JPS6123433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a level control valve for supplying liquid to a tank or the like while maintaining the liquid level at a predetermined position, and particularly to a pilot-operated level control valve.

Some conventional pilot-operated level control valves use a piston valve as the pressure-responsive main valve, but this has the disadvantage of being bulky, and some use a diaphragm valve.
This had the disadvantage that its range of application was limited by pressure, temperature, and fluid, and it was also poor in durability. Therefore, the present applicant previously proposed a pressure-responsive main valve using a disc valve, but the structure was such that the inflow passage opened in the center of the valve chamber, and the starting end of the outflow passage opened around it. There was a problem in that the liquid on the back side of the valve disk flowed out into the outflow passage through the gap between the outer peripheral edge of the valve disk and the inner peripheral wall of the valve chamber, making it impossible to close the valve, especially in the case of low-pressure liquid.

The present invention aims to solve the above problems, and the technical means of the present invention taken for this purpose are as follows: a valve chamber having a circular inner peripheral wall; an annular valve seat formed at one end of the valve chamber; An outflow passage whose starting end is formed at the seat, an inflow passage that opens around the annular valve seat, and a sealing surface that seats on the annular valve seat on one side, the outer periphery of which is separated from the peripheral wall of the valve chamber by a minute gap. The valve disk has a diameter and is arranged in the valve chamber, the pilot valve hole opens at the other end of the valve chamber, and the float opens and closes the pilot valve hole by ascending and descending with the liquid level of the tank etc. to be supplied with liquid. It is what it is.

The action is as follows.

Since the inflow passage opens around the outflow passage, fluid from the inflow passage can easily flow into the back side of the valve disk through the gap between the outer peripheral edge of the valve disk and the inner peripheral wall of the valve chamber. Therefore, it becomes difficult for the fluid on the back side of the valve disk to flow out to the outflow passage. Furthermore, since the gap between the outer peripheral edge of the valve disk and the peripheral wall of the valve chamber is small, this also makes it difficult for the fluid on the back side of the valve disk to flow out into the outflow passage. Therefore, even with low-pressure fluid, pressure can be stored on the back side of the valve disk, and the valve can be closed reliably.

Next, a more detailed explanation will be given based on the illustrated embodiment.

The casing of the level control valve 1 according to the present invention is constructed by attaching a bottom cover member 4 to a main body 2 with bolts (not shown) via an O-ring gasket 3 for airtightness. A substantially cylindrical valve chamber 5 is formed between the main body 2 and the bottom cover member 4. Main body 2
An annular valve seat 6 is formed at the center of the valve chamber 5 side end. An outflow channel 7 starting with an annular valve seat 6 communicates with an outlet 8 . An outer ring valve seat 9 is formed around the outer circumference of the circular valve seat 6. The outer ring valve seat 9 has a valve seat surface flush with the annular valve seat 6 . An annular groove 10 between the two valve seats 6 and 9 forms the terminal opening of an inlet channel 12 which communicates with the inlet 11 . A plug 14 in which a pilot valve hole 13 is formed is hermetically screwed onto the end wall of the valve chamber 5 opposite to the valve seat 6. A cutout groove 15 is formed inside the pilot valve hole 13, and a pilot valve seat 16 made of synthetic rubber is fixed to the plug 14 at the outside end. A valve disk 17 is arranged within the valve chamber 5. The valve disk 17 may be made of metal, or only the portion that contacts the annular valve seat 6 may be made of synthetic rubber, or may be made of synthetic resin such as Teflon. Valve disk 17
A sealing surface that seats on the valve seat 6 and closes the outflow passage 7 is formed on one side 18 of the valve. The side surface 18 is formed on the same plane so as to sit on the valve seat 6 and the outer ring seat 9 at the same time. Valve disk 1
The diameter of the valve chamber 7 is large enough to provide a small gap between its outer peripheral edge and the inner peripheral wall 19 of the valve chamber 5 . The lower part of the bottom cover member 4 has a skirt shape, and a cylindrical hollow float 20 is arranged inside. The float 20 is guided by a skirt-shaped portion so that it can move up and down. The pilot valve seat 1 is placed on the upper surface of the float 20 during floating.
A sealing surface 21 is formed which contacts the pilot valve hole 6 and closes the pilot valve hole 13. The float 20 can be attached or detached using a bolt 22 screwed onto the lower end of the skirt portion. A ventilation hole 23 is formed at the upper end of the skirt-like part to communicate the inside and outside.

Next, the operation of the above level control valve will be explained. Inlet 11 is connected to a suitable source of pressurized water. On the other hand, the outlet 8 opens, for example, into a tank, and the valve 1 itself is also arranged inside the tank. At this time, the valve 1 is installed so that the float 20 is located at the water level to be maintained in the tank.

The figure shows a state where the water level in the tank is low. That is, the float 20 is in the lowered position, the pilot valve hole 13 is open, and the water in the space below the valve disk 17 of the valve chamber 5 is discharged to the outside from the pilot valve hole 13, so that the pressure is reduced. falling,
The valve disk 17 is separated from the valve seat 6 as shown, and the water in the inlet passage 12 flows out through the outlet passage 7 and into the tank through the outlet 8. From the inflow passage 12 to the valve chamber 5
A part of the water that has entered flows into the lower part of the valve disc 17 through the minute gap between the outer peripheral edge of the valve disc 17 and the inner peripheral wall 19 of the valve chamber 5, but the amount of water discharged from the pilot valve hole 13 The pressure in the space below the valve disk 17 of the valve chamber 5 does not increase because of the large amount of pressure, and the valve is maintained in the open state shown in the figure. If water continues to be supplied in this way, the water level in the tank will rise and the float 20 will rise.
floats up and its sealing surface 21 becomes the pilot valve seat 1.
6, the pilot valve hole 13 is closed. Then, the pressure in the space below the valve disk 17 of the valve chamber 5 increases and approaches the pressure on the inlet 11 side. On the other hand, the pressure between the annular valve seats 6 of the valve disc 17 decreases due to the flow, and the valve disc 17 is drawn toward the outflow passage 7, and the sealing surface 18 is seated on the annular valve seat 6, causing the outflow passage to 7. occlude. At this time, the sealing surface 18 of the valve disk 17 is a flat surface, and the outer ring valve seat 9 also has a valve seat surface formed on the same plane as the valve seat 6, so the sealing surface 18 is a flat surface.
be seated at the same time. The corners of the inner annular valve seat 6 do not wear out. Next, as the use of the stored water progresses and the water level in the tank decreases, the float 20 descends and the pilot valve hole 13 is opened. Valve disc 1 of valve chamber 5
Water in the space below 7 jumps out of the pilot valve hole 13 and the pressure decreases. Since the sealing surface 18 of the valve disk 17 is also in contact with the outer ring valve seat 9, the inflow of water from the inflow passage 12 into the space below the valve disk 17 is prevented, and the outer peripheral edge of the valve disk 17 and the valve chamber 5 are prevented from flowing into the space below the valve disk 17. Due to the small gap with the inner peripheral wall 19, the supply of water from the inflow channel 12 to the space below the valve disk 17 is restricted. Therefore, the valve disc 17 can be easily separated from the valve seat 6, and the valve disc 17 can be easily removed from the valve seat 6.
Since the space below the valve is maintained at a low pressure, the valve is maintained in the open position as shown. In this way, the level control valve 1 supplies water to the tank while keeping the water level constant.

As is clear from the above description, the valve according to the present invention uses a valve disk as the main valve, so it is small, and since there are less restrictions on materials, it can be applied over a wide range of pressure, temperature, and fluid. It opens at the center of one end of the chamber, and the terminal end of the inflow passage communicates with the periphery, so that water from the inflow passage passes between the outer peripheral edge of the valve disk and the peripheral wall of the valve chamber and circulates around the back side of the valve disk. Easy and reliable valve closing operation can be obtained.

[Brief explanation of the drawing]

The figure is a sectional view of a level control valve according to the invention. 1: Level control valve, 5: Valve chamber,
6: Valve seat, 7: Outflow passage, 12: Inflow passage, 1
3: Pilot valve hole, 17: Valve disk, 20:
float.

Claims (1)

[Claims] 1. A valve chamber having a circular inner peripheral wall, an annular valve seat formed at one end of the valve chamber, an outflow passage whose starting end is formed at the annular valve seat, and an inflow passage opening around the annular valve seat. a valve disk disposed within the valve chamber, the sealing surface of which is seated on the annular valve seat formed on the side surface, the outer peripheral edge having an outer diameter separated by a small gap from the peripheral wall of the valve chamber;
A level control valve characterized by having a pilot valve hole that opens at the other end of the valve chamber, and a float that rises and falls with the liquid level of a tank or the like to which liquid is to be supplied to open and close the pilot valve hole.