JP2001073418A - Ice-free fire hydrant and ice-free sprinkler head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ice-free fire hydrant and an ice-free sprinkler head facilitated in exchange of an underground part thereof for repair and capable of preventing the damage of the underground part even in the case where an impact is applied to a ground part thereof in the case of using the fire hydrant and the sprinkler head in a cold district. SOLUTION: A part of an outer surface of a piston 20 is formed with a male screw part, and the piston 20 is screwed to a valve main body 18 formed with a female screw part to be engaged with the male screw. When the piston 20 is rotated in one direction so as to be raised, a water service pipe and a lifting pipe are communicated with each other, and when the piston 20 is rotated in the opposite direction, the communication of the water service pipe with the lifting pipe is cut by a main valve 22, and the lifting pipe and a drain pipe 24 are set to communicate with each other through a clearance formed between the valve main body 18 and the piston 20. An inner pipe is housed inside of a lower lifting pipe 14, and a lower end of the inner pipe 36 comes into contact with the valve main body 18 sat on a stage part inside of the valve casing 12, and the upper end of the inner pipe 36 in contact with a removable stopper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire hydrant used for extinguishing a fire, especially in a cold region. The present invention also relates to an antifreeze sprinkler used for watering agricultural lands, especially in cold regions.

[0002]

2. Description of the Related Art A fire hydrant is used by opening a main valve when extinguishing a fire and closing the main valve after use. However, once the plug is opened and then closed, water remains in the fire hydrant, and such a fire hydrant may freeze in winter, especially in cold regions.
Therefore, the following two types of fire hydrants have been put into practical use as fire hydrants for cold regions.

[0003] In the first type of fire hydrant, a drain pipe is inserted in the fire hydrant in advance, and water in the fire hydrant can be pumped out through the drain pipe before winter. In the second type of fire hydrant, an automatic drain valve is installed at the lower part. This automatic drain valve is configured to be automatically opened by a spring force when the water pressure stops working, and when water pressure is applied, the valve is closed by the water pressure, but the operating shaft is operated. When the main valve is closed, the downstream side of the main valve is only the water head to the water outlet of the fire hydrant, and the spring force of the drain valve becomes larger than the water pressure,
The drain valve is opened and the water in the fire hydrant is drained.

[0004] On the other hand, a conventional water sprinkler for cold districts is generally of a type in which a telescoping riser is attached to a drain plug and an opening / closing valve is arranged on a head.

[0005]

However, the conventional fire hydrant has the following problems. In other words, in the case of a pump suction type hydrant, if the main valve has poor water stopping performance, it may leak and cause a freezing accident, and all installed hydrants must be pumped out before winter. And it takes a lot of time and effort.

In the case of a fire hydrant of the automatic drain valve type, when the water pressure in the water pipe is low, the static water pressure near the automatic drain valve at the time of water supply becomes smaller than the spring force in the automatic drain valve, thereby causing automatic drainage. There is a problem that the valve opens and leaks underground. In order to solve such problems, if the spring force of the automatic drain valve is reduced, the spring force of the automatic drain valve becomes smaller than the head position when the main valve is opened. And it may cause a freezing accident.

On the other hand, when an impact is applied to a fire hydrant due to a traffic accident or the like, the fire hydrant may be damaged not only on the ground but also on an underground valve or a water main, so that a great expense is required for restoration. There is a problem that it takes time and effort. In order to solve such a problem, the present applicant has proposed a knockdown hydrant that does not transmit the impact to the underground part even if the impact is applied to the ground part and the base part is damaged (Japanese Patent No. 2649769). However, this fire hydrant has a water stop mechanism provided outside the fire hydrant and does not have a water stop mechanism inside the fire hydrant. Therefore, in the case of a fire hydrant provided with a water shutoff mechanism inside the fire hydrant, there is a disadvantage that the above-mentioned falling down fire hydrant cannot be used as it is because it is necessary to consider the ejection of water when the ground portion is damaged.

Further, in the case of a conventional fire hydrant, when the main valve or the like is damaged and repaired or replaced, it is necessary to excavate around the buried portion of the fire hydrant, so that there is a problem that the operation is very complicated.

[0009] On the other hand, in the case of a conventional water tap, as in the case of a fire hydrant, when the main valve or the like is damaged and repaired and replaced, it is necessary to dig around the buried part of the water tap, which makes the operation very complicated. There is a problem that is.

An object of the present invention is to provide an antifreeze fire hydrant suitable for use in cold regions. Another object of the present invention is to provide an antifreeze fire hydrant that does not damage an underground portion when an impact is applied to the above-ground portion. It is a further object of the present invention to provide an antifreeze fire hydrant and an antifreeze sprinkler that allow easy replacement and repair of underground parts.

[0011]

According to a first aspect of the present invention, there is provided an antifreeze fire hydrant having a male screw portion formed on a part of an outer surface of a piston, and a piston body formed with a female screw portion engaging with the male screw portion. When the piston is rotated in one direction and raised, the water pipe and the water pipe communicate with each other. When the piston is rotated in the opposite direction and lowered, the main valve connects the water pipe and the water pipe. It is characterized in that the communication is cut off and the pumping pipe and the drain valve communicate with each other via a gap formed between the valve body and the piston.

According to a second aspect of the present invention, there is provided the antifreeze fire hydrant according to the first aspect, wherein a square pipe or a square rod is joined to an upper end of the piston, and a square rod or a square pipe is connected to an upper end of the square pipe or the square rod. It is slidably inserted, and by rotating the handle, a square rod, square pipe,
And when the piston is rotated and the piston moves up and down, the square pipe or the square rod moves up and down along the square rod or the square pipe.

The antifreeze fire hydrant according to claim 3 of the present invention is the antifreeze fire hydrant according to claim 1 or 2, wherein the pumping pipe has a lower pumping pipe whose upper end is located at a position slightly protruding from the ground;
The lower pumping pipe and the upper pumping pipe are connected by a connecting structure, and the connecting structure has an allowable bending stress smaller than the allowable bending stress of the lower pumping pipe and the upper pumping pipe. A part having bending stress is formed, and the square rod or the square pipe is provided at the height at which the connecting structure is located or at a height slightly higher than the height of the connecting structure. A portion having an allowable bending stress smaller than the portion is formed, and the square pipe or the square rod is substantially hinged to the piston.

According to a fourth aspect of the present invention, there is provided the antifreeze fire hydrant according to any one of the first to third aspects, wherein a lower end of the inner pipe housed in the lower pumping pipe is provided at a stepped portion in the valve box. The valve is in contact with a seated valve body, and the upper end of the inner pipe is in contact with a removable stopper to prevent the inner pipe from rising due to water pressure.

In the antifreeze sprinkler according to claim 5 of the present application, a male screw portion is formed on a part of the outer surface of the piston, and the piston is
Screwed into the valve body formed with a female thread that engages with the male thread, and when the piston is rotated in one direction and raised, the water pipe and the water pump communicate, and the piston is rotated in the opposite direction to descend. Then, the communication between the water pipe and the pumping pipe is interrupted by the main valve, and the pumping pipe and the drain valve are configured to communicate with each other through a gap formed between the valve body and the piston. The square pipe or square rod is joined to the upper end of the piston, the square rod or square pipe is slidably inserted at the upper end of the square pipe or square rod, and by rotating the handle, the square rod, square pipe, When the piston was rotated and the piston was moved up and down, the square pipe or square rod was moved up and down along the square rod or square pipe, and the lower end of the inner pipe housed in the lower pumping pipe was seated on the step in the valve box. valve Body is in contact with the upper end of the inner tube,
In order to prevent the inner pipe from rising due to water pressure, the inner pipe is in contact with a removable stopper.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, with reference to the drawings, embodiments of the present invention will be described in detail in relation to an antifreeze fire hydrant. 1 and FIG.
The antifreeze fire hydrant according to a preferred embodiment of the present invention, which is indicated by a symbol, includes a valve box 12 and a lower pumping pipe 14 joined to an upper end of the valve box 12. An inflow port 16 is provided below the valve box 12, and a water pipe (not shown) is connected to the inflow port 16. Note that the upper end of the lower pumping pipe 14 is located at a position slightly protruding from the ground as shown in FIGS.

In the valve box 12, a substantially cylindrical main body 18a is provided.
And the longitudinal axis z of the main body 18a (see FIGS. 3 and 4).
(See FIG. 1) is arranged so that the longitudinal axis z is oriented in the vertical direction. As best shown in FIG. 1B, the flange portion 18b of the valve body 18 has a plurality of circumferential portions 18c and a plurality (4 in FIG. 1B) connecting the circumferential portion 18c and the main body portion 18a. (Shown in FIG. 1). Valve body 18
Is the valve box 1 as best shown in FIGS.
2 is seated on a step 12a.

A female thread 18e is provided inside the body 18a of the valve body 18. On the other hand, a piston 20 having an external thread 20a engaging with the internal thread 18e is screwed into the main body 18a.
At the lower end of 0, a main valve 22 with a packing 22a is attached. The main valve 22 is configured to be seated on the valve seat 12b of the valve box 12 at the time of drainage shown in FIGS. At the approximate center of the piston 20, a reduced diameter portion 20b formed to have a small diameter is provided.
Is provided.

At the side of the valve box 12, the hydrant 1
A drain valve 24 for discharging the water in the chamber 0 is provided. The drain valve 24 is connected to the connecting portion 1 of the flange portion 18 b of the valve body 18.
8d, a horizontal portion having one end joined to the valve box 12 so as to communicate with the reduced diameter portion 20b of the piston 20 via a passage 18f provided in the piston 20d, and a vertical portion extending upward to communicate with the horizontal portion and having an open upper end. And a drain valve main body 24a composed of a portion. A drain valve cap 24b is placed over the opening of the vertical portion of the drain valve body 24a.
A drain valve ball 24c is accommodated in the vertical portion of the first embodiment. An O-ring 24d is attached to the vertical portion of the drain valve main body 24a adjacent to the opening thereof.
When the seat 4c is seated on the vertical portion, the vertical portion is sealed by the drain valve ball 24c.

With the above arrangement, when draining water as shown in FIG. 1 and FIG. 3, the valve case is inserted through the gap between the inner wall of the body 18a of the valve body 18 and the reduced diameter portion 20b of the piston 20. The interior of the valve box 12 communicates with the drain valve 24, and when water is supplied as shown in FIGS. 2 and 4, the communication between the interior of the valve box 12 and the drain valve 24 is shut off.

At the upper end of the lower pumping pipe 14, the connecting structure 2
6, the lower end of the upper pumping pipe 32 is connected.
As shown in FIG. 5, the connecting structure 26 includes a substantially cylindrical lower connecting member 28 screwed to the upper end of the lower pumping pipe 14.
And a substantially cylindrical upper connector 30 screwed to the lower end of the upper pumping pipe 32. A lower end of the upper connector 30 is provided on a step 28 a formed at the upper end of the lower connector 28. It fits in.

A groove 28b is formed in the step portion 28a of the lower connecting member 28 over the entire periphery thereof. on the other hand,
The upper connector 30 has a large number of screw holes 3 at locations corresponding to the grooves 28b of the lower connector 28 over the entire periphery thereof.
0a is formed, a screw (not shown) is screwed into the screw hole 30a, and the tip of the screw is brought into contact with the groove 28b, so that the lower connecting member 28 and the upper connecting member 30 (therefore, the lower pumping pipe 14 and The upper pumping pipe 32) is joined. The screw holes 30a of the upper connecting tool 30 serve to reduce the allowable bending stress of the upper connecting tool 30 (therefore, the connecting structure 26). Since it becomes larger, the allowable bending stress of the connection structure 26 becomes smaller.

It is to be noted that an appropriate contact portion between the lower pumping pipe 14 and the lower connecting member 28, a contact portion between the upper pumping pipe 32 and the upper connecting member 30, and a contact portion between the lower connecting member 28 and the upper connecting portion 30 are provided. In order to maintain the watertightness of the fire hydrant 10,
A packing 34 is mounted.

An inner pipe 36 is accommodated in the lower pumping pipe 14. 3 and 4, the lower end of the inner pipe 36 abuts on a step provided at the upper end of the circumferential portion 18c of the valve body 18, and the upper end of the inner pipe 36 is shown in FIG. 29, which is screwed to the lower connecting member 28
, So that the valve body 18 is
Is pressed against the step 12a. Valve body 18 at the time of water supply
, An upward water pressure acts on the inner pipe 36.
Is pressed against the step portion 12a by the
Is held at a predetermined position in the valve box 12.

As shown in FIG. 6, a joining fitting 38 is attached to the upper end of the piston 20. Joint fitting 3
8, a protrusion 38a having a rectangular cross section is provided at the upper end, and a through hole 38b is formed in the protrusion 38a. The square pipe 40 is connected to the protrusion 38 a of the joint fitting 38.
Is fitted with a play 2d. Projection 38a
The upper edge may be chamfered, as indicated by reference numeral 38c, to facilitate fitting of the square pipe 40. A hole 40a is formed in the square pipe 40 at a position corresponding to the through hole 38b when the square pipe 40 is fitted into the protruding portion 38a.
By inserting the pin 42 into the hole 40a and the through hole 38b, the joint fitting 38 and the square pipe 40 are connected. The hole 40a has a diameter larger than the diameter of the pin 42. As described above, there is play between the protrusion 38a of the joint fitting 38 and the inner dimension of the square pipe 40, and the pin 42
Is larger than the diameter of the pin 42, the square pipe 40 is substantially hinged to the joint fitting 38. In other words, the square pipe 40
Does not affect the portion below the joint fitting 38.

At the upper end of the square pipe 40, a square rod 44 is slidably inserted. The square rod 44 is smaller than the inner dimension of the square pipe 40 so that when the square rod 44 is rotated, the torque is smoothly transmitted to the square pipe 40 and the square pipe 40 easily moves up and down along the square rod 44. Also have slightly smaller outer dimensions. Also, the square rod 44 has
The reduced diameter portion 44a may be provided at the height where the connecting structure 26 is located or at a height slightly higher than the height where the connecting structure 26 is located (see FIG. 7). The reduced diameter portion 44a
It serves to reduce the allowable bending stress of the square rod 44.

A spindle 48 rotatably supported by a gland 46 attached to the upper end of the upper pumping pipe 32 is accommodated in the upper pumping pipe 32, and the lower end of the spindle 48 is attached to the upper end of the square rod 44. Are joined.
Thus, by rotating the handle 48a attached to the upper end of the spindle 48, the spindle 48 is rotated.
And the square rod 44 can be rotated.

The handle 48a is usually provided with a cover 49.
Covered with. A water outlet 50 is provided on the side of the upper part of the upper pumping pipe 32.

The operation of the thus-configured antifreeze fire hydrant 10 of the present invention will be described. First, when water is to be supplied, the handle 48a is rotated counterclockwise. Then, the spindle 48, the square rod 44, the square pipe 40, the joint fitting 38, and the piston 20 also rotate in the same direction. Thereby, the male screw portion 20a of the piston 20
Are engaged with the female threaded portion 18e of the valve body 18, and the square rod 44 is slidably inserted into the upper end of the square pipe 40, as shown in FIG.
0 rises, the main valve 22 opens, and water is supplied from the water outlet 50. On the other hand, to drain the water, the handle 48a is rotated clockwise. Then, the spindle 48, the square rod 44, the square pipe 40, the joint fitting 38
Rotational force is transmitted to the piston 20 via the piston, and as shown in FIG.
2b, the communication between the water pipe (not shown) and the fire hydrant 10 is interrupted, and at the same time, the connection portion 18d of the flange portion 18b of the valve body 18 and the inner wall of the body portion 18a of the valve body 18 and the piston 20 are connected. Valve box 1 through a gap between reduced diameter portion 20b
The inside of the hydrant 2 (accordingly, the hydrant 10) communicates with the drain valve 24, whereby the water in the hydrant 10 is discharged from the drain valve 24.

Next, referring to FIG. 7, the antifreeze fire hydrant 1 of the present invention when an impact force due to a collision of a car or the like acts.
The operation of 0 will be described. When a horizontal force is applied to the above-ground portion of the antifreeze fire hydrant 10 as indicated by the arrow in FIG. 7, the allowable bending stress in the portion of the upper connector 30 where the screw hole 30a is provided is smaller than in the other portions. Screw hole 3
It breaks at the location where 0a is provided, and the upper part of the antifreeze fire hydrant 10 from the upper connector 30 is inclined. At the same time, when the reduced diameter portion 44a is provided on the square rod 44,
The square rod 44 breaks at the reduced diameter portion 44a, and the square rod 44 tilts. Further, as described above, since the square pipe 40 is substantially hinged to the joint fitting 38, even if the square rod 44 is inclined, the influence is not exerted on the piston 20 and the valve body 18.

Next, repair and replacement of the valve body 18, the piston 20, the main valve 22, and the like will be described with reference to FIG. In order to repair or replace these parts, first, the main plug (not shown) of the water pipe is closed, and then the connecting structure 26 is closed.
And remove the upper pumping pipe 32 together with the square rod 44. Next, the stopper 29 is loosened and removed, and the inner pipe 3 is removed.
After pulling up 6, the square pipe 40 is pulled up, so that components such as the valve body 18 can be collected.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 9 shows the antifreeze sprinkler in the extended state;
FIG. 10 shows the antifreeze sprinkler in a contracted state. The antifreeze sprinkler according to the preferred embodiment of the present invention, which is generally indicated by reference numeral 110 in FIGS. 9 and 10, does not include the connecting structure 26 provided in the antifreeze fire hydrant 10, and It has substantially the same configuration as the antifreeze fire hydrant 10 except that it has a telescopic mechanism described later.

That is, the antifreeze sprinkler 110 is connected to the valve box 11
2 and a lower pumping pipe 114 joined to the upper end of the valve box 112
In the valve box 112, a valve body 118 is provided.
It is arranged so that its longitudinal axis is oriented vertically. The valve body 118 is the valve body 1 of the antifreeze fire hydrant 10.
As in the case of 8, it is seated on the step provided in the valve box 112. A piston 120 is screwed into the valve body 118, and a main valve 122 is attached to a lower end of the piston 120. A drain valve 2 is provided beside the valve box 112.
A drain valve 124 having the same structure as in No. 4 is provided. And at the time of drainage, like the antifreeze fire hydrant 10,
The inside of the valve box 112 communicates with the drain valve 124, and when water is supplied, the communication between the inside of the valve box 112 and the drain valve 124 is cut off. 9 and 10, the left half shows a state where the main valve 122 is open, and the right half shows a state where the main valve 122 is closed.

At the upper end of the lower pumping pipe 114, an extension mechanism 1 is provided.
The lower end of the upper pumping pipe 132 is connected via 26. The telescopic mechanism 126 is a mechanism configured so that when the upper pumping pipe 132 is extended, the upper pumping pipe 132 is locked at a predetermined position without falling off. The telescopic mechanism 126 itself is a known technique. Therefore, detailed description is omitted. In order to maintain the watertightness of the water faucet 110, packing is attached to an appropriate portion of a contact portion between the lower water pipe 114 and the expansion mechanism 126 and a contact portion between the upper water pipe 132 and the expansion mechanism 126. I have.

An inner pipe 136 is accommodated in the lower pumping pipe 114. Like the inner pipe 36, the lower end of the inner pipe 136 is connected to a step provided at the upper end of the circumferential portion of the valve body 118. The upper end of the inner tube 136 comes into contact with a stopper (not shown) screwed to the telescopic mechanism 126, whereby
The valve body 118 is pressed against the step of the valve box 112.

At the upper end of the piston 120, the joining fitting 13
8, a square pipe 140 is attached. On the other hand, a square rod 144 is slidably inserted into the upper end of the square pipe 140. Square rod 144 is square rod 4
4, the outer dimensions are slightly smaller than the inner dimensions of the square pipe 140. The upper pumping pipe 132 houses a spindle 148 rotatably supported by a gland 146 attached to the upper end of the upper pumping pipe 132, and the lower end of the spindle 148 is joined to the upper end of the square rod 144. I have. Thereby, the spindle 148
By rotating the handle 148a attached to the upper end of the spindle 148, the spindle 148 and the square rod 144 can be rotated. A water outlet 150 is provided on the side of the upper part of the upper pumping pipe 132. Also, the lower pumping pipe 114 and the upper pumping pipe 132 are usually
It is housed in a manhole 152 buried underground.

When the valve body 118, the piston 120, the main valve 122 and the like of the antifreeze sprinkler 110 are to be repaired and replaced, the same as described with reference to FIG. Can be done in a way.

The present invention is not limited to the above embodiments of the invention, and various modifications can be made within the scope of the invention described in the claims. It goes without saying that it is included in.

For example, in the above embodiment, two drain valves 24 are provided, but one drain valve may be provided.
Alternatively, three or more may be used. In the above-described embodiment, the square rod 44 is inserted into the upper end of the square pipe 40. However, the positional relationship between the square pipe and the square rod is reversed, the square rod is joined to the joining fitting, and the upper end of the square rod is A square pipe may be inserted. In such a configuration, a portion having a small allowable bending stress is formed in the square pipe.

[0040]

According to the present invention, there can be obtained a fire hydrant having a simple structure capable of draining water easily and reliably.
In addition, when a shock is applied to the aboveground part, a fire hydrant that does not affect the underground part can be obtained. Further, when it becomes necessary to replace and replace parts in the underground part, it is possible to obtain a fire hydrant and a water tap which can easily and quickly replace and replace parts without performing excavation work.

[Brief description of the drawings]

1 (a) is an overall sectional view showing an antifreeze fire hydrant of the present invention in a drained state, and FIG. 1 (b) is a line 1 in FIG. 1 (a).
It is sectional drawing of the collar part of a valve main body along b-1b.

FIG. 2 is an overall sectional view showing the antifreeze fire hydrant of the present invention in a water supply state.

FIG. 3 is an enlarged sectional view showing the vicinity of a valve body in FIG. 1;

FIG. 4 is an enlarged sectional view showing the vicinity of a valve body in FIG. 2;

FIG. 5 is an enlarged sectional view of a connection structure of the antifreeze fire hydrant of the present invention.

FIG. 6 is an enlarged sectional view showing the vicinity of a fitting of the antifreeze fire hydrant of the present invention.

FIG. 7: By applying a horizontal force to the antifreeze fire hydrant of the present invention,
It is the schematic sectional drawing which showed the state where the ground part of the antifreeze fire hydrant was inclined.

FIG. 8 is a view showing a repair / replacement operation of a main valve or the like of the antifreeze fire hydrant of the present invention.

FIG. 9 is an overall sectional view showing the antifreeze sprinkler according to the present invention in an extended state.

FIG. 10 is an overall sectional view showing the antifreeze water tap according to the present invention in a contracted state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Antifreeze fire hydrant 12 Valve box 14 Upper pumping pipe 16 Inflow port 18 Valve body 20 Piston 22 Main valve 24 Drainage valve 26 Connection structure 32 Upper pumping pipe 36 Inner pipe 38 Joining fitting 40 Square pipe 44 Square rod 48 Spindle 50 Spout port 110 Antifreeze sprinkler tap 112 Valve box 114 Upper pumping pipe 118 Valve body 120 Piston 122 Main valve 124 Drain valve 126 Expansion mechanism 132 Upper pumping pipe 136 Inner pipe 138 Joining fitting 140 Square pipe 144 Square rod 148 Spindle 150 Spout port 152 Manhole

Claims (5)

[Claims] 1. A valve box to which a water pipe is connected, a pumping pipe joined to an upper end of the valve box, and a main valve arranged in the valve box for interrupting communication between the water pipe and the pumping pipe. An antifreeze fire hydrant having a piston attached to a main valve and a drain valve attached to a valve box, wherein a male screw portion is formed on a part of the outer surface of the piston, and the piston meshes with the male screw portion. When the piston is rotated in one direction and raised, the water pipe and the pumping pipe communicate.When the piston is rotated in the opposite direction and lowered, the main valve is Thus, the communication between the water pipe and the pumping pipe is interrupted, and the pumping pipe and the drain valve are configured to communicate with each other through a gap formed between the valve body and the piston. Antifreeze fire hydrant. 2. A square pipe or square rod is joined to the upper end of the piston, and the square rod or square pipe is slidably inserted into the upper end of the square pipe or square rod. The hydrant according to claim 1, wherein the square pipe or the rod is moved up and down along the square rod or the square pipe when the piston, the square pipe, and the piston are rotated. 3. The pumping pipe comprises a lower pumping pipe whose upper end is slightly protruded from the ground and an upper pumping pipe, wherein the lower pumping pipe and the upper pumping pipe are connected to each other. The connection structure has a portion having an allowable bending stress smaller than the allowable bending stress of the lower pumping pipe and the upper pumping pipe, and the square rod or the square pipe has a connecting structure. Is formed at a height at or slightly higher than the height of the square pipe or the square pipe having a smaller allowable bending stress than other portions of the square pipe or the square pipe. 3. An antifreeze fire hydrant according to claim 1, wherein the hydrant is substantially hingedly connected to the piston. 4. A lower end of the inner pipe housed in the lower pumping pipe is in contact with a valve body seated on a step portion in the valve box, and an upper end of the inner pipe prevents the inner pipe from rising due to water pressure. The antifreeze fire hydrant according to any one of claims 1 to 3, wherein the antifreeze fire hydrant is in contact with a removable stopper. 5. A valve box to which a water pipe is connected, a pumping pipe joined to an upper end of the valve box, and a main valve arranged in the valve box for interrupting communication between the water pipe and the pumping pipe. , Equipped with a piston attached to the main valve and a drain valve attached to the valve box,
An antifreeze sprinkler, wherein the pumping pipe has a lower pumping pipe and an upper pumping pipe, and is configured to extend the upper pumping pipe when used and to contract the upper pumping pipe when not in use. A male thread is formed on a part of the valve body, and the piston is screwed into a valve body having a female thread engaged with the male thread. When the pipe communicates and the piston is rotated in the opposite direction and lowered, the communication between the water pipe and the pumping pipe is interrupted by the main valve, and through the gap formed between the valve body and the piston. A pump and a drain valve are configured to communicate with each other, and a square pipe or a square rod is joined to an upper end of the piston, and a square rod or a square pipe is slidably inserted into an upper end of the square pipe or the square rod. And turn the handle By rotating the square rod, the square pipe, and the piston by moving the piston up and down, the square pipe or the square rod moves up and down along the square rod or the square pipe, and the lower end of the inner pipe housed in the lower pumping pipe is raised. Abuts the valve body seated on the step in the valve box, and the upper end of the inner pipe is in contact with a removable stopper to prevent the inner pipe from rising due to water pressure. Water tap.