove 104 formed between the outer periphery of the fitting 102 and the mounting portion 82 to which the fitting 102 is screwed. The upper end of the mounting portion 82 forming the outer peripheral groove 104 has a function of holding the position of the push ring 103 , which corresponds to a retaining ring that determines the lower 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 mouthpiece 84, the operator puts his hand into the operation space and pushes up the push ring 103, thereby removing the hose.

5 and 6, the base 84 does not necessarily have to be provided separately from the mounting portion 82, and may be provided integrally. In this case, in addition to integrally forming the mouthpiece and the mounting portion, for example, the fitting portion and the mouthpiece are provided so as to be assembled by screwing or fitting, and an O-ring 94 is mounted or mounted therebetween. In the omitted state, these may be sealed and adhered with an adhesive. Moreover, the inner diameter of the fitting 102 is larger than the outer diameter of the piston 90 so that the upper end side of the piston 90 can protrude from the hole 89 in anti-freezing action, which will be described later.

Next, the operation and assembly/disassembly operations of the air valve according to the first embodiment of the present invention will be described. In the air valve of this example, a guide cylinder body 2 containing a float valve body 3 and a floating valve body 4 is arranged in a valve body 1, and a large air hole 12 is formed in an upper opening 6 of the valve body 1. The freezing damage prevention unit 61 is always fixed by an appropriate fixing means 11, and if necessary, the unit 61, the float valve body 3, and the floating valve body 4 are accommodated in the guide cylinder body 2. Since the unit 61 is taken out from the opening 6 of the box 1 and has the large air holes 12 fixed in the opening 6, the valve box 1 can be prevented from becoming large and the internal structure can be prevented from becoming complicated. Without increasing the number of parts, it is possible to exhibit the air valve function as a freeze damage prevention type while maintaining the performance of a simple disassembly type.

When removing the float valve element 3, the floating valve element 4, and the guide cylinder 2 from the air valve of this embodiment, first, the flow path from the water flow path to the air valve is shut off. At this time, since there is a residual pressure in the air valve, the unit 61 is pushed up and comes into close contact with the bottom surface of the fixed lid 7, preventing rotation. From this state, if a cock (not shown) provided in the valve box 1 is opened, the residual pressure in the air valve is released and the pushing force to the unit 61 is released, so that the unit 61 can be disassembled.

Next, the cover 60 is removed from the valve body 1. As shown in FIG. In this case, after loosening the bolt 80, which is a hexagonal screw, with a screwdriver or the like, the cover 60 is rotated along the guide hole so that the bolt hole is aligned with the head of the bolt 80, and in this state the cover is mounted. It can be removed by pulling 60 upward.

When the freeze damage prevention unit 61 is removed, the lock pin 54 is grasped and pulled to unlock the steep inclined surface 50a, and the fixed cylinder 64 (unit 61) is rotated by a predetermined angle in the removal direction. In this case, since the arm engaging piece 50 is supported by the thrust ring 26 while being in contact with the stepped portion 25, the rotation becomes smooth. When the steeply inclined surface 50a of the arm engaging piece 50 abuts against the steeply inclined surface 53a of the stopper 53 of the fixed lid 7, the fixed cylinder 64 (unit 61) can be removed by pulling it up.

At this time, the unit 61 and the guide cylindrical body 2 are connected and held via the temporary connecting portions 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 it is possible to pull up and take out the guide cylinder 2 containing the , there is no need to remove the unit 61, the guide cylinder 2, the float valve body 3, and the floating valve body 4 separately from the valve case 1, and the procedure is simple. , they can be removed together. In this state, dust and the like on each part may be removed, and cleaning and inspection may be performed. It is not necessary to remove the fixed lid 7 during this cleaning and inspection.

FIG. 7 shows the air valve of this example disassembled as described above, and the cover 60, freeze damage prevention unit 61, and guide cylinder body 2 containing the float valve body 3 and the floating valve body 4 are assembled into the valve. FIG. 4 is a separated 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 unit for preventing freezing damage is provided with a function as a cover member for the valve box having large air holes. It is a simple disassembly type air valve that allows efficient replacement of limited components.

On the other hand, when the unit 61 is attached to the valve body 1, first, the float valve body 3 and the floating valve body 4 are accommodated in the guide cylinder 2, and the guide cylinder 2 is fitted into the fixed cylinder 64. connect. At this time, the temporary connecting portions 62 and 63 connect the lower inner circumference or the lower outer circumference of the fixed cylinder 64 and the upper outer circumference or the upper inner circumference of the guide cylinder 2 by a press-fit structure that allows one-touch attachment and detachment. Attachment and detachment are facilitated, rattling between them is suppressed, and since the guide cylinder 2 is stably attached to the fixed cylinder, rattling of the floating valve body 4 and the float valve body 3 is relatively suppressed, Operation stabilizes.

Next, the unit 61 is placed over the valve body 1, and the fixed cylinder 64 is inserted while aligning the steeply inclined surface 50a of the arm engaging piece 50 with the mounting groove 52 (steeply inclined surface 53a of the fixed lid 7), and the stopper is inserted. The fixed cylinder 64 (unit 61 ) is rotated by a predetermined angle in the direction in which the arm engaging piece 50 is engaged with 53 . By this rotation, the arm engaging piece 50 (locking portion) is locked in the mounting groove 52, and the lock pin 54 is automatically moved in the retracting direction by the slightly inclined surface 50b of the arm engaging piece 50. As shown in FIG. 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 sloping surface 50b collides with the slightly sloping surface 53b of the stopper 53, the arm engaging piece 50 is sandwiched from both sides and is fixedly held.

In the case of a separate structure that does not have the temporary connecting portions 62 and 63, the float valve body 3 and the floating valve body 4 are housed in the guide cylinder 2 before the unit is fixed to the valve box. After the cylindrical body 2 is inserted from the opening 6, it is stored in the storage chamber 21. - 特許庁

As a result, it is possible to form the unit 61 so that the diameter of the large air hole 12 is greatly increased. Compared to the case where the entrance side of the air hole 12 has a diameter of 42 mm, the provision of the temporary connecting portions 62 and 63 of the press-fit structure allows the entrance side of the large air hole 12 to be expanded to a diameter of approximately 44 mm. As a result, the pressure loss can be reduced by smoothing the inflow portion, so that the fluid discharge efficiency is enhanced.

Furthermore, since the press-fit structure can be set up to approximately the same height as the peripheral seal portion of the U-packing 24, there is no need to shift the temporary connecting portions 62 and 63 from the peripheral sealing positions. It is possible to suppress the extension of the dimension in the height direction by the amount of . Therefore, the valve body 1 can be formed low while securing the same height of the guide cylinder 2, and the entire air valve can be made compact.

As a result, the guide cylinder 2 housing the float valve body 3 and the floating valve body 4 together with the unit 61 is mounted at a predetermined position in the valve box 1 . When the arm engaging piece 50 is engaged with the stopper 53, the base of the fixed cylinder 64 is engaged with the engaging portion 22, and the unit 61 is retained in the valve body 1. As shown in FIG. After the unit 61 is attached, the U packing 24 is attached to the outer circumference of the base of the fixed cylinder 64 to prevent leakage between the valve body 1 and the unit 61 . The unit 61 is attached to and detached from, for example, the fixed lid 7 by rotating within a range of 60°.

Furthermore, since the air valve of the present invention has a function of preventing freezing damage as a unit, it can be easily disassembled without compromising the easy disassembly of the existing easily disassembled air valves as disclosed in Patent Documents 1 and 2, for example. It is also possible to provide the air valve with a freeze damage prevention function very easily. Although not shown, when the valve body of an existing air valve is covered from above by a lid body having a structure different from that of the unit of the present invention via the fixing means as described above, the lid body is removed from the valve box, the float body in the valve box is taken out, and then the unit 61 of the present invention is mounted, the state shown in FIG. The air valve can be provided with a freeze-damage prevention function simply by fixing it via the fixing means 11 to the air valve.

When used as an air valve, first, in FIG. 1, when there is no water in the valve box 1, the float valve body 3 and the floating valve body 4 are lowered to open the large air hole 12, and from this state rapidly. Exhaust and rapid intake operations are performed. In this case, since the float valve body 3 and the floating valve body 4 are both short and flat, the contact resistance against the inner circumference of the guide cylinder body 2 is reduced, so that they drop reliably.

Rapid exhaust is an operation for rapidly exhausting a large amount of air in the pipeline through the large air hole 12 when filling the pipeline of a water main (not shown) with water. During rapid exhaust, both the floating valve element 4 and the float valve element 3 are positioned below the guide cylinder 2 without being lifted up, so that the large air hole 12 is fully opened, and the air in the pipeline flows through the air valve. Efficiently discharged to the outside.

Rapid intake is an operation in which a large amount of air is rapidly drawn into the pipeline through the air valve when the water in the pipeline is discharged. During rapid intake, the floating valve body 4 and the float valve body 3 are lowered. In this case, the large air holes 12 are opened, and the air is efficiently sucked through the large air holes 12 to quickly drain the water in the pipeline. 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 2 do not rise. These rapid exhaust and rapid intake operations allow the initial supply of water to the water main and the draining of water from the water main in a short period of time.

When the filling of the air valve is completed and the inside of the pipeline is filled with water and the inside of the valve body 1 is filled with water, the float valve body 3 and the floating valve body 4 are lifted by buoyancy, and the floating valve The seal ring 38 of the body 4 closes the lower end face of the piston 66 to block the large air hole 12 , and the float valve body 3 blocks 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 the outflow of water to the outside is prevented.

Under this pressure at the time of water filling, the air mixed in the water main pipe gradually gathers in the air valve and accumulates in the valve box 1. - 特許庁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 opens. This is because the floating valve element 4 does not move away from the lower end surface of the piston 66 having the large air hole 12 due to the size relationship between the large air hole 12 and the small air hole 37. As a result, only the float valve element 3 descends by its own weight.

At that time, as shown in FIG. 2, the small air hole 37 of the floating valve body 4 is arranged at the eccentric position of the float valve body 3, so that the small air hole 37 in which the negative pressure is generated As the float valve body 3 descends from the side, a force in the direction of inclination is applied to the float valve body 3. Further, as described above, the float valve body 3 has a short cylindrical shape and a flat shape. Less is. For these reasons, the float valve body 3 is easily tilted with respect to the floating valve body 4, and can be separated from the floating valve body 4 and reliably lowered. As a result, adsorption between the float valve body 3 and the floating valve body 4 is prevented, and the air in the air valve can be smoothly discharged to the outside through the small air hole 37 of the open floating valve body 4 . Further, since the lower corners of the float valve body 3 are formed in a rounded shape, the float valve body 3 can be more easily inclined and lowered.

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

In this case, as described above, the guide cylinder 2 is held by the fixed cylinder 64 by the temporary connecting portions 62 and 63, and furthermore, it is housed in a state where it is surrounded by the guide pedestal 32, the side guides 33, and the unit 61 in all directions. As a result, there is no deviation from the center of the valve body 1. In addition, since the upper part of the cylindrical part receives force evenly, for example, when compared with a guide body provided with a clamping flange on the upper side (not shown), bending stress is less likely to be applied, and impact load due to water hammer etc. is less likely to be applied. It has a very strong shape.

Next, the action of preventing freezing damage in this example will be described. When a water-conducting structure such as a faucet or a water-conducting pipe is used in a cold region or in winter, there is a problem of so-called freezing 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 water freezes at 0° C. under 1 atmospheric pressure, 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 closes the large air hole tightly and the float valve also floats on the water surface and closes the small air hole. Although it is tightly closed, if, for example, freezing progresses from near the water surface in this state, the float valve body will gradually be surrounded by frozen solids and will lose its float function while being restrained near the water surface. As the volume expands due to freezing, the float valve body is gradually pushed upward, and the float valve body in close contact with the small air hole immediately pushes up the floating valve body. In the valve body, the space for the volumetric expansion due to freezing is practically only the space of the air pool. As a result, the floating valve body is also pushed up, and an increase in the internal pressure of the air reservoir may occur. Alternatively, the ice block itself in the valve box may press against the floating valve body and the inner wall as the volume expands, or push up the lid body and the guide member to press the floating valve body and the inner wall.

However, the pushing force at this time, that is, the volumetric expansion pressure is strong enough to be used for concrete crushing technology, for example, the volumetric expansion pressure from about 10 degrees to -0.5 degrees is about 24.1 Mpa ( -22.3 degrees to a maximum of about 209 MPa). Therefore, in a conventional air valve structure in which a deformation allowance (expansion absorption allowance) for such deformation pressure of the internal structure is not substantially ensured, even a slight deformation (expansion) can be extremely strong. Fracture (freeze damage) may occur due to the action of stress. 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 body caused by such expansion to prevent damage to the air valve, and is easily attachable and detachable. Since it is a standardized ASSY, it is possible to independently handle the freezing damage prevention function of the air valve easily at any time, such as replacement, replacement, and maintenance.

In the air valve of this example, in a normal use state in which air is stored, that is, in a stable state for a certain amount of time in which the water inside the valve box 1 can freeze, if the water freezes, the structure inside the valve box will be affected. As a result, an upward force acts on the lower end surface 77 of the floating valve body 4 and the piston 66, which are in close contact with the large air hole 12. It will be.

On the other hand, the lower end surface 77 of the unit 61 receives such a pushing force, thereby applying a lifting force to the piston 66 . Since the piston 66 is in a state of being locked by the engaging portion 73 and pushed toward the inside of the storage chamber 21 by the disc spring 68, this rising force is combined with the biasing force of the disc spring 68 and the weight of the piston 66. , the piston 66 slides upward while compressing the coned disc spring 68, and as a result, the upward force acting on the floating valve element 4, etc., is applied to the storage chamber. Movement of the component parts and internal pressure in the storage chamber 21 are absorbed, and freezing damage of the component parts and the valve body 1 in the storage chamber 21 can be prevented. The resilient force of the coned disc spring 68 and the stroke of the piston 66 act at least as a deformation allowance as described above, thereby ensuring sufficient characteristics to prevent freeze damage of the air valve.

Next, the operation and assembly/disassembly operations of the air valve according to the second embodiment of the present invention will be described. In the air valve of this example as well, the freezing damage prevention unit 85 can be attached and detached, or the lid body and the freezing damage prevention unit can be replaced in an existing easily disassembled air valve covered with a lid body of another structure. The disassembly/assembly operation of the air valve, rapid air intake/exhaust, action as an air valve, and action to prevent freeze damage are the same as those of the above-described first embodiment.

FIG. 6 shows an example of the freezing damage preventing action of the present invention. In this posture, the small air hole 37 is closely closed, and the seal ring 38 of the floating valve body 4 is also in close contact with the lower end surface 101 of the piston 90 to close the large air hole 83. Further, these forces move the piston 90 near the top dead center. It shows a state of being pushed up. In this state, the receiving portion 99 of the piston 90 is separated from the engaging portion 95 of the cover body 86a and the disc spring 87 is compressed. is accommodated in the inner peripheral side of the mouthpiece 84 by protruding from the hole portion 89 by an amount corresponding to the rise of . At this time, the sliding of the outer peripheral surface of the piston 90 is sealed by an O-ring 91 between the inner periphery of the hole portion 89 and an O-ring 100 between the inner peripheral surface of the fixed cylinder 88 and the lower side. As described above, such a lifting action of the piston is the same in the unit 61 of the first embodiment shown in FIGS.

As shown in FIG. 6, the length of the cylindrical portion 96 guided by the inner peripheral surface of the fixed cylinder 88 when the piston 90 moves up and down is the maximum stroke of the up-and-down motion (the length of the engaging portion 95 in the same figure). Since a sufficient length is ensured with respect to the distance from the receiving portion 99), the piston 90 can move smoothly during the vertical movement, thereby obtaining a reliable freeze damage prevention effect. This also applies to the tubular portion 74 of the piston 66 in the first embodiment shown in FIGS.

5 and 6, in addition to the action and operation described above, in this example, a base 84 is further used to form an air valve that can be used for the base as described below.

When the air valve of this example is used for washing pipes or as a temporary fire hydrant through the mouthpiece 84, the valve box 1 from which the float valve body 3, the floating valve body 4, and the guide cylinder body 2 are 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 the fixed cylinder 88 is inserted while aligning the positions of the arm engaging piece 97 and the mounting groove 52, and rotated by a predetermined angle. By this rotation, the lock pin 54 is automatically moved in the retracting direction by the slightly inclined surface 97b of the arm engaging piece 97. As shown in FIG. When the fixed barrel 88 reaches the set position, the steeply inclined surface 97a reaches the position of the lock pin 54, so that 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 sloping surface 97b collides with the slightly sloping 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 mouthpiece 84 to the valve box 1 in this way, the large air holes 83 of the unit 85 can exhibit the water flow function without requiring a new mouthpiece separate from the unit 85. . Therefore, there is no need to carry other parts to the place where the air valve is installed, and by attaching and detaching the float valve body 3, the floating valve body 4, and the guide cylinder body 2 to and from the valve box 1, the air valve and the fire hydrant can be easily switched. can be used At this time, compared to the pressure loss of a fire hydrant with a general globe valve structure, the flow path of the air valve of this embodiment has a straight structure, so when it is used for a fire hydrant, etc. Pressure loss can be reduced.

A hose or the like can be connected to the mouthpiece 84 of the unit 85. Through this hose, the inside of the pipeline can be cleaned or used as a temporary fire hydrant. Furthermore, it can be used for various purposes such as water pressure measurement in pipelines. When the unit 85 is attached and used as a fire hydrant or the like, the mouthpiece 84 can ensure a flow rate equivalent to that of a fire hydrant of, for example, 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, the valve can be opened and closed to secure a flow path while providing a suitable fire hydrant for cleaning pipes or as a temporary fire hydrant. At this time, since the guide base 32 is provided in the lower part of the valve body 1, the jet flowing through the repair valve is prevented from striking the guide base 32 and directly ejecting out of the valve.

In the above embodiment, an example of the air valve in which the flange 31 is integrally provided at the bottom of the air valve has been described. , a so-called air valve with a ball valve may be used, and in this case also, the same function as described above can be exhibited.

Furthermore, the present invention, including materials, etc., is not limited to the description of the above embodiments, and various modifications can be made without departing from the gist of the invention described in the claims of the present invention. It is a thing.

REFERENCE SIGNS LIST 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 inlet 37 small air hole 50 97 arm engaging piece (locking portion)
52 Mounting groove 54 Lock pin device (stopper)
60 Cover 61 85 Unit for preventing freezing damage 64 88 Fixed cylinder 65 92 Expansion absorption chamber 66 90 Piston 67 86 Piston case 68 87 Disc spring (spring)
78 flange piece 79 attachment piece 80 bolt 82 attachment portion 84 cap

Claims (4)

It comprises an inflow port provided at the bottom of a 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 . An air valve, wherein a freezing damage prevention unit is detachably attached to an opening provided in the upper part of the valve box via a fixing means, and the freezing damage prevention unit is provided with a cylindrical fixed cylinder, The outer peripheral surface of a cylindrical portion provided on a piston having a large air hole is slidably fitted to the lower inner peripheral surface of the fixed cylinder, and the fixed cylinder is expanded in diameter to form a stepped portion. a piston case is formed by the upper end opening of the fixed cylinder and a cylindrical cover body, and an expansion absorption chamber is formed by surrounding the piston case and the outer peripheral surface of the piston, A spring is housed in the expansion absorption chamber, and a receiving portion protruding from the outer periphery of the piston is provided so as to be engageable with the stepped engaging portion, and when a pushing force acts on the piston, the piston is pushed up. The piston is raised while compressing the spring at the receiving portion of the piston, and the lower end of the receiving portion of the piston is engaged with the engaging portion in a state in which the spring is elastically biased at the receiving portion of the piston in normal times. A pneumatic valve, characterized in that it is held in a state . A mouthpiece communicating with the large air hole is attached to a cylindrical mounting portion provided on the cover body of the freeze damage prevention unit to form a mouthpiece - integrated freeze damage prevention air valve. 2. The air valve according to claim 1, wherein the upper end side of the piston is vertically movable . The fixing means has an engaging portion projecting from the outer circumference of a fixed cylinder provided on the lower outer circumference of the piston, and the engaging portion is engaged with the mounting groove provided in the opening. 3. The air valve according to claim 1 , wherein the air valve is locked and fixed with a stopper projecting in the centripetal direction of the opening. A flange piece is formed at the lower end of a cover that surrounds the upper side of the valve body, and the cover is detachably attached to the flange piece and a mounting piece provided on the valve body via bolts. 4. The air valve according to any one of 1 to 3 .

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