JP3801392B2 - Ball valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ball valve.
[0002]
[Prior art]
As shown in FIG. 9, the conventional ball valve is configured such that a spherical valve body 2 is provided inside a valve box 1, and the valve body 2 is rotated in the direction of arrow A by a valve rod 3. . 4 is a fluid passage in the valve body 2, and 5 is a port in the valve box 1. A valve seat 6 is provided around the port 5, and the valve seat 6 is in contact with the spherical surface 7 of the valve body 2, thereby sealing between the valve box 1 and the valve body 2. The center 8 of the spherical surface 7 is located on the rotation center 9 of the valve body 2. Then, when the valve body 2 is rotated in a state where the space between the valve box 1 and the valve box 1 is sealed in this way, the communication state between the port 5 and the fluid passage 4 changes, and the opening degree of the valve is adjusted. It will be.
[0003]
[Problems to be solved by the invention]
However, in such a conventional configuration, the valve seat 6 and the spherical surface 7 of the valve body 2 are always in contact with each other, so that the seal portion is easily worn, and the sealing performance becomes unstable when the valve is opened and closed frequently. There is a problem that there is a possibility.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems and make it difficult to wear the seal portion of the ball valve so as to ensure stable sealing performance.
[0004]
[Means for Solving the Problems]
In order to achieve this object, the present invention is a ball valve having a valve body and a valve box, wherein the valve box has three ports every 90 degrees, and the valve body has three passage openings of 90. Formed every 3 degrees to form a three-pronged fluid passage corresponding to the three ports of the valve box, the portion of the valve body where the passage opening is not formed, and at a position protruding 90 degrees from the passage opening, The valve body sheet | seat formed with the plate body which has this is provided, and this valve body sheet | seat is comprised so that it may closely_contact | adhere with a valve box sheet | seat in the perimeter only at the time of closing.
In such a configuration, the valve seat is in close contact with the valve casing sheet all around only when it is closed, and in other cases, the close contact with the valve casing seat is released, so wear is less likely to occur. A stable sealing property is ensured.
[0005]
According to the present invention, the three passage openings forming the fluid passage have a gap formed between the front end portion and the valve box sheet without contact when the front end portion faces the valve box seat. It is preferable that
With such a configuration, the occurrence of wear on the valve box seat is reduced, so that a stable sealing performance is ensured over a long period of time, and the sealing performance is not easily lowered even with a valve that is frequently opened and closed. . Also, the torque required for valve operation is reduced.
[0006]
Furthermore , according to the present invention, the valve body is configured such that four cylindrical portions protrude radially every 90 degrees, the three cylindrical portions form passage openings, and the remaining cylindrical portions are partition walls. Therefore, it is preferable that the fluid passage is formed so as not to communicate with the fluid passage and is provided with a valve body sheet.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the ball valve shown in FIG. 1, reference numeral 11 denotes a valve box which can be configured as a three-way valve including a first port 12, a second port 13, and a third port 14.
A valve body 15 is provided inside the valve box 11. One end of the valve body 15 is rotatably supported by a bearing 16, and the other end is connected to the valve stem 17 so that the valve stem 17 rotates integrally with the valve stem 17 by rotating the valve stem 17. It is configured.
[0008]
FIG. 2 shows the three-dimensional structure of the valve body 15. As shown in FIGS. 1 and 2, the valve body 15 includes a seat portion 18 on one end side for housing the bearing 16 and a seat portion 19 on the other end side for housing the end portion of the valve rod 17. And has a three-way fluid passage 20 corresponding to the first to third ports 12 to 14 of the valve box 11. The fluid passage 20 includes three cylindrical portions 21, 22, and 23 that are integrally formed in a T shape. That is, these cylindrical portions 21, 22, and 23 are formed so as to protrude in three directions with an angle of 90 degrees along the circumferential direction of the valve body 15.
[0009]
Another cylindrical portion 24 is formed on the valve body 15 so as to protrude outward from the cylindrical portions 21 and 23 at positions of 90 degrees. That is, the valve body 15 is formed such that the four cylindrical portions 21 to 24 protrude radially every 90 degrees. The cylindrical portion 24 is formed by the partition wall 25 so that the inside thereof does not communicate with the fluid passage 20.
[0010]
A columnar mounting seat 26 that projects from the partition wall 25 in the same direction as the cylindrical portion 24 is formed integrally with the partition wall 25 at a central position of the cylindrical portion 24. The protruding height of the mounting seat 26 is formed to be substantially equal to the protruding height of the cylindrical portion 24. A plate-shaped valve body seat 28 is attached using this attachment seat 26. An attachment bolt 29 is screwed into the attachment seat 26, and the valve seat 28 is sandwiched and fixed between the attachment seat 26 and the attachment seat 26.
[0011]
The valve body sheet 28 is formed in a disc shape by a disc body, and integrally includes a central circular flat plate portion 30 and a peripheral sheet portion 31 of the flat plate portion 30. The flat plate portion 30 is formed to have a slightly larger diameter than the cylindrical portion 24 of the valve body 15. The seat portion 31 is formed in a spherical shape centering on a center point 33 on the rotation center axis 32 of the valve body 15. As described above, since the cylindrical portion 24 of the valve body 15 is formed with a protruding height equivalent to that of the mounting seat 26, when the valve body seat 28 is fixed to the mounting seat 26 with the bolts 29, the seat in the valve body seat 28. The vicinity of the portion 31 is backed up by the cylindrical portion 24. The valve body sheet 28 is made of an elastic material such as spring steel, for example, a JIS SUP material. In that case, the sheet portion 31 is preferably subjected to chrome plating or the like.
[0012]
In FIG. 1, reference numeral 35 denotes an annular valve box sheet, which is provided in the first port 12 so that the valve body sheet 28 can be brought into close contact by its elasticity as shown in the figure. In the valve of FIG. 1, similar valve box seats are provided not only on the first port 12 but also on the third port 14. However, the illustration is omitted. In the valve of FIG. 1, the second port 13 is not provided with a valve box seat.
[0013]
FIG. 3 shows a state where the valve body 15 is rotated from the state shown in FIG. 1 and, for example, the cylindrical portion 22 faces the valve box seat 35 of the first port 12. As illustrated, in this state, the cylindrical portion 22 and the valve box seat 35 are not in contact with each other, and a gap 36 is formed between them.
When the first port 12 is on the upstream side and, for example, the third port 14 is on the downstream side, the valve seat 28 is in close contact with the valve box seat 35 due to its elasticity, and the first port 12 is closed. FIG. 4 shows the state at the time. At this time, the fluid pressure P acts on the flat plate portion 30 of the valve body seat 28 from the first port 12, but the flat plate portion 30 is backed up by the cylindrical portion 24 of the valve body 15 as described above. The backup portion serves as a fulcrum, and the force F in the direction of pressing the valve box seat 35 acts on the elastic seat portion 31 over the entire circumference. That is, due to the pressure of the fluid in the valve box 11, the seat part 31 of the valve body sheet 28 having elasticity is pressed against the valve box sheet 35 with a predetermined force.
[0014]
On the other hand, when the first port 12 is on the downstream side in FIGS. 1 and 4, the pressure of the fluid in the valve box 11 acts on almost the entire surface of the valve seat 28, that is, both the flat plate portion 30 and the seat portion 31. For this reason, the pressure of the fluid can also be received at the inner peripheral portion of the flat plate portion 30 with respect to the cylindrical portion 24, so that the seat portion 31 of the valve body seat 28 having elasticity by the fluid pressure is also applied to the valve box seat 35. It will be pressed.
[0015]
As for the member on the valve body 15 side, only the annular seat portion 31 in the valve body sheet 28 contacts the valve box sheet 35 when fully closed, and the other members do not contact the valve box sheet 35. For example, FIG. 5 shows a state in which the first port 12 is in an intermediate state between the fully open state and the fully closed state. At this time, as shown in FIG. Although the portions 37 and 37 are close to the valve box seat 35, they are not in contact with each other. For this reason, the occurrence of wear in the valve box seat 35 and the valve body seat 28 is reduced, so that a stable sealing performance is ensured over a long period of time, and the sealing performance is not easily lowered even with a valve that is frequently opened and closed. is there. Also, the torque required for valve operation is reduced. In addition, no member other than the seat portion 31 contacts the valve box seat 35 in this intermediate state.
[0016]
6 to 8 illustrate the open / closed state of the three-way valve described above. 6 shows a state in which the valve body sheet 28 is separated from both of the pair of valve box sheets 35, 35, that is, the cylindrical portion 23 of the valve body 15 faces the first port 12 of the valve box 11. The state where the part 22 faces the second port 13 and the cylindrical part 21 faces the third port 14 is shown. Here, when the first port 12 and the third port 14 constitute the main pipe 38 and the second port constitutes the branch pipe 39, as shown in FIG. FIG. 6 shows a state where the main pipe 38 is in a fully opened state and communicates with the branch pipe 39. At this time, the valve body seat 28 does not face any port.
[0017]
FIG. 7 shows a state in which the valve body sheet 28 is in close contact with the valve box sheet 35 of the third port 14. In this case, the third port 14 is closed and the first port 12 and the second port 13 communicate with each other.
FIG. 8 shows a state in which the valve body sheet 28 is in close contact with the valve box sheet 35 of the first port 12. In this case, the first port 12 is closed and the second port 13 and the third port 14 communicate with each other.
[0018]
【The invention's effect】
As described above, according to the present invention, the valve body sheet is configured by the elastic plate body, and the valve body sheet is configured to be in close contact with the valve box sheet all around only when the valve body is closed. The intimate contact with the valve box seat is released, so that it is possible to make it difficult for wear to occur, and thus it is possible to ensure a stable sealing property.
[0019]
Further, according to the present invention, the three passage openings forming the fluid passages are not in contact with the front end portion and the valve box seat when the front end portion faces the valve case seat, so that a gap is formed between them. Therefore, there is an advantage that the occurrence of wear in the valve box seat is reduced, and thus stable sealing performance is ensured over a long period of time, and the sealing performance is not easily lowered even with a valve that is frequently opened and closed. Also, the torque required for valve operation is reduced.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front view of a main part of a ball valve according to an embodiment of the present invention.
2 is a perspective view of the valve body in FIG. 1. FIG.
FIG. 3 is an enlarged view of a main part showing a state when the valve body rotates from the state of FIG. 1 and the cylindrical part faces the valve box seat of the first port.
4 is a view showing a state in which a fluid pressure acts on the valve body in the state of FIG. 1;
FIG. 5 is a diagram showing a state when the first port is in an intermediate state between fully open and fully closed.
6 is a diagram showing a first open / close state of a three-way valve configured with the ball valve of FIG. 1; FIG.
FIG. 7 is a view showing a second open / close state of the three-way valve.
FIG. 8 is a view showing a third opening / closing state of the three-way valve.
FIG. 9 is a cross-sectional view of a main part of a conventional ball valve.
[Explanation of symbols]
15 Valve body 28 Valve body sheet 30 Flat plate part 31 Sheet part 35 Valve box sheet

Claims (3)

A ball valve having a valve body and a valve box,
The valve box has three ports every 90 degrees,
In the valve body, three passage openings are formed every 90 degrees to form a fluid passage having a three-pronged structure corresponding to three ports of the valve box,
A valve body sheet formed of an elastic plate is provided at a position where the passage opening in the valve body is not formed and protrudes 90 degrees from the passage opening. A ball valve characterized in that it is configured so as to be in intimate contact with the valve box seat only on the entire circumference. The three passage openings forming the fluid passages are such that when the tip part faces the valve box sheet, the tip part and the valve box sheet are not in contact with each other and a gap is formed between them. The ball valve according to claim 1 . The valve body is configured such that four cylindrical portions protrude radially every 90 degrees, the three cylindrical portions form passage openings, and the remaining cylindrical portions communicate with the fluid passage by a partition wall. The ball valve according to claim 1, wherein a valve body seat is provided and the valve body seat is provided .

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