JP2018204713A - Valve mechanism - Google Patents

Abstract

To discharge liquid from a valve port, even in a case where pressure of liquid is low.SOLUTION: A flow control valve 10 comprises: a casing 11 formed with an inflow port 12 and outflow port 13 for liquid and a flow passage 14 connecting between the inflow port 12 and the outflow port 13; a valve port 26 provided in the flow passage 14; and a valve body 32c having a tapered part 32e at its tip, and configured to advance/retreat from an upstream side to the valve port 26 to make the tapered part 32e enter/exit with respect to the valve port 26, to control opening of the valve port 26. An axial length Lb of the tapered part 32e becomes such a length that when the opening of the valve port 26 is not larger than predetermined opening, the tapered part 32e is positioned over the whole area in an axis direction of the valve port 26, and projects from the valve port 26 toward a downstream side.SELECTED DRAWING: Figure 3

Description

  The present application relates to a valve mechanism for discharging liquid from a valve port.

  For example, as disclosed in Patent Document 1, a valve mechanism that discharges liquid from a valve port is known. This valve mechanism includes a valve body having a tapered portion at the tip and a valve port. In the valve mechanism, the opening degree of the valve port is adjusted by moving the valve body back and forth to the valve port and the tapered portion entering and exiting the valve port.

JP 2009-52742 A

  By the way, in the valve mechanism as described above, when the pressure of the liquid is low, the valve port is blocked by the liquid film formed by the surface tension, and the liquid is hardly discharged from the valve port. In particular, when the diameter of the valve port is a very small diameter compared with the diameter of the upstream channel of the valve port, the above problem becomes significant.

  The technology disclosed in the present application has been made in view of such circumstances, and an object thereof is to provide a valve mechanism that can discharge liquid from a valve port even when the pressure of the liquid is low. is there.

  The valve mechanism of the present application includes a casing, a valve port, and a valve body. The casing is formed with a liquid inlet and outlet and a flow path connecting the inlet and outlet. The valve port is provided in the flow path. The valve body has a tapered portion at the tip, and adjusts the opening degree of the valve port by advancing and retracting from the upstream side to the valve port and the taper portion going into and out of the valve port. The axial length of the tapered portion is such that the tapered portion is located over the entire axial direction of the valve port and is downstream from the valve port when the valve port has an intermediate opening degree equal to or less than a predetermined opening degree. The length is such that it protrudes to the side.

  According to the valve mechanism of the present application, the liquid can be discharged from the valve port even when the liquid pressure is low.

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a flow control valve according to an embodiment. FIG. 2 is an enlarged cross-sectional view showing a main part of the flow rate control valve. FIG. 3 is a cross-sectional view showing the state of the main part of the flow rate control valve when the opening is halfway.

  Hereinafter, embodiments of the present application will be described with reference to the drawings. Note that the following embodiments are essentially preferable examples, and are not intended to limit the scope of the technology disclosed in the present application, applications thereof, or uses thereof.

  The flow rate control valve 10 of the present embodiment is provided in, for example, a steam system and discharges a drain by a constant flow rate, and corresponds to a valve mechanism according to the claims of the present application. The drain is an example of a liquid targeted by the flow control valve 10.

  As shown in FIG. 1, the flow rate adjustment valve 10 of this embodiment includes a casing 11, a screen 20, a valve port member 25, and a flow rate adjustment mechanism 30.

  The casing 11 is formed in a substantially Y shape, and the drain circulates inside. The casing 11 is formed with a drain inlet 12 and an outlet 13 and a flow path 14 connecting the inlet 12 and the outlet 13. The inflow port 12 and the outflow port 13 are opposed to each other in the upstream / downstream direction, and the opening axes thereof are formed coaxially with each other. The flow path 14 includes a blow passage 15, a connection passage 16, a valve chamber 17, and a valve port passage 18.

  The blow passage 15 is provided to be inclined from the opening axis and is connected to the inflow port 12. The connecting passage 16 is a passage extending in a substantially radial direction around the opening axis (a radial direction of a circle having the opening axis as a center), and connects (communicates) the blow passage 15 and the valve chamber 17. The valve chamber 17 is a space formed between the outer peripheral wall of the casing 11 and a holding member 31 of a flow rate adjusting mechanism 30 described later. The valve port passage 18 is a passage extending in a substantially radial direction around the opening axis, and connects (communicates) the valve chamber 17 and the outlet 13. A valve port member 25 is provided in the valve port passage 18.

  The screen 20 is provided in the blow passage 15. The screen 20 is formed in a cylindrical shape extending in the axial direction of the blow passage 15, and one end opens toward the inflow port 12. A plug 21 that holds the screen 20 is screwed and joined to the opening end of the blow passage 15 in the casing 11. The screen 20 constitutes a filter member that captures foreign substances contained in the drain that flows into the blow passage 15 from the inlet 12. In the blow passage 15, by removing the plug 21, the foreign matter captured by the screen 20 is discharged to the outside by the flow of drain.

  The valve port member 25 is formed in a substantially cylindrical shape, and is provided in the valve port passage 18 as described above. As shown in FIG. 2, the valve port member 25 is attached to the passage wall of the valve port passage 18 by being screwed in the upstream / downstream direction. The valve port member 25 is formed with a projecting portion 29 in which the center of the upstream end surface is raised to the upstream side. A valve port 26 penetrating in the upstream and downstream direction is formed at the center of the protruding portion 29. That is, the end surface 29a of the protrusion 29 is an opening surface of the valve port 26 and is formed in a flat surface.

  The valve port member 25 is formed with an expanded portion 27 continuously formed on the downstream side of the valve port 26 and a cylindrical portion 28 formed continuously on the downstream side of the expanded portion 27. . The expanded portion 27 and the cylindrical portion 28 constitute a part of the valve port passage 18 and the flow path 14. The expanding portion 27 is a tapered passage that gradually increases as the passage cross-sectional area (flow passage cross-sectional area) decreases toward the downstream side. The cylindrical portion 28 is a passage having a constant passage cross-sectional area in the axial direction.

  The flow rate adjusting mechanism 30 adjusts the drain discharge flow rate at the valve port 26 by adjusting the opening degree of the valve port 26. The flow rate adjusting mechanism 30 is attached to the outer peripheral wall of the casing 11 where the outer end of the valve port passage 18 is located, that is, the outer peripheral wall of the casing 11 facing the valve port member 25. The flow rate adjusting mechanism 30 includes a holding member 31, a valve member 32, and a cap 35.

  The holding member 31 holds the valve member 32 and is screwed to the outer peripheral wall of the casing 11. In this manner, the holding member 31 is joined to the outer peripheral wall of the casing 11, whereby the valve chamber 17 is formed between the holding member 31 and the casing 11.

  The valve member 32 includes a main shaft portion 32 a and a valve body 32 c and is provided at a position facing the valve port 26. The main shaft portion 32a is formed in a rod shape with a circular cross section, and is provided coaxially with the valve port 26 (valve port member 25). The main shaft portion 32 a is held by being screwed into the screw hole 31 a of the holding member 31. Specifically, the lower end portion (the end portion on the valve port 26 side) of the main shaft portion 32a is a screwing portion 32b in which a male screw is formed on the outer peripheral surface, and this screwing portion 32b is a screw hole 31a of the holding member 31. Threaded onto. The valve body 32c is continuously formed at the lower end of the main shaft portion 32a.

  A packing 33 that seals the gap between the holding member 31 and the main shaft portion 32 a of the valve member 32 is mounted by a pressing member 34 above the screw hole 31 a in the holding member 31. And the cap 35 which covers the upper end part of the valve member 32 and the pressing member 34 is attached to the holding member 31 by screwing. A spring washer 36 is mounted between the holding member 31 and the cap 35.

  In the flow rate adjusting mechanism 30, the valve body 32 c moves forward and backward from the upstream side to the valve port 26 by rotating the valve member 32 (main shaft portion 32 a) so as to adjust the opening degree of the upstream side opening 26 a in the valve port 26. It is configured. By adjusting the opening degree of the valve port 26, the drain discharge flow rate at the valve port 26 is adjusted. Specifically, the main shaft portion 32a moves (displaces) in the arrow direction shown in FIG. 1 by being rotated. Thereby, the valve body 32c moves forward and backward toward the valve port 26. As the valve body 32c moves forward and enters the valve port 26, the opening area (opening degree) of the upstream side opening 26a of the valve port 26 decreases, and the drain discharge flow rate decreases.

<Detailed configuration of valve opening and valve disc>
As shown in FIGS. 2 and 3, the valve port 26 has a circular opening shape, and the opening diameter Da is constant in the axial direction. Here, the axial direction is the direction of the central axis C of the valve port 26 and the direction of the central axis C of the main shaft portion 32a. The valve opening 26 has a very small opening diameter Da as compared with the width of the valve chamber 17 (the length in the left-right direction in FIG. 1), which is the flow path width on the upstream side, and constitutes a so-called orifice. Yes. And the valve opening 26 is formed in the magnitude | size whose opening diameter Da is more than axial length La.

  The valve body 32c has a flange portion 32d and a tapered portion 32e in order from the main shaft portion 32a side. That is, the valve body 32c has a tapered portion 32e at the tip. The flange portion 32d and the tapered portion 32e are integrally formed with each other. The flange portion 32d is a disk member having an outer diameter larger than that of the main shaft portion 32a. Further, the flange portion 32 d is formed so that the outer diameter is larger than the upper end portion of the protruding portion 29 of the valve port member 25. The flange 32d has an outer diameter that is larger than the diameter of the screw hole 31a of the holding member 31, and the retreating operation (moving upward) of the valve member 32 is restricted by contacting the holding member 31. Is done.

  The tapered portion 32e is formed in a tapered conical shape and is provided coaxially with the main shaft portion 32a. That is, the tapered portion 32e extends from the lower end surface of the flange portion 32d to the downstream side, and the outer diameter decreases toward the downstream side, and is provided coaxially with the valve port 26. The valve body 32c advances and retreats toward the valve port 26, and the taper portion 32e enters and exits the valve port 26, whereby the opening degree of the valve port 26 can be adjusted.

  The axial length Lb of the tapered portion 32e is longer than the axial length La of the valve port 26. The maximum outer diameter Db (that is, the diameter of the conical bottom surface) of the tapered portion 32e is smaller than the outer diameter of the flange portion 32d and larger than the opening diameter Da of the valve port 26. As shown in FIG. 3, the axial length Lb of the tapered portion 32 e is such that the tapered portion 32 e extends over the entire axial direction of the valve port 26 when the valve port 26 has a halfway opening degree equal to or less than a predetermined opening degree. It is formed in such a length that it is located and protrudes downstream from the valve port 26. That is, when the valve opening 26 has a halfway opening, the tapered portion 32e enters the entire length in the axial direction of the valve opening 26, and the tip of the tapered portion 32e protrudes from the downstream opening 26b of the valve opening 26. It will be in the state. Here, the halfway opening is an opening larger than 0% (fully closed state) and smaller than 100% (fully opened state). The predetermined opening is an opening at which there is a possibility that a drain liquid film is formed by surface tension at the valve opening 26 and the valve opening 26 may be blocked by the liquid film.

  In the flow control valve 10, as described above, the size of the valve port 26 is very small compared to the size of the valve chamber 17. Therefore, a drain liquid film is easily formed at the valve port 26 due to surface tension. As a result, the valve opening 26 may be blocked. Even if a drain liquid film is formed, if the pressure of the drain is high, the liquid film is broken by the pressure, and the drain is discharged from the valve port 26. On the other hand, when the pressure of the drain is low, there is a possibility that the liquid film is not broken, and it becomes difficult to discharge the drain.

  The flow control valve 10 of this embodiment is based on the premise that the valve port 26 is used in a halfway opening state that is equal to or less than a predetermined opening. In this case, the tapered portion 32e enters the entire valve port 26 and protrudes from the downstream opening 26b of the valve port 26 toward the downstream side. Therefore, a part of the drain that has flowed between the flange portion 32d and the valve port 26 flows down to the expanding portion 27 along the wall surface of the valve port 26, while the tip thereof flows along the wall surface of the tapered portion 32e. Flow down to the side. Thereby, the flow down of the drain is promoted, and the drain flowing between the flange portion 32d and the valve port 26 is difficult to form a liquid film.

  In addition, when the flow control valve 10 of this embodiment is used by displacing the valve opening 26 from the opening degree larger than the predetermined opening degree described above to the halfway opening state described above, the flow regulating valve 10 is formed in the valve opening 26. The liquid film is broken by the tapered portion 32e. Thereby, even if the valve port 26 is closed by the liquid film, the drain can be reliably discharged from the valve port 26.

  In other words, since the tapered portion 32e is located over the entire length of the valve port 26 in the axial direction, the drain flow area at the valve port 26 is minimized at the upstream opening 26a, and downstream from the upstream opening 26a. As it goes further, it becomes larger and becomes maximum at the downstream opening 26b. For this reason, for example, compared with a case where the flow passage area of the drain is constant in the axial direction at the valve port, the flow resistance at the valve port 26 is reduced, and the drain easily flows. Furthermore, it can be said that the surface tension of the drain is suppressed at the valve port 26 and the formation of the liquid film is suppressed. Further, since the opening diameter Da of the valve port 26 is formed to be greater than or equal to the axial length La, the surface tension of the drain at the valve port 26 is suppressed, and the formation of a liquid film at the valve port 26 is suppressed accordingly. .

  Further, in the valve port 26, when the tapered portion 32e further enters from the state shown in FIG. 3, for example, and the outer peripheral surface of the tapered portion 32e is in contact (line contact) with the edge of the upstream opening 26a of the valve port 26, the valve port 26 is fully closed. It becomes a state. That is, in the valve port 26, the edge of the upstream opening 26a is a seat portion, and in the valve body 32c, the outer peripheral surface of the tapered portion 32e is a seat portion. The flow control valve 10 of the present embodiment is not used in a state where the valve port 26 is fully opened (the state shown in FIG. 1), and is always used in a state where the valve port 26 is halfway opened or fully closed. .

  As described above, according to the flow control valve 10 of the above embodiment, the shape of the valve port 26 is defined. Specifically, the valve opening 26 has an opening diameter Da that is greater than or equal to the axial length La. Thereby, the surface tension of the drain (liquid) at the valve port 26 can be suppressed, and the formation of a liquid film at the valve port 26 can be suppressed.

Further, the axial length La of the tapered portion 32e of the valve body 32c is such that when the valve port 26 has a halfway opening degree equal to or less than a predetermined opening degree, the tapered portion 32e is positioned over the entire axial direction of the valve port 26 and The length is formed so as to protrude downstream from the valve port 26. With this configuration, the liquid film formed at the valve port 26 can be broken by the tapered portion 32e. Moreover, since the taper part 32e is located over the whole axial direction of the valve port 26 in the halfway opening degree, it becomes easy to flow a drain in the valve port 26, and formation of a liquid film can be suppressed.

  From the above, when the valve opening 26 has a halfway opening degree, the effect of the shape of the valve opening 26 described above can be combined to prevent the valve opening 26 from being blocked by the liquid film. The drain (liquid) can be discharged from the tank.

  Further, in the flow rate control valve 10 of the above-described embodiment, the flow path 14 is continuously formed on the downstream side of the valve port 26 and has an expanded portion 27 that gradually increases as the cross-sectional area of the flow path goes downstream. ing. According to this configuration, since the flow resistance of drain (liquid) is reduced on the downstream side of the valve port 26, the drain is more easily discharged from the valve port 26.

  In the flow rate control valve 10 of the above embodiment, the outer peripheral surface of the tapered portion 32e of the valve body 32c is in contact (line contact) with the edge of the upstream opening 26a in the valve port 26, so that the valve port 26 is fully closed. become. For example, in the case where the valve port 26 is fully closed by contacting (surface contact) the end surface 29a of the protruding portion 29 of the valve port 26 with the flange portion 32d of the valve body 32c, the halfway opening degree close to full close in particular. In this case, the gap between the flange 32d, which is a drain passage, and the protruding portion 29 is very small, so that a liquid film may be generated in the gap. That is, the gap formed between the flange portion 32d and the protruding portion 29 is longer than the gap formed between the upstream opening 26a of the valve port 26 and the tapered portion 32e. Accordingly, a liquid film is easily generated. In this regard, in the above embodiment, the taper portion 32e is fully closed by contacting the upstream opening 26a of the valve port 26, so that the generation of a liquid film can be suppressed.

  Moreover, in the flow control valve 10 of the said embodiment, the taper part 32e is formed in the cone shape. According to this configuration, since the tip of the tapered portion 32e is pointed, it is easy to break through the liquid film by the tapered portion 32e by reducing the opening of the valve port 26.

(Other embodiments)
The technology disclosed in the present application may be configured as follows in the above embodiment. For example, the tapered portion 32e of the valve body 32c may be formed in a truncated cone shape instead of the cone shape.

  In the above embodiment, the outer peripheral surface of the tapered portion 32 e is in contact with the edge of the upstream opening 26 a of the valve port 26 to fully close the valve port 26, but the flange portion 32 d is a protruding portion 29 of the valve port 26. The valve port 26 may be fully closed by contacting the end face 29a.

  Moreover, in the said embodiment, it is good also considering liquids other than drain.

  The technology disclosed in the present application is useful for a valve mechanism that discharges liquid from a valve port.

10 Flow control valve (valve mechanism)
11 Casing 12 Inlet 13 Outlet 14 Channel 26 Valve Port 26a Upstream Opening 27 Expanded Portion 32c Valve Body 32e Taper La La Axial Length Lb Axial Length Da Opening Diameter Db Outer Diameter

Claims (5)

A casing formed with a liquid inlet and outlet, and a flow path connecting the inlet and outlet;
A valve port provided in the flow path;
A tapered body having a tapered portion at the tip, and a valve body that adjusts the opening degree of the valve port by moving back and forth from the upstream side to the valve port and the taper unit enters and exits the valve port;
The length of the tapered portion in the axial direction is such that when the valve opening has a halfway opening degree equal to or less than a predetermined opening degree, the tapered portion is positioned over the entire axial direction of the valve opening and is downstream from the valve opening. A valve mechanism characterized in that the valve mechanism is formed in a protruding length. The valve mechanism according to claim 1, wherein
The valve mechanism is characterized in that an opening diameter is formed to be larger than an axial length. The valve mechanism according to claim 1 or 2,
The valve mechanism is characterized in that the flow path is formed continuously on the downstream side of the valve port, and has an expanded portion that gradually increases as the cross-sectional area of the flow path decreases toward the downstream side. The valve mechanism according to any one of claims 1 to 3,
The valve body is characterized in that the valve port is fully closed when the outer peripheral surface of the tapered portion is in contact with the edge of the upstream opening of the valve port. The valve mechanism according to any one of claims 1 to 4,
The said taper part is formed in the cone shape, The valve mechanism characterized by the above-mentioned.

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