JP2001140292A - Fire hydrant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain secure passage of water in next emergency by automatically draining remaining water in a valve casing upper chamber when a valve is opened after completing fire-extinguishing operation or the like. SOLUTION: An inclination valve passage 16 for connecting the inside and outside of a valve casing upper chamber 3 is provided, and a drainage valve 17 is accommodated in the valve passage 16 so that it can be elevated freely. When a ball valve 4 is to be opened on emergency, the drainage valve 17 is raised by the water pressure of water for extinguishing fire flowing inside the valve casing upper chamber 3 for seating at a valve seat 16C. On the other hand, when the ball valve 14 is to be closed after the fire-extinguishing operation is completed, the drainage valve 17 is lowered due to dead weight for opening the valve passage 16, and water remaining in the valve casing upper chamber 3 is automatically drained from a drainage passage 19 to the outside of the fire hydrant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire hydrant, and more particularly to a fire hydrant capable of reliably preventing fire water from remaining in a chamber above a valve box after a fire extinguishing operation.

[0002]

2. Description of the Related Art A fire hydrant shown in FIG. 4 is conventionally known. The fire hydrant includes, for example, a valve box 2 having a longitudinal axis which is removably mounted in communication with a water supply main pipe 1 extending in a lateral direction, and a plug which is provided in communication with an upper portion of the valve box 2. And a box upper chamber 3. A ball valve 4 is housed in the valve box 2, and the ball valve 4 is opened and closed by an opening and closing operation of a valve body opening and closing mechanism 5. That is, the valve body opening / closing mechanism 5 includes a valve stem 5A having a horizontal axis, a worm wheel 5B attached to the outer end of the valve stem 5A so as to be able to rotate simultaneously, and a worm 5C meshing with the worm wheel 5B. And a worm shaft 5D having a longitudinal axis provided on the ball valve 4A. A square inner end 5a of the valve stem 5A is fitted in a square recess 4A provided in the ball valve 4, and the worm wheel 5B and the worm 5C are attached to and detached from the valve box 2. The worm shaft 5D is rotatably housed inside the gear case 6 which is attached so as to be able to rotate. The upper end of the worm shaft 5D protrudes upward from the gear case 6, and the cap 7 is covered with the rectangular upper end 5d so as to be rotatable simultaneously. I have. The upper end opening of the valve box upper chamber 3 formed by a fitting is closed by a mouth cap 8 so as to be openable and closable.
In the drawings, O denotes a seal ring, 9 denotes a valve seat, 10 denotes a press ring, 11 denotes a parallel pin, 12 denotes a worm bearing, and 13 denotes a set screw.

In the fire hydrant having such a structure, in normal times, the ball valve 4 is held in a valve closed state (fully closed state) in which the ball valve 4 is rotated by 90 degrees around the horizontal axis (in the direction of arrow R) from the state shown in the figure. In an emergency such as a fire, first, after the base cap 8 is removed, an inlet of a fire hose (not shown) is connected to an upper end opening of the valve box upper chamber 3 formed by a fitting. Thereafter, by the opening operation of the valve body opening / closing mechanism 5, the ball valve 4 is rotated 90 degrees around the horizontal axis (the direction opposite to the arrow R), and is held in the valve open state (full open state) as shown in the figure.
For example, when a square box provided at the lower end of a manual tool such as a T-box wrench (not shown) is fitted to the cap 7 and the T-box wrench is rotated in the valve opening direction, the valve is opened. Rotation in the opening direction is the worm shaft 5D →
The worm 5C is transmitted to the ball valve 4 through the worm wheel 5B → the valve rod 5A → the valve stem 5A → the square inner end 5a → the square recess 4A, and the ball valve 4 is rotated 90 degrees around the horizontal axis (the direction opposite to the arrow R). As shown in the figure, the valve can be held in the open state (full open state). When the ball valve 4 is held in the valve open state, the valve box 2 and the valve box upper chamber 3 communicate with each other, and the fire extinguishing water in the water supply main pipe 1 is supplied to the fire hose connected to the valve box upper chamber 3. Fire extinguishing work can be performed.

On the other hand, after the end of the fire extinguishing operation, the ball valve 4 is rotated 90 degrees around the horizontal axis (in the direction of arrow R) by the closing operation of the valve body opening / closing mechanism 5 to close the valve (fully closed state). ). Thereby, communication between the valve box 2 and the valve box upper chamber 3 is interrupted, and water remains in the valve box upper chamber 3.

[0005] If water is left in the interior of the valve box upper chamber 3 as described above, the remaining water freezes over time in winter when the outside air temperature is low. Therefore, even if the ball valve 4 is opened in the above-described manner in the next emergency, the fire extinguishing water in the water supply main pipe 1 is not supplied to the valve box upper chamber 3 and the fire hose. Therefore, in the conventional fire hydrant, a water drain passage 14 is provided at the lower end of the valve box upper chamber 3 to communicate the inside of the valve box upper chamber 3 and the outside of the valve box upper chamber 3 with each other. 14 is closed by a plug 15 and the ball valve 4 is closed after a fire extinguishing operation or the like is completed. Then, the plug 15 is removed to discharge the residual water from the drain passage 14. The outlet side of the drain passage 14 is closed by a plug 15.

[0006]

However, in the conventional fire hydrant which needs to be manually drained by removing the plug 15 after the ball valve 4 is closed after the fire extinguishing operation or the like is completed, the plug 15 must be removed. Absence of valve box 3 by forgetting
There is a risk that the remaining water in the interior will freeze and impede water flow in an emergency.

Therefore, the present invention automatically drains the remaining water in the upper chamber of the valve box when the valve body is closed after a fire extinguishing operation or the like, so that reliable water flow can be ensured in the next emergency. The aim is to provide a fire hydrant that can be obtained.

[0008]

In order to achieve the above object, a fire hydrant according to the present invention comprises a valve box connected to a water supply main pipe and a valve provided at an upper portion of the valve box. Comprising a box upper chamber, the valve body housed in the valve box is opened and closed by the opening and closing operation of a valve body opening and closing mechanism connected to the valve body,
When the valve is opened, the valve box communicates with the upper chamber of the valve, water in the water supply main pipe is supplied to the upper chamber of the valve, and when the valve body is closed, communication between the valve box and the upper chamber of the valve box is performed. In a fire hydrant configured to be shut off, a valve passage for communicating the inside of the valve box upper chamber and the outside of the valve box upper chamber with each other is provided so as to house a drain valve so as to be movable up and down, and The valve passage is opened by a drain valve that descends by its own weight when the valve body is closed, and the drain valve that rises with the water pressure of the water supplied to the inside of the valve box upper chamber when the valve body is opened opens the valve passage. The valve passage is closed, and a drain passage is provided to connect the valve box upper chamber and the outside of the valve box upper chamber to each other when the valve passage is opened.

According to the present invention, if the valve body is closed after a fire extinguishing operation or the like, water remains in the upper chamber of the valve box and the water pressure applied to the drain valve becomes substantially non-pressure. Become. For this reason, the drain valve descends by its own weight and opens the valve passage,
The residual water in the valve box upper chamber is automatically drained to the outside of the valve box upper chamber via the valve passage opened from the drain passage.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall sectional view showing one embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a main part. The structure and operation of the valve case 2, the valve case upper chamber 3, the ball valve 4, the valve body opening / closing mechanism 5, the gear case 6, the cap 7, the cap 8 and the like are the same as those of the conventional example shown in FIG. Therefore, the same reference numerals are given and their detailed description is omitted. 1 and 2, a valve passage 16 for communicating the inside of the valve box upper chamber 3 with the outside of the valve box upper chamber 3 has an inclined axis, and the valve box upper chamber 3 at the upper end of the valve box 2. And is provided through the boundary portion between them. This valve passage 16
A large-diameter large-diameter portion 16A having a uniform inner diameter whose inner end opens into the interior of the valve box upper chamber 3 and a short-diameter opening whose outer end opens outside the valve box upper chamber 3, that is, outside the fire hydrant. A small-diameter portion 16B, and the large-diameter portion 16A and the small-diameter portion 16B are conical valve seats 16.
Continuous through C.

A drain valve 17 made of a metal ball or a resin ball having an outer diameter slightly smaller than the inner diameter of the large diameter portion 16 is housed inside the large diameter portion 16A so as to be able to move up and down. A drain valve supporting member 18 having a through hole 18a is attached to the inner end of the drain valve. In addition, a small-diameter drain passage 1 having a horizontal axis whose inner end is opened inside the valve box upper chamber 3 and whose outer end is opened at the large-diameter portion 16A of the valve passage 16.
9 are provided.

In the above configuration, when the ball valve 4 is opened in an emergency, the pressure of the fire-extinguishing water flowing inside the valve box upper chamber 3 is applied to the drain valve 17 through the through hole 18a of the drain valve support member 18. As shown in FIG. 3, the valve passage 16 in which the drain valve 17 is raised and seated on the conical valve seat 16C is formed.
Is closed. Therefore, the fire extinguishing water in the water supply main pipe 1 is connected to the valve box upper chamber 3 in a state where the fire extinguishing water flowing inside the valve box upper chamber 3 is prevented from being drained from the valve passage 16 and the drain passage 19. For example, a fire extinguishing work can be performed by effectively supplying the fire extinguishing hose (not shown).

On the other hand, the ball valve 4
Is closed, water remains inside the valve box upper chamber 3 and the water pressure applied to the drain valve 17 becomes substantially non-pressure. For this reason, the drain valve 17 descends by its own weight, and as shown in FIG. 2, opens the valve passage 16, so that the residual water in the valve box upper chamber 3 removes the valve passage 16 opened from the drain passage 19. After that, the water is automatically drained to the outside of the valve box upper chamber 3, that is, to the outside of the fire hydrant. Therefore, water can be reliably passed in the next emergency.

More specifically, a small amount of water indicated by water level H in FIG. 1 remains in the valve box upper chamber 3 and freezes in winter. However, because of the thin ice, the water can be easily broken and water can be passed by the fire-extinguishing water pressure when the ball valve 4 is opened in an emergency.

[0015]

As described above, according to the present invention, if the valve body is closed after the fire extinguishing operation or the like is completed, the drain valve descends by its own weight to open the valve passage. The remaining water is automatically drained to the outside of the valve box upper chamber through the valve passage opened from the drain passage. For this reason, reliable water flow can be obtained in an emergency.

[Brief description of the drawings]

FIG. 1 is an overall sectional view showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing an open state of a valve passage by a drain valve.

FIG. 3 is an enlarged sectional view showing a closed state of a valve passage by a drain valve.

FIG. 4 is an overall sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water supply main pipe 2 Valve box 3 Valve box upper chamber 4 Ball valve (valve element) 5 Valve element opening / closing mechanism 16 Valve passage 17 Drain valve 18 Drain passage

Claims (1)

[Claims] 1. A valve body connected to a water supply main pipe and mounted, and a valve box upper chamber provided in communication with an upper part of the valve box, and a valve body housed in the valve box is provided with a valve body. The valve is opened and closed by an opening and closing operation of a valve body opening and closing mechanism connected to the body, and when the valve is opened, the valve box and the valve box upper chamber communicate with each other, and water in the water supply main pipe is supplied to the valve box upper chamber, In a fire hydrant configured to cut off communication between the valve box and the valve box upper chamber when the valve body is closed, a valve that connects the inside of the valve box upper chamber and the outside of the valve box upper chamber to each other. A passage is provided so as to accommodate the drain valve so as to be able to move up and down, and the valve passage is opened by the drain valve which descends by its own weight when the valve body is closed, and the valve box upper chamber is opened when the valve body is opened. The valve passage is closed by a drain valve that rises due to the pressure of the water supplied to the inside, and when the valve passage is opened, A fire hydrant, wherein a water drain passage is provided for communicating the valve box upper chamber and the outside of the valve box upper chamber with each other.