JP2003186547A - Pressure-reducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-reducing device that can minutely regulate a pressure and moreover hardly causes water hammer. <P>SOLUTION: In the pressure-reducing device that has coil springs 74, 76 that exert forces on a valve body 5 toward a secondary side, and if the fluid pressure on the secondary side rises, displaces the valve body 5 to a valve seat 7 side against the forces exerted with the coil springs 74, 76 so that the flow rate of the fluid is reduced and the fluid pressure on the secondary side is reduced and regulated, the coil spring 74 of one side is fitted in a spring chamber 72 in a distorted state and the coil spring 76 of other side is fitted in a gap in the spring chamber 72 valve in a free state so that the spring constant of the coil springs 74, 76 is increased as the displacement of the valve body 5 to a primary side increases. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes an urging means for urging the valve body toward the secondary side, and when the fluid pressure on the secondary side increases, the urging force of the urging means is prevented. Then, by displacing the valve element toward the valve seat side, the flow rate of the fluid is reduced,
The present invention relates to a pressure reducing device for reducing the pressure of a fluid on the secondary side.

[0002]

2. Description of the Related Art Conventionally, an urging means for urging the valve body toward the secondary side is provided, and when the fluid pressure on the secondary side increases, the valve body is resisted against the urging force of the urging means. A pressure reducing device as shown in FIG. 4 is known as a pressure reducing device for reducing the flow rate of the fluid by displacing the valve to the valve seat side to reduce the pressure of the fluid on the secondary side. In this decompression device 80, a main body 10 of the decompression device 80 is constituted by a primary body 1 and a secondary body 2, and the primary body 1 is supplied from a fluid supply source (not shown) side such as a water supply source. An inlet 3 for introducing the fluid is provided, and an outlet 4 for introducing the fluid is provided on the secondary body 2 on the side of a water outlet or the like (not shown).
In the main body 10, a valve body 5 is provided that is movable and displaceable along the axis of the pressure reducing device, and a valve seat 7 that is arranged so that the valve body 5 can be closed by the movement of the valve body 5. Is provided.

The valve body 5 is provided so as to be movable and displaceable to the primary side by the fluid pressure applied to the pressure receiving portion 8 on the secondary side thereof, and when the fluid pressure on the secondary side exceeds a predetermined value, The valve body 5 is displaced toward the valve seat 7 side against the biasing force of the coil spring 9 that is mounted on the outer periphery of the valve body 5 and biases the valve body 5 to the secondary side. At this time, the flow passage in the valve opening 6 is blocked and the flow rate is throttled, so that the fluid pressure on the secondary side becomes low and the valve body 5 returns to the secondary side. Further, when the valve body 5 returns to the secondary side, the flow passage in the valve opening 6 is opened, a large amount of fluid flows to the secondary side, and if the fluid pressure on the secondary side increases, the valve will operate in the same manner as above. The body 5 is displaced toward the valve seat 7, and by repeating this, the pressure reduction is adjusted so that the fluid pressure on the secondary side does not rise above a predetermined level.

[0004]

The above-described decompression device 80.
If a coil spring 9 having a small spring constant is adopted, the valve body 5 can be largely displaced in response to a rise in pressure on the secondary side, and fine pressure adjustment can be performed. When a sudden and large pressure rise occurs on the next side, the valve body 5 largely moves to the valve seat 7 side and the flow rate of the fluid is throttled all at once. As a result, a water hammer is likely to occur. On the other hand, when a large spring constant is used, even if a large pressure rise occurs rapidly on the secondary side, the valve body 5
Although the water hammer is less likely to occur as described above, this time, the valve body 5 does not move sensitively in response to a slight increase in pressure, and thus the problem that fine pressure adjustment cannot be performed occurs. .

The present invention solves the above-mentioned problems of the conventional pressure reducing device, and an object of the present invention is to provide a pressure reducing device capable of fine pressure adjustment and in which water hammer is unlikely to occur.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the means adopted by the respective inventions will be described below. The decompression device according to claim 1 of the present invention includes "a biasing means for biasing the valve element toward the secondary side, and when the fluid pressure on the secondary side increases, the biasing force of the biasing means. A pressure reducing device for displacing the valve body toward the valve seat side against the flow of the fluid to reduce the flow rate of the fluid to reduce the pressure of the fluid on the secondary side, wherein the spring constant of the urging means is the valve body. The pressure reducing device is characterized by increasing in accordance with an increase in the displacement amount to the primary side.

Since the spring constant of the biasing means increases as the displacement amount of the valve body to the primary side increases, it is small when the displacement amount of the valve body is small, that is, when the pressure increase on the secondary side is small. Against the biasing force of the spring constant biasing means,
The valve body reacts sharply to the increase in pressure and moves greatly. As a result, fine pressure adjustment is performed. On the other hand, when the amount of displacement of the valve element increases, that is, when the pressure increase on the secondary side increases, the spring constant of the biasing means increases, and the amount of movement of the valve element corresponding to the pressure increase decreases. As a result, a sharp decrease in the fluid is suppressed, and a water hammer is less likely to occur.

The biasing means may be, for example, a non-uniform pitch coil spring, a conical coil spring, or a compression spring whose spring constant increases as the amount of compression increases.
By using a single spring whose spring constant changes according to such a displacement amount, the decompression device can be realized in a small space and with a simple structure.

Further, for example, a plurality of compression springs having different free lengths are used in parallel, and depending on the fluid pressure up to a predetermined value, an interval in which other compression springs are accommodated so that only some compression springs are compressed. Is adjusted (for example, in the initial state where no fluid pressure is generated on the secondary side, a gap is provided in the free length direction of the compression spring in the spring chamber only for the other compression springs), and a predetermined value or more. An urging means provided so that the other compression spring is also compressed when a high fluid pressure is applied can be exemplified. By using such a biasing means, a general-purpose compression spring is appropriately combined and used, or the interval at which the springs are accommodated is appropriately changed, so that the fluid pressure on the secondary side can be easily set to a desired set value. Can be set. Therefore, the present decompression device can be easily realized without using an unequal pitch spring whose spring constant changes. Further, similarly, the biasing means using a plurality of coil springs having different pitches in series can be used. Furthermore, not only the compression spring but also a plurality of tension springs are used in parallel, and the tension of other tension springs is adjusted so that only some tension springs are stretched depending on the fluid pressure up to a predetermined value. An example of the biasing means is such that the locking tool for locking the hook has a margin and the other tension spring is also expanded when a high fluid pressure of a predetermined value or more is applied. Even in such an urging means, the decompression device can be easily realized only by appropriately combining and using general-purpose compression springs and tension springs, as in the above example.

Further, the biasing means is not limited to the spring,
It may be rubber or resin that urges the valve element by elastic deformation of itself, or a shock absorber having a piston that slides in a cylinder sealed with a fluid such as air or oil. Even in these cases, the value indicated by W / L (W: stress, L: displacement amount) is the "spring constant".

A decompression device according to claim 2 of the present invention is
"The biasing means includes two coil springs arranged side by side, one coil spring is mounted in a spring chamber in a flexed state, and the other coil spring is in a free state via a gap. The decompression device according to claim 1, wherein the decompression device is mounted in the spring chamber.

When the pressure increase on the secondary side is small, the valve body is moved in a state where the spring constant of one coil spring is small, and fine pressure adjustment is performed. Then, when the pressure increase on the secondary side becomes large, the movement of the valve element causes the other coil spring to bend, and thereafter, the valve element is moved in a state of a large spring constant due to the sum of the spring constants of the two coil springs. Moving. By using the pressure reducing device equipped with such biasing means, the pressure reducing device can be realized without using expensive and less versatile members such as an unequal pitch coil spring and a shock absorber. Further, compared with the case where a plurality of coil springs having different spring constants are used in series, the total length of the biasing means can be shortened, and the entire decompression device can be made compact with a short length. it can.

The pressure reducing device according to claim 3 of the present invention is
The pressure reducing device according to claim 2, wherein the two coil springs are arranged side by side coaxially.

By arranging the above-mentioned at least two coil springs side by side coaxially, the two coil springs can be arranged in a small space, and the entire decompression device can be compactly housed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a pressure reducing device 20 to which the inventions of claims 1 to 3 are applied will be described in detail with reference to FIGS. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. As shown in FIG. 1, the decompression device 20 includes a conventional decompression device 80 described above.
Similarly, the main body 10 is composed of the primary body 1 and the secondary body 2, and a fluid supplied from a fluid supply source (not shown) such as a water supply source is introduced into the primary body 1. An inlet 3 is provided in the secondary body 2, and an outlet 4 for leading out a fluid is provided on the side of a water outlet or the like (not shown). Further, a valve body 5 is provided inside the main body 10 so as to be movable and displaceable along the axis of the decompression device 20, and a valve seat that is arranged so that the valve opening 6 can be closed by the movement of the valve body 5. The same applies to that 7 and 7 are provided.

A connecting portion 22 to which a pipe (not shown) is engraved with an internal thread is provided on one end side of the substantially cylindrical primary body 1, and a connecting portion 22 is provided on the other end side from this connecting portion 22. Is also formed with a large inner diameter and a joint portion 24 for accommodating the valve body 5 and the like is provided, and a step portion 26 is formed at the boundary between the connection portion 22 and the joint portion 24. Also,
The joint portion 24 is provided with a hole 28 that communicates with a spring chamber 72 described below and opens the spring chamber 72 to the atmosphere.
Further, on the inner peripheral surface of the front end portion of the joint portion 24, a female screw to which the secondary body is screwed is engraved.

A male thread is engraved on one end side of the secondary body 2 formed in a substantially cylindrical shape, and the primary body 1 described above is formed.
A joint portion 30 that can be screwed is provided on the joint portion 24, and a connection portion 32 to which a male screw is similarly engraved and a pipe (not shown) is connected is provided on the other end side. Further, the inner peripheral surface of the secondary side body 2 is formed with an inner diameter larger than the connecting portion 32 side on the joint portion 30 side, and a step portion 34 is formed on the boundary with the connecting portion 32 side. There is. The valve body 5 and the like are housed and held between the primary body 1 and the secondary body 2.

Inside the primary body 1, there are provided a packing retainer 54 and a guide member 40, which will be described later, and a valve fitting 36 which is sandwiched and fixed to the step portion 26. Valve fitting 36
Is formed in a substantially disc shape, the valve seat 7 is attached to the center thereof, and a large number of circulation ports 38 for circulating a fluid are provided around the valve seat 38.

A guide member 40 is attached to the inside of the primary body 1 so as to be sandwiched and fixed in the joint 24 inside the primary body 1 by the end of the joint 30 of the secondary body 2. The guide member 40 includes a cylindrical portion 42 that is fitted into the joint portion 24, and a holding portion 44 that extends inward of the cylindrical portion 42 and that slidably holds the valve body 5. . Further, a peripheral groove 48 into which the O-ring 46 is mounted is formed on the outer peripheral surface of the cylindrical portion 42.
Thus, the inner peripheral surface of the joint portion 24 and the outer peripheral surface of the cylindrical portion 42 are watertight. Further, on the inner peripheral surface of the holding portion 44, a peripheral groove 52 into which the X packing 50 is mounted is formed.
The packing 50 ensures watertightness between the inner peripheral surface of the holding portion 44 and the outer peripheral surface of the valve body 5. Further, the X packing 50 is held by the packing retainer 54 which is mounted on the outer peripheral surface of the valve body 5 and is sandwiched and fixed by the guide member 40 and the valve fitting 36.

Further, on the secondary side surface of the holding portion 44, a step portion 56 and a concave portion 58 which form a part of a spring chamber 72 for accommodating coil springs 74 and 76, which will be described later, are circumferentially formed. The step portion 56 is formed on the inner side of the holding portion 44 and on the side of the secondary body 2. A recess 58 is formed on the outer side of the step 56 and on the primary body 1 side of the step 56.

Next, the valve body 5 will be described. Disc 5
The main body 60 has a substantially cylindrical shape, and a pressure receiving portion 62 for receiving the fluid pressure on the secondary side and displacing the valve body 5 to the primary side. The valve body 5 is urged by the coil spring 74 to bring the pressure receiving portion 62 into contact with the step portion 34 of the secondary body 2 in a state where no fluid pressure is generated on the secondary side, and in the joint portion 30. It is mounted in the main body 10 so as to be slidable and displaceable on the primary side.

The main body portion 60 is the connecting portion 3 of the secondary body 2.
The secondary side opening 64 is inserted into and attached to the inside of the unit 2. In addition, the inner peripheral surface of the secondary side opening 64 is formed in a tapered shape that widens toward the secondary side so that the fluid flowing through the main body portion 60 can easily flow to the secondary side. A valve opening 6 that opens toward the valve seat 7 is provided on the primary side of the main body 60.

The pressure receiving portion 62 is provided so as to protrude from the outer peripheral surface of the main body portion 60 in a substantially flange shape, and its secondary side surface is configured to serve as a pressure receiving surface when the fluid pressure on the secondary side rises. There is. Further, the X packing 66 is provided on the outer peripheral surface of the pressure receiving portion 62.
Is formed with a circumferential groove 68 in which the attached X
By the packing 66, the outer peripheral surface of the pressure receiving portion 62 and the secondary body 2
Watertightness with the inner peripheral surface of the joint portion 30 is achieved.

Further, on the primary side surface of the pressure receiving portion 62, there are formed a concave portion 70 whose inner side is concave toward the secondary side, and an outer edge portion 71 outside the concave portion 70. And this pressure receiving portion 6
The coil spring 7 is formed of the primary side surface of the coil spring 7, the outer peripheral surface of the main body portion 60, the inner peripheral surface of the joint portion 30, and the secondary side surface of the guide member 40.
A spring chamber 72 that houses 4, 76 is formed. The spring chamber 72 is communicated with the hole 28 as described above.

The coil springs 74 and 76 having different free lengths are
Inside the spring chamber 72, they are coaxially arranged side by side around the main body 60 of the valve body 5. Of these, the coil spring 74 disposed inside has a longer free length than the other coil spring 76, and is mounted between the concave portion 70 of the pressure receiving portion 62 and the step portion 56 of the guide member 40. There is. Pressure receiving part 62
The distance between the concave portion 70 and the stepped portion 56 of the guide member 40 and the free length of the coil spring 74 urges the valve body 5 to the secondary side in the state where no fluid pressure is generated on the secondary side, and receives the pressure. The portion 62 is provided so as to abut the step portion 34.

On the other hand, the coil spring 76 is the coil spring 74.
Is disposed on the outer side of and is mounted between the outer edge portion 71 and the concave portion 58. Here, the distance between the outer edge portion 71 and the recess 58 and the free length of the coil spring 76 are such that when the valve body 5 is biased by the coil spring 74 and is displaced to the most secondary side, the outer edge portion 71. As shown in FIG. 1, a gap is provided between the recess 58 and the end of the coil spring 76 in the free length direction. Therefore, in the state where the valve body 5 is displaced to the most secondary side, the valve body 5 does not receive the biasing force of the coil spring 76.

Next, the operation of the decompression device 20 will be described. When the fluid pressure on the secondary side is less than or equal to a predetermined value, as shown in FIG. 1, the urging force of the coil spring 74 causes the valve body 5 to move to the pressure receiving surface of the pressure receiving portion 62 (the secondary side surface of the pressure receiving portion 62). Against the fluid pressure of (1), it is in a state of being displaced to the secondary side (in FIG. 1, the pressure receiving portion 62 is displaced to a state of being in contact with the step portion 34). When the fluid pressure on the secondary side rises above a predetermined level, as shown in FIG. 2, the valve body 5 is displaced to the primary side against the biasing force of the coil spring 74, and the length of the spring chamber 72 becomes shorter. However, at this stage, the coil spring 76
Is merely contacted with the primary side surface of the pressure receiving portion 62 and the recess 58, the valve body 5 is not subjected to the biasing force of the coil spring 76, and only the compressed coil spring 74 of one side is used. 5 is biased. At this time, at the same time, the valve opening 6 approaches the valve seat 7, and the valve opening 6 is throttled so that the flow rate of the fluid is throttled and the fluid pressure on the secondary side is reduced. The pressure is set to a predetermined value. Then, when the fluid pressure on the secondary side decreases, the valve body 5 is displaced to the secondary side by the biasing force of the coil spring 74,
When the fluid pressure on the secondary side further increases, these operations are repeated to reduce the fluid pressure on the secondary side to a predetermined value.

Further, when the fluid pressure on the secondary side becomes higher than that described above, the valve body 5 tends to be displaced to the primary side further than described above, as shown in FIG.
At this time, the valve opening 6 comes close to contact with the valve seat 7, and the valve opening 6 is almost closed to reduce the fluid pressure on the secondary side. The pressure is reduced and adjusted to a predetermined value. At this time, the coil spring 76 is also compressed together with the coil spring 74, and the valve body 5 is biased by the biasing force of both coil springs 74, 76. The spring constant of the coil spring 74 is set smaller than the spring constant of the coil spring 76, and minute pressure fluctuations on the secondary side allow precise pressure adjustment until the coil spring 76 functions. I am doing it.

Here, as shown in FIG. 3, when the valve body 5 is abruptly displaced and seated on the valve seat 7 and the valve opening 6 is closed, the flow rate is suddenly narrowed and a water hammer is likely to occur. . However, in the decompression device 20, as described above, both coil springs 74 and 76 function to urge the valve body 5 just before the valve body 5 is seated on the valve seat 7, so that the valve body 5 suddenly moves. Is difficult to be displaced to the primary side, and therefore the flow rate is difficult to be reduced at once. Therefore, the risk of a water hammer can be reduced. On the other hand, when the pressure increase on the secondary side is small, the valve body 5 is urged by the urging force of only the coil spring 74. Therefore, the valve body 5 quickly responds to the predetermined fluid pressure on the secondary side. The fluid pressure on the secondary side can be quickly reduced to a predetermined value and adjusted. Further, the pressure reduction adjustment and the water hammer prevention can be realized by an extremely simple structure including only the two coil springs 74 and 76.

In this example, the connection portion 22 on the primary side and the connection portion 32 on the secondary side are arranged coaxially, and the valve seat 7 is arranged on the primary side inside and the valve body 5 is arranged on the secondary side. Although the compact decompression device 20 described above is used, the present invention is not limited to the decompression device 2 described above.
The invention is not limited to 0 and can be applied to various pressure reducing devices. For example, the connection part 22 on the primary side and the connection part 32 on the secondary side
A decompression device in which and are arranged in the intersecting direction may be used. Further, a diaphragm or the like may be used as the pressure receiving portion 62 of the valve body 5.

[0031]

EFFECTS OF THE INVENTION Since each of the present inventions is constructed as described above, it is possible to provide a decompression device capable of finely adjusting the pressure and being less likely to cause a water hammer.

[Brief description of drawings]

FIG. 1 is a vertical cross section of the decompression device.

FIG. 2 is a vertical cross section of the present decompression device when the pressure increase on the secondary side is small.

FIG. 3 is a vertical cross section of the decompression device when the pressure increase on the secondary side is large.

FIG. 4 is a vertical cross section of a conventional pressure reducing device.

[Explanation of symbols]

1; primary body, 2; secondary body, 3; inlet,
4; Outlet port, 5; Valve body, 6; Valve port, 7; Valve seat, 8; Pressure receiving part, 9; Coil spring, 10; Main body, 20; Pressure reducing device, 2
2; connection part, 24; joining part, 26; step part, 28; hole, 3
0: Joining part, 32; Connection part, 34; Step part, 36; Valve fitting, 38; Flow port, 40; Guide member, 42; Cylindrical part,
44; holding part, 46; O-ring, 48; circumferential groove, 50; X
Packing, 52; circumferential groove, 54; packing retainer, 56;
Step portion, 58; concave portion, 60; main body portion, 62; pressure receiving portion, 6
4; secondary side opening, 66; X packing, 68; peripheral groove, 7
0: concave portion, 71; outer edge portion, 72; spring chamber, 74, 76;
Coil spring, 80; pressure reducing device.

Claims (3)

[Claims] 1. A urging means for urging the valve body toward the secondary side, and when the fluid pressure on the secondary side rises, the valve body is valved against the urging force of the urging means. A pressure reducing device that reduces the flow rate of fluid by displacing to the seat side to reduce the fluid pressure on the secondary side, wherein the spring constant of the biasing means is:
A decompression device which increases in accordance with an increase in the displacement amount of the valve element to the primary side. 2. The biasing means comprises two coil springs arranged in parallel with each other, one coil spring is mounted in a spring chamber in a flexed state, and the other coil spring is provided with a gap therebetween. The decompression device according to claim 1, wherein the decompression device is mounted in a spring chamber in a freely movable state. 3. The decompression device according to claim 2, wherein the two coil springs are arranged side by side coaxially.