JP2008267455A - Ball check valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball check valve for preventing the vibration of a ball during the flow of fluid and suppressing the occurrence of noises without reducing a flow amount. <P>SOLUTION: The ball check valve comprises a cylindrical valve body 1 having at least two opening portions 8, 9 in which protruded portions 7 are provided in the inner-face axial direction, the ball 2 held in a valve body 1 movably forward and backward in the axial direction by the protruded portions 7, a seat ring 4 held in one opening portion 8 of the valve body 1 via the protruded portion 7 and a stopper ring 3, a collared short pipe 5 held via the seat ring 4 in the state of being sealed to the valve body 1, and a cap nut 6 threaded to the valve body 1 to fix the collared short pipe 5 to the valve body 1. During opening the valve, the ball 2 is held by the protruded portions 7 so that its center is shifted from the axis of the valve body 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a ball check valve used in piping lines of various industries such as chemical factories, water and sewage, agriculture / fishery industry, semiconductor manufacturing field, and food field, and more specifically, generated when water flows. The present invention relates to a ball check valve that prevents vibrations of the ball that travels, suppresses the generation of noise, and does not reduce the flow rate.

  Conventionally, there has been a ball check valve as shown in FIG. 4 (see Patent Document 1). The structure is such that an inlet 31, a valve chamber 32 and an outlet 33 are formed by a valve casing, a valve seat 34 is provided between the inlet 31 and the valve chamber 32, and a spherical valve body 35 which is separated from and seated on the valve seat 34 is provided in the valve chamber. 32, a ball check valve provided with a plurality of ribs 36 on the inner wall of the valve chamber 32 for guiding the spherical valve body 35 to the valve seat 34. The inlet 31, the valve chamber 32, and the outlet 33 are formed side by side in the vertical direction. The spherical valve body 35 is formed of a hollow float made of a metal shell.

Japanese Patent Laid-Open No. 6-185543

However, in the conventional ball check valve, when the fluid passes between the inner circumference of the valve casing and the spherical valve body 35 held by the rib 36, the flow of the fluid is easily disturbed, and thereby the flow rate of the flowing fluid is particularly large. If this becomes larger, the spherical valve body 35 may be vibrated. When vibration occurs, the vibrating spherical valve body 35 obstructs the flow of fluid, and the flow rate of the fluid flowing through the ball check valve decreases, or the valve casing and the spherical valve body 35 collide intermittently due to vibration. There is a problem that the sound becomes a noise, and the spherical valve body 35 and the rib 36 are brought into contact with each other due to vibration, so that the fluid is leaked from the gap between the contact parts of the spherical valve body 35 and the valve seat 34. there were.

  The present invention has been made in view of the above-described problems of the prior art, and prevents the ball from vibrating when the fluid flows, suppresses the generation of noise, and does not reduce the flowing flow rate. The purpose is to provide a check valve.

  The configuration of the valve of the present invention for solving the above problems will be described with reference to FIG. 1. A cylindrical valve body having at least two openings provided with protrusions in the inner surface axial direction, and in the axial direction. A substantially spherical valve body that is held by the protruding portion within the valve body so as to be movable back and forth, and a seat ring that is held by interposing the protruding portion and a stopper portion at one opening of the valve body. In the ball check valve provided, the first feature is that the substantially spherical valve element is held by the protrusion so that the center of the substantially spherical valve element is shifted from the axis of the valve body when the valve is opened.

  Also, at least three ridges are provided, and at least one elongated ridge formed with a height higher than the other ridges from the inner circumferential surface of the opening, and from the inner circumferential surface of the opening At least one short ridge formed lower than the other ridges, and the center of the substantially spherical valve body from the axis of the valve body due to the difference in height of these ridges A second feature is that the position is held at a shifted position.

  Further, the third feature is that the shortest distance from the center of the substantially spherical valve body to the valve body axis when the valve is opened is within a range of 2% to 6% of the diameter of the substantially spherical valve body.

  Furthermore, a flanged short tube that is held in a sealed state with the valve body via the seat ring, and a cap nut that fixes the flanged short tube to the valve body by screwing to the valve body. It is the fourth feature to have.

  In addition, an O-ring mounted in an annular groove provided on the other opening end face of the valve main body, a flanged short tube contacting the valve main body via the O-ring, and a threaded engagement with the outer periphery of the valve main body Thus, a fifth feature is provided with a cap nut that clamps and fixes the short tube with a flange between the valve main body.

  In the present invention, the vibration means that the ball 2, which is a substantially spherical valve body, vibrates in the valve body 1, and does not include tremors caused by factors such as fluid and other external forces.

  In the present invention, the valve body 1 needs to have at least two openings. If there is no problem in structure, a large number of openings may be provided.

  The substantially spherical valve element may be oval or eccentric as long as it is substantially spherical and functions as a valve element, but is preferably a true spherical ball 2. Further, it is desirable that the shortest distance from the center of the ball 2 to the valve body 1 axis when the valve is opened is within a range of 2% to 6% of the diameter of the ball 2. This is preferably 2% or more in order to obtain the effect of preventing the occurrence of vibration by shifting the center of the ball 2 from the axis of the valve body 1, and 6% or less in order to move the ball 2 linearly with good responsiveness. Is good.

  The method in which the center of the substantially spherical valve body is held at a position deviated from the axis of the valve body 1 is such that the height from the inner peripheral surface 24 of the inlet opening 7 of the ridge 7 is higher than the other ridges. At least one elongated ridge portion formed, and at least one short ridge portion formed so that the height from the inner peripheral surface 24 of the inlet opening 7 of the ridge portion 7 is lower than the other ridge portions; It is desirable that the protrusion is provided depending on the height of the protrusion. For example, when four ridges 7 are provided on the inner side of the valve body 1 at equal intervals (positions facing each other) radially along the axis, the long and short ridges face each other. It is arranged at the position where the ridge part of the intermediate height is opposed (not shown), or it is arranged at the position adjacent to the long ridge part and the short ridge part, respectively. The center of the substantially spherical valve body is held at a position shifted from the axis of the valve main body 1 by arranging the strip portion and the short projecting portion at positions facing each other (see FIG. 2). In addition, when the ridge 7 has three ridges, a long ridge, a short ridge, and an intermediate height ridge are arranged (not shown), or a single long ridge By arranging two short ridges, or two long ridges and one short ridge (not shown), the center of the substantially spherical valve body is displaced from the axis of the valve body 1. Held in a different position.

  In the present invention, the stopper portion is a portion in which the ball 2 abuts against the taper portion 13 of the stopper portion, thereby holding the ball 2 in a fixed position without causing the ball 2 to dig deeply into the seat ring 4. The stopper portion may be provided integrally with the valve body 1, or may be provided as a stopper ring 3 that is separate from the valve body 1 sandwiched between the protrusion 7 and the seat ring 4 in the valve body 1. good.

  In the present invention, the material of the seat ring 4 may be a rubber-like elastic body, such as ethylene propylene rubber, isoprene rubber, chloroprene rubber, chlorosulfonated rubber, nitrile rubber, styrene butadiene rubber, chlorinated polyethylene, and fluorine rubber. Although it is mentioned as a suitable thing, it does not specifically limit.

  Further, in the present invention, the material of the valve body 1 of the ball check valve, the ball 2, the flanged short pipe 5, the cap nut 6 and the stopper ring 3 are polyvinyl chloride (hereinafter referred to as PVC), polypropylene, polyvinylidene fluoride. Ride, polystyrene, ABS resin, polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, polychlorotrifluoroethylene and other resins, metals such as iron, copper, copper alloys, brass, aluminum and stainless steel, or Either ceramic or porcelain may be used.

The present invention has the structure as described above, and the following excellent effects can be obtained.
(1) It is possible to prevent vibration of the substantially spherical valve body (ball) when the ball check valve is passed through.
(2) By preventing vibration of the substantially spherical valve body (ball), noise due to vibration is eliminated, and noise during water flow can be suppressed.
(3) By preventing the vibration of the substantially spherical valve body (ball), it is possible to prevent a decrease in the flow rate and to cope with a large flow rate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. FIG. 1 is a longitudinal sectional view showing an embodiment of a ball check valve according to the present invention. 2 is a cross-sectional view taken along line AA in FIG.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

  Reference numeral 1 denotes a PVC valve body having a diameter of 50 mm. The valve main body 1 has a substantially hollow cylindrical shape, and the inlet opening 8 on the upstream side (lower side in FIG. 1) has a larger diameter than the outlet opening 9 on the downstream side (upper side in FIG. 1). The inside of the main body 1 has a structure having a curved surface that is gradually reduced in diameter slightly downstream from the central portion. On the inner side of the valve body 1, four ridges 7 project radially at equal intervals along the axis and are provided integrally with the valve body 1, and the ridges 7 are formed in the inlet opening of the valve body 1. Are provided at specific heights from the inner peripheral surface 24 of the inlet opening 8 at intervals from the end face of the portion 8, and gradually decrease in the vicinity of the outlet opening 9, and are substantially the same as the outlet opening 9. It becomes the diameter. At this time, the ridge 7 is the same height from the adjacent long ridges 7 a and 7 b set at the same height from the inner peripheral surface 24 of the inlet opening 8 and the inner peripheral surface 24 of the inlet opening 8. The short ridges 7c and 7d adjacent to each other are set, and the long ridges 7a and 7b and the short ridges 7c and 7d are arranged at positions facing each other (see FIG. 2). By this protrusion 7, the shortest distance to the center of the ball 2 with respect to the axis of the valve body 1 when the valve is opened is formed to be 4% of the ball diameter. An annular groove 10 is provided on the end face of the outlet opening 9 of the valve body 1, and an O-ring 11 is attached to the annular groove 10. As shown in FIG. 2, the four protrusions 7 are provided at equal positions and at equal intervals, but the number of the protrusions 7 can be maintained if the center of the ball 2 can be held at a position shifted from the axis of the valve body 1. Is not particularly limited as long as it is at least 3 or more.

  2 is a ball which is a substantially spherical valve body made of PVC. The ball 2 is held inside the valve body 1 by a protrusion 7 so as to be movable along the axis. The ball 2 has a diameter larger than the diameter of the outlet opening 9 of the valve body 1 and is in contact with the contact portion 12 of the protrusion 7 when the ball 2 is urged downstream by the flow of fluid. Held in.

  3 is a stopper ring made of PVC that forms a stopper portion. The stopper ring 5 is cylindrical and has an outer diameter that is substantially the same as the inner diameter of the end of the inlet opening 8 of the valve body 1. The stopper ring 5 is sandwiched between the protrusion 7 and a seal ring 4 to be described later. Is retained. Further, a tapered portion 13 that is temporarily reduced in diameter toward the upstream side is provided on the inner periphery of the stopper ring 3, and the minimum inner diameter of the tapered portion 13 is smaller than the diameter of the ball 2. The tapered portion 13 at this time is provided so as to be 23 ° with respect to the axis, and the minimum inner diameter of the tapered portion 13 is set to 0.93 L with respect to the diameter L of the ball 2. The angle of the tapered portion 13 is preferably 10 ° to 30 ° with respect to the axis, and the diameter of the stopper ring 3 is reduced so as to be 0.9 L to 0.97 L with respect to the diameter L of the ball 2. Preferably it is.

  4 is a rubber elastic sheet ring. The seat ring 4 is formed of a barrel portion 14 having a tapered portion on the inner periphery and a flange portion 15. The barrel portion 14 is fitted into the inlet opening portion 8 of the valve body 1, and the flange portion 15 is connected to the inlet opening portion 8. Abutting on the end face, the valve body 1 and the short tube 5 with a post described later are sealed by the seat ring 4.

  5 is a PVC short tube with a flange. The flanged short tube 5 is provided with a flange portion 17 at one end of the short tube portion 16.

  6 is a PVC cap nut. The cap nut 6 has a cylindrical shape, and is provided with a female screw portion 19 to be screwed to a male screw portion 18 provided on the outer periphery of both ends of the valve body 1 on the inner periphery of one end portion, and on the inner end of the other end portion. An inner flange 20 that protrudes in the circumferential direction is provided. On the upstream side of the valve body 1, the cap nut 6 abuts the end surface of the flanged short tube 5 on the end surface of the flanged portion 15 of the seat ring 4, and engages the inner flange portion 20 with the flanged portion 17 of the flanged short tube 5. The threaded short pipe 5 and the valve main body 1 are fixed in a sealed state by screwing them onto the male threaded portion 18 of the valve main body 1. Similarly, on the downstream side of the valve body 1, the flanged short tube 21 abuts the end surface of the valve body 1 via the O-ring 11, and the flanged short tube 21 and the valve body 1 are sealed by the cap nut 22. Secure with.

  Next, the operation when the ball check valve of the embodiment of the present invention is opened and closed will be described. When the fluid flows from the upstream side to the downstream side (forward flow), the ball 2 moves to the position indicated by the solid line in FIG. 1 and passes through the flow path 23 formed between the ball 2 and the protrusion 7 of the valve body 1. Fluid flows downstream. At this time, the ball 2 is in contact with the contact portion 12 of the ridge portion 7 of the valve body 1, and the ridge portions 7a and 7b set higher and the ridge portions 7c and 7d set lower. Thus, the center of the ball 2 is held at a position displaced from the axis of the valve body 1. The flow of fluid passing through the flow path 23 formed between the ball 2 and the ridge 7 of the valve body 1 is large because the flow path 23 formed between the ridges 7a and 7b is wide. Since the flow path 23 formed between the ridges 7c and 7d is narrow, the fluid flows in a small amount, so that it is difficult to be disturbed by imparting a bias to the fluid flow. Further, since the flow velocities are different between the flow passages 23 on the ridges 7a, 7b side and the ridges 7c, 7d side, a pressure difference is generated, and the ball 2 is urged toward the pressure decreasing side to contact the contact part. 12 becomes difficult to move. For these reasons, the ball 2 is prevented from vibrating perpendicularly to the axis of the valve body 1. Next, when the fluid from the upstream side stops, the ball 2 moves to the upstream side by the backflow pressure of the fluid and is closed by being pressed by the seat ring 4 to prevent backflow of the fluid (indicated by a broken line in FIG. 1). State shown).

  Next, in the ball check valve of the present invention, the capacity coefficient, vibration, and noise were evaluated by the following test methods.

(1) Capacity coefficient measurement test In accordance with the test method for valve capacity coefficient (Cv value) in JIS B 2005, the pressure and flow rate on the upstream and downstream sides of the valve are measured with horizontal piping, and the capacity coefficient (Cv value). Was calculated.
(2) Confirmation of the presence or absence of vibration The hand touched the ball check valve connected to the pipe, and touched the ball 2 to see if there was any vibration except for the tremor generated when fluid flows in the pipe.
(3) Confirmation of the presence or absence of noise At the location of the ball check valve connected to the pipe, a sound was heard using a stethoscope to check whether there was any noise caused by vibration other than the sound generated when the fluid flows in the pipe.

  Using the ball check valve of the present embodiment as shown in FIGS. 1 and 2, flow characteristics (capacity coefficient), vibration, and noise were measured. The test results are shown in Table 1. In addition, nominal diameters of 15 mm and 50 mm were used.

(Comparative example)
As shown in FIG. 3, the protrusion 26 is set at the same height from the inner peripheral surface 27 of the valve body 25 with respect to the embodiment, and the center of the ball is located on the axis of the valve body 25 when the valve is opened. Using a check valve, flow characteristics (capacity coefficient), vibration and noise were measured. The test results are shown in Table 1.

  As is apparent from Table 1, no vibration or noise was generated in the example, whereas vibration or noise was generated in the comparative example. At this time, the Example obtained a Cv value slightly more than twice that of the Comparative Example. That is, by disposing the center of the ball 2 away from the axis of the valve body 1, the Cv value can be improved more than twice and not only a good flow characteristic can be obtained, but also the vibration and noise of the ball 2 are generated. No longer. Thus, by eliminating the vibration and noise of the ball 2, it is possible to predict that the wear of the ball 2 is reduced and the sealing performance can be maintained for a long time.

It is a longitudinal section showing one embodiment of a ball check valve concerning the present invention. It is the sectional view on the AA line of FIG. It is sectional drawing which shows the comparative example of FIG. It is a longitudinal cross-sectional view which shows the conventional ball check valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Valve | bulb main body 2 ... Ball | bowl 3 ... Stopper ring 4 ... Seat ring 5 ... Short pipe 6 with a hook ... Cap nut 7 ... Projection part 8 ... Inlet opening part 9 ... Outlet opening part 10 ... Annular groove 11 ... O-ring 12 ... Abutting part 13 ... taper part 14 ... trunk part 15 ... collar part 16 ... short pipe part 17 ... collar part 18 ... male thread part 19 ... female thread part 20 ... collar part 21 ... short tube 22 with flange ... cap nut 23 ... flow path 24 ... Inner surface

Claims (5)

A cylindrical valve body having at least two openings provided with protrusions in the inner surface axial direction, and a substantially spherical valve body held by the protrusions in the valve body so as to be movable back and forth in the axial direction; A ball check valve having a seat ring that is held by interposing the protrusion and a stopper at one opening of the valve body, and the center of the substantially spherical valve body is the center of the valve body when the valve is opened. A ball check valve, wherein the ball check valve is held by the protrusion so as to be in a position deviated from the axis. At least one elongated protrusion provided with at least three protrusions, the height from the inner peripheral surface of the opening being higher than the other protrusions, and the height from the inner peripheral surface of the opening Has at least one short ridge formed lower than the other ridges, and the center of the substantially spherical valve body is displaced from the axis of the valve body due to the difference in height of these ridges. 2. The ball check valve according to claim 1, wherein the ball check valve is held in position. 3. The shortest distance from the center of the substantially spherical valve body to the valve body axis when the valve is opened is within a range of 2% to 6% of the diameter of the substantially spherical valve body. Ball check valve as described. A short tube with a flange that is held in a sealed state with the valve body via the seat ring, and a cap nut that is screwed into the valve body to fix the short tube with the flange to the valve body. The ball check valve according to any one of claims 1 to 3, wherein: An O-ring mounted in an annular groove provided on the other opening end face of the valve main body, a flanged short tube contacting the valve main body via the O-ring, and screwing onto the outer periphery of the valve main body The ball check valve according to any one of claims 1 to 4, further comprising a cap nut that clamps and fixes the flanged short tube with the valve body.