WO2018181532A1

WO2018181532A1 - Ball valve

Info

Publication number: WO2018181532A1
Application number: PCT/JP2018/012887
Authority: WO
Inventors: 洋繁瀬戸
Original assignee: 旭有機材株式会社
Priority date: 2017-03-28
Filing date: 2018-03-28
Publication date: 2018-10-04
Also published as: JP2018165540A; JP6914072B2

Abstract

Provided is a ball valve configured to prevent foreign substances from occurring within the ball valve and also to prevent fluid from stagnating within the ball valve. This ball valve is provided with a flow rate regulation seat (4) located inside a valve chamber (13) at a position close to a second flow passage (12) and configured to adjust the flow rate of fluid flowing through a first flow passage (11) and the second flow passage (12). The flow rate regulation seat (14) is provided with an annular seat section (42) and a flow rate regulation section (44) which is located on the inner peripheral side of the seat section (42). The seat section (42) is provided with a seal surface (43) on which a ball valve body (2) slides and which seals fluid. The flow rate regulation section (44) is provided with: a flow rate regulation opening (46) for providing communication between the second flow passage (12) and the valve chamber (13); and a guide surface (47) continuously connected to the seal surface (43) and configured to separate from the ball valve body (2) and to guide fluid. The gap between the guide surface (47) and the ball valve body (2) continuously increases from the outer peripheral edge of the guide surface (47) toward a flow passage axis.

Description

Ball valve

The present invention relates to a ball valve used in fluid transport piping lines of various industries such as chemical plant, water and sewage, agriculture, fishery industry, semiconductor manufacturing field, food field and the like.

The ball valve can normally be opened and closed by rotation by approximately 90 degrees and has a simple structure and is excellent in economic efficiency. However, since the flow rate changes rapidly according to the degree of opening, two open and fully closed states are opened. Often used in degrees.

As a ball valve whose flow rate can be adjusted by changing the opening degree, for example, there is a ball valve described in Patent Document 1. The configuration mounted a volume control insert with a laterally shaped or parabolic shaped elongated slot for flow regulation at the position where the ball valve fluid passage and the valve seat of the valve housing are attached to give a predetermined flow condition It was a thing.

In addition, when the ball valve is fully closed, the fluid stays in the pipe on the upstream side of the ball valve or in the ball valve, and bacteria easily propagates, and the fluid expands and contracts due to freezing etc. May be damaged. In order to prevent fluid from staying in the piping or ball valve, the degree of opening of the ball valve may be made a minute degree of opening, and the fluid may flow slightly, but setting of the degree of opening is difficult and unexpected external force on the handle There is a risk that the degree of opening may change if it takes time.

As a ball valve capable of stably adjusting the flow rate to a minute flow rate, for example, there is a ball valve described in Patent Document 2. In the configuration, a sub flow passage smaller in diameter than the main flow passage is formed at a position orthogonal to the main flow passage formed in the ball of the ball valve.

JP-A-11-270711 JP, 2005-98425, A

However, in the valve according to Patent Document 1, when the volume control insert is attached to the valve housing, the surface on the ball valve side of the volume control insert fully contacts the ball valve. Therefore, each time the ball valve is opened and closed, the volume control insert and the ball valve slide, and the volume control insert or the ball valve is scraped to generate foreign matter. In addition, when the volume control insert or the ball valve is worn, there is a possibility that foreign matter may be accumulated in the gap caused by the wear or fluid may be accumulated to propagate bacteria. Moreover, in the valve | bulb which concerns on patent document 2, the small diameter sub flow path is formed in the ball | bowl of thickness. In order to form the sub flow passage, the thickness of the drill needs to be a thickness that does not break when cutting the sub flow passage, and a flow rate larger than the desired flow rate may flow. In particular, when the fluid is expensive, the cost of the fluid is increased to prevent internal retention in order to prevent the fluid from staying in the piping or ball valve.

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems of the prior art as described above, and to provide a ball valve capable of reducing the flow rate when flowing fluid for the purpose of preventing generation of foreign matter and fluid retention inside the ball valve. It is to be.

According to the first aspect of the present invention, a valve main body provided with a first flow passage, a second flow passage, and a valve chamber communicating the first flow passage and the second flow passage, and the first flow passage side in the valve chamber A seat positioned on the second flow path side of the valve chamber and configured to adjust the flow rate of the fluid flowing through the first flow path and the second flow path; And a ball valve body having a through hole serving as a valve body flow path, and a ball valve body communicating or blocking the first flow path and the second flow path. An annular seat portion and a flow rate adjustment portion positioned on the inner peripheral side of the seat portion, the seat portion includes a seal surface on which the ball valve element slides and seals the fluid, and the flow rate adjustment portion A flow rate adjustment opening communicating the second flow passage with the valve chamber and a seal surface are continuously connected to And a guide surface configured to guide the fluid while being separated from the valve body, and the clearance between the guide surface and the ball valve body is continuously large as it approaches the flow path axis from the outer peripheral edge of the guide surface. The ball valve is provided.

That is, in the first aspect of the present invention, the guiding surface of the flow rate adjustment sheet is continuously connected to the sealing surface and is separated from the ball valve body. Further, the gap between the guide surface and the ball valve body continuously increases as it approaches the flow path axis from the outer peripheral edge of the guide surface. According to this aspect, when the ball valve body rotates, the ball valve body and the flow rate adjusting portion can be brought into non-contact with each other, so that the ball valve body does not slide in contact with the flow rate adjusting portion. It is possible to reduce the generation of foreign matter due to wear and sliding. Furthermore, since the fluid flowing in the valve body flow path easily flows along the guiding surface from the outer peripheral edge of the guiding surface toward the center, stagnant parts are less likely to be generated in the gap between the guiding surface and the ball valve body. Effective flushing can be performed, and foreign matter can be prevented from being accumulated in the gap and bacteria can be prevented from being generated.

According to a second aspect of the present invention, in the first aspect, the sealing surface is a spherical surface having the same radius as the radius of the ball valve body, and the guiding surface is a spherical surface having a smaller radius than the radius of the ball valve body. , A ball valve is provided.

That is, since the guiding surface is a spherical surface that bulges toward the second flow path, the fluid flowing in the valve body flow path can more easily flow along the outer peripheral edge of the guiding surface, and flushing the outer peripheral edge of the guiding surface more effectively it can.

According to a third aspect of the present invention, in the first aspect or the second aspect, the seat member has a communication groove communicating the first flow path and the valve chamber, and the ball valve body has a valve body flow path. A ball valve having an auxiliary flow passage having an inner diameter smaller than that of the valve flow passage, the auxiliary flow passage communicating the valve flow passage with the second flow passage at least in a fully closed state; Be done.

That is, when the ball valve is fully closed, the first flow passage, the valve chamber, the valve body flow passage, and the second flow passage communicate with each other, so that fluid can be allowed to flow little by little in the ball valve even in the fully closed state. The fluid retention in the valve chamber and the valve body flow path can be suppressed, and the generation of bacteria, the accumulation of foreign matter, and the fixation can be reduced.

According to the fourth aspect of the present invention, in the third aspect, the auxiliary flow path communicates the large diameter flow path located on the outer peripheral side of the ball valve body, the large diameter flow path and the valve body flow path and is large A ball valve is provided, which has a small diameter flow passage with an inner diameter smaller than the radial flow passage, and the length of the small diameter flow passage is shorter than the large diameter flow passage.

That is, the auxiliary flow passage is formed stepwise by the large diameter flow passage and the small diameter flow passage shorter than the large diameter flow passage. In this aspect, the drill used for drilling the small diameter flow path is less likely to break and the outer diameter of the drill can be reduced, so the inner diameter of the small diameter flow path can be reduced and the flow rate for preventing retention in the ball valve is reduced. it can.

According to a fifth aspect of the present invention, there is provided a ball valve as defined in the fourth aspect, wherein the inner diameter of the small diameter passage is 0.1 mm or more and less than 1 mm.

According to this aspect, since the drill used when drilling the small diameter flow path is not easily broken, the small diameter flow path having an inner diameter of less than 1 mm can be stably drilled. Further, since the inner diameter of the small diameter flow passage is 0.1 mm or more, a fluid such as pure water can stably flow in the small diameter flow passage.

According to the present invention, foreign matter is generated by reducing the contact area between the flow rate adjustment sheet and the ball valve body and increasing the gap between the flow rate adjustment sheet and the ball valve body as it approaches the flow path axis. It is possible to provide a ball valve capable of preventing fluid from staying in the gap. Furthermore, a communication groove is formed in the seat to connect the first flow path and the valve chamber, and the auxiliary flow path connecting the valve flow path and the second flow path to the ball valve body is a relatively large diameter hole By forming stepwise with small diameter holes, it is possible to provide a ball valve capable of preventing the fluid from staying in the ball valve at a low flow rate.

It is a sectional view showing a fully open state of a ball valve concerning a first embodiment of the present invention. It is a figure showing a flow control sheet used for a ball valve concerning a first embodiment of the present invention, (a) is a perspective view, (b) is a perspective view from another angle, (c) ) Is a cross-sectional view. It is a principal part expansion AA sectional view showing each opening degree state of a ball valve concerning a first embodiment of the present invention, (a) is a drawing showing a fully closed state, (b) is a half open state It is a figure which shows and (c) is a figure which shows a full open state. It is a side view from the 2nd channel side of a ball valve concerning a first embodiment of the present invention. It is a principal part expanded sectional view showing a fully closed state of a ball valve concerning a second embodiment of the present invention. It is sectional drawing which shows the method of drilling an auxiliary flow path in the ball valve body used for the ball valve which concerns on 2nd embodiment of this invention, and (a) is drawing which shows the state which pierced the large diameter flow path. (B) is a figure which shows the state which pierced the small diameter channel.

(First embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings, but it goes without saying that the present invention is not limited to the present embodiment.

FIG. 1 is a cross-sectional view showing a fully open state of the ball valve according to the first embodiment, FIG. 2 is a drawing showing a flow rate adjustment sheet used for the ball valve according to the first embodiment, and FIG. It is a principal part expanded AA sectional view showing each opening degree state of a ball valve concerning a first embodiment, and Drawing 4 is a side view from the 2nd channel side of a ball valve concerning a first embodiment .

As shown in FIG. 1 to FIG. 4, the ball valve is a first class of the valve body 1 so as to always abut on the valve body 1, the ball valve body 2 disposed inside the valve body 1, and the ball valve body 2. The flow rate of the fluid flowing through the first flow passage 11 and the second flow passage 12 is determined by the seat 3 located on the passage 11 side and the second flow passage 12 side of the valve main body 1 so as to always contact the ball valve body 2. And a flow control sheet 4 configured to adjust. The ball valve body 2 is connected to a handle 6 which is an operation unit via a stem 5. The ball valve body 2 is rotated following the rotation of the handle 6 to connect or block the first flow path 11 and the second flow path 12 of the valve body 1.

The valve body 1 is made of polyvinyl chloride (hereinafter referred to as PVC) and has a bore of 25 mm. The valve main body 1 has a substantially hollow cylindrical shape, and has a first flow passage 11, a second flow passage 12 having the same flow passage axis as the first flow passage 11, and a first flow passage 11 and a second flow passage 12 inside. And a valve chamber 13 communicating with each other. An annular recess 14 centered on the flow channel axis is formed on the wall surface of the valve chamber 13 on the second flow passage 12 side, and the flow rate adjustment sheet 4 is inserted into the recess 14. Further, an annular groove 10 is formed on the bottom of the recess 14, and the first cushion 16 is inserted into the annular groove 10. A cutout groove 15 is formed on the outer peripheral edge of the recess 14 so as to protrude radially outward of the recess 14. A through hole into which the stem 5 is inserted is formed in communication with the valve chamber 13 in a direction intersecting the flow passage axis of the valve body 1. A male screw is formed on the outer peripheral surface of each end of the valve body 1, and a female screw is formed on the inner peripheral surface of the end on the first flow passage 11 side.

The ball valve body 2 is made of PVC and has a spherical shape. In the upper surface of the ball valve body 2, an engagement groove having a trapezoidal cross section in which the stem 5 is engaged is formed. In the inside of the ball valve body 2, a through hole having a circular cross-section to be the valve body channel 21 is formed.

The stem 5 is made of PVC and has a substantially cylindrical shape. The upper end portion of the stem 5 is formed with an engagement portion to be engaged with the engagement groove of the handle 6, and the lower end portion of the stem 5 is trapezoidal in cross section to be engaged with the engagement groove of the ball valve body 2 In the outer peripheral surface of the stem 5, an annular groove in which the O-ring is fitted is formed. The handle 6 is made of acrylonitrile butadiene styrene copolymer synthetic resin (hereinafter referred to as ABS), and an engagement groove engaged with the engagement portion of the stem 5 is formed at the center of the lower surface. When the handle 6 is rotated with the axis of the stem 5 as a rotation axis, the ball valve 2 connected to the handle 6 via the stem 5 rotates following the rotation of the handle 6. By the rotation of the ball valve body 2, the valve body flow path 21 and the first flow path 11 and the second flow path 12 are communicated or blocked.

The valve body retainer 9 is made of PVC and has a cylindrical shape. The seat 3 and the second cushion 17 are fitted to the end surface of the valve body retainer 9 on the ball valve body 2 side, and the O ring is disposed on the other end surface of the valve body retainer 9. In addition, an O-ring is disposed on the outer peripheral surface of one end of the valve holder 9, and on the outer peripheral surface of the other end of the valve holder 9, there is an external thread that is screwed with the female screw of the valve body. It is formed. By screwing the valve body retainer 9 to the valve body 1, the ball valve body 2 is pressed to the second flow path 12 side. At this time, the ball valve body 2 is pressed from the flow passage directions in the valve chamber 13 to the flow control sheet 4 and the sheet 3 through the first cushion 16 and the second cushion 17, respectively.

The sheet 3 is made of polytetrafluoroethylene (hereinafter referred to as PTFE) and has an annular disc shape. The seat 3 is disposed in the valve chamber 13, and the center of the seat 3 is located on the flow path axis. The seat 3 is provided with a sealing surface 31 on which the ball valve body 2 slides and seals the fluid, and the sealing surface 31 is formed by an inclined surface which is a conical surface. By making the sealing surface 31 conical, the contact between the ball valve body 2 and the sealing surface 31 can be made line contact, and the operation torque for rotating the ball valve body 2 can be reduced.

The flow rate adjustment sheet 4 is made of PTFE and has an annular disc shape. The flow control sheet 4 is disposed in the valve chamber 13, and the center of the flow control sheet 4 is located on the flow path axis. The flow rate adjustment sheet 4 has an annular seat portion 42 fitted in an annular recess 14 disposed in the valve chamber 13 and a flow rate adjustment portion 44 located on the inner peripheral side of the seat portion 42. . At the outer peripheral edge of the flow rate adjustment sheet 4, a protrusion 41 is formed which is inserted into the notch groove 15 formed in the recess 14 of the valve chamber 13. The projection 41 prevents the flow control sheet 4 from rotating when the flow control sheet 4 is inserted into the valve body 1.

The seat portion 42, like the seat 3, comprises a sealing surface 43 on which the ball valve body 2 slides and seals the fluid. The sealing surface 43 is formed to be a spherical surface having a radius substantially the same as the radius R1 of the ball valve body 2. When the seal surface 43 is thus spherical instead of conical, the contact between the ball valve body 2 and the seal surface 43 is a surface contact. The ball valve according to the present embodiment is a ball valve having a flow rate adjusting function, and is often used in a half-opened state. Therefore, when the ball valve is in a half-opened state, the ball valve body 2 is pressed against the sealing surface 43 to seal It is possible to reduce the damage of the surface 43 and the biting of the ball valve body 2. Here, if the outer shape such as the thickness of the sheet 3 is substantially the same as the shape of the sheet portion 42, the sheet 3 can be inserted into the recess 14 like the flow rate adjusting sheet 4, so that a standard without flow adjusting function is provided. At the time of specification, it is preferable to insert the sheet 3 into the recess 14 instead of the flow rate adjusting sheet 4.

A cylindrical projecting portion 45 slightly smaller in diameter than the second flow passage 12 is formed on the second flow passage 12 side of the flow rate adjustment unit 44. Since the projecting portion 45 is inserted into the second flow path 12, the thickness of the flow rate adjusting portion 44 can be increased while suppressing the change in the total length of the ball valve, and the strength of the flow rate adjusting sheet 4 can be secured. Further, the flow rate adjusting portion 44 is formed with a flow rate adjusting opening 46 which communicates with the second flow passage 12 and the valve chamber 13 and adjusts the flow rate of the ball valve. The flow rate adjustment opening 46 is generally fan-shaped, and extends from one of the axes orthogonal to the central axis of rotation of the ball valve body 2 to the other. That is, the area of the opening S (see FIG. 4) formed by the flow rate adjustment opening 46 and the through hole of the ball valve 2 increases as the ball valve changes from the fully closed state to the fully open state. By forming the flow rate adjustment opening 46 not in the ball valve body 2 but in the flow rate adjustment sheet 4, processing is easier as compared to the case where the flow rate adjustment opening 46 is formed in the ball valve body 2, and bulk of parts inventory is increased. It can be reduced. In particular, when the flow rate adjustment sheet 4 is formed of PTFE, it can be applied to many usage conditions with one kind of material, so the number of parts stock can be reduced.

The flow rate adjusting unit 44 is formed with a guiding surface 47 which is continuously connected to the sealing surface 43 and guides the fluid to the second flow passage 12. The guiding surface 47 is formed into a spherical surface having a radius R2 smaller than the radius R1 of the ball valve 2 and is separated from the ball 2. Here, in FIG. 2C, the radius R2 of the guiding surface 47 is made easy to understand by an imaginary line. The guiding surface 47 is formed to approach the surface of the flow rate adjustment sheet 4 on the second flow passage 12 side as it approaches the flow passage axis. That is, the gap 25 between the guide surface 47 and the ball valve body 2 becomes larger as it approaches the flow path axis.

The cap nut 7 is made of PVC and has a substantially cylindrical shape. On the inner peripheral surface of one end of the cap nut 7, a female screw portion screwed to the male screw formed at both ends of the valve main body 1 is formed, and the other end of the cap nut 7 is formed An inner flange portion protruding to the inner diameter side is formed. The flanged short pipe 8 is made of PVC, and has an outer diameter portion projecting to the outer diameter side at one end. The flanged short pipe 8 is clamped and fixed to both end surfaces of the valve body 1 by a cap nut 7.

Next, with reference to FIGS. 1 to 4, the operation of the ball valve of the first embodiment will be described. When the handle 6 of the ball valve is pivoted, the stem 5 is pivoted following the handle 6 and the ball valve 2 pivots further. The ball valve 2 pivots within a range of 90 degrees. When the ball valve body 2 is turned from the fully closed state (FIG. 3a), it becomes a half open state (FIG. 3b), and the first channel 11 and the second channel 12 communicate with each other by the valve channel 21. The fluid flowing in the valve body channel 21 flows from the outer peripheral edge of the guiding surface 47 along the guiding surface 47 and flows into the flow rate adjustment opening 46. When the ball valve body 2 is further rotated, it is fully opened (FIG. 3c). The opening S (see FIG. 4) formed by the valve flow passage 21 and the flow rate adjustment opening 46 changes in accordance with the rotation of the ball valve 2 and the opening S increases as the amount of rotation of the ball valve 2 increases. The area of the

The guiding surface 47 of the flow rate adjustment sheet 4 is formed to be a spherical surface having a radius R2 smaller than the radius R1 of the ball valve body 2 and is separated from the ball valve body 2. Therefore, even if the ball valve body 2 rotates, the ball valve body 2 and the flow rate adjusting unit 44 do not come in contact with each other, and the foreign matter is generated due to wear or sliding of the flow rate adjusting sheet 4 accompanying the rotation of the ball valve body 2 Can be reduced. Further, since the ball valve body 2 and the flow rate adjusting unit 44 are separated, even if the flow rate adjusting unit 44 is provided, the operating torque can be equivalent to that of a general ball valve without the flow rate adjusting unit 44. Further, the guiding surface 47 is formed such that the clearance 25 between the guiding surface 47 and the ball valve body 2 becomes larger as it approaches the flow path axis. Furthermore, the guiding surface 47 is continuously connected to the sealing surface 43. Therefore, the fluid flowing in the valve flow passage 21 easily flows along the guiding surface 47 from the outer peripheral edge of the guiding surface 47 toward the center, so that the stagnation portion is formed in the gap 25 (particularly, in the vicinity of the outer peripheral edge of the guiding surface 47). It becomes difficult to occur. In the ball valve, foreign matter is likely to be deposited in the gap 25 in the fully closed state or in the gap 25 far from the valve flow path 21 in the half open state, or fluid tends to be accumulated to generate bacteria. By setting the state, the entire gap 25 can be flushed and effectively cleaned.

In the first embodiment, the flow rate adjustment opening 46 is formed in a generally fan shape, but the shape of the flow rate adjustment opening 46 can be appropriately selected depending on what flow rate adjustment is performed, and other shapes such as rectangles or sparks Shape, right-angled trapezoid etc. are raised. Further, the opening for forming the flow adjustment opening 46 is not limited to one, and the flow adjustment opening 46 may be formed by a plurality of holes.

In the first embodiment, the seal surface 31 of the seat 3 is formed as an inclined surface which becomes a conical surface, but like the seal surface 43 of the flow rate adjustment sheet 4, the seal surface 31 is substantially the same as the radius R1 of the ball valve body 2. It may be formed to be a spherical surface having a radius. Further, although the seal surface 43 of the flow rate adjustment sheet 4 is formed to be a spherical surface having a radius substantially the same as the radius R1 of the ball valve body 2, it is a conical surface like the seal surface 31 of the sheet 3. You may form by an inclined surface.

In the first embodiment, the guiding surface 47 is formed to be a spherical surface having a radius R2 smaller than the radius R1 of the ball valve body 2, but the gap 25 between the guiding surface 47 and the ball valve body 2 It should be larger as it gets closer to the axis. Other shapes include a combination of a conical surface, a pyramidal surface, an ellipsoidal surface, and a plurality of curved surfaces and tapered surfaces, but when the outer peripheral edge of the guiding surface 47 is formed by a curved surface that bulges in the second channel 12 direction It is suitable. By doing this, the fluid flowing through the valve body channel 21 can more easily flow along the outer peripheral edge of the guide surface 47, and the outer peripheral edge of the guide surface 47 can be flushed more effectively.

Next, a ball valve according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an enlarged sectional view of an essential part showing a fully closed state of the ball valve according to the second embodiment, and FIG. 6 is a sectional view of the ball valve used in the ball valve according to the second embodiment. It is sectional drawing which shows the method to perforate. The second embodiment is different from the first embodiment mainly in that an auxiliary flow passage 22 is formed to prevent fluid from staying in the ball valve. 5 to 6, the components having the same operations and functions as those of the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 4. In the following, the differences from the first embodiment are mainly described. explain.

In the second embodiment, on the outer peripheral edge of the seat 3, a communication groove 32 is formed which constantly communicates the first flow passage 11 and the valve chamber 13. Further, in the circumferential direction of rotation of the ball valve body 2, a communication hole to be the auxiliary flow path 22 orthogonal to the valve body flow path 21 is formed. The auxiliary flow passage 22 has a large diameter flow passage 23 with an inner diameter of 4 mm, and a small diameter flow passage 24 with an inner diameter of 0.3 mm and shorter than the large diameter flow passage 23.

In the method of processing the communication hole to be the auxiliary flow passage 22, first, a bottomed hole to be the large diameter flow passage 23 is formed by a drill having an outer diameter of 4 mm from the outer peripheral surface of the ball valve body 2 toward the valve flow passage 21. . It is preferable to form the bottom of the large diameter flow passage 23 so as to be recessed toward the valve body flow passage 21 because positioning of the drill forming the small diameter flow passage 24 is facilitated. Next, a through hole to be the small diameter flow passage 24 is formed by a drill having an outer diameter of 0.3 mm from the center of the bottom surface of the large diameter flow passage 23 toward the valve body flow passage 21. The processing method in which the auxiliary flow passage 22 is formed stepwise by the large diameter flow passage 23 and the small diameter flow passage 24 is such that the drill used for drilling the small diameter flow passage 24 is easily broken. The inner diameter of the small diameter flow passage 24 is less than 1 mm. Is preferred. When the through hole is drilled on the outer peripheral surface of the ball valve body 2 with a thin drill, the drill is slippery and easily broken as the through hole becomes longer. However, the auxiliary flow passage 22 includes the large diameter flow passage 23 and the small diameter flow passage 24 If the length of the small diameter flow path 24 is shortened by dividing and forming the through hole, the through hole becomes easy to process. In particular, when the inner diameter of the small diameter flow passage 24 is less than 1 mm, the drill is easily broken. Therefore, when the length of the small diameter flow passage 24 is 3 mm or less, the drill is not easily broken and becomes easy to process. Further, the inner diameter of the small diameter flow passage 24 may be 0.1 mm or more in order to stably pass a fluid such as pure water through the small diameter flow passage 24. The other structure of the ball valve according to the second embodiment is the same as that of the ball valve according to the first embodiment, and thus the description thereof is omitted.

Next, with reference to FIGS. 5 to 6, the operation of the ball valve of the second embodiment will be described. When the ball valve is fully closed, the fluid flowing through the first flow passage 11 flows into the valve chamber 13 from the communication groove 32 of the seat 3. Then, the gas flows from the valve chamber 13 into the valve flow passage 21, passes through the auxiliary flow passage 22, and flows into the second flow passage 12. In the ball valve according to the present embodiment, since a small amount of fluid can flow stably even in the fully closed state, fluid retention in the valve chamber 13 and the valve channel 21 can be suppressed, generation of bacteria, accumulation of foreign matter, and sticking Can be reduced. At this time, since the auxiliary flow passage 22 is formed stepwise by the large diameter flow passage 23 and the small diameter flow passage 24, the inner diameter of the small diameter flow passage 24 can be reduced, and the flow rate for the purpose of retention prevention can be suppressed. The other actions and effects of the ball valve of the first embodiment are the same as those of the ball valve of the first embodiment, and thus the description thereof is omitted.

In the second embodiment, the auxiliary flow passage 22 is formed by a drill, but may be formed in advance when the ball valve body 2 is formed by injection molding. Also in this case, since the auxiliary flow passage 22 includes the large diameter flow passage 23 and the small diameter flow passage 24, the small diameter flow passage 24 is thinner than when the auxiliary flow passage 22 is configured with only the small diameter flow passage 24. It will be easier. Further, only the large diameter flow passage 23 of the auxiliary flow passage 22 may be formed by injection molding. Further, in the second embodiment, the numbers of the communication grooves 32 and the auxiliary flow channels 22 are one at a time, but the numbers of the communication grooves 32 and the auxiliary flow channels 22 are freely designed according to the desired flow rate. it can.

In the present invention, the material of the valve body 1, stem 5, ball valve body 2, valve body press 9, seat 3, flow rate adjustment seat 4, handle 6, cap nut 7 and flanged short pipe 8 has strength as a valve or The material which fulfills functions such as chemical resistance to fluid can be selected appropriately. For example, resins such as PVC, polypropylene, polyethylene, polyvinylidene fluoride, ABS, PTFE, stainless steel, iron, copper alloys, metals such as aluminum, or ceramics such as porcelain can be mentioned as suitable materials.

Preferred embodiments of the present invention are as described above, but the present invention is not limited thereto. Various other embodiments can be made without departing from the spirit and scope of the present invention. Furthermore, the operations and effects described in the present embodiment are merely examples, and are not intended to limit the present invention.

Reference Signs List 1 valve body 2 ball valve body 3 seat 4 flow rate adjustment seat 5 stem 6 handle 7 cap nut 8 short pipe with flange 9 valve body presser 10 annular groove 11 first flow passage 12 second flow passage 13 valve chamber 14 recess 15 cutout groove 16 First cushion 17 Second cushion 21 Valve body flow path 22 Auxiliary flow path 23 Large diameter flow path 24 Small diameter flow path 25 Clearance 31 Seal surface 32 Communication groove 41 Protrusion 42 Seat section 43 Seal surface 44 Flow adjustment section 45 Projection 46 Flow rate Adjustment opening 47 Guide surface

Claims

A valve body comprising a first flow passage, a second flow passage, and a valve chamber communicating the first flow passage and the second flow passage;
A sheet positioned on the first flow path side in the valve chamber;
A flow rate adjustment sheet positioned on the second flow path side in the valve chamber and configured to adjust the flow rate of the fluid flowing through the first flow path and the second flow path;
A ball valve body rotatably disposed between the seat and the flow rate adjustment sheet, having a through hole serving as a valve flow path, and communicating or blocking the first flow path and the second flow path; In a ball valve comprising
The flow rate adjustment sheet includes an annular sheet portion and a flow rate adjustment portion positioned on the inner peripheral side of the sheet portion,
The seat portion includes a sealing surface on which the ball valve body slides and seals the fluid.
The flow rate adjustment unit is connected continuously to the flow rate adjustment opening that communicates the second flow path and the valve chamber, and the seal surface, and is apart from the ball valve body and guides the fluid. Comprising a guiding surface,
A ball valve characterized in that a gap between the guide surface and the ball valve body continuously increases as it approaches a flow path axis from an outer peripheral edge of the guide surface.
The sealing surface is a spherical surface having the same radius as the radius of the ball valve body,
The ball valve according to claim 1, wherein the guide surface is a spherical surface having a radius smaller than the radius of the ball valve body.
The sheet member has a communication groove communicating the first flow path and the valve chamber,
The ball valve body has an auxiliary flow path which is orthogonal to the valve body flow path and has an inner diameter smaller than the valve body flow path, and at least in the fully closed state, the auxiliary flow path is the valve body flow path The ball valve according to claim 1 or 2, wherein the second flow path and the second flow path communicate with each other.
The auxiliary flow passage includes a large diameter flow passage located on the outer peripheral side of the ball valve body, and a small diameter flow passage connecting the large diameter flow passage and the valve flow passage and having an inner diameter smaller than the large diameter flow passage. Have
The ball valve according to claim 3, wherein a length of the small diameter flow passage is shorter than that of the large diameter flow passage.
The ball valve according to claim 4, wherein an inner diameter of the small diameter flow passage is 0.1 mm or more and less than 1 mm.