JP2001146768A - Hydrant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low and inexpensive hydrant that can be accommodated in a pit even when the burying depth of a main pipe becomes shallow in the lifting type hydrant being installed in an underground bit. SOLUTION: The opening area of an opening inflow part is set larger than the maximum sectional area of a valve 12a, and the flange of a sub valve 5a being connected to the opening inflow part is set to a valve seat, thus eliminating the need for providing the valve seat in a valve box 10a, and hence reducing the height of a hydrant 1a. At the same time, an up and down movement mechanism such as the valve 12a and valve rod 20a can be inserted from the opening inflow part of the valve box 10a and a cylinder part 30 for assembly, thus greatly reducing the number of components, the man-hours of assembly, and costs. Also, by this structure, the height of the hydrant 1a can be further reduced, thus preventing the hydrant from being exposed on the earth's surface for sufficiently installing in the pit even when the burying depth of a main pipe becomes shallow, namely 600 to 800 mm from the earth's surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire hydrant branched from a water pipe, and more particularly to a lift-type underground fire hydrant.

[0002]

2. Description of the Related Art A water pipe buried underground is provided with a fire hydrant at an appropriate interval on a branch pipe rising from the water pipe. The fire hydrant itself is also installed in the underground pit, and when used, the lid of the pit is opened and a hose is connected to the water outlet of the fire hydrant to discharge water.

Fire hydrants are generally installed as shown in FIG. There is a main pipe 2 consisting of water pipes in the ground
The fire hydrant 1 is installed at the location where the main
Are formed. In this pit, a connecting pipe 4 and a sub-valve 5 are sequentially connected to a branch section 3 which is formed as a T-shaped pipe and rises upward from the main pipe, and a fire hydrant 1 is connected thereto. Here, the auxiliary valve 5 is also referred to as a repair valve, and is closed when performing maintenance work on the fire hydrant main body, and is normally opened.

Next, the structure of a conventional fire hydrant will be described with reference to FIGS. 6 and 7. FIG. The upper surface of the opening inflow portion of the valve box 10 serves as a valve seat surface 11, and the rubber lining portion 13 of the valve body 12 contacts and separates over the entire circumference of the valve seat surface 11. It controls the inflow of water. Valve body 1
2 moves up and down to open and close the valve, and is generally called a lift type.

[0005] A flange at the lower part of the valve box is connected to the sub-valve (see FIG. 5), and a water outlet 16 is connected to the upper part of the valve box 10 via a refill pipe 15. At the time of water discharge, the water outlet cap 17 is removed, a hose is attached to the water outlet 16 and the valve body 12 is raised, so that water in the main pipe is discharged from the hose.

The valve body 12 can be moved up and down by the structure described below. The valve stem 20 is fitted into the outer lid 21, and several concave portions are provided around the fitting hole in the outer lid 21, and the female screw top 22 and the packing 23 for sealing are fitted therein. Screw top 2 to be fitted
2 does not rotate. The valve stem 20 has a valve body 12
However, a cap 24 is connected to the upper portion, and a lower thread portion is screwed into the female screw top 22. The outer lid 21 has a flange connected to the valve box 10 with bolts and nuts, and a packing retainer 25 is bolted from above the outer lid 21. Therefore, when the cap 24 having a chamfered side surface is turned with a predetermined tool, the valve element 12 moves up and down.

Here, the above-mentioned valve body 12, valve stem 20,
The valve body up-and-down moving part reaching the cap 24 and the outer lid 21 is assembled in advance, and is connected to the valve set 10 with bolts and nuts via the flange of the outer lid 21. Also, if the height of the cap 24 and the outlet 16 is too different,
Since the operation at the time of water discharge is difficult, the extension pipe 15 is connected to the water discharge port 1.
6 and the valve box 10.

[0008]

At present, as shown in FIG. 5, the main pipe of a water pipe has an upper surface of 1200 mm underground.
It is buried in the position. However, recently, in order to reduce the construction cost, the above burial depth is set to 600 to 800 m.
A notice to make it shallow to about m is being issued.

Then, in the conventional configuration shown in FIG.
In order for the fire hydrant to protrude to the surface, the height of the main pipe after the branch pipe must be reduced. Even if the connecting pipe is somehow omitted, the auxiliary valve required for maintenance work on the fire hydrant body cannot be removed, and a ball valve is often used as the auxiliary valve, and its overall height is high enough to be considered a problem Not something. However, in order to keep the fire hydrant out of the ground, it is essential to lower the fire hydrant itself.

As means for lowering the fire hydrant, a ball valve type fire hydrant often used for the above-mentioned auxiliary valve is commercialized instead of the lift type described in the conventional example (not shown). In the case of the ball valve type, the overall height can be suppressed as low as possible, but there are the following problems.

Since the fire hydrant is installed in the pit,
During rainfall, rainwater containing sediment and mud enters the pit and floods the pit. Then, the rainwater easily enters the inside of the fire hydrant from the water outlet palate, and the ball portion replacing the valve body of the lift type is covered with the rainwater. Then, when the rainwater is pulled and dried, the soil and mud on the ball surface are stuck. When opening and closing the valve in that state,
The spherical sliding part was damaged, and the essential sealing function was gradually impaired.

In addition, the processing of the spherical ball portion and the ball receiving portion matching the spherical surface requires precise processing accuracy. Further, the opening and closing operation of the valve needs to be the same as that of the lift type, and the operation is performed by turning the cap from the vertical direction. In order to rotate the ball, the cap must rotate a vertically extended axis attached to the tip, which must be changed to the rotation of a horizontal axis connected to the side of the ball. After applying worm gear processing,
Both had to engage. Therefore, the fire hydrant of the ball valve type became considerably expensive compared with the lift type. For this reason, lift hydrants have been preferred and used at present in terms of both quality and cost.

[0013]

Accordingly, the present invention is a lift-type fire hydrant proposed to solve the above-mentioned problems. First, it is the same as a conventional fire hydrant that a valve body that moves up and down is provided at an opening inflow portion in a valve box, but a flange of a connection partner connected to the opening inflow portion of the valve box is used as a valve seat, and a valve body is provided. By moving up and down, the inflow of water into the valve box can be opened and closed to reduce the overall height.

Further, the opening area of the opening inflow portion is characterized by being larger than the maximum cross-sectional area of the valve body. When assembling, the vertically moving mechanism parts such as the valve body and the valve rod are passed through the opening inflow portion from below. It is also characterized by a structure that can be inserted and assembled in a valve box formed of an integral body.
Further, the water outlet can be not only a single outlet but also a double outlet fire hydrant.

The fire hydrant itself has no valve seat surface,
Since a water tightness test alone cannot be performed, in such a case, a water tightness test can be performed by connecting a test joint tube having a flange with which the valve body comes into contact with and separates from the opening inflow portion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fire hydrant according to the present invention will be described below with reference to FIGS. Note that the same components as those of the conventional example are denoted by the same reference numerals. FIG. 1 is a front view of a fire hydrant of the present invention, and FIG. 2 is a side view.
FIG. 1 shows the valve closed, FIG. 2 shows the valve open,
In both cases, the inside (particularly, the vertically moving portion) is also drawn as a partial cross section.

The valve box 10a is a cast product, has an opening inflow portion on the bottom surface, and a cylindrical portion 30 above which the valve stem 20a is inserted.
There is. At the lower end of the valve stem 20a, a valve body 12a having a rubber-lined surface 13a is fixed with a nut. The threaded portion of the valve stem 20a is screwed into a female screw top 22a fitted into a frame receiving portion 31 provided on the valve box 10a (the fitting method will be described later). Female thread top 2
2a has an outer periphery chamfered or the like,
When fitted into one, it does not rotate. Therefore, the stem 20
With rotation of a, the valve body 12a moves up and down. On the other hand, the O-ring 32 is fitted into the valve stem 20a,
The water leakage from the valve box 10a is prevented by being inserted into the cylindrical portion 30 of FIG. A cap 24a is connected to the upper part of the valve stem 20a (outside of the valve box).
If the cap 24a is turned with a predetermined tool, the valve element 12a moves up and down.

The water outlet 16a is the same as in the prior art.
The flange is connected to the valve box 10a, and the sub-valve 5a is connected to the lower part of the valve box 10a by a flange.

FIG. 1 shows a state in which the fire hydrant 1a is closed, but when the valve body 12a descends and comes into contact with the upper surface of the flange of the sub-valve 5a, water flows from the sub-valve 5a into the fire hydrant 1a. Have stopped. That is, the upper surface of the flange of the sub-valve 5a is a conventional valve seat. The opening area of the opening inflow portion is larger than the cross-sectional area of the valve element 12a, and the valve element 12a can be lowered until it comes into contact with the upper surface of the flange of the sub-valve 5a. Note that the flange upper surface of the sub-valve 5a has a high surface finishing accuracy, and exhibits a water stopping effect without any problem if it comes into contact with the valve body 12a.

Therefore, unlike the conventional valve box, there is no need to provide a valve seat inside, so that the dimensions of the bottom of the fire hydrant can be omitted and the height can be reduced. Further, regarding the valve stem, in the past, the valve stem has passed through the outer lid and the packing retainer on the upper part thereof, but in the present invention, the valve stem only has to pass through the cylindrical portion which is a part of the valve box. The length of the cylindrical portion can be made as short as possible in accordance with a desired vertical movement stroke of the valve body. Therefore, the valve stem becomes shorter, and the position of the cap can be lowered. Therefore, the height of the fire hydrant can be further reduced. As a result, in the fire hydrant having a connection diameter of φ75 mm, the height when the conventional fire hydrant was fully closed (see FIG. 4) was 420 mm, but in the present invention, it can be suppressed to 210 mm, and the height can be reduced by half. did it.

Next, a method of assembling a vertically moving portion such as a valve rod into a valve box will be described. First, the female screw top 22 is provided on the valve box 10a along the path shown by the arrow C in FIG.
a is fitted from the opening inflow portion into the frame receiving portion 31 into which the a is fitted. The frame receiver 31 has upper and lower holes or long holes through which the valve stem 20a penetrates, and holds the female screw frame 22a substantially horizontally. Next, the valve stem 20a on which the O-ring 32 is set is inserted from above the cylindrical portion 30, and the lower end thereof is taken out toward the opening inflow portion while being screwed and rotated with the female screw top 22a.

Thereafter, the valve body 12a is fitted to the lower end of the valve stem 20a, and a spring washer is sandwiched between the valve body 12a and tightened with a bolt. On the other hand, a cap 24a is fitted to the upper end of the valve stem 20a and fixed with a set bolt. Thus, when the cap 24a is rotated, the valve element 12a can be moved up and down. That is, by inserting the female screw top 22a and the valve body 12a from the opening inflow portion at the bottom of the valve box 10a, and inserting the valve rod 20a from the cylindrical portion 30 above the valve box 10a,
The vertical moving part can be assembled. From another viewpoint, this assembling method is possible because the opening area of the opening inflow portion is larger than the cross-sectional area of the valve body 12a.

When the present invention is compared with a conventional fire hydrant (see FIG. 4), as in the conventional case, the valve body vertical moving parts leading to the valve body, valve stem, cap and outer lid are assembled in advance and the There is no need to connect it to the valve set via bolts and nuts, etc., via the lid flange. Naturally, the number of components has been greatly reduced, achieving a significant cost reduction. Further, in the case of a structure having a valve seat inside the valve box as in the related art, it took time and labor to grind the valve seat surface of the cast valve box once flat, but the present invention does not require such a work. It also contributes to cost reduction.

FIG. 3 shows the fire hydrant of the present invention installed in the pit. In this case, the burial depth of the main pipe 2 is 6
Even if it is shallow to about 00 to 800 mm and the conventional auxiliary valve 5 is provided between the main pipe 2 and the hydrant 1a, the fire hydrant 1a can be sufficiently installed in the pit without coming out to the surface of the ground.

FIG. 4 shows another embodiment of the present invention.
Shows a fire hydrant 1b having a water outlet 16b as a double mouth. This is also the same as the single-port type described so far in that the up and down mechanism of the valve body 12b and the upper surface of the flange of the connected sub-valve 5b are used as a valve seat. In the valve box 10b, it is necessary to provide a frame receiving portion 31b into which the female screw frame 22b fits, on the back side of the drawing, but as in the case of the single-port type, the overall height can be reduced as compared with the conventional double-mouthed hydrant. Further, it is possible to significantly reduce costs due to the reduction in the number of components.

In the above description, the auxiliary valve was connected to the opening of the fire hydrant and the upper surface of the flange of the auxiliary valve was used as the conventional valve seat.
It may be a simple connecting pipe. In short, all that is needed is a flange corresponding to the valve seat.

When a watertightness test is performed for the fire hydrant of the present invention by itself, the following procedure may be taken. Even if water is supplied, the fire hydrant itself cannot stop water because there is no valve seat. Therefore, a watertight test can be performed by preparing a test joint tube provided with a detachable flange on the valve box and connecting it instead of the sub-valve described above.

[0028]

As described above, in the fire hydrant of the present invention, the opening area of the opening inflow portion is set to be larger than the maximum cross-sectional area of the valve body, and the connection partner flange connected to the opening inflow portion is connected to the valve. By providing a seat, there is no need to provide a valve seat in the valve box, and the height of the fire hydrant can be reduced.

At the same time, the up-and-down movement mechanism such as the valve body and the valve stem is assembled separately from the valve box, and then inserted from the opening inflow portion or the cylindrical portion of the valve box without being connected to the valve box with bolts and nuts. Can be assembled. As a result, the number of components can be significantly reduced, and the number of assembling steps is also reduced. In addition, the height of the fire hydrant can be further reduced by this structure, and as a result, even if the burial depth of the main pipe becomes shallow to about 600 to 800 mm from the ground surface, the fire hydrant does not appear on the ground surface and is sufficiently installed in the pit. be able to.

Furthermore, unlike the fire hydrant of the ball valve type,
It is difficult for earth and sand and mud to get into the seal part of the valve body. Therefore, a high sealing function can be maintained without deterioration of the sealing function.

[Brief description of the drawings]

FIG. 1 is a front view showing a fire hydrant of the present invention in a partial cross section.

FIG. 2 is a side view showing the fire hydrant of the present invention in a partial cross section.

FIG. 3 is a piping connection diagram using the fire hydrant of the present invention.

FIG. 4 is a front view showing another embodiment of the fire hydrant of the present invention in a partial cross section.

FIG. 5 is a piping connection diagram using a conventional fire hydrant.

FIG. 6 is a front view showing a conventional fire hydrant in a partial cross section.

FIG. 7 is a side view showing a conventional fire hydrant in a partial cross section.

[Explanation of symbols]

 1, 1a, 1b Fire hydrant 2 Main pipe 3 Branch pipe 5, 5a, 5b Secondary valve (repair valve) 10, 10a, 10b Valve box 12, 12a, 12b Valve body 13, 13a Rubber lining 16, 16a, 16b Outlet 17 , 17a Water outlet cap 20, 20a, 20b Valve stem 22, 22a, 22b Female screw top 24, 24a Cap 30 Cylindrical part 31, 31b Frame receiving part 32 O-ring

Claims (5)

[Claims] 1. A fire hydrant having a valve body that moves up and down at an opening inflow portion in a valve box, wherein a flange connected to the opening inflow portion of the valve box is used as a valve seat, and the valve body moves up and down. A fire hydrant characterized by being able to open and close water inflow into a valve box. 2. The fire hydrant according to claim 1, wherein an opening area of the opening inflow portion is larger than a maximum sectional area of the valve body. 3. The assembling method according to claim 2, wherein the vertical movement mechanism component of the valve body can be inserted from below through the opening inflow portion and assembled into a valve box formed as an integral body. The fire hydrant according to 2. 4. The fire hydrant according to claim 3, which has a plurality of water outlets. 5. The fire hydrant according to claim 3, wherein a test joint tube having a flange with which the valve body comes into contact with and separates from the valve case is detachable from an opening inflow portion of the valve box.