JP5524392B2 - Valve device - Google Patents

Description

  The present invention relates to a valve device used for controlling the flow rate of a fluid in a pipeline or the like.

  As is well known, examples of the valve device include a ball valve, a gate valve, a butterfly valve, a ball valve, a needle valve, etc., but the type and nature of the fluid (toxic, flammable, corrosive, etc. ), An optimal structure is selected according to the use conditions such as pressure and temperature characteristics.

  For example, a ball valve is a valve device having a partition inside a valve box, a fluid inlet and a fluid outlet provided in a straight line, and a fluid flowing in an S shape. This ball-shaped valve has the advantage that it has a simple structure and relatively little damage, and can be fully opened and closed with a small amount of movement of the valve body. It is used.

  By the way, in such a ball valve, when the valve body and the valve seat are brought close to each other, the fluid passing between the valve body and the valve seat becomes a high-speed jet that easily causes pressure pulsation. A phenomenon (so-called “chattering” or “hunting”) in which self-excited vibration occurs and the valve body and the valve seat repeatedly collide occurs.

  In Patent Document 1 below, two ball valves are connected in parallel, and the two ball valves are selectively used according to the flow rate, so that the distance between the valve body and the valve seat is widened and the valve body is self-excited. A technique for suppressing the occurrence of the above is disclosed.

JP 2000-161529 A

  By the way, since the above-mentioned spherical valve requires two spherical valves, there is a problem that the device configuration becomes complicated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a valve device that can suppress self-excited vibration generated in the valve body with a simple configuration.

In order to achieve the above object, the present invention employs the following means.
That is, the valve device according to the present invention is configured such that the upstream flow path on the fluid inlet side and the downstream flow path on the fluid outlet side are continuous in a direction intersecting each other through the valve chamber, and partition the valve chamber. A valve box provided with a valve seat that gradually increases in diameter as it progresses downstream, and an annular seal portion that can be seated on the valve seat are provided at the opening of the upstream flow path, and can be advanced and retracted relative to the valve seat And a driving force reducing means for reducing a driving force acting on the valve body from the fluid, the driving force reducing means comprising: the valve seat and the annular seal portion. It is provided in at least one of them, and is a vortex forming part that generates a vortex.
According to this configuration, since the excitation force reducing means for reducing the excitation force acting on the valve body from the fluid is provided, the self-excited vibration generated in the valve body can be suppressed.
Further, according to this configuration, since the excitation force reducing means generates a vortex, the damping effect can be increased and the valve body can be attenuated even if the valve body causes self-excited vibration.

Further, the eddy current forming portion has a vortex forming groove formed in an annular shape.
According to this structure, since it has the vortex formation groove | channel formed in cyclic | annular form, a vortex | eddy_current can be generated with a simple structure.

Further, the vortex forming groove is divided into a plurality in the circumferential direction.
Further, a plurality of vortex forming grooves are provided concentrically.
According to these configurations, the effect of generating vortex can be enhanced.

  The valve device according to the present invention can suppress self-excited vibration generated in the valve body with a simple configuration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view showing an overall configuration of a ball valve 1 according to a first reference example of the present invention. It is a principal part expanded sectional view of the ball-shaped valve 1 which concerns on the 1st reference example of this invention. It is principal part sectional drawing of the ball-shaped valve 1 which concerns on the 1st reference example of this invention, Comprising: It is the II sectional view taken on the line in FIG. It is operation | movement explanatory drawing of the ball-shaped valve 1 which concerns on the 1st reference example of this invention. It is effect explanatory drawing of the ball-shaped valve 1 which concerns on the 1st reference example of this invention, Comprising: The graph which shows the relationship between the displacement of the valve body 20 and time, The relationship between the fluid force which acts on the valve body 20, and time The graph shown is superimposed and displayed. It is an operation explanatory view of the conventional ball valve, and is a comparative view of FIG. It is a principal part expanded sectional view of the ball-shaped valve 2 which concerns on the 2nd reference example of this invention. It is principal part sectional drawing of the ball-shaped valve 2 which concerns on the 2nd reference example of this invention, Comprising: It is the II-II sectional view taken on the line in FIG. It is effect explanatory drawing of the ball-shaped valve 2 which concerns on the 2nd reference example of this invention, Comprising: The graph which shows the relationship between the displacement of the valve body 20 and time, The relationship between the fluid force which acts on the valve body 20, and time The graph shown is superimposed and displayed. It is a principal part expanded sectional view of the ball-shaped valve 3 which concerns on the 3rd reference example of this invention. It is a principal part expanded sectional view of the ball-shaped valve 4 which concerns on the 4th reference example of this invention. It is a principal part expanded sectional view of the ball-shaped valve 5 which concerns on the 5th reference example of this invention. It is a principal part expanded sectional view of the ball-shaped valve 5 which concerns on the 5th reference example of this invention, and is an enlarged view of the principal part III in FIG. It is a principal part expanded sectional view of the ball-shaped valve 6 which concerns on the 6th reference example of this invention. It is a principal part expanded sectional view of the ball-shaped valve 6 which concerns on the 6th reference example of this invention, and is an enlarged view of the principal part IV in FIG. It is a principal part expanded sectional view of the ball-shaped valve 7 which concerns on 1st embodiment of this invention. It is a principal part expanded sectional view of the ball-shaped valve 7 which concerns on 1st embodiment of this invention, and is an enlarged view of the principal part V in FIG.

Hereinafter, reference examples and embodiments of the present invention will be described with reference to the drawings.
(First reference example)
FIG. 1 is a schematic overall configuration diagram showing the overall configuration of a ball valve (valve device) 1 according to a first reference example of the present invention. As shown in FIG. 1, the ball valve 1 includes a valve box 10 and a valve body 20. Note that the axis of the valve body 20 in the figure is P.

  In the valve box 10, the fluid inlet 10a and the fluid outlet 10b are provided on the same straight line, the upstream flow path 11 on the fluid inlet 10a side, the valve chamber 13 that accommodates the valve body 20, and the fluid outlet 10b side. An internal flow path is constituted by the downstream flow path 12. This internal flow path is configured such that the upstream flow path 11 and the downstream flow path 12 are continuous in a direction intersecting with each other via the valve chamber 13.

The upstream flow path 11 extends from the fluid inlet 10 a toward the fluid outlet 10 b and then bends and extends to the valve chamber 13.
The downstream flow path 12 extends in one direction from the valve chamber 13 to the fluid outlet 10b.
The valve chamber 13 is partitioned by a partition wall 14, and an opening portion 11 a of the upstream flow channel 11 and an opening portion 12 a of the downstream flow channel 12 are opened in a direction intersecting each other.
A tapered valve seat 15 is formed at the edge of the opening 11a of the upstream flow path 11 formed in the partition wall 14 and gradually increases in diameter as it goes downstream.

As shown in FIG. 1, the valve body 20 is formed in a columnar body, and has a tapered annular seal portion 21 that gradually increases in diameter as it goes downstream, and has a substantially constant diameter along the axis P. And an outer peripheral portion 22.
The annular seal portion 21 comes into surface contact with the valve seat 15 and can be seated on the valve seat 15, and seals the fluid F in the upstream flow path 11 when seated.
The valve body 20 is connected to a valve rod 29 and is configured to be movable back and forth with respect to the valve seat 15 in the axial direction.

  The thus configured ball valve 1 includes a separation promoting portion 30 as an excitation force reducing unit that reduces the excitation force acting on the valve body 20 from the fluid F.

2 is an enlarged cross-sectional view of the main part of the ball valve 1, and FIG. 3 is a cross-sectional view taken along the line II of FIG.
As shown in FIGS. 2 and 3, the separation promoting portion 30 extends in a radial shape from the outer peripheral portion 22 of the valve body 20 and is provided on the entire periphery of the outer peripheral portion 22. The separation promoting portion 30 is adjacent to the annular seal portion 21 on the downstream side in the axial direction, and is formed at a position that does not interfere with the adhesion between the annular seal portion 21 and the valve seat 15 when the valve is fully closed. .

Next, the excitation reducing action of the ball valve 1 having the above-described configuration will be described with reference to FIG.
First, when the annular seal portion 21 is slightly separated from the state in which the annular seal portion 21 is in close contact with the valve seat 15 (sitting state), the fluid F sealed in the upstream flow path 11 enters a minute gap and becomes a jet to form an annular seal. It flows along the part 21.

  The fluid F that has reached the end 21 a on the downstream side of the annular seal portion 21 flows radially outward along the separation promoting portion 30 in the valve chamber 13, and then the downstream end 30 a of the separation promoting portion 30. In FIG. 2, the air flows away from the outer peripheral portion 22.

The fluid F peeled off at the end 30a flows out to the downstream flow path 12 without reattaching to the outer peripheral portion 22 of the valve body 20, and is discharged from the fluid outlet 10b (see FIG. 1).
In this way, even if the fluid F that has become a jet flows continuously, it flows away from the outer peripheral portion 22 by separating at the end portion 30a of the separation promoting portion 30, so that the outer peripheral portion of the valve body 20 22 does not reattach.

As described above, according to the ball valve 1, the valve F is provided with the separation promoting portion 30 that separates the fluid F flowing out between the valve seat 15 and the annular seal portion 21 from the valve body 20. The fluid F which has passed through between 15 and the annular seal portion 21 to become a jet is separated from the valve body 20 to suppress the exciting force generated in the valve body 20.
More specifically, since the separation promoting portion 30 extends in a radial shape from the outer peripheral portion 22 and is adjacent to the annular seal portion 21, the position where the fluid F that has become a jet peels is fixed. Thus, fluctuations in the peeling position are suppressed. Thereby, the action direction of the fluid force generated in the valve body 20 can be fixed with a simple configuration, and the self-excited vibration generated in the valve body 20 can be suppressed.

  FIG. 5 is an explanatory diagram of the effect of the ball-shaped valve 1, and a graph showing the relationship between the displacement of the valve body 20 and time and a graph showing the relationship between the fluid force acting on the valve body 20 and time are overlapped. Is displayed. FIG. 6 is an operation explanatory view of a conventional ball valve (a configuration not including the separation promoting portion 30), and is a comparative view of FIG.

As shown in FIG. 6, the conventional ball valve changes while the displacement acting on the valve body 20 and the value of the fluid force change greatly, and the amplitude gradually increases and becomes self-excited that becomes unstable. Vibration is occurring. On the other hand, as shown in FIG. 5, the ball-shaped valve 1 has a displacement and fluid force acting on the valve body 20 changing in a substantially constant range (amplitude), and has a very stable behavior. ing.
As apparent from FIGS. 5 and 6, according to the ball valve 1 having the separation promoting portion 30, the self-excited vibration of the valve body 20 can be reduced with a high effect.

  Further, since the adhesiveness between the valve seat 15 and the annular seal portion 21 is not changed, the valve characteristics (the relationship between the valve opening degree and the flow rate, etc.) can be obtained by improving the existing valve body as the valve body 20. The self-excited vibration suppression effect can be easily obtained without affecting the above.

  Further, since the separation promoting portion 30 is provided on the entire circumference of the outer peripheral portion 22, the separation point is prevented from fluctuating in all the circumferential directions of the valve body 20, and the fluid F that has become a jet flow is re-applied to the valve body 20. Adhesion can be suppressed in all circumferential directions.

  In this reference example, as shown in FIG. 1, the cross-sectional shape in the axial direction of the separation promoting portion 30 is rectangular, but it may be polygonal such as triangular or trapezoidal. Further, at least a part of the cross-sectional contour may be curved, at least one side of the polygonal shape may be curved, and the corner may be R-shaped.

(Second reference example)
Next, the ball valve 2 according to the second reference example of the present invention will be described.
7 is an enlarged cross-sectional view of the main part of the ball valve 2, and FIG. 8 is a cross-sectional view taken along the line II-II in FIG. 7 and 8, the same components as those in FIGS. 1 to 6 are denoted by the same reference numerals and description thereof is omitted.

The ball valve 2 includes a separation promoting portion 50 in the valve body 20.
As shown in FIGS. 7 and 8, the separation promoting portion 50 extends in a radial shape from the outer peripheral portion 22 of the valve body 20, and in a part of the outer peripheral portion 22 on the downstream flow path 12 side. Is provided. As shown in FIG. 8, the separation promoting portion 50 has an arc shape in which a central angle θ formed by both end portions 50 b and 50 c in the circumferential direction and the axis P is approximately 110 degrees. The center angle θ of the separation promoting unit 50 is preferably set in the range of 45 degrees to 180 degrees.

Next, the excitation reducing action of the ball valve 2 having the above-described configuration will be described with reference to FIG.
First, when the annular seal portion 21 is slightly separated from the state where the annular seal portion 21 is in close contact with the valve seat 15 (sitting state), the fluid F becomes a jet and flows along the annular seal portion 21.

The fluid F that has reached the end portion 21a on the downstream side of the annular seal portion 21 is roughly divided into the following two flows in the circumferential direction.
First, of the fluid F that has reached the end 21 a on the downstream side of the annular seal portion 21, the fluid F in the portion where the separation promoting portion 50 is formed flows radially outward along the separation promoting portion 50. Later, it peels from the valve body 20 at the downstream end 50a of the separation promoting portion 50. Thereafter, the fluid F peeled off at the end portion 50 a flows away from the outer peripheral portion 22 and does not reattach to the outer peripheral portion 22.

  On the other hand, the fluid F in the portion where the separation promoting portion 50 is not formed among the fluid F reaching the end portion 21 a flows in the axial direction along the outer peripheral portion 22. In the course of this flow, the fluid F is peeled off from the outer peripheral portion 22, and a part of the peeled fluid F is reattached to the outer peripheral portion 22.

  In this way, the fluid F flowing out from the gap between the valve body 20 and the valve seat 15 is unevenly flowed in the circumferential direction, and a steady fluid force acts in the direction opposite to the downstream flow path 12 side. It will be in the state which shakes to the flow path 12 side. However, since the direction of the fluid force applied to the valve body 20 by the fluid F is fixed to a part of the radial direction, the dynamic characteristics of the valve body 20 as a whole can be stabilized.

FIG. 9 is an explanatory view of the effect of the target valve 2 by the display method similar to that of FIG.
As shown in FIG. 9, the ball-shaped valve 2 has a slightly unstable fluid force for a while from time 0 s when the fluid F flows from the upstream flow path 11 to the valve chamber 13. Therefore, the displacement and the fluid force change within a substantially constant range (amplitude). Thus, compared with the conventional ball valve shown in FIG. 6, the ball valve 2 has a very stable behavior. Compared with FIG. 5, the values of both the displacement and the fluid force are generally lower than 0. However, as described above, the valve body 20 is in a one-sided state. The dynamic characteristics are stable.

  As described above, according to the ball valve 2, the flow is biased in advance in the circumferential direction of the valve body 20, and the action direction of the fluid force by the fluid F on the valve body 20 is a part of the radial direction. Therefore, the dynamic characteristics of the entire valve body 20 can be stabilized.

  In this reference example, as shown in FIG. 7, the separation promoting portion 50 is provided on a part of the outer peripheral portion 22 of the valve body 20 on the downstream flow channel 12 side. It may be provided in a part. According to this configuration, since a steady fluid force acts on the downstream flow path 12 side, a state in which one side swings to the side opposite to the downstream flow path 12 side is obtained. Also in this configuration, the dynamic characteristics of the valve body 20 as a whole can be stabilized because the direction of the fluid force applied to the valve body 20 by the fluid F is fixed to a part of the radial direction.

(Third reference example)
Then, the ball-shaped valve 3 which concerns on the 3rd reference example of this invention is demonstrated.
FIG. 10 is an enlarged cross-sectional view of the main part of the ball valve 3. In FIG. 10, the same components as those in FIGS. 1 to 9 are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 10, the ball valve 3 is different from the ball valves 1 and 2 in that the outer peripheral portion 23 of the valve body 20 is configured to have a smaller diameter than the annular seal portion 21.
More specifically, the diameter of the outer peripheral portion 23 is smaller than the diameter of the downstream end portion 21a of the annular seal portion 21, and the downstream end portion 21a is sharp. As described above, the outer peripheral portion 23 having a smaller diameter than the end portion 21a is used as a separation promoting portion of the ball valve 3 (hereinafter, referred to as “separation promoting portion 23” as appropriate).

Next, the excitation reduction action of the ball valve 3 having the above-described configuration will be described.
First, when the annular seal portion 21 is slightly separated from the state where the annular seal portion 21 is in close contact with the valve seat 15 (sitting state), the fluid F becomes a jet and flows along the annular seal portion 21 and is peeled off at the end portion 21a. And in the state spaced apart from the separation promotion part (outer peripheral part) 23, it flows toward the axial direction and does not reattach to the separation promotion part (outer peripheral part) 23.

  As described above, according to the ball valve 3, the outer peripheral portion 23 of the valve body 20 is configured to have a smaller diameter than the downstream end portion 21 a of the annular seal portion 21. The fluid F, which has passed through the space 21 and becomes a jet, is peeled off at the end 21 a and does not flow along the outer peripheral portion 23 of the valve body 20. Thereby, it can suppress that the fluid F adheres to the outer peripheral part 23, and can suppress the self-excited vibration of the valve body 20. FIG.

  Further, according to the configuration of the ball-shaped valve 3, the outer peripheral portion 23 can be formed by cutting with a lathe, so that the valve chamber 13 cannot be added with the above-described separation promoting portions 30, 50, for example. It is effective when it is something.

  In this reference example, the entire circumference of the outer peripheral portion 23 is formed with a small diameter. However, a part of the outer peripheral portion 23 may be formed with a small diameter, or the outer peripheral portion 23 may be tapered (tapered).

(Fourth reference example)
Next, the spherical valve 4 according to the fourth reference example of the present invention will be described.
FIG. 11 is a cross-sectional view of the main part of the ball valve 4. In FIG. 11, the same components as those in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 11, the ball valve 4 is configured such that a covering member 24 is provided on the outer peripheral portion 22 of the valve body 20 and has a larger diameter than the downstream end portion 21 a of the annular seal portion 21. . With such a configuration, the annular end surface 24 a of the covering member 24 extends in the radial direction from the downstream end portion 21 a of the annular seal portion 21.

  According to the ball valve 4, the covering member 24 of the valve body 20 is configured to have a larger diameter than the downstream end portion 21 a of the annular seal portion 21. In the process in which the fluid F that has passed through the nozzle and flows as a jet flows along the annular end surface 24a, the flow direction is changed radially outward. Thereby, the fluid F that has passed between the valve seat 15 and the annular seal portion 21 can be separated from the valve body 20 in the radially outward direction.

  Furthermore, by providing the covering member 24 on the outer peripheral portion 22 of the valve body 20, the natural frequency of the valve body 20 can be changed to suppress self-excited vibration. The covering member 24 can be processed to change the natural frequency of the valve body 20 to suppress self-excited vibration.

(Fifth reference example)
Next, a description will be given of a ball valve 5 according to a fifth reference example of the present invention.
12 is a cross-sectional view of a main part of the ball valve 5, and FIG. 13 is an enlarged view of a main part III in FIG. 12 and 13, the same components as those in FIGS. 1 to 11 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 12, the ball-shaped valve 5 includes a gently inclined portion 16 that is inclined more gently than the valve seat 15 downstream in the flow direction of the valve seat 15 in the partition wall 14 that defines the valve chamber 13. An upper step portion 17 adjacent to the downstream side of the inclined portion 16 is provided.

  As shown in FIG. 13, when the annular seal portion 21 and the valve seat 15 are in close contact with each other, a slight gap is formed between the annular end surface (annular flat surface portion) 24 a and the upper step portion 17. Due to such a relationship, when the annular seal portion 21 is slightly separated from the valve seat 15, as shown in FIG. 12, the gap between the gently inclined portion 16 and the valve body 20 in the cross section along the axial direction of the valve body 20. Becomes larger, and a flow path (separation promoting portion) R1 is formed in which the gap between the upper stage portion 17 and the valve body 20 is reduced.

Next, the action of reducing the excitation of the ball valve 5 having the above-described configuration will be described.
The fluid F that has passed between the annular seal portion 21 and the valve seat 15 flows in the order of the gap between the gently inclined portion 16 and the valve body 20 and the gap between the upper stage portion 17 and the valve body 20 and flows into the valve chamber 13. To do. At this time, the fluid F flowing into the gap between the upper step portion 17 and the valve body 20, which has become relatively small, from the gap between the gently inclined portion 16 and the valve body 20, becomes a contracted flow and flows into the valve chamber 13. , And away from the valve body 20 outward in the radial direction.

As described above, the ball valve 5 has the flow path R1 in which the gap between the gently inclined portion 16 and the valve body 20 is large and the gap between the upper stage portion 17 and the valve body 20 is small. Therefore, when the fluid F that has passed through the gap between the gently inclined portion 16 and the valve body 20 flows into the gap between the upper stage portion 17 and the valve body 20, the flow velocity increases. As a result, the fluid F that has passed between the valve seat 15 and the annular seal portion 21 becomes a contracted flow directed radially outward, and is further easily separated from the valve body 20.
That is, since the fluid F does not flow along the outer peripheral portion 22 of the valve body 20, the fluid F can be prevented from reattaching to the outer peripheral portion 22, and the self-excited vibration of the valve body 20 can be suppressed.
Further, the processing is relatively easy, and the adhesion between the valve seat 15 and the annular seal portion 21 is not affected.

In this reference example, when the annular seal portion 21 and the valve seat 15 are in close contact with each other, a slight gap is formed between the annular end surface 24a and the upper step portion 17, but the annular seal portion 21 is formed. The annular end surface 24a and the upper step portion 17 may be in contact with each other on the condition that the adhesion between the valve seat 15 and the valve seat 15 is not hindered.
In addition, in this reference example, as shown in FIG. 12, the annular end surface 24a is a flat surface. However, the taper shape (tapered shape) gradually approaches the upper step portion 17 from the radially inward side toward the outward side. Good.
Similarly, when the annular seal portion 21 is slightly separated from the valve seat 15, the gap between the gently inclined portion 16 and the valve body 20 becomes large, and the gap between the upper step portion 17 and the valve body 20 becomes small (flow). On condition that the road R1) is satisfied, a tapered shape (tapered shape) gradually separating from the upper step portion 17 as it goes from the radially inner side to the outer side may be used.
Even in the case of these tapered shapes, a slight gap may be formed between the annular end surface 24a and the upper step portion 17, and the adhesion between the annular seal portion 21 and the valve seat 15 is not hindered. It is good also as a structure which the cyclic | annular end surface 24a and the upper step part 17 contact on condition of these.

(Sixth reference example)
Next, a description will be given of a ball valve 6 according to a sixth reference example of the present invention.
FIG. 14 is a cross-sectional view of the main part of the ball valve 6, and FIG. 15 is an enlarged view of the main part IV in FIG. 14 and 15, the same components as those in FIGS. 1 to 13 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 14, the ball valve 6 is the same as the ball valve 5 in that the partition wall 14 has a gently inclined portion 16 and an upper step portion 17, but from the annular seal portion 21 to the outer peripheral portion 22. Are connected by a smooth annular curved surface (annular curved surface portion) 24b. That is, as shown in FIG. 14, R processing is performed from the annular seal portion 21 to the outer peripheral portion 22 in the cross-sectional contour in the axial direction.

  As shown in FIG. 15, when the annular seal portion 21 and the valve seat 15 are in close contact with each other, a slight gap is formed between the annular curved surface 24 b and the upper step portion 17. Due to such a relationship, when the annular seal portion 21 is slightly separated from the valve seat 15, the gap between the gently inclined portion 16 and the valve body 20 in the cross section along the axial direction of the valve body 20 as shown in FIG. 14. Becomes larger, and a flow path R2 is formed in which the gap between the upper stage portion 17 and the valve body 20 becomes smaller.

Next, the excitation reduction action of the ball valve 6 having the above-described configuration will be described.
When the fluid F that has passed between the annular seal portion 21 and the valve seat 15 flows from the gap between the gently inclined portion 16 and the valve body 20 into the gap between the upper step portion 17 and the valve body 20 that have become relatively small. Then, it becomes a contracted flow and flows into the valve chamber 13 with the flow velocity increased.
In the process of this flow, the fluid F flowing through the gap between the gently inclined portion 16 and the upper step portion 17 and the valve body 20 flows stably along the annular curved surface 24b.

  According to this configuration, when the fluid F that has passed through the gap between the gently inclined portion 16 and the valve body 20 flows into the gap between the upper stage portion 17 and the valve body 20, the flow velocity increases. As a result, the fluid F that has passed between the valve seat 15 and the annular seal portion 21 becomes a contracted flow directed radially outward, and is further easily separated from the valve body 20.

In addition, since the annular seal portion 21 and the outer peripheral portion 22 are connected by a smooth annular curved surface 24b, the fluid F flowing through the gap between the gently inclined portion 16 and the upper step portion 17 and the valve body 20 flows into the annular curved surface 24b. Flows stably along. Thereby, the disturbance of the fluid F flowing through the gap between the gentle slope portion 16 and the upper step portion 17 and the valve body 20 can be reduced and the pressure loss can be reduced.
In this reference example, as shown in FIG. 14, the valve body 20 side is R-processed, but the valve seat 15 side may be R-processed.

  In this reference example, when the annular seal portion 21 and the valve seat 15 are in close contact with each other, a slight gap is formed between the annular curved surface 24b and the upper step portion 17, but the annular seal portion 21 is formed. The annular curved surface 24b and the upper step portion 17 may be in contact with each other on the condition that the adhesion between the valve seat 15 and the valve seat 15 is not hindered.

(First embodiment)
Next, the ball valve 7 according to the first embodiment of the present invention will be described.
16 is a cross-sectional view of a main part of the ball valve 7, and FIG. 17 is an enlarged view of a main part V in FIG. 16 and 17, the same components as those in FIGS. 1 to 15 are denoted by the same reference numerals, and the description thereof is omitted.

The ball valve 7 includes a vortex forming portion 90 that functions as an excitation force reducing unit that reduces the excitation force acting on the valve body 20 from the fluid F.
The vortex forming portion 90 includes three vortex forming grooves 90 a to 90 c, and these vortex forming grooves 90 a to 90 c are annular grooves formed concentrically on the valve seat 15, respectively.

  A part of the fluid F passing between the annular seal portion 21 and the valve seat 15 flows into the vortex forming grooves 90a to 90c and forms vortices in the vortex forming grooves 90a to 90c.

  According to this configuration, since vortices are generated in the vortex forming grooves 90a to 90c, the damping effect can be increased and the valve body 20 can be damped even if the valve body 20 causes self-excited vibration.

In the present embodiment, the vortex forming grooves 90 a to 90 c are formed in the valve seat 15, but may be provided in the annular seal portion 21, or may be provided in both the valve seat 15 and the annular seal portion 21. Good.
Moreover, in this embodiment, although it was set as the structure which provides the some eddy current formation groove | channels 90a-90c concentrically, it does not necessarily need to provide it concentrically.
Moreover, in this embodiment, although it was set as the structure which provides the some eddy current formation groove | channels 90a-90c, it is good also as a structure provided only one.
Further, in the present embodiment, the vortex forming grooves 90a to 90c are configured to communicate with each other in an annular shape, but may be formed into a plurality of intermittent grooves or honeycombs partitioned in the circumferential direction.

Note that the operation procedures shown in the reference examples and the embodiments described above, or the shapes and combinations of the components are examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention. is there.
For example, in each of the reference examples and embodiments described above, the case where the present invention is applied to a ball-shaped valve has been described. However, the present invention can also be suitably applied to valves having other structures, for example, angle valves. it can.

1 to 7 ... Girdle valve (valve device)
DESCRIPTION OF SYMBOLS 10 ... Valve box 10a ... Fluid inlet 10b ... Fluid outlet 11 ... Upstream flow path 12 ... Downstream flow path 13 ... Valve chamber 14 ... Partition 15 ... Valve seat 16 ... Slightly inclined part 17 ... Upper stage part 20 ... Valve body 21 ... Annular seal Part 21a ... end 22 ... outer peripheral part 23 ... outer peripheral part (separation promoting part)
24 ... covering member 24a ... annular end face (annular flat surface portion)
24b ... annular curved surface (annular curved surface portion)
29 ... Valve rod 30, 50 ... Separation promoting part 90 ... Eddy current forming part 90a-90c ... Eddy current forming groove R1 ... Channel R2 ... Channel F ... Fluid P ... Axis line

Claims (4)

The upstream flow path on the fluid inlet side and the downstream flow path on the fluid outlet side are configured to be continuous in a direction intersecting each other via the valve chamber, and at the opening of the upstream flow path of the partition wall that partitions the valve chamber, A valve box provided with a valve seat that gradually increases in diameter as it goes downstream;
An annular seal portion that can be seated on the valve seat, and a valve body configured to be movable forward and backward with respect to the valve seat,
An excitation force reducing means for reducing an excitation force acting on the valve body from the fluid;
The valve device according to claim 1, wherein the excitation force reducing means is a vortex forming portion that is provided in at least one of the valve seat and the annular seal portion and generates a vortex.   The valve device according to claim 1, wherein the vortex forming portion has a vortex forming groove formed in an annular shape.   The valve device according to claim 2, wherein the vortex forming groove is divided into a plurality in the circumferential direction.   The valve device according to claim 2 or 3, wherein a plurality of the vortex forming grooves are provided concentrically.

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