JP2022068059A - Valve device and pressure reduction valve using the same - Google Patents

Abstract

To provide a valve device preventing scale deposition and a pressure reduction valve using the same.SOLUTION: A valve device 34 comprises: a cylindrical valve body 32 that opens and closes a space between an inflow passage 62 and an outflow passage 68 for a fluid S; a first spring body 44 that seats the valve body 32 on a valve seat 40 by means of a spring force; and a shaft member 42 that presses the valve body 32 in a valve opening direction and separates the valve body from the valve seat 40. A vane 45 that rotates the valve body 32 around an axial center by means of a flow of the fluid S when the valve body is opened is provided on an outer peripheral surface of the valve body 40.SELECTED DRAWING: Figure 5

Description

The present invention relates to a valve device provided in a fluid passage and adjusting the pressure of the passage by opening and closing the passage, and a pressure reducing valve using the valve device.

Various valve devices are arranged in the fluid passage to regulate the pressure in the passage. Such a valve device closes and opens the valve by seating and separating the valve body from the valve seat. The valve body is pressed against the valve seat by a spring body (usually a coil spring). At that time, the valve body always comes into contact with the valve sheet at the same ring-shaped contact portion. As a result, as shown in FIG. 6, the scale 80 was deposited in a ring shape at the contact point between the valve body and the valve seat or the spring body. If the scale 80 gets caught between the valve body and the valve seat, fluid leakage may occur.

Further, the valve body also contacts the spring body at the same ring-shaped contact point. The reason is that the tip of the spring body is cut so as to be flat in order to stabilize the contact with the valve body, so that the contact surface with the valve body becomes a ring shape. As a result, a ring-shaped scale is also deposited at the contact point between the valve body and the spring body. The following are prior arts for valve devices and pressure reducing valves.

Japanese Unexamined Patent Publication No. 2020-029872

It is an object of the present invention to provide a valve device for preventing such scale accumulation and a pressure reducing valve using the valve device.

In order to achieve the above object, the valve device of the present invention has a cylindrical valve body that opens and closes between an inflow path and an outflow path of a fluid, and a first valve body that is seated on a valve seat by a spring force. It includes a spring body and a shaft member that presses the valve body in the valve opening direction to separate it from the valve seat. The outer peripheral surface of the valve body is provided with blades or grooves that rotate the valve body around the axis by the flow of the fluid when the valve is opened.

According to this configuration, blades or grooves are provided on the outer peripheral surface of the cylindrical valve body, and the flow of fluid when the valve is opened acts on the blades or grooves, so that the valve body moves around the axis. Rotate. Therefore, each time the valve is opened, the valve body rotates. As a result, the contact points between the valve body and the valve seat and the contact points between the valve body and the spring body change, so that it is possible to prevent scale from accumulating at such contact points.

In the valve device of the present invention, the flat top surface of the valve body may come into contact with the valve seat when the valve is closed. Alternatively, when the valve is closed, the inclined surface provided on the outer periphery of the top of the valve body may come into contact with the valve seat.

In the valve device of the present invention, the blade or the groove may be curved when viewed from the radial direction of the valve body. Here, "the blade or groove is curved when viewed from the radial direction of the valve body" means that the blade or groove is smoothly curved so as to bulge outward with the straight line connecting one end and the other end of the blade or groove inward. Say that.

The pressure reducing valve according to the first configuration of the present invention is called a pilot actuated type, and is a pressure reducing valve arranged in the main passage of the fluid to reduce the pressure on the primary side to the pressure on the secondary side, and is the main passage. It is provided with a main valve body that opens and closes the main valve body and a pilot valve unit that opens and closes the main valve body. The pilot valve unit has a valve device of the present invention and a first valve drive unit that presses the shaft member of the valve device in the valve opening direction to separate the ball-shaped valve body from the valve seat. are doing. The first valve driving portion uses a second spring body that moves forward and presses the shaft portion in the valve opening direction, and the second spring body that receives the pressure on the secondary side as its spring force. It has a valve closing force adding member that retracts in the valve closing direction. Further, a second valve drive unit for opening the main valve body by receiving the pressure of the outflow passage is provided, and the inflow passage of the valve device communicates with the primary side of the main passage.

The pressure reducing valve according to the second configuration of the present invention is called a direct acting type, and is a pressure reducing valve arranged in the main passage of the fluid to reduce the pressure on the primary side to the pressure on the secondary side, and is the main passage. It is provided with a valve device of the present invention that opens and closes the valve device, and a valve drive unit that presses the shaft member of the valve device in the valve opening direction to separate the ball-shaped valve body from the valve seat. The valve driving portion advances and presses the shaft portion in the valve opening direction, and receives the pressure on the secondary side to push the second spring body against the spring force. It has a valve closing force adding member that retracts in the valve closing direction. The primary side and the secondary side of the main passage form an inflow path and an outflow path of the valve device, respectively.

According to the pressure reducing valves of the first configuration and the second configuration, as described above, it is possible to prevent scale from accumulating at the contact points between the valve body and the valve seat and the contact points between the valve body and the spring body.

According to the valve device and the pressure reducing valve of the present invention, scale accumulation can be prevented.

It is a vertical sectional view which shows the pressure reducing valve provided with the valve device which concerns on 1st Embodiment of this invention. It is a vertical sectional view schematically showing the state before decompression of the pressure reducing valve. It is a vertical sectional view schematically showing the pressure adjustment state of the pressure reducing valve. It is a vertical sectional view schematically showing the decompression holding state of the pressure reducing valve. It is a vertical sectional view which shows the valve device. It is a vertical sectional view which shows the conventional valve device. It is a perspective view which shows the state which the scale is accumulated in the contact point between the valve body and the valve seat of the valve device. It is a vertical sectional view which shows the valve device which concerns on 2nd Embodiment of this invention. It is a vertical sectional view which shows the valve device which concerns on 3rd Embodiment of this invention. It is a vertical sectional view which shows the modification of the pressure reducing valve provided with the valve device of this invention.

Prior to explaining the embodiment of the present invention, the pressure reducing valve used for the steam passage will be described. In various industries, steam is used as a heat medium from the viewpoint of cost, convenience and safety. The biggest merits are that the latent heat amount per unit weight is large and that the temperature can be kept constant by controlling the pressure.

When steam is used, instead of generating steam at each required pressure, high-pressure steam is generated in the boiler, and the steam is reduced to the required pressure according to the product and application. In that case, the automatic valve that keeps the steam pressure almost constant is the pressure reducing valve. The purpose of lowering the pressure is to lower the steam temperature and keep it at the desired heating temperature.

The basic principle of decompression is called the squeezing phenomenon, and when steam flows through the pipe, if the passage through which the steam flows is squeezed, the steam pressure on the downstream side of the squeezed part becomes lower. This is the depressurization of steam. If it is simply throttled, there is a method of fixing the valve to an intermediate opening or providing an orifice plate, but this method has a problem that the pressure changes when the flow rate changes. Therefore, even if the flow rate or the pressure on the primary side (pressure on the upstream side of the throttle point) changes, the energy of the fluid passing through the valve does not change so that the pressure on the secondary side (pressure on the downstream side of the throttle point) does not change. The pressure reducing valve is a valve that is set so that the valve opening is automatically changed by directly using.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a pilot-operated pressure reducing valve using the valve device according to the first embodiment of the present invention. In FIG. 1, the pressure reducing valve is arranged in the main passage 1 through which steam S, which is a kind of fluid, flows. The casing 2 of the pressure reducing valve PRV is formed by connecting the main body case 4, the upper case 6 and the lower case 8. Inside the main body case 4, a primary side passage 10, a secondary side passage 12, and a valve chamber 14 between them are formed. The primary side passage 10 and the secondary side passage 12 form a part of the main passage 1 through which the valve steam S flows. In the valve chamber 14, a valve holder 16 and a main valve body 18 sliding inside the valve holder 16 are arranged. The upper portion of the valve holder 16 is supported by a screw connection to the main body case 4.

A spring force is applied to the main valve body 18 in the direction of contacting and closing the main valve seat 22 formed on the valve holder 16 by the main spring body 20 made of a coil spring. A main valve driving unit 24 for driving the main valve body 18 is arranged above the valve chamber 14. In the main valve drive unit 24, the piston 26 that abuts on the main valve body 18 is slidably inserted into the cylinder 28 supported by the main body case 4. Above the piston 26 is a main valve body drive chamber 27, which will be described later. The piston 26 is provided with a relief hole 29 for releasing the pressure of the main valve body drive chamber 27.

The pilot valve unit 30 is arranged on the upper part of the upper case 6. That is, the upper case 6 forms the casing of the pilot valve unit 30. The pilot valve unit 30 has a valve device 34 including a cylindrical valve body 32, and a valve drive unit 36 that opens and closes the valve device 34. The valve device 34 has a valve seat block 37, and a valve seat 40 is formed at the tip end portion (left end portion in FIG. 1). A valve opening 41 opened and closed by the valve body 32 is opened at the center of the valve seat 40.

A shaft member 42 is inserted into the valve seat block 37 so as to penetrate in the front-rear direction (left-right direction in FIG. 1). The tip portion 42a of the shaft member 42 is in contact with the valve body 32, and the rear end portion 42b faces the tip plate 38 described later of the valve drive portion 36. The valve body 32 is pressed against the valve seat 40 by a first spring body 44 made of a coil spring. That is, when the valve is closed, the flat top surface 32a of the cylindrical valve body 32 comes into contact with the valve seat 40, and between the flat bottom surface 32b of the valve body 32 and the first spring receiver 48 provided in the upper case 6. A first spring body 44 is interposed in the body.

The valve drive unit 36 has a second spring body 54 in which the pressing plate 38 at the tip (left end in FIG. 1) is formed of a coil spring from the rear (right side in FIG. 1) to the front (left side in FIG. 1). Is being pressed by. The second spring body 54 is interposed between the tip member 56 in contact with the pressing plate 38 and the second spring receiver 58 arranged inside the cover member 50. The cover member 50 is screwed to the upper case 6 (casing). A push rod 60 is arranged between the cover member 50 and the tip member 56, and the push rod 60 passes through the inner space of the second spring body 54.

The valve drive unit 36 has a pressure adjusting means 49. The pressure adjusting means 49 has the pressing plate 38 and the bellows 43, and retracts the second spring body 54 in the valve closing direction (rightward direction). That is, the pressure adjusting means 49 constitutes a valve closing force adding member that retracts the second spring body 54 in the valve closing direction against the spring force.

The tip portion 43a of the bellows 43 is connected to the pressing plate 38, and the base end portion 43b of the bellows 43 is fixedly supported between the upper case 6 and the cover member 50. An adjustment handle 52 for pressure adjustment is rotatably screwed to the cover member 50.

A pilot chamber 62 for accommodating the first spring body 44 is arranged on the front side (left side) of the valve device 34. The primary side passage 10 communicates with the pilot chamber 62 via a primary conduction path 64. A screen 66 for removing foreign matter is arranged in the pilot chamber 62. Further, a gangway 68 communicating with the valve opening 41 is formed on the downstream side of the valve body 32 in the valve device 34. The pilot chamber 62 and the gangway 68 form an inflow path and an outflow path for the pilot valve unit 30, respectively. On the other hand, the secondary side passage 12 communicates with the pressure introduction chamber 70 in which the pressure applying means 49 is housed via the secondary conduction path 72.

Next, the operation of the above configuration will be described.
[Before decompression]
FIG. 2 shows before the start of the decompression operation, and the main valve body 18 is in the closed state. When the steam S is ventilated through the pressure reducing valve, the steam S reaches the pilot chamber 62 from the primary side passage 10 through the primary conduction path 64.

[Pressure adjustment]
When the adjusting handle 52 is rotated in the depressurizing direction (counterclockwise), the push rod 60 of the pressure applying means 49 moves forward (counterclockwise) as shown in FIG. Along with this, the bellows 43 extends and the tip plate 38 moves the shaft member 42 forward (to the left) to open the valve body 32. As a result, steam S flows through the outflow path (gangway) 68 and pushes down the piston 26 to open the main valve body 18. At this time, there is a slight gap G between the pressing plate 38 at the tip of the pressure applying means 49 and the back surface of the valve seat block 37. When the main valve body 18 is opened, the steam S in the primary side passage 10 flows into the secondary side passage 12 and is depressurized.

[Maintaining decompression]
As shown in FIG. 4, a part of the steam S flowing into the secondary side passage 12 reaches the pressure introduction chamber 70 through the secondary conduction path 72. The bellows 43 of the pressure applying means 49 is compressed by the steam pressure in the pressure introduction chamber 70, and the tip plate 38 retracts to the right. As a result, the valve body 32 is moved in the valve closing direction by allowing the shaft member 42 to move backward (to the right). By adjusting the pressure of the main valve body drive chamber 27 in this way, the opening degree of the main valve body 18 is adjusted, and the pressure of the secondary side passage 12 is kept constant.

Next, the valve device 34, which is a main part of the present invention, will be described. As shown in FIG. 5, the shaft member 42 of the valve device 34 is in contact with the valve body 32 so that the axial center C1 of the shaft member 42 coincides with the axial center CP of the valve body 32. A plurality of blades 45 are provided on the outer peripheral surface of the valve body 32 so as to be arranged in the circumferential direction. The blade 45 projects radially outward from the outer peripheral surface of the valve body 32 and extends in the axial direction CP of the valve body 32. The blade 45 rotates the valve body 32 around the axis (R1 direction) by the flow of the fluid S when the valve body 32 is opened.

In the present embodiment, the blade 45 is curved when viewed from the radial direction of the valve body 32. Here, "the blade 45 is curved when viewed from the radial direction of the valve body 32" means that the straight line L1 connecting one end (front end) 45a and the other end (rear end) 45b of the blade 45 is inside and outside. It means that it bends smoothly so that it swells. The straight line L1 is inclined so that the front end 45a deviates from the rear end 45b in the rotation direction R1.

By providing such a blade 45, the flow of the fluid S when the valve body 32 is opened acts on the blade 45, so that the valve body 32 rotates around the axis CP in the direction of the arrow R1. Therefore, the valve body 32 rotates each time the valve is opened. As a result, the contact points between the valve body 32 and the valve seat 40 and the contact points between the valve body 32 and the first spring body 44 change, so that it is possible to prevent scale from accumulating at such contact points. ..

Here, the conventional valve body 32 without the blade 45 shown in FIG. 6 does not rotate even when the valve is opened. Therefore, the valve body 32 was always in contact with the valve sheet 40 at the same contact point CT in the circumferential direction on the top surface 32a. As a result, as shown in FIG. 7, the scale 80 was deposited in a ring shape around the contact point CT at the contact point between the valve body 32 and the valve sheet 40.

Further, the contact portion of the first spring body 44 of FIG. 6 with the bottom surface 32b of the valve body 32 is ring-shaped and is the same portion in the valve body 32. As a result, the scale 80 was also deposited in a ring shape around the contact point.

On the other hand, in the first embodiment of FIG. 5, as described above, the flow of the fluid S when the valve body 32 is opened acts on the blade 45, so that the valve body 32 has an arrow R1 around the axis CP. Since it rotates in the direction, the contact point is not constant and scale does not accumulate around the contact point.

FIG. 8 shows a valve device according to the second embodiment. In the second embodiment, the groove 75 is formed on the outer peripheral surface of the valve body 32 instead of the blade 45. A plurality of grooves 75 are provided side by side in the circumferential direction of the valve body 32. The groove 75 is recessed inward in the radial direction from the outer peripheral surface of the valve body 32, and is curved in the same manner as the blade 45 in FIG. 5 and extends in the direction of the axial center CP when viewed from the radial direction.

The groove 75 rotates the valve body 32 around the axis in the rotation direction R1 by the flow of the fluid S when the valve body 32 is opened. As a result, the contact points between the valve body 32 and the valve seat 40 and the contact points between the valve body 32 and the first spring body 44 change, so that it is possible to prevent scale from accumulating at such contact points. .. Other configurations are the same as those of the first embodiment.

FIG. 9 shows the valve device according to the third embodiment. In the third embodiment, an inclined surface 82 is provided on the outer periphery of the top of the valve body 32. Specifically, the top of the valve body 32 has a truncated cone shape, and the outer peripheral surface of the truncated cone constitutes an inclined surface 82. When the valve body 32 is closed, the inclined surface 82 comes into contact with the valve seat 40. Other configurations are the same as those of the first embodiment. The third embodiment also has the same effect as the first embodiment.

The present invention is not limited to the pilot actuated type, but can be applied to the direct acting type pressure reducing valve PRV1 shown in FIG. The pressure reducing valve PRV1 has substantially the same structure as the pilot valve unit 30 of FIG. 1, and the same parts are designated by the same reference numerals. The pressure reducing valve PRV1 uses the valve device 34 of the first embodiment of FIG. In FIG. 10, the primary side passage 10 serving as an inflow passage is depressurized by opening the valve body 32, and flows out from the secondary side passage 12 which is an outflow passage.

The operation of this direct acting pressure reducing valve PRV1 is as follows.
[Before decompression]
The valve body 32 is pressed against the valve seat 40 by the first spring body 44 and is in the valve closed state.

[Pressure adjustment]
When the handle 52 is turned counterclockwise, the second spring body 54 included in the pressure adjusting means 49 of the valve drive unit 36 expands and pushes down the shaft member 42 to open the valve body 32. As a result, the steam S of the primary side passage 10 flows into the secondary side passage 12.

[Maintaining decompression]
When the pressure in the secondary side passage 12 becomes high, the bellows 43 contracts, the shaft member 42 is allowed to rise, and the valve body 32 moves in the valve closing direction (upward). As a result, the opening degree of the valve body 32 is adjusted.

The present invention also includes a combination of a plurality of configurations disclosed in the above embodiments. For example, the inclined surface 82 of the third embodiment of FIG. 9 may be provided at the bottom of the valve body 32 provided with the groove 75 of the second embodiment of FIG.

The present invention is not limited to the above embodiments, and various additions, changes, or deletions can be made without departing from the gist of the present invention. For example, in the above embodiment, the valve device 34 of FIG. 5 is used for the pressure reducing valve PRV, but the valve device 34 is not limited to the pressure reducing valve PRV, and can be used, for example, for a steam trap. Therefore, such things are also included within the scope of the present invention.

18 Main valve body 24 Main valve drive unit (second valve drive unit)
30 Pilot valve unit 32 Ball-shaped valve body 34 Valve device 36 Valve drive unit (first valve drive unit)
40 Valve seat 42 Shaft member 44 First spring body (coil spring)
45 Blade 49 Pressure adjusting means (valve closing force addition member)
54 Second spring body 62 Pilot chamber (inflow path)
68 Gangway (outflow)
75 Groove 82 Inclined surface PRV, PRV1 Pressure reducing valve S Fluid

Claims (6)

A cylindrical valve body that opens and closes between the inflow path and the outflow path of the fluid,
A first spring body that seats the valve body on the valve seat by spring force, and
A shaft member that presses the valve body in the valve opening direction to separate it from the valve seat is provided.
A valve device provided with blades or grooves on the outer peripheral surface of the valve body to rotate the valve body around the axis by the flow of the fluid when the valve is opened. The valve device according to claim 1, wherein the flat top surface of the valve body comes into contact with the valve seat when the valve is closed. The valve device according to claim 1, wherein the inclined surface provided on the outer periphery of the top of the valve body comes into contact with the valve seat when the valve is closed. The valve device according to any one of claims 1 to 3, wherein the blade or the groove is curved when viewed from the radial direction of the valve body. A pressure reducing valve located in the main passage of the fluid that reduces the pressure on the primary side to the pressure on the secondary side.
The main valve body that opens and closes the main passage,
A pilot valve unit that opens and closes the main valve body is provided.
The pilot valve unit is the valve device according to any one of claims 1 to 4.
It has a first valve drive unit that presses the shaft member of the valve device in the valve opening direction to separate the ball-shaped valve body from the valve seat.
The first valve driving portion uses a second spring body that moves forward and presses the shaft portion in the valve opening direction, and the second spring body that receives the pressure on the secondary side as its spring force. It has a valve closing force adding member that retracts in the valve closing direction against it.
Further, a second valve drive unit is provided to open the main valve body by receiving the pressure of the outflow passage.
A pressure reducing valve in which the inflow path of the valve device communicates with the primary side of the main passage. A pressure reducing valve located in the main passage of the fluid that reduces the pressure on the primary side to the pressure on the secondary side.
The valve device according to any one of claims 1 to 4, which opens and closes the main passage.
A valve drive unit that presses the shaft member of the valve device in the valve opening direction to separate the ball-shaped valve body from the valve seat is provided.
The valve drive portion advances and presses the shaft portion in the valve opening direction, and receives the pressure on the secondary side to push the second spring body against the spring force. It has a pressure applying member that retracts in the valve closing direction,
A pressure reducing valve in which the primary side and the secondary side of the main passage form an inflow path and an outflow path of the valve device, respectively.

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