JPS5842542Y2 - Automatic pressure reducing fire hydrant - Google Patents

Description

[Detailed description of the invention] The present invention relates to a fire hydrant equipped with a pressure reduction mechanism that can automatically reduce pressure, and the secondary side (downstream side) pressure is adjusted to a predetermined value in response to fluctuations in the primary side (upstream side) pressure. To provide an automatic depressurizing fire hydrant with a simple structure that has excellent performance in reducing pressure within a range and ensures safety even at extremely high pressures.

The present invention provides a through space BB in the outflow side pipe part 1a of the fire hydrant
A flanged valve body 2 consisting of a flanged portion 11a provided with... and a main body portion 2a provided with a central through hole 3 is arranged so as to be slidable in the axial direction of the tube portion 1a. 4 biases the upstream side, and by providing an orifice 7 in the outflow pipe portion 1a at a position facing the downstream end of the main body portion 2a of the flanged valve body 2, the primary side The fourth feature is the ability to reduce the secondary pressure within a predetermined range in response to pressure fluctuations.
In addition to making it extremely excellent as shown in the figure performance curve,
Due to the action of the through hole 3, it is constructed so that it is not affected by water hammer and safety is ensured even under extremely high pressure.

The present invention will be specifically described below based on embodiments shown in the drawings.

In this embodiment, the outflow side pipe portion 1a is composed of the fitting 1 attached to the outflow portion 6 of the fire hydrant valve housing 5 and the tubular casing 8.

The fitting 1 is screwed onto the open end of the water outlet 6a, for example, as shown in the figure.

As shown in FIG. 2, the tubular casing 8 having an orifice 7 at its tip is mounted inside the fitting 1. As shown in FIG.

A fixed ring 9 is screwed onto the base end of the casing 8 to prevent the flanged valve body 2 from moving back at a certain position.

A flanged valve body 2 is disposed within the casing 8 so as to be slidable in the axial direction of the casing 8.

This flanged valve body 2 has a plurality of radial projections 11, 11...
The main body part 2a includes a flange part 11a consisting of a flange part 11a, and a main body part 2a having a central through hole 3 passing through the central axis and a pressure control part 12 formed in the shape of a truncated cone.

The flange portion 11a is provided at the upstream end of the flange-equipped valve body 2, and the outer periphery 13.13 of the protrusion 11.11...
. . . is formed into an arcuate surface having the same curvature as the inner periphery of the casing 8, so that the flanged valve body 2 can slide smoothly inside the casing 8.

The downstream end (corresponding to the pressure control unit 12 in this embodiment) of the main body portion 2a is disposed at a position facing the orifice 7, and is moved between the downstream end and the downstream end by moving the flanged valve body 2 back and forth. The area of a variable flow path C, which will be described later, formed between the flow path C and the orifice 7 is configured to be increased or decreased.

Reference numeral 4 denotes a bullet that elastically supports the flanged valve body 2 toward the upstream side (primary side), specifically, the protrusions 1, 1, 11, etc.
It can be constructed by interposing a compression coil spring between the inner flange portion 7a of the orifice 7 and the inner flange portion 7a of the orifice 7.

In addition, 14 is a water volume adjustment valve, 15 is a bundle, 16 is an inflow part, and 17 is a push ring.

According to the present invention, the amount of water flowing from the inflow portion 16 is adjusted by the water amount adjustment valve 14, passes through the fitting 1, and flows out to a fire hose (not shown).

When passing through the fitting 1, a portion of the flow passes straight through the central through hole 3 and the orifice 7 and reaches the inside of the fire hose.

On the other hand, the remainder of the flow sequentially passes through the protrusions 11, 11...
...The through space B (Fig. 3) formed between them, the flow path formed around the main body part 2a, the downstream end of the main body part 2a (in this embodiment, the pressure control part 12) It passes through the variable flow path C formed between the and orifice 7 and reaches the inside of the fire hose.

Therefore, when the pressure on the primary side (upstream side) P is large, the second pressure acting on the pressure receiving surface 10 formed on the upstream side surface of the flanged valve body 2
The force in the direction of the arrow in the figure increases, and the flanged valve body 2 moves in the direction of the arrow while compressing the coil spring 4. As a result, the variable flow path C is narrowed, and the pressure on the secondary side (downstream side) Q is reduced. The pressure will be significantly reduced.

Figure 4 is a performance curve showing the relationship between the primary pressure and the secondary pressure in the device with the above configuration.
g/cm2 in the range of 13kg/cm2
The next side pressure is approximately constant (3 kg/cm” to 4 kg/cm”)
) It has an unprecedented performance of being able to control the pressure reduction.

Moreover, according to the Fire Service Act, the secondary pressure is 1.7 kg/Cm.
Although it is specified to be 2 to 7 kg/Cm2, as is clear from FIG. 4, it is possible to reduce the primary pressure within a considerably wide range within the above range.

The present invention can be configured in various ways other than those shown in the above embodiments.

For example, in the above embodiment, the outflow side pipe portion 1a of the fire hydrant
Although the outflow side pipe portion 1a is formed by the insert fitting 1 and the tubular casing 8, other structures may be used, such as forming the outflow side pipe portion 1a integrally with the fire hydrant valve housing 5.

Further, in the above embodiment, a plurality of protrusions 11, 11...
. . . constitutes the flange portion 11 a of the flanged valve body 2, and the protrusion 1
1.11...Penetrating space B, B...
... is formed, but the flange 11 has a through hole.
a, and the through holes are connected to the through spaces B, B...
...may be done.

Further, in the above embodiment, the upstream end of the main body 2a of the flanged valve body 2 is formed into a truncated conical shape, but the shape is not limited to this.

Since the present invention has the above configuration, it is possible to provide a substantially constant pressure reduction effect through the center through hole 3 provided in the flanged valve body 2, and also to increase or decrease the primary side pressure by increasing or decreasing the flow path area of the variable flow path C. As a result of being able to provide a pressure reduction effect corresponding to the pressure reduction effect, as shown in FIG. 4, there is an effect of having extremely excellent pressure reduction performance.

Furthermore, since the present invention has the through hole 3, safety is ensured even if the primary pressure becomes extremely high, and there is also the effect that it is not affected by water hammer.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway front view, FIG. 2 is a vertical sectional view of the main part, FIG. 3 is a sectional view taken along line A-A in FIG. 2, and FIG. It is a performance curve showing the relationship between primary side pressure and secondary side pressure. 1a...Outflow side pipe portion, 2...Flanged valve body, 2a...Main body portion, 3...Center through hole, 4... ...Bullet machine, 7... Orifice.

Claims (1)

[Scope of utility model registration request] A flange-equipped valve body consisting of a flange portion with a through space and a main body portion with a central through hole is arranged in the outflow side pipe portion of the fire hydrant so as to be slidable in the axial direction of the pipe portion. An automatic decompression type fire hydrant characterized in that an orifice is provided in the outflow side pipe portion at a position facing the downstream end of the main body portion of the flanged valve body while being biased toward the upstream side.