JPS5929887B2 - Pressure switching device for pressure reducing valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure switching device for a pressure reducing valve.

5 Conventionally, the valve seat of the differential pressure reducing valve is opened and closed using the differential pressure generated by a pilot valve that operates by detecting the secondary pressure of the differential pressure reducing valve, thereby supplying water to the secondary side until a constant pressure is reached. There are things that have been done.

However, there is a large difference in water demand between daytime and nighttime.
be. Therefore, even though the demand for water is low at night, high pressure acts, causing water leakage. The object of the present invention is to provide a pressure switching device for a pressure reducing valve that solves the above-mentioned drawbacks. 15 This invention is a differential pressure type in which a valve element that opens and closes a valve seat between a primary side and a secondary side and whose diameter on the opposite side is larger than that on the valve seat side is slidably held in a cylinder part. A valve box 2 provided with a pressure reducing valve and having a valve seat formed between a communication port and a connection port connected to the secondary side.
0, a valve body that detects the pressure on the secondary side and slides, and a force that resists the pressure on the secondary side is set to either strong or weak and urges the valve body in the opening direction. A switching rod is provided with a high-pressure pilot valve and a low-pressure pilot valve housing a pressure setting spring, an outer cylinder is fixed to the 25-end wall of the cylinder part, and a hollow part is formed in which one end on the cylinder part side is opened. is fitted into the outer cylinder, and connects the cylinder part to the connection port of the low pressure pilot valve at all times, and the hollow part to the connection port of the high pressure pipe head.
an annular passage is formed independently between the outer cylinder and the switching rod, and is connected to the valve element of the differential pressure reducing valve and inserted into the hollow part, and is inserted into the hollow part by the opening operation of the valve element. The present invention is characterized in that a valve rod is provided that opens between the open end of the hollow portion and the cylinder portion, and a valve is formed by this valve rod, the 35 outer cylinder, and the switching rod.

In other words, if the pressure on the secondary side is low, the cylinder communicates with the secondary side via a high-pressure or low-pressure pilot valve, and the valve body of the differential pressure reducing valve is operated by the pressure on the primary side to close the valve seat. When the pressure on the secondary side reaches the set value or higher, the valve element of the high pressure or low pressure pilot slides against the force of the pressure setting spring and closes the valve seat. The pressure in the cylinder section is made equal to the primary pressure and the valve seat of the differential pressure reducing valve is closed, thereby supplying water within the set pressure range, and the high pressure pilot valve and low pressure pilot valve resist the secondary pressure. Although the set pressures are different, during the daytime when demand is high, the valve is operated by a large opening action of the valve body of the differential pressure reducing valve and placed under the control of the high pressure pilot valve, and during the night when demand is low, the high pressure pilot valve is operated from the cylinder section. Therefore, a small amount of water is supplied at night to prevent water leakage, and the high-pressure pilot valve and the cylinder part of the differential pressure reducing valve are connected intermittently. The valve is formed by coaxially fitting an outer cylinder, a switching rod, and a valve stem so that the structure of the valve can be downsized and simplified. An embodiment of the present invention will be described based on the drawings.

Reference numeral 1 designates a differential pressure reducing valve, in which a valve box 2 is formed with an opening 3 on the primary side, an opening 4 on the secondary side, a valve seat 5, and a cylinder portion 6 located above the valve seat 5. A valve body 7 is provided in the portion 6 and is movable up and down, the diameter of the upper part being larger than the diameter of the lower part.

Further, a tapered needle 9 is erected in the valve box 2 to be inserted into a pore 8 formed in the center of the valve body 7. Next, a high pressure pilot valve 10 and a low pressure pilot valve 11 are provided.

Since the structures of both valves are the same, only one valve box 12 is provided as shown in FIG. This valve box 12 has a communication port 15 connected to the secondary side of the differential pressure reducing valve 1 via pipes 13 and 14, a connection port 16 connected to the cylinder part 6, and a connection port 16 between them. A valve seat 17 and a pressure receiving chamber 18 are formed to communicate with each other. Further, the valve box 12 houses a pressure setting spring 20 whose upper end is joined to the spring receiver 19 and a valve body 21 . This valve body 21 is constructed by inserting a pressure receiving metal fitting 23 into a valve stem 22, and attaching a bellofram 24, a collar 25, a bellofram 26, and a spring receiver 2 to the pressure receiving metal fitting 23.
7 are inserted and fixed in a stacked state. The outer peripheries of these belloframs 24 and 26 are connected to the valve box 12, respectively.
It is held between a trunk ring 28, a lower lid 29, and an upper lid 30 that constitute the. A detection body 31 is attached to the valve box 12. This detection body 31 includes the verofram 24,
26, a detection rod 33 that rises as the internal pressure of the cylinder 32 increases, and a transparent tube that is fitted into the soil of the cylinder 32 and surrounds the detection rod 33. 34 and more. Next, a valve 35 is provided at the top of the valve box 2.

That is, an outer cylinder 38 having two connection ports 36 and 37 provided with a height difference on the outer periphery is screwed into the upper part of the valve box 2 while being sealed. A switching rod 39 is inserted through the outer cylinder 38, and the upper part of the switching rod 39 is screwed to the upper end of the outer cylinder 38, and an operating section 40 is formed in the upper part. This switching rod 39 has a hollow portion 41 that is open at the lower end. Further, a monkey-shaped passage 42 communicating with the connection port body 36 is formed in the center of the inner periphery of the outer cylinder 38, and this passage 4
2 is communicated with the hollow portion 41 through a through hole 43.
Furthermore, the connection port body 37 is located at the lower part of the inner circumference of the outer cylinder 38.
An annular passage 44 is formed that communicates the cylinder portion 6 with the cylinder portion 6 . A valve rod 46 having a seal portion 45 with a large diameter is inserted into the hollow portion 41 so as to be relatively movable. The lower end of this valve stem 46 is the expanded portion 7a of the valve body 7.
Fixed. Therefore, the high pressure pilot valve 1
The connection port 16 of the low pressure pilot valve 11 is connected to the connection port body 37 by a pipe 49, and the connection port 16 of the low pressure pilot valve 11 is connected to the connection port body 37 via the passage 44. is always connected to.
In such a configuration, for example, the high pressure pilot valve 1
The force of the pressure setting spring 20 at 0 is set to a force opposite to the water pressure of 3 kg/Cllt, and the force of the low pressure pilot valve 11 is set to the force opposite to the water pressure of 1 kg/Cllt.
These adjustments, which are determined at a force opposite kg/d, are carried out by changing the set height of the pressure setting spring 20 by turning the adjusting bolts 10a, 11a.

Therefore, the water pressure on the secondary side acts on the pressure receiving chambers 18 of the high pressure and low pressure pilot valves 10 and 11 via the pipes 13 and 14. Now, if the water pressure on the secondary side exceeds even slightly 3 kg/Cflt, which pilot valve 10, 11
Also, the valve body 21 rises and the valve seat 17 is maintained in a closed state. Therefore, the water that reaches the cylinder part 6 from the primary side through the pores 8 has no place to escape, and the valve body 7 receives a downward force because its upper surface has the largest pressure receiving area, and the valve body 7 is shown in FIG. so that it remains closed. The valve stem 46 is also located in the lowered position to close the seal portion 45. Water pressure on the secondary side is 3kg
/d, the high-pressure pilot valve 10 opens because the valve body 21 is lowered by the force of the setting spring 20, but since the seal part 45 is closed, the water pressure in the cylinder part 6 has no escape and the difference The valve body 7 of the pressure-type pressure reducing valve 1 remains closed. Therefore, if there is demand, the water pressure on the secondary side will continue to decrease, and the water pressure on the secondary side will decrease to 1 kg/CW.
When the pressure drops below L, the force of the setting spring 20 becomes greater than the water pressure on the secondary side of the low pressure pilot valve 11, so the valve body 21 descends and opens, and the water pressure in the cylinder section 6 is transferred from the passage 44 to the connection port 16 of the low pressure pilot valve 11. and communication port 15 and pipe 14,1
3 and escapes to the secondary side, thereby opening the valve body 7.
After this point, if the demand is large, such as during the day, a large amount of water is supplied by controlling the high pressure pilot valve 10.
When demand is low, such as at night, a small amount of water is supplied by controlling the low pressure pilot valve 11. That is, when the water pressure on the secondary side drops below 1 kg/d, the low-pressure pilot valve 11 opens, and the valve body 7 opens to supply water, if the demand is high, the water pressure on the secondary side becomes even lower.

Therefore, when water is supplied, the opening operation of the valve body 7 is large and the rising level is also high. Therefore, the level at which the valve stem 46 of the valve 35 rises is also high, and a gap is created between the valve stem 46 and the seal portion 45. As a result, the water pressure in the cylinder part 6 escapes to the secondary side via the hollow part 41, the passage 42, the pipe 48, the connection port 16 of the high-pressure pilot valve 10, the communication port 15, and the pipes 13, 14. A large amount of water is supplied until the water pressure on the next side exceeds 3 kg/d. When the water pressure on the secondary side drops below 1 kg/d and the low-pressure pilot valve 11 opens, the water pressure on the secondary side will not drop extremely if the demand is small.

Therefore, the opening operation of the valve body 7 and the valve stem 46 is small and does not reach the extent of opening the seal portion 45'.

Therefore, although the high-pressure pilot valve 10 is maintained in an open state, water supply is controlled by the opening and closing operations of the low-pressure pilot valve 11. In other words, a small amount of water is supplied at night to meet the demand. Therefore, the water pressure acting on the secondary side can be lowered to prevent water leakage and extend the life of the pipe member. Note that the pressure acting on the pressure receiving chamber 18 of the pilot valve 1011 causes the bellofram 2 to
Even if 4 breaks, there is no problem because the other bellofram 26 maintains watertightness. In addition, in this case, pressure acts on the cylinder 32 of the detection body 31 and the detection rod 33 rises.
Warns that the verofram 24 has run out. Also, valve 35
is formed by coaxially fitting the outer cylinder 38, the switching rod 39, and the valve rod 46, thereby simplifying the structure and reducing the size.

Since this invention is configured as described above, by selecting a high pressure pilot valve and a low pressure pilot valve with different set pressures, it is possible to supply water in accordance with the demand. It is possible to reduce the pressure on the next side, thereby preventing water leakage and extending the life of the pipe members.Moreover, the structure of the valve can be simplified and miniaturized, etc. It is effective.

Easy drawing. The explanatory drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view, and FIG. 2 is an enlarged longitudinal sectional side view of the high-pressure and low-pressure pilot valves.

1... Differential pressure reducing valve, 5... Valve seat, 6
...... Cylinder part, 7... Valve body, 10.
...High pressure pilot valve, 11...Low pressure pilot, 12...Valve box, 15...
Communication port, 16... Connection port, 17... Valve seat, 18... Pressure receiving chamber, 20... Pressure setting spring, 21...・Valve body, 35...Valve,
38...Outer cylinder, 39...Switching rod, 41
... Nakakubu, 42, 44 ... Passage, 45
... Seal, 46 ... Valve stem.

Claims (1)

[Claims] 1. To open and close the valve seat between the primary side and the secondary side, a differential pressure reducing valve is used, in which a valve body whose diameter on the opposite side is larger than that on the valve seat side is slidably held in the cylinder part. A valve body is provided in each of the valve boxes in which a valve seat is formed between a communication port connected to the secondary side and a connection port, and a valve body that slides upon detecting the pressure on the secondary side and the secondary side. A high-pressure pilot valve and a low-pressure pilot valve are provided, each housing a pressure setting spring configured to have either a strong or weak force resisting the pressure of the valve body and biasing the valve body in the opening direction. an annular shape in which an outer cylinder is fixed to the outer cylinder, a switching rod having a hollow portion with one end open on the cylinder side is fitted into the outer cylinder, and the cylinder part is always connected to the connection port of the low pressure bay lot valve; and an annular passage connecting the hollow portion to the connection port of the high-pressure pilot are independently formed between the outer cylinder and the switching rod, and connected to the valve body of the differential pressure reducing valve. A valve rod is provided which is inserted into the hollow portion and opens a gap between the open end of the hollow portion and the cylinder portion by the opening operation of the valve body, and the valve rod, the outer cylinder and the switching rod are used to control the valve. A pressure switching device for a pressure reducing valve, characterized in that: