JPH06149381A - Liquid face controller for liquid storage tank - Google Patents

Abstract

PURPOSE:To make the device compact, to prevent it from being bulky, to provide it anywhere on the ceiling wall of a liquid storage tank, to easily detach it, and to prevent a chattering phenomenon at the time of a high liquid level, in the liquid face controller of the liquid storage tank which controls the supply and stoppage of liquid, to the liquid storage tank. CONSTITUTION:This device is constituted of a main valve cylinder 10 incorporating a main valve body 20 which supplies water to the liquid storage tank when a main water ejecting port 14 is opened, and supplies water from a water hole 24 to a back pressure chamber 25. And also, the device is constituted of a sub-valve cylinder 30 incorporating a sub-valve body 40 which opens and closes a sub-water ejecting port 34 according to the buoyancy and gravity of a float 44, and supplies the water of a middle space 35 to the liquid storage tank when the sub-water ejecting port 34 is opened. The middle space 35 between a sub-sliding valve 42 and a sub-pressurizing valve 43 is connected through a sub-water supply passage 36 with the back pressure chamber 25. And also, the device is constituted of a float 44 attached to the lower edge of a downward extending part 41' of a sub-valve shaft 41 constituting the sub- valve body 40. Then, an upper space 37 of a sub-valve cylinder 40 on the sub-sliding valve 42 is connected with air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies liquid to a liquid storage tank when the liquid level in the liquid storage tank falls below a liquid supply start level, and the liquid level in the liquid storage tank is increased by the supply of the liquid. The present invention relates to a liquid level control device for a liquid storage tank, which stops the supply of liquid when the liquid level rises to recover the liquid supply stop level.

[0002]

2. Description of the Related Art In a conventional liquid level control device for a liquid storage tank, for example, a ball tap, a float which is vertically displaced according to the vertical direction of the liquid level in the liquid storage tank is attached to a free end of a lever to lower the liquid level. When the float displaces downwards, the float opens the valve that closes the water outlet via the lever lever to start water supply, and when the liquid level rises and the water supply stop level is restored, the float uses its own buoyancy to discharge water. The lever is pushed up against the water force coming out of, and the spout is closed with a valve.

[0003]

Therefore, since a float having a large buoyancy is used, it is necessary to make the float and the lever lever strong, which results in a heavy weight. Further, since the ball tap is fixed on the upper side wall of the liquid storage tank, it is difficult to inspect and repair. In addition, when there is an earthquake when the valve is closed due to the buoyancy of the float and the water level is full, the liquid level undulates and displaces up and down, causing the liquid level to displace downward and move away from the float. The float uses the lever to move the valve away from the water discharge port to supply water, and then the liquid level is displaced upward, causing the valve to close the water discharge port again. May occur and cause a failure.

Further, since the flow rate of the water supply due to the chattering phenomenon is very small, the water meter often does not detect it. In such a case, the water supply company (mainly local government)
Had an inconvenience such as not being able to collect the fee while actually supplying water. The present invention has been made in order to eliminate the above-mentioned inconvenience, and is small and not bulky, and can be installed anywhere on the ceiling wall of a liquid storage tank, and can be easily removed from outside the liquid storage tank for maintenance and inspection. (EN) A liquid level control device for a water storage tank, which can eliminate the chattering phenomenon when the liquid level is full.

[0005]

A liquid level control device for a water tank according to the present invention stores a liquid from a liquid supply pipe connected when a main liquid outlet is opened and closed and the main liquid outlet is opened. A main valve cylinder having a main valve body for supplying into the liquid tank and having a back pressure chamber into which a part of the liquid from the liquid supply pipe flows through a small-diameter liquid passage hole formed in the main valve body. And the back pressure chamber is communicated with the sub liquid supply passage, the sub liquid discharge port is opened and closed by the buoyancy of the float and gravity, and liquid flowing through the sub liquid supply passage is opened when the sub liquid discharge port is opened. A sub-valve cylinder having a built-in sub-valve body to be supplied into the liquid storage tank, the sub-valve body moving up and down in the sub-valve cylinder, and the sub-valve shaft attached to the sub-valve shaft. A sub-sliding valve that slides inside the upward sub-cylinder of the valve cylinder and a sub-pressing valve that opens and closes the sub-exhaust port of the downward sub-cylinder of the sub-valve from below. The back pressure chamber and the middle space of the sub valve cylinder between the sub sliding valve and the sub pressure valve are communicated with each other through the sub liquid supply passage, and the above-mentioned sub sliding valve is provided. The upper space of the sub valve cylinder is communicated with the atmosphere, and the float is attached to the sub valve shaft at the lower end of a downward extension portion extending downward from the lower end of the downward sub cylinder portion.

[0006]

Since the liquid level control device for a liquid storage tank according to the present invention is constructed as described above, when the liquid level in the liquid storage tank falls and the buoyancy does not act on the float, the gravity of the float is subordinated. By acting on the valve element, the sub pressure valve lowers to open the sub liquid discharge port, so that the liquid in the intermediate space of the sub valve cylinder flows into the liquid storage tank. For this reason, the pressure in the back pressure chamber of the main valve cylinder that communicates with the intermediate space and the sub liquid supply passage decreases, and the main valve body moves, so that the main valve body opens the main discharge port, and the main discharge Liquid is supplied from the liquid port into the liquid storage tank.

When the liquid level rises by supplying the liquid into the liquid storage tank, the sub pressure valve closes the sub liquid discharge port by the buoyancy of the float, so that the pressure in the intermediate space and the back pressure chamber rises. Since the main valve body moves and closes the main liquid outlet, the liquid supply from the main liquid outlet into the storage tank is stopped.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view of a liquid level control apparatus for a liquid storage tank according to a first embodiment of the present invention when water supply is stopped, and FIG. 2 is a sectional view of the liquid level control apparatus for a liquid storage tank shown in FIG. 3 is a cross-sectional view showing a state in which the sub water outlet of the liquid level control device for the liquid storage tank shown in FIG. 1 is closed and water is being supplied from the main water outlet, and FIG. 4 is the liquid storage tank shown in FIG. FIG. 3 is a cross-sectional view of the liquid level control device of FIG.
In each of the following examples, the case where the liquid is water will be described.

In these figures, 10 indicates a main valve cylinder whose lower end is fixed around the opening 2 of the ceiling wall 1 of the liquid storage tank and stands outside the liquid storage tank, and a water supply pipe 3 as a liquid supply pipe. A main water supply passage 11 as a main water supply passage to which the
Upward main cylinder part 1 concentrically connected in the vertical direction to the tip of 1
2 and a downward main tubular portion 13 having a main water outlet 14 as a main liquid outlet having a diameter smaller than that of the upward main tubular portion 12, and the upper end of the upward main tubular portion 12 is closed by an upper lid 12 '. There is.

Reference numeral 21 denotes a series of main valve shafts that move up and down at the centers of the upward main cylinder portion 12 and the downward main cylinder portion 13 of the main valve cylinder 10, and the upward main cylinder portion 12 is provided at the upper end of the main valve shaft 21. A main sliding valve 22 that slides inside, and a main pressing valve 23 that opens and closes an upward valve seat around the main discharge port 14 from the top is attached to the lower end, and the main valve shaft 21 and the main sliding valve 22 are attached. And the main valve body 20 is constituted by the main push valve 23. A water passage hole 24 having a small diameter, for example, a diameter of about 1 mm to 1.5 mm is formed in the main sliding valve 22 in the vertical direction.

Further, the diameter of the main push valve 23 is almost equal to the inner diameter of the downward main cylinder portion 13, and the main slide valve 22 and the main push valve 23 are configured so that the main valve body 20 moves up and down in the main valve cylinder 10. Guide with. If necessary, a cutout for water passage may be provided in the peripheral portion of the main pressing valve 23.

Reference numeral 30 denotes a sub valve cylinder whose lower end is fixed around the opening 2 of the ceiling wall 1 of the liquid storage tank and stands outside the liquid storage tank.
The diameter is much smaller than that of the main valve cylinder 10. The sub valve cylinder 30 is provided with an upward sub cylinder portion 31 and a downward sub cylinder portion 32 concentrically in the vertical direction, and the upward sub cylinder portion 31 and the downward sub cylinder portion 3 are provided.
A boundary wall 33 is provided at the boundary with the second wall 33, and the boundary wall 33 is provided with a secondary outlet port 34 as a secondary outlet port having a small diameter.

Reference numeral 41 designates a sub valve shaft which moves up and down at the center of the sub valve cylinder 30. On the sub valve shaft 41, a sub slide valve 42 which slides in the upward sub cylinder portion 31 and a sub water outlet 34 are provided. A sub pressure valve 43 that opens and closes a downward valve seat around the is attached, and the sub valve shaft 41, the sub slide valve 42, and the sub pressure valve 43 constitute a sub valve body 40. The sub-valve element 40 is the sub-valve cylinder 3
Since the sub valve shaft 41 and the sub pressure valve 43 guide the vertical movement inside the 0, the thickness of the sub valve shaft 41 is adjusted to the inner diameter of the sub water outlet 34, and the diameter of the sub pressure valve 43 is directed downward. Tube 32
As shown in FIG. 4, a notch 34 'for water discharge and a notch 43' are provided on the inner circumference of the sub water discharge port 34 and the peripheral portion of the sub pressure valve 43. It is provided.

The total cross-sectional area of the cutout 34 'of the sub water outlet 34 may be slightly larger than the water passage hole 24 of the main sliding valve 22. In addition, the sub valve shaft 41 includes the downward sub tube portion 32.
Has a downward extending portion 41 ′ extending downward from the open lower end thereof to reach the inside of the liquid storage tank, and a float 44 is attached to the lower end of the downward extending portion 41 ′. The downward length of the downward extension portion 41 'is determined according to the full water level in the liquid storage tank.

Further, the main sliding valve 2 in the upward main cylinder portion 12
The back pressure chamber 25 above 2 and the middle space 35 between the sub-sliding valve 42 and the sub-pressurizing valve 43 in the upward sub-cylinder portion 31 are connected by a sub-water supply passage 36 as a sub-liquid supply passage. To do. 1 to 4 in which the main valve cylinder 10 and the auxiliary valve cylinder 30 are integrally formed in parallel with each other.
In the case of the first embodiment, the sub water supply passage 36 is formed at the time of molding. Further, in order to communicate the upper space 37 above the auxiliary sliding valve 42 in the upward sub-cylinder portion 31 with the atmosphere, the upward sub-cylinder portion 31 is provided.
The upper end of the auxiliary sub-cylindrical part 31 to the upper lid 3
Although it may be closed with 1'and a ventilation hole may be opened in the upper lid 31 'or the upper end of the upward sub-cylindrical portion 31, dust will enter the upward sub-cylindrical portion 31 from above, which is unsanitary. is there.

Therefore, in the first embodiment, the upward sub-cylinder portion 31 is used.
The upper end of is closed by an upper lid 31 ', and one end is opened to the upper end of the sub valve shaft 41, and the other end is provided with a vent hole 38 that is opened to the peripheral surface below the sub pressure valve 43. Normally, a through cylinder 7 is erected on the ceiling wall 1 of the liquid storage tank as shown in FIG. 5, and a liquid storage tank is provided through a filter provided in the through cylinder 7 to prevent entry of insects and dust. Since the liquid level inside is communicated with the atmosphere, the upper space 37 is communicated with the atmosphere by the ventilation hole 38 even if the upper end of the upward sub-cylinder portion 31 is closed by the upper lid 31 '.

Next, the operation will be described. The water level in the liquid storage tank shown in FIG. 1 is the full water level, the float 44 is immersed in water, and the buoyant force and the differential pressure due to the difference in pressure receiving area between the auxiliary sliding valve 42 and the auxiliary pressure valve 43, which will be described later, The sub pressure valve 43 presses the valve seat around the sub water outlet 34 to close the sub water outlet 34. Then, the tap water from the water supply pipe 3 fills the space between the main sliding valve 22 and the main pressing valve 23 inside the main valve cylinder 10, and a part of the tap water passes through the water passage hole 24 and the back pressure chamber. 25, the auxiliary water supply passage 36, and the middle space 35 of the auxiliary valve cylinder 30 are filled.

When the back pressure chamber 25, the sub water supply passage 36, and the middle space 35 are filled with water in this manner, equal water supply pressure acts on the main slide valve 22 located in the upward main cylinder portion 12 from above and below. , The main valve body 20 uses its own weight and water pressure to supply the main pressure valve 2
3 is pressed against the valve seat around the main water outlet 14 from above, and the main water outlet 14 is closed. Further, the main pressure valve 23 is connected to the main spout 1
In order to ensure the closing of the valve 4, the weak spring 26 may be housed in the back pressure chamber 25, and the main valve body 20 may be lightly pressed by the spring 26.

It should be noted that the float 44 is buoyant so that the auxiliary pressure valve 43
When the central space 35 is filled with water after the sub-spout 34 is pressed against the sub-spout 34 and closed, the water pressure acting upward on the sub-slide valve 42 passes through the notch 34 ′ of the sub-spout 34 and the sub-pressurization valve 43.
Since it is larger than the water pressure acting downward on the sub valve body 4,
0 is urged upward due to the pressure difference, and the sub pressure valve 43 is pressed against the valve seat around the sub water discharge port 34 from below, and the float 44
The secondary spout 34 is securely closed in cooperation with the buoyancy.

When the water level in the liquid storage tank drops and the float 44 loses its buoyancy, as shown in FIG.
4 and the sub valve body 40 are lowered by their own weight against the bias due to the pressure difference between the sub slide valve 42 and the sub pressure valve 43, and the sub pressure valve 43
Moves downward from the valve seat around the secondary water outlet 34. When the sub pressure valve 43 is separated from the sub water outlet 34 in this way, the back pressure chamber 2
5, the water that has filled the sub water supply passage 36 and the middle space 35 flows down into the downward sub cylinder portion 32 through the notch 34 ′ of the sub water outlet 34 and the notch 43 ′ of the sub pressure valve 43, and inside the liquid storage tank. At the same time, a part of tap water from the water supply pipe 3 flows into the back pressure chamber 25 through the water passage hole 24, and similarly falls into the liquid storage tank.

In this way, the sub water outlet 34 is opened, and the back pressure chamber 25
When the pressure is released, the main sliding valve 22 having a large pressure receiving area and the main pressing valve 23 having a smaller pressure receiving area are instantly released.
The main valve body 20 rises due to the pressure difference based on the difference in the pressure receiving area of the main pressure valve 23. Tap water falls into the liquid storage tank from the main spout 14. That is, water is supplied to the liquid storage tank from both the main water outlet 14 and the sub water outlet 34.

When the water level in the liquid storage tank rises due to the supply of water to the liquid storage tank, the float 44 first pushes up the sub valve body 40 by buoyancy, as shown in FIG. The sub water outlet 34 is closed by pressing the valve seat around the water outlet 34 from below. When the sub water outlet 34 is closed in this manner, the water supply from the sub water outlet 34 to the liquid storage tank is stopped, but the main pressure valve 23 keeps the main water outlet 14 open due to the above-mentioned differential pressure. Water supply from the main spout 14 to the liquid storage tank continues.

A part of the tap water from the water supply pipe 3 flows into the back pressure chamber 25 through the water passage hole 24, and the back pressure chamber 25, the sub water supply passage 36, and the sub water outlet 34 are closed. When 35 is satisfied, the water pressure acting on the main sliding valve 22 from above and below becomes equal. When the water pressures acting on the main sliding valve 22 from above and below become equal in this way, as shown by the broken line in FIG. 3, the main valve body 20 is lowered by its own weight or gradually by its own weight and the spring force of the spring 26. When the volume of the back pressure chamber 25 increases due to the lowering of the main valve body 20, the tap water from the water supply pipe 3 fills the back pressure chamber 25 whose volume has increased from the water passage hole 24, and finally, in FIG. As shown, the main pressure valve 23 closes the main water outlet 14 from above by the water supply pressure acting from above and the weight of the main valve body 20, or the weight of the main valve 20 and the spring force of the spring 26 to supply water to the liquid storage tank. Stop it completely. At this time, the water level in the liquid storage tank becomes full.

It should be noted that, after the float 44 pushes up the sub valve body 40 by buoyancy and the sub pressure valve 43 closes the sub water outlet 34, the time until the main pressure valve 23 closes the main water outlet 14 is the back pressure chamber. 25, the total capacity of the sub water supply passage 36 and the middle space 35, the supply flow rate of the tap water supplied from the water supply pipe 3, and the hole diameter of the water passage hole 24. The total capacity mentioned above is
Depending on the supply flow rate, the full water level is about 1 compared to the water level WL when the float 44 closes the sub water outlet 34 with the sub pressure valve 43.
The height is set to about 0 cm.

As a result, the float 44 is submerged in water deeper than the water level WL. Therefore, even if the liquid level undulates due to an earthquake when the water level is full, the float 44 is submerged in water, so the sub-spout It is possible to prevent the chattering phenomenon from occurring without opening the valve 34. Then, a check valve 27, which can pass water from the bottom to the top and blocks water from the top to the bottom, is mounted on the water passage hole 24 on the upper surface of the main sliding valve 22. 25
Since the water does not flow back, water hammer and vibration of the main valve body 20 can be prevented.

Further, a screw rod 15 may be vertically penetrated through the upper lid 12 'of the upward main tubular portion 12 and the screw rod 15 may be moved up and down so that the highest lifted position of the main valve body 20 can be adjusted. desirable. A stopper 16 is provided on the main valve body 20.
So that the main slide valve 22 is positioned below the upper end opening of the sub water supply passage 36 even when the main valve body 20 is raised to the maximum. Further, as shown in FIG. 2, an L-shaped pipe 17 is connected to the lower end of the downward main tubular portion 13 so that the downward main tubular portion 13 is
It is preferable to divert the water flowing down from the float 44.

FIG. 5 is an explanatory view showing a second embodiment of the liquid level control device for a liquid storage tank according to the present invention, which is installed on the ceiling wall of the liquid storage tank, and is the same as FIG. 1 to FIG. Are denoted by the same reference numerals and description thereof will be omitted. In FIG. 5, one or a plurality of auxiliary floats which vertically overlap the float 44 or the auxiliary valve shaft 41 downwardly on the float 44 and float as a unit, in this second embodiment, two auxiliary floats 45A vertically. , 45B are connected by a string-like connecting tool 46 such as a chain.

Then, the upper and lower auxiliary floats 45A, 45
As a guide 47 that vertically floats B integrally under the float 44, the guide shaft is attached to the float 44 downward, and the auxiliary floats 45A and 45B are skewered on the guide shaft so as to be movable in the vertical direction. Instead of the guide shaft, as shown by a broken line, a water pipe that surrounds the float 44 and the auxiliary floats 45A and 45B is vertically provided around the main valve pipe 10 or the opening 2 of the ceiling wall 1, and the float inside the water pipe. 44 and the auxiliary floats 45A and 45B may be moved up and down.

With the configuration shown in FIG. 5, even if the liquid level in the liquid storage tank is lowered and the float 44 comes out above the liquid level and loses its buoyancy, the liquid level is further lowered and the auxiliary float 45 above.
Even if A comes out on the liquid surface and loses buoyancy, the auxiliary pressure valve 43 of the auxiliary valve body 40 closes the auxiliary discharge port 34 from below due to the above-mentioned water pressure difference, and the liquid surface reaches the drought level near the bottom of the liquid storage tank. When the auxiliary float 45B below also loses its buoyancy, each of the three floats 4
With the total weight of 4,45A and 45B, the sub valve body 40 is lowered,
The sub pressure valve 43 can be separated from the valve seat around the sub water outlet 34 downward to start water supply.

In this case, by continuing the water supply, first, the lower auxiliary float 45B floats below the upper auxiliary float 45A, and further, the upper and lower auxiliary floats 45A and 45B integrally overlap with each other under the float 44. Only when the three floats 44, 45A, and 45B are integrally floated, the sub valve body 40 is raised and the sub pressure valve 43 is used to feed the sub water discharge port 3
Close 4 from below. In this way, the water supply can be started freely when the liquid level in the liquid storage tank reaches the dry water level, and the water supply start water level can be freely set.

FIG. 6 is a sectional view of the third embodiment of the liquid level control device for a liquid storage tank of the present invention when water supply is stopped. The same parts as those in FIGS. To do. In FIG. 6, the main valve cylinder 10 and the sub valve cylinder 30 are configured separately, and the main valve cylinder 10 and the sub valve cylinder 30 are connected by a tube having a small diameter to communicate with each other. The path is 36. The diameter of the opening 2 provided in the portion of the ceiling wall 1 for fixing the lower end of the sub valve cylinder 30 is made larger than that of the float 44, and the sub valve cylinder 30 is removed from the ceiling wall 1 at the time of maintenance and inspection to remove the float 44. Be able to go out.

FIG. 7 is a sectional view of a fourth embodiment of the liquid level control apparatus for a liquid storage tank of the present invention when water supply is stopped. The same parts as those in FIGS. To do. In FIG. 7, reference numeral 50 denotes a main valve cylinder whose lower end is fixed around the opening 2 of the ceiling wall 1 of the liquid storage tank and stands outside the liquid storage tank. Main water supply passage 51 as a main liquid supply passage provided with a main water discharge outlet 51 'as a main liquid discharge outlet
And an outer cylindrical portion 52 that is concentrically formed outside the main water supply passage 51 and has an open tip, and a main water supply passage 51 and an outer cylindrical portion 52 that are connected to a side portion of the outer cylinder portion 52. And a communication cylinder portion 53 for communicating the space formed by the above with the liquid storage tank, and the tip of the outer cylinder portion 52 is fixed with a fitting 54.
It is closed at 2 '.

Reference numeral 61 denotes a diaphragm serving as a main valve body for opening and closing the main water outlet 51 ', and the peripheral edge of the diaphragm 61 is fixed to a step inside the outer tubular portion 52 by a lid 52'. The diaphragm 61 has a water passage hole 62 having a small diameter, for example, about 1 mm to 1.5 mm.
Is opened in the left-right direction. 63 is a diaphragm 61
The back pressure chamber formed by the back pressure chamber 6 and the lid 52 'is shown.
3 is connected to the middle space 35 of the sub valve cylinder 30 by a sub water supply passage 36.

Reference numeral 64 denotes a spring loaded between the diaphragm 61 and the lid 52 '. When the left and right pressures of the diaphragm 61 become the same, the diaphragm 61 closes the main outlet 51' by its own elastic force, but the spring 64 The diaphragm 61 surely applies a biasing force to close the main water outlet 51 '. Reference numeral 65 indicates a check valve, which allows water in the back pressure chamber 63 to pass through the water passage 6
It prevents the backflow to 2.

By configuring as shown in FIG. 7, the operation becomes the same as that of each of the above-mentioned embodiments, and therefore the description of the operation will be omitted. Also in the fourth embodiment of FIG. 7, it is possible to obtain the same effects as those of the previous embodiments.

In the first and second embodiments, the main valve cylinder 1
0 and the auxiliary valve cylinder 30 are integrated, and the main valve cylinder 10 or the main valve cylinder 50 and the auxiliary valve cylinder 30 are separate bodies in the third and fourth embodiments. To install 50 and the sub valve cylinder 30 on the ceiling wall 1, as shown in FIG.
A bolt 4 is set up around the opening 2 with a nut 5, and a hole in a flange at a lower end of the valve cylinder is fitted to the bolt 4 and the nut 5 so that the main valve cylinder 10 or the main valve cylinder 50 and the auxiliary valve cylinder 30 are inserted. The ceiling wall 1
Stand up and fit the washer from above onto the bolt 4 and then the nut 6
It can be installed easily because it can be screwed in from above and tightened.

Then, by removing the nut 6 from the bolt 4, the float 44, or each float 44, 45
Since the main valve cylinder 10 or the main valve cylinder 50 and the auxiliary valve cylinder 30 for each A and 45B can be removed from the ceiling wall 1, inspection and repair can be easily performed. The main valve cylinder 10 of the first, second and third embodiments may be horizontal, and the main valve cylinder 5 of the fourth embodiment may be horizontal.
0 forms the outer cylinder portion 52 and the communication cylinder portion 53 concentrically,
It may be mounted vertically on the ceiling wall 1.

Further, in the fourth embodiment, the float 4
4 may be configured as in the third embodiment, or the main valve cylinder 50 and the sub valve cylinder 30 may be integrated. Further, it goes without saying that the liquid is not limited to water and may be another liquid having fluidity such as water.

[0039]

As described above, the liquid level control device for a liquid storage tank according to the present invention controls the start and stop of the liquid supply by the vertical displacement of the float without using the lever. The float operates because it is the auxiliary valve body that moves up and down in the auxiliary valve cylinder whose diameter can be made extremely smaller than that of the main valve cylinder, so the float may be a lightweight and small-sized one. Therefore, it is possible to provide a liquid level control device for a liquid storage tank which is small and not bulky.

Further, it can be easily installed anywhere on the ceiling wall of the liquid storage tank, and at the time of maintenance and inspection, each float can be easily removed from the ceiling wall by an operation outside the liquid storage tank. Furthermore, after the sub-exhaust port of the sub-valve is closed by the sub-valve due to the floatation of the float, the liquid continues to be supplied to the full level where the main exhalation port of the main valve is closed, and the float becomes full-level liquid. Since it is soaked deeply, the chattering phenomenon does not occur even if there is an earthquake when the liquid level is full, so no failure occurs and insensitive water supply that the water meter or the like does not detect is not performed.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid level control device for a liquid storage tank according to a first embodiment of the present invention when water supply is stopped.

FIG. 2 is a cross-sectional view of the liquid level control device for the liquid storage tank shown in FIG. 1 during water supply.

FIG. 3 is a cross-sectional view showing a state in which a sub water outlet of the liquid level control device for the liquid storage tank shown in FIG. 1 is closed and water is being supplied from the main water outlet.

FIG. 4 is a cross-sectional view taken along the line AB of the liquid level control device for the liquid storage tank shown in FIG.

FIG. 5 is an explanatory diagram showing a state in which the liquid level control device for a liquid storage tank according to the second embodiment of the present invention is installed on the ceiling wall of the liquid storage tank.

FIG. 6 is a cross-sectional view of the third embodiment of the liquid surface level control device for a liquid storage tank of the present invention when water supply is stopped.

FIG. 7 is a sectional view of a liquid level control device for a liquid storage tank according to a fourth embodiment of the present invention when water supply is stopped.

[Explanation of symbols]

 1 Ceiling Wall 2 Opening 3 Water Supply Pipe 4 Bolt 5,6 Nut 7 Through Cylinder 10 Main Valve Cylinder 11 Main Water Supply Channel 12 Upward Main Cylinder 13 Downward Main Cylinder 14 Main Discharge Port 20 Main Valve 21 Main Valve Axis 22 Main Slide Valve 23 Main push valve 24 Water passage hole 25 Back pressure chamber 26 Spring 30 Sub valve cylinder 31 Upward auxiliary cylinder part 31 'Upper lid 32 Downward auxiliary cylinder part 34 Secondary discharge port 35 Middle space 36 Secondary water supply channel 37 Upper space 40 Secondary valve Body 41 Sub-valve shaft 41 'Downward extension 42 Sub-sliding valve 43 Sub-pressing valve 44 Float 45A, 45B Auxiliary float 46 String-like connector 47 Guide 50 Main valve cylinder 51 Main water supply passage 51' Main water outlet 52 Outer cylinder 52 'Lid 53 Communication Cylindrical Portion 54 Mounting Tool 61 Diaphragm 62 Water Passage Hole 63 Back Pressure Chamber 64 Spring

Claims (5)

[Claims] 1. A main valve body for opening and closing the main liquid outlet and supplying liquid from a liquid supply pipe connected when the main liquid outlet is opened into a liquid storage tank, and A main valve cylinder provided with a back pressure chamber into which a part of the liquid from the liquid supply pipe flows through a small-diameter liquid passage hole formed in the valve body; The sub-valve with a built-in sub-valve body that opens and closes the sub-exhaust port by the buoyancy and gravity and supplies the liquid flowing in through the sub-liquid supply passage into the liquid storage tank when the sub-exhaust port is opened. A sub-valve body, the sub-valve body moving up and down inside the sub-valve cylinder, and a sub-sliding attached to the sub-valve shaft and sliding inside the upward sub-cylinder portion of the sub-valve cylinder. A valve and a sub-pressing valve that opens and closes the sub-exhaust port of the downward sub-cylindrical portion of the sub-valve from below, the back pressure chamber, the sub-sliding valve, and the sub-pressing valve. And the middle space of the sub valve cylinder between the sub valve cylinder and the sub liquid supply path, and communicates the upper space of the sub valve cylinder above the sub slide valve to the atmosphere, and to the sub valve shaft. The liquid level control device for a liquid storage tank, wherein the float is attached to a lower end of a downward extension portion extending downward from a lower end of the downward sub cylinder portion. 2. The liquid level control device for a liquid storage tank according to claim 1, wherein the main valve cylinder and the sub valve cylinder are integrally formed around an opening formed in a ceiling wall of the liquid storage tank. A liquid level control device for a liquid storage tank, which is attached and stands outside the liquid storage tank. 3. The liquid surface level control device for a liquid storage tank according to claim 1, wherein the main valve cylinder and the sub valve cylinder are separate bodies and are provided around an opening provided in a ceiling wall of the liquid storage tank. A liquid level control device for a liquid storage tank, wherein the liquid level control device is attached to a stand and individually stands outside the liquid storage tank. 4. The liquid level control device for a liquid storage tank according to claim 1, wherein the upper end of the upward sub-cylindrical portion of the sub-valve is closed with an upper lid, and the sub-valve shaft is attached to the sub-valve shaft. A liquid level control device for a liquid storage tank, characterized in that a vent hole is provided in which one end is opened in the upper space and the other end is opened in a peripheral surface below the sub pressure valve. 5. The liquid surface level control device for a liquid storage tank according to claim 1, wherein the float or the auxiliary valve shaft downwardly extending portion is vertically overlapped and floats as a unit. A liquid level control device for a liquid storage tank, characterized in that one or a plurality of auxiliary floats are connected by a string-shaped connecting tool.