JPH0814333B2 - Relief valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a relief valve that opens and closes a valve by a change in pressure in a flow passage.

[Prior art]

This type of relief valve is provided, for example, in the middle of a cable or the like in which a fluid such as dry air or nitrogen gas flows from the supply side (upstream side) to the receiving side (downstream side), and the gas pressure on the receiving side is set to a predetermined value. When the pressure falls below a certain value, the valve is opened to supply gas to the receiving side, and when the pressure rises to a specified value, the valve is closed to stop gas supply, and the gas pressure on the receiving side is always set to the specified value. It is intended to be kept within the range of.

FIG. 4 is a view showing a conventional relief valve 1, 2 is a supply side, 3
Is the recipient. Reference numeral 4 is a main body of the relief valve 1, and a conduction hole 5 is formed from the supply side 2 to the reception side 3 so as to extend vertically through the shaft core. A valve seat 6 and a valve chamber 7 formed by enlarging the inner diameter of the communication hole 5 are formed in the middle (center) of the communication hole 5, and the valve seat 6 is formed in the valve chamber 7 by a coil spring 8. Further, a valve 9 which is airtightly pressed from the receiving side 3 is reciprocally housed.

In this relief valve 1, the pressure on the receiving side 3 drops below a predetermined value, and the pressing force from the supplying side 2 to the valve body 9 due to the pressure difference between the supplying side 2 and the receiving side 3 causes a coil spring from the receiving side 3. When the pushing force is larger than 8, the valve body 9 opens and the gas flows from the supply side 2 to the reception side 3. As a result, the pressure on the receiving side 3 starts to rise, and when the pressure difference reaches within a predetermined value, the valve body 9 is closed and the gas flow is stopped.

However, in the above-mentioned structure, since the valve seat 6 is single, the opening and closing pressure of the valve body 9 is almost the same, and when the valve body 9 opens the valve seat 6, the opening is small and the gas is small. Since the flow rate is also extremely low, the receiving side 3
There was a risk that the pressure in the tank would drop further. Further, when the valve body 9 is closed, the operation is such that the opening degree of the valve body 9 gradually decreases as the pressure on the receiving side 3 approaches the predetermined value.
It took a considerable time to return to the predetermined pressure.

[Object of the Invention]

An object of the present invention is to provide a relief valve which solves the above problems by making the pressures at the time of opening and closing the valve different from each other so that the opening / closing operation of the valve body (fully opened, fully closed) is instantaneously performed. It is also provided.

[Structure of Invention]

For this reason, the relief valve of the present invention forms the valve chamber and the first valve seat provided on the supply side of the valve chamber in the middle of the communication hole through which the fluid flows, and the first valve seat is provided in the valve chamber. A valve body that is pressed in the direction of the first valve seat by a spring is loaded, and the valve body opens and closes the first valve seat due to the difference in fluid pressure between the supply side and the reception side of the communication hole. In the relief valve configured as described above, a flow passage that surrounds the outside of the first valve seat side communication hole and communicates with the valve chamber is formed, and a weir is provided in the flow passage, and the flow passage has the above-mentioned structure. A cylindrical second valve seat having a larger diameter than that of the first valve seat is slidably mounted, and a flange that is in airtight contact with the weir by the second spring is provided on the second valve seat.

〔Example〕

Hereinafter, embodiments of the relief valve of the present invention will be described. In this embodiment, two valve seats having a small diameter and a large diameter are provided in the valve seat portion, and the pressure applied to the large-diameter valve seat causes the pressures on the supply side and the reception side to be exchanged with each other. The valve can instantly fully open and fully close the valve seat.

1 to 3, reference numeral 10 denotes a relief valve of this embodiment, which is disposed between the supply side 2 and the reception side 3. Reference numeral 11 denotes a main body of the relief valve 10, which has a through hole 12 formed vertically therethrough.
One end of the conduction hole 12 is connected to the supply side 2 and the other end is connected to a cable serving as the receiving side 3 via a conduit (not shown).

The first valve seat 13 and the conduction hole are provided in the middle of the conduction hole 12.
A valve chamber 14 formed by enlarging the inner diameter of 12 is formed.
A cylindrical flow passage 15 is formed so as to surround the conduction hole 12 on the supply side 2 of the valve seat 13 from the outside. An open side of the flow passage 15 communicates with the first valve seat 13, an annular weir 16 is formed on the outer periphery of the open side, and a slidable second valve seat 17 is formed inside.
Is loaded. The second valve seat 17 is formed in a cylindrical shape, and a flange 18 that comes into contact with and separates from the weir 16 is formed at one end of the outer peripheral surface of the second valve seat 17.

Reference numeral 19 denotes a coil spring (second coil spring) attached to the flow passage 12, one end of which is fixed to the collar 18 and the collar 18 is constantly pressed toward the weir 16.

On the other hand, in the valve chamber 14, a valve body 21 which is pressed by a coil spring (first coil spring) 20 toward the first valve seat 13 and the second valve seat 17 is reciprocally loaded. ing. The relief valve of the present embodiment is configured as described above. Next, the operation will be described. First, a supply source such as a gas equipped with a flowmeter is connected to the end of the supply hole 2 on the supply side 2, and the end of the reception side 3 is connected to a cable via a conduit. The supply of gas etc. can be confirmed by the above flow meter.

FIG. 1 shows a state in which gas is sufficiently supplied to the cable on the receiving side 3 and the gas pressure in the cable is substantially equal to the gas pressure on the supplying side 2. The first valve seat 13 and the second valve seat 17 are pressed to close the communication hole 12, and the gas supply from the supply side 2 to the reception side 3 is stopped. At this time, there is a gap between the collar 18 and the weir 16, the flow passage 12 is electrically connected to the receiving side 3, and there is a pressure on the receiving side 3.

Next, when the pressure on the receiving side 3 drops to a predetermined value, first,
The force of the coil spring 20 that presses the valve body 21 in the direction of the supply side 2 with a predetermined load is balanced with the pressure of the supply side 2 applied to the opening area of the first valve seat 13, and further the pressure of the reception side 3 When is lowered, the valve body 21 moves to the receiving side 3 and separates from the first valve seat 13, and accordingly, the second valve seat 17 moves to the receiving side 3 and
When 18 comes into close contact with the weir 16, the flow passage 15 is disconnected from the supply side 3 and is instead connected to the high pressure supply side 2.
As a result, the gas pressure on the supply side 2 applied to the valve body 21 is
Since its working surface is expanded from the opening surface of the first valve seat 13 to the opening surface of the second valve seat 17, it instantaneously increases, and thus the valve body 21
Instantaneously fully separates from the second valve seat 17 and a large amount of gas is supplied to the receiving side 3 (Fig. 2).

When the gas is supplied to the receiving side 3 as described above, the gas pressure on the receiving side 3 gradually rises, and first, the gas pressure on the supplying side 2 applied to the valve body 21 and the pressing force of the coil spring 20. Are balanced and when the pressure on the receiving side 3 reaches a predetermined pressure, the valve body 21 closes the second valve seat 17 (FIG. 3). When the pressure further rises and the valve body 21 presses the second valve seat 17, the second valve seat 17 also moves, the collar 18 separates from the weir 16, and the flow passage 15 and the second valve seat 17 receive. The valve body 21 instantly closes the first valve seat 13 (FIG. 1) by establishing continuity with the side 3.

The operating pressure for opening and closing the valve body 21 is set by the valve body 21
It is performed by the ratio of the elastic force of the coil spring 20 that presses against the cross-sectional area (opening area) of each of the first valve seat 13 and the second valve seat 17.

〔The invention's effect〕

From the above, according to the relief valve of the present invention, on the receiving side,
It is possible to set a difference between the pressure when the valve is opened and the pressure when the valve is closed, so that the valve opening / closing operation (fully opened, fully closed) can be performed instantaneously.
Therefore, when the pressure of the cable connected to the receiving side drops to the set pressure, gas etc. is quickly supplied, and when it rises to the set pressure, the supply is stopped instantaneously, and the gas etc. pressure on the receiving side drops abnormally. It is possible to prevent the influence of the cable on the cable (for example, flooding).

[Brief description of drawings]

1 to 3 are sectional views of a relief valve according to an embodiment of the present invention. FIG. 1 shows the fully closed state, FIG. 2 shows the fully opened state, and FIG. FIG. 4 is a cross-sectional view of a conventional relief valve, each showing a state in which only the valve seat is closed. 2 ... Supply side, 3 ... Receiving side, 10 ... Relief valve, 11 ... Main body, 12 ... Communication hole, 13 ... First valve seat, 14 ... Valve chamber, 15
...... flow passage, 16 …… weir, 17 …… second valve seat, 18 …… Tsuba,
19: second coil spring, 20: first coil spring, 21
...... Valve.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshio Kanemitsu 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Rokuro Sato 2391 Kamiyabe-cho, Totsuka-ku, Yokohama-shi, Kanagawa 1 Kakumaru Seiki Co., Ltd.

Claims (1)

[Claims] 1. A valve chamber and a first valve seat provided on the supply side of the valve chamber are formed in the middle of a communication hole through which a fluid flows, and the first spring is provided in the valve chamber by a first spring. A relief valve in which a valve body that is pressed in the valve seat direction is loaded, and the valve body opens and closes the first valve difference by the difference in pressure between the fluid on the supply side and the fluid on the receiving side of the communication hole. In the above, a flow passage that surrounds the outside of the first valve seat side communication hole and communicates with the valve chamber is formed, and a weir is provided in the flow passage,
In addition, a tubular second valve seat having a larger diameter than the first valve seat is slidably mounted in the flow passage, and the second valve seat is in airtight contact with the weir by a second spring. Relief valve with a collar.