JP2015146163A - Flow rate control valve and flow rate control device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate control valve for holding the cleanliness of fluid in a higher state by suppressing an unexpected contact between a valve seat and a valve body or the like, and for maintaining the fluid at a fixed flow rate.SOLUTION: A flow rate control valve 10A includes: a diaphragm part 15 disposed on a channel between an inflow side chamber 20 and an outflow side chamber 25 of fluid Fm to be controlled; a valve main body part 11 having a valve seat 16; a first diaphragm 30 dividing the inflow side chamber into a first chamber 21 and a second chamber 22; a second diaphragm 35 dividing the outflow side chamber into a third chamber 26 and a fourth chamber 27, and having a valve body 38 configured to receive a fluid pressure, and to be always energized by energization means 55, and to move backward and forward with respect to the valve seat; and an inter-chamber connection part 70 connecting the second chamber to the fourth chamber, therein the backward and forward movement of both diaphragms generated due to pressure fluctuation before and after the diaphragm part is transmitted to the mutual diaphragms by pressurized gas 60 to allow the valve body to move backward and forward with respect to the valve seat.

Description

  The present invention relates to a flow rate control valve and a flow rate control device using the same, and more particularly, to a flow rate control valve having a function of making a fluid flow rate constant or variable after a predetermined fluid flow rate, and the flow rate control valve. The present invention relates to a flow control device.

  In a semiconductor manufacturing process, a process of cleaning the surface of a silicon wafer (substrate) with a diluted chemical is performed. This is intended to remove particles, metal contaminants, oxide films, and the like, and a treatment liquid in which a plurality of types of chemical liquids and pure water are mixed at an appropriate ratio is used. Treatment liquids include APM (ammonia, hydrogen peroxide and pure water), HPM (hydrochloric acid, hydrogen peroxide and pure water), DHF (hydrofluoric acid and pure water), SPM (sulfuric acid and hydrogen peroxide), etc. Is mentioned. For example, when this cleaning process is performed in a single wafer type apparatus, a processing liquid or the like is supplied to the surface of the wafer held and rotated horizontally.

  In a single wafer cleaning apparatus, a mixed processing solution is stored in a tank, and there are a cabinet method for supplying the processing solution to the wafer and an in-line mixing method for directly supplying the processing solution mixed immediately before the wafer. The apparatus has a fluid mixing section, and a pipe through which a high concentration chemical solution (raw solution) and pure water circulates is connected to generate a mixed solution. According to a single wafer processing apparatus that processes wafers one by one, a small amount of liquid mixture is supplied to the wafer surface, and when an in-line method is used, a small amount of chemical liquid is supplied to the mixing unit. For example, in the production of DHF, when the flow rate ratio of hydrofluoric acid to pure water is 1: 100, and the flow rate of pure water is set to 2.0 L / min, the required flow rate of hydrofluoric acid is 0.02 L / min. min. In such a process that needs to control a very small amount of a chemical solution, a slight variation in flow rate causes a large variation in the cleaning effect. Therefore, a constant flow valve capable of supplying a chemical solution and pure water to the mixing unit with high accuracy is required.

  In addition, with the progress of large-scale integration and finer processing in semiconductor manufacturing, the International Semiconductor Technology Roadmap (ITRS) stipulates that the process will be 24 nm in 2014. The number (24 nm) represented by the process is defined as half (half pitch) of the pitch (line width + line interval) of the narrowest wiring in the lowest layer in the MPU. While the wiring width is determined in this way, the entry of fine dust (particles) into the fluid flow path in the semiconductor manufacturing process greatly affects the product yield. Since the particles need to be ¼ or less of the wiring pitch (12 nm in the case of the 2014 process), a member that circulates while maintaining the cleanliness of the fluid has great significance.

  The constant flow valve disclosed in Patent Document 1 is configured such that a plurality of coaxially arranged diaphragms fluctuate integrally with the pressure of the controlled fluid. A valve body that fluctuates integrally with each diaphragm opens and closes the valve seat that exists on the inflow side. Thus, the outflow amount of the controlled fluid can be controlled to a predetermined flow rate by adjusting the differential pressure in the constant flow valve. Further, the flow path structure does not cause the controlled fluid to stay, can easily adjust the differential pressure, and has good responsiveness.

  However, when control is performed in a minute flow range, it is necessary to advance and retract the valve body with a narrow opening. This constant flow valve has a configuration in which a plurality of diaphragms are connected by a shaft portion and the shaft portion is inserted into a flow path in which a valve seat is formed. For this reason, there exists a possibility that a valve seat and a valve body may slide by operation | movement of the valve body at the time of control.

  In the flow control device disclosed in Patent Document 2, when a pressure fluctuation occurs in the primary fluid, the secondary pressure side of the first pressure control valve unit is maintained at a predetermined pressure by the first pressure control valve unit to control the flow rate. The On the other hand, when a pressure fluctuation occurs in the secondary side fluid, the second pressure control valve unit maintains the primary side of the second pressure control valve unit at a predetermined pressure to control the flow rate. Therefore, even when a pressure fluctuation occurs on the primary side or the secondary side of the flow control device, it is possible to achieve stabilization of the fluid flow rate with high accuracy.

  However, in the above flow control device, the fluid pressure in the flow control device may increase due to the fluid outflow being stopped on the secondary side. At this time, the valve body may collide strongly against the valve seat of the first pressure control valve portion by the sudden closing operation of the first pressure control valve portion.

  In the conventional constant flow valve and flow control device, there is a concern that the valve seat and the valve body may cause an unexpected contact with each other due to the above operation and generate dust. Therefore, there is a demand for an apparatus that can supply a minute flow rate with high accuracy and can maintain a higher degree of cleanliness.

  Furthermore, if the above requirements are satisfied and the setting can be changed to a desired flow rate, and if a constant flow rate can be maintained even after the change, the apparatus is consolidated. In particular, if there is a device that realizes constant flow in a minute flow rate range and control of the flow rate itself, the convenience of fluid supply can be improved more than before, and the cleanliness of the fluid can be further maintained. Therefore, there has been a demand for a new apparatus that realizes constant control of the fluid flow rate and control of the flow rate in a lump.

Japanese Patent No. 4022438 (corresponding patent: US 6805156B2, EP 1321841B1) JP 2007-102754 A (corresponding patent: US 2007/0056640 A1)

  The present invention has been made in view of the above points, and suppresses unexpected contact between the valve seat and the valve body to maintain a higher fluid cleanliness and maintain the fluid at a constant flow rate. A flow control valve and a flow control device using the same are provided.

  That is, the invention of claim 1 is a throttle portion provided in a flow path between an inflow side chamber connected to an inflow portion of a controlled fluid and an outflow side chamber connected to an outflow portion of the controlled fluid; A valve main body having a valve seat formed in the outflow side chamber; a first chamber disposed in the inflow side chamber and contacting the inflow side chamber with the controlled fluid; and a back side of the first chamber and contacting the controlled fluid. A first diaphragm that receives the fluid pressure in the first chamber, a third chamber that is disposed in the outflow side chamber, contacts the controlled fluid with the outflow side chamber, and the third chamber It is divided into a fourth chamber that is on the back side and does not contact the controlled fluid, receives the fluid pressure in the third chamber, and is constantly urged toward the fourth chamber by the urging means in the fourth chamber. And a second diaphragm having a valve body that moves forward and backward with respect to the valve seat, and an inter-chamber connecting portion that connects the second chamber and the fourth chamber, and the first diaphragm is in the second chamber. The pressurized gas supplied to the first chamber is constantly pressurized to the first chamber side, and the second diaphragm flows into the second chamber and then flows into the fourth chamber through the inter-chamber connection. The pressurized gas is constantly pressurized to the third chamber side, and the forward and backward movements of the first diaphragm and the second diaphragm caused by pressure fluctuations before and after the throttle portion are transmitted to each diaphragm through the pressurized gas. The valve body is moved forward and backward with respect to the valve seat by the forward and backward movement of the first diaphragm and the second diaphragm, and the flow rate of the controlled fluid is kept constant. That the the according to the flow control valve according to claim.

  The invention according to claim 2 relates to the flow control valve according to claim 1, wherein the biasing means is a biasing spring.

  According to a third aspect of the present invention, a throttle opening is formed in the throttle and the throttle control valve body controls the flow rate of the controlled fluid passing through the throttle by moving forward and backward with respect to the throttle opening. And a throttle control valve body advancing / retreating means for moving the throttle control valve body forward and backward.

  According to a fourth aspect of the present invention, there is provided the flow control valve according to the third aspect, wherein the throttle control valve body advance / retreat means is a motor.

  According to a fifth aspect of the present invention, there is provided the flow control valve according to the third aspect, wherein the throttle control valve body advancing / retreating means is an advancing / retreating pressure gas.

  A sixth aspect of the present invention relates to the flow control valve according to the third aspect, wherein the throttle control valve body advancing / retreating means is a screw member.

  In the invention of claim 7, the throttle opening is formed as a flat throttle valve seat, and the tip of the throttle control valve body facing the throttle valve seat is also formed as a flat plate tip. It concerns on the flow control valve of claim | item 3.

  An eighth aspect of the invention includes the flow rate control valve according to claim 3, a flow rate detection unit for the controlled fluid, and a calculation unit, wherein the flow rate control valve and the flow rate detection unit are supply units for the controlled fluid. And a fluid mixing section connected to a fluid mixing portion of the controlled fluid.

  A ninth aspect of the present invention relates to the flow rate control device according to the eighth aspect, wherein a control unit that generates a signal for controlling the throttle control valve body advancing / retreating means is provided.

  The invention according to claim 10 relates to the flow rate control device according to claim 8, wherein the calculation unit performs feedback control based on a flow rate measurement value of the flow rate detection unit.

  According to the flow control valve of the first aspect of the present invention, the restriction provided in the flow path between the inflow side chamber connected to the inflow portion of the controlled fluid and the outflow side chamber connected to the outflow portion of the controlled fluid. A valve body having a valve seat formed in the outflow side chamber, a first chamber disposed in the inflow side chamber and contacting the inflow side chamber with a controlled fluid, and a back side of the first chamber. A first diaphragm that is partitioned into a second chamber that is not in contact with the control fluid and receives the fluid pressure in the first chamber; a third chamber that is disposed in the outflow side chamber and that is in contact with the controlled fluid; The rear surface of the third chamber is divided into a fourth chamber that is not in contact with the fluid to be controlled, receives the fluid pressure in the third chamber, and constantly moves to the fourth chamber side by the biasing means in the fourth chamber. A second diaphragm having a valve body that is biased and moves forward and backward with respect to the valve seat; and an inter-chamber connecting portion that connects the second chamber and the fourth chamber, wherein the first diaphragm is The pressurized gas supplied into the second chamber is constantly pressurized toward the first chamber, and the second diaphragm flows into the second chamber and then flows into the fourth chamber through the inter-chamber connection. Is constantly pressurized by the pressurized gas flowing into the third chamber, and the forward and backward movements of the first diaphragm and the second diaphragm caused by pressure fluctuations before and after the throttle portion are mutually transmitted through the pressurized gas. Transmitted to the diaphragm, the valve body is moved forward and backward with respect to the valve seat by the forward and backward movement of the first diaphragm and the second diaphragm, so that the flow rate of the controlled fluid is constant. Since to hold can be maintained with keeping the cleanliness of the fluid to a higher state by suppressing the unexpected contact between the valve seat and the valve body or the like, a fluid to a constant flow rate.

  According to the flow control valve of the invention of claim 2, in the invention of claim 1, since the urging means is an urging spring, the urging mechanism of the diaphragm is inexpensive and simple.

  According to the flow control valve of the third aspect of the present invention, in the first aspect of the present invention, the throttle portion is formed with a throttle opening, and passes through the throttle portion by moving forward and backward with respect to the throttle opening. The throttle control valve body that controls the flow rate of the controlled fluid and the throttle control valve body advancing / retreating means for moving the throttle control valve body forward and backward are provided, so that unexpected contact between the valve seat and the valve body is suppressed. Thus, it is possible to maintain a constant flow rate with a higher degree of fluid cleanliness, and to change the setting of the circulating fluid flow rate range so that the apparatus can be consolidated.

According to the flow control valve of the fourth aspect of the invention, in the third aspect of the invention, since the throttle control valve body advance / retreat means is a motor, the advance / retreat amount of the throttle control valve body can be accurately reproduced.

  According to the flow control valve of the fifth aspect of the present invention, in the third aspect of the invention, the throttle control valve body advance / retreat means is an advancing / retreating pressure gas, so that the response of the throttle control valve body to advance / retreat can be enhanced. .

  According to the flow control valve of the invention of claim 6, in the invention of claim 3, since the throttle control valve body advancing / retreating means is a screw member, the members related to opening adjustment are simplified and the structure is simplified. be able to.

  According to the flow control valve of the invention of claim 7, in the invention of claim 3, the throttle opening is formed as a flat throttle valve seat, and the tip of the throttle control valve body facing the throttle valve seat Since it is also formed as a flat plate tip, it can cope with flow rate control in a minute flow rate range, and can prevent contact of the valve body with the valve seat from shaft misalignment.

  According to the flow control device according to the invention of claim 8, the flow control valve according to claim 3, a flow rate detection unit of the controlled fluid, and a calculation unit, wherein the flow control valve and the flow rate detection unit, Since it is connected to the fluid piping between the supply part of the controlled fluid and the fluid mixing part of the controlled fluid, downsizing of the entire apparatus proceeds. In addition, the number of members in contact with the controlled fluid is suppressed, and the cleanliness of the controlled fluid is easily maintained.

  According to the flow control device of the ninth aspect of the invention, in the eighth aspect of the invention, since the control unit for generating a signal for controlling the throttle control valve body advance / retreat means is provided, smooth control of the throttle control valve advance / retreat means is provided. Is possible.

  According to the flow control device of the invention of claim 10, in the invention of claim 8, the calculation unit performs feedback control based on the flow rate measurement value of the flow rate detection unit. The flow rate of the controlled fluid can be increased or decreased immediately in response to the flow rate change that has occurred on the side), and the controlled fluid can be circulated at a constant flow rate at all times.

1 is a longitudinal sectional view of a flow control valve according to a first embodiment of the present invention. It is the elements on larger scale near a narrow part and a movable shaft. It is a longitudinal cross-sectional view of the flow control valve concerning 2nd Example of this invention. FIG. 4 is a longitudinal sectional view of a state in which the first diaphragm of FIG. 3 is retracted. FIG. 4 is a longitudinal sectional view of a state in which the first diaphragm of FIG. 3 has advanced. It is a longitudinal cross-sectional view of the state where the throttle control valve body of FIG. It is a principal part enlarged view of the throttle control valve body vicinity of 2nd Example. It is a longitudinal cross-sectional view of the flow control valve concerning 3rd Example of this invention. It is a longitudinal cross-sectional view of the flow control valve which concerns on 4th Example of this invention. It is the schematic of the substrate processing apparatus incorporating the flow control device of the present invention.

  The flow control valves 10A, 10X, 10Y, and 10Z of the embodiments that are defined and illustrated in the present invention are mainly disposed in fluid conduits of semiconductor manufacturing factories and semiconductor manufacturing apparatuses, and are used for fluid flow control. It is done. Specifically, the flow rate control valve has a function of stabilizing the flow rate of chemicals used for various treatments such as ultrapure water used for cleaning silicon wafers, hydrofluoric acid, hydrogen peroxide solution, ammonia water, hydrochloric acid, and the like. It is a valve provided. Further, the flow rate of the fluid flowing through the inside of the valve can be changed to a desired flow rate range.

  The flow rate control valve 10A is a valve that exhibits a constant flow rate function within a single valve. The flow control valves 10X, 10Y, and 10Z are positioned as valves that have two different functions of a constant flow function and a variable control function in a single valve. Since it is such a functional valve, the number of places required for installation is reduced. In addition, since the functions separated into a plurality of valves are integrated, the piping of the controlled fluid is simplified and the cleanliness of the controlled fluid is increased. In particular, the flow rate control valve of the present invention is suitable for controlling a controlled fluid corresponding to cleaning of a silicon wafer by a single wafer method.

  The flow control valve 10A according to the first embodiment is configured to include only a constant flow rate function unit CF that has a constant flow rate function for making the fluid flow rate constant. On the other hand, the flow control valves 10X, 10Y, and 10Z of the second to fourth embodiments are variable control that can be variably controlled in a desired flow rate region and a constant flow rate function unit CF that has a constant flow rate function that makes the fluid flow rate constant. It is the structure provided with two site | parts of functional part VFx, VFy, VFz. Main members such as the valve body 11, the first diaphragm 30, the second diaphragm 35, etc. included in the constant flow rate function unit CF, and the throttle control valve body 120 of the variable control function units VFx, VFy, VFz The property which does not affect the corrosion by the controlled fluid or the cleanliness of the controlled fluid is required.

  The main components of the flow control valve of each embodiment are made of other highly corrosion- and chemical-resistant materials such as fluororesins such as PTFE, PFA, and PVDF, corrosion-resistant metals such as stainless steel, or combinations thereof. It is formed. In particular, the resin material described above is used for a member in a portion that comes into contact with the controlled fluid. The flow control valves of the embodiments shown and disclosed in the present application are all processed and formed by cutting from a fluororesin block.

  The flow control valve 10A according to the first embodiment having a function of stabilizing the flow rate will be described with reference to the longitudinal sectional view of FIG. The valve body 11 includes a throttle 15 provided in a flow path between an inflow side chamber 20 connected to the controlled fluid inflow portion 12 and an outflow side chamber 25 connected to the controlled fluid outflow portion 13. The valve seat 16 is formed in the outflow side chamber 25. The valve body 11 is formed by a combination of a plurality of body blocks 11A, 11C, 11D. The throttle unit 15 causes the fluid pressure in the flow path to be lost, thereby causing a differential pressure in the fluid pressure between the inflow side chamber 20 and the outflow side chamber 25. Reference numeral 17 in the drawing denotes an outflow opening of the valve seat 16 that connects the outflow side chamber 25 and the outflow portion 13. Reference sign Fm in each of the subsequent drawings is a controlled fluid. The figure attached with Fm shows the flow state of the controlled fluid.

  In the valve main body 11 of the embodiment, the inflow portion 12, the outflow portion 13, the throttle portion 15, and the valve seat 16 are formed in the main body block 11A. The main body block 11A and the main body block 11B are combined to form the inflow side chamber 20. The main body block 11A and the main body block 11C are combined to form the inflow side chamber 25. The fixed guide portion 40 is attached to the main body block 11B. The movable guide part 50 is accommodated by the combination of the main body block 11C and the main body block 11D. The valve body 11 is provided with an inter-chamber connection part 70.

  The inflow side chamber 20 is divided by the first diaphragm 30 into a first chamber 21 that comes into contact with the controlled fluid and a second chamber 22 that becomes the back side of the first chamber 21 and does not come into contact with the controlled fluid. The The first diaphragm 30 according to the embodiment includes a thin movable film part 31 serving as a diaphragm surface and an outer peripheral part 32 disposed on the outer periphery of the movable film part 31. The outer peripheral portion 32 is tightly fitted between the main body block 11A and the main body block 11B and fixed at a predetermined position.

  The second chamber 22 is connected to the accommodating portion 23 formed in the main body block 11B through the narrow portion 24. The fixed guide part 40 is accommodated in the accommodating part 23. A guide tube portion 43 is formed at the distal end portion 41 of the fixed guide portion 40, and the movable shaft 34 is inserted into the guide tube portion 43 so as to freely advance and retract. In the illustrated first diaphragm 30, a protective plate member 33 is provided in the central portion on the second chamber 22 side. The distal end of the movable shaft 34 is connected to the protection board member 33. Both connections are not mechanical connections but only contact (abut) each other. The protective plate member 33 is provided with a groove for preventing the first diaphragm and the main body block 11B from being in close contact with each other.

  An air supply inlet 62 and an air supply guiding portion 63 are formed in the main body block 11B. Further, the air supply guiding unit 63 is connected to the housing unit 23. Therefore, the pressurized gas 60 that has flowed into the main body block 11 </ b> B can flow into the second chamber 22 through the housing portion 23 and the narrow portion 24. As a result, the pressure of the pressurized gas 60 that has passed through the narrow portion 24 is applied to the second chamber 22, and the first diaphragm 30 is pressed toward the first chamber 21 (see FIG. 2 for details).

  An auxiliary spring 45 (coil spring) is disposed at the distal end portion 41 of the fixed guide portion 40. Due to the elasticity of the spring 45, the plate portion 48 of the movable shaft 34 is separated from the step portion 42 of the fixed guide portion 40. The biasing force of the auxiliary spring 45 is applied to the movable shaft 34 side, and the first diaphragm 30 is constantly pressurized to the first chamber 21 side through the movable shaft 34. A biasing force of the auxiliary spring 45 is applied to the first diaphragm 30 together with pressurization by the pressurized gas 60 that has passed through the narrow portion 24.

  The outflow side chamber 25 is partitioned by the second diaphragm 35 into a third chamber 26 that comes into contact with the controlled fluid and a fourth chamber 27 that becomes the back side of the third chamber 26 and does not come into contact with the controlled fluid. The The second diaphragm 35 according to the embodiment includes a thin movable film portion 36 that serves as a diaphragm surface and an outer peripheral portion 37 that is disposed on the outer periphery of the movable film portion 36. The outer peripheral portion 37 is tightly attached between the main body block 11A and the main body block 11C and fixed at a predetermined position.

  The third chamber 26 is formed in the main body block 11 </ b> A and forms a flow path of a controlled fluid that extends from the throttle portion 15 to the outflow portion 13 through the outflow opening 17. The fourth chamber 27 is formed in the main body block 11 </ b> C and is integrated with the accommodating portions 28 and 53 that accommodate the movable guide portion 50. A narrow portion 29 is placed between the two.

  In the illustrated embodiment, a biasing spring 56 is provided as a biasing means 55 around the movable guide portion 50 accommodated in the fourth chamber 27 (accommodating portions 28 and 53). Further, the second diaphragm 35 is fixed to the distal end portion 51 of the movable guide portion 50 through the fixed portion 39 of the diaphragm. Both fixing methods are appropriate, and the embodiment is a mechanical connection in which both are screwed together. Therefore, the operations of the movable guide portion 50 and the second diaphragm 35 are always integrated. Further, the step portion 52 and the narrow portion 29 are separated from each other by the action of the urging spring 56 accommodated between the step portion 52 of the movable guide portion 50 and the narrow portion 29 of the main body block 11C. Therefore, the second diaphragm 35 is always biased toward the fourth chamber 27 by being pulled by the movable guide portion 50. Grooves are also formed on the upper surface portion of the stepped portion 52 of the movable guide portion 50 to prevent adhesion with the main body block 11D.

  The second diaphragm 35 is provided with a valve body 38. The second diaphragm 35 receives the fluid pressure of the controlled fluid in the third chamber 26 and moves the valve body 38 forward and backward (forward and backward movement) with respect to the valve seat 16. The valve body 38 is a protruding portion that protrudes toward the valve seat 16 side, and is formed in a tapered shape in the embodiment. By the action of the biasing spring 56 described above, the valve body 38 does not contact the valve seat 16 and does not close (close) the outflow opening 17 but always forms an appropriate gap. Inadvertent contact between the valve body 38 and the valve seat 16 is also avoided. In particular, since the biasing spring 56 (coil spring) is used as the biasing means 55, the mechanism for biasing the diaphragm becomes inexpensive and simple, and the cost can be reduced accordingly.

  As can be easily understood from the division of the inflow side chamber 20 and the outflow side chamber 25 by the first diaphragm 30 and the second diaphragm 35, the contact (wetted) part of the controlled fluid flowing through the flow path is limited. Therefore, the controlled fluid flowing through the constant flow valve of the present invention is maintained with high cleanliness. In addition, the shape of the valve body 38 formed in the 2nd diaphragm 35 is not restricted to the cone shape of illustration, It is appropriate, such as a cylindrical body. In addition to the biasing spring 56, the biasing means 55 that constantly biases the second diaphragm 35 toward the fourth chamber 27 side is provided with an appropriate partition, and biasing air (not shown) that flows into the partition is provided. It can also be used.

  Furthermore, as can be understood from the drawing, an inter-chamber connection portion 70 for connecting the second chamber 22 and the fourth chamber 27 is provided. The inter-chamber connecting portion 70 is arranged in the order in which the pressurized gas 60 flows, the first pipe portion 71 and the first connecting port 73 formed in the main body block 11B, the connecting pipe portion 75, and the second connecting port formed in the main body block 11D. 74, a second pipe portion 72 formed in the main body block 11C. The connecting pipe portion 75 is a resin or metal pipe.

  The pressurized gas 60 that flows into the second chamber 22 and pressurizes the first diaphragm 30 toward the first chamber 21 is supplied from the second chamber 22 to the first pipe portion 71, the connecting pipe portion 75, and the second pipe portion. It flows into the fourth chamber 27 via 72. Therefore, the second diaphragm 35 is pressed through the pressurized gas 60 flowing into the fourth chamber 27. In this way, the second diaphragm 35 is also pressed to the third chamber 26 side.

  In addition, arrangement | positioning of the connection part 70 between chambers, a formation site | part, etc. are suitable in the said flow control valve. For example, the pipe part constituting the inter-chamber connection part 70 may be directly formed in the main body block of the valve main body part 11. As long as the movement of the pressurized gas 60 is not hindered, the design is relatively free.

  In the flow control valve 10A, the exhaust block 64 and the exhaust outlet 65 are formed in the main body block 11C. Then, the pressurized gas 60 that has flowed into the fourth chamber 27 is exhausted to the outside of the flow rate control valve 10 </ b> A via the exhaust guiding portion 64 and the exhaust outlet 65. The pressurized gas 60 is always supplied from the electropneumatic converter (electropneumatic regulator) 61 into the flow control valve 10A at a constant pressure, and is exhausted from the flow control valve.

  Here, the vicinity of the narrow portion 24 and the movable shaft 34 and the flow path of the pressurized gas 60 will be described using a partially enlarged view of FIG. As can be understood from the drawing, a valve seat portion 24 e is formed in the narrow portion 24 at the end of the accommodating portion 23. The plate portion 48 of the movable shaft 34 can come into contact with the valve seat portion 24e and also acts as a valve body. When the first diaphragm 30 receives the fluid pressure from the first chamber 21, the plate portion 48 is separated from the valve seat portion 24 e, and the pressurized gas 60 (broken arrow) flowing into the housing portion 23 from the supply air guiding portion 63 is generated. It flows into the second chamber 22. The gas pressure flowing into the second chamber 22 decreases due to the pressure loss when passing through the narrow portion 24 functioning as an orifice. The pressurized gas after depressurization is 60 t (broken line arrow). In the inter-chamber connection part 70 and the fourth chamber 27 after the second chamber 22, since no pressure loss part such as an orifice is provided in the middle, the pressure state of the pressurized gas 60t is maintained and circulated. Therefore, the gas pressures in the second chamber 22 and the fourth chamber 27 are the same.

  The flow control valves 10X, 10Y, and 10Z of the second to fourth embodiments after FIG. 3 are added to the constant flow rate function unit CF having a constant flow rate function for stabilizing the fluid flow rate of FIG. Corresponding to the above, a variable control function unit VFx, VFy, VFz that can be variably controlled in a desired flow rate range is also provided. The operations and mechanisms related to the forward and backward movement of the first diaphragm 30 and the second diaphragm 35 in the constant flow rate function part CF of the flow control valve of the second to fourth embodiments are all the same as the flow control of the first embodiment. It is the same as valve 10A. Therefore, only the different portions will be described, and the common portions will be denoted by the same reference numerals and description thereof will be omitted.

  In the constant flow rate functional part CF of the flow control valve 10X of the second embodiment shown in the longitudinal sectional view of FIG. 3, the valve main body part 11 has an inflow part 12, an outflow part 13, a throttle part 15, and a valve seat 16 in the main body block 11A. Is formed. Then, the control valve chamber 100 connected to the throttle opening 18 is formed in the throttle 15 together with the throttle opening 18. Furthermore, a communication flow path 108 that connects the control valve chamber 100 and the third chamber 26 of the outflow side chamber 25 is also formed. Therefore, the controlled fluid that has flowed into the inflow portion 12 of the flow control valve 10X is the third chamber 21 of the inflow side chamber 20, the throttling portion 15 (throttle opening portion 18), the control valve chamber 100, and the third of the outflow side chamber 25. It flows out of the flow rate control valve 10X from the outflow portion 13 via the chamber 26 and the flow opening 17 (valve seat 16).

  The relationship between the advance / retreat of the first diaphragm 30 and the second diaphragm 35 and the advance / retreat of the valve body 38 of the constant flow rate function unit CF will be described below using the flow control valve 10X of FIGS. 4 and 5. FIG. 4 shows a state in which the fluid pressure of the controlled fluid on the first diaphragm 30 side is increased by the increase in the primary pressure of the flow control valve 10X. Compared with the state of the first diaphragm 30 in FIG. 3, the first diaphragm 30 is pushed (retracted) from the first chamber 21 side to the second chamber 22 side, and between the plate portion 48 and the narrow portion 24 of the movable shaft 34. The amount of opening increases.

  The second chamber 22 and the fourth chamber 27 are connected by an inter-chamber connection part 70. At the same time, the pressurized gas 60 (particularly, the pressurized gas 60t in FIG. 2) always flows, and a predetermined pressure is applied to both the chambers 22 and 27, respectively. Therefore, the second diaphragm 35 is pushed from the fourth chamber 27 side to the third chamber 26 side (advance) from the pressure change of the pressurized gas 60t accompanying the volume change of the second chamber 22. Then, the valve body 38 provided in the second diaphragm 35 moves forward with respect to the valve seat 16, and the opening amount of the flow opening is reduced.

  FIG. 5 shows a state in which the fluid pressure of the controlled fluid on the first diaphragm 30 side is lowered due to a decrease in the primary pressure of the flow control valve 10X. Contrary to the description of FIG. 4, the first diaphragm 30 is pushed back from the second chamber 22 side to the first chamber 21 side (advance). As a result, the opening amount between the plate portion 48 and the narrow portion 24 of the movable shaft 34 is reduced. As the plate portion 48 of the movable shaft 34 moves, the pressure of the pressurized gas 60t changes, and the second diaphragm 35 is fourth from the third chamber 26 side as compared with the state of the second diaphragm 35 in FIG. Pushed to the chamber 27 side (retreat). The second diaphragm 35 moves backward from the valve seat 16 together with the valve body 38, and the opening amount of the flow opening 17 is enlarged.

  The first diaphragm 30 and the second diaphragm 35 constantly receive pressure fluctuations of the controlled fluid before and after the throttle unit 15. Then, the pressurized gas 60 t adjusted by the advance and retreat of the first diaphragm 30 is transmitted to the advance and retreat of the second diaphragm 35.

  Thus, the internal pressure of the second chamber 22 and the fourth chamber 27 changes as the gas pressure 60 (60t) of the pressurized gas changes following the advance and retreat of the first diaphragm 30, and the second diaphragm 22 changes. The advance / retreat position of 35 also changes. As a result, the pressure fluctuation of the controlled fluid generated upstream or downstream of the flow control valve is accurately reflected in the advance / retreat operation of the second diaphragm 35 and the valve body 38, and the valve body 38 moves forward / backward with respect to the valve seat 16. . Therefore, the opening degree (opening amount) of the outflow opening 17 is adjusted, and as a result, the flow rate of the controlled fluid passing through the flow rate control valve 10X is maintained constant.

  The relationship between the flow rate of the controlled fluid and the fluid pressure in the constant flow rate function unit CF of the flow rate control valve 10X will be described with reference to FIG. In the following description, the fluid pressure applied to the first diaphragm 30 is “P1”, the fluid pressure applied to the second diaphragm 35 is “P2”, the fluid pressure on the outflow portion 13 side applied to the second diaphragm 35 is “P3”, and the flow rate. The pressure of the pressurized gas 60 supplied into the control valve 10X is “P4”. “P4” is the pressure after the pressure loss that has passed through the narrow portion 24.

  Further, the load applied to the first diaphragm 30 by the auxiliary spring 45 (the spring load of the auxiliary spring) is “SP1”, and the load applied in the direction in which the second diaphragm 35 is separated from the valve seat 16 by the biasing spring 56 which is the biasing means 55. (Spring load of the urging spring) is assumed to be “SP2”. The effective pressure receiving area of the first diaphragm 30 is “S1”, the effective pressure receiving area of the second diaphragm 35 is “S2”, and the area of the flow opening 17 of the valve seat 16 is “S3”. The effective pressure receiving area in the diaphragm referred to here is an area where the movable film portion of the diaphragm surface composed of a thin film portion which is the movable portion is effectively subjected to pressure.

The pressure “P4” of the pressurized gas 60 can be expressed as follows when the spring load “SP1” of the auxiliary spring is included. This formula is the balance formula of the first diaphragm 30.
P4 = P1- (SP1 / S1)

Regarding the balance type of the second diaphragm 35, the force (Fu) on the fourth chamber 27 side (upward in the drawing) is as follows.
Fu = (S2-S3) * P2 + S3 * P3 + SP2
Further, the force (Fd) on the third chamber 26 side (downward in the drawing) of the second diaphragm 35 is as follows.
Fd = S2 × P4

In the second diaphragm 35, since both forces are balanced (Fu = Fd), both equations are equal and are expressed as follows.
(S2-S3) * P2 + S3 * P3 + SP2 = S2 * P4
The balance formula P4 of the first diaphragm 30 is substituted here, and is expressed as follows.
(S2-S3) * P2 + S3 * P3 + SP2 = S2 * {P1- (SP1 / S1)}

Here, by making the area S3 of the flow opening 17 of the valve seat 16 extremely small, the fluid pressure P3 on the outflow portion 13 side applied to the second diaphragm 35 can be ignored. Therefore, the term including S3 and P3 is ignored, and the following equation is obtained.
S2 * P2 + SP2 = S2 * {P1- (SP1 / S1)}

In addition, since the effective pressure receiving area S1 of the first diaphragm 30 and the effective pressure receiving area S2 of the second diaphragm 35 are equal (S1 = S2), both S1 and S2 are replaced with a common “S” (S = S1 = S2), the following equation is obtained.
S * P2 + SP2 = S * P1-SP1
To summarize, the following formula is obtained.
S (P1-P2) = SP1 + SP2

Since the differential pressure (P1−P2) generated before and after the throttle portion 15 is expressed as “ΔP”, the above equation is as follows.
ΔP = {(SP1 + SP2) / S}

Assuming that the flow rate of the controlled fluid is “Q” and the flow coefficient set by the opening area of the throttle unit 15 is “A”, the difference between the throttle unit 15 of the flow control valve 10X as understood from the above formula. The pressure (ΔP) is determined by the sum of the spring load of the auxiliary spring and the spring load of the biasing spring (SP1 + SP2) and the effective pressure receiving area S (= S1 = S2) of the first diaphragm 30 and the second diaphragm 35. Therefore, since the flow rate (Q) of the fluid is determined by the differential pressure (ΔP), it is expressed by the following equation.
Q = A × √ (ΔP) (i)
= A × √ {(SP1 + SP2) / S}

  Therefore, the constant flow rate function unit CF of the flow control valve 10X changes the fluid flow rate (Q) by changing the differential pressure (ΔP) by adjusting the spring load of the auxiliary spring and the spring load of the biasing spring. It becomes possible. The adjustment of the spring load includes a method of changing the spring load by exchanging the spring itself, manually or by motor drive. For example, you may adjust the approaching amount at the time of attachment of the fixed guide part 40 fixed by screwing.

  The variable control function unit VFx, which is another feature of the flow control valve 10X, has a function of increasing or decreasing the opening amount (opening degree) of the throttle unit 15 between the first chamber 21 and the third chamber 26. . The variable control function unit VFx of the flow control valve 10X will be described with reference to FIG. 3, FIG. 6, FIG.

  In the flow control valve 10X of the illustrated embodiment, a control valve chamber 100 is formed in the main body block 11A. The control valve chamber 100 is a space that connects both of the fluid to be controlled that has flowed from the throttle portion 15 connected to the first chamber 21 to pass to the communication flow path 108 connected to the third chamber 26. . The control valve chamber 100 is provided with a throttle control valve body 120.

  Further, as shown in the enlarged view of the vicinity of the throttle control valve body 120 in FIG. 7, the portion where the throttle portion 15 is connected to the control valve chamber 100 is a throttle opening portion 18, and this throttle opening portion 18 is the throttle control valve body 120. Is the throttle valve seat 19 corresponding to The throttle valve seat 19 is the same plane as the bottom surface of the control valve chamber 100 on the main body block 11A side, and is formed flat. The throttle control valve body 120 has a diaphragm structure with a valve including a tip portion (seal portion) 121 facing the throttle valve seat 19, a throttle control valve thin film portion 123, a throttle control valve outer peripheral portion 124, and the like. In order to correspond to the flat shape of the throttle valve seat 19, the front end portion 121 of the throttle control valve body 120 is also formed in a flat plate shape and becomes a flat plate front end portion 122. The flat plate front end 122 has a diameter larger than the aperture diameter of the aperture opening 18. The throttle control valve outer peripheral portion 124 is tightly fitted between the main body block 11A and the housing block (housing block) 101 and fixed at a predetermined position.

  As in the embodiment, the reason why the throttle control valve body 120 and the throttle control valve body 120 are also the flat plate front end portion 122 is that the controlled fluid in a micro flow rate range of 150 mL / min or less, more preferably 5 to 20 mL / min or less. This is to cope with the flow rate control. For example, when miniaturizing a member in accordance with flow control in a minute flow rate range in a conventional needle valve, the valve element is likely to contact the valve seat side due to factors such as the tolerance of the member itself and shaft misalignment during manufacturing and assembly. Become. Then, the valve seat and the valve body are scraped, and the size of the opening of the valve seat may change to change the flow rate of fluid passing therethrough. On the other hand, as described in the illustrated embodiment, both the valve body side and the valve seat side are flattened to avoid the above-described problem. Of course, it is not desired to control the flow rate of the controlled fluid in the minute flow rate range, and when using it for normal flow rate control, an existing needle valve or the like can be used.

  The throttle control valve body 120 is joined to the piston joint 114 which is the lower end of the adjustment piston part 111 via the joint 125. For the sake of precise control of the tip 121 of the throttle control valve body 120, each is mechanically connected by screwing or the like. Air accumulated in the space behind the throttle control valve thin film portion 123 of the throttle control valve body 120 enters and exits through the breathing hole 109. For convenience of illustration, the end of the breathing hole 109 leads to the back side of the drawing (not shown).

  Returning to FIG. 3, as can be understood from FIG. 3, the variable control function unit VFx is provided with a throttle control valve advance / retreat means 110. The throttle control valve advance / retreat means 110 moves the throttle control valve body 120 forward and backward toward the throttle opening 18. In the variable control function unit VFx of the flow control valve 10X of the second embodiment shown in FIGS. 3 to 6, the throttle control valve advance / retreat means 110 is a motor 130.

  The adjustment piston part 111 with the piston part spring 112 is inserted into the accommodation space part 103 of the accommodation block 101 inserted into the main body blocks 11B and 11C, and the motor 130 is arranged on the upper side. A piston passive portion 113 at the upper end of the adjustment piston portion 111 is rotatably connected to a motor shaft (rotating shaft) 132 of the motor 130. And after accommodating each member, the seal block 102 is put on the accommodation block 101. The piston passive part 113 at the upper end of the adjustment piston part 111 is provided with a protrusion 115 for preventing the adjustment piston part 111 from rotating. And the adjustment piston part 111 is inserted in the accommodation groove part 107 by the side of the accommodation block 101. FIG.

  Any motor 130 may be used as long as the amount of advancement / retraction of the tip 121 (flat plate tip 122) of the throttle control valve body 120 can be accurately reproduced. For example, a known stepping motor or servo motor is preferably used. In addition, an ultrasonic motor may be used. The embodiment schematically illustrates a known stepping motor that rotates a motor shaft 132 by a driving unit 131 such as a stator and a rotor. Since members such as screws related to the rotation of the motor shaft 132 are self-evident, they are not shown. Control of the rotation amount of the motor 130 with respect to the drive unit 131 is executed through the calculation unit 7 and the control unit 8 connected to the wiring cable 133. These will be described later with reference to FIG. Various motors are also provided with an encoder or the like (not shown).

  The advance / retreat operation of the throttle control valve body 120 will be described with reference to FIGS. 3, 6, and 7. A state in which the opening (aperture amount) of the aperture opening 18 is large corresponds to FIGS. 3 and 7A. An appropriate distance is maintained between the tip 121 (flat plate tip 122) of the throttle control valve body 120 and the throttle valve seat 19.

  Next, the motor shaft 132 rotates by a predetermined amount in the drive unit 131 of the motor 130, and the adjustment piston unit 111 is pushed down via the motor shaft 132. Then, the throttle control valve body 120 moves forward in conjunction with the adjustment piston portion 111. As shown in FIGS. 6 and 7B, the tip 121 (flat plate tip 122) is closer to the throttle valve seat 19, and the opening (opening amount) of the throttle opening 18 is reduced. Thus, the flow rate of the controlled fluid that passes through the throttle portion 15 of the flow control valve 10X is suppressed.

  When the flow rate is increased again, the motor shaft 132 rotates in the reverse direction by a predetermined amount in the drive unit 131 of the motor 130, the adjustment piston unit 111 is pushed up via the motor shaft 132, and interlocked with the adjustment piston unit 111. The throttle control valve body 120 moves backward. The distal end portion 121 (flat plate distal end portion 122) is separated from the throttle valve seat 19 and returns to the distance shown in FIGS. 3 and 7A. In this way, by operating the drive unit 131 of the motor 130 in a timely manner, the throttle control valve body 120 can be moved back and forth to an optimal position, and the opening degree of the throttle opening 18 is adjusted to pass through the throttle unit 15. The increase / decrease adjustment of the flow rate of the fluid becomes easy.

The relationship between the flow rate (Q) of the fluid and the differential pressure (ΔP) is as in the above-described equation (i).
Q = A × √ (ΔP) (i)
In the equation (i), when the flow rate (Q) is to be increased or decreased by changing the differential pressure (ΔP), the flow rate (Q) changes by a power of 1/2 of the differential pressure (ΔP). For this reason, even if the amount of change in the differential pressure (ΔP) is changed, it is difficult to change the flow rate (Q) corresponding to the change in the differential pressure (ΔP). Further, adjustment of the differential pressure (ΔP) is not always easy because it involves adjustment of a spring and the like.

  However, in the equation (i), the flow rate (Q) is a simple proportional relationship with respect to the flow rate coefficient (A). Then, the flow rate (Q) can be effectively changed by changing the flow rate coefficient (A). That is, the matter corresponding to the increase / decrease of the flow coefficient (A) in the equation is the opening amount of the throttle opening 18.

  Therefore, the flow control valve 10X includes the variable control function unit VFx in addition to the constant flow function unit CF, so that the flow coefficient can be changed relatively easily. Therefore, a wider range of flow rate can be variably adjusted. Further, since the motor 130 is used for the throttle control valve advance / retreat means 110 that adjusts the opening degree of the throttle opening 18, the change to the target flow rate range can be easily made.

  FIG. 8 is a longitudinal sectional view of the flow control valve 10Y of the third embodiment. The flow rate control valve 10Y also has two parts, a constant flow rate function unit CF that assumes a constant flow rate function that makes the fluid flow rate constant, and a variable control function unit VFy that can be variably controlled in a desired flow rate range. The constant flow rate function unit CF in the flow rate control valve 10Y has the same configuration as the constant flow rate function unit of the flow rate control valves 10A and 10X described above. The description is abbreviate | omitted using the same code | symbol.

  The variable control function unit VFy of the flow control valve 10Y of the third embodiment is an example in which the advance / retreat adjusted pressure gas 150 is used as the throttle control valve advance / retreat means 110. The adjustment piston portion 111 is housed in the housing block 101 together with the piston portion spring 151 and connected and fixed to the seal block 102. The piston passive portion 113 has a T-shape in sectional view, and its edge is in contact with the inner wall 106 of the accommodation block 101. An inlet 104 is formed in the storage block 101 connected to the seal block 102. Reference numeral 105 denotes a breathing hole. The housing block 101 is in contact with the main body block 11B and the like. For this reason, the inflow port 104 and the breathing hole 109 are opened to the front side or the rear side of the paper surface so as not to contact the main body block 11B and the like.

  When the advance / retreat pressure gas 150 flows into the housing space 103 of the housing block 101 from the inlet 104, the adjustment piston 111 acts against the piston spring 112 in the direction of contracting the spring according to the inflow pressure. Then, in the illustrated example, since the throttle control valve body 120 is connected to the adjustment piston portion 111, the throttle control valve body 120 always moves away from the throttle valve seat 19 of the throttle opening 18. Conversely, when the throttle control valve body 120 is brought closer to the throttle valve seat 19, it is possible to reduce the inflow pressure of the advance / retreat adjusted pressure gas 150.

  The inflow pressure of the advance / retreat pressure gas 150 is adjusted by an electropneumatic converter (electropneumatic regulator) (not shown). The control of the electropneumatic converter will be described with reference to FIG. Since the flow control valve 10Y of the third embodiment uses the advance / retreat pressure gas 150 as the throttle control valve advance / retreat means 110, the advance / retreat amount of the throttle control valve body 120 can be adjusted quickly, and the responsiveness can be improved. .

  FIG. 9 is a longitudinal sectional view of the flow control valve 10Z of the fourth embodiment. In the flow rate control valve 10Z, there are a constant flow rate function unit CF having a constant flow rate function that makes the fluid flow rate of the same structure as the flow rate control valves 10A and 10X constant, and a variable control function unit VFz that can be variably controlled in a desired flow rate range. Has two sites. The constant flow rate function unit CF in the flow rate control valve 10Z has the same configuration as the constant flow rate function units of the flow rate control valves 10A and 10X described above. The description is abbreviate | omitted using the same code | symbol.

  The variable control function unit VFz of the flow control valve 10Z of the fourth embodiment is an example including a screw member (bolt member) 140 as the throttle control valve advance / retreat means 110. In the flow control valve 10Z, the throttle control valve body 120 is tightly attached to the main body block 11A by the seal block 102 and fixed at a predetermined position. Then, the adjustment piston part 111 is accommodated in the accommodation block 101 together with the piston part spring 112 and connected and fixed to the seal block 102. The screw groove 141 of the screw member 140 is inserted into the screw hole 142 of the housing block 101. Reference numeral 143 denotes a fixing nut.

  The piston passive portion 113 of the adjustment piston portion 111 is pushed against the piston portion spring 112 by the rotation (forward rotation) of the adjustment screw 141. As a result, the throttle control valve body 120 approaches the throttle valve seat 19 of the throttle opening 18. When the adjustment screw 141 is rotated in the reverse direction (reverse rotation), the piston spring 112 is extended, and the throttle valve seat 19 of the throttle opening 18 with the throttle control valve body 120 joined to the piston joint 114 of the adjustment piston 111. Separate from. In this way, a desired opening (amount of opening) of the aperture 18 can be obtained according to the rotation of the adjusting screw 141. By adopting the screw member 140 for the throttle control valve advance / retreat means 110, the members related to the opening degree adjustment can be simplified and the structure can be simplified.

  The flow control valve 10A of the first embodiment shown and described so far, and the flow control valves 10X, 10Y, and 10Z of the second to fourth embodiments are not limited to the above-described embodiments. A part of the configuration can be changed as appropriate without departing from the spirit of the invention.

  The flow control device of the present invention will now be described with reference to FIG. The flow rate control valve used in the flow rate control device is a flow rate control valve that includes the throttle control valve body advance / retreat means 110 in the flow rate control valve, and adjusts the opening of the flow path under the control of an external signal to vary the flow rate. . Hereinafter, the flow control valve 10 will be illustrated and described.

  The schematic diagram of FIG. 10 is a single wafer type substrate processing apparatus for processing silicon wafers W one by one. The silicon wafer W is placed on the rotating disk of the spin chuck 1. A processing liquid nozzle 2 that discharges the processing liquid is provided immediately above the silicon wafer W. A processing liquid for cleaning the silicon wafer or the like is supplied to the processing liquid nozzle 2 through the fluid pipe 3.

  The treatment liquid is a controlled fluid that has already been described with reference to the flow control valve, such as ultrapure water, hydrofluoric acid, hydrogen peroxide water, ammonia water, hydrochloric acid, or the like. Each controlled fluid is stored in the supply units 9A, 9B, and 9C for each type, and is supplied to the fluid mixing unit 4 through the fluid pipes 3a, 3b, and 3c corresponding to the respective supply units. The supplied controlled fluid is uniformly mixed in the fluid mixing unit 4 and supplied to the processing liquid nozzle 2 through the fluid pipe 3. The flow rate control devices 5A, 5B, and 5C that control the supply of the controlled fluid are connected to the fluid pipes 3a, 3b, and 3c as illustrated. Each flow control device corresponds to a supply part of a controlled fluid for each type.

  The flow rate control devices 5A, 5B, and 5C are provided with a flow rate control valve 10, a flow rate detection unit 6 for the controlled fluid, and a calculation unit 7. Furthermore, the control part 8 which produces | generates the signal which controls the throttle control valve body advancing / retreating means in a flow control valve is also provided. The flow rate control valve 10, the flow rate detection unit 6, the calculation unit 7, and the control unit 8 are connected by a signal line s. Therefore, taking the flow rate control device 5A as an example, the flow rate control valve 10 and the flow rate detection unit 6 are connected to a fluid pipe 3a between the controlled fluid supply unit 9A and the controlled fluid fluid mixing unit 4. . As in the illustrated flow control device, the member related to the flow control of the controlled fluid is only the flow control valve. For this reason, the whole apparatus can be miniaturized. Further, the number of members that come into contact with the controlled fluid is suppressed, and the cleanliness of the controlled fluid is easily maintained.

  As the flow control valve 10, any of the flow control valves 10X or 10Y of the second embodiment or the third embodiment described above may be used. The flow rate detection unit 6 is a known flow meter that detects the flow rate on the secondary side (downstream side) of the flow rate control valve 10. For example, a differential pressure flow meter, an ultrasonic flow meter, or the like. The calculation unit 7 is a known calculation device such as a microcomputer or a PLC (programmable logic controller). A signal for controlling the flow rate of the flow rate control valve 10 is generated according to an instruction from the outside or a change in the measured flow rate value of the controlled fluid detected by the flow rate detection unit 6.

  The control unit 8 is a pulse transmitter, a controller, a driver, or the like necessary for driving a stepping motor, a servo motor, or the like of the throttle control valve advance / retreat means. When the throttle control valve advance / retreat means is a pressurized gas, the control unit 8 is an electropneumatic converter, and the pressurized gas adjusted to a predetermined pressure is supplied from the control unit to the variable control function unit. The control unit 8 is indispensable when a motor or pressurized gas is used as the throttle control valve advance / retreat means in the flow control valve 10. In particular, it is important in specific operation control such as smooth control of the rotation amount of a motor that is a throttle control valve advance / retreat means or adjustment of supply pressure of pressurized gas.

  An example of a signal flow from the flow rate detection unit 6 to the flow rate control valve 10 is as follows. A change in the flow rate of the controlled fluid in the fluid piping is measured through the flow rate detection unit 6, and the signal is transmitted to the calculation unit 7. In the calculation unit 7, the optimum advance / retreat position of the throttle control valve body 120 is calculated so as to obtain the opening degree of the throttle opening 18 (throttle valve seat 19) corresponding to the change in flow rate. In addition, an operation signal for operating the motor is generated. Then, the operation signal is transmitted from the calculation unit 7 to the control unit 8. In the control unit 8, a pulse signal for specifically driving the motor is generated, and this pulse signal is converted into a motor driving current. The motor drive current is transmitted to a motor that is a throttle control valve advance / retreat means in the flow control valve 10. Therefore, the motor rotates by a specified amount. In this way, the throttle control valve body 120 advances and retracts the optimum amount with respect to the throttle opening 18.

  As understood from the signal flow from the flow rate detection unit 6 to the flow rate control valve 10, the calculation unit 7 performs feedback control based on the flow rate measurement value of the flow rate detection unit 6. Accordingly, in response to the flow rate change that has occurred on the secondary side (downstream side) of the flow rate control valve 10, the flow rate of the controlled fluid can be increased or decreased, and the controlled fluid can be circulated constantly at a constant flow rate. In particular, the flow control valve 10 can cope with a fluid in a minute flow range, and is convenient for precise control of the controlled fluid. Note that the calculation unit 7 and the control unit 8 may be integrated into a calculation control unit.

  The flow rate control valve disclosed in the present invention can realize a constant flow rate by reacting sensitively to a change in the pressure of the flowing fluid, and can maintain a higher fluid cleanliness. . At the same time, it has a function of changing the fluid flow rate range of the controlled fluid. In addition, the flow control device equipped with the flow control valve disclosed in the present invention can be reduced in size due to the integration of components. Therefore, it is convenient for applications requiring extremely precise flow rate control and high cleanliness in the semiconductor manufacturing field, fuel cell, and medical field.

5A, 5B, 5C Flow rate control device 6 Flow rate detection unit 7 Calculation unit 8 Control unit 10A, 10X, 10Y, 10Z Flow rate control valve 11 Valve body unit 11A, 11B, 11C, 11D Body block 12 Inflow unit 13 Outflow unit 15 Restriction unit 16 valve seat 17 outflow opening 18 throttling opening 19 throttling valve seat 20 inflow side chamber 21 first chamber 22 second chamber 23, 28 accommodating portion 24, 29 narrow portion 25 outflow side chamber 26 third chamber 27 fourth chamber 30 1st diaphragm 34 Movable shaft 35 2nd diaphragm 38 Valve body 40 Fixed guide part 45 Auxiliary spring 50 Movable guide part 53 Storage part 55 Energizing means 56 Energizing spring 60 Pressurized gas 62 Supply air inlet 65 Exhaust outlet 70 Between chambers Connection part 75 Connection pipe part 100 Control valve chamber 101 Housing block 102 Control block 108 communication flow path 110 throttle control valve advance / retreat means 111 adjustment piston part 120 throttle control valve element 121 tip (seal part)
122 flat plate tip 130 motor 140 screw member 150 advance / retreat pressure gas 155 electropneumatic converter (electropneumatic regulator)
CF Constant flow rate function unit VFx, VFy, VFz Variable control function unit Fm Controlled fluid

Claims (10)

A throttle portion provided in a flow path between an inflow side chamber connected to the inflow portion of the controlled fluid and an outflow side chamber connected to the outflow portion of the controlled fluid, and a valve seat formed in the outflow side chamber A valve body having
The fluid pressure in the first chamber is divided into a first chamber that is disposed in the inflow side chamber and that is in contact with the controlled fluid, and a second chamber that is on the back side of the first chamber and is not in contact with the controlled fluid. A first diaphragm for receiving pressure;
Disposed in the outflow side chamber is a third chamber that is in contact with the controlled fluid and a fourth chamber that is on the back side of the third chamber and is not in contact with the controlled fluid, and fluid pressure in the third chamber And a second diaphragm having a valve body that is constantly urged toward the fourth chamber by the urging means in the fourth chamber and that moves forward and backward with respect to the valve seat;
An inter-chamber connection for connecting the second chamber and the fourth chamber;
The first diaphragm is constantly pressurized to the first chamber side by the pressurized gas supplied into the second chamber, and the second diaphragm flows into the second chamber and then passes through the inter-chamber connecting portion. And constantly pressurized to the third chamber side by the pressurized gas flowing into the fourth chamber,
The forward and backward movements of the first diaphragm and the second diaphragm caused by pressure fluctuations before and after the throttle portion are transmitted to the diaphragms through the pressurized gas, and the valves are driven by the forward and backward movements of the first diaphragm and the second diaphragm. A flow rate control valve characterized in that the flow rate of the controlled fluid is kept constant by moving the body forward and backward with respect to the valve seat.   The flow control valve according to claim 1, wherein the biasing means is a biasing spring.   A throttle opening is formed in the throttle, and a throttle control valve that controls the flow rate of the controlled fluid that passes through the throttle by moving forward and backward with respect to the throttle opening, and the throttle control valve The flow control valve according to claim 1, further comprising a throttle control valve body advancing / retreating means for moving the valve back and forth.   The flow control valve according to claim 3, wherein the throttle control valve body advancing / retreating means is a motor.   The flow control valve according to claim 3, wherein the throttle control valve body advancing / retreating means is an advancing / retreating pressure gas.   The flow control valve according to claim 3, wherein the throttle control valve body advancing / retreating means is a screw member.   The flow control according to claim 3, wherein the throttle opening is formed as a flat throttle valve seat, and the tip of the throttle control valve body facing the throttle valve seat is also formed as a flat plate tip. valve. The flow rate control valve according to claim 3, a flow rate detection unit for a controlled fluid, and a calculation unit,
The flow rate control device, wherein the flow rate control valve and the flow rate detection unit are connected to a fluid pipe between a controlled fluid supply unit and a controlled fluid fluid mixing unit.   The flow control device according to claim 8, further comprising a control unit that generates a signal for controlling the throttle control valve body advancing / retreating means.   The flow rate control device according to claim 8, wherein the calculation unit performs feedback control based on a flow rate measurement value of the flow rate detection unit.

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