JPS5917311B2 - Float control structure of float valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a float control structure for a valve controlled by a float such as a ball tap.

It is desirable for a float valve to open and close at two liquid levels, upper and lower, separated by an appropriate distance in the liquid container.

Otherwise, the float will oscillate due to the ripples and turbulence of the liquid level in the container due to the liquid flowing out from the float valve, causing the valve to repeatedly open and close in small steps, shortening the life of the valve.

Therefore, Japanese Patent Application No. 54-131108 (see Japanese Patent Application Laid-open No. 56-55774) proposed a float valve that opens and closes at two liquid levels, upper and lower, separated by an appropriate distance.

In the proposed system, a float is housed in a float chamber formed by a casing that opens downward, and a
It is equipped with a check valve that allows flow from inside the float chamber to the outside and prohibits reverse flow.

Since the float chamber can freely flow out to the outside, the liquid level inside the float chamber rises with the external liquid level, but even if the external liquid level falls, it does not fall due to the action of the check valve, and the external liquid level remains at the specified level. It descends to the normal position, and gas begins to flow into the float chamber from the bottom, and then it descends all at once.

Therefore, the float valve opens and closes at two liquid levels, the upper and lower liquid levels, but this happens suddenly and easily causes water hammer.

Buoyancy is created on the float according to the volume submerged below the liquid surface,
The buoyancy opens and closes the float valve.

The force required to open and close the valve varies depending on the pressure of the controlled liquid.

Therefore, the immersion state of the float changes depending on the pressure of the controlled liquid, in other words, the upper liquid level changes.

For this reason, in the control of low-pressure liquids, the distance between the upper and lower liquid levels becomes shorter, resulting in frequent opening and closing valves.

The purpose of the present invention is to provide a float valve with two liquid levels, upper and lower, separated by an appropriate distance, so that the valve always opens and closes, regardless of the pressure of the liquid to be controlled.
It is an object of the present invention to provide a float control structure that does not cause small opening/closing valves due to ripples in the liquid surface, and does not cause water hammer due to rapid opening/closing valves.

Next, a detailed explanation will be given based on an embodiment of the present invention applied to the illustrated float valve.

A lower casing 3 is attached to the upper casing 1 with an O-ring gasket 2 interposed therebetween using bolts (not shown).

A valve chamber 4 having a cylindrical space is formed at the joint between the two casings.

The ceiling of the valve chamber, that is, the lower end surface of the upper casing 1 forms a circular plane valve seat surface, with an inlet valve port 5 in the center and a plurality of outlet valve ports 6 opening on the circumference around the inlet valve port.

The inlet valve ports terminate the inlet passage 7 and the outlet valve ports 6 all communicate through an annular cavity 8 with an outlet passage 9.

A disk-shaped valve plate 10 made of synthetic rubber is accommodated in the valve chamber 4 in a free state.

A communication hole 11 is formed in the valve plate at a portion facing the inlet valve port.

A pilot valve port 12 is provided passing through the lower end wall of the valve chamber, and the lower end portion thereof is formed of a valve seat member made of synthetic rubber.

The lower casing 3 has a downwardly opened cylindrical wall portion, ie, a skirt portion, and accommodates a substantially cylindrical float 13 in an internal float chamber 18 .

The float has a valve surface 14 at a position facing the pilot valve port 12 that abuts against the valve seat member and closes the valve port 12.

At the bottom end of the skirt part there is a bolt 1 to prevent the float from falling off.
5 is installation.

a connecting portion between the valve chamber forming portion and the skirt portion of the lower casing 3;
That is, a control passage 16 is formed in the shoulder.

The control passage 16 is a pore with a diameter of about 1 millimeter, and its inner end opens at the upper part of the float chamber 18, facing the upper surface of the float 13, and its outer end communicates with a liquid reservoir 17 having a larger diameter. There is.

The operation of the above float valve is as follows.

The inlet passage 7 is connected to a suitable source of pressurized liquid and the outlet passage 9 opens into a liquid container in which the float valve is mounted.

FIG. 1 shows the valve in the closed state, and FIG. 2 shows the valve in the open state. Visit, H1
~H4 indicates the liquid level.

In the closed state of FIG. 1, it is assumed that the liquid level outside the float chamber 18 is at Hl.

The float 13 obtains a light buoyancy and closes the pilot valve port 12.

The liquid in the inlet passage I is introduced to the back side of the valve plate 10 through the inlet valve port 5 and the communication hole 11, and is pressed toward the outlet valve port 6 of the valve plate, thereby closing both the inlet and outlet valve ports.

At this time, the control passage 16 is sealed with the liquid used when the valve was opened last time.
A liquid is collected in the liquid reservoir 17 as shown in the figure.

When the amount of liquid in the liquid container decreases, the liquid level outside the skirt portion decreases, but the liquid level in the float chamber 18 is maintained as it is because the control passage 16 is sealed with liquid.

Then, when the external liquid level drops to, for example, H3, the liquid seal in the control passage is broken, external air flows into the float chamber 18 through the passage 16, and the liquid level in the float chamber begins to fall.

Since the control passage 16 is composed of pores to improve the liquid sealing effect, air passage is restricted, the liquid level in the float chamber and the float 13 are slowly and quietly lowered, and the pilot valve port 12 is gently opened. For example, at the liquid level H4, the liquid levels inside and outside the float chamber are the same.

When the pilot valve hole 12 is opened, the valve chamber 4 passes through it.
The fluid inside flows out and the pressure on the back side of the valve plate 10 decreases, so that the central part bulges out, opening both the inlet and outlet valve ports 5 and 6, as shown in FIG.

In this way, the liquid is supplied into the liquid container.

As the amount of liquid in the container increases, the liquid level outside the skirt portion rises.

When the liquid level in the float chamber 18 attempts to rise, the air inside must flow out through the control passage 16, but on this air exhaust, it flows out from the pilot valve port 12 and hits the top surface of the float. The liquid flows out from the pores and is supplied to the liquid reservoir 17.

The pores are extremely thin with a diameter of about 1 inch, and since the difference in liquid level between the inside and outside of the float chamber is small at the beginning of the rise in liquid level, the control passage 16 is sealed with a very small amount of liquid.

Thereafter, as the liquid level outside the skirt portion rises, air and liquid flow out from the control passage, and the liquid supplied to the liquid reservoir 1T increases.

Since this air outflow occurs intermittently and minutely through the liquid-sealed pores, the liquid level in the float chamber 18 hardly rises.

Then, after the outside liquid level rises to, for example, Hl, the air inside flows out through the control passage 16 while breaking the liquid seal, the inside liquid level and the float 13 rise, and the skirt part When the outside liquid level reaches the initial liquid level H1,
The float 13 receives sufficient buoyancy and closes the pilot valve port 12 with the valve surface 14.

When the pilot valve port 12 is closed, the pressure inside the valve chamber 4 gradually increases due to replenishment from the communication hole 11, and the pressure inside the valve chamber 4 increases gradually.
0 closes both the inlet and outlet valve ports 5 and 6 as shown in FIG.

As described above, the float control structure according to the present invention takes advantage of the fact that a liquid seal is provided in the control passage, and that a predetermined liquid level difference must be created between the outside and the outside of the float chamber in order to destroy this liquid seal. Therefore, regardless of the pressure of the liquid to be controlled, the float always rises and falls at two liquid levels, upper and lower, separated by an appropriate distance.

Moreover, since the flow of air into and out of the float chamber is restricted by the control passage, the liquid level in the float chamber and the rise and fall of the float are gradual.

Therefore, the float valve equipped with the float control structure of the present invention opens and closes less frequently, does not open and close in small steps, and is less likely to cause water hammer.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a float valve having a float control structure according to the present invention in a closed state, and FIG. 2 is a cross-sectional view showing a float valve in an open state. 4... Valve chamber, 7... Inlet passage, 9... Outlet passage,
10... Valve plate, 12... Pilot valve port, 13...
Float, 16... Control passage, 17... Liquid reservoir, 18
...Float chamber, H1-H4...Water level.

Claims (1)

[Claims] 1. A float is housed in a float chamber formed by a downward-opening casing, and the float is moved up and down intermittently in response to changes in the water level in the liquid container, and a pilot valve port formed at the top of the float chamber is opened and closed to transform pressure. In a float valve that controls the pressure in the chamber and drives the pressure-responsive main valve to open and close the pressure-responsive main valve intermittently at two predetermined water levels in the liquid container, the inside of the float chamber is located above the float chamber. The control passage is formed of a pore opening facing the upper surface of the float and a liquid reservoir portion having a diameter larger than the pore and facing the outside, and the control passage is formed of a pore opening facing the top surface of the float and a liquid reservoir portion facing the outside. A float control structure for a float valve, in which liquid flowing into the float chamber from the pilot valve port when the temperature rises bounces off the upper surface of the float and is supplied to the liquid reservoir through the pores.