JPH0747666Y2 - Steam control valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to a steam control valve used as a steam flow rate adjusting valve in a steam turbine or the like in a nuclear power plant or a thermal power plant, and more particularly to vibration of its valve body and muffler. Technology to prevent. However, the present invention is not limited to the steam control valve, but can be similarly applied to flow rate control valves for other fluids such as gas used in gas turbines, blowers, and the like.

2. Description of the Related Art Conventional steam control valves include, for example, those shown in FIGS. 8 to 11. FIG. 8 is a longitudinal sectional perspective view showing an internal structure by cutting a part thereof, and FIG. IX-IX is a cross-sectional view showing a portion along the line IX-IX, FIG. 10 is a vertical cross-sectional view showing the internal structure of a conventional steam control valve as in FIG. 8, and FIG. 11 is XI of FIG.
It is an enlarged detailed view of a part.

In these drawings, reference numeral 1 denotes a valve body casing having left and right steam inlets 2a and 2b on both sides thereof and a single steam outlet 3 at a lower portion thereof, and a valve inside the steam outlet 3 is provided. A valve seat 4 is formed inside the body casing 1.
The distal end outer peripheral wall 5a of the valve body 5 which can be brought into and out of contact with the valve seat 4 is disposed in the interior of the valve body casing 1 so that the valve body 5 is slightly projected as shown in FIG. The inner peripheral surface of the muffler 6 is slidable.

The muffler 6 is, for example, an annular perforated plate having a large number of pores 7 for adjusting the flow rate all around the height (thickness) of 50 mm. A plurality of valve body guide ribs 8 for guiding the movement of the outer peripheral wall 5b of the remaining portion of 5 are integrally formed.

The valve rod 9 that moves the valve body 5 has one end connected to the center of the lower end of the valve body 5 and the other end formed inside the outer peripheral wall 5b of the remaining portion of the valve body 5 described above. Interior space
It extends through 10 and movably penetrates inside an elongated cylindrical valve rod guide 11.

The valve rod guide 11 penetrates through the central portion of a bonnet 13 attached to the upper opening of the valve body casing 1 with a plurality of bolts 12, and is supported by the bonnet 13. The bonnet 13 also integrally has a cylindrical portion 14 that extends downward and is open, and the upper end portion of the valve body 5 is slidably fitted inside the lower end of the cylindrical portion 14 and these A plurality of seal rings 15 are interposed between them. Further, the upper end surfaces of the plurality of valve body guide ribs 8 described above are fitted into the lower end surface of the cylindrical portion 14 in a concavo-convex manner, and are fixed by the plurality of pins 16.

In the steam control valve configured as described above, the tip end surface of the valve body 5 contacts the valve seat 4 when fully closed, and enters the inside of the valve body casing 1 through the inlets 2a and 2b on both sides of the valve body casing 1. The steam flow is blocked at the contact portion between the valve body 5 and the valve seat 4, and does not flow through the outlet 3.

Then, the valve body 5 is slightly moved upward by the valve rod 9 to be in a slightly opened state, the steam passes through the pores 7 of the muffler 6, and then the gap formed between the valve body 5 and the valve seat 4. The flow rate of the steam flowing out of the outlet 3 also gradually increases by going out from the outlet 3 through the through hole 3 and gradually moving the valve body 5 upward.

Problems to be Solved by the Invention As described above, in the conventional steam control valve, the steam flow rate is controlled by moving the valve body 5 up and down by the valve rod 9. When the tip outer peripheral wall 5a of the body 5 is positioned in contact with the inner peripheral surface of the muffler 6, a large amount of steam turbulence may occur and the valve body 5 and the muffler 6 may vibrate significantly.

The cause of this vibration is that it is very difficult to accurately align the center of the valve body 5 with the center of the muffler 6 in terms of assembly and structure, and the valve body 5 and the muffler 6 are eccentric. That is, when the valve body 5 and the muffler 6 are eccentric, the vapor pressure increases when the gap between them becomes small,
Conversely, if the gap becomes large, the vapor pressure will drop,
A large vibration is generated by self-excitation, and the fluid pressure acting on the valve body 5 also becomes large in this range, so that a large vibration is caused by the interference between the pores 7 of the muffler 6 and the valve body 5.

When the valve element 5 and the muffler 6 vibrate in such a large amount, not only large noise is generated but also the valve element and the muffler may be damaged.

Therefore, the present invention has been made to solve such conventional problems, and an object thereof is to prevent vibration of a valve body and a muffler in a steam control valve.

Means for Solving the Problems The first aspect of the present invention includes a valve body that can be brought into and out of contact with a valve seat formed inside a valve body casing having a steam inlet and a steam outlet, and a tip outer peripheral wall of the valve body. Is slidable on the inner peripheral surface of the muffler disposed inside the valve body casing, and a plurality of valve body guide ribs for guiding the movement of the outer peripheral wall of the remaining portion of the valve body are integrated with the muffler. In the steam control valve molded in, a plurality of protrusions are provided around the outer peripheral wall of the remaining portion of the valve body, and these protrusions are slidably fitted in the guide grooves formed in the valve body guide ribs. It is a thing.

A second aspect of the present invention includes a valve body formed inside a valve body casing having a steam inlet and a steam outlet, the valve body being capable of coming into contact with and separating from a valve seat, and a tip outer peripheral wall of the valve body is inside the valve body casing. In the steam control valve, which is slidable on the inner peripheral surface of the muffler disposed in the above, an annular recess is formed on the outer peripheral wall of the tip end of the valve body.

A third aspect of the present invention includes a valve body formed inside a valve body casing having a steam inlet and a steam outlet, the valve body being capable of coming into contact with and separating from a valve seat, the tip outer peripheral wall of the valve body being inside the valve body casing. Is slidable on the inner peripheral surface of the muffler, and one end of which is connected to the valve body to move the valve body has the other end inside the outer peripheral wall of the remaining portion of the valve body. In the steam control valve extending through the formed internal space and movably passing through the inside of the elongated cylindrical valve rod guide,
A cylindrical valve body guide that surrounds the valve rod extending in the inner space of the valve body is arranged, and one end of the valve body guide is fixed to the bottom of the inner space of the valve body, and the other end is the valve rod guide. It is movably fitted to the outside of the.

A fourth aspect of the present invention includes a valve body formed inside a valve body casing having a steam inlet and a steam outlet, the valve body being capable of coming into contact with and separating from a valve seat, the tip outer peripheral wall of the valve body being inside the valve body casing. In the steam control valve which is slidable on the inner peripheral surface of the muffler disposed in, the plurality of support rods supporting the outer peripheral surface of the muffler are attached to the valve body casing.

Therefore, according to the first aspect of the present invention, the plurality of protrusions provided on the valve body side are constantly in contact with the valve body guide ribs on the muffler side,
As a result, when the vibration of the valve element occurs, it has a damping effect.

Further, according to the second aspect of the present invention, the annular recess formed on the valve body side eliminates the change in the vapor pressure between the valve body and the muffler over the entire circumference, thereby preventing vibration of the valve body.

Further, according to the third aspect of the present invention, the movement of the valve body is regulated by the valve rod guide via the valve body guide provided on the valve body side,
This prevents the valve body from vibrating.

Furthermore, according to the fourth aspect of the present invention, the movement of the muffler is restricted by a plurality of support rods provided on the valve body casing side,
This prevents vibration of the muffler.

Embodiments Embodiments of the present invention will be described in detail below with reference to FIGS. In these figures, the same parts as those shown in FIGS. 8 to 11 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIGS. 1 and 2 correspond to FIGS. 8 and 9 of the conventional example, and show the first embodiment of the present invention, in which the outer peripheral wall 5b of the valve body 5, that is, the inner peripheral surface of the muffler 6 is slidable. A plurality of protrusions 20 are preferably equal to each other around a part of the outer peripheral wall 5b other than the distal outer peripheral wall 5a, preferably around the portion close to the distal outer peripheral wall 5a as shown in FIG. Provided at intervals,
Each of these protrusions 20 is slidably fitted in a guide groove 21 formed in the valve body guide rib 8 formed integrally with the muffler 6.

Therefore, the plurality of projections 20 provided on the valve body 5 side are constantly in contact with the valve body guide ribs 8 on the muffler 6 side, and thereby, when the vibration of the valve body 5 occurs, a damping action is provided. FIG. 3 shows a comparative example of the generated vibration of the valve body in the valve of the present invention having such a damping protrusion and the conventional valve not having such a damping protrusion. As is apparent from FIG. It is possible to greatly reduce the vibration value of, especially the vibration value at the time of slight opening.

Next, FIGS. 4 and 5 show the second embodiment of the present invention corresponding to FIGS. 10 and 11 of the conventional example, and the tip of the valve body 5 slidable on the inner peripheral surface of the muffler 6. The annular recesses 30 are preferably formed in 2 to 3 rows and have a depth of about 3 mm in the outer peripheral wall 5a.

Therefore, due to the annular recess 30 formed on the valve body 5 side,
The change in the vapor pressure between the valve body 5 and the muffler 6 is eliminated over the entire circumference, whereby the vibration of the valve body 5 does not occur.

FIG. 6 shows a third embodiment of the present invention corresponding to FIG. 10 of the conventional example, in which a cylindrical valve body guide 40 surrounding the valve rod 9 extending in the internal space 10 of the valve body 5 is arranged. This valve body guide 40
Has one end fixed to the bottom of the internal space 10 of the valve body 5 and the other end movably fitted to the outside of the valve rod guide 11, and the inside of the valve rod guide 11 is as described above. A valve rod 9 for moving the pierce movably.

Therefore, the movement of the valve body 5 is restricted by the valve rod guide 11 via the valve body guide 40 provided on the side of the valve body 5,
This prevents the valve body 5 from vibrating.

FIG. 7 shows a fourth embodiment of the present invention corresponding to FIG. 10 of the conventional example, in which the outer peripheral surface of the muffler 6 is supported by a plurality of support rods 50.

That is, in the conventional example, as shown in FIGS.
Valve body guide rib 8 formed integrally with the muffler 6
Is fixed to and supported by the cylindrical portion 14 of the bonnet 13 through the pin 16, but the muffler 6 itself is not supported by any member, and therefore the muffler 6 and the valve body guide rib 8 are integrally formed. The object had a cantilever support structure in which only the end (upper end) on the valve body guide rib side was supported, and the end (lower end) on the muffler side was very easily shaken.

Therefore, according to the present invention, as shown in FIG. 7, a plurality of support rods 50 for supporting the outer peripheral surface of the muffler 6, preferably 4 to 8 support rods 50, are arranged at equal intervals in the valve body casing 1. It is designed to be attached. Such a support rod 50 is, for example, as shown in the drawing, after the bonnet 13, the valve rod guide 11 and the valve body 5 are assembled in the valve body casing 1, and then in a through hole 51 which is pre-drilled in the valve body casing 1. A structure can be adopted in which the tip end is in contact with the outer peripheral surface of the muffler 6 to support the outer peripheral surface of the muffler, and the rear end side is fixed to the valve body casing 1 by welding.

Thus, by supporting the outer peripheral surface of the muffler 6 with the plurality of support rods 50 in this manner, the integrally molded product of the muffler 6 and the valve body guide rib 8 has a two-sided support structure, and the initial vibration and the natural vibration of the muffler are generated. The number will be higher, which will prevent the muffler from vibrating.

Effect of the Invention As described above, according to the present invention, it is possible to reduce or prevent the vibration of the valve body and the muffler in the steam control valve, so that it is possible to prevent a large noise from being generated and also to prevent these valve bodies from being generated. The muffler can be prevented from being damaged.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional perspective view of a steam control valve showing an embodiment of the first invention, FIG. 2 is a lateral sectional view showing a part along line II-II in FIG. 1, and FIG. It is a figure which compares and shows the generated vibration of the steam control valve by this invention of 1, and the conventional valve. FIG. 4 is a vertical sectional view of a steam control valve showing a second embodiment of the present invention, and FIG. 5 is an enlarged detailed view of a V portion of FIG. FIG. 6 is a vertical sectional view of a steam control valve showing a third embodiment of the present invention. FIG. 7 is a vertical cross-sectional view of a steam control valve showing a fourth embodiment of the present invention. FIG. 8 is a longitudinal sectional perspective view showing a conventional steam control valve, and FIG. 9 is a lateral sectional view showing a part along line IX-IX in FIG.
The figure is also a longitudinal sectional view of the conventional valve, and FIG. 11 is an enlarged detailed view of a portion XI of FIG. 1 ... Valve casing, 2a, 2b ... Steam inlet, 3 ... Steam outlet, 4 ... Valve seat, 5 ... Valve body, 6 ... Muffler, 7
…… Pore, 8 …… Valve guide rib, 9 …… Valve rod, 10 ……
Internal space, 11 …… valve rod guide, 12 …… bolt, 13 …… bonnet, 14 …… cylindrical part, 15 …… seal ring, 16
...... Pin, 20 ...... Projection, 21 ...... Guide groove, 30 ...... annular recess, 40 …… Valve guide, 50 …… Muffler support rod, 51 ……
Through hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Takuo Yoshikawa 2-1-1, Niihama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Plant (56) Reference JP 62-137484 (JP, A) Special Kai 54-154831 (JP, A) Japanese Patent Sho 51-48566 (JP, B2)

Claims (4)

[Scope of utility model registration request] Claim: What is claimed is: 1. A valve body is provided inside a valve body casing having a steam inlet and a steam outlet, the valve body being capable of coming into contact with and separating from a valve seat,
A plurality of valve bodies whose tip outer peripheral wall is slidable on the inner peripheral surface of a muffler disposed inside the valve body casing and which guides movement of the outer peripheral wall of the remaining part of the valve body. In the steam control valve in which the guide rib is integrally formed with the muffler, a plurality of projections are provided around the outer peripheral wall of the remaining portion of the valve body, and each of these projections is provided in a guide groove formed in the valve body guide rib. A steam control valve that is slidably fitted. 2. A valve body which is movable into and out of contact with a valve seat formed inside a valve body casing having a steam inlet and a steam outlet,
In the steam control valve in which the tip outer peripheral wall of the valve body is slidable on the inner peripheral surface of the muffler disposed inside the valve body casing, an annular recess is formed in the tip outer peripheral wall of the valve body. And steam control valve. 3. A valve body which is movable into and out of contact with a valve seat formed inside a valve body casing having a steam inlet and a steam outlet,
The tip outer peripheral wall of the valve body is slidable on the inner peripheral surface of a muffler disposed inside the valve body casing, and one end is connected to the valve body and the other end of the valve rod moves the valve body. In a steam control valve that extends through an inner space formed inside the outer peripheral wall of the remaining portion of the valve body and movably penetrates inside an elongated cylindrical valve rod guide, A cylindrical valve body guide that surrounds the valve rod extending through the internal space is arranged, one end of the valve disc guide is fixed to the bottom of the internal space of the valve disc, and the other end is moved to the outside of the valve rod guide. A steam control valve characterized by being freely fitted. 4. A valve body, which is movable into and out of contact with a valve seat formed inside a valve body casing having a steam inlet and a steam outlet,
In a steam control valve in which a tip outer peripheral wall of the valve body is slidable on an inner peripheral surface of a muffler disposed inside the valve body casing, a plurality of support rods supporting the outer peripheral surface of the muffler are provided on the valve body. A steam control valve that is mounted on a casing.