Flow control valve and flow control device

Abstract

To provide a versatile flow control valve that can be applied to flow control devices that control a wide range of fluid flow rates, from minute flow rates to large flow rates.SOLUTION: A flow control valve is composed of a valve body 10 having a valve function and a pipe connection part 5 having a communication passage 6 coaxially connected to a pipe 100 through which a fluid flows. The valve body 10 incorporates a linear motor 12 as an actuator for opening and closing a valve element 11. As the valve element 11 is in the form of a needle valve constituted by a tapered needle, and the needle 11 is configured to open and close a valve seat orifice 15 in a direction perpendicular to the axis of the communication passage 6 of the pipe connection part 5, it is applicable to a flow control device that controls a wide range of fluid flow rates, from minute flow rates to large flow rates.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a flow control valve and a flow control device, and more particularly to a flow control technology that is interposed in piping through which various fluids flow and controls the flow rate of the fluid. [Background technology]

[0002] 2. Description of the Related Art Various flow rate control devices have been developed and are widely used in various fields. The flow rate control devices are disposed in communication paths for various fluids to control the flow rate of the fluids.

[0003] For example, the flow control device disclosed in Patent Document 1 is suitable for controlling small gas flow rates, and as shown in FIG. 9(a), is composed of a gas flow meter a, a flow control valve b, and a control unit c, and is disposed in a pipe d through which gas flows.

[0004] The gas flow meter a measures the mass flow rate of the gas (oxygen) flowing through the pipe d, and is a thermal flow meter, with a sensor unit e provided in the pipe d and a bypass capillary tube f branching off from the pipe d, into which a portion of the gas flowing through the pipe d flows. Thermoresistors f1 and f2 are provided in the bypass capillary tube f. In addition, the flow control valve b is provided downstream of the gas flow meter a in the pipe d to control the flow rate of the gas flowing through the pipe d.

[0005] When gas flows through the bypass capillary tube f while current flows through the thermoresistors f1 and f2, heating them up (generating heat), a temperature difference occurs between the thermoresistors f1 and f2, and the resulting change in resistance is picked up by the bridge circuit g, and the total flow rate of the gas is detected based on the electric signal output through the amplifier h. This detection value is compared by the comparison and calculation circuit j with a setting signal from a setting device i with a preset flow rate, and the control unit c drives and controls the flow control valve b according to the measurement result of the gas flowmeter a, thereby controlling and adjusting the flow rate of the gas flowing through the pipe d to the preset flow rate. A solenoid valve or a piezoelectric valve is used as the flow control valve b.

[0006] Moreover, the flow control device disclosed in Patent Document 2 is suitable for controlling a large gas flow rate, and as shown in FIG. 9(b), is composed of a gas flow meter k, a flow control valve l, and a control unit m, and is disposed in a pipe d through which gas flows.

[0007] The flow control valve l comprises a hydraulic cylinder n as a hydraulic actuator and a valve body o that opens and closes the communication opening of the piping d by the hydraulic cylinder n, and a hydraulic pump p that is a hydraulic source for the hydraulic cylinder n is electrically connected to the control unit m.

[0008] The gas flow meter k measures the mass flow rate of the gas flowing through the pipe d, and may be, for example, a thermal flow meter similar to that disclosed in Patent Document 1.

[0009] Then, when the mass flow rate of the gas is measured by the gas flow meter k, The control section m drives and controls the flow control valve l in response to the measurement result of the gas flow meter k, thereby controlling and adjusting the flow rate of the gas flowing through the pipe d to a preset set flow rate. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2001-259039 A [Patent Document 2] Japanese Patent Application Publication No. 11-338548 Summary of the Invention [Problem to be solved by the invention]

[0011] However, the flow rate control devices disclosed in the above Patent Documents 1 and 2 each have the problems described below, and improvements thereon have been desired.

[0012] That is, in the flow control device of Patent Document 1, a solenoid valve or a piezo valve is used as the flow control valve b, but in the solenoid valve, the actuator that opens and closes the valve body is a solenoid, and in the piezo valve, the valve body is opened and closed by a piezo element as an actuator. Both of these actuators have a small reciprocating stroke for opening and closing the valve body, and the opening and closing forces are also relatively small, so they cannot be applied to control large flow rates of fluid.

[0013] On the other hand, in the flow control device of Patent Document 2, the flow control valve l is a hydraulic cylinder n hydraulically driven by an actuator that opens and closes the valve body, and the hydraulic drive circuit is complex and large, and the reciprocating stroke for opening and closing the valve body is also large. Therefore, unlike the gas flow control device of Patent Document 1, it cannot be applied to gas flow control of small or minute flow rates.

[0014] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and an object of the present invention is to provide a versatile flow control valve that can be applied to flow control devices that control a wide range of fluid flow rates, from minute flow rates to large flow rates.

[0015] Another object of the present invention is to provide a flow control device which is equipped with the above-mentioned flow control valve as a flow adjustment means, has a simple and compact structure for the valve body, and is suitable for controlling the flow rate of a wide range of fluids, from minute flow rates to large flow rates. [Means for solving the problem]

[0016] In order to achieve this object, the flow control valve of the present invention adjusts the flow rate of various fluids flowing through a pipe, and comprises a valve body having a valve function, and a pipe connection part having a communication passage coaxially connected to the pipe, the valve body has a built-in linear stepping motor as an actuator for opening and closing a valve body, and the valve body is in the form of a needle valve composed of a tapered needle, the linear stepping motor has a linear shaft journaled so as to be non-rotatable and reciprocatable in the axial direction, and a built-in feed screw mechanism for reciprocating the linear shaft in the axial direction, the built-in feed screw mechanism comprising a female screw portion formed on an inner diameter cylindrical surface of an internal rotor of the linear stepping motor, and a male screw portion formed on the linear shaft and engaged with the female screw portion so as to be capable of threading forward and backward, and the linear shaft is non-rotatably and reciprocally moved in the axial direction by the feed screw action of the built-in feed screw mechanism due to the rotation of the rotor. the needle is provided coaxially and integrally with the linear motion shaft of the linear motion stepping motor and moves back and forth without rotation in a direction perpendicular to the axis of the communication passage of the pipe connection part to open and close the valve seat orifice; a fluid flow passage from the pipe connection part to the inlet of the valve seat orifice is composed of an outer annular communication passage that communicates with the fluid flow passage inlet of the pipe connection part and extends to the cylindrical outer periphery of the valve seat orifice, an inner annular communication passage that communicates with the inlet of the valve seat orifice and extends to the cylindrical outer periphery of the valve seat orifice, and a plurality of small diameter communication passages that are connected to and communicate with the outer annular communication passage and the inner annular communication passage, and these small diameter communication passages are uniformly arranged extending radially from the inlet of the valve seat orifice, thereby ensuring a uniform and stable flow rate of the fluid flowing from the pipe connection part to the inlet of the valve seat orifice from a small flow rate to a large flow rate. the valve seat orifice is replaceably set to a plurality of types of valve seat orifices having diameters corresponding to a plurality of different flow rates of the fluid to be controlled, while the needle is set to a shape and size compatible with the different diameters of the plurality of types of valve seat orifices in common; the valve body comprises a valve body main part including the linear type stepping motor and the needle, and an orifice part including the valve seat orifice, and the orifice part is configured to be separable from the valve body main part; the above The valve body and the pipe connection part are integrally connected to each other so as to be separable from each other. It is characterized by:

[0019] As a preferred embodiment, the following configuration is adopted. ( 1) The orifice fluid flow passage from the inlet to the outlet of the valve seat orifice extends in a straight line with its axis perpendicular to the axis of the communication passage of the piping connection portion, and communicates with the fluid flow passage outlet of the piping connection portion in the vicinity of this orifice fluid flow passage.

[0025] ( 2 ) The feed screw mechanism is a ball screw mechanism.

[0028] Furthermore, the flow control device of the present invention is a device that is interposed in a pipe through which various fluids flow and controls the flow rate of the fluid, and is characterized in that it comprises a flow adjustment means for adjusting the flow rate of the fluid flowing through the pipe, a flow measurement means for measuring the flow rate of the fluid flowing through the pipe, and a control means for driving and controlling the flow adjustment means in accordance with the measurement result of the flow measurement means, and the flow adjustment means is composed of the flow control valve. Effect of the Invention

[0029] According to the flow control valve of the present invention, the valve body includes a valve function and a pipe connection portion including a communication passage coaxially connected to pipes through which various fluids flow. The valve body includes a built-in linear stepping motor as an actuator for opening and closing the valve body, and the valve body is in the form of a needle valve formed of a tapered needle. The linear stepping motor includes a linear shaft journaled so as to be non-rotatable and reciprocatable in the axial direction, and a built-in feed screw mechanism for reciprocating the linear shaft in the axial direction. The built-in feed screw mechanism includes a female screw portion formed on the inner diameter cylindrical surface of the internal rotor of the linear stepping motor, and a male screw portion formed on the linear shaft and engaged with the female screw portion so as to be capable of threadably advancing and retreating. The linear shaft reciprocates in the axial direction without rotating due to the feed screw action of the built-in feed screw mechanism caused by the rotation of the rotor. a connecting member for connecting the valve seat orifice to the inlet of the valve seat orifice, the connecting member being provided coaxially and integrally with the linear shaft of the linear stepping motor and reciprocating non-rotatably in a direction perpendicular to the axis of the communication passage of the pipe connection portion to open and close the valve seat orifice; a fluid flow passage from the pipe connection portion to the inlet of the valve seat orifice comprising an outer annular communication passage communicating with the fluid flow passage inlet of the pipe connection portion and extending to the cylindrical outer periphery of the valve seat orifice, an inner annular communication passage communicating with the inlet of the valve seat orifice and extending to the cylindrical outer periphery of the valve seat orifice, and a plurality of small diameter communication passages connected to and flowing through the outer annular communication passage and the inner annular communication passage, the small diameter communication passages extending radially from the inlet of the valve seat orifice being centered and evenly arranged, whereby a uniform and stable flow rate of the fluid flowing from the pipe connection portion to the inlet of the valve seat orifice is ensured from a minute flow rate to a large flow rate. the valve seat orifice is replaceably set to a plurality of types of valve seat orifices having diameters corresponding to a plurality of different flow rates of the fluid to be controlled, while the needle is set to a shape and size compatible with the different diameters of the plurality of types of valve seat orifices in common; the valve body comprises a valve body main part including the linear type stepping motor and the needle, and an orifice part including the valve seat orifice, and the orifice part is configured to be separable from the valve body main part; the above The valve body and the pipe connection part are integrally connected to each other so as to be separable from each other. As a result, the unique effects listed below can be obtained, and a flow control valve having a simple and compact structure for the valve body and applicable to flow control of a wide range of fluids, from minute flow rates to large flow rates, can be provided, making it highly versatile.

[0030] (1) The valve body having a valve function incorporates a direct-acting motor as an actuator for opening and closing the valve element, and the valve element is in the form of a needle valve composed of a tapered needle, so that the structure of the valve body is simple and compact.

[0031] (2) Since the actuator that opens and closes the valve body is a linear motor, the reciprocating stroke for opening and closing the valve body can be adjusted from small to large. In addition, since the valve body is composed of a tapered needle, the opening degree of the valve seat orifice (annular opening orifice) can be adjusted from small to large depending on the reciprocating stroke position of the needle relative to the valve seat orifice. This makes it possible to adjust the flow rate of fluids from small to large, and is applicable to flow rate control of a wide range of fluids from small to large flow rates.

[0032] (3) The needle is configured to open and close the valve seat orifice in a direction perpendicular to the axis of the fluid communication passage, and the fluid flow path from the piping connection part to the inlet of this valve seat orifice has a plurality of small diameter communication passages toward the inlet around the vicinity of the inlet of the valve seat orifice, and these small diameter communication passages extend radially and are evenly arranged from the inlet as a center. Therefore, even though the space for forming the fluid flow path is structurally narrow and restricted, a stable flow rate of fluid flowing to the inlet of the valve seat orifice can be ensured. As a result, in a configuration in which the needle opens and closes the valve seat orifice in a direction perpendicular to the fluid flow direction, the flow rate of fluid can be adjusted with high precision.

[0033] (4) The fluid flow path from the piping connection part to the inlet of the valve seat orifice is composed of an outer annular communicating passage that communicates with the fluid flow path inlet of the piping connection part and extends to the cylindrical outer periphery of the valve seat orifice, an inner annular communicating passage that communicates with the inlet of the valve seat orifice and extends to the cylindrical outer periphery of the valve seat orifice, and the plurality of small diameter communicating passages that are connected to and flow through the outer annular communicating passage and the inner annular communicating passage, so that the effect of (3) achieved by the arrangement of the plurality of small diameter communicating passages can be more reliably achieved.

[0034] (5) The valve seat orifices of multiple types, each having a diameter corresponding to a different flow rate of the fluid to be controlled, can be interchangeably set, while the needle is set to a shape and dimensions that can be commonly used for the different diameters of the multiple types of valve seat orifices, so that it can be appropriately and selectively used to control the flow rate of a wide range of fluids, from minute flow rates to large flow rates.

[0035] (6) The valve body comprises a valve body main part having the linear motor and needle, and an orifice part having the valve seat orifice. This orifice part is configured to be separable from the valve body main part. By adopting the configuration of (5) above for the needle and the valve seat orifice, a flow control valve can be constructed that can flexibly respond to the flow rate of the fluid to be controlled, and manufacturing costs and product costs can be reduced.

[0036] (7) The valve body and the piping connection portion are configured to be separably connected together, thereby facilitating disassembly and assembly of the flow control valve and facilitating maintenance. In addition, the orifice portion can be separated and replaced from the main portion of the valve body, making it possible to construct a flow control valve in which the effect of (6) above can be more effectively exerted.

[0037] (8) The flow control device of the present invention comprises a flow adjustment means for adjusting the flow rate of a fluid flowing through a pipe, a flow measurement means for measuring the flow rate of the fluid through the pipe, and a control means for driving and controlling the flow adjustment means in accordance with the measurement result of the flow measurement means. Since the flow adjustment means is composed of the flow control valve of the present invention, all of the effects enumerated in (1) to (7) above can be effectively exerted, and a flow control device suitable for controlling the flow rate of a wide range of fluids from minute flow rates to large flow rates can be provided. [Brief description of the drawings]

[0038] [Figure 1] 1 is a perspective view showing an external configuration of a flow control device according to the present invention; [Diagram 2] FIG. 2 is a schematic configuration diagram of the flow rate control device. [Diagram 3] FIG. 2 is a front cross-sectional view showing the internal configuration of the main components of the flow control device. [Figure 4] FIG. 4(a) shows an enlarged internal configuration of the connection portion between the valve body of the flow control valve and the piping connection portion, which constitute the main component of the same, and FIG. 4(b) is a plan sectional view taken along line BB in FIG. 4(a). [Diagram 5] FIG. 5 is a cross-sectional view for explaining the opening and closing operation of the needle and the valve seat orifice in the valve body, where FIG. 5(a) shows the valve seat orifice in a fully open state, and FIG. 5(b) shows the valve seat orifice in a fully closed state. [Figure 6] 4 is a front cross-sectional view showing the flow control valve in a state where a main part of the valve body and an orifice part of the valve body are separated. FIG. [Figure 7] FIG. 2 is a front cross-sectional view showing the flow control valve with the valve body and the pipe connection portion separated. [Figure 8] FIG. 2 is a block diagram showing a control configuration of the flow rate control device. [Figure 9] 9A and 9B show conventional flow control devices, in which FIG. 9A shows a device suitable for controlling a small gas flow rate, and FIG. 9B shows a device suitable for controlling a large gas flow rate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same reference numerals denote the same components or elements throughout the drawings.

[0040] A flow control device according to the present invention is shown in Figs. 1 to 8. Specifically, this flow control device 1 is a gas flow control device that is interposed in a pipe 100 (Fig. 2) through which various gases flow and controls the mass flow rate of the gas. As shown in Figs. 1 to 3, the flow control device is mainly composed of a flow control valve 2 as a flow adjustment means, a gas flow meter 3 as a flow measurement means, and a control unit (control means) 4.

[0041] The flow rate control device 1 of the illustrated embodiment has a unit structure that is disposed at an appropriate position in the piping 100 and used.

[0042] Specifically, a pipe connection part 5 which is connected in communication with the pipe 100 is in the form of a base block serving as an apparatus base, and the flow control valve 2 and the gas flow meter 3 are integrally assembled on this pipe connection part 5, with the gas flow meter 3 being disposed upstream and the flow control valve 2 being disposed downstream with respect to the gas flowing through the pipe 100. In addition, behind the gas flow meter 3 on the pipe connection part 5, a control board 80 incorporating various electronic circuits is provided in an upright position.

[0043] As shown in Figures 2 and 3, the piping connection part 5 has a communication passage 6 which is connected to a piping 100 through which gas flows, and the flow control valve 2 and the gas flow meter 3 are connected to this communication passage 6.

[0044] As shown in FIG. 2, the communication passage 6 comprises an upstream communication passage 7 that is connected to the upstream portion 100a of the piping 100, and a downstream communication passage 8 that is connected to the downstream portion 100b of the piping 100, and these upper and lower communication passages 7, 8 are connected to each other via the flow control valve 2 that adjusts and controls the gas flow rate.

[0045] The upstream communicating passage 7 has an inflow side communicated with the upstream portion 100a of the pipe 100, and an outflow side communicated with the flow rate adjustment portion 2a of the flow control valve 2. A connection orifice 9a for diverting the gas flowing through the upstream communicating passage 7 to the sensor portion 60 of the gas flow meter 3, and a connection orifice 9b for returning the gas from the sensor portion 60 to the upstream communicating passage 7 are provided midway through the upstream communicating passage 7.

[0046] 3, a laminar flow element 65 is fitted inside the upstream communicating passage 7 via a laminar flow element holder 66. This laminar flow element 65 has a laminar flow effect of making the gas flowing through the upstream communicating passage 7 into a laminar flow, and a function of diverting this gas to the bypass thin tube 62 of the sensor section 60 at a predetermined diversion ratio.

[0047] The downstream communication passage 8 has an inflow side communicated with the flow rate adjustment section 2a of the flow control valve 2, and an outflow side communicated with the downstream portion 100b of the pipe 100. As will be described later, the downstream communication section 8 of the pipe connection section 5 forms a part of the gas flow path in the flow rate adjustment section 2a of the flow control valve 2, and thus the pipe connection section 5 constitutes a main component of the flow control valve 2.

[0048] The flow control valve 2 adjusts the mass flow rate of gas flowing through the piping 100, and specifically, is composed of a valve body 10 having a valve function and the piping connection part 5 that is connected in communication with the piping 100 as its main parts.

[0049] As shown in Figures 2, 3 and 4, the valve body 10 incorporates a linear motor 12 as an actuator for opening and closing the valve element 11, and the valve element 11 is in the form of a small and simple needle valve constituted by a tapered needle.

[0050] In the illustrated embodiment, a linear stepping motor is preferably used as the linear motor 12, and this stepping motor 12 is electrically connected to the control unit 4 via a motor driver 71 (FIG. 8) on a motor driver board 70 provided on the top (upper end) of the valve body 10.

[0051] In this embodiment, since the motor driver board 70 is provided at the top of the valve body 10, the installation space for the motor driver board 70 can be freely secured. This makes it possible to separate the functions of the flow control valve 2 and the gas flow meter 3 into separate and independent forms, which has the advantage of facilitating maintenance.

[0052] The valve body 10 in the illustrated embodiment has a basic configuration in which a needle 11 moves to open and close in a direction perpendicular to the flow direction of the gas flowing through the piping 100. Specifically, the needle 11 is configured to open and close a valve seat orifice 15 in a direction perpendicular to the axis of the communicating passage 6 of the piping connection part 5.

[0053] The valve body 10 comprises a valve body main part 20 having the linear stepping motor 12 and the needle 11, and an orifice part 21 having the valve seat orifice 15. As a characteristic configuration of the present invention, as described later, the orifice part 21 is configured to be separable from the valve body main part 20 (FIG. 6), and further, the valve body 10 and the piping connection part 5 are configured to be separably connected together (FIG. 7).

[0054] In the valve body main portion 20, the stepping motor 12 is integrally held and fixed to a valve housing 27 via upper and lower motor holders 25, 26, and is built in the valve housing 27 coaxially.

[0055] The upper motor holder 25 is integrally fitted and fixed to the valve housing 27 by a fastening means (not shown) such as a tightening screw, and is structured to prevent the stepping motor 12 from rotating by a rotation stop screw or the like (not shown).

[0056] In addition, the lower motor holder 26 is integrally fitted and fixed to the valve housing 27 by a fixing means such as a tightening screw (not shown), and its lower end portion (tip portion) 26a protrudes to the lower side (tip side) of the valve housing 27, and this lower end portion 26a of the lower motor holder 26 is structured to be fitted and fixed to the fitting connection portion 29 of the piping connection portion 5.

[0057] When the lower motor holder 26 is fitted and fixed to the fitting connection portion 29 of the piping connection portion 5 and the valve body 20 is integrally connected to the piping connection portion 5, the axes of the stepping motor 12 and needle 11 of the valve body 20 are positioned and fixed so as to be perpendicular to the axis of the communicating passage 6 of the piping connection portion 5.

[0058] In addition, a valve chamber 28 is formed between the lower end portion 26a of the lower motor holder 26 and the orifice portion 21, and the tip tapered portion 11a of the needle 11 faces this valve chamber 28, as described below.

[0059] In FIG. 3, 31, 32 and 33 respectively denote O-rings for maintaining the airtightness of these parts, thereby ensuring the airtightness and sealing of the storage space surrounding the stepping motor 12 and the needle 11.

[0060] As described above, the linear stepping motor 12 which opens and closes the needle 11 is in the form of a built-in motor integrally provided within the valve housing 27, and its linear shaft 35 is adapted to reciprocate in the axial direction by the built-in feed screw mechanism 36, thus providing a space-saving structure.

[0061] As shown generally in FIG. 2, the built-in feed screw mechanism 36 comprises a female threaded portion 36a formed on the inner diameter cylindrical surface of a rotor 37 of the stepping motor 12, and a male threaded portion 36b formed on the linear motion shaft 35 and engaged with the female threaded portion 36a so as to be capable of threadably advancing and retreating, and the feed screw action of the feed screw mechanism 36 caused by the rotation of the rotor 37 causes the linear motion shaft 35 to reciprocate in the up and down axial directions.

[0062] In relation to this, the linear motion shaft 35 has its two side shaft portions 35a and 35b sandwiched between the male thread portion 36b, which are supported by bearings 38, 39 of the stepping motor 12 so as to be able to slide back and forth in the axial direction, and is prevented from rotating by a rotation prevention structure (not shown).

[0063] Then, due to the feed screw action of the feed screw mechanism 36, the linear motion shaft 35 is slidably guided by the bearings 38 and 39, and moves in the vertical axial direction. Non-rotating It is configured to perform a linear reciprocating motion.

[0064] As shown in Figure 5, The lower end (tip) of the linear motion shaft 35 35a The needle 11 as a valve body is integrally formed or connected coaxially to the valve body. , are provided integrally. In relation to this, a guide sleeve 40 that slides and guides the needle 11 is provided on the lower motor holder 26, and the tapered tip portion 11a of the needle 11 faces the valve chamber 28 via this guide sleeve 40. Reference numeral 41 denotes an O-ring for maintaining airtightness of the sliding portion between the guide sleeve 40 and the needle 11.

[0065] The needle 11 moves vertically up and down by the vertical reciprocating motion of the linear motion shaft 35 driven by the stepping motor 12. Non-rotating It moves back and forth linearly, and its tip tapered portion 11 a opens and closes the valve seat orifice 15 in a direction perpendicular to the axis of the communication passage 6 of the pipe connection portion 5 .

[0066] Specifically, the needle 11 moves downward and its tip tapered portion 11a comes into close contact with the valve seat orifice 15 to enter a closed state (see FIG. 5(a)), and conversely, the needle 11 moves upward and its tip tapered portion 11a moves away from the valve seat orifice 15 to enter an open state (see FIG. 5(b)). Depending on the vertical axial position of the tip tapered portion 11a of the needle 11 relative to the valve seat orifice 15, the opening degree of the valve seat orifice 15 changes, and the mass flow rate of the gas flowing through the downstream communication passage 8 of the pipe connection portion 5 and further through the pipe 100 is adjusted.

[0067] The valve chamber 28, which forms an operating boundary space between the needle 11 and the valve seat orifice 15, regulates a uniform and stable flow rate of the gas flowing from the upstream communication passage 7 of the piping connection portion 5 into the valve body 10 in order to perform high-precision gas flow rate regulation by the needle 11 and the valve seat orifice 15. From small flow rates to large flow rates It is necessary to ensure that the axes of the needle 11 and the valve seat orifice 15 are perpendicular to the axis of the communicating passage 6 of the pipe connection part 5. Therefore, the flow of gas flowing through the upstream communicating passage 7 is bent vertically through the valve chest 28, and the space for forming the gas flow passage at this portion is structurally narrow, restricted, and complex.

[0068] The inventors have attempted to obtain a uniform and stable flow rate of gas flowing from the upstream communication passage 7 of the pipe connection portion 5 to the valve chamber 28 of the valve body 10 in such a structurally narrow and complicated space in which the gas flow passage is formed. From small flow rates to large flow rates As a result of various tests and researches conducted to ensure this, the following gas flow path 45 was completed.

[0069] That is, referring to Figure 4, the fluid flow path 45 from the upstream communicating passage 7 of the piping connection part 5 to the inlet 15a of the valve seat orifice 15 (i.e., the valve chamber 28) has a plurality of (four in the illustrated example) small diameter communicating passages 47, 47, ... leading to the inlet 15a around the vicinity of the inlet 15a of the valve seat orifice 15, as shown in Figures 4(a) and 4(b), and these small diameter communicating passages 47, 47, ... extend radially in the horizontal direction from the inlet 15a as a center and are evenly arranged in the circumferential direction (equally spaced into four).

[0070] The specific configuration of the gas flow path 45 in the illustrated embodiment is composed of an outer annular communicating passage 46 that communicates with the gas flow path inlet (fluid flow path inlet) 45a of the upstream communicating passage 7 and extends around the entire cylindrical outer periphery of the valve seat orifice 15, an inner annular communicating passage 48 that communicates with the inlet 15a (valve chamber 28) of the valve seat orifice 15 and extends around the entire cylindrical outer periphery of the valve seat orifice 15, and four small diameter communicating passages 47, 47, ... that are connected to and communicate with the outer annular communicating passage 46 and the inner annular communicating passage 48.

[0071] In this case, the connection between the gas flow passage inlet 45a from the upstream communication passage 7 and the outer annular communication passage 46 is formed by three straight small diameter communication passages 49, 49, 49, and a predetermined flow rate of gas is ensured at this portion. This is because, in the illustrated embodiment, the connection portion is structurally unable to ensure a sufficient opening cross-sectional space for forming a single communication passage. Therefore, if a sufficient opening cross-sectional space can be ensured, a single communication passage (not shown) having the total opening cross-sectional area of ​​the three straight small diameter communication passages 49, 49, 49 may be formed.

[0072] The total opening cross-sectional area of ​​the three straight small diameter communication passages 49, 49, 49 is set to be equal to or larger than the opening cross-sectional area of ​​the valve seat orifice 15 (i.e., the opening cross-sectional area of ​​the orifice gas flow passage 50) and equal to or smaller than the opening cross-sectional area required for the gas flow passage outlet 8a from the valve seat orifice 15 to the downstream communication passage 8. With this configuration, a pressure difference is generated between the gas flow passage inlet 45a and the gas flow passage outlet 8a, making it possible to control the mass flow rate of the gas flowing through the piping 100 with high precision.

[0073] Furthermore, with regard to the three straight small diameter communicating passages 49, 49, 49 which form the connection between the gas flow path inlet 45a from the upstream communicating passage 7 and the outer annular communicating passage 46, the total opening cross-sectional area of ​​these straight small diameter communicating passages 49, 49, 49 is determined by the flow rate desired to flow through the gas flow path 45.

[0074] In other words, the total opening cross-sectional area of ​​the three straight small diameter communicating passages 49, 49, 49 is set equal to the opening cross-sectional area of ​​the required input pipe of the gas flow path 45. In the illustrated example, however, since three straight small diameter communicating passages 49, 49, 49 with the same opening cross-sectional area are formed, the opening cross-sectional area of ​​each of the three straight small diameter communicating passages 49, 49, 49 is set to 1 / 3 of the opening cross-sectional area of ​​the required input pipe of the gas flow path 45.

[0075] In addition, the orifice portion 21 having the above-mentioned valve seat orifice 15 is designed to have a valve seat orifice 15 corresponding to the standard dimensions, etc., in relation to the piping 100 to which it is applied, i.e., the piping connection portion 5.

[0076] That is, in the orifice portion 21, an orifice gas flow passage (orifice fluid flow passage) 50 is formed from the inlet 15a to the outlet 15b of the valve seat orifice 15, and this orifice gas flow passage 50 extends in a straight line whose axis is perpendicular to the axis of the downstream side communicating passage 8 of the pipe connection portion 5, and communicates with a gas flow passage outlet (fluid flow passage outlet) 8a of the downstream side communicating passage 8 in the vicinity of this orifice gas flow passage 50. In the illustrated example, a gas flow space (fluid flow space) 51 is provided between the outlet of the orifice gas flow passage 50, i.e., the outlet 15a of the valve seat orifice 15, and the gas flow passage outlet 8a of the downstream side communicating passage 8.

[0077] By adopting such a structure of the orifice portion 21, that is, by setting the axis from the inlet 15a to the outlet 15b of the valve seat orifice 15 perpendicular to the axis of the communicating passage 6 of the connecting piping, and by making the flow path forming portion from the valve seat orifice 15 to the gas flow path outlet 8a to the downstream communicating passage 8 into an integral structure, in the gas flow path from the inlet 15a of the valve seat orifice 15 to the downstream communicating passage 8 of the piping connection portion 5, the gas flow path outlet 8a to the downstream communicating passage 8 is positioned at a lower position than the outlet 15a of the valve seat orifice 15, as shown in Figure 4(a).

[0078] As described above, gas flow paths 45, 50, 51 are formed from the upstream communicating path 7 of the pipe connection part 5 through the flow rate adjustment part 2a of the valve body 10 to the downstream communicating path 8, and as shown in Figures 4(a) and 4(b), gas flows through these gas flow paths 45, 50, 51 as indicated by the arrows. This ensures a uniform and stable flow rate of gas flowing through the valve seat orifice 15, and enables highly accurate gas flow rate adjustment by the needle 11 and the valve seat orifice 15.

[0079] The flow control valve 2 of this embodiment is configured to be able to appropriately and selectively control the flow rate of gas over a wide range from a minute flow rate to a large flow rate, as described below.

[0080] That is, in this embodiment, a plurality of types of valve seat orifices 15, 15, ... (a plurality of types of orifice portions 21, 21, ... each including a plurality of types of valve seat orifices 15, 15, ...) having diameters corresponding to a plurality of different flow rates of the gas to be controlled are replaceably set, while the needle 11 is set to a shape and dimensions compatible with the different diameters of the plurality of types of valve seat orifices 15, 15, .... Therefore, by applying to the needle 11 the orifice portion 21 including the valve seat orifice 15 having a diameter corresponding to the flow rate of the gas to be controlled, it is possible to appropriately and selectively control the flow rate of the gas over a wide range from a minute flow rate to a large flow rate.

[0081] For this purpose, as described above, the orifice portion 21 having the valve seat orifice 15 is configured to be separable from the valve body main portion 20 as shown in FIG.

[0082] 6, the orifice portion 21 is structured so that its cylindrical body 21a is coaxially inserted into the valve chamber forming recess 55 of the lower motor holder 26 and the fitting flange portion 21b is abutted against and supported by the fitting shoulder portion 26b of the lower motor holder 26, and is assembled and fixed integrally, removably and replaceably to the lower end portion 26a of the lower motor holder 26 by a fixing means such as a tightening screw (not shown). 56 denotes an O-ring for maintaining airtightness between the valve chamber forming recess 55 and the cylindrical body 21a when the lower motor holder 26 and the orifice portion 21 are assembled and fixed integrally.

[0083] In this integrally assembled and fixed state, the valve chamber 28 and the inner annular communication passage 48 (FIG. 4) are formed between the cylindrical inner circumferential surface 55a of the valve chamber forming recess 55 and the cylindrical main body 21a of the orifice portion 21.

[0084] Furthermore, the flow control valve 2 of this embodiment has a structure that allows for easy disassembly and assembly.

[0085] That is, in this embodiment, as described above, the valve body 10 and the pipe connection portion 5 are integrally connected to each other so as to be separable from each other, as shown in FIG.

[0086] 7, the pipe connection part 5 is provided with a fitting connection part 29 that opens upward, and the tip part of the valve body 10, i.e., the integral assembly part of the lower end part 26a of the lower motor holder 26 and the orifice part 21 is fitted and connected to this fitting connection part 29 from above, and with the abutment engagement part 26c of the lower motor holder 26 abutting and engaging with the abutment shoulder part 5a of the pipe connection part 5, the valve body 10 and the pipe connection part 5 are integrally and separably connected and fixed by a fixing means such as a tightening screw (not shown). 57 denotes an O-ring for maintaining airtightness between the fitting connection part 29 and the fitting flange part 21b of the orifice part 21 when the valve body 10 and the pipe connection part 5 are integrally connected and fixed.

[0087] In this integrally connected and fixed state, an outer annular communicating passage 46 (Figure 4) of the gas flow passage 45 is formed between the cylindrical inner surface 29a of the fitting connection portion 29 and the cylindrical outer surface 26d of the lower end portion 26a of the lower motor holder 26.

[0088] The gas flow meter 3 measures the mass flow rate of the gas flowing through the above-mentioned piping 100, and specifically consists of a thermal mass flow meter, and its main parts are the upstream communicating passage 7 of the piping connection part 5, a sensor part 60, and a flow measuring part 61.

[0089] 2 and 3, the sensor section 60 is a thermal sensor section, and includes a bypass thin tube 62 consisting of a capillary tube branched off from the piping 100 through which the gas flows, and is configured so that a part of the gas flowing through the piping 100 flows into the bypass thin tube 62. Two wire-wound heaters (heating resistance wires) 63a and 63b are provided on the upstream and downstream sides of the bypass thin tube 62.

[0090] The bypass capillary tube 62 has an inlet 62a and an outlet 62b which are connected to the upstream communicating passage 7 via connecting orifices 9a, 9b provided in the middle of the upstream communicating passage 7, and the gas flowing through the upstream communicating passage 7 is made into a laminar flow by the laminar flow element 65 and flows into the bypass capillary tube 62 from the inlet 62a, and is returned to the upstream communicating passage 7 from the outlet 62b.

[0091] The flow rate measurement unit 61 is a part that supplies power to the two winding heaters 63a, 63b of the sensor unit 60 and calculates the mass flow rate of the gas by calculating the measurement signal input from the sensor unit 60. As shown in FIG. 2, the flow rate measurement unit 61 is composed of a bridge circuit 65, an amplifier circuit 66, and a calculation unit 67, and is incorporated on the control board 80 (FIG. 1).

[0092] When the flow rate measuring unit 61 supplies power to the winding heaters 63a, 63b of the sensor unit 60 and these two winding heaters 63a, 63b are heated (generate heat), the upper and lower winding heaters 63a, 63b are balanced at the same temperature if no gas flows through the bypass thin tube 62, but if gas flows through the bypass thin tube 62, the upstream winding heater 63a loses heat to the flowing gas, and conversely, the downstream winding heater 63b rises in temperature due to the heat lost from the upstream winding heater 63a by the gas. This causes a temperature difference between the winding heaters 63a, 63b acting as a temperature sensor, and the resulting change in resistance (temperature change) is converted into an electric signal (voltage difference) by the bridge circuit 65, and this electric signal is amplified by the amplifier circuit 66 and sent to the calculation unit 67 as a measurement signal corresponding to the gas flow rate. This calculation unit 67 compares the measurement signal from the amplifier circuit 66 with a setting signal previously input from a flow rate setting unit 85 to calculate the flow rate, and sends the calculation result to the control unit 44 and displays it on the display unit 84.

[0093] The control unit 4 controls the drive of the flow control valve 2 in response to the measurement result of the gas flow meter 3, and is incorporated on a control board 80 provided in the pipe connection unit 5.

[0094] Specifically, the control unit 4 is composed of a microcomputer consisting of a CPU, ROM, RAM, and I / O ports, and has programs and the like built in for executing the flow rate adjustment process of the flow rate control valve 2 according to the measurement results from the flow rate measurement unit 61 of the gas flow meter 3, and various information necessary for driving the stepping motor 12, which is the actuator of the flow rate control valve 2, is input and set in advance as data or appropriately and selectively via a keyboard, etc. For example, the gas flow rate to be flowed through the target piping 100 is input and set appropriately via a flow rate setting unit 85 (FIGS. 2 and 8) consisting of an operation panel, which is an external setting input means.

[0095] Furthermore, the gas flow meter 3 of this device is optionally provided with a pressure sensor (not shown) that detects the pressure of the gas. This pressure sensor detects the pressure of the gas flowing through the upstream portion 100b of the pipe 100 (FIG. 2).

[0096] The detection result of this pressure sensor is sent from a pressure measuring unit 86 (FIG. 8) to the control unit 4 and is also displayed on the display unit 84.

[0097] The flow rate control valve 2 performs highly accurate gas flow rate control by the control unit 4, taking into account the pressure in addition to the measured mass flow rate of the gas.

[0098] In the gas flow control device 1 configured as described above, the mass flow rate of the gas flowing through the piping 100 is measured by the gas flow meter 3, and in accordance with the measurement result, the control unit 4 drives and controls the direct-acting stepping motor 12, which is the actuator of the flow control valve 2, to open and close the needle 11, which is the valve body, relative to the valve seat orifice 15, thereby automatically adjusting the mass flow rate of the gas flowing through the piping 100 to a preset value.

[0099] As described above in detail, the flow control valve 2 of this embodiment provides the following unique effects.

[0100] (a) The valve body 10 having a valve function incorporates a direct-acting stepping motor 12 as an actuator for opening and closing the valve element 11, and the valve element 11 is in the form of a needle valve composed of a tapered needle. Therefore, the structure of the valve body 10 is simple and small.

[0101] (b) Since the actuator for opening and closing the needle (valve body) 11 is a linear stepping motor 12, the reciprocating stroke for opening and closing the needle 11 can be adjusted from small to large, and since the needle 11 has a tapered shape, the opening degree (annular opening orifice) of the valve seat orifice 15 can be adjusted from small to large depending on the reciprocating stroke position of the needle 11 relative to the valve seat orifice 15.As a result, it is possible to adjust a wide range of gas flow rates from small to large, and it is applicable to flow control of gas from small flow rates to large flow rates.

[0102] (c) The needle 11 is configured to open and close the valve seat orifice 15 in a direction perpendicular to the axis of the gas communication passage, and the gas flow passage 45 from the piping connection part 5 to the inlet 15a of the valve seat orifice 15 has a plurality of small diameter communication passages 47, 47, ... leading to the inlet 15a around the vicinity of the inlet 15a of the valve seat orifice 15, and these small diameter communication passages 47, 47, ... are evenly arranged extending radially from the inlet 15 as a center. As a result, even though the formation space of the gas flow passage 45 is structurally narrow and restricted, a stable flow rate of gas flowing to the inlet 15a of the valve seat orifice 15 can be ensured. As a result, in a configuration in which the needle 11 opens and closes the valve seat orifice 15 in a direction perpendicular to the gas flow direction, the gas flow rate can be adjusted with high precision.

[0103] (d) The gas flow path 45 from the pipe connection part 5 to the inlet 15a of the valve seat orifice 15 is composed of an outer annular communicating passage 46 that communicates with the gas flow path inlet 45a of the pipe connection part 5 and extends around the entire circumference of the cylindrical outer periphery of the valve seat orifice 15, an inner annular communicating passage 48 that communicates with the inlet 15a of the valve seat orifice 15 and extends around the entire circumference of the cylindrical outer periphery of the valve seat orifice 15, and the plurality of small diameter communicating passages 47, 47, ... that are connected to and communicate with the outer annular communicating passage 46 and the inner annular communicating passage 48, so that the above-mentioned effects obtained by the arrangement of the plurality of small diameter communicating passages 47, 47, ... can be more reliably achieved.

[0104] (e) The multiple types of valve seat orifices 15, 15, ... (in the illustrated example, multiple types of orifice portions 21, 21, ... each having a diameter corresponding to a multiple different flow rates of the gas to be controlled) are replaceable, while the needle 11 is set to a shape and dimensions that can be commonly used for the different diameters of the multiple types of valve seat orifices 15, 15, .... This makes it possible to appropriately and selectively control the flow rate of a wide range of fluids, from minute flow rates to large flow rates.

[0105] (f) The valve body 10 comprises a valve body main part 20 having the linear stepping motor 12 and the needle 11, and an orifice part 21 having the valve seat orifice 15. This orifice part 21 is configured to be separable from the valve body main part 20. Therefore, by adopting the configuration of (e) above for the needle 11 and the valve seat orifice 15, it is possible to construct a flow control valve that can flexibly respond to the flow rate of the gas to be controlled, and it is possible to reduce manufacturing costs and product costs.

[0106] (g) The valve body 10 and the piping connection portion 5 are configured to be separably connected together, thereby facilitating disassembly and assembly of the flow control valve 2 and facilitating maintenance. In addition, the orifice portion 21 can be separated and replaced from the valve body main portion 20, thereby enabling the construction of a flow control valve 2 in which the effect of (f) above can be more effectively exerted.

[0107] Furthermore, according to the flow control device 1 of this embodiment, by being equipped with the above-mentioned flow control valve 2, all of the above-mentioned unique effects of this flow control valve 2 can be exerted, and a flow control device 1 suitable for flow control of a wide range of fluids, from minute flow rates to large flow rates, can be provided.

[0108] It should be noted that the above-described embodiment merely indicates a preferred embodiment of the present invention, and the present invention is not limited to this embodiment. Various design changes are possible within the scope of the present invention. For example, the following modifications are possible.

[0109] (1) In the flow control valve 2 of the illustrated embodiment, the gas flow path 45 from the piping connection part 5 to the inlet 15a of the valve seat orifice 15 is configured such that, around the vicinity of the inlet 15a of the valve seat orifice 15, four small diameter communicating passages 47, 47, ... leading to the inlet 15a are evenly arranged radially from the inlet 15a as shown in FIG. 4(b). However, the number of these small diameter communicating passages 47 is not limited to the illustrated example and can be increased or decreased as appropriate depending on the flow rate of the gas to be controlled, etc.

[0110] (2) In the flow control valve 2 of the illustrated embodiment, in order to be able to appropriately and selectively control the flow rate of gas over a wide range from minute flow rates to large flow rates, multiple types of orifice sections 21, 21, ... are prepared, each of which has multiple types of valve seat orifices 15, 15, ... having diameters corresponding to the multiple different flow rates of the gas to be controlled. However, it is also possible to configure a single orifice section 21 so that the diameter of the valve seat orifice 15 can be adjusted to correspond to the multiple different flow rates of the gas to be controlled.

[0111] For example, although not specifically shown, an orifice diameter defining part that defines the diameter (inlet diameter) of the inlet 15a of the valve seat orifice 15 is configured to be removable and replaceable at the top (tip) of the cylindrical body 21a of a single orifice portion 21 by a detachable structure such as a screw-fitting attachment, and multiple types of the above-mentioned orifice diameter defining parts having inlet diameters corresponding to multiple different flow rates of the gas to be controlled are prepared.

[0112] (3) In the illustrated embodiment, the specific structures of the separable configuration of the orifice portion 21 relative to the valve body main portion 20 (FIG. 6) and the separable integral connection configuration of the valve body 10 and the piping connection portion 5 (FIG. 7) are not limited to the illustrated embodiment, and may be appropriately modified in design as long as similar functions are achieved.

[0113] (4) In the illustrated embodiment, a linear stepping motor 12 is provided as a linear motor for opening and closing the needle 11. However, depending on the purpose, it is also possible to provide a linear servo motor (not shown) instead of this linear stepping motor 12.

[0114] (5) The gas flow meter 3 in the illustrated embodiment employs a thermal sensor using two winding heaters 63a, 63b as its sensor unit 60. However, for example, as disclosed in JP 2016-42047 A, a thermal sensor (not shown) equipped with a thermal MEMS (Micro-Electro-Mechanical-Systems) flow sensor chip that detects gas flow may also be employed.

[0115] (6) The flow control valve 2 in the illustrated embodiment is employed in a gas flow control device 1 that controls the mass flow rate of a gas. However, the flow control valve of the present invention is not limited to such a gas flow control device 1 and can be widely applied to flow control devices that control the flow rate of a fluid flowing through various fluid passages. For example, the flow control valve of the present invention can be applied to a liquid flow control device that controls the flow rate of a liquid. In this case, various liquid flow meters are used as flow measurement means for measuring the flow rate of the fluid. [Explanation of symbols]

[0116] 1 Flow control device 2 Flow control valve (flow adjustment means) 2a Flow rate adjustment part of flow control valve 3 Gas flow meter (flow measurement means) 4 Control section (control means) 5 Pipe connection 6 Pipe connection passage 7 Upstream communication path 8 Downstream communication path 10 Valve body 11 Needle (valve body) 11a Tapered tip of needle 12. Linear stepping motor (linear motor) 15 Valve seat orifice 15a Inlet of valve seat orifice 20 Valve body main part 21 Orifice section 28 Valve chamber 35 Linear axis 45 Gas flow path (fluid flow path) 45a Gas flow path inlet (fluid flow path inlet) 46 Outer annular passage 47 Small Path Connecting Passage 48 Inner annular passage 49 Straight small diameter communication path 59 Orifice gas flow passage (orifice fluid flow passage) 51 Gas flow space (fluid flow space) 100 Piping 100a Upstream part of the pipe 100b Downstream part of the piping

Claims

1. This adjusts the flow rate of various fluids flowing through piping, a valve body having a valve function and a pipe connection part having a communication passage coaxially connected to the pipe, the valve body has a built-in direct-acting stepping motor as an actuator for opening and closing a valve element, and the valve element is in the form of a needle valve constituted by a tapered needle; The linear stepping motor includes a linear shaft supported so as to be non-rotatable and reciprocatable in the axial direction, and a built-in feed screw mechanism for reciprocating the linear shaft in the axial direction; the built-in feed screw mechanism comprises a female screw portion formed on the inner diameter cylindrical surface of the internal rotor of the linear stepping motor, and a male screw portion formed on the linear shaft and engaged with the female screw portion so as to be capable of threadably advancing and retreating, and the linear shaft reciprocates in the axial direction without rotating due to the feed screw action of the built-in feed screw mechanism caused by the rotation of the rotor, the needle is provided coaxially and integrally with the linear shaft of the linear stepping motor and reciprocates non-rotatably in a direction perpendicular to the axis of the communication passage of the pipe connection portion to open and close the valve seat orifice, a fluid flow path from the piping connection part to the inlet of the valve seat orifice comprises an outer annular communicating passage which communicates with the fluid flow path inlet of the piping connection part and extends to the cylindrical outer periphery of the valve seat orifice, an inner annular communicating passage which communicates with the inlet of the valve seat orifice and extends to the cylindrical outer periphery of the valve seat orifice, and a plurality of small diameter communicating passages which are connected to and communicate with the outer annular communicating passage and the inner annular communicating passage, and these small diameter communicating passages are uniformly arranged extending radially from the inlet of the valve seat orifice as a center, thereby ensuring a uniform and stable flow rate of fluid flowing from the piping connection part to the inlet of the valve seat orifice from a minute flow rate to a large flow rate, The valve seat orifice is exchangeably set to a plurality of types of valve seat orifices having diameters corresponding to a plurality of different flow rates of the fluid to be controlled, while the needle is set to a shape and size that can be commonly used for the different diameters of the plurality of types of valve seat orifices; the valve body comprises a valve body main part having the linear stepping motor and the needle, and an orifice part having the valve seat orifice, the orifice part being separable from the valve body main part; The valve body and the pipe connection portion are configured to be separably connected to each other. A flow control valve comprising:

2. The orifice fluid flow passage from the inlet to the outlet of the valve seat orifice extends in a straight line whose axis is perpendicular to the axis of the communication passage of the piping connection portion, and communicates with the fluid flow passage outlet of the piping connection portion in the vicinity of the orifice fluid flow passage.

2. The flow control valve according to claim 1.

3. The built-in feed screw mechanism is a ball screw mechanism.

2. The flow control valve according to claim 1.

4. A device that is interposed in a pipe through which various fluids flow and controls the flow rate of the fluid, A flow rate adjusting means for adjusting the flow rate of the fluid flowing through the pipe; A flow rate measuring means for measuring a flow rate of a fluid flowing through the pipe; a control means for controlling the flow rate adjusting means in response to a measurement result of the flow rate measuring means, The flow rate adjusting means is constituted by a flow rate control valve according to any one of claims 1 to 3. A flow rate control device.

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