JP2005155878A - Flow rate adjustment valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow rate adjustment valve capable of finely adjusting a flow rate within a wide flow rate range, stably keeping flow rate adjusting characteristic for a long period and being miniaturized. <P>SOLUTION: A valve seat face 2 is formed on a bottom face of a valve chest 3 formed at an upper part of a main body 1, a first flow channel 5 communicated with a communication port 4 formed on a center of the valve seat face 2, and a second flow channel 6 communicated with the valve chest 3 are respectively formed, and a diaphragm 10 is formed by integrally mounting a first valve element 11 capable of being inserted into the communication port 4 by the axial forward and backward movement of a stem and dropping and projecting from a liquid contact face, an annular projected second valve element 12 capable of being kept into contact with and separated from the valve seat face 2 and formed on a position radially separated from the first valve element 11, and a thin film part 13 formed continuously from the second valve element 1 in the radial direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flow control valve used for fluid transport piping in various industries such as a chemical factory, a semiconductor manufacturing field, a food field, and a bio field.

  Conventionally, various types of flow control valves have been used, but generally those shown in FIG. In this type of flow control valve, the peripheral edge of the communication port on the bottom surface of the valve chamber 100 is a valve seat portion 101, a needle-type valve body 102 that is inserted into the valve seat portion 101 is provided, and the handle 103 is rotated. Accordingly, the valve body 102 connected to the lower portion of the handle 103 is moved up and down to change the opening area with the valve seat portion 101, and the flow rate is adjusted. When the valve body 102 is fully closed, the tapered portion 104 of the valve body 102 is adjusted. Is in contact with the valve seat portion 101 and closes the flow path.

  However, since the tapered portion 104 of the valve body 102 closes the flow path, the contact portion between the valve seat portion 101 and the tapered portion 104 comes into sliding contact with the opening and closing of the valve, and the valve seat portion 101 and Since the sliding contact portion of the taper portion 104 is deformed due to wear, the problem that the flow rate adjustment characteristics cannot be stabilized for a long period of time, for example, when a conventional flow rate adjustment valve is used in the process of mixing a chemical solution that requires flow rate adjustment, When used for a long period of time, the mixing ratio of the chemicals is out of order, and the degree of cleaning and the degree of etching vary, resulting in problems such as greatly affecting semiconductor production. In addition, since many particles are generated from the sliding contact portion between the valve seat portion 101 and the taper portion 104 of the valve body 102, there is a problem that the use in applications that dislike the generation of particles, such as a semiconductor manufacturing apparatus, is avoided. It was.

  In order to solve these problems, there has been a flow rate adjustment valve in which the valve seat 105 and the tapered portion 107 of the valve body 106 do not contact each other as shown in FIG. 14 (see, for example, Patent Document 1). This flow control valve is opened and closed by air pressure, and has a valve body 106 that is crimped to the valve seat 105 at the center of the diaphragm 108, and an annular thin film portion 109 that is integrally formed around the valve body 106. In addition, a cylindrical holding portion 110 formed integrally around the annular thin film portion 109 is provided, and a taper pin 112 to be inserted into the fluid inflow passage 111 is attached to the center of the lower surface of the valve body 106 at the center of the diaphragm 108. Since the taper pin 112 for adjusting the flow rate does not slidably contact the opening edge of the fluid inflow passage 111 and the flat lower surface of the valve body 106 at the center of the diaphragm 108 is pressure-bonded to the valve seat 105, the particle The generation | occurrence | production of was able to be suppressed.

Further, in order to adjust the minute opening degree of the flow control valve, there is a stem structure flow control valve provided with a first screw portion 117 and a second screw portion 119 having different pitches as shown in FIG. (For example, see Patent Document 2). The flow rate adjusting valve is attached to a linearly moving member 114 whose needle member is linearly moved by the rotation of the adjusting screw 113, and the adjusting screw 113 is screwed into the thread groove 116 of the valve body main body 115. And the second threaded portion 119 screwed into the inner threaded portion 118 of the linear motion member 114, and the thread pitch of the second threaded portion 119 is configured to be smaller than the thread pitch of the first threaded portion 117. By providing the difference, a slight adjustment of the opening degree can be performed.
Japanese Patent Laid-Open No. 10-153268 (page 4, FIG. 1) Japanese Patent Laid-Open No. 11-051217 (page 4, FIG. 1)

  However, the conventional flow rate adjustment valve (see Patent Document 1) in which the valve seat 105 and the tapered portion 107 of the valve body 106 do not contact each other is not in contact with the fluid inflow passage 111 and has a tapered taper pin for adjusting the opening area. 112 and the valve body 106 that is in pressure contact with the valve seat 105 in order to block the flow path, the taper portion 107 of the taper pin 112 does not slide in contact with the valve seat 105, but the taper pin 112 and the fluid inflow passage 111 is always in a slightly opened state, and the valve body 106 is not provided with a mechanism for adjusting a minute flow rate, and thus there is a problem that the flow rate cannot be adjusted in the slightly opened region. Even if the minute flow rate is adjusted by controlling the opening degree of the valve seat 105 and the valve body 106, the opening formed by the taper pin 112 and the fluid inflow passage 111 is formed in the slightly opened region. There is nothing that suppresses the flow of fluid until it passes through and reaches the space formed by the valve seat 105 and the valve body 106, and the space formed by the protrusion of the valve seat 105 and the flat lower surface of the valve body 106. Even if you try to adjust the flow rate in part, the flow rate will increase rapidly with respect to the opening, so the flow rate adjustment will not catch up with the flow of the fluid, and the flow rate will be larger than the flow rate you want to adjust, and the minute flow rate will be adjusted It was very difficult to do. Further, since the taper pin 112 is opened and closed by air pressure, it is difficult to finely adjust the flow rate, and it is very difficult to control the opening degree in the minute opening region.

    Further, in the conventional flow rate adjusting valve for adjusting the minute opening degree (see Patent Document 2), the first screw portion 117 and the second screw portion 119 of the adjusting screw 113 are formed in series in the vertical axis direction. Therefore, since the configuration for adjusting the minute opening becomes longer in the vertical direction, the vertical dimension of the flow control valve becomes larger, and the device itself becomes larger when installed in the device. There was a problem that it was impossible to make it compact.

  The present invention has been made in view of the above-mentioned problems of the prior art, can finely adjust the flow rate in a wide flow range, can stably maintain the flow rate adjustment characteristics for a long period of time, and An object of the present invention is to provide a flow control valve that can be made compact.

  The configuration of the present invention will be described with reference to FIGS. 1 to 3. The valve seat surface 2 is formed on the bottom surface of the valve chamber 3 provided at the upper portion, and the communication port 4 provided at the center of the valve seat surface 2. A main body 1 having a first flow path 5 communicating with the second flow path 6 and a second flow path 6 communicating with the valve chamber 3, and can be inserted into the communication port 4 by advancing and retreating in the axial direction of the stem and projecting from the center of the wetted surface. The first valve body 11, the second valve body 12 having an annular ridge formed at a position separated from the first valve body 11 in the radial direction and capable of contacting and separating from the valve seat surface 2, and the second valve body The first feature is that the diaphragm 10 is provided integrally with the thin film portion 13 continuously formed in the radial direction from 12.

  Further, a handle 32 is fixed to the upper portion, a first stem 27 having a female screw portion 28 on the lower inner peripheral surface, a male screw portion 29 having a pitch larger than the pitch of the female screw portion 28 on the outer peripheral surface, and a first stem 27 on the inner peripheral surface. A first stem support 34 having a female screw portion 36 screwed with a male screw portion 29 of one stem 27 and a male screw portion 20 screwed with a female screw portion 28 of the first stem 27 are provided on the upper outer peripheral surface. A second stem 19 to which the diaphragm 10 is connected at the lower end, a diaphragm retainer 21 which is positioned below the first stem support 34 and supports the second stem 19 so as to be movable up and down and unrotatable, and the first stem A second feature is that a support body 34 and a bonnet 38 for fixing the diaphragm retainer 21 are provided.

  Further, the difference in pitch between the male screw portion 29 provided on the outer peripheral surface of the first stem 27 and the female screw portion 28 provided on the lower inner peripheral surface is from 1/20 to 5 minutes of the pitch of the male screw portion 29. The third characteristic is that it is 1.

  Further, the fourth feature is that the diaphragm 10 is made of polytetrafluoroethylene (hereinafter referred to as PTFE).

The present invention has the structure as described above, and the following excellent effects can be obtained by using this structure.
1. Since the two flow rate control units are switched according to the opening degree of the flow rate control valve to adjust the flow rate, the flow rate can be adjusted in a wide flow rate range.
2. Since the minute opening degree of the flow control valve can be adjusted easily and precisely, fine adjustment of the flow rate can be performed in a short time in a wide flow range.
3. Since the valve body and the valve seat surface are not in sliding contact with each other, the flow rate adjusting characteristics can be stably maintained for a long period of time, and the generation of particles can be suppressed.
4). Since the stem for finely adjusting the flow rate is small, the flow rate adjustment valve can be formed compactly.

  Hereinafter, examples 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 examples. 1 is a longitudinal sectional view showing a fully opened state of a flow rate regulating valve according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is an enlarged longitudinal sectional view of a main part of FIG. 4 is a longitudinal sectional view showing the fully closed state of FIG. 1, and FIG. 5 is an enlarged longitudinal sectional view of a main part of FIG. 6 is a longitudinal sectional view showing the half-opened state of FIG. 1, and FIG. 7 is an enlarged longitudinal sectional view of a main part of FIG. FIG. 8 is an enlarged vertical cross-sectional view of the main part of a flow rate control valve whose diaphragm is constituted only by the first valve body. FIG. 9 is an enlarged vertical cross-sectional view of a main part of a flow rate control valve that includes only a first valve body having a diaphragm whose shape is a cylinder. FIG. 10 is an enlarged vertical cross-sectional view of a main part of a flow rate control valve whose diaphragm is constituted only by the second valve body. FIG. 11 is a conceptual configuration diagram showing a test apparatus for measuring the flow rate Q. FIG. 12 is a graph showing the relationship between the lift amount L and the flow rate Q of the flow control valve.

  1 to 3, reference numeral 1 denotes a PTFE main body. The main body 1 has a substantially mortar-shaped valve chamber 3 formed with a diaphragm 10 which will be described later, and the bottom of the valve chamber 3 is sealed by a second valve body 12 which will be described later to fully close the flow path. The valve seat surface 2 is formed, and has a first flow channel 5 communicating with a communication port 4 provided at the center of the valve seat surface 2 and a second flow channel 6 communicating with the valve chamber 3. A concave portion 8 for receiving the fitting portion 23 of the post-membrane diaphragm 21 is provided above the valve chamber 3, and an annular concave portion 7 in which the annular locking portion 14 of the post-diaphragm 10 is fitted is provided on the bottom surface thereof. ing. A male screw portion 9 to which a bonnet 38 to be described later is screwed is provided on the upper outer peripheral surface of the main body 1. Although PTFE is used as the material of the main body 1, other fluororesin, PP, polyvinyl chloride, polyvinylidene fluoride, other plastics or metals may be used depending on the characteristics of the fluid.

  A PTFE diaphragm 10 has a first valve body 11 projecting from the center of the liquid contact surface at the lower part of the diaphragm 10 and a tip formed at a position separated from the first valve body 11 in the radial direction. An annular convex second valve body 12 having an arcuate cross section, a thin film portion 13 formed continuously from the second valve body 12 in the radial direction, and an annular locking portion having a rectangular cross section on the outer periphery of the thin film portion 13 14 and the connection part 16 connected to the lower end part of the 2nd stem 19 mentioned later in the upper part of the diaphragm 10 are provided integrally. The first valve body 11 is provided with a linear portion 17 and a tapered portion 18 continuously downward, and an annular groove portion 15 is formed between the first valve body 11 and the second valve body 12. Yes. The outer diameter D1 of the straight portion 17 of the first valve body 11 is set to 0.97D with respect to the inner diameter D of the communication port 4, and the taper angle of the taper portion 18 of the first valve body 11 is 15 ° with respect to the axis. The diameter D2 of the annular ridge of the second valve body 12 is set to 1.5D with respect to the inner diameter D of the communication port 4. The diaphragm 10 is sandwiched and fixed between the main body 1 and the diaphragm retainer 21 described later in a state where the annular locking portion 14 is fitted in the annular recess 7 of the main body 1.

  When the flow control valve is fully closed, the second valve body 12 and the valve seat surface 2 are pressed against each other to perform a fully closed seal. When the opening degree is increased, the diaphragm 10 rises, and the first valve body 11 and the second valve body 12 Rises to full open as the diaphragm 10 rises. Even when fully open, the first valve body 11 does not come out of the communication port 4, so the flow rate is adjusted from fully closed to fully open.

  The outer diameter D1 of the straight portion 17 of the first valve body 11 of the present embodiment is set to 0.97D with respect to the inner diameter D of the communication port 4, but the outer diameter D1 of the straight portion 17 is equal to that of the communication port 4. It is desirable that the inner diameter D is in the range of 0.95D ≦ D1 ≦ 0.995D. D1 ≦ 0.995D is good in order to prevent the first valve body 11 and the communication port 4 from sliding, and 0.95D ≦ D1 is good in order to smoothly adjust the flow rate.

Moreover, although the taper angle of the taper part 18 of the 1st valve body 11 is set at 15 degrees with respect to the axis line, it is desirable to exist in the range of 12 degrees-28 degrees. In order to adjust a wide flow rate range without increasing the valve, 12 ° or more is good, and in order not to change the flow rate rapidly with respect to the opening degree, 28 ° or less is good. Moreover, the shape of the taper part 18 is set so that the opening area S1 of the first flow rate adjustment part 41 formed by the first valve body 11 and the communication port 4 increases in proportion to the opening degree. For this reason, the flow rate can be adjusted so as to increase linearly as the opening degree of the flow rate control valve is increased.
Further, the diameter D2 of the annular ridge of the second valve body 12 is set to 1.5D with respect to the inner diameter D of the communication port 4, but the diameter D2 of the annular ridge of the second valve body 12 is The inner diameter D of the communication port 4 is preferably in the range of 1.1D ≦ D2 ≦ 2D. 1.1D ≦ D2 is good for obtaining a space portion in which the annular groove portion 15 is reliably provided between the first valve body 11 and the second valve body 12 and the fluid flow is suppressed in the annular groove portion 15. On the other hand, in order to suppress the increase rate of the opening area formed by the second valve body 12 and the valve seat surface 2, D2 ≦ 2D is good.

  Further, in order to suppress the flow of fluid in the space portion of the annular groove portion 15, the volume of the space portion formed by the annular groove portion 15 and the valve seat surface when fully closed is equal to the linear portion of the first valve body 11 when fully closed. 17 and the volume of the space formed by the communication port 4 are set to be twice or more.

  In addition, although the material of the diaphragm 10 is PTFE, since it is easy to process and dimensional stability in cutting work, and the fluid is a corrosive fluid, it can be used without worrying about corrosion. Preferably used. In addition to PTFE, other fluororesins can provide chemical resistance, and rubber or metal may be used if the chemical resistance requirement is not so strict.

  Reference numeral 19 denotes a second stem made of polypropylene (hereinafter referred to as PP). The upper outer peripheral surface of the second stem 19 is provided with a male screw portion 20 that is screwed into the female screw portion 28 of the first stem 27 described later, the lower outer periphery is formed in a hexagonal shape, and the diaphragm 10 is connected to the lower end portion. The parts 16 are connected by screwing. In the present embodiment, the connecting portion 16 of the diaphragm 10 is screwed to the lower end portion of the second stem 19, but it may be connected by fitting or the like, and the connecting method is not particularly limited. The lower portion of the second stem 19 has a hexagonal shape, but the shape is not particularly limited as long as the second stem 19 is supported by the diaphragm retainer 21 described later so as to be movable up and down and unrotatable.

  21 is a PP diaphragm holder. A hexagonal insertion portion 22 is provided on the upper portion of the diaphragm retainer 21, a fitting portion 23 having a hexagonal outer periphery is provided on the lower portion, and a flange portion 24 is provided on the outer periphery of the central portion. A hexagonal through hole 25 is provided on the inner periphery of the diaphragm retainer 21, and a tapered portion 26 that is reduced in diameter from the lower end surface toward the through hole 25 is provided. The insertion portion 22 is non-rotatably fitted to a hollow portion 36 of the first stem support 34 described later, and the fitting portion 23 is non-rotatably fitted to the recess 8 of the main body 1. The second stem 19 is inserted into the through hole 25, and the second stem 19 is supported so as to be movable up and down and not rotatable. In addition, although the insertion part 22 and the fitting part 23 of the diaphragm retainer 21 are hexagonal, the diaphragm retainer 21 is fitted to the hollow part 36 of the first stem support 34 and the concave part 8 of the main body 1 to be non-rotatable, respectively. As long as it is formed, a quadrangular shape or an octagonal shape may be used, and the shape is not particularly limited. Similarly, the through hole 25 has a hexagonal shape, but the shape is not particularly limited as long as the second stem 19 is supported so as to be vertically movable and non-rotatable.

Reference numeral 27 denotes a PP first stem. A female screw portion 28 having a pitch of 1.25 mm and a male screw portion 29 having a pitch of 1.5 mm are arranged on the outer peripheral surface of the first stem 27. The pitch difference between the male screw portion 29 and the female screw portion 28 is 0.25 mm, and is formed to be one sixth of the pitch of the male screw portion 29. A stopper portion 30 is provided on the outer periphery of the lower portion of the first stem 27 so as to protrude in the radial direction, and a handle 32 having a grip portion 33 to be described later is fixed to the upper portion. The pitch difference between the male screw portion 29 provided on the outer peripheral surface of the first stem 27 and the female screw portion 28 provided on the lower inner peripheral surface is formed to be 1/6 of the pitch of the male screw portion 29. However, it is desirable that the pitch difference be in the range of 1/20 to 1/5. Since the valve body obtains a lift amount within a certain range from fully closed to fully open, it is preferable to make the pitch difference larger than 1/20 in order to prevent the stroke of the handle 32 from becoming too large and the valve height to become large. It is preferable to make the pitch difference smaller than 1/5 in order to adjust the valve with a fine order and high accuracy.
In this embodiment, the stopper portion 30 does not contact the upper end surface of the insertion portion 22 of the diaphragm retainer 21 even when fully closed, but contacts the upper end surface of the insertion portion 22 of the diaphragm retainer 21 when fully closed. Then, the rotation may be stopped to prevent the valve seat surface 2 and the second valve body 12 from being overloaded.

Reference numeral 34 denotes a first stem support made of PP. A female screw part 35 to be screwed into the male screw part 29 of the first stem 27 is provided on the upper inner peripheral surface of the first stem support 34, and the insertion part 22 for the diaphragm retainer 21 to be described later is provided on the lower inner periphery. Is provided with a hexagonal hollow portion 36 that is non-rotatably fitted, and a collar portion 37 that is fixed by a bonnet 38 to be described later is provided on the outer periphery of the lower portion.
The hollow portion 36 of the first stem support 34 has a hexagonal shape. However, if the insertion portion 22 of the diaphragm retainer 21 is non-rotatably fitted to the hollow portion 36 of the first stem support 34, a square is obtained. The shape or octagonal shape may be used, and the shape is not particularly limited.

  Reference numeral 38 denotes a PP bonnet. A locking portion 39 having an inner diameter smaller than the outer diameter of the collar portion 37 of the first stem support 34 is provided on the upper portion of the bonnet 38, and is screwed to the male screw portion 9 of the main body 1 on the lower inner peripheral surface. A female screw portion 40 is provided. The bonnet 38 is screwed into the main body 1 in a state in which the flange portion 37 of the first stem support 34 and the flange portion 24 of the diaphragm retainer 21 are sandwiched between the locking portion 39 and the main body 1. Can be fixed.

  The female screw portion 40 is connected to the main body 1 by screwing, but may be connected by a bayonet method or a bolt, and is not particularly limited as long as the first stem support 34 and the diaphragm retainer 21 can be sandwiched and fixed to the main body 1.

  The material of each member such as the first stem 27 excluding the main body 1 and the diaphragm 10 in this embodiment is PP, but may be polyvinyl chloride, polyvinylidene fluoride, fluororesin, other plastics or metals.

  Next, the operation of the flow control valve of this embodiment will be described with reference to FIGS. 1 and 3 to 7.

  First, when the flow control valve of the present embodiment is in the fully closed state (the state shown in FIGS. 4 and 5), the fluid flowing in from the first flow path is closed by the second valve body 12 pressed against the valve seat surface 2. The

  When the handle 32 is rotated in the direction in which the valve is opened, the first stem 27 is raised by the pitch of the external thread portion 29 on the outer peripheral surface as the handle 32 is rotated. The second stem 19 screwed into the female screw portion 28 on the peripheral surface descends by the pitch of the female screw portion 28 of the first stem 27. However, since the second stem 19 is accommodated in the through hole 25 of the diaphragm retainer 21 in a non-rotatable state and can move only in the vertical direction, the second stem 19 is located on the outer periphery of the first stem 27 with respect to the main body 1. The pitch difference between the male screw portion 29 on the surface and the female screw portion 28 on the inner peripheral surface, in this embodiment, the pitch of the male screw portion 29 of the first stem 27 is 1.5 mm, and the pitch of the female screw portion 28 of the first stem 27 is Therefore, when the handle 32 interlocked with the first stem 27 is rotated once, the second stem 19 is raised by 0.25 mm (1/6 of the pitch of the male screw portion 29). Along with this, the diaphragm 10 connected to the second stem 19 rises, so that the second valve body 12 initially pressed against the valve seat surface 2 of the main body 1 is separated from the valve seat surface 2, and the first The valve body 11 rises as the diaphragm rises, and the flow rate control valve is in a half-open state (the state shown in FIGS. 6 and 7). The fluid flows from the first flow path 5 into the valve chamber 3, passes through the second flow path 6, and is discharged.

  Next, when the handle 32 is further rotated in the opening direction from the half-open state (the state shown in FIGS. 6 and 7), the stopper portion 30 on the outer periphery of the lower portion of the first stem 27 is moved to the first stem support 34. The rotation is stopped by pressing against the ceiling surface 43. The diaphragm 10 rises in conjunction with the rotation of the handle 32, the first stem 27, and the second stem 19, the first valve body 11 and the second valve body 12 rise as the diaphragm 10 rises, and the valve It will be in a fully open state (state of FIG. 1, FIG. 3).

  In the above operation, the opening area S1 of the first flow rate adjusting part 41 formed by the first valve body 11 and the communication port 4 according to the opening degree, and the second valve body 12 until the flow rate control valve is fully closed to fully open. The opening area S2 of the second flow rate adjusting portion 42 formed by the valve seat surface 2 varies, but the action of adjusting the flow rate differs depending on the magnitude relationship between S1 and S2. The relationship between S1 and S2 from the fully closed position of the flow rate adjustment valve to the fully open position and the mechanism for adjusting the flow rate will be described below with reference to FIGS.

  In the case of S1> S2, the opening degree of the flow rate adjusting valve is from fully closed to slightly opened, and the flow rate is adjusted by the second flow rate adjusting unit 42, that is, by the magnitude of S2. Within the range of S1> S2, the first flow rate adjustment unit 41 can adjust the flow rate to be constant by the straight portion 17 and the communication port 4 of the first valve body 11, and the fluid is flowed by the first flow rate adjustment unit 41. Is made constant and then flows into the space formed by the annular groove 15 before reaching the second flow rate adjusting portion 42. The fluid hits the bottom surface of the annular groove 15, spreads in the radial direction, hits the inner peripheral surface of the second valve body 12, and further changes the flow direction to reach the second flow rate adjusting portion 42, so that the fluid flows once in the space portion. Stagnated. For this reason, the flow of the fluid is suppressed in the space portion, and a rapid increase in the flow rate can be suppressed. The flow reaches the second flow rate adjustment unit 42 with a flow sufficiently controllable by the second flow rate adjustment unit 42, and the second flow rate adjustment unit Since the flow rate is accurately adjusted at 42, it is possible to adjust the minute flow rate when the flow rate control valve is slightly opened. At this time, since the diameter D2 of the annular ridge of the second valve body 12 is provided within the range of 1.1D ≦ D2 ≦ 2D with respect to the inner diameter D of the communication port 4, an increase in flow rate is suppressed. An effective annular groove portion 15 can be formed between the first valve body 11 and the second valve body 12, and the flow of fluid from the first flow rate adjusting portion 41 in the space formed by the annular groove portion 15. Can be suppressed.

  In the case of S1 = S2, the opening area S1 of the first flow rate adjustment unit 41 and the opening area S2 of the second flow rate adjustment unit 42 are the same, and the part that adjusts the flow rate at this time is the second flow rate adjustment unit 42 from the second flow rate adjustment unit 42. The flow is switched to the single flow rate adjustment unit 41. That is, the flow rate is adjusted by the magnitude of S1.

  In the case of S1 <S2, the opening of the flow rate adjustment valve is from slightly open to fully open, and fine flow rate adjustment becomes difficult in the second flow rate adjustment unit 42, and the first flow rate adjustment unit 41, that is, S1 Adjusted according to the size of. Within the range of S1 <S2, the first flow rate adjusting unit 41 adjusts the flow rate by the tapered portion 18 of the first valve body 11 and the communication port 4, and the tapered portion 18 of the first valve body 11 is controlled by the flow rate adjusting valve. Since the opening area S1 is set so as to increase in proportion to the opening, the flow rate can be adjusted to increase linearly as the opening of the flow control valve is increased.

  Note that the opening area S1 of the first flow rate adjusting unit 41 from S1> S2 to S1 = S2 is set by the outer diameter D1 of the linear portion 17 of the first valve body 11 and the inner diameter D of the communication port 4, and is linear. If the outer diameter D1 of the portion 17 is set in the range of 0.95D ≦ D1 ≦ 0.995D with respect to the inner diameter D of the communication port 4, only the fine opening region is adjusted by the magnitude of S2, and then S1 The flow rate can be adjusted so as to increase linearly and proportionally, and the first valve body 11 and the communication port 4 are not brought into sliding contact.

  From the above, the flow rate adjustment valve of the present invention adjusts the flow rate by the second flow rate adjustment unit 42 when the opening is very small, and increases the opening from the second flow rate adjustment unit 42 to the first flow rate adjustment unit 41. Since the flow rate is adjusted by switching, the flow rate can be proportionally proportional to the opening from fully closed to fully open, and the flow rate can be reliably adjusted from minute flow rates to large flow rates. The flow rate can be adjusted within the range.

  The shape of the tapered portion 18 of the first valve body 11 is provided so that the opening degree and the flow rate are linearly proportional, but the shape is changed so that it can be adjusted by the relationship between the opening degree and the equal percentage of the flow rate. It does not matter if it is provided.

  In particular, in the flow control valve of the present invention, the difference in pitch between the male screw portion 29 on the outer peripheral surface of the first stem 27 and the female screw portion 28 on the inner peripheral surface is from 1/20 to 5 minutes of the pitch of the male screw portion 29. 1 makes it possible to finely adjust the opening, fine adjustment of the opening is possible when adjusting the flow path from fully closed to fully open, and from minute flow to large flow Can adjust the flow rate with high accuracy.

  Further, the male screw portion 20 of the second stem 19 is screwed into the female screw portion 28 of the lower inner peripheral surface of the first stem 27, so that, for example, as in the conventional flow control valve shown in Patent Document 2. If the stem structure is provided with male thread portions having different pitches, the size in the vertical direction becomes large. In contrast, in the flow control valve of the present invention, the second stem 19 is provided on the inner periphery of the first stem 27. The size in the vertical direction can be kept small, and the flow control valve can be made compact.

  Next, when the handle 32 is turned in the closing direction from the fully opened state, the valve body is lowered by the reverse operation of the turning in the opening direction, and the flow regulating valve is opened. The flow rate is adjusted according to the degree. When the handle 32 is rotated in the closing direction to be in the fully closed state, the second valve body 12 and the valve seat surface 2 can be surely fully sealed by line contact. The stopper portion 30 on the outer periphery of the lower portion of the first stem 27 may be configured to stop the rotation by contacting the upper end surface of the insertion portion 22 of the diaphragm retainer 21, and in this case, the valve seat surface when fully sealed 2 and the second valve body 12 can be prevented from being overloaded.

  Further, since the first valve body 11 is always in non-contact with the communication port 4 when the flow control valve is fully closed, the valve body and the valve seat surface 2 are worn due to wear and the like due to long-term use of the flow control valve. Without being deformed, it is possible to prevent the flow rate adjustment characteristics from becoming unstable due to long-term use, and to suppress the generation of particles during sliding.

(Example of use)
An example of use of the present invention will be described with reference to FIG. The fluid flows in from the first flow path 5, passes through the communication port 4 and the valve chamber 3, and flows out from the second flow path 6. The fluid flows into the inlet of the first flow path 5 and the outlet of the second flow path 6, respectively. A pipe joint (not shown) is provided, a chemical liquid feed line (not shown) such as a pump is connected to the first flow path 5, and a line up to a point where the chemical liquid is used in the second flow path 6. (Not shown) is connected.

  Next, the amount of lift of the valve body was set to L, and the flow rate Q (mL / min) adjusted by the valve with respect to the opening degree of the flow rate control valve in which the shape of the valve body was changed was evaluated according to the following method.

(Flow measurement)
As shown in FIG. 11, a fluid is flowed from the pump 62 with the primary pressure being 0.05 MPa and the secondary pressure being opened to the atmosphere, and the flow rate control valve of the present embodiment is used as the valve 61, and a line for measuring the flow rate of the fluid with the balance 63 is provided. Used to measure the flow rate. In an atmosphere of 23 ° C. ± 2 ° C., the fluid is pure water, the pipe diameter is 6 mm, the lift amount L of the valve body is changed, the weighing per minute for each lift amount L is measured, and the flow rate Q Was calculated. Each flow control valve differs only in the shape of the valve body, that is, the diaphragm, and all other parts were measured using the same dimensions.

(Example 1)
As shown in FIG. 7, the flow rate Q with respect to the lift amount L was measured in the structure of the diaphragm 10 provided with the first valve body 11 and the second valve body 12 of the present invention. The measurement results are shown in FIG.

(Comparative Example 1)
As shown in FIG. 8, the flow rate Q with respect to the lift amount L was measured in the structure of the diaphragm 44 provided with only the first valve body 45. The measurement results are shown in FIG.

(Comparative Example 2)
As shown in FIG. 9, the flow rate Q with respect to the lift amount L was measured in the structure of the diaphragm 49 in which the first valve body 50 had a cylindrical shape with the same diameter as the straight portion 17 of the first valve body 11 of Example 1. The measurement results are shown in FIG.

(Comparative Example 3)
As shown in FIG. 10, the flow rate Q with respect to the lift amount L was measured in the structure of the diaphragm 57 provided with only the second valve body 58. The measurement results are shown in FIG.

  As can be seen from FIG. 12, in the first embodiment, the second flow rate adjustment by the opening area S2 between the second valve body 12 and the valve seat surface 2 when the opening degree is very small from the fully closed state to the fully opened state of the flow rate adjusting valve. When the flow rate is adjusted by the unit 42 and the opening degree is increased, the flow rate is adjusted by switching from the second flow rate control unit 42 to the first flow rate control unit 41 by the opening area S1 between the first valve body 11 and the communication port 4. It can be seen that the flow rate Q shows a good proportional relationship over the entire range of the lift amount L.

  In Comparative Example 1, since the first valve body 45 of the diaphragm 44 does not contact the communication port 46, the first valve body 45 and the communication port 46 are always in a slightly open state, and the first valve body 45 is raised and the first valve body is raised. It can be seen that the flow rate cannot be adjusted until the 45 straight portion 47 passes through the communication port 46 and the tapered portion 48 rises to the communication port 46 (see FIG. 12). When the taper portion 48 rises to the communication port 46, the same flow rate characteristic as that of the flow rate control valve of the first embodiment is obtained thereafter. The state in which the flow rate cannot be adjusted in this slightly open region is the same as the state in which the slightly open region of the conventional flow control valve shown in Patent Document 1 cannot be adjusted.

  In the second comparative example, the first valve body 50 of the diaphragm 49 has the first valve body 50 of the first embodiment having a columnar shape, and therefore the first flow rate adjustment unit 52 including the first valve body 50 and the communication port 51. In relation to the opening area S2 of the second flow rate adjusting unit 55 composed of the second valve element 53 and the valve seat surface 54, the first flow rate adjusting unit 52 is a cylindrical first when S1> S2. The flow rate is always adjusted to be constant by the valve body 50 and the communication port 4, and the flow rate of the fluid is made constant to some extent by the first flow rate adjustment unit 52, and then the fluid flow is suppressed in the space formed by the annular groove portion 56. A rapid increase in the flow rate can be suppressed, and the flow rate can be accurately adjusted by the second flow rate adjustment unit 55. However, in the case of S1 ≦ S2, the part for adjusting the flow rate is switched from the second flow rate adjusting unit 55 to the first flow rate adjusting unit 52, while the opening area S1 of the first flow rate adjusting unit 52 is constant. Although the flow rate can be adjusted in the open region, the flow rate remains constant even if the lift amount L is increased thereafter (see FIG. 12).

  In Comparative Example 3, when the flow rate adjustment valve is rotated in the opening direction, the flow rate is adjusted only by the second flow rate adjustment unit 60 including the second valve body 58 and the valve seat surface 59 of the diaphragm 57. As a result, the flow rate suddenly increases (see FIG. 12).

  From the comparison between Comparative Example 2 and Comparative Example 3 in FIG. 12, when the flow rate adjustment valve of the present embodiment is slightly opened, only the second flow rate adjustment unit 42 formed by the second valve body 12 and the valve seat surface 2 is used. The flow rate adjustment in the slightly open region is impossible, and after a certain flow rate is made constant by the first flow rate adjustment unit 41 having a constant opening area formed by the linear portion 17 of the first valve body 11 and the communication port 4, It is shown that by adjusting the second flow rate adjustment unit 42, the flow rate adjustment in the slightly open region can be performed.

  Further, it can be seen that when the flow rate adjustable region is overlapped from the flow rate characteristics of Comparative Example 1 and Comparative Example 2, the flow rate characteristic result of this example is almost the same. That is, the flow rate adjustment valve of the present invention has the first flow rate adjustment unit 41 and the second flow rate adjustment unit 42, so that the flow rate can be adjusted in a wide flow range.

  The present invention requires a fine flow rate adjustment in a wide flow range in various industries such as chemical factories, semiconductor manufacturing fields, food fields, bio fields, etc. It is suitably used as a flow control valve used for piping. Moreover, since it is compact, piping space can be made small and it is suitable for the use for which downsizing of an apparatus is calculated | required.

It is a longitudinal cross-sectional view which shows the full open state of the flow control valve which shows the Example of this invention. FIG. 2 is an exploded perspective view of FIG. 1. It is a principal part expanded longitudinal cross-sectional view of FIG. It is a longitudinal cross-sectional view which shows the fully closed state of FIG. It is a principal part expanded longitudinal cross-sectional view of FIG. It is a longitudinal cross-sectional view which shows the half open state of FIG. FIG. 7 is an enlarged vertical cross-sectional view of a main part of FIG. 6. It is a principal part expansion longitudinal cross-sectional view of the flow control valve in which a diaphragm is comprised only with a 1st valve body. It is a principal part expansion longitudinal cross-sectional view of the flow control valve comprised only by the 1st valve body in which the diaphragm made the shape a cylinder. It is a principal part expanded longitudinal cross-sectional view of the flow control valve in which a diaphragm is comprised only with a 2nd valve body. It is a conceptual block diagram which shows the test apparatus for measuring the flow volume Q. FIG. It is the graph which showed the lift amount L and the flow volume Q of the flow control valve. It is a longitudinal cross-sectional view which shows the flow control valve in which the conventional valve seat part and the taper part of a valve body contact. It is a longitudinal cross-sectional view which shows the flow volume adjustment valve which the conventional valve seat and the taper part of a valve body do not contact. It is a longitudinal cross-sectional view which shows the flow control valve which adjusts the conventional minute opening degree.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Valve seat surface 3 Valve chamber 4 Communication port 5 1st flow path 6 2nd flow path 7 Annular recessed part 8 Recessed part 9 Male thread part 10 Diaphragm 11 First valve body 12 Second valve body 13 Thin film part 14 Annular locking part DESCRIPTION OF SYMBOLS 15 Annular groove part 16 Connection part 17 Straight line part 18 Tapered part 19 2nd stem 20 Male thread part 21 Diaphragm presser 22 Insertion part 23 Fitting part 24 Gutter part 25 Through-hole 26 Taper part 27 First stem 28 Female thread part 29 Male thread Part 30 stopper part 32 handle 33 gripping part 34 first stem support 35 female thread part 36 hollow part 37 flange part 38 bonnet 39 locking part 40 female screw part 41 first flow rate adjustment part 42 second flow rate adjustment part 43 ceiling surface 44 Diaphragm 45 First Valve Body 46 Communication Port 47 Linear Portion 48 Tapered Portion 49 Diaphragm 50 First Valve Body 51 Communication Port 52 First Flow Control Portion 53 Second Valve Body 54 Valve Seat Surface 5 5 Second Flow Control Unit 56 Annular Groove 57 Diaphragm 58 Second Valve Element 59 Valve Seat Surface 60 Second Flow Control Unit 61 Valve 62 Pump 63 Scale

Claims (4)

A valve seat surface is formed on the bottom surface of the valve chamber provided in the upper portion, and a main body having a first flow path communicating with a communication port provided at the center of the valve seat surface and a second flow path communicating with the valve chamber,
A first valve body that can be inserted into the communication port by axial movement of the stem and projecting from the center of the wetted surface, and a valve seat surface that can be contacted and separated from the first valve body in the radial direction A second valve body of an annular ridge formed at the position, and a diaphragm integrally provided with a thin film portion formed continuously from the second valve body in the radial direction. Flow control valve. A first stem having a handle fixed to the upper part and a female screw part on the lower inner peripheral surface and a male screw part having a pitch larger than the pitch of the female screw part on the outer peripheral surface;
A first stem support having a female threaded portion threadedly engaged with the male threaded portion of the first stem on the inner peripheral surface;
A second stem having a male screw portion screwed to the female screw portion of the first stem on the upper outer peripheral surface and having a diaphragm connected to the lower end portion;
A diaphragm retainer that is positioned below the first stem support and supports the second stem vertically movable and non-rotatable;
The flow control valve according to claim 1, further comprising a first stem support and a bonnet for fixing the diaphragm presser.   The difference in pitch between the male screw portion provided on the outer peripheral surface of the first stem and the female screw portion provided on the lower inner peripheral surface is 1/20 to 1/5 of the pitch of the male screw portion. The flow control valve according to claim 2, wherein   The flow regulating valve according to any one of claims 1 to 3, wherein the diaphragm is made of polytetrafluoroethylene.

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