JP3734394B2 - Constant pressure regulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a constant pressure regulator that keeps the fluid pressure on the secondary side (downstream side) constant even when the fluid pressure on the primary side (upstream side) fluctuates. More specifically, the present invention mainly relates to an ultrapure water line and various chemicals. The present invention relates to a constant pressure regulator that is suitably used in a chemical liquid line and that can obtain a compact and stable pressure control and generates less dust.
[0002]
[Prior art]
Conventional constant pressure regulators are generally as shown in FIG. In the figure, reference numeral 30 denotes a main body, and a lower portion is provided with a first valve chamber 35, and a fluid inlet 37 that communicates with the first valve chamber 35 and an outlet 38 that communicates with a second valve chamber 36 described later are provided on the side surfaces. It has been. The upper part of the main body 30 forms a second valve chamber 36 together with the diaphragm 32. Reference numeral 31 denotes a lid, which forms an air chamber 39 with the diaphragm 32, and has an air port 42 communicating with the air chamber 39 in the upper part. A constant air pressure is always applied to the air chamber 39. A rod 33 is joined to the center of the diaphragm 32, and a plug 34 having a diameter larger than the diameter of the flow path 41 of the main body 30 is joined to the tip of the rod 33.
[0003]
In such a constant pressure regulator, the fluid pressure in the second valve chamber 36 is kept substantially the same as the pressure applied to the air chamber 39 due to the balance of the forces applied to the diaphragm 32. When the fluid pressure on the primary side increases, the pressure on the secondary side also increases, and the fluid pressure becomes larger than the pressure in the air chamber 39, so that the diaphragm 32 is pushed upward. At this time, the rod 33 and the plug 34 joined to the diaphragm 32 are also moved upward accordingly, and the opening area of the control unit 40 formed between the plug 34 and the main body is reduced and passes through the control unit 40. The pressure loss of the fluid increases, and the secondary pressure in the second valve chamber 36 again decreases to the same pressure as the pressure in the air chamber. On the other hand, when the pressure on the primary side decreases, the pressure in the air chamber becomes larger than the fluid pressure, so that the diaphragm 32 is pushed downward, and the opening area of the control unit 40 is increased contrary to the above case. As a result, the pressure loss of the fluid is reduced, and the fluid pressure in the second valve chamber again rises to the same pressure as the pressure in the air chamber. As described above, in the conventional constant pressure regulator, even if the primary pressure varies, the secondary pressure is kept constant.
[0004]
[Problems to be solved by the invention]
However, the conventional constant pressure regulator has a structure in which the rod passes through the flow path. Therefore, when the fluctuation of the fluid pressure on the primary side frequently occurs or when the pressure fluctuation is large, the rod tilts and the pressure is increased. There was a problem that the control became unstable or the rod and the main body contacted to cause wear or dust generation. Moreover, in order to cope with a minute flow rate, it is necessary to reduce the diameter of the flow path. However, in such a structure, if the diameter of the flow path is reduced, the diameter of the rod must be reduced. There were also problems such as insufficient strength and difficulty in processing and assembly.
[0005]
The present invention has been made in view of the problems of the above-described conventional constant pressure regulator, and an object thereof is to provide a compact and highly accurate constant pressure regulator that can be used in a highly corrosive chemical liquid line or a chemical liquid line that does not like dust generation. To do.
[0006]
[Means for Solving the Problems]
The configuration of the present invention includes a cylindrical body having a first valve chamber, a step portion provided at an upper portion of the first valve chamber, and a fluid inlet communicating with the first valve chamber, and a second valve A lid having a chamber and a fluid outlet communicating therewith, joined to the upper part of the main body, and an annular projection provided on the peripheral part joined to a joint provided on the upper peripheral part of the first valve chamber The first diaphragm, the annular protrusion provided at the peripheral edge is joined to the second diaphragm sandwiched between the main body and the lid, and the both annular joints provided at the center of the first and second diaphragms A sleeve which is movable in the axial direction and a plug which is fixed to the bottom of the first valve chamber and forms a fluid control unit between the lower end of the sleeve, and a step portion of the main body Having an air chamber surrounded by the inner circumferential surface of the first diaphragm and the second diaphragm, and the second diaphragm Receiving area of the ram is configured larger than the pressure receiving area of the first diaphragm, an air supply port communicating with the air chamber, characterized in that provided in the main body.
[0007]
In addition, an orifice portion is provided between the second valve chamber and a fluid outlet that communicates with the second valve chamber.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, it goes without saying that the present invention is not limited to the embodiments.
[0009]
FIG. 1 is a longitudinal sectional view of a constant pressure regulator of the present invention. FIG. 2 is a longitudinal sectional view showing a state where the primary pressure is increased in the constant pressure regulator of the present invention.
[0010]
In the figure, reference numeral 1 denotes a cylindrical main body, and an air supply that communicates with a fluid inlet 7 that communicates with a first valve chamber 9 provided inside the main body 1 and an air chamber 11 that will be described later. The first valve chamber 9 has a joint 12 (annular notch) 13 to which an annular protrusion 17 of the first diaphragm 3 to be described later is joined. Further, a step portion 21 that forms the air chamber 11 together with the first and second diaphragms described later is provided on the upper portion of the first valve chamber 9. Note that the stepped portion 21 is not necessarily formed integrally with the main body 1 and may be formed as a separate annular part.
[0011]
Reference numeral 2 denotes a lid, which has a second valve chamber 10 inside, an outlet 8 communicating with the second valve chamber 10 on the outer peripheral side surface, an upper end of the main body 1, bolts and the like (not shown). )). An annular groove portion 14 into which an annular protrusion 18 of the second diaphragm 4 to be described later is fitted is provided at the peripheral edge portion of the second valve chamber 10 at the lower end portion.
[0012]
Reference numeral 3 denotes a PTFE (polytetrafluoroethylene) first diaphragm formed in a donut shape. An annular joint 15 is provided at the center, and an annular ring having a rectangular cross section is provided at the outer peripheral edge. A protrusion 17 is provided. A sleeve 5 to be described later is screwed onto the inner peripheral surface of the annular joint 15 of the first diaphragm 3, while the annular protrusion 17 is joined to a joint 13 provided inside the main body 1.
[0013]
Reference numeral 4 denotes a second diaphragm made of PTFE. Like the first diaphragm 3, an annular joint 16 is provided at the center and an annular protrusion 18 having a rectangular cross section is provided at the outer peripheral edge. The annular protrusion 18 is fitted in the annular groove 14 of the lid 2 and is sandwiched between the main body 1 and the lid 2 by joining the lid 2 to the upper end surface of the main body 1. The pressure receiving area of the second diaphragm 4 is designed to be sufficiently larger than that of the first diaphragm 3.
[0014]
Reference numeral 5 denotes a cylindrical sleeve, and a threaded portion 19 is provided on the outer peripheral surface. The threaded portion 19 is screwed to the annular joint portions 15 and 16 of the first and second diaphragms 3 and 4. Thus, both diaphragms are integrated and held so as to be movable in the axial direction. Further, the inside of the sleeve 5 is a fluid flow path.
[0015]
A plug 6 is fixed to the bottom of the first valve chamber 9 by screwing or the like. The tip of the plug 6 forms a fluid control unit 20 with the lower end surface of the sleeve 5, and the opening area of the fluid control unit 20 changes with the vertical movement of the sleeve 5, and the second valve chamber 10. The internal pressure, that is, the secondary pressure is designed to be kept constant.
[0016]
Reference numeral 11 denotes an air chamber formed by being surrounded by the stepped portion 21 of the main body 1 and the first and second diaphragms 3 and 4. Compressed air, inert gas, or the like is introduced into the air chamber 11 from the air supply port 12 and is always maintained at a constant pressure.
[0017]
As can be seen from the above description, the first and second diaphragms 3 and 4 integrated by the sleeve 5 are connected to the step portion 21 provided in the main body 1 and the second valve chamber 10 provided in the lid body 2. Arranged in the enclosed space, the air chamber 11 is thereby formed.
[0018]
The material of the main body or the like is preferably a fluororesin such as PTFE or PFA, but may be other plastics or metals such as polyvinyl chloride or polypropylene, and is not particularly limited. Further, the material of the first and second diaphragms is preferably a fluororesin such as PTFE, but may be rubber or metal and is not particularly limited.
[0019]
Next, the operation of the constant pressure regulator of this embodiment will be described.
[0020]
In the state of FIG. 1, the first diaphragm 3 receives an upward force due to the pressure inside the first valve chamber 9, that is, a primary pressure, and a downward force due to the pressure inside the air chamber 11. On the other hand, the second diaphragm 4 receives a downward force due to the pressure inside the second valve chamber 10, that is, a secondary pressure, and an upward force due to the pressure inside the air chamber 11. The position of the sleeve 5 joined to the first and second diaphragms 3 and 4 is determined. The sleeve 5 forms a fluid control unit 20 between the sleeve 5 and the plug 6, and the fluid pressure on the secondary side is controlled by the area.
[0021]
If the primary pressure increases in this state, the secondary pressure and flow rate also temporarily increase. At this time, an upward force acts on the first diaphragm 3 and a downward force acts on the second diaphragm 4 due to the fluid pressure, but the pressure receiving area of the second diaphragm 4 is designed to be sufficiently larger than that of the first diaphragm 3. Therefore, the downward force becomes larger, and as a result, the sleeve 5 is pushed downward (state shown in FIG. 2). As a result, the opening area of the fluid control unit 20 decreases, the fluid pressure on the secondary side instantaneously decreases to the original pressure, and the balance between the internal pressure of the air chamber 11 and the fluid pressure is maintained again. Usually, a fixed throttle or valve (not shown) is attached downstream of the constant pressure regulator of the present invention. If the downstream side of the fixed throttle or valve is open to the atmosphere, the differential pressure before and after the fixed throttle or valve will always be kept constant, and the flow rate corresponding to the flow coefficient of the fixed throttle or valve will always be maintained. It becomes.
[0022]
On the other hand, when the pressure on the primary side decreases in the state of FIG. 2, the pressure and flow rate on the secondary side also temporarily decrease. At this time, a downward force and an upward force are applied to the first and second diaphragms 3 and 4, respectively, due to the internal pressure of the air chamber 11. Even in this case, the pressure receiving area is larger in the second diaphragm 4, Becomes dominant, and the position of the sleeve 5 is pushed upward. As a result, the opening area of the fluid control unit 20 increases (the state shown in FIG. 1), the secondary fluid pressure instantaneously rises to the original pressure, and the balance between the internal pressure of the air chamber 11 and the fluid pressure is balanced again. The original flow rate is also maintained.
[0023]
As described above, even if the primary pressure increases or decreases, the position of the sleeve 5 changes instantaneously, and the pressure on the secondary side is always kept constant, so that the set flow rate can be obtained.
[0024]
If the internal pressure of the air chamber 11 is changed, the secondary pressure is maintained at a value corresponding thereto, so that the set flow rate can be changed if there is no change in the fixed throttle or valve installed on the downstream side. .
[0025]
Next, the characteristics of the constant pressure regulator in the present invention will be described.
[0026]
FIG. 6 shows the results of measuring how the secondary pressure changes when a fixed restrictor (orifice diameter 2 mm) is installed downstream of the constant pressure regulator of the present invention and the primary pressure of the regulator is changed. Show. In the figure, the solid line and the broken line indicate the case where the pressure in the air chamber is 0.04 MPa and 0.08 MPa, respectively. In either case, even if the primary pressure rises, the secondary pressure is constant at substantially the same pressure as the pressure in the air chamber.
[0027]
FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention. The difference from the first embodiment is that the first and second diaphragms, the sleeve, and the main body are formed integrally. Here, the step portion 21 of the main body forming the air chamber is a separate component from the main body. Since the operation of the valve is the same as described above, the description thereof is omitted.
[0028]
FIG. 4 is a longitudinal sectional view showing a third embodiment of the present invention. The difference from the first embodiment is that an orifice portion 22 is provided between the second valve chamber 10 and the fluid outlet 8 communicating therewith. If the downstream side of the orifice part 22 is opened to the atmosphere, the differential pressure before and after the orifice part is always kept constant even if the pressure on the primary side fluctuates. Can be used as a valve. Since the operation of the valve is the same as described above, the description thereof is omitted.
[0029]
【The invention's effect】
The constant pressure regulator of the present invention has the structure as described above, and the following excellent effects can be obtained by using this regulator.
[0030]
(1) Since there is no rod portion as in the conventional product, there is no control failure due to the tilt of the rod during operation, and stable pressure control can be obtained.
[0031]
(2) Since all the members that come into contact with liquid can be made of a material having excellent chemical resistance such as PTFE, in that case, there is very little elution of impurities and contamination of chemicals.
[0032]
(3) Since there is no rod part, there is no wear or dust generation, and even a compact product can provide sufficient component strength, so that it can handle very small flow rates and is easy to process and assemble.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a constant pressure regulator of the present invention.
2 is a longitudinal sectional view showing a state in which the primary pressure has increased in FIG.
FIG. 3 is a longitudinal sectional view showing a second embodiment in which the first and second diaphragms, the sleeve, and the main body are all integrally formed.
FIG. 4 is a longitudinal sectional view showing a third embodiment in which an orifice portion is provided between a second valve chamber and a fluid outlet that communicates with the second valve chamber.
FIG. 5 is a longitudinal sectional view of a conventional constant pressure regulator.
FIG. 6 is a graph showing characteristics of the constant pressure regulator of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main body 2 ... Cover body 3 ... 1st diaphragm 4 ... 2nd diaphragm 5 ... Sleeve 6 ... Plug 7 ... Fluid inflow port 8 ... Fluid outflow port 9 ... 1st valve chamber 10 ... 2nd valve chamber 11 ... Air chamber 12 ... Air supply port 13 ... Joint part 14 ... Annular groove part 15 ... Annular joint part 16 ... Annular joint part 17 ... Annular protrusion 18 ... Annular protrusion 19 ... Screw part 20 ... Fluid control part 21 ... Step part 22 ... Orifice part

Claims (4)

A cylindrical main body having a first valve chamber, a step provided at an upper portion of the first valve chamber, and a fluid inlet communicating with the first valve chamber, and a second valve chamber and the second valve chamber. A lid that has a fluid outlet and is joined to the upper part of the main body, and a first diaphragm in which an annular protrusion provided on the peripheral edge is joined to a joint provided on the upper peripheral edge of the first valve chamber; The annular protrusion provided at the peripheral edge is joined to the second diaphragm sandwiched between the main body and the lid, and the two annular joints provided at the center of the first and second diaphragms and moved in the axial direction. A free sleeve and a plug fixed to the bottom of the first valve chamber and forming a fluid control part between the lower end of the sleeve, and an inner peripheral surface of the stepped portion of the main body A pressure receiving surface of the second diaphragm having an air chamber surrounded by the first and second diaphragms There pressure regulator air supply port is configured larger than the pressure receiving area of the first diaphragm, communicating with the air chamber, characterized in that provided in the main body. 2. The constant pressure regulator according to claim 1, wherein the first and second diaphragms, the sleeve and the main body are integrally formed. The constant pressure regulator according to claim 1 or 2, wherein a material of the diaphragm is polytetrafluoroethylene. 4. The constant pressure regulator according to claim 1, wherein an orifice portion is provided between the second valve chamber and a fluid outlet that communicates with the second valve chamber.

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